Results 71 to 80 of about 20,406 (216)
Jacking resistance in collapsed body considering buckling of force chain [PDF]
In order to establish an effective and secure emergency rescue channel within a collapsed structure using the pipe jacking method, understanding the evolution mechanism of jacking resistance is crucial.
Chuanbo HAO +5 more
core +1 more source
Effects of parachute science on local research capacity 降落伞科学对当地研究能力的影响
Conservation Biology, EarlyView.Abstract Strengthening research capacity is essential to address the global biodiversity crisis. Yet, parachute science often undermines this goal, and its prevalence, costs, and benefits are unclear. We analyzed 13,502 publications on primate research that we extracted from Scopus (1960–2022) to evaluate the effects of parachute science on local ...
Li Yang +11 more
wiley +1 more source
Shipboard transducer vibration isolation based on stiffness compensation and eddy current damping [PDF]
ObjectiveThis paper addresses problems of shipboard transducers such as large-angle tilt during multi-dimension steering and small-space compensation suppression by proposing an isolator based on stiffness compensation (SC) and eddy current damping (ECD).
Huayan PU +4 more
core +1 more source
Lessons from an eradication under multiple constraints of an island rat population of record density
Conservation Biology, EarlyView.Abstract Invasive rats threaten island biodiversity, disrupting ecosystems and endangering native species. Although rat eradication has succeeded on many islands, tropical islands present unique management challenges. Strict regulations and financial constraints on some tropical islands further limit proven eradication methods, complicating rodent ...
Tatiane Micheletti +7 more
wiley +1 more source
Shuitu Baochi Xuebao, 2016 为阐明双季稻—绿肥种植模式下长期施肥对赤红壤肥力性状的影响，探讨土壤持续利用的培肥模式。通过长期定位田间试验，研究了长期不同施肥处理对赤红壤性水稻土土壤养分、酶活性及微生物性状的影响。结果表明：与不施肥相比，长期施肥显著增加了土壤有机质、碱解氮、有效磷、速效钾等养分含量，提高土壤蔗糖转化酶、脲酶、磷酸酶活性以及土壤微生物量碳氮含量和微生物群落物种丰富度、优势度、均匀度。其中土壤养分含量增加了4.5%～117.2%，酶活性提高了4.9%～68.1%，微生物多样性提高了3.2%～71.9 ...
张成兰, 艾绍英
doaj
Analysis of the Content of Stevia Sweeteners by Capillary Zone Electrophoresis [PDF]
, 2001 本文介绍了一种用毛细管区带电泳法筛选甜菊糖苷突变体的有效方法。根据实验结果 ,优化的电泳条件为 :60mmol/LTris 硼酸缓冲液 (pH 8.0 ) ,柱温 30℃ ,工作电压 2 5kV。优化条件下 ,甜菊苷 (Ste vioside)迁移时间的R .S .D为 0 .45% (1 5次 ) ,且在 7.45× 1 0 - 5～ 1 .74× 1 0 - 2 mol/L的浓度范围内存在良好的线性关系 (r=0 .9994) ,甜菊主要糖苷在 5min内均可实现分离。在优化条件下 ...
丁亮 +5 more
core
Conservation Biology, EarlyView.Abstract Consumer demand for ivory perpetuates the unsustainable and illegal killing of African elephants and other wildlife species. Interventions that aim to change consumer behavior are increasingly recognized as a crucial element of demand management. However, poor design and implementation have limited their effectiveness.
Molly R. C. Brown +2 more
wiley +1 more source
Shuitu Baochi Xuebao, 2007 对流动沙丘上栽植的6年和11年生小叶锦鸡儿灌木林防风固沙效应进行了测定与分析,研究结果表明：（1）在小叶锦鸡儿灌木林内各个高度风速和输沙量均显著低于流动沙丘,防风固沙效果明显。（2）小气候得到改善,小叶锦鸡儿林内空气温度低于流动沙丘,相对湿度则高于流动沙丘,土壤浅层温度变幅明显小于流动沙丘,有利于植物生长。（3）随着植被生长发育年限的增加,土壤理化性质均得到不同程度改善。土壤中微沙（0.05-0.1mm）和粘粒（〈0.05 mm）含量增加,表层土壤容重减小,孔隙度增大,土壤持水能力提高;土壤中有机碳 ...
贺山峰 +4 more
doaj +2 more sources
Shuitu Baochi Xuebao, 2016 通过野外水流冲刷试验，对比分析了不同坡长条件下坡面产流产沙及氮磷流失特征。结果表明，上方来水流量一定时，坡长越长，其坡面入渗量越大，径流量越小，且存在一个临界坡长，使得径流量和入渗量相当，累计径流量与坡长是负线性关系。随着坡长增加，产沙量增大，单位坡长的泥沙流失量在各坡长条件下差异并不显著（P＞0.05）。累计泥沙量随着坡长增大而增大；幂函数比指数函数能更好的描述硝态氮和水溶性磷浓度变化过程；泥沙中硝态氮和有效磷的含量整体上随时间呈减小趋势。坡长越长，其养分富集率越大；随着坡长增大 ...
赵光旭, 张鹏宇
doaj
Shuitu Baochi Xuebao, 2020 研究旨在通过大田试验了解水分调亏对膜下滴灌板蓝根生长、耗水规律、产量、水分利用效率及品质的影响。于2018年在甘肃河西中部的民乐县益民灌溉试验站开展板蓝根水分控制试验，在板蓝根苗期和肉质根生长期保持充分灌水，营养生长期和肉质根生长期分别进行不同梯度（轻度、中度和重度）的水分调亏处理，并测定各项生长指标、产量、水分利用效率和品质。结果表明：（1）营养生长期和肉质根生长期中度和重度水分调亏显著降低了板蓝根株高、叶片数、主根长和主根直径，且降幅随调亏程度的加剧而增大，而轻度水分调亏与对照组无显著差异。（2 ...
王泽义 +5 more
doaj