Results 31 to 40 of about 23,510 (147)

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  

Use of species’ responses to cryptic anthropogenic disturbances for monitoring biodiversity outcomes in tropical forests

open access: yesConservation Biology, EarlyView.
Abstract Measuring area‐based conservation outcomes in tropical forests is challenging due to cryptic human disturbances (e.g., hunting). As a result, comparative studies of management strategies providing quantitative outcomes remain scarce, especially in the Neotropics.
Lucy Perera‐Romero   +5 more
wiley   +1 more source

open access: yes野生动物学报, 1994
貉貉(NyctereutesProcxonoidesGray)属于食肉目犬科。主要分布于亚洲东南部。在原苏联分布在黑龙江流域、乌苏里江流域向北分布到萨哈林半岛。在中国分布在东北、华北、华中、华南和西南地区一直延伸到越南北部。在日本和朝鲜半岛也有分布。...
高犁为
doaj  

Evaluating past and future contributions of conservation programs to species recovery

open access: yesConservation Biology, EarlyView.
Abstract Impact evaluation of conservation actions is a crucial step in global efforts to curb the biodiversity crisis. Through robust impact evaluation, practitioners can assess the effectiveness of conservation strategies and optimize the use of limited resources.
Rebeca E. Young   +10 more
wiley   +1 more source

基于ART算法的运动阳极弧根电流密度分布重建研究

open access: yesGaoya dianqi, 2009
笔者提出应用ART算法根据测量得到的两个垂直方向上的弧根线性电流分布重建弧根电流密度分布的方法。对Drouet M G实验测量的弧根在2个互相垂直方向的电流分布进行计算,获得了2-D弧根电流密度分布并加以讨论。结果表明,ART重建算法结合分离极板法所测的弧根电流分布是获得其电流密度分布的一个切实可行而有效的途径。
徐铁军, 荣命哲, 吴翊, 马强
doaj  

Effects of parachute science on local research capacity 降落伞科学对当地研究能力的影响

open access: yesConservation Biology, EarlyView.
Abstract Strengthening research capacity is essential to address the global biodiversity crisis. Yet, parachute science often undermines this goal, and its prevalence, costs, and benefits are unclear. We analyzed 13,502 publications on primate research that we extracted from Scopus (1960–2022) to evaluate the effects of parachute science on local ...
Li Yang   +11 more
wiley   +1 more source

Research on Face Load Distribution for Narrow Helioal Gears

open access: yesJixie chuandong, 1994
本文用三维边界元程序计算了窄斜齿轮在不同接触线上的载荷分布,分析了齿轮齿面载荷的分布规律。同时还计算出齿轮副的平均刚度kn1和载荷分布系数Kβ计算结果表明荷载分布规律与轴向重合度εβ及传动比有关,载荷分布系数Kβ在1.04至1.23之间。
王宪法
doaj  

A link between increased temperature and avian body condition in a logged tropical forest

open access: yesConservation Biology, EarlyView.
Abstract The combined effects of anthropogenic disturbances, such as logging and climate change, remain poorly understood; yet, they are the main threats to tropical biodiversity. Most tropical African countries lack long‐term climate data, so climate impacts on biodiversity cannot be assessed.
Moreen Uwimbabazi   +7 more
wiley   +1 more source

中国降雨侵蚀力R值的计算与分布(I)

open access: yesShuitu Baochi Xuebao, 1995
对中国降雨侵蚀力R值的计算与分布进行了系统研究。主要内容包括R指标的确定;次降雨R失真、R值以及多年平均R值的简易计算方法;我国不同地区年R值的月分布、次分布、频率分布和年际变化特征,以及R值的雨量、雨强分布特征;对我国140多个重点站的R值进行了计算;在分析我国降雨侵蚀力R值区域分布特征的基础上,编制了中国降雨侵蚀力等值线图,进行了降雨侵蚀力分区。
王万中 张宪奎
doaj  

Distribution, scale, and drivers of mass mortality events in Europe's freshwater bivalves

open access: yesConservation Biology, EarlyView.
Abstract Mass mortality events (MMEs) are decimating populations and compromising key ecosystem functions around the globe. One taxon particularly vulnerable to MMEs is freshwater bivalve mollusks. This group has important ecosystem engineering capacities and includes highly threatened and highly invasive taxa.
Daniel A. Cossey   +39 more
wiley   +1 more source

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