Results 1 to 10 of about 5,485 (108)
Region‐wide retreats from lower elevations of range‐restricted birds across the Northern Andes
Conservation Biology, Volume 37, Issue 5, October 2023., 2023 Abstract Local studies show upslope shifts in the distribution of tropical birds in response to warming temperatures. Unanswered is whether these upward shifts occur regionally across many species. We considered a nearly 2000‐km length of the Northern Andes, where deforestation, temperature, and extreme weather events have increased during the past ...
Wilderson Medina +2 more
wiley +1 more source
Methods in Ecology and Evolution, Volume 14, Issue 6, Page 1443-1456, June 2023., 2023 Abstract Successful use of stable isotopes (δ2H and δ18O) in ecohydrological studies relies on the accurate extraction of unfractionated water from different types of soil samples. Cryogenic vacuum distillation (CVD) is a common laboratory‐based technique used for soil water extraction; however, the reliability of this technique in reflecting soil ...
Bin Yang +14 more
wiley +1 more source
, 2021 对少齿差直线共轭齿廓进行了研究。根据齿轮啮合原理及齿廓法线法，推导了直线共轭齿廓的参数方程，并详述了啮合线和重合度的求解方式及齿侧间隙的处理方法；讨论了齿廓干涉的验证原理，提出基于面积量的齿廓旋轮线干涉验证方法。设计制造了以少齿差直线共轭齿廓为主要传动结构的减速器样机，并进行了效率对比试验和温升试验 ...
周孔涛 +4 more
core +2 more sources
Gaoya dianqi, 2023 文中针对高压开关温升预测缺少电流同温升关系模型这一难点，首次建立导电部位稳定温升τw与电流I的数学模型，得出τw与I的变化规律，通过高压开关柜系列电流下的温升试验，验证了该模型的合理性和准确性。阐述了电器发热基本理论中温升τ与时间t关系模型的推导过程，通过高压开关柜系列电流下的温升试验，进一步研究了该模型下不同试验时间段的拟合温升规律。在温升预测应用中，按文中τw与I的数学模型，求解形成稳定温升与电流标准曲线，作为温度在线监测的判断标准，从而实现故障提前预警。
兰剑, 韩冬, 冯英, 陆德鹏
doaj
Gaoya dianqi, 2020 为了验证晶闸管可否承受设计要求的最高结温及高低温循环应力,在出厂试验阶段需要开展换流阀温升试验。首先介绍了温升试验参数的计算方法,其次设计了采用直流电流加热原理的温升试验回路,最后结合某换流阀实例计算了温升试验参数,在试验室中开展了温升试验。试验结果显示温升试验参数的试验值和计算值基本一致,试验前后晶闸管性能未有下降。试验结果表明,结合给出的温升试验参数计算方法和温升试验回路可以完成温升试验,验证晶闸管的温升性能。
张翔 +5 more
doaj
Gaoya dianqi, 2021 以隔离开关关键零部件触头为研究对象,建立温升理论模型,通过±60℃高低温试验平台,测试了1 000次机械操作前后触头表面夹紧力、压紧弹簧力值、触头磨损率和回路电阻等通流参数,设计触头温升试验,定量研究高低温对触头通流能力的影响。建立温度与触头夹紧力、镀银层磨损量和接触电阻的关系曲线,分析了触头夹紧力、镀银层和接触电阻随温度变化情况,通过试验研究可知,低温环境对触头温升变化没有高温影响大,为隔离开关触头优化改进和通流能力的提升奠定理论基础。
徐刚 +9 more
doaj
Temperature Rise Experiment and Control of Machine Tool Spindle [PDF]
, 2013 在静压轴承主轴的实验平台上开展了主轴温升试验,通过对主轴转速与温升试验数据的分析,得出了影响主轴温升的主要因素,并提出了控制主轴温升的一些措施。Temperature rise experiment is carried out on a machine tool spindle.The main factors influencing the spindle temperature rise are pointed out by analyzing the experiment data of ...
冯伟, 张祥雷
core
Effects of solar radiation on cabin temperature inside special vehicles and human heat transfer [PDF]
BackgroundDue to the strong sunlight in summer, the temperature on the vehicle deck rises significantly under solar radiation and the internal structures are heated, resulting in prominent heat stress problems in the cabin and seriously affecting the ...
Ping LI +3 more
core +1 more source
Rare Metals, Volume 45, Issue 4, April 2026.ABSTRACT A comparative study was performed to elucidate the temperature‐dependent corrosion kinetics and the semiconductor/structural characteristics of the passive film formed on Fe40Ni7Cr17Mo12C13B9Y2 (at%) amorphous alloy coatings. The results indicate that increasing temperature accelerates the corrosion kinetics of the coating.
Yang Lv +12 more
wiley +1 more source
Spindle Vibration Test and Influence of Temperature Rise to the Vibration [PDF]
, 2014 在液体静压轴承主轴的实验平台上,采用激光位移传感器测量主轴在不同转速下的振动值。根据实验条件设计主轴温升试验方案,并测量主轴在指定转速运转15 MIn的温升情况以及振动量,研究温升对主轴振动的影响。On the experiment platform of hydrostatic bearing spindle,the spindle vibration value under different rotational speed measurement is obtained by the laser
冯伟, 张祥雷, 李睿, 陈站
core