Results 41 to 50 of about 13,177 (167)
ABSTRACT Water security in tropical regions faces escalating pressures from climate change, land‐use shifts, and population growth. We conducted a bibliometric review of 1146 peer‐reviewed articles (1964–2023) on tropical water security. Latent Dirichlet Allocation identified 13 thematic topics and their evolution. Publications rose sharply after 2012,
Karling Fernanda Schuster +3 more
wiley +1 more source
Modification of the Optical Polarization in High Al-Content AlGaN [PDF]
相比于传统紫外光源(如汞灯和氙灯),AlGaN半导体紫外光电子器件具有无汞污染、波长可调、体积小、集成性好、耐高温、抗辐射以及能耗低、寿命长等优点,在工业、农业、国防和医疗卫生等领域都有着广阔的应用前景和巨大的市场需求。然而,由于高Al组分AlGaN材料中存在诸多问题,例如外延生长困难、p型掺杂率低、发光偏振特性独特等等,导致深紫外波段器件的发光效率普遍较低,制约了深紫外发光器件的发展与应用。本论文采用第一性原理的计算模拟方法,围绕AlGaN材料中的光学偏振特性及其调控开展了系统的研究工作 ...
季桂林
core
ABSTRACT This theoretical article examines the dynamics of stability and change in public policy coalitions using the Advocacy Coalition Framework as a foundation. We focus on how intra‐coalition and inter‐coalition coordination serves as a causal factor influencing the stability of coalition composition and the mobility of actors over time, especially
Dyego Alves da Silva +2 more
wiley +1 more source
为了更好地研究直流电压下油纸绝缘系统针板电极局部放电的电荷分布特性,文中基于流体动力学扩散—漂移方程和双极电荷传输方程搭建仿真模型用以模拟空间电荷的分布,研究了电荷产生的和流注发展的过程与放电特性,得到了局部放电过程中电荷,电场和电势的发展趋势。研究表明:油纸绝缘针板电极的局放过程分为流注击穿油隙与电荷在纸板上积累两个阶段,油隙的击穿过程中,流注头部的电场强度与净电荷密度会不断增加,形成自持放电;当流注到达绝缘纸板表面并在纸面积累电荷,将形成屏蔽层,导致流注的电场分布与电荷分布减弱,逐渐形成零电场区域 ...
姚竣严 +4 more
doaj
ABSTRACT The escalating issue of drug‐resistant pathogens, largely driven by the overuse of conventional antibiotics, has become a significant global health threat. Developing alternative therapeutic strategies and fabricating natural biological enzyme materials that mimic the high efficiency, selectivity, and mild‐operating conditions of natural ...
Shuai He +11 more
wiley +1 more source
体外循环应用于心内直视手术已有20多年的历史。但目前通用的体外循环机是以恒流血液注入动脉,不符合正常的循环生理。因此,要提高心脏手术的水平,需寻找一种更接近生理的灌注技术。根据人类心脏产生的血流灌注是一种搏动性灌注的原理,我们把我院研制的助搏器应用于体外循环手术,目的是使血流变为搏动性 ...
林志华
doaj
Development and Optimization of a Cylindrical Laminated Methanol Steam Reforming Microreactor with Porous Metal as Catalyst Support [PDF]
摘要 以低碳醇为燃料的制氢微反应器可为燃料电池等微小型电子装置提供安全可靠的在线氢源,从而引起世界各国研究者的广泛关注。本文以多孔金属材料为载体,设计制造了一种新型层叠式柱形甲醇水蒸气重整制氢微反应器,可获得较佳的制氢效果。论文主要研究内容如下: (1)载体结构甲醇水蒸气重整制氢微反应器设计 利用Solidworks软件设计了一种新型层叠式柱形甲醇水蒸气重整制氢微反应器。其中蒸发腔设计栅板结构,可有效增强反应溶液的汽化效果以及重整腔入口流体分布的均匀性。载体板采用多孔金属材料,降低加工成本 ...
张军鹏
core
Gathering Intelligence for Robust Crisis Governance: A Literature Review and Research Agenda
ABSTRACT The COVID‐19 crisis has highlighted the critical role and challenges of information processing during turbulent times. While expert knowledge can reassure citizens, it may also seem exclusive, and government communication often risks being overwhelming or unclear.
Chiara Russo
wiley +1 more source
【目的】探讨体外循环中低流量肺动脉灌注对肺功能影响的作用机理。【方法】体质量18-22kg的杂种犬10只,随机分为对照组(n=5)和肺灌注组(n=5)。常规建立体外循环。肺灌注组用氧合血30mL/(kg·min)灌注肺动脉。分别于转流前,停体外循环即刻,转流后1h,转流后2h采集数据,计算氧合指数、肺动态顺应性。检测肺静脉血丙二醛(MDA)、超氧化物歧化酶(SOD)、细胞间黏附分子1(ICAM-1)和P选择素。【结果】转流后肺灌注组犬的肺动态顺应性和氧合指数明显高于对照组(P〈0.05 ...
周成斌 +5 more
doaj
GaAs/AlAs タジュウ リョウシ イド コウゾウ ニオケル キャリア ブンプ ノ セイギョ ト チュウセキガイイキ サブバンドカン センイ エレクトロルミネッセンス ニ カンスル ケンキュウ [PDF]
博士(工学 ...
堂本, 千秋
core

