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BPOB的绝对不对称合成机理及固体CD光谱

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物理化学学报 2008年第6期24卷 955-960页

作者：宣为民邹方陈雷奇方雪明连伟章慧厦门大学化学化工学院化学系固体表面物理化学国家重点实验室福建厦门361005

以苯乙酮与间苯二甲酸甲酯为原料经由Claisen缩合制备了1,3-二(3-苯基-3-氧代丙烯醇)苯(BPOB).用元素分析、MS、1H NMR、UV吸收光谱、X射线单晶衍射和固体CD光谱等对其进行了表征.晶体结构数据显示,BPOB属于Sohncke空间群P212121,UV和1H... 详细信息

以苯乙酮与间苯二甲酸甲酯为原料经由Claisen缩合制备了1,3-二(3-苯基-3-氧代丙烯醇)苯(BPOB).用元素分析、MS、1H NMR、UV吸收光谱、X射线单晶衍射和固体CD光谱等对其进行了表征.晶体结构数据显示,BPOB属于Sohncke空间群P212121,UV和1H NMR谱表明,BPOB在溶液中主要以烯醇式存在,固体CD光谱和重结晶实验证明,BPOB手性晶体的形成是结晶诱导的绝对不对称合成.

关键词： 1,3-二(3-苯基-3-氧代丙烯醇)苯手性对称性破缺绝对不对称合成手性晶体固体CD光谱

Dispersion effects on performance of free-electron laser based on laser wakefield accelerator

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High Power Laser Science and Engineering 2018年第4期6卷 125-132页

作者： Ke Feng Changhai Yu Jiansheng Liu Wentao Wang Zhijun Zhang Rong qi ming fang Jiaqi Liu Zhiyong qin Ying Wu Yu chen Lintong Ke cheng Wang Ruxin Li State Key Laboratory of High Field Laser Physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China Collaborative Innovation Center of IFSA Shanghai Jiao Tong UniversityShanghai 200240China School of Physical Science and Technology ShanghaiTech UniversityShanghai 200031China

In this study, we investigate a new simple scheme using a planar undulator(PU) together with a properly dispersed electron beam(e beam) with a large energy spread(～1%) to enhance the free-electron laser(FEL) gain. For a dispersed e beam in a PU, the resonant condition is satisfied for the center electrons, while the frequency detuning increases for the off-center electrons, inhibiting the growth of the radiation. The PU can act as a filter for selecting the electrons near the beam center to achieve the radiation. Although only the center electrons contribute, the radiation can be enhanced significantly owing to the high-peak current of the beam. Theoretical analysis and simulation results indicate that this method can be used for the improvement of the radiation performance, which has great significance for short-wavelength FEL applications.

关键词： free-electron lasers X-rays soft X-rays extreme ultraviolet

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黄河下游造床流量的变化及其对河槽的影响

水利学报 2007年第1期38卷 15-22页

作者：陈绪坚韩其为方春明中国水利水电科学研究院泥沙研究所北京100044

本文通过计算黄河下游的第一造床流量和第二造床流量，分析了黄河下游河槽的萎缩过程。第一造床流量与年水沙量的关系分析表明，黄河下游的深槽平浅滩流量700—1000m^3／s是相对稳定的，恒定流的平衡输沙能力约为18-21kg／m^3。通过小... 详细信息

本文通过计算黄河下游的第一造床流量和第二造床流量，分析了黄河下游河槽的萎缩过程。第一造床流量与年水沙量的关系分析表明，黄河下游的深槽平浅滩流量700—1000m^3／s是相对稳定的，恒定流的平衡输沙能力约为18-21kg／m^3。通过小浪底水库拦粗排细年平均拦沙约3亿t，并在汛期强化调水调沙运用，基本可以控制黄河下游河槽的淤积萎缩。第二造床流量和平滩流量的关系分析表明黄河下游恢复和维持平滩流量约4000m^3／s的中水河槽是比较合理的。根据小浪底水库调水调沙运用状况，提出了恢复和维持黄河下游稳定中水河槽的措施，并探讨了强化小浪底水库调水调沙运用的方案。

关键词：黄河下游第一造床流量第二造床流量平滩流量中水河槽调水调沙小浪底水库

Stepped-up development of accelerator mass spectrometry method for the detection of ^(60)Fe with the HI-13 tandem accelerator

