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Characterization of laser cooling in microgravity via long-term operations in TianGong-2 space lab

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National Science Review 2023年第4期10卷 69-75页

作者： De-Sheng Lü Wei Ren Yuan Sun Tang Li Qiu-Zhi Qu Bin Wang Lin Li Jian-bo Zhao Xin Zhao Jing-Wei Ji Mei-Feng Ye Jing-Feng xiang Wei-Biao Chen Yu-Zhu Wang Liang Liu CAS Key Laboratory of Quantum Optics and Center of Cold Atom Physics Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Aerospace Laser Engineering Department Shanghai Institute of Optics and Fine MechanicsChinese Academy of Sciences

The invention of laser cooling has fundamentally influenced the research frontier of atomic physics and quantum physics, and recently an intense focus has been on the studies of cold atom physics in microgravity environments. Herein, we report the results of our laser cooling experiment in Tian Gong-2 space lab, which operated for 34 consecutive months in orbit. Over such an extended operation time, the quality of laser cooling did not experience any significant decline, while the properties of laser cooling in orbital microgravity were systematically studied. In particular, we demonstrate magneto-optical trapping and polarization-gradient cooling in orbit and carefully examine their performances. A comparison of the in-orbit and on-ground results indicates that a higher cooling efficiency exists in microgravity, including a smaller loss rate during the trapping and cooling process and lower ultimate temperature of laser-cooled atoms. Our progress has laid the technical foundations for future applications of cold atoms in space missions with operation times of the order of years.

关键词： laser cooling polarization-gradient cooling orbital microgravity space lab

Program Monitoring Based on Automaton Simulation

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Wuhan University Journal of Natural Sciences 2013年第2期18卷 102-108页

作者： LING xiang HUANG bo WU Guoqing School of Computer Wuhan University

To check whether a program behaves in expectation, program monitoring systems are used for intrusion detection. This article presents a program monitoring system using automaton simulation based on the state graphs extracted from C programs through static analysis. For complete state graph construction, a pointer alias analysis method is proposed to solve the function pointers for obtaining actual control flows. After compiling, pro- grams are instrumented with probes to report the internal states when they are running. A program monitor is built in the kernel of Linux system, which monitors the states of programs from probes and checks the paths of execution. This monitoring system could respond to the abnormal behaviors immediately to protect the sys- tems and programs from further damages.

关键词： program monitonng intrusion detection h.mCtlOncall state graph

Image Field Deformation of LAMOST due to Differential Atmospheric Refraction

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Chinese Journal of Astronomy and Astrophysics 2006年第4期6卷 495-502页

作者： Jin-Ling Li bo Zhang Yong Yu Zhao-xiang Qi Ming Zhao Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai 200030

A vectorial expression of the image field deformation of LAMOST due to the differential atmospheric refraction is presented. The calculated results are compared with those from previous analyses based on the traditional spherical trigonometric formulas. It is demonstrated that different tangential displacements of star images during the observation tracking given by various authors are simply due to different reference points adopted. It is pointed out that the observational celestial pole is the center of the apparent diurnal motion, that, by referring to the observational celestial pole, the effect of the differential refraction on the image field of LAMOST during the 1.5-hour tracking period is approximately equivalent to a constant rotation of - 13.65″ for all declination belts. It is therefore unnecessary to design a particular tracking velocity for each observation, and this will be obviously advantageous to the observation implementation. If the maximum tracking error of the fibers is 0.2″, then the fibers are required to be able to re-position during observational tracking for sky regions south of declination ＋20° and north of declination ＋60°.

关键词： telescopes -- atmospheric effects -- methods: analytical-- methods: statistical-- astrometry

Prevalence and risk factors of stroke in China:a national serial cross-sectional study from 2003 to 2018

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Stroke & Vascular Neurology 2023年第3期8卷 238-248,I0086-I0095页

作者： Dai-Shi Tian Chen-Chen Liu Chao-Long Wang Chuan Qin Ming-Huan Wang Wen-Hua Liu Jian Liu Han-Wen Zhang Rong-Guo Zhang Shao-Kang Wang Xiao-xiang Zhang Liang Wang Deng-Ji Pan Jian-Ping Hu xiang Luo Sha-Bei xu Wei Wang Department of Neurology Tongji Hospital of Tongji Medical College of Huazhong University of Science and TechnologyWuhanHubeiChina Department of Epidemiology and Biostatistics Tongji Medical College of Huazhong University of Science and TechnologyWuhanHubeiChina Department of Scientific Research Management Tongji Hospital of Tongji Medical College of Huazhong University of Science and TechnologyWuhanHubeiChina Infervision Medical Technology Co. LtdBeijingChina Department of Computer Center Tongji Hospital of Tongji Medical College of Huazhong University of Science and TechnologyWuhanHubeiChina Centre for Health Statistics Information National Health Commission of the People's Republic of ChinaBeijingChina

