Taiyuan, China

Taiyuan University of Technology is a university in Shanxi, People's Republic of China, under the authority of the provincial government. In 2012 it celebrated its 110th anniversary. It is listed officially as one of the 'Top 100 universities in China', according to the Chinese government. Wikipedia.


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Chen Z.,CAS Shanghai Institute of Ceramics | Gao Y.,CAS Shanghai Institute of Ceramics | Gao Y.,Shanghai University | Kang L.,Taiyuan University of Technology | And 4 more authors.
Journal of Materials Chemistry A | Year: 2014

A simulation of the optical properties of nanocomposite coatings derived from VO2 nanoparticles (NPs) shows that the nanocomposite coatings have advantages over pure VO2 thin films in their solar energy modification ability (ΔTsol) and luminous transmittance (T lum). These nanocoatings rely on fine quality VO2 NPs; methods to prepare NPs for this purpose are yet to be developed. By studying the formation mechanism of VO2 NPs, the NP preparation process was optimized, and fine crystal quality VO2 NPs with diameters from 25-45 nm were synthesized. The highest latent heat of these VO2 NPs is 43 J g-1, which is considerably higher than the 25 J g-1 reported previously and close to the 51 J g-1 of bulk VO2, which indicates that these VO2 NPs are highly crystalline. These NPs showed an asymmetrical phase transition and increased insulator-metal transition (IMT) temperatures. According to our results, the size of particles is not the only reason that should be responsible for the increased IMT temperatures. The high-quality NPs were dispersed in polyurethane (PU) and coated on polyethylene terephthalate (PET). The relationship between the solar energy modification ability (ΔTsol) and the luminous transmittance (Tlum) was studied by experiments and simulation. Although the best experimental values of ΔTsol = 22.3% and Tlum = 45.6% are still lower than the simulation results of ΔTsol = 23.7% and Tlum = 32.4%, these values represent the best for reported VO2 smart films or coatings. © 2014 The Royal Society of Chemistry.


Jing L.,Taiyuan University of Technology | Jing L.,National University of Singapore | Wang Z.,Taiyuan University of Technology | Shim V.P.W.,National University of Singapore | Zhao L.,Taiyuan University of Technology
International Journal of Impact Engineering | Year: 2014

The deformation/failure modes and blast resistance of cylindrical sandwich shells comprising two aluminum face-sheets and an aluminum foam core, subjected to air blast loading, were investigated experimentally. Specimens of two different radii of curvature and geometrical configurations, clamped along their peripheries, were studied. A four-cable ballistic pendulum system was employed to measure the impulse imparted to the specimens. Typical deformation/failure modes were classified and analyzed; the effects of face-sheet thickness, core relative density, arrangement of foam core layers of different densities, specimen curvature and mass of charge on the structural response were also examined. The results indicate that both the deformation/failure modes and the structural response of the shells are sensitive to the geometrical configurations and blast impulse. Various failure modes - indentation or tearing of the front face-sheet, collapse of the core, severe inelastic deformation or tearing of the rear face-sheet, and failure between the face-sheets and foam core, were observed. The findings are useful for validating theoretical predictions, as well as to guide application of cellular metal sandwich structures for blast protection purposes. © 2014 Published by Elsevier Ltd.


Su Q.,Zhejiang Normal University | Su Q.,Taiyuan University of Technology | Du G.,Zhejiang Normal University | Zhang J.,Zhejiang Normal University | And 5 more authors.
ACS Nano | Year: 2014

The comprehension of fundamental electrochemical behavior and sodiation mechanism is critical for the design of high-performance electrode materials for sodium-ion (Na-ion) batteries. In this paper, the electrochemical sodiation process and microstructure evolution of individual Co9S 8-filled carbon nanotubes (CNTs) have been directly visualized and studied using in situ transmission electron microscopy. Upon the first sodiation, a reaction front propagates progressively along the filling nanowire, causing the filled CNT to inflate. The filled CNTs behave differently depending on their structures and the magnitude of the sodiation voltage. For a Co 9S8-filled CNT with an open end, the sodiated Co 9S8 filler shows a substantial axial elongation of 120.8% and a small radial swelling due to the extrusion of CNT walls. In contrast, the closed CNT shows a major radial expansion of 40.6% and a small axial elongation because of the mechanical confinement of the carbon shells. After sodiation, the spacing between the carbon shells increases from 3.4 to 3.8 Å due to the Na+-ion insertion and the single-crystalline Co9S 8 filler converts to numerous Co nanograins dispersed in a Na 2S matrix. Compared with the gentle microstructure evolution of the CNT under small charging voltage, a strong electrochemical reaction accompanying drastic swelling and fracturing of CNT shells is observed for the CNT electrode under large charging voltage. Our observations provide direct evidence and important insights for the electrochemical process of CNT-based composite materials in Na-ion batteries. © 2014 American Chemical Society.


Su Q.,Zhejiang Normal University | Li J.,Zhejiang Normal University | Zhong G.,Zhejiang Normal University | Du G.,Zhejiang Normal University | And 2 more authors.
Journal of Physical Chemistry C | Year: 2011

We present a one-step chemical vapor deposition method to prepare iron/nickel sulfide nanostructures-filled carbon nanotubes (CNTs) by pyrolysis of dimethyl sulfide on stainless steel substrate. Dimethyl sulfide is used as the carbon and sulfur source, and the stainless steel substrate acts as both the catalyst and support. The as-grown products were characterized using scanning electron microscopy, transmission electron microscopy, and X-ray diffraction, and the results demonstrate that the encapsulated compounds in CNTs are Fe 7S8 and Ni17S18 with hexagonal crystal structure. The possible growth mechanism is proposed. The complex permittivity and permeability of the CNT composites were measured at a frequency range of 2-18 GHz, and the microwave-absorbing performance was analyzed. With a matching thickness of 2 mm, the maximum reflection loss is about -29.58 dB at 14.80 GHz for the absorber. The bandwidth corresponding to the reflection loss at -10 dB is more than 5.58 GHz. The strong reflection loss is mainly caused by the magnetic loss originating from the encapsulated two-component sulfide nanostructures. © 2011 American Chemical Society.


Su Q.,Zhejiang Normal University | Su Q.,Taiyuan University of Technology | Xie J.,Zhejiang University | Zhang J.,Zhejiang Normal University | And 3 more authors.
ACS Applied Materials and Interfaces | Year: 2014

Metal sulfides are a type of potential anode materials for lithium-ion batteries (LIBs). However, their electrochemical behaviors and mechanism during the charge and discharge process remain unclear. In the present paper, we use CoS2 as a model material to investigate their electrochemical process using in situ transmission electron microscopy (TEM). Two kinds of reaction behaviors are revealed. The pure CoS2 particles show a side-to-side conversion process, in which large and anisotropic size expansion (47.1%) occurs that results in the formation of cracks and fractures in CoS2 particles. In contrast, the CoS2 particles anchored on reduced graphene oxide (rGO) sheets exhibit a core-shell conversion process involving small and homogeneous size expansion (28.6%) and few fractures, which attributes to the excellent Li+ conductivity of rGO sheets and accounts for the improved cyclability. Single-crystalline CoS2 particle converts to Co nanocrystals of 1-2 nm embedded within Li2S matrix after the first lithiation. The subsequent electrochemical reaction is a reversible phase conversion between Co/Li2S and CoS2 nanocrystals. Our direct observations provide important mechanistic insight for developing high-performance conversion electrodes for LIBs. © 2014 American Chemical Society.


Meng Q.S.,Taiyuan University of Technology | Fan W.H.,Taiyuan University of Technology | Chen R.X.,Taiyuan University of Technology | Munir Z.A.,University of California at Davis
Journal of Alloys and Compounds | Year: 2010

Field-activated pressure-assisted process was applied to fabricate "pure" and doped iron disilicide (FeSi2, FeSi2Ge0.01, and FeSi2Cu0.1) by reactive sintering from elemental powders. The products has an average grain size of about 0.3 μm. Significantly lower thermal conductivity measured on these materials provides a figure of merit, ZT of 28.50 × 10-4 in the temperature range of 330-450 K, a value that represents a 17.1-47.2% increase over that published on materials prepared by other methods. © 2009 Elsevier B.V.


Zhang H.-X.,Tarim University | Bai H.-J.,Tarim University | Dong X.-S.,Taiyuan University of Technology | Wang Z.-Z.,Taiyuan University of Technology
Fuel Processing Technology | Year: 2012

Enhanced desulfurizing flotation of different size fractions of high sulfur coal was investigated using the sonoelectrochemical method. The supporting electrolyte used in this process was calcium hydroxide and the additive was anhydrous ethanol. The effects of treatment conditions on desulfurization were studied by a single-factor method. The conditions include anhydrous ethanol concentration, sonoelectrolytic time, current density, and ultrasound intensity. For the coal samples with different size fractions, the optimal experimental conditions for anhydrous ethanol concentration, sonoelectrolytic time, current density, and ultrasound intensity, respectively, are achieved. Under optimal conditions, the raw and treated coals were analyzed by infrared spectroscopy and a chemical method. Pyritic sulfur, organic sulfur, and ash are partially removed. Compared with different size fractions coal, desulfurizing flotation of high sulfur coal by sonoelectrochemistry is an effective technology. Crown Copyright © 2012 Published by Elsevier B.V. All rights reserved.


Zhao C.,University of Hertfordshire | Chen Y.K.,University of Hertfordshire | Chen Y.K.,Taiyuan University of Technology | Ren G.,University of Hertfordshire
Tribology Transactions | Year: 2013

This article presents an investigation on the potential tribological properties of water-based cerium dioxide nanofluids. Nanofluids with different nanoparticle concentrations were prepared in a materials laboratory. A stable dispersion of nanoparticles in the fluids was achieved with an appropriate percentage of the surfactant sorbitan monostearate. The stability of particle dispersion was studied using zeta potential measurement. Additive conglomerate size in the nanofluids was measured using dynamic light scattering. It was observed that the dispersibility of nanoparticles played an important role in the frictional properties of the nanofluids. The tribological properties of the water-based nanofluids were evaluated using a pin-on-disc tester under different loading conditions. A significant improvement in the tribological properties of the waterbased cerium dioxide nanofluids was observed. The worn surfaces of the contact elements were characterized using scanning electron microscopy (SEM) and a nanotester. According to the test results, the significant reductions in the friction coefficients and antiwear properties of water-based cerium dioxide nanofluids were attributed to the deposition of nanoparticles on worn contact surfaces. © Society of Tribologists and Lubrication Engineers.


Li G.,Taiyuan University of Technology | Li G.,Buskerud and Vestfold University College | Chen X.,Buskerud and Vestfold University College
Applied Physics A: Materials Science and Processing | Year: 2012

Charge injection behaviours in silicon nitride of an Al/Si 3N4/n-Si metal-insulator-semiconductor (MIS) device are systematically studied before and after applying different high constant DC bias conditions with the aim of controlling charge accumulation in the dielectric when a high actuation voltage is applied.We found that both polarity and magnitude of charge accumulation in silicon nitride depend on the biasing direction. Charge injection from the semiconductor to the silicon nitride always dominates over charge injection from the Al electrode to the silicon nitride. Negative charge accumulation happens in silicon nitride when the Al electrode is positively biased, and positive charge accumulation occurs in silicon nitride when the Al electrode is negatively biased. The positive charge accumulation is much bigger than the negative charge accumulation under the same magnitude of stress voltage. Furthermore, the experimental results also show that the charge injection level exponentially increases with the applied voltage across the silicon nitride. These observed experimental results can be well explained by a modified Fowler-Nordheim tunnelling charge injection model, which takes into account the roles of both electrons and holes in the process of charge injection. © Springer-Verlag Berlin Heidelberg 2012.


Liu Z.,Taiyuan University of Technology | Fan W.,China Institute of Technology | Ma J.,China Institute of Technology | Li R.,Taiyuan University of Technology | Li R.,China Institute of Technology
Adsorption | Year: 2012

Adsorption and diffusion properties of n-octane in meso-structured HZSM-5 zeolites were studied by high precision intelligent gravimetric analysis (IGA) and ZLC technology between 293 K and 393 K. As expected, great increase in adsorption capacity and diffusion efficient of noctane in the mesostructured HZSM-5 zeolites was observed compared with conventional HZSM-5. At the same time, the adsorption activation energy of n-octane in the mesostructured HZSM-5 zeolites was significantly decreased. The adsorption heats with low n-octane loading showed a clear decline with increase of mesoporosity in the zeolite samples. These results clearly indicate that introduction of mesopores into the zeolites offered a short diffusion path and high diffusion rate for reactants and products, which resulted in a high yield of fuel oil and an enhanced resistance against the catalyst deactivation in the reaction of methanol to gasoline. © Springer Science+Business Media New York 2012.


Su Q.,Zhejiang Normal University | Zhong G.,Zhejiang Normal University | Li J.,Zhejiang Normal University | Du G.,Zhejiang Normal University | And 2 more authors.
Applied Physics A: Materials Science and Processing | Year: 2012

Fe/Fe 3C-functionalized carbon nanotubes (CNTs) have been prepared by the floating catalyst chemical vapor-deposition method. It is demonstrated that the Fe and Fe 3C nanostructures are both encapsulated in the CNTs or decorated on the surface of CNTs. The Fe/Fe 3C content in the composites can easily be adjusted by changing the ferrocene concentration in the preparation. The electromagnetic properties of the CNTs have been evaluated in the frequency range of 2-18 GHz, and the nanocomposites exhibit excellent microwave absorbing performance. The CNT composites with higher Fe/Fe 3C content show enhanced microwave reflection losses. The significant influence of the Fe/Fe 3C nanostructures on the microwave absorption is realized by tuning the characteristic impedance of the nanocomposites. With increasing thickness, the maximum reflection loss peak shifts to lower frequency. The microwave absorbing performance of the composites is mainly caused by dielectric loss, resulting from the continuous CNT networks with excellent electrical conductivity. © 2011 Springer-Verlag.


Du J.,Taiyuan University of Technology | Zhao R.,Shanxi Kunming Tobacco Ltd Liability Company | Xue Y.,Taiyuan University of Technology
Journal of Chemical Thermodynamics | Year: 2012

Thermodynamic properties and equilibrium constant of reaction in nanosystems were analyzed theoretically. The effects of sizes of nano-CuO on thermodynamic properties and equilibrium constant were studied using the reaction of nano-copper oxide and sodium bisulfate as a system. The experimental results indicate that with the sizes of reactant decreasing, the molar Gibbs free energy (ΔrGm), the molar enthalpy (ΔrHm) and the molar entropy (Δ rSm) decrease, but the equilibrium constant (K) increases and there are linear trends between the reciprocal of sizes for nano-CuO and the values of ΔrGm, ΔrHm, ΔrSm and Ln K, which are in agreement with the theoretical analysis. © 2011 Elsevier Ltd. All rights reserved.


Su Q.,Zhejiang Normal University | Su Q.,Taiyuan University of Technology | Du G.,Zhejiang Normal University | Zhang J.,Zhejiang Normal University | And 6 more authors.
ACS Nano | Year: 2013

Carbon nanotube (CNT)-encapsulated metal sulfides/oxides are promising candidates for application as anode materials in lithium ion battery (LIB), while their electrochemical behavior and mechanism still remain unclear. A comprehensive understanding of the lithiation mechanism at nanoscale of this type of composites will benefit the design and development of high-performance LIB materials. Here, we use Co9S8/Co nanowire-filled CNTs as a model material to investigate the lithium storage mechanism by in situ transmission electron microscopy. For a Co9S8/Co nanowire-filled closed CNT, the reaction front propagates progressively during lithiation, causing an axial elongation of 4.5% and a radial expansion of 32.4%, while the lithiated nanowire core is still confined inside the CNT. Contrastingly, for an open CNT, the lithiated Co9S8 nanowire shows an axial elongation of 94.2% and is extruded out from the open CNT. In particular, a thin graphite shell is drawn out from the CNT wall by the extruded lithiated Co9S8. The thin graphite shell confines the extruded filler and protects the filler from pulverization in the following lithiation-delithiation cycles. During multiple cycles, the Co segment remains intact while the Co9S8 exhibits a reversible transformation between Co9S8 and Co nanograins. Our observations provide direct electrochemical behavior and mechanism that govern the CNT-based anode performance in LIBs. © 2013 American Chemical Society.


Jing L.,Taiyuan University of Technology | Jing L.,National University of Singapore | Xi C.,Taiyuan University of Technology | Wang Z.,Taiyuan University of Technology | Zhao L.,Taiyuan University of Technology
Materials and Design | Year: 2013

The dynamic response, energy absorption capability, and deformation and failure of clamped aluminum face-sheet cylindrical sandwich shells with closed-cell aluminum foam cores were investigated numerically by impacting the shells at central area with metallic foam projectiles in this paper. Typical deformation/failure modes and deflection response of sandwich shells, obtained from the experiments, were employed here to validate the numerical simulation. Numerical results indicate that the shock resistance of sandwich shells could be enhanced significantly by optimizing their geometrical configurations; the thickness of back face-sheet has a greater contribution than that of front face-sheet. Increasing of impact velocity and decreasing of face-sheet thickness, core relative density and curvature radius can enhance the energy absorption capability of sandwich shells. The initial curvature of sandwich shells may induce easily tearing failure along their circumferential directions. These findings can guide well the theoretical study and optimal design of metallic sandwich structures subjected to impulsive loading. © 2013 Elsevier Ltd.


Yuan W.,Zhejiang Normal University | Xie D.,Zhejiang Normal University | Dong Z.,Zhejiang Normal University | Su Q.,Taiyuan University of Technology | And 3 more authors.
Materials Letters | Year: 2013

Novel porous Co3O4 polyhedral architectures have been successfully prepared by combining a facile hydrothermal synthesis of uniform cobalt oxalate precursors with subsequent heat treatment. The Co 3O4 products are in truncated hexahedral shape, and are composed of many interconnected nanoparticles and a large number of macro-/mesopores. When tested as an anode material for lithium-ion battery, the porous polyhedral Co3O4 presents an initial discharge capacity of 1546 mA h g-1, and maintains a reversible capacity of 432 mA h g-1 after 45 discharge/charge cycles. The enhanced lithium-storage performance can be attributed to the unique porous architecture, which provides the structural flexibility for volume change and the routes for fast Li+ diffusion. © 2013 Elsevier B.V.


Jing L.,Taiyuan University of Technology | Jing L.,National University of Singapore | Wang Z.,Taiyuan University of Technology | Zhao L.,Taiyuan University of Technology
Composite Structures | Year: 2013

Deformation/failure modes, blast resistance and energy absorption of metallic cylindrical sandwich shells with closed-cell aluminum foam cores were investigated in this paper. A brief of experimental result on the dynamic response of blast-loaded sandwich shells was firstly reported. Based on the experiments, corresponding finite element simulations have been undertaken by employing the LS-DYNA software. Numerical simulation results show a good agreement on the deformation/failure modes and back face-sheet center-point deflection of specimens, with those of experimental results. Results indicate that the deformation/failure, deflection response and energy absorption of sandwich shells are sensitive to the loading intensity and geometric configuration. Energy absorption capability of specimens is monotonically increasing and decreasing with the increase of impulse level and core relative density, respectively. However, it does not change monotonically with the face-sheet thickness of specimens. These simulation findings are worthy of the theoretical study and optimal design of metallic sandwich structures under air blast loading. © 2012 Elsevier Ltd.


Zhang Z.-Q.,Institute of High Performance Computing of Singapore | Zhang Z.-Q.,National University of Singapore | Liu G.R.,University of Cincinnati | Liu G.R.,Taiyuan University of Technology
Engineering Analysis with Boundary Elements | Year: 2014

Node-based and edge-based smoothed FEM (NS-FEM and ES-FEM), and α-FEM are extended to solve nonlinear problems. The nonlinear strain field is smoothed using the gradient smoothing. The continuous scalar scaling factor α enables the α-FEM continuously transforming from overestimated model to underestimated model. Numerical examples reveal that ES-FEM is a robust and stable method with high accuracy and computational efficiency for nonlinear problems. The exact solution in strain energy of force driven problems can be bounded by NS-FEM and FEM. The α-FEM can also be "tuned" to find nearly exact solution to nonlinear mechanics problems of solids of complicated geometry. © 2014 Elsevier Ltd. All rights reserved.


Shen J.,Swinburne University of Technology | Lu G.,Nanyang Technological University | Zhao L.,Taiyuan University of Technology | Zhang Q.,Beijing Institute of Technology
Engineering Structures | Year: 2013

The response of sandwich tubes under internal explosive loading was investigated experimentally, numerically and analytically in this paper. Experiments were conducted first to capture the fundamental deformation and failure patterns and they served as a basis of validation for both the FE and analytical models. Further detailed deformation and blast loading history were revealed by the FE model. An explicit analytical solution for the deformation of sandwich tubes under blast loading has been worked out and used to obtain the optimum sandwich configurations, which would outperform their corresponding monolithic tubes. © 2011 Elsevier Ltd.


Wang W.,Taiyuan University of Technology | Hao Y.,Taiyuan University of Technology | Cui Y.,Taiyuan University of Technology | Tian X.,Taiyuan University of Technology | And 5 more authors.
Optics Express | Year: 2014

Metal nanogratings as one of the promising architectures for effective light trapping in organic photovoltaics (OPVs) have been actively studied over the past decade. Here we designed a novel metal nanowall grating with ultra-small period and ultra-high aspect-ratio as the back electrode of the OPV device. Such grating results in the strong hot spot effect in-between the neighboring nanowalls and the localized surface plasmon effect at the corners of nanowalls. These combined effects make the integrated absorption efficiency of light over the wavelength range from 400 to 650 nm in the active layer for the proposed structure, with respect to the equivalent planar structure, increases by 102% at TM polarization and by 36.5% at the TM/TE hybrid polarization, respectively. Moreover, it is noted that the hot spot effect in the proposed structure is more effective for ultra-thin active layers, which is very favorable for the exciton dissociation and charge collection. Therefore such a nanowall grating is expected to improve the overall performance of OPV devices. © 2014 Optical Society of America.


Yu J.,Shenyang Aerospace University | Yu J.,University Of Science And Technology Liaoning | Yin F.,Shenyang Aerospace University | Yin F.,University Of Science And Technology Liaoning | And 3 more authors.
Fuel | Year: 2013

An integrated hot coal gas cleaning process is proposed with emphasis on simultaneous removal of multiple impurities including sulfur containing species, NOx precursors, mercury and tarry materials. Acti-vated- char-supported sorbents were synthesized by gasifying Fe and Mo impregnated Chinese lignite coal in steam (15%, vol) at 1100 K for 15 min. Sulfur removal properties of the sorbent samples were examined by sulfidation experiments using simulated coal gases (with 4700 ppmv H2S and 470 ppmv COS) at a space velocity of 1000 h-1 using a fixed-bed quartz reactor at the temperature range of 673-873 K. The SEM with EDS and XRD were used to examine the physical and chemical changes in the sorbents during sulfidation. The active metal oxides components were dispersed in the char matrix as nanosize particles resulting in a high reactivity of the sorbents towards H2S and COS contained in coal gases. Under the conditions in this study, the sorbents can effectively remove H2S and COS from the simulated coal gases with high efficiency. Sulfur removal is influenced by the level of iron-loading. The presence of Mo along with Fe in the char-supported sorbents can significantly increase the desulfurization efficiency. © 2010 Elsevier Ltd. All rights reserved.


Cheng H.,Taiyuan University of Technology | Zhang S.,BYD Company Ltd | Quan L.,Taiyuan University of Technology
Jixie Gongcheng Xuebao/Journal of Mechanical Engineering | Year: 2015

To increase the power coefficient of blade at both rated and low wind conditions, the distribution of aerodynamic shape parameter at each blade element is studied. The wind turbine is typically operated under low wind conditions, however the influence has rarely been considered in blade optimization model. Hence, a nonlinear constrained optimization model with power coefficient under low wind conditions is introduced based on the blade element momentum theory and Wilson theory. Since the penalty factor is difficult to be determined in penalty function method when dealing with constraints, which may lead to prematurity phenomenon that the algorithm falls into local solution, a hybrid particle swarm algorithm combined with feasible dominated-constraint method is brought up. Based on particle swarm optimization theory and simulated annealing theory, the algorithm applies feasible dominated-constraint method to perform random survival selection under drifting annealing probability, which keeps the population diverse and can be evolving in more optimized direction, thus solves the problem that nonlinear constraint is difficult to handle and the population's tendency to fall into local solution. So as to verify the algorithm, a nonlinear constrained optimization model for the 1.5MW wind turbine blade is established. The results indicate that the method can effectively handle nonlinear constraints, avoid prematurity of the process and increase the power coefficient of blade under rated and low wind conditions. It provides an excellent way of theoretical analysis to handle nonlinear constraints. ©2015 Journal of Mechanical Engineering.


Zuo Z.-J.,Key Laboratory of Coal Science and Technology | Li J.,Key Laboratory of Coal Science and Technology | Han P.-D.,Taiyuan University of Technology | Huang W.,Key Laboratory of Coal Science and Technology
Journal of Physical Chemistry C | Year: 2014

To better understand the autoxidation mechanism of Cu-based catalysts, we studied the oxidation of Cu sheet exposed to ultrahigh vacuum and air at ambient temperature using X-ray photoelectron spectroscopy (XPS) and density functional theory. Six main stages of Cu autoxidation are revealed: (1) dissociative adsorption of O2, (2) coexistence of nondissociative and dissociative H2O adsorption, (3) diffusion of O and OH into Cu bulk, (4) formation of metastable Cu2O layer, (5) further oxidation and formation of metastable Cu(OH)2 and CuO layer, and (6) transformation phase of the metastable Cu(OH)2 to CuO. The formation of Cu(OH)2 depends on the relative humidity of air and the concentration of adsorbed OH of the Cu sheet. On the basis of these results, we propose that the preservation time of the Cu-based catalysts should be decreased or the catalysts should be preserved in a high vacuum and at low relative humidity. Considering the time of the sample preparation before ex situ XPS analysis and other surface characterizations, the Cu-based catalysts need to be etched by ∼10 s using an Ar ion gun. These findings serve as a guide for the preservation and preparation of Cu-based catalysts before actual measurement. © 2014 American Chemical Society.


Zhao B.,Taiyuan University of Technology | Liu J.,Shanxi Polytechnic College
Journal of Computational Information Systems | Year: 2011

The constant modulus algorithm (CMA) is a stochastic gradient adaptive algorithm that results from minimizing a no-quadratic cost function of the equalizer coefficience involving higher order statistics. The variable step-size constant modulus algorithm (CMA) solves the contradiction between convergence speed and convergence precision of the fixed step-size CMA. Among many variable step-size constant modulus algorithms, a common method is using MSE to control the step-size variation. This paper studies the influence of MSE on tracking channel and anti-interference performance of an improved variable step-size constant modulus algorithm. The computer simulation result is in good agreement with theoretical analysis. © 2011 Binary Information Press.


Liu S.-D.,Key Laboratory of Advanced Transducers and Intelligent Control System of Ministry of Education and | Liu S.-D.,Taiyuan University of Technology | Leong E.S.P.,Institute of Materials Research and Engineering of Singapore | Li G.-C.,Hong Kong Polytechnic University | And 5 more authors.
ACS Nano | Year: 2016

Plasmonic oligomers composed of metallic nanoparticles are one class of the most promising platforms for generating Fano resonances with unprecedented optical properties for enhancing various linear and nonlinear optical processes. For efficient generation of second-harmonic emissions at multiple wavelength bands, it is critical to design a plasmonic oligomer concurrently having multiple Fano resonances spectrally matching the fundamental excitation wavelengths and multiple plasmon resonance modes coinciding with the harmonic wavelengths. Thus far, the realization of such a plasmonic oligomer remains a challenge. This study demonstrates both theoretically and experimentally that a plasmonic nonamer consisting of a gold nanocross surrounded by eight nanorods simultaneously sustains multiple polarization-independent Fano resonances in the near-infrared region and several higher-order plasmon resonances in the visible spectrum. Due to coherent amplification of the nonlinear excitation sources by the Fano resonances and efficient scattering-enhanced outcoupling by the higher-order modes, the second-harmonic emission of the nonamer is significantly increased at multiple spectral bands, and their spectral positions and radiation patterns can be flexibly manipulated by easily tuning the length of the surrounding nanorods in the nonamer. These results provide us with important implications for realizing ultrafast multichannel nonlinear optoelectronic devices. © 2016 American Chemical Society.


Kosec G.,Jozef Stefan Institute | Kosec G.,University of Nova Gorica | Sarler B.,University of Nova Gorica | Sarler B.,Slovenian Institute of Metals And Technology | Sarler B.,Taiyuan University of Technology
Engineering Analysis with Boundary Elements | Year: 2014

Simulation of macrosegregation with mesosegregates as a consequence of solidification of a binary Sn-10%Pb alloy in a 2-dimensional rectangular cast is tackled in the present paper. Coupled volume averaged governing equations for mass, energy, momentum and species transfer are considered by incorporating Lever solidification rule and incompressible Newtonian fluid with Darcy limit in the mushy zone. Solid phase is assumed stationary. Double diffusive effects in the melt are modeled by the thermal and solutal Boussinesq hypothesis. The physical model is solved by the meshless Local Radial Basis Function Collocation Method (LRBFCM) by using 5-noded influence domains, multiquadrics radial basis functions and explicit time stepping. Pressure-velocity coupling is based on local pressure correction. Adaptive upwinding has to be used for stabilization of the convective terms. The numerical simulations reveal instabilities during solidification process that introduce anomalies in the final segregation map that scale with the typical cast as well as sub-cast dimensions. The main advantages of choosing the represented meshless approach for solving the problem are in its simplicity and similar coding in 2D and 3D, as well as straightforward applicability in non-uniform node arrangements. The locality of the proposed numerical approach is also convenient for parallel execution. It is demonstrated that LRBFCM can be advantageously used in casting simulations where the chemical segregation exhibits industrially relevant multi-scale patterns. © 2014 Elsevier Ltd.


Su Q.,Taiyuan University of Technology | Dong Z.,Zhejiang Normal University | Zhang J.,Zhejiang Normal University | Du G.,Taiyuan University of Technology | And 2 more authors.
Nanotechnology | Year: 2013

The lithiation reaction of ZnO as an anode in a lithium-ion battery (LIB) is unclear. The electrochemical behavior of ZnO was investigated inside a transmission electron microscope (TEM) by constructing a nano-LIB using an individual ZnO/graphene sheet as the electrode. The lithiation reaction of ZnO/graphene was monitored by simultaneous determination of the structure with high-resolution TEM, electron diffraction pattern and electron energy-loss spectroscopy. Two kinds of reaction modes were revealed in terms of different reaction rates. One was the violent reaction mode, in which one particle can evolve into an aggregate of many nanoparticles within the Li2O matrix in 1-2 min. The other was the peaceful evolution mode, in which each ZnO nanoparticle evolves into a core-shell particle with multi-domains constituted of Zn and LiZn nanograins. Abnormally large Zn nanocrystals grow quickly in the violent reaction mode, which can suppress the formation of LiZn and impair the reversible capacity. Our observations give direct evidence and important insights for the lithiation mechanism of metal oxide anodes in LIBs. © 2013 IOP Publishing Ltd.


Su Q.,Taiyuan University of Technology | Chang L.,Zhejiang Normal University | Zhang J.,Zhejiang Normal University | Du G.,Taiyuan University of Technology | And 2 more authors.
Journal of Physical Chemistry C | Year: 2013

The reaction mechanism of ceria as an anode in a lithium ion battery (LIB) is unknown. To solve this issue, a nano-LIB was constructed inside a transmission electron microscope (TEM) using an individual CeO 2/graphene composite as the anode. The lithiation/delithiation cycles of the CeO2/graphene composite were conducted inside the TEM, and the electrochemical process was in situ monitored by simultaneous determination of the microstructure with high-resolution TEM, electron diffraction, and electron energy loss spectroscopy. The surfaces of the graphene nanosheets and ceria nanoparticles were covered by a nanocrystalline Li2O layer after lithiation, and the Li2O layer shrank and showed partially reversible changes after delithiation. The CeO2 nanoparticles showed imperceptible volumetric and morphological changes, while comprehensive analysis revealed a fully reversible phase transformation between fluorite CeO 2 and cubic Ce2O3 during the electrochemical process. These results give direct evidence and profound insights into the lithiation/delithiation mechanism of CeO2/graphene anode in a LIB. © 2013 American Chemical Society.


Jing L.,Taiyuan University of Technology | Jing L.,National University of Singapore | Wang Z.,Taiyuan University of Technology | Zhao L.,Taiyuan University of Technology
Composite Structures | Year: 2014

The dynamic response of peripherally clamped cylindrical sandwich shells with two aluminum face-sheets and an aluminum foam core has been experimentally investigated using an improved loading technique. The resistance to impact loading is assessed by using the permanent transverse deflection at central point of back face-sheet of the sandwich shell. The comprehensive deformation and failure modes of specimens were classified and analyzed in term of face-sheets and core, and then the failure mode map of specimens was presented. Effects of impulse, face-sheet thickness, core thickness and relative density of core on the resistance to impact loading were discussed in detail. Deformation mechanism of sandwich shells subjected to projectile impact was explored based on the results of strain gauges adhered on the face-sheets. Results indicate that both the deformation/failure modes and back face-sheet deflection of sandwich shells are sensitive to impulse and their geometrical configurations, and the curved sandwich structures have an evident advantage on the resistance to deform, to the flatted sandwich panels. The experimental results have important reference value to the further study and engineering application of metallic sandwich structures. © 2013.


Jing L.,Taiyuan University of Technology | Jing L.,National University of Singapore | Wang Z.,Taiyuan University of Technology | Zhao L.,Taiyuan University of Technology
Composites Part B: Engineering | Year: 2014

A simplified theoretical analysis is developed to predict the dynamic response of clamped cylindrical sandwich shells with aluminum foam cores under air blast loading. In this analytical solution, the whole response of the sandwich shell is split into three sequential stages, similar with the existing three-stage theoretical framework of sandwich structures. In the first stage the blast impulse is assumed to only transfer to the velocity of the front face-sheet. The metallic foam core is considered approximately to be a progressive compressive mode in the second stage, while the back face-sheet is still stationary. In the final stage, the classical monolithic shell theory based on an energy dissipation rate balance approach is employed; and the "upper" and "lower" bounds of the maximum back face-sheet central point deflections and response time are obtained by incorporating a comprehensive circumscribing and inscribing yield loci. A reasonable agreement between the theoretical predictions and experimental results is found for the maximum back face-sheet central point deflection of sandwich shells. The proposed theoretical consideration is significant to guide the engineering applications of cellular metal sandwich structures subjected to air blast loading. © 2013 Elsevier Ltd. All rights reserved.


Zhong C.,Ningbo University | Yue X.,Shanghai University | Zhang Z.,Taiyuan University of Technology | Lei J.,Shanghai University of Electric Power
Pattern Recognition | Year: 2015

Abstract The aim of clustering ensemble is to combine multiple base partitions into a robust, stable and accurate partition. One of the key problems of clustering ensemble is how to exploit the cluster structure information in each base partition. Evidence accumulation is an effective framework which can convert the base partitions into a co-association matrix. This matrix describes the frequency of a pair of points partitioned into the same cluster, but ignores some hidden information in the base partitions. In this paper, we reveal some of those information by refining the co-association matrix from data point and base cluster level. From the data point level, as pairs of points in the same base cluster may have varied similarities, their contributions to the co-association matrix can be different. From the cluster level, since the base clusters may have diversified qualities, the contribution of a base cluster as a whole can also be different from those of others. After being refined, the co-association matrix is transformed into a path-based similarity matrix so that more global information of the cluster structure is incorporated into the matrix. Finally, spectral clustering is applied to the matrix to generate the final clustering result. Experimental results on 8 synthetic and 8 real data sets demonstrate that the clustering ensemble based on the refined co-association matrix outperforms some state-of-the-art clustering ensemble schemes. © 2015 Elsevier Ltd. All rights reserved.


Deng J.,Taiyuan University of Technology | Kang L.,Taiyuan University of Technology | Bai G.,China Institute of Technology | Li Y.,Taiyuan University of Technology | And 6 more authors.
Electrochimica Acta | Year: 2014

Co3O4 and Co3O4/CoO nanoparticles have been synthesized by a one-step solution combustion process by adjusting the molar ratio of citric acid (fuel) and Co(NO3) 2·6H2O (oxidizer). The effects of citric acid/Co(NO3)2·6H2O molar ratios on phase composition and morphology of products were investigated by XRD and SEM. With the increase of the fuel dosage, the products transformed from granular aggregates of cubic Co3O4 into a mixture of cubic Co 3O4 and tetragonal CoO with fluffy sheet morphologies. Electrochemical measurements indicated that the products (Co3O 4) showed a capacitance up to 179.7 F·g-1 (at 0.2 A·g-1) when the citric acid/Co(NO3) 2·6H2O molar ratio was 7/27. Significantly, the capacitance could be further improved by 102% (362.8 F·g-1 at 0.2 A·g-1) after annealing at 350 °C for 3 h under nitrogen atmosphere. This annealed sample also demonstrated decent rate performance (285.7 F·g-1 at 4 A·g-1) and cycling stability (73.5% retention after 1000 cycles). The current study suggests that this process has promise in large-scale production of electrode materials for supercapacitors. © 2014 Elsevier Ltd.


Yuan W.,Zhejiang Normal University | Zhang J.,Zhejiang Normal University | Xie D.,Zhejiang Normal University | Dong Z.,Zhejiang Normal University | And 3 more authors.
Electrochimica Acta | Year: 2013

Uniform, hierarchical and porous CoO/C polyhedra were synthesized by impregnating hydrothermally fabricated Co3O4 polyhedra with sugar solution followed by calcination in inert atmosphere. Each CoO/C polyhedron was built up of numerous ordered nanoparticles (around 100 nm). As anode material for Li-ion batteries, the CoO/C polyhedra exhibited an initial discharge capacity of 1025 mAh g-1, and remained a reversible capacity of 510mAhg-1 after 50 cycles at a current density of 100mAg-1. High Coulombic efficiency over 99% and improved rate capability were achieved for the CoO/C polyhedra. Hierarchical structure and high porosity was benefit to the infiltration of electrolyte and tolerant volume expansion, and hence was responsible for the good electrochemical performance. © 2013 Elsevier Ltd. All rights reserved.


Guan G.,Hirosaki University | Chen G.,Hirosaki University | Kasai Y.,Industrial Research Institute | Lim E.W.C.,National University of Singapore | And 5 more authors.
Applied Catalysis B: Environmental | Year: 2012

Calcined scallop shell (CS) exhibits alkaline property with a porous structure, and could be applied for the adsorption and decomposition of biomass-derived tar. In this study, steam reforming of tar derived from pruned apple branch over CS was investigated in a fixed bed at 650°C. It was found that CS had good activity for the steam reforming of tar to produce synthesis gas (syngas), and was able to be recycled. To promote the gas production efficiency, iron or nickel was supported on the CS, and used for the reforming of tar. The effect of heating rate on the gas production rate was investigated, and it was found that reduced iron- or nickel-supported CS showed better activities under the condition of rapid heating. Iron- or nickel-based catalyst in its oxide state was also investigated for the reforming of tar. No catalytic activity was found at the beginning, but good activity appeared after approximately 30min of reaction when the metal oxide was reduced to its metallic form by the initially generated syngas (CO and H 2) from the pyrolysis of biomass without the aid of catalyst. Iron and nickel in their metallic forms rather than their oxide ones were considered as active sites for the reforming of tar. Furthermore, the alkaline elements in the biomass, which could enhance the activity of the catalysts, were identified to be accumulated on the surface of the catalysts with the biomass-derived tar. As a result, a larger amount of syngas was produced when the regenerated catalysts were applied. Based on these experimental results, a possible catalytic process was proposed. © 2011 Elsevier B.V..


