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High Voltage 2020年第6期5卷 688-696页

作者： Feng Bin Feng Wang Qiuqin Sun She Chen Jingmin Fan Huisheng Ye College of Electrical and Information Engineering Hunan UniversityChangsha 410082People's Republic of China College of Electronic and Information Engineering Yili Normal UniversityYili 835000People's Republic of China School of Automation Guangdong University of TechnologyGuangzhou 510012People's Republic of China Equipment Condition Assessment Center Hunan Electric Power Research InstituteChangsha 410000People's Republic of China

The feature extraction and pattern recognition techniques are of great importance to assess the insulation condition of gas-insulated *** this work,the ultra-high-frequency partial discharge(PD)signals generated from four types of typical insulation defects are analysed using S-transform,and the greyscale image in time-frequency representation is divided into five regions according to the cutoff frequencies of TEm1 ***,the three low-order moments of every subregion are extracted and the feature selection is performed based on the J *** confirm the effectiveness of selected moment features after considering the electromagnetic modes,the support vector machine,k-nearest neighbour and particle swarm-optimised extreme learning machine(ELM)are utilised to classify the type of PD,and they achieve the recognition accuracies of 92,88.5 and 95%,*** addition,the results show that the ELM offers good generalisation performance at the fastest learning and testing speeds,thus more suitable for a real-time PD detection.

关键词： insulation moment features

Radiation studies for the moment target station

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Chinese Physics C 2016年第12期40卷 120-126页

作者： Qing-Nian XU Jian-Fei Tong Nikolaos Vassilopoulos Jun Cao Miao He Zhi-Long Hou Han-Wao Jing Huai-Min Liu Xiao-Rui Lii Jing-Yu Tang Ye Yuan Guang Zhao Yang-Heng Zheng University of Chinese Academy of Sciences Beijing 100049 China Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China Harbin Institute of Technology Harbin 150001 China

The discovery of the neutrino mixing angle θ13 opens new opportunities for the discovery of leptonic CP violation at high intensity neutrino beams. moment, a future neutrino facility with a high-power proton beam of 15 MW from a continuous-wave linac, is focused on that discovery. The high power of the proton beam causes extreme radiation conditions for the facility and especially for the target station, where the pion capture system of five superconducting solenoids is located. In this paper initial studies are performed for the effects of the radiation on the solenoid structure and the area surrounding it. A concept cooling system is also proposed.

关键词： moment high intensity beam neutrino target station radiation damage

Application of Ultrasonic Motor to Control of moment Gyroscope Gimbal Servo System

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Transactions of Nanjing University of Aeronautics and Astronautics 2017年第1期34卷 15-21页

作者： Wu Jintao Pan Song Zhao Lei Wu Dengyun Zhang Jiyang Beijing Institute of Control Engineering Beijing 100190P.R.China Precision Driving Laboratory Nanjing University of Aeronautics and AstronauticsNanjing 210016P.R.China

Attitude control system is one of the most important subsystems in a *** a key actuator,the control moment gyroscope(CMG)mainly determines the performance of attitude control ***,the control accuracy and output torque smoothness of the CMG depends more on its gimbal servo *** the constraints of size,mass and power consumption for a small satellite,here,a mini-CMG is designed,in which the gimbal servo system is driven by an ultrasonic *** good performances of the CMG are obtained by both the ultrasonic motor and the rotary *** direct drive of gimbal improves its dynamic performance,with the output bandwidth above 20 *** angular and speed closed-loop control obtains the 0.02°/s gimbal rate,and the output torque resolution better than 2×10^(-3) N·*** ultrasonic motor provides 1.0N·m self-lock torque during power-off,with 12arc-second position accuracy.

关键词： control moment gyroscope gimbal servo system ultrasonic motor

Low dipole moment large β electrooptic chromophores based on exocyclic double bond conjugated bridge

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Chinese Science Bulletin 2001年第18期46卷 1517-1522页

作者： WANG Peng, LI Shaojun & YE ChengCenter for Molecular Science, Organic Solids Laboratory, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China Center for Molecular Science Organic Solids Laboratory Institute of Chemistry Chinese Academy of Sciences Beijing China

Novel low dipole moment (μ) and large first hyperpolarizability (β) electrooptic chromophores have been designed based on the special characteristic of reversed dipole moment in the excited state of exocyclic double bond (ECDB) conjugated bridge by the optimization of the substituted method, and their electronic and second-order nonlinear optical properties have been theoretically investigated by employing the AM1/FF and ZINDO/S-CI approaches. By extending the conjugation length and optimizing the donor/acceptor strength, the oscillator strength of the excited transition that contributes to the molecular nonlinearity can be further enhanced. The designed chromophores possess a larger figure of merit (FOM) than that of 4-N,N-dimethylamino-4’-nitrostilbene (DANS), and lower (5 D) ground state dipole *** low dipole moment (μ) and large first hyperpolarizability (β) electrooptic chromophores have been designed based on the special characteristic of reversed dipole moment in the excited state

关键词： AM1/FF ZINDO/S-CI molecular design dipole moment (μ) first hyperpolarizability (β) exocyclic double bond.

