Results 51 to 60 of about 13,167 (170)
, 1997 做 对压敏电阻主原料ZnO粉的特性、添加剂粉料的掺杂方法和化学共沉淀制备ZnO压敏电阻粉体进行了研究。 利用SEM、TEM、红外吸收谱、比表面积和粒度分布测定表征了所制备的球状、棒状和不同颗粒大小的ZnO粉。压敏电阻研究表明,颗粒细的球状ZnO粉有利于获得微结构均匀的压敏电阻。 对添加剂采用溶液形式进行了有选择的定量掺杂研究,结果表明,对晶粒固溶添加剂采用溶液形式掺杂,可以使它们更有效地固溶入ZnO晶粒中,获得的压敏电阻小电流区的电气性能优异,且电压温度系数表现为正值。所有添加剂采用溶液形式掺杂 ...
袁方利
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
Dianci bileiqi, 2003 氧化锌电阻片的通流能力主要取决于电阻片的微观均匀性。使用纳米材料,有助于提高瓷体均匀性和致密性,使得氧化锌电阻片电气性能尤其是通流能力得到改善。为使纳米材料充分发挥作用,必须解决纳米材料自身的团聚,并提高料浆混合的均匀性。
刘勇飞
doaj
, 1997 对于多晶陶瓷烧结体，初始粉料的颗粒形状和大小会影响烧成多晶陶瓷的微观结构，进而影响到陶瓷性能。本文研究了不同颗粒形状和大小的ＺｎＯ粉料对压敏电阻性能的影响。结果表明，颗粒细的球状ＺｎＯ粉有利于获得微观结构均匀的压敏电阻 ...
季幼章, 李晋林, 袁方利
core
Scientists in power plays: How substantive were scientists' narratives during the COVID‐19 pandemic?
Policy Studies Journal, EarlyView.Abstract Scientists who provide expert advice must engage with policy processes. Little is known about whether and how scientists deal with the political dynamics of policy processes that are inherent to policymaking. We study this question by building on the policy dimension concept within the Narrative Policy Framework.
Jule Ksinsik, Caroline Schlaufer
wiley +1 more source
Dianci bileiqi, 2012 在电力系统中使用的10 kV避雷器数量巨大,其质量对10 kV架空线路防雷水平至关重要。通过对10 kV复合外套金属氧化物避雷器进行整只4/10μs、65 kA大电流冲击耐受试验,分析结果得出:10 kV复合外套避雷器生产工艺对其大电流冲击耐受能力有重要影响,在非电阻片因素下,通过改进生产工艺可提高大电流冲击耐受能力。
苏宁 +4 more
doaj
Policy Studies Journal, EarlyView.Abstract Studies of lobbying typically look at the extent to which interest groups realize political goals on issues they actively lobby for. Little is known, however, about the extent to which interest groups attain their political goals without making an active lobbying effort.
Marcel Hanegraaff +2 more
wiley +1 more source
Shuitu Baochi Xuebao目的作为新建型河湖水系连通工程，运河改变河湖水系连通网络的连通格局，影响河湖水系连通网络内物质、能量和风险的传递路径，但对河湖水系连通网络水文连通性的影响机制尚不清晰。方法以环莱州湾地区作为研究区，应用SWAT+模型和图论方法，分析有运河和无运河2种情景下河湖水系连通网络的水文连通性，探究运河对区域内不同流域、不同水体类型的影响机制。结果运河对不同流域水文连通性的影响受流域河网结构、河流流量、运河连接数量和连接位置主导，潍河流域和弥河流域河网结构复杂，自身水文连通性较高，受运河影响程度较低，黄河 ...
孙光茹 +4 more
doaj
Policy &Internet, Volume 18, Issue 1, March 2026.ABSTRACT This article investigates how TikTok Shop reproduces the e‐commerce model of Douyin Shop against a backdrop of divergent regulatory challenges and geopolitical distrust. One of the strategic changes we observe in TikTok Shop is the shift of consumer goods suppliers from local merchants to China‐based sellers.
Shuaishuai Wang, Jing Meng, Yitong Li
wiley +1 more source