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High power, longevity gallium arsenide photoconductive semiconductor switches

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Chinese Science Bulletin 2010年第13期55卷 1331-1337页

作者： yang hongchun CUI HaiJuan SUN YunQing ZENG Gang WU MingHe Institute of Applied Physics University of Electronic Science and Technology of China Chengdu 610054 China

A GaAs Photoconductive Semiconductor Switch (PCSS) with a 3-mm gap between the two opposed contact electrodes was developed with carefully chosen GaAs material, mechanical structure design, contact fabrication techniques and its insulation protection. It is charged by a pulse power supply under a bias of 15 kV, illuminated by laser pulses of 1064 nm in wavelength, 56.12 μJ in optical energy per shot and 1 kHz pulse repetition rate (PRR). The GaAs PCSS can last for more than 3.6×106 shots and produce output pulses of 2 MW in peak power, 2 ns pulse duration and 65 ps time jitter from a 50-Ω load of the oscilloscope. When an electric field of 100 kV/cm bias was applied, the peak power of the load was measured at 10 MW. A series of measurements on the voltage conversion rates (VCR) and time jitters have been carried out as the bias voltage increases. In particular, taking into account the dependence of optical absorption coefficient on the bias voltages, the curve of the VCR changes with the bias voltages were analyzed quantitatively.

关键词：砷化镓材料光电开关半导体开关高功率长寿命砷化镓半导体机械结构设计脉冲持续时间

Polycomb-based quantitative epigenetic silencing at FLC in vernalization

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Polycomb-based quantitative epigenetic silencing at FLC in v...

Epigenetics in the modern era of crop improvements

中国植物学会第十六次全国会员代表大会暨85周年学术年会

作者： hongchun yang

We are studying the chromatin dynamics underlying cold-induced epigenetic silencing of Arabidopsis *** determines when plants flower and how they respond to different winter *** epigenetic silencing involves a Polycomb-based epigenetic switching *** expression is bistable and cold exposure promotes a switch in individual cells form a transcriptional active（marked by H3 K36 me3） to a Polycomb-silenced state（marked by H3 K27 me3）.The memory of this silenced state is then inherited in cis through many cell divisions until the plant has flowered,after which point the switch is *** talk will describe our latest understanding of this switching *** recent work reveals the switching can be separated to mechanistically distinct two phases of Polycomb *** of specific Polycomb factors holds a metastable memory of cold in the short-term with subsequent transfer to a long-term histone-modification-based memory via general Polycomb *** mechanistic understanding is likely to be general relevant to Polycomb targets in all *** mechanistic understanding is likely to be general relevant to Polycomb targets in all organisms.

关键词： Polycomb Epigenetic switching FLC Vernalization

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Science China Life Sciences 2025年

