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Tianjin, China

Tianjin University of Technology is a university in Tianjin, China under the municipal government. It is a public university approved by the State Council in 1981. As an engineering based multi-discipline university, it now has over 16,000 students, 988 teaching faculty and offers 45 Bachelor programs and 39 Master programs in areas such as science, engineering, humanities and management on 2 campuses. Wikipedia.

Gao Z.-K.,Tianjin University | Yang Y.-X.,Tianjin University | Fang P.-C.,Tianjin University | Zou Y.,East China Normal University | And 2 more authors.
EPL | Year: 2015

The multiscale phenomenon widely exists in nonlinear complex systems. One efficient way to characterize complex systems is to measure time series and then extract information from the measurements. We propose a reliable method for constructing a multiscale complex network from multivariate time series. In particular, for a given multivariate time series, we first perform a coarse-grained operation to define temporal scales and then reconstruct the multivariate phase-space for each scale to infer multiscale complex networks. In addition, we develop a novel clustering coefficient entropy to assess the derived multiscale complex networks, aiming to characterize the coupled dynamical characteristics underlying multivariate time series. We apply our proposed approach to the analysis of multivariate time series measured from gas-liquid two-phase flow experiments. The results yield novel insights into the inherent coupled flow behavior underlying a realistic multiphase flow system. Bridging multiscale analysis and complex network provides a fascinating methodology for probing multiscale complex behavior underlying complex systems. © Copyright EPLA, 2015.

Song Q.,Tianjin Chengjian University | Shi K.,Tianjin University of Technology
Journal of Intelligent and Fuzzy Systems | Year: 2014

This paper discusses on the problem of optimal decisions for waiting time contract in a fuzzy public health care market with two participants: the public health administration (PHA) and the patient. In order to maximize the expected utility of the PHA, a fuzzy waiting time model is established in the framework of principal-agent theory, where the PHA's assessment on the patient's health index is subjective, and should be described as a fuzzy variable. The equivalent model is then provided to get the optimal solution. The results illustrate that if the patient's health index is higher, he may spend more time on waiting and less money on public treatment; the optimal contract depends only on utility function of PHA, so long as patient's utility rises in his wealth; treating patient with relatively lower or relatively higher health index make less utility for the PHA, and only treating patient with a special moderate health index can make the PHA's utility reach highest value. Finally, a numerical example is provided, which illustrates the effectiveness of the presented model. © 2014-IOS Press and the authors. All rights reserved.

Wang J.,University of Macau | Li Y.,University of Macau | Li Y.,Tianjin University of Technology
International Journal of Humanoid Robotics | Year: 2012

Based on the screw theory and Lie group notations, this paper presents a modeling method for a kind of wheeled humanoid robot whose upper human-like body is mounted on the top of a mobile platform with three wheels. By combining the reciprocal product of the twist and wrench with Jourdain variation principle, a general formulation method is proposed to model the whole system's dynamics that represents directly the relationship between the input and the resultant external and inertial wrench. Both the system kinematics and dynamics are derived carefully. The simulations are made to verify the proposed modeling methodology and the simulation results are also compared with the results obtained from the multi-body dynamics software. © 2012 World Scientific Publishing Company.

Kong K.F.,University of Macau | Li Y.,Tianjin University of Technology
Chinese Control Conference, CCC | Year: 2013

In this paper, two kinds of methods are used to control the mobile manipulator in terms of voice signal control approach and visual signal control approach. In voice signal control approach, the mobile manipulator can perform some actions according to the operator's speaking voice input through a microphone. For example, the robot can be commanded to go forward or backward in specified distance, turn left or right with specified angle, even can follow up '8' shape trajectory and catch a ball. In visual approach, the mobile robot can accomplish some actions according to the operator's gestures of two hands using Kinect sensor information. It gets the depth image of two hands in spatial coordinates and calculates the relative distance of them to take some actions by an onboard computer. An embedded single board computer is installed in mobile robot Pioneer2 DX for enhancing remote control and running program's ability. © 2013 TCCT, CAA.

Sanz J.,University of Zaragoza | Xia C.-Y.,University of Zaragoza | Xia C.-Y.,Tianjin University of Technology | Meloni S.,University of Zaragoza | And 2 more authors.
Physical Review X | Year: 2014

Current modeling of infectious diseases allows for the study of complex and realistic scenarios that go from the population to the individual level of description. However, most epidemic models assume that the spreading process takes place on a single level (be it a single population, a metapopulation system, or a network of contacts). In particular, interdependent contagion phenomena can be addressed only if we go beyond the scheme-one pathogen-one network. In this paper, we propose a framework that allows us to describe the spreading dynamics of two concurrent diseases. Specifically, we characterize analytically the epidemic thresholds of the two diseases for different scenarios and compute the temporal evolution characterizing the unfolding dynamics. Results show that there are regions of the parameter space in which the onset of a disease's outbreak is conditioned to the prevalence levels of the other disease. Moreover, we show, for the susceptible-infected-susceptible scheme, that under certain circumstances, finite and not vanishing epidemic thresholds are found even at the limit for scale-free networks. For the susceptibleinfected-removed scenario, the phenomenology is richer and additional interdependencies show up. We also find that the secondary thresholds for the susceptible-infected-susceptible and susceptibleinfected-removed models are different, which results directly from the interaction between both diseases. Our work thus solves an important problem and paves the way toward a more comprehensive description of the dynamics of interacting diseases.

Wei K.,Tianjin University of Technology | Chen Q.,Tianjin University
Advanced Materials Research | Year: 2012

This paper introduces multi-model adaptive kalman filter estimation algorithm.Based on the battery thevenin model,the multi-model adaptive kalman filter is applied to the battery SOC(state of charge) estimation, which solute the battery SOC estimation in conditions that the battery model parameters change caused by temperature changing. Simulation results show that compared to the single model kalman filter algorithm, multi-model adaptive kalman filter algorithm improves the estimation precision and reliability greatly. © (2012) Trans Tech Publications, Switzerland.

Li T.,Tianjin University of Technology
Lecture Notes in Electrical Engineering | Year: 2012

Ecological environment evaluation is an indispensible premise for environmental protection, achievement of scientific development outlook, and economic sustainable development. In recent years study on the evaluation of ecological environment has been more and more in depth. Many evaluation methods are proposed, and many evaluation models and indicator systems are established. Evaluation researches can be applied to realistic regions or cities, and quantitative results can be given. Some new methods, new concepts and new trains of thought are put forward, and the scope of research is enlarged. But at present studies especially in the domestic are still facing some problems: theories and practices are isolated; the channel of thought is still narrow; consideration to factors influencing environment is not comprehensive; studies from angles such as economics, management and social science are insufficient. © Springer-Verlag 2012.

Zhao J.-P.,Nankai University | Zhao J.-P.,Tianjin University of Technology | Song W.-C.,Nankai University | Zhao R.,Nankai University | And 3 more authors.
Crystal Growth and Design | Year: 2013

Different ways of anions introduction were applied to construct cluster-based frameworks, owning to the versatile coordination ability of the formate anion and its sensitivity to the pH value of the reaction system. Three tetra-, penta-, and hexanuclear cluster-based cobalt-organic frameworks, [Co2(L)3(HCO2)·MeOH]n (1), [Co5(L)6(OH)2(NO3) 2·2H2O]n (2), and [CoL(HCO 2)]n (3) [L = (E)-3-(pyridin-3-yl)acrylate], have been successfully synthesized. In these complexes, each CoII cluster is linked by twelve L ligands with different connectivities to generate unique topological nets. In 1, two formate anions link four CoII ions forming a tetranuclear cluster, and each of the tetranuclear clusters is connected to eight neighbors by L ligands, giving an 8-connected 3 6418536 net. In 2, the pentanuclear cluster is formed by five CoII ions linked through two OH- and six carboxylate groups, which are further connected by L ligands to afford a pcu (primitive cubic lattice) net. Different from 1 and 2, complex 3 is a 2-fold interpenetrating pcu net based on hexanuclear clusters, which are formed by the linkage of six CoII ions with six syn,syn,anti formate anions and six syn syn carboxylate groups. Magnetic studies indicated that domain antiferromagnetic interactions exist between CoII ions, and spin competition exists in 2 and 3. © 2013 American Chemical Society.

Li N.,Tianjin University of Technology
Energy Education Science and Technology Part A: Energy Science and Research | Year: 2014

For nonstandard description of objects, weak semantics, not sharing and reuse of knowledge of traditional user interest model building, ontology technology, as a new semantic technology, can accurately describe the domain knowledge system, and has obvious advantages in knowledge sharing and reuse. Therefore, in this paper, based on domain ontology, building user interest modeling conducted a tentative research, and applied to the digital library users interested in modeling. © Sila Science. All Rights Reserved.

Hu K.,Nankai University | Zhao D.,Nankai University | Wu G.,Nankai University | Ma J.,Tianjin University of Technology
Polymer Chemistry | Year: 2015

Two eugenol-based aromatic dimethyl terephthalate (DMT)-like monomers were prepared via a thiol-ene click reaction and a subsequent nucleophilic substitution reaction with methyl chloroacetate or 1,4-dibromobutane. Two series of thermoplastic polyesters derived from renewable eugenol and linear aliphatic α,ω-diols HO-(CH2)n-OH (n = 2, 3, 4, 6, 10, 12) were successfully synthesized. These prepared polyesters have weight-average molecular weights in the range of 18-500-90-500 g mol-1, and polydispersity indexes (PDIs) between 1.8 and 2.2. Their chemical structures were all accurately characterized by 1H NMR spectroscopy, 13C NMR spectroscopy and FTIR spectroscopy. The random microstructures of the synthetic polyesters were also explored by 13C NMR spectroscopy. The obtained polyesters all exhibit a thermal stability above 330 °C. More importantly, the thermal stability, the maximum degradation rate and the residue weight are intimately associated with the length of the linear aliphatic α,ω-diol. Their thermo-mechanical properties were studied by differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). The length of the linear aliphatic α,ω-diol crucially influences the glass transition temperature (Tg). With the gradual increase in the α,ω-diol length, the Tg of the synthesized polyester exhibits a tendency to decrease. The polyesters are all amorphous materials at room temperature, with Tg values ranging from -28.4 to 7.6 °C. The incorporation of aromatic eugenol into the polyester chains reduces the crystallinity significantly. The Young's modulus and ultimate strength are in the range of 1.2-6.9 MPa and 0.96-3.37 MPa, respectively. On the contrary, the elongation at break reaches up to 840-1000%, indicating the excellent viscosity properties for such unmanageable viscous materials. © The Royal Society of Chemistry 2015.

Wang X.,Nankai University | Zhou M.,Nankai University | Jin X.,Tianjin University of Technology
Electrochimica Acta | Year: 2012

During last few years, large number of papers published on direct current glow discharge plasma (GDP) in and in contact with liquids due to the increasing interest for its application for wastewater treatment. In this paper, recent progress of GDP on wastewater treatment has been systematically reviewed, covering the degradation of organic pollutants, the reduction of Cr(VI) and the inactivation of algae. This contribution also provides comprehensive insights into reactors, generation mechanisms, physical characteristics, influence of operating parameters and energy efficiency comparing with other AOPs. The emphasis in this paper is on the mechanism of the removal of hazardous chemicals induced by GDP and the combined process. It ends by shortly mentioning theoretical fundamentals and promising actual application of GDP which call for further study. © 2012 Elsevier Ltd. All rights reserved.

Liu Y.,Tianjin University | Xin F.,Tianjin University | Wang F.,Tianjin University | Luo S.,Tianjin University | Yin X.,Tianjin University of Technology
Journal of Alloys and Compounds | Year: 2010

A series of Bi2O3-TiO2 composite photocatalysts were prepared with a facile nonaqueous sol-gel method through varying the Bi-Ti atomic ratio and calcination temperature. The catalyst structures had been extensively characterized by using X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), UV-visible diffuse reflectance spectroscopy (UV-vis DRS). The characterization results revealed that all of the Bi2O3-TiO2 composites exhibited smaller crystallite size, higher thermal stability and stronger absorbance in visible light range than pure TiO2. The photocatalytic activities of as-prepared catalysts were evaluated by the degradation of methyl orange (MO). The results showed that the Bi-Ti atomic ratio of 0.0175 was an optimum in the photocatalytic activities under visible light irradiation and the calcination temperature affected both the physicochemical properties and photocatalytic activities of the catalysts. XPS and XRD were further used to characterize the stability of the photocatalyst, which maintained a high activity without obvious deactivation after five recycles of the degradation. © 2010 Elsevier B.V. All rights reserved.

Ping S.,Tianjin University of Technology
Advanced Materials Research | Year: 2014

Based on the premise of an existing condition data, using factor analysis methods to build a cultural industry competitiveness evaluation index system and evaluation model, the corresponding indicators in the model will be evaluated at the final evaluation results. Statistical analysis using SPSS software, score differences in various parts of, analyses the major gaps. © (2014) Trans Tech Publications, Switzerland.

Tang H.,Guangdong University of Technology | Li Y.,Tianjin University of Technology
Robotics and Computer-Integrated Manufacturing | Year: 2015

Recently, flexure-based micromanipulators with a large workspace, high motion precision, and high positioning bandwidth are really attractive for performing practical micro/nano manipulation tasks. Thus, a piezo-actuated flexible two-degrees-of-freedom (2-DOF) micromanipulator integrated with a pair of modified differential lever displacement amplifiers (MDLDA) is developed. To enhance the practical positioning performance of the micromanipulator, a novel feedforward nonlinear Proportion-Integration-Differentiation (FNPID) control strategy combining a nonlinear PID controller with an inverted hysteresis compensator is first proposed and implemented in detail. With the consideration of hysteresis effect inherent in piezoelectric ceramics (PZT) actuators, the hysteresis nonlinearity modeling is conducted by using the Preisach theory. Finally, a series of precision motion trajectory tracking experiments are successfully conducted by using the proposed closed-loop control strategy. The experimental results indicate that the mechanism has achieved a satisfactory performance for performing robotic biomanipulations. © 2014 Elsevier Ltd.

Liu D.-B.,Tianjin University of Technology | Huang Y.,Brunel University | Prangnell P.B.,University of Manchester
Materials Letters | Year: 2012

A biodegradable magnesium matrix and nano β-tricalcium phosphate (β-TCP) particles reinforced composite Mg-2Zn-0.5Ca-1β-TCP was fabricated for biomedical applications by high shear solidification and equal channel angular extrusion (ECAE). The high shear solidification resulted in a fine and uniform grain structure with β-TCP particle clusters of 5-25 μm in size evenly distributed in the magnesium alloy matrix while the ECAE processing led to further microstructural refinement and a uniform dispersoid of β-TCP particles in the matrix, giving rise to an increase in both the hardness and the corrosion resistance for the material. The formation of a passive surface film consisting of β-TCP nano particles was considered to be an important reason for the increased corrosion performance. © 2012 Elsevier B.V. All rights reserved.

Song X.-J.,Tianjin University of Technology
Applied Mechanics and Materials | Year: 2013

This design in certain food products factory for intelligent control of wastewater treatment processes, monitoring and management. The system consists of lower and upper computer. The lower-level computer consists of PLC and the intelligent instruments. The intelligent instruments can process control the frequency conversion timing machine, opening valve and so on. The PLC can receive all data from the controlling instruments of the upper-level one. Eventually MCGS configuration software, real-time monitoring of wastewater treatment processes and changes of analog. So as to realize combination of automatic and manual control, field and remote control with the combination of purpose. © (2013) Trans Tech Publications, Switzerland.

Wu D.Y.,Tianjin University of Technology
Applied Mechanics and Materials | Year: 2013

Electromagnetism based detection has advanced rapidly in recent years because of its characteristics of non-contact and non-invasion nature. An electromagnetic measurement system for monitoring the crack of conductivity material was presented in this paper. The system consists of signal source module, measuring module and demodulation module. In order to evaluate the system performance, some prime experimental work was undertaken, the results showed the feasibility of the system. © (2013) Trans Tech Publications, Switzerland.

Zhao J.,Tianjin University of Technology | Guo H.,China University of Geosciences
Applied Mechanics and Materials | Year: 2013

The effects of arsenic uptake by Pteris vittata L. and Polystichum craspedosorum were examined. Pteris vittata L. were exposed hydroponically to 4.8 mg/L As(V) for 16 d and 4.05 mg/L As(V) for 24 h. Arsenic concentration in solution respectively decreased to 1.61 mg/L and 3.86mg/L. TF after 24 h was 0.81(<1) while TF after 16 d was 2.83 (>1). Polystichum craspedosorum were exposed hydroponically to 3.26 mg/L As(V) for 20 days. As concentration decreased to 2.83mg/L after 16d and then increased slowly in the later four days. As contents in roots and fronds of Polystichum craspedosorum were 147 mg/kg and 90mg/kg. The results indicated that Polystichum craspedosorum was not good candidate for removal As(V) from water compared with Pteris vittata L. © (2013) Trans Tech Publications, Switzerland.

Xin L.,Tianjin Polytechnic University | Xin L.,Tianjin University of Technology | Lianhe Y.,Tianjin Polytechnic University
Journal of Convergence Information Technology | Year: 2012

By analyzing the structure of three-dimensional woven fabric, establishing a simple model, programming based on OpenGL and C++ technology, simulating the structure of the threedimensional woven fabric. With outstanding modeling and rendering capabilities of OpenGL, we can see the appearance and structure of the fabric before weaving. It is convenience for the material developer to assess the quality of the material.

Zhang C.,Jiangsu University of Science and Technology | Qu Y.-F.,Tianjin University of Technology
Transactions of Nonferrous Metals Society of China (English Edition) | Year: 2012

The dielectric properties and phase transition characteristics of La 2O3- and Sb2O3-doped barium strontium titanate ceramics prepared by solid state route were investigated. The microstructure was identified by X-ray diffraction method and scanning electron microscope was also employed to observe the surface morphologies. It is found that (La, Sb)-codoped barium strontium titanate ceramics exhibit typical perovskite structure and the average grain size decreases dramatically with increasing the content of Sb2O3. Both La3+ ions and Sb3+ ions occupy the A-sites in perovskite lattice. The dielectric constant and dielectric loss of barium strontium titanate based ceramics are obviously influenced by La2O3 as well as Sb2O3 addition content. The tetragonal-cubic phase transition of La2O3 modified barium strontium titanate ceramics is of second order and the Curie temperature shifts to lower value with increasing the La2O3 doping content. The phase transition of (La, Sb)-codoped barium strontium titanate ceramics diffuses and the deviation from Curie-Weiss law becomes more obvious with the increase in Sb 2O3 concentration. The temperature corresponding to the dielectric constant maximum of (La, Sb)-codoped barium strontium titanate ceramics decreases with increasing the Sb2O3 content, which is attributed to the replacement of host ions by the Sb3+ ions. © 2012 The Nonferrous Metals Society of China.

Shen J.,Nanyang Technological University | Shen J.,Institute of Chemical and Engineering Sciences, Singapore | Liu A.,Nanyang Technological University | Tu Y.,Nanyang Technological University | And 4 more authors.
Electrochimica Acta | Year: 2012

Manganese oxide (MnO 2) is a promising pseudocapacitive electrode material because of its high capacitance, abundant resource, low-cost, and environmental friendliness. However, its poor electrical and ionic conductivities and low stability hinder applications. Forming MnO 2 nanocomposites with high surface area porous metal, carbon materials, or conducting polymers is a possible solution. In this work, we have developed a facile and scalable asymmetric in situ deposition method to incorporate MnO 2 nanoparticles in conductive single walled carbon nanotube (SWCNT) films. The high porosity of vacuum filtrated SWCNT films accommodates pseudocapacitive MnO 2 nanoparticles without sacrificing the mechanical flexibility and electrochemical stability of SWCNT films. We exposed one side of SWCNT films to acidic potassium permanganate (KMnO 4) solution. The infiltrated KMnO 4 solution partially etches SWCNTs to create abundant mesopores, which ensure electrolyte ions efficiently access deposited MnO 2. Meanwhile, the remaining SWCNT network serves as excellent current collectors. The electrochemical performance of the SWCNT-MnO 2 composite electrodes depends on the porosity of SWCNT films, pH, and concentration of KMnO 4 solution, deposition temperature and time. Our optimized two-electrode electrochemical capacitor, with 1 M Na 2SO 4 in water as electrolyte, showed a superior performance with specific capacitance of 529.8 F g -1, energy density of 73.6 Wh kg -1, power density of 14.6 kW kg -1, excellent capacitance retention (99.9%) after 2000 charge and discharge cycles, and one of the highest reported frequency responses (knee frequency at 1318 Hz). The high performance flexible electrochemical capacitors have broad applications in portable electronics and electrical vehicles, especially when high frequency response is desired. © 2012 Elsevier Ltd.

Zhen X.,Tianjin University of Technology | Wang Y.,Tianjin UniversityTianjin
Renewable and Sustainable Energy Reviews | Year: 2015

Abstract Methanol is an alternative, renewable, environmentally and economically attractive fuel; it is considered to be one of the most favorable fuels for conventional fossil-based fuels. Methanol has been recently used as an alternative to conventional fuels for internal combustion (IC) engines in order to satisfy some environmental and economical concerns. Because of a number of relatively large research projects that have been ongoing recently, much progress has been made that is worth reporting. This paper systematically describes the methanol productions, including the productions from coal, natural gas, coke-oven gas, hydrogen, biomass etc. It introduces the potentials of methanol as a renewable resource taking into account the world supply and demand, economic benefits and the effects on human health and the environment. Thirteen methods of application such as methanol/gasoline, methanol/diesel blends which can be used on the IC engines are summarized. Finally, this paper puts forward some new suggestions on the weakness in the researches of methanol engine. © 2015 Elsevier Ltd.

Wu F.-Y.,Tianjin University of Technology
Gongcheng Kexue Xuebao/Chinese Journal of Engineering | Year: 2015

An analytical model of air-gap flux density and the Lorenz force law were used to establish radial and tangential electromagnetic force models in the spherical coordinate system for the stator coils. Then, a finite element model of the stator casing and coil holder was applied to compute the strain of the coil holder caused by electromagnetic force, and the influences of the stator casing's thickness, the diameter and the length of the coil holder's connecting rod on this strain were analyzed. Finally, the finite element method and the analytical method were used to analyze a prototype motor and their results were compared, which verified the validity and accuracy of the analytical models. This analysis shows that when the stator casing becomes thin or the connecting rod slenderizes, the strain of the stator coil holder produced by electromagnetic force increases linearly within a certain range and then grows significantly. ©, 2015 All right reserved.

Bai Y.-C.,South China University of Technology | Zhang W.-D.,South China University of Technology | Chen C.-H.,South China University of Technology | Zhang J.-Q.,Tianjin University of Technology
Journal of Alloys and Compounds | Year: 2011

PtAu-alloy nanoparticles supported on multi-walled carbon nanotubes (MWCNTs) were successfully prepared by simultaneous reduction of H 2PtCl6·6H2O and HAuCl 4·3H2O with sodium borohydride as a reducing reagent and sodium citrate as a stabilizing reagent. The morphology and composition of the composite catalyst were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy and X-ray diffraction. The results show that the PtAu alloy nanoparticles with an average diameter of about 3.5 nm and narrow size distribution are supported on MWCNTs. Electrocatalytic oxidation of formic acid at the PtAu/MWCNTs nanocomposite electrode was investigated in a solution containing 0.50 M H2SO 4 as a supporting electrolyte and 0.50 M formic acid by cyclic voltammogram and chronoamperometry. The results demonstrate that the PtAu/MWCNTs catalyst exhibits higher activity and stability for electro-oxidation of formic acid than the commercial Pt/C catalyst, reflecting by its lower onset potential (-0.05 V), oxidation mainly occurring in low potential range of -0.05 ± 0.65 V and higher peak current density of 3.12 mA cm-2. The result of CO stripping voltammetry discloses that gold in the PtAu/MWCNTs nanocomposite enhances the catalytic activity and stability. © 2010 Elsevier B.V. All rights reserved.

Wang L.-M.,Langfang Teachers College | Wu F.,Tianjin University of Technology
Wuli Xuebao/Acta Physica Sinica | Year: 2013

The dynamic behaviors of coupled fractional order bistable oscillators are investigated extensively and various phenomena such as synchronization, anti-synchronization, and amplitude death, etc. are explored. Based on the bistable characteristics of P-R oscillator with specific parameters, effects of initial conditions and coupling strength on the dynamic behaviors of the coupled fractional order bistable oscillators are first investigated by analyzing the maximum condition of Lyapunov exponent, the maximum Lyapunov exponent and the bifurcation diagram, etc. Further investigation reveals that the coupled fractional order bistable oscillators can be controlled to form chaotic synchronization, chaotic anti-synchronization, synchronous amplitude death, anti-synchronous amplitude death, partial amplitude death, and so on by changing the initial conditions and the coupling strength. Then, based on the principle of Monte Carlo method, by randomly choosing the initial conditions from the phase space, we calculate the percentage of various states when changing the coupling strength, so the dynamic characteristics of coupled fractional-order bistable oscillators can be represented by using the perspective of statistics. Some representative attractive basins are plotted, which are well coincident with numerical simulations. © 2013 Chinese Physical Society.

