Results 21 to 30 of about 1,415,976 (155)
六十年代中期,美国和加拿大在离心压气机的研究工作中获得了新的突破,他们分别研究成功了单级压比为6~10的离心压气机,从此,高压比离心压气机就成为叶轮机械研究工作中一个很活跃的领域。本文首先介绍高压比离心压气机的发展过程和现状,然后着重对提高离心压气机元件性能和改善设计方法的若干问题进行了讨论 ...
刁正纲, 陈静宜
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Scientists’ warning on the global destruction of rock outcrop ecosystems
Abstract Rock outcrops are geological formations that harbor a highly specialized biota adapted to harsh environmental conditions that differ from their surrounding landscapes. They are globally distributed, especially in old, highly weathered landscapes, and can function as habitat islands containing high levels of endemism and distinct evolutionary ...
Luiza F. A. de Paula +19 more
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ABSTRACT Efficient hole injection at metal‐semiconductor interfaces remains a central challenge for high‐performance p‐type transistors based on two‐dimensional (2D) semiconductors. Although substantial efforts have been devoted to reducing Schottky barrier height through contact engineering, the barrier width is rarely addressed, thereby limiting ...
Zhe Zhang +7 more
wiley +1 more source
基于快放电(毫微秒)XeCl激光器电极两端电压和电流的精确测量和计算机分析,给出高气压(3—8大气压力)激光放电等离子体的动态阻抗特性。在几毫微秒内,阻抗降到欧姆量级。研究了放电峰值电流和平均阻抗与充电电压和气体压力的关系。结果显示 ...
刘达伟
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为了确保特高压工程跨电网、跨区域电能计量的准确可靠,促使发电、输电及用电三方的利益得到明确和保证,解决特高压交流电网中电容式电压互感器(CVT)误差特性的现场校准试验难题,研制了一种特高压标准电压互感器一体化装置。基于工频电压加法原理,采用特殊的罐式结构紧凑化设计思路,将特高压电压互感器标准电压互感器设计成上下两级GIS单元,缩小了装置的体积和重量,以适应特高压互感器现场校验车的装载。通过理论计算确定罐体尺寸及材料,使用电磁场仿真软件对隔离互感器进行3D建模及优化设计。样机的测试结果表明 ...
姜春阳 +6 more
doaj
ABSTRACT With the rapid development of flexible electronics, there is an increasing demand for hydrogel‐based sensors with rapid fabrication, robust mechanical performance, and stable sensing behavior. Herein, a green and ultrafast self‐catalytic strategy is developed to fabricate a multifunctional hydrogel based on tannic acid‐coated cellulose ...
Jin Qian +6 more
wiley +1 more source
前言采用特高压系统输电,已成为大容量电力输送的必然之路。日本特高压输电委员会已经确定,日本特高压输电的额定电压为1000千伏,最大系统电压为1100千伏。在特高压输电系统中,由于系统的操作冲击电压较低,防污设计已成为外绝缘设计的决定因素。因此 ...
尾崎勇造
doaj
ABSTRACT The escalating severity of global environmental pollution necessitates the development of sustainable and efficient adsorption materials. Nanocellulose (NC), sourced from the most abundant natural polymer on earth, has shown great potential in this field due to its renewability, biodegradability, and exceptional nanoscale properties.
Yaqian Yu +5 more
wiley +1 more source
越宽。由于采用高电压输出损耗小,所以高电压和超高电压输电线路发展很快,西方发达国家的高压输电线路电压已超过800kV,我国目前的高压输电线路电压也已超过500kV。为保证高压线路安全运行 ...
曹树祥
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综述了国内外特高压电力变压器交流耐压和局部放电试验装置的现状;以武汉高压研究院特高压试验基地1 000 kV变压器的试验数据为参考,提出了特高压电力变压器的交流耐压和局部放电的试验方法和试验电路。论述了装置中变频电源和高压电抗器的设计方法;进行了750 kV电压等级超高压电力变压器的交流耐压和局部放电试验,对试验数据进行了分析。试验结果证明了该试验装置及试验方法的合理性,同时表明该试验装置具有可靠性高、安全性好、实用性强的特点。
仇新艳 +4 more
doaj