Zhang L.,Beijing Normal University | Zhang L.,Taiyuan University of Technology | Li X.,Taiyuan University of Technology | Li Y.,Beijing Normal University | And 3 more authors.
Analytical Chemistry | Year: 2015

On-site oral fluid testing for drugs of abuse has become prominent in order to take immediate administrative action in an enforcement process. Herein, we report a DVD technology-based indirect competitive immunoassay platform for the quantitative detection of drugs of abuse. A microfluidic approach was adapted to prepare multiplex immunoassays on a standard DVD-R, an unmodified multimode DVD/Blu-Ray drive to read signal, and a free disc-quality analysis software program to process the data. The DVD assay platform was successfully demonstrated for the simultaneous, quantitative detection of drug candidates (morphine and cocaine) in oral fluids with high selectivity. The detection limit achieved was as low as 1.0 ppb for morphine and 5.0 ppb for cocaine, comparable with that of standard mass spectrometry and ELISA methods. © 2014 American Chemical Society.


Xue H.-B.,Taiyuan University of Technology | Nie Y.-H.,Shanxi University | Chen J.,Shanghai University | Ren W.,Shanghai University
Annals of Physics | Year: 2015

We study theoretically the full counting statistics of electron transport through a quantum dot weakly coupled to two ferromagnetic leads, in which an effective nuclear-spin magnetic field originating from the configuration of nuclear spins is considered. We demonstrate that the quantum coherence between the two singly-occupied eigenstates and the spin polarization of two ferromagnetic leads play an important role in the formation of super-Poissonian noise. In particular, the orientation and magnitude of the effective field have a significant influence on the variations of the values of high-order cumulants, and the variations of the skewness and kurtosis values are more sensitive to the orientation and magnitude of the effective field than the shot noise. Thus, the high-order cumulants of transport current can be used to qualitatively extract information on the orientation and magnitude of the effective nuclear-spin magnetic field in a single quantum dot. © 2015 Elsevier Inc.


Sun S.,Peking University | Niu Y.,Peking University | Niu Y.,Taiyuan University of Technology | Sun Z.,Peking University | And 2 more authors.
RSC Advances | Year: 2015

Solubilities of SO2 in ethylene glycol derivatives were determined by dynamic isothermal gas-liquid equilibrium (GLE) experiments, and the thermodynamic parameters of the absorption processes were calculated. The GLE results indicated that the solubilities of SO2 in ethylene glycol derivatives increase in the order: diols < monomethyl ethers < dimethyl ethers, with the enthalpy values ranging from -23.2 to -43.3 kJ mol-1. The regeneration experiment found that the absorption of SO2 in tetraethylene glycol dimethyl ether is reversible, and the solvents can be reused without a significant loss of absorption capacity. The interactions between SO2 and ethylene glycol derivatives were investigated by UV, IR and NMR. In addition, a 1H-NMR spectroscopy technique with external references was used to investigate the physical absorption process of SO2 for the first time, in order to avoid the influence of deuterated solvents. Spectroscopic investigations showed that the interactions between SO2 and ethylene glycol derivatives are based on both the charge-transfer interaction and hydrogen bond. Ethylene glycol derivatives with desirable absorption capacities and excellent regeneration abilities are promising alternatives to conventional sorbents in SO2 separation. © The Royal Society of Chemistry 2015.


Xie D.,Zhejiang Normal University | Chang L.,Zhejiang Normal University | Wang F.,Zhejiang Normal University | Du G.,Zhejiang Normal University | Xu B.,Taiyuan University of Technology
Journal of Alloys and Compounds | Year: 2012

We report a facile, surfactant-free method for synthesizing double pyramid-like ZnO architectures via an ultrasound-assisted route. The morphology, microstructures, and porosity of the materials have been studied and the formation mechanism has been discussed. Uniform octahedral ZnC 2O 4 precursors were first formed during ultrasound irradiation, and then transformed to macro-/mesoporous ZnO with the preservation of original shape after calcination at 350 °C. The obtained hierarchical ZnO double-pyramids were composed of ZnO nanoparticles of ∼35 nm and pores with the main distribution between 20 and 100 nm. Raman and photoluminescence measurements reveal the presence of intrinsic defects in the porous ZnO, which accounts for the narrowed band gap (3.16 eV) and the sharp blue emission at 472 nm. Moreover, the ZnO product possesses large specific surface area and exhibits extraordinary photocatalytic activity to degrade organic pollutants. © 2012 Elsevier B.V. All rights reserved.


Su Q.,Zhejiang Normal University | Su Q.,Taiyuan University of Technology | Xie D.,Zhejiang Normal University | Zhang J.,Zhejiang Normal University | And 2 more authors.
ACS Nano | Year: 2013

Transition metal oxides have attracted tremendous attention as anode materials for lithium ion batteries (LIBs) recently. However, their electrochemical processes and fundamental mechanisms remain unclear. Here we report the direct observation of the dynamic behaviors and the conversion mechanism of Fe2O3/graphene in LIBs by in situ transmission electron microscopy (TEM). Upon lithiation, the Fe 2O3 nanoparticles showed obvious volume expansion and morphological changes, and the surfaces of the electrode were covered by a nanocrystalline Li2O layer. Single-crystalline Fe2O 3 nanoparticles were found to transform to multicrystalline nanoparticles consisting of many Fe nanograins embedded in Li2O matrix. Surprisingly, the delithiated product was not Fe2O 3 but FeO, accounting for the irreversible electrochemical process and the large capacity fading of the anode material in the first cycle. The charge-discharge processes of Fe2O3 in LIBs are different from previously recognized mechanism, and are found to be a fully reversible electrochemical phase conversion between Fe and FeO nanograins accompanying the formation and disappearance of the Li2O layer. The macroscopic electrochemical performance of Fe2O3/graphene was further correlated with the microcosmic in situ TEM results. © 2013 American Chemical Society.


Ma J.,Taiyuan University of Technology | Ma J.,University of Texas at Dallas | Loizou P.C.,University of Texas at Dallas
Speech Communication | Year: 2011

Most of the existing intelligibility measures do not account for the distortions present in processed speech, such as those introduced by speech-enhancement algorithms. In the present study, we propose three new objective measures that can be used for prediction of intelligibility of processed (e.g.; via an enhancement algorithm) speech in noisy conditions. All three measures use a critical-band spectral representation of the clean and noise-suppressed signals and are based on the measurement of the SNR loss incurred in each critical band after the corrupted signal goes through a speech enhancement algorithm. The proposed measures are flexible in that they can provide different weights to the two types of spectral distortions introduced by enhancement algorithms, namely spectral attenuation and spectral amplification distortions. The proposed measures were evaluated with intelligibility scores obtained by normal-hearing listeners in 72 noisy conditions involving noise-suppressed speech (consonants and sentences) corrupted by four different maskers (car, babble, train and street interferences). Highest correlation (r = -0.85) with sentence recognition scores was obtained using a variant of the SNR loss measure that only included vowel/consonant transitions and weak consonant information. High correlation was maintained for all noise types, with a maximum correlation (r = -0.88) achieved in street noise conditions. © 2010 Elsevier B.V. All rights reserved.


Cao Y.,Zhejiang Normal University | Su Q.,Zhejiang Normal University | Che R.,Fudan University | Du G.,Zhejiang Normal University | And 2 more authors.
Synthetic Metals | Year: 2012

We present the first report concerning the one-step synthesis of Ni/graphene nanocomposites via a substrate-free, atmospheric-pressure chemical vapor deposition process. The as-grown thin graphene sheets are produced in large scale with the thickness of ∼2 nm, and they are decorated with numerous Ni/graphene core-shell nanoparticles. The nucleation and growth mechanism of the composite has been proposed based on careful transmission electron microscopy analysis. Ni 3C domains within Ni nanoparticles have been observed, indicating a transformation between nickel and nickel carbide during graphene growth owing to the diffuse and precipitation of carbon atoms. Moreover, such Ni/graphene nanocomposites exhibit excellent microwave absorption and electrochemical ethanol sensing properties. This study opens up a new synthesis route for graphene-based materials. © 2012 Elsevier B.V. All rights reserved.


Xie D.,Zhejiang Normal University | Su Q.,Taiyuan University of Technology | Dong Z.,Zhejiang Normal University | Zhang J.,Zhejiang Normal University | Du G.,Zhejiang Normal University
CrystEngComm | Year: 2013

Porous NiO hollow microspheres have been synthesized via a simple hydrothermal process using l-cysteine as a structure-directing agent followed by calcination. The as-synthesized NiO microspheres are hollow with diameters of 2-3 μm. The shells of the microspheres are built from nanoparticles with diameters of 30-50 nm, and the interior cavities are around 0.75 μm in diameter. A plausible mechanism has been proposed to explain the formation of the porous NiO hollow spheres. When evaluated as anode materials for lithium ion batteries, the porous NiO hollow microspheres show outstanding electrochemical performances, including high reversible capacity of 847.2 mAh g-1 after 50 cycles at 100 mA g-1, high rate capability with a discharge capacity of 470 mAh g-1 at a current density of 800 mA g -1, and good cycling stability. The excellent lithium-storage performance can be attributed to the porous hollow architectures, which provide fast ion/electron transfer and the structural flexibility for volume change during the cycling process. © 2013 The Royal Society of Chemistry.


Shen J.,Swinburne University of Technology | Lu G.,Nanyang Technological University | Wang Z.,Taiyuan University of Technology | Zhao L.,Taiyuan University of Technology
International Journal of Impact Engineering | Year: 2010

In this paper curved sandwich panels with two aluminium face sheets and an aluminium foam core under air blast loadings were investigated experimentally. Specimens with two values of radius of curvature and different core/face sheet configurations were tested for three blast intensities. All the four edges of the panels were fully clamped. The experiments were carried out by a four-cable ballistic pendulum with corresponding sensors. Impulse acting on the front face of the assembly, deflection history at the centre of back face sheet, and strain history at some characteristic points on the back face were obtained. Then the deformation/failure modes of specimens were classified and analysed systematically. The experimental data show that the initial curvature of a curved sandwich panel may change the deformation/collapse mode with an extended range for bending dominated deformation, which suggests that the performance of the sandwich shell structures may exceed that of both their equivalent solid counterpart and a flat sandwich plate. © 2010 Elsevier Ltd. All rights reserved.


Weiming C.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research | Shangmin Z.,Xinjiang Institute of Ecology and Geography | Shangmin Z.,Taiyuan University of Technology | Shangmin Z.,University of Chinese Academy of Sciences | And 2 more authors.
Permafrost and Periglacial Processes | Year: 2012

Decadal changes in permafrost distribution on the Qinghai-Tibet Plateau (QTP) over the past 50years (1960-2009) were simulated with a response model that uses data from a digital elevation model, mean annual air temperature (MAAT) and the vertical lapse rate of temperature. Compared with published maps of permafrost distribution, the accuracy of the simulated results is about 85 per cent. The simulation results show: (1) with the continuously rising MAAT over the past 50years, the simulated areas of permafrost on the QTP have continuously decreased; (2) through areal statistics, the simulated areas of permafrost were 1.60×106km2, 1.49×106km2, 1.45×106km2, 1.36×106km2 and 1.27×106km2, respectively, in the 1960s, 1970s, 1980s, 1990s and 2000s; and (3) the rate of permafrost loss has accelerated since the 1980s, and the total area of degraded permafrost is about 3.3×105km2, which accounts for about one-fifth of the total area of permafrost in the 1960s. © 2012 John Wiley & Sons, Ltd.


Guan G.,Hirosaki University | Kaewpanha M.,Hirosaki University | Hao X.,Taiyuan University of Technology | Wang Z.,Taiyuan University of Technology | And 3 more authors.
Fuel | Year: 2013

(Graph Presented) Decomposition of tar derived from 4 biomass resources, i.e., cellulose, lignin (alkaline and dealkaline), pruned apple branch (PAB) and rice straw over calcined scallop shell (CS) and iron (Fe)-loaded CS were performed in a fixed bed reactor at different temperatures. It was found that alkali species such as potassium in the biomass could migrate to the surface of catalyst with the tar, and hence promote catalytic activity ofthe regenerated catalyst. In order to reveal this phenomenon, in this study a small amount of K was doped on CS and Fe-loaded CS and applied in the steam reforming of tar derived from cellulose and dealkaline lignin. The results indicated that the addition of K greatly enhanced hydrogen production rate. © 2012 Elsevier Ltd. All rights reserved.


Su Q.,Zhejiang Normal University | Li J.,Zhejiang Normal University | Du G.,Zhejiang Normal University | Du G.,Taiyuan University of Technology | Xu B.,Taiyuan University of Technology
Journal of Physical Chemistry C | Year: 2012

The electrical and electron field-emission characteristics of individual Fe 3C-filled CNTs were investigated using a scanning tunneling microscope inside a transmission electron microscope. Larger bias sweeping across a CNT can bring about the melting, resolidifying, and decomposition of the encapsulated Fe 3C, which causes structural damage to the CNT. However, the resistance of the CNT reduces significantly after large bias sweep because the graphitization of CNT walls improves and the contact resistance reduces. To get more insights into the mechanism, the microstructure evolution of Fe 3C and the reaction between Fe 3C and CNT during near-equilibrium reaction processes were studied. It was found that thin graphenes form when the Fe 3C fillers decompose by joule heating, which may open up a new route for the graphene fabrication. The field-emission behavior of a single Fe 3C-filled CNT was analyzed based on Fowler-Nordheim theory, which suggested only 8.4% of the hemispherical cap is responsible for the electron emission. © 2012 American Chemical Society.


Sheng Y.,Australian National University | Kong Q.,Shanghai University | Wang W.,Taiyuan University of Technology | Kalinowski K.,Australian National University | Krolikowski W.,Australian National University
Journal of Physics B: Atomic, Molecular and Optical Physics | Year: 2012

We theoretically study the second-harmonic generation via nonlinear Raman-Nath diffraction in an optical medium with the spatial modulation of quadratic nonlinearity. We derive analytical equations that govern the emission properties of this nonlinear wave phenomenon. We also discuss how a substantial range of parameters such as the thickness of a nonlinear medium and the condition of a pump laser affect the strength of the emitted harmonic signals. © 2012 IOP Publishing Ltd.


Fu T.,Taiyuan University of Technology | Li Z.,Tianjin University of Technology
Chemical Engineering Science | Year: 2015

Diminishing petroleum reserves, sharp fluctuations of crude oil prices, increasingly stringent environmental regulations and the global demand for a decreased dependence on petroleum for the production of fuels and chemicals, are the main driving force for the recent renewed interest in Fischer-Tropsch (FT) synthesis in academia and industry. Cobalt catalyst is the preferred catalyst for the production of long-chain paraffins because of its high activity, low water-gas shift activity and comparatively low price. Carbon materials including traditional activated carbons, carbon nanotubes and nanofibres, carbon spheres and mesoporous carbons have been used as the support for cobalt catalyst in the past 10 years for its inert property. The microstructures (e.g., carbon porosity, cobalt particle size, cobalt location and cobalt dispersion) of these carbon supported cobalt catalyst determine the CO conversion and product selectivity. In this paper, we focus on the most recent developments around carbon support structure effect, cobalt intrinsic properties and promoter effect on carbon supported cobalt catalyst for FT synthesis. The nitrogen doping effect, confinement effect and cobalt particle size effect on carbon nanotubes supported Co catalysts are further presented in this review. © 2015 Elsevier Ltd. All rights reserved.


Cui X.,Tsinghua University | Zhao L.,Swinburne University of Technology | Zhao L.,Taiyuan University of Technology | Wang Z.,Swinburne University of Technology | And 4 more authors.
International Journal of Impact Engineering | Year: 2012

The dynamic response of metallic lattice sandwich plates under impulsive loading is studied by experimental investigation. The sandwich structures composed of two identical face sheets and tetrahedral lattice cores, were designed and fabricated through perforated metal sheet forming and welding technology. The air blast experiment of lattice sandwich structures was performed by use of a four-cable ballistic pendulum system. The deformation/failure mechanisms were investigated through experimental observation and analysis. The impulsive resistance of the tetrahedral lattice sandwich structures is quantified by the maximum permanent transverse deflection of the back face sheet as a function of transmitted impulse. The maximum transverse deflections of tetrahedral lattice sandwich plates are compared with that of hexagonal honeycomb ones with identical parent materials and core relative density. The comparison implies that the tetrahedral lattice sandwich structures possess a better impulsive resistance. © 2011 Elsevier Ltd. All rights reserved.


Zhu F.,Swinburne University of Technology | Wang Z.,Swinburne University of Technology | Wang Z.,Taiyuan University of Technology | Lu G.,Swinburne University of Technology | And 2 more authors.
International Journal of Impact Engineering | Year: 2010

A theoretical solution is obtained to predict the dynamic response of peripherally clamped square metallic sandwich panels with either honeycomb core or aluminium foam core under blast loading. In the theoretical analysis, the deformation of sandwich structures is separated into three phases, corresponding to the transfer of impulse to the front face velocity, core crushing and overall structural bending/stretching, respectively. The cellular core is assumed to have a progressive crushing deformation mode in the out-of-plane direction, with a dynamically enhanced plateau stress (for honeycombs). The in-plane strength of the cellular core is assumed unaffected by the out-of-plane compression. By adopting an energy dissipation rate balance approach developed by earlier researchers for monolithic square plates, but incorporating a newly developed yield condition for the sandwich panels in terms of bending moment and membrane force, "upper" and "lower" bounds are obtained for the maximum permanent deflections and response time. Finally, comparative studies are carried out to investigate: (1) influence of the change in the in-plane strength of the core after the out-of-plane compression; (2) performances of a square monolith panel and a square sandwich panel with the same mass per unit area; and (3) analytical models of sandwich beams and circular and square sandwich plates. © 2009 Elsevier Ltd. All rights reserved.


Shan S.,University of Texas at Dallas | Wu W.,University of Texas at Dallas | Wang W.,Xi'an Jiaotong University | Du H.,University of Texas at Dallas | And 2 more authors.
International Journal of Sensor Networks | Year: 2012

Multi-hop wireless networks have no fixed physical backbone infrastructure, so Connected Dominating Set (CDS) is frequently selected as virtual backbone to improve network efficiency. Interference is a big problem which prevents wireless networks from reaching efficiency; however, previous works construct CDS as virtual backbone without consideration of interference. In this paper, we consider the problem of how to construct Minimum Interference Connected Dominating Set (MICDS) in multi-channel multi-radio multi-hop wireless networks. Multi-channel communication helps to reduce interference and improve network performance. A two-phase algorithm named MIS-colouring is presented for MICDS problem, and theoretical analysis is also given. However, due to the characteristics of the problem itself, it is quite difficult to compute the approximation ratio for MIS-colouring. Simulation results show that through proper CDS structure selection and channel assignment, MIS-colouring algorithm can minimise the total interference of CDS as a virtual backbone for multi-channel multi-radio multi-hop wireless networks. © 2012 Inderscience Enterprises Ltd.


Meng Q.S.,Taiyuan University of Technology | Fan W.H.,Taiyuan University of Technology | Chen R.X.,Taiyuan University of Technology | Munir Z.A.,University of California at Davis
Journal of Alloys and Compounds | Year: 2011

Sc- and Y-doped-Mg2Si samples were reactively sintered by the field-activated and pressure-assisted synthesis (FAPAS) method. The incorporation of these rare-earth elements in this silicide resulted in an n-type semiconductor. The addition of Sc and Y had no discernable effect on the lattice constant of Mg2Si. The average grain size of the Y-doped Mg2Si was about 2 μm, which was smaller than that of the sintered pure Mg2Si. The power factor of samples doped with 2500 ppm Sc was consistently higher than that of pure Mg2Si in the temperature range of 300-550 K. Similarly, the power factor of 2000 ppm Y doped Mg2Si samples was higher than that of pure Mg2Si over the temperature range of 300-675 K; the highest value being about 2.2 × 10-3 W m-1 k-2 at 468 K. This value is about two times that of the undoped Mg2Si at the same temperature. The thermal conductivity of Mg2Si doped with 2000 ppm Y was 80% of that of pure Mg 2Si. The highest figure of merit (ZT) for the Y doped (2000 ppm) samples was 0.23 at 600 K which was higher by a factor of 1.6 than the corresponding value of pure Mg2Si at the same temperature. The results demonstrate the benefits of doping of Mg2Si with Sc and Y in enhancing its thermoelectric properties. © 2011 Elsevier B.V. All rights reserved.


Qiao J.W.,University of Science and Technology Beijing | Qiao J.W.,Taiyuan University of Technology | Sun A.C.,Yuan Ze University | Huang E.W.,National Central University | And 3 more authors.
Acta Materialia | Year: 2011

A Ti-based bulk metallic glass matrix composite (BMGMC) with a homogeneous distribution of dendrites and the composition of Ti46Zr 20V12Cu5Be17 is characterized by a high tensile strength of ∼1640 MPa and a large tensile strain of ∼15.5% at room temperature. The present BMGMC exhibits the largest tensile ductility and highest fracture absorption energy under the stress-strain curve of all dendrite-reinforced BMGMCs developed to date. Tensile deformation micromechanisms are explored through experimental visualization and theoretical analyses. After tension, fragmentation of the dendrites, rather than crystallization within the glass matrix and/or atom debonding near the interface of dual-phase composites, is responsible for the high tensile ductility. The subdivisions within the interior of dendrites are separated by shear bands and dense dislocation walls, and local separation of dendrites under modes I and II prevails. The multiplication of dislocations, severe lattice distortions, and even local amorphization dominate within the dendrites. Good structural coherency of the interface is demonstrated, despite being subjected to significant plastic deformation. Theoretical analyses reveal that the constitutive relations elastic-elastic, elastic-plastic, and plastic-plastic of dual-phase BMGMC generally correspond to the (1) elastic, (2) work-hardening, and (3) softening deformation stages, respectively. The capacity for work-hardening is highly dependent on the large plastic deformation of the dendrites and the high yield strength of the glass matrix. The present study provides a fundamental basis for designing work-hardening dual-phase BMGMCs exhibiting remarkably homogeneous deformation. © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.


Loizou P.C.,University of Texas at Dallas | Ma J.,Taiyuan University of Technology
Journal of the Acoustical Society of America | Year: 2011

The conventional articulation index (AI) measure cannot be applied in situations where non-linear operations are involved and additive noise is present. This is because the definitions of the target and masker signals become vague following non-linear processing, as both the target and masker signals are affected. The aim of the present work is to modify the basic form of the AI measure to account for non-linear processing. This was done using a new definition of the output or effective SNR obtained following non-linear processing. The proposed output SNR definition for a specific band was designed to handle cases where the non-linear processing affects predominantly the target signal rather than the masker signal. The proposed measure also takes into consideration the fact that the input SNR in a specific band cannot be improved following any form of non-linear processing. Overall, the proposed measure quantifies the proportion of input band SNR preserved or transmitted in each band after non-linear processing. High correlation (r 0.9) was obtained with the proposed measure when evaluated with intelligibility scores obtained by normal-hearing listeners in 72 noisy conditions involving noise-suppressed speech corrupted in four different real-world maskers. © 2011 Acoustical Society of America.


Ban H.,University Of Science And Technology Liaoning | Li C.,Taiyuan University of Technology | Li C.,Tokyo Gas Co. | Asami K.,University of Kitakyushu | Fujimoto K.,Tokyo Gas Co.
Catalysis Communications | Year: 2014

A series of Cu/Zn/Zr (CZZ) catalysts with different rare earth elements (La, Ce, Nd and Pr) were prepared by co-precipitation method and tested for CO2 hydrogenation to methanol. The influence of modifier (La, Ce, Nd and Pr) on the physicochemical properties of CZZ catalysts was studied. The results of catalytic test reveal that CO2 conversion was correlated to the introduction of different promoters. The introduction of La and Ce favors the production of methanol, and Nd and Pr modified CZZ catalysts show relative low activity compared with the reference CZZ catalyst. © 2014 The Authors. Published by Elsevier B.V.


Chen X.-B.,Beijing University of Posts and Telecommunications | Xu G.,Taiyuan University of Technology | Niu X.-X.,Beijing University of Posts and Telecommunications | Wen Q.-Y.,Beijing University of Posts and Telecommunications | Yang Y.-X.,Beijing University of Posts and Telecommunications
Optics Communications | Year: 2010

The central theme of this paper is that we propose an efficient protocol for comparing the equal information with the help of a third party (TP). We assume that TP is semi-honest, i.e., TP executes the protocol loyally, keeps a record of all its intermediate computations and might try to steal the players' private inputs from the record, but he cannot be corrupted by the adversary. The security of this protocol with respect to various kinds of attacks is discussed. Our protocol utilizes the triplet entangled states and the simple single-particle measurement. The particles carried the secret messages do not be repeatedly transmitted. The players' messages are divided into many groups. Sometimes, the protocol is already successfully completed, but all data are not compared. Thus, many time and huge quantum resources can be saved. © 2009 Elsevier B.V. All rights reserved.


Chen X.-B.,Beijing University of Posts and Telecommunications | Xu G.,Taiyuan University of Technology | Yang Y.-X.,Beijing University of Posts and Telecommunications | Wen Q.-Y.,Beijing University of Posts and Telecommunications
Optics Communications | Year: 2010

Through designing a quantum communication network, we propose a protocol for the teleportation between multiple senders and multiple receivers via only one controller. In order to rationally employ the quantum entanglement resources, the controller shares the entangled state with every sender, while there is no directly shared entanglement link between sender and receiver. The security is analyzed in detail. Moreover, this protocol reduces the classical communication cost in the public channel by means of the coding. © 2010 Elsevier B.V. All rights reserved.


Yuan H.-P.,Shanghai JiaoTong University | Cheng X.-B.,Shanghai Municipal Drainage Operation Ltd. | Chen S.-P.,Shanghai Environmental Sanitation Engineering Design Institute | Zhu N.-W.,Shanghai JiaoTong University | Zhou Z.-Y.,Taiyuan University of Technology
Bioresource Technology | Year: 2011

The enhancements of electrolysis-pretreated conditioning were investigated in this study. Normalized capillary suction time (CST) was used to evaluate sludge dewaterability. Extracellular polymeric substance (EPS) concentration, viscosity and scanning electron microscopy (SEM) were determined to explain the observed changes in conditioning process. It indicated that pretreatment at 50v and 5min with Ti/RuO2 anode was determined to be the optimal condition, which generated the lowest normalized CST and optimal soluble EPS concentration, leading to the decreasing of viscosity. EPS had positive correlation with the normalized CST. Subjecting to a combination of electrolysis pretreatment and flocculants conditioning, 50% dosage of cationic polyacrylamide (PAM) could be reduced. When co-conditioned with electrolysis and polymerization ferric sulfate (PFS), it did not present any clear advantages over PFS conditioning alone. Furthermore, SEM investigation indicated that electrolysis pretreatment could rupture sludge, release the interstitial water and extracellular substances, especially protein and polysaccharide, and consequently enhance its dewaterability. © 2011 Elsevier Ltd.


Zhu Z.,Beijing Materials University | Zhang D.,Taiyuan University of Technology | Yan H.,Beijing Materials University | Li W.,University of Science and Technology Beijing | Qilu,Beijing Materials University
Journal of Materials Chemistry A | Year: 2013

This work developed a novel ammonium oxalate-carbonate composite co-precipitation method to prepare spinel LiNi0.5Mn 1.5O4. By this method combined with a facile hydrothermal treatment and particular cooling process, an ideal spinel with precise stoichiometric Ni/Mn and classic Fd3m structure is obtained, and furthermore, the Mn3+ content can be strictly limited. Additionally, the prepared LiNi0.5Mn1.5O4 has a spherical hierarchical morphology, composed of nano or submicron primary particles. This LiNi 0.5Mn1.5O4 shows superlative electrochemical performance. It delivers a discharge capacity of 141.2 mA h g-1, and importantly 98.2% of which discharges at 4.7 V. After 200 cycles at 0.3 C, 1 C and 3 C, the capacity retentions are 96.3%, 94.4% and 91.1%, respectively. Chemical and electrochemical measurements indicate that the elimination of the majority of Mn3+ in the obtained LiNi0.5Mn 1.5O4 results in the high capacity proportion at 4.7 V. Additionally, the retained Fd3m structure and spherical hierarchical morphology also effectively favour the cycling and rate performances. This journal is © 2013 The Royal Society of Chemistry.


Ren L.,Shanxi Institute of Coal CAS Chemistry | Ren L.,University of Chinese Academy of Sciences | Yang J.,Shanxi Institute of Coal CAS Chemistry | Gao F.,Taiyuan University of Technology | Yan J.,Basic Research Service
Energy and Fuels | Year: 2013

The gasification reactivity of 13 carbonaceous materials in CO2 or in steam was studied in the temperature range 1000-1600 C. The gasification reaction was carried out in a drop-in-fixed-bed reactor under atmospheric pressure. The gasifying agent fed into the reactor either as pure gas or as 36% volumetric concentration in argon with a total gas flow rate of 500 mL/min. The test samples included different rank coals, petcokes, and graphites. The raw materials were used to eliminate the problem related to char prepreparation. The dynamic profiles of gasification rate were used to compare the gasification behaviors for different samples. The physicochemical characteristics of chars were evaluated by scanning electron microscopy and N2 adsorption method. The experimental results reveal that the difference in gasification reactivity among samples decreases as the temperature increases and is not distinguishable for most coals at 1600 C. However, the temperature is still critical for gasification of petcokes and some high-rank coals at high temperature. The gasification reactivity of petcokes is 2-9 times lower than that of coals at 1600 C. The kinetic analysis reveals that the temperature dependence of reactivity varies with the type of materials. It is interested to find that, in the temperature range 1400-1600 C, the gasification reactivity in CO2 is higher than that in steam for coals but not for petcokes. From the views of the reaction thermodynamics, the gas diffusion difficulty, and the catalytic effect, the high temperature is favorable to the CO 2-gasification. The effect of AAEMs (alkali and alkaline earth metals) should be a key factor. The content of AAEMs is apparent in coals but limited in petcokes. The Arrhenius plots reveal that the gasification mechanism may be altered around 1200 C for most of coals. The petcokes are appeared with the most compact physical structure and the least gasification reactivity. Either the shrinking core model (SCM) or the volume reaction model (VRM) is suitable for most of the samples and conditions but not suitable for the petcokes. A diffusion term associated with the carbon structure may be needed for modelling the gasification behaviors of the petcoke-like materials. © 2013 American Chemical Society.


Guo R.,Beijing University of Posts and Telecommunications | Guo R.,Taiyuan University of Technology | Tian B.,Beijing University of Posts and Telecommunications | Wang L.,Beihang University
Nonlinear Dynamics | Year: 2012

Under investigation in this paper is the reduced Maxwell-Bloch system, which describes the propagation of the intense ultra-short optical pulses through a two-level dielectric medium. Through symbolic computation, conservation laws are derived and N-fold Darboux transformation (DT) is constructed for that system. By virtue of the DT obtained, multisoliton solutions are generated. Figures are plotted to reveal the following dynamic features of the solitons: (1) Elastic interactions between two bright one-peak solitons, between two bight two-peak solitons and between two dark two-peak solitons; (2) Parallel propagations between two bright one-peak solitons, between two bright two-peak solitons and between two dark two-peak solitons; (3) Periodic propagations of hump solitons, of a pair of bound hump solitons with the same amplitude and of dark solitons. © Springer Science+Business Media B.V. 2012.


Cui Y.,Zhejiang University | Cui Y.,University of Illinois at Urbana - Champaign | Cui Y.,Taiyuan University of Technology | Fung K.H.,University of Illinois at Urbana - Champaign | And 8 more authors.
Nano Letters | Year: 2012

We present an ultrabroadband thin-film infrared absorber made of sawtoothed anisotropic metamaterial. Absorptivity of higher than 95% at normal incidence is supported in a wide range of frequencies, where the full absorption width at half-maximum is about 86%. Such property is retained well at a very wide range of incident angles too. Light of shorter wavelengths are harvested at upper parts of the sawteeth of smaller widths, while light of longer wavelengths are trapped at lower parts of larger tooth widths. This phenomenon is explained by the slowlight modes in anisotropic metamaterial waveguide. Our study can be applied in the field of designing photovoltaic devices and thermal emitters. © 2012 American Chemical Society.


Zhang W.,Taiyuan University of Technology | Yin R.,Taiyuan University of Technology | Wang Y.,CAS Institute of Physics
Physical Review B - Condensed Matter and Materials Physics | Year: 2013

We systematically study an extended Bose-Hubbard model with atom hopping and atom-pair hopping in the presence of a three-body constraint on the triangular lattice. By means of large-scale quantum Monte Carlo simulations, the ground-state phase diagram is studied. We find a first-order transition between the atomic superfluid phase and the pair superfluid phase when the ratio of the atomic hopping and the atom-pair hopping is adapted. The first-order transition remains unchanged under various conditions. We then focus on the interplay among the atom-pair hopping, the on-site repulsion, and the nearest-neighbor repulsion. With on-site repulsion present, we observe first-order transitions between the Mott insulators and pair superfluid driven by the pair hopping. With the nearest-neighbor repulsion turning on, three typical solid phases with 2/3, 1, and 4/3 filling emerge at small atom-pair hopping region. A stable pair supersolid phase is found at small on-site repulsion. This is due to the three-body constraint and the pair hopping, which essentially make the model a quasihardcore boson system. Thus the pair supersolid state emerges basing on the order-by-disorder mechanism, by which hardcore bosons avoid classical frustration on the triangular lattice. Without on-site repulsion, the transitions between the pair supersolid and the atom superfluid or pair superfluid are first order, except for the particle-hole symmetric point. With weak on-site repulsion and atom hopping turning on, the transition between the pair supersolid and pair superfluid phase becomes continuous. The transition between solid and pair supersolid is three-dimensional XY university, with dynamical exponent z=1 and correlation exponent ν=0.67155. The thermal melting of pair supersolid belongs to the two-dimensional Ising university. We check both energetic and mechanical balance of pair supersolid phase. Lowering the three-body constraint, no pair supersolid is found due to the absence of degeneracy of pair solids in classical limits. We describe the experimental realization of pair tunneling on state dependent lattice. © 2013 American Physical Society.


Hou Y.,Taiyuan University of Technology | Hou Y.,Tohoku University | Chen L.,Tohoku University | Liu P.,Tohoku University | And 5 more authors.
Journal of Materials Chemistry A | Year: 2014

We report a flexible asymmetric supercapacitor assembled by polypyrrole (PPy) and manganese oxide supported by ultrathin three-dimensional nanoporous gold (NPG) electrodes. The highly conductive and free-standing NPG films act as both supports of the active materials and current collectors of the supercapacitor, which evidently enhance the specific capacitance of active materials of both the conducting polymer and the metal oxide. The high energy density and high power density can be realized from the PPy-NPG//MnO 2-NPG asymmetric supercapacitor because of the wide cell voltage in an aqueous electrolyte and high specific capacitances of both PPy and MnO 2 enhanced by NPG. This journal is © the Partner Organisations 2014.


Zhu Z.,Beijing Materials University | Yan H.,Beijing Materials University | Zhang D.,Taiyuan University of Technology | Li W.,University of Science and Technology Beijing | Lu Q.,Beijing Materials University
Journal of Power Sources | Year: 2013

LiNi0.5Mn1.5O4 as a 4.7 V cathode material is prepared through an oxalic acid-pretreated solid-state method. Oxalic acid is added to react with the mixture of LiOH•H2O, MnO2 and Ni(OH)2. This chemical pretreatment results in a sufficient mixing of Li, Ni and Mn ions in the precursor, and therefore promotes the generation of pure LiNi0.5Mn1.5O4 in the following calcination even at a temperature as low as 500 °C. The material prepared at 750 °C has a highest crystallinity and a regular crystal shape with smoothly surface. Compared to traditional method, the LiNi 0.5Mn1.5O4 synthesized by this novel method shows much better electrochemical performances with an initial discharging capacity of 136.9 mAh g-1 and capacity retention of 93.4% after 300 cycles under 0.3C. And most importantly 97.2% of the total capacity displays at 4.7 V, which significantly favors the cell energy density. The novel preparation technique is also available to get high rate performance for LiNi 0.5Mn1.5O4. The material synthesized at 900 °C has a capacity of 121.2 mAh g-1 and stable cycling performance under 3C due to its lower polarization resistance. © 2012 Elsevier B.V. All rights reserved.


Cui Y.,University of Illinois at Urbana - Champaign | Cui Y.,Zhejiang University | Cui Y.,Taiyuan University of Technology | Xu J.,University of Illinois at Urbana - Champaign | And 5 more authors.
Applied Physics Letters | Year: 2011

We experimentally demonstrate an infrared broadband absorber based on an array of nanostrip antennas of several different sizes. The broadband property is due to the collective effect of magnetic responses excited by these nanoantennas at distinct wavelengths. By manipulating the differences of the nanostrip widths, the measured spectra clearly validate our design for the purpose of broadening the absorption band. © 2011 American Institute of Physics.


Li D.-A.,Taiyuan University of Technology | Wang H.-B.,Taiyuan University of Technology | Zhao J.-M.,Taiyuan University of Technology | Yang X.,Purdue University Calumet
Materials Chemistry and Physics | Year: 2011

The objective of this study is to develop microwave absorbers using both dielectric and magnetic lossy materials. Polypyrrole (PPY) is used as dielectric lossy materials and carbonyl iron particles is used as magnetic lossy materials. Polypyrrole powders are prepared by in situ polymerization method. Then PPY-carbonyl iron composite with different mixture ratios have been prepared by as-prepared material. The structure, morphology and properties of the composites are characterized with IR, XRD, scanning electron microscope (SEM), Net-work Anlyzer. The complex permittivity (′r-j ′′r) and reflection loss (dB) of the composites have been measured at different microwave frequencies in S-band and C-band (30-6000 MHz) employing vector network analyzer model HP 8722ET vector. The effect of the mass ratio of PPY-carbonyl iron on the microwave loss properties of the composites is investigated. A possible microwave absorbing mechanism of PPY-carbonyl iron composite has been proposed. The PPY-carbonyl iron composite can find applications in suppression of electromagnetic interference (EMI), and reduction of radar signature. © 2011 Elsevier B.V. All rights reserved.


Zhao J.-M.,Taiyuan University of Technology | An W.-X.,Taiyuan University of Technology | Li D.-A.,Taiyuan University of Technology | Yang X.,Purdue University Calumet
Synthetic Metals | Year: 2011

SiC powders were synthesized from the Si/C system in a nitrogen atmosphere by combustion synthesis. The carbon fiber/SiC composite with different mixture ratios have been prepared by as-prepared material. The structure, morphology and properties of the composites are characterized with IR, XRD, scanning electron microscope (SEM), Network Analyzer. The complex permittivity (ε′r-jε″r) and reflection loss (dB) of the composites have been measured at different microwave frequencies in S-band and C-band (30-6000 MHz) employing vector network analyzer model PNA 3629D vector. The effect of the mol ratio of carbon fiber/SiC on the microwave loss properties of the composites is investigated. A possible microwave absorbing mechanism of carbon fiber/SiC composite has been proposed. The carbon fiber/SiC composite can find applications in suppression of electromagnetic interference (EMI), and reduction of radar signature. © 2011 Elsevier B.V. All rights reserved.


Feng L.,CAS Institute of Physics | Feng L.,Taiyuan University of Technology | Ma L.,Hebei Normal University | Liu E.K.,CAS Institute of Physics | And 3 more authors.
Applied Physics Letters | Year: 2012

A series of Heusler-type MnNiCoAl alloys have been prepared, and the composition dependence of the martensitic transformation has been investigated. Due to the formation of a local Mn-Co-Mn ferromagnetic structure in the antiferromagnetic matrix, a large magnetization difference of 48 Am 2/kg and a driving efficiency of 2.14 K/T can be observed in Mn 50Ni 32Co 6Al 12 sample in which a field-induced transformation can be realized. X-ray diffraction results further indicate that the high temperature phase has a high level of atomic disorder which causes an increase of the thermal hysteresis of the transformation when increasing Co content. © 2012 American Institute of Physics.