Measurement of moment of Inertia Based on Hilbert Transform

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Transactions of Tianjin University 2013年第3期19卷 225-230页

作者：赵岩张晓琳王军唐文彦 School of Electrical Engineering and Automation Harbin Institute of Technology

A measurement model based on torsion pendulum was established,in which nonlinear damping and nonlinear restoring force were *** calculation method of the moment of inertia was based on Hilbert *** motion of torsion pendulum showed the time-frequency characteristics due to the nonlinear factors,which were validated by the experimental *** analytical signal was formed by Hilbert transform of the angular displacement signal of the test *** moment of inertia can be computed by the instantaneous undamped natural frequency with Hilbert *** to the implementation of Hilbert transform,the empirical mode decomposition was used to filter the experimental *** moment of inertia of the test object was measured by the torsion pendulum *** experimental results show that the relative measurement error of the moment of inertia was within 0.7%,which indicated the validity of the measurement method.

关键词： moment of inertia Hilbert transform empirical mode decomposition nonlinear system

Applications of the molecular orbital graph theory (XI)——The molecular moment's method of evaluating π-bond grade and judging relative reactivity of even AH

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Science China Chemistry 2000年第1期43卷 17-26页

作者：胡式贤刘晓平赵洪刚曹阳 Department of Chemistry Liaoning Normal University Dalian 116029 China Department of Chemistry.Suzhou University.Suzhou 215006 China

The tree graph method of evaluating the local molecular moment is proposed. By applying this method and the molecular moment formula of π-electron energy in the molecular orbital graph theory, a topological method of... 详细信息

关键词： molecular moment π-bond grade reactivity molecular topology.

Motion Track Modeling and Analysis of Belt Spindle under Combined Effects of Bending moment-Torque-Thermal Deformation

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Transactions of Tianjin University 2015年第3期21卷 209-215页

作者：齐向阳高卫国刘腾张大卫 Mao Ken Tianjin Key Laboratory of Equipment Design and Manufacturing Technology Tianjin University School of Mechanical Engineering Tianjin Polytechnic University School of Engineering University of Warwick

The motion track of belt spindle is important for the radial error of belt spindle. An analytical modeling method for the motion track of belt spindle under the combined effects of bending moment-torque-thermal deformation is proposed in this paper. Three running phases of belt spindle have been analyzed and modeled: the start-up phase with leaping change due to the change in force and bending moment, the accelerating phase with axis deflection, and the constant speed phase with axis regression because of the combined effects of bending moment-torque-thermal deformation. The simulation and test were completed on the belt spindle of SKVM850 machine tool, which illustrates the variation law of the radial error of belt spindle during the whole running phases.

关键词： belt spindle torque moment thermal deformation deflection regression

Wavelet moment Invariants Extraction of Underwater Laser Vision Image

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Journal of Shanghai Jiaotong university(Science) 2013年第6期18卷 712-718页

作者：黄蜀玲庞永杰王博万磊 Science and Technology on Underwater Vehicle Laboratory Harbin Engineering University

Wavelet moment invariants are constructed for object recognition based on the global feature and local feature of target, which are brought for the simple background of the underwater objects, complex structure, similar form etc. These invariant features realize the multi-dimension feature extraction of local topology and in- variant transform. Considering translation and scale invariant characteristics were ignored by conventional wavelet moments, some improvements were done in this paper. The cubic B-spline wavelets which are optimally localized in space-frequency and close to the forms of Li's(or Zernike's) polynomial moments were applied for calculating the wavelet moments. To testify superiority of the wavelet moments mentioned in this paper, generalized regres- sion neural network(GRNN) was used to calculate the recognition rates based on wavelet invariant moments and conventional invariant moments respectively. Wavelet moments obtained 100% recognition rate for every object and the conventional moments obtained less classification rate. The result shows that wavelet moment has the ability to identify many types of objects and is suitable for laser image recognition.

关键词： wavelet moment invariants underwater optical vision images underwater laser imaging feature extraction object recognition

Changes of dipole moment in intramolecular proton transfer process of perylenequinone

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Chinese Science Bulletin 1998年第16期43卷 1380-1384页

作者： ZHANG Hongyu Department of Biology, Provincial Key Laboratory of Animal Resistance Biology, Shandong Teachers University, Jinan 250014, China Department of Biology Provincial Key Laboratory of Animal Resistance Biology Shandong Teachers University Jinan China

Semiempirical quantum chemistry method AM1 was employed to calculate dipole moment of perylenequinone (PQ) in intramolecular proton transfer (IPT) process. It was found that there existed a maximum of dipole moment in all IPT process except PQ anion (PQ) which possessed a minimum. Moreover, almost all states of PQ except ground state had high changes in dipole moment. All of these laid foundations to clarify solvent effects in IPT of PQ.

关键词： perylenequinone intramolecular proton transfer dipole moment AM1 method.

ON INCREMENTS OF SUMS OF RANDOM VARIABLES WITHOUT moment HYPOTHESES

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Science China Mathematics 1990年第9期33卷 1047-1059页

作者：林正炎 Hangzhou University Hangzhou 310028 PRC

The a. s. limiting behavior of increments of partial sums for a sequence of random variables has been discussed by many authors. A series of fine and elegant results have been obtained. However, up to now, the results of this kind have all required the existence of moments. In this paper we try to drop this condition. The existing results with moment conditions become special cases of our theorems.

关键词： increments of partial sums a.s. limit without moment hypothesis.