Ping S.,Tianjin University of Technology
Advanced Materials Research | Year: 2014

This article describes a standard document similarity measure, and is used for cultural archives category. And should be used in the classification of cultural archives. The results show that, based on graph model of this representation is valid and feasible. © (2014) Trans Tech Publications, Switzerland.

Zhao K.,Harbin Institute of Technology | Li Y.,Tianjin University of Technology
Chinese Control Conference, CCC | Year: 2013

This paper addresses the problem of implementing Rapidly-exploring Random Tree (RRT) in a large-scale indoor environment. The details of environment modeling based on real indoor metric map are described, thereafter a novel method is used to construct a topological map. A series of tests indicate that RRT planner using this topological map can efficiently search for appropriate path by reducing the search space size. © 2013 TCCT, CAA.

Xia C.-Y.,Tianjin University of Technology | Xia C.-Y.,University of Zaragoza | Meloni S.,University of Zaragoza | Perc M.,University of Maribor | And 3 more authors.
EPL | Year: 2015

Individuals might abstain from participating in an instance of an evolutionary game for various reasons, ranging from lack of interest to risk aversion. In order to understand the consequences of such diverse activity patterns on the evolution of cooperation, we study a weak prisoner's dilemma where each player's participation is probabilistic rather than certain. Players that do not participate get a null payoff and are unable to replicate. We show that inactivity introduces cascading failures of cooperation, which are particularly severe on scale-free networks with frequently inactive hubs. The drops in the fraction of cooperators are sudden, while the spatiotemporal reorganization of compact cooperative clusters, and thus the recovery, takes time. Nevertheless, if the activity of players is directly proportional to their degree, or if the interaction network is not strongly heterogeneous, the overall evolution of cooperation is not impaired. This is because inactivity negatively affects the potency of low-degree defectors, who are hence unable to utilize on their inherent evolutionary advantage. Between cascading failures, the fraction of cooperators is therefore higher than usual, which lastly balances out the asymmetric dynamic instabilities that emerge due to intermittent blackouts of cooperative hubs. © CopyrightEPLA, 2015.

Pan M.,University of Texas at Austin | Gong J.,Tianjin University of Technology | Dong G.,University of Texas at Austin | Mullins C.B.,University of Texas at Austin
Accounts of Chemical Research | Year: 2014

Historically, scientists have considered gold an inert catalyst constituent. However, in recent decades, chemists have discovered that nanoscale gold shows exceptional activity for many chemical reactions. They have investigated model gold surfaces in order to obtain fundamental understanding of catalytic properties. In this Account, we present our current understanding of oxidation and hydrogenation reactions on the Au(111) single crystal as a planar representative of gold catalysts, revealing the interesting surface chemistry of gold.We begin by comparing two inverse reactions, alcohol oxidation and aldehyde hydrogenation, on a Au(111) surface. Beyond the expected different chemistry, we observe intriguing similarities since the same surface is employed. First, both molecular oxygen and hydrogen have high barriers to dissociation on Au(111), and frequently chemists study reactions here by using atomic O and H to populate the surfaces. Recombinative desorption features of oxygen and hydrogen are apparent at ∼500 and ∼110 K, lower than other transition metals. These results indicate that oxygen and hydrogen have low desorption activation energies and weakly chemisorb on the surface, likely leading to selective reactions. On the oxygen-precovered Au(111) surface, alcohols are selectively oxidized to aldehydes. Similarly, weakly bound hydrogen atoms on Au(111) also show chemoselective reactivity for hydrogenation of propionaldehyde and acetone.The second similarity is that the gold surface activates self-coupling of alcohol or aldehyde with oxygen or hydrogen, resulting in the formation of esters and ethers, respectively, in alcohol oxidation and aldehyde hydrogenation. During these two reactions, both alkoxy groups and alcohol-like species show up as intermediates, which likely play a key role in the formation of coupling products. In addition, the cross coupling reaction between alcohol and aldehyde occurs on both O- and H-modified surfaces, yielding the production of esters and ethers, respectively. Thus, we can tune the molecular structure of both esters and ethers by selecting the corresponding aldehyde and alcohol for the coupling reaction.These studies indicate that gold is a versatile active catalyst for various reactions, including oxidation and hydrogenation transformations. Despite the very different chemistry for these two reactions, we can establish an intrinsic relationship due to the distinct catalytic properties of gold. It can show activity for selective reactions on both O- and H-covered Au(111) and further induce the coupling reaction between surface reactants and adsorbed O/H to produce esters and ethers. This comparison demonstrates the unique surface chemistry of gold and enhances understanding of its catalytic properties. © 2013 American Chemical Society.

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

SME plays an irreplaceable role in the national economy and plays a huge role in China's economic development. However, SME faces many difficulties because of its characteristics. Especially financial difficulty has become the biggest bottleneck. The article indicates from internal and external factors that information asymmetry and higher costs owing to its own governance structure are the main reason of financing difficulties of SME, and then put forward the corresponding solutions. © 2012 Springer-Verlag Berlin Heidelberg.

Muroya Y.,Waseda University | Enatsu Y.,Waseda University | Li H.,Tianjin University of Technology
International Journal of Computer Mathematics | Year: 2014

We propose a delayed SIRS computer virus propagation model. Applying monotone iterative techniques and Lyapunov functional techniques, we establish sufficient conditions for the global asymptotic stability of both virus-free and virus equilibria of the model. © 2013 Taylor & Francis.

Qin W.-J.,Tianjin University | Qin W.-J.,Tianjin University of Technology | Sun J.,Tianjin University | Yang J.,Tianjin University | Du X.-W.,Tianjin University
Materials Chemistry and Physics | Year: 2011

Cu doping of ZnO quantum dots (QDs) was carried out by laser ablation of Zn/Cu composite targets immersed in PVP aqueous solution. Zn/Cu core-shell particles were firstly prepared by a galvanic replacement reaction, and then they were pressed into targets with different Zn/Cu ratios for laser ablation. Under the extremely non-equilibrium conditions generated by the pulse laser used, a large amount of Cu-doped ZnO QDs were produced with ultrafine size, good dispersibility, and high stability. On the other hand, the dopant concentration was feasibly controlled from 1.8% to 4.8% by changing the atomic content of Cu in Zn/Cu composite targets. Cu-doped QDs exhibited blue emission with tunable wavelength, which was ascribed to electronic transitions from the conductor band of ZnO to the acceptor levels related to Cu dopants. As a facile and versatile technique, laser ablation is believed to be an effective way for fabricating various doped nanocrystals. © 2011 Elsevier B.V. All rights reserved.

Zhang A.,Tianjin University of Technology
Microwave and Optical Technology Letters | Year: 2011

Multiple mode instabilities in erbium-doped fiber laser are undesirable due to the large amplitude noise in the laser. One scheme is proposed to suppress this kind of instabilities by inserting a highly nonlinear photonic crystal fiber in the ring cavity. The results show that the nonlinear effect not only eliminates the laser instability but also suppresses the noise in the laser. Copyright © 2011 Wiley Periodicals, Inc.

Xiao S.,University of Macau | Li Y.,King Abdulaziz University | Li Y.,Tianjin University of Technology
Journal of Microelectromechanical Systems | Year: 2014

This paper presents a novel micro manipulation system based on visual servo feedback control, which is composed of a micro/nano positioning stage with large workspace, a micro gripper, and a microscope-based visual servo system. The positioning stage is featured with compliant flexure-based totally decoupled characteristics, which is driven by electromagnetic actuators. The gripper is designed with its arms moving completely parallel, which has a large displacement of gripping range. In this research, the gripper is mounted onto the micro positioning stage to form a micro-hand dedicated to micro assembly application. A microscope is adopted to observe this tiny view field and capture the information about the position of the gripping fingers and the objects. Meanwhile, a small piece of silver wire with a diameter of about 30 microns is used as the micro part. The positioning information about tips of the gripping fingers and the object can be captured via the digital microscope and processed by a novel rapid identification method. A kind of visual servo feedback tracking and gripping control algorithm is developed. The algorithm is validated through experiments by realizing the task of picking up a small piece of silver wire then placing it to a new place precisely. © 2013 IEEE.

Zhu B.,Beijing Jiaotong University | Ren G.,Beijing Jiaotong University | Gao Y.,Beijing Jiaotong University | Yang Y.,Tianjin University of Technology | And 2 more authors.
Optics Express | Year: 2014

We propose in this paper a graphene-coated tapered nanowire probe providing strong field enhancement in the infrared regimes. The analytical field distributions and characteristic equation of the supported surface plasmons mode are derived. Based on the adiabatic approximation, analytic methods are adopted in the investigation of field enhancement along the tapered region and show well consistence with the rigorous numerical simulations. Both the numerical and analytical results have shown that the graphene-coated nanowire probe could achieve an order of magnitude larger field enhancement than the metal-coated probes. The proposed probe may have promising applications for single molecule detection, measurement and nano-manipulation techniques. ©2014 Optical Society of America.

Sun X.,Nankai University | Sun X.,Tianjin University of Technology | Shi Y.,Hangzhou Normal University | Zhang P.,University of California at Santa Barbara | And 7 more authors.
Journal of the American Chemical Society | Year: 2011

We report a general reaction container effect in the nanocasting synthesis of mesoporous metal oxides. The size and shape of the container body in conjunction with simply modifying the container opening accessibility can be used to control the escape rate of water and other gas-phase byproducts in the calcination process, and subsequently affect the nanocrystal growth of the materials inside the mesopore space of the template. In this way, the particle size, mesostructure ordering, and crystallinity of the final product can be systemically controlled. The container effect also explain some of the problems with reproducibility in previously reported results. © 2011 American Chemical Society.

Pan Y.,CAS Research Center for Eco Environmental Sciences | Shi Y.,CAS Research Center for Eco Environmental Sciences | Wang J.,CAS Research Center for Eco Environmental Sciences | Jin X.,Tianjin University of Technology | Cai Y.,CAS Research Center for Eco Environmental Sciences
Bulletin of Environmental Contamination and Toxicology | Year: 2011

Detectable PFCs could be found in all samples. Perfluorooctanoic acid (PFOA) was the major PFC in river water, while perfluorooctane sulfonate (PFOS) was dominant in sediment and were 17- to 153-fold higher than those in water. PFCs concentrations in soil were little higher than those in sediment. In fish muscles PFOS showed the highest concentrations. Generally, PFC concentrations in fish were in the following rank order: crucian carp > silver carp> common carp. We suggested that there may be constant and diffuse pollution sources in Tianjin. Point sources also appeared to make significant contribution in the present study. © 2011 Springer Science+Business Media, LLC.

Yu D.,Nanyang Technological University | Wei L.,Nanyang Technological University | Jiang W.,Nanyang Technological University | Wang H.,Nanyang Technological University | And 5 more authors.
Nanoscale | Year: 2013

Electrocatalysts for anode or cathode reactions are at the heart of electrochemical energy conversion and storage devices. Molecular design of carbon based nanomaterials may create the next generation electrochemical catalysts for broad applications. Herein, we present the synthesis of a three-dimensional (3D) nanostructure with a large surface area (784 m 2 g-1) composed of nitrogen doped (up to 8.6 at.%) holey graphene. The holey structure of graphene sheets (∼25% of surface area is attributed to pores) engenders more exposed catalytic active edge sites. Nitrogen doping further improves catalytic activity, while the formation of the 3D porous nanostructure significantly reduces graphene nanosheet stacking and facilitates the diffusion of reactants/electrolytes. The three factors work together, leading to superb electrochemical catalytic activities for both hydrazine oxidation (its current generation ability is comparable to that of 10 wt% Pt-C catalyst) and oxygen reduction (its limiting current is comparable to that of 20 wt% Pt-C catalyst) with four-electron transfer processes and excellent durability. © The Royal Society of Chemistry 2013.

Wang Y.,Tianjin University of Technology
Civil Engineering and Urban Planning III - Proceedings of the 3rd International Conference on Civil Engineering and Urban Planning, CEUP 2014 | Year: 2014

Some typical methods used in the reutilization of European old buildings from the angel of the modernization of traditional buildings are introduced in this paper. Corresponding design principles and overall thoughts from art perspective are summarized. The paper also investigates some basic attitudes and utilization methods of typical western designers through specific reconstruction plans, which give beneficial inspiration to similar projects in China. © 2014 Taylor & Francis Group.

Yuan W.-J.,Huaibei Normal University | Xia C.-Y.,Tianjin University of Technology
PLoS ONE | Year: 2014

Public cooperation plays a significant role in the survival and maintenance of biological species, to elucidate its origin thus becomes an interesting question from various disciplines. Through long-term development, the public goods game has proven to be a useful tool, where cooperator making contribution can beat again the free-rides. Differentiating from the traditional homogeneous investment, individual trend of making contribution is more likely affected by the investment level of his neighborhood. Based on this fact, we here investigate the impact of heterogeneous investment on public cooperation, where the investment sum is mapped to the proportion of cooperators determined by parameter α. Interestingly, we find, irrespective of interaction networks, that the increment of α (increment of heterogeneous investment) is beneficial for promoting cooperation and even guarantees the complete cooperation dominance under weak replication factor. While this promotion effect can be attributed to the formation of more robust cooperator clusters and shortening END period. Moreover, we find that this simple mechanism can change the potential interaction network, which results in the change of phase diagrams. We hope that our work may shed light on the understanding of the cooperative behavior in other social dilemmas. © 2014 Yuan, Xia.

Shuping Z.,Tsinghua University | Shuping Z.,Tianjin University of Technology | Yulong W.,Tsinghua University | Mingde Y.,Tsinghua University | And 2 more authors.
Bioresource Technology | Year: 2010

A genus of unicellular green marine microalgae, Dunaliella tertiolecta, was pyrolysed in a thermogravimetric analyzer from room temperature to 900 °C in a highly purified N2 atmosphere at different heating rates of 5, 10, 20, and 40 °C/min. The results showed that three stages appeared in this thermal degradation process, with increasing temperature, initial temperature, and peak temperature of pyrolysis shifting to a higher value as the heating rate increased. The increased heating rate also resulted in increased total volatile matter. The kinetic analysis of the main pyrolysis process used a composite procedure involving the iso-conversional method and the master-plots method. The iso-conversional method indicated that the pyrolysis reaction should conform to a single reaction model with an activation energy of 145.713 kJ mol-1 using Kissinger's method and 146.421 kJ mol-1 using Flynn-Wall-Ozawa's method, respectively. The master-plots method suggested that the most probable reaction mechanism was described by an Fn model. Finally, it was estimated that the pre-exponential factor was A = 2.28 × 1013 s-1, the kinetic exponent was n = 2.4, and the reaction model function was f(α) = (1 - α)2.4. The results of this study provide useful information for designing a pyrolytic processing system using microalgae D. tertiolecta as feedstock. © 2009 Elsevier Ltd. All rights reserved.

Wu Z.,University of Macau | Li Y.,Tianjin University of Technology
Advances in Mechanical Engineering | Year: 2014

A new 2-DOF microgripper, which can perform the processing of the objects assembly and biological cells injection, is designed and modeled in this paper. The clamping action of the microgripper with the x direction is completed, however, when anything is clamped by the end effector, which can be completely driven by an actuator generated in y direction, at last clamping and pushing motion are realized. The flexure hinge, which takes place of the conventional joint, is used as the translational and rotational hinges in the new structure. Otherwise, the whole microgripper is monolithic processing, which can efficiently overcome the disadvantages of the conventional hinge with friction, backlash, and errors caused by the hinge assembly. Firstly, a kind of novel microgripper is designed in this paper, which can accomplish two-dimensional independent motions including a separate grip and single track push without interfering with each other. The bridge type amplifying structure with two-end output is adopted in the gripper to increase the motion range and the capacity of the microgripper. The piezoelectric actuator with fast response and high resolution is used as the drive element. Secondly, the geometrical and kinematical models are established and the formulas of the amplifying ratio, stiffness, maximum stress, and the natural frequency of this model are calculated, respectively. Finally, the FEM (finite element modeling) based on ANSYS software is built up to validate the formulas. © 2014 Zhigang Wu and Yangmin Li.

Lin W.,Nankai University | Zhang H.,Nankai University | Song B.,Nankai University | Miao Y.,Tianjin University of Technology | And 3 more authors.
Optics Express | Year: 2015

In this paper, a magnetically controllable wavelength-divisionmultiplexing (WDM) fiber coupler has been proposed and experimentally demonstrated. A theoretical model has been established to analyze the influences of the weak as well as strong couplings to the wavelength tunability of this coupler. Experimental results show that the operation wavelength tunability of the proposed WDM coupler could be fulfilled for an applied magnetic field intensity range of 0 Oe to 500 Oe, and particularly it possesses high operation performances within the magnetic field intensity ranging from 25 Oe to 125 Oe when additional transmission loss and isolation are both considered. Within this range, the two selected channels show the wavelength tunability of 0.05 nm/Oe and 0.0744 nm/Oe, respectively, and the isolation between the two branches is higher than 24.089 dB. Owing to its high isolation, good splitting ratio stability, and high wavelength tunability, the proposed controllable WDM coupler is anticipated to find potential applications in such fields as fiber laser, fiber sensing and fiber-optic communications. Moreover, the fiber coupler integrated with the magnetic fluid would be valuable for the design of magnetically controllable mode-division-multiplexing devices. © 2015 Optical Society of America.

Xu C.,Tianjin University of Technology
2014 IEEE International Conference on Mechatronics and Automation, IEEE ICMA 2014 | Year: 2014

Grounding resistance is the main technical qualification of grounding system about Power plant and substation. We analyzed the feasibility of the method of measurement with short leads and discussed the current electrode lead length by comparing Common measurement methods of grounding resistance, a MATLAB software calculating program was compiled, and we calculated the position of measurement compensation point under the condition of uniform and vertical layered soil; The potential distribution of grounding grids was simulated under the uniform and vertical layered soil with ground simulation software CDEGS, the revised position of the result of measurement with short leads was compared with the real grounding resistance of grounding grids. Comparison results show that the rationality of the Measurement with short Leads method and the modifier formulas. © 2014 IEEE.

Li T.,Tianjin University of Technology
Lecture Notes in Electrical Engineering | Year: 2012

With the increase of life quality of our people, and with the new medical reform stepping onto the quick track, medical instrument industry is developing rapidly. The domestic portable medical electronic products are facing competition from both domestic and overseas. As the new listed company in the A stock market SME board, Jiuan Medical needs to conscientiously analyze its own strengths, weakness, environmental opportunities, and external threads (SWOT), nicely design its positioning in the market, and correctly set up marketing scheme, in order to win in the market with fierce competition. This paper made SWOT analysis for Jiuan portable medical electronic products on the basis of analyzing market environment of domestic portable medical electronic products, finding solutions of SWOT strategy and tactics. © Springer-Verlag 2012.

Chen W.,Henan University | Liu H.,Tianjin University of Technology | Zhang Q.,Nankai University | Dai S.,Nankai University
Journal of Applied Phycology | Year: 2011

As a common pollutant, nitrite concentrations can approach 15 mg NO2 --N L-1 in some aquatic systems. Microcystis aeruginosa blooms are common and widespread in eutrophic freshwater bodies. In this study, M. aeruginosa was exposed to nitrite concentrations ranging from 0 to 15 mg NO2 --N L-1, and the responses of M. aeruginosa were investigated. The specific growth rates, maximum cell densities, light-saturated photosynthetic rates (Pm chla), dark respiration rates (Rd chla), and apparent photosynthetic efficiencies (αchla) showed a significant decline with nitrite concentrations increasing. Electrical conductivity and malondialdehyde contents investigation revealed cell membrane damage and apparent leakage of intracellular contents under high nitrite level conditions due to oxidative stress enhancement. Intracellular microcystin (MC)-LR content reached the highest value at 10 mg NO2 --N L-1; however, extracellular MC-LR contents showed a continuous increase until 15 mg NO2 --N L-1 owing to the increasing leakage of intracellular contents. These results elucidated that the high-level nitrite inhibited M. aeruginosa growth by rising oxidative stress, damaging cell membrane, and reducing photosynthesis. However, the moderate increase in nitrite concentrations promoted toxin production and release of toxin. © 2010 Springer Science+Business Media B.V.

Zeng L.,Ohio State University | Zeng L.,Tianjin University of Technology | Tong A.,Ohio State University | Kathe M.,Ohio State University | And 2 more authors.
Applied Energy | Year: 2015

Chemical looping technologies have the potential to reduce the natural-gas conversion cost in a carbon-constrained scenario. Given the increasing importance of natural gas to global energy supply, this work investigates the application of an iron oxide based chemical looping technology for natural gas conversion. A thermodynamic criterion for selecting iron oxide based oxygen carrier material and designing the reaction system is developed using an adapted Ellingham diagram. Equilibrium modeling for detailed thermodynamic analysis is conducted for verifying the Ellingham diagram analysis. The thermodynamic equilibrium model also establishes a system baseline performance, and experimental proof of concept bench-scale demonstration is investigated. The bench-scale testing is used to characterize the effect of parameters like solids to gas ratio and temperature of the reactor on system performance. An optimal set of operating conditions is identified for further testing on a larger scale. © 2015 Elsevier Ltd.

Yu H.,Tianjin University of Technology
Applied Mechanics and Materials | Year: 2014

Some researches on the key technologies of automatic fare collection (AFC) system in the rail transit are conducted systematically in this article. Besides, the studies on the station device application conditions of AFC system and the functional analysis of the ticket machine, the gate and the station computer system in Tianjin Metro are taken in detail. © (2014) Trans Tech Publications, Switzerland.

Jie L.,Tianjin University of Technology
IET Conference Publications | Year: 2013

This paper illustrates the urgency of the development of public logistics information platform with strong instantaneity and large amount of information, and the problems should be solved for developing the public logistics information platform. In addition, it puts forward a system structure of the platform, and the key technology of the system are analyzed, as well as the defects of the system design are pointed out.

Chen X.-D.,Tianjin University of Technology
2013 25th Chinese Control and Decision Conference, CCDC 2013 | Year: 2013

For transportation Networks that can be staging, we suggest a combination optimization model of multiple transportation modes. By constructing a virtual transportation networks, the original problem is converted to a specific shortest path problem. First optimize the network, and then this paper gives the application of genetic algorithm for this problem. © 2013 IEEE.

Du H.,South China University of Technology | Du H.,Guizhou University for Nationalities | Ye J.,South China University of Technology | Zhang J.,Tianjin University of Technology | And 2 more authors.
Electroanalysis | Year: 2010

Graphene nanosheets modified glassy carbon electrode (GNs/GCE) was fabricated as voltammetric sensor for rutin with good sensitivity, selectivity and reproducibility. The sensor exhibits an adsorption-controlled, reversible twoproton and two electron transfer reaction for the oxidation of rutin with a peak-to-peak separation (ΔEp) of 26 mV as revealed by cyclic voltammetry. Moreover, the redox peak current increased about 14 times than that on bare glassy carbon electrode (GCE). The linear response of the sensor is from 1×10-7 to 1×10-5 M with a detection limit of 2.1 × 10-8 M (S/N = 3). The method was successfully applied to determine rutin in tablets with satisfied recovery. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Liu J.-Y.,Tianjin University of Technology | Zhou S.,KTH Royal Institute of Technology
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

Motivated by recent measurements of a relatively large θ13 in the Daya Bay and RENO reactor neutrino experiments, we carry out a systematic analysis of the hybrid textures of Majorana neutrino mass matrix Mν, which contain one texture zero and two equal nonzero matrix elements. We show that three neutrino masses (m1,m2,m 3) and three leptonic CP-violating phases (δ,ρ,σ) can fully be determined from two neutrino mass-squared differences (δm2,Δm2) and three flavor mixing angles (θ12, θ23,θ13). Out of sixty logically possible patterns of Mν, thirty-nine are found to be compatible with current experimental data at the 3σ level. We demonstrate that the texture zero of Mν is stable against one-loop quantum corrections, while the equality between two independent elements not. Phenomenological implications of Mν for the neutrinoless double-beta decay and leptonic CP violation are discussed, and a realization of the texture zero and equality by means of discrete flavor symmetries is illustrated. © 2013 American Physical Society.

Krishnan D.,Northwestern University | Raidongia K.,Northwestern University | Shao J.,Northwestern University | Shao J.,Tianjin University of Technology | Huang J.,Northwestern University
ACS Nano | Year: 2014

Hydrothermal carbonization (HTC) of biomass such as glucose and cellulose typically produces micrometer-sized carbon spheres that are insulating. Adding a very small amount of Graphene oxide (GO) to glucose (e.g., 1:800 weight ratio) can significantly alter the morphology of its HTC product, resulting in more conductive carbon materials with higher degree of carbonization. At low mass loading level of GO, HTC treatment results in dispersed carbon platelets of tens of nanometers in thickness, while at high mass loading levels, free-standing carbon monoliths are obtained. Control experiments with other carbon materials such as graphite, carbon nanotubes, carbon black, and reduced GO show that only GO has significant effect in promoting HTC conversion, likely due to its good water processability, amphiphilicity, and two-dimensional structure that may help to template the initially carbonized materials. GO offers an additional advantage in that its graphene product can act as an in situ heating element to enable further carbonization of the HTC products very rapidly upon microwave irradiation. Similar effect of GO is also observed for the HTC treatment of cellulose. © 2013 American Chemical Society.