Yan S.,Taiyuan University of Technology | Gao L.,Taiyuan University of Technology | Gao L.,University of Western Australia | Zhang S.,Beihang University | And 2 more authors.
International Journal of Hydrogen Energy | Year: 2013

AuNi nanoparticles supported on the activated carbon (AuNi/C) are synthesized by the impregnation method in the ethyleneglycol system using NH2NH2·H2O as a reducing agent. The alloying of Au and Ni and the removal of unalloyed Ni in the AuNi/C composition are achieved by heat and acid treatments in sequence. Research results reveal that the average size and alloying degree of the AuNi nanoparticles in the AuNi/C catalyst increase with the enhancement of the annealing temperature. However, the Ni content of the AuNi/C catalyst firstly goes up and then down with the rising of heat treatment temperature due to the AuNi system phase-separates. Moreover, the electrocatalytic activity normalized by the electrochemically active surface area of each AuNi/C catalyst is far better than that of the Au/C catalyst, because of the bifunctional mechanism and the electrocatalytic activity of the NiOOH. In particular, the AuNi/C catalyst annealed at 400 C exhibits the most excellent activity, due to its small AuNi particles and proper alloying degree. Furthermore, its mass-specific electrochemical activity is higher than that of the Au/C catalyst, although the mean diameter of the AuNi nanoparticles in this catalyst is larger than that of the Au nanoparticles. © 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.


Yan S.,Taiyuan University of Technology | Gao L.,Taiyuan University of Technology | Gao L.,University of Western Australia | Zhang S.,Beihang University | And 2 more authors.
Electrochimica Acta | Year: 2013

Au nanoparticles (AuNPs) supported on activated carbon (Au/C) were prepared by a modified chemical reduction method. The morphology, structure, surface chemical state and electro-oxidation activity of AuNPs were investigated by the transmission electron microscope (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV) and chronoamperometry. Results indicated that the Au/C catalyst possessed small AuNPs with a certain number of gold oxide species. This intrinsic property resulted in the high catalytic activity of the Au/C catalyst for the electro-oxidation of alcohol molecule. The peak values of anodic mass-specific current densities on AuNPs reached 69.5, 442 and 660 mA mg-1Au, respectively in 0.1 M KOH solutions with 6 M methanol, 2 M ethanol and 0.5 M ethylene glycol. © 2013 Elsevier Ltd. All rights reserved.


Zhang M.,Taiyuan University of Technology | Wu S.,Taiyuan University of Technology | Wang Y.,Shanxi Coking Coal Group Co.
Safety Science | Year: 2012

While coal seam is being mined, an annular fissure circle with gas accumulation will be formed in the fissure zone as a result of desorption, dissipation and permeation of gas in the goaf area and overlying strata due to fissures from rock caving and mitigation in the roof. The methods for computation of spatial locations of the fissure circle are researched in this paper. Based on these methods, gas drainage technique for the fissure zone is optimized. By applying drill hole returning water method of variables, the height of caving zone that most affects the drainage effects of inclined high dip drill hole was measured on the site. Due to the consistency of the expected height with the computed height of caving lines at different positions, the correctness of the theoretical computation method is further validated. Meanwhile, the parameters of the inclined high dip drill hole at #3311 working face of Hexi Coal Mine are determined by a case study. © 2011 Elsevier Ltd.


Zhao Z.,Taiyuan University of Technology | Cui X.,Taiyuan University of Technology | Zhang H.,Sany Automation Technology Co.
Advanced Materials Research | Year: 2012

The advantage and potential applications of cloud storage technology in video surveillance, on the basis of the concept and technology character of the cloud storage, have been discussed in the paper. Some important problems of the cloud storage technology applications in video surveillance have also been analyzed. © (2012) Trans Tech Publications, Switzerland.


Cui J.L.,Ningbo University of Technology | Zhang X.J.,China University of Mining and Technology | Deng Y.,Beihang University | Fu H.,China University of Mining and Technology | And 3 more authors.
Scripta Materialia | Year: 2011

α-In2Se3 has a two-layer structure with 1/3 of the cation sites vacant. After addition of Ag to In2Se3, we identified the main phase as In5AgSe8 with nanoinclusions of InSe forming in situ. Ag incorporation favors the formation of Ag2Se slab, which is largely responsible for the decrease in band gap Eg, accounting for much of the increase (decrease) in electrical conductivity (Seebeck coefficient). This effect, combined with a reduction in lattice thermal conductivity, results in a big improvement in thermoelectric property over α-In2Se3. © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.


Shen L.,Taiyuan University of Technology | Wang P.,China Agricultural University | Zhang L.,China Agricultural University
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2011

Aiming at reducing agricultural pollution caused by plastic film, effect of degradable film on soil temperature, soil moisture, maize growth and development, maize yield and relevant characteristics were studied through comparing with the plastic film and open field. The results indicated that soil temperature at surface and 10 cm depth in two months after sowing, soil moisture in 0-20 and >20-40 cm profile from sowing to big trumpet stage, were all higher for degradable film covering than open field. Growth progress, seedling rate, root number during shooting stage, plant height, leaf area and dry weight of maize in different stages were all higher for degradable film covering. Kernel number, thousand-grain weight, and yield of maize under degradable film covering were increased by 9.6%, 20.9%, 35.1% respectively. Degradable film did not show significant difference with plastic film, and it could be applied to agriculture instead of plastic film.


Zhang X.,Taiyuan University of Technology | Liu X.,Taiyuan University of Technology | Wang Z.J.,Taiyuan University of Technology | Wang Z.J.,Virginia Wesleyan College
Engineering Applications of Artificial Intelligence | Year: 2013

The kernel function is the core of the Support Vector Machine (SVM), and its selection directly affects the performance of SVM. There has been no theoretical basis on choosing a kernel function for speech recognition. In order to improve the learning ability and generalization ability of SVM for speech recognition, this paper presents the Optimal Relaxation Factor (ORF) kernel function, which is a set of new SVM kernel functions for speech recognition, and proves that the ORF function is a Mercer kernel function. The experiments show the ORF kernel function's effectiveness on mapping trend, bi-spiral, and speech recognition problems. The paper draws the conclusion that the ORF kernel function performs better than the Radial Basis Function (RBF), the Exponential Radial Basis Function (ERBF) and the Kernel with Moderate Decreasing (KMOD). Furthermore, the results of speech recognition with the ORF kernel function illustrate higher recognition accuracy. © 2013 Elsevier Ltd. All rights reserved.


Cao S.,Taiyuan University of Technology | Cao S.,Ningbo University of Technology | Zheng J.,Ningbo University of Technology | Zhao J.,CAS Changchun Institute of Optics and Fine Mechanics and Physics | And 6 more authors.
Journal of Materials Chemistry C | Year: 2013

We demonstrate a strategy for the growth of Mn2+ ion doped cadmium based II-VI semiconductor quantum dots (QDs) with a designed buffer layer of ZnS (MnS/ZnS/CdS or Mn:CdS QDs), which aims to meet the challenge of obtaining highly efficient and well-resolved Mn2+ ion emission. First, small, high quality MnS cores are obtained by using thiols to replace conventional alkyl amines as capping ligands. Then a buffer layer of ZnS with a tailored thickness is introduced to the QDs before the growth of CdS shells to reduce the size mismatch between the Mn2+ (dopant) and Cd 2+ (host) ions. The fabricated MnS/ZnS/CdS core/shell QDs exhibit a high PL QY of up to 68%, which is the highest ever reported for any type of Mn2+ ion doped cadmium based II-VI semiconductor QD. The photoluminescence (PL) of the QDs consists of well-resolved Mn2+ ion emission without any detectable emission from the CdS band edge or surface defects. In addition, our MnS/ZnS/CdS QDs cannot only be made water-soluble, but can also be coated by ligands with short carbon chain lengths, nearly without cost to the PL QY, which could make them strong candidates for practical applications in biology/biomedicine and opto/electronic devices. © The Royal Society of Chemistry 2013.


Wang Y.,Taiyuan University of Technology | Wang Y.,Nanjing Southeast University | Zheng J.,Taiyuan University of Technology | Zhang M.,Taiyuan University of Technology | Wang A.,Taiyuan University of Technology
IEEE Photonics Technology Letters | Year: 2011

We propose and experimentally demonstrate an approach to generate ultra-wideband (UWB) pulse based on period-one oscillation of semiconductor laser. The baseband UWB signal with - 10-dB bandwidth of 5.59 GHz is generated when the gain-switched pulse train is injected into the slave laser diode. Moreover, the center frequency of the generated UWB signal can be continuously tuned and converted up to 19.53 GHz by adjusting the optical frequency detuning in optical domain directly. © 2011 IEEE.


Lu L.,North University of China | Zhang S.,Beihang University | Yan S.,Taiyuan University of Technology
International Journal of Electrochemical Science | Year: 2015

AuNi/C catalyst (AuNi nanoparticles supported on activated carbon) is prepared by a polyol reduction process. The alloying between Au and Ni and the removal of unalloyed Ni are achieved by the heat and acid treatment. The electrochemical measurement results indicate that the alloying treatment process is favourable to improve the electrocatalytic activity of the AuNi/C catalyst. Moreover, the area-specific electrochemical activity of each AuNi/C catalyst is better than that of the Au/C catalyst, showing the effect of the Ni component on the electrocatalytic activity of the Au/C catalyst is significant. © 2015 The Authors.


Jiang J.,Taiyuan University of Technology | Huo Z.,China Agricultural University | Feng S.,China Agricultural University | Feng S.,Yangzhou University | Zhang C.,Taiyuan University of Technology
Field Crops Research | Year: 2012

Sustainable development of agriculture is restricted by fresh water shortage and water quality deterioration in some arid and semi-arid areas. Therefore, deficit irrigation and saline water irrigation have to be applied for sustaining crop yield. In order to determine the rational irrigation management practice in an arid region of Northwest China, field experiments were conducted in 2008, 2009 and 2010 to study the effects of irrigation amount and water salinity on water consumption and water productivity of spring wheat. Altogether nine irrigation treatments including three levels of irrigation water amount with 375, 300, and 225mm (w1, w2 and w3) and three levels of irrigation water salinity with 0.65, 3.2, and 6.1dSm -1 (s1, s2 and s3) were arranged in a randomized split-plot design with three replications for each treatment. In 2008, yield increased with increasing irrigation amount under both fresh and saline water irrigation. However, in 2009 and 2010, the highest yield at the same salinity level under saline water irrigation was obtained by w2. Actual evapotranspiration (ET a) decreased with decreasing irrigation amount. Therefore, w2 got higher water use efficiency (WUE) (1.25-1.63kgm -3) and irrigation water use efficiency (IWUE) (2.11-2.36kgm -3) than w1, which indicated that irrigation amount 300mm is beneficial to yield and water use efficiency at water salinity 3.2 and 6.1dSm -1. Thus, for the purpose of highest yield and WUE, irrigation amount should be controlled at appropriate level under saline water irrigation. The effect of irrigation water salinity on ET a was significant in 2009 and 2010, while the effect on yield, WUE and IWUE was only significant in 2010. However, the differences of yield, ET a, WUE and IWUE between s2 and s1 were statistically insignificant in the 3 years. It can be concluded that irrigation water salinity 3.2dSm -1 has no significant effect on wheat yield and water productivity. The interaction effects of irrigation amount and water salinity on yield, ET a and WUE were statistically insignificant in the experiments. © 2012 Elsevier B.V.


Wang J.,New Mexico State University | Krishna R.,University of Amsterdam | Yang J.,Taiyuan University of Technology | Dandamudi K.P.R.,New Mexico State University | Deng S.,New Mexico State University
Materials Today Communications | Year: 2015

Nitrogen-doped microporous activated carbon adsorbents were synthesized by a self-template method with KOH as the porogen agent at pyrolysis temperatures of 600, 700, and 800°C. The carbon adsorbent samples were characterized with N2 adsorption at 77K, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, thermal gravimetric analysis, Raman spectroscopy, Fourier transformed infrared spectroscopy, and energy-dispersive X-ray spectroscopy mapping. Single component gas adsorption equilibrium of CO2, CH4, and N2 on the carbon adsorbents were measured at gas pressures up to 100kPa and temperatures of 273, 298, and 323K. Adsorption breakthrough performance of a fixed bed packed with the carbon adsorbents for separation of CO2/CH4/N2 gas mixture was simulated using the adsorption equilibrium data collected in this work. A high CO2 adsorption capacity (6.36mmolg-1 on N-AC 600 at 100kPa and 273K) and large selectivites for the separation of CO2/CH4 (9.2), CO2/N2 (47.3) and CH4/N2 (3.6) mixtures were achieved with the carbon adsorbents due to their N-containing groups, narrow pore size distribution, and large specific surface area. The nitrogen-doped porous carbon adsorbents look very promising for flue gas treatment and natural gas upgrading applications. © 2015.


Yang Y.,Taiyuan University of Technology | Ji C.,China Building Material Geology Investigation Center Shanxi Unit | Kang T.,Taiyuan University of Technology | Chai Z.,Taiyuan University of Technology
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2011

The deformation characteristics of surrounding rock after excavating and supporting of coal roadway with great-thick mudstone roof, its failure mechanism and its controlling countermeasures are systematically researched through field investigation, laboratory test, numerical testing, similar simulation and theoretical analysis. Meanwhile these methods are used to represent dynamically the process of rock deformation and failure in the roadways, and the roadway's behaviors including deformation characteristics, failure mechanisms, stress distribution in the surrounding rocks and the effects of various support systems on roadway stability are studied. Some conclusions can be drawn as follows:(1) The fracture, cracking and separating layer of the thick mudstone roof occurred and promoted promote by two ways, such as the weathering, disintegrating, disruption, dilatancy of the mudstone, as well as the concentrated tensile stress and shear stress in the stress adjustment. (2) Based on the study, it is shown that the original supports in the absence of accurate judgment of the surrounding rock result in the roadway destruction and the supports system abated. (3) The principles to support the mudstone roof are enclosing in time, enhancing the stiffness of the lower rock layer of the roof and disposing the anchor cables along the cracks. (4) Based on the geological mechanics and environmental conditions of the roadway surrounding rock, an optimized roadway support design is provided that effectively avoid the multiple recondition by changing the cross-section and modulating the support parameters. The long-term stability of the thick mudstone roof had been realized. After several successful engineering practices, research results have been adopted in Qipanjing mining area;and the results have great theoretical and practical values to similar roadway supports.


Wang N.,Shandong University | Bai Z.,Taiyuan University of Technology | Qian Y.,Shandong University of Science and Technology | Yang J.,Shandong University
Advanced Materials | Year: 2016

Double-walled Sb@TiO2- x nanotubes take full advantage of the high capacity of Sb, the good stability of TiO2- x, and their unique interaction, realizing excellent electrochemical performance both in lithium-ion batteries and sodium-ion batteries. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Jiang T.,Linyi Normal University | Li M.,Taiyuan University of Technology | Chen C.S.,University of Southern Mississippi
Numerical Heat Transfer; Part A: Applications | Year: 2012

A new version of the method of particular solutions (MPS) has been proposed for solving inverse problems for nonhomogeneous convection-diffusion equations with variable coefficients (IPCD). Coupled with the time discretization and MPS, the proposed method is a truly meshless method which requires neither domain or boundary discretization. Even though the final temperature is almost undetectable or is disturbed by significant noise, the proposed method can still recover the initial temperature very well. The effectiveness of the proposed inverse scheme using radial basis functions is demonstrated by several examples in 2-D and 3-D. Copyright © Taylor & Francis Group, LLC.


Li Y.,Taiyuan University of Technology | Meng Q.,Taiyuan University of Technology | Deng Y.,Beihang University | Zhou H.,China University of Mining and Technology | And 3 more authors.
Applied Physics Letters | Year: 2012

We synthesized the solid solutions CuGa 1-xIn xTe 2 (x 0-1.0) by isoelectronic substitution of element In (Ga) for Ga(In) in the CuMTe 2 (M Ga, In) lattices and examined their thermoelectric properties. The structure upon substitution provides much high Seebeck coefficient (α), relatively low thermal (κ), and electrical conductivity (σ). AT 701 K, the α, σ, and κ are 283.15 V K -1, 1.15 × 10 4 Ω -1 m -1, and 0.71 W m -1 K -1, respectively, for CuGa 0.36In 0.64Te 2, which give the figure of merit (ZT) of 0.91, about two times those of the mother compounds CuGaTe 2 and CuInTe 2. This material holds great application perspectives at intermediate temperatures. © 2012 American Institute of Physics.


Li Z.,Taiyuan University of Technology | Yan X.,Wuhan University of Technology
Insight: Non-Destructive Testing and Condition Monitoring | Year: 2013

The sensor fusion of multi-sensory measurements is believed to improve the defect detection ability for machinery condition monitoring. A new fault diagnosis method for rolling bearings based on the sensor fusion of oil analysis data, microscopic debris analysis data and vibration analysis data is proposed in this paper. Multi-dimensional sensors were used to record the tribological and vibration data of rolling bearings in typical fault experiments. Oil and microscopic debris analysis was applied to obtain the wear particle number and size distribution, chemical compositions and particle textures, etc. Wavelet transform (WT) and empirical mode decomposition (EMD) were employed to attain the distinguishing features of the vibration data. Then, an intelligent data fusion method based on principal component analysis (PCA) and a genetic algorithm fuzzy neural network (GAFNN) was employed to identify the rolling bearing conditions. Experimental tests have been carried out to evaluate and verify the proposed method. The analysis results show that the fault detection model using the sensor fusion technique produces superior results to those using single measurements and thus it has application importance.


Su P.,Taiyuan University of Technology | Liao H.,State Key Laboratory of Hydraulics and Mountain River Engineering
Shuili Fadian Xuebao/Journal of Hydroelectric Engineering | Year: 2012

Shape parameters of bottom aerator adopted by an actual project are analyzed for its cavity properties with numerical simulation based on an orthogonal design method. The weight coefficients of all influencing factors, near-wall cavity length and middle cavity length, etc., are calculated by range and variance analysis. The results provide a theoretical foundation and a reference for shape design of aerator.


Zhang A.,Taiyuan University of Technology | Wang X.,Taiyuan University of Technology | Wang X.,Zhuzhou Electrical Company | Jia W.,Taiyuan University of Technology | And 2 more authors.
IEEE Transactions on Power Electronics | Year: 2014

The brushless doubly fed induction machine (BDFIM) shows potential in replacing the wound rotor machines for certain industrial applications due to its higher reliability, a benefit of the absence of brush gears. This paper proposes an indirect stator-quantities control (ISC) strategy for the BDFIM. Theoretical derivation has been carried out to demonstrate the control principle for the proposed strategy. ISC provides the benefit of a simple structure, since it is implemented in two static reference frames and no rotating coordinate transformation is required. Furthermore, only two stator winding resistances are used, and therefore, the controller structure is less dependent on machine parameters. The experimental results of the prototype show the feasibility of the proposed strategy for the BDFIM. © 2013 IEEE.


Cheng K.-K.,Tsinghua University | Liu Q.,Tsinghua University | Liu Q.,Taiyuan University of Technology | Zhang J.-A.,Tsinghua University | And 3 more authors.
Process Biochemistry | Year: 2010

Corncob acid hydrolysate, detoxed by sequently boiling, overliming and activated charcoal adsorption, was used for 2,3-butanediol production by Klebsiella oxytoca ACCC 10370. The effects of acetate in hydrolysate and pH on 2,3-butanediol production were investigated. It was found that acetic acid in hydrolysate inhibited the growth of K. oxytoca while benefited the 2,3-butanediol yield. With the increase in acetic acid concentration in medium from 0 to 4 g/l, the lag phase was prolonged and the specific growth rate decreased. The acetic acid inhibition on cell growth can be alleviated by adjusting pH to 6.3 prior to fermentation and a substrate fed-batch strategy with a low initial acetic acid concentration. Under the optimum condition, a maximal 2,3-butanediol concentration of 35.7 g/l was obtained after 60 h of fed-batch fermentation, giving a yield of 0.5 g/g reducing sugar and a productivity of 0.59 g/h l. © 2009 Elsevier Ltd. All rights reserved.


Zhang Y.,University of Science and Technology Beijing | Lu Z.P.,University of Science and Technology Beijing | Ma S.G.,Taiyuan University of Technology | Liaw P.K.,University of Tennessee at Knoxville | And 4 more authors.
MRS Communications | Year: 2014

With multiple elements mixed at equal or near-equal molar ratios, the emerging, high-entropy alloys (HEAs), also named multi-principal elements alloys (MEAs), have posed tremendous challenges to materials scientists and physicists, e.g., how to predict high-entropy phase formation and design alloys. In this paper, we propose some guidelines in predicting phase formation, using thermodynamic and topological parameters of the constituent elements. This guideline together with the existing ones will pave the way toward the composition design of MEAs and HEAs, as well as property optimization based on the composition-structure-property relationship. © 2014 Materials Research Society.


Li M.,Taiyuan University of Technology | Chen C.S.,Taiyuan University of Technology | Chu C.C.,National Taiwan University | Young D.L.,National Taiwan University
Engineering Analysis with Boundary Elements | Year: 2014

In this paper, the three-dimensional transient heat conduction problems in functionally graded materials (FGMs) have been solved using the method of fundamental solutions (MFS). To be more specific, we consider the FGMs with thermal conductivity and specific heat vary exponentially in z-direction. In the numerical simulation, we coupled the fundamental solution of diffusion equation with the method of time-space unification which provides a simple and direct approach for solving time-dependent problems. The parameter transformation technique is also utilized to obtain the fundamental solutions which contain the thermal conductivity and the specific heat conditions. The MFS is very attractive in handling problems with irregular domain due to the simplicity of the method. The numerical results are in good agreement comparing with analytical solution and results obtained from the finite element method. © 2014 Elsevier Ltd.


Li M.,Taiyuan University of Technology | Chen W.,Hohai University | Chen C.S.,Taiyuan University of Technology | Chen C.S.,University of Southern Mississippi
Engineering Analysis with Boundary Elements | Year: 2013

In this paper we present a localized meshless method using radial basis functions (RBFs) for solving up to six dimensional problems. To improve the difficulty of selecting a shape parameter of RBF-MQ, a normalized scheme is introduced. We also make a comparison between the global and local RBF methods in terms of stability and accuracy. To demonstrate the applicability of the localized RBF method for high dimensional problems, two numerical examples with Dirichlet boundary conditions are given. © 2013 Elsevier Ltd.


Li X.,Taiyuan University of Technology | Wang Z.,Taiyuan University of Technology | Zhu F.,Wayne State University | Wu G.,Taiyuan University of Technology | Zhao L.,Taiyuan University of Technology
International Journal of Impact Engineering | Year: 2014

Corrugated sandwich panels are widely used in various fields because such panels have lower density, easier fabrication methods and higher strength compared with monolithic plates. In this study, the dynamic response of corrugated sandwich panels under air blast loading was investigated using a ballistic pendulum system. Two configurations of the specimen were considered. The residual deflection of the back face sheet and the deformation/failure modes of the sandwich panel under different impulse levels were analysed. Finite element simulations were performed by using AUTODYN. The deformation process and energy absorption of the face sheets and the core were investigated in the numerical simulation. © 2013 Elsevier Ltd. All rights reserved.


Qiao J.,Taiyuan University of Technology | Jia H.,University of Tennessee at Knoxville | Liaw P.K.,University of Tennessee at Knoxville
Materials Science and Engineering R: Reports | Year: 2016

The mechanical properties of ex-situ and in-situ metallic glass matrix composites (MGMCs) have proven to be both scientifically unique and of potentially important for practical applications. However, the underlying deformation mechanisms remain to be studied. In this article, we review the development, fabrication, microstructures, and properties of MGMCs, including the roomerature, cryogenicerature, and higherature mechanical properties upon quasi-static and dynamic loadings. In parallel, the deformation mechanisms are experimentally and theoretically explored. Moreover, the fatigue, corrosion, and wear behaviors of MGMCs are discussed. Finally, the potential applications and important unresolved issues are identified and discussed. © 2015 Published by Elsevier B.V. All rights reserved.


Cheng K.-K.,Tsinghua University | Wang W.,Taiyuan University of Technology | Zhang J.-A.,Tsinghua University | Zhao Q.,Taiyuan University of Technology | And 2 more authors.
Bioresource Technology | Year: 2011

In this study, a central composite design of response surface method was used to optimize sulfite pretreatment of corncob residues, in respect to sulfite charge (5-10%), treatment time (1-2h), liquid/solid (l/s) ratio (6:1-10:1) and temperature (150-180°C) for maximizing glucose production in enzymatic hydrolysis process. The relative optimum condition was obtained as follows: sulfite charge 7.1%, l/s ratio 7.6:1, temperature 156°C for 1.4h, corresponding to 79.3% total glucan converted to glucose+cellobiose. In the subsequent simultaneous saccharification and fermentation (SSF) experiments using 15% glucan substrates pretreated under this kind of conditions, 60.8g ethanoll-1 with 72.2% theoretical yield was obtained. © 2010 Elsevier Ltd.


Xu L.-C.,Taiyuan University of Technology | Du A.,Queensland University of Technology | Kou L.,Queensland University of Technology
Physical Chemistry Chemical Physics | Year: 2016

The recent synthesis of monolayer borophene (triangular boron monolayer) on a substrate has opened the era of boron nanosheets (Science, 2015, 350, 1513), but the structural instability and a need to explore the novel physical properties are still open issues. Here we demonstrated that borophene can be stabilized by full surface hydrogenation (borophane), from first-principles calculations. Most interestingly, our calculations show that borophane has direction-dependent Dirac cones, which are mainly caused by the in-plane px and py orbitals of boron atoms. The Dirac fermions possess an ultrahigh Fermi velocity of up to 3.5 × 106 m s-1 under the HSE06 level, which is 4 times higher than that of graphene. The Young's moduli are calculated to be 190 and 120 GPa nm along two different directions, which are comparable to those of steel. The ultrahigh Fermi velocity and good mechanical features render borophane ideal for nanoelectronic applications. © 2016 the Owner Societies.


Qiao J.W.,Taiyuan University of Technology | Qiao J.W.,University of Science and Technology Beijing | Jia H.L.,University of Tennessee at Knoxville | Zhang Y.,University of Science and Technology Beijing | And 2 more authors.
Materials Chemistry and Physics | Year: 2012

Analysis of energy dissipation during shear-banding aids to understand plastic deformations of bulk metallic glasses (BMGs). For Zr 55Al 10Ni 5Cu 30 BMGs at 298 K, multi-step shearing is proposed, and the thermal energy during serrations cannot result in a temperature rise (ΔT) higher than T m. At 77 K, N-step shearing is supposed. When N is in the range of 24-47, it is reasonable to deduce the resulting temperature from 0.8T g to T m, accompanied by a continuous plastic deformation. Highlights: Multi-step shearing is reasonable to analyze energy conversion upon shear banding. At 77 K, the serrations disappear, and an N-step method is chosen to analyze the energy dissipation. The present investigation gives a proper method to reveal the shear banding for BMGs at different temperatures. © 2012 Published by Elsevier B.V. All rights reserved.


Ji J.,Taiyuan University of Technology | Zhou Z.,Tsinghua University | Yang X.,Tsinghua University | Zhang W.,Taiyuan University of Technology | And 2 more authors.
Small | Year: 2013

Interconnection of one-dimensional nanomaterials such as nanowires and carbon nanotubes with other parts or components is crucial for nanodevices to realize electrical contacts and mechanical fixings. Interconnection has been being gradually paid great attention since it is as significant as nanomaterials properties, and determines nanodevices performance in some cases. This paper provides an overview of recent progress on techniques that are commonly used for one-dimensional interconnection formation. In this review, these techniques could be categorized into two different types: two-step and one-step methods according to their established process. The two-step method is constituted by assembly and pinning processes, while the one-step method is a direct formation process of nano-interconnections. In both methods, the electrodeposition approach is illustrated in detail, and its potential mechanism is emphasized. Techniques used for interconnection formation, which is crucial for nanodevice performance, are categorized into two types. The two-step method is constituted by assembly and pinning processes, while the one-step method is a direct formation process of nano-interconnections. In both methods, contact resistances are compared and the electrodeposition approach is emphasized. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Wang R.,Taiyuan University of Technology | Wang R.,Tsinghua University | Han L.-H.,Tsinghua University | Hou C.-C.,Tsinghua University
Journal of Constructional Steel Research | Year: 2013

This paper reports an investigation into the impact performance of concrete filled steel tubular (CFST) members. A series of tests were carried out to obtain the failure modes and the time history of the impact forces for the composite components under lateral impact. The testing parameters include the axial load level on CFST specimens, constraining factor and the impact energy. A finite element analysis (FEA) model was developed, in which the strain rate effects of steel and concrete materials, interaction between the steel tube and the core concrete, as well as the confinement effect of the outer steel tube provided to the core concrete were considered. The test data were then used to verify the accuracy of the FEA model and generally a good agreement was achieved. A full-range analysis on the impact behavior of CFST member was performed by using the FEA model. © 2012 Elsevier Ltd. All rights reserved.


Wang Z.,Taiyuan University of Technology | Qiao J.W.,Taiyuan University of Technology | Yang H.J.,Taiyuan University of Technology | Liaw P.K.,University of Tennessee at Knoxville | And 2 more authors.
Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science | Year: 2015

Intermittent or serrated plastic flows have been widely observed in irreversible deformation through shear banding in bulk metallic glasses (BMGs). The strain-rate-dependent plasticity under uniaxial compression at 2 × 10−3, 2 × 10−4, and 2 × 10−5 s−1 in a Zr-based BMG is investigated. Serration events have a typical time scale at a relatively higher strain rate (2 × 10−3 s−1), while at lower strain rates, there is a lack of typical time scale. During serrations, the stress is falling rapidly, and the amplitude of the stress drop between the neighboring serrations is approximately equal. The stress drop vs time satisfies the exponential decay rule during jerk flows. Due to the serrated flow corresponding to the internal shear process, the free-volume model and stick–slip model are introduced to explain how the shear bands form and propagate and the cooperation of multiple shear bands. The mechanism is explained by relating the atomic-scale deformation with the macroscopic shear-band behavior, offering key ingredients to fundamentally cognize serrations in jerk flows. © 2014, The Minerals, Metals & Materials Society and ASM International.


Wang S.,Jilin University | Wang S.,Taiyuan University of Technology | Li G.,Jilin University | Huo Q.,Jilin University | Liu Y.,Jilin University
Inorganic Chemistry Communications | Year: 2013

Two new coordination polymers, |DMF|[Zn2(C7N 2O4H6)2(C10N 2H8)] (1) and |(H2O)3|[Co(C 8N2O4H9)2(H 2O)2] (2) have been synthesized based on 2-ethyl-1H-imidazole-4,5-dicarboxylic acid (H3EtImDC) and 2-propyl-1H-imidazole-4,5-dicarboxylic acid (H3PrImDC) as organic ligands, respectively. Single-crystal X-ray diffraction analysis reveals that compound 1 is a two dimensional layered structure constructed from two types of six-membered metallocycle, and the layers are stacked in an -ABCABC- sequence. For 2, the mononuclear [Co(C8N2O4H 9)2(H2O)2] molecules are connected with each other through hydrogen bonds forming a three dimensional supermolecular structure. Further characterizations including elemental analyses, IR spectra, and thermogravimetric analyses have been studied. © 2013 Elsevier B.V.


Qiao J.W.,Taiyuan University of Technology | Zhang Y.,University of Science and Technology Beijing | Jia H.L.,University of Tennessee at Knoxville | Yang H.J.,Taiyuan University of Technology | And 2 more authors.
Applied Physics Letters | Year: 2012

A Ti-based metallic-glass-matrix composite exhibits tensile softening (necking) in the supercooled liquid region, accompanied by a large tensile ductility and a fragmentation of dendrites. Subjected to high temperatures, concurrent crystallization does not occur, suggesting a good thermal stability of the glass matrix. The presence of high-volume-fractioned dendrites lowers the rheology of the viscous glass matrix at high temperatures, which results in an absence of super elongation as monolithic bulk metallic glasses (BMGs). A tensile strength of 970 MPa is higher than those of most BMGs under varying strain rates, ascribing to the retardation of softening by the dendrites. © 2012 American Institute of Physics.


Huang D.,Chongqing University | Huang D.,Key Laboratory of New Technology for Construction of Cities in Mountain Area | Li Y.,Taiyuan University of Technology
International Journal of Rock Mechanics and Mining Sciences | Year: 2014

Axisymmetric triaxial compression loading-unloading tests are conducted on twenty-seven marble specimens with initial confining pressures of 20, 30 and 40. MPa and unloading rates of 0.1, 1.0 and 10. MPa/s. It is found that magnitude of initial confining pressure and unloading rate significantly influence rock failure modes and strain energy conversion (accumulation, dissipation and release) during unloading. The failure mode of rock specimen is gradually changed from shear to tensile with increasing unloading rate. The pre-peak conversion rate of strain energy is increased with increasing unloading rate. This increase trend is enhanced by initial confining pressure. The post-peak conversion rate of strain energy has the similar increasing pattern of the pre-peak one, though it is several to ten times greater. Much strain energy is released after peak strength from the tested specimen and it may account for the occurrence of flying fragments. The higher the unloading rate and/or the initial confining pressure, the more severe the "flying fragment" phenomenon. The characteristics of strain energy accumulation, dissipation and release are investigated in three stages, i.e., elastic compression, pre-peak unloading, and post-peak fracturing. The rule of strain energy conversion for each stage is derived, and triaxial unloading tests and conventional triaxial compression are compared in terms of strain energy and its conversion. © 2013 Elsevier Ltd.


Yi Q.,Taiyuan University of Technology | Yi Q.,Training Base of State Key Laboratory of Coal Science | Feng J.,Taiyuan University of Technology | Feng J.,Training Base of State Key Laboratory of Coal Science | And 4 more authors.
Energy | Year: 2014

To resolve problems surrounding simultaneous CO2 conversion and COG (coke oven gas) utilization, a novel system combining a dual-gas of CGG (coal gasified gas) and COG with the technology of CO2 recycling into a single gasifier and reforming unit is proposed. 3E performance (energy, environmental, and economic) analysis showed that this novel system renders unnecessary the traditional water-gas shift process, and realizes the conversion and utilization of CH4 and CO2 that would otherwise be directly discharged into the air. Under a weak carbon mitigation policy, the economics of co-producing low-carbon fuels and electricity from a dual-gas of CGG and COG are promising. The "dual-gas" technology is a potentially viable option for clean coal and its efficient use in the co-production of low-carbon fuels and electricity in areas possessing COG, natural gas or other unconventional natural gas resources. © 2014 Elsevier Ltd.


Yao X.-L.,Taiyuan University of Technology | Liu Y.,Harbin Institute of Technology | Liu Y.,Ecole Polytechnique - Palaiseau | Yan X.,University of Management and Economics
Energy Policy | Year: 2014

A one-year subsidy program for energy-efficient home appliances has been implemented in China. We construct a dataset consisting of participant and non-participant households in both urban and rural areas of Rizhao city. By applying a quantile regression and counterfactual analysis, this study disentangles the impact of this subsidy program and inherent household attributes on per capita residential electricity consumption. First, contrary to the mean regression, the elasticity of electricity consumption to household[U+05F3]s income, age, education and energy-saving awareness, varies markedly across the electricity consumption distribution and shows discrepancy between urban and rural areas. Second, while inherent household attributes are identified as a primary determinant to the changes in residential electricity consumption, the effect induced by the subsidy incentive is more significant at the middle of the electricity consumption distribution than at the tails. Third, there are significant rebound effects that lead to overall increase in household electricity consumption. Our results suggest that the disparity between urban and rural regions and targeted consumer behavior changes should be taken into account to ensure the effectiveness of a future energy-efficient subsidy program. © 2014 Elsevier Ltd.


Chen B.-Y.,Hebei Medical University | Chen B.-Y.,Bethune International Peace Hospital of PLA | Ma J.-X.,Hebei Medical University | Wang C.-Y.,Bethune International Peace Hospital of PLA | Chen W.-Y.,Taiyuan University of Technology
Graefe's Archive for Clinical and Experimental Ophthalmology | Year: 2012

Background The study aims to determine the changes in the biomechanical properties of the anterior and extreme posterior portions of experimental near-sighted eyes by examining the mechanical behavior of guinea pig scleral desmocytes, thus finding a new approach to the pathogenesis of myopia and their corresponding therapies. Methods Guinea pigs (2 weeks old) were numbered and assigned into three groups (A, B, and C) with ten guinea pigs each. Concave lens-induced myopic (LIM) animal models were prepared via the out-of-focus method. The other eye in the same guinea pig served as the self-control (SC) group. After modeling groups A, B, and C for 6, 15, and 30 days respectively, the lenses from the guinea pigs in the experimental group were removed. The scleral fibroblasts in each group were cultured, and passaged twice in vitro. The micropipette aspiration technique coupled with a viscoelastic solid model was utilized to investigate the viscoelastic properties of the scleral fibroblasts in normal and myopic guinea pigs. The mechanical behavior of the scleral desmocytes of the LIM and SC groups were compared. Results The mechanical behavior of the scleral desmocytes was compared between the LIM and SC groups. The Young's modulus at equilibrium and the apparent cellular viscosity of the anterior portion of the sclera in the LIM group at 6 days and 15 days after myopic induction were not significantly different from that of the SC group (P<0.05). However, the results for the anterior portions of the sclera in the LIM group at 30 days were significantly higher than those of the LIM group at 6 and 15 days, as well as those in the SC group (P<0.05). The Young's modulus at equilibrium and the apparent cellular viscosity of the extreme posterior portions of the sclera in the LIM group at 6 days after myopic induction not significantly from those of the SC group (P<0.05). However, the results for the extreme posterior portions of the sclera in the LIM group after 15 days and 30 days were significantly higher than those in the LIM group at 6 days and the SC group (P<0.05). Conclusions The Young's modulus at equilibrium or apparent cellular viscosity of all the anterior portions of the sclera in the LIM group were longer than those in the SC group at 30 days after the induction, and the results for all the extreme posterior portions of the LIM group were larger than those of the SC group on the 15th and 30th day. Therefore, the Young's modulus and apparent viscosity of the anterior and extreme posterior portions of the sclera changed on the 15th and 30th day after induction respectively. © 2011 Springer-Verlag.


Xue J.,Taiyuan University of Technology | Xue J.,Key Laboratory of Interface Science and Engineering in Advanced Materials | Shen Q.,Taiyuan University of Technology | Liang W.,Taiyuan University of Technology | And 4 more authors.
Electrochimica Acta | Year: 2013

CdSe nanoparticles with well-defined crystallinity were assembled into vertically aligned TiO2 nanotube arrays (TiO2 NTAs) by cyclic voltammetry electrochemical deposition with an aim to tune the response of photoelectrochemical cell in visible region. Through this method, CdSe nanocrystals were deposited into intra- and inter-tubular space of the TiO 2 nanotubes (TNTs) to form three-dimensional (3D) multijunction structure. The amount of SeO2 added during electrodeposition of CdSe played an important role in formation of the heterostructures. A maximum short-circuit photocurrent of 7.72 mA/cm2 and open circuit potential of 1.24 V were achieved under visible light illumination. The remarkable photoresponse should ascribe to the high-quality of 3D multijunction structure. Such heterostructure system would serve as a promising candidate for solar energy conversion. © 2013 Elsevier Ltd. All rights reserved.


Wang Z.,Taiyuan University of Technology | Yu H.,Harbin Institute of Technology
Theoretical and Applied Fracture Mechanics | Year: 2015

An extended-finite-element-based method is proposed to accommodate the arbitrary motion of a crack in a general two-dimensional domain containing different kinds of material interfaces. To obtain the accurate stress intensity factors (SIFs) when the crack tip approaches the interface, the interpolation method in the vicinity of the crack tip employed in the extended finite element method (XFEM) is replaced with one that is derived from a moving mesh patch. Mesh configurations in this patch are the same as that adopted in the finite element method (FEM) for crack problems. The boundary of the patch is required to be coincident with background-mesh element edges and only the patch mesh works during the computation. As a result, the major advantages of the XFEM for modeling crack growth are preserved. The simulations are accomplished using a new domain expression of an interaction integral for evaluating stress intensity factors, and the maximum hoop stress criterion for crack-growth direction prediction. Several numerical examples are presented to prove the capability and practicability of the proposed technique and the program. © 2014 Elsevier Ltd.


