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Shijiazhuang, China

Shijiazhuang University of Economics is a university in Hebei, China under the provincial government. Wikipedia.

Zheng C.,Beijing Institute of Technology | Zheng C.,Shijiazhuang University of Economics | Cao C.,Beijing Institute of Technology | Ali Z.,Beijing Institute of Technology | Hou J.,Beijing Institute of Technology
Journal of Materials Chemistry A | Year: 2014

In the present work, we report the enhanced electrochemical performance of ball milled CoO nanoparticles for supercapacitor applications. The mechanical ball milling provides clean physical processes to prepare nanoparticles from CoO micropowders for excellent electrochemical performances. The performances of CoO samples at different milling times have been researched. With the increase of milling time the specific capacitance of CoO samples increases. The average size of CoO nanoparticles which have been milled for 96 h is estimated to be 5-20 nm by Transmission Electron Microscopy (TEM) analysis showing clear edges having superior boundary crystallinity. This clear edge superior boundary crystalline shape favours rapid electron and ion transport. The electrochemical behaviour is analyzed in a three electrode system using 1 M KOH solution as the electrolyte in terms of cyclic voltammetry, cyclic charge-discharge, and electrochemical impedance spectra. The CoO nanoparticle electrode exhibits a specific capacitance of 600 F g-1 at 0.5 A g-1 constant discharge current density. The high specific capacitance and the stability of the CoO nanoparticle electrode are attributed to good crystallinity and large specific surface area. The specific capacity retention is 96.6% at a current density of 2 A g-1 and 95.3% at a current density of 4 A g-1 over 2000 charge-discharge cycles. The excellent cyclic stability indicates that nanocrystalline CoO is an excellent supercapacitor electrode material. This journal is © the Partner Organisations 2014.

Wu J.-Z.,Beijing Institute of Technology | Wu J.-Z.,Shijiazhuang University of Economics | Zhang Q.,Beijing Institute of Technology
Expert Systems with Applications | Year: 2011

This paper proposes the concept of intuitionistic fuzzy weighted entropy, and presents a new method for intuitionistic fuzzy multicriteria decision making problems. We first introduce some classical intuitionistic fuzzy entropy measures and verify the entropy of the intuitionistic fuzzy set is the average value of the entropies of its intuitionistic fuzzy values. Then, we present the concept of the intuitionistic fuzzy weighted entropy, which is a natural extension of the entropy for intuitionistic fuzzy sets. Some important weight entropy measures, such as the weighted Szmidt and Kacprzyk entropy, the weighted De Luca-Termini entropy, the weighted score function based entropy, and the weighted min-max entropy, are also given. According to the minimum entropy principle, we establish the programming model to generate optimal weight of criteria, and present the corresponding multicriteria decision making method. Finally, two illustrative examples are given to verify the developed approach. © 2010 Elsevier Ltd. All rights reserved.

An H.,Shijiazhuang University of Economics
Jisuan Wuli/Chinese Journal of Computational Physics | Year: 2014

To study linkage fluctuation of double variables of time series, we took London Gold and Au9999. Model of linkage fluctuation is consisted of characters {P, N, M}, using coarse graining process. Nodes of complex network are 5-symbol strings. Linkage fluctuation complex network is composed of all models and link edges between them. It indicates that models have power-law distribution, clustering and periodicity. Transmission and evolution are finished mainly by few models. It provides an analyzing method for many kinds of double variables of time series and ideas for general law of multi-variables of time series, as well. ©, 2014, The Editorial Board of Chinese Journal of Computational Physics. All right reserved.

Li Y.-C.,Beijing Normal University | Li Y.-C.,Shijiazhuang University of Economics | Zhu J.-R.,Beijing Normal University
Applied Microbiology and Biotechnology | Year: 2014

N-acyl homoserine lactone (AHL)-based quorum sensing (QS) has been recognized to play an important role in the formation of biofilm. However, aerobic granular sludge is considered as a special biofilm, and its biological implication and role of AHL-based QS still remain unclear. This study investigated the role of AHL-based QS in aerobic granulation. Results showed that AHLs were necessary to the typical aerobic granulation, and AHL-associated coordination of bacteria in sludge aggregation was sludge density dependent only when it reached a threshold of 1.010 g/mL; AHL-based QS was activated to regulate aerobic granulation. Furthermore, a quorum quenching method was firstly adopted to investigate the role of AHLs in aerobic granules. Results showed inhibition of AHL by acylase that reduced the AHL content in aerobic granules and further weakened its attachment potential, which proved that AHLs play an important role in the formation of aerobic granules. Additionally, the assay of quorum quenching not only proved that AHL-based QS could regulate EPS production but also provided additional evidence for the role of AHLs in aerobic granulation by regulating EPS content and its component proportion. © 2014 Springer-Verlag.

Cao H.,Shijiazhuang University of Economics
Active and Passive Electronic Components | Year: 2016

Transformerless photovoltaic (PV) power system is very promising due to its low cost, small size, and high efficiency. One of its most important issues is how to prevent the common mode leakage current. In order to solve the problem, a new inverter is proposed in this paper. The system common mode model is established, and the four operation modes of the inverter are analyzed. It reveals that the common mode voltage can be kept constant, and consequently the leakage current can be suppressed. Finally, the experimental tests are conducted. The experimental results verify the effectiveness of the proposed solution. © 2016 Haiyan Cao.

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