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LNG三偏心低温蝶阀密封副结构和密封比压研究

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阀门 2024年第8期 951-958页

作者：周位伟刘伯圻刘诗梅余晓光重庆川仪调节阀有限公司重庆400700

在液化天然气(LNG)工况下,三偏心蝶阀的密封性能至关重要,而低温环境对密封副的影响尤为显著。本文旨在分析低温对三偏心蝶阀密封副的影响,并优化其结构和密封比压,以提高密封性能的可靠性。通过实际低温试验、CAE有限元仿真分析和理论... 详细信息

在液化天然气(LNG)工况下,三偏心蝶阀的密封性能至关重要,而低温环境对密封副的影响尤为显著。本文旨在分析低温对三偏心蝶阀密封副的影响,并优化其结构和密封比压,以提高密封性能的可靠性。通过实际低温试验、CAE有限元仿真分析和理论计算,对密封圈、密封副和阀门力矩进行了综合研究。研究发现低温环境对密封副造成了一系列问题,通过优化设计,改善了密封副结构,并修正了密封比压的计算方法。优化后的三偏心蝶阀在超低温工况下展现出了稳定的密封性能,为LNG等低温工程的应用提供了技术支撑。

关键词：超低温三偏心蝶阀 LNG 密封比压空分

Discrepancies in boreal summer monsoon rainfall between GPCP and CMAP products during 1979–2014

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Atmospheric and Oceanic Science Letters 2016年第3期9卷 226-233页

作者： HAO Yu-qian ZHU Cong-Wen liu bo-qi Institute of Climate System Chinese Academy of Meteorological Sciences State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG) Institute of Atmospheric Physics Chinese Academy of Sciences

This study compares the boreal summer monsoon （BSM） precipitation between the GPCP and CMAP products during 1979-2014. The authors apply temporal, spatial correlation and error evaluation methods to evaluate their discrepancies in terms of BSM distribution and summer rainfall interannual variability over the five BSM regions. The results suggest that the climatology of the seasonal evolution of BSM rainfall is reflected well in both datasets, and the summer rainfall anomalies of the two products are highly correlated. However, major diversity is found in the rainfall pattern and the magnitude in climatology over the oceanic monsoon areas, especially the western North Pacific monsoon region, as well as in the interannual variability of summer rainfall anomalies over the North Africa and India monsoon regions. Although inconsistency between the two datasets is evident before the 1990s, the use of their arithmetic mean is demonstrated to be an efficient way to reduce the uncertainty between them.

关键词： GPCP CMAP boreal summermonsoonl interannualvariability data evaluation

基于PLC冗余控制的微机励磁调节控制系统设计

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广西水利水电 2024年第1期 115-119页

作者：周涛李兼伐刘电波季锐陈炳森刘奇波广西水利电力职业技术学院南宁530023 南宁精能发电设备有限公司南宁530033

为满足中小型水电站智能化建设对水轮发电机励磁调节控制系统提出的高可靠性要求,有效解决基于单CPU的PLC励磁调节控制系统“死机”问题,基于西门子S7-1500系列具有冗余功能的PLC设计了水轮发电机励磁调节控制系统。系统采用2台CPU 1513... 详细信息

为满足中小型水电站智能化建设对水轮发电机励磁调节控制系统提出的高可靠性要求,有效解决基于单CPU的PLC励磁调节控制系统“死机”问题,基于西门子S7-1500系列具有冗余功能的PLC设计了水轮发电机励磁调节控制系统。系统采用2台CPU 1513R组成冗余控制器,并通过MRP冗余环网和分布式I/O实现对发电机励磁调节的过程控制。励磁调节采用PLC内部集成且具有抗积分饱和的PID控制器,通过定时中断方式对励磁调差计算结果进行PID运算,得到晶闸管控制角后再与机端电压同步信号合成控制脉冲,完成对励磁主回路晶闸管的控制。

关键词：励磁调节 PLC 冗余设计

Recursive Filtering for Stochastic Systems With Filter-and-Forward Successive Relays

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IEEE/CAA Journal of Automatica Sinica 2024年第5期11卷 1202-1212页

作者： Hailong Tan bo Shen qi Li Hongjian liu School of Mathematics-Physics and Finance Anhui Polytechnic UniversityWuhu 241000China Anhui Future Technology Research Institute Anhui Polytechnic UniversityWuhu 241000China College of Information Science and Technology Donghua UniversityShanghai 201620China Engineering Research Center of Digitalized Textile and Fashion Technology Ministry of EducationShanghai 201620China School of Information Science and Engineering Hangzhou Normal UniversityHangzhou 311121China