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Nuclear Science and Techniques 2024年第4期35卷 136-143页

作者： Yang Zhang Sheng-Quan Yan ming He qing-Zhang Zhao Wen-Hui Zhang Chao-Xin Kan Jian-ming Zhou Kang-Ning Li Xiao-Fei Wang Jian-cheng Liu Zhao-Hua Peng Zhuo Liang Ai-Ling Li Jian Zheng qi-Wen Fan Yun-Ju Li You-Bao Wang Zhi-Hong Li Yang-Ping Shen Ding Nan wei Nan Yu-qiang Zhang Jia-Ying-Hao Li Jun-Wen Tian Jiang-Lin Hou Chang-Xin Guo Zhi-cheng Zhang ming-Hao Zhu Yu-Wen chen Yu-chen Jiang Tao Tian Jin-Long Ma Yi-Hui Liu Jing-Yu Dong Run-Long Liu Mei-Yue-Nan Ma Yong-Shou chen wei-Ping Liu Bing Guo China Institute of Atomic Energy P.O.Box 275(10)Beijing 102413China College of Science Southern University of Science and TechnologyShenzhen 518055China School of Physics Xi’an Jiaotong UniversityXi’an 710049China

The Moon provides a unique environment for investigating nearby astrophysical events such as *** samples retain valuable information from these events,via detectable long-lived“fingerprint”radionuclides such as^(60)*** this work,we stepped up the development of an accelerator mass spectrometry(AMS)method for detecting^(60)Fe using the HI-13tandem accelerator at the China Institute of Atomic Energy(CIAE).Since interferences could not be sufficiently removed solely with the existing magnetic systems of the tandem accelerator and the following Q3D magnetic spectrograph,a Wien filter with a maximum voltage of±60 kV and a maximum magnetic field of 0.3 T was installed after the accelerator magnetic systems to lower the detection background for the low abundance nuclide^(60)Fe.A 1μm thick Si_(3)N_(4) foil was installed in front of the Q3D as an energy *** particle detection,a multi-anode gas ionization chamber was mounted at the center of the focal plane of the ***,an^(60)Fe sample with an abundance of 1.125×10^(-10)was used to test the new AMS *** results indicate that^(60)Fe can be clearly distinguished from the isobar^(60)*** sensitivity was assessed to be better than 4.3×10^(-14)based on blank sample measurements lasting 5.8 h,and the sensitivity could,in principle,be expected to be approximately 2.5×10^(-15)when the data were accumulated for 100 h,which is feasible for future lunar sample measurements because the main contaminants were sufficiently separated.

关键词： Accelerator mass spectrometry Wien filter Isobar separation Supernovae Chang'e-5 lunar samples

Advanced Space-based Solar Observatory(ASO-S):an overview

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Research in Astronomy and Astrophysics 2019年第11期19卷 3-10页

作者： wei-Qun Gan cheng Zhu Yuan-Yong Deng Hui Li Yang Su Hai-Ying Zhang Bo chen Zhe Zhang Jian Wu Lei Deng Yu Huang Jian-Feng Yang Ji-Jun Cui Jin Chang Chi Wang Ji Wu Zeng-Shan Yin Wen chen cheng fang Yi-Hua Yan Jun Lin wei-ming Xiong Bin chen Hai-Chao Bao Cai-Xia Cao Yan-Ping Bai Tao Wang Bing-Long chen Xin-Yu Li Ye Zhang Li Feng Jiang-Tao Su Ying Li wei chen You-Ping Li Ying-Na Su Hai-Yan Wu Mei Gu Lei Huang Xue-Jun Tang Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 210034China Innovation Academy for Microsatellites Chinese Academy of SciencesShanghai 201203China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Nanjing Institute of Astronomical Optics&Technology National Astronomical ObservatoriesChinese Academy of SciencesNanjing 210042China Changchun Institute of Optics Fine Mechanics and PhysicsChangchun 130033China Xi’an Institute of Optics and Precision Mechanics Chinese Academy of SciencesXi’an 710119China National Space Science Center Chinese Academy of SciencesBeijing 100190China School of Astronomy and Space Science Nanjing UniversityNanjing 210023China Yunnan Observatories Chinese Academy of SciencesKunming 650011China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 101408China Beijing Special Engineering and Design Institute Beijing 100028China Beijing Institute of Tracking and Telecommunications Technology Beijing 100094China Shanghai Academy of Spaceflight Technology Shanghai 201109China

