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Reciprocating Magnetic Fields in the Pulsar Wind Observed from the Black Widow Pulsar J1720-0534

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Research in Astronomy and Astrophysics 2023年第10期23卷 255-266页

作者： Chen-Chen Miao Victoria Blackmon Wei-Wei Zhu Dong-Zi Li Ming-Yu Ge Xiao-Peng You Maura McLaughlin Di Li Na Wang Pei Wang Jia-Rui Niu M.Cruces Jian-Ping Yuan Jun-Tao Bai D.J.Champion Yu-Tong Chen Ming-Min Chi P.C.C.Freire Yi Feng zhen-ye gan M.Kramer Fei-Fei Kou Yu-Xi Li Xue-Li Miao Ling-Qi Meng Chen-Hui Niu Sheng-Nan Sun Zhong-Yi Sun H.M.Tedila Shuang-Qiang Wang Qing-Dong Wu Jing-Bo Wang Zhi-gang Wen Shen Wang Ya-Biao Wang Cheng-Jie Wang Meng-Yao Xue You-Ling Yue Mao Yuan Ju-Mei Yao Wen-Ming Yan Ru-Shuang Zhao Lei Zhang De Zhao National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China West Virginia University 1500 University AveMorgantownWV 26506USA Institute for Frontiers in Astronomy and Astrophysics Beijing Normal UniversityBeijing 102206China Cahill Center for Astronomy and Astrophysics California Institute of Technology1216 E California BoulevardPasadenaCA 91125USA Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China School of Physical Science and Technology Southwest UniversityChongqing 400715China Research Center for Intelligent Computing Platforms Zhejiang LaboratoryHangzhou 311100China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China Max-Planck Institut für Radioastronomie Auf dem Hügel 69D-53121 BonnGermany School of Computer Science Fudan UniversityShanghai 200433China Tencent Youtu Lab Shanghai 200233China College of Physical Science and Technology Central China Normal UniversityWuhan 430079China Institute of Optoelectronic Technology Lishui UniversityLishui 323000China Guizhou Normal University Guiyang 550001China

We report the radio observations of the eclipsing black widow pulsar J1720-0534, a 3.26 ms pulsar in orbit with a low mass companion of mass 0.029 to 0.034 M⊙. We obtain the phase-connected timing ephemeris and polarization profile of this millisecond pulsar(MSP) using the Five-hundred-meter Aperture Spherical radio Telescope(FAST), the Green Bank Telescope(GBT), and the Parkes Telescope. For the first time from such a system, an oscillatory polarization angle change was observed from a particular eclipse egress with partial depolarization, indicating 10-milliGauss-level reciprocating magnetic fields oscillating in a length scale of 5 ×10^(3)km(assuming an orbital inclination angle of 90°) outside the companion's magnetosphere. The dispersion measure variation observed during the ingresses and egresses shows the rapid raising of the electron density in the shock boundary between the companion's magnetosphere and the surrounding pulsar wind. We suggest that the observed oscillatory magnetic fields originate from the pulsar wind outside the companion's magnetosphere.

关键词： (stars:)pulsars:general (stars:)pulsars:individual(J1720-0534) (stars:)binaries:eclipsing

Achieving and maintaining biological nitrogen removal via nitrite under normal conditions

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Journal of Environmental Sciences 2005年第5期17卷 794-797页

作者： CUI You-wei PENG Yong-zhen gan Xiang-qing ye Liu WANG Ya-yi College of Environmental and Energy Engineering Beijing University of Technology Beijing 100022 China Department of Chemistry Fuling Normal University Chongqing 408003 China School of Civil Engineering and Architecture Zhejiang University of Technology Hangzhou 310014 China

The principal aim of this paper is to develop an approach to realize stable biological nitrogen removal via nitrite under normal conditions. Validation of the new method was established on laboratory-scale experiments applying the sequencing batch reactor（SBR） activated sludge process to domestic wastewater with low C/N ratio. The addition of sodium chloride（NaCI） to influent was established to achieve nitrite build-up. The high nitrite accumulation, depending on the salinity in influent and the application duration of salt, was obtained in SBRs treating saline wastewater. The maintenance results indicated that the real-time SBRs can maintain stable nitrite accumulation, but conversion from shorter nitrification-denitrification to full nitrification-denitrification was observed after some operation cycles in the other SBR with fixed-time control. The presented method is valuable to offer a solution to realize and to maintain nitrogen removal via nitrite under normal conditions.

