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STABILITY AND LOCAL BIFURCATION IN A SIMPLY-SUPPORTED BEAM CARRYING A MOVING MASS

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Acta Mechanica Solida Sinica 2007年第2期20卷 123-129页

作者： Liu Pan Ni qiao Wang lin Yuan Liang Department of Mechanics Huazhong University of Science and Technology Wuhan 430074 China

The stability and local bifurcation of a simply-supported flexible beam （Bernoulli- Euler type） carrying a moving mass and subjected to harmonic axial excitation are investigated. In the theoretical analysis, the partial differential equation of motion with the fifth-order nonlinear term is solved using the method of multiple scales （a perturbation technique）. The stability and local bifurcation of the beam are analyzed for 1/2 sub harmonic resonance. The results show that some of the parameters, especially the velocity of moving mass and external excitation, affect the local bifurcation significantly. Therefore, these parameters play important roles in the system stability.

关键词： stability local bifurcation simply-supported beam moving mass

SDSS J012119.10 001949.9:a very short period M dwarf contact binary from SDSS stripe 82

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Research in Astronomy and Astrophysics 2015年第12期15卷 2237-2243页

作者： lin-qiao Jiang Sheng-Bang Qian Jia Zhang Yunnan Observatories Chinese Academy of Sciences Key Laboratory of the Structure and Evolution of Celestial Objects Chinese Academy of Sciences University of Chinese Academy of Sciences

We present the first multicolor photometric observations of the short period low-mass eclipsing binary SDSS J012119.10-4301949.9. By using the 2013 version of the Wilson-Devinney code, the photometric solutions are derived. It is found that the system is in a contact configuration （f = 18.9± 6.0%） with a moderate mass ratio of 0.5 ± 0.01. A third light contributing about 6.1± 1.3% of the total luminosity in the V band was found, which may come from a cool tertiary component. The derived high orbital inclination （i - 83.9°± 0.5°） and the almost symmetric three light curves suggest that the determined parameters are reliable. Both the color class and spectral class of the system correspond to a spectral type of M0, which may indicate that SDSS J012119.10-001949.9 belongs to a very rare class of M dwarf contact binaries that are below the theoretical short period limit.

关键词： binaries: eclipsing -- stars: individual (SDSS J012119.10-001949.9) --techniques: photometric

弥漫大B细胞淋巴瘤初诊时合并噬血细胞综合征的临床特征与预后分析

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中国实验血液学杂志 2024年第2期32卷 466-469页

作者：魏小芳冯友繁伏媛刘菲陈巧琳张启科甘肃省人民医院血液科甘肃兰州730000

目的:比较弥漫大B细胞淋巴瘤初诊时合并噬血细胞综合征(HPS)与不合并HPS患者的临床特征和预后差异。方法:回顾性分析2012年1月至2021年12月就诊甘肃省人民医院的45例弥漫大B细胞淋巴瘤患者的临床资料,按初诊时是否伴HPS分为合并HPS组(15... 详细信息

目的:比较弥漫大B细胞淋巴瘤初诊时合并噬血细胞综合征(HPS)与不合并HPS患者的临床特征和预后差异。方法:回顾性分析2012年1月至2021年12月就诊甘肃省人民医院的45例弥漫大B细胞淋巴瘤患者的临床资料,按初诊时是否伴HPS分为合并HPS组(15例)和不合并HPS组(30例),比较两组患者临床特征及预后差异,并应用Kaplan-Meier法进行生存分析。结果:合并HSP组的患者多以发热、血细胞减少、脾大为突出表现;所有患者铁蛋白、可溶性CD25水平升高;66.67%的患者纤维蛋白原水平降低,53.33%的患者甘油三酯水平升高,80.00%的患者出现骨髓噬血现象。与不合并HSP组相比,合并HSP组的进展期(Ann Arbor分期Ⅲ/Ⅳ期)患者和乳酸脱氢酶≥240 U/L患者所占比例较高(均P<0.05)。合并HSP组中位生存时间为8.0个月,而不合并HSP组的中位生存时间为45.5个月,比较差异有统计学意义(P<0.001)。结论:弥漫大B细胞淋巴瘤初诊时合并HPS的患者与不合并HPS的患者相比,Ann Arbor分期晚、乳酸脱氢酶水平高,总体生存时间较短。

关键词：弥漫大B细胞淋巴瘤噬血细胞综合征临床特征预后

A New Phosphine-Amine-Oxazoline Ligand for Ru-Catalyzed Asymmetric Hydrogenation of N-Phosphinylimines

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Chinese Journal of Chemistry 2018年第12期36卷 1151-1155页

作者： Xiaochen Ma lin qiao Guixia Liu Zheng Huang State Key laboratory of Organometallic Chemistry Center for Excellence in Molecular SynthesisShanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of Sciences345 Lingling RdShanghai 200032China

A series of chiral phosphine‐amine‐oxazoline (PAO) ligands with an NH moiety were synthesized and applied to the ruthenium‐catalyzed asymmetric hydrogenation of N ‐phosphinylimines. The ligand bearing phenyl groups at the phosphorus moiety and isopropyl at the oxazoline moiety exhibits good activity and excellent enantioselectivity (up to 99% ee ). This catalytic system provides an efficient and mild approach to access enantioriched amines.