Zang J.,Tianjin University | Jia S.,Tianjin University | Liu Y.,Tianjin University of Technology | Wu S.,Tianjin University | Zhang Y.,Tianjin Entry and Exit Inspection and Quarantine Bureau
Catalysis Communications | Year: 2012

In this paper, polyvinyl alcohol (PVA) was modified with 3-aminopropyl triethoxysilane (APTES) and formed chemically crosslinked beads with chitosan. FTIR and SEM were used to characterize the support and immobilized catalase. Compared with control group, the activity of modified group increased about 1400 U/g support. The optimal temperature and optimal pH of immobilized catalase were 45°C and pH 7.0. The thermal stability of catalase also enhanced after immobilization. Moreover, the immobilized catalase retained more than 90% of its original activity after using it for 9 times. © 2012 Elsevier B.V.

Liu S.,Nanyang Technological University | Hu M.,Nanyang Technological University | Zeng T.H.,Nanyang Technological University | Wu R.,Nanyang Technological University | And 6 more authors.
Langmuir | Year: 2012

Graphene oxide (GO) is a promising precursor to produce graphene-family nanomaterials for various applications. Their potential health and environmental impacts need a good understanding of their cellular interactions. Many factors may influence their biological interactions with cells, and the lateral dimension of GO sheets is one of the most relevant material properties. In this study, a model bacterium, Escherichia coli (E. coli), was used to evaluate the antibacterial activity of well-dispersed GO sheets, whose lateral size differs by more than 100 times. Our results show that the antibacterial activity of GO sheets toward E. coli cells is lateral size dependent. Larger GO sheets show stronger antibacterial activity than do smaller ones, and they have different time- and concentration-dependent antibacterial activities. Large GO sheets lead to most cell loss after 1 h incubation, and their concentration strongly influences antibacterial activity at relative low concentration (<10 μg/mL). In contrast, when incubating with small GO sheets up to 4 h, the inactivation rate of E. coli cells continues increasing. The increase of small GO sheet concentration also results in persistent increases in their antibacterial activity. In this study, GO sheets with different lateral sizes are all well dispersed, and their oxidation capacity toward glutathione is similar, consistent with X-ray photoelectron spectroscopy and ultraviolet-visible absorption spectroscopy results. This suggests the lateral size-dependent antibacterial activity of GO sheets is caused by neither their aggregation states, nor oxidation capacity. Atomic force microscope analysis of GO sheets and cells shows that GO sheets interact strongly with cells. Large GO sheets more easily cover cells, and cells cannot proliferate once fully covered, resulting in the cell viability loss observed in the followed colony counting test. In contrast, small GO sheets adhere to the bacterial surfaces, which cannot effectively isolate cells from environment. This study highlights the importance of tailoring the lateral dimension of GO sheets to optimize the application potential with minimal risks for environmental health and safety. © 2012 American Chemical Society.

Chen J.,Tianjin University | Qin S.,Tianjin University | Song G.,Tianjin University | Xiang T.,Tianjin University | And 2 more authors.
Dalton Transactions | Year: 2013

Different shape of bismuth sulfide (Bi2S3), including nanoparticles, and urchin-like, microspheres hierarchical nanostructures, have been successfully fabricated using a facile and template-free solvothermal method. Their crystal and porous structures, morphologies, as well as the optical absorption were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-vis diffuse reflection spectroscopy (DRS) and nitrogen sorption. The electron microscopy observations showed that both the sulfur sources and solvents greatly affected the morphologies of the as-prepared Bi2S3. Compared with Bi2S 3 nanoparticles, the hierarchical architectures exhibited higher activity for photocatalytic reduction of CO2 to methyl formate (MF) in methanol, and Bi2S3 microspheres showed the highest activity. This was attributed to their special hierarchical structure, good permeability and high light-harvesting capacity. © 2013 The Royal Society of Chemistry.

Dong X.,Nankai University | Zhang H.,Nankai University | Liu B.,Nankai University | Miao Y.,Tianjin University of Technology
Photonic Sensors | Year: 2011

In this paper, the mode coupling mechanism of tilted fiber Bragg gratings (TFBGs) is briefly introduced at first. And a general review on the fabrication, theoretical and experimental research development of TFBGs is presented from a worldwide perspective, followed by an introduction of our current research work on TFBGs at the Institute of Modern Optics, Nankai University (IMONK), including TFBG sensors for single-parameter measurements, temperature cross sensitivity of TFBG sensors, and TFBG-based interrogation technique. Finally, we would make a summary of the related key techniques and a remark on prospects of the research and applications of TFBGs. © The Authors(s) 2010.

Han S.-D.,Nankai University | Zhao J.-P.,Nankai University | Zhao J.-P.,Tianjin University of Technology | Liu S.-J.,Nankai University | Bu X.-H.,Nankai University
Coordination Chemistry Reviews | Year: 2015

Hydro(solvo)thermal synthesis is a widely-used method to assemble various molecular magnetic materials based on different types of ligands. This review mainly focuses on the study of the magnetochemistry of azide/formate-mediated molecule-based magnetic materials of our lab synthesized under hydro(solvo)thermal conditions in the presence of coligand, with an emphasis on anionic coligand of carboxylate. The first section gives a brief discussion of azido and formato complexes and some important principles obtained from magneto-structural correlation; hydro(solvo)thermal synthetic strategies will also be referred to and elucidated in this part. The next six sections give overviews of the main results obtained in our group in recent years, that is, azide/formate-mediated ferromagnetism, ferrimagnetism, spin canting (or weak ferromagnetism), antiferromagnetism, single-molecule magnets (SMMs) and single-chain magnets (SCMs), and metamagnetism. Finally, the conclusions and perspectives of azido/formato-mediated molecular magnetic materials will be presented. Some of the trends identified could provide new insights into the further development of this promising area. © 2014 Elsevier B.V..

Meng F.-J.,Tianjin University of Technology
Advanced Materials Research | Year: 2014

Based on economic distance weights matrix, using the R&D input-output panel data sets of high technological industry and traditional industry in 29 provinces in China from 2001 to 2010 and spatial econometric method, this paper analyzes their R&D spillover effects respectively between provinces. The results indicate: Even though R&D in the high technology industry in China are active, the R&D spillover in this industry is lower than that in the traditional industries; R &D capital contributes to R&D output more than R&D labor for high technological industry, while the traditional industry is just the opposite. © (2014) Trans Tech Publications, Switzerland.

Li B.-Z.,Tianjin University of Technology
Applied Mechanics and Materials | Year: 2014

In this paper, we focused on the measurement and demonstration of technology innovation spillovers effects between sections. The forward R&D flux coefficient matrix model and backward R&D flux coefficient matrix model are established based on the input-output model, and then the beneficiary's effects and contributor's effects of ten leading industries within the Tangshan City are calculated. In the end, we found that the oil and natural gas industry got the highest score. The result can be used to make better suggestions for management of Tangshan regional innovation system. © (2014) Trans Tech Publications, Switzerland.

Wang Y.,Nankai University | Wu G.,Nankai University | Li X.,Nankai University | Chen J.,Nankai University | And 2 more authors.
Journal of Materials Chemistry | Year: 2012

A series of biodegradable poly(ether urethane)s that responded to changes in temperature and redox potential was synthesized via a facile one-pot method. The amphiphilic poly(ether urethane)s were comprised of 2,2′- dithiodiethanol, hydrophobic hexamethylene diisocyanate and hydrophilic poly(ethylene glycol) (PEG) segments. The phase transition temperature (T p) of the prepared poly(ether urethane)s in aqueous solution could be easily controlled by changing the length of the PEG segment or the ratio of PEG to 2,2′-dithiodiethanol and it could be used to trigger the redox-degradable behavior. The redox-responsive disulfide bonds in the polymers could be cleaved in the presence of glutathione (GSH) when the temperature was above Tp, while the degradation was inhibited below Tp. The doxorubicin (DOX)-loaded poly(ether urethane) nanoparticles were prepared in order to investigate their stimuli-responsive release. These nanoparticles also showed a temperature-triggered redox-degradable release profile. Toxicity tests showed that the blank nanoparticles had no toxicity, whereas the DOX-loaded nanoparticles showed high cytotoxicity for liver hepatocellular cells (HepG2). Microscopic observations also revealed that the DOX molecules within the poly(ether urethane) nanoparticles could be released into HepG2 cells in the presence of higher temperature and GSH. © 2012 The Royal Society of Chemistry.

Zhu B.,Beijing Jiaotong University | Zhu B.,University of Bristol | Ren G.,Beijing Jiaotong University | Cryan M.J.,University of Bristol | And 4 more authors.
Optics Express | Year: 2015

We propose a tunable circular polarization analyzer based on a graphene-coated spiral dielectric lens. Spatially separated solid dot shape (or donut shape) field can be achieved if the geometric shape of analyzer and incident circular polarization possess the opposite (or same) chirality. Moreover, distinct from the narrow working bandwidth of a traditional circular polarization analyzer, the focusing and defocusing effects in the analyzer are independent of the chemical potential of graphene, and depend only on the dielectric permittivities and the grating occupation ratio. Combined with the strong tunability of graphene plasmons, the operation wavelength of analyzer can be tuned by adjusting the graphene chemical potential without degrading the performance. The proposed analyzer could be used in applications in chemistry or biology, such as analyzing the physiological properties of chiral molecules based on circular polarization. © 2015 Optical Society of America.

Zhang Y.,South China University of Technology | Mo G.,South China University of Technology | Li X.,South China University of Technology | Zhang W.,South China University of Technology | And 4 more authors.
Journal of Power Sources | Year: 2011

Graphene with a Brunauer-Emmett-Teller (BET) specific surface area of 264 m2 g-1 has been used as anodic catalyst of microbial fuel cells (MFCs) based on Escherichia coli (ATCC 25922). The electrochemical activities of plain stainless steel mesh (SSM), polytetrauoroethylene (PTFE) modified SSM (PMS) and graphene modified SSM (GMS) have been investigated by cyclic voltammetry (CV), discharge experiment and polarization curve measurement. The GMS shows better electrochemical performance than those of SSM and PMS. The MFC equipped with GMS anode delivers a maximum power density of 2668 mW m-2, which is 18 times larger than that obtained from the MFC with the SSM anode and is 17 times larger than that obtained from the MFC with the PMS anode. Scanning electron microscopy (SEM) results indicate that the increase in power generation could be attributed to the high surface area of anode and an increase in the number of bacteria attached to anode. © 2011 Elsevier B.V. All rights reserved.

Zhu T.,Tianjin University of Technology | Zhu T.,Inha University | Row K.H.,Inha University
Separation Science and Technology (Philadelphia) | Year: 2013

A 17-run Box-Behnken design (BBD) with three factors was used to improve the conditions for extracting astaxanthin from shrimp waste. The astaxanthin level was determined by high performance liquid chromatography (HPLC) using a C18 column and a UV detector at 476 nm. The mean extraction yield of astaxanthin at the improved conditions (extraction time 1.4 h, extraction temperature 72.4°C, and liquid-solid ratio 27.3) was 98.7 ± 2.6 μg g-1. A solid-phase extraction (SPE)-HPLC method was developed with a new hybrid organic-inorganic hybrid monolith for further purification of astaxanthin from shrimp waste. The SPE recoveries were ranging from 81.3 ± 2.4% to 86.5 ± 3.3%, and the intra-day and inter-day relative standard deviations (RSDs) of the proposed method were less than 4.3 ± 0.5% and 4.8 ± 0.2%, respectively. BBD increased the extraction efficiency and shortened extraction times significantly. SPE-HPLC with hybrid monolith showed good selectivity and purified astaxanthin from shrimp waste. © 2013 Copyright Taylor and Francis Group, LLC.

Xiao S.,University of Macau | Li Y.,Tianjin University of Technology
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2012

Smart material actuators like Piezoelectric(PZT) are widely used in Micro/Nano manipulators, but their hysteresis behaviors are complex and difficult to model. Most hysteresis models are based on elementary quasistatic operators and are not suitable for modeling rate-dependent or thermal-drift behaviors of the actuators. This work proposes a Preisach model based neurodynamic optimization model to account for the complex hysteresis behaviors of the smart material actuator system. Through simulation study, the rate-dependent and the thermal-drift behaviors are simulated via Bouc-Wen model. The μ-density function of the Preisach model is identified on-line through neurodynamic optimization method to suit for the varied rate of the input signals. The output of the actuator system is predicated in realtime based on the on-line identified μ-density plane. It is shown experimentally that the predicated hysteresis loops match the simulated PZT loops very well. © 2012 Springer-Verlag.

Yan T.,University of Texas at Austin | Gong J.,University of Texas at Austin | Gong J.,Tianjin University of Technology | Flaherty D.W.,University of Texas at Austin | And 2 more authors.
Journal of Physical Chemistry C | Year: 2011

The effect of moisture on CO oxidation on Au/TiO2(110) model catalysts is investigated using temperature-programmed desorption and molecular beam reactive scattering under ultrahigh vacuum (UHV) conditions. Oxygen exchange is observed between adsorbed atomic oxygen and isotopically labeled water. Coadsorbed water (H2 18O) takes part in CO oxidation on Oa precovered Au/TiO2(110) model catalysts, leading to the formation of C16O18O and C16O 16O. The amount of C16O18O produced increases with increasing water coverages; however, the total amount of CO2 produced decreases. Although coadsorbed Oa and H2O have a minimal influence on the initial adsorption probability of CO, the total uptake of CO decreases as H2O coverages increase. Interestingly, the adsorption of water induces desorption of predeposited molecularly chemisorbed O2. Thus, adsorbed water slightly inhibits CO oxidation on atomic oxygen precovered Au/TiO2(110) model catalysts under UHV conditions. © 2010 American Chemical Society.

Ma Z.,Nankai University | Deng L.,Nankai University | Yang Y.,Nankai University | Zhai H.,Nankai University | Ge Q.,Tianjin University of Technology
Optics Express | Year: 2013

A novel numerical iterative approach is proposed to effectively eliminate the zero-order term and to improve the signal-to-noise ratio of the reconstructed image in off-axis digital holography. The iterations are conducted in the spatial domain, resulting in considerable reduction in the computational time and avoiding the subjectivity involved in selecting a filter window in spectral domain. These advantages promote the application of this approach in real-time detection processes. The feasibility of this approach is confirmed by mathematical deductions and numerical simulations, and the robustness of the proposed approach is tested by means of an experimentally obtained hologram.

Zhu Z.,Tianjin University of Technology | Wu R.-J.,Providence University
Journal of the Taiwan Institute of Chemical Engineers | Year: 2015

A Pt@TiO2 core-shell material was prepared by a reverse micelle sol-gel method to develop an efficient photocatalyst for the degradation of formaldehyde (HCHO). The properties of the photocatalytic materials were analyzed with UV-vis spectra, X-ray diffraction spectra, energy-dispersive X-ray spectroscopy, transmission electron microscopy, and BEL-MINI adsorption analyzer. Photocatalytic capabilities of photocatalytic materials were investigated in degradation of formaldehyde in presence of visible light irradiation. The experimental result indicates that the Pt@TiO2 nanoparticles achieved 98.3% formaldehyde degradation, while TiO2 (P25), TiO2 (home made), and 1 wt% Pt/TiO2 (home made) achieved 92.4%, 75.2%, and 85.6% respectively. Thus, the Pt@TiO2 displayed excellent formaldehyde degradation efficiency. In addition, Pt@TiO2 can be used repeatedly without significantly changing their formaldehyde degradation capacities. Therefore, the Pt@TiO2 core-shell material has potential as a promising application in the field of formaldehyde degradation. © 2015 Taiwan Institute of Chemical Engineers.

Chen S.,Nankai University | Fan F.,Nankai University | Chang S.,Nankai University | Miao Y.,Tianjin University of Technology | And 4 more authors.
Optics Express | Year: 2014

The dielectric property and magneto-optical effects of ferrofluids have been investigated in the terahertz (THz) regime by using THz timedomain spectroscopy. The experiment results show that the refractive index and absorption coefficient of ferrofluid for THz waves rise up with the increase of nanoparticle concentration in the ferrofluid. Moreover, two different THz magneto-optical effects have been found with different external magnetic fields, of which mechanisms have been theoretically explained well by microscopic structure induced refractive index change in the magnetization process and the transverse magneto-optical effect after the saturation magnetization, respectively. This work suggests that ferrofluid is a promising magneto-optical material in the THz regime which has widely potential applications in THz functional devices for THz sensing, modulation, phase retardation, and polarization control.© 2014 Optical Society of America.

Chen W.,Henan University | Tong H.,Henan University | Liu H.,Tianjin University of Technology
Marine Pollution Bulletin | Year: 2012

The aim of this study was to investigate the effect of nitrate on nitrite toxicity to Microcystis aeruginosa. Short-term uptake experiment revealed nitrate could depress the nitrite active uptake. The long-term experiment of nitrate effects on nitrite toxicity showed a negative relationship between the growth and intracellular nitrite levels of M. aeruginosa. The net nitrite uptake displayed a decline in the range of 0-150. mg NO3--NL-1 and an elevation at 200. mg NO3--NL-1, whereas the activities of nitrate reductase (NR) were more sensitive to nitrate than nitrite reductase (NiR). As a result, the total intracellular nitrite levels tended to decrease up to 100. mg NO3--NL-1 then increased at 150-200. mg NO3--NL-1. These results suggested the existence of external nitrate could affect the toxicity of nitrite to alga through changing intracellular nitrite content. © 2012 Elsevier Ltd.

Han S.-D.,Nankai University | Song W.-C.,Nankai University | Zhao J.-P.,Nankai University | Zhao J.-P.,Tianjin University of Technology | And 4 more authors.
Chemical Communications | Year: 2013

An unprecedented polynuclear cobalt complex with a [Co24] macrocycle in the presence of [Co(H2O)6]2+ has been prepared and characterized. In this complex, [Co(H2O) 6]2+ not only acts as a counterion to balance the negative charge of the 2D layer, but may also serve as a template in the assembly of the [Co24] macrocyclic complex through hydrogen-bond interactions. Magnetic analyses indicate that the title compound shows homometallic ferrimagnetic behavior. © The Royal Society of Chemistry 2013.

Liu T.,Tianjin University | Liu T.,Tianjin University of Technology | Chen Y.,Tianjin University | Han Q.,Tianjin University | Lu X.,Tianjin University
IEEE Photonics Journal | Year: 2014

In this paper, an all-fiber magnetic field sensor based on a U-bent single-mode fiber and magnetic fluid (MF) is proposed and investigated. Because of the tunable refractive index and absorption coefficient of MF, the transmission spectrum will change with the magnetic field strength (H), which can be used to demodulate H through the wavelength shift or the intensity change. The influence of the diameter of the U shape to the performance of the sensor is investigated and discussed. In the experiments, the highest sensitivities achieved with wavelength and intensity demodulation are 0.374 nm/Oe and -0.4821 dB/Oe, respectively. The reproducibility of the sensor is studied as well. © 2009-2012 IEEE.

Meng Q.,University of Macau | Li Y.,Tianjin University of Technology
IFAC Proceedings Volumes (IFAC-PapersOnline) | Year: 2013

This paper proposes a novel analytical model for flexure-based proportion compliant mechanisms. The displacement and stiffness calculations of such flexure-based compliant mechanisms are formulated based on the principle of virtual work and pseudo rigid body model(PRBM). According to the theory and method, a set of closed-form equations are deduced in this paper, which incorporate the stiffness characteristics of each flexure hinge, together with the other geometric and material properties of the compliant mechanism. Displacement proportion, input stiffness, and output stiffness calculations can simply be performed for any serial compliant mechanism. Corner-filleted and circular flexure hinges that are utilized as connectors in proportion compliant mechanisms in this paper. Two types of flexure-based compliant proportion mechanisms based on the novel analytical model are designed and optimized based on these proposed equations. Finite element analysis results show that these design equations are reliable and easier to be used in the design of such proportion compliant mechanisms. This proposed novel analytical model gives a new viewpoint on the design of flexure-based proportion compliant mechanisms. © 2013 IFAC.

Zhao H.,Nankai University | Meng X.,Nankai University | Meng X.,Tianjin University of Technology | Huang Y.,Nankai University
Chemical Communications | Year: 2013

PPh3-Catalyzed aza-MBH domino reaction of salicyl N-tosylimines with γ-CH3 substituted allenoates is reported. Readily available imines and allenoates are converted to benzoxazepine derivatives in one step. Wherein, functionalization of C-H bonds of γ-substituted allenoate has been developed in this domino process. © 2013 The Royal Society of Chemistry.

Liu B.,Tianjin University of Technology | Wang T.,Transportation Institute
Zidonghua Xuebao/Acta Automatica Sinica | Year: 2012

Convex hull is one of the basic structures in computational geometry, which is used in many fields of computer graphics and image. A novel algorithm of convex hull is proposed. Principle component analysis (PCA) is used to do the pretreatment on the planar point set. The applicable sort regulation and determinant principle of edge points in convex hull are studied. The new algorithm is applied to a fast 3D measurement system based on digital fringe projection to extract the minimal convex hull formed by the intensive residual points in the phase interferogram. The system can avoid the phase unwrapping error caused by the residual points by masking the area of the extracted convex hull to guarantee the accuracy of three-dimensional shape reconstruction. Experimental results prove that the presented algorithm not only has high reliability, but also gets better operational efficiency. Copyright © 2012 Acta Automatica Sinica. All rights reserved.

Zhao N.,Tianjin University of Technology
Nature Photonics | Year: 2015

Increasing the information capacity per unit bandwidth has been a perennial goal of scientists and engineers. Multiplexing of independent degrees of freedom, such as wavelength, polarization and more recently space, has been a preferred method to increase capacity in both radiofrequency and optical communication. Orbital angular momentum, a physical property of electromagnetic waves discovered recently, has been proposed as a new degree of freedom for multiplexing to achieve capacity beyond conventional multiplexing techniques, and has generated widespread and significant interest in the scientific community. However, the capacity of orbital angular momentum multiplexing has not been established or compared to other multiplexing techniques. Here, we show that orbital angular momentum multiplexing is not an optimal technique for realizing the capacity limits of a free-space communication channel and is outperformed by both conventional line-of-sight multi-input multi-output transmission and spatial-mode multiplexing. © 2015 Nature Publishing Group

Zhao J.Y.,Tianjin University of Technology | Guo H.M.,China University of Geosciences
Advanced Materials Research | Year: 2013

Arsenic concentration changes in small-scale simulating constructed wetland composed with shale ceramic, zeolite, quartz sand and Pteris vittata were examined. During arsenic removal by the constructed wetlands, arsenic interception by the natural media played the main role in the early stage and Pteris vittata uptake played the key role for arsenic removal in the later stable stage. When As (III) concentration in inflow was about 1 mg/L, the arsenic removal ratio by the two was between 22.2% and 66.6% and kept about 33% in the end. Arsenic average content in fronds and roots of Pteris vittata after experiments were respectively 17610 and 2491 mg/kg. Transfer factor was 7.08. Compared with batch tests, arsenic content accumulated in plants increased significantly. © (2013) Trans Tech Publications, Switzerland.

Yang Y.,Tianjin University of Technology | Meng F.,Qufu Normal University
Mathematical Methods in the Applied Sciences | Year: 2013

This paper deals with the existence of positive solution for impulsive boundary value problem with p-Laplacian in Banach spaces. There is no literature researching on p-Laplacian boundary value problem in Banach spaces. The main difficulty that appears when passing from p = 2 to p ≠ 2 is that for p ≠ 2, it is impossible for us to find a Green's function in the equivalent integral operator because the differential operator (φp(u ′)) ′ is nonlinear, so it is difficult for us to prove that the equivalent integral operator is a strict-set-contraction operator. Even in the absence of pulse effect, these results are new. © 2012 John Wiley & Sons, Ltd.

Wang Z.,Northwestern Polytechnical University | Wang Z.,Kyushu University | Andrews M.A.,University of Guelph | Wu Z.-X.,Lanzhou University | And 2 more authors.
Physics of Life Reviews | Year: 2015

It is increasingly recognized that a key component of successful infection control efforts is understanding the complex, two-way interaction between disease dynamics and human behavioral and social dynamics. Human behavior such as contact precautions and social distancing clearly influence disease prevalence, but disease prevalence can in turn alter human behavior, forming a coupled, nonlinear system. Moreover, in many cases, the spatial structure of the population cannot be ignored, such that social and behavioral processes and/or transmission of infection must be represented with complex networks. Research on studying coupled disease-behavior dynamics in complex networks in particular is growing rapidly, and frequently makes use of analysis methods and concepts from statistical physics. Here, we review some of the growing literature in this area. We contrast network-based approaches to homogeneous-mixing approaches, point out how their predictions differ, and describe the rich and often surprising behavior of disease-behavior dynamics on complex networks, and compare them to processes in statistical physics. We discuss how these models can capture the dynamics that characterize many real-world scenarios, thereby suggesting ways that policy makers can better design effective prevention strategies. We also describe the growing sources of digital data that are facilitating research in this area. Finally, we suggest pitfalls which might be faced by researchers in the field, and we suggest several ways in which the field could move forward in the coming years. © 2015 Elsevier B.V..

