Results 41 to 50 of about 25,073 (140)

棒形抗折试条的统计强度

open access: yesDianci bileiqi, 1980
本文研究了具有内部微观结构缺陷的瓷件在单轴向应力状态下强度的维布尔分布,给出δu=0情况下决定维布尔参数的一个图解方法。根据维布尔分布导出抗折瓷件在一定可靠性下极限应力下限值的计算公式,并比较了按维布尔分布和按正态分布计算的在相同可靠性下瓷件极限应力下限值的结果,结果表明按维布尔分布计算的下限位偏于安全。
马功勋, 刘长荣, 陶增炎
doaj  

Improving efficiency in conservation planning by modeling species‐specific responses to threat abatement

open access: yesConservation Biology, EarlyView.
Abstract Reversing ongoing biodiversity loss requires effectively managing anthropogenic threats. Although conservation actions can mitigate these threats, prioritizing and targeting such actions remain challenging because species respond differently depending on the nature of the threats and their biological traits.
Camila Guerrero‐Pineda   +3 more
wiley   +1 more source

Comparative species distribution model framework for marine conservation and its application to loggerhead turtles in the Mediterranean

open access: yesConservation Biology, EarlyView.
Abstract Modeling species distributions in dynamic pelagic environments remains challenging, particularly for wide‐ranging and highly mobile species when there is limited guidance on model performance. This limitation constrains the effective use of species distribution models (SDMs) in marine conservation, where robust and transferable predictions are
E. Pasanisi   +32 more
wiley   +1 more source

合成绝缘子表面电压和场强计算

open access: yesGaoya dianqi, 2003
利用表面电荷法对绝缘子表面的电压分布和场强进行了计算,研究了影响电压分布的某些因素,如均压环、伞裙对电压分布的影响。计算表明,合成绝缘子的电压分布特性与瓷质绝缘子有很大不同,其电压分布非常不均匀,高压端承受了更高的电压。伞裙和均压环均能改善电压、场强分布,但合成绝缘子均压环对电压分布均匀性的改善不如瓷质悬式绝缘子。
郭效金
doaj  

Subspecies taxonomy reflects social and geographic patterns of taxonomic effort in tetrapods

open access: yesConservation Biology, EarlyView.
Abstract Subspecies have been used in conservation biology to account for intraspecific patterns in genetic diversity, which is crucial to long‐term population viability. Although over 3200 subspecies are currently assessed by the International Union for Conservation of Nature Red List, their biological relevance remains controversial.
Jhonny J. M. Guedes   +3 more
wiley   +1 more source

A Systematic Scoping Review of Self‐Regulated Learning With AI in Language Education

open access: yesInternational Journal of Applied Linguistics, EarlyView.
ABSTRACT The rapid development of artificial intelligence (AI) technology has brought new opportunities for second/foreign language (L2) education while also raising concerns about the use of AI tools. This systematic scoping review provides a snapshot of the current state of research situated at the intersection of self‐regulated learning (SRL) and AI
Zheng Zhang, Sihan Zhou, Barry Bai
wiley   +1 more source

避雷器电位分布及温度分布无线检测系统

open access: yesDianci bileiqi, 2018
电位分布及温度分布情况是对避雷器健康运行进行评价的重要指标,直接关系到整支避雷器的运行寿命,在无均压措施的情况下,将导致老化速度加快,甚至发生热崩溃。对避雷器的电位分布情况进行测试是对避雷器进行均压的首要条件,但传统检测手段均为基于有线光纤方式进行电位分布采集。本项目基于高性能AVR微处理器,便携式单片微型计算机采样,无线通信,同步采样分析等手段,成功研制了避雷器电位分布及温度分布无线检测系统。对避雷器电位分布及温度分布情况以无线同步方式进行测试,避免了测试现场繁琐的光纤布线 ...
李佳奇   +5 more
doaj  

Asymptotic distribution of the product of trimmed sums(一类截断部分和乘积的渐近正态性)

open access: yesZhejiang Daxue xuebao. Lixue ban, 2007
对于取值为正的独立同分布且平方可积的随机变量X1,X2,…且有连续的分布函数,令Mn = max{X1,X2, …,Xn},对某固定常数a>0,令,截断和Tn(a)= Sn — Sn(a),在X的分布满足中尾分布的条件时,截断和Tn(a)的乘积为渐近对数正态.
ZOUHai-lian(邹海连)   +1 more
doaj   +1 more source

Co‐Teaching in a Virtual Intensive Study Language Programme: Insights From Team Ethnography

open access: yesInternational Journal of Applied Linguistics, EarlyView.
ABSTRACT As virtual study abroad becomes an increasingly important form of international education, little is known about how transnational teaching is organised and sustained across institutions. Using activity theory as an analytical framework and team ethnography as methodology, this study examines a virtual intensive study (VIS) programme delivered
Zhu Hua   +7 more
wiley   +1 more source

阿克苏拜城天山区盘羊和北山羊的分布与种群资源现状

open access: yes野生动物学报, 2010
根据2008~2009年实地考察研究结果,着重就该区2种有蹄类动物的分布、种群数量以及有关问题作概要性探讨。调查研究结果表明:(1)老虎台盘羊分布区盘羊平均密度=8.49/8=1.06只/km2,黑英山盘羊分布区盘羊平均密度=5.34/3=1.78只/km2。整个分布区盘羊种群数量1 488只,其中,老虎台分布区种群数量=480×1.06=509只,黑英山分布区种群数量=550×1.78=979只。(2)老虎台北山羊分布区北山羊平均密度=14.59/5=2.92只/km2 ...
阿布力米提·阿布都卡迪尔   +5 more
doaj  

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