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Influence of Prior Austenite Deformation and Non-Metallic Inclusions on Ferrite Formation in Low-Carbon Steels

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Journal of Iron and Steel Research International 2010年第6期17卷 36-42页

作者： ZHANG Chi XIA zhi-xin YANG zhi-gang liu zhi-hao Department of Materials Science and Engineering Tsinghua University Beijing 100084 China

Effects of prior austenite deformation and non-metallic inclusions on the ferrite nucleation and grain refine- ment of two kinds of low-carbon steels have been studied. The ferrite nucleation on MnS and V（C, N） is observed. The combination of thermomeehanical processes with adequate amounts of non-metallic inclusions formed in low-car- bon steels could effectively refine the grain size and the microstructure. Ferrite nucleated on the single MnS or V（C, N） inclusions and complex MnS＋V（C,N） inclusion. The proper addition of elements S and V could effectively promote the formation of ferrite and further refinement of ferrite grains.

关键词： austenite deformation non-metallic inclusion ferrite nucleation low-carbon steel

Regional Stability of Positive Switched Linear Systems with Multi-equilibrium Points

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International Journal of Automation and computing 2017年第2期14卷 213-220页

作者： zhi liu Yu-Zhen Wang School of Control Science and Engineering Shandong University Ji'nan 250061 China

This paper studies the regional stability for positive switched linear systems with multi-equilibrium points （PSLS-MEP）. First, a sufficient condition is presented for the regional stability of PSLS-MEP via a common linear Lyapunov function. Second, by establishing multiple Lyapunov functions, a dwell time based condition is proposed for the regional stability analysis. Third, a suprasphere which contains all equilibrium points is constructed as a stability region of the considered PSLS-MEP, which is less conservative than existing results. Finally, the study of an illustrative example shows that the obtained results are effective in the regional stability analysis of PSLS-MEP.

关键词： Regional stability positive switched linear system multi-equilibrium points common linear Lyapunov function multipleLyapunov function.

Automatic pattern acquisition from game records in GO

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The Journal of China Universities of Posts and Telecommunications 2007年第1期14卷 100-105页

作者： liu zhi-qing DOU Qing School of Software Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

Computer programs of GO are typically constructed using a knowledge-based approach with heuristics and pattern matching because of enormous complexities of the game. In this approach, quantity, quality, and consistency of patterns used in computer programs of GO to a large extent determine the strengths of the programs. This study presents an effective method to acquire automatically comprehensive GO patterns from large collections of game records. Statistical usages of the patterns ensure consistency and quality of the patterns, which in turn can help improve the strengths of computer GO programs. Additionally, statistical usages of patterns from different sources of game records clearly show subtle and significant discrepancies among various types of GO players, and clarify certain myths in the playing of GO.

关键词： computer games automatic knowledge acquisition,spatial patterns recognition

Repurposing cancer drugs to treat neurological diseases–Src inhibitors as examples

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Neural Regeneration Research 2017年第6期12卷 910-911页

作者： Da zhi liu Department of Neurology University of California at Davis

Aberrant cell cycle diseases：The cell cycle is an irreversible,ordered set of events that normally leads to cellular division,consisting of quiescent state（G0）,the first gap phase（G1）,DNA synthetic phase（S）,the second gap phase（G2）and mitosis phase（M）.After the cell has split into its two daughter cells,the new cells enter either G1 or G0.

关键词： neurological cycle irreversible daughter normally neuronal postmortem thrombin split DNA

Effect of preparation method on the bimetallic NiCu/SAPO-11 catalysts for the hydroisomerization of n-octane

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Journal of Energy Chemistry 2019年第1期28卷 23-30页

作者： zhichao Yang Yunqi liu Yanpeng Li Lingyou Zeng zhi liu Xueying liu Chenguang liu State Key Laboratory of Heavy Oil Processing Key Laboratory of Catalysis China National Petroleum Corp. (CNPC) China University of Petroleum (East China)

The bimetallic NiCu/SAPO-11 catalysts were prepared by co-impregnation, sequential impregnation, coprecipitation, and mechanical mixing methods. Powder X-ray diffraction, nitrogen adsorption-desorption,temperature-programmed desorption of ammonia, transmission electron microscopy, temperatureprogrammed reduction of hydrogen, and X-ray photoelectron spectroscopy were used to characterize the physicochemical properties of the catalysts. The catalytic performance of the catalysts was assessed by the hydroisomerization of n-octane. Results indicated that the conversion of n-octane and selectivity to n-octane isomers were related to the preparation methods of the catalysts. The catalysts with Ni-Cu alloy effectively restrained the hydrogenolysis reaction that decreases the selectivity of isomerization. The catalyst prepared by the mechanical mixing of NiO and CuO hardly formed Ni-Cu alloy, showing obvious hydrogenolysis and low selectivity to n-octane isomers. The unbalance between the metal and acid sites resulted in the low conversion of n-octane and selectivity to n-octane isomers. Among all the catalysts,the catalyst prepared by the co-impregnation method exhibited high catalytic activity and selectivity to n-octane isomers.

