Results 31 to 40 of about 1,799,214 (159)
Pest‐preservation paradox among insects
Conservation Biology, EarlyView.The pest‐preservation paradox is a non‐binary perspective that insects range from those that are harmful and requiring management on the one side, to those requiring conservation intervention on the opposite end of the spectrum. Importantly, the vast majority of insects occur somewhere in the center of the two extremes, and their position along the ...
Michael J. Samways +3 more
wiley +1 more source
Jianzhu Gangjiegou Jinzhan, 2013 为研究正弦波纹腹板工字钢梁的受弯性能,设计了此种钢梁的受弯试验,并采用有限元方法对其受弯性能进行了数值模拟,然后对其抗弯承载能力进行了理论分析。分析结果表明,波纹腹板工字钢梁表现出较好的抗弯变形能力,并且具有良好的塑性性能;波纹腹板工字钢梁在竖向荷载作用下波纹腹板几乎不产生任何弯曲正应力,弯矩基本由翼缘承担;波纹腹板工字钢梁的极限弯矩可由近似的截面受弯承载力公式求得。
周学军 +4 more
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Protected areas on international borders show uneven conservation outcomes
Conservation Biology, EarlyView.Abstract Border protected areas (BPAs) are national protected areas that are immediately adjacent to a country's border or span two or more countries; they are characterized by distinctive opportunities and pressures. They play a critical role in protecting carbon‐rich ecosystems, conserving endangered biodiversity, reducing cross‐border environmental ...
Rachakonda Sreekar +10 more
wiley +1 more source
, 2012 [[abstract]]以往人力資源相關領域的學者與專家，在分析員工訓練之成效時，多僅就訓練的ADDIE模式來進行探討。然而，針對員工受訓後是否能夠將所學有效的應用在工作崗位上，則著墨不多。且過去學者們在探討訓練遷移時，大多著重在單一遷移模式(one model of transfer)上，甚少依工作特性之不同而採取不同的遷移策略。因此，本文以多向度訓練遷移模式為主軸，針對工作的兩大向度---任務調適性與工作自主程度，區分為封閉或開放型技能，高或低自主性等四種不同的工作特性，分別依訓練設計 ...
王誕生; 徐其力
core
, 2015 笔者读到《中国科技术语》2015年第1期赵中平的《mechanical properties中文译名演变过程及定义》一文,很受启发,但也有一些不同看法。该文斩钉截铁地说,"力学性能"并不存在,只有"机械性能",恐怕事实并不那么简单。问题的起源大概是对英文中mechanical和mechanics的理解。我们查找一本英文辞典(比如Webster’s New World College Dictionary ...
王克仁
core +1 more source
A framework for integrating resilience indicators into risk assessments
Conservation Biology, EarlyView.Abstract Globally, ecosystems are increasingly threatened by climate change and human pressures, yet ecosystem risk assessments predominantly emphasize exposure to stressors while overlooking intrinsic ecosystem resilience—the capacity to absorb and recover from disturbances.
Benoît Pichon +4 more
wiley +1 more source
, 2023 【目的】初步探究田菁根瘤菌Sinorhizobium alkalisoli YIC4027中唯一含有PAS结构域可溶性趋化受体Tlp1的功能机理。【方法】本研究基于Red重组系统以及三亲接合技术进行缺失突变株的构建。对野生型和突变株的生长情况、趋化能力、趋氧性、细胞凝结、生物膜的形成、胞外多糖产量、在宿主根表的定殖及竞争性结瘤等表型进行了测定。【结果】与野生型相比,突变株的生长不受影响,趋化和趋氧能力降低,在宿主根表的定殖及竞争性结瘤能力降低,而细胞凝结能力、生物膜形成以及胞外多糖产生能力等均有所提高。【
董小燕 +4 more
core +2 more sources
The Academic Literacy of International Postgraduate Students in Australia: A Cause for Concern?
International Journal of Applied Linguistics, EarlyView.ABSTRACT This article discusses the academic literacy challenges faced by international postgraduate students at a South Australian university and evaluates the effectiveness of existing institutional support mechanisms. Drawing on survey data, the study highlights significant difficulties in academic reading, writing, and spoken communication, with ...
Werner Botha +6 more
wiley +1 more source
, 2018 受电弓是安装于机车车顶上、从接触网获取电能的电气设备。获取受电弓的整体结构特性,对于受电弓结构优化、弓网受流性能提升及高速列车运营安全具有重大意义。本文使用Abaqus有限元分析软件对某型受电弓进行仿真分析,研究了受电弓的静态结构特性与有/无预应力条件下的动力结构特性。于受电弓上臂杆交叉管处施加300N横向集中力,得到整弓偏离中心面的最大位移小于20mm,该型号受电弓横向刚度满足国际电工委员会标准;于弓头滑板处施加静态接触力,分析受电弓的应力集中情况,发现应力最大值在安全范围内;在受力 ...
张志奇 +5 more
core +1 more source
Jianzhu Gangjiegou Jinzhan, 2011 为了研究实腹式钢骨混凝土异形柱在偏心荷载下的破坏机理、受力性能及变形能力。本文通过对12个十字形钢骨混凝土异形柱进行偏心受压承载力的试验研究,观察了含钢率和偏心距不同情况下的试件受力过程和破坏形态,分析了钢骨混凝土异形柱的荷载-位移曲线、承载力、位移延性等力学性能。通过试验,明确了钢骨混凝土异形柱的破坏特征,含钢率对承载力的影响。试验结果表明,含钢率越大,构件的承载力及延性也会相应增加,钢骨混凝土异形柱具有较高的承载能力和较好的延性。
刁晓征, 徐亚丰
doaj