Zhejiang, China
Zhejiang, China

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Yu Z.,Zhejiang University of Technology | Lv Y.,Zhejiang University of Technology | Lv Y.,Quzhou University | Yu C.,Zhejiang University of Technology
Organic Process Research and Development | Year: 2012

An expeditious and multikilogram-scale process for the Balz-Schiemann synthesis of o-difluorobenzene from ofluoroaniline via two separate continuous flow reactors in 90.0% yield has been set up. The main steps involved the generation of stable diazonium fluoborate intermediate in situ via continuous diazotization reactor at 20 °C, and the choice of odifluorobenzene as cosolvent to achieve the continuous flow fluorodediazoniation system. Reaction time of both steps could be brought down to within 10 s and 2 min, respectively, by increasing the reaction temperature and thereby taking advantage of improved mass and heat American Chemical Society. © 2012 American Chemical Society.

Yu Z.,Zhejiang University of Technology | Lv Y.,Zhejiang University of Technology | Lv Y.,Quzhou University | Yu C.,Zhejiang University of Technology | Su W.,Zhejiang University of Technology
Organic Process Research and Development | Year: 2013

A practical continuous nitration process for 2,5-difluoronitrobenzene via nitration of p-difluorobenzene with fuming nitric acid in 98% yield has been developed. The excellent yield of this liquid/liquid biphasic reaction resulted from the advantages of a continuous flow system. The 2.0 equiv sulfuric acid could be used three times directly with product yields in the range of 96-98%, and further recycling of waste acid could be partly achieved by adjusting the concentration of sulfuric acid. Reaction time could be brought down to 2 min by increasing the reaction temperature and thereby taking advantage of superior mass and heat transfer of this continuous flow system. © 2013 American Chemical Society.

Hu L.,Quzhou University
RISTI - Revista Iberica de Sistemas e Tecnologias de Informacao | Year: 2016

The integration of computer network and foreign language teaching is quite different from computer-assisted instruction in essence: Computer-assisted instruction focuses on assistant function, namely, assisting teachers to improve the teaching effect; while the integration of computer and teaching becomes an organic component of the whole teaching system. The paper carries out a discussion from following aspects based on investigations and surveys on a large number of literatures: Through the sound function of "individuation" feature emphasized by Web2.0 computer network environment in terms of the teaching mode: (such as Blog, Wiki, etc.), the communication between teachers and students as well as among students is promoted to a higher level so as to realize the innovation and share of knowledge. The application of computer network environment interaction technology based on Web2.0 into English language teaching mode can construct a kind of new interactive teaching mode between teachers and students.

Zhang Y.,Quzhou University
Engineering Transactions | Year: 2015

Electromigration (EM) in solder joints under high current density has become a critical reliability issue for the future high density microelectronic packaging. A practical method of atomic density integral (ADI) for predicting solder bump electromigration reliability is proposed in this paper. The driving forces in electromigration include electron wind force, stress gradient, temperature gradient as well as atomic density gradient. The electromigration simulation is performed on flip chip ball grid array (FCBGA) package based on ADI method, and the simulation results for void generation and time to failure (TTF) have a reasonably good correlation with the testing results. Orthogonal experimental design has been used to evaluate the effect of design parameters on TTF of electromigration. Based on this study, some practical recommendations are made to optimize the package design and improve the solder bump electromigration reliability. © 2015, Polish Academy of Sciences. All rights reserved.

We present a local convergence analysis of inexact Newton method for solving singular systems of equations. Under the hypothesis that the derivative of the function associated with the singular systems satisfies a majorant condition, we obtain that the method is well defined and converges. Our analysis provides a clear relationship between the majorant function and the function associated with the singular systems. It also allows us to obtain an estimate of convergence ball for inexact Newton method and some important special cases. © 2014 Fangqin Zhou.

Zhou F.,Quzhou University
The Scientific World Journal | Year: 2014

We study the local convergence properties of inexact Newton-Gauss method for singular systems of equations. Unified estimates of radius of convergence balls for one kind of singular systems of equations with constant rank derivatives are obtained. Application to the Smale point estimate theory is provided and some important known results are extended and/or improved. © 2014 Fangqin Zhou.

Song X.H.,Quzhou University | Wu S.L.,Quzhou Colledge of Technology
Applied Mechanics and Materials | Year: 2013

This paper describes the inherent characteristics, dynamic response and dynamic stability dynamics of vibration capability that impacts of high-speed electric spindle. Taking the high-speed, high-power electric spindle milling center on as the object of the research, modal analyzing of electric spindle with the finite element software ANSYS Workbench, researching the spindle modes, natural frequencies and critical speed of electric spindle, to get each frequency and vibration type, pointed the affection of what spindle away from the anti-vibration frequency requirements, well before bearing stiffness and damping of the vibration to the spindle system. It provides the necessary basis for further dynamic analysis by modal analysis. © (2013) Trans Tech Publications, Switzerland.

Lyu C.,Quzhou University
Tumu Jianzhu yu Huanjing Gongcheng/Journal of Civil, Architectural and Environmental Engineering | Year: 2014

Reasonable choice of rock strength criteria is crucial for stress and displacement prediction and support design in tunnel engineering. Based on Mogi-Coulomb strength criterion and elastic-perfectly plastic model, analytical solutions of stress and displacement for surrounding rocks around a circular tunnel were derived The intermediate principal stress coefficient was used to present the intermediate principal stress effect. The results in this study were compared with the current solutions in the literatures and the influence of intermediate principal stress and shear strength parameters of surrounding rocks was discussed. The results showed extensive applicability and the Mohr-Coulomb strength criterion and Matsuoka-Nakai criterion are two special cases; when the intermediate principal stress coefficient b was equals to 0.5, the results indicated that the intermediate principal stress effect and its range for rock strength; the influence of cohesion and internal friction angle on the plastic radius and tunnel wall displacement was significant; Care should be taken to the effects of intermediate principal stress and shear strength parameter variations of surrounding rocks on tunnel design and construction.

Huang Y.F.,Quzhou University
Applied Mechanics and Materials | Year: 2011

For the problem that power circulation and low efficiency easily occur in closed Continuously Variable Transmission (CVT), the input-coupled CVT drive system was taken as the object of study, the fundamental structure and working principle of the input-coupled CVT drive system were briefly introduced. In the circumstances of no energy loss, the sufficient condition for the input-coupled CVT drive system to realize power split was deduced in detail. Next, the meshing efficiency expression for the 2K-H type differential gear train was simplified under the sufficient condition. The condition for maximizing the meshing efficiency of the 2K-H type differential gear train was demonstrated. Finally, the conclusion was verified by example. The results show that the condition of maximum meshing efficiency ensures the highest meshing efficiency of the 2K-H type differential gear train from the design point of view. © (2011) Trans Tech Publications, Switzerland.

Lei H.,Quzhou University
Advanced Materials Research | Year: 2014

This article Synthesis of carbohydrate ligands of coordination ability, to react with metal Chlorides to get more stable complexes, and elemental analysis, infrared, Ultraviolet Spectroscopic characterization and analysis of nuclear magnetic resonance. Characterization of its structure and study on the hydrolysis activity of pnitrophenyl picolinate lipid and the activity of pnitrophenol solution of phosphate, disodium macrocyclic polyamine catalyzed by macrocyclic polyamine metal complexes. The results show that the effect of hydrolytic activity of macrocyclic polyamine complexes is much larger than the hydrolysis activity of ordinary metal complexes; it can be important significance to find a better way of cutting nucleic acid by hydroxylation. © (2014) Trans Tech Publications, Switzerland.

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