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生物合成FeS及其稳定性柱迁移研究

岩石矿物学杂志 2024年第1期43卷 117-124页

作者：任霞严宁珍刘璟西南大学资源环境学院重庆400716

金属纳米硫化亚铁(FeS)在重/类金属修复上具有广阔的应用前景。使用嗜酸性铁还原菌(JF-5)和硫酸盐还原菌(SRB)合成生物纳米FeS,探讨其自然沉降规律,并使用羧甲基纤维素钠(CMC)作为稳定剂,探讨CMC-FeS在石英砂柱中的迁移特性。结果表明,... 详细信息

金属纳米硫化亚铁(FeS)在重/类金属修复上具有广阔的应用前景。使用嗜酸性铁还原菌(JF-5)和硫酸盐还原菌(SRB)合成生物纳米FeS,探讨其自然沉降规律,并使用羧甲基纤维素钠(CMC)作为稳定剂,探讨CMC-FeS在石英砂柱中的迁移特性。结果表明,SRB和JF-5菌液在一定比例下混合即能生成纳米FeS,且当混合菌液中n(Fe)/n(S)=0.2时FeS生成量最多,颗粒物浓度达2400 mg/L;FeS的自然沉降速率在0.1%CMC溶液中得到有效减缓。对流扩散模型能很好地描述CMC-FeS悬浮颗粒在石英砂柱中的迁移行为,相比于纯水-FeS体系(R^(2)=0.20),其模型相关性最高达0.85;在90、180和360 mL/h这3种输入流速下,中等流速180 mL/h能够获得最佳渗透性,其渗透系数平均值为243.97 cm/h。实验结果表明,CMC-FeS的稳定性和迁移性较纯水-FeS均得到加强,可为土壤污染修复提供理论参考。

关键词：生物合成FeS 沉降柱迁移

美国教师评估与退出机制的构建及其启示:基于对IMPACT教师评估系统的剖析

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成都师范学院学报 2024年第4期40卷 43-54页

作者：王莹任霞华中师范大学教育学院湖北武汉430000

为探索我国教师评估与退出机制的建立与运行,采用文本分析方法对美国华盛顿哥伦比亚特区IMPACT评估系统操作指南进行分析,总结IMPACT评估系统的运行体系与特点,为我国教师评估与退出机制提供借鉴。IMPACT评估系统通过覆盖全体的评估对... 详细信息

为探索我国教师评估与退出机制的建立与运行,采用文本分析方法对美国华盛顿哥伦比亚特区IMPACT评估系统操作指南进行分析,总结IMPACT评估系统的运行体系与特点,为我国教师评估与退出机制提供借鉴。IMPACT评估系统通过覆盖全体的评估对象、专业多元的评估责任主体、丰富具体的评估内容、清晰透明的评估流程以及奖罚分明的评估结果对华盛顿特区公立学校系统教师进行评估,整个系统呈现出评估内容专业化、评估过程公正化、评估结果差异化和评估系统动态化等特点。综观IMPACT评估系统的设计与运行,我国在构建教师评估与退出机制时,应注意在体系建设上强调政府提供制度支持;在评估内容与标准上关注教师能力;在评估责任主体上要兼顾多方利益群体;在系统设计上要因地制宜;最后在系统实施过程中更要注重宽严适度。

关键词： IMPACT教师评估系统华盛顿哥伦比亚特区公立学校系统教育评估教师队伍建设教师退出机制美国教师

Properties of Super-Poisson Processes and Super-Random Walks with Spatially Dependent Branching Rates

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Acta Mathematica Sinica,English Series 2008年第2期24卷 275-284页

作者： Yan xia ren LMAM School of Mathematical Sciences Peking University Beijing 100871 P.R. China

The global supports of super-Poisson processes and super-random walks with a branching mechanism ψ（z）=z^2 and constant branching rate are known to be noncompact. It turns out that, for any spatially dependent branching rate, this property remains true. However, the asymptotic extinction property for these two kinds of superprocesses depends on the decay rate of the branching-rate function at infinity.