Stroke imposes a substantial burden *** the rapid economic and lifestyle transition in China,trends of the prevalence of stroke across different geographic regions in China remain largely *** on the data in the National Health Services Surveys(NHSS),we assessed the prevalence and risk factors of stroke in China from 2003 to *** this study,data from 2003,2008,2013,and 2018 NHSS were *** cases were based on participants’self-report of a previous diagnosis by *** estimated the trends of stroke prevalence for the overall population and subgroups by age,sex,and socioeconomic factors,then compared across different geographic *** applied multivariable logistic regression to assess associations between stroke and risk *** number of participants aged 15 years or older were 154,077,146,231,230,067,and 212,318 in 2003,2008,2013,and 2018,respectively,among whom,1435,1996,3781,and 6069 were stroke *** age and sex standardized prevalence per 100,000 individuals was 879 in 2003,1100 in 2008,1098 in 2013,and 1613 in *** per 100,000 individuals in rural areas increased from 669 in 2003 to 1898 in 2018,while urban areas had a stable trend from 1261 in 2003 to 1365 in *** geographic regions,the central region consistently had the highest prevalence,but the western region has an alarmingly increasing trend from 623/100,000 in 2003 to 1898/100,000 in 2018(Ptrend<0.001),surpassing the eastern region in *** age,male sex,rural area,central region,hypertension,diabetes,depression,low education and income level,retirement or unemployment,excessive physical activity,and unimproved sanitation facilities were significantly associated with *** conclusion,the increasing prevalence of stroke in China was primarily driven by economically underdeveloped *** is important to develop targeted prevention programs in underdeveloped *** traditional risk factors,more attenti

关键词： prevention sectional income

A new lignan derivative from the root of Ilex pubescens

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Chinese Chemical Letters 2008年第5期19卷 550-552页

作者： Yu bo Zhou Jin Hui Wang xiang Mei Li Xian Li School of Traditional Chinese Materia Medica Shenyang Pharmaceutical University Shenyang 110016 China

One new compound, ilexlignan A （1）, was isolated from the root of llex pubescens. Its structure was elucidated by the combination of one- and two-dimensional NMR analysis, mass spectrometry, CD spectrum measurement ... 详细信息

关键词： llex pubescens llexlignan A Lignan

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“双循环”新发展格局与创新

北京工商大学学报(社会科学版) 2022年第6期37卷 101-110页

作者：钱学锋向波中南财经政法大学工商管理学院

“双循环”新发展格局与创新是事关中国经济发展和未来竞争的关键，“双循环”与创新关系密切、相互促进。将“双循环”和创新纳入统一的分析框架，厘清“双循环”需要什么样的创新，“双循环”如何促进创新，以及创新如何促进“双循环... 详细信息

“双循环”新发展格局与创新是事关中国经济发展和未来竞争的关键，“双循环”与创新关系密切、相互促进。将“双循环”和创新纳入统一的分析框架，厘清“双循环”需要什么样的创新，“双循环”如何促进创新，以及创新如何促进“双循环”,具有重大现实意义。具体而言，“双循环”需要构建多层次创新系统、打造全要素创新类型、培育多元化创新主体作为支撑。从“双循环”促进创新的角度来看，国内大循环通过扩大市场规模、促进市场竞争、优化需求结构、加快市场整合推动创新，国际循环通过商品和要素流动型开放、高水平制度型开放以及“一带一路”高质量发展促进创新。从创新促进“双循环”的角度来看，创新通过驱动高质量供给、创造新需求促进国内大循环，通过推动科技自立自强、稳链强链补链促进国际循环。因此，应充分发挥国内大循环与国际循环在推动创新方面的独特优势和功能，同时坚持以创新持续赋能“双循环”。

关键词： “双循环”新发展格局创新国内大循环国际循环高质量发展

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基于激光器调制的微光栅加速度计噪声抑制

兵器装备工程学报 2022年第10期43卷 300-305页

作者：郑翔杨波东南大学仪器科学与工程学院南京210096

设计了一个基于激光器调制的微光栅加速度计信号检测系统。对微光机电系统的噪声来源进行了分析与建模,采用激光器高频调制的方法抑制1/f噪声和背景光噪声。实验结果表明,激光器调制降低了1/f噪声,改善了信噪比。相比较未调制系统,调制... 详细信息

