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Gravity anomaly during the Mohe total solar eclipse

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chinese Science Bulletin 2001年第21期46卷 1833-1836页

作者： wang qianshen YANG Xinshe TANG Keyun institute of geophysics Chinese Academy of SciencesBeijing 100101China Department of Applied Mathematics University of LeedsLeeds LS2 9JTUK

By using a high-precision LaCoste-Romberg (D-12.#) gravimeter, continuous and precise measurements were carried out during the March 9,1997 total solar eclipse in the Mohe region in Northeast china. The gravity variations were digitally recorded during the total solar eclipse so as to investigate the possible anomaly of the sun and the moon’s gravitational fields on the earth. After the careful processing and analysis of the observed data, no significant anomaly during the very solar eclipse has been found. However, there are two ’gravity anomaly valleys’ with near symmetrical decrease of about 6-7 μGal at the first contact and the last contact. This is the anomaly phenomenon observed and reported for the first time in the literature. This note presents some analyses and discussions.

关键词： Mohe total solar eclipse gravity anomaly.

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新型抗生素筛选的研究进展

中国抗生素杂志 2024年第7期49卷 764-771页

作者：徐敏王丽卫辛念邓玉林刘凤北京理工亘舒科技有限公司北京100081 北京理工大学北京100081

抗生素耐药性是一个重要的公共卫生问题,由于细菌耐药性的不断进化和传播,尤其是“超级细菌”的出现,导致传染病发病率和死亡率不断增加,治疗也变得更具挑战性,因此,新型抗生素的研究至关重要。进入抗生素后时代以来,大批新技术、新方... 详细信息

抗生素耐药性是一个重要的公共卫生问题,由于细菌耐药性的不断进化和传播,尤其是“超级细菌”的出现,导致传染病发病率和死亡率不断增加,治疗也变得更具挑战性,因此,新型抗生素的研究至关重要。进入抗生素后时代以来,大批新技术、新方法为新型抗生素的筛选提供了思路。本文对新型抗生素筛选和替代方法的进展进行了总结,包括从天然产物中筛选、采用化学合成或合成生物学方法筛选、基于组学技术的筛选、人工智能辅助筛选、药物再利用和联合用药以及抗生素的替代疗法如单克隆抗体疗法、噬菌体疗法。新型抗生素的筛选对于应对多耐药菌、治疗新兴疾病、提高治疗效果都具有重要意义,药物再利用、联合用药及抗生素的替代疗法可以降低药物开发的时间和成本,为医疗领域带来更多的创新和进步。

关键词：新型抗生素耐药性抗菌疗法筛选人工智能

Carrying Capacity and Coupling Coordination of Water and Land Resources Systems in Arid and Semi-arid Areas: A Case Study of yulin City, china

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chinese Geographical Science 2024年第5期34卷 931-950页

作者： ZHANG Qianxi CAO Zhi wang Yongsheng HUANG Yijia institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China

Quantitatively assessing the carrying capacity of water and land resources systems in arid and semi-arid areas is crucial for achieving the 2.30 Sustainable Development *** this work,taking yulin City in china as a case study and employing the Criteria Importance Through Intercriteria Correlation(CRITIC)method,a modified model of coupling degree was developed to evaluate the car-rying capacity of water and land resources systems endowment and utilization,as well as their coupling coordination degree from 2.13 to *** findings indicate that the water and land resources of yulin are diminishing due to declines in agriculture,higher industrial water use,and wetland ***,reallocating domestic water for ecological sustainability and reducing sloping farmland can mitigate this trend of ***,as the coupling coordination between water and land resources system endowment in yulin continuously improved,the coupling coordination between water and land resources system utilization first decreased and then in-creased with 2.16 as the turning ***,the carrying capacity of water and land resources systems,the coupling coordination degree between water and land resources system endowment,and the coupling coordination degree between water and land resources system utilization in yulin exhibited the same pattern of being higher in the six northern counties than in the six southern *** the water resources endowment is vital for the highly efficient use of water and land resources.