作者： Yan Xue Xiaofeng Cao Xiangsong Chen Xian Deng Xingwang Deng Yong Ding Aiwu Dong Chengguo Duan Xiaofeng Fang Lei Gong Zhizhong Gong Xiaofeng Gu Chongsheng He Hang He Shengbo He Xinjian He Yan He Yuehui He Guifang Jia Danhua Jiang Jianjun Jiang Jinsheng Lai Zhaobo Lang Chenlong Li Qing Li Xingwang Li Bao Liu Bing Liu Xiao Luo Yijun Qi Weiqiang Qian Guodong Ren Qingxin Song Xianwei Song Zhixi Tian Jiawei Wang Yuan Wang Liang Wu Zhe Wu Rui Xia Jun Xiao Lin Xu Zhengyi Xu Wenhao Yan hongchun yang Jixian Zhai Yijing Zhang Yusheng Zhao Xuehua Zhong Daoxiu Zhou Ming Zhou Yue Zhou Bo Zhu Jiankang Zhu Qikun Liu College of Life Sciences Institute of Life Science and Green Development Hebei University Biotechnology Research Institute Chinese Academy of Agricultural Sciences College of Biology Hunan Key Laboratory of Plant Functional Genomics and Developmental Regulation Hunan Engineering and Technology Research Center of Hybrid Rapeseed Hunan University Institute of Advanced Agricultural Sciences School of Advanced Agricultural Sciences Peking University State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources Guangdong Laboratory for Lingnan Modern Agriculture South China Agricultural University National Institute of Biological Sciences Key Laboratory of Seed Innovation Institute of Genetics and Developmental Biology Chinese Academy of Sciences School of Advanced Agricultural Sciences Peking-Tsinghua Center for Life Sciences Peking University Synthetic and Functional Biomolecules Center Beijing National Laboratory for Molecular Sciences Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education College of Chemistry and Molecular Engineering Peking University Key Laboratory of Seed Innovation State Key Laboratory of Plant Genomics and National Center for Plant Gene Research Institute of Genetics and Developmental Biology Chinese Academy of Sciences State Key Laboratory of Wheat Improvement Peking University Institute of Advanced Agricultural Sciences Shandong Laboratory of Advanced Agricultural Sciences in Weifang State Key Laboratory of Crop Stress Adaptation and Improvement School of Life Sciences Henan University State Key Laboratory of Maize Bio-breeding National Maize Improvement Center Department of Plant Genetics and Breeding China Agricultural University Frontiers Science Center for Molecular Design Breeding China Agricultural University Center for Crop Functional Genomics and Molecular Breeding China Agricultural University Sanya Institute of China Agricultural University Hainan Yazhou Bay Seed Laboratory Institute of Advan

Epigenetic mechanisms are integral to plant growth, development, and adaptation to environmental stimuli. Over the past two decades,our comprehension of these complex regulatory processes has expanded remarkably, producing a substantial body of knowledge on both locus-specific mechanisms and genome-wide regulatory patterns. Studies initially grounded in the model plant Arabidopsis have been broadened to encompass a diverse array of crop species, revealing the multifaceted roles of epigenetics in physiological and agronomic traits. With recent technological advancements, epigenetic regulations at the single-cell level and at the large-scale population level are emerging as new focuses. This review offers an in-depth synthesis of the diverse epigenetic regulations, detailing the catalytic machinery and regulatory functions. It delves into the intricate interplay among various epigenetic elements and their collective influence on the modulation of crop traits. Furthermore, it examines recent breakthroughs in technologies for epigenetic modifications and their integration into strategies for crop improvement. The review underscores the transformative potential of epigenetic strategies in bolstering crop performance, advocating for the development of efficient tools to fully exploit the agricultural benefits of epigenetic insights.

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X射线荧光光谱法测定高铬型钒渣中主次组分

理化检验（化学分册） 2018年第6期54卷 640-643页

作者：杨洪春攀枝花钢钒有限公司制造部攀枝花617000

称取于750~800℃灼烧2h后的试样0.300 0g,置于盛有4.000 0g四硼酸锂、3.000 0g偏硼酸锂、0.500 0g碳酸锂的铂黄坩埚中,搅匀,加入300g·L-1溴化锂溶液0.5mL,在(1 050±20)℃熔融制片,采用X射线荧光光谱法测定高铬型钒渣中主次组分含量。... 详细信息

称取于750~800℃灼烧2h后的试样0.300 0g,置于盛有4.000 0g四硼酸锂、3.000 0g偏硼酸锂、0.500 0g碳酸锂的铂黄坩埚中,搅匀,加入300g·L-1溴化锂溶液0.5mL,在(1 050±20)℃熔融制片,采用X射线荧光光谱法测定高铬型钒渣中主次组分含量。采用钒渣标准样品和由标准样品加基准物质配制成的系列校准样品绘制校准曲线以消除基体效应,选择分析谱线并进行谱线重叠干扰校正。各组分的质量分数在一定范围内与荧光强度呈线性关系。方法用于分析高铬型钒渣样品,所得结果与滴定法、电感耦合等离子体原子发射光谱法的结果一致,测定值的相对标准偏差(n=10)在0.030%~7.3%之间。