设计了一个基于激光器调制的微光栅加速度计信号检测系统。对微光机电系统的噪声来源进行了分析与建模,采用激光器高频调制的方法抑制1/f噪声和背景光噪声。实验结果表明,激光器调制降低了1/f噪声,改善了信噪比。相比较未调制系统,调制系统输出在0.01 Hz处的噪声水平降低了约10 dB,符合预期。功率谱密度图显示系统本底噪声达到-100 dB,降低约10 dB。

关键词：微光栅加速度计激光器调制 1/f噪声信噪比

Sensitivity of seismic attenuation and dispersion to dynamic elastic interactions of connected fractures: Quasi-static finite element modeling study

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Petroleum Science 2023年第1期20卷 177-198页

作者： Yan-Xiao He Wen-Tao He Meng-Fan Zhang Jia-Liang Zhang Wei-Hua Liu Xiao-Yi Ma Gen-Yang Tang Shang-xu Wang Guo-Fa Li Jun-Zhou Liu xiang-Long Song State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development Beijing100083China Sinopec Key Laboratory of Seismic Elastic Wave Technology Beijing100083China State Key Laboratory of Petroleum Resources and Prospecting CNPC Key Lab of Geophysical ExplorationChina University of Petroleum(Beijing)Beijing102249China CNOOC(China)Co. Ltd.Hainan BranchHaikouHainan570311China PetroChina Dagang Oilfield Tianjin300280China Sinopec Geophysical Research Institute NanjingJiangsu211103China Sinopec Petroleum Exploration and Production Research Institute Beijing100083China Chinese Academy of Geological Sciences Beijing100037 China

Prediction of seismic attenuation and dispersion that are inherently sensitive to hydraulic and elastic properties of the medium of interest in the presence of mesoscopic fractures and pores,is of great interest in the characterization of fractured *** has been very difficult,however,considering that stress interactions between fractures and pores,related to their spatial distributions,tend to play a crucial role on affecting overall dynamic elastic properties that are largely *** thus choose to quantitatively investigate frequency-dependent P-wave characteristics in fractured porous rocks at the scale of a representative sample using a numerical scale-up procedure via performing finite element *** on 2-D numerical quasi-static experiments,effects of fracture and fluid properties on energy dissipation in response to wave-induced fluid flow at the mesoscopic scale are quantified via solving Biot's equations of *** show that numerical results are sensitive to some key characteristics of probed synthetic rocks containing unconnected and connected fractures,demonstrating that connectivity,aperture and inclination of fractures as well as fracture infills exhibit strong impacts on the two manifestations of WIFF mechanisms in the connected scenario,and on resulting total wave attenuation and phase ***,in turn,illustrates the importance of these two WIFF mechanisms in fractured rocks and thus,a deeper understanding of them may eventually allow for a better characterization of fracture systems using seismic ***,this presented work combines rock physics predictions with seismic numerical simulations in frequency domain to illustrate the sensitivity of seismic signatures on the monitoring of an idealized geologic CO_(2) sequestration in fractured *** simulation demonstrates that these two WIFF mechanisms can strongly modify seismic records and hence,indicating that incorporating the two energy dis

关键词： Attenuation and dispersion Rock physics Fractured media Frequency dependence Numerical study

Synthesis and Surface Modification of CdTe Nanocrystals

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Chemical Research in Chinese Universities 2007年第1期23卷 5-7页

作者： ZHUANG Hong LIU Jing-bo ZHANG Chun-ling KONG xiang-gui College of Light industry and Economics ＆ Management Jilin University Changchun 130062 P. R. China Physics Key Laboratory of Excited State Process Changchun Institute of Optics Fine Mechanics and Chinese Academy of Sciences Changchun 130033 P. R. China College of Materials Science and Engineering Jilin University Changchun 130012 P. R. China Received Apr. 12 2006

CdTe nanocrystals were prepared in aqueous solution via the reaction between Cd^2＋ and NaHTe in the presence of mercaptoacetic acid. Interactions between CdTe nanocrystals and phenylalanine were formed via electrostatic/coordinate self-assembly. The photoluminescence intensity of CdTe nanocrystals was improved obviously. The interaction mechanism was discussed and was considered to be surface passivation.

关键词： CdTe Phenylalanine Electrostatic function Photoluminescence