The Advanced Space-based Solar Observatory(ASO-S)is a mission proposed for the 25 th solar maximum by the Chinese solar *** scientific objectives are to study the relationships between the solar magnetic field,solar flares and coronal mass ejections(CMEs).Three payloads are deployed:the Full-disk vector Magneto Graph(FMG),the Lyman-αSolar Telescope(LST)and the Hard X-ray Imager(HXI).ASO-S will perform the first simultaneous observations of the photospheric vector magnetic field,non-thermal imaging of solar flares,and the initiation and early propagation of CMEs on a single ***-S is scheduled to be launched into a 720 km Sun-synchronous orbit in *** paper presents an overview of the mission till the end of Phase-B and the beginning of Phase-C.

关键词： space vehicles instruments-Sun magnetic fields-Sun flares-Sun CMEs-Sun UV radiation-Sun X-ray,gamma-rays

Analysis of tensile strain enhancement in Ge nano-belts on an insulator surrounded by dielectrics

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Chinese Physics B 2013年第10期22卷 539-543页

作者：卢卫芳李成黄诗浩林光杨王尘严光明黄巍赖虹凯陈松岩 Department of Physics Semiconductor Photonics Research CenterXiamen University

Ge nano-belts with large tensile strain are considered as one of the promising materials for high carrier mobility metal- oxide-semiconductor transistors and efficient photonic devices. In this paper, we design the Ge nano-belts on an insulator surrounded by Si3N4 or SiO？ for improving their tensile strain and simulate the strain profiles by using the finite difference time domain （FDTD） method. The width and thickness parameters of Ge nano-belts on an insulator, which have great effects on the strain profile, are optimized. A large uniaxial tensile strain of 1.16% in 50-nm width and 12-nm thickness Ge nano-belts with the sidewalls protected by Si3N4 is achieved after thermal treatments, which would significantly tailor the band gap structures of Ge-nanobelts to realize the high performance devices.

关键词： Ge nano-belts FDTD Si3N4 or SiO2 uniaxially strain

光储式充电站基于SOC的改进型准PR下垂控制研究

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电机与控制学报 2016年第2期20卷 61-69页

作者：程启明陈根程尹曼郭凯黄伟徐聪上海电力学院自动化工程学院上海200090 上海电力公司市北供电分公司上海200041

针对光储式电动汽车充电站以DG形式接入微电网的情况,提出了一种基于SOC的改进型功率耦合下垂控制,在系统孤岛运行时,能根据充电站储能系统SOC的变化,改善充电站与其他DG之间的功率分配;在微电网并网/孤岛双模式切换时,结合相应的并网... 详细信息

针对光储式电动汽车充电站以DG形式接入微电网的情况,提出了一种基于SOC的改进型功率耦合下垂控制,在系统孤岛运行时,能根据充电站储能系统SOC的变化,改善充电站与其他DG之间的功率分配;在微电网并网/孤岛双模式切换时,结合相应的并网输出功率的改变和预同步控制,来实现双模式切换的平滑过渡。在逆变器的双环控制中,电压外环采用准PR控制,电流内环采用比例P控制,实现对参考信号的快速跟踪和无差控制。最后,基于MATLAB/Simulink针对不同工况对控制策略进行了对比研究,仿真结果表明,所提出的改进型下垂控制能实现充电站向电网方向放电的灵活有效控制。

关键词：光储式电动汽车充电站准PR控制下垂控制

Alcohol consumption in relation to the incidence of atrial fibrillation in an elderly Chinese population

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Journal of Geriatric Cardiology 2022年第1期19卷 52-60页

作者： Xiao-Fei YE wei ZHANG Yi chen Chao-Ying MIAO qi-fang HUANG Chang-Sheng SHENG Shuai SHAO Dian WANG Shao-Kun XU Lei LEI Di ZHANG Yi-Lin chen Lei-Xiao HU Jia-Hui XIA Yi-Bang cheng Ying WANG qian-Hui GUO Yan LI Nicole Lowres Ben Freedman Ji-Guang WANG School of Public Health Shanghai Jiao Tong University School of MedicineShanghaiChina Department of Cardiovascular Medicine The Shanghai Institute of HypertensionRuijin HospitalShanghai Jiao Tong University School of MedicineShanghaiChina Heart Research Institute Sydney Medical SchoolCharles Perkins Centerand Cardiology DepartmentConcord HospitalUniversity of SydneySydneyAustralia

