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Two Types of Compact UHF Antennas for Partial Discharge Measurement

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高电压技术 2008年第11期34卷 2305-2310页

作者： JIN Zhuo-rui SUN Cai-xin CHENG Chang-kui li jian State Key Laboratory of Power Transmission Equipment ＆ System Security and New Technology Department of High Voltage and Insulation Engineering Chongqing University Chongqing 400044 China

To investigate the partial discharge (PD) online monitoring of transformers by ultra-high-frequency (UHF) approaches,high-qualified UHF antennas are focused on as one key technique. The size of UHF sensor used for PD UHF online monitoring in transformer is excessively large,therefore,it is not convenient for internal installation of transformer. Two types of compact UHF antennas with small sizes,a Hilbert fractal antenna and a small loop antenna are presented. PD experiments of three typically artificial insulation defects are executed and both antennas are used for PD measurement. The spectra of power via frequency of detected PD signals are analyzed and compared. The experimental results show that the Hilbert fractal antenna and small loop antenna are qualified for PD online UHF monitoring.

关键词：超高频天线局部放电测量方法电压

Facile and Stereoselective Synthesis of N-Substituted Benzotriazole with Baylis-Hillman Adducts

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Chinese Chemical Letters 2006年第7期17卷 877-879页

作者： jian li Yun kui liU Yong Min ZHANG Department of Chemistry Shanghai University Shanghai 200436 Department of Chemistry Zhejiang University Xixi Campus Hangzhou 310028 State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology Catalytic Hydrogenation Research Center Zhejiang University of Technology Hangzhou 310014 State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic Chemistry Chinese Academy of Sciences Shanghai 200032

A convenient method has been developed toward the stereoselective synthesis of N-substituted benzotriazole derivatives under mild conditions. The good stereolectivity, high yields and the simple procedure make the pre... 详细信息

关键词： Benzotriazole N-substituted Baylis-Hillman adduct.

Spectroscopic and Electrochemical Studies of the Interaction Between Fuchsin Basic and DNA

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Chemical Research in Chinese Universities 2006年第3期22卷 292-296页

作者： YANG Tao WANG Zeng-jian JIAO kui li Qing-Jun College of Chemistry ＆ Chemical Engineering Ocean University of China Qingdao 266003 P. R. China College of Chemistry ＆ Molecular Engineering Qingdao University of Science ＆ Technology Qingdao 266042 P. R. China

Visible spectroscopic and electrochemical methods were used to study the interactions between DNA and fuchsin basic（FB）. FB has an irreversible electro-oxidation peak in 5 mmol/L Tris-HCl buffer solution at pH = 7.4 on a glassy carbon electrode（GCE）. After adding certain concentration of dsDNA, the oxidation peak current of FB decreases, but the peak potential hardly changes. The visible absorption spectroscopic study shows that the binding mode of FB to dsDNA is intercalative binding and electrostatic binding when the ratio of the concentration of dsDNA to FB is smaller than 0. 2, and anew substance, which produces a new absorption peak, is obtained via a covalent binding between dsDNA and FB apart from intercalative binding and electrostatic binding when the ratio of the concentration of dsDNA to FB is larger than 0. 2. The visible absorption spectra varies no longer when the ratio of the concentration of dsDNA＇to FB is larger than 1.5. A mean binding ratio of dsDNA to FB was determined to be 1.4： 1, suggesting that two complexes FB-dsDNA and FB-2dsDNA be formed. The interaction between FB and ssDNA was only electrostatic binding. The more powerful interaction of FB with dsDNA than with ssDNA may be applied for the recognition of dsDNA and ssDNA, and in DNA biosensor as hybridization indicator.

