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Shijiazhuang, China

Hebei University of Science and Technology is one of the key, multi-disciplinary universities in Shijiazhuang, Hebei province. It offers undergraduate degrees in science and engineering courses. Wikipedia.


Yu X.,Fudan University | Yu X.,Hebei University of Science and Technology | Chen L.,Fudan University | Zhang M.,Fudan University | Yi T.,Fudan University
Chemical Society Reviews | Year: 2014

In this review, we focus on the types of smart supramolecular gels whose self-assembly processes are affected or even triggered by physical forces including sonication and mechanical stress (mechanical force). The types of gels that are responsive to sonication and mechanical stress are examined and summarised. The gels exhibit non-covalent interactions among the gelator molecules and show dynamic and reversible properties controlled by the stimuli. Upon stimulation, the gelators cause instant and in situ gelation of organic solvents or water with different modes and outcomes of self-assembly. On the other hand, sonication and mechanical stress, as external factors, can give rise to dynamic changes in microscopic morphology, optical properties, etc. Certain thixotropic supramolecular gels exhibit perfect self-healing characteristics. The driving forces and the mechanism of the self-assembly process and the responsive outcome of morphological and spectroscopic changes are discussed. Those supramolecular gels responding to sonication and mechanical stress offer a wide range of applications in fields such as smart and adaptive materials, switches, drug control and release, and tissue engineering. This journal is © the Partner Organisations 2014. Source


Jiang W.,Hebei University of Science and Technology
Nonlinear Analysis: Real World Applications | Year: 2012

By using the coincidence degree theory due to Mawhin and constructing suitable operators, we study the existence of solutions for a coupled system of fractional differential equations at resonance. An example is given to illustrate our result. © 2012 Elsevier Ltd. All rights reserved. Source


Liang Y.,Hebei University of Science and Technology
IEEE Transactions on Dielectrics and Electrical Insulation | Year: 2012

In this paper, numerical steady-state thermal analysis and ampacity evaluation of underground power cable systems placed in PVC ducts are presented. Between the outer surface of the cable and inner surface of the duct, there are three heat transfer modes, thermal conduction, thermal natural convection and thermal radiation. A Streamline-upwind/Petrov-Galerkin (SUPG) stabilized finite element method is proposed to solve the air governing formulas including the mass conservation equation, the momentum conservation equation and the energy conservation equation in the region between the cables and the containment ducts. During the numerical thermal field analysis, the Newton-Raphson iteration method is used to solve the weak electromagnetic-thermal coupling of underground power cable systems. The radiation heat exchange between the outer surface of the cable and inner surface of the duct is solved by the Newton-Raphson iteration method too. An experiment with several holes and three cables was conducted and the test results were compared with the results of analytical method and SUPG finite element method. The comparison reveals that the convection induced heat exchange is much stronger than the conduction induced heat exchange in the air between the outer cable surface and inner duct surface and calculation accuracy of SUPG finite element method is better than the analytical method. Finally, the Newton-Raphson iteration method is used to evaluate the ampacity of power cable systems placed in PVC ducts. © 2012 IEEE. Source


Yao W.,Hebei University of Science and Technology
Fuzzy Sets and Systems | Year: 2010

This paper deals with quantitative domain theory via fuzzy sets. It examines the continuity of fuzzy directed complete posets (dcpos for short) based on complete residuated lattices. First, we show that a fuzzy partial order in the sense of Fan and Zhang and an L-order in the sense of Bělohlávek are equivalent to each other. Then we redefine the concepts of fuzzy directed subsets and (continuous) fuzzy dcpos. We also define and study fuzzy Galois connections on fuzzy posets. We investigate some properties of (continuous) fuzzy dcpos. We show that a fuzzy dcpo is continuous if and only if the fuzzy-double-downward-arrow-operator has a right adjoint. We define fuzzy auxiliary relations on fuzzy posets and approximating fuzzy auxiliary relations on fuzzy dcpos. We show that a fuzzy dcpo is continuous if and only if the fuzzy way-below relation is the smallest approximating fuzzy auxiliary relation. © 2009 Elsevier B.V. All rights reserved. Source


Cui H.T.,Hebei University of Science and Technology
Applied Thermal Engineering | Year: 2012

An experimental setup was designed and built in which the paraffin was used as phase change materials and copper foam as filled materials. Experiments examining the heat charging process were carried out under two conditions: paraffin filled with and without copper foam. The time histories of the collected temperature under various conditions were plotted and the results were discussed. The results indicate that the foam material not only leads to a more uniform temperature distribution within the thermal energy storage unit, but also extensively shortens the charging time. © 2011 Elsevier Ltd. All rights reserved. Source

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