关键词： X射线荧光光谱法主次成分高铬型钒渣熔融制样

最大等长收缩过程中及恢复期表面肌电信号的变化

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体育与科学 2006年第1期27卷 72-75页

作者：王明暄杨红春江苏省体育科学研究所浙江大学体育系

为了了解sEMG信号在运动诱发的疲劳恢复期内的规律,本研究以肱二头肌持续最大收缩至肌力下降到初始值的50%以及恢复期120秒内不同时刻获得的sEMG信号为研究对象,采用线性和非线性分析方法(FFT和RQA)计算出AEMG、MF和Determ%这些指标以... 详细信息

为了了解sEMG信号在运动诱发的疲劳恢复期内的规律,本研究以肱二头肌持续最大收缩至肌力下降到初始值的50%以及恢复期120秒内不同时刻获得的sEMG信号为研究对象,采用线性和非线性分析方法(FFT和RQA)计算出AEMG、MF和Determ%这些指标以及肌力(MVC)的变化情况。结果发现,在等长收缩过程中,AEMG迅速增加然后呈线性递减,MF从收缩的一开始一直呈现出线性下降的变化模式,而Determ%除了第1个值显著大于第2个外,其余表现出线性递增的变化模式。在恢复期内,AEMG的变化没有明显的规律性,MF随着和Determ%均表现出良好的恢复趋势。MF和Determ%为半时恢复期为12.9和5.2秒,显著低于MVC的19.2秒。在恢复期内没有出现在等长收缩过程中的第1段信号的Determ%大于第2段信号的情形。研究提示,sEMG信号可能更主要受CNS对肌肉控制策略的影响,Determ%的变化可能揭示包含肌肉功能状态的生物学信息。

关键词：表面肌电信号快速傅立叶变换定量回归分析

具有活跃节点的多层网络作用下时滞SEQS模型分析

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电子科技大学学报 2024年第2期53卷 277-283页

作者：曹铃苓杨宏春高雅纯张虎杨春付传技电子科技大学物理学院成都611731 电子科技大学数学学院成都611731

疾病传播的研究使得对疫情分布和发展的预测更为准确。现有的疾病传播模型对不同城市间流动人口对疾病传播造成的影响研究较少,为此,该文提出了具有活跃节点的多层网络作用下的时滞SEQS(Susceptible-Exposed-Quarantined-Susceptible)... 详细信息

疾病传播的研究使得对疫情分布和发展的预测更为准确。现有的疾病传播模型对不同城市间流动人口对疾病传播造成的影响研究较少,为此,该文提出了具有活跃节点的多层网络作用下的时滞SEQS(Susceptible-Exposed-Quarantined-Susceptible)模型。其中,时滞SEQS重点研究疾病潜伏期、恢复期及恢复后可再次感染等特性对传播行为的影响,模型中每层静态网络表示不同城市的社交网络,活跃节点表示城市间流动人口,活跃节点的存在使得该多层网络具有时变性,同时模型引入检测机制,以隔离态节点为中心,对在其检测半径内的邻接节点进行检测。研究表明,该模型的传播行为最终演化状态存在3种主要模式:稳态、周期性振荡和非周期性振荡,在能有效降低疾病传染率的情况下,划定精准检测范围可有效控制疾病大规模传播。

关键词：活跃节点检测半径多层网络 SEQS模型时滞

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星载偏振扫描仪的星上偏振定标方法

中国激光 2018年第11期45卷 254-261页

作者：杨洪春杨本永宋茂新邹鹏孙晓兵洪津中国科学院安徽光学精密机械研究所安徽合肥230031 中国科学技术大学研究生院科学岛分院安徽合肥230026 中国科学院通用光学定标与表征技术重点实验室安徽合肥230031