关键词： Fuchsin basic DNA Visible absorption spectroscopy Cyclic voltammetry Interaction

Synthesis of texture-excellent mesoporous alumina using PEG1000 as structure-directing agent

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Chinese Journal of Chemical Engineering 2017年第1期25卷 137-141页

作者： kui Zhang Changming li jian Yu Shiqiu Gao Guangwen Xu State Key Laboratory of Multiphase Complex Systems Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China University of Chinese Academy of Sciences Beijing 100049 China

By varying concentration of PEG1000 as a structure-directing agent,mesoporous alumina with excellent textural properties was *** prepared mesoporous alumina displays high thermal stability,as shown by its textural properties at different calcination temperatures of 600-850 °*** by SEM and TEM revealed that the added PEG surfactant induced the formation of petal-like *** results clarified that all samples were amorphous and their peaks were around the peaks of γ-alumina.N_2 adsorption-desorption analysis showed that the prepared mesoporous alumina,if with PEG1000 in hydrolysis of aluminum isopropoxide,had excellent textural properties with large specific surface area,high pore volume and suitable pore *** petal-like structure existing in the alumina samples improved their textural parameters,and the role and influential mechanism of PEG1000 were analyzed.

关键词： Alumina PEG1000 Surfactant Stability

Fracture behaviors of commercially pure titanium under biaxial tension:Experiment and modeling

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Journal of Materials Science & Technology 2023年第9期140卷 176-186页

作者： Jin-kui Meng li liu jian-Tang jiang Guo Huang liang Zhen School of Materials Science and Engineering Harbin Institute of Technology(Shenzhen)Shenzhen 518055China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China National Key Laboratory of Precision Hot Processing of Metals Harbin Institute of TechnologyHarbin 150001China

The fracture behaviors and associated mechanisms of metallic materials under biaxial stress are vital for their manufacturability and service *** this work,the fracture behaviors of commercially pure titanium(CP-Ti)under quasi-uniaxial and equi-biaxial tension were investigated by using the digital image correlation technique and finite element *** fracture behaviors under quasi-uniaxial tension were characterized by a general normal *** contrast,normal fracture firstly occurred per-pendicular to the rolling direction(RD)under equi-biaxial tension,followed by secondary shear fracture along the 45°direction relative to the *** normal fracture was attributed to the lower strain hard-ening ability in RD compared to the transverse direction(TD)induced by the TD-split type basal *** different hardening abilities introduced large shear stress in the 45°direction,which contributed sig-nificantly to the secondary shear *** anisotropy parameter K(△S_(s)/σ_(s)),defined as the ratio of the equivalent effective traction stress to the yield strength,was proposed for the first time,to predict the fracture path with the impact of crystallographic preferred orientation.

关键词： Titanium Biaxial tension Fracture behavior Digital image correlation(DIC)technique Finite element modeling

Local buckling failure analysis of high-strength pipelines

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Petroleum Science 2017年第3期14卷 549-559页

作者： Yan li jian Shua Zhong-li Jin Ya-Tong Zhao kui Xu Faculty of Mechanical and Transportation Engineering China University of Petroleum Beijing 102249 China China ENFI Engineering Corporation Beijing 100038China

Pipelines in geological disaster regions typically suffer the risk of local buckling failure because of slender structure and complex load. This paper is meant to reveal the local buckling behavior of buried pipelines with a large diameter and high strength, which are under different conditions, including pure bending and bending combined with internal pressure. Finite element analysis was built according to previous data to study local buckling behavior of pressurized and unpressurized pipes under bending conditions and their differences in local buckling failure modes. In parametric analysis, a series of parameters,including pipe geometrical dimension, pipe material properties and internal pressure, were selected to study their influences on the critical bending moment, critical compressive stress and critical compressive strain of *** the hardening exponent of pipe material was introduced to the parameter analysis by using the Ramberg–Osgood constitutive model. Results showed that geometrical dimensions, material and internal pressure can exert similar effects on the critical bending moment and critical compressive stress, which have different, even reverse effects on the critical compressive strain. Based on these analyses, more accurate design models of critical bending moment and critical compressive stress have been proposed for high-strength pipelines under bendingconditions, which provide theoretical methods for highstrength pipeline engineering.