Zhang S.,Tianjin University of Technology | Liu H.,Nankai University | Mu G.,Nankai University
Optics Letters | Year: 2012

A semianalytical Fabry-Perot model is presented to investigate the electromagnetic enhancement by double grooves in gold substrate. The influence of hybrid wave (HW) propagating along the metal surface on field enhancement is explored systematically with a HW model. Simulation results imply that the hybrid generated by one groove can affect the mode fields in the other groove after propagating along the metallic surface. Giant electromagnetic field intensity at resonance condition is found for the groove distance of 0.6? with the contribution of surface waves,which is nearly independent of the incidence wavelength and groove width. © 2012 Optical Society of America.

Yang S.,Tianjin University of Technology
19th International Conference on Industrial Engineering and Engineering Management: Engineering Management | Year: 2013

The research based on the theory of facilities management theory, and it puts forward the scientific and rational large centralized management model of Tianjin Station Facilities Project. The model solves the problem of Tianjin Railway Station Project that investors are not clear and unclear property rights, and making the equipment system achieves the desired function, and the hub project gets efficient operation, and it achieved win-win social and economic benefits. © 2013 Springer-Verlag Berlin Heidelberg.

Jia S.-Y.,Tianjin University | Zhang Y.-F.,Tianjin University | Liu Y.,Tianjin University of Technology | Qin F.-X.,Tianjin University | And 2 more authors.
Journal of Hazardous Materials | Year: 2013

Hybrid nanomaterials comprising phosphotungstic acid (PTA) and MIL-101(Cr) were prepared through one-pot synthesis and post-modification methods and then were used as adsorbents of dibenzothiophene (DBT) from simulated diesel fuels. Samples obtained by different ways (encapsulation and impregnation) were characterized by nitrogen adsorption, transmission electron microscope (TEM), X-ray diffraction (XRD), Fourier transform infrared spectrum (FT-IR) and series of adsorption experiments. The equilibrium adsorption capacities of PTA@MIL-101(Cr) illustrated that the direct introduction of PTA into MIL-101(Cr) during synthesis resulted in a 10.7% increase compared with MIL-101(Cr). However, porous hybrid adsorbent PTA/MIL-101(Cr) prepared via post-modification method exhibited lower adsorption capacity than virgin MIL-101(Cr). The theoretical maximum adsorption capacity (Q0) of PTA@MIL-101(Cr) is 136.5mg S/g adsorbent, 4.2 times of MIL-101(Cr). Even in competitive adsorption between aromatic compounds, which possess strong affinity with MOFs, and DBT, PTA@MIL-101(Cr) and MIL-101(Cr) remained their effectiveness in removal of DBT in the system. Based on these results, it can be presumed that MIL-101(Cr), modified properly, can be used as a promising adsorbent for eliminating aromatics and S-compounds in commercial fuels simultaneously. © 2013 Elsevier B.V.

Li X.,Tianjin University of Technology
Civil Engineering and Urban Planning III - Proceedings of the 3rd International Conference on Civil Engineering and Urban Planning, CEUP 2014 | Year: 2014

With the outdoor game facilities for children and the design of outdoor environment as the research topic, this paper points out that only the design with meticulous planning and with nature can be accepted, which help to achieve the ultimate aim of improving the human settlements in urban communities and the quality of outdoor recreation for children, and to motivate the vitality and frequency in outdoor social contacts among people, and to benefit the healthy development of the ecological environment in urban communities. © 2014 Taylor & Francis Group.

Zhang J.,Tianjin Polytechnic University | Shi Z.,Tianjin Polytechnic University | Wang C.,Tianjin University of Technology
Electrochimica Acta | Year: 2014

Lithium ion capacitors are assembled with pre-lithiated mesocarbon microbeads (LMCMB) anode and activated carbon (AC) cathode. The effect of pre-lithiation degrees on the crystal structure of MCMB electrode and the electrochemical capacitance behavior of LIC are investigated by X-ray diffraction (XRD) and the charge-discharge test of three-electrode cell. The structure of graphite still maintained when the pre-lithiation capacity is less than 200 mAh g-1, phase transition takes place with the increase of pre-lithiation capacity from 250 mAh g-1 to 350 mAh g-1. Pre-lithiation degrees of MCMB anode greatly affect the charge-discharge process and behavior, which impact on the electrochemical performance of LIC. The LIC with pre-lithiation capacity of 300 mAh g-1 has the optimal electrochemical performance. The energy density of LIC300 is up to 92.3 Wh kg-1, the power density as high as 5.5 kW kg-1 and the capacity retention is 97.0% after 1000 cycles. The excellent electrochemical performance benefits from the appropriate pre-lithiation capacity of negative electrode. The appropriate pre-lithiation ensures the working voltage of negative electrode in low and relative stable charge-discharge platform corresponding to the mutual phase transition from the second stage graphite intercalation compound (LiC12) to the first stage graphite intercalation compound (LiC6). The stable charge-discharge platform of negative electrode is conductive to the sufficient utilization of AC positive electrode. © 2014 Published by Elsevier Ltd.

Wang C.,Tianjin University | Fu L.,Tianjin University | Tong X.,Tianjin University | Tong X.,Tianjin University of Technology | And 2 more authors.
Carbohydrate Research | Year: 2012

The highly efficient and selective production of 5-hydroxymethylfurfural (HMF) from sucrose has been achieved in the presence of metal chlorides and ammonium halides under mild conditions. Notably, an 87% yield of HMF from sucrose was obtained with a catalyst system composed of CrCl 3 and NH 4Br at 100 °C for 1.0 h in N,N-dimethylacetamide (DMAc) solvent. The effect of the reaction temperature and time was investigated in detail, and a possible mechanism for this catalytic process has been proposed. In addition, NH 4Br is an effective promoter in the conversion of glucose and fructose to HMF. © 2011 Elsevier Ltd. All rights reserved. 29.

Pan J.,Tianjin Polytechnic University | Wan D.,Tianjin Polytechnic University | Gong J.,Tianjin University of Technology
Chemical Communications | Year: 2011

This paper describes the synthesis and application of PEGylated liposome-coated quantum dots (QDs)/mesoporous silica core-shell nanoparticles (NPs) for molecular imaging. This system increases biocompatibility and stability of QDs, thus improving the imaging effects in labeling of cancer cells. © 2011 The Royal Society of Chemistry.

Tang H.,University of Macau | Li Y.,Tianjin University of Technology
IEEE/ASME International Conference on Advanced Intelligent Mechatronics, AIM | Year: 2012

This paper presents the analytical modeling and optimal design of the flexure-based lever displacement (FBLD) amplifiers for a piezo-stage, which can be selected to drive at two different points on the stage. In order to overcome the effect of displacement loss of the FBLD amplifiers caused by the combination of the lever bending and the flexure stretching, the bearing modeling and analysis for the levers are conducted. Then, a series of optimal designs are carried out accordingly. Afterwards, mechanism modeling based on matrix method is implemented. Furthermore, the performance of the stage with the optimized amplification levers is evaluated by finite-element analysis (FEA). It indicates that the amplification ratio in two axes is about 4, thus the maximum workspace of the stage can reach up to around 341 μm × 341 μm without material failure, which makes the proposed dual-mode stage possess a good performance for the micro/nano manipulations with the requirements in different levels. © 2012 IEEE.

Tang H.,Macau University of Science and Technology | Li Y.,Tianjin University of Technology
IEEE International Conference on Intelligent Robots and Systems | Year: 2012

A compliant 2-DOF nanopositioning stage with a novel concept of dual-mode driven is proposed in this paper aiming to improve the scanning performance of the Atomic Force Microscope (AFM). The stage is featured with nanoscale positioning precision, high bandwidth, long scanning range and fully decoupled structure, which can be selected to work in dual working modes. Based upon the matrix method, the discussions in terms of output compliance, input stiffness and dynamics modeling via Lagrange equation have been performed in detail. Moreover, a series of optimal designs have been implemented using Particle Swarm Optimization (PSO) algorithm. The results of the finite-element analysis (FEA) indicate that the first natural frequency is approximated 583 Hz, the amplification ratio in two axes is about 4, thus the maximum scanning range can reach up to around 341 μm × 341 μm without material failure, while the cross-coupling between the two axes is kept within 2%. All the results indicate that the presented mechanism possesses a good performance for high-rate AFM scanning. © 2012 IEEE.

Ren H.-T.,Tianjin University | Jia S.-Y.,Tianjin University | Wu S.-H.,Tianjin University | Liu Y.,Tianjin University of Technology | And 2 more authors.
Journal of Hazardous Materials | Year: 2013

Manganese (hydr)oxides are powerful oxidants mediating the transformation of As(III) to As(V) under natural conditions, however, the presence of Mn(II) on the oxidation of As(III) in the pH range of 7.0-9.0 has not been reported so far. In this study, abiotic oxidation of Mn(II) to amorphous Mn(III, IV) (hydr)oxides (MnOx) on magnetite and hematite was confirmed, and the impact of newly formed MnOx on the fate of As(III) was investigated. With the addition of Mn(II) into As(III)-preloaded systems, the dissolved and the adsorbed As(III) was oxidized to As(V) at high pH, and Mn(II) mobilized the adsorbed As(III) and As(V) in hematite system. High production of dissolved As(V) and significant mobilization of As(III) were even more significant in hematite suspension (total As was 18.96mgL-1 after 60h at pH 8.62) with simultaneous addition of Mn(II) and As(III), while magnetite showed a higher capacity for the retention of As(III) and As(V). It could therefore be deduced that the newly formed MnOx on iron oxides could oxidize the dissolved and the adsorbed As(III) to As(V). In addition, the MnOx formed at high pH would take up the sorption sites previously occupied by the adsorbed As(III), and then mobilized a fraction of the adsorbed As(III) into solution. The present study reveals that MnOx formed via abiotic oxidation on iron oxides plays an important role in the oxidation and mobilization of both dissolved and adsorbed As(III) in aquatic environment. © 2013 Elsevier B.V.

Liu X.,National Taiwan University | Li Y.,Texas A&M University-Commerce | Li Y.,Tianjin University of Technology | Lee J.W.,National Taiwan University | And 3 more authors.
Applied Catalysis A: General | Year: 2012

Supported gold nanocatalysts have been reported to be active in selective hydrogenation of acetylene. In this work, SiO 2 supported Au-Ag bimetallic catalyst is studied in the selective hydrogenation of acetylene in excess ethylene. Au and Ag were reductively deposited on a silica surface functionalized by APTES (3-aminopropyltriethoxysilane). They form Au-Ag alloy nanoparticles of very small size. The catalytic activity of Au-Ag bimetallic system showed better catalytic activity at high temperature than that of monometallic gold catalyst. According to the TEM and XRD results, Ag stabilized the nanoparticles against sintering during high temperature calcinations. Non-thermal O 2 plasma was applied to remove the APTES under mild conditions instead of high temperature calcination. The results showed that the conversion of acetylene was much higher over Au-Ag/SiO 2 catalyst pretreated by O 2 plasma than that of pretreated by calcination at 500 °C, although the latter catalyst had similar particle size. © 2012 Elsevier B.V.

Zhao H.,Tianjin University | Ye F.,Tianjin University | Ye F.,Tianjin University of Technology
Applied Surface Science | Year: 2015

WSiN coatings with silicon content ranging from 0 to 27.7 at.% were deposited by reactive magnetron sputtering technique. The structure, mechanical, tribological properties and corrosion performance were investigated by XPS, XRD, SEM, HRTEM, nano-indentation CSM, ball-on-disc tribo-meter, AFM, Bruker 3D Profiler and corrosion testers. The results indicated that the incorporation of silicon did not affect the cubic structure. WSiN coatings consist of WSiN and amorphous Si3N4 phases. The incorporation of silicon induced the crystallite size refinement and reduced the average roughness. The growth pattern changed from continuous columnar to discontinuous columnar. The hardness first increased and then decreased. The highest hardness of 37.0 GPa was maintained as the silicon content was 13.4 at.%. The friction coefficient and wear rate of WSiN coatings first decreased and then increased with increasing silicon content. The best wear resistance was found for the coating which has the highest hardness. The corrosion resistance of the substrate which coated with W2N or WSiN coatings was superior to the bare substrate. The corrosion resistance of the W2N coatings was improved by doping some silicon content. © 2015 Elsevier B.V. All rights reserved.

Meng X.,University of Macau | Li Y.,Tianjin University of Technology
2012 IEEE International Conference on Information and Automation, ICIA 2012 | Year: 2012

In this paper, a (t, n) threshold signature scheme is constructed without a trusted party, which has provable security in Mobile Ad Hoc Network, and its security fits with terminal device with limited resource. Any participant can compute the system public key, but can not recover the system secret key without any other t-1 participants' help. In this proposed scheme, ECC-based threshold polynomial is intrinsically safer and easier to realize than the presented schemes' based on prime-field. A verifiable threshold signature scheme is proposed such that all participants must provide confidential and verifiable information λ j each other. We design a new bilinear pairing-based threshold signature scheme which is efficient in terms of both the communication overhead and the computational requirement. So the new threshold signature scheme is more secure, verifiable, and efficient compared with the presented schemes for Mobile Ad Hoc Network. © 2012 IEEE.

Xu L.,Tianjin University of Technology | Mathiyazhagan K.,Indian National Institute of Engineering | Govindan K.,University of Southern Denmark | Noorul Haq A.,Indian National Institute of Engineering | And 2 more authors.
Resources, Conservation and Recycling | Year: 2013

Environmental sustainability is of great concern among world organizations and enterprises due to recent trends in global warming. Many developed nations have put in place stricter environmental regulations. Industries in such nations have established full-fledged systems to adopt environment friendly operation strategies to lower their overall carbon footprint. Currently, there is increased awareness among customers even in developing countries about eco friendly manufacturing solutions. Multi-national firms have identified economies of developed nations as a potential market for their products. Such organizations in developing countries like India and China are under pressure to adopt green concepts in supply chain operations to compete in the market and satisfy their customers' increasing needs. This paper offers a comparative study of pressures that impact the adoption of Green Supply Chain Management (GSCM). Thirty two pressures are identified from extensive literature reviews and they are classified into five distinct groups based on their similarities. A detailed questionnaire is prepared and circulated among industries in various sectors. Industries were requested through this survey to rate the impact of each pressure. Two independent hypotheses were formulated from literature to test the nature of impact and the differences affecting Indian industries. Statistical data analysis through one-way single factor Analysis of Variance (ANOVA), followed by pair-wise comparison of means using Tukey's test was used. The analysis was performed for different sectors and different scales of production categories. The results and their implications are also discussed. © 2013 Elsevier B.V. All rights reserved.

Wu H.,Tianjin University of Technology
Journal of Forestry Research | Year: 2015

Platycladus orientalis is one of the most popular afforestation species and greening species for water management in arid and semi-arid regions of northern China. We applied various models to estimate and validate artificial P. orientalis forest evapotranspiration features with the goal of accurately estimating the water use of a P. orientalis plantation. The American Society of Civil Engineers Evapotranspiration–Penman–Monteith model (APM) and FAO56–Penman–Monteith model (FPM) are extensively applied for vegetation evapotranspiration estimation because their reliability has been validated by many scholars. The Priestley–Taylor model (PT) and Hargreaves model (HS) require only the daily maximum temperature, daily minimum temperature and solar radiation to estimate evapotranspiration and are thus widely applied to grasslands but not to forests. We used the Energy Balance Bowen Ratio (EBBR) system to validate the accuracy of the four models. The results indicated that: (1) Compared to the EBBR measurement annual value, APM was the most accurate, followed by FPM, and PT; (2) During the year, the accuracies of the four models varied. APM and FPM underestimated evapotranspiration during June, July and August, whereas PT and HS overestimated evapotranspiration during this period. In the rest of the year, the estimation accuracies were reversed; (3) An analysis of the possible reasons indicated that wind speed, air temperature and precipitation were the most important contributors. High temperatures were measured in June, July and August, which led to an overestimation by PT and HS because these two models only calculated the temperature and radiation without vegetation information. Underestimation also occurred when a low temperature was recorded. Though APM and FPM addressed both meteorological and vegetation factors, slight deviations still existed; and (4) The two models were modified based on EBBR-measured data. Relative humidity was introduced into PT, and parameter “A” in the HS estimation model was amended to 1.41. The accuracy of the modified models significantly increased. The study highlighted the application, comparison and improvement of four models in estimating evapotranspiration and offers more approaches to assess forest hydrological functions. © 2015 Northeast Forestry University and Springer-Verlag Berlin Heidelberg

Wang M.,Key Laboratory of Display Materials and Photoelectric Devices | Xie F.,Tianjin University of Technology | Li W.,Key Laboratory of Display Materials and Photoelectric Devices | Chen M.,Key Laboratory of Display Materials and Photoelectric Devices | Zhao Y.,University of Wollongong
Journal of Materials Chemistry A | Year: 2013

Various kinds of copper sulfides (CuS, a mixture of Cu7S 4-CuS and Cu9S5) were synthesized by simply adjusting the amount of copper chloride and sodium sulfide in a solvothermal process. The different molar ratios of copper chloride and sodium sulfide result in the formation of different kinds of copper sulfides with various morphologies, such as tiny particle, hexagonal plate and octahedron. The products were characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. And the optical properties of the products were recorded by means of UV-Vis absorption and photoluminescence spectroscopy. Moreover, due to the presence of visible light, we found that the catalytic activities of the products for oxidation and decomposition of Rhodamine B with the assistance of hydrogen peroxide were enhanced, and the degradation efficiency of RhB was increased from 40% to 98% in 15 minutes at room temperature. © 2013 The Royal Society of Chemistry.

Li Z.R.,Tianjin University | Mi W.B.,Tianjin University | Wang X.C.,Tianjin University of Technology | Bai H.L.,Tianjin University
Journal of Magnetism and Magnetic Materials | Year: 2015

Exchange bias has been observed in the full-nitride epitaxial γ′-Fe4N/CoN bilayers. With the increase of temperature, the sign of exchange bias (EB) is inverse, which is independent on the cooling field and training effect. This novel behavior appears in the bilayers with different CoN and γ′-Fe4N thicknesses. The inversion of EB sign not only occurs at low temperatures, but also takes place even at 200 K for the 10 and 12 nm thick CoN layer. With the decreased γ′-Fe4N layer thickness, the inversion temperature of EB sign shows a roughly increased tendency. For the bilayer with a 4 nm-thick γ′-Fe4N, the interfacial magnetization reversal presents a complex trend, which is considered as the combined actions of the disordered ferromagnetic spins and various competed magnetic structures. This new manifestation of EB has been discussed in terms of the complicated interfacial spin structures and frustration effects due to the competition between the ferromagnetic and antiferromagnetic exchange interactions at the interface. © 2014 Elsevier B.V. All rights reserved.

Nie D.,Tianjin University of Technology
Applied Mechanics and Materials | Year: 2013

The bidding control price is the highest price of the project bidding price which is set beforehand. The appropriately bidding control price which tenders compile can embody the excellent enterprise's competitiveness, improve the efficiency of bidding and reduce the project cost. So how to forecast the bidding control price accurately and rapidly has important significance for the bidding work. In this paper, based on the gray system theory and taking the interaction between main variables of the bidding control price into due consideration, the gray prediction model is established to forecast the bidding control price. The building, calculation, error precision of the model is explained in details. Finally, the result is verified by real projects. © (2013) Trans Tech Publications, Switzerland.

Li Q.,Tianjin University of Technology
Lecture Notes in Electrical Engineering | Year: 2012

Based on the analysis on the application of e-commerce application, a hierarchy e-commerce index system is constructed. Analytic hierarchy process has been used to quantify, index system and its feasibility is verified, and finally a linear function evaluation model is concluded, which is used to evaluate the application degree of e-commerce of enterprise. © Springer-Verlag Berlin Heidelberg 2012.

Wu X.W.,Tianjin University of Technology
Applied Mechanics and Materials | Year: 2013

the development of low carbon building is not only the requirement of current economic transition,it is also the realistic choice to implement Scientific Development Concept and to build "two type society". This paper briefly describes the connotation of low carbon buildings, and then illustrates the low-carbon economy background, the necessity of low carbon building development, and finally put forward the corresponding path selection. © (2013)Trans Tech Publications,Switzerland.

Gu X.,Nankai University | Wang J.,Nankai University | Liu X.,Nankai University | Zhao D.,Nankai University | And 3 more authors.
Soft Matter | Year: 2013

To develop poly(amino acid)s with temperature-sensitivity, a series of polyaspartamides with isopropylamide and hydroxyalkylamide pendant groups were synthesized by a successive aminolysis reaction of polysuccinimide. The structure of the resulting polymers was examined by 1H NMR and FT-IR. The polyaspartamide derivatives self-assembled into nanoparticles in water and showed sharp temperature-responsive phase transition behaviour. The phase transition temperature (Tp) could be modulated by the hydrophilic-hydrophobic balance of the copolymer controlled by altering the composition of both pendants. Besides, an antitumor agent, doxorubicin, was successfully loaded into the polymeric nanoparticles via a dialyzing method. The drug release profile was temperature-dependent accelerating significantly above the Tp and decelerating below the Tp. This easily prepared polymeric nanoparticle with excellent biocompatibility and tunable temperature responsiveness has significant potential for controlled drug release applications. This journal is © 2013 The Royal Society of Chemistry.

Zeng X.,University of Paris Descartes | Zeng X.,Tianjin University of Technology | Bornholdt C.,University of Paris Descartes | Over D.,University of Paris Descartes | Reinaud O.,University of Paris Descartes
Organic Letters | Year: 2011

The first four members of a new family of C 3v-symmetrical "two-story" calix[6]aza-cryptands have been synthesized. These large funnel shaped aza-ligands are formed through introduction of three aromatic arms as spacers onto the small rim of a calix[6]arene and subsequently capped with the tripodal aza caps tacn [1,3,5-triazacyclononane] or tren [tris(aminoethyl)amine]. A key feature for an efficient final 1:1 macrocyclization appears to be an adequate geometrical fit between the extended calixarene scaffold and the aza caps. © 2011 American Chemical Society.

Xiao S.,Macau University of Science and Technology | Li Y.,King Abdulaziz University | Li Y.,Tianjin University of Technology
Robotics and Computer-Integrated Manufacturing | Year: 2014

Piezoelectric actuator, which is widely used in micro-/nano-manipulation, often demonstrates nonlinear rate-dependent hysteresis characteristics. This paper proposes a Bouc-Wen model based inverse hysteresis compensator for rate-dependent hysteresis in PZT. The classical Bouc-Wen model for hysteresis is introduced firstly, then the identification of the parameters through the particle swarm optimization (PSO) method is conducted. A novel modified inverse Bouc-Wen model is proposed and verified through experiment. The proposed modified inverse Bouc-Wen model with a parametric selector constructs a real-time online rate-dependent compensator for handling PZT's hysteresis. During experiments of tracking multi-frequency composed of signals, the rate-dependent hysteresis of the PZT can be consistently compensated. The experimental results show that the proposed open loop hysteresis canceling method greatly improves the PZT's tracking control accuracy. © 2013 Elsevier Ltd.

Chen J.,Tianjin University | Xin F.,Tianjin University | Qin S.,Tianjin University | Yin X.,Tianjin University of Technology
Chemical Engineering Journal | Year: 2013

A series of ZnS photocatalysts were prepared via simple precipitation, ion-exchange and hydrothermal methods, respectively; meanwhile, various Ni-doped ZnS photocatalysts were synthesized by hydrothermal method. The obtained photocatalysts were characterized by XRD, UV-Vis, BET and SEM, and used for photocatalytically reducing CO2 to produce methyl formate in methanol, which worked as both solution of absorbing CO2 and sacrificial reagent. Under the analysis of an on-line ATR-FTIR spectroscopy for CO2 in methanol and detection of GC for the products, the experimental results showed that the ZnS photocatalysts prepared by hydrothermal method had higher photocatalytic activity, which increased rapidly with the increasing hydrothermal time and reached a maximum at 24h. Besides, the doping of Ni2+ could further enhance this activity, the optimal content of Ni dopant was about 0.3wt% and the corresponding methyl formate production rate was 121.4μmolg-1h-1. The high photocatalytic activity could be attributed to that the Ni2+ doping facilitated the separation of photogenerated electron-hole pairs and reduced their recombination probability. © 2013 Elsevier B.V.

Zhao J.-P.,Tianjin University of Technology | Zhao J.-P.,Nankai University | Zhao R.,Nankai University | Yang Q.,Nankai University | And 4 more authors.
Dalton Transactions | Year: 2012

The Cu II ions usually have different coordinated geometry to other 3d ions, especially Ni II and Co II ions, in azido-carboxylate mixed ligand systems. That provides a potential way to synthesize rare heterometallic 3d-3d azido complexes with peculiar magnetic properties. Assembling Cu II, M II (M = Ni and Co), azido and nicotinic acid in hydrothermal condition, two novel isomorphic 3D heterometallic 3d-3d azido complexes, [CuM(N 3) 2(nicotinate) 2] ∞ (M = Ni II for 1 and Co II for 2) were obtained. The structure of the complexes can be described as EO azido and syn,syn carboxylate mixed bridged spin sequence chains (-1/2-J 1-1-J 2-1/2- for 1 and -1/2-J 1-3/2-J 2-1/2- for 2) linked by the pyridyl groups. Dominant ferromagnetic interactions were observed between the Cu II and M II ions in the chains despite the largest M-N-M angle of about 129° in the 3d metal azido-carboxylate mixed coordinated systems and weak antiferromagnetic interactions between the chains. At low temperature, a spin-flop phase transition was present in the Co II involved complex 2. © The Royal Society of Chemistry 2012.

