Taiyuan University of Technology

Taiyuan, China

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

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

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

Hou J.,Taiyuan University of Technology
Journal of Physics A: Mathematical and Theoretical | Year: 2010

Let H and K be (finite-or infinite-dimensional) complex Hilbert spaces. A characterization of positive completely bounded normal linear maps from B(H) into B(K) is given, which particularly gives a characterization of positive elementary operators including all positive linear maps between matrix algebras. This characterization is then applied to give a representation of quantum channels (operations) between infinite-dimensional systems. A necessary and sufficient criterion of separability is given which shows that a state ρ on H ⊗ K is separable if and only if (Φ ⊗ I)ρ ≥ 0 for all positive finite-rank elementary operators Φ. Examples of NCP and indecomposable positive linear maps are given and are used to recognize some entangled states that cannot be recognized by the PPT criterion and the realignment criterion. © 2010 IOP Publishing Ltd.

Guo R.,Taiyuan University of Technology | Hao H.-Q.,Taiyuan University of Technology
Annals of Physics | Year: 2014

In nonlinear erbium doped fibers, the Hirota-Maxwell-Bloch system with higher order effects usually governs the propagation of ultrashort pulses. New soliton solutions for this system are constructed on the constant backgrounds including one and two breathers and first and higher order localized soliton solutions. Considering the influence of higher order effects, propagation properties of those soliton solutions are discussed. © 2014 Elsevier Inc.

Teng K.,Taiyuan University of Technology
Nonlinear Analysis: Real World Applications | Year: 2013

In this paper, we establish the existence of two nontrivial solutions to a class of nonlocal hemivariational inequalities depending on two parameters. Our methods are based on critical point theory for non-differentiable functionals. © 2012 Published by Elsevier Ltd.

Xue H.-B.,Taiyuan University of Technology
Annals of Physics | Year: 2013

We study theoretically the full counting statistics of electron transport through side-coupled double quantum dot (QD) based on an efficient particle-number-resolved master equation. It is demonstrated that the high-order cumulants of transport current are more sensitive to the quantum coherence than the average current, which can be used to probe the quantum coherence of the considered double QD system. Especially, quantum coherence plays a crucial role in determining whether the super-Poissonian noise occurs in the weak inter-dot hopping coupling regime depending on the corresponding QD-lead coupling, and the corresponding values of super-Poissonian noise can be relatively enhanced when considering the spins of conduction electrons. Moreover, this super-Poissonian noise bias range depends on the singly-occupied eigenstates of the system, which thus suggests a tunable super-Poissonian noise device. The occurrence-mechanism of super-Poissonian noise can be understood in terms of the interplay of quantum coherence and effective competition between fast-and-slow transport channels. © 2013 Elsevier Inc.

Teng K.,Taiyuan University of Technology
Nonlinear Analysis: Real World Applications | Year: 2015

In this paper we study the fractional Schrödinger type equations (-Δ)su+V(x)u=f(x,u),x ∈ ℝN. The nonlinearity f is assumed to be asymptotically linear or superquadratic growth. Using variant Fountain theorems, we prove the existence of infinitely many nontrivial high or small energy solutions. © 2014 Elsevier Ltd. All rights reserved.

Qiao J.,Taiyuan University of Technology
Journal of Materials Science and Technology | Year: 2013

The advanced fabrication of in-situ dendrite/metallic glass matrix (MGM) composites is reviewed. Herein, the semi-solid processing and Bridgman solidification are two methods, which can make the dendrites homogeneously dispersed within the metallic glass matrix. Upon quasi-static compressive loading at room temperature, almost all the in-situ composites exhibit improved plasticity, due to the effective block to the fast propagation of shear bands. Upon quasi-static tensile loading at room temperature, although the composites possess tensile ductility, the inhomogeneous deformation and associated softening dominates. High volume-fractioned dendrites and network structures make in-situ composites distinguishingly plastic upon dynamic compression. In-situ composite exhibits high tensile strength and softening (necking) in the supercooled liquid region, since the presence of high volume-fractioned dendrites lowers the rheology of the viscous glass matrix at high temperatures. At cryogenic temperatures, a distinguishingly-increased maximum strength is available; however, a ductile-to-brittle transition seems to be present by lowering the temperature. Besides, improved tension-tension fatigue limit of 473MPa and four-point-bending fatigue limit of 567MPa are gained for Zr58.5Ti14.3Nb5.2Cu6.1Ni4.9Be11.0 MGM composites. High volume-fraction dendrites within the glass matrix induce increased effectiveness on the blunting and propagating resistance of the fatigue-crack tip. The fracture toughness of in-situ composites is comparable to those of the toughest steels and crystalline Ti alloys. During steady-state crack-growth, the confinement of damage by in-situ dendrites results in enhancement of the toughness. © 2013.

Huang X.,Taiyuan University of Technology
Journal of Alloys and Compounds | Year: 2015

Dual-model upconversion luminescence in NaGdF4:Nd/Yb/Tm@NaGdF4:Eu/Tb core-shell nanoparticles under 980 and 808 nm laser excitation has been demonstrated. Effects of the doping concentrations of Eu3+ and Tb3+ ions on the upconversion emissions were investigated, and two possible processes were proposed as mechanisms responsible for the dual-model upconversion luminescence. These upconverting nanoparticles are promising for biological applications. © 2014 Elsevier B.V. All rights reserved.

Taiyuan University of Technology | Date: 2014-09-24

A double-loop control system with a single hydraulic motor relates to a technical field of hydraulic transmission control, including a hydraulic motor (1), a positive control loop (2), a negative control loop (3), a hydraulic pump (4), an accumulator (5), and an oil tank, wherein the hydraulic motor (1) adopts a unique thrust structure with four inlet/outlet ports; the positive control loop (2) and the negative control loop (3) independently control the hydraulic motor (1), wherein the positive control loop (2) and the negative control loop (3) drive together or only one drives; or braking kinetic energy and potential energy of loads are stored in the accumulator (5) for energy recovery. The present invention uses only one hydraulic motor for satisfying different work conditions and different load driving requirements with advantages such as simple structure, high system reliability and high energy efficiency.

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