Results 1 to 10 of about 695 (102)
Measurement of the A-Value of the Intersystem Transition in Al II at 2670 Å: Å Progress Report [PDF]
International Astronomical Union Colloquium, 1984 Ratios of intensities of spectral lines produced in the radiative decay of collisionally-excited levels of atomic ions are versatile indicators of electron density in astrophysical plasmas when one of the lines involves a metastable level (see the review by Feldman 1981 and references therein). Radiative transition probabilities (A-values) and electron
B. Carol Johnson, H.S. Kwong
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Optical spectrum of the post-AGB Star HD56126 in the wavelength interval 4010-8790 Å Å [PDF]
Astrophysical Bulletin, 2007 The optical spectrum of the post-AGB star HD56126 identified with the infrared source IRAS07134+1005 is studied in detail using high spectral resolution observations (R = 25000 and 60000) performed with the echelle spectrographs of the 6-m telescope. A total of about one and a half thousand absorptions of neutral atoms and ions, absorption bands of C2,
V. G. Klochkova +3 more
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Prediction of landslide hazard based on support vector machine theory(基于支持向量机理论的滑坡灾害预测——以浙江庆元地区为例)
Zhejiang Daxue xuebao. Lixue ban, 2003 滑坡发生受很多因素影响,揭示因素与发生滑坡事件的关系是当前滑坡研究中的一个重要内容.运用支持向量机理论,利用数字高程和遥感数据,构建了滑坡预测的支持向量机模型,并以浙江庆元县境内滑坡发生集中区为试验区,开展滑坡灾害的预测与评价,取得了与实际滑坡较为一致的结果.认为基于支持向量机理论建立的滑坡预测与评价模型可以快速准确地实现滑坡灾害区域评价与预测.
MAZhi-jiang(马志江) +2 more
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Shuitu Baochi Xuebao, 2022 为探究喀斯特地区林木根系分布方式对坡面土壤侵蚀的影响，采用人工模拟降雨方法，研究林木根系3类分布方式：根系横坡方向局部裸露（横向）、根系顺坡方向局部裸露（顺向）、根系垂直坡面（垂直）的土壤侵蚀特征。降雨强度为75 mm/h，降雨历时为90 min，坡度为25°。结果表明：（1）降雨过程中，横向和垂直生长根系影响土壤入渗，壤中流和地下径流产流时间表现为顺向>横向>垂直；顺向坡面地表径流初始产流时间比横向和垂直坡面略有提前，但差异不显著（p>0.05）；（2）横向、顺向及垂直坡面地表径流总量大小表现为顺向 ...
杨秀超 +4 more
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Dizhen xuebao, 2020 本文采用隐式动力有限单元法研究了不同的边坡角度和边坡高度对地形放大效应的影响，并以位移峰值放大系数为衡量地震动放大效应的标准，计算了不同边坡角度和边坡高度条件下的地震响应，在此基础上对模型关键监测点的输出波形以及位移峰值放大系数的变化趋势进行了分析，获得了不同监测点处的地震动时程曲线，揭示了坡角和坡高对单体边坡地震动放大效应的定量作用规律。数值结果表明，相同高度处坡面监测点的水平向位移峰值放大系数大于坡内监测点的，地形放大效应在水平方向具有趋表效应。由于坡面存在入射波和反射波的叠加 ...
Peng Deng
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Shuitu Baochi Xuebao, 2004 通过解译同源不同时期卫星遥感影像数据,应用GIS对空间数据和属性数据的有效管理和分析,阐述了大宁河流域土地利用/覆盖随坡度和坡向的分布规律以及坡度和坡向的变化对土地利用/覆盖动态变化度和综合土地利用动态变化度的影响,分析了社会经济和政治因素对流域内土地利用/覆盖动态变化的正向和负向的驱动力作用。研究表明,大宁河流域内人类活动主要集中在坡度较低的区域,受社会因素的影响,人类活动正向较陡坡区域发展,陡坡耕地和极陡坡耕地在流域内分布过多,森林面积分布过少,从而对环境造成了负面影响。
周爱霞 马泽忠 周万村
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Shuitu Baochi Xuebao, 2023 针对坡耕地横坡、顺坡垄作模式土壤水分及溶质迁移过程的差异,采用田间模拟试验的方法,以坡度为7°的大豆坡耕地为研究对象,以Br-为示踪剂,监测不同垄作模式垄台、垄侧、垄沟各位置的土壤水分和Br-浓度,探究坡耕地横坡、顺坡垄作模式对土壤中水分迁移及可溶性养分分布的影响。结果表明:2种模式最大土壤体积含水量横坡垄作分布在10—20 cm土层,顺坡垄作分布在5—15 cm土层,证明横坡垄作对雨水的拦蓄作用。横坡垄作模式最大土壤贮水量位置在垄上侧的垄侧处,顺坡垄作模式在垄沟处 ...
江鑫 +4 more
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Review of Policy Research, Volume 43, Issue 2, March 2026.ABSTRACT This study applies the Narrative Policy Framework (NPF) within a non‐democratic context, exploring the role of policy narratives in the implementation of patient‐centred healthcare policy in China. Drawing on a dataset of academic journal articles that reference both “market” and “patient‐centredness,” the research reveals how local ...
Jingqing Yang
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Legislative Attention and Nonprofit Efficiency: A Link Across Sectoral Boundaries
Policy Studies Journal, Volume 54, Issue 1, February 2026.ABSTRACT Government attention matters for nonprofit management and nonprofit‐government interactions. This study focuses on legislative attention, an important yet less‐studied aspect of government attention in public policy research, and examines its impact on nonprofit efficiency.
Yuhao Ba, Jessica Berrett, Jason Coupet
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Shuitu Baochi Xuebao, 2023 为了明确等高犁耕条件下黄土坡耕地地形与坡度的变化特征,基于6个坡度(3°,5°,10°,15°,20°,25°)和5个耕作强度(6,12,18,24,30次)的组合,开展模拟耕作试验,利用测针法获取耕作后地表高程数据,探讨耕作强度和坡度对黄土直线形坡演化特征的影响。结果表明,在等高向下犁耕条件下,不同坡度的直线坡随着耕作强度的增加逐渐向"∽"形复合坡演化。同一坡度下,随着耕作强度的增加,坡脚延伸,整体小区投影坡长增大,坡脚高程增加幅度大,堆积现象明显,坡度大幅度减小;坡中高程增加,逐渐抬起坡度减小 ...
张泽瑜 +4 more
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