Results 31 to 40 of about 18,969 (167)
Comprehensive framework for assessing and optimizing existing research networks
Conservation Biology, EarlyView.Abstract Conservation, monitoring, and research networks, or collections of ecological research sites unified under a common mission of data collection or a research mission, are essential infrastructure for understanding large landscapes. However, most networks developed opportunistically over decades rather than through systematic design, creating ...
Alyson East +2 more
wiley +1 more source
Gaoya dianqi, 2016 开关设备（例如高压SF6断路器）触头表面产生的铜金属蒸气会改变电弧等离子体的物理化学特性。因此在建立考虑金属烧蚀的流体仿真模型之前,需要确定含有金属蒸气的电弧等离子体的性质。文中基于吉布斯自由能最小化原理和Chapman-Enskog理论,计算了SF6-Cu混合气体电弧在0.6 MPa压强下、温度区间为30030 000 K时的物性参数,包括平衡态粒子组分、统计热力学参数、输运系数和混合扩散系数,着重分析了铜蒸气浓度（最大90%）对上述物性参数的影响。结果表明少量的铜对物性参数无明显影响 ...
袁端磊 +5 more
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MH(81) equation of state and calculation of liquid viscosity(MH(81)状态方程与液体粘度的计算)
Zhejiang Daxue xuebao. Lixue ban, 2002 在Eyring的液体粘性流动分子模型基础上, 导出一个双参数粘度新模型, 把属于传递性质的粘度与物质的体积、蒸发内能以及过量函数等平衡性质联系起来,为状态方程在粘度推算中的应用构筑了桥梁.用MH(81)状态方程计算了40个液体纯物质和19个二元液体混合物的粘度,总体平均偏差分别为1.82%和1.78%.
LEIQun-fang(雷群芳) +2 more
doaj +1 more source
Study on reductive amination of biobased levulinic acid [PDF]
, 2016 乙酰丙酸是重要的生物基平台化合物，其转化利用受到科研工作者的广泛关注。乙酰丙酸的还原胺化是制备高附加值乙酰丙酸胺化衍生产品的重要途径，近年来成为研究的热点。本论文建立了无催化剂乙酰丙酸还原胺化的反应体系，探讨了乙酰丙酸还原胺化合成直链氨基酸4-二甲氨基戊酸（4-DAPA）和环状化合物5-甲基-2-吡咯烷酮（5-MeP）的反应途径。 首先，研究了以N，N-二甲基甲酰胺为胺源，在无催化剂条件下直接还原胺化乙酰丙酸合成新型化合物4-二甲氨基戊酸（4-DAPA）的反应途径。在200℃条件下反应4h，4 ...
王彦钧
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Conservation Biology, EarlyView.Abstract Recognition and engagement of Indigenous Peoples and local communities (IP&LCs) and other traditional knowledge (TK) holders in formal biodiversity governance remain limited, despite their significant contribution to the conservation and sustainable use of biodiversity through their knowledge, innovations, practices, and land stewardship.
Kinga Öllerer +8 more
wiley +1 more source
Zhongshan Daxue xuebao. Yixue kexue ban, 2019 【目的】探索青光眼患者角膜生物力学与视盘生物力学间的关系。【方法】前瞻性病例观察研究。观察32例原发性开角型青光眼（POAG）患者、20例正常眼压性青光眼（NTG）患者、15例高眼压症（OHT）者和26例正常者的角膜生物力学参数及筛板厚度特征，评估测量筛板厚度（LCT）的可重复性，采用单因素方差分析比较不同类型青光眼者间筛板厚度差异，并应用Spearman相关分析方法分析角膜生物力学参数与筛板厚度相关性。【结果】扫频OCT所测量筛板厚度的Cronbach′sα系数0.911，组内相关系数ICC也大于0 ...
杜绍林
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Intensity Distribution Design for Laser-Induced Thermal Loading Based on Numerical Simulation [PDF]
, 2006 To accomplish laser-induced thermal loading simulation tests for pistons,the Gaussian beam was modulated into multi-circular beam with specific intensity distribution.A reverse method was proposed to design the intensity distribution for the laser ...
Li SX(李少霞) +2 more
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Evaluating the empirical basis for threat attribution in the IUCN Red List
Conservation Biology, EarlyView.Abstract Understanding the impacts of different threats on species is key to successful conservation interventions and policies. The International Union for Conservation of Nature (IUCN) assesses threats to species, and the organization's Red List of Threatened Species is a key conservation tool.
Ena Humphries +5 more
wiley +1 more source
Zhongguo shiyan zhenduanxue, 2015 目的应用三维能量多普勒超声对盆腔肿物内血流参数进行定量分析,探讨三维能量多普勒鉴别盆腔肿物良恶性的价值。方法测量24例盆腔包块,其中包括血流指数(flow index,FI)、血管形成指数(vascularization index,VI)、血管形成-血流指数(vascularization-flow index,VFI)。对比分析两组血管参数值。结果 1三维能量多普勒血管成像可较清晰显示肿物内血流架构;2恶性肿物组的VI、FI和VFI值均明显高于良性肿物组 ...
蒋雪, 冯蕾, 王琼, 杜领娣
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Gaoya dianqi, 2022 植物绝缘油因其较好的绝缘性能及绿色环保等优势,逐渐成为传统矿物绝缘油替代品研究的热点。太赫兹波段光谱具有独一无二的指纹特征吸收峰,使其成为近年来物质检测热点技术之一。文中利用绝缘油的太赫兹时域光谱快速、准确、稳定的数据采集特性,对植物绝缘油的老化状态进行诊断。首先,利用改进的电磁波传递函数消除了仪器和容器的法布里—珀罗(F-P)效应。然后计算出植物绝缘油的吸收系数、折射率等THz谱参数,分析了植物绝缘油在太赫兹区域的介电性能。最后,与相应老化状态下的糠醛浓度进行对比,结果表明 ...
郭丽 +4 more
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