Teng K.,Taiyuan University of Technology | Zhang C.,Harbin Institute of Technology
Nonlinear Analysis: Real World Applications | Year: 2016

In this paper, under some superquadratic conditions made on the nonlinearity f, we use variational approaches to establish the existence of infinitely many solutions to quasilinear elliptic equations with (p,q)-Laplacian -Ⅎpu-Ⅎqu+a(x)|u|p-2u+b(x)|u|q-2u=f(x,u)in ℝ, where 1


Deng K.,Taiyuan University of Technology | Wang C.,Taiyuan University of Technology | Wang X.,Harbin Institute of Technology | Wu K.,Harbin Institute of Technology | Zheng M.,Harbin Institute of Technology
Materials and Design | Year: 2012

In this paper, 1.5vol.% submicron-SiCp/AZ91 composite is fabricated by stir casting technology. After be forged at 420°C with 50% reduction initially, the composite is subjected to extrusion at 370°C with the ratio of 16. Results illustrates that the combination of forging and extrusion process has significant effect on refining grain size and improving particle distribution, which results in the obvious improvement of ambient tensile strength. Tensile testing at elevated temperatures also has been performed on the as-extruded composites at temperatures from 593K to 643K with initial strain rates from 8.3×10-4 to 1.67×10-2s-1. It demonstrates that the composite exhibits higher plasticity at elevated temperatures, which is mainly attributed to significant grain refinement and uniform particle distribution after hot deformation. Besides, the shape of stress-strain curves of submicron-SiCp/AZ91composite depends very sensitively on the strain rate and testing temperature. The strain-rate sensitivity exponent m is about 0.4 in the temperature and strain-rate range investigated, which suggests that the deformation probably occurred through grain boundary sliding accommodated by diffusional transport. © 2012 Elsevier Ltd.


Deng K.,Taiyuan University of Technology | Shi J.,Taiyuan University of Technology | Wang C.,Taiyuan University of Technology | Wang X.,Harbin Institute of Technology | And 3 more authors.
Composites Part A: Applied Science and Manufacturing | Year: 2012

One kind of (submicron + micron) bimodal size SiCp/AZ91 composite was fabricated by the stir casting technology. After hot deformation process, the influence of bimodal size particles on microstructures and mechanical properties of AZ91 matrix was investigated by comparing with monolithic A91 alloy, submicron SiCp/AZ91 and micron SiCp/AZ91 composites. The results show that micron particles can stimulate dynamic recrystallized nucleation, while submicron particles may pin grain boundaries during the hot deformation process, which results in a significant grain refinement of AZ91 matrix. Compared to submicron particles, micron particles are more conducive to grain refinement through stimulating the dynamic recrystallized nucleation. Besides, the yield strength of bimodal size SiCp/AZ91 composite is higher than that of single-size particle reinforced composites. Among the strengthening mechanisms of bimodal size particle reinforced composite, it is found that grain refinement and dislocation strengthening mechanism play a larger role on improving the yield strength. © 2012 Elsevier Ltd. All rights reserved.


Deng K.K.,Taiyuan University of Technology | Wang X.J.,Harbin Institute of Technology | Zheng M.Y.,Harbin Institute of Technology | Wu K.,Harbin Institute of Technology
Materials Science and Engineering A | Year: 2013

In this paper, 0.2. μm SiCp/AZ91 composite was fabricated by stir casting technology. The influence of fine (<1. μm) particles on the dynamic recrystallization (DRX) behavior of AZ91 matrix was investigated by researching the microstructure evolution of 0.2. μm 1. vol% SiCp/AZ91 composite during the hot extrusion process. Results showed that the DRXed ratio of AZ91 matrix increased as well as the average size of DRXed grains reduced due to the addition of fine particles. The SiCp could not only pin dislocation, but also was helpful to generate dislocations owing to the deformation mismatch between matrix and particles, thus causing the increase of dislocation density around SiCp, which was benefit to stimulate DRX nucleation. Meanwhile, the growth of DRXed grains was suppressed in the following deformation process due to the pinning effect of fine particles on grain boundaries. Thus, the fine particles had significant effect on stimulating DRXed nucleation and refining grain size. The yield strength and ultimate tensile strength of the as-deformed 0.2. μm 1. vol% SiCp/AZ91 composite are 275 and 335. MPa, respectively, which are mainly attributed to the grain refinement, basal plane texture and uniform particle distribution induced by hot deformation. © 2012 Elsevier B.V.


Ouyang T.,Xiangtan University | Chen Y.,Xiangtan University | Xie Y.,Xiangtan University | Wei X.L.,Xiangtan University | And 3 more authors.
Physical Review B - Condensed Matter and Materials Physics | Year: 2010

Graphene nanojunctions (GNJs) are important components of future nanodevices and nanocircuits. Using the nonequilibrium Green's function method, we investigate the phononic properties of three-terminal GNJs (TGNJs). The results show that the heat flux runs preferentially along the direction from narrow to wide terminals, presenting an evident ballistic thermal rectification effect in the asymmetric TGNJs. The rectification efficiency is strongly dependent on the asymmetry of the nanojunctions, which increases rapidly with the width discrepancy between the left and right terminals. Meanwhile, the corner form of the TGNJs also plays an important role in the rectification effect. The mechanism of this thermal rectification is explained by a qualitative analysis. Compared to previous thermal rectifiers based on other materials, the asymmetric nanojunctions based on graphene possess much high rectification ratio which can approach about 200%. These indicate that asymmetric TGNJs might be a promising candidate for excellent ballistic thermal (phononic) devices. © 2010 The American Physical Society.


Xiao B.,Queen's University of Belfast | Xiao B.,Taiyuan University of Technology | Yuan Q.,Aston University | Williams R.A.,University of Birmingham
Chemical Communications | Year: 2013

A new concept of nanoporous metal organic framework particles stabilising emulsions was investigated. The copper benzenetricarboxylate MOF particles adsorbed at the oil/water interface play an exceptional role in stabilising both oil-in-water and water-in-oil emulsions. © 2013 The Royal Society of Chemistry.


Dong Y.,University of Birmingham | Li X.,University of Birmingham | Tian L.,Taiyuan University of Technology | Bell T.,University of Birmingham | And 2 more authors.
Acta Biomaterialia | Year: 2011

Antibacterial surface modification of biomedical materials has evolved as a potentially effective method for preventing bacterial proliferation on the surfaces of devices. However, thin antibacterial coatings or modified layers can be easily worn down when interacting with other surfaces in relative motion, thus leading to a low durability of the antibacterial surface. To this end, novel biomaterial surfaces with antibacterial Ag agents and a wear-resistant S-phase have been generated on stainless steel by duplex plasma silvering-nitriding techniques for application to load-bearing medical devices. The chemical composition, microstructure, surface topography, roughness and wettability of SS surfaces were characterised using glow discharge optical emission spectroscopy, energy-dispersive spectroscopy/wavelength dispersive spectrometry (WDS), X-ray diffraction, atomic force microscopy and a contact angle goniometer. Optimal surface design for high antimicrobial activity and prolonged durability has been achieved, as evidenced by rapid bacterial killing rates (within 6 h), an ultra hard matrix (875 ± 25 Hv), high load-bearing capacity (critical load 37 N) and excellent wear resistance (wear rate 4.9 × 10-6 mm3 m-1). Ag embedded in the hard substrate of fcc compounds M4N (M = Fe, Cr, Ag, etc.) and the expanded fcc nitrogen S-phase shows deep infiltration of 6 ± 1 μm, and provides bactericidal activity against both Gram-negative Escherichia coli NCTC 10418 and Gram-positive Staphylococcus epidermidis NCTC 11047 of over 97% and 90%, respectively, within 6 h. The presence of silver in the surface before and after scratching under a progressive load applied up to 60 N using a diamond stylus was confirmed by WDS. © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.


Chen B.-Y.,Bethune International Peace Hospital of PLA | Wang C.-Y.,Bethune International Peace Hospital of PLA | Chen W.-Y.,Taiyuan University of Technology | Ma J.-X.,Hebei Medical University
Graefe's Archive for Clinical and Experimental Ophthalmology | Year: 2013

Purpose: To determine changes in expression of transforming growth factor β-2 (TGF-β2) and basic fibroblast growth factor (bFGF) in scleral desmocytes from anterior and posterior portions of experimentally-induced myopic eyes of guinea pigs. Methods: Three groups (n = 10) of 2-week-old guinea pigs were used to develop concave lens-induced myopia (LIM) in one eye via the out-of-focus method for 6, 15, or 30 days respectively, while the other eye in each guinea pig served as the self-control (SC). After myopia induction, lenses were removed, and scleral fibroblasts were cultured and passaged twice. TGF-β2 and bFGF expression levels of scleral desmocytes in LIM and SC groups were compared by immunocytochemistry, quantitative real-time PCR (qRT-PCR) and Western blot analyses. Results: The TGF-β2 expression of the anterior portion of the sclera in the LIM group was significantly higher at 15 days, and at its highest at 30 days after myopia induction compared with the SC group (P < 0.05). The TGF-β2 staining of the posterior sclera in the LIM group began to rise significantly at 6 days, peaked at 15 days and remained significantly higher than that of the anterior part, as well as the SC group, even at 30 days after myopia induction (P < 0.05). BFGF levels in scleral desmocytes from the anterior and posterior regions in the LIM group were both significantly lower than those of the SC group at all time points after myopia induction (P < 0.05). Furthermore, as the myopia progressed, bFGF expression in the anterior and posterior sclera in the LIM group gradually and statistically significantly decreased compared with the SC group (P < 0.05); however, no significant differences were observed between the anterior and posterior parts in the LIM group at any time after myopia induction (P > 0.05). All these results were consistent at the mRNA and protein levels. Conclusions: During myopia development in lens-induced guinea pigs, the increase in TGF-β2 activity of scleral desmocytes initiated at the posterior pole. Along with the induction time, the TGF-β2 activity in all scleral desmocytes became elevated. By contrast, the bFGF activity showed a general decline in all scleral desmocytes, rather than mainly in the posterior pole. These results imply that expression of TGF-β2 in scleral desmocytes plays a direct role, while that of bFGF exerts an indirect role in myopia development. © 2013 Springer-Verlag Berlin Heidelberg.


Liang W.,Taiyuan University of Technology | Zhao Y.,Taiyuan University of Technology | Wu D.,Taiyuan University of Technology | Dusseault M.B.,University of Waterloo
Rock Mechanics and Rock Engineering | Year: 2011

Carbon dioxide (CO2) is considered to be the most important greenhouse gas in terms of overall effect. CO2 geological storage in coal beds is of academic and industrial interest because of economic synergies between greenhouse gas sequestration and coal bed methane (CH4) recovery by displacement/adsorption. Previously, most work focused on either theoretical analyses and mathematical simulations or gas adsorption-desorption experiments using coal particles of millimeter size or smaller. Those studies provided basic understanding of CH4 recovery by CO2 displacement in coal fragments, but more relevant and realistic investigations are still rare. To study the processes more realistically, we conducted experimental CH4 displacement by CO2 and CO2 sequestration with intact 100 × 100 × 200 mm coal specimens. The coal specimen permeability was measured first, and results show that the permeability of the specimen is different for CH4 and CO2; the CO2 permeability was found to be at least two orders of magnitude greater than that for CH4. Simultaneously, a negative exponential relationship between the permeability and the applied mean stress on the specimen was found. Under the experimental stress conditions, 17.5-28.0 volumes CO2 can be stored in one volume of coal, and the displacement ratio CO2-CH4 is as much as 7.0-13.9. The process of injection, adsorption and desorption, displacement, and output of gases proceeds smoothly under an applied constant pressure differential, and the CH 4 content in the output gas amounted to 20-50% at early stages, persisting to 10-16% during the last stage of the experiments. Production rate and CH4 fraction are governed by complex factors including initial CH4 content, the pore and fissure fabric of the coal, the changes in this fabric as the result of differential adsorption of CO2, the applied stress, and so on. During CO2 injection and CH4 displacement, the coal can swell from effects of gas adsorption and desorption, leading to changes in the microstructure of the coal itself. Artificial stimulation (e.g. hydraulic fracturing) to improve coalbed transport properties for either CO2 sequestration or enhanced coal bed methane recovery will be necessary. The interactions of large-scale induced fractures with the fabric at the scale of observable fissures and fractures in the laboratory specimens, as well as to the pore scale processes associated with adsorption and desorption, remain of profound interest and a great challenge. © Springer-Verlag 2011.


Zhang G.,Taiyuan University of Technology | Dong Y.,Taiyuan Heavy Machinery Technical Center | Feng M.,Taiyuan Science and Technology Enducation Center | Zhang Y.,Taiyuan University of Technology | And 2 more authors.
Chemical Engineering Journal | Year: 2010

The CO2 reforming of methane (in coke oven gas) on the coal char catalyst was performed in a fixed bed reactor at temperatures between 800 and 1200 °C under normal pressure. The effects of the coal char catalyst pretreatment and the ratio of CO2/CH4 were studied. Experimental results showed that the coal char was an effective catalyst for production of syngas, and addition of CO2 did not enhance the CH4 reforming to H2. It was also found that the product gas ratio of H2/CO is strongly influenced by the feed ratio of CO2/CH4. The modified coal char catalyst was more active during the CO2-CH4 reforming than the coal char catalyst based on the catalyst volume, furthermore the modified catalyst exhibited high activity in CO2-CH4 reforming to syngas. The conversion of methane can be divided into two stages. In the first stage, the conversion of CH4 gradually decreased. In the second stage, the conversion of methane maintained nearly constant. The conversion of CO2 decreased slightly during the overall reactions in CO2-CH4 reforming. The coal char catalyst is a highly promising catalyst for the CO2 reforming of methane to syngas. © 2009 Elsevier B.V. All rights reserved.


Zhao T.,Taiyuan University of Technology | Wang A.,Taiyuan University of Technology | Wang Y.,Taiyuan University of Technology | Zhang M.,Taiyuan University of Technology | And 3 more authors.
Optics Express | Year: 2013

We propose and experimentally demonstrate a method for fault location in optical communication network. This method utilizes the traffic signal transmitted across the network as probe signal, and then locates the fault by correlation technique. Compared with conventional techniques, our method has a simple structure and low operation expenditure, because no additional device is used, such as light source, modulator and signal generator. The correlation detection in this method overcomes the tradeoff between spatial resolution and measurement range in pulse ranging technique. Moreover, signal extraction process can improve the location result considerably. Experimental results show that we achieve a spatial resolution of 8 cm and detection range of over 23 km with ?8-dBm mean launched power in optical network based on synchronous digital hierarchy protocols. ©2013 Optical Society of America.


Li Y.,Taiyuan University of Technology | Li Y.,AGECON Ltd.
Bulletin of Engineering Geology and the Environment | Year: 2013

The effects of particle shape and size distribution on the constitutive behavior of composite soils with a wide range of particle size were investigated. Two comparable sets of specimens were prepared: (1) mixtures of fines (clay and silt) and an ideal coarse fraction (glass sand and beads), and (2) mixtures of fines and natural coarse fraction (river sand and crushed granite gravels). Direct shear box testing was undertaken on 34 samples and the structure of the shear surfaces, change in volume and water content and the particle shape coefficient of the sheared specimens were examined. The results indicate that the contraction/dilation a specimen exhibits is restrained within the shear zone while the outer zones remain unchanged during shearing. An increased coarse fraction leads to an increase in constant volume shear strength. In addition, increasing elongation or decreasing convexity of the coarse fraction increases the constant volume friction angle. The overall roughness of the shear surface at constant volume state is negatively related to particle smoothness (convexity) and positively related to the area of the shear surface occupied by particles with particular shapes. Two equations are proposed for the estimation of constant volume friction angle based on the proportion and shape coefficient of the coarse fraction. It is hoped this will assist in considering the shear strength of mixed soils when the size of the coarse fraction makes laboratory testing difficult. © 2013 Springer-Verlag Berlin Heidelberg.


Zhu X.,Taiyuan University of Technology | Zhu X.,Huaibei Normal University | Han X.-Q.,Taiyuan University of Technology | Qin W.-P.,Taiyuan University of Technology | And 2 more authors.
Renewable and Sustainable Energy Reviews | Year: 2015

Micro-grids have been developed for over two decades as building blocks for future smart grids. Microgrids have appeared with the advantages such as control flexibility, easy connection of renewable resources, high efficiency and immunity to large area blackouts. Similar to other countries, development of micro-grids in China has gone through from the early stage of AC microgrids to the current varieties of AC, DC and hybrid AC/DC micro-girds based on their applications. Many technical problems have been solved and new problems are continuously appeared during the development process. This paper presents a past, today and future for development of micro-grids in China. The current status of microgrids and renewable energy sources in China is presented first. The topologies of the micro-grids in China are then introduced and classified into three types. Different control techniques of the micro-grids are introduced. Finally, technical challenges and future prospect of micro-grids in China are discussed. © 2014 Elsevier Ltd. All rights reserved.


Zhao J.-J.,Taiyuan University of Technology | Ji G.-H.,Taiyuan University of Technology | Xia Y.,Northwestern Polytechnical University | Zhang X.-L.,Pennsylvania College of Technology
International Journal of Bio-Inspired Computation | Year: 2015

Lung nodule segmentation is an important pre-processing step for analysis of solitary pulmonary nodules in computed tomography (CT) imaging. However, the previous nodule segmentation methods cannot segment the cavitary nodules entirely. To address this problem, an automated segmentation method based on self-generating neural networks and particle swarm optimisation (PSO) is proposed to ensure the integrity of cavitary nodule segmentation. Our segmentation method first roughly segments the image using a general region-growing method. Thereafter, the PSO-self-generating neural forest (SGNF)-based classification algorithm is used to cluster regions. Finally, grey and geometric features are utilised to identify the nodular region. Experimental results show that our method can achieve an average pixel overlap ratio of 88.9% compared with manual segmentation results. Moreover, compared with existing methods, this algorithm has higher segmentation precision and accuracy for cavitary nodules. Copyright © 2015 Inderscience Enterprises Ltd.


Li M.,Taiyuan University of Technology | Chen C.S.,Taiyuan University of Technology | Chen C.S.,University of Southern Mississippi | Karageorghis A.,University of Cyprus
Computers and Mathematics with Applications | Year: 2013

We investigate applications of the method of fundamental solutions (MFS) for the numerical solution of two-dimensional boundary value problems in complex geometries, governed by the Laplace equation and subject to Dirichlet boundary conditions which are not harmonic. Such problems can be very challenging because of the appearance of boundary singularities. We consider several ways of choosing the boundary collocation points as well as the source points in the MFS. We show that with an appropriate such choice the MFS yields highly accurate results. © 2013 Elsevier Ltd. All rights reserved.


Liu L.,Taiyuan University of Technology | Yang J.,Taiyuan University of Technology | Li J.,Taiyuan University of Technology | Dong J.,Taiyuan University of Technology | And 3 more authors.
Angewandte Chemie - International Edition | Year: 2011

Less is more: An open-framework zirconium phosphate with unusual 7-ring channels was synthesized ionothermally from a deep-eutectic solvent. This small-pore material displays a CO2/CH4 adsorption ratio (17.3 at 1 bar) that is significantly higher than that of typical 8-ring materials, making it highly attractive for CO2/CH4 separations. © 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.


Li H.,Taiyuan University of Technology | Han P.D.,Taiyuan University of Technology | Zhang X.B.,Huaibei Normal University | Li M.,Huaibei Normal University
Materials Chemistry and Physics | Year: 2013

An integrated model based on bond number and bond strength in a system with a cubo-octahedral structure is developed to predict the size-dependent thermal characteristics of nanoparticles. Without any adjustable parameters, this model can be used to predict the melting point and cohesive energy of low-dimensional materials, suggesting that both depend on the size and on the atomic distance. The good agreement of the theoretical prediction with the experimental and molecular dynamic simulation results confirms the validity of the cubo-octahedron in describing the thermodynamic behaviors of nanoparticles even without considering their crystalline structures. © 2012 Elsevier B.V. All rights reserved.


Li X.,Taiyuan University of Technology | Li X.,Simon Fraser University | Weng S.,Simon Fraser University | Ge B.,Biogate Laboratories Ltd. | And 3 more authors.
Lab on a Chip - Miniaturisation for Chemistry and Biology | Year: 2014

A diagnosis platform based entirely on DVD technology was developed for on-site quantitation of molecular analytes of interest, e.g., human chorionic gonadotropin (hCG) in urine samples ("quantitative pregnancy test on a disc"). An hCG-specific monoclonal antibody-binding assay prepared on a regular DVD-R was labeled with nanogold-streptavidin conjugates for signal enhancement with a customized silver-staining protocol. An unmodified, conventional computer optical drive was used for assay reading, and free disc-quality analysis software for data processing. The performance (sensitivity and selectivity) of this DVD assay is comparable to that of well-established colorimetric methods (determination of optical darkness ratios) and standard enzyme-linked immunosorbent assays (ELISA). As validated by examining its linear correlation with the ELISA results on the same set of samples, the DVD assay promises to be a low-cost, multiplex, point-of-care (POC) diagnostic tool for physicians and even for individuals at home, producing prompt results. © 2014 the Partner Organisations.


Li H.,Taiyuan University of Technology | Liang X.H.,Taiyuan University of Technology | Li M.,Huaibei Normal University
Materials Chemistry and Physics | Year: 2014

A new model for the solid melting point Tm(D) from nanovoids is proposed through considering the liquid layer growth behavior. This model, which does not have any adjustable parameter, introduces the classical thermodynamic treatment, i.e., the liquid nucleation and growth theory, for nanoparticle melting. With increased void diameter D, Tm(D) approaches to T m0. Moreover, Tm(D) > Tm0 for a small void (Tm0 is the bulk melting point). In other words, the solid can be significantly superheated especially when D decreases, even if the difference of interface energy is larger than zero. This finding can be expected from the negatively curved surface of the void. The model predictions are consistent with the molecular dynamic (MD) simulation results for argon solids. Moreover, the growth of liquid layer from void surface relies on both size and temperature, which directly determine liquid layer thickness, and only when liquid layer thickness reaches to a critical value, can void become instable. © 2014 Elsevier B.V. All rights reserved.


Wang Z.,Taiyuan University of Technology | Wang Z.,University of Waterloo | Feng Y.,Taiyuan University of Technology | Hao X.,Taiyuan University of Technology | And 2 more authors.
Journal of Materials Chemistry A | Year: 2014

In this study, we report on a novel potential-responsive hybrid film system for heavy metal removal, which was composed of a layered α-zirconium phosphate (α-ZrP) nanosheet and a conducting polyaniline (PANI)-intercalated chain that functioned as a proton pumping element. The proposed system features a quick responsive uptake/release rate that was about 10 times the adsorption/desorption rate with an open circuit. The potential-responsive film system exhibited a high electroactivity because of an acidic micro-environment for the nitrogen atoms in the PANI chains due to protons available on the electronegative α-ZrP nanosheets and their ion exchangeability. The uniform and dense hybrid film was formed on platinum electrodes using a one-step electrosynthesis based on unipolar pulse electrodeposition (UPED). By simply switching the operating potential applied to the electrode, heavy metal uptake onto the film from aqueous solutions and metal release for film regeneration were accomplished. This film system is shown to be a promising alternative to conventional techniques for heavy metal capture from wastewater. 2014 This journal is © the Partner Organisations.


Guo R.,Taiyuan University of Technology | Liu Y.-F.,Taiyuan University of Technology | Hao H.-Q.,Taiyuan University of Technology | Qi F.-H.,Beijing Wuzi University
Nonlinear Dynamics | Year: 2015

Under investigation in this paper is a coherently coupled nonlinear Schrödinger system which describes the propagation of polarized optical waves in an isotropic medium. By virtue of the Darboux transformation, some new solutions have been generated on the vanishing and non-vanishing backgrounds, including multi-solitons, bound solitons, one-breathers, bound breathers, two-breathers, first-order and higher-order rogue waves. Dynamic behaviors of those solitons, breathers and rogue waves have been discussed through graphic simulation. © 2015, Springer Science+Business Media Dordrecht.


Wang Z.,Taiyuan University of Technology | Hao X.,Taiyuan University of Technology | Zhang Z.,Taiyuan University of Technology | Liu S.,Taiyuan University of Technology | And 2 more authors.
Sensors and Actuators, B: Chemical | Year: 2012

Unipolar pulse waveforms consist of an applied anode potential during the on-period and an open-circuit potential during the off-period. Unipolar pulse electrodeposition (UPED) was used to fabricate nickel hexacyanoferrate/chitosan/ carbon nanotubes (NiHCF/CS/CNTs) nanocomposite films with controllable structure on the electrode surface of a hydrogen peroxide (H 2O 2) sensor. One-step electrodeposition of NiHCF/CS/CNTs film with insoluble-structure NiHCF nanoparticles was performed, and the whole procedure took only several minutes. The morphology and the composition of the NiHCF/CS/CNTs film were characterized by scanning electron microscopy (SEM) and energy dispersive X-ray (EDS). With the introduction of CNTs, the NiHCF/CS/CNTs system formed showed synergy between CNTs and NiHCF with a significant improvement of redox activity of NiHCF due to the excellent electron-transfer ability of CNTs. Electrochemical experiments revealed that the modified electrode allowed low potential (-0.2 V) detection of H 2O 2 and showed high electrocatalytic activity towards the reduction of H 2O 2. The linear range for the detection of H 2O 2 was 0.04-5.6 mM with a high sensitivity of 654 mA M -1 cm -2 and a rapid response (less than 2 s). The detection limit for H 2O 2 was as low as 2.8 × 10 -7 M (S/N = 3). © 2012 Elsevier B.V. All rights reserved.


Wang Z.,Taiyuan University of Technology | Sun S.,Taiyuan University of Technology | Hao X.,Taiyuan University of Technology | Ma X.,Taiyuan University of Technology | And 3 more authors.
Sensors and Actuators, B: Chemical | Year: 2012

Electroactive hybrid films with cubic nickel hexacyanoferrate/polyaniline (NiHCF/PANI) were synthesized on carbon nanotubes (CNTs) modified platinum electrodes by a facile one-step electrosynthesis method using cyclic voltammetry (CV). The morphologies and structures of the as-prepared NiHCF/PANI/CNTs films were characterized using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR), respectively. Due to the introduction of CNTs with carboxyl groups, an acidic micro-environment was provided for the nitrogen atoms in the PANI chains, which could maintain its electroactivity in neutral aqueous solutions. The hybrid films were applied for hydrogen peroxide (H 2O 2) detection and showed synergy and higher electrocatalytic activity with a higher sensitivity, a faster response time and a lower detection limit. It was found that detection sensitivity could be regulated by controlling the time of CV of electrosynthesis during the preparation of the hybrid film. A catalytic rate constant of 1.29 × 10 8 cm 3 mol -1 s -1 was obtained from an investigation of the kinetics of the catalytic reaction. SEM images showed that the cubic composite nano-particles of PANI and NiHCF were formed and distributed uniformly on the CNTs. The hybrid film prepared had good stability and reproducibility in the detection of H 2O 2, and should be useful in practical H 2O 2 sensors. © 2012 Elsevier B.V. All rights reserved.


Wang Z.,Taiyuan University of Technology | Ma Y.,Taiyuan University of Technology | Hao X.,Taiyuan University of Technology | Huang W.,Taiyuan University of Technology | And 2 more authors.
Electrochimica Acta | Year: 2014

A concept of electrochemically switched ion exchange (ESIX) film with potential-triggered proton self-exchange effect (PTPS) for removal of Cu 2+ ions was proposed. Based on this concept, a novel ESIX film made of poly (2,6- pyridinedicarboxylic acid) (PPDA) was successfully fabricated, and applied to remove Cu2+ ions from aqueous solution. It is found that Cu2+ ions were rapidly removed with a high selectivity and this film was reproducible by simple changing the applied potential. Herein, the mechanism of the potential-triggered proton self-exchange (PTPS) effect on the ion-exchange process using this kind of film was proposed. Electrochemical quartz crystal microbalance, IR spectroscopy and X-ray photoelectron spectra methods were used to characterize and attest the proposed mechanism. This PPDA film showed high potential for the Cu2+ detection and the treatment of wastewater containing heavy metal ions in various industrial processes. © 2014 Elsevier Ltd.


Du X.,Taiyuan University of Technology | Zhang H.,Taiyuan University of Technology | Hao X.,Taiyuan University of Technology | Guan G.,Hirosaki University | Abudula A.,Hirosaki University
ACS Applied Materials and Interfaces | Year: 2014

A facile unipolar pulse electropolymerization (UPEP) technique is successfully applied for the preparation of ion-imprinted composite film composed of ferricyanide-embedded conductive polypyrrole (FCN/PPy) for the selective electrochemical removal of heavy metal ions from wastewater. The imprinted heavy metal ions are found to be easily removed in situ from the growing film only by tactfully applying potential oscillation due to the unstable coordination of FCN to the imprinted ions. The obtained Ni2+ ion-imprinted FCN/PPy composite film shows fast uptake/release ability for the removal of Ni2+ ions from aqueous solution, and the adsorption equilibrium time is less than 50 s. The ion exchange capacity reaches 1.298 mmol g-1 and retains 93.5% of its initial value even after 1000 uptake/release cycles. Separation factors of 6.3, 5.6, and 6.2 for Ni 2+/Ca2+, Ni2+/K+, and Ni 2+/Na+, respectively, are obtained. These characteristics are attributed to the high identification capability of the ion-imprinted composite film for the target ions and the dual driving forces resulting from both PPy and FCN during the redox process. It is expected that the present method can be used for simple preparation of other ion-imprinted composite films for the separation and recovery of target heavy metal ions as well. © 2014 American Chemical Society.


Kaewpanha M.,Hirosaki University | Guan G.,Hirosaki University | Hao X.,Taiyuan University of Technology | Wang Z.,Taiyuan University of Technology | And 3 more authors.
Fuel Processing Technology | Year: 2014

Alkali and alkaline earth species in biomass have self-catalytic activity on the steam gasification to produce hydrogen-rich gas. In this study, three types of biomass, i.e., brown seaweed, Japanese cedar, apple branch containing different concentrations of alkali and alkaline earth species, and the mix of both of them were gasified with steam in a fixed-bed reactor under atmospheric pressure. The effects of reaction temperature, steam amount and mixing ratio in co-gasification on gas production yields were investigated. The results showed that higher gas production yields (especially for H2 and CO 2) were obtained when the brown seaweed was used than the other two types of biomass since the ash content in brown seaweed was much higher than in land-based biomass and contained a large amount of alkali and alkaline earth species. The yield of hydrogen increased with an increase in the amount of steam, but excessive steam use reduced the hydrogen production yield. From the co-gasification experiments, the gas production yields (especially for H 2 and CO2) from the land-based biomass increased with the increase in brown seaweed ratio, suggesting that the alkali and alkaline earth species in brown seaweed acted as the catalysts to enhance the gasification of land-based biomass in co-gasification process. © 2013 Elsevier B.V.


Liu S.-D.,Taiyuan University of Technology | Liu S.-D.,Wuhan University | Yang Z.,Taiyuan University of Technology | Liu R.-P.,Taiyuan University of Technology | Li X.-Y.,Taiyuan University of Technology
Journal of Physical Chemistry C | Year: 2011

Practical implementations of biosensing with metallic nanostructures often suffer from the large line width of the plasmon resonances induced by large radiative damping. A double split nanoring cavity is designed to suppress the radiative damping. The coupling between the superradiant quadrupole mode of a split nanoring with one gap and the subradiant quadrupole mode of a split nanoring with two gaps leads to splitting of the modal energies into bonding and antibonding quadrupole-quadrupole modes. The radiative damping is suppressed effectively, leading to a narrow line width for both bonding and antibonding quadrupole-quadrupole modes. Calculation results show that bulk refractive index sensitivities exceeding 1200 nm/RIUwith a figure of merit exceeding 8.5 in the near-infrared are obtained with a Au double split nanoring cavity. The large cavity volumes and uniform electric fields inside the cavity make the double split nanoring cavity a good platform for surface-enhanced molecular sensing. © 2011 American Chemical Society.


Liu S.-D.,Taiyuan University of Technology | Liu S.-D.,Wuhan University | Yang Z.,Taiyuan University of Technology | Liu R.-P.,Taiyuan University of Technology | Li X.-Y.,Taiyuan University of Technology
ACS Nano | Year: 2012

Fano resonances in plasmonic nanostructures are important for plasmon line shaping. Compared to a single Fano resonance, multiple Fano resonances can modify plasmon lines at several spectral positions simultaneously, but they often suffer from weak modulation depths. In this paper, plasmonic heptamer clusters comprising split nanorings are designed to form multiple Fano resonances. Three prominent Fano resonances are observed in the spectra due to the formation of multiple narrow subradiant resonances, and the multiple Fano resonances can be switched on and off by adjusting the polarization direction. Particularly, by modifying the geometry parameters, there is a large tunability of the modulation depth of each Fano resonance. Heptamer clusters comprising split nanorings are highly suitable for plasmon line shaping, and it is expected that they are useful for multiwavelength biosensing and surface-enhanced Raman scattering. © 2012 American Chemical Society.


Wang Z.,Taiyuan University of Technology | Wang Y.,Taiyuan University of Technology | Hao X.,Taiyuan University of Technology | Liu S.,Taiyuan University of Technology | And 2 more authors.
Electrochimica Acta | Year: 2013

An all cis-polyaniline nanotube film was successfully prepared using a novel unipolar pulse electro-polymerization method and its formation mechanism was analyzed and discussed. Due to its unique chemical molecular conformation, many excellent performances such as low charge transfer resistance, good water wettability, high apparent diffusion coefficient, large redox site capacity and super-stability were identified. When it was applied for the supercapacitor electrode, a high specific capacitance of 1007.7 F g-1 with a dramatic retention life of 99% after 2000 charge/discharge cycles was obtained. The ascorbic acid sensor fabricated by this film showed a large linear range for the detection of ascorbic acid between 1.0 × 10-6 and 1 × 10-2 M with a high sensitivity of 182 mA M-1 cm-1. © 2013 Elsevier Ltd. All rights reserved.


Zhang R.,Taiyuan University of Technology | Liu H.,Taiyuan University of Technology | Liu H.,Shanxi Datong University | Li J.,Taiyuan University of Technology | And 2 more authors.
Applied Surface Science | Year: 2012

The interaction mechanism of H 2S with different Cu 2O(1 1 1) surfaces, including perfect, oxygen-vacancy and sulfur-containing surfaces, have been systematically studied using periodic density functional calculations. Different kinds of possible modes of H 2S, as well as the resultant SH and S species adsorbed on these surfaces are identified. Two types of pathways via molecular and dissociative adsorption processes are mapped out. Our results show that sulfur species (H 2S, SH and S) interact with surface Cu centers; H 2S exists in the form of molecular adsorption on perfect and sulfur-containing surfaces; the dissociative adsorption of H 2S occurs predominantly on oxygen-vacancy surface, suggesting that oxygen-vacancy exhibits a strong catalytic activity toward the dissociation of H 2S. On the other hand, the dissociation processes of the molecular and dissociative adsorption H 2S, leading to final product S species on these Cu 2O(1 1 1) surfaces, show that the overall dissociation process is exothermic. Meanwhile, with respect to molecular adsorption H 2S, the activation barrier and reaction energy of the overall dissociation process on perfect and oxygen-vacancy surfaces indicate that H 2S can easily dissociate into S species. Importantly, in the case of dissociative adsorption of H 2S, the dissociation of H 2S into S species is a spontaneous process with respect to molecular adsorption H 2S. However, on sulfur-containing surface, the presence of surface S atom goes against the HS bond-breaking process both thermodynamically and kinetically. Finally, the vibrational frequencies for the adsorbed H 2S, SH and S species on these surfaces have been obtained, which can be applied to guide surface vibrational spectroscopy in experiment. © 2012 Elsevier B.V.


Zhang Y.,Henan University of Science and Technology | Zhang Y.,Nanjing University | Hou Y.,Xi'an Jiaotong University | Jia H.,Taiyuan University of Technology
Computers and Mathematics with Applications | Year: 2014

In this paper, we consider a subgrid stabilized defect-correction method for the steady-state natural convection problem. We state the stabilities and error results for the defect step and the first correction step of the defect correction method. The derived theoretical results are supported by several numerical examples. © 2013 Elsevier Ltd. All rights reserved.


Wei Z..-Z.,Tianjin Environmental Engineering Assessment Center | Li D..-C.,Taiyuan University of Technology | Pang X..-Y.,Taiyuan University of Technology | Lv C..-Q.,Shanxi Datong University | And 2 more authors.
ChemCatChem | Year: 2012

CO oxidation on the IB group metals [Cu(111), Ag(111), and Au(111)] and corresponding metal oxides [Cu 2O(100), Ag 2O(100), and Au 2O(100)] has been studied by means of density functional theory calculations with the aim to shed light on the reaction mechanism and catalytic activity of metals and metal oxides. The calculated results show that 1)the molecular oxygen mechanism is favored on Ag(111) and Au(111), but the atomic oxygen mechanism is favored on Cu(111); 2)the metal-terminated metal oxide shows very low activity for CO oxidation; 3)the lattice oxygen can react either with gas phase CO or the absorbed CO molecule on oxygen-terminated metal oxides; and 4)the reaction barrier for CO oxidation follows the order of M 2O(100)-O


He L.L.,China Academy of Engineering Physics | Chen X.W.,China Academy of Engineering Physics | Wang Z.H.,Taiyuan University of Technology
International Journal of Impact Engineering | Year: 2016

Two-group penetration tests of Concept Projectile for High-speed Penetration (CPHP) are carried out with striking velocity ranging from 1130 m/s to 1650 m/s. Almost all projectiles are integral after penetration except the one at striking velocity 1650 m/s. The maximum dimensionless Depth of Penetration (DOP) reaches 78.9 at striking velocity 1415 m/s with the concrete strength as 33.4 MPa. It further confirms that CPHP has excellent structural stability and penetration performance into concrete target at high striking velocities. The penetration performances of CPHP made of different materials are also compared. It indicates that the strength and ductility of material jointly control the penetration performance of CPHP. The mass loss of CPHP distributes not only in its nose but also in its shank. The CPHP nose still keeps ogival and the surface of CPHP shank recedes inward. Furthermore, the mass loss mechanism is studied by metallographic observation. It indicates that the heat transformed from frictional work between target and projectile is the main cause of Heat Affected Zone (HAZ), and the peeling of molten surface layer is the main cause of mass loss. Several White Narrow Bands (WNBs) in CPHP nose tip contribute minor mass loss due to its rare number and limited dimensions. Finally, the analytical model for DOP of CPHP was derived. The model prediction is validated by the available experimental result. © 2016 Elsevier Ltd. All rights reserved.


Luo H.,Shanxi Datong University | Shen J.,Taiyuan University of Technology | Zhang C.,Taiyuan University of Technology
Composites Part B: Engineering | Year: 2013

The Li0.35Zn0.3Fe2.35O4 micro-belts were prepared by cotton template method. The nickel-coated carbon fibers were obtained by electroless plating method. The formation mechanism of the ferrite micro-belt was studied. The microwave absorption properties of the Li0.35Zn0.3Fe2.35O4 micro-belts/nickel-coated carbon fibers composites were investigated in the frequency range of 30-6000 MHz. The absorbers of the Li0.35Zn 0.3Fe2.35O4 micro-belts/nickel-coated carbon fibers composites have much better microwave absorption properties than the nickel-coated carbon fibers absorbers, and the microwave absorption properties of the composites are influenced by the thickness of the absorber. © 2013 Elsevier Ltd. All rights reserved.


