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MEASUREMENT OF PLASMA PARAMETERS IN THE EDGE REGION OF A TOKAMAK

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Chinese Physics Letters 1989年第3期6卷 130-134页

作者： qin jiang WANG Long Institute of Physics Academia SinicaBeijing

A space-time resolution measurement of plasma parameters in the edge region of CT-6B tokamak has been performed using Langmuir *** diffusion in the region is of an order of the Bohm *** propagation time of MHD perturb... 详细信息

关键词： TOKAMAK tokamak interior

Determination of Surface Roughness in Wire and Arc Additive Manufacturing Based on Laser Vision Sensing

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Chinese Journal of Mechanical Engineering 2018年第4期31卷 133-139页

作者： Jun Xiong Yan-jiang Li zi-Qiu Yin Hui Chen School of Materials Science and Engineering Southwest Jiaotong University

Wire and arc additive manufacturing(WAAM) shows a great promise for fabricating fully dense metal parts by means of melting materials in layers using a welding heat source. However, due to a large layer height produced in WAAM, an unsatisfactory surface roughness of parts processed by this technology has been a key issue. A methodology based on laser vision sensing is proposed to quantitatively calculate the surface roughness of parts deposited by *** for a camera and a laser plane of the optical system are presented. The reconstruction precision of the laser vision system is verified by a standard workpiece. Additionally, this determination approach is utilized to calculate the surface roughness of a multi-layer single-pass thin-walled part. The results indicate that the optical measurement approach based on the laser vision sensing is a simple and effective way to characterize the surface roughness of parts deposited by WAAM. The maximum absolute error is less than 0.15 mm. The proposed research provides the foundation for surface roughness optimization with different process parameters.

关键词： Wire and arc additive manufacturing Surface roughness measurement Laser vision sensing Three-dimensional reconstruction

Controllable synthesis of novel mono-and di-terpyridine derivatives

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Chinese Chemical Letters 2009年第2期20卷 168-170页

作者： Peng Fei Shi qin jiang Chemistry Department Huaihai Institute of Technology Lianyungang 222005 China State Key Laboratory of Coordination Chemistry Nanjing University Nanjing 210093 China

A series of novel mono- and di-terpyridine derivatives with purinyl and pyrimidyl group were obtained from the reaction of 4′-p- bromomethylphenyl-2,2′：6,2″-terpyridine with 6-mercaptopurine, 2,6-dimercaptopurine and thymine, respectively. The active hydrogens on these alkaloids could be abstracted stepwise using different bases, which made the addition controllable.

关键词： Terpyridine Thymine Mercaptopurine

Multi-symplectic method for the generalized(2+1)-dimensionalKdV-mKdV equation

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Acta Mechanica Sinica 2012年第3期28卷 793-800页

作者： Wei-Peng Hu zi-Chen Deng Yu-Yue qin Wen-Rong Zhang School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnincal University710072 Xi'anChina State Key Laboratory of Mechanical System&Vibration Shanghai Jiao Tong University200240 ShanghaiChina State Key Laboratory of StructuralAnalysis of Industrial Equipment Dalian University of Technology116023 DalianChina

In the present paper, a general solution involv- ing three arbitrary functions for the generalized （2＋1）- dimensional KdV-mKdV equation, which is derived from the generalized （1＋1）-dimensional KdV-mKdV equa- tion, is first introduced by means of the Wiess, Tabor, Carnevale （WTC） truncation method. And then multi- symplectic formulations with several conservation laws taken into account are presented for the generalized （2＋1）- dimensional KdV-mKdV equation based on the multi- symplectic theory of Bridges. Subsequently, in order to simulate the periodic wave solutions in terms of rational functions of the Jacobi elliptic functions derived from thegeneral solution, a semi-implicit multi-symplectic scheme is constructed that is equivalent 1：o the Preissmann scheme. From the results of the numerical experiments, we can con- clude that the multi-symplectic schemes can accurately sim- ulate the periodic wave solutions of the generalized （2＋1）- dimensional KdV-mKdV equation while preserve approxi- mately the conservation laws.

关键词： Generalized (2+ 1)-dimensional KdV-mKdVequation Multi-symplectic Periodic wave solution Con-servation law ~ Jacobi elliptic function

Design Near-threshold Photoelectron Imaging Spectrometer Based on UV Laser Induced Photoelectron Emission Anion Source

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Chinese Journal of Chemical Physics 2013年第6期26卷 774-779,I0005页

作者： Zheng-bo qin Xia Wu zi-chao Tang State Key Laboratory of Molecular Reaction Dynamics Dalian Institute of Chemical Physics ChineseAcademy of Sciences Dalian 115023 China

We have developed a compact photoelectron imaging facility, including an anion source with dissociative photoelectron attachment to molecules, a linear time-of-flight mass spec-trometry （TOFMS）, and an orthogonal high-resolution threshold photoelectron velocity map imaging spectrometer （VMI）. Intense and cold cluster anions were prepared in photoelectron- attachment processes upon pulsed UV laser ablation of metal target. Combining this anion source with TOFMS-VMI, the achieved mass resolution is about 200, and the electron ki- netic energy resolution is better than 3%, i.e., 30 meV for 1 eV electrons. More importantly, low-energy photoelectron imaging spectra for CH3S- and S2- at 611.46 nm are obtained. In both cases, the refined electron affinities are determined to be 1.86264-0.0020 eV for CH3S and 1.67444-0.0035 eV for S2, respectively. Preliminary results suggest that the apparatus is a powerful tool for estimating precise electron affinities values from threshold photoelectron imaging spectroscopy.