Zhao D.-X.,Tianjin University of Technology
Optoelectronics Letters | Year: 2014

Due to the encephalic tissues are highly irregular, three-dimensional (3D) modeling of brain always leads to complicated computing. In this paper, we explore an efficient method for brain surface reconstruction from magnetic resonance (MR) images of head, which is helpful to surgery planning and tumor localization. A heuristic algorithm is proposed for surface triangle mesh generation with preserved features, and the diagonal length is regarded as the heuristic information to optimize the shape of triangle. The experimental results show that our approach not only reduces the computational complexity, but also completes 3D visualization with good quality. © 2014 Tianjin University of Technology and Springer-Verlag Berlin Heidelberg.

Wei T.,Civil Aviation University of China | Li C.P.,Tianjin University of Technology | Zhou Q.J.,Civil Aviation University of China | Zou Y.L.,Civil Aviation University of China | Zhang L.S.,Civil Aviation University of China
Materials Letters | Year: 2014

Er3+ doped intergrowth Bi4Ti3O 12-SrBi4Ti4O15 (BIT-SBTi: xEr 3+) ceramics have been synthesized by a solid state processing. Upconversion (UC) luminescence and ferroelectric (FE) polarization properties were first investigated. Bright UC green emission, originating from ( 2H11/2,4S3/2)-4I 15/2 transitions, was confirmed to be a two-photon energy transfer process by pumping laser power dependence of emission intensity. The UC green luminescence can be seen by the naked eye at room temperature. Furthermore, it is found that a proper Er3+ doping can also remarkably enhance the FE polarization of BIT-SBTi: xEr3+. The results indicated that BIT-SBTi: xEr3+ with good UC emission and high FE polarization can act as a potentially multifunctional optical-electro-material. © 2013 Elsevier B.V.

Zhao J.-P.,Nankai University | Zhao J.-P.,Tianjin University of Technology | Yang Q.,Nankai University | Liu Z.-Y.,Tianjin Normal University | And 5 more authors.
Chemical Communications | Year: 2012

A magnetic isolated chain-based substituted cobalt-formate framework was obtained with isonicotine as a spacer. In the chain, canted antiferromagnetic interactions exist in between the Co II ions, and slow magnetic relaxation is detected at low temperature. For the block effects of the isonicotine ligands, the complex could be considered as a peculiar example of a weak ferromagnetic single-chain-magnet. © 2012 The Royal Society of Chemistry.

Yu X.,Tianjin University of Technology
Infrared Physics and Technology | Year: 2014

This paper proposes an image segmentation method for blurred trace infrared images, exploring statistical properties of blurred infrared data to segment target regions. I consider the function of immune factors for blurred infrared image segmentation, combined to the template algorithm framework. First, all of the pixel antigens are divided into three classes by innate recognition factors: target antigens, background antigens and blurred antigens. Next, the innate presentation factors present template characteristics as new features for each antigen. Finally, target and background antigens are used for generating mature adaptive immune factors, and these mature factors will recognise each blurred antigen into two classes: a target pixel or a background pixel. Experimental results indicate that the superstring galaxy template algorithm can improve the target segmentation rate and reduce the segmentation error rate. © 2014 Elsevier B.V. All rights reserved.

Kong J.,Tianjin University of Technology | Kong J.,University of Georgia | Schleyer P.V.R.,University of Georgia | Rzepa H.S.,Imperial College London
Journal of Organic Chemistry | Year: 2010

(Figure presented) Along with the directly related Wagner-Meerwein camphene hydrochloride-isobornyl chloride rearrangement, the racemization of isobornyl chloride involves intermediate carbocation-anion ion pairs; both processes have become mechanistic icons in organic chemistry. The two known racemization pathways, involving either a hydride transfer or a methyl migration, are observed to be concurrent. However, prior quantitative computational modeling has not been able to reproduce the fine kinetic balance of these processes. We demonstrate that a density functional approach, which includes two explicit solvent molecules embedded in a continuum solvent field, coupled with full geometric optimization using smoothed solvent cavities and free energy calculation, yields results in accord with experiment. Alternative racemization routes also have been explored. © 2010 American Chemical Society.

Xiao S.,University of Macau | Li Y.,Tianjin University of Technology
IEEE Transactions on Control Systems Technology | Year: 2013

Hysteresis of a piezoelectric actuator is rate-dependent, but most hysteresis models are based on elementary rate-independent models, which are not suitable for modeling actuator behavior across a wide range of frequencies. This paper presents a novel modified inverse Preisach model to compensate the hysteresis of a piezoelectric actuator at varying frequency ranges. The classical Preisach model for hysteresis is introduced first, the identification of \mu-function through least square method is conducted afterwards. The linearity property of the Preisach model is analyzed and verified by experiment. A novel modified inverse Preisach model featured with weighed sum of μ -density functions is proposed, which is based on the linearity property. The fast Fourier transform method is adopted to select the proper μ-density functions and weights to form a real-time online rate-dependent compensator for piezoceramic (PZTs) hysteresis. During experiments with tracking multifrequency composed signals, we have observed that the hysteresis features of the PZT can be consistently compensated. The experimental results show that the proposed open-loop hysteresis adjust method greatly improves the tracking control accuracy of the PZT. © 2013 IEEE.

Han S.-D.,Nankai University | Zhao J.-P.,Nankai University | Zhao J.-P.,Tianjin University of Technology | Chen Y.-Q.,Nankai University | And 4 more authors.
Crystal Growth and Design | Year: 2014

A polynuclear manganese complex composed of alternating cyclic tetramer and monomer has been solvothermally prepared and magnetically characterized. Magnetic analyses indicate that the title compound shows spin-canting behavior. © 2013 American Chemical Society.

Feng N.,Tianjin University | Mi W.,Tianjin University | Wang X.,Tianjin University of Technology | Bai H.,Tianjin University
RSC Advances | Year: 2014

The geometry, bonding, electronic and magnetic properties of Fe4N/oxides (MgO, BaTiO3 and BiFeO3) interfaces with different configurations are performed using first-principles calculations. The n- and p-type doping of MgO are induced in FeIFeII/MgO and (FeII)2N/MgO interfaces, respectively. The metallic characteristics are induced in BaTiO3 by contact with FeIFeII termination, followed by p-type doping in the (FeII)2N/BaO interface and n-type doping in the (FeII)2N/TiO2 interface. The interfacial dipole due to charge rearrangement may induce the Fermi level pinning in the Fe4N/MgO and (FeII)2N/BaTiO3 systems. The deposition of Fe4N on BiFeO3 leads to a metallic character of BiFeO3 with total magnetic moments of 0.33-1.54 μB. The different electronic and magnetic characters are governed by interfacial bonding between Fe4N and oxides. These findings are useful for the future design of Fe4N/oxides based spintronics devices. © the Partner Organisations 2014.

Zhang D.,Tianjin University | Gao H.,Tianjin University | Gao L.,Tianjin University | Gao L.,Tianjin University of Technology | Ma J.,Tianjin University
Polymer Testing | Year: 2013

A series of uniaxial ratcheting experiments on anisotropic conductive adhesive film (ACF) were conducted under stress-control at elevated temperature using a DMA-Q800. The ratcheting behavior of ACF specimens with different hygrothermal aging times was investigated at room temperature and 120 C. The effects of loading rate, mean stress and stress amplitude on the ratcheting behavior of unaged and aged specimens were compared. The results show that the ratcheting strains of aged specimens are smaller than those of unaged specimens under the same experimental conditions. The cycling stability of aged specimens is increased by hygrothermal aging. At room temperature, with the increase of aging time, the ratcheting strains of aged specimens increase with hygrothermal aging time when it is less than or equal to 96 h but, however, decrease when it exceeds 96 h. At 120 C the ratcheting strains of ACF only decrease with the increase of hygrothermal aging time. Additionally, the effects of loading rate, mean stress and stress amplitude on the ratcheting behavior of unaged and aged ACF are different and their effects are weakened by hygrothermal aging. © 2013 Elsevier Ltd. All rights reserved.

Wang C.,Tianjin University | Dong X.-Y.,Tianjin University | Jiang Z.,Tianjin University of Technology | Sun Y.,Tianjin University
Journal of Chromatography A | Year: 2013

Novel composite cryogel monoliths were fabricated by incorporating polymeric resin particles and grafting anion-exchange groups on the pore wall surfaces. The embedded resin particles in different size distributions were prepared by grinding poly(glycidyl methacrylate-ethylene glycol dimethacrylate) monoliths. Observations by scanning electron microscopy clearly indicated that the composite cryogel had interconnected large pores (10-100. μm in width), similar to normal (pure) cryogel. However, the composite material had very rough pore walls, which provided larger surface area for protein adsorption. As a result, the dynamic binding capacity of bovine serum albumin (BSA) on the composite cryogel bed reached 6. mg/mL bed (flow velocity, 5. cm/min), which was 2.8 times higher than a cryogel bed without embedding the ground resin particles. The capacity value was also much higher than the BSA capacities of cryogel beds reported in literature (1-4. mg/mL). Though the capacity decreased by about 1. mg/mL with the increase of flow rate from 0.5 to 5. cm/min, it then kept almost unchanged till a flow rate up to 15. cm/min. The height equivalent to a theoretical plate of the composite bed was in the range of 1.1-1.4. mm, and kept nearly constant in a flow rate range of 5-20. cm/min. The results indicated that the composite cryogel bed offered a large improvement in protein adsorption capacity and was suitable for high-speed protein chromatography. © 2012 Elsevier B.V..

Tang Y.-R.,University of Macau | Li Y.,Tianjin University of Technology
2013 IEEE International Conference on Information and Automation, ICIA 2013 | Year: 2013

The UAV quadrotor is considerably difficult to be controlled due to its inherently unstable and complex multi-variable properties. To realize the control, a nonlinear dynamic model is firstly derived and formulated. A control approach employing hierarchical multiple-layer structure is then developed. The detailed hardware components, software as well as the working principle of the system are described. The entire UAV control system is tested and verified in actual flight tests. © 2013 IEEE.

Rostamnia S.,Islamic Azad University at Maragheh | Xin H.,CAS Qingdao Institute of Bioenergy and Bioprocess Technology | Liu X.,Tianjin University of Technology | Lamei K.,Islamic Azad University at Maragheh
Journal of Molecular Catalysis A: Chemical | Year: 2013

Sonicated catalytically amount of the SBA-15/SO3H nanoreactor with organic substrate was found to be an efficient, ultra-fast and waste-free green approach for the synthesis of the indazolophthalazinetriones, polyhydroquinolines and α-aminophosphonates as models of organic reactions. The advantages of present combined method are the use of a low scale catalyst, simple procedure with an easy filterable work-up method, waste-free, green and direct synthetic entry to excellent yield of products in a high reusability and a short reaction time. SBA-15 nanoreactor anchored covalently bonded PrSO3H organic groups, to produce organic-inorganic mesochannels, in reaction condition (combined ultrasound/nanoreactor system) as catalyst provide a synergistic means of an efficient approach of the reactants to acidic sites, and suitable mesochannels to drive out the products and water for next recycles. © 2013 Elsevier B.V. All rights reserved.

Li Y.,Tianjin University of Technology | Wu Z.,University of Macau
Mechanism and Machine Theory | Year: 2016

A novel 3-DOF translational compliant mechanism based on flexure hinges is designed, analyzed and simulated in this paper. The mechanism is completely decoupled in XY directions, while there is a very small parasitic motion in Z direction when the XY axes are driven due to the lack of symmetry in Z direction. The pseudo-rigid-body model (PRBM) of the mechanism is established to analyze the relationship between the stiffness of the beam and the input displacement. Considering the flexible characteristics and displacement loss of mechanism, the displacement transformation efficiency from the input-end to the output-end is calculated firstly in the flexure-based micromanipulator field. To obtain the natural frequencies of the mechanism, the Hamilton's principle is successfully used to establish the dynamic model. The analytical results are validated by the finite element model, which indicate that the calculations and designs for the compliant mechanism are feasible. The maximal coupling error is only 1.82% when input displacement is maximal. The dynamic simulation using the backstepping dynamic surface control (BDSC) method is successfully applied in the compliant mechanism to obtain a good tracking performance, the tracking errors gradually decrease along with the input frequency reduction. © 2016 Elsevier Ltd. All rights reserved.

Meng Q.,Macau University of Science and Technology | Li Y.,Tianjin University of Technology
2013 IEEE/ASME International Conference on Advanced Intelligent Mechatronics: Mechatronics for Human Wellbeing, AIM 2013 | Year: 2013

Compliant joints can functionally act as connectors as the traditional rigid joints in compliant mechanisms. A new compliant joint that composed of revolute together with prismatic is proposed in this paper. Closed form equations for describing the stiffness and stress characteristics are derived based on the Castigliano's displacement theorem. Two comparisons that made with two common flexure hinges (corner-filleted flexure hinges and circular flexure hinges) indicate that the new joint is more flexible and produces low stress concentrations than circular and corner-filleted flexures in terms of being a revolute joint. In addition, the proposed joint can implement axial translational motion due to decreasing axial stiffness. These predictions are confirmed by finite element simulations. © 2013 IEEE.

Ji D.,Tianjin University of Technology
Advanced Materials Research | Year: 2014

To ensure the normal operation of the coal mine production and the demand for the safety management of the coal mine is increasing. the management of the coal mining explosive library is more important. © (2014) Trans Tech Publications, Switzerland.

Zhang G.,University of Macau | Li Y.,Tianjin University of Technology
2013 6th International Conference on Advanced Computational Intelligence, ICACI 2013 - Proceedings | Year: 2013

Orthogonal Experimental Design (OED) method is usually used to study the effect of several factors simultaneously and the best combination of factor levels can be found in several tests. The Particle Swarm Optimization (PSO) can utilize OED to improve the searching ability. However, the main effect of OED holds only when no or weak interaction of factors exists. This limitation of OED makes PSO search effective on unimodal or simple problems but very vulnerable on complex multimodal problems. This paper presents an effective method utilizing OED on multimodal problems. A new vector is formed through learning particle's previous and neighborhood's best vector. Instead of treating the new vector as exemplar for others to follow, this new vector is treated as base vector which needs to be explored further. Experimental studies on a set of test functions show that OED method used in this way has better robustness and converges closer to the global optimum than several other peer algorithms. © 2013 IEEE.

Lin W.,Nankai University | Miao Y.,Tianjin University of Technology | Zhang H.,Nankai University | Liu B.,Nankai University | And 2 more authors.
Applied Physics Letters | Year: 2013

A compact magnetic field sensor has been proposed based on multimode interference effects. It consists of typical multimode interferometer (MMI) immersed into the magnetic fluid (MF) which is formed by a section of square no-core fiber (NCF) spliced between two single-mode fibers. The transmission spectral characteristics of this MMI have been analyzed, and the spectral magnetic response of the proposed sensor has been investigated by immersing the NCF into the MF environment. The transmission response of the interference maxima exhibits a sensitivity of -0.01939 dB/Oe in the relatively linear range. Due to its low cost and compactness, this sensor would find potential applications in the measurement of magnetic field. © 2013 AIP Publishing LLC.

Han Q.,Missouri University of Science and Technology | Han Q.,Tianjin University of Technology | Lan X.,Missouri University of Science and Technology | Huang J.,Missouri University of Science and Technology | And 4 more authors.
IEEE Photonics Technology Letters | Year: 2012

In this letter, a kind of long-period fiber grating (LPFG) that is capable of simultaneous measurement of temperature and surrounding refractive index (RI) is fabricated and demonstrated. The compact LPFG is written on a piece of spliced standard single-mode fiber (SMF) and double-clad fiber (DCF) with the CO 2 laser point-by-point irradiation technique. The LPFG section in the DCF is solely sensitive to temperature, while the section of the LPFG in the SMF is sensitive to both temperature and surrounding RI. After temperature and RI calibration, the LPFG has been used to measure the RI change of ethylene glycol with the change of temperature to demonstrate its capability for dual parameter simultaneous measurement. © 2012 IEEE.

Ma J.,Tianjin University | Gao H.,Tianjin University | Gao L.,Tianjin University | Gao L.,Tianjin University of Technology | Chen X.,Tianjin University
Polymer Testing | Year: 2011

A series of uniaxial ratcheting experiments on anisotropic conductive adhesive films (ACFs) were conducted under stress-control at elevated temperature using DMA (DMA-Q800). The effects of mean stress, stress amplitude, applied temperature and loading history on the uniaxial ratcheting behavior of ACF were investigated. The results show that Young's modulus of the ACF declines rapidly with increasing temperature. The ratcheting strain increases as the mean stress, stress amplitude and temperature increased. Especially, when the temperature was over 80 °C, the ratcheting strain accumulated rapidly. There are significant differences in the uniaxial ratcheting behavior of ACF at 80 °C and 120 °C. The ratcheting strain rate at 120 °C is nearly twenty times that at 80 °C. The ratcheting strain decreases with increasing stress rate. Furthermore, the loading history also plays an important role in the progress of ratcheting. Previous cycling with higher stress amplitude greatly reduces ratcheting strain of subsequent cycling at lower stresses. © 2011 Elsevier Ltd. All rights reserved.

Sun X.,Tianjin Polytechnic University | Gao H.,Nankai University | Zhang S.,Tianjin University of Technology | Liu W.,Nankai University
Journal of Modern Optics | Year: 2013

The implementation of an axicon array is proposed for generation of regularized multiple laser filaments. The results of numerical simulations demonstrate that the transverse patterns of multiple filaments are determined by the arrangement of the axicon array. Parallel filaments are generated by each axicon unit. Meanwhile, it is shown how the the length of filaments can be increased. ©2013 Taylor & Francis.

Zhu Z.,Tianjin University of Technology | Kao C.-T.,Providence University | Wu R.-J.,Providence University
Applied Surface Science | Year: 2014

In this study, the ethanol-sensing characteristics of Ag@TiO2 nanoparticles were investigated. The morphology, structure, and formation mechanism of the Ag@TiO2 core-shell nanoparticles were carefully studied using X-ray diffraction, transmission electron microscopy, ultraviolet-visible spectroscopy, ZetaSizer Nano ZS and energy-dispersive X-ray spectroscopy. A gas sensing study showed that Ag@TiO2 is a promising sensor for detecting ethanol gas at low concentrations (below 5 ppm) at room working temperature. Ag@TiO2 exhibited a sensor response of 1.04-4.35 at the ethanol concentration from 0.15 ppm to 5 ppm. In addition, the sensor presented an excellent selectivity and stability for ethanol gas. This systematic study of the promising ethanol-sensing characteristics of Ag@TiO2 nanoparticles can facilitate the development of sensors that detect ethanol gas. © 2014 Elsevier B.V. All rights reserved.

Hou L.,Tianjin Normal University | Hou Z.,Tianjin University of Technology
Applied Mechanics and Materials | Year: 2013

Aiming at the stochastic vehicle routing problems with simultaneous pickups and deliveries, a novel discrete differential evolution algorithm is proposed for routes optimization. The algorithm can directly be used for the discrete domain by special design. Computational simulations and comparisons based on a medium-sized problem of SVRPSPD is provided. Results demonstrate that the proposed algorithm obtains better results than the basic differential evolution algorithm and the existing genetic algorithm. © (2013) Trans Tech Publications, Switzerland.

Meng X.,University of Macau | Li Y.,Tianjin University of Technology
IEEE International Conference on Automation and Logistics, ICAL | Year: 2012

A dynamic threshold key management scheme based on bilinear pairing without a trusted party is proposed in this paper. The system can dynamically add, modify and remove a member in MANET, and can change the threshold value according to the scale of the group. Adopting distributed framework generates the system key, which is constructed by all participants collectively, it is not like most presented schemes generated by Key Generation Center (KGC). In our threshold scheme, any participant can recover the system public key, but can not reconstruct the system secret key without any other-1 participants' help. The designated combiner (DC) can verify the correctness of shared secret during the recovery phase of system key. Simultaneously, the threshold polynomial based on elliptic curve cryptography (ECC) is obviously more secure and efficient than the previous schemes' polynomial based on prime-field. Additionally, we design a new feasible bilinear pairing based signcryption scheme, which is efficient in terms of both computational complexity and communication load and can realize security communication between any two participants. The security analysis shows that the proposed scheme is more feasible, secure and efficient compared with the previous schemes on Mobile Ad Hoc Network. © 2012 IEEE.

Zhao J.-P.,Nankai University | Zhao J.-P.,Tianjin University of Technology | Han S.-D.,Nankai University | Zhao R.,Nankai University | And 3 more authors.
Inorganic Chemistry | Year: 2013

Three new heterometallic formate coordination polymers formulated as [Na2Co(HCOO)4]∞ (1), [NaCo(HCOO) 3]∞ (2), and [Na2Co7(HCOO) 16]∞ (3) were obtained by adjusting the solvent and ratio of the reactants. In 1, a (4,4) cobalt formate layer is formed and the sodium ions connect the layers to form a three-dimensional (3D) framework. In 2, each formate ligand binds two Co2+ and two Na+ ions with a syn,syn,anti,anti coordination mode to form a chrial network with 4,6-connected topology. 3 is a Na+-ion-linked 3D framework based on the cobalt formate layer, which has a 10-membered metal ring. Magnetic studies indicate the existence of ferromagnetic interactions between adjacent Co 2+ ions in 1, while dominating antiferromagnetic couplings in 2 and 3. © 2013 American Chemical Society.

Zhu B.,KTH Royal Institute of Technology | Fan L.,KTH Royal Institute of Technology | Fan L.,Tianjin University of Technology | Lund P.,Aalto University
Applied Energy | Year: 2013

Recent scientific and technological advancements have provided a wealth of new information about solid oxide-molten salt composite materials and multifunctional ceria-based nano-composites for advanced fuel cells (NANOCOFC). NANOCOFC is a new approach for designing and developing of multi-functionalities for nanocomposite materials, especially at 300-600 °C. NANOCOFC and low temperature advanced ceramic fuel cells (LTACFCs) are growing as a new promising area of research which can be explored in various ways. The ceria-based composite materials have been developed as competitive electrolyte candidates for low temperature ceramic fuel cells (LTCFCs). In the latest developments, multifunctional materials have been developed by integrating semi- and ion conductors, which have resulted in an emerging insight knowledge concerned with their R&D on single-component electrolyte-free fuel cells (EFFCs) - a breakthrough fuel cell technology. A homogenous component/layer of the semi- and ion conducting materials can realize fuel cell all functions to avoid using three components: anode, electrolyte and cathode, i.e. " three in one" highlighted by Nature Nanotechnology (2011). This report gives a short review and advance knowledge on worldwide activities on the ceria-based composites, emphasizing on the latest semi-ion conductive nanocomposites and applications for new applied energy technologies. It gives an overview to help the audience to get a comprehensive understanding on this new field. © 2013 Elsevier Ltd.

Cao L.R.,Tianjin University of Technology
Applied Mechanics and Materials | Year: 2014

From the perspective of user's experience and starting from the user's emotional experience, it particularly analyzes the interactive need of user to smartphone and interactive design of smartphone. Take a specific research case of iPhone and specifically analyze the emotional experience in the interactive design of iPhone, as well as elaborately analyze specific functions of emotion in the interactive design of iPhone. © (2014) Trans Tech Publications, Switzerland.

Yang S.,South China University of Technology | Xu B.,Linyi Normal University | Zhang J.,Tianjin University of Technology | Huang X.,Fudan University | And 2 more authors.
Journal of Physical Chemistry C | Year: 2010

This paper describes a facile and effective method to construct graphene nanosheet film (GNF) by controllable adsorption of reduced graphene oxide (rGO) onto the self-assembled monolayer (SAM) of n-octadecyl mercaptan (C 18H37SH) at Au electrodes. Nyquist plots show a gradual decrease of the charge transfer resistance (Rct) of the [Fe(CN) 6]3-/4- redox couple at the GNF/SAM electrode with prolonging the self-assembly time, suggesting the controllable adsorption of rGO onto the SAM. Cyclic voltammetry (CV) studies reveal that the GNF/SAM electrodes have tunable dimensions ranging from a nanoelectrode ensemble to a conventional electrode, depending on the self-assembly time of rGO. The excellent electrocatalytic activity of the GNF/ SAM electrode toward ascorbic acid, dopamine, and uric acid further indicates that our approach is successful for the fabrication of stable GNF with excellent electrochemical properties, which is very attractive for electrochemical studies and electroanalytical applications. At the same time, as a new kind of nanosheet film electrode, the GNF electrode could be exploited in a new field for micro- and nanoelectrodes in electrochemical investigations and practical applications, e.g., electroanalysis in vivo and in vitro.© 2010 American Chemical Society..

Dong E.Z.,Tianjin University of Technology
Applied Mechanics and Materials | Year: 2013

In this paper, an tracking algorithm combing color and LBP texture features based on particle filter is proposed to overcome the disadvantages of existing particle filter object tracking methods. A color histogram and a texture histogram were combined to build the object's reference model, effectively improving the accuracy of object tracking. Experimental results demonstrate that, compared with the method based on single feature, the proposed method is highly effective, valid and is practicable. © (2013) Trans Tech Publications, Switzerland.

