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Front-end signal analysis of the transverse feedback system for SSRF

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Nuclear Science and Techniques 2008年第5期19卷 274-277页

作者： han lifeng YUAN Renxian YU Luyang YE Kairong Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai 201800 China

Multi-bunch instabilities degrade beam quality through increased beam emittance,energy spread and even cause beam loss.A feedback system is used to suppress multi-bunch instabilities associated with resistive wall of the beam ducts,cavity-like structures,and trapped ions.A digital TFS (Transverse Feedback System) is in construction at the SSRF (Shanghai Synchrotron Radiation Facility),which is based on the latest generation of FPGA (Field Programmable Gate Array) *** we get such FPGA disital board,investigation and simulation of the front-end were done in the first *** signal flow was analyzed by *** and optimization of the entire system is our next goal.

关键词：同步加速器前置电路信号分析横向反馈系统

Digital bunch-by-bunch transverse feedback system at SSRF

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Science China(Physics,Mechanics & Astronomy) 2011年第S2期54卷 305-308页

作者： YUAN RenXian LENG YongBin YU LuYang han lifeng YE KaiRong Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China

In order to suppress multi-bunch couple instabilities caused by transverse impedance, a bunch-by-bunch transverse feedback system based on a FPGA digital processor is commissioned at SSRF storage ring. The RF front end has two COD pre-rejected attenuators for increasing the system arrangement and signal noise ratio, and the 3*RF Local signal comes from the BPM's sum signal using a FIR filter for avoiding the effect of longitudinal oscillation. The digital processor receives the coupled horizontal and vertical oscillation signals in the base band and transforms the coupled signals to the horizontal and vertical feedback signals with two series double-zeroes FIR filters. A matlab GUI is applied for producing the FIR coefficients when the tune is shifted. The horizontal and vertical Kickers have a special design for increasing the shunt impedance. Then the multi-bunch instabilities are suppressed respectively and the minimum damping time is about 0.4 ms.

关键词： transverse feedback multi-bunch instability

The remarkable but varied photosensitized oxidation by atmospheric humic-like substances at the air-water interface

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Science China Chemistry 2024年第12期67卷 4251-4258页

作者： Ning Yang Chu Gong Dongmei Zhang Xufeng Gao lifeng han Pingqing Fu Xinxing Zhang Institute of Surface-Earth System Science School of Earth System ScienceTianjin UniversityTianjin 300072China College of Chemistry Frontiers Science Center for New Organic MatterState Key Laboratory of Advanced Chemical Power SourcesKey Laboratory of Advanced Energy Materials Chemistry(Ministry of Education)Tianjin Key Laboratory of Biosensing and Molecular RecognitionRenewable Energy Conversion and Storage Center(ReCAST)Nankai UniversityTianjin 300071China State Key Laboratory of Component-Based Chinese Medicine Haihe Laboratory of Modern Chinese MedicineTianjin University of Traditional Chinese MedicineTianjin 301617China

Humic-like substances(HULIS),a class of macromolecular photosensitizers,are major components of light-absorbing aerosols in the *** to the amphiphilic nature of HULIS,they tend to appear at the air-water interface of atmospheric ***,there have been limited studies on the photosensitized chemistry of HULIS at the air-water interface owing to the lack of methods with high interface ***,a unique field-induced droplet ionization mass spectrometry(FIDI-MS)technique was used to investigate the photosensitized chemistry of several samples at the air-water *** samples include commercially available humic acid and the PM_(2.5)sample collected during Beijing′s severe winter haze in December ***-resolution Fourier transform-ion cyclotron resonance mass spectrometry(FT-ICR MS)was also applied to analyze the atomic compositions,the degree of unsaturation and the aromaticity of these *** TypeⅠand TypeⅡphotosensitized oxidation pathways were observed,which were postulated to be dictated by the packing density of the molecules at the air-water *** findings reveal that the photosensitization of HULIS at the air-water interface contributes greatly to the formation of atmospheric aerosols,further advancing our understanding of the important roles played by photosensitized chemistry in the atmosphere.