关键词： Threshold photoelectron imaging Dissociative photoelectron attachment Laser induced photoelectron emission

C-CORE:Clustering by Code Representation to Prioritize Test Cases in Compiler Testing

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Computer Modeling in Engineering & Sciences 2024年第5期139卷 2069-2093页

作者： Wei Zhou Xincong jiang Chuan qin School of Electronic Information and Electrical Engineering Shanghai Jiao Tong UniversityShanghai200240China Hikvision Research Institute Hangzhou Hikvision Digital Technology Co.Ltd.Hangzhou310051China

Edge devices,due to their limited computational and storage resources,often require the use of compilers for program ***,ensuring the security and reliability of these compilers is of paramount importance in the emerging field of edge *** widely used testing method for this purpose is fuzz testing,which detects bugs by inputting random test cases into the target ***,this process consumes significant time and *** improve the efficiency of compiler fuzz testing,it is common practice to utilize test case prioritization *** researchers use machine learning to predict the code coverage of test cases,aiming to maximize the test capability for the target compiler by increasing the overall predicted coverage of the test ***,these methods can only forecast the code coverage of the compiler at a specific optimization level,potentially missing many optimization-related *** this paper,we introduce C-CORE(short for Clustering by Code Representation),the first framework to prioritize test cases according to their code representations,which are derived directly from the source *** approach avoids being limited to specific compiler states and extends to a broader range of compiler ***,we first train a scaled pre-trained programming language model to capture as many common features as possible from the test cases generated by a *** this pre-trained model,we then train two downstream models:one for predicting the likelihood of triggering a bug and another for identifying code representations associated with ***,we cluster the test cases according to their code representations and select the highest-scoring test case from each cluster as the high-quality test *** reduction in redundant testing cases leads to time *** evaluation results reveal that code representations are better at distinguishing test capabilities,and C-CORE significantly enhanc

关键词： Compiler testing test case prioritization code representation

Hydraulic turbine system identification and predictive control based on GASA-BPNN

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International Journal of Minerals,Metallurgy and Materials 2021年第7期28卷 1240-1247页

作者： Xiao-ping jiang zi-ting Wang Hong Zhu Wen-shuai Wang School of Mechanical Electrical and Information Engineering China University of Mining and Technology(Beijing)Beijing 100083China

Based on the characteristics of nonlinearity,multi-case,and multi-disturbance,it is difficult to establish an accurate parameter mod-el on the hydraulic turbine system which is limited by the degree of fitting between parametric model and actual model,and the design of con-trol algorithm has a certain degree of *** at the modeling and control problems of hydraulic turbine system,this paper proposes hydraulic turbine system identification and predictive control based on genetic algorithm-simulate anneal and back propagation neural network(GASA-BPNN),and the output value predicted by GASA-BPNN model is fed back to the nonlinear optimizer to output the control *** results show that the output speed of the traditional control system increases greatly and the speed of regulation is slow,while the speed of GASA-BPNN predictive control system increases little and the regulation speed is obviously faster than that of the traditional control *** with the output response of the traditional control of the hydraulic turbine governing system,the neural network predictive control-ler used in this paper has better effect and stronger robustness,solves the problem of poor generalization ability and identification accuracy of the turbine system under variable conditions,and achieves better control effect.

关键词： hydraulic turbine system system identification genetic algorithm simulated annealing algorithm predictive control

Drag reduction and hairpin packets of the turbulent boundary layer over the superhydrophobic-riblets surface

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Journal of Hydrodynamics 2021年第3期33卷 621-635页

作者： Xin-wei Wang zi-ye Fan Zhan-qi Tang Nan jiang School of Mechanical Engineering Tianjin UniversityTianjin300354China Tianjin Key Laboratory of Modern Engineering Mechanics Tianjin300354China

This paper presents experimental measurements by the time-resolved particle image velocimetry(TR-PIV)for the turbulent boundary layer(TBL)over the smooth surface,the superhydrophobic(SH)surface,and the superhydrophobic-riblets(SR)surface in an open-surface recirculating water *** Reynolds number based on the wall friction velocity and the thickness of the TBL over the smooth surface is *** SH surface and the SR surface are manufactured by the laser texturing method on the smooth surface and the riblets surface,*** employing the(modified)Clauser method,a superior efficacy of the drag reduction of about 22.1%is obtained on the SR surface,while the drag reduction rate for the SH surface is about 18.7%.Comparing with the SH surface,the declining 2-order statistics in the near-wall region also indicates a significant drag reduction over the SR *** large-scale structure components extracted by the proper orthogonal decomposition are found to generate a majority of the Reynolds shear stress in the region y^(+)>*** strength of the large-scale features over the rough surfaces(SH and SR surfaces)at disparate wall-normal positions is visualized by the Quadrant splitting method and the conditional *** appearance of the large-scale structures such as the hairpin packets characterized by the two-point correlation shows an excellent consistency with the statistics *** hairpin packets over the SH surface seem always smaller and weaker than those over the smooth *** the SR surface,the hairpin packets in the region 0.1≤y/δ<0.3 are the smallest and weakest among those over the three surfaces,while the scale and the strength of the hairpin packets exceed those over the smooth surface in the region 0.3

关键词： Turbulent boundary layer superhydrophobic riblets drag reduction hairpin packets

On Generic Extensions of Representations of a Dynkin Quiver of Type D

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Acta Mathematica Sinica,English Series 2005年第3期21卷 613-622页

作者： Xiao qin DENG jiang Rong CHEN School of Sciences Beijing Jiaotong University Beijing 100044 P. R. China Department of Mathematics Beijing Normal University Beijing 100875 P. R. China

The notion of generic extensions of representations of a Dynkin quiver plays a big role in the study of the structure of the corresponding quantum group. In this paper, we describe the generic extensions of a simple representation by any representation and that of any representation by a simple representation of a Dynkin quiver Q of type D.

关键词： Dynkin quiver Representation Generic extension