Whittaker P.B.,University of Western Australia | Wang X.,University of Tasmania | Regenauer-Lieb K.,University of Western Australia | Chua H.T.,University of Western Australia | Chua H.T.,Taiyuan University of Technology
Physical Chemistry Chemical Physics | Year: 2013

A method for predicting the isosteric heat of gas adsorption on solid materials is developed which requires the measurement of a single isotherm - where previous methods, such as the Clausius-Clapeyron approach, require either multiple isotherms or complex calorimetric measurement. The Tóth potential function, stemming from the Polanyi potential function, is evaluated using the Langmuir and Tóth isotherm equations to generate new equations for the isosteric heat. These new isosteric heat equations share common parameters with the isotherm equations and are determined from isotherm fitting. This method is demonstrated in the literature for gas adsorption onto solid adsorbates including zeolites of various surface charge character and non-porous rutile phase titanium dioxide. Predictions are made using the new isosteric heat equations and then compared to calorimetric data. © the Owner Societies 2013.


Pang X.-Y.,Taiyuan University of Technology | Liu C.,Nankai University | Li D.-C.,Taiyuan University of Technology | Lv C.-Q.,Shanxi Datong University | And 2 more authors.
ChemPhysChem | Year: 2013

The reaction mechanism of CO oxidation on the Co3O4 (110) and Co3O4 (111) surfaces is investigated by means of spin-polarized density functional theory (DFT) within the GGA+U framework. Adsorption situation and complete reaction cycles for CO oxidation are clarified. The results indicate that 1) the U value can affect the calculated energetic result significantly, not only the absolute adsorption energy but also the trend in adsorption energy; 2) CO can directly react with surface lattice oxygen atoms (O2f/O3f) to form CO2 via the Mars-van Krevelen reaction mechanism on both (110)-B and (111)-B; 3) pre-adsorbed molecular O2 can enhance CO oxidation through the channel in which it directly reacts with molecular CO to form CO2 [O2(a)+CO(g)→CO2(g)+O(a)] on (110)-A/(111)-A; 4) CO oxidation is a structure-sensitive reaction, and the activation energy of CO oxidation follows the order of Co3O4 (111)-A(0.78 eV)>Co3O4 (111)-B (0.68 eV)>Co3O 4 (110)-A (0.51 eV)>Co3O4 (110)-B (0.41 eV), that is, the (110) surface shows higher reactivity for CO oxidation than the (111) surface; 5) in addition to the O2f, it was also found that Co3+ is more active than Co2+, so both O2f and Co3+ control the catalytic activity of CO oxidation on Co 3O4, as opposed to a previous DFT study which concluded that either Co3+ or O2f is the active site. Different mechanisms of CO oxidation depending on the surface structure of Co 3O4 are found by DFT calculations, which also show that CO oxidation on Co3O4 (110)-B has higher activity than that on Co3O4(111)-B (see reaction energy profiles in the picture), that is, it is a structure sensitive reaction. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Hou J.,Shanxi University | Hou J.,Taiyuan University of Technology | Guo Y.,Shanxi University | Guo Y.,Shanxi Datong University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2010

The question of under what conditions different witnesses (e.g., W 1,W 2) may detect some common entangled states [i.e., there exists some state ρ so that Tr(W 1ρ) < 0andTr(W 2ρ) < 0] is answered for both finite-dimensional and infinite-dimensional bipartite systems. Finitely many different witnesses W 1,W 2,...,W n can detect some common entangled states if and only if ∑ n i=1 d iW i is still a witness for any nonnegative numbers d 1,d 2,...,d n with∑ n i=1 d i = 1; they cannot detect any common entangled state if and only if ∑ n i=1 c iW i is a positive operator for some nonnegative numbers c 1,c 2,...,c n with ∑ n i=1 c i = 1. For two witnesses W 1 and W 2 more can be said. First, W 1 and W 2 can detect the same set of entangled states if and only if W 1 = aW 2 for some number a > 0. Second, W 2 can detect more entangled states than W 1 can if and only if W 1 = aW 2 + D for some numbera > 0 and a positive operator D. As an application, some characterizations of the optimal witnesses are given and some structural properties of the decomposable optimal witnesses are presented. © 2010 The American Physical Society.


Sun B.,Taiyuan University of Technology | Hao X.-G.,Taiyuan University of Technology | Wang Z.-D.,Taiyuan University of Technology | Guan G.-Q.,Hirosaki University | And 3 more authors.
Journal of Hazardous Materials | Year: 2012

A series of experiments were performed to evaluate the continuous separation of cesium based on an electrochemically switched ion exchange (ESIX) process using a diaphragm-isolated reactor with two identical nickel hexacyanoferrate/porous three-dimensional carbon felt (NiHCF/PTCF) electrodes as working electrodes. The effects of applied potential, initial concentrations and pH values of the simulation solutions on the adsorption of cesium ion were investigated. The adsorption rate of cesium ion in the ESIX process was fitted by a pseudo-first-order reaction model. The experiments revealed that the introduction of applied potential on the electrodes greatly enhanced the adsorption/desorption rate of Cs+ and increased the separation efficiency. H3O+ was found to play a dual role of electrolyte and competitor, and the adsorption rate constant showed a curve diversification with an increase in pH value. Also, it was found that the electrochemically switched adsorption process of Cs+ by NiHCF/PTCF electrodes proceeded in two main steps, i.e., an ESIX step with a fast adsorption rate and an ion diffusion step with a slow diffusion rate. Meanwhile, the NiHCF/PTCF film electrode showed adsorption selectivity for Cs+ in preference to Na+. © 2012 Elsevier B.V.


Ma N.,Taiyuan University of Technology | Ma N.,Xi'an Jiaotong University | Zhang S.,Xi'an Jiaotong University | Liu D.,Changzhou University | Wang V.,Xi'an University of Technology
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2014

Recent theoretical works have predicated the appearance of Weiss oscillations in the magnetoconductivity with a one-dimensional periodic electrical or magnetic modulation in graphene. This paper further explores the electrostatic field effect on the Weiss oscillations in the presence of crossed uniform in-plane electric field and perpendicular magnetic field that is weakly and periodically modulated along one direction. We find that the oscillation amplitude (OA) of Weiss oscillations and the value of conductivity are both shown to increase as the electric field E increases for a given magnetic field B. More interestingly, the electric field leads to an abrupt disappearance of the Weiss oscillations, when the value of electric to magnetic field ratio approaches a threshold value, i.e., γe = E/υFB = 1. These phenomena, not known in the conventional 2D electron gas, are a consequence of the anomalous spectrum of electron in graphene. © 2014 Elsevier B.V. All rights reserved.


Guo Y.,Shanxi Datong University | Guo Y.,Taiyuan University of Technology
International Journal of Modern Physics B | Year: 2013

Measurement-induced nonlocality (MIN), introduced by Luo and Fu [Phys. Rev. Lett. 106, 120401 (2011)], is a kind of quantum correlation which is different from entanglement and quantum discord (QD). MIN is defined over one-sided projective measurements. In this paper, we introduce a MIN over two-sided projective measurements. The nullity of this two-sided MIN is characterized, a formula for calculating two-sided MIN for pure states is proposed, and a lower bound of (two-sided) MIN for maximally entangled mixed states is given. In addition, we find that (two-sided) MIN is not continuous. Both finite- and infinite-dimensional cases are considered. © 2013 World Scientific Publishing Company.


Liu S.-D.,Taiyuan University of Technology | Liu S.-D.,Wuhan University | Zhang M.-J.,Taiyuan University of Technology | Wang W.-J.,Taiyuan University of Technology | Wang Y.-C.,Taiyuan University of Technology
Applied Physics Letters | Year: 2013

Multiple Fano resonances in plasmonic pentamer clusters composed of nanorings are observed and investigated. Molecular point group theory is used to understand the formation of multiple Fano resonances. By modifying the radius of the center ring or the angle between the center and the surrounding rings, the modulation depths and the spectral positions of the multiple Fano resonances can be tuned within a wide range. For pentamers composed of split nanorings, another Fano resonance can be excited because of the excitation of the quadrupole mode of the surrounding split nanorings. © 2013 American Institute of Physics.


Liu S.-D.,Taiyuan University of Technology | Liu S.-D.,Wuhan University | Yang Z.,Taiyuan University of Technology | Liu R.-P.,Taiyuan University of Technology | Li X.-Y.,Taiyuan University of Technology
Optics Express | Year: 2011

Plasmonic-induced optical transparency with double split nanoring cavity is investigated with finite difference time domain method. The coupling between the bright third-order mode of split nanoring with one gap and the dark quadrupole mode of split nanoring with two gaps leads to plasmonic analogue of electromagnetically induced transparency. The transparence window is easily modified to the near-infrared and visible range. Numerical results show a group index of 16 with transmission exceeding 0.76 is achieved for double split nanoring cavity. There is large cavity volume of double split nanoring, and the field enhancement inside the cavity is homogenous. Double split nanoring cavity could be a good platform for slow light and sensing applications. © 2011 Optical Society of America.


Ma Y.,Hirosaki University | Guan G.,Hirosaki University | Shi C.,Dalian University of Technology | Zhu A.,Dalian University of Technology | And 4 more authors.
International Journal of Hydrogen Energy | Year: 2014

Various transition metals (M = Pt, Fe, Co, and Ni) were selected to support on molybdenum carbides by in-situ carburization metal-doped molybdenum oxide (M-MoOx) via temperature-programmed reaction (TPR) with a final temperature of 700 °C in a reaction gas mixture of 20% CH4/H 2. XRD analysis results indicated that β-Mo2C phase was formed in the case of Fe, Co, or Ni doping while α-Mo2C phase was appeared with the β-MoC1-x phase in the case of Pt doping. With the increase in Pt doping amount, more α-MoC1-x phase was produced. As-prepared metal doped molybdenum carbides were investigated as alternative catalysts for the steam reforming of methanol. Comparing with the undoped molybdenum carbide such as β-Mo2C, metal-doped one showed higher methanol conversion and hydrogen yield. It is found that Pt doped molybdenum carbide had the highest catalytic activity and selectivity among the prepared catalysts and methanol conversion reached 100% even at a temperature as low as 200 °C, and remained a long-time stability with a stable methanol conversion. Copyright © 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.


Ma Y.,Hirosaki University | Guan G.,Hirosaki University | Phanthong P.,Hirosaki University | Hao X.,Taiyuan University of Technology | And 4 more authors.
Journal of Physical Chemistry C | Year: 2014

Molybdenum carbides were modified by nickel with different doping amounts by using a temperature-programmed reaction (TPRe) process and used for steam reforming of methanol (SRM). XRD analysis results indicated that the β-Mo2C phase was easily formed in Ni-modified carbide samples. The doping amount of Ni had great effect not only on the activity of the molybdenum carbide catalyst, but also on the catalyst stability. For relatively lower Ni doping amounts, i.e., Ni/Mo molar ratio = 0.8/99.2 to 2.4/97.6, the catalysts exhibited almost the same methanol conversion in the reaction temperature range. Meanwhile, when the Ni/Mo molar ratio was over 5/95, the catalytic activity was decreased greatly. Furthermore, Ni-Mo2C with Ni/Mo molar ratios of 1.6/98.4 and 2.4/97.6 showed longer term stability than other samples. Compared with the pure β-Mo2C and other iron group element modified carbide samples, the Ni-modified one showed higher catalytic activity and stability. The fresh and spent catalysts were characterized by XRD, XPS, BET, and TEM and it is found that the resistance to the oxidation of molybdenum carbide and carbon deposition could be enhanced by the loading of Ni with low amounts. © 2014 American Chemical Society.


Gao A.,Taiyuan University of Technology | Hang R.,Taiyuan University of Technology | Huang X.,Taiyuan University of Technology | Zhao L.,PLA Fourth Military Medical University | And 5 more authors.
Biomaterials | Year: 2014

A versatile strategy to endow biomaterials with long-term antibacterial ability without compromising the cytocompatibility is highly desirable to combat biomaterial related infection. TiO2 nanotube (NT) arrays can significantly enhance the functions of many cell types including osteoblasts thus having promising applications in orthopedics, orthodontics, as well as other biomedical fields. In this study, TiO2 NT arrays with Ag2O nanoparticle embedded in the nanotube wall (NT-Ag2O arrays) are prepared on titanium (Ti) by TiAg magnetron sputtering and anodization. Well-defined NT arrays containing Ag concentrations in a wide range from 0 to 15 at % are formed. Ag incorporation has little influence on the NT diameter, but significantly decreases the tube length. Crystallized Ag2O nanoparticles with diameters ranging from 5nm to 20nm are embedded in the amorphous TiO2 nanotube wall and this unique structure leads to controlled release of Ag+ that generates adequate antibacterial activity without showing cytotoxicity. The NT-Ag2O arrays can effectively kill Escherichia coli and Staphylococcus aureus even after immersion for 28 days, demonstrating the long lasting antibacterial ability. Furthermore, the NT-Ag2O arrays have no appreciable influence on the osteoblast viability, proliferation, and differentiation compared to the Ag free TiO2 NT arrays. Ag incorporation even shows some favorable effects on promoting cell spreading. The technique reported here is a versatile approach to develop biomedical coatings with different functions. © 2014 Elsevier Ltd.


Guo Y.,Shanxi Datong University | Guo Y.,Taiyuan University of Technology | Hou J.,Taiyuan University of Technology
Journal of Physics A: Mathematical and Theoretical | Year: 2013

Measurement-induced nonlocality is a measure of nonlocality introduced recently by Luo and Fu. We present here sufficient and necessary conditions for a quantum state for which this quantity is equal to zero. Furthermore it is shown that for such a state ρab with any local channel acting on Ha cannot create measurement-induced nonlocality if and only if either it is a completely contractive channel or it is a nontrivial isotropic channel. For the qubit case this property is an additional characteristic of the completely contractive channel or the commutativity-preserving unital channel. © 2013 IOP Publishing Ltd.


Guo Y.,Shanxi Datong University | Guo Y.,Taiyuan University of Technology | Hou J.,Taiyuan University of Technology
Reports on Mathematical Physics | Year: 2013

The realignment operation and the computable cross norm or realignment (CCNR) criterion of separability for states in infinite-dimensional bipartite quantum systems are established. Let HA and HB be complex Hilbert spaces with dim HA ⊕ HB ≤ +∞. Let ρ be a quantum state acting on HA ⊕ HB and {δk} be the Schmidt coefficients of ρ as a vector in the Hilbert space C2(HA) ⊕ C2(HB). We introduce the realignment operator ρR and the computable cross norm ||ρ||CCN of ρ and show that if ρ is separable, then ||ρR||Tr = ||ρ||CCN = σk δ ≤ 1. In particular, if ρ is a pure state, then ρ is separable if and only if ||ρR||Tr = ||ρ||CCN = σk δk = 1. For the finite-dimensional case, this recovers the original computable cross norm criterion. © 2013 Polish Scientific Publishers.


Guo Y.,Shanxi Datong University | Guo Y.,Taiyuan University of Technology | Hou J.,Taiyuan University of Technology
Journal of Physics A: Mathematical and Theoretical | Year: 2013

Quantum discord (QD) is one of the main quantum correlations in quantum information theory. In this paper, we show that a local channel cannot create QD for zero QD states of size d 3 if and only if either it is a completely decohering channel or it is a nontrivial isotropic channel. For the qubit case this property is an additional characteristic of the completely decohering channel or the commutativity-preserving unital channel. In particular, the exact forms of the completely decohering channel and the commutativity-preserving unital qubit channel are proposed. Consequently, our results confirm and improve the conjecture proposed by Hu et al for the case of d 3 and improve the result proposed by Streltsov et al for the qubit case. © 2013 IOP Publishing Ltd.


Wang L.,North China Electrical Power University | Zhu Y.-J.,North China Electrical Power University | Qi F.-H.,Beijing Wuzi University | Li M.,North China Electrical Power University | Guo R.,Taiyuan University of Technology
Chaos | Year: 2015

In this paper, the nonautonomous Lenells-Fokas (LF) model is investigated. The modulational instability analysis of the solutions with variable coefficients in the presence of a small perturbation is studied. Higher-order soliton, breather, earthwormon, and rogue wave solutions of the nonautonomous LF model are derived via the n-fold variable-coefficient Darboux transformation. The solitons and earthwormons display the elastic collisions. It is found that the nonautonomous LF model admits the higher-order periodic rogue waves, composite rogue waves (rogue wave pair), and oscillating rogue waves, whose dynamics can be controlled by the inhomogeneous nonlinear parameters. Based on the second-order rogue wave, a diamond structure consisting of four first-order rogue waves is observed. In addition, the semirational solutions (the mixed rational-exponential solutions) of the nonautonomous LF model are obtained, which can be used to describe the interactions between the rogue waves and breathers. Our results could be helpful for the design of experiments in the optical fiber communications. © 2015 AIP Publishing LLC.


Liu S.-D.,Taiyuan University of Technology | Liu S.-D.,Wuhan University | Yang Z.,Taiyuan University of Technology | Liu R.-P.,Taiyuan University of Technology | Li X.-Y.,Taiyuan University of Technology
Applied Physics Letters | Year: 2012

Radiative damping and refractive index sensing performances of elliptical split nanorings are investigated. The third order resonance can be viewed as two electric dipoles in opposite directions, leading to a cancellation of their dipole moments. The scattering quantum yield decreases from 0.647 to 0.183 by adjusting the outer radii, and the corresponding largest figure of merit of sensing performance is 10.6, which is 61% and 86% larger than the split and perfect rings, respectively. Radiative damping can be further suppressed by increasing the gap size; the scattering quantum yield is decreased to 0.138 when the gap size is 35 nm. © 2012 American Institute of Physics.


Zhao B.,Taiyuan University of Technology | Wang Q.,Chinese People's Armed Police forces Academy | Zhang C.,Chinese People's Armed Police forces Academy
Journal of Magnetism and Magnetic Materials | Year: 2013

Li0.35Zn0.3Fe2.35O4 micro-belts were prepared by cotton template. The nickel-coated carbon fibers were obtained by electroless plating method. The formation mechanism of the ferrite micro-belt was studied. The electromagnetic properties of the microwave absorbers were investigated in the frequency range of 30-6000 MHz. The double-layer absorbers have better microwave absorption properties than the nickel-coated carbon fibers single-layer absorbers and the microwave absorption properties of the composites are influenced by the thickness of the absorber. © 2013 Elsevier B.V. All rights reserved.


Guo Y.,Shanxi Datong University | Guo Y.,Taiyuan University of Technology | Hou J.,Taiyuan University of Technology
Journal of Physics A: Mathematical and Theoretical | Year: 2012

We present a sufficient condition for a bipartite state to be separable via the strong positive partial transposition structure introduced in Chruściński et al (2008 Phys. Rev. A 77 022113), from which we obtain a class of separable states. In particular, we prove that any classical-quantum state is a state of our class but not vice versa. Both finite- and infinite-dimensional systems are considered. © 2012 IOP Publishing Ltd.


Luo C.,Taiyuan University of Technology | Liang W.,Taiyuan University of Technology | Chen Z.,Taiyuan University of Technology | Zhang J.,Taiyuan University of Technology | And 2 more authors.
Materials Characterization | Year: 2013

Using a two-pass hot rolling process, Al(5052)/Mg(AZ31)/Al(5052) alloy laminated composite plates were fabricated. The first pass was performed at relatively low temperatures, and the second pass was performed at higher temperatures. No new phases formed at the bond interface after the first hot rolling pass. High temperature annealing with the annealing temperature at or above 300 C caused the formation of continuous layers of the intermetallics Mg17Al12 and Al3Mg2 at the bond interface of Al(5052)/Mg(AZ31). The growth rate of the intermetallic layers increased with increasing the annealing temperature, while the incubation time decreased with increasing the temperature. A kinetic equation was developed to describe the growth of the intermetallic compound layers. The second hot rolling pass caused the break of the continuous intermetallic layers into fragments, which were intermittently dispersed at the bond interface. © 2013 Elsevier Inc.


Liu Z.,Taiyuan University of Technology | Wang Y.,Beijing Institute of Technology | Li J.,Taiyuan University of Technology | Zhang R.,Taiyuan University of Technology
RSC Advances | Year: 2014

Using recent well-defined models of γ-Al2O3 surfaces, the interactions of Nin(n = 1-7) clusters with different γ-Al2O3 surfaces have been investigated in order to illustrate, by density functional theory periodic calculations, the effect of γ-Al2O3 surface hydroxylation on the stability and nucleation of Ni in Ni/γ-Al2O3 catalyst. Three types of γ-Al2O3 surfaces, dehydrated γ-Al 2O3(100), dehydrated γ-Al2O 3(110) and hydrated γ-Al2O3(110) were considered. Our results show that for the adsorption of Nin(n = 3-7) clusters, the γ-Al2O3(110) surface is more favorable than the γ-Al2O3(100) surface, however, for single Ni atoms and Ni2 clusters, the reverse becomes true. Meanwhile, for the adsorption of Nin(n = 2-7) clusters, the hydrated (110) surface is not favorable compared to the dehydrated (110) surface, due to the presence of surface hydroxyls on the former. The reverse is true for single Ni atoms due to weaker surface deformation. Further, the support stabilizes Nin(n = 2-7) clusters well in the supported state, in which the presence of surface hydroxyls reduces the stability of the supported Nin clusters. On the other hand, the nucleation ability of Nin clusters on different γ-Al2O3 surfaces, is more favorable on the γ-Al2O3(110) surface than on the γ-Al 2O3(100) surface, and the dehydrated (110) surface is more favorable than the hydrated (110) surface due to the presence of surface hydroxyls, namely, surface hydroxylation reduces the nucleation ability of Nin clusters on the γ-Al2O3 surface. More importantly, the exothermicity of supported Nin(n = 2-7) clusters on different γ-Al2O3 surfaces is lower than that of isolated Nin clusters, indicating that the support is not favorable for the nucleation of Nin(n = 2-7) clusters, as a result, the support can inhibit the aggregation of clusters, and favors the formation of small clusters. This journal is © the Partner Organisations 2014.


Zhang R.,Taiyuan University of Technology | Song L.,Taiyuan University of Technology | Wang Y.,Beijing Institute of Technology
Applied Surface Science | Year: 2012

A density functional theory slab calculations of CH 4 dissociation on Pt(h k l) surfaces have been systematically presented. On the basis of the energetic analysis, the favorable adsorption sites and stable configurations of CH x(x = 0-4) and H species on Pt(1 1 1), Pt(1 1 0) and Pt(1 0 0) surfaces are first obtained, respectively. Afterwards, the most stable configurations of coadsorbed CH x/H(x = 0-3) are located. Further, the kinetic and thermodynamical results of CH 4 dissociation on Pt(h k l) surface suggest that CH is the most abundant CH x species. Our results mean that Pt catalyst can resist the carbon deposition in the CH 4 dissociation, which can give a microscopic reason that why Pt catalyst can lead to lower carbon deposition and show a high activity in the reaction related to CH 4. © 2012 Elsevier B.V.


Liu J.-J.,Taiyuan University of Technology | Wang J.-M.,Beijing Institute of Technology
International Journal of Robust and Nonlinear Control | Year: 2016

In this paper, we are concerned with a cascade of ODE-wave systems with the control actuator-matched disturbance at the boundary of the wave equation. We use the sliding mode control (SMC) technique and the active disturbance rejection control method to overcome the disturbance, respectively. By the SMC approach, the disturbance is supposed to be bounded only. The existence and uniqueness of solution for the closed-loop via SMC are proved, and the monotonicity of the 'reaching condition' is presented without the differentiation of the sliding mode function, for which it may not always exist for the weak solution of the closed-loop system. Considering that the SMC usually requires the large control gain and may exhibit chattering behavior, we then develop an active disturbance rejection control to attenuate the disturbance. The disturbance is canceled in the feedback loop. The closed-loop systems with constant high gain and time-varying high gain are shown respectively to be practically stable and asymptotically stable. Then we continue to consider output feedback stabilization for this coupled ODE-wave system, and we design a variable structure unknown input-type state observer that is shown to be exponentially convergent. The disturbance is estimated through the extended state observer and then canceled in the feedback loop by its approximated value. These enable us to design an observer-based output feedback stabilizing control to this uncertain coupled system. © 2016 John Wiley & Sons, Ltd.


Rahimi B.,University of Western Australia | May J.,University of Western Australia | Regenauer-Lieb K.,University of New South Wales | Chua H.T.,Taiyuan University of Technology | Chua H.T.,University of Western Australia
Desalination | Year: 2015

Two novel desalination processes that utilise low grade sensible heat sources have been modelled and both have been shown to be more thermally efficient means of desalinating water than conventional Multi Effect Distillation (MED). The novel Boosted MED (B-MED) and Flash Boosted MED (FB-MED) processes are capable of higher production rates than conventional MED, enabled by the addition of process components and by an increase in specific electrical power consumption. A simple method of estimating the capital and operational costs of MED, B-MED and FB-MED desalination installations is presented. A generalised comparison of the economics of these three processes is conducted, asserting the economic viability of the novel desalination processes. © 2015 Elsevier B.V.


Yan K.,Taiyuan University of Technology | Yan K.,Lakehead University | Liao J.,Taiyuan University of Technology | Wu X.,Taiyuan University of Technology | Xie X.,Taiyuan University of Technology
RSC Advances | Year: 2013

A Cu-catalyst derived from hydrotalcite precursor was highly selective for the hydrogenation of biomass-derived furfural and levulinic acid. 90% yield of furfuryl alcohol and 51% yield of 2-methylfuran were achieved selectively in the hydrogenation of furfural. 91% yield of γ-valerolactone was achieved in the hydrogenation of levulinic acid. This journal is © 2013 The Royal Society of Chemistry.


Lu Y.-B.,Southwest University of Science and Technology | Wu H.-J.,Beijing Institute of Technology | Zhao L.-M.,Taiyuan University of Technology
Baozha Yu Chongji/Explosion and Shock Waves | Year: 2013

Dynamic splitting experiments on cement mortar specimens were performed to experimentally investigate the crack initiation and propagation under various loading rates. And a micro-mechanical model was developed to deeply analyze this problem. The results demonstrate that the micro-crack inertia is one of the mechanisms responsible for the increase of dynamic tensile strength with strain rate which can be observed in the dynamic tensile experiments on concrete-like materials.


Yan K.,Brown University | Yan K.,Taiyuan University of Technology | Lafleur T.,Lakehead University | Wu X.,Taiyuan University of Technology | And 3 more authors.
Chemical Communications | Year: 2015

Cascade upgrading of γ-valerolactone (GVL), produced from renewable cellulosic biomass, with selective conversion to biofuels pentyl valerate (PV) and pentane in one pot using a bifunctional Pd/HY catalyst is described. Excellent catalytic performance (over 99% conversion of GVL, 60.6% yield of PV and 22.9% yield of pentane) was achieved in one step. These biofuels can be targeted for gasoline and jet fuel applications. This journal is © The Royal Society of Chemistry.


Zhang X.,Taiyuan University of Technology | Guo T.,Shanxi Province Industry and Trade College | Wang X.,Taiyuan University of Technology | Wang Y.,Taiyuan University of Technology | And 2 more authors.
Applied Catalysis B: Environmental | Year: 2014

The BiOCl, BiOCl/Bi2O2CO3 composites and Bi2O2CO3 were successfully fabricated by a facile composition-controlled preparation technology at room temperature for the first time. The X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) adsorption isotherm, UV-vis diffuse reflectance spectra (UV-vis DRS) and first-principles methods were employed to characterize the phase structures, morphologies, surface areas, optical properties, and photocatalytic mechanism of as-prepared samples. The BiOCl/Bi2O2CO3 composites exhibited the higher photocatalytic activity than individual BiOCl and Bi2O2CO3 for the degradation of MO under simulated sunlight irradiation. The COD removal efficiency of MO solution over BiOCl/Bi2O2CO3 composite achieved 95% after 8h reaction time. In addition, the formation mechanism and excellent photocatalytic activity of BiOCl/Bi2O2CO3 composite have been investigated and discussed in detail. The enhanced photocatalytic performance of BiOCl/Bi2O2CO3 composites is closely related to the suitable conduction band (CB) interaction and efficient separation of photo-induced electron-hole pairs by the synergistic effect of BiOCl and Bi2O2CO3 under the simulated sunlight irradiation. Combined with the theoretical and experimental findings, the photocatalytic mechanism of BiOCl/Bi2O2CO3 composite and the charge carrier transfer process between Bi2O2CO3 and BiOCl semiconductors have been proposed and investigated. © 2014 Elsevier B.V.


Hu C.,University of Hong Kong | Ting S.-W.,University of Hong Kong | Chan K.-Y.,University of Hong Kong | Huang W.,Taiyuan University of Technology
International Journal of Hydrogen Energy | Year: 2013

The catalytic dehydrogenation of formic acid (HCOOH) on heterogeneous catalysts in aqueous solution to produce CO-free H2 has received intense investigation due to its promising application in portable power devices. In this work, we present a study on the mechanism of HCOOH dehydrogenation on the PtRuBiOx catalyst using density functional theory (DFT) calculations supported by complementary experiments. The catalyst's activity at room temperature was clarified by investigating HCOOH dehydrogenation on PtRu alloy and Bi2O3 surface with a focus on the key reaction steps. The PtRu with different alloying degree was modeled by a four-layer p (2 × 2) unit cell with Pt-skin and leaving Ru atoms in the second and the third layer based on the surface energy and the formation energy. The Bi2O3 surface was represented by the most stable (111) surface of δ-Bi2O3. Based on the computational and experimental results, a reaction pathway for HCOOH dehydrogenation on the PtRuBiOx in aqueous solution was proposed. The results suggest that the promotion of HCOOH dissociation on the Bi 2O3 surface and the ligand effect between Pt and Ru are responsible for the activity of PtRuBiOx toward HCOOH dehydrogenation in aqueous solution at room temperature. Furthermore, the PdBiOx system was also prepared and investigated as a catalyst for HCOOH decomposition at room temperature. The catalytic behavior of PdBiOx for HCOOH dehydrogenation in aqueous solution was compared with that of the PtRuBiO x. Copyright © 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.


Yan K.,Lakehead University | Jarvis C.,Lakehead University | Lafleur T.,Lakehead University | Qiao Y.,Max-Planck-Institut für Kohlenforschung | Xie X.,Taiyuan University of Technology
RSC Advances | Year: 2013

Robust Pd nanoparticles were novel and successfully synthesized on the γ-Al2O3 support by a simple and ecofriendly route through the assistance of CO2. The unsupported and supported Pd nanoparticles were initially characterized with a combination of several techniques such as powder X-ray diffraction, energy-dispersion X-ray, X-ray photoelectron spectroscopy and transmission electron microscopy. The face-centered cubic Pd nanoparticles with uniform dispersion were successfully achieved with the Pd loading ranging from 1 wt% to 5 wt%. The resulting Pd nanoparticles (Pd/Al2O3) catalysts were found to be efficient and versatile for the hydrogenation of biomass-derived platform chemicals furfural and levulinic acid under very mild conditions, respectively, showing enhanced catalytic performance. © 2013 The Royal Society of Chemistry.


Li Z.,Xi'an University of Technology | Li Z.,Taiyuan University of Technology | Ma J.,Taiyuan University of Technology
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2012

In order to analyze the flow pattern and the critical Reynolds number of flow pattern conversion to each other in the runner of the labyrinth emitter, the tests of the water flow for the model with five different sizes of runner were conducted, the phenomena of water flow were observed and analyzed, the relationship between the head loss and average velocity in the labyrinth runner was analyzed, and the relationship between friction loss and average velocity along the straight runner that with the same section size as the labyrinth runner was analyzed. The results show that: The labyrinth path has great disturbance on the flow, making the laminar flow change into the transition region when Reynolds number is 41.5; the laminar flow may occur in the labyrinth units at the entrance section which accounts for 10%-12% of the whole labyrinth units. as a whole, the flow pattern can be regarded as turbulence or transition region; unlike the classical Reynolds test, the head loss in the labyrinth path is proportional to the 2.0-2.5th power of average velocity of section; the flow pattern index of labyrinth emitter can be 0.4-0.5; and the critical Reynolds number of flow state conversion between transition region and the turbulence ranges from 87.5 to 125.0 in the test.


Ren L.W.,Taiyuan University of Technology | Meng M.M.,Taiyuan University of Technology | Wang Z.,Taiyuan University of Technology | Yang F.Q.,University of Kentucky | And 3 more authors.
Intermetallics | Year: 2015

Electrodeposition was used to coat copper films on the surface of the BMG pillars (bulk metallic glasses) of Zr52.5Cu17.9Ni14.6Al10Ti5 (Vit. 105) with the film thicknesses of 71.5 and 161.1 μm. The experimental results of the compression tests of the bare Vit. 105 pillars and the coated Vit. 105 pillars revealed that the copper costing increased the density of shear bands in the Vit. 105 pillars formed during the tests, resulting in the improvement of plasticity. The plastic strain was 6.1% for the coated pillars with a coating thickness of 161.1 μm, which is 3.59 times of 1.7% of the bare Vit. 105 pillars. The deformation of the copper films dissipated the strain energy and limited the propagation of shear bands, which led to the initiation and formation of multiple shear bands. The technique developed in this work provides an effective way to enhance the plasticity of BMGs at room temperature. Crown Copyright © 2014 Published by Elsevier Ltd. All rights reserved.


Hu C.,University of Hong Kong | Ting S.-W.,University of Hong Kong | Chan K.-Y.,University of Hong Kong | Huang W.,Taiyuan University of Technology
International Journal of Hydrogen Energy | Year: 2012

Formic acid decomposition on noble metals is considered to be a potential method to produce CO-free hydrogen at near ambient temperatures. However, the reaction mechanism, as well as the key points, for HCOOH decomposition on noble metals in aqueous solution remains unclear at microscopic level. In the present work, we employed density functional theory (DFT) calculation to investigate HCOOH decomposition in gas and aqueous phases on four common noble metals (Pt, Pd, Rh, and Au). Based on the present theoretical calculation results and experimental results being available in literature, two reaction pathways were proposed to understand gas- and aqueous-phase HCOOH decomposition on the noble metals. The key points that determine the activities of the metals toward HCOOH decomposition into CO2 and H2 in aqueous solution are clarified. Furthermore, the proposed reaction mechanism can be well extended to interpret the excellent activity of Ag-Pd core-shell bimetallic catalyst for HCOOH decomposition in aqueous solution. It is expected the present reaction mechanisms would enable us to rationally design more active heterogeneous catalysts for HCOOH decomposition into CO-free H2 at relatively low temperatures. Copyright © 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.


Yan G.,Taiyuan University of Technology | Zhang Z.,Taiyuan University of Technology | Yan K.,CAS Guangzhou Institute of Energy Conversation | Yan K.,CAS Guangzhou Center for Gas Hydrate Research | Yan K.,University of Chinese Academy of Sciences
Molecular Physics | Year: 2013

To investigate the detailed mechanisms for brown coal oxidation at high temperatures, a ReaxFF reactive forcefield was used to perform a series of molecular dynamics simulations from 1000 K to 2500 K. Analyses indicated that the chemical system tend to be more reactive with increasing temperature. It was found that the oxidation process of brown coal primarily initiates from hydrogen abstraction reactions by O2 and related oxygenated radicals from phenolic hydroxyl groups, methyl groups, especially carboxyl groups in lower temperature to form peroxygen species, or by either thermal decomposition of brown coal backbone in higher temperature. These peroxygen species usually could chemically adsorb on the C-centered radicals of brown coal backbone. The weak O-O bond in peroxygen makes them easier to break into oxygenated radical, which could also chemically adsorb on the C-centred radical to form hydroxyl group and other oxygenated compounds. In the oxidation process of brown coal, the decomposition and oxidation of aliphatic chain is easier than aromatic ring. The chemisorption of peroxygen radical induces the breakage of aromatic ring and accelerates the depth oxidation of brown coal. An increasing number of products are observed with increasing temperature. © 2013 Taylor and Francis.


Wang Z.,Taiyuan University of Technology | Wang Z.,Beijing Institute of Technology | Jing L.,Taiyuan University of Technology | Ning J.,Beijing Institute of Technology | Zhao L.,Taiyuan University of Technology
Composite Structures | Year: 2011

The structural response of dynamically loaded monolithic and sandwich beams made of aluminum skins with different cores is determined by loading the end-clamped beams at mid-span with metal foam projectiles. The sandwich beams comprise aluminum honeycomb cores and closed-cell aluminum foam cores. Laser displacement transducer was used to measure the permanent transverse deflection of the back face mid-point of the beams. The resistance to shock loading is evaluated by the permanent deflection at the mid-span of the beams for a fixed magnitude of applied impulse and mass of beam. It is found that sandwich beams with two kind cores under impact loading can fail in different modes. Experimental results show the sandwich beams with aluminum honeycomb cores present mainly large global deformation, while the foam core sandwich beams tend to local deformation and failure, but all the sandwich beams had a higher shock resistance, then the monolithic beam. For each type of beams, the dependence of transverse deflection upon the magnitude of the applied impulse is measured. Moreover, the effects of face thickness and core thickness on the failure and deformation modes were discussed. Results indicated that the structural response of sandwich beams is sensitive to applied impulse and structural configuration. The experimental results are of worth to optimum design of cellular metallic sandwich structures. © 2010.


Jing L.,Taiyuan University of Technology | Wang Z.,Taiyuan University of Technology | Wang Z.,Beijing Institute of Technology | Ning J.,Beijing Institute of Technology | Zhao L.,Taiyuan University of Technology
Composites Part B: Engineering | Year: 2011

The deformation and failure modes of dynamically loaded sandwich beams made of aluminum skins with open-cell aluminum foam cores were investigated experimentally. The dynamic compressive stress-strain curves of core materials, open-cell aluminum foam, were obtained using Split Hopkinson Pressure Bar. And then the dynamic impact tests were conducted for sandwich beams with open-cell aluminum foam cores. The photographs showing the deflected profiles of the dynamically loaded sandwich beams are exhibited. Several impact deformation modes of sandwich beams can be observed according to contrastive photographs, i.e. large inelastic deformation, face wrinkle and core shear with interfacial failure. A comparison of the measurements is made with analytical predictions, which indicates that the experimentally measured deflections agree well with predictions employing both the inscribing and circumscribing yield loci. For comparison, the quasi-static punching deformation and failure modes of sandwich beams is presented. © 2010 Elsevier Ltd. All rights reserved.


Yan K.,Lakehead University | Lafleur T.,Lakehead University | Wu G.,Lakehead University | Liao J.,Tianjin University | And 2 more authors.
Applied Catalysis A: General | Year: 2013

A series of Pd nanoparticles deposited on the SiO2 support were facilely and successfully synthesized in the presence of the green solvent CO2, where the uniform distribution of Pd with small particle size was successfully achieved. The resulting Pd/SiO2 nanoparticles catalysts exhibited excellent catalytic performances in the selective hydrogenation of biomass-derived levulinic acid, showing close to perfect selectivity of biofuel γ-valerolactone with the TON of 884.7 at 97.3% conversion of levulinic acid. The catalytic performance was superior to the activities of the 5 wt% Pd/SiO2 nanoparticle catalyst prepared by the traditional impregnation method. Besides, the reaction parameters (e.g., the Pd loading, reaction time, reaction temperature, and hydrogen pressure), catalyst stability and reaction mechanism on the hydrogenation performance were studied. The resulting Pd nanoparticles catalysts behaved high stability in the hydrogenation. © 2013 Elsevier B.V. All rights reserved.