Gao L.,Tianjin University | Gao L.,Tianjin University of Technology | Chen X.,Tianjin University | Gao H.,Tianjin University
International Journal of Adhesion and Adhesives | Year: 2012

The shear strength behaviors of Anisotropic Conductive Adhesive Film (ACF) joints were investigated experimentally with various environments. The shear tests of ACF joints were performed at different constant temperature conditions. It is found that the shear behaviors of the ACF joints are strongly dependent on testing temperature, and the shear strength decrease and the maximum displacement increases with increasing temperature. The shear strength of ACF joints was also investigated under hygrothermal aging and thermal cycling. The results show that the shear strength of ACF joints gradually decreases at first, then quickly decreases and finally the rate of decrease slows down again with increasing hygrothermal aging time. However the shear strength of ACF joints after thermal cycling increases firstly and then decreases with increasing thermal cycling time. © 2011 Elsevier Ltd. All rights reserved.

Shi Z.,Tianjin Polytechnic University | Zhang J.,Tianjin Polytechnic University | Wang J.,Tianjin Polytechnic University | Shi J.,Tianjin Polytechnic University | Wang C.,Tianjin University of Technology
Electrochimica Acta | Year: 2015

Lithium-ion capacitors (LICs) are assembled with activated carbon (AC) cathode and pre-lithiated mesocarbon microbeads (MCMB) anode. The effect of AC cathode capacity design on the electrochemical performance of LIC is investigated by the galvanostatic charging-discharging and electrochemical impedance tests. As the designed capacity of AC positive electrode is lower than 50 mAh g-1, the working potential of negative electrode is always in the low and stable plateau, which is conductive to the sufficient utilization and the working potential stability of positive electrode. When the designed capacity of positive electrode is higher than 50 mAh g-1, the instability of negative electrode directly causes the reduced utilization and shortened working potential range of the positive electrode, which is responsible for the capacity attenuation and cycle performance deterioration of LIC. The positive electrode capacity design can realize the optimization of electrochemical performance of LIC. LIC50 exhibits the optimal electrochemical performance, high energy density up to 92.3 Wh kg-1 and power density as high as 5.5 kW kg-1 (based on active material mass of two electrodes), excellent capacity retention of 97.0 % after 1000 cycles. The power density and cycle performance of LIC can be further improved by reducing the AC positive electrode designed capacity. © 2014 Elsevier Ltd. All rights reserved.

Fu W.,Tianjin University of Technology
Transactions - Geothermal Resources Council | Year: 2014

The Great Rift Valley, an area of Eastern Africa with strong tectonic activity, offers immense potential for large-scale geothermal projects. The geothermal energy is also considered clean and renewable, so this paper presents the exploitation of geothermal energy with Kalina cycle in Kenya. The software Engineering Equation Solver (EES) is used to run the models for each op-erating condition, using the thermodynamic properties data of ammonia and water supplied with that software package. Based on the good agreements with the actual operating parameters, the thermodynamics analysis of Kalina geothermal power cycle was analyzed. The optimum of the system is influenced by the condensation temperature, ammonia mass fraction, turbine inlet pressure and the temperature of heat source. The cycle efficiency and the electricity generation for the Kalina cycle are illustrated with different conditions. The ammonia content and the pressure of turbine is needed to be less than the optimum point. The largest cycle efficiency is found 20%, but the pressure is so high that the cost of components should be considered. Thermodynamic analysis of an operational 1 MWe binary geothermal power plant in Kenya is performed. Through energy and exergy, the energy efficiency is about 6.9% and the largest exergy destruction occurs at the condenser. The utilization of the low-temperature energy will increase efficiency and reduce the consumption of the fossil fuels. Copyright © (2014) by the Geothermal Resources Council.

Zhang L.,Tianjin University of Technology
SAE International Journal of Passenger Cars - Mechanical Systems | Year: 2014

Existing multi-axle steering system designs generally use the deterministic optimization method without considering the uncertainties during the design process; therefore an actual steering movement may deviate from the ideal movement calculated by some mathematical models. In order to make design results have less sensitive to the uncertainties in the design process, some uncertainties need be taken into account at the early design stage. This paper proposes a robust optimization design method for a double front axle steering system (DFASS) of heavy trucks based on Monte Carlo method. The DFASS consists of two trapezoidal steering mechanisms (TSM) and one rocker system, and the optimization objectives of DFASS include the minimum mean value and variance of the maximum turning angle error of the TSM and rocker system. In addition, the robust optimization model includes 13 design variables which are all geometry parameters of DFASS and represented by normal distribution. Through the orthogonal experiment, we obtain the important factors affecting optimization objectives and build the response surface models of optimization objective. Based on the response surfaces, robustness design of DFASS is performed. By simulating analysis, the improved robustness of DFASS based on robust design method is approved. © 2014 SAE International.

Ding R.,Nankai University | Han Z.-L.,Nankai University | Liao Y.,Nankai University | Liao Y.,CAS Institute of Theoretical Physics | And 2 more authors.
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2014

We make a comprehensive analysis of the phenomenology in the minimal version of the cascade seesaw mechanism for tiny neutrino masses. The seesaw mechanism induces, at tree level, a neutrino mass operator at dimension nine by introducing a quadruple scalar Φ of hypercharge unity and a quintuple fermion Σ of hypercharge zero. We work in a framework that handles the complicated Yukawa couplings without losing generality. All mixing matrices are essentially expressed in terms of the vacuum expectation value of the quadruple scalar vΦ, a free complex parameter t, and known neutrino parameters. We show that the low-energy lepton-flavor-violating transitions of the charged leptons set strong constraints on the free parameters. The constraints have a significant impact on collider physics and are incorporated in our signal analysis at the LHC. We investigate the signatures of new particles by surveying potentially important channels. We find that the 4j2± signal is the most important for the detection of scalars, and the 2±22j, 3 ± 2j, and 3±2 +ET signals are quite promising for the fermions. © 2014 American Physical Society.

Liang M.,Tianjin University of Technology | Liang M.,Nankai University | Chen J.,Nankai University
Chemical Society Reviews | Year: 2013

Arylamine organic dyes with donor (D), π-bridge (π) and acceptor (A) moieties for dye-sensitized solar cells (DSCs) have received great attention in the last decade because of their high molar absorption coefficient, low cost and structural variety. In the early stages, the efficiency of DSCs with arylamine organic dyes with D-π-A character was far behind that of DSCs with ruthenium(ii) complexes partly due to the lack of information about the relationship between the chemical structures and the photovoltaic performance. However, exciting progress has been recently made, and power conversion efficiencies over 10% were obtained for DSCs with arylamine organic dyes. It is thus that the recent research and development in the field of arylamine organic dyes employing an iodide/triiodide redox couple or polypyridyl cobalt redox shuttles as the electrolytes for either DSCs or solid-state DSCs has been summarized. The cell performance of the arylamine organic dyes are compared, providing a comprehensive overview of arylamine organic dyes, demonstrating the advantages/disadvantages of each class, and pointing out the field that needs to reinforce the research direction in the further application of DSCs. © 2013 The Royal Society of Chemistry.

Huang W.,Tianjin University of Technology | Ding L.,Wuhan University
IEEE Transactions on Communications | Year: 2012

In this study, we introduce a Fuzzy Time-Dependent Network (FTDN) and analyze its shortest path problem. The FTDN is a network in which travel times are represented as fuzzy sets and are also time-dependent. Under these circumstances, the shortest path problem on the FTDN is far more complex in comparison with the shortest path problem on the existing networks. To highlight the complexity, we show that on the FTDN, "standard" shortest path algorithms (e.g., the well-known Dijkstra algorithm) are not able to come up with solutions. Subsequently, we construct a suitable method which is suitable to deal with the shortest problem. A fuzzy programming model is presented for finding the shortest path on the FTDN. The proposed model is handled through the techniques which combine mechanisms of fuzzy simulation and genetic optimization. In this particular setting, fuzzy simulation is exploited to estimate the value of uncertain functions, which do not exist in the general networks. The proposed model is evaluated with the use of numerical experimentation. A comparative analysis demonstrates that the proposed model leads to the shortest path while standard algorithms are not capable of finding the path when dealing with the shortest path problem on the FTDN. © 2012 IEEE.

Huang W.,Beihang University | Huang W.,Tianjin University of Technology | Oh S.-K.,University of Suwon | Pedrycz W.,University of Alberta | Pedrycz W.,Polish Academy of Sciences
Information Sciences | Year: 2013

In this study, we introduce a Fuzzy Time-dependent Project Scheduling Problem (FTPSP), in which activity duration times are represented in the form of fuzzy sets. The duration times are considered to be time-dependent as well. Under these circumstances, the resulting FTPSP becomes far more complex when compared with the existing project scheduling problems. The complexity stems from the fact of computing the completion time of the entire project, a core issue when dealing with project scheduling problems. We first elaborate on the difficulties with the computing of the completion time. Subsequently, we develop a computational formula for estimating the overall completion time of FTPSP. Next, we formulate the FTPSP and propose three fuzzy programming models to address various requirements arising within this framework. The proposed models are handled through techniques that combine mechanisms of fuzzy simulation and genetic optimization. In this setting, fuzzy simulation is exploited to estimate the value of uncertain functions that do not exist in conventional certain project scheduling problems. Numerical experiments are included to illustrate the effectiveness of the algorithm. © 2013 Elsevier Inc. All rights reserved.

Gao H.,Tianjin University of Technology | Gao H.,University of Montreal | Elsabahy M.,University of Montreal | Giger E.V.,University of Montreal | And 3 more authors.
Biomacromolecules | Year: 2010

Over the past 10 years, polyglycerols and their structurally related analogs have received considerable attention in the biomedical field. Poly(glycidyl methacrylate) (PGMA) is a versatile polymer because its pendant epoxide groups can be opened with different functional groups to generate poly(glycerol methacrylate)s (PGOHMA) derivatives. In this work, linear and star-shape PGMAs were synthesized by atom transfer radical polymerization and then functionalized with four different amines by ring-opening addition. This resulted in the formation of polyglycerol-like polymers having both hydroxyl and amine moieties and different water-solubility. The water-insoluble polymers could form pH-sensitive nanoassemblies, while the soluble derivatives efficiently complexed a short strand polynucleotide. The aminated polyglycerol interacted more avidly with the oligonucleotide than the control poly(ethyleneimine), and high transfection efficacy could be obtained with the linear derivative. Such polymers could find practical applications for the delivery of drugs and nucleic acids. © 2010 American Chemical Society.

Zhao H.,Tianjin University of Technology
Applied Mechanics and Materials | Year: 2014

The hierarchy design method of digital system based on EDA is proposed through the design of digital frequency meter system in this paper. Firstly, it divides the frequency meter into different function module and Writes VHDL code to describe each module circuit. Then, it creates the schematic diagram of top circuit. Design input, compiled, logic synthesize and function simulation are accomplished use MAX+PLUS II. In the end, digital frequency meter is implemented in CPLD. The results show that the design method can greatly simplify the complexity of hardware circuit structure. Its characteristic is high reliability and strong flexibility. © (2014) Trans Tech Publications, Switzerland.

Zhong X.H.,Wuhan Institute of Technology | Wang R.,Wuhan Institute of Technology | Wen Y.Y.,Tianjin University of Technology
Physical Chemistry Chemical Physics | Year: 2013

A carbon-nanotube (CNT)/silver/polymer composite fiber was fabricated using carbon nanotube fiber (CNTF) to infiltrate silver-paste liquid for effective reinforcement of electrical conductivity and strength of the CNT fibers. The as-obtained composite fiber is still flexible with a content of 43 wt% CNTs. Scanning electronic microscopy (SEM) observation shows that the silver-paste layer covering on the surface of the CNTF and polymer infiltrated into the CNTFs. The electrical conductivity and strength of the achieved composite fiber were effectively improved. Mechanical measurement of the composite fiber gave a strength of 940 MPa, 2.7 times that of a reference CNTF. The electrical conductivity of the composite fiber is 5.0 × 105 S m -1, 2.6 times that of the referenced CNTF. Additionally, through control of the fabrication process, a coaxial fiber comprising a silver-paste "tube" and pure CNT fiber can be achieved. This route for making composite fibers is easy and controllable, apt for development of high-performance fibers. © the Owner Societies 2013.

Xie L.-L.,Henan University of Technology | You L.-Q.,Henan University of Technology | Cao X.-Y.,Henan University of Technology | Zhang C.-F.,Henan University of Technology | And 2 more authors.
Electronic Materials Letters | Year: 2012

Co 3(PO 4) 2-coated LiV 3O 8 has been successfully synthesized and used as positive material for rechargeable lithium batteries by a facile liquid phase method. The as-prepared powders were characterized by x-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and the galvanostatic discharge/charge experiments. As-prepared Co 3(PO 4) 2-coated LiV 3O 8 forms a good layered structure with a poor cyrstallinity. SEM reveals that Co 3(PO 4) 2-coated LiV 3O 8 has uniform particle distribution and reduced particle size when compared with bare one. The Co 3(PO 4) 2 coating layer is about 33-59 nm forming a continuous lumps attached to LiV 3O 8 particle surface. Co 3(PO 4) 2-coated LiV 3O 8 electrode shows increased capacity and more stable cycling. The first and 35th discharge capacities of the Co 3(PO 4) 2-coated LiV 3O 8 electrode are 322. 8 mAh g -1 and 235. 7 mAh g -1 in the range of 4. 0-1. 8 V at a current rate of 30 mA g -1, respectively. The improved electrochemical performance is assigned to the greatly reduced LiV 3O 8 particle with uniform morphology. Co 3(PO 4) 2-coating further benefits the phase transitions of LiV 3O 8 during discharge/ charge while preventing parasite reactions between electrode surface and electrolyte. © 2012 The Korean Institute of Metals and Materials and Springer Netherlands.

Lin D.,Tianjin University | Cheng Q.,Beijing Institute of Technology | Jiang Q.,Beijing Institute of Technology | Huang Y.,Beijing Institute of Technology | And 6 more authors.
Nanoscale | Year: 2013

A low cytotoxicity and high efficiency delivery system with the advantages of low cost and facile fabrication is needed for the application of small interfering RNA (siRNA) delivery both in vitro and in vivo. For these prerequisites, cationic polymer-mesoporous silica nanoparticles (ssCP-MSNs) were prepared by surface functionalized mesoporous silica nanoparticles with disulfide bond cross-linked poly(2-dimethylaminoethyl methacrylate) (PDMAEMA). In vitro and in vivo evaluations were performed. The synthesized ssCP-MSNs are 100-150 nm in diameter with a pore size of 10 nm and a positively charged surface with a high zeta potential of 27 mV. Consequently, the ssCP-MSNs showed an excellent binding capacity for siRNA, and an enhancement in the cell uptake and cytosolic availability of siRNA. Furthermore, the intracellular reducing cleavage of the disulfide bonds cross-linking the PDMAEMA segments led to intracellular cleavage of PDMAEMA from ssCP-MSNs, which facilitated the intracellular triggered release of siRNA. Therefore, promoted RNA interference was observed in HeLa-Luc cells, which was equal to that of Lipofectamine 2000. Significantly, compared to Lipofectamine 2000, the ssCP-MSNs were more biocompatible, with low cytotoxicity (even non-cytotoxicity) and promotion of cell proliferation to HeLa-Luc cells. The in vivo systemic distribution studies certified that ssCP-MSNs/siRNA could prolong the duration of siRNA in vivo, and that they accumulated in the adrenal gland, liver, lung, spleen, kidney, heart and thymus after intravenous injection. Encouragingly, with the ability to deliver siRNA to a tumor, ssCP-MSNs/siRNA showed a tumor suppression effect in the HeLa-Luc xenograft murine model after intravenous injection. Therefore, the ssCP-MSNs cationic polymer-mesoporous silica nanoparticles with low cytotoxicity are promising for siRNA delivery. This journal is © 2013 The Royal Society of Chemistry.

Li T.,Tianjin Chengjian University | Wang Q.,Tianjin University | Zhu J.,Tianjin University | Hu K.,Tianjin University | Fu W.,Tianjin University of Technology
Renewable Energy | Year: 2015

Organic Rankine cycle (ORC) is a promising technology to recover low-grade heat, but it leads to a low efficiency due to the highest irreversible loss caused by the single-stage evaporation. The present work concerns the performance enhancement of a two-stage serial organic Rankine cycle (TSORC) for geothermal power generation. The heat source is divided into two separate temperature ranges. The main goal of the current simulation is to evaluate system performance of TSORC, as well as, to calculate the influence of two-stage evaporation on system performance. The ratio of the net power output to the total thermal conductance was chosen as the objective function. Results show that the system performance is coupled with geothermal water inlet temperature (GWIT), intermediate geothermal water temperature (IGWT), and evaporating temperatures. The two-stage evaporation significantly reduces the irreversible loss, thereby enhancing the net power output. The TSORC presents excellent systematic performances and deserves to be popularized in engineering applications. © 2014 Elsevier Ltd.

Li T.,Tianjin Chengjian University | Zhu J.,Tianjin University | Fu W.,Tianjin University of Technology | Hu K.,Tianjin University
International Journal of Energy Research | Year: 2015

An experimental test was conducted to compare R245fa with R245fa/R601a on the organic Rankine cycle performance. The major objective of this paper is to ascertain the highest thermal efficiency and the optimal dimensionless volume ratio using the two working fluids. The experimental system consists of an electrically heated boiler, a vapor generator, a scroll expander, a condenser, a working fluid pump, and so on. For the typical weather conditions of May in Tianjin, the experiment results show that the working fluid charge has an important influence on the organic Rankine cycle performances. The optimal isentropic efficiency of the scroll expander corresponds to the design expansion ratio. Underexpanded and overexpanded processes result in the decline of the isentropic efficiency of the scroll expander, with the former playing a major role. R245fa/R601a improves the heat transfer performance in the vapor generator because of the nonisothermal phase change. The highest thermal efficiency for R245fa and R245fa/R601a is 4.38% and 4.45%, thereby illustrating that R245fa/R601a precedes R245fa. The optimal dimensionless volume ratios for R245fa and R245fa/R601a are 0.38 and 0.41, respectively. The experimental test lays foundation of the 500-kW geothermal plant for demonstration in the next step. © 2014 John Wiley & Sons, Ltd.

Chen G.,Tianjin University | Ren C.,Tianjin University of Technology | Qin X.,Tianjin University | Li J.,Tianjin University
Materials and Design | Year: 2015

The plastic deformation behaviors of Ti-6Al-4V alloy over wide ranges of strain rate (from 10-4 to 104s-1) and temperature (from 20 to 900°C) are investigated by the quasi-static and dynamic uniaxial compression tests. The microstructure evolution of Ti-6Al-4V alloy at different temperatures is discussed. Material generates higher ductility and formability when temperature is higher than 500°C, which leads to the decrease of work hardening rate. The true stress-strain responses are modeled with the JC, modified JC, KHL and modified KHL models. In detail, a temperature dependent work hardening function is introduced into the original JC and KHL models. The parameters of the four models for Ti-6Al-4V alloy are calculated by GA optimization method. The average standard deviations between the experimental and calculated flow stresses range from 4% to 13%, which validates the accuracy of the models. In addition, comparison of flow stresses at dynamic (10,000s-1), the work hardening rates at dynamic (7500s-1), as well as the quasi-static jump experiments were proposed to further validate the models. The modified JC and modified KHL models could characterize the temperature dependent work hardening effect for Ti-6Al-4V alloy over large strain rate and temperature ranges. © 2015 Elsevier Ltd.

Over D.,University of Paris Descartes | Zeng X.,University of Paris Descartes | Zeng X.,Tianjin University of Technology | Bornholdt C.,University of Paris Descartes | And 2 more authors.
Inorganic Chemistry | Year: 2013

First insights into the coordination properties and host-guest behavior of a "two story" calix[6]aza-cryptand (1) are described. The ligand is constituted of a triazacyclononane (TACN) cap and three pyridine (PY) spacers connected to the calix[6]arene small rim. The resulting N6 donor site coordinates PbII ions to give complexes that are highly stable. X-ray diffraction structures reveal a hemidirected environment for Pb II with strong coordination to the TACN cap and weaker bonds with the three PY residues. A guest molecule, either water or EtOH, sitting in the calixarene macrocycle and hydrogen-bonded to the phenoxyl units at the level of the small rim further stabilizes the complexes through electrostatic interactions with the metal center and the calixarene core. In-depth 1H NMR studies confirm the host-guest behavior of the complexes in solution, with evidence of embedment of neutral guest molecules such as EtOH, BuOH, and N-Me-formamide. Hence, in spite of the presence of a N6 donor, the calixarene macrocycle can be open to guest interaction, giving rise to seven-coordinate dicationic complexes. Noteworthy also is the flexibility of the macrocycle that allows PbII to adopt its preferred hemidirected environment in spite of the three covalent links connecting the calixarene core to the three PY groups. The flexibility of the system is further illustrated by the possible coordination of an exogenous anionic ligand in the exo position. Hence, compared to the previously described "one story" calix[6]aza-cryptands, ligand 1 displays several similar but also new features that are discussed. © 2013 American Chemical Society.

Song X.,Tianjin University of Technology
Yi Qi Yi Biao Xue Bao/Chinese Journal of Scientific Instrument | Year: 2013

This design uses a three-level computer architecture for intelligent control of wastewater treatment processes, monitoring and management. According to the tasks required of the system consists of lower, middle, upper consisting of three parts. Slave smart meters, frequency converter, open valves and other process control. Computer controlled motor, solenoid valve switches such as programmable logic controllers (PLC) that while dealing with the acceptance of the measurement and control system to the data on the slave, and in accordance with appropriate communication protocols to upload first. Eventually installed in MCGS configuration software in the PC, real-time monitoring of wastewater treatment processes and changes of analog. To implement in a wastewater treatment process combining automatic and manual control, with the purpose of combining remote control.

Li T.,Tianjin Chengjian University | Fu W.,Tianjin University of Technology | Zhu J.,Tianjin University
Energy | Year: 2014

The organic Rankine cycle has been one of the essential heat-work conversion technologies nowadays. Lots of effectual optimization methods are focused on the promotion of the system efficiency, which are mainly relied on engineering experience and numerical simulations rather than theoretical analysis. A theoretical integrated optimization method was established based on the entransy theory and thermodynamics, with the ratio of the net power output to the ratio of the total thermal conductance to the thermal conductance in the condenser as the objective function. The system parameters besides the optimal pinch point temperature difference were obtained. The results show that the mass flow rate of the working fluid is inversely proportional to the evaporating temperature. An optimal evaporating temperature maximizes the net power output, and the maximal net power output corresponds to the maximal entransy loss and the change points of the heat source outlet temperature and the change rates for the entropy generation and the entransy dissipation. Moreover, the net power output and the total thermal conductance are inversely proportional to the pinch point temperature difference, contradicting with each other. Under the specified condition, the optimal operating parameters are ascertained, with the optimal pinch point temperature difference of 5K. © 2014 Elsevier Ltd.

Wang J.,Tianjin University | Gao C.,Tianjin University | Zhang Y.,Tianjin University | Wan Y.,Tianjin University | Wan Y.,Tianjin University of Technology
Materials Science and Engineering C | Year: 2010

In order to investigate the potential use for bacterial cellulose (BC) as a novel artificial cornea replacement, BC/poly(vinyl alcohol) (BC/PVA) hydrogel composites were synthesized by freezing-thaw method. The BC/PVA composites were characterized by UV-Vis spectrophotometer (UV-Vis), X-ray diffraction (XRD), thermogravimetric (TG) analysis, mechanical property tests and scanning electron microscope (SEM) analyses. Our results showed that the resultant BC/PVA composites exhibited desirable properties as artificial cornea replacement biomaterial including high water content, high visible light transmittance and suitable UV absorbance, increased mechanical strength and appropriate thermal properties. Results of this work revealed that the BC/PVA composites exhibited some promising characteristics as artificial cornea composite material and may be improved further for its realistic applications. © 2009 Elsevier B.V. All rights reserved.

Li X.,Nanchang University | Hu Q.,Nanchang University | Yang Y.,Nanchang University | Wang Y.,Nanchang University | He F.,Tianjin University of Technology
Applied Catalysis A: General | Year: 2012

Wt.%BaTiO 3-Al 2O 3 (wt.%BaTiO 3 = 0-100%) composite supports were synthesized through varying the BaTiO 3 content by the "sol-(xero)gel" method. Ni/wt.%BaTiO 3-Al 2O 3 nickel-based catalysts prepared by incipient wetness method were evaluated for dry reforming of methane carried out between 690 °C and 800 °C. Characterizations using XRD, IR, N 2 adsorption-desorption, H 2-TPR, SEM, and XPS were conducted to investigate the structure or properties of the wt.%BaTiO 3-Al 2O 3 composite supports as well as the Ni/wt.%BaTiO 3-Al 2O 3 catalysts. The results demonstrate that BaTiO 3 particles are discontinuously dispersed on the surface of γ-Al 2O 3 in the form of individual isolated particles for the wt.%BaTiO 3-Al 2O 3 composite supports. Meanwhile, it is probably that the coexistence of BaAl 2O 4 spinel phase with the BaTiO 3 phase on the surface of γ-Al 2O 3 inhibits the Ni/wt.%BaTiO 3-Al 2O 3 catalysts from the formation of NiAl 2O 4 spinel phase, improving the catalytic performance of the catalysts. The Ni/BaTiO 3 catalyst showed poor stability and severe coke formation in the dry reforming of methane tested at 690 °C, which was thought to be mainly originated from the excessive strong electronic donor intensity of Ni/BaTiO 3 catalyst as well as the resulted CO disproportionation reaction. Compared with the Ni/BaTiO 3 catalyst, the Ni/wt.%BaTiO 3-Al 2O 3 catalysts with the addition of BaTiO 3 had a higher dispersion of active nickel and a weakened electronic donor intensity of the NiO x species. As a result, the synthesized Ni/32.4%BaTiO 3-Al 2O 3 catalyst exhibited a high catalytic activity, excellent stability as well as coking resistance for lower temperature dry reforming of methane. © 2011 Elsevier B.V.