关键词： nitrite accumulation salt selective inhibition real-time control of nitrification biological nitrogen removal via nitrite nitrite-oxidizers ammonium-oxidizers

THE EXISTENCE AND ASYMPTOTIC BEHAVIOR OF PERIODIC SOLUTIONS TO A QUASILINEAR PARABOLIC SYSTEM

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International Journal of Biomathematics 2013年第2期6卷 191-203页

作者： WEN-zhen gan School of Mathematics and PhysicsJiangsu Teachers University of TechnologyChangzhou Jiangsu 213001 P. R. China

In this paper, we investigate the existence, stability and global attractivity of T-periodic solutions for a class of quasilinear parabolic equations under Robin boundary conditions. We obtain that periodic solutions exist if the inter-specific competition rates are weak. The numerical simulations are also presented to illustrate our result.

关键词： Competitor-competitor-mutualist model quasilinear T-periodic solution asymptotic behavior.

High-voltage Ride Through Strategy for DFIG Considering Converter Blocking of HVDC System

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Journal of Modern Power Systems and Clean Energy 2020年第3期8卷 491-498页

作者： Changping Zhou zhen Wang Ping Ju Deqiang gan College of Electrical Engineering Zhejiang UniversityHangzhou 310027China

This paper presents a P-Q coordination based highvoltage ride through(HVRT) control strategy for doubly fed induction generators(DFIGs) based on a combined Q-V control and P-V de-loading control. The active/reactive power injection effect of DFIG on transient overvoltage is firstly analyzed and the reactive power capacity evaluation of DFIG considering its de-loading operation is then conducted. In the proposed strategy, the reactive power limit of DFIG can be flexibly extended during the transient process in coordination with its active power adjustment. As a result, the transient overvoltage caused by DC bipolar block can be effectively suppressed. Moreover, key outer loop parameters such as Q-V control coefficient and deloading coefficient can be determined based on the voltage level of point of common coupling(PCC) and the available power capacity of DFIG. Finally, case studies based on MATLAB/Simulink simulation are used to verify the effectiveness of the proposed control strategy.

关键词： Active power de-loading control high-voltage ride through(HVRT) inductive power absorption transient overvoltage

RNA interference with DNA polymerase and synthesis

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Science China Chemistry 2014年第7期57卷 954-960页

作者： ABDUR Rob gan JianHua HUANG zhen Department of Chemistry Georgia State University

RNA can catalyze and participate in many chemical and biochemical reactions. Non-coding RNAs （ncRNA） can regulate cellular transcription and translation reactions. We have demonstrated biochemically that RNA can also interfere with DNA polymerization via transforming DNA polymerase into deoxyribonucleoside triphosphate diphosphatase （dNTP-DPase）. RNA, even with six nucleotides, can transform DNA polymerase into dNTP-DPase, and the dNTP-DPase activity causes the hydrolysis of dNTPs into dNMPs and pyrophosphate. Moreover, we have found that DNA polymerases from several families generally have similar RNA-dependent dNTP-DPase activity. We have also observed that in the presence of RNA, when the dNTP concentrations are relatively low, and that the dNTP-DPase activity can deplete dNTPs and interfere with DNA polymerization Thus, we have discovered for the first time that in the presence of RNA, DNA polymerase can behave as a diphosphatase and inhibit DNA synthesis when dNTP quantity is low. These in vitro observations might imply a plausible role of RNA in vivo, such as suppressing DNA synthesis during a resting phase （Go） of the cell cycle, when RNA quantity is high and dNTP quantity is low.

关键词： RNA interference alternative activity of DNA polymerase non-coding RNA deoxyribonucleoside triphosphatediphosphatase DNA polymerization and synthesis

Noise Reduction of an Axial Piston Pump by Valve Plate Optimization

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Chinese Journal of Mechanical Engineering 2018年第3期31卷 85-100页

作者： Shao-gan ye Jun-Hui Zhang Bing Xu State Key Laboratory of Fluid Power and Mechatronics Systems Zhejiang University Ocean College Zhejiang University

Current researches mainly focus on the investigations of the valve plate utilizing pressure relief grooves. However,air?release and cavitation can occur near the grooves. The valve plate utilizing damping holes show excellent perfor?mance in avoiding air?release and cavitation. This study aims to reduce the noise emitted from an axial piston pump using a novel valve plate utilizing damping holes. A dynamic pump model is developed,in which the fluid properties are carefully modeled to capture the phenomena of air release and cavitation. The causes of di erent noise sources are investigated using the model. A comprehensive parametric analysis is conducted to enhance the understanding of the e ects of the valve plate parameters on the noise sources. A multi?objective genetic algorithm optimization method is proposed to optimize the parameters of valve plate. The amplitudes of the swash plate moment and flow rates in the inlet and outlet ports are defined as the objective functions. The pressure overshoot and undershoot in the piston chamber are limited by properly constraining the highest and lowest pressure values. A comparison of the various noise sources between the original and optimized designs over a wide range of pressure levels shows that the noise sources are reduced at high pressures. The results of the sound pressure level measurements show that the optimized valve plate reduces the noise level by 1.6 d B(A) at the rated working condition. The proposed method is e ective in reducing the noise of axial piston pumps and contributes to the development of quieter axial piston machines.