Sutrisno A.,University of Western Ontario | Terskikh V.V.,NRC Steacie Institute for Molecular Sciences | Shi Q.,Taiyuan University of Technology | Song Z.,Taiyuan University of Technology | And 7 more authors.
Chemistry - A European Journal | Year: 2012

Metal-organic frameworks (MOFs) are an extremely important class of porous materials with many applications. The metal centers in many important MOFs are zinc cations. However, their Zn environments have not been characterized directly by 67Zn solid-state NMR (SSNMR) spectroscopy. This is because 67Zn (I=5/2) is unreceptive with many unfavorable NMR characteristics, leading to very low sensitivity. In this work, we report, for the first time, a 67Zn natural abundance SSNMR spectroscopic study of several representative zeolitic imidazolate frameworks (ZIFs) and MOFs at an ultrahigh magnetic field of 21.1-T. Our work demonstrates that 67Zn magic-angle spinning (MAS) NMR spectra are highly sensitive to the local Zn environment and can differentiate non-equivalent Zn sites. The 67Zn-NMR parameters can be predicted by theoretical calculations. Through the study of MOF-5 desolvation, we show that with the aid of computational modeling, 67Zn-NMR spectroscopy can provide valuable structural information on the MOF systems with structures that are not well described. Using ZIF-8 as an example, we further demonstrate that 67Zn-NMR spectroscopy is highly sensitive to the guest molecules present inside the cavities. Our work also shows that a combination of 67Zn-NMR data and molecular dynamics simulation can reveal detailed information on the distribution and the dynamics of the guest species. The present work establishes 67Zn-SSNMR spectroscopy as a new tool complementary to X-ray diffraction for solving outstanding structural problems and for determining the structures of many new MOFs yet to come. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Xie Q.,Taiyuan University of Technology | Jing L.,Taiyuan University of Technology | Wang Z.,Taiyuan University of Technology | Wang Z.,Beijing Institute of Technology | Zhao L.,Taiyuan University of Technology
Composites Part B: Engineering | Year: 2013

The dynamic response of clamped shallow sandwich arches with core of aluminum foam has been experimentally studied by impacting the arches at mid-span with metal foam projectiles. The resistance to shock loading is measured by the permanent transverse deflection at mid-span of the arches. The deformation mechanisms of shallow sandwich arches were investigated. In addition, the deformation/failure modes of the shallow sandwich arch were classified and analyzed systematically. The effects of initial projectile momentum, face sheet thickness, core thickness and radius of curvature on the structural response were obtained. The results indicated that permanent deflection at mid-span can be efficiently controlled by increasing face sheet thickness, core thickness or appropriately increasing curvature. Meanwhile, shock resistance of the shallow sandwich arch can also be improved. The experimental results are useful in the optimum design of cellular metallic sandwich structures. © 2012 Published by Elsevier Ltd.


Sutrisno A.,University of Western Ontario | Liu L.,Taiyuan University of Technology | Dong J.,Taiyuan University of Technology | Huang Y.,University of Western Ontario
Journal of Physical Chemistry C | Year: 2012

Layered and open framework zirconium phosphates (ZrPs) have many current and potential applications in the areas of catalysis, sorption, protonic conductors, solar energy storage, crystal engineering, and ion exchange. Characterization of ZrP-based materials is important because understanding the relationship between the properties of these materials and their structures is crucial for developing new uses and for improving their performances in current applications. However, local Zr environments in many ZrPs have not been characterized directly by 91Zr solid-state NMR (SSNMR). This is because 91Zn (I = 5/2) is an unreceptive nucleus with many NMR unfavorable characteristics, leading to low sensitivity. In this work, the local environments of the zirconium centers in several ion-exchanged derivatives of layered α-ZrP (K +-, Li +-, Co(NH 3) 6 3+-ZrP) have been probed directly using 91Zr MAS, static quadrupolar echo, and/or quadrupolar Carr-Purcell-Meiboom-Gill NMR. Several layered and three-dimensional framework zirconium phosphates (ZrPO 4-DES8, ZrPO 4-DES1, ZrPO 4-DES2, ZrPOF-pyr, ZrPOF-Q1, ZrPOF-EA, and ZrPOF-DEA) with novel structures were also examined. Theoretical calculations using the CASTEP and Gaussian model cluster approaches were also performed in order to provide insights into the observed spectra. In addition to 91Zr SSNMR, 31P, 13C, and 19F SSNMR spectroscopy was also utilized to characterize the above-mentioned materials. © 2012 American Chemical Society.


Zhang X.,Taiyuan University of Technology | Liu X.,Taiyuan University of Technology | Fan C.,Taiyuan University of Technology | Wang Y.,Taiyuan University of Technology | And 2 more authors.
Applied Catalysis B: Environmental | Year: 2013

In this study, a novel BiOCl thin film with flakelike structures has been successfully prepared through electrochemical method composed of a cathodic electrodeposition and an anodic oxidation at room temperature. The samples obtained at the different oxidation voltages were analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM), electronic energy spectrum (EDS), and UV-vis diffuse reflectance spectra (UV-vis DRS). The analysis results show that the morphological, structural, and optical characteristics of BiOCl thin films depend markedly on the anode oxidation voltage and the lattice orientation of BiOCl thin film is transformed mainly into (110) surface with the increasing oxidation voltages. The observed results of high-resolution transmission electron microscopy (HRTEM) confirm that pure tetragonal BiOCl thin film with the highly exposed (110) surface is obtained at 2.0V and consists of interlaced nanosheets. First-principles calculations reveal that the existence of BiOCl (110) surface states enhances the electron transition and efficient separation of photo-induced electron-hole pairs. The optimized BiOCl thin film can not only guarantee the intrinsic photochemical properties of BiOCl bulk but also exhibit additional electronic characteristics of BiOCl (110) surface, and consequently the wonderful synergistic effect between BiOCl bulk and BiOCl (110) surface accelerates the efficient separation of electron-hole pairs and produces the high reducing superoxide radicals O2 - and strong oxidizing hydroxyl radicals OH required for the degradation of organic compounds. For as-prepared BiOCl thin film, the degradation ratio of methyl orange (MO) reaches 98% under 2.5h UV irradiation at the first cycle and still remains 90% at the fifth cycle, and the COD removal efficiency of 50mg/L MO solution over BiOCl thin film achieves 73.47% after 8h reaction time. The BiOCl thin film with highly exposed {110} facets exhibits the excellent photocatalytic performance and potential application in photocatalysis field. © 2012 Elsevier B.V.


Li H.-Y.,University of Shanghai for Science and Technology | Li X.,University of Shanghai for Science and Technology | Song J.-C.,Taiyuan University of Technology
Meitan Xuebao/Journal of the China Coal Society | Year: 2012

To fully access online safety condition of mining high voltage (HV) cable and ensure the safety operation of the mine, a new notion of safety early warning system for mining HV cable was developed. Based on the research about cable aging, a set of index characterizing the insulation parameters was proposed and the weight of each index was determined with analytic hierarchy process (AHP). To compare each index from persperitive of time and space, "perfection degree" was introduced to deal with the data in the same measuring scale. Then an improved radar chart method with eigenvalue calculating algorithm was applied to the safety early warning system, in the process of which the reference samples characterizing the impairment of cable and equilibrium factor reflecting the multisource information fusion are adopted, and the result is concise, clear and intuitive. Finally, the system is tested by monitoring the 10 kV mining HV cable, the state of the cable is effectively represented by multi-dimensional data and picture, and with more superiority than other method.


In this Letter, I present a versatile strategy to enhance the near-infrared to near-infrared (NIR-to-NIR) upconversion luminescence from sub-10-nm ultra-small LaF3:Yb3+/Tm3+ colloidal nanoparticles through lanthanide doping under 980 nm laser excitation. It is interesting that the NIR-to-NIR upconversion emission at 801 nm of LaF3:Yb3+/Tm3+ nanoparticles can be improved by increasing the Tm3+ doping concentration or by introducing another lanthanide activator (Er3+ or Ho3+) as a sensitizer. The luminescence enhancement effect showed a strong dependence on the doping concentrations of activator ions (Tm3+, Er3+, or Ho3+). Particularly, adding 1 mol. % Ho3+ ions into LaF3:Yb3+/Tm3+ nanoparticles induced a 2.85-fold enhancement in NIR 801 nm emission of Tm3+ ions. The related upconversion emission mechanisms were investigated and discussed. © 2015 Optical Society of America.


Xue G.,Taiyuan University of Technology | Xue G.,Shanxi University | Liu H.,Taiyuan University of Technology | Li W.,Taiyuan University of Technology
International Journal of Mining Science and Technology | Year: 2012

Based on SEM observance, the methods of low-temperature nitrogen and isothermal adsorption were used to test and analyze the coal samples of Hancheng, and pore structure characteristics of tectonic coals were discussed. The results indicate that in the same coal rank, stratification and crack are well developed in cataclastic coal, which is mostly filled by mineral substance in the geohydrologic element abundance, results in pore connectivity variation. Granulated and mylonitic coal being of these characteristics, as develop microstructures and exogenous fractures as well as large quantity of pores resulted from gas generation and strong impermeability, stimulate the recovery of seepage coal, improve coal connectivity and enhance reservoir permeability. Absorption pore (micro-pore) is dominant in coal pore for different coal body structure, the percentage of which pore aperture is from 1 to 100 nm is 71.44% to 88.15%, including large of micro-pore with the 74.56%-94.70%; with the deformation becoming more intense in the same coal rank, mesopore enlarge further, open-end pores become thin-neck-bottle-shaped pores step by step, specific surface area of micro-pore for cataclastic coal is 0.0027 m 2/g, while mylonitic coal increases to 7.479 m 2/g, micro-pore gradually play a dominant role in effecting pore structural parameters. © 2012 Published by Elsevier B.V. on behalf of China University of Mining & Technology.


Yang H.-L.,Taiyuan University of Technology | Fan M.-Q.,Taiyuan University of Technology
Meitan Xuebao/Journal of the China Coal Society | Year: 2012

In order to discharge the slime with high ash content and thus decrease the middling cycling of column flotation, a new classification device designed for flotation tailings was developed and the classification experiments on it were carried out. The results show that effective classification can be obtained for flotation tailings. About 1/2 to 2/3 of the slime with high ash can be discharged when the proportion for underflow and the feeding flow rates are 0.2~0.4 and <40 m 3/(m 2·h), respectively. A mathematical model for the classification curve based on particle size was constructed involving a classification function and an entrainment function. It can prettily fit the partition curve with fish-hooks observed in the experiments. By introducing the flow rate, feeding concentration and the underflow proportion ratio into the model, a comprehensive multi-variant model was established. It realized the quantitative description of the partition ratio in the underflow for this new classification device employing the operating conditions and the particle size. The comprehensive model indicates that the flow rate and the concentration of the feeding play a decisive role on the classification while the underflow proportion ratio mainly influences the entrainment.


Jiao H.-Z.,Taiyuan University of Technology | Yang Z.-J.,Taiyuan University of Technology | Wang S.-P.,Taiyuan University of Technology
Meitan Xuebao/Journal of the China Coal Society | Year: 2012

Based on virtual prototyping software MSC. ADAMS, the paper built the virtual prototyping model for sprocket transmission system of scraper conveyor, the dynamic characteristics of this system under various work conditions were simulated. The distributions and rules of driving torque and it's resultant moment of motor at scraper head and tail are discussed, the driving torque reaches maximal quickly at the moment of launch and presents cyclical variability in the process of smooth running, which provides reference for the allocation of the motors power. The distributions and rules of contact force between chains and sprockets, the maximal contact force and it's corresponding position are discussed, which provides reference for finite element analysis and structure optimization of sprocket. The distributions and rules of the chain tension are discussed, which provides reference for transient dynamic analysis of sprocket transmission system.


Ding H.,Taiyuan University of Technology | Yang Z.-J.,Taiyuan University of Technology
Meitan Xuebao/Journal of the China Coal Society | Year: 2012

For the realization of the shearer cutting unit intelligent design, the principles of KBE was applied to the shearer cutting unit modern design. The knowledge acquisition method of a rough set extended model based on ε coherence criterion about the overall technical parameter of the shearer was presented and laied a reasoning foundation for the design of cutting unit. The hybrid knowledge expression model was put forward, which was mainly to the knowledge representation of object-oriented, as supplement to production rules and process knowledge representation method, and realized the integration of design object and knowledge. According to the process of design of shearer cutting unit, the fusion reasoning model building was accomplished based on the integration of CBR, RBR and MBR. The modern design system of shearer cutting unit was developed based on UG platform, which proved that the method is feasible and effective.


Niu Z.,Taiyuan University of Technology | Shi S.,Taiyuan University of Technology | Sun J.,Taiyuan University of Technology | He X.,Taiyuan University of Technology
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2011

Outlier detection is a data analysis method and has been used to detect and remove anomalous observations from data. In this paper, we firstly introduced some current mainstream outlier detection methodologies, i.e. statistical-based, distance-based, and density-based. Especially, we analyzed distance-based approachandreviewed several kinds of peculiarity factors in detail. Then, we introduced sampled peculiarity factor (SPF) and a SPF-based outlier detection algorithm in order to explore a lower-computational complexity approach to compute peculiarity factor for real world needs in our future work. © 2011 Springer-Verlag.


Wang R.,Taiyuan University of Technology | Sun X.,Taiyuan University of Technology | Li Y.,Taiyuan University of Technology
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2011

For pipeline risk in the capsule object hydraulic transportation, the paper introduces Fuzzy Analytic Hierarchy Process (FAHP), which gives security policy for the reasonable design of the capsule object hydraulic transportation technology, to reflect the risk of pipeline by the calculation of risk indicators' weights on the advantages of fuzzy events. © 2011 Springer-Verlag.


Wang R.,Taiyuan University of Technology
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2011

Realizes the flotation process cleaned coal ash soft Sensor is the key of flotation process automation. First introduction to least square support vector machines algorithm, subsidiary variable choice research on flotation process cleaned coal ash soft sensor is carried out, reasonable subsidiary variable is selected by experiment, soft sensor accuracy of coal change is proposed, experiment show that model accuracy is sensitive for coal change. This soft sensor model is help to flotation process automatic control. © 2011 Springer-Verlag.


Donghua C.,Taiyuan University of Technology | Wenjie Y.,Taiyuan University of Technology
2011 International Conference on Consumer Electronics, Communications and Networks, CECNet 2011 - Proceedings | Year: 2011

Ant colony algorithm is a bionic optimization algorithm, it can solve combinatorial problems effectively. For the problem of the test suite reduction, this algorithm could find the balance point between the speed and the accuracy of solution. Unlike other existing algorithms, this algorithm used test cost criteria, as well as the test coverage criteria. Finally, the paper presented the results, the results is given by the others classical algorithms compared with this algorithms. The results show that this algorithm can significantly reduce the size and the cost of the test-suite, and achieved higher effectiveness of test-suite minimization. © 2011 IEEE.


Li H.,University of Shanghai for Science and Technology | Liu Z.,University of Shanghai for Science and Technology | Song J.,Taiyuan University of Technology
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2015

Aim to the integration of cyber physical systems (CPS), a relevance vector machine (RVM) based data-driven method was proposed for real-time static security situational awareness. RVM is a general Bayesian probabilistic framework to learn the kernel-based classification model, in which a set of hyperparameters are imposed to the hierarchical priors over model parameters for obtaining the sparse solutions, and the Bernoulli distribution is incorporated to output a consistent estimation of the posterior probability. The operation conditions were firstly generated according to the dispatches of the day-ahead markets and the pre-fault feature sets with contingency class memberships were obtained. Then a distance-based Relief algorithm was employed for feature rank and selection. Finally, RVM learning for classification was applied for security recognition. A case studied in the IEEE 30-bus system shows the proposed method can provide exceedingly sparse solutions, high accuracy and probabilistic outputs, further clarifying its superiority in security awareness. © 2015 Chin. Soc. for Elec. Eng.


Li M.,Taiyuan University of Technology | Lei M.,Taiyuan University of Technology | Munjiza A.,Queen Mary, University of London | Wen P.H.,Taiyuan University of Technology | Wen P.H.,Queen Mary, University of London
International Journal for Numerical Methods in Engineering | Year: 2015

Based on the one-dimensional differential matrix derived from the Lagrange series expansion, the finite block method was recently developed to solve both the elasticity and transient heat conduction problems of anisotropic and functionally graded materials. In this paper, the formulation of the Lagrange finite block method with boundary type in the strong form is presented and applied to non-conforming contact problems for the functionally graded materials subjected to either static or dynamic loads. The first order partial differential matrices are only needed both in the governing equations and in the Neumann boundary condition. By introducing the mapping technique, a block of quadratic type is transformed from the Cartesian coordinate of global system to the normalized coordinate with eight seeds. Time dependent partial differential equations are analyzed in the Laplace transformed domain and the Durbin's inversion method is applied to determine all the physical values in the time domain. Conforming and non-conforming contacts are investigated by using the iterative algorithm with full load technique. Illustrative numerical examples are given and comparisons have been made with analytical solutions. © 2015 John Wiley & Sons, Ltd.


Qi X.,Shanxi University | Hou J.,Taiyuan University of Technology
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2012

In this paper, we present a characterization of optimal entanglement witnesses in terms of positive maps and then provide a general method of checking optimality of entanglement witnesses. Applying it, we obtain indecomposable optimal witnesses that have no spanning property. These also provide examples that support a recent conjecture saying that the so-called structural physical approximations to optimal positive maps (optimal entanglement witnesses) give entanglement breaking maps (separable states). © 2012 American Physical Society.


Cheng H.-Q.,Taiyuan University of Technology | Wang H.-K.,Taiyuan University of Technology | Wang H.,Taiyuan University of Technology
Proceedings - 2011 International Conference on Network Computing and Information Security, NCIS 2011 | Year: 2011

In wireless sensor networks' (WSNs') applications, the ability of sensor node to estimate their accurate position is crucial. In this paper, we develop a modified weighted centroid location algorithm (WCA), which can degrade the effects of the density of beacon nodes and uniformity of deployment. By using weighted average of the received beacon nodes' coordinates instead of arithmetic mean as the estimation results, receivers can obtain optimum localization results. The performance analysis of both WCA and centroid algorithm (CA) are presented. Simulation results show that WCA can operate efficiently by using weighted centroid mechanisms. © 2011 IEEE.


Bai Z.,Taiyuan University of Technology | Zhang X.,Taiyuan University of Technology | Zhang Y.,Taiyuan University of Technology | Guo C.,Taiyuan University of Technology | Tang B.,Taiyuan University of Technology
Journal of Materials Chemistry A | Year: 2014

In this work, porous Mn3O4 nanorods have been fabricated through the decomposition of MnOOH nanorods under an inert gas. The sample shows a high BET surface area of 27.6 m2 g-1 and a narrow pore size distribution of 3.9 nm. Because of the excellent porous geometry and one-dimensional structure, the porous Mn3O4 nanorods display outstanding electrochemical performance, such as high specific capacity (901.5 mA h g-1 at a current density of 500 mA g-1), long cycling stability (coulombic efficiency of 99.3% after 150 cycles) and high rate capability (387.5 mA h g-1 at 2000 mA g-1). Very interestingly, the porous Mn3O4 nanorods are converted to Mn3O4 following electrochemical reaction, which does not occur with nonporous Mn3O4 nanorods. The possible reason may be ascribed to the improved kinetics of the porous structure. This journal is © the Partner Organisations 2014.


Xi S.,Taiyuan University of Technology
2010 IEEE 11th International Conference on Computer-Aided Industrial Design and Conceptual Design, CAID and CD'2010 | Year: 2010

With the development of network technology and multimedia technology, Virtual Reality makes multimedia information more effective in idea presentation. At the same time it helps users perceive products styling and evaluate products prototype. On the basis of the constructing VR system in design and arts, this paper demonstrates concepts and methods of Virtual Reality, meanwhile talks about the problems in the nowadays situation. In the end the paper gives my opinion upon the future direction of the virtual reality application in design and arts. © 2010 IEEE.


Wang W.,Taiyuan University of Technology | Zhao Q.,Taiyuan University of Technology | Dong J.,Taiyuan University of Technology | Li J.,Taiyuan University of Technology
International Journal of Hydrogen Energy | Year: 2011

A novel silver oxides oxygen evolving catalyst (Ag-OEC) for hydrogen production by water splitting was formed in situ on an indium tin oxide anode, in a near-neutral potassium tetraborate (K2B4O 7) electrolyte. The catalyst exhibited high activity and low overpotential for O2 evolution under mild conditions. The main functional composition of the catalyst was a redox couple of Ag 2O/AgO. Catalytic activity during oxygen evolution was evaluated by cyclic voltammetry and Tafel plot. The effects of the concentration, temperature, and pH of K2B4O7 solution on the catalyst, and the Faradaic efficiency of the oxygen evolving reaction were examined. The results show that the Ag-OEC exhibits excellent oxygen evolution properties, with an oxygen evolving overpotential of 318 mV at a current density of 1 mA/cm2. © 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights.


Zhang X.,Taiyuan University of Technology | Zhang X.,Shanxi Institute of Mechanical and Electrical Engineering | Huang W.,Taiyuan University of Technology
Journal of Natural Gas Chemistry | Year: 2011

MgO-CaO/SiO2 solid catalysts derived from waste slag (WS) of metal magnesium plant were prepared. The catalytic performances were evaluated in the transesterification of rapeseed oil with methanol to biodiesel in a 500 mL three-necked reactor under atmospheric pressure. The basic strengh of the catalyst reached 22.0 measured by indicators accroding to Hammett scale. The results show that the MgO-CaO/SiO2 is an excellent catalyst for transesterification, and the conversion of rapeseed oil reach 98 under the optimum condition. © 2011 CAS/DICP.


Jun Y.,Taiyuan University of Technology | Xueying Z.,Taiyuan University of Technology
Communications in Computer and Information Science | Year: 2011

It is the key for improving the control and management of smart grid to know how to make multiple utilization of internet of things technologies better. In this paper, the relationship between internet of things and smart grid is analyzed. This paper shows that smart grid is based on internet of things. The internet of things technologies needs of smart grid are put forward. Finally, detailed application process and the corresponding technologies are proposed aiming at the transmission link of smart grid. © 2011 Springer-Verlag.


Wang Y.,Taiyuan University of Technology | Li Y.,Taiyuan University of Technology
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2011

Because of light scattering and absorbing in dust environment, it is difficult to detect obstacles with camera. In order to solve this problem, a method of obstacles detection in dust environment from a single image was presented. The method realized distance detection and contour detection for obstacle in dust environment. First, depth map of dust image and geometric reasoning approach based on imaging model of a camera were combined to detect the distance between camera and obstacle of any shape. Then, depth map was applied to detect the contour of the obstacle in dust environment. Namely, edges belonging to contours were selected by using depth map. The validity and feasibility of the method was fully demonstrated by the experiments. The method provides a simple and economical way to detect obstacles in dust environment. © 2011 Springer-Verlag.


Rui W.,Taiyuan University of Technology | Gang L.,Taiyuan University of Technology
Communications in Computer and Information Science | Year: 2011

Considering the stochastic volatility of the wind turbine gearbox oil temperature, the wavelet packet is used to eliminate its noise. On this basis, the grey model is applied to forecast the wind turbine gearbox oil temperature. The predicted results show that the wavelet packet and the grey prediction method have better forecast accuracy. The wind turbine gearbox oil temperature trends can be predicted timely and accurately. © 2011 Springer-Verlag.


Zhang R.,Taiyuan University of Technology | Wang B.,Taiyuan University of Technology | Liu H.,Taiyuan University of Technology | Ling L.,Taiyuan University of Technology
Journal of Physical Chemistry C | Year: 2011

Catalytic hydrogenation of CO2 to methanol is a promising way to recycle and utilize CO2. In this study, the elementary steps leading to HCOO and CO formation have been explored to identify hydroxylation effect of the oxide support on the selectivity in CO2 hydrogenation on Cu/γ-Al2O3 catalyst by the density functional theory (DFT) slab calculations. Two models: Cu4 cluster supported on the dry γ-Al2O3(110) surface, D(Cu4), and on the hydroxylated γ-Al2O3(110) surface, H(Cu4), have been used to model Cu/γ-Al2O3. On D(Cu4), the formation of HCOO is preferred kinetically. On H(Cu4), HCOO formation is still kinetically favorable. These results indicate that the hydroxylation of γ-Al 2O3 support cannot alter the pathway of CO2 hydrogenation forming the dominate product HCOO, and ultimately, the selectivity of CO2 hydrogenation for HCOO formation on Cu/γ-Al 2O3 is higher, which supports the experimental fact that Al2O3-supported Cu catalyst is widely used to synthesize methanol by CO2 hydrogenation. © 2011 American Chemical Society.


Wei G.,Taiyuan University of Technology | Wei G.,Ningbo University of Technology | Liu H.,Taiyuan University of Technology | Shi C.,Ningbo University of Technology | And 3 more authors.
Journal of Physical Chemistry C | Year: 2011

In this work, we report the temperature-dependent field emission properties of 3C-SiC nanoneedles (SiCNNs) in the range of room temperature (RT) to 500 °C. SiCNNs are synthesized via catalyst-assisted pyrolysis of a polyaluminasilazane precursor. The obtained SiC nanostructures are needlelike shaped with numerous sharp corners around the tiny tips. Field emission characteristics show that turn-on field (Eto) of as-synthesized SiCNNs are ranged in 1.30 to 0.66 V/μm with the temperature raised from RT to 500 °C. At a fixed electric field of 1.37 V/μm, about a three-order-of-magnitude increase of the emission current level has been observed. We attribute the significant reduction of Eto and the remarkable increase of emission current to the decrease of work function induced by the raise of temperatures. © 2011 American Chemical Society.


In this work, colloidal hexagonal-phase -NaYF4:Nd3+/ Yb3+/Ho3+/NaYF4:Nd3+/Yb3+ core/shell nanoparticles with intense visible upconversion emissions under 808-nm laser excitation were prepared. Compared with the core-only nanoparticles, a maximum 990-fold overall enhancement in the emission intensity of Ho3+ ions was achieved with the help of active-shell coating design, due to the significant increase in the near-infrared absorption and efficient energy transfer from Nd3+ primary-sensitizers to Ho3- activators via Yb3+ bridging sensitizers. The luminescence-enhancement effect exhibited a strong dependence on the doping concentrations of NaYF4:Nd3+/Yb3+ active-shell. The optimal concentrations of Nd3+ and Yb3+ ions in the active-shell layer were found to be 30 and 5 mol. %, respectively.Moreover, the upconversion emission intensity of NaYF4:Nd3+/Yb3+- coated nanoparticles was about 2.5 times higher than the one coated with a NaYF4:Nd3+ active-shell. © 2015 Optical Society of America.


Liu B.-S.,Taiyuan University of Technology | Wei Y.-H.,Taiyuan University of Technology | Wei Y.-H.,Shanxi University | Hou L.-F.,Taiyuan University of Technology
Journal of Materials Engineering and Performance | Year: 2013

A notebook (NB) computer component was manufactured from AZ91D Mg alloy by a die-casting process. After chemical conversion treatment, a discoloration was noted on the component surface. The source of this discoloration has been studied in detail by scanning electron microscopy, energy dispersive spectroscopy, and spark atomic absorption spectroscopy. The corrosion resistance was also measured by potentiodynamic polarization, hydrogen evolution and salt spray testing. The formation mechanism for the discoloration which was caused by the residue left behind by excess mold release agent sprayed during the die-casting was discussed in detail. After chemical conversion treatment, the residual-baked mold release agent was apparent on the component surface as "white ash." Consequently, it degraded seriously both the appearance and the corrosion resistance of the manufactured component. © 2012 ASM International.


cui H.,Taiyuan University of Technology | Yao R.,China Institute for Radiation Protection | Xu X.,China Institute for Radiation Protection | Xin C.,China Institute for Radiation Protection | Yang J.,Taiyuan University of Technology
Atmospheric Environment | Year: 2011

CALPUFF is an atmospheric source-receptor model recommended by the US Environmental Protection Agency (EPA) for use on a case-by-case basis in complex terrain and wind condition. As the bulk of validation of CALPUFF has focused on long-range or short-range but long-term dispersion, we can not gauge the reliability of the model for predicting the short-term emission in near-field especially complex terrain, and sometimes this situation is important for emergency emission. To validate the CALPUFF's application in such condition, we carried out a tracer experiment in a near-field complex terrain setting and used CALPUFF atmospheric dispersion model to simulate the tracer experiment in real condition. From the centroid trajectory comparison of predictions and measures, we can see that the model can correctly predict the centroid trajectory and shape of tracer cloud, and the results also indicate that sufficient observed weather data only can develop a good wind field for near-field. From the concentration comparison in each arc, we can see the model underestimate horizontal extent of tracer puff and can not reflect the irregular characters showed in measurements. The result of global analysis is FOEX of -25.91%, FA2 of 27.06%, FA5 of 61.41%. The simulations shows that the CALPUFF can simulate the position and direction of tracer cloud in near-field complex terrain but underestimate over measurements especially in peak concentrations. © 2011 Elsevier Ltd.


Liu Z.-X.,Taiyuan University of Technology | Feng Z.-C.,Taiyuan University of Technology
Meitan Xuebao/Journal of the China Coal Society | Year: 2012

Microscopic mechanism of adsorption heat's generation was expounded systematically. On the basis of the potential energy model, two-energy-state model was got and the computational formula of the corresponding adsorption heat was deduced. On the basis of the grand canonical ensemble theory, the Langmuir monolayer model of statistical mechanics was got, and the computational formula of the corresponding adsorption heat was deduced. This paper cited De Broglie thermal average wavelength, and got the approximate computational formula of adsorption heat based on the Langmuir monolayer model. To compare the two models, it shows that adsorption heat is much affected by the adsorption capacity, adsorption centers and the average distance between molecules, and that we should use different physical models for analysis towards the outer layer of methane (relative to the coal surface) and the inner methane. On the basis of the Langmuir monolayer model, from perspective of adsorption, the fractal features of pore structure and fracture structure was studied, the two-dimensional flat surface adsorption to the fractal surface adsorption was extended, and a fractal dimension based on De Broglie thermal average wavelength was got.


Yan K.,Taiyuan University of Technology | Wu X.,Taiyuan University of Technology | An X.,Taiyuan University of Technology | Xie X.,Taiyuan University of Technology
Journal of Alloys and Compounds | Year: 2013

Four spinel ferrites (CuFe2O4, NiFe2O 4, CoFe2O4 and ZnFe2O4) were successfully synthesized by a citrate assisted sol-gel method using ethylenediaminetetraacetic acid (EDTA) as a templating agent. The four resultant spinel ferrites were systematically characterized by different techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM). It was indicated that all the resultant spinel ferrites obtained by this novel method had the single-phase with high crystallinity. Meantime, highly homogeneous cubic structure with nice morphology was successfully fabricated. The resultant spinel ferrites were highly selective for the oxidation of benzyl alcohol and display significant difference among their activities. It was found that the spinel CoFe2O4 catalyst display the best performance, whereby 93% selectivity of benzaldehyde was achieved at close to 63% conversion. © 2012 Elsevier B.V. All rights reserved.


Guo M.L.,Taiyuan University of Technology
Advanced Materials Research | Year: 2014

Expansive soil mixed with a certain amount of lime in the post-isostatic pressing, as measured through the oedometer specimen expansion and contraction coefficient changes. Test divided load and no-load charge plus two groups, drawn economically reasonable dosage of lime for building design and construction to provide evidence. © (2014) Trans Tech Publications, Switzerland.


Jianfang C.,Xinzhou Teachers University | Junjie C.,Taiyuan University of Technology | Qingshan Z.,Xinzhou Teachers University
Cybernetics and Information Technologies | Year: 2014

In order to solve the problems of security threats on workflow scheduling in cloud computing environments, the security of tasks and virtual machine resources are quantified using a cloud model, and the users' satisfaction degree with the security of tasks assigned to the virtual resources is measured through the similarity of the security cloud. On this basis, combined with security, completion time and cost constraints, an optimized cloud workflow scheduling algorithm is proposed using a discrete particle swarm. The particle in the particle swarm indicates a different cloud workflow scheduling scheme. The particle changes its velocity and position using the evolution equation of the standard particle swarm algorithm, which ensures that it is a feasible solution through the feasible solution adjustment strategies. The simulation experiment results show that the algorithm has better comprehensive performance with respect to the security utility, completion time, cost and load balance compared to other similar algorithms.


Pan P.J.,Taiyuan University of Technology
Advanced Materials Research | Year: 2014

The energy dissipation design method has received more attention by engineering circle. Nowadays, the buckling restrained braces (BRBs) are used in higher structures being dissipation energy components. So, it is very necessary to determine the damage quantity of BRBs under earthquake. Firstly, the meaning of the damage quantity of BRBs is clarified based on the energy theory. Secondly, a single degree of freedom analyses model which is suitable to the frame structure is proposed. The nonlinear dynamic time-history analysis of BRBs system is carried out by using FEMS software of ANSYS 11.0 and seismic response of BRBs is obtained. Finally, a practical calculation model of the Damage quantity of BRBs is established. Using MATLAB software, the Damage quantity of BRBs is obtained. © (2014) Trans Tech Publications, Switzerland.


Li T.T.,Taiyuan University of Technology
Advanced Materials Research | Year: 2014

Abundant historic buildings still exist in Shanxi, of which architectures built in Song, Liao and Jin Dynasty are in the majority, especially the number and area of murals in this period ranking first in the nationwide, which embody the essence of Chinese traditional culture with great artistic value. The constant abundance and development of culture and art in ancient China are represented on murals of this period, and valuable materials have been provided for our understanding towards the painting technique of ancient murals in Shanxi, which is beneficial for our study on the historical origin of traditional architecture and mural art meanwhile. This paper focuses on the discussion and analysis comprehensively of 6 existing murals including murals of Shousheng Temple of Ruicehng, Shanxi, murals of the Great Hall of Mahavira in Kaihua Temple, Gaoping, murals of Sheli Tower in Jueshan Temple of Lingqiu, murals of Sakyamuni Pagoda in Fogong Temple of Ying County, murals of Amitabha Hall in Chongfu Temple of ShuoZhou and murals of Wenshu Hall in Yanshan Temple of Fanshi. The emergence of mural art dates back to the primitive society, patterns of design relating to daily life have been painted on the rock or on the wall of the cavern where human beings live, which are the embryonic form of murals. Ultimately, the emergence and development of murals depend on the architectural development. With the introduction of Buddhism into China after Tang Dynasty, the transmission of Buddhist culture and the development of Buddhist temple art are promoted, while the mural has been developed into a mature stage in Song, Liao and Jin Dynasty. Abundant resources in architecture and valuable relics of murals in Taoist temples exist in Shanxi Region. Existing murals of Song, Liao and Jin Dynasty in Shanxi have reached to a thousand square meter ranking first in the nationwide. This paper discusses the interdependent origin of architectures and murals through investigation, classification and analysis on Song, Liao and Jin Dynasty in Shanxi Region. © (2014) Trans Tech Publications, Switzerland.


With the environment increasingly worsening, global warming has become an environmental problem challenged around the world. The cognition of low carbon and environmental protection has been widely spread and applied in urban planning construction. Universities are the frontiers of scientific research. At university such aspects like construction energy conservation and the use of new material have been put into practice, and under the guidance of planning, construction, management departments and others, the ideas of low carbon and ecology is promoted to build the campus with sustainable development. Universities play a leading role for all walks of life in society. © (2014) Trans Tech Publications, Switzerland.


Xi S.,Taiyuan University of Technology
Applied Mechanics and Materials | Year: 2010

Although Chinese industrial design has developed for over 30 years, the combination of design principles and practice could not meet the challenges of the new era. Design management could be used in reconstructing the core competence of Chinese enterprises. An atmosphere of effective communication and respect for each other is useful in achieving design objective. Design-appraising system will be eventually established by integrating design theory with practice. © (2010) Trans Tech Publications.


Wang L.,Taiyuan University of Technology
Aggression and Violent Behavior | Year: 2016

Attitude toward intimate partner violence has been consistently demonstrated as one of the prominent predictors of IPV. Studies have frequently indicated several factors influencing attitude concerning IPV including age, gender, education, residency, economic status, patriarchal gender role and so on. Yet there is surprisingly little research focusing on the relationship of those factors. To promote the understanding of attitude toward IPV, and to contribute to the campaign of IPV-prevention, this study reviewed the factors associated with attitude concerning IPV and concluded that education might be the most crucial one among all the factors, as factors such as age, gender and residency were substantively reflected different education level, and factors as economic status, participating in household decision, ability to access media, and patriarchal gender role were deeply rooted in education. As a result, further research of specific population-based which might offer clearer insight into factors influencing attitude concerning IPV is required, and more effort of government in promoting individual's education level is demanded. © 2016 Elsevier Ltd


Duan F.,Taiyuan University of Technology | Chen C.,Shanxi Institute of Coal CAS Chemistry | Wang G.,Shanxi Institute of Coal CAS Chemistry | Yang Y.,Taiyuan University of Technology | And 2 more authors.
RSC Advances | Year: 2014

Molecularly imprinted polymers on GO nanosheets (MIPs/GO) for desulfurization are synthesized using dibenzothiophene (DBT) as template, methacrylic acid (MAA) as monomer and ethylene glycol dimethacrylate (EGDMA) as cross-linker. The formation of this hybrid material is verified by Fourier transform infrared spectroscopy, thermal gravimetric and atomic force microscopy analysis. The adsorption results show that the prepared MIPs/GO exhibit excellent adsorption capacity (up to 181.9 mg g-1 at 298 K) and fast mass transfer and binding kinetics for DBT. The kinetics and isotherm data can be well described by the pseudo-first-order kinetic model and the Freundlich isotherm, respectively. Competitive adsorption experiments demonstrate that MIPs/GO show higher affinity toward target molecule DBT than toward structural analogue benzothiophene. © 2014 The Royal Society of Chemistry.


Li C.,Yangtze Normal University | Dang S.,Yangtze Normal University | Han P.,Taiyuan University of Technology
Guangxue Xuebao/Acta Optica Sinica | Year: 2010

Geometrical structure of CdS with vacancy was optimized by using density functional theory (DFT) based on first-principle ultrasoft pseudopotential method. Optimized results showed that the vacancy resulted in local lattice distortion and the relaxation of neighboring atoms. Then vacancy effects on electronic structure (energy-band structure and electron-state density) of CdS were analyzed. The results revealed that S vacancy made the band gap narrower and Cd vacancy made it wider, but CdS with S and Cd vacancy were direct band gap semiconductor. The optical properties of CdS with vacancies were investigated. The results indicated that changes on optical properties mainly focused on low-energy region because of the change of electronic structure of atom neighbor vacancy.


Zhang X.,Taiyuan University of Technology | Huang X.,Taiyuan University of Technology | Ma Y.,Taiyuan University of Technology | Lin N.,Taiyuan University of Technology | And 2 more authors.
Applied Surface Science | Year: 2012

Stainless steels are one of the most common materials used in health care environments. However, the lack of antibacterial advantage has limited their use in practical application. In this paper, antibacterial stainless steel surfaces with different Cu contents have been prepared by plasma surface alloying technology (PSAT). The steel surface with Cu content 90 wt.% (Cu-SS) exhibits strong bactericidal activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) within 3 h. Although the Cu-containing surface with Cu content 2.5 wt.% (CuNi-SS) can also kill all tested bacteria, this process needs 12 h. SEM observation of the bacterial morphology and an agarose gel electrophoresis were performed to study the antibacterial mechanism of Cu-containing stainless steel surfaces against E. coli. The results indicated that Cu ions are released when the Cu-containing surfaces are in contact with bacterial and disrupt the cell membranes, killing the bacteria. The toxicity of Cu-alloyed surfaces does not cause damage to the bacterial DNA. These results provide a scientific explanation for the antimicrobial applications of Cu-containing stainless steel. The surfaces with different antibacterial abilities could be used as hygienic surfaces in healthcare-associated settings according to the diverse requirement of bactericidal activities. © 2012 Elsevier B.V.