为保障偏振扫描仪长期在轨的偏振测量精度,研究了偏振扫描仪的星上偏振定标原理与方法。首先,针对分孔径和分振幅的技术特点,结合实际的误差来源,理论推导了系统探测矩阵;其次,根据仪器参数,利用已知偏振态的线偏振光和非偏振光,推导了... 详细信息

为保障偏振扫描仪长期在轨的偏振测量精度,研究了偏振扫描仪的星上偏振定标原理与方法。首先,针对分孔径和分振幅的技术特点,结合实际的误差来源,理论推导了系统探测矩阵;其次,根据仪器参数,利用已知偏振态的线偏振光和非偏振光,推导了星上偏振定标方程;然后,设计了用于星上偏振定标的线偏振定标器和非偏振定标器;最后,提出了利用已知偏振度的太阳漫射板辐射定标数据来校正偏振扫描仪的低偏振度测量精度和稳定性。所提出的星上偏振定标方法具有高精度、高频次、高效率等特点,可满足长期在轨偏振测量精度为0.005的应用需求。

关键词：遥感偏振定标偏振测量偏振扫描仪星上定标器

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星载偏振扫描仪星上偏振定标器

光学学报 2019年第9期39卷 205-213页

作者：杨洪春洪津邹鹏宋茂新杨本永刘振海中国科学院安徽光学精密机械研究所安徽合肥230031 中国科学技术大学安徽合肥230026 中国科学院通用光学定标与表征技术重点实验室安徽合肥230031

为了满足偏振扫描仪的偏振测量精度要求,提出一种利用偏振扫描仪星上偏振定标器精确测量标准偏振态数值的方法。首先介绍了偏振扫描仪的技术特点、测量原理和偏振定标模型;其次结合仪器特性,将地球反照光+线偏振定标器/非偏振定标器作... 详细信息

为了满足偏振扫描仪的偏振测量精度要求,提出一种利用偏振扫描仪星上偏振定标器精确测量标准偏振态数值的方法。首先介绍了偏振扫描仪的技术特点、测量原理和偏振定标模型;其次结合仪器特性,将地球反照光+线偏振定标器/非偏振定标器作为在轨偏振定标的偏振态标准源;然后分别设计了专用的线偏振定标器和非偏振定标器;最后利用马吕斯定律确定线偏振定标器的偏振态数值,将星下点数据筛选出线偏振度小于0.4的下垫面反射光作为非偏振定标器的有效光源,以获得符合要求的非偏振光。所设计的定标器符合全光路、全孔径、端到端的要求,可保障长期在轨偏振测量精度为0.005。

关键词：测量偏振定标偏振定标器偏振扫描仪偏振测量气溶胶

中南大学湘雅三医院打造“一体三翼”高质量发展格局实践

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中国医院 2022年第3期26卷 85-87页

作者：肖睿杨洪春刘巧中南大学湘雅三医院湖南省长沙市410013 中南大学湘雅三医院院办湖南省长沙市410013

目前,公立医院进入高质量发展新时期。中南大学湘雅三医院秉承百年"湘雅"精神积淀,以国内一流大学为学科依托,坚持以人民健康为中心的发展思想,着力打造"以医疗服务为主体,人才培养、科学研究为侧翼,现代医院科学管理为尾翼"的"一体三翼... 详细信息

目前,公立医院进入高质量发展新时期。中南大学湘雅三医院秉承百年"湘雅"精神积淀,以国内一流大学为学科依托,坚持以人民健康为中心的发展思想,着力打造"以医疗服务为主体,人才培养、科学研究为侧翼,现代医院科学管理为尾翼"的"一体三翼"发展新格局,推动医院实现高质量发展。医院始终坚持党建引领,在疑难杂症诊治、医疗新技术应用、现代化医学教育、医学科学研究、人才培养、运营管理等方面开展了系列探索与创新,取得了明显成效,积累了公立医院高质量发展的实践经验。

关键词：党建引领高质量发展公立医院