BACKGROUND Alcohol consumption is a known modifiable risk factor for atrial *** association,however,might differ according to *** investigated gender-specific associations between alcohol consumption and incident atrial fibrillation in an elderly Chinese *** Our study participants were elderly residents(≥65 years)recruited from five community health centers in the urban area of Shanghai(n=6,618).Alcohol intake was classified as never drinkers and current light-to-moderate(<40 g/day)and heavy drinkers(≥40 g/day).Atrial fibrillation was detected by a 30-s single-lead electrocardiography(ECG,AliveCor®Heart Monitor)and further evaluated with a regular 12-lead *** During a median of 2.1 years(interquartile range:2.0−2.2)follow-up,the incidence rate of atrial fibrillation was 1.10%in all study *** was slightly but non-significantly higher in men(n=2849)than women(n=3769,1.30%vs.0.96%,P=0.19)and in current drinkers(n=793)than never drinkers(n=5825,1.64%vs.1.03%,P=0.12).In both unadjusted and adjusted analyses,there was interaction between sex and current alcohol intake in relation to the incidence of atrial fibrillation(P<0.0001).After adjustment for confounding factors,current drinkers had a significantly higher incidence rate of atrial fibrillation than never drinkers in women(12.96%[7/54]vs.0.78%[29/3715],adjusted odds ratio[OR]=10.25,95%confidence interval[CI]:3.54−29.67,P<0.0001),but not in men(0.81%[6/739]vs.1.47%[31/2110],OR=0.62,95%CI:0.25−1.51,P=0.29).CONCLUSIONS Our study showed a significant association between alcohol intake and the incidence of atrial fibrillation in elderly Chinese women,but not men.

关键词： fibrillation intake Alcohol

HNTs@CeO_(2)-Au@Co_(3)O_(4)催化还原对硝基苯酚和染料污染物

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中国环境科学 2024年第1期44卷 193-201页

作者：方嘉声陈铭刁琪琪赵硕黄振庭卫昆卓琼芳东莞理工学院生态环境与建筑工程学院广东东莞523808 东莞市新污染物重点实验室广东东莞523808 山东理工大学化学化工学院山东淄博255049

制备了HNTs@CeO_(2)-Au@Co_(3)O_(4)核壳中空管状复合催化剂,用于还原降解水体中对硝基苯酚(4-NP)和染料(MB,MO)污染物.采用TEM,SEM,EDS,XRD,N_(2)吸脱附,XPS等方法对催化剂微观结构和物化特征进行表征.结果表明,CeO_(2)和Co_(3)O_(4)作为内外活性层较好地分散固载Au纳米颗粒,通过界面反应构筑于埃洛石纳米管中,形成CeO_(2)/Co_(3)O_(4)叠层结构封装埃洛石载金核壳复合催化剂(HNTs@CeO_(2)-Au@Co_(3)O_(4)).该催化剂分别在3.5,8和3min内可还原去除96%以上的4-NP,MB和MO污染物,其相应的一级反应动力学速率常数(0.856,0.370,1.337min^(-1))和转换频率(10.99,1.90,2.80min^(-1))均明显优于HNTs-Au@Co_(3)O_(4),HNTs@CeO_(2)-Au和HNTs@CeO_(2)@Co_(3)O_(4)对照材料.HNTs@CeO_(2)-Au@Co_(3)O_(4)催化剂连续进行6次使用后,仍保持较高的4-NP,MB和MO污染物还原转化率(91.2%,87.3%,89.5%)和结构稳定性.独特的CeO_(2)/Co_(3)O_(4)叠层结构特征和复合组分协同增强效应有效促进了高性能催化体系的构建,极大提升了Au颗粒的催化活性和稳定性,使HNTs@CeO_(2)-Au@Co_(3)O_(4)催化剂呈现较为优异的催化效能和循环使用性能.

关键词：纳米金催化剂埃洛石核壳结构对硝基苯酚染料污染物催化还原