In this paper,the recursive filtering problem is considered for stochastic systems over filter-and-forward successive relay(FFSR)*** FFSR is located between the sensor and the remote filter to forward the *** the successive relay,two cooperative relay nodes are adopted to forward the signals alternatively,thereby existing switching characteristics and inter-relay interferences(IRI).Since the filter-and-forward scheme is employed,the signal received by the relay is retransmitted after it passes through a linear *** objective of the paper is to concurrently design optimal recursive filters for FFSR and stochastic systems against switching characteristics and IRI of ***,a uniform measurement model is proposed by analyzing the transmission mechanism of ***,novel filter structures with switching parameters are constructed for both FFSR and stochastic *** the help of the inductive method,filtering error covariances are presented in the form of coupled difference ***,the desired filter gain matrices are further obtained by minimizing the trace of filtering error ***,the stability performance of the filtering algorithm is analyzed where the uniform bound is guaranteed on the filtering error ***,the effectiveness of the proposed filtering method over FFSR is verified by a three-order resistance-inductance-capacitance circuit system.

关键词： filtering successive stochastic

Subseasonal variation of winter rainfall anomalies over South China during the mature phase of super El Ni?o events

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Atmospheric and Oceanic Science Letters 2018年第5期11卷 396-403页

作者： GUO Li ZHU Cong-Wen liu bo-qi MA Shuang-Mei Institute of Climate System Chinese Academy of Meteorological SciencesBeijingChina

The authors explore the intraseasonal oscillation(ISO)of rainfall anomalies in South China,the related circulation regimes,and discuss the possible causes of the large variability of the positive rainfall anomalies over South China during the winter of the 1982/83,1997/98 and 2015/16 super EI Nino ***-by-case analysis shows that the 10–20-day ISO associated with the successive heavy rainfall events lead to the positive anomalies of winter rainfall in the three ***,the 20–50-day ISO is relatively stronger in the winter of 1982/83 and 2015/16 but weaker in the winter of 1997/*** for a different speed,the anomalies of the 200-hPa wave train associated with the two ISOs both propagate eastward along the westerly jet between 20 N and 30 *** the winter of 1982/83 and 2015/16,when the upper-level subseasonal wave trains in different periods pass through South China,the in-phase enhancement of upper-level divergences and the pumping effect could induce the persistent heavy rainfall events,which facilitate the stronger seasonal-mean *** the 10–20-day ISO alone in the winter of 1997/98 could cause the higher-frequency rainfall events,the weaker 20–50-day ISO attenuates the anomalies of the South China winter ***,the joint effects of the 10–20-and 20–50-day ISOs are critical for the larger amount of above-normal rainfall over South China during the mature phase of super EI Nino events.

关键词： Super EI Nino event South China winter rainfall Intraseasonal Oscillation(ISO)

Exploring hidden-charm and hidden-strange hexaquark states from lattice QCD

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Science China(Physics,Mechanics & Astronomy) 2024年第1期67卷 30-37页

作者： Hang liu Jinchen He liuming liu Peng Sun Wei Wang Yi-bo Yang qi-An Zhang INPAC Key Laboratory for Particle Astrophysics and Cosmology(MOE)Shanghai Key Laboratory for Particle Physics and CosmologySchool of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China Maryland Center for Fundamental Physics Department of PhysicsUniversity of MarylandCollege ParkMaryland 20742USA Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China Department of Physics and Institute of Theoretical Physics Nanjing Normal UniversityNanjing 210023China Southern Center for Nuclear-Science Theory(SCNT) Institute of Modern PhysicsChinese Academy of SciencesHuizhou 516000China CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUCASHangzhou 310024China International Centre for Theoretical Physics Asia-Pacific Beijing 100049/Hangzhou 310024China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China School of Physics Beihang UniversityBeijing 102206China

Based on five different ensembles of newly generated(2+1)-flavor configurations with pion mass of approximately mπ■(140-310)MeV,we present a lattice analysis of hidden-charm and hidden-strange hexaquarks with the quark content■.The correlation matrices of two types of operators with JPC=0++,0-+,1++and 1--are simulated to extract the masses of the hexaquark candidates,which are subsequently extrapolated to the physical pion mass and continuum *** results indicate that ground state masses are below the■threshold and provide a characteristic signal for the experimental discovery of hexaquark candidates,which may enrich the versatile structure of multiquarks;moreover,it is an indispensable step to decipher the nonperturbative nature of the fundamental interactions of quarks and gluons.

关键词： quantum chromodynamics lattice QCD multiquark states

Development of a high-repetition-rate lumped-inductance kicker magnet prototype for the beam switchyard of SHINE

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Nuclear Science and Techniques 2024年第2期35卷 20-31页

作者： Yong-Fang liu Rui-Ping Wang Jin Tong bo Zhang Si Chen qi-Bing Yuan Hai-Xiao Deng Ming Gu bo liu Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201412People’s Republic of China

The Shanghai high-repetition-rate X-ray free-electron laser and extreme light facility(SHINE)operates at a maximum repetition rate of 1 *** magnets are key components that distribute electron bunches into three different undulator lines in a bunch-by-bunch *** kicker field width must be less than the time interval between bunches.A lumpedinductance kicker prototype was developed using a vacuum chamber with a single-turn *** full magnetic field strength was 0.005 *** paper presents the requirements,design considerations,design parameters,magnetic field calculations,and measurements of the kicker *** relevant experimental results are also *** pulse width of the magnetic field was approximately 600 ns,and the maximum operation repetition rate was 1 *** developed kicker satisfies the requirements for the SHINE ***,numerous recommendations for the future optimization of kicker magnets are provided.