Yang Y.,Taiyuan University of Technology | Zhang Y.,Taiyuan University of Technology | Li S.,Taiyuan University of Technology | Liu X.,Taiyuan University of Technology | Xu B.,Taiyuan University of Technology
Applied Surface Science | Year: 2012

Poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) was grafted on the surface of carbon microspheres (CMSs), which were modified in prior by a mixed acid (HNO 3 and H 2SO 4) oxidation and 3-methacryloxypropyl trimethoxysilane silanization. Then, the molecularly imprinting polymerization was carried out towards the macromolecule PAMPS grafted on the surface of CMSs using dibenzothiophene (DBT) as template, ethylene dimethacrylate as cross-linking agent and (NH 4) 2S 2O 8 (APS) as initiator to prepare surface molecularly imprinted polymer (MIP-PAMPS/CMSs) for adsorbing DBT. The optimized conditions of grafting PAMPS, including AMPS dosage, APS content, reaction temperature and reaction time, were emphasized in this paper. The morphology of the samples was characterized by field emission scanning electron microscopy. The functional groups were analyzed qualitatively by Fourier transform infrared spectrometry. The grafting degree of PAMPS was investigated by thermogravimetry. The results show that the preferable AMPS dosage, APS content, reaction temperature and time were 5 g, 0.15 g, 70°C and 12 h, respectively, for preparing PAMPS/CMSs composite on the basis of 1.0 g of silanized-CMSs. The absorbing characteristic of MIP-PAMPS/CMSs toward DBT was studied preliminarily with dynamic adsorption. In the experiment of dynamic adsorption, MIP-PAMPS/CMSs and non-imprinted polymer (NIP-PAMPS/CMSs) were compared with respect to their rapid adsorption in 1 mmol/L of DBT solution in n-hexane. When the first 1 mL of 1 mmol/L DBT solution was injected and flowed through a column packed with 0.1 g of MIP-PAMPS/CMSs, the content of DBT reduced to 0.265 mmol/L, that is, decreased significantly from 279 to 74 ppm. When 3 mL of DBT solution was flowed through the packed column, the adsorption of MIP-PAMPS/CMSs toward DBT reached saturation with the maximum adsorption amount of 1.38 × 10 -2 mmol/g and the overall adsorption efficiency of 46%, while NIP-PAMPS/CMSs adsorbed only 1.66 × 10 -3 mmol/g of DBT. It is suggested that the MIP-PAMPS/CMSs had much better adsorption property towards DBT than NIP-PAMPS/CMSs. © 2012 Elsevier B.V.


Han G.,Taiyuan University of Technology | Wang Y.,Taiyuan University of Technology
Zhongguo Jiguang/Chinese Journal of Lasers | Year: 2010

This paper proposes a method of faults location for transmission lines by using broadband chaotic signals, which is experimentally demonstrated with a chaotic semiconductor laser. Chaotic signal is obtained by converting the chaotic light from the chaotic laser diode, and divided into two signals, one serving as probe signal and the other serving as reference signal. Faults are located by correlating the echo of probe signal with the reference one. The spatial resolution is determined by the time resolution of correlation curve. Experimental results show that 7.5 cm resolution can be readily achieved by common laser diode.


Wang B.,Taiyuan University of Technology | Zhao T.,Taiyuan University of Technology | Wang H.,Taiyuan University of Technology
Chinese Optics Letters | Year: 2012

Chaotic laser radar based on correlation detection is a high-resolution measurement tool for remotely monitoring targets or objects. However, its effective range is often limited by the side-lobe noise of correlation trace, which is always increased by the randomness of the chaotic signal itself and other transmission channel noises or interferences. The experimental result indicates that the wavelet denoising method can recover the real chaotic lidar signal in strong period noise disturbance, and a signal-to-noise ratio of about 8 dB is increased. Moreover, the correlation average discrete-component elimination algorithm significantly suppresses the side-lobe noise of the correlation trace when 20 dB of chaotic noise is embedded into the chaotic probe signal. Both methods have advantages and disadvantages. © 2012 Chinese Optics Letters.


Zuo Z.-J.,Taiyuan University of Technology | Han P.-D.,Taiyuan University of Technology | Li Z.,Taiyuan University of Technology | Hu J.-S.,Taiyuan University of Technology | Huang W.,Taiyuan University of Technology
Applied Surface Science | Year: 2012

Methanol synthesis from CO by direct hydrogenation has been studied using the density-functional theory (DFT). The charge of Cu has been found to be transferred to the ZnO carrier having low Cu cover. Due to the electron-charge transfer between the metallic Cu and the ZnO carrier, the Cu valency is greater than zero and less than one. Consideration of the water-gas-shift reaction and hydrogenation of CO 2 to CHOO and COOH, the result shows that the active sites for the synthesis of methanol from CO 2 and CO are different. Methanol is synthesized from CO by direct hydrogenation over Cu δ+ (0 < δ < 1) species through the intermediates CHO, CH 2O, and CH 3O, and the rate-limiting step is the hydrogenation of CHO, indicating that the Cu δ+ (0 < δ < 1) species comprise the active sites for the synthesis of methanol from CO by direct hydrogenation. © 2012 Elsevier B.V. All rights reserved.


Zuo Z.,Taiyuan University of Technology | Huang W.,Taiyuan University of Technology | Han P.,Taiyuan University of Technology
Applied Surface Science | Year: 2012

Density functional theory (DFT) combined with conductor-like solvent model (COSMO) have been performed to study the solvent effects of H 2 adsorption on Cu(h k l) surface. The result shows H 2 can not be parallel adsorbed on Cu(h k l) surface in gas phase and only vertical adsorbed. At this moment, the binding energies are small and H 2 orientation with respect to Cu(h k l) surfaces is not a determining parameter. In liquid paraffin, when H 2 adsorbs vertically on Cu(h k l) surface, solvent effects not only influences the adsorptive stability, but also improves the ability of H 2 activation; When H 2 vertical adsorption on Cu(h k l) surface at 1/4 and 1/2 coverage, H-H bond is broken by solvent effects. However, no stable structures at 3/4 and 1 ML coverage are found, indicating that it is impossible to get H 2 parallel adsorption on Cu(h k l) surfaces at 3/4 and 1 ML coverages due to the repulsion between adsorbed H 2 molecules. © 2011 Elsevier B.V. All rights reserved.


Wang B.,Taiyuan University of Technology | Song L.,Taiyuan University of Technology | Zhang R.,Taiyuan University of Technology
Applied Surface Science | Year: 2012

CH 4 dehydrogenation on Rh(1 1 1), Rh(1 1 0) and Rh(1 0 0) surfaces has been investigated by using density functional theory (DFT) slab calculations. On the basis of energy analysis, the preferred adsorption sites of CH x (x = 0-4) and H species on Rh(1 1 1), Rh(1 1 0) and Rh(1 0 0) surfaces are located, respectively. Then, the stable co-adsorption configurations of CH x (x = 0-3) and H are obtained. Further, the kinetic results of CH 4 dehydrogenation show that on Rh(1 1 1) and Rh(1 0 0) surfaces, CH is the most abundant species for CH 4 dissociation; on Rh(1 1 0) surface, CH 2 is the most abundant species, our results suggest that Rh catalyst can resist the carbon deposition in the CH 4 dehydrogenation. Finally, results of thermodynamic and kinetic show that CH 4 dehydrogenation on Rh(1 0 0) surface is the most preferable reaction pathway in comparison with that on Rh(1 1 1) and Rh(1 1 0) surfaces. © 2011 Elsevier B.V. All rights reserved.


Xu Y.,Taiyuan University of Technology | Zhang Y.,Taiyuan University of Technology | Wang Y.,Taiyuan University of Technology | Zhang G.,Taiyuan University of Technology | Chen L.,Taiyuan University of Technology
Journal of Analytical and Applied Pyrolysis | Year: 2013

The results of low-temperature pyrolysis of lignite are presented in this paper. The investigation focused on the effect of pyrolysis temperature on the gaseous product distribution, as well as morphological and structural variation. The gases evolved were analyzed by gas chromatography. Graphs of evolved gaseous components versus temperature were constructed to study their evolution characteristics. Morphological characteristics were observed at different pyrolysis temperatures. The semi-char surface had numerous bumps and hollows with deep cracks after low-temperature pyrolysis. The structural variation between the raw lignite and semi-char product was determined by Brunauer-Emmett-Teller techniques. The semi-char had well-developed flow structures with irregular shapes and appeared fairly molten, which indicated structural change during the evolution of the gaseous products. © 2013 Elsevier B.V. All rights reserved.


Dong J.,Taiyuan University of Technology | Cheng Z.,Taiyuan University of Technology | Li F.,Taiyuan University of Technology
Journal of Analytical and Applied Pyrolysis | Year: 2013

Several organic and inorganic pollutants are released during coal utilization such as polycyclic aromatic hydrocarbons (PAHs). PAHs, due to their carcinogenic properties pose potential health hazards. The current work focused on the behavior of the 16 PAHs during pyrolysis process, an important step of all coal thermal conversion including combustion, gasification, and carbonization. The experiments were performed using a CDS-5250 pyroprobe which could be heated fast. The pyroprobe was coupled with GC-MS (Thermo DSQII/FOCUS GC) and the pyrolysis products were analyzed in situ. The emissions of the 16 USEPA priority-controlled polycyclic aromatic hydrocarbons from Western Chinese coal were measured under different pyrolysis conditions. The results showed that the emission concentrations of PAHs reach a maximum at a pyrolysis temperature of 800 C. Emission concentrations of PAHs decreased with increasing rates of pyrolysis heating. PAHs emissions increased gradually with coal rank under the same pyrolysis conditions. A correlation between the yield of PAHs, coal rank and maceral was also demonstrated. Also in this study, the variety trend of the each species of 16 PAHs with pyrolysis temperature was observed and the reasons were discussed. © 2013 Elsevier B.V. All rights reserved.


Wang M.,Taiyuan University of Technology | Hu Y.,Canadian Light Source Inc. | Wang J.,Taiyuan University of Technology | Chang L.,Taiyuan University of Technology | Wang H.,University of Saskatchewan
Journal of Analytical and Applied Pyrolysis | Year: 2013

Sulfur transformation of inertinite-rich coals, which were sampled from three Western China coal mines, Xinjiang Hami (HM), Ningxia Lingwu (LW) and Shendong (SD), during pyrolysis is studied through measuring the release of H2S and COS gases by gas chromatography with flame photometric detector and through analyzing the sulfur forms in raw coals and chars from pyrolysis by X-ray absorption spectroscopy (XAS). It is revealed that the transformation of sulfur during coal pyrolysis is closely linked with coal properties, such as the vitrinite/inertinite ratio, alkaline mineral contents (especially calcium compounds) and H/C atomic ratio for three inertinite-rich coals. Comparisons are performed with a coal sample taken from Pingsuo (PS) coal mine located in North China, of which the properties are significantly different. The maximal release temperature of sulfur-containing gases for the pyrolysis of inertinite-rich coal is higher than that of the PS coal. The release of the S-containing gases in inertinite-rich coals has a maximal temperature interval around 600 C and this is associated with the conversions of inorganic sulfur species, such as pyrite transforming to FeS observed by the XAS in chars of these coals. During the process of pyrolysis, the organic sulfur compounds in inertinite-rich coal can be oxidized to form sulfoxide-like species due to the decomposition of oxygen-containing function groups in the coal matrix, but the active sulfur in PS coal can react with fresh char to form relatively stable thiophene structures. The formation of COS during the pyrolysis of inertinite-rich coals is mainly due to secondary reactions between H2S with CO and/or CO2. © 2013 Elsevier B.V. All rights reserved.


Wang X.,Taiyuan University of Technology | Xue Y.,Taiyuan University of Technology
Fuzzy Sets and Systems | Year: 2014

In this paper, we focus on the characterizations of various property indicators of fuzzy relations by means of left and right traces. The characterized indicators include those of reflexivity, T-asymmetry, S-completeness, T-transitivity, negative S-transitivity, T-S-semitransitivity and T-S-Ferrers property. The investigation can be regarded as an extension of and complement to the work done by Fodor on characterizing these properties in terms of traces. © 2014 Elsevier B.V.


Jiao Y.,Taiyuan University of Technology | Shi J.,Taiyuan University of Technology
Proceedings - 2012 International Conference on Computing, Measurement, Control and Sensor Network, CMCSN 2012 | Year: 2012

The particle filtering(PF) algorithm, which is proposed recently, is an efficient method dealing with nonlinear and non-Gaussian problems. It is widely used in the field of maneuvering target tracking which is easily disturbed by the circumstances to solve non-linear or non-Gaussian problems. However, PF is not always satisfactory as it always need to use a large number of particles to estimate the true state of the target accurately. If the number of the particles is too large, the real-time performance of the filter will become lower. But if decrease the particles, the validity and diversity of the particles will become worse. So an improved PF algorithm is proposed in this paper. The new method uses a residual, which is equal to the value of the predict measurement reducing the latest measurement, to adjust the likelihood distribution of the particle filter. Via this adjust process, the sampling particles tend to the high-likelihood region before the weights of the particles are updated. The effectiveness and diversity of the sampling particles can be maintained through the method, and the sample-dilution problem can be overcome. The simulation results show that the improved particle filtering algorithm applied in maneuvering target tracking can improves the tracking performance. © 2012 IEEE.


Guo H.-X.,Taiyuan University of Technology
Wool Textile Journal | Year: 2013

In this paper, several innovative racked stitch sweater hand samples were developed after several debugging. That could be formed by the applying of drop needle, widening and narrowing, loop transfer and the two kinds stitches. And weaving after choice of the appropriate yarn, machine gauge and repeatedly debugging on hand knitting machine, forming a variety of racked stitch fabric sample, such as gradient, convex, and so on, which showed the new organization structures very well. The design of fabric sample completely changed the traditional single basic organizational structure, while its appearance effect can satisfy people's requirements of diversification and fashion to knitting machine fabric. At the same time, these fabric fully reflected the development trend of contemporary fashion sweaters. In practice, you can directly use the several racked stitch fabric sample in the overall sweater production or can also combined use them according to the overall style of sweaters.


Li J.J.,Taiyuan University of Technology | Wang Z.,Taiyuan University of Technology | Qiao J.W.,Taiyuan University of Technology
Materials and Design | Year: 2016

Discrete, jerky stress-drop bursts (serrated flows) during plastic deformation of a Zr-based bulk metallic glass exhibit different magnitudes in response to variant strain rates. Through the classical statistical analysis of stress-strain curves during serrated flow, plastic dynamic behavior changes from Gauss to the power-law distribution with increasing the strain rates. In addition, a quantitative liner relation between mean stress drops and the logarithm of strain rates is obtained to describe the influence of strain rates on mean amplitudes of the stress drop. The power-law scaling behavior is illustrated in different views including the strain-rate dependence, energy dynamics, the Poisson's ratio of material, and shear-banding operation. These results are helpful for understanding the serration behavior at room temperature. © 2016 .


Zhang Y.,Taiyuan University of Technology | Yang L.,Taiyuan University of Technology
Zhongguo Jiguang/Chinese Journal of Lasers | Year: 2012

Chaos generation of the He-Ne laser, whose central wavelength is 632.8 nm, is demonstrated theoretically and experimentally based on the external optical feedback mechanism. The impact of different feedback coefficients on the dynamics of the He-Ne laser is studied under the condition of fixed pump current and of fixed external cavity length. The numerical and experimental results show that the He-Ne laser can enter chaos by the route of periodic state with the feedback coefficient increasing.


Zhang Z.,Taiyuan University of Technology | Qu Y.,Beijing University of Chemical Technology | Wang S.,Beijing University of Chemical Technology | Wang J.,Beijing University of Chemical Technology
Journal of Molecular Catalysis A: Chemical | Year: 2010

The conversion of methyl lactate (ML) over sodium tripolyphosphate, a model catalyst derived from silica supported sodium polyphosphate, was studied systematically by quantum mechanical calculations using MP2 and B3LYP methods. The reaction profiles of ML and its reaction products, acrylic acid (AA), methyl acrylate (MA) and lactic acid (LA) via various reactions such as dehydration, decomposition, decarbonylation, hydrolysis and esterification has been determined with the catalyst. For each reaction, the intermediate and transition state as well as their energetics were calculated. Over the catalyst, the main consumption routes for ML were identified to be the direct decomposition to AA and methanol and decarbonylation to acetaldehyde (AD), methanol and carbon monoxide. Both of the above reactions start from the same reaction intermediate. The main route for the formation of MA was supposed to be via esterification of AA with methanol. The values of activation barriers also indicate that over the sodium polyphosphate catalyst conversion of ML to AA has a higher selectivity than that from LA to AA. © 2010 Elsevier B.V. All rights reserved.


Zhang R.,Taiyuan University of Technology | Ma J.,Taiyuan University of Technology | Wang W.,Taiyuan University of Technology | Wang B.,Taiyuan University of Technology | Li R.,Taiyuan University of Technology
Journal of Electroanalytical Chemistry | Year: 2010

Zeolite-encapsulated transition metal complexes of SALEN [N, N′-bis(salicylidene) ethylenediamine] have been used as catalysts of oxidation reactions of hydrocarbons with oxidants including dioxygen. But in these processes molecular oxygen as oxidant did not show good activity compared with other oxidants such as TBHP, PhIO and H2O2. In order to evaluate the catalytical effect of the hybrid materials on the process of activating molecular oxygen, zeolite-encapsulated M(Co, Fe, Mn)(SALEN) complexes modified glassy carbon electrodes [M(SALEN)/Y/GCEs (M = Mn, Fe, Co)] were prepared and used as electrocatalysts of oxygen reduction reaction (ORR). The electrocatalytic reduction of dioxygen, thus, was investigated by cyclic voltammetry (CV) and chronocoulometry (CC) at glassy carbon electrodes (GCEs) modified with metal (Co, Fe, Mn) complexes of SALEN encapsulated inside NaY in pH 6.90 aqueous solutions. The results have shown that the M(SALEN)/Y/GCEs (M = Mn, Fe, Co) exhibited efficient electrocatalytic activity towards dioxygen reduction with reduced overpotentials of about 505 mV, 393 mV and 397 mV for Co(SALEN)/Y, Fe(SALEN)/Y and Mn(SALEN)/Y, respectively, lower than bare GC electrode and enhanced peak currents. The electroreduction of O2 on these modified GCEs is an irreversible and diffusion-controlled process. The transferred number of electrons and the transfer coefficient for dioxygen reduction reaction were determined by CV and CC. These results suggest that zeolite-encapsulated M(Co, Fe, Mn)SALEN complexes can efficiently activate molecular oxygen by decreasing the overpotential and increasing current of oxygen reduction reaction. And dioxygen is reduced to form water in the process. The significance of this work lies in evaluating the catalysis of the hybrid catalysts for oxidation reaction by electrochemical techniques. © 2010 Elsevier B.V. All rights reserved.


Ma J.,Taiyuan University of Technology | Li L.,Taiyuan University of Technology | Ren J.,Taiyuan University of Technology | Li R.,Taiyuan University of Technology
Separation and Purification Technology | Year: 2010

Cu-based adsorbents for CO adsorption were efficiently prepared by impregnation activated carbon (AC) with aqueous solution of copper (II) chloride and copper (II) carboxylate. The effects of preparation condition on CO adsorption capacity of the adsorbents were investigated. Characterization of the adsorbents by XRD and N2 adsorption at 77 K showed that cupric salts were completely converted to highly dispersed CuCl on activated carbon after pre-activation, resulting in the stoichiometric adsorption by the coordination of CO with Cu(I). The resulting adsorbents displayed high adsorption selectivity and good adsorption-desorption reversibility for CO with the small adsorption heat, and exhibited broad prospects for the selective separation of CO from mixture gas containing CO2, CH4 and N2 by pressure swing adsorption. © 2010 Elsevier B.V. All rights reserved.


Zhang X.,Taiyuan University of Technology | Fan C.,Taiyuan University of Technology | Wang Y.,Taiyuan University of Technology | Liang Z.,Taiyuan University of Technology | Han P.,Taiyuan University of Technology
Computational Materials Science | Year: 2013

In order to provide fundamental understanding and guidance for the effective Mn doping BiOCl and enhanced physicochemical properties derived from the interplay between Mn dopant and oxygen defect, the density functional theory (DFT)+U calculations were adopted to evaluate the effects of Mn doping and oxygen vacancy defects on the geometric structure, electronic property, optical absorption, Mulliken charge and effective mass of BiOCl. The suitable theoretical models were built up and their relaxed structural parameters agree well with the experiment values. It is found that both substitutional and interstitial Mn doping BiOCl not only are energetically favorable but also modify band structures to achieve remarkable optical red-shift of BiOCl, and the substitutional Mn-doped BiOCl show better feasible Mn doping behavior due to the beneficial p-type doping characteristic and p-d hybridization between substitutional Mn and adjacent Bi (or O) atoms in the CB (or VBM). The occurrence of oxygen vacancy in BiOCl crystal significantly influences the neighboring Bi 6p states, forming a capture center of photo-excited electrons in the forbidden band, which enhances the efficient mobility of photo-generated carriers and improves the effective separation rate of electron-hole pairs. The better negative formation energy of substitutional Mn-doped BiOCl with oxygen vacancy (BiOCl:VO) demonstrates thermodynamically its favorable structural stability. Besides, the higher relative ratio value for the effective masses of activated holes and electrons in the Mn-doped BiOCl:VO system implies the lower recombination rate of electron-hole pairs. Furthermore, our calculated optical absorption spectra exhibit that the spectral absorption edge of BiOCl is obviously red-shifted and extends to visible, red and infrared light region by the synergistic effect of oxygen vacancy and Mn dopant. Therefore, we theoretically predicted that Mn-doped BiOCl:VO system is expected to become highly promising semiconductor material applied in photocatalytic field for effectively photochemical decomposition of organics or water splitting under the sunlight irradiation. © 2013 Elsevier B.V. All rights reserved.


Xing B.,Taiyuan University of Technology | Pang X.-Y.,Taiyuan University of Technology | Wang G.-C.,Nankai University | Shang Z.-F.,Nankai University
Journal of Molecular Catalysis A: Chemical | Year: 2010

The adsorption and dissociation of CH4 on clean Ni(1 0 0), oxygen atom pre-adsorbed Ni(1 0 0) and NiO(1 0 0) surfaces have been studied using density functional theory calculations with the periodic slab model. The activation barrier for methane dissociation on clean Ni(1 0 0) is much lower than that on the oxygen atom pre-adsorbed Ni(1 0 0) and NiO(1 0 0) surface. Thus the active site for methane dissociation is the metallic Ni instead of the oxidized Ni. Moreover, the decomposition of activation barrier has been performed. The result further explains how the existence of oxygen atom increases the barrier. Though the pre-adsorbed oxygen atom decreases the interaction between CH3 and H in the transition state, it greatly decreases the interaction of CH3 and H with substrate. So the overall result is that the oxygen atom inhibits the dissociation of methane on Ni surface. Importantly, it was found that a three-center bond formed in the transition state when oxygen atom acts as a spectator, which leading to a smaller energy barrier for the reaction of CH4 + O → CH3 + H + O than that of CH4 + O → CH3 + OH. © 2009 Elsevier B.V. All rights reserved.


Tian Y.-L.,Taiyuan University of Technology
Proceedings of the 2012 24th Chinese Control and Decision Conference, CCDC 2012 | Year: 2012

Computation spending is great and false detection rate is high using the traditional immune theory based on SNS(Self-NonSelf) Recognition model in the detection of a network composed of multiple test points. Inspired by danger model theory in biological immunology, in this paper, it is proposed a novel immune faults detection algorithm by combining traditional immune algorithm with danger model theory, and this algorithm is applied to a network composed of multiple test points. In this algorithm, a danger signal is considered to be a fault signal by analysis and comprehensive evaluation. The experimental results proved that the algorithm not only simplifies the calculation process, but also has a higher efficiency and low false detection rate. © 2012 IEEE.


Xue C.X.,North University of China | Xue C.X.,University of Akron | Pan E.,University of Akron | Zhang S.Y.,Taiyuan University of Technology | And 2 more authors.
Mechanics Research Communications | Year: 2011

Based on the von Karman plate theory of large deflection, we derive the nonlinear partial differential equation for a rectangular magnetoelectroelastic thin plate under the action of a transverse static mechanical load. By employing the Bubnov-Galerkin method, the nonlinear partial differential equation is transformed to a third-order nonlinear algebraic equation for the maximum deflection where a coupling factor is introduced for determining the coupling effect on the deflection. Numerical results are carried out for the thin plate made of piezoelectric BaTiO 3 and piezomagnetic CoFe 2O 4 materials. Some interesting results are obtained which could be useful to future analysis and design of multiphase composite plates. © 2011 Elsevier Ltd. All rights reserved.


Li Z.,Taiyuan University of Technology | Shu X.,Taiyuan University of Technology
Science China: Physics, Mechanics and Astronomy | Year: 2013

Thermal cracking occurs in the plastic packaging materials due to the presence of moisturized micro-cavities in the material. The moisture resident in the micro-cavities gives rise to the internal vapor pressure that drives the thermal expansion of micro-cavities as temperature rises. The plastic packaging materials are considered a class of thermo-hyperelastic materials, thus allowing the micro-cavities to thermally expand to the substantial extent before the cracking failure. The micro-cavities can be moisture-abundant (i.e., wet) or substantially dry when cracking occurs. Cracking appears to be almost certain in the presence of wet cavities. The possibility of cracking in dry cavities turns to be two-sided: when the initial volume fraction of the micro-cavities is relatively small, cracking cannot occur in the dry cavities regardless of the phase transition temperature; when the initial cavity volume fraction is relatively large, cracking tends to occur in the dry cavities especially when the phase transition temperature is large. Because of the two-sided cracking possibility, the dry-cavity cracking mode presents a scenario that might reveal the mechanism of popcorning-type cracking failure in plastic packaging materials. © Science China Press and Springer-Verlag Berlin Heidelberg 2013.


Wang W.,Taiyuan University of Technology | Sheng Y.,Australian National University | Roppo V.,CNRS Laboratory for Photonics and Nanostructures | Chen Z.,Taiyuan University of Technology | And 2 more authors.
Optics Express | Year: 2013

We study second harmonic generation via nonlinear Raman- Nath diffraction in an optical superlattice that maintains a periodic modulation of the second-order nonlinear coefficient X(2) in transverse direction but undergoes random modulation in longitudinal direction. We show that the random X(2) modulation offers a continuous set of reciprocal lattice vectors to compensate for the phase mismatch of nonlinear Raman- Nath diffraction in the longitudinal direction, leading to more efficient harmonic generation for a wide range of wavelengths. We also characterize the intensity dependence of nonlinear Raman-Nath diffraction on the degree of randomness of the optical supperlattice. © 2013 Optical Society of America.


Zhao B.,Taiyuan University of Technology
Natural Hazards | Year: 2016

This paper presents facts related to the explosion accident that occurred on August 12, 2015, in Tianjin Port, China. Two serious explosions occurred continuously. Six large fire points and dozens of small ones occurred, and they resulted in heavy casualties and property losses. This paper discusses the catastrophe, causes, and related emergency response. © 2016 Springer Science+Business Media Dordrecht


Wang A.,Taiyuan University of Technology | Li P.,Taiyuan University of Technology | Zhang J.,Taiyuan University of Technology | Li L.,Taiyuan University of Technology | Wang Y.,Taiyuan University of Technology
Optics Express | Year: 2013

We report a prototype of high-speed real-time physical random bit generator based on a chaotic laser. The chaotic laser consists of a semiconductor laser with optical feedback in fiber external cavity configuration. The chaotic laser intensity signal is quantized into binary stream by differential comparison which makes the amplitude distribution symmetric with respect to zero mean value. An exclusive-OR gate operation between two raw binary streams from the chaotic signal and its delayed signal is used to overcome the influences of the weak periodicity induced by the external cavity resonance inherent in the chaotic laser. After exclusive-OR operation, the prototype can generate a single fast random bit stream in real time without any off-line processing procedures. Its bit rate can be handily and continuously tuned up to 4.5 Gbps by a trigger clock. Experiment results demonstrate that our generator possesses high-quality randomness with verified by the three-standard-deviation criterion and industry-benchmark statistical tests. ©2010 Optical Society of America.


Li G.,Taiyuan University of Technology | Cui Y.,Taiyuan University of Technology | Wang J.,Taiyuan University of Technology
Optics Express | Year: 2013

The inhibition of high power second-harmonic generation (SHG) in a periodically poled MgO doped LiNbO3 (PPMgLN) waveguide operating at near the room temperature has been interpreted by systematically investigating the SHG process based on the coupled mode equations in combination with the photorefraction and the temperature nonuniformities. The simulation results show that significant refractive index nonuniformities are induced by the photorefractive effect along the irradiated zone while those induced by the thermal effect are very minor. Therefore, the photorefractive effect instead of the thermal effect is the main factor that inhibits the SHG conversion efficiency. In addition, comparison of PPMgLN waveguides with different transverse dimensions shows that the waveguides with larger transverse dimension is advantageous in high power SHG since the photorefractive effect is weaker. © 2013 Optical Society of America.


Zhang X.-L.,Taiyuan University of Technology | Zhang X.-L.,Nankai University | Liu Z.-B.,Nankai University | Zhao X.,Nankai University | And 3 more authors.
Optics Express | Year: 2013

A versatile solid Poly-methyl-methacrylate (PMMA) composite containing porphyrin-covalently functionalized multi-walled carbon nanotubes (MWNTs-TPP) was prepared through free radical polymerization without additional dispersion stabilizer. Using nanosecond, femtosecond pulse Z-scan and degenerate femtosecond pump-probe techniques, we studied the optical limiting effect, ultrafast saturable absorption and transient differential transmission of the composite. Results show that the solid composite exhibits weaker optical limiting effects than that of the suspension at 532 nm under nanosecond pulse, due to the absence of nonlinear scattering mechanism. The composite also shows ultrafast saturable absorption with a relaxation time about 190 fs at 800 nm under femtosecond pulse due to band-filling effect, comparably to the suspension. The versatile solid composite can be the candidate for uses in applications of ultrafast optical switching and mode-locking element or optical limiter for nanosecond pulse. © 2013 Optical Society of America.


Li Y.,Taiyuan University of Technology | Chen W.,Taiyuan University of Technology
Science China: Physics, Mechanics and Astronomy | Year: 2013

Micropipette aspiration (MA) is widely applied in cell mechanics, however, at small deformations a common model corresponding to the MA is the half-space model wherein the finite cell size and cell compressibility are neglected. This study extends the half-space model by accounting for the influence of cell geometry and compressibility (sphere model). Using a finite element analysis of cell aspiration into a micropipette, an elastic approximation formula of the aspirated length was derived for the sphere model. The approximation formula includes the geometry parameter ξ of the sphere model (ξ= R/a, R is the radius of the cell, and a is the inner radius of the micropipette) and the Poisson's ratio v of the cell. The results indicate that the parameter ξ and Poisson's ratio v markedly affect the aspirated length, particularly for smallξ and v. Whenξ→∞ and v→0.5, the approximation formula tends to the analytical solution for the half-space model. In the incompressible case (v = 0.5), within the general experimental range (ξ varying from 2 to 4), the difference between the analytical solution and the approximate one is significant, and is up to 29% of the approximation solution whenξ = 2. Additionally, parametere was introduced to evaluate the error of elastic moduli between the half-space model and sphere model. Based on the approximation formula, theξ thresholds, beyond which e becomes larger than 10% and 20%, were derived. © 2013 Science China Press and Springer-Verlag Berlin Heidelberg.


Zuo Z.-J.,Taiyuan University of Technology | Wang L.,Taiyuan University of Technology | Han P.-D.,Taiyuan University of Technology | Huang W.,Taiyuan University of Technology
International Journal of Hydrogen Energy | Year: 2014

Cu-based catalysts have been widely used for hydrogen production from methanol decomposition, methanol oxidation and steam reforming of methanol (MSR). In this study, we have systematically identified possible reaction paths for the thermodynamics and dynamics involved in the three reactions on a Cu(111) surface at the molecular level. We find that the reaction paths of the three reactions are the same at the beginning, where methanol scission is favourable involving O-H bond scission followed by sequential dehydrogenation to formaldehyde. Formaldehyde is an important intermediate in the three reactions, where direct dehydrogenation of formaldehyde to CO is favourable for methanol decomposition; for methanol oxidation, formaldehyde tends to react with oxygen to form dioxymethylene through C-H bond breaking and finally the end products are mainly CO2 and hydrogen; for MSR, formaldehyde tends to react with hydroxyl to form hydroxymethoxy through formic acid and formate formation, followed by dissociation to CO2. CH2O formation from methoxy dehydrogenation is considered to be the rate-limiting step for the three reactions. In general, the thermodynamic and kinetic preference of the three reactions shows the order methanol oxidation > MSR > methanol decomposition. Methanol oxidation and MSR are faster than methanol decomposition by about 500 and 85 times at typical catalytic conditions (e.g., 523 K), respectively. The result may be useful for computational design and optimization of Cu-based catalysts. Copyright © 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.


Li P.,Taiyuan University of Technology | Wang Y.-C.,Taiyuan University of Technology | Wang A.-B.,Taiyuan University of Technology | Wang B.-J.,Taiyuan University of Technology
IEEE Journal on Selected Topics in Quantum Electronics | Year: 2013

We present numerically an all-optical approach to generate fast physical random numbers. This approach is based on chaotic self-pulsations, a kind of chaos superimposed on periodic pulse trains. Two-section semiconductor lasers (TSSLs) can exhibit this phenomenon of chaos, under an appropriate external optical injection. Simulations demonstrate that, without sampling and postprocessing procedures, this technique can produce random numbers at gigabit per second rates through directly quantizing the chaotic self-pulsations via an all-optical flip-flop. Further simulation results show that the random number generation rate can be continuously and easily tuned in a large range from 5 to 10 Gb/s by adjusting some control parameters of the TSSL subject to continuous-wave optical injection, such as injection strength, frequency detuning, gain current, and absorber bias. Moreover, our numerical studies show that these generated random numbers sequences above with the proposed method can pass successfully standard benchmark tests for randomness. © 1995-2012 IEEE.


Bai Y.,Taiyuan University of Technology | Wang Y.,Taiyuan University of Technology | Zhu S.,Taiyuan University of Technology | Yan L.,Taiyuan University of Technology | And 2 more authors.
Fuel | Year: 2014

In this study, the gasification reactivity of coal chars using CO 2/H2O mixtures was investigated and the synergistic effect in reactivity between H2O and CO2 gasification was revealed. First, the coal samples were pyrolyzed under an argon atmosphere at four different temperatures (800-1100 C in 100 C increments). These four different char samples were then gasified isothermally at the four temperatures and five environments ranging from pure CO2 to pure H2O in 20 vol% increments. The results suggest that the addition of CO2 improved the char reactivity, which is higher than the sum of the individual reactivity using either CO2 or H2O below 900 C. At higher temperatures, H2O gasification occurs most rapidly; however, its rate decreased with increasing volume fraction of CO2. The high catalytic activity of Ca species in CO2 gasification was the critical factor for the synergy between CO2 and H2O. © 2014 Elsevier Ltd. All rights reserved.


Li J.,Taiyuan University of Technology | Yang J.,Taiyuan University of Technology | Li L.,Taiyuan University of Technology
Journal of Energy Chemistry | Year: 2014

In this paper we used MOF-5 and Cu3(BTC)2 to separate CO2/CH4 and CH4/N2 mixtures under dynamic conditions. Both materials were synthesized and pelletized, thus allowing for a meaningful characterization in view of process scale-up. The materials were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). By performing breakthrough experiments, we found that Cu 3(BTC)2 separated CO2/CH4 slightly better than MOF-5. Because the crystal structure of Cu3(BTC) 2 includes unsaturated accessible metal sites formed via dehydration, it predominantly interacted with CO2 molecules and more easily captured them. Conversely, MOF-5 with a suitable pore size separated CH 4/N2 more efficiently in our breakthrough test. © 2014 Dalian Institute of Chemical Physics, the Chinese Academy of Sciences. Published by Elsevier B.V.


Wang Y.,Taiyuan University of Science and Technology | Hou J.,Taiyuan University of Technology
Quantum Information Processing | Year: 2015

The detection of entanglement for quantum states in multipartite systems is very significant. In this paper, we firstly give a necessary and sufficient condition for k-separability(2≤k≤m) of m-partite pure states. Furthermore, we derive some equivalent conditions for k-separability of pure states in any multipartite quantum systems of finite or infinite dimension. Lastly, we give some examples to explain the application of our results. © 2015, Springer Science+Business Media New York.


Liu S.,Taiyuan University of Technology | Zhang Z.,Taiyuan University of Technology | Wang H.,Taiyuan University of Technology
Journal of Molecular Modeling | Year: 2012

Different reaction pathways of the carboxylic group in a brown coal model were investigated by applying density function quantum chemical theory, examining the possible cross-linking and decomposition reactions between the hydrogen bonded carboxylic group-carboxylic group and the carboxylic group-hydroxyl group during the thermal pyrolysis process. The results show that bimolecular dehydration and decarboxylation of hydrogen bonded carboxylic groups have distinctly lower activation barriers and therefore, proceed preferentially at low temperature. The esterification reaction between the hydrogen bonded carboxylic group and hydroxyl group, together with unimolecular decarboxylation of isolated single carboxylic groups were also possible at moderate temperature. Aryl-aryl coupling is thought to occur via radical pyrolysis and recombination at relatively high temperature. © 2011 Springer-Verlag.


Zhang R.,Taiyuan University of Technology | Wang G.,Taiyuan University of Technology | Wang B.,Taiyuan University of Technology
Journal of Catalysis | Year: 2013

Cu-based catalysts have been widely used and produced promising results for ethanol formation from syngas; understanding the underlying mechanism at the molecular level is the key to rational design of catalytically selective and inexpensive Cu-based catalysts. In this study, the thermochemistry and activation barriers for all possible elementary steps involved in ethanol formation from syngas on Cu catalyst have been systematically investigated. Then, on the basis of the results on Cu catalyst, an extended prediction for the selective modification of Cu-based catalyst has been proposed to improve catalytic performance toward ethanol formation from syngas. Our results show that an optimal route of ethanol formation on Cu catalyst starts with the first process of CO + H → CHO → CH2O → CH3O + H → CH3 + OH to produce CH3; subsequently, CO insertion into CH3 leads to CH3CO, followed by successive hydrogenation to form ethanol. Meanwhile, an optimal route of methanol formation via CO → CHO → CH2O → CH3O → CH 3OH is found to be favored compared with CH3 formation; thus, the productivity and selectivity of ethanol is low due to the preferable methanol formation rather than CH3. Interestingly, the hydrogenation, dissociation, and coupling of CH3 leading to CH4, CH 2, and C2H6 are all very difficult to occur due to the high activation barrier in comparison with CO insertion into CH 3, and this result suggests that starting from CH3, Cu catalyst is favorable for CO insertion into CH3 to CH3CO, and further hydrogenates to ethanol rather than CH2, CH4, and C2H6. The overall process of ethanol formation is controlled by CH3 formation and CO insertion into CH3, and the productivity and selectivity of ethanol is controlled by methanol and CH3 formations; therefore, to achieve high productivity and selectivity of ethanol, Cu has to get help from the promoters, which should be able to boost CH3 formation and/or decrease methanol formation. As a result, an expanded prediction strategy of fabricating an inexpensive Rh-decorated Cu catalyst is demonstrated to tune the relative activity of the key elementary steps that determine the productivity toward ethanol, and our results indicate that the promoter Rh can facilitate CH3 formation and CO insertion into CH3; moreover, it can effectively decrease methanol formation to achieve high productivity and selectivity for ethanol. The present study provides the basis to understand and develop novel Cu-based catalysts for ethanol formation from syngas. © 2013 Elsevier Inc. All rights reserved.


Liu M.,Taiyuan University of Technology | Fan B.,Taiyuan University of Technology | Shi X.,Taiyuan University of Technology | Li R.,Taiyuan University of Technology
Catalysis Communications | Year: 2013

A series of Ru/ZIF-8 (Zeolitic imidazolate framework) catalysts was prepared in the different impregnation solvents and characterized by ICP, XRD, TEM, and N2 adsorption. The obtained catalysts exhibited different catalytic performances in the presence of achiral modifier triphenylphosphine (TPP) and chiral modifier (1S,2S)-1,2-diphenylethylenediamine [(1S,2S)-DPEN] for asymmetric hydrogenation of acetophenone. Ethanol was found to be the most effective impregnation solvent, while low activity and enantioselectivity were observed for water. The prepared Ru/ZIF-8 catalyst was stable and could be reused at least five times without significant loss in activity and entantioselectivity. © 2013 Elsevier B.V.