关键词： amines chiral ligand hydrogenation imines ruthenium

Analysis of ecological quality in Lhasa Metropolitan Area during 1990-2017 based on remote sensing and Google Earth Engine platform

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Journal of Geographical Sciences 2021年第2期31卷 265-280页

作者： HUANG Huiping CHEN Wei ZHANG Yuan qiao lin DU Yunyan Aerospace Information Research Institute CASBeijing 100094China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China

Based on a total of 519 images,the composite images with the lowest possible cloud cover were generated at pixel level with image synthesis method on Google Earth Engine(GEE)*** Remote Sensing Ecological Index(RSEI)was adopted,and calculated in an efficient way with the assistance of parallel cloud computing of the GEE *** RSEI was used in this paper to evaluate and monitor the eco-environmental quality of the Lhasa Metropolitan *** show that:(1)The ecological quality is better in the west than in the east of Lhasa Metropolitan Area,with Lhasa as an approximate dividing *** ecological quality improved and then deteriorated dramatically before 2000,with the mean RSEI value dropping from 0.51 to 0.46;the trend was followed by a gradual increase up until 2017,with the mean RSEI value increased from 0.46 to 0.55.(2)The RSEI is weakly and positively correlated with socioeconomic *** indicates that the population growth and economic development did not negatively influence the ecological quality,but actually boosted it.(3)The GEE can serve as an efficient computing platform for the assessment and monitoring of eco-environmental quality in vast regions.

关键词： Lhasa Metropolitan Area ecological quality remote sensing ecological index Google Earth Engine

Physics-constrained neural network for solving discontinuous interface K-eigenvalue problem with application to reactor physics

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Nuclear Science and Techniques 2023年第10期34卷 178-200页

作者： Qi-Hong Yang Yu Yang Yang-Tao Deng qiao-lin He He-lin Gong Shi-Quan Zhang School of Mathdematics Sichuan UniversityChengdu 610065China Paris Elite Institute of Technology Shanghai Jiao Tong UniversityShanghai 200240China

Machine learning-based modeling of reactor physics problems has attracted increasing interest in recent *** some progress in one-dimensional problems,there is still a paucity of benchmark studies that are easy to solve using traditional numerical methods albeit still challenging using neural networks for a wide range of practical *** present two networks,namely the Generalized Inverse Power Method Neural Network(GIPMNN)and Physics-Constrained GIPMNN(PC-GIPIMNN)to solve K-eigenvalue problems in neutron diffusion *** follows the main idea of the inverse power method and determines the lowest eigenvalue using an iterative *** PC-GIPMNN additionally enforces conservative interface conditions for the neutron ***,Deep Ritz Method(DRM)directly solves the smallest eigenvalue by minimizing the eigenvalue in Rayleigh quotient form.A comprehensive study was conducted using GIPMNN,PC-GIPMNN,and DRM to solve problems of complex spatial geometry with variant material domains from the fleld of nuclear reactor *** methods were compared with the standard flnite element *** applicability and accuracy of the methods are reported and indicate that PC-GIPMNN outperforms GIPMNN and DRM.

关键词： Neural network Reactor physics Neutron diffusion equation Eigenvalue problem Inverse power method

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中国农业服务贸易发展现状及建议

农业展望 2024年第5期20卷 107-111页

作者：王晓梅林巧田芳杨小薇中国农业科学院农业信息研究所北京100081 中国农业科学院植物保护研究所北京100083

农业服务贸易是推进中国农业供给侧结构性改革、畅通国内外农业服务市场、提升中国农业服务水平和培育国际竞争新优势的关键增长点。当前,中国农业服务贸易的发展形式主要以产品贸易为主,深层次的服务贸易开展仍处于初级探讨阶段。随着... 详细信息