Li Y.,Nankai University | Xu L.,Nankai University | Xu L.,Tianjin University of Technology | Choi T.-M.,Hong Kong Polytechnic University | Govindan K.,University of Southern Denmark
IEEE Transactions on Systems, Man, and Cybernetics: Systems | Year: 2014

Advance-selling (AS) is a commonly observed industrial practice in which a retailer allows consumers to prebook the fashionable product before the real selling season starts. Motivated by this practice, this paper studies AS strategy for a retailer who sells a newsvendor-type of fashionable product in light of potential consumer opportunistic returns. In our model, the consumers face valuation uncertainty and know their valuation realization only after product acquisition. There also exists aggregate demand uncertainty, captured in the conventional newsvendor model. All preorders are fulfilled at the beginning of a normal-selling season. We build analytical optimization models and consider three strategic options for the retailer, namely, no advance-selling allowed (NAP), advance-selling with full refund (AFP) and advance-selling with partial refund (APP), where there are two suboptions under APP. We derive the retailer's optimal pricing and refund policies for each option. By comparing the results in the above options, important insights are generated. Finally, we conduct a numerical analysis to further examine the impacts brought by consumers valuation, market condition, and consumers classification on the optimal strategy. © 2013 IEEE.

Li C.,Japan National Institute of Advanced Industrial Science and Technology | Li C.,Tianjin University of Technology | Murase N.,Japan National Institute of Advanced Industrial Science and Technology
Journal of Colloid and Interface Science | Year: 2013

A synthesis process was reconsidered for encapsulating hydrophobic quantum dots (QDs) into silica capsules with high photoluminescent (PL) efficiency. The process comprises three steps: silanization of QD surfaces, seed formation by assembly of the QDs, and coating of the QD seeds with a silica shell. Analysis of the encapsulation mechanism enabled this process to be adapted for application to CdSe-based core-shell QDs with various organic ligands such as oleic acid and with various emission wavelengths. Formation of the seeds is the key step in synthesizing the silica capsules, so that they have high PL efficiency. Due to the differences in QD size and in the affinity of the ligands on their surfaces, the concentration of QDs used in the synthesis must be optimized to maximize emission efficiency. Contrary to an initial assumption, several ligands remained on the QD surfaces even after the QDs were transferred from organic solution to water. This greatly affected the size and PL efficiency of the seeds. Judicious selection of the conditions for seed and silica capsule synthesis resulted in seeds with PL efficiency greater than 70% and in silica capsules encapsulating multiple CdSe/CdZnS QDs with PL efficiency as high as 41%. Silica capsules incorporating QDs with various emission peak wavelengths from green to red were also prepared. The process presented serves as a guideline for encapsulating various types of hydrophobic QDs into silica capsules for biological tagging applications. © 2013 Elsevier Inc.

Wu F.,Tianjin University of Technology
Journal of Low Temperature Physics | Year: 2014

The ex-situ method to prepare MgB2 superconductors is favorable in terms of bulk density compared to the in-situ method. Since the packing factor of ex-situ MgB2 is higher than that of in-situ MgB2, a better Jc, even higher than that of in-situ, is naturally expected if strong grain connectivity is achieved. In the present work, ex-situ MgB2 polycrystalline bulks with Mg addition were prepared by sintering. Combined with phase composition analysis, microstructure observation and superconducting properties measurement, it is found that Mg addition can obviously reduce MgO impurities, accelerate the self-sintering of MgB2 and even promote the formation of sintering necks between MgB2 grains. Consequently, the sintering density and grain connectivity is enhanced, and the Jc is improved across the whole magnetic field in the ex-situ MgB2 sample with Mg addition. Mg addition is a promising and effective way to further enhance Jc of ex-situ MgB2 superconductors. © 2014, Springer Science+Business Media New York.

Yu Y.,University of California at Riverside | Liu Y.,Tianjin University of Technology | Liu Y.,University of California at Riverside | Wu L.,University of California at Riverside
Environmental Science and Pollution Research | Year: 2013

Pharmaceuticals and personal care products (PPCPs) are one class of the most urgent emerging contaminants, which have drawn much public and scientific concern due to widespread contamination in aquatic environment. Most studies on the environmental fate and behavior of PPCPs have focused on nonsteroidal anti-inflammatory drugs. Some other compounds with high concentrations were less mentioned. In this study, sorption and degradation of five selected PPCPs, including bisphenol A (BPA), carbamazepine (CBZ), gemfibrozil (GFB), octylphenol (OP), and triclosan (TCS) have been investigated using three different soils. Sorption isotherms of all tested PPCPs in soils were well described by Freundlich equation. TCS and OP showed moderate to strong sorption, while the sorption of GFB and CBZ in soils was negligible. Degradation of PPCPs in three soils was generally fitted first-order exponential decay model, with half-lives (t 1/2) varying from 9.8 to 39.1 days. Sterilization could prolong the t 1/2 of PPCPs in soil, indicating that microbial activity played an important role in the degradation of these chemicals in soils. Degradation of PPCPs in soils was also influenced by the soil organic carbon (f oc) contents. Results from our data show that sorption to the soils varied among the different PPCPs, and their sorption affinity on soil followed the order of TCS > OP > BPA > GFB > CBZ. The degradation of the selected PPCPs in soil was influenced by the microbial activity and soil type. The poor sorption and relative persistence of CBZ suggest that it may pose a high leaching risk for groundwater contamination when recycled for irrigation. © 2013 Springer-Verlag Berlin Heidelberg.

Zheng C.,Tianjin Polytechnic University | Sun X.,Tianjin University of Technology
Journal of Fluorine Chemistry | Year: 2012

Fluorinated alumina was modified with different alkaline and alkaline earth metals. And fluorinated alumina modified with magnesium was found to show the best reactivity and selectivity for condensation of aniline to diphenylamine (DPA) under fix-bed continuous flow reaction conditions. Various characterizations involving X-ray diffraction, nitrogen-adsorption measurements, inductive coupled plasma emission spectrum as well as infrared spectrum has integrally testified the structure of fluorinated alumina modified with magnesium. The preparation of fluorinated alumina modified with magnesium was simply convenient and, importantly, environmentally benign for non-surfactant needed in comparison with H-beta zeolite. Meanwhile, the catalyst even exhibited higher conversion of aniline than H-beta zeolite. Such alumina-based catalyst can be readily recovered for at least 5 times, while the conversion of aniline and productivity for DPA was almost maintained during the reaction. © 2011 Elsevier B.V. All rights reserved.

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.

Elleuch A.,University of Sfax | Boussetta A.,University of Sfax | Halouani K.,University of Sfax | Li Y.,Tianjin University of Technology
International Journal of Hydrogen Energy | Year: 2013

NiO-Samaria-Doped-Ceria (NiO-SDC) composite powders was synthesized by a traditional mechanical mixing process and tested as anode material for Direct Carbon Fuel Cell (DCFC), which uses almond shell biochar as fuel and molten carbonate-doped ceria composite as electrolyte. A three-layer pellet cell, viz. cathode (Lithiated NiO-SDC), composite electrolyte and anode (NiO-SDC) is fabricated by a die-pressing, screen printing and sintering method. In Part I, a bi-layer DCFC pellet powered by almond shell biochar was tested and demonstrated a good potential. In this paper, we report an improvement in the cell stability and performance by adding the (NiO-SDC) anode layer to the bi-layer pellet containing only cathode and electrolyte. The peak power density of the three-layer pellet cell at 700 C increases to reach 150 mW cm -2 instead of 127 mW cm-2 while, the stability period is ameliorated to be around 130 min. The results indicated that this porous anode material is promising as anode for DCFCs. The DCFC single cells experiments demonstrated that the anode polarization is dominating the total cell polarization. Therefore, improved power output could be achieved with an improved anode. © 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights.

Guo X.-G.,Tianjin University of Technology | Yang G.-H.,Northeastern University China
Journal of Dynamic Systems, Measurement and Control, Transactions of the ASME | Year: 2014

This paper studies the problem of designing insensitive H∞ output-feedback controllers for linear discrete-time systems. The designed controllers are insensitive to additive/multiplicative controller coefficient variations. An LMI-based procedure, which is a sequential linear programming matrix method (SLPMM), is proposed to solve the considered problem which is a nonconvex problem itself. It is worth mentioning that the nonfragile control design method is adopted to obtain an effective solution for accelerating convergence of SLPMM algorithm due to the fact that a good starting point for the iteration is very important. © 2013 by ASME.

Zhang L.,Tianjin University of Technology | Yin Y.,Nankai University
Sensors and Actuators, B: Chemical | Year: 2013

In this contribution, hierarchical tin dioxide (SnO2) nanosheets were successfully synthesized via a simple, cost-effective and environment-friendly hydrothermal method at a relatively low temperature (90 C) after calcination in air. The post-heat treatment not only improved the crystallinity, but also increased the visible emission (refer to intrinsic crystal defects) of the hydrothermal products, which were proved by X-ray diffraction and room temperature photoluminescence, respectively. Electronmicroscopy analysis and nitrogen adsorption-desorption results confirmed the mesoporous feature of these nanosheets. Gas sensors based on these SnO 2 nanosheets exhibited high response, fast response-recovery and good selectivity to 1-1000 ppm ethanol vapor at a relatively low operating temperature (165 C). The excellent ethanol-sensing property, especially high response value can be mainly attributed to the mesoporous texture, characteristically small grain size, abundant surface defects, and the plane-contact feature between the neighboring SnO2 nanosheets. © 2013 Elsevier B.V.

Wei T.,Civil Aviation University of China | Sun F.C.,Civil Aviation University of China | Zhao C.Z.,Tianjin Polytechnic University | Li C.P.,Tianjin University of Technology | And 2 more authors.
Ceramics International | Year: 2013

Sm3+ ions doped Bi1/2Na1/2TiO3 (BNTO: xSm3+) polycrystalline samples with different Sm3+ concentrations were synthesized through the solid-state reaction method. Their microstructural, photoluminescence, and ferroelectric (FE) properties were investigated. Strong reddish-orange emission centered at 597 nm has been successfully observed at room temperature. More importantly, the strong emission of BNTO: xSm3+ can be excited by both blue light and near ultraviolet radiation which indicates that BNTO: xSm3+ can act as a potential phosphor. Furthermore, the optimized photoluminescence is realized in BNTO: xSm3+ with x=0.02 sample which also shows relatively good ferroelectric properties. © 2013 Elsevier Ltd and Techna Group S.r.l.

Ao X.-P.,Tianjin University of Technology
Engineering Technology, Engineering Education and Engineering Management - International Conference on Engineering Technology, Engineering Education and Engineering Management, ETEEEM 2014 | Year: 2015

The current definitions of an asset focus on “the past” and “the future”, but do not mention “the present”, therefore do not reveal the substance of an asset. The article analyzed the shortcomings of the current definitions of an asset, and proposed that the definition of an asset must highlight “the present” and grasp the substance of an asset. © 2015 Taylor & Francis Group, London.

Tang H.,Guangdong University of Technology | Li Y.,Tianjin University of Technology
IEEE/ASME Transactions on Mechatronics | Year: 2015

In this paper, the development of a flexure-based two-degree-of-freedom (2-DOF) nanomanipulator with modified differential lever displacement amplifier is conducted, which aims to break through the millimeter-range barrier. The kinetostatics modeling of the mechanism is established by using the pseudorigid body method, also the analytical modeling of lever is built up, as well as the dimension optimizations and the mechanism performance validations are conducted by using the Particle Swarm Optimization algorithm and the finite-element analysis method, respectively. With the consideration of hysteresis effect inherent in piezoelectric ceramics actuators, the hysteresis modeling is conducted by using the Preisach theory. To enhance the mechanism positioning performance, a novel feedforward nonlinear proportion-integration-differentiation control strategy composed by the nonlinear PID controller and the inverted Preisach hysteresis compensator is proposed in this paper. Finally, a series of closed-loop motion tracking experiments have been carried out. It indicates that the developed mechanism has achieved a millimeter workspace (3.1273 mm × 26.5°), nanometer scale motion resolution (40 nm), as well as a closed-loop positioning bandwidth of over 10 Hz. © 1996-2012 IEEE.

Liu W.,Tianjin University of Technology
Proceedings - 2015 8th International Symposium on Computational Intelligence and Design, ISCID 2015 | Year: 2016

The Safety streams of LTE/SAE system include AS (Access Stratum) and NAS (Non-Access Stratum) two security levels. The AS security is the security between the UE (User Equipment) and eNB (evolved Node-B), mainly to complete the encryption and integrity protection for AS signaling, the integrity protection for the data of UP (User Plane). In this paper, through the analysis of the SAE security architecture protocol, We describe the security access layer activation process and algorithm selection process, analyze the implementation algorithm of SAE access layer encryption and integrity mechanism. At the same time, it also introduces the common algorithm used in encryption and integrity protection algorithm-SNOW 3G algorithm, and the cost in terms of time and space of encryption and integrity protection algorithm are analysed. © 2015 IEEE.

Liao Y.,Nankai University | Liu J.-Y.,Tianjin University of Technology
European Physical Journal Plus | Year: 2012

We study the most general Fierz identities for a pair of non-contracted Dirac matrices both in the standard basis and for chiral spinors. These identities are useful in building independent effective operators of fermions that involve derivatives or sextuple and more fields. We apply them to construct independent effective four-fermion interactions that contain one to three spin-3/2 chiral fields. These operators could be relevant to physics of higher-spin baryons and phenomenology of a neutral, massive spin-3/2 particle as a dark-matter candidate. © 2012 Società Italiana di Fisica and Springer-Verlag Berlin Heidelberg.

Daojin F.,Tianjin University of Technology
2010 2nd International Conference on Industrial and Information Systems, IIS 2010 | Year: 2010

The success of IT project related to numerous factors. It had an important significance to find the critical factors for the success of project. Based on the general analysis of IT project management, this paper analyzed some factors of project management for successful IT project from the angle of modern project management. These factors include project participators, project communication, collaboration, and information sharing mechanism as well as project management process. In the end, it analyzed the function of each factor for a successful IT project. On behalf of the collective goal, by the use of the favorable project communication and collaboration, the project participants carry out successfully to the management of the process, which is significant to the project, and make project achieve success eventually. © 2010 IEEE.

Wang J.H.,Tianjin Key Laboratory of Intelligence Computing and Novel Software Technology | Zhao Y.C.,Tianjin University of Technology
Advanced Materials Research | Year: 2011

In this paper, a novel blind separation approach using wavelet and cross-wavelet is presented. This method extends the separate technology from time-frequency domain to time-scale domain. The simulation showed that this method is suitable for dealing with non-stationary signal. © 2011 Trans Tech Publications.

Huang F.-G.,Tianjin University | Jia S.-Y.,Tianjin University | Liu Y.,Tianjin University of Technology | Wu S.-H.,Tianjin University | Han X.,Tianjin University
Journal of Hazardous Materials | Year: 2015

In this study, reductive dissolution of As(V)-ferrihydrite and the mobilization of As(V) in the presence of S(-II) were investigated under anoxic conditions. Mobilization of As(V) strongly depended on the S(-II):Fe ratio and the amount of As(V) loading on ferrihydrite. High S(-II):Fe ratio caused a more complete dissolution of ferrihydrite and a large fraction of As(V) could be released into solution. The percentages of the released As(V) were 2.5% and 7.5% at S(-II):Fe ratios of 0.240 and 24.0, respectively, at pH 6.1, while the released As(V) were 5.5%, 16.3% at pH 8.0 under similar conditions. As(V) loading showed a negative effect on the release of arsenate, with smaller fraction of arsenate released into solution when more As (V) adsorbed on ferrihydrite. After 43h, 14.1%, 5.5%, 1.6% and 0.7% of As(V) were released as for 10, 20, 50 and 100mgL-1 of As(V) loading, respectively, at pH 8.0. During the dissolution, secondary minerals such as goethite, magnetite and FeS were detected and played different roles in the mobilization of As(V). The released As(V) was mainly repartitioned on the residual ferrihydrite, the newly-formed goethite and magnetite but not FeS. © 2014 Elsevier B.V.

Qi K.,Nankai University | Yang J.,Nankai University | Fu J.,Nankai University | Wang G.,Nankai University | And 3 more authors.
CrystEngComm | Year: 2013

Morphology-controllable ZnO rings with high crystallinity were synthesized by a simple hydrothermal approach, using ionic liquid (through surface energy conditioning) as a stabilizing agent or template. The growth mechanism of these ring-like ZnO crystals was explored based on first-principles calculations and a series of controlled experiments where the concentration of the ionic liquid 1-propyl-3-methylimidazolium bromide ([C3mim]Br) was tuned. With the increase of the concentration of [C3mim]Br, the aspect ratio of ZnO product increases, and the morphology changes from ring to tube. FTIR and theoretical calculations indicate that [C3mim]Br prefers to adsorb on the ZnO (1010) facets, which lowers the surface energy so as to protect the lateral facets from growing too fast to vanish and result in the formation of disk-like structures. Furthermore, the relatively high density of the defects and dislocations on the exposed (0001) facet at the center of ZnO disks results in a higher etching rate of (0001) facet by H+, driven by the reduction of strain energy associated with dislocations. Therefore, the selective etching of ZnO disks leads to formation of ring-like structure for final products. With the increase of the concentration of [C3mim]Br, the selective adsorption of [C3mim]Br will also promote the growth along the [0001] direction to form a tube-like structure. In addition, the photoluminescence spectra reveal that the as-prepared ZnO rings exhibit blue emission related to their oxygen vacancy as well as various other barely avoidable impurities and defects. © 2013 The Royal Society of Chemistry.

Wang H.Y.,Nanyang Technological University | Wang H.Y.,Tianjin University of Technology | Lua A.C.,Nanyang Technological University
Chemical Engineering Journal | Year: 2015

A series of Ni-Cu alloy particles with different atomic ratios of Ni/Cu were prepared by the thermal decomposition of fibrous Ni-Cu oxalate precursors in methane atmosphere. The resulting porous aggregates of Ni-Cu alloy particles showed promising catalytic activities for methane decomposition at temperatures of 700 and 750. °C. A Ni-Cu alloy catalyst with 62.5% nickel content was able to achieve the highest methane conversion of about 82% at a reaction temperature of 750. °C. The addition of the right amount of copper led to the formation of alloy particles with small crystalline and particle sizes. Unlike the supported catalysts, the self-regulating system of the unsupported catalysts led to the formation of isometric, round catalyst particles which showed stable catalytic activity even at 750. °C. The frequent appearance in the supported catalyst system of liquid-like Ni-Cu catalyst at temperatures above 700. °C was suppressed in the unsupported Ni-Cu alloy catalyst system. The stability of the catalysts is discussed and a deactivation mechanism is proposed. © 2014 Elsevier B.V.

Elleuch A.,University of Sfax | Sahraoui M.,University of Carthage | Boussetta A.,University of Sfax | Halouani K.,University of Sfax | Li Y.,Tianjin University of Technology
Journal of Power Sources | Year: 2014

A two-dimensional modeling of a lab-scale planar Direct Carbon Fuel Cell (DCFC) of 20 mm in diameter is developed by taking into account of the electrochemical mechanisms and mass and heat transfer phenomena in all regions of the cell simultaneously. The electrodes and the electrolyte of the DCFC are both considered as distinct regions with different local properties such as permeability, conductivity and diffusivity. An improved packed bed anodic structure with a finite thickness is also adopted. General boundary conditions are implemented by taking into consideration the species concentrations at the DCFC inlet such as oxygen concentration which is a very important parameter to determine the cell efficiency. The effects of the main operating parameters such as temperature, inlet gas flow velocity and porosity of the electrolyte matrix on the DCFC efficiency are investigated. A sensitivity analysis based on numerical simulations of the effects of cathode kinetic parameters and the anode specific surface area is also performed. Good agreement is obtained between numerical results and experimental data with an absolute average deviation of about 9%. © 2013 Elsevier B.V. All rights reserved.

Wang X.C.,Tianjin University of Technology | Mi W.B.,China Institute of Advanced Materials Physics | Kuang D.F.,China Institute of Technology
Applied Surface Science | Year: 2010

Microstructure, magnetic and optical properties of polycrystalline Fe-doped ZnO films fabricated by cosputtering with different Fe atomic fractions (xFe) have been examined systematically. Fe addition could affect the growth of ZnO grains and surface morphology of the films. As xFe is larger than 7.0%, ZnFe2O4 grains appear in the films. All the films are ferromagnetic. The ferromagnetism comes from the ferromagnetic interaction activated by defects between the Fe ions that replace Zn ions. The average moment per Fe ion reaches a maximum value of 1.61 μB at xFe = 4.8%. With further increase in xFe, the average moment per Fe ion decreases because the antiferromagnetic energy is lower than the ferromagnetic one due to the reduced distance between the adjacent Fe ions. The optical band gap value decreases from 3.245 to 3.010 eV as xFe increases from 0% to 10%. Photoluminescence spectra analyses indicate that many defects that affect the optical and magnetic properties exist in the films. © 2009 Elsevier B.V. All rights reserved.

Xu Z.,Tianjin University of Technology | Le Y.,Nankai University | Zhang L.,Nankai University
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2014

In this paper, we investigate the evolution of cooperation in the spatial prisoner's dilemma game by incorporating partner choice into the framework of evolutionary game theory. Our research shows that the introduction of partner choice can notably promote the cooperative behavior in the prisoner's dilemma game. All the players are more likely to play the game with cooperators, which makes it easier for cooperators to form alliances. In particular, the system will be dominated completely by cooperators in a comfortable environment (i.e., with lower survival cost) because the cooperators can get more benefits than the defectors in this case due to their good reputation. In addition, we have found that the sustenance of cooperators improves notably as well in the snowdrift game and the stag-hunt game due to this introduction. © 2014 American Physical Society.

Tang H.,University of Macau | Li Y.,Tianjin University of Technology | Li Y.,King Abdulaziz University
IEEE Transactions on Industrial Electronics | Year: 2014

In the atomic force microscope (AFM) scanning system, the piezoscanner is significant in realizing highperformance tasks. To cater to this demand, a novel compliant two-degrees-of-freedom (2-DOF) micro-/nanopositioning stage with modified lever displacement amplifiers is proposed in this paper, which can be selected to work in dual modes. Moreover, the modified double four-bar P (P denotes prismatic) joints are adopted in designing the flexible limbs. The established models for the mechanical performance evaluation in terms of kinetostatics, dynamics, and workspace are validated by finite-element analysis. After a series of dimension optimizations carried out via particle swarm optimization algorithm, a novel active disturbance rejection controller, including the components of nonlinearity tracking differentiator, extended state observer, and nonlinear state error feedback, is designed for automatically estimating and suppressing the plant uncertainties arising from the hysteresis nonlinearity, creep effect, sensor noises, and other unknown disturbances. The closed-loop control results based on simulation and prototype indicate that the two working natural frequencies of the proposed stage are approximated to be 805.19 and 811.31 Hz, the amplification ratio in two axes is about 4.2, and the workspace is around 120 × 120 μm2, while the cross-coupling between the two axes is kept within 2%. All of the results indicate that the developed micro-/nanopositioning system has a good property for high-performance AFM scanning. © 1982-2012 IEEE.

Pei S.-L.,Tianjin University of Technology
Journal of Digital Information Management | Year: 2014

The paper introduces the EA (electric acupuncture) treatment system based on expert database diagnosis technique. The system is a expert database of automatic reasoning diagnosis by the combining the maximum likelihood method and relation database. It integrates symbolic measurement theory, computer technology and electronic technology, which develops EA needling method by imitating classical acupuncture techniques. The system effectively achieves the integration of diagnosis and treatment.