Zuo Z.-J.,Taiyuan University of Technology | Shen C.-F.,Taiyuan University of Technology | Tan P.-J.,Taiyuan University of Technology | Huang W.,Taiyuan University of Technology
Catalysis Communications | Year: 2013

A series of new dual support Ni catalysts consisting of Mg-Al mixed oxides and SBA-15 was prepared. The performance of the catalysts in the dry reforming of methane to syngas was investigated at 800°C, atmospheric pressure and gas hourly space velocity of 12000 mL/gcat · h. The ordered hexagonal mesoporous structure of SBA-15 coated with Mg-Al mixed oxides was found to be maintained. One of the composite catalysts exhibited excellent anti-deposition of carbon and high stability for 500 h on stream. It is concluded that strong metal-support interaction promoted catalyst performance by inhibiting carbon deposition and metal sintering. © 2013 Elsevier B.V.


Liu Z.,Taiyuan University of Technology | Wang W.,North University of China
Electronics Letters | Year: 2016

A flow measurement method based on fringing field capacitors is proposed. Alternate annular electrodes are fabricated on the surface of the tube to constitute the capacitor structure, and the fringing field penetrates the wall to achieve the detection of fluid. The electric field between two electrodes distributes along the annular wall, which is conducive to analyse the relationship of the capacitance and the flow. The proposed measurement method is suitable for the industrial applications due to the simple structure and low cost. A water flow measurement experiment was implemented by making foil capacitor on the surface of a plastic tube.


Han X.,Taiyuan University of Technology | Chang X.,Taiyuan University of Technology
Information Sciences | Year: 2012

Research in recent years has seen the development of chaotic systems for secure communication. However, most chaotic systems fail to compensate for channel noise which often degrades the performance of chaos-based secure communication systems. In this work, we propose a chaotic secure communication scheme based on the Modified Gravitational Search Algorithm (MGSA), which minimizes premature convergence of Gravitational Search Algorithm (GSA). Here, we apply the MGSA-based filter to the proposed communication scheme to reduce channel noise. Computer simulations with the unified chaotic map are done to verify the feasibility of the proposed secure communication scheme. The results show that the proposed new scheme accurately estimates the states and information symbols, and provides a lower bit error rate (BER) than existing secure communication schemes. Furthermore, the MGSA is tested on the nonlinear filter modeling and compared with GSA and particle swarm optimization (PSO). The results confirm the high performance of the MGSA-based filter in parameters estimation of nonlinear filter modeling. In other words, the more accurately the MGSA estimates the parameters, the more noise the filter reduces. © 2012 Elsevier Inc. All rights reserved.


Xu H.,Taiyuan University of Technology | Guo C.-Y.,University of Chinese Academy of Sciences
European Polymer Journal | Year: 2015

Polyethylene (PE) and ethylene copolymers (ECP) play significant roles in modern society. Molecular sieves (MS) act as both the catalyst support and nanoreactor for ethylene (co)polymerization. Mesoporous molecular sieves (MMS, typically MCM-41 and SBA-15) offer suitable pore sizes for ethylene (co)polymerizations to proceed in an extrusion mode in which the formation of polymeric nano-fibers composed of extended polymer chains from the nanopores of MMS is completed in one step. Additionally, the PE and ECP are compounded with MMS particles to form polymer nanocomposites when the MMS framework collapses due to polymeric chain growth and/or enormous polymerization exotherms. Such a unique methodology integrates numerous merits into one and endows the resultant ethylene (co)polymers with significant advantages, such as increased molecular weights and their distribution, elevated strength and modulus, and improved processability. This review addresses the progress in ethylene (co)polymerization catalyzed by organometallic complexes (pre-catalysts) immobilized onto various molecular sieves and property investigation on the resultant polymers over the past 16 years. This article comprises three major parts which focus on pre-catalysts immobilization, ethylene (co)polymerization in different molecular sieves, and the structure and properties of the as-prepared ethylene (co)polymer nanocomposites. Finally, the outlook for future research and development trends is proposed. © 2014 Elsevier Ltd. All rights reserved.


Yang J.,Taiyuan University of Technology | Yang J.,Ningbo University of Technology | Chen S.,Taiyuan University of Technology | Du Z.,Ningbo University of Technology | And 2 more authors.
Dalton Transactions | Year: 2014

I-III-VI2 chalcopyrites have unique inherent crystal structure defects, and hence are potential candidates for thermoelectric materials. Here, we identified mixed polyanionic/polycationic site defects (ZnIn-, VCu-, InCu2+ and/or ZnCu+) upon Zn substitution for either Cu or In or both in CuInTe2, with the ZnIn- species originating from the preference of Zn for the cation 4b site. Because of the mutual reactions among these charged defects, Zn substitution in CuInTe2 alters the basic conducting mechanism, and simultaneously changes the lattice structure. The alteration of the lattice structure can be embodied in an increased anion position displacement (u) or a reduced bond length difference (Δd) between d(Cu-Te)4a and d(In-Te)4b with increasing Zn content. Because of this, the lattice distortion is diminished and the lattice thermal conductivity (κL) is enhanced. The material with simultaneous Zn substitution for both Cu and In had a low κL, thereby we attained the highest ZT value of 0.69 at 737 K, which is 1.65 times that of Zn-free CuInTe2. © the Partner Organisations 2014.


Tang Y.,Taiyuan University of Technology
Arabian Journal of Geosciences | Year: 2015

As a kind of global disaster, the methane hazards extensively exist in the major coal-production countries. At present, conventional techniques, such as ventilation or drilling bore in coal seam, fail to completely solve the methane problem. To improve the methane drainage efficiency, a new method called roof-borehole, instead of traditional drainage methods (laying pipes in goaf and drilling hole in coal seam), was used to manage the gas disaster in goaf. Therefore, this study used the physical simulation experiment to study and determine the distribution characteristics of the fissure zone and methane zone in the overlying strata of coal seam and the necessary parameters of roof-borehole in turn. In addition, according to the experiment results, the optimal parameters for the position of roof-borehole (vertical distance and horizontal distance) were designed. By testing the effects of different drainage methods in field, it was found that the efficiency of methane drainage was significantly improved by the roof-borehole. © 2015 Saudi Society for Geosciences


Jia X.M.,Taiyuan University of Technology | Zheng C.C.,Taiyuan University of Technology
Applied Mechanics and Materials | Year: 2014

Based on the SITE algorithm, this paper proposed a wireless sensor network node coverage discrimination model based on the average distance of neighbor node(ADDM), which can discriminate whether the node is redundant node or not by computing the average distance of the neighbor nodes and the radius angle of overlap area. Theoretical analysis and simulation results showed that the ADDM algorithm better to improve the SITE algorithm, resolve the shortage that the SITE algorithm neglects the effect of the node of distance is greater than the radius of perception, realize the regional coverage with fewer nodes, So as to prolong the network life time. © (2014) Trans Tech Publications, Switzerland.


Liu Y.-Z.,Taiyuan University of Technology
2011 International Conference on Electric Technology and Civil Engineering, ICETCE 2011 - Proceedings | Year: 2011

Thermal insulation glazed hollow bead and ceramisite concrete aimed at building energy conservation of the development of the research of the structure of self- thermal insulation material. The performance optimization research on mechanical properties and thermal properties is the key problem in developing process. The objectives of performance optimization were proposed firstly. Based on the performance requirements of strength and thermal properties, the theories of interface strengthening and pore structure were introduced. And then, the optimization approaches of thermal insulation concrete were proposed according to theoretical analysis. Through the experimental study the effect regularity of the concrete aggregate on mechanical properties and thermal properties were analyzed. Meanwhile, appropriate and effective modification technology and crystallization technology were proposed. The conclusion shows that, the material is bearing general physical and mechanical properties of concrete, and it also has excellent thermal insulation performance. It can be proved that insulation concrete could be used in structural insulation engineering. © 2011 IEEE.


Nie Y.,Taiyuan University of Technology | Li T.,Taiyuan University of Technology
Advanced Materials Research | Year: 2011

In this paper, taking a practical project for the study, using the finite element analysis software ANSYS, static analyses under different load conditions are performed on a single beam string structure (BSS) and a one-way beam string structure with the cooperation of the supporting structure, respectively. Moreover, influence of factors on mechanical properties of the one-way BSS with the cooperation of the supporting structure is investigated. The factors include grouting, support form, corrosion. The results can provide a reference for design and construction of the same type of structure. © (2011) Trans Tech Publications.


Tian Y.,Taiyuan University of Technology | Zhang H.,Taiyuan University of Technology
PLoS ONE | Year: 2016

For the purposes of information retrieval, users must find highly relevant documents from within a system (and often a quite large one comprised of many individual documents) based on input query. Ranking the documents according to their relevance within the system to meet user needs is a challenging endeavor, and a hot research topic-there already exist several rank-learning methods based on machine learning techniques which can generate ranking functions automatically. This paper proposes a parallel B cell algorithm, RankBCA, for rank learning which utilizes a clonal selection mechanism based on biological immunity. The novel algorithm is compared with traditional rank-learning algorithms through experimentation and shown to outperform the others in respect to accuracy, learning time, and convergence rate; taken together, the experimental results show that the proposed algorithm indeed effectively and rapidly identifies optimal ranking functions. © 2016 Tian, Zhang. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


Xing J.,Taiyuan University of Technology | Jia X.,Taiyuan University of Technology
Advanced Materials Research | Year: 2011

A series of Cu-based catalysts for the synthesis of indole by the reaction of aniline and ethylene glycol were prepared and characterized by ICP-AES and XRD. The results indicated that the activity and stability of Cu/SiO 2 catalyst was increased after adding Zn, Mn, Cr and Fe promoters. Mn promoter was favorable for the dispersion of Cu, Zn, Cr, Fe and enlarged the specific surface area of catalysts. It could be seen that the catalysts prepared by impregnation method had better stability and higher activity than the catalysts prepared by co-precipitation method. The catalysts with small grain size of Cu had higher activity than those with big grain size. Some catalysts showed excellent performances in this reaction. © (2011) Trans Tech Publications.


Lili L.,Taiyuan University of Technology
Communications in Computer and Information Science | Year: 2012

In recent years, labor productivity increase a lot and production cost is decreasing with the modern production development and popularity of computer information technology. However, the cost of logistic plays more and more important place in the whole cost. Therefore, as the third profit source after the first profit source of cost decreasing in enterprises and the second profit source of efficiency improvement, modern logistic development is focusing by various walks of life in the whole society. Electronic commerce logistics bring the huge revolution into the logistic field. More and more enterprises become positive on the electronic commerce and use the electronic commerce mode. Although the logistics of electronic commerce is paid much attention, the limitation of perception, system and technology lead our electronic commerce logistics is still in the slow development that has huge distance with the social requirement. © 2012 Springer-Verlag Berlin Heidelberg.


Zhu M.,Taiyuan University of Technology | Liu Y.,Taiyuan University of Technology
Advanced Materials Research | Year: 2011

The composite shear wall system with permanent thermal-insulation wall form of glazed hollow bead is a new kind of energy-saving building. the experimental study on the seismic performance of composite shear wall structure was proposed. Through the tests of the walls with different shear-span ratio and axial compression ratio under vertical force and low cyclic horizontal load, the seismic behaviors of slitted shear walls under low cyclic load tests were studied. Through the expemental study, the calculation methods for load-bearing capacity of walls with different shear-span ratio were obtained. and then the laws for the energy dissipation and ductility feature were revealed. Besides, the comparison analysis were made on the seismic behaviors between composite shear walls and common shear walls.The study could provide a foundation for the designing evaluating on the performance for the new structure. © (2011) Trans Tech Publications.


Yan Y.,Taiyuan University of Technology
Advanced Materials Research | Year: 2012

According to the sloping roof engineering characteristics of multi-storied buildings, summarized from architectural design, structural design and other aspects, the roof forms, slope, structure, drainage organization, ventilation, lighting, lightning protection and other related issues were discussed in this paper. The common problems about changing the plane roof to the sloping roof in the old buildings, such as deal with the water tanks, inner courtyard and solar water heaters of the old buildings were also investigated in this paper. The design methods and ideas of dealing with the sloping roof series' design problems were proposed. Some reasonable suggestions about structural analysis methods, key parts of the sloping roof, cornice and plinth were given as references for the future selection of sloping roof scheme, design and other aspects of treatment. In southern China, climate is rainy and humid. In order to draining the rain water facilitate and timely and make full use of headspace emissions, the top of the building was set a loft. But Affacted by the traditional architectural style, urban renewal requirements, the use of sloping roof was increased developed rapidly in the north of China, such as Beijing, Shanghai, Jinan, Qingdao, Taiyuan and other cities [1-3]. In recent years, the proportion of using sloping roof in new residential is higher. The house located on both sides of the landscape road in the city's main, regardless of North and South, and weather conditions, was required to change the plane roof to the sloping roof(hereinafter referred to as "plane to slope"), named as "crowned hats". Even in some places, the requirement of plane to slope was written in planning and administration provisions. The battle of the plane roof and sloping roof in domestic is very intense [4-14], the main points are as follow: (1) Sloping roof is construct waterproofing while flat roof is material waterproofing. The use of plane roof is the technological progress. (2) The old residential buildings's plane roofs leaked severely, repair times shorter, and the cost higher,"pane to slope" is an effective way. (3) Old plane roof residential buildings are hot in summer and cold in winter. " pane to slope " transform's energy-saving effect is very good. (4) Under the requirements of sunshine spacing, using the sloping roof of the building can increase its height.add a slope top, increased the building area and beautify the urban landscape. (5) With the improved requirements of the building comfortable, the top sloping roof can be used as the "second line of defense" of waterproof and thermal insulation. The advantages and disadvantages of the sloping roof were not discussed in this paper. However, the sloping roof in a large number of practical engineering applications is an objective fact, sloping roof and the substructure is often quite different, future maintenance is aerial work, construction difficult and higher risk. Therefore, as designers, to ensure the structural safety of the roof slope is very important. How to considering the issues related to the sloping roof design and what is the solutions will be the main contents of this paper.


Sun Y.,Taiyuan University of Technology | Fan S.,Taiyuan University of Technology | Zhang S.,Shanxi Academy of Analytical science | Zhao D.,Taiyuan University of Technology | And 2 more authors.
Sensors and Actuators, B: Chemical | Year: 2014

A new fluorescent turn-on probe for HSO3 - bearing a benzo[e]indolium moiety was developed. The HSO3 - undergoes 1,4-addition reaction with the C-4 atom in the ethylene group, resulting in a prominent fluorescence enhancement and a fluorescent color change. The reaction could be completed in 1 min in PBS buffer, and displayed a high selectivity and sensitivity for HSO3 - against other anions, including CN-. Moreover, the practical value of the probe was confirmed by application to detect the level of HSO3 - in sugar samples. © 2013 Elsevier B.V.


Liu J.-X.,Taiyuan University of Technology | Wang Y.-F.,Taiyuan University of Technology | Wang Y.-W.,Taiyuan University of Technology | Fan C.-M.,Taiyuan University of Technology
Wuli Huaxue Xuebao/ Acta Physico - Chimica Sinica | Year: 2014

Ag/Ag3PO4/g-C3N4 (g denotes graphitic) was synthesized via an anion-exchange precipitation method, and its photocatalytic activity under visible light and regeneration with H2O2 and NaNH4HPO4 were investigated. The structural characteristics were analyzed using X- ray diffraction (XRD), field- emission scanning electron microscopy (FESEM), ultraviolet- visible (UV- Vis) absorption spectroscopy, and X- ray photoelectron spectroscopy (XPS). The XRD results showed that the structure of the regenerated catalyst was unchanged. The FESEM and UV-Vis absorption spectroscopy results showed that the Ag/Ag3PO4/g- C3N4 catalyst was composed of Ag3PO4 and g-C3N4. XPS showed that a small amount of Ag particles were present on the catalyst surface. The photocatalytic activity was evaluated using phenol degradation under visible light (λ & >420 nm) and the photocatalytic mechanism was discussed based on the active species during the photocatalytic process and the band structure. Experimental studies showed that the photocatalytic activity of the as-prepared Ag/Ag3PO4/g-C3N4 was higher than those of pure Ag3PO4 and g- C3N4. The high photocatalytic performance of the Ag/Ag3PO4/g-C3N4 composite can be attributed to the synergistic effect of Ag3PO4, g-C3N4, and a small amount of Ag0. Regeneration using H2O2 and NaNH4HPO4· 4H2O fully restored the photoactivity of the catalyst, showing that this green regeneration method could make Ag/Ag3PO4/g-C3N4 an environmentally friendly catalyst for practical applications. © Editorial office of Acta Physico-Chimica Sinica.


Yang Y.,Taiyuan University of Technology | Xie G.,Taiyuan University of Technology
Information Processing and Management | Year: 2016

In social networks, identifying influential nodes is essential to control the social networks. Identifying influential nodes has been among one of the most intensively studies of analyzing the structure of networks. There are a multitude of evaluation indicators of node importance in social networks, such as degree, betweenness and cumulative nomination and so on. But most of the indicators only reveal one characteristic of the node. In fact, in social networks, node importance is not affected by a single factor, but is affected by a number of factors. Therefore, the paper puts forward a relatively comprehensive and effective method of evaluation node importance in social networks by using the multi-objective decision method. Firstly, we select several different representative indicators given a certain weight. We regard each node as a solution and different indicators of each node as the solution properties. Then through calculating the closeness degree of each node to the ideal solution, we obtain evaluation indicator of node importance in social networks. Finally, we verify the effectiveness of the proposed method experimentally on a few actual social networks. © 2016.


Ge Y.,Taiyuan University of Science and Technology | Wang W.,Taiyuan University of Technology
Advanced Materials Research | Year: 2011

In order to improve the corrosion and wear resistance of AZ31B magnesium alloy, Ni alloy cladding layer which had no crack and hole on AZ31B magnesium substrate was created by a 5kW continuous wave CO2 laser. The microstructure was analysed by means of OM(Optical Microscope) and XRD(X-ray Diffraction), the electrochemical corrosion and the abrasion performance were also tested by electrochemical corrosion equipment and the abrasion testing machine. The results show that: the Ni alloy cladding layer can combine with the substrate metallargically, the microstructure of cladding layer is dendritic crystal, and becomes fine significantly from the interface to surface, and the phase of the cladding layer are MgNi2, Mg2Ni, Mg 2Ni3Si, Mg2Si and FeNi. Micro-hardness of the cladding layer is 470∼601HV which is improved 840%∼1102% to the substrate(40∼50HV). Average friction coefficient of the cladding layer is 0.321 lower than AZ31B substrate, and the wear mass loss is 91.43% less than the substrate, the wear resistance of the cladded layer has been improved observably. The corrosion voltage of cladding layer moves 136∼417mV to plus direction compared to AZ31B magnesium substrate, and the corrosion current of the cladding is 2∼3 stages lower. © (2011) Trans Tech Publications, Switzerland.


Zhen D.,University of Huddersfield | Wang T.,Taiyuan University of Technology | Gu F.,University of Huddersfield | Ball A.D.,University of Huddersfield
Mechanical Systems and Signal Processing | Year: 2013

Electrical motor stator current signals have been widely used to monitor the condition of induction machines and their downstream mechanical equipment. The key technique used for current signal analysis is based on Fourier transform (FT) to extract weak fault sideband components from signals predominated with supply frequency component and its higher order harmonics. However, the FT based method has limitations such as spectral leakage and aliasing, leading to significant errors in estimating the sideband components. Therefore, this paper presents the use of dynamic time warping (DTW) to process the motor current signals for detecting and quantifying common faults in a downstream two-stage reciprocating compressor. DTW is a time domain based method and its algorithm is simple and easy to be embedded into real-time devices. In this study DTW is used to suppress the supply frequency component and highlight the sideband components based on the introduction of a reference signal which has the same frequency component as that of the supply power. Moreover, a sliding window is designed to process the raw signal using DTW frame by frame for effective calculation. Based on the proposed method, the stator current signals measured from the compressor induced with different common faults and under different loads are analysed for fault diagnosis. Results show that DTW based on residual signal analysis through the introduction of a reference signal allows the supply components to be suppressed well so that the fault related sideband components are highlighted for obtaining accurate fault detection and diagnosis results. In particular, the root mean square (RMS) values of the residual signal can indicate the differences between the healthy case and different faults under varying discharge pressures. It provides an effective and easy approach to the analysis of motor current signals for better fault diagnosis of the downstream mechanical equipment of motor drives in the time domain in comparison with conventional FT based methods. © 2012 Elsevier Ltd.


Zhao J.,Taiyuan University of Technology | Shi D.,Taiyuan University of Technology | Zhao Y.,Taiyuan University of Technology
Oil and Gas Science and Technology | Year: 2012

The numerical model for the depressurization of methane hydrates in a confined reservoir is presented based on mass conservation in porous media, incorporating multiphase flow theory and kinetics of gas hydrate dissociation. The universal implicit difference method is adopted, and the corresponding computer program is developed. During the production of the hydrate reservoir, distribution and the physical changes are analyzed and the gas hydrate dissociation and gas production law are studied from the computation. A numerical simulation shows that the reservoir pressure is descending slowly, which benefits the stabilization of the reservoir and inevitably decreases the efficiency in the production of gas hydrates in the depressurizing process. The gas production rate is controlled by the well pressure. The results are presented to show how this model may be used to estimate a lower downhole pressure of the well for hydrate recovery and how these results depend on reservoir and hydrate properties. © 2012, IFP Energies nouvelles.


Ruan X.,Dalian University of Technology | Song Y.,Dalian University of Technology | Liang H.,Taiyuan University of Technology | Yang M.,Dalian University of Technology | Dou B.,Dalian University of Technology
Energy and Fuels | Year: 2012

To evaluate the potential for the commercially viable production of gas from hydrate reservoirs, several pieces of key information are needed to examine in hydrate dissociation process in porous media. In this study, a two dimensional (2D) axisymmetric finite-difference, fully implicit model was developed to investigate the gas production behavior of hydrate dissociation by depressurization in hydrate-bearing porous media. The simulation results indicated that the hydrates dissociate along the radial and longitudinal direction, and the dissociation in the radial direction is earlier than that of the longitudinal direction of the laboratory-scale hydrate sample. Moreover, a series of simulations was performed to study the effect of several parameters including initial hydrate saturation, permeability reduction index N, absolute/relative permeability, intrinsic porosity, and the assumption of stationary water phase on the gas production behavior from hydrate dissociation in hydrate-bearing porous media. The results of the sensitivity analysis showed that significant amelioration of gas production behavior is obtained with high initial hydrate saturation, low permeability reduction index, high gas relative permeability, and high intrinsic porosity. On the other hand, it can be found that the cumulative gas production is not affected by the absolute permeability and the assumption of stationary water phase with the condition of simulation scale length vs diameter L/d < 50; however, there would be some opposite results presented in gas production performance under a larger simulation scale L/d > 50. Finally, the simulation results also suggested that the reliable relative permeability model and the reasonable value of the permeability reduction index corresponding to different forms of hydrate occupying in the porous media should be very important to predict the gas production performance from hydrate dissociation by depressurization and improve the accuracy of numerical simulator. © 2012 American Chemical Society.


Han L.,Taiyuan University of Technology | Lv X.,Taiyuan University of Technology | Wang J.,Taiyuan University of Technology | Chang L.,Taiyuan University of Technology
Energy and Fuels | Year: 2012

Fe 2O 3/γ-Al 2O 3, PdO/γ-Al 2O 3, and PdO-Fe 2O 3/γ-Al 2O 3 sorbents were prepared using the pore volume impregnation method. Experiments to study the removal of Hg and H 2S from simulated syngas were carried out using a conventional flow-type packed-bed reactor system over the temperature range of 100-300 °C. Sorbents before and after the adsorption of Hg and H 2S were analyzed by Raman spectroscopy, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The experimental results show that the bimetal oxide PdO-Fe 2O 3/γ-Al 2O 3 sorbent can simultaneously remove Hg and H 2S in syngas and the operation temperature can be as high as 200-300 °C. The high efficiency of Hg removal by PdO/γ-Al 2O 3 and H 2S removal by Fe 2O 3/γ-Al 2O 3 enhances the ability of PdO-Fe 2O 3/γ-Al 2O 3 to remove Hg and H 2S simultaneously at a relatively high temperature. H 2 and CO can enhance the efficiency of the removal of Hg over the PdO-Fe 2O 3/γ-Al 2O 3 sorbent at 250 °C, but there is apparently no influence on the removal of H 2S. On the basis of the analysis of the different capture performances for Hg and H 2S between PdO/γ-Al 2O 3 and PdO-Fe 2O 3/γ-Al 2O 3, there are two possible mechanisms for the capture of Hg over bimetal oxides, namely, by formation of HgS or HgO and Pd-Hg amalgam. The reactions of Hg (adsorbed on the surface of the sorbent) with Pd (formed by reduction of PdO) and S ad [formed by the reaction of H 2S with lattice oxygen in Fe 2O 3 (3H 2S + Fe 2O 3 → 2FeS + S ad + 3H 2O)] are the dominant factors. © 2012 American Chemical Society.


Lu J.,Taiyuan University of Technology | Liu S.,Taiyuan University of Technology | Shangguan J.,Taiyuan University of Technology | Du W.,Taiyuan University of Technology | And 2 more authors.
Minerals Engineering | Year: 2013

A series of nickel laterite ores with different calculated amounts of anhydrous sodium sulphate were prepared by physical blending or sodium sulphate solution impregnation. The reduction of the prepared nickel laterite ore by H2 was carried out in a fluidised-bed reactor with provisions for temperature and agitation control, and the magnetic separation of the reduced ore was performed using a Davis tube magnetic separator. The mineralogical properties of the raw laterite ore, reduced ore and magnetic concentrate were characterised using ICP, TG-DSC, N2 adsorption, X-ray diffraction and optical microscopy. The catalytic activity of sodium sulphate was also studied by using Hydrogen temperature-programed reduction. The experimental results indicate that Na2SO4 could overcome the kinetic problems faced by the laterite ore and that it exhibited noticeable catalytic activity only if the temperature reached at least 750 C. This high temperature accelerated the crystal phase transition of the silicate minerals and increased the utilisation of H2. In comparing the results from the two different methods for adding Na2SO4, the nickel content and recovery of the magnetic concentrate were increased by using the impregnation method rather than the physical blending method and the increasing amount of sodium sulphate assisted in the further beneficiation of nickel. The partial pressure of H2 and the reducing time also affected the reduction process of the iron oxides. The results of the microscopic study indicated that the formation of a Fe-S solid solution, which was derived from the SO2 sulphide reduction of FeO, was conducive to mass transfer and accelerated the coalescence of metallic ferronickel particles. For the nickel laterite ore, under the synergistic effect of sodium sulphate and hydrogen, a nickel content and nickel recovery of 6.38% and 91.07% were obtained, respectively, with high product selectivity. © 2013 Elsevier Ltd. All rights reserved.


Du J.,Taiyuan University of Technology | Wang H.,Taiyuan University of Technology | Zhao R.,Taiyuan University of Technology | Xie Y.,Taiyuan University of Technology | Yao H.,Taiyuan University of Technology
Materials Letters | Year: 2013

The pencil-like ZnO (PLZ) with long pen tips was synthesized by surfactant-assisted method. The growth mechanism and the gas sensing properties were also investigated. The results show that PLZ exhibits a good response and reversibility to dimethylamine, and the response and recovery time are 1 s and 20 s, respectively, which suggest that PLZ with long pen tips is very efficient for detecting toxic gas with low concentration. © 2013 Elsevier B.V.


Cao L.,Taiyuan University of Technology | Jiang J.,Zhejiang University | Zhu L.,Zhejiang University
Materials Letters | Year: 2013

We report on Zn1-xCaxO ternary alloy thin films prepared on quartz substrates by pulsed laser deposition. The effects of different Ca contents on the structural and optical properties of the films are investigated in detail. The results indicate that the Ca content in the Zn 1-xCaxO alloy thin films should not be more than 22.4 at% in the present study to keep the hexagonal wurtzite structure of ZnO. A 16.2% broadening in the optical band-gap of ZnO thin films has been realized by using Ca alloying. The optical band-gap has been extended to 3.81 eV for the film containing 22.4 at% Ca. © 2013 Elsevier B.V.


This paper reports a new development based on the manifold learning and intelligent classifier for the nonlinear feature extraction and fault pattern recognition of mine hoists. The wavelet packet was firstly used to extract the statistic characteristics of the hoist vibrations to obtain the original feature space. Then the locally linear embedding (LLE) was employed to learn the underlying nonlinear manifold in the original feature space to select distinct features. Following, the support vector machine (SVM) was applied to the fault pattern recognition. The energy-entropy based genetic algorithm was used to optimize the SVM parameters. The experimental vibration data measured on a mine hoist test rig was used to evaluate the proposed method. The diagnosis results show that the proposed method is efficient for the mine hoist and can increase the detection rate by 2.5% or better when compared with existing diagnosis approaches.


Du J.,Taiyuan University of Technology | Zhao R.,Taiyuan University of Technology | Xue Y.,Taiyuan University of Technology
Journal of Chemical Thermodynamics | Year: 2012

The theoretical relations of thermodynamic properties, the equilibrium constant and reactant size in nanosystem are described. The effects of size on thermodynamic properties and the equilibrium constant were studied using nanosize zinc oxide and sodium bisulfate solution as a reaction system. The experimental results indicated that the molar Gibbs free energy, the molar enthalpy and the molar entropy of the reaction decrease, but the equilibrium constant increases with decreasing reactant size. Linear trends were observed between the reciprocal of size for nano-reactant and thermodynamic variable, which are consistent with the theoretical relations. © 2012 Elsevier Ltd. All rights reserved.


Niu Q.-Y.,Taiyuan University of Technology | Liu J.-J.,Taiyuan University of Technology | Zhang M.,Taiyuan University of Technology | Liu S.-W.,Shanxi Traffic Science Research Institute
Gongcheng Lixue/Engineering Mechanics | Year: 2011

In the paper, the liquefiable sand soil non-improved and improved by gravel piles under earthquake action is numerically simulated by using the three-dimensional finite difference program 'FLAC3D' (Fast Lagrangian Analysis of Continua), and a model to analyze seismic response is established in order to investigate the results of liquefiable sand soil reinforced by gravel piles. According to the analysis of the numerical simulation, the gravel piles confirmed have remarkable drainage effect. Compared with the result of shaking table tests, it is demonstrated that the test of Numerical simulation is reliable.


Liu L.,Taiyuan University of Technology
Journal of Materials Science: Materials in Electronics | Year: 2015

Further enhancement of the piezoelectric response in lead-free piezoelectric ceramics can be accomplished by inducing preferred orientation. In this paper, attempts have been made to review the progress on the fabrication of lead-free textured piezoelectric ceramics by the (reaction) templated grain growth method. The preparation (molten salt synthesis) and alignment (tape casting and extrusion molding) of anisometric template particles were introduced in detail. The texture evolution with heating was visualized by computer simulation. The review of lead-free textured piezoelectric ceramics focused on four promising systems: Na0.5Bi0.5TiO3-based, K0.5Na0.5NbO3-based, Ba(Zr0.2Ti0.8)O3–(Ba0.7Ca0.3)TiO3 and KSr2Nb5O15. It is suggested that texturing of lead-free morphotropic phase boundary compositions will be required in order to realize viable lead-free alternatives to current lead-based materials. © 2015, Springer Science+Business Media New York.


Huang X.,Taiyuan University of Technology | Lin J.,CAS Changchun Institute of Applied Chemistry
Journal of Materials Chemistry C | Year: 2015

In recent years, intensive research efforts around the world have been devoted to lanthanide-doped upconversion nanoparticles because of their promising application in biological imaging. However, the overheating issue caused upon 980 nm laser irradiation in conventional Yb3+-based nanoparticles is needed to be addressed, and thus Nd3+/Yb3+-based upconversion nanoparticles with 808 nm excitation are investigated as promising alternatives because they can significantly decrease the optical absorption of water. Due to the cascade sensitization process, Nd3+/Yb3+-based upconversion nanoparticles, however, always suffer from the intrinsic low luminescence efficiency. To solve this problem, here we proposed the active-core/active-shell nanostructured design as an effective strategy for upconversion improvement of Nd3+/Yb3+-based upconversion nanoparticles. We found that after growing an optimized active-shell containing both Nd3+ and Yb3+ ions, a maximum 522-fold enhancement in upconversion luminescence was realized upon excitation at 808 nm. These findings would be of great importance to the community developing high-performance upconversion nanoparticles for bioimaging applications. © The Royal Society of Chemistry 2015.


Xue R.,Taiyuan University of Technology | Zhao H.,Taiyuan University of Technology
MATEC Web of Conferences | Year: 2016

In recent years, the scales and works for local Chinese original furniture designs have been rapidly increasing. This article elaborated the inner requirement for modern families to local furniture designs. And by comparing circle chairs of "Moreless", "Fnji", "pusu", "Lost&Found" and "LEXTO" with those made in Ming Dynasty, deeply analysis the modifying ways of modern local furniture design to the circle chairs with Ming style, such as tenon structure, matierals and so on. It aimed at increasing peoples' understanding for local furniture designs, improving peoples' attention for local original furniture design. Finally, this article supplied reference for the development of the local furniture design. © The Authors, published by EDP Sciences, 2016.


Liu X.,Nanyang Technological University | Loh P.C.,Nanyang Technological University | Wang P.,Nanyang Technological University | Han X.,Taiyuan University of Technology
IEEE Transactions on Power Electronics | Year: 2012

Z-source energy conversion is a recent concept introduced for adding voltage-boost functionality to the traditional buck-only dc-ac inverter. The same concept can equally be extended to the indirect ac-ac matrix converter, where only a single Z -source impedance network needs to be inserted to its intermediate dc link. The topology formed is, thus, quite straightforward. Its modulation is, however, nontrivial if advantages like buck-boost flexibility, minimum commutation count, ease of implementation, and sinusoidal input and output quantities are to be attained simultaneously. This capability is now pursued through unveiling related modulation theories, so as to better present the indirect Z-source matrix converter as an attractive alternative for ac-ac buck-boost energy conversion. Findings presented have already been verified in simulation and experiment. © 2012 IEEE.


Gao X.,Taiyuan University of Technology | Wei L.,Taiyuan University of Technology | Yan H.,Taiyuan University of Technology | Xu B.,Taiyuan University of Technology
Materials Letters | Year: 2011

An eco-friendly method was put forward to synthesize Ag nanoparticles (Ag NPs) by using biodegradable starch as a stabilizing agent. The silver ion from AgNO 3 was reduced by glucose in soluble starch solution. Morphological observation and characterization of Ag NPs were performed by using high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and UV-vis absorption spectroscopy. HRTEM showed that Ag NPs were covered by starch layer to form spherical core-shell Ag/starch NPs with diameter ranging from 5 to 20 nm. XRD pattern confirmed the presence of Ag NPs with face-centered cubic (fcc) structure. All these results indicated that starch played an important role in stabilizing Ag NPs. © 2011 Elsevier B.V. All Rights Reserved.


Li H.,University of Shanghai for Science and Technology | Feng D.,University of Shanghai for Science and Technology | Song J.,Taiyuan University of Technology
Dianwang Jishu/Power System Technology | Year: 2013

The overall online healthy assessment is the best strategy for the balance between the economy and the reliability of power equipment, this paper focuses on the online healthy condition-based assessment model of the medium voltage (MV) vacuum circuit breakers (VCB). Various performance indices are firstly proposed to assess the VCB's condition by analyzing the fault characteristics of its main components. Then, the perfection degree is defined to make the sampling data normalized. Based on indices coupling relationships, the weights are determined with analytic hierarchy process (AHP). The entropy is employed to quantify the nonequilibrium impairment of all indices. Finally, an improved radar chart method with eigenvalue calculating algorithm is applied to the VCB's condition assessment. In the method, the reference samples considering the impairment speed in thresholds design, especially the nonequilibrium entropy are incorporated to ensure VCB's safety early warning adequately and timely. The test results on monitoring 10 kV VCB show that the model is concise, intuitive and feasible.


Rui-Gang Y.,Taiyuan University of Science and Technology | Rui-Gang Y.,Taiyuan University of Technology
Journal of Magnetism and Magnetic Materials | Year: 2011

BaTiO3 powders are prepared by solgel method. The carbonyl iron powder is prepared via thermal decomposition of iron pentacarbonyl. Then BaTiO3carbonyl iron composite with different mixture ratios was prepared using the as-prepared material. The structure, morphology, and properties of the composites are characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction, scanning electron microscopy (SEM), and a network analyzer. The complex permittivity and reflection loss of the composites have been measured at different microwave frequencies in S- and C-bands employing vector network analyzer model PNA 3629D vector. The effect of the mass ratio of BaTiO3/carbonyl iron on the microwave loss properties of the composites is investigated. A possible microwave absorbing mechanism of BaTiO3carbonyl iron composite has been proposed. The BaTiO3carbonyl iron composite can find applications in suppression of electromagnetic interference, and reduction of radar signature. © 2011 Elsevier B.V. All rights reserved.


Wang X.,Taiyuan University of Technology
Energy Education Science and Technology Part A: Energy Science and Research | Year: 2013

Aiming at reasonable parameters approximation for the electro-hydraulic servo system, and parameters offset due to temperature changes caused, and as well as system inherent in the dead zone, hysteresis effect nonlinear factors, analysis of approximate dynamic mathematical model based on the position of the servo proportional valve control. On the basis of conventional PID, fuzzy PID control is proposed to be applied to the servo proportional valve controlled cylinder system. And joint simulation results showed that the Fuzzy PID control system based on servo proportional valve electro-hydraulic servo system, compared with the traditional PID control system has a fast response, short rise time, overshoot characteristics. This in theory of electro-hydraulic servo control system has certain reference significance. © Sila Science.


Wang H.,Taiyuan University of Technology | Wang X.,Taiyuan University of Technology
RSC Advances | Year: 2015

Graphene quantum dots surface passivated by polyethylenimine (GQDs-PEI) were prepared with a simple solvothermal method. Compared with the unfunctionalized graphene quantum dots (GQDs), the GQDs-PEI were well dispersed with an ultrasmall average diameter of ca. 1.66 nm, and have achieved better optical properties including high quantum yield (53.0%) and narrow emission spectral features which is probably because of the positively charged amines on PEI which facilitated the dispersion of GQDs. By being applied to the bioimaging of MG-63 cells, the GQDs-PEI showed brighter luminescence and minor cytotoxicity. Moreover, the GQDs-PEI are clearly rendered in the nucleus region, which offered a further application in the diagnosis of diseased phenotypes and the targeted therapy of tumour cells. © 2015 The Royal Society of Chemistry.


Lei Y.G.,Taiyuan University of Technology | Zhao C.H.,Taiyuan University of Technology | Song C.F.,Taiyuan University of Technology
Chemical Engineering and Technology | Year: 2012

Numerical simulations were performed to study the fluid flow and heat transfer in a tube with staggered twisted tapes with central holes. In the range of Reynolds numbers between 6000 and 28000, the modified twisted tapes increased the Nusselt number by 76.2∼149.7% and the friction factor by 380.2∼443.8% compared to the smooth tube. Compared to the typical twisted tapes, the modified twisted tapes produced an acceleration flow through the triangle regions leading to the enhancement of heat transfer, and the holes in the modified tapes reduced the severe pressure loss. It was found that the modified twisted tapes decreased the friction factor by 8.0∼16.1% and enhanced the heat transfer by 34.1∼46.8% in comparison with the typical tapes. These results indicated that the performance ratio values of the tube with modified twisted tapes were higher than 1.0 in the range of Reynolds numbers studied. The computed performance ratios of the tube with modified twisted tapes were much higher than those of the tube with typical twisted tapes. This means that the integrated performance of the tube with staggered twisted tapes with central holes is superior to that of the tube with typical twisted tapes. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Wang Y.-Q.,Nankai University | Wang Y.-Q.,Taiyuan University of Technology | Zhao T.,Nankai University | He X.-W.,Nankai University | And 3 more a