关键词： water and land resources systems carrying capacity coupling coordination human-earth system sustainable development yulin City,china

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地震作用下的干法赤泥堆场稳定性分析

应用力学学报 2024年第3期41卷 651-658页

作者：卢玉林何金泽陈晓冉王丽林玮防灾科技学院土木工程学院北京101601 中国地震局建筑物破坏机理与防御重点实验室北京101601 防灾科技学院地质工程学院北京101601

地震是影响赤泥堆体场稳定性的重要因素之一。采用有限元强度折减法和规范指导方法对龙塔崖沟干法赤泥堆场进行了静力稳定性分析,确定了滑动面的位置和形状,计算了静力条件下的安全系数。以拟静力法不同烈度工况下的堆积体安全系数为标... 详细信息

地震是影响赤泥堆体场稳定性的重要因素之一。采用有限元强度折减法和规范指导方法对龙塔崖沟干法赤泥堆场进行了静力稳定性分析,确定了滑动面的位置和形状,计算了静力条件下的安全系数。以拟静力法不同烈度工况下的堆积体安全系数为标定值,分析了两条实测地震波作用下的堆积体位移、加速度以及动力安全系数的变化规律,计算结果满足规范设定的阈值,可确定堆积体是稳定的。通过与不同方法、不同规范的评价要求对比,判定有限元强度折减法可作为稳定性分析的评价标尺。

关键词：赤泥堆场干法地震稳定性

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对生态屏障概念内涵与价值的认识

山地学报 2005年第4期23卷 4431-4436页

作者：王玉宽孙雪峰邓玉林彭培好范建容中国科学院水利部成都山地灾害与环境研究所国家环保总局对外合作中心四川农业大学成都理工大学中国科学院水利部成都山地灾害与环境研究所四川成都610041 北京100035 四川雅安62.000 四川成都610059

“生态屏障”概念源于我国生态环境建设实践。学术界对此概念的科学内涵和价值进行了有益的探讨,但目前还尚未形成统一的认识。本文通过对生态屏障概念的理论与实践基础的分析,在总结前人研究成果的基础上,提出了对生态屏障概念的新的... 详细信息

“生态屏障”概念源于我国生态环境建设实践。学术界对此概念的科学内涵和价值进行了有益的探讨,但目前还尚未形成统一的认识。本文通过对生态屏障概念的理论与实践基础的分析,在总结前人研究成果的基础上,提出了对生态屏障概念的新的认识和理解,认为生态屏障就是指“处于某一特定区域的生态系统,其结构与功能符合人类生存和发展的生态要求”。在此基础上对生态屏障的社会实践意义和科学价值进行了探讨,认为生态屏障概念提出的科学价值在于它丰富和拓展了生态系统生态学的内容,促进了恢复生态学理论的发展,同时对生态系统服务功能评价提出了新的要求;其社会实践意义表现在生态屏障概念的提出强调了人与生态环境的关系,明确了生态环境建设的目标;强调了区域性和时序性原则,为生态环境建设规划与实施提供了决策指南,为生态环境建设实践中实施系统工程和长远布局提出了更高的决策目标。

关键词：生态屏障内涵生态系统

Sub-optimal fixed-finite-horizon spacecraft configuration control on SE(3)

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chinese Journal of Aeronautics 2022年第6期35卷 250-261页

作者： yulin wang Wei SHANG Haichao HONG institute of Remote-sensing Satellite China Academy of Space TechnologyBeijing 100094China School of Mechanical Engineering Hubei University of TechnologyWuhan 430068China institute of Flight System Dynamics Technical University of MunichGarching 85748Germany

For achieving the desired configuration of spacecraft at the desired fixed time,a suboptimal fixed-finite-horizon configuration control method on the Lie group SE(3)is developed based on the Model Predictive Static Programming(MPSP).The MPSP technique has been widely used to solve finite-horizon optimal control problems and is known for its high computational efficiency thanks to the closed-form solution,but it cannot be directly applied to systems on SE(3).The methodological innovation in this paper enables that the MPSP technique is extended to the geometric control on SE(3),using the variational principle,the left-invariant properties of Lie groups,and the topology structure of Lie algebra ***,the energy consumption,which is crucial for spacecraft operations,is considered as the objective function to be optimized in the optimal control *** effectiveness of the designed sub-optimal control method is demonstrated through an online simulation under disturbances and state measurement errors.

关键词： Configuration control Lie groups Model Predictive Static Programming Optimal control Spacecraft control

Coupled modeling and analysis of radiometer effect and residual gas damping on proof mass in purely gravitational orbit

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Science china(Technological Sciences) 2011年第4期54卷 894-902页

作者： LIU HongWei wang ZhaoKui ZHANG yulin institute of Aerospace and Material Engineering National University of Defense TechnologyChangsha 410073China School of Aerospace Tsinghua UniversityBeijing 100084China

Spacecrafts free of all but gravitational forces are important in precision navigation,gravity field measurement and basic scientific *** Inner-formation Flying System,one kind of spacecrafts free of all but gravitational forces,is used for gravitational field measurement with high *** the interfering factors on the inner-satellite is one of the keys to gravitational field *** effect and residual gas damping are both interfering forces on the inner-satellite caused by gas *** analyzing the mechanism of the two forces,a coupled model for radiometer effect and residual gas damping was established,which contained the coupling term and reflected the actual force of gas molecules on the *** simulation results showed the coupling property of radiometer effect and residual gas damping:The actual force of gas molecules is directly proportional to the average pressure in the cavity and the largest cross-sectional area of the inner-satellite,but is inversely proportional to the square root of the average temperature in the cavity.

