Results 141 to 150 of about 66,434 (223)
在大型建筑楼宇电气系统中,需要设置电涌过电压保护器(SPD),对雷电或者其他瞬时过压的电涌进行保护。传统的建筑电气SPD电压保护装置采用本机振荡幅度调制的SPD电压保护器设计,但该设计装置会产生电涌过载失真,误差补偿性能。提出一种基于电压增益分配均衡处理的大型建筑电气SPD电压保护方法。进行了建筑电气SPD电压保护系统的等效电路设计,在SPD电压保护等效电路分析的基础上,构建SPD电压保护电力控制功率放大器,对SPD电压保护中出现较大偏差进行电磁耦合补偿 ...
李林琛
doaj
Application of hysteroscopy in female fertility preservation. [PDF]
Zhang L, Feng L.
europepmc +1 more source
Abstract Human development is a driver of global change and a major threat to biodiversity. Protected areas maintain and support biodiversity, but outside stressors, such as climate change and land use change, can negatively influence natural resources within protected areas.
Leah J. Rudge +2 more
wiley +1 more source
半波长交流输电线路输送距离长、电压等级高,呈现出明显的分布参数特性,传统的继电保护原理不再适用。文中提出了一种高灵敏度、低灵敏度相配合的贝瑞隆差动保护改进算法,保护半波长交流输电线路的全长。其中低灵敏度贝瑞隆差动,用于保护半波长线路区内两端区域短路故障。高灵敏度贝瑞隆差动,用于保护半波长线路区内中间段区域短路故障。基于电磁暂态仿真软件PSCAD搭建特高压半波长输电线路仿真模型,并对提出的保护算法进行了大量的仿真实验。结果表明,低灵敏度贝瑞隆差动保护可以保证区内两端区域保护快速性 ...
陆金凤 +4 more
doaj
Protective effect of borneol on the cutaneous toxicity of gilteritinib. [PDF]
Zhou Y, Yin Y, Huang X, Hu Y, He Q.
europepmc +1 more source
Abstract Achieving global conservation policy goals requires the ability to set and measure progress toward science‐based targets for biodiversity. The species threat abatement and restoration (STAR) metric was developed to enable actors to set science‐based targets for species.
Louise Mair +17 more
wiley +1 more source
在防雷保护的实际应用中,针对同一种被保护系统往往会有许多不同保护方案,这些方案在防护性能和成本等方面都存在着较大差异,这对我们选用方案带来了很多的困扰。为了在众多AC220V电源口保护方案中选出一种最佳保护方案,选取了行业常用的两种AC220V电源端口保护方案,首先讨论了两种保护方案本身所选器件的优缺点,然后对比分析了两种保护方案各自的耐压能力以及在标准测试条件和极限测试条件下的残压情况。结果表明:在差模和共模保护中,同时使用压敏电阻与GDT串联的保护方案在安全性、稳定性等方面都存在着明显的优势 ...
许斌 +4 more
doaj
Biodiversity‐driven spatial conservation planning to delineate temporally stable regions
Abstract The accelerating loss of biodiversity underscores the critical need for effective conservation strategies, particularly in the face of climate change and anthropogenic pressures. We devised a conservation planning framework that adopts a temporal stacking approach to species distribution models and landscape connectivity analyses. These models
Mattia Iannella +5 more
wiley +1 more source
Defining and identifying relevant stakeholders to advance effective conservation
The challenge of defining stakeholders in environmental science and an approach for refining existing definitions. Abstract Stakeholder is a contested term that has spawned a multitude of ad hoc definitions. The ambiguity of these definitions has oftentimes impeded transdisciplinary research in environmental governance and conservation science because ...
Milan Büscher +5 more
wiley +1 more source

