Results 41 to 50 of about 16,292 (168)

吸入性糖皮质激素对稳定期COPD获益及风险的meta分析

open access: yesZhongguo shiyan zhenduanxue, 2017
慢性阻塞性肺疾病(COPD)是以进行性气流受限及肺功能下降为特征的肺部疾病。研究表明,吸入性糖皮质激素(ICS)在COPD急性加重期的应用可明显缓解患者症状及改善肺功能,但ICS治疗稳定期COPD尚无明确研究。本研究旨在采用系统评价方法,探讨吸入性糖皮质激素对于稳定期COPD肺功能、呼吸困难改善情况、肺炎发生率,死亡率影响。为ICS在COPD稳定期临床应用提供可靠的证据。
吴蕾, 许凡凡, 关英慧, 盛辉
doaj  

Preparation, modification and electrochemical properties of LiNi 0.8 Co 0.1 Mn 0.1 O 2 cathode material [PDF]

open access: yes, 2015
LiNixCoyMn1-x-yO2作为层状正极材料,同时具有层状钴酸锂、镍酸锂和锰酸锂材料的优点。因其具有的成本低、容量高和环境污染小等特点,已经在某些应用上取代传统的钴酸锂正极材料。尽管如此,让LiNixCoyMn1-x-yO2具有更高的能量密度、循环稳定性和热稳定性仍是亟待解决的需求。 本论文选取Ni含量高的LiNi0.8Co0.1Mn0.1O2为研究对象,对其合成与表面修饰进行研究。本论文首先采用共沉淀法合成前驱体Ni0.8Co0.1Mn0.1(OH)2,然后高温煅烧出产品,通过优化合成条件 ...
张宏龙
core  

Electrospinning Synthesized Cd0.3Zn0.7S@PVDF/PAN Piezoelectric Nanofiber Membrane for Efficient Photocatalytic Hydrogen Evolution

open access: yesRare Metals, Volume 45, Issue 4, April 2026.
ABSTRACT Photocatalytic hydrogen evolution technology is a crucial approach to achieve efficient solar energy conversion and green hydrogen production. However, traditional semiconductor photocatalysts often face issues such as weak visible‐light response, high photogenerated charge carrier recombination, and poor structural stability, severely ...
Longtao Guo   +8 more
wiley   +1 more source

半导体釉高压悬式绝缘子

open access: yesDianci bileiqi, 1985
半导体釉绝缘子的试运行(有时称为稳定绝缘子),不仅能够确定对釉的理化性能要求,而且可以确定对绝缘子的结构,以及对其制造工艺的要求。实践证明,输电线路绝缘子的运行可靠性和稳定性既决定于半导体釉的性能,也决定于绝缘部件(瓷件)的结构形状,绝缘子串每片绝缘子的电阻与规定值的偏差,施釉厚度以及釉与绝缘子的金具(钢帽和钢脚)之间电接触的可靠性等。
Н·П·ЛЕШ、ЕНКО, 王振林
doaj  

Design and Implementation of Exhibits Information Management System for Science and Technology Museum [PDF]

open access: yes, 2016
科技馆是从自然科学博物馆发展出来的具有高新技术特征的场所,科技馆的发展随着社会进步一步步走向成熟,未来的科技馆正在发展成为公众科学中心。科技馆展示设计创新理念是从一种积极的态度出发,进而发掘观众主动学习科学知识、发现科学原理、继承科学精神的潜力。对科技馆而言,展品本身是其之所以存在的重要因索,及时、准确地获取展品及其动态信息,才能有效地保护展品,实现对展品更深层次的利用。因此,需要改变这种传统的管理模式,积极的响应国家的相关号召,尽快开发出一套专门针对科技馆的科技馆展品信息管理系统 ...
邹云龙
core  

Edge‐Fluorinated Flower‐Like Porous Graphene Microspheres With Enlarged Interlayer Spacing for High‐Performance Potassium‐Ion Batteries

open access: yesRare Metals, Volume 45, Issue 4, April 2026.
ABSTRACT The utilization of carbonaceous anodes in electrochemical systems, particularly potassium‐ion batteries (PIBs), remains hindered by sluggish kinetics and modest capacities, which are caused by the intrinsic ion storage mechanisms and constrained interlayer spacings.
HaiSong Chen   +7 more
wiley   +1 more source

Analysis of Mechanical Behavior and Anti-overturning Stability of Ramp Bridge [PDF]

open access: yes, 2017
匝道弯桥线型优美、适应性强,广泛应用于城市道路交通建设中。然而,较小的曲率半径也容易引发一些病害事故,例如支座脱空,梁体侧移,预应力筋崩出,甚至梁体倾覆等。为了分析匝道弯桥的受力性能,同时找出这些问题产生的主要原因以及作用规律,本文以厦门实际匝道弯桥为背景,通过有限元建模进行了研究分析。 首先,运用有限元软件建立不同曲率半径以及不同支座布置形式的多座预应力匝道弯桥实体模型,分析它们在多种荷载工况下的受力性能,研究引起匝道弯桥发生支座脱空、梁体爬移、预应力筋崩出等病害的原因。有限元分析结果表明 ...
裘是
core  

MXene‐Based Materials Contribute Better Alkali Metal–Chalcogen Batteries: Progress, Challenges, and Perspectives

open access: yesRare Metals, Volume 45, Issue 4, April 2026.
ABSTRACT Alkali metal–chalcogen batteries (AMCBs) are one of the most promising next‐generation energy storage systems because of their high energy density and reasonably low cost. However, the practical application of AMCBs is severely hindered by the volume expansion of the chalcogen cathode, the shuttle effect of polychalcogenides, and unstable ...
Yong Liu   +11 more
wiley   +1 more source

Design and Implementation of Positioning System for Fireman Based on ZigBee [PDF]

open access: yes, 2015
近年来火灾的次数呈几何倍数增长,很多消防员都在救火中失去生命。房屋的倒塌、烟雾引起的窒息、烧伤等都是严重威胁生命安全的因素。很多火灾场面十分凄惨,房屋倒塌的瞬间,消防员根本无力自救,如果没人帮助他们,只能看着一个个鲜活的生命瞬间离去。当前消防员只是依靠呼救器来实现救助,在实际的火灾中,呼救器存在很多弊端,无法判断消防员的位置。很多科学家都在研究,怎样才能在浓烟滚滚和烟火中锁定消防员的位置,并能够实现全程监控,这就能够及时的进行援助和救助,这对保障消防员生命安全有着重要的意义 ...
林群
core  

Improving the Electrochemical Properties of SiOx/Graphite Anode for High‐Performance Lithium‐Ion Batteries by Ultrathin Lithium Film Prelithiation

open access: yesRare Metals, Volume 45, Issue 4, April 2026.
ABSTRACT High‐capacity SiOx/graphite (SiO/G) anodes offer great potential for advancing lithium‐ion battery technology; however, their practical application is limited by low initial coulombic efficiency (ICE) and rapid capacity decay. These challenges primarily arise from unstable phase transitions and the formation of the solid electrolyte interphase
Wan‐Xing Zhang   +14 more
wiley   +1 more source

Home - About - Disclaimer - Privacy