农业服务贸易是推进中国农业供给侧结构性改革、畅通国内外农业服务市场、提升中国农业服务水平和培育国际竞争新优势的关键增长点。当前,中国农业服务贸易的发展形式主要以产品贸易为主,深层次的服务贸易开展仍处于初级探讨阶段。随着中国服务贸易政策的逐步落地,农业服务贸易组织得到稳步发展,贸易总量逐年递增,贸易业态也不断向纵深拓展,但发展中仍暴露出农业服务链条短、贸易结构单一,技术产品服务滞后、优质企业匮乏,相关配套体系不健全、服务管理欠规范,国际环境复杂多变、双多边标准规范差异等问题。为把握农业服务贸易发展的新机遇、抓住重要战略窗口期,建议进一步完善国家政策布局、创新驱动发展战略,打造农业行业优势、塑造全球话语体系,加快企业转型升级、补齐产业发展短板,搭建对话合作平台、推动信息互联共享,以此推动中国农业服务贸易的高质量发展。

关键词：农业服务贸易政策布局合作平台建设配套体系国际环境

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基于STIRPAT模型的辽宁省能源碳排放影响因素分析

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中国农机化学报 2024年第4期45卷 180-185,230页

作者：曲睿婷乔林王浩淼王天博高强郭美洁王体朋国网辽宁省电力有限公司信息通信分公司沈阳市110006 华北电力大学北京市102206

辽宁省是传统的工业和农业大省,在能源结构持续调整和农业机械化水平逐渐提高的背景下,为制定科学合理的减排措施,必须探明其碳排放主要来源。为此,采用排放因子法计算2012—2021年主要能源消耗碳排放量,利用STIRPAT模型构建辽宁省能源... 详细信息

辽宁省是传统的工业和农业大省,在能源结构持续调整和农业机械化水平逐渐提高的背景下,为制定科学合理的减排措施,必须探明其碳排放主要来源。为此,采用排放因子法计算2012—2021年主要能源消耗碳排放量,利用STIRPAT模型构建辽宁省能源消耗碳排放测算模型,分析影响能源消耗碳排放的主导因素。结果发现,煤炭是辽宁省消耗的最主要能源,占总能耗的55%左右;能源消耗碳排放总量整体呈明显增加趋势,而碳排放强度呈下降趋势,10年间降低11.3 kt CO_(2)/亿元;第二产业产值、农业碳排放效率、农业经济发展水平、第一产业产值、人口、人均GDP、城镇化率、农业机械化程度、能源加工转换效率是影响辽宁省碳排放的主要因素;基于STIRPAT模型构建辽宁省碳排放测算模型,通过验证发现平均相对误差为-4.91%,准确度较好;对模型分析发现人口变化对辽宁省能源碳排放呈负向影响,而人均GDP、第二产业产值、农业经济发展水平、农业机械化程度对辽宁省能源碳排放呈正向影响。因此为抑制辽宁省能源碳排放量的快速增加,需要控制人口数量,优化产业结构,保持人均GDP增速,第二产业产值和农业机械化程度在一个合理的水平。

关键词：农业机械化能源碳排放 STIRPAT模型影响因素节能减排

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肌骨超声在恶性肿瘤患者行静脉输液港植入术及术后监测中的应用

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海南医学 2024年第15期35卷 2210-2213页

作者：程巧琳陈金华施晓琳闵伟深圳市龙岗中心医院超声科广东深圳518116

目的研究肌骨超声在静脉输液港(IVAP)植入术及术后监测中的应用效果。方法选取2020年2月至2022年1月于深圳市龙岗中心医院接受IVAP植入术的216例恶性肿瘤化疗患者作为研究对象,按随机数表法分为观察组和对照组各108例。对照组患者采用... 详细信息

目的研究肌骨超声在静脉输液港(IVAP)植入术及术后监测中的应用效果。方法选取2020年2月至2022年1月于深圳市龙岗中心医院接受IVAP植入术的216例恶性肿瘤化疗患者作为研究对象,按随机数表法分为观察组和对照组各108例。对照组患者采用传统检测方式进行IVAP植入术的引导及术后监测,观察组患者采用肌骨超声进行IVAP植入术的引导及术后监测。比较两组患者的手术成功率、前期并发症及后期并发症发生情况,同时比较两组患者的满意度和舒适度。结果观察组患者的手术成功率为99.07%,明显高于对照组的91.67%,差异有统计学意义(P<0.05);观察组患者的前期并发症与后期并发症发生率分别为2.78%、4.63%,明显低于对照组的10.19%、14.81%,差异均有统计学意义(P<0.05);观察组患者的满意度和总舒适度分别为98.15%,97.22%,明显高于对照组的91.67%,89.81%,差异均有统计学意义(P<0.05)。结论肌骨超声应用于IVAP植入术及术后监测可提高患者的手术成功率,避免和减少相关并发症发生、发展,提升患者的满意度和舒适度。

关键词：恶性肿瘤化疗肌骨超声植入式静脉输液港成功率并发症

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