Results 11 to 20 of about 22,433 (139)

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

Technical design and applied implementation on massive rater spatial database engine which based on CORBA(基于CORBA技术的海量栅格空间数据库引擎的设计与应用)

open access: yesZhejiang Daxue xuebao. Lixue ban, 2007
自主设计了海量栅格空间数据库的逻辑模型和物理模型,实现将海量栅格数据存储于大型商业关系型数据库中;提出了基于CORBA(Commoh Object Request Broker Architecture)技术的海量栅格空间数据库引擎四层体系结构,并在此基础上给出运行实例,取得了良好效果,证明了自主栅格空间数据库引擎的可行性.
WANGNa(王娜)   +3 more
doaj   +1 more source

Study on the Mechanical Property of the “Turning” Structure System in Tall Buildings [PDF]

open access: yes, 2008
“扭转体型”的高层建筑,由于其独特的几何形状给建筑的立面处理带来新意,近些年已有一些工程案例。众所周知,结构是建筑赖以存在的物质基础,与这种“扭转体型”建筑相配合的结构体系的抗侧力性能,是工程上关心的问题之一,然而国内外这方面的报道甚少。本文采用计算机数值模拟的方法,建立起扭转体型结构的计算模型,分析了不同荷载形式下结构受力和变形情况,并与框架结构形式进行了比较。研究分析表明,这种结构形式主要是由斜柱的轴力来抵抗水平荷载,属轴力体系范畴,并具有高效的抗侧力性能。在相同荷载作用下 ...
智平
core  

An experimental approach to assess the combined effects of multiple stressors on a large vertebrate species

open access: yesConservation Biology, EarlyView.
Abstract The design of experiments to investigate the combined effects of multiple stressors requires exposing target organisms to multiple combinations of stressor doses. Concurrent manipulation of stressors is often infeasible with wildlife, but long‐lasting health effects allow individual health to be used as an integrator of prior stressor exposure.
Enrico Pirotta   +24 more
wiley   +1 more source

红细胞输注无效与意外抗体关系:基于观察性研究的meta分析

open access: yesZhongguo shiyan zhenduanxue, 2022
目的 系统评价红细胞输注无效与输血次数、妊娠次数、有无意外抗体和有无IgG型抗体的关系,为预防红细胞输注无效的发生提供循证医学证据。方法 meta分析。检索国内外重要数据库,收集存在输血史、妊娠史和含有意外抗体、IgG型抗体的患者产生红细胞输注无效的相关文献,并按照纳入标准和排除标准筛选文献,提取数据,通过固定效应模型合并I2检验,绘制森林图来评估输血次数、妊娠次数、有无意外抗体和有无IgG型抗体与红细胞输注无效的关系。结果 经过筛选,共检索8篇中英文文献符合本文标准,共计17750例