关键词： X-ray free-electron laser Kicker magnet Beam switchyard High repetition rate Ni-Zn ferrites

A Novel RT-LAMP Assay for Rapid and Simple Detection of Classical Swine Fever Virus

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Virologica Sinica 2010年第1期25卷 59-64页

作者： Lei CHEN Xue-zheng FAN qin WANG Lu XU qi-zu ZHAO Yuan-chen ZHOU Jun liu bo TANG Xing-qi ZOU China Institute of Veterinary Drug Control Beijing 100081 China

A simple and rapid assay for the detection of Classical swine fever virus(CSFV)was established using reverse transcription loop-mediated isothermal amplification(RT-LAMP).This study describes the amplification of the genomic RNA of CSFV under isothermal conditions(63℃)within one hour,using a set of six primers(two outer primers,two inner primers and two loop primers).This RT-LAMP assay showed 100-fold higher sensitivity than the standard RT-PCR method and identified eighteen additional positive cases that were negative when tested by *** RT-LAMP was able to detect all the 13 strains of CSFV but not the ***. PRV-PCV,thus showed a good *** amplified by RT-LAMP can be visualized by agarose gel electrophoresis and in addition,either as a white precipitate at the bottom of the tube after a pulse spin or as a color change when dyed with SYBR Green I which are visible to the naked *** RT-LAMP is low-cost and produces rapid results,it has the potential to be an excellent tool for CSFV surveillance in the field,especially in developing countries.

关键词： Classical swine fever virus (CSFV) Reverse transcription loop-mediated isothermal amplification(RT-LAMP) Rapid detection

Enhancing thermoelectric performance in P-type Mg_(3)Sb_(2)-based Zintls through optimization of band gap structure and nanostructuring

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Journal of Materials Science & Technology 2024年第3期170卷 25-32页

作者： Yi-bo Zhang Ji-Sheng Liang Chengyan liu qi Zhou Zhe Xu Hong-bo Chen Fu-cong Li Ying Peng Lei Miao Guangxi Key Laboratory of Information Material Engineering Research Center of Electronic Information Materials and DevicesMinistry of EducationSchool of Material Science and EngineeringGuilin University of Electronic TechnologyGuilin 541004China Guangxi Key Laboratory for Relativity Astrophysics Center on Nanoenergy ResearchGuangxi Key Laboratory of Processing for Nonferrous Metal and Featured MaterialsSchool of Physical Science&TechnologyGuangxi UniversityNanning 530004China Guangxi Key Laboratory of Precision Navigation Technology and Application Guilin University of Electronic TechnologySchool of Information and CommunicationGuilin 541004China

P-type Mg_(3)Sb_(2)-based Zintls have attracted considerable interest in the thermoelectric(TE)field due to their environmental friendliness and low ***,compared to their n-type counterparts,they show relatively low TE performance,limiting their application in TE *** this work,we simultaneously introduce Bi alloying at Sb sites and Ag doping at Mg sites into the Mg_(3)Sb_(2)to coopera-tively optimize the electrical and thermal properties for the first time,acquiring the highest ZT value of∼0.85 at 723 K and a high average ZT of 0.39 in the temperature range of 323-723 K in sample Mg_(2.94)Ag_(0.06)Sb_(1.9)Bi_(0.1).The first-principle calculations show that the codoping of Ag and Bi can shift the Fermi level into the valence band and narrow the band gap,resulting in the increased carrier concentration from 3.50×10^(17)cm^(-3)in the reference Mg 3 Sb 0.9 Bi 0.1 to∼7.88×10^(19)cm^(-3)in sample Mg 2.94 Ag 0.06 Sb 0.9 Bi *** a result,a remarkable power factor of∼778.9μW m^(-1)K^(-2)at 723 K is achieved in sample Mg 2.94 Ag 0.06 Sb 0.9 Bi ***,a low lattice thermal conductivity of∼0.48 W m^(-1)K^(-1)at 723 K is also obtained with the help of phonon scattering at the distorted lattice,point defects,and nano-precipitates in sample Mg 2.94 Ag 0.06 Sb 0.9 Bi *** synergistic effect of using the multi-element co-doping/-alloying to optimize electrical properties in Mg_(3)Sb_(2)holds promise for further improving the TE performance of Zintl phase materials or even others.

关键词： Thermoelectric materials Band engineering Nanostructuring P-type Mg_(3)Sb_(2) Ag and Bi Co-doping