Results 21 to 30 of about 3,201 (117)
The Optimal Design of Annuler-Generated Envelope Cylindrical Worm Drive With Two Degree-of-Freedom
针对双自由度环面包络加工圆柱蜗杆这种新型蜗杆成形及传动方式,本文从提高啮合质量与改善接触、润滑性能的角度出发.考虑该蜗杆副参数.采用模糊优化方法对其进行了多目标优化.结果表明,接触线的形状明显陡于优化前.润滑角显著增大,接触线分布有很大改善.
王树人, 张鹏程, 李贵涛
doaj
分别研究了不同水滴体积和测量时间、喷雾次数及静置时间对聚烯烃材料表面静态接触角和HC分级的影响,并通过使用不同目数的砂纸打磨聚烯烃材料表面,研究表面粗糙度对其憎水性能的影响。结果表明:进行聚烯烃材料的憎水性试验时,采用4μL~8μL的水滴在10 s~40 s内测量其静态接触角较为准确,θs值随时间变化较小,水滴边缘接近圆形。喷雾20次~30次,在30 s内完成HC分级图像的采集较能准确评估聚烯烃材料的HC分级特性。随着表面粗糙度的增大,打磨聚烯烃材料的静态接触角平均值呈现震荡上升的变化趋势 ...
彭静 +6 more
doaj
复合绝缘子优异的防污闪性能主要得益于硅橡胶材料表面的憎水性及其迁移特性。在近几年有关表面和界面的研究中,超疏水材料以其优异的超级憎水性和自清洁特性引起了电力行业研究人员广泛的关注。静态接触角大于150°,滚动角小于10°的材料表面被称之为超疏水表面。以往的研究表明,电晕放电是造成硅橡胶表面憎水性下降乃至丧失的主要因素之一。文中以自制的2种超疏水表面硅橡胶和1种普通表面硅橡胶为研究对象,开展了交流电晕对其憎水性及憎水恢复特性的影响研究。考虑到电晕后硅橡胶表面的滚动角会大于90 ...
沈浩, 梁曦东, 阎志鹏, 李少华
doaj
Research on digital discretion—The subjectification of street‐level work in public administration
Abstract The article presents a systematic review of scholarly articles (n = 168) focused on digital discretion—how digital technologies affect the discretionary autonomy of street‐level bureaucrats. Two analytical tasks are performed concerning how digital transformation has affected (1) the relations between top‐down governing and the work of street ...
Jörgen Johansson
wiley +1 more source
准确获得水珠的接触角对硅橡胶憎水性的研究具有重要意义。在手动获得水珠边缘点的基础上,根据水珠体积很小时其所拍得图像中的水珠边缘成圆形的原理运用最小二乘算法拟合水珠边缘,根据圆方程计算获得接触角,结果表明,本文方法的精确度远高于常用的量角器方法。通过实验分析了多种因素对计算所得接触角精确度和实时性的影响。实验结果表明:拟合点数选择3个即可,点数的增加对精确度提高作用不大但会增加计算时间;选择的拟合点应在水珠边缘圆弧上均匀分布;接触角的真实值对拟合精度影响不大,但会影响最小乘法的最佳拟合次数 ...
徐志钮 +3 more
doaj
Return from exile: Mythology and heritage in American Born Chinese and its Disney adaptation
Abstract Though American Born Chinese has received a significant degree of scholarly study, the prevalence of cultural exile in the text has not received sufficient attention. Said's theorization on exile provides a guide to examining the mindset of Jin, who willfully accepts exile from his Chinese‐American heritage because of how he feels neither ...
Joshua Fagan
wiley +1 more source
GB/T 24622—2009/IEC/TS 62073:2003《绝缘子表面湿润性测量导则》已经颁布实施,笔者按照标准规定的测量方法A进行了试验验证,提出了实现标准规定测量方法的途径和实际操作控制手段,分析了可能影响试验结果的几个关键因素:接触角的测量与液滴体积大小的关系;静态接触角的测量与试品表面和水平面夹角大小的关系;针头偏离水珠的最高点对接触角的影响,并就验证过程中所遇到的问题做出了分析和讨论,为试验数据的客观性和结果判定的准确性和有效性奠定了基础。
危鹏, 何远华, 胡文岐
doaj
稀土萃取分离生产过程中会产生大量的含油废水亟待处理,超亲水-水下超疏油过滤膜为稀土冶炼含油废水带来了新的解决方案。以过滤棉为基材,以富含羟基的聚乙烯醇(PVA)与亲水的纳米二氧化硅溶胶为前驱体,以戊二醛为交联剂制备了PVA型超亲水-水下超疏油过滤膜。接触角测试表明,在空气介质中对水的接触角为0°,在水介质中对油的接触角为155.3°,具备优良的超亲水-水下超疏油性能。对制备的PVA型超亲水-水下超疏油过滤膜进行油水分离实验发现,3次重复实验过滤膜的平均油水分离率为97.5%,膜通量为11.89 L ...
肖信锦 +4 more
doaj
Olfactory receptor neurons (ORNs) in insect antennae project axons to glomeruli in the antennal lobe for odor processing by local interneurons. Uniglomerular projection neurons (PNs) relay processed odor information to the mushroom body and lateral horn.
Saleem Jaffar, Guy Smagghe, Yongyue Lu
wiley +1 more source
DHR‐PA—Democracy and human rights in public administration in Africa
Abstract While public administration research has traditionally paid profound attention to democratic values in government‐citizen relations, public institutions are still wrestling with entrenching human rights norms today. This article's Democracy and Human Rights in Public Administration (DHR‐PA) perspective offers a view that a human rights ...
Gedion Onyango
wiley +1 more source