关键词： super-Poisson process super-random walk global support asymptotic extinction

间隙性压力治疗系统对乳腺癌术后下肢深静脉血栓形成的预防效果

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医疗装备 2024年第5期37卷 16-18,23页

作者：任霞陈黎黎浙江省台州医院浙江台州318050

目的探讨间隙性压力治疗系统对乳腺癌术后下肢深静脉血栓形成(DVT)的预防作用。方法选择2020年5月至2022年6月于医院行乳腺癌根治术后患者120例,根据治疗方法不同,分为对照组与试验组,每组60例。对照组予踝泵运动治疗,试验组在对照组基... 详细信息

目的探讨间隙性压力治疗系统对乳腺癌术后下肢深静脉血栓形成(DVT)的预防作用。方法选择2020年5月至2022年6月于医院行乳腺癌根治术后患者120例,根据治疗方法不同,分为对照组与试验组,每组60例。对照组予踝泵运动治疗,试验组在对照组基础上采用间隙性压力治疗系统治疗,两组治疗均>7 d。比较两组下肢血流动力学指标(股静脉和足背静脉血流速度)、凝血功能指标[血清活化部分凝血活酶时间(APTT)和D-二聚体]、术后7 d内DVT发生情况。结果治疗后3 d,两组下肢股静脉和足背静脉血流速度快于治疗前,且试验组快于对照组,差异有统计学意义(P<0.05)。治疗后3 d,两组血清APTT水平较治疗前上升,D-二聚体水平较治疗前下降,差异有统计学意义(P<0.05),且试验组血清APTT水平高于对照组,D-二聚体水平低于对照组,差异有统计学意义(P<0.05)。治疗后7 d内,试验组DVT发生率低于对照组,差异有统计学意义(P<0.05)。结论间隙性压力治疗系统用于乳腺癌术后,不仅可加快股静脉和足背静脉血流速度,改善下肢血流动力学指标,且可改善凝血功能,降低下肢DVT的发生率。

关键词：乳腺癌间隙性压力治疗系统血流动力学凝血功能下肢深静脉血栓形成

Development trends of the national secure PNT system based on BDS

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Science China Earth Sciences 2023年第5期66卷 929-938页

作者： Yuanxi YANG xia ren xiaolin JIA Bijiao SUN State Key Laboratory of Geo-Information Engineering Xi’an 710054China Xi’an Research Institute of Surveying and Mapping Xi’an 710054China

Satellite navigation systems are *** guarantee the positioning,navigation and timing(PNT)safety of core infrastructure,it is necessary to establish a secure PNT system with hybrid physical *** this paper,the augmentations of the BeiDou satellite system(BDS)itself are analysed,namely augmentations through the BDS inter-satellite link,BDS geostationary orbit(GEO)and inclined geostationary orbit(IGSO)satellites,and BDS PNT services supported by low earth orbit(LEO)***,taking BDS as the core component,the comprehensive PNT infrastructure seamlessly covering deep space and deep ocean is described,consisting of the deep space PNT constellation,the sea-floor PNT sonar beacon network,and the ground-based low frequency and very low frequency(VLF)long wave radio ***,the key technologies of resilient PNT application matching comprehensive PNT and various autonomous perception PNT information are discussed,such as resilient PNT sensor integration,the resilient PNT functional model and the resilient stochastic *** a future development direction,the key factors of intelligent PNT services are analysed,including the intelligent perception of PNT application scenes,the intelligent optimization of PNT functional and stochastic models and the intelligent fusion of multisource PNT information.

关键词： Secure PNT system Comprehensive PNT infrastructure Resilient PNT application Intelligent PNT application

Diffusion tensor interpolation profile control using non-uniform motion on a Riemannian geodesic

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Journal of Zhejiang University-Science C(Computers and Electronics) 2012年第2期13卷 90-98页

作者： Chang-II SON Shun-ren xia MOE Key Laboratory of Biomedical Engineering Zhejiang UniversityHangzhou 310027China Department of Electronics Kim Chaek University of TechnologyPyongyang 104919DPR of Korea

Tensor interpolation is a key step in the processing algorithms of diffusion tensor imaging (DTI), such as registration and tractography. The diffusion tensor (DT) in biological tissues is assumed to be positive definite. However, the tensor interpolations in most clinical applications have used a Euclidian scheme that does not take this assumption into account. Several Rie-mannian schemes were developed to overcome this limitation. Although each of the Riemannian schemes uses different metrics, they all result in a ‘fixed’ interpolation profile that cannot adapt to a variety of diffusion patterns in biological tissues. In this paper, we propose a DT interpolation scheme to control the interpolation profile, and explore its feasibility in clinical applications. The profile controllability comes from the non-uniform motion of interpolation on the Riemannian geodesic. The interpolation experiment with medical DTI data shows that the profile control improves the interpolation quality by assessing the reconstruction errors with the determinant error, Euclidean norm, and Riemannian norm.