Sha K.,Shandong Jianzhu University | Wu S.,Tianjin University of Technology
Building Research and Information | Year: 2016

Under the city–countryside dual structure, the existing building governance system in China differentiates between urban and rural areas. When updating building regulations and related policies to meet challenges in the built environment, it is essential to develop different strategies for different locations according to local circumstances, requirements and capabilities. Based on two research projects, this article examines the mechanisms and strategies for promoting building energy conservation in rural China from the perspective of economic governance. The challenges and potentials of building energy conservation in rural China are analyzed. The essence of the governance paradigm is briefly reviewed. A three-level analysis framework is developed in which markets, governments and the third party (professionals and others) play complementary roles in regulating stakeholders’ behaviour. A key question addressed is how to create a favourable institutional environment in which people are willing to do the right things. Different strategy portfolios are proposed for different levels, including technology strategy, financing strategy, as well as regulations and incentive policies. In conclusion, there is no ‘best’ but rather the ‘most suitable’ approach to building governance. In this light, the principle of discriminating alignment and the multilevel analysis approach provides conceptual insights. © 2016 Taylor & Francis

Transparent luminescent bulk nanocomposites of polysiloxane (PSO) embedded with semiconductor nanocrystals (NCs) have been fabricated by the direct dispersion of CdS NCs in alkyl-(poly)siloxane (APS) followed by co-polymerization. The non-polar characteristics of the APS precursor are compatible with the CdS NC surface (oleylamine), which allows the direct dispersion of the CdS NCs without the need of any surfactant exchange. Chemical crosslinking of the NC-APS dispersion via hydrosilylation between Si-H and the vinyl group in APS immobilizes the CdS NCs in the polysiloxane network. Net-shaped three-dimensional bulk transparent polysiloxane/CdS NC composites were obtained by liquid casting of the NC-precursor dispersion and chemical crosslinking. The PSO/CdS NC composites show visible luminescence under ultraviolet excitation and the luminescent color is tunable from blue to red by controlling the NC concentration in the composite. Photoluminescence spectral analyses reveal the origin of the luminescence as being from the defect emission of the CdS NCs (550-900 nm) and an emission from the PSO matrix (380-550 nm). The luminescent spectra covered a wide range from the ultraviolet to the near-infrared region. The luminescence of the PSO/CdS NC nanocomposites was stable without any apparent degradation after exposure to air for a long time. This simple direct dispersion process is feasible for the fabrication of luminescent nanocomposites with useful optical properties for potential applications in optics and photoelectron devices.

Muroya Y.,Waseda University | Li H.,Tianjin University of Technology | Kuniya T.,University of Tokyo
Acta Mathematica Scientia | Year: 2014

In this paper, we establish new sufficient conditions for the infected equilibrium of a nonresident computer virus model to be globally asymptotically stable. Our results extend two kind of known results in recent literature. © 2014 Wuhan Institute of Physics and Mathematics.

Wu R.-J.,Tianjin University of Technology
Journal of Tianjin Polytechnic University | Year: 2014

In order to find the internal mechanism and boundary conditions between the relationship of online store telepresence and consumer attitude toward online store, 209 students are recruited to record their online store experience. Factor analysis and regression analysis of SPSS 19.0 and LISREL 8.70 are used to verify the hypotheses. The result shows that online store telepresence and consumer attitude toward online store are positively significantly related. The effects of online store teleprence on consumer attitude are fully mediated by cognitive pleasure. In the relationship between online store telepresence and cognitive pleasure, online store usefulness is an important moderator. The effects of online store telepresence on cognitive pleasure are not moderated by online store ease of use.

Zhang L.,Tianjin University of Technology | Yin Y.,Nankai University
Sensors and Actuators, B: Chemical | Year: 2013

In this paper, flower-like zinc oxide (ZnO) nanorods were successfully synthesized via a simple, cost-effective and environment-friendly wet-chemical method at a relatively low temperature (90 C). X-ray diffraction indicated that the ZnO nanorods are crystallized in a hexagonal wurtzite structure. Electron microscopy observations confirmed the nanorod assembled flower-like morphology. And, high-resolution transmission electron microscopy (HRTEM) images proved that plenty of defects exist on the surface of ZnO nanorods. Photoluminescence analysis showed that abundant intrinsic defects are present on the ZnO crystal surfaces, the content of which is far more than that of commercial ZnO powders. X-ray photoelectron spectrometry revealed that considerable oxygen species (23.29%) chemisorbs on the surface of the as-prepared ZnO nanorods. Gas sensors based on these ZnO nanorods exhibit high response, fast response-recovery and good selectivity to 1-1000 ppm ethanol vapor at 400 C. The excellent ethanol-sensing performance, particularly high response values, is considered to be mainly originated from plenteous defects formed on ZnO surfaces. © 2013 Elsevier B.V. All rights reserved.

Wang X.,Tianjin University of Technology | Wang X.,Heriot - Watt University | Wang N.,Heriot - Watt University | Wang L.,Baosteel
International Journal of Hydrogen Energy | Year: 2011

Thermodynamic features of hydrogen production by sorption enhanced steam reforming (SESR) of propane have been studied with the method of Gibbs free energy minimization and contrasted with propane steam reforming (SR). The effects of pressure (1-5 atm), temperature (700-1100 K) and water to propane ratio (WPR, 1-18) on equilibrium compositions and carbon formation are investigated. The results suggest that atmospheric pressure and a WPR of 12 are suitable for hydrogen production from both SR and SESR of propane. High WPR is favourable to inhibit carbon formation. The minimum WPR required to eliminate carbon production is 6 in both SR and SESR. The most favourable temperature for propane SR is approximately 950 K at which 1 mol of propane has the capacity to produce 9.1 mol of hydrogen. The optimum temperature for SESR is approximately 825 K, which is over 100 K lower than that for SR. Other key benefits include enhanced hydrogen production of nearly 10 mol (stoichiometric value) of hydrogen per mole of propane at 700 K, increased hydrogen purity (99% compared with 74% in SR) and no CO2 or CO production with the only impurity being CH4, all indicating a great potential of SESR of propane for hydrogen production. © 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.

Ding S.,Hefei University of Technology | Ding S.,Key Laboratory of Process Optimization and Intelligent Decision making | Yang S.,Hefei University of Technology | Yang S.,Key Laboratory of Process Optimization and Intelligent Decision making | And 4 more authors.
Knowledge-Based Systems | Year: 2014

The collection and combination of assessment data in trustworthiness evaluation of cloud service is challenging, notably because QoS value may be missing in offline evaluation situation due to the time-consuming and costly cloud service invocation. Considering the fact that many trustworthiness evaluation problems require not only objective measurement but also subjective perception, this paper designs a novel framework named CSTrust for conducting cloud service trustworthiness evaluation by combining QoS prediction and customer satisfaction estimation. The proposed framework considers how to improve the accuracy of QoS value prediction on quantitative trustworthy attributes, as well as how to estimate the customer satisfaction of target cloud service by taking advantages of the perception ratings on qualitative attributes. The proposed methods are validated through simulations, demonstrating that CSTrust can effectively predict assessment data and release evaluation results of trustworthiness. © 2013 Elsevier B.V. All rights reserved.

Fan D.,Tianjin University of Technology
2010 2nd International Conference on Industrial and Information Systems, IIS 2010 | Year: 2010

This paper summarized and classified series of risk factors that affect the risk management of project, then use widely-applied methods, such as Delphi and Analytical Hierarchy Process (AHP), to score these risk factors accordering to their importance degree. this paper also reported the results of a case study where the Analytical Hierarchy Process (AHP) was employed to make decision in project management. The paper uses the knowledge of AHP which combines the qualitative analysis with quantitative research and puts forward a new project risk management idea. © 2010 IEEE.

Chen Z.,Tianjin University of Technology
Applied Mechanics and Materials | Year: 2013

In this paper we propose a new steganographic method, which based on wet paper codes and wavelet transformation. The method is designed to embed secret messages in images' wavelet coefficients and depends on images' texture characters in local neighborhood. The receivers can extract secret bits from carrier images only by some matrix multiplications without knowing the formulas written by senders, which further improves steganographic security and minimizes the impact of embedding changes. The experimental results show that our proposed method has good robust and visual concealment performance and proves out it's a practical steganographic algorithm. © (2013) Trans Tech Publications, Switzerland.

Li H.,Nankai University | Jia D.,Tianjin University of Technology | Liu R.,Nankai University | Shen B.,Nankai University
Fluid Phase Equilibria | Year: 2015

The expanded liquid model was investigated and a modified solution model was proposed in this paper. The results showed that in the expanded liquid model the accuracy of the solubility parameters of supercritical CO2 (sc-CO2) can affect the change of the variables. If the solubility parameters of sc-CO2 are accurate, the variables in the expanded liquid model are nearly temperature-independent. If the inaccurate solubility parameters of sc-CO2 were used, the variables in the model would be slightly temperature-dependent. When using the solubility parameter of the solute as variable and calculating the solubility parameters of sc-CO2 with accurate method in the expanded liquid model, it is found that the solubility parameter of the solute is the linear function of the ratio of the solubility parameter and molar volume of sc-CO2 (δ1/v1). Based on this linear function, the expanded liquid model was modified. In the modified model, the slope and the intercept of the linear function were used as the fitting parameters. The modified model was compared with the other two-parameter expanded liquid models and the results showed the modified model can provide better correlation results with the average absolute relative deviation (AARD) being 13.31%. A group contribution method was developed to estimate the parameters in the modified model. Based on the modified model and the group contribution method, the solubilitis of most of the solutes in sc-CO2 can be estimated in the order of magnitude. © 2014 Elsevier B.V.

Li T.,Tianjin University of Technology
2012 2nd International Conference on Consumer Electronics, Communications and Networks, CECNet 2012 - Proceedings | Year: 2012

Practice teaching is an important link in teaching process. An analysis on features of practice teaching in the Britain university will bring enlightments and creative thoughts to our teaching process. Through analysis on its features of practice teaching, the thesis further explores a practice teaching method which is more scientific, operable and conforming to the actual situation of Chinese universities. The teaching method will cultivate students'ability to analyze and solve concrete problems independently as well as fully reflect a process of self-study and self-education among students. © 2012 IEEE.

Li T.,Tianjin University of Technology
Applied Mechanics and Materials | Year: 2013

"Internet of things" (IOT) is a very new concept created and developed in recent years. It had not been paid front attention until one or two years ago, when Chinese and US leaders announced emphasis on the development of IOT. To recover global economy under the economic and monetary crisis background, innovative technologies such as IOT are critical to create new economic development growth points. This paper first introduces the concept and origin of IOT, then describes basic principles of IOT, next illustrates the framework of IOT, and finally takes two examples to suggest applications of IOT. The paper intends to help readers recognize IOT as a whole, to hold the clue and venation of the development of IOT, and to forecast future trends of IOT development. © (2013) Trans Tech Publications, Switzerland.

Gong J.,Tianjin University of Technology
ACS Sustainable Chemistry and Engineering | Year: 2013

This paper describes an investigation regarding the influence of Ni precursors on catalytic performances of Ni/Al2O3 catalysts in glycerol steam reforming. A series of Ni/Al2O3 is synthesized using four different precursors, nickel nitrate, nickel chloride, nickel acetate, and nickel acetylacetonate. Characterization results based on N2 adsorption-desorption, X-ray diffraction, H2 temperature-programmed reduction, H2 chemisorption, transmission electron microscopy, and thermogravimetric analysis show that reduction degrees of nickel, nickel dispersion, and particle sizes of Ni/Al2O 3 catalysts are closely dependent on the anion size and nature of the nickel precursors. Ni/Al2O3 prepared by nickel acetate possesses the moderate Ni reduction degree, high Ni dispersion, and small nickel particle size, which possesses the highest H2 yield. Reaction parameters are also examined, and 550 C and a steam-to-carbon ratio of 3 are optimized. Moreover, coke deposition, mainly graphite species, leads to the deactivation of Ni/Al2O3 catalysts in glycerol steam reforming. Nickel chloride-derived Ni/Al2O3 catalysts suffer from severe coke deposition and low reaction activity due to large Ni particle size, low Ni dispersion, and residual chloride. © 2013 American Chemical Society.

Sunzhimin,Tianjin University of Technology
International Journal of Digital Content Technology and its Applications | Year: 2012

There is not only the known information but also uncertain information. Therefore, it can be seen as one gray system. Considering the above mechanism synthetically, we built two-dimensional gray model about groundwater pollution in this paper. It has the significant practical value for the research of gray simulation of groundwater pollution. It is reasonable and reliable, simulation and forecast the groundwater quality is uncertain information by gray mathematics, it provides a new method to simulate and predict the groundwater quality. It is than analytical solutions, and in some uncertain grey model parameters, such as dispersion coefficient, seepage velocity can get the range of gray. The result is a gray zone has great application advantages model and decision making. It is based on the numerical model also has universal applicability of surface water pollution and advection-diffusion equation.

Huang S.,Tianjin University of Technology | Shi J.,Tianjin University
Industrial and Engineering Chemistry Research | Year: 2014

Carbon materials have shown great potential in solving environmental problems resulting from the pollution from oils or organic solvents. However, developing low-cost and high-performance carbon-based three-dimensional (3D) frameworks is still a great challenge and highly desired. Herein, monolithic macroporous carbon (MMC) materials have been synthesized through the pyrolysis of kapok wadding materials (ultralow-cost fibrous materials, those comprised of fibers with the highest hollow degree in nature). Owing to their unique and superior properties, such as tubular structure, light weight, high porosity, desirable flexibility, and strong thermal/mechanical stability, the MMC materials exhibit a high loading capacity for organic solvents and oils (87-273 times their own weight) and excellent recyclability. Coupled with the easy, economical, and environment-friendly synthesis process, MMC materials will be promising candidates for industrial application for removing organic pollutants. Hopefully, the MMC materials and the corresponding synthesis approach will be further applied to wider applications (e.g., energy storage, synthesis of composite materials, and so on). © 2014 American Chemical Society.

Song G.,Tianjin University | Xin F.,Tianjin University | Yin X.,Tianjin University of Technology
Journal of Colloid and Interface Science | Year: 2015

A series of ZnFe2O4/TiO2 heterostructure photocatalysts with different mass percentages of ZnFe2O4 were synthesized through hydrothermal deposition method. The photocatalysts were characterized by SEM, TEM, XRD, XPS, and UV-vis DRS techniques. It is observed that ZnFe2O4 nanoparticles grew on the TiO2 nanobelts, and the obtained nanocomposites have ordered nanobelt structure with a high crystallinity. The photocatalytic activities of the nanocomposites were tested by photocatalytic reduction of CO2 in cyclohexanol under UV light (main wave length at 360nm) irradiation. The experimental results showed that the main products were cyclohexanone (CH) and cyclohexyl formate (CF). Compared with pure TiO2 and ZnFe2O4 samples, the obtained ZnFe2O4/TiO2 nanocomposites showed much higher photocatalytic performance. The loading amount of ZnFe2O4 was an important factor affecting the generation yields of the products. When the loading amount of ZnFe2O4 reached 9.78%, the ZnFe2O4/TiO2 heterostructure sample displayed the highest activity. The Z-scheme system reaction mechanism was proposed to explain the photocatalytic activity of the ZnFe2O4/TiO2 heterostructure sample. © 2014 Elsevier Inc.

Gao X.-Z.,Tianjin University of Technology
Proceedings - 2010 IEEE 17th International Conference on Industrial Engineering and Engineering Management, IE and EM2010 | Year: 2010

BT model is widely used in municipal infrastructure construction financing in recent years. The repurchase price of BT project is the core issues between project sponsor and BT investors. Repurchase price consists of two parts: project settlement price and investment income. Return on investment is closely related to bank lending rates, social discount rate and the risk level of investor tolerance. By utilizing CAPM model, the author analyzed how to determine the rate of return required by investors, which effects the return on investment of BT project. The calculating formula of return on investment of BT project is proposed according to different repurchase manner. © 2010 IEEE.

Li Z.Q.,Tianjin University of Technology
Applied Mechanics and Materials | Year: 2013

Planner multi-bar mechanisms are widely used in the machinery industry. In this article, a typical planner six-bar mechanism is researched. The kinematics and dynamics mathematical model is established for this kind of mechanism. On the basis of it, a relevant simulation is carried out through MATLAB/Simulink. Thus, the motion rules and stress state for all parts of the mechanism are described vividly. The simulation results show that this method is much more effective and efficient when the simulation is implemented for a certain machine system. Meanwhile, it provides a theoretical foundation and a better analytical approach of simulation for the design and analysis of complex multi-linkage mechanisms in the future. © (2013) Trans Tech Publications, Switzerland.

Elleuch A.,University of Sfax | Halouani K.,University of Sfax | Li Y.,Tianjin University of Technology
Journal of Power Sources | Year: 2015

Direct carbon fuel cell (DCFC) is a high temperature fuel cell using solid carbon as fuel. The use of environmentally friendly carbon material constitutes a promising option for the DCFC future. In this context, this paper focuses on the use of biomass-derived charcoal renewable fuel. A practical investigation of Tunisian olive wood charcoal (OW-C) in planar DCFCs is conducted and good power density (105 mW cm-2) and higher current density (550 mA cm-2) are obtained at 700 °C. Analytical and predictive techniques are performed to explore the relationships between fuel properties and DCFC chemical and electrochemical mechanisms. High carbon content, carbon-oxygen groups and disordered structure, are the key parameters allowing the achieved good performance. Relatively complex chain reactions are predicted to explain the gas evolution within the anode. CO, H2 and CH4 participation in the anodic reaction is proved. © 2015 Elsevier B.V.

Wang C.,Tianjin University of Technology
Advanced Materials Research | Year: 2013

Based on giving the scientific definition of efficiency of engineering cost consulting industry,this paper gives an empirical analysis on efficiency of engineering cost consulting industry in China by using DEA (Data Envelopment analysis) model. The main results are as follows: on one hand, the efficiency of engineering cost consulting industry in China is affected by environmental variables significantly and other factors, such as local economical-level and perfection in policy, have a positive influence on this industry. On the other hand, after excluding the environmental variables and random statistical factors, the industrial concentration and scale efficiency in all regions were low.As the regional analysis shows, the east region is best, the middle region is second and the west is the lowest. To promote the efficiency of the whole industry in China, related suggestions are given. © (2013) Trans Tech Publications, Switzerland.

Liu C.,Tianjin University | Wang J.,Tianjin University | Chen Y.-Y.,Tianjin University | Deng B.,Tianjin University | And 2 more authors.
International Journal of Neural Systems | Year: 2013

A novel closed-loop control strategy is proposed to control Parkinsonian state based on a computational model. By modeling thalamocortical relay neurons under external electric field, a slow variable feedback control is applied to restore its relay functionality. Qualitative and quantitative analysis demonstrates the performance of feedback controller based on slow variable is more efficient compared with traditional feedback control based on fast variable. These findings point to the potential value of model-based design of feedback controllers for Parkinson's disease. © 2013 World Scientific Publishing Company.

Yang J.,Tianjin University | Ling T.,Tianjin University | Wu W.-T.,Tianjin University | Liu H.,Tianjin University | And 4 more authors.
Nature Communications | Year: 2013

Monodisperse colloidal quantum dots with size dispersions <10% are of great importance in realizing functionality manipulation, as well as building advanced devices, and have been normally synthesized via 'bottom-up' colloidal chemistry. Here we report a facile and environmentally friendly 'top-down' strategy towards highly crystalline monodisperse colloidal PbS quantum dots with controllable sizes and narrow dispersions 5.5%<σ<9.1%, based on laser irradiation of a suspension of polydisperse PbS nanocrystals with larger sizes. The colloidal quantum dots demonstrate size-tunable near-infrared photoluminescence, and self-assemble into well-ordered two-dimensional or three-dimensional superlattices due to the small degree of polydispersity and surface capping of 1-dodecanethiol, not only serving as a surfactant but also a sulphur source. The acquisition of monodisperse colloidal PbS quantum dots is ascribed to both the quantum-confinement effect of quantum dots and the size-selective-vaporization effect of the millisecond pulse laser with monochromaticity and low intensity. © 2013 Macmillan Publishers Limited. All rights reserved.

Chao Y.,Tianjin University of Technology
Energy Science and Applied Technology - Proceedings of the 2nd International Conference on Energy Science and Applied Technology, ESAT 2015 | Year: 2015

A new combined forecasting model is presented in this paper, because mid-long term load forecasting has the problem of long time and low precision. First, this method utilizes the moving average method to adjust the original load data. Then, it combines the GM (1, 1) model and the BP neural network in a special way to forecast the mid-long term load. The validity of the new model has been evaluated by utilizing the actual data of a certain area. The experimental results indicate that the new combined model can improve the accuracy of load forecasting results, and it has an application value to mid-long term load forecasting. © 2016 Taylor & Francis Group, London.

Song G.,Tianjin University | Xin F.,Tianjin University | Chen J.,Tianjin University | Yin X.,Tianjin University of Technology
Applied Catalysis A: General | Year: 2014

A nanosheet of CdS-TiO2 with heterojunction was prepared by a two-step hydrothermal synthesis method and used as a photocatalyst for reducing CO2 in cyclohexanol. This heterostructured composite has been characterized by X-ray diffractometer (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and ultraviolet-visible (UV-vis) diffuse reflectance spectroscopy (DRS). The activity of the CdS-TiO2 composite was tested in a batch slurry bed reactor. The results showed that CO2 absorbed in cyclohexanol was reduced to cyclohexyl formate (CF) on conduction band and the absorbent cyclohexanol was oxidized to cyclohexanone (CH) on valance band of the photocatalyst. It was revealed that the highest formation rates of 20.2 μmol/(gcat h) and 20.0 μmol/(g cat h) for CF and CH could be obtained when TiO2/CdS with the molar ratio of 8 was used. Overall, this work provides a novel pathway for photocatalytically reducing CO2 and preventing the catalyst from photocorrosion. © 2014 Elsevier B.V.

Du H.,South China University of Technology | Du H.,Guizhou University for Nationalities | Ye J.,South China University of Technology | Zhang J.,Tianjin University of Technology | And 2 more authors.
Journal of Electroanalytical Chemistry | Year: 2011

In this report, a voltammetric sensor for simultaneous determination of hydroquinone (HQ) and catechol (CC) was developed at a glassy carbon electrode modified with graphene (GR/GCE). The separation of oxidation and reduction peak (ΔE) is decreased from 281 to 31 mV for HQ and from 250 to 26 mV for CC at GR/GCE, respectively. Separation of the oxidation peak potentials for HQ and CC was about 112 mV in 0.10 M acetate buffer solution (pH 4.5), and the anodic currents for the oxidation of both HQ and CC are greatly increased at GR/GCE, which makes it suitable for simultaneous determination of these compounds. Under the optimized condition, the anodic peak current of HQ is linear with the concentration of HQ from 1 × 10-6 to 5 × 10-5 M in the presence of 5 × 10-5 M CC. A detection limit of 1.5 × 10-8 M (S/N = 3) can be achieved. At the same time, the anodic current of CC is linear with the concentration of CC from 1 × 10-6 to 5 × 10-5 M with a detection limit of 1.0 × 10-8 M (S/N = 3) in the presence of 5 × 10-5 M HQ. The proposed sensor was successfully applied to the simultaneous determination of HQ and CC in tap water, and the results are satisfactory. © 2010 Elsevier B.V. All rights reserved.

Zhang Z.,Tianjin University of Technology and Education | Bin L.,Tianjin University of Technology | Jiang Y.,Tianjin University of Technology and Education
Optik | Year: 2014

In order to detect the slag content in the pouring or tapping stream of a basic oxygen furnace (BOF), a slag detection system is designed. The temperature of pouring stream is measured using the infrared temperature measurement system. The molten steel and slag could be distinguished according to their infrared emissivities that have a great difference in far-infrared band. A calibration method for the temperature threshold that is used to distinguish the molten steel and slag in a certain environment is proposed and the amount of slag is calculated in real-time. To avoid the situation that the amount of slag is incapable of being calculated due to the change of BOF angle (moving of pouring stream), a method that can quickly find the edge of the pouring stream is applied to implement the tracking of molten steel pouring stream. Experimental results prove that this system is effective to control the amount of slag that comes into the ladle.

Shi J.,Tianjin University of Technology
WIT Transactions on Information and Communication Technologies | Year: 2014

The development of student cadres is considered more and more important by every university. However, the research on it is still lack of practice and theory. This thesis, on the basis of the featured experience and achievement of development of student cadres of School of Management in Tianjin University of Technology, and expresses its points by three aspects as below. The first is the basic information and problems of student cadres of this school. The second is the development and training model of elite student cadres. The third is the preliminary achievement of development of elite student cadres. The road of featured development of student cadres is found, which set an example to students affairs of other universities. © 2014 WIT Press.

Wang C.,Tianjin University of Technology
WIT Transactions on Information and Communication Technologies | Year: 2014

The trusting and cooperative relation between government principal and Construction Agency (CA) which is based on the reputation effect from repeated game of principal and agent is a long-term incentive mechanism in government investment project. The importance of reputation effect is increasing in the construction agency competition, and the selection of CA based on reputation needs an effective measurement of the reputation for CA. The paper analyzed driving factors of CA reputation, establishing CA reputation measurement indexes system from the view of owners. And the primary empirical study has been finished. Only by this, the reputation evaluations can be introduced into CA Market Access management in order to establish a kind of cooperative relation in CA market and make it more perfect. © 2014 WIT Press.

Li W.,Tianjin University of Technology
WIT Transactions on Information and Communication Technologies | Year: 2014

Venture capital (VC) institutions will need to be innovative on the governance based on the principle of encouraging investment and prevention risk. The system innovation of operating structure determines the accommodation of industrial development and operations, thus affecting the industry development process. Analyzing the adaptability of the VC governance principles and the organizational form, it should facilitate the institutions in VC area to improve operational efficiency, reduce operational risk. In the realistic legal environment, the corporate and limited partnership are the main organizations in the VC area, depend on the different characteristics of the each operating modes. © 2014 WIT Press.