关键词： Local buckling High-strength pipeline Finiteelement analysis Critical bending moment Criticalcompressive stress Critical compressive strain

Collective Excitations and Nonlinear Dynamics of 1D BEC with Two-and Three-body Interactions in Anharmonic Traps

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Communications in Theoretical Physics 2008年第11期50卷 1129-1136页

作者： li Guan-Qiang PENG Ping liU jian-Ke XUE Ju-kui Faculty of Science Shaanxi University of Science and Technology Xi＇an 710021 China physics and Electronics Engineering College Northwest Normal University Lanzhou 730070 China

The collective excitations of low-dimensional Bose-Einstein condensates with two- and three-body interactions in anharmonic potentials are investigated. Using the standard variational approach, the governing equations of motions for the low-energy excitations are obtained by solving time-dependent Gross-Pitaevskii-Ginzburg equation, and the excitation spectrums are calculated in small amplitude limit. The frequency shift and nonlinear mode coupling induced by the anharmonic distortion （adding cubic, quartic, or quintic terra to a harmonic trap） are studied.

关键词： collective excitations Gross-Pitaevskii-Ginzburg equation anharmouic trapping potentials frequency shift of low-energy excitations non-resonant mode coupling

Research on the overload protection reliability of moulded case circuit-breakers and its test device

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第3期8卷 453-458页

作者： li kui LU jian-guo WU Yi QIN Zhi-jun YAO Dong-mei Electrical Apparatus Institute Hebei University of Technology Tianjin 300130 China

This paper analyzed the reliability and put forward the reliability index of overload protection for moulded case circuit breaker. The success rate was adopted as its reliability index of overload protection. Based on the reliability index and the reli- ability level, the reliability examination plan was analyzed and a test device for the overload protection of moulded case cir- cuit-breaker was developed. In the reliability test of overload protection, two power sources were used, which reduced the time of conversion and regulation between two different test currents in the overload protection test, which made the characteristic test more accurate. The test device was designed on the base of a Windows system, which made its operation simple and friendly.

关键词： Moulded case circuit breakers Overload protection Reliability Test device

Uniaxial experimental study of the acoustic emission and deformation behavior of composite rock based on 3D digital image correlation(DIC)

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Acta Mechanica Sinica 2017年第6期33卷 999-1021页

作者： jian-Long Cheng Sheng-Qi Yang kui Chen Dan Ma Feng-Yuan li li-Ming Wang State Key Laboratory for Geomechanics and Deep Underground Engineering School of Mechanics and Civil Engineering China University of Mining and Technology State Key Laboratory of Shield Machine and Boring Technology China Railway Tunnel Group Co. Ltd.

In this paper, uniaxial compression tests were carried out on a series of composite rock specimens with different dip angles, which were made from two types of rock-like material with different strength. The acoustic emission technique was used to monitor the acoustic signal characteristics of composite rock specimens during the entire loading process. At the same time, an optical non-contact 3 D digital image correlation technique was used to study the evolution of axial strain field and the maximal strain field before and after the peak strength at different stress levels during the loading process. The effect of bedding plane inclination on the deformation and strength during uniaxial loading was analyzed. The methods of solving the elastic constants of hard and weak rock were described. The damage evolution process, deformation and failure mechanism, and failure mode during uniaxial loading were fully determined. The experimental results show that the θ = 0?–45?specimens had obvious plastic deformation during loading, and the brittleness of the θ = 60?–90?specimens gradually increased during the loading process. When the anisotropic angle θincreased from 0?to 90?, the peak strength, peak strain,and apparent elastic modulus all decreased initially and then increased. The failure mode of the composite rock specimen during uniaxial loading can be divided into three categories:tensile fracture across the discontinuities(θ = 0?–30?), slid-ing failure along the discontinuities(θ = 45?–75?), and tensile-split along the discontinuities(θ = 90?). The axial strain of the weak and hard rock layers in the composite rock specimen during the loading process was significantly different from that of the θ = 0?–45?specimens and was almost the same as that of the θ = 60?–90?specimens. As for the strain localization highlighted in the maximum principal strain field, the θ = 0?–30?specimens appeared in the rock matrix approximately parallel to the loading direction,while in the θ =

关键词： Uniaxial compression tests on composite rock Anisotropy Elastic constant Failure mode 3D digital image correlation Acoustic emission Strain field