关键词： purely gravitational orbit proof mass radiometer effect residual gas damping coupled modeling

Compressed Sensing of IR-UWB Wireless Sensor Network Data Based on Two-Dimensional Measurements

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chinese Journal of Electronics 2015年第3期24卷 627-632页

作者： wang Kai LIU yulin WAN Qun JING Xiaojun Chongqing Communication institute china Electronic System Engineering Company University of Electronic Science and Technology of china beijing University of Posts and Telecommunications

A novel Compressed sensing(CS) method based on two-dimensional measurements is proposed that can be effectively utilized in Impulse radio ultra-wideband wireless sensor networks(IR-UWB WSNs) to significantly reduce the energy consumption and sampling rate in sensor data transferring. We start by establishing the CS measurement model by taking both spatial and temporal correlations of Wireless sensor network(WSN) data into account. Since our model incorporates a new type of measurement matrix: the block quasi-Toeplitz structured matrix, we derive the Restricted isometry property(RIP)of the block quasi-Toeplitz structured matrix to ensure the performance of the two-dimensional recovery of WSNs data. We substantiate our mathematical analysis by numerical examples in the context of ideal spares vector and real WSN data, and results demonstrate that the approach achieves significantly saving of energy and sampling rate with small reconstruction error.

关键词： Compressed sensing Wireless sensor net-works IR-UWB Measurement Restricted isometry property

考虑日变化过程的寒区隧道温度场解析解与现场监测研究

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铁道科学与工程学报 2024年第6期21卷 2406-2416页

作者：张力杰穆彦虎田毅王玉林朱小明张坤郑波李凌洁中国科学院西北生态环境资源研究院冻土工程国家重点实验室甘肃兰州730000 中国科学院大学北京100049 甘肃省公路交通建设集团有限公司甘肃兰州730000 甘肃省交通规划勘察设计院股份有限公司甘肃兰州730030 西北民族大学土木工程学院甘肃兰州730124 中铁西南科学研究院有限公司四川成都611731

负温环境是隧道冻害发生的必要条件,因此隧道内气温、衬砌和围岩体温度的空间分布与时间变化过程是寒区隧道冻害机理和防治研究的关键。目前,已有研究多采用月平均值来描述隧道内的温度环境及其影响因素,忽略了其日变化过程,可能低估隧... 详细信息

负温环境是隧道冻害发生的必要条件,因此隧道内气温、衬砌和围岩体温度的空间分布与时间变化过程是寒区隧道冻害机理和防治研究的关键。目前,已有研究多采用月平均值来描述隧道内的温度环境及其影响因素,忽略了其日变化过程,可能低估隧道内负温段长度和冻结深度以及衬砌结构经历的冻融作用,由此造成保温设防设计的不足。以青藏高原东北缘的一高海拔寒区公路特长隧道为例,通过对洞内气温的自动连续观测,统计分析了隧道内气温的日变化特征。运用叠加原理将寒区隧道径向温度场分为稳态和瞬态,在求解瞬态温度场过程中采用Laplace变换,同时考虑隧道内气温的日变化和年变化过程,构建了包括保温层、衬砌和围岩体等多层介质的寒区隧道径向温度场解析解,对比分析了考虑与不考虑气温日变化过程隧道衬砌结构温度的变化规律。结果表明,隧道内气温的日变化幅度在进、出口段较为显著,日振幅可达11℃以上,随着进深增加逐渐减小,至隧道中部气温日振幅降至2.以内。同时,隧道内气温日振幅表现出明显的季节性,冷季明显大于暖季。考虑气温的日变化过程的解析解能够更准确地反映隧道结构所经历的冻结时长和冻融循环次数,与隧道结构层内实测温度的波动范围更加接近。现场监测结果和理论解析方法对于寒区隧道衬砌混凝土抗冻等级选择和冻融损伤预测以及衬砌挂冰和路面结冰预警等具有积极意义。

关键词：寒区隧道温度场日变化现场监测解析解