关键词： Diffusion tensor (DT) DT imaging (DTI) DT interpolation Interpolation profile control Riemannian geodesic

北斗三号PPP-B2b信号精密单点定位服务可用性分析

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全球定位系统 2024年第3期49卷 10-19页

作者：许扬胤任夏明锋地理信息工程国家重点实验室西安710054 西安测绘研究所西安710054

针对北斗三号(BeiDou-3 Navigation Satellite System,BDS-3)PPP-B2b信号精密单点定位(precise point positioning,PPP)服务可用性,以改正参数的可用性比例、平均可用卫星数和改正参数匹配性为指标进行了系统分析.结果表明:在中国及周... 详细信息

针对北斗三号(BeiDou-3 Navigation Satellite System,BDS-3)PPP-B2b信号精密单点定位(precise point positioning,PPP)服务可用性,以改正参数的可用性比例、平均可用卫星数和改正参数匹配性为指标进行了系统分析.结果表明:在中国及周边地区,BDS-3 PPP-B2b信号改正参数的可用性在71%~95%,且在北京地区达到最大,GPS改正参数可用性在68.5%~88.6%,差于BDS-3.中国及周边地区用户缺少PPP-B2b信号改正参数的卫星观测弧段主要集中在低高度角时段,其改正参数的可用性随着截止高度角的增大而增大;BDS-3、GPS和BDS-3/GPS在中国及周边地区的改正数可用平均卫星数分别约为8颗、7颗和15颗,可以确保有效的实时PPP(real time PPP,RT-PPP)服务性能,但平均约有1颗BDS-3卫星和2颗GPS卫星因为缺少PPP-B2b信号改正参数而无法参与RT-PPP服务;对于赤道以南地区,单个系统基本无法提供有效的PPPB2b服务,其改正参数的平均可用性低于50%,但BDS-3/GPS双系统在部分低纬度地区可提供约7~11颗的可用卫星;由于轨道改正参数和钟差改正参数更新频率不一致,在钟差改正数版本号(IOD Corr)参数更新时,会出现短暂的改正参数不匹配情况.

关键词：北斗三号(BDS-3) PPP-B2b信号改正参数实时精密单点定位(RT-PPP) 可用性可用卫星数匹配性

L log L criterion for a class of multitype superdiffusions with non-local branching mechanisms

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Science China Mathematics 2019年第8期62卷 1439-1462页

作者： Zhen-Qing Chen Yan-xia ren renming Song Department of Mathematics University of Washington Seattle WA 98195 USA LMAM School of Mathematical Sciences & Center for Statistical SciencePeking University Beijing 100871 China Department of Mathematics University of Illinois Urbana IL 61801 USA

In this paper, we provide a pathwise spine decomposition for multitype superdiffusions with nonlocal branching mechanisms under a martingale change of measure. As an application of this decomposition,we obtain a necessary and sufficient condition(called the L log L criterion) for the limit of the fundamental martingale to be non-degenerate. This result complements the related results obtained in Kyprianou et al.(2012),Kyprianou and Murillo-Salas(2013) and Liu et al.(2009) for superprocesses with purely local branching mechanisms and in Kyprianou and Palau(2018) for super Markov chains.

关键词： multitype superdiffusion non-local branching mechanism switched diffusion spine decomposition martingale

Development of Comprehensive PNT and Resilient PNT

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Journal of Geodesy and Geoinformation Science 2023年第3期6卷 1-8页

作者： xia ren Yuanxi YANG Xi’an Research Institute of Surveying and Mapping Xi’an 710054China State Key Laboratory of Geo-Information Engi-neering Xi’an 710054China

Any single Positioning,Navigation and Timing(PNT)technology has its vulnerability and limits,even the powerful Global Navigation Satellite System(GNSS)is no *** provide continuous and reliable PNT information to users,the theory and technique of comprehensive PNT information system and resilient PNT application system have attracted great attention from Chinese *** try to summarize the progress and development of the synthetic PNT system,including the proposal,the modification and the improvement of the comprehensive PNT,as well as the follow-up resilient *** frame of China’s comprehensive PNT system consisted of comprehensive PNT infrastructure and comprehensive PNT application system is initially described;the achievements on some main PNT technologies are introduced;the conceptual models of resilient PNT are given;besides,existing researches on resilient function models and stochastic models are summarized according to different user scenarios.

关键词： GNSS comprehensive PNT resilient PNT resilient function model resilient stochastic model