关键词： Ni-Cu/SAPO-11 Bimetallic Preparation method Hydroisomerization Hydrogenolysis n-Octane

Balanced augmented jackknife empirical likelihood for two sample U-statistics

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Science China Mathematics 2018年第6期61卷 1129-1138页

作者： Conghua Cheng Yiming liu zhi liu Wang Zhou School of Mathematics and Statistics Zhaoqing University Division of Mathematical Sciences School of Physical and Mathematical SciencesNanyang Technological University Department of Mathematics University of Macao Department of Statistics and Applied Probability National University of Singapore

In this paper, we investigate the two sample U-statistics by jackknife empirical likelihood(JEL),a versatile nonparametric approach. More precisely, we propose the method of balanced augmented jackknife empirical likelihood(BAJEL) by adding two artificial points to the original pseudo-value dataset, and we prove that the log likelihood ratio based on the expanded dataset tends to the χ~2 distribution.

关键词： jackknife empirical likelihood U-statistics ROC curves balanced augmented empirical likelihood

Calculation and Analysis of Valence Electron Structure of Mo_2C and V_4C_3 in Hot Working Die Steel

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Journal of Iron and Steel Research International 2006年第1期13卷 50-56页

作者： liu Yan liu zhi-lin ZHANG Cheng-weit College of Material and Chemical Engineer Liaoning Institute of Technology Jinzhou 121001 Liaoning China China National Oil and Gas Exploration and Development Corporation Beijing 100011 China

Taking the hot working die steel （HWDS） 4Cr3Mo2NbVNi as an example, the phase electron structures （PES） and the biphase interface electron structures （BIES） of Mo2C and V4 C3 , which are two kinds of important carbides precipitated during tempering in steel were calculated, on the basis of the empirical electron theory of solids and molecules and the improved TFD theory. The influence of Mo2 C and V4 C3 on the mechanical properties of HWDS has been analyzed at electron structure level, and the fundamental reason that the characteristic of the PES and the BIES of carbides decides the behavior of them has been revealed.

关键词： phase structure factor interface conjunction factor hot working die steel carbide

Robust Control Strategy for the Speed Control of Brushless DC Motor

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Journal of Harbin Institute of Technology(New Series) 2013年第2期20卷 90-94页

作者： zhi liu Bai-Fen liu School of Traffic and Transportation Engineering Central South University School of Electrical and Electronic Engineering East China Jiaotong University

Brushless DC motor ( BLDCM) speed servo system is multivariable,nonlinear and strong coupling. The parameter variation, the cogging torque and the load disturbance easily influence its performance. Therefore,it is difficult to achieve superior performance by using the conventional PID controller. To solve the deficiency,the paper represents the algorithm of active-disturbance rejection control ( ADRC) based on back-propagation ( BP) neural network. The ADRC is independent on accurate system and its extended-state observer can estimate the disturbance of the system accurately. However,the parameters of Nonlinear Feedback ( NF) in ADRC are difficult to obtain. So in this paper,these parameters are self-turned by the BP neural network. The simulation and experiment results indicate that the ADRC based on BP neural network can improve the performances of the servo system in rapidity,control accuracy,adaptability and robustness.

关键词： brushless DC motor ( BLDCM) BP ( back propagation algorithms) ADRC ( active-disturbance rejection control) parameters self-turning.

Cognitive Study of the Linear Order of the English Construction“X and Y”

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Journal of Electronic Science and Technology 2017年第1期15卷 20-24页

作者： Yong-zhi liu Fan Fan College of Foreign Languages&Cultures Chengdu University of TechnoiogyChengdu 610059China

The English construction “X and Y ”refers to the coordination of two words with and as conjunction, X and Y being of the same part of speech and parallel meanings. This paper is a cognitive study of the linear order of the English construction “X and Y ”from the perspectives of cognitive salience, cognitive iconicity, and cognition of formal rules. The linear characteristics of “X and Y ” are revealed as follows： 1）salience-downgrading order; 2） chronological iconicity;3） cognition of alphabetic order and prosodic order.

关键词： cognition conjunction syntactic linguistics salient formal bread X and Y discussion father