Results 21 to 30 of about 10,256 (170)

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

The Research of MiRNA-Disease Correlation Prediction [PDF]

open access: yes, 2016
MiRNA是一类重要的非编码RNA,它在许多的生命活动中扮演着非常重要的角色。经研究证实,miRNA与disease的产生有着密切的联系。本文主要基于生物异构网络和机器学习的方法对miRNA-disease关系进行分析与预测。主要包括以下几个方面的内容: (1)本文详细介绍了当前已提出的miRNA-disease关联预测的主要方法,并且对比了不同方法之间的差异,为生物信息研究人员后续对miRNA-disease关联分析和预测的研究提供参考。现已提出的miRNA-disease关联分析和预测方法 ...
李金金
core  

Comprehensive framework for assessing and optimizing existing research networks

open access: yesConservation Biology, EarlyView.
Abstract Conservation, monitoring, and research networks, or collections of ecological research sites unified under a common mission of data collection or a research mission, are essential infrastructure for understanding large landscapes. However, most networks developed opportunistically over decades rather than through systematic design, creating ...
Alyson East   +2 more
wiley   +1 more source

TCP - HY :Improving TCP Performance in Hybrid IP Network [PDF]

open access: yes, 2007
摘 要:在混合网络环境下,由于数据包传输的非时序性以及在传输过程中相对较高的误码率, TCP 的传输效率极大地被 降低了。对此,提出了一种新的TCP 改进版本: TCP - HY,它能够有效解决数据包延迟以及高误码率的问题。试验表明,TCP - HY在混合网络环境中能够大大提高TCP 的效率,充分利用有效带宽,是一种优秀的解决方案。Abstract :In hybrid network environment ,since the package often disordered during ...
徐航宇, 罗键
core   +1 more source

Representation of obligate groundwater‐dwelling copepod diversity in European protected areas

open access: yesConservation Biology, EarlyView.
Abstract Groundwaters sustain diverse surface ecosystems and are populated by metazoan species, mostly invertebrates, that provide fundamental ecological functions and are often of prominent conservation value due to narrow endemism and high phylogenetic rarity.
Francesco Cerasoli   +7 more
wiley   +1 more source

试验回路布置对变电站地网冲击特性测试的影响

open access: yesDianci bileiqi, 2020
开展地网冲击特性测试需搭建冲击放电回路,试验回路布置的差异会对地网冲击特性测试产生较大影响。在分析现有接地装置冲击试验系统构成的基础上,搭建试验回路对110 kV变电站地网进行了现场试验,研究了注流点对地网冲击特性的影响,并通过仿真计算研究了回流点对地网冲击特性的影响。试验结果表明,试验回路中注流点、回流点的选择会明显影响地网电位分布和电流的大小。在雷电冲击下地网高电位区域会集中在注流点附近,远离注流点的区域地网电位分布较均匀,注流点附近区域的地网散流变化大,远离注流点区域的地网散流较平均。仿真结果表明,
黄佳瑞   +4 more
doaj  

Design and Implementation of the Online Course Learning System for a College [PDF]

open access: yes, 2016
随着科技的进步和社会竞争的日益加剧,学习已经成为人们日常生活中不可缺少的一部分。当前人们的学习方式有很多种,如何更有效地学习知识、如何将被动学习转化为主动学习已经成为一个重要问题。选择有利于自己的学习方式进行学习,能够有效地提高自己的学习效率。一定程度上有利于提高学习效率,节约人力物力,同时加强人与人之间的学习交流与互动。 本课题根据师生的网上学习需求,采用J2EE技术架构,分为三个不同的处理层:表示层、业务逻辑层、数据层来完成网上课程学习系统。表示层由JSP和Web页面构成 ...
蒋晓琳
core  

Harnessing social media data to track species range shifts

open access: yesConservation Biology, EarlyView.
Abstract Biodiversity monitoring programs and citizen science data remain heavily biased toward the Global North. Especially in megadiverse countries with limited biodiversity records, incorporating social media data can help address existing data gaps.
Shawan Chowdhury   +15 more
wiley   +1 more source

圆环地网与方形地网冲击特性对比仿真

open access: yesDianci bileiqi, 2013
为了更好的解决接地网散流、均压以及降阻问题,对圆环形接地网的均压特性及接地电阻进行了研究,并与传统的方形地网进行比较,采用电磁暂态仿真程序(ATP)对不形状的接地网,在雷电冲击作用下的电压大小进行仿真,以及对同一地网雷电流入地点不同时,入地点处的电压大小进行了仿真分析。结果分析表明:周长相同的圆环形地网与方形地网相比,圆环形地网的接地电阻比方形地网的小,并且雷电流入地点处的电压只有方形地网的一半左右,散流效果比方形地网好。在同跨度下,圆环地网的跨步电压也明显小于方形地网,均压效果好 ...
杨廷方, 张航, 陈智翔, 罗星辰
doaj  

基于地电位均布的共享铁塔接地网设计方案

open access: yesDianci bileiqi, 2022
共享铁塔中移动基站的接地标准较为苛刻,需要对传统输电铁塔接地网进行改造以满足基站接地要求。笔者采用场路结合的方法,对接地导体进行分段处理,计算各分段导体的自电阻和互电阻,推导了共享铁塔接地网地电位的求解公式,进而判断接地网地电位的均匀程度。参照现有电力与通信的接地标准,提出了共享铁塔接地网的设计思路以及4种设计方案。计算结果表明,网状结构加垂直接地极的接地网设计方案可保证地电位分布最均匀,最大地电位梯度相比于简单扩大接地网面积的设计方案降了43.83%。
匡宇来   +4 more
doaj  

Home - About - Disclaimer - Privacy