关键词： Axial piston pump Noise reduction Fluid?borne noise Structure?borne noise Parametric analysis Multi?objective optimization

Structural and Photoluminescence Characterization of gan Film Grown on Si(111)Substrate

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Chinese Physics Letters 1999年第4期16卷 293-294页

作者： ye Zhi-zhen ZHANG Hao-xiang LU Huan-ming ZHAO Bing-hui State Key Laboratory of Silicon Materials Zhejiang UniversityHangzhou 310027

gan epilayer grown on Si(111)substrate by a novel vacuum reaction method rather than metal organic chemical vapor deposition or molecule beam epitaxy is *** electron micrograph shows that surface of gan film is flat and crack-free.A pronounced gan(0002)peak appears in the x-ray diffraction *** full width at half-maximum(FWHM)of the double-crystal x-ray rocking curve for(0002)diffraction from the gan epilayer is *** photoluminescence spectrum shows that the gan epilayer emits light at the wavelength of 365nm with an FWHM of 8nm(74.6meV).

关键词： Si(111) gan vacuum

Differential Evolution Hemivariational Inequalities with Anti-periodic Conditions

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Acta Mathematica Sinica,English Series 2024年第4期40卷 1143-1160页

作者： Jing ZHAO Chun Mei gan zhen Hai LIU School of Mathematics and Quantitative Economics Guangxi University of Finance and EconomicsNanning 530003P.R.China Guangxi Colleges and Universities Key Laboratory of Optimization Control and Engineering Calculation Guangxi Minzu UniversityNanning 530006P.R.China

The goal of this paper is to deal with a new dynamic system called a differential evolution hemivariational inequality(DEHVI)which couples an abstract parabolic evolution hemivariational inequality and a nonlinear differential equation in a Banach ***,by apply ing surjectivity result for pseudomonotone multivalued mappins and the properties of Clarke's subgradient,we show the nonempty of the solution set for the parabolic hemivariational ***,some topological properties of the solution set are established such as boundedness,closedness and ***,we explore the upper semicontinuity of the solution ***,we prove the solution set of the system(DEHVI)is nonempty and the set of all trajectories of(DEHVI)is weakly compact in C(I,X).

关键词： Differential parabolic hemivariational inequality Clarke subdifferential hyperbolicparabolic system parabolic-parabolic system existence result

Low-frequency fluctuation in continuous real-time feedback of finger force:a new paradigm for sustained attention

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Neuroscience Bulletin 2012年第4期28卷 456-467页

作者： Zhang-ye Dong Dong-Qiang Liu Jue Wang Zhao Qing zhen-Xiang Zang Chao-gan Yan Yu-Feng Zang National Key Laboratory of Cognitive Neuroscience and Learning Beijing Normal UniversityBeo'ing 100875China Center for Cognition and Brain Disorders Affiliated HospitalHangzhou Normal UniversityHangzhou 310015China Department of Mathematics Beijing Jiaotong UniversityBeijing 100044China The Nathan Kline Institute for Psychiatric Research OrangeburgNY 10962USA

Objective Behavioral studies have suggested a low-frequency（0.05 Hz） fluctuation of sustained attention on the basis of the intra-individual variability of *** task designs for functional magnetic resonance imaging（fMRI） studies are not appropriate for frequency *** present study aimed to propose a new paradigm,real-time finger force feedback（RT-FFF）,to study the brain mechanisms of sustained attention and *** We compared the low-frequency fluctuations in both behavioral and fMRI data from 38 healthy adults（19 males;mean age,22.3 years）.Two fMRI sessions,in RT-FFF and sham finger force feedback（S-FFF） states,were acquired（TR 2 s,Siemens Trio 3-Tesla scanner,8 min each,counter-balanced）.Behavioral data of finger force were obtained simultaneously at a sampling rate of 250 *** Frequency analysis of the behavioral data showed lower amplitude in the lowfrequency band（0.004-0.104 Hz） but higher amplitude in the high-frequency band（27.02-125 Hz） in the RT-FFF than the S-FFF *** mean finger force was not significantly different between the two *** data analysis showed higher fractional amplitude of low-frequency fluctuation（fALFF） in the S-FFF than in the RT-FFF state in the visual cortex,but higher fALFF in RT-FFF than S-FFF in the middle frontal gyrus,the superior frontal gyrus,and the default mode *** The behavioral results suggest that the proposed paradigm may provide a new approach to studies of sustained *** fMRI results suggest that a distributed network including visual,motor,attentional,and default mode networks may be involved in sustained attention and/or real-time *** paradigm may be helpful for future studies on deficits of attention,such as attention deficit hyperactivity disorder and mild traumatic brain injury.

关键词： biofeedback amplitude of low-frequency fluctuation sustained attention fMRI