关键词： mass spectrometry humic-like substances photosensitized oxidation air-water interface secondary organic aerosols

Eight darmarane-type saponins isolated from the roots of Panax notoginseng

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Acta Pharmaceutica Sinica B 2013年第6期3卷 381-384页

作者： Kaunda Joseph Sakah Tao Wang Lili Liu Yue Chen lifeng han Yi Zhang Tianjin Key Laboratory of TCM Chemistry and Analysis Institute of Traditional Chinese MedicineTianjin University of Traditional Chinese MedicineTianjin 300193China Tianjin State Key Laboratory of Modern Chinese Medicine Tianjin University of Traditional Chinese MedicineTianjin 300193China

Eight darmarane-type saponins,named as sanchirhinoside D(1),3β,6 α-20(S)-6,20-bis(β-D-glucopyranosyloxy)-3-hydroxy dammar-24-en-12-one(2),20(R)-ginsenoside Rg3(3),ginsenosides F2(4)and Rd(5),gypenoside XVII(6),ginsenosides Rb1(7)and ginsenoside V(8)were isolated from the 70%ethanol extract of Panax notoginseng roots by silica gel,octadecyl silane(ODS)column chromatography and HPLC,and identified by chemical and physical methods,especially by spectral *** them,1 was a new compound and 2 was a new natural product.

关键词： Panax notoginseng Darmarane type saponins Sanchirhinoside D

Fabrication and characteristics of ZnO MOS capacitors with high-K HfO_2 gate dielectrics

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Science China(Technological Sciences) 2010年第9期53卷 2333-2336页

作者： han DeDong,WANG Yi,ZhanG ShengDong,SUN Lei,KANG JinFeng,LIU XiaoYan,DU Gang,LIU lifeng & han RuQi Institute of Microelectronics,Peking University,Beijing 100871,China Institute of Microelectronics Peking University Beijing China

ZnO thin films are first deposited on n-type silicon by radio frequency (rf) magnetron sputtering at room *** high-K HfO2 gate dielectrics thin films are deposited on ZnO films to form metal-oxide semiconductor (MOS) *** temperature to fabricate ZnO MOS capacitors is 400°C,and the low temperature process is applicable for thin film transistors,flat-panel display (FPD),flexible display,*** electronic availability of ZnO thin films,which serve as a semiconductor material for MOS capacitors with HfO2 gate dielectric is *** frequency (1 MHz) capacitance-voltage (C-V) and current-voltage (I-V) characteristics of ZnO-based MOS capacitors are *** thermal stability and electronic stability of the ZnO capacitors are investigated,*** results indicate that good electrical characteristics can be obtained on ZnO substrates with high-K HfO2 gate ***,the ZnO capacitors can exhibit high thermal and electronic stabilities.

关键词： ZnO high-K HfO2 low temperature process

Mechanistic investigation on Ag-Cu_(2)O in electrocatalytic CO_(2) to CH_(4) by in situ/operando spectroscopic and theoretical analysis

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Journal of Energy Chemistry 2024年第1期88卷 521-531,I0012页

作者： Min Sun Luxiao Zhang Fuli Tian Jiaxin Li Yanqiu Lei Heng Zhang lifeng han Zhihua Guo Yonghui Gao Fenrong Liu Yan Wang Luhui Wang Shanghong Zeng School of Chemistry and Chemical Engineering Inner Mongolia UniversityHohhot 010021Inner MongoliaChina Key Laboratory of Medicinal and Edible Plants Resources of Hainan Province Hainan Vocational University of Science and TechnologyHaikou 571126HainanChina State Key Laboratory of Baiyunobo Rare Earth Resource Research and Comprehensive Utilization Baotou Research Institute of Rare EarthsBaotou 014030Inner MongoliaChina Zhejiang Key Laboratory of Petrochemical Environmental Pollution Control Zhejiang Ocean UniversityZhoushan 316022ZhejiangChina

Silver-copper electrocatalysts have demonstrated effectively catalytic performance in electroreduction CO_(2) toward CH_(4),yet a revealing insight into the reaction pathway and mechanism has remained ***,we construct chemically bonded Ag-Cu_(2)O boundaries,in which the complete reduction of Cu_(2)O to Cu has been strongly impeded owing to the presence of surface Ag *** interfacial confinement effect helps to maintain Cu^(+)sites at the Ag-Cu_(2)O *** in situ/operando spectroscopy and theoretical simulations,it is revealed that CO_(2) is enriched at the Ag-Cu_(2)O boundaries due to the enhanced physisorption and chemisorption to CO_(2),activating CO_(2) to form the stable intermediate^(*)*** boundaries between Ag shell and the Cu_(2)O mediate local^(*)CO coverage and promote^(*)CHO intermediate formation,consequently facilitating CO_(2)-to-CH_(4) *** work not only reveals the structure-activity relationships but also offers insights into the reaction mechanism on Ag-Cu catalysts for efficient electrocatalytic CO_(2) reduction.

关键词： Ag shell Interfacial confinement effect Cu~+ Local*CO coverage CO_(2)reduction

Digital bunch-by-bunch transverse feedback system at SSRF

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Digital bunch-by-bunch transverse feedback system at SSRF

第一届中国粒子加速器会议

作者： YUAN RenXian LENG YongBin YU LuYang han lifeng YE KaiRong Shanghai Institute of Applied Physics Chinese Academy of Sciences

In order to suppress multi-bunch couple instabilities caused by transverse impedance,a bunch-by-bunch transverse feedback system based on a FPGA digital processor is commissioned at SSRF storage *** RF front end has two COD pre-rejected attenuators for increasing the system arrangement and signal noise ratio,and the 3*RF Local signal comes from the BPM’s sum signal using a FIR filter for avoiding the effect of longitudinal *** digital processor receives the coupled horizontal and vertical oscillation signals in the base band and transforms the coupled signals to the horizontal and vertical feedback signals with two series double-zeroes FIR filters.A matlab GUI is applied for producing the FIR coefficients when the tune is *** horizontal and vertical Kickers have a special design for increasing the shunt *** the multi-bunch instabilities are suppressed respectively and the minimum damping time is about 0.4 ms.

关键词： transverse feedback multi-bunch instability

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注水型菲涅耳聚光器的设计和初步试验

光学学报 2021年第14期41卷 173-180页

作者：肖君曹云韩利峰中国科学院上海应用物理研究所仪控工程部上海201800

研发低成本的聚光器是大规模降低太阳能热利用成本的重要途径之一。为了降低材料成本,提出注水型菲涅耳聚光器的设计新思路。注水型菲涅耳聚光器采用由薄平板玻璃组成的中空三角形棱柱,通过在中空部分注入纯净水来减少透镜材料的使用,... 详细信息

研发低成本的聚光器是大规模降低太阳能热利用成本的重要途径之一。为了降低材料成本,提出注水型菲涅耳聚光器的设计新思路。注水型菲涅耳聚光器采用由薄平板玻璃组成的中空三角形棱柱,通过在中空部分注入纯净水来减少透镜材料的使用,从而降低成本。研究该聚光器的设计理论并建立相应的光学模型,采用蒙特-卡罗光线追迹方法研究不同太阳入射角度下聚光器的光学性能,并与传统菲涅耳聚光器进行对比。搭建试验样机并进行初步的聚光实验。研究结果表明,相较于传统菲涅耳聚光器,注水型菲涅耳聚光器虽然聚光效果有一定的损失,聚光效率平均损失为5.40%,但试验样机具有明显的聚光效果,光斑宽度与理论情况也较吻合,具备工程应用的可行性。

关键词：光学设计太阳能热利用菲涅尔聚光器聚光器设计光学性能

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网络环境下图书馆的参考咨询服务

图书馆工作与研究 1999年第5期 12-14页

作者：韩丽风清华大学图书馆!北京100084

通过与传统图书馆工作的比较分析，从服务形式、内容、手段等各方面探讨了网络环境下图书馆参考咨询服务的特征，讨论了网络发展对参考咨询服务的巨大影响。

关键词：网络环境图书馆工作参考咨询读者服务