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中国化学会第十三届金属有机化学学术讨论会

作者： Congyang Wang. Qiuling Song, and Zhenfeng Xi college of chemistry, Peking university, Beijing 100871, china

＜正＞ Isothiocyanates RN=C=S are a class of important synthetic intermediates. Site-selectivities of these unsymmetrical heterocumulenes toward nucleophiles are of great interest in heteroatom chemistry and controlled synthetic chemistry. Carbophilic addition of organolithium reagents to isothiocyanates RN=C=S （1） usually takes place to generate lithium thioamidates 2 （eq 1）. Trapping of these lithiated intermediates with electrophiles provides

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Research on the Monitoring System of CNC Grinding Process Based on Acoustic Emission

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武汉理工大学学报 2006年第S1期28卷 310-313页

作者： HU Zhongxiang1,TENG Jiaxu1,YANG Junwei1,HUO Xiaojing2,SHI Xiaojun1 (1.National Key Laboratory for Remanufacturing,Beijing 100072,china 2.M&E Engineering college of Hebei Agricultural university,Baoding 071001,china) National Key Laboratory for Remanufacturing Beijing 100072China M&EEngineering college of Hebei Agricultural university Baoding 071001China

Using on-line monitoring during the CNC grinding process,the hazard case such as the crushing of grinding wheel and various safety accidents could be avoided,and the optimum time for dressing and replacing grinding wheel could also be determined,and hence,the service life of the grinding wheel could be prolonged and grinding quality could be improved. To overcome the limitation of some traditional techniques in which some parameters including the grinding power and force,torque and so on were monitored,the acoustic emission (AE) technique,which provides high sensitivity and responding speed,were developed in the present paper. The mechanism of AE during grinding was reviewed. Moreover,a virtual AE monitoring system,which could monitor the grinding state under different working conditions during the grinding,has been developed based on the Virtual Instruments technique. Some experiments were also performed on the internal grinder. The results showed that the AE signals became stronger with increasing the main shaft speed and grinding depth or decreasing the distance between the AE sensor and grinding area.

关键词： on-line monitoring virtual instruments CNC grinding acoustic emission

Realization and Optimization of Video Encoder Based on TMS320C6455 DSPs

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Realization and Optimization of Video Encoder Based on TMS32...

2010 International Conference on Computer,Mechatronics, Control and Electronic Engineering (CMCE 2010)

作者： Wang Gang Department of Communication Engineering School of Electrical & Information Engineering Beihua university jilin 132021,china Wang Shigang Department of Communication Engineering School of Communication Engineering jilin university changchun 130012,china

In view of serious cache missing of each macro block of MPEG-4(Moving Picture Experts Group-4) video encoder in transmission and the video sequence frame rate is low,We proposed the motion estimation algorithm optimization,Cache optimization,SAD(Sum of Absolute Difference) and pixel interpolation optimization,data removal using EDMA(Extended Direct Memory Access),and it has enhanced memory speed and realized the MPEG-4 video encoder optimization on TMS320DM6455 DSP *** performance of the video encoder is evaluated,the experimental result proved that the image and the video processing function computing speed increase 17.18～139.98 times and the coding efficiency is improved eleven times at least,and the research results can be used to real time video communication for more than 25 frames per second.

关键词： Digital Signal Processors(DSPs) Video Encoder Optimization Embedded Systems

Fuzzy Scheduling of Coupled Customers toa Queueing Network with Parallel Servers

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Systems Science and Systems Engineering 1998年第4期8卷 482-487页

作者： ZHU Xiaomin(Department of Economics college of Economics and AdministratinNorthern Jiaotong university Beijing 100044, china)ZHANG Runtong(Institute of Information Systems college of Economics and AdministrationNorthern Jiaotong university Beijing 100044,

In this paper we consider a queueing network consisting of two parallel servers and threearrival streams generated by independent Poisson sources. Each server has its own queue and receivescustomers from its own arrival stream. A third arrival stream consists of customers which place resourcedemands on both servers, which are handled separately by each server once the request is made. Eachservice time is independent and exponentially distributed. Each customer in the system pays a holdingcost per unit time. The objective is to dynamically determine the optimal scheduling policy to the thirdstream of conupled customers. based on the state of the system, so as to minimize the average cost. Thismodel is new, and has Policy implications for computer or communication networks. A fuzzy approachis presented to solve this problem. Simulation shows that the approach is efficient and promising.

关键词： Fuzzy Scheduling of Coupled Customers toa Queueing Network with Parallel Servers

Direct simulation of MHD flows in dual-coolant liquid metal fusion blanket using a consistent and conservative scheme

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Theoretical & Applied Mechanics Letters 2011年第1期1卷 58-61页

作者： Shi-Jing Xu and Ming-Jiu Ni~(a)) college of Physical Sciences,Graduate university of Chinese Academy of Sciences,Beijing 100049,china college of Physical Sciences Graduate University of Chinese Academy of Sciences Beijing 100049 China

Direct simulation of 3-D MHD(magnetohydrodynamics) flows in liquid metal fusion blanket with flow channel insert(FCI) has been *** kinds of pressure equilibrium slot (PES) in FCI,which are used to balance the pressure difference between the inside and outside of FCI,are considered with a slot in Hartmann wall or a slot in side wall,*** velocity and pressure distribution of FCI made of SiC/SiC_f are numerically studied to illustrate the 3-D MHD flow effects,which clearly show that the flows in fusion blanket with FCI are typical three-dimensional issues and the assumption of 2-D fully developed flows is not the real physical problem of the MHD flows in dual-coolant liquid metal fusion *** optimum opening location of PES has been analyzed based on the 3-D pressure and velocity distributions.

关键词： MHD flows consistent and conservative scheme flow channel insert(FCI) dual-coolant liquid metal blanket

Synthesis of Cinchonidine-TBS-SCH2 CH2OR Catalysts and Their Applications in Asymmetric Catalysis

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Synthesis of Cinchonidine-TBS-SCH2 CH2OR Catalysts and Their...

中国化学会第八届天然有机化学学术研讨会

作者： Liang Zhou~*,Yonghua Wang college of chemistry and Chemical Engineering,Southwest university,Chongqing 400715,PR china

＜正＞The cinchona alkaloids,with cinchonidine（CD）as a prominent member,are among the most well-known natural *** extensive and eventful medicinal history of cinchonidine is the main reason for its *** is commercial...

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Preparation of Titanium Nitride Nanoparticles from a Novel Refluxing Derived Precursor

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Journal of Wuhan university of Technology(Materials Science) 2011年第3期26卷 429-433页

作者：刘飞姚亚东 college of Materials Science and Engineering Sichuan University

Titanium nitride （TiN） nanoparticles were prepared from a novel refluxing-derived *** organic/inorganic hybrid precursor was prepared by a two-stage refluxing method using hydrous TiO2 as titania source and n-dodecane as carbon *** precursor was heat-treated to 1 200 °C in flowing ammonia （NH3） to get TiN *** phase and chemical compositions were investigated by means of XRD,Raman spectroscopy and *** microstructure was studied by means of SEM,TEM and *** pattern indicated that the product was face-centered cubic TiN with a lattice constant a = 4.236 · and average crystallite sizes of 35.2 *** spectra indicated that long time refluxing results in Alkane dehydrogenation and the formation of coke on TiO2 *** presence in TiN lattice was confirmed by XPS *** particle size that was showed by Electron microscopy photographs ranged from 20 to 60 nm.

关键词： titanium nitride coke refluxing dehydrogenation raman spectroscopy

The Shannon capacity of a communication channel,graph Ramsey number and a conjecture of Erds

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Chinese Science Bulletin 2001年第24期46卷 2025-2028页

作者： LI Yushengcollege of Sciences, Hohai university, Nanjing 210098, china college of Sciences Hohai University Nanjing China

We briefly introduce the connection between the Shannon capacity of a communication channel and graph Ramsey number, which may receive attention from researchers on communication theory and graph theory.

关键词： communication channel Shannon capacity Ramsey number.

A Novel PSO-PID Controller Application to Bar Rolling Process

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A Novel PSO-PID Controller Application to Bar Rolling Proces...

第三十届中国控制会议

作者： WU Dongsheng~(1,2),YANG Qing~(1,2),WANG Dazhi~(1,3) 1.college of Optical and Electronical Engineering,changchun university of Science and Technology,changchun,130022,P.R.china 2.School of Information Science,Shenyang Ligong university,Shenyang 110159,P.R.china 3.college of Infomation Science,Northeast university,Shenyang 110004,P.R.china

＜正＞A novel particle swarm optimization algorithm for adjusting the gains of a PID controller used for controlling the process of bar rolling is *** PID controller can not satisfy static and dynamic performances requirement of continuous rolling *** order to overcome the shortcomings of conventional PID controller,a new type of PID controller based on improved particle swarm optimization（IPSO） algorithm is *** new PSO-PID controller combines the advantages of conventional PID controller and PSO *** simulation results show that the performance of the IPSO- PID controller is better than that of traditional PID controller.

关键词： Bar rolling Particle Swarm Optimization PID IPSO- PID Computer simulations

Calcium Overload Is A Critical Step in Programmed Necrosis of ARPE-19 Cells Induced by High-Concentration H_2O_2

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Biomedical and Environmental Sciences 2010年第5期23卷 371-377页

作者： GUANG-YU LI BIN FAN YONG-CHEN ZHENG Department of Ophthalmology Second Hospital of Jilin University Changchun 130041 Jilin China

Objective Oxidative stress plays an important role in retinal pigmental epithelium （RPE） death during aging and the development of age-related macular *** early reports indicate that reactive oxygen species （ROS） including H2O2 can trigger apoptosis at lower concentrations and necrosis at higher concentrations,the exact molecular mechanism of RPE death is still *** purpose of this study was to investigate the molecular pathways involved in RPE death induced by exogenous ROS,especially at higher *** Cultured ARPE-19 cells were treated with H2O2 at different concentrations and cell viability was measured with the MTT *** death was morphologically studied by microscopy using APOPercentage assay and PI ***,the impact of oxidative stress on ARPE-19 cells was assessed by HO-1 and PARP-1 Western blotting and by the protection of antioxidant *** influx was determined using the fura-2 calcium indicator and the role of intracellular calcium overload in ARPE-19 cell death was evaluated following cobalt treatment to block calcium *** H2O2 reduced the viability of ARPE-19 cells in a concentration-dependent manner,which was presented as a typical s-shaped *** death caused by high concentrations of H2O2 was confirmed to be programmed ***,dying ARPE-19 cells were extremely swollen and lost the integrity of their plasma membrane,positively detected with APOPercentage assay and PI staining.24-hour treatment with 500 ？mol/L H2O2 induced remarkable up-regulation of HO-1 and PARP-1 in ARPE-19 ***,antioxidant treatment using EGCG effectively protected cells from H2O2-induced injury,increasing cell viability from 14.17%±2.31% to 85.77%±4.58%.After H2O2 treatment,intracellular calcium levels were highly elevated with a maximum concentration of ***,the calcium channel inhibitor cobalt was able to blunt this calcium influx and blocked the necrotic

关键词： Apoptosis ARPE-19 cell Necrosis Oxidative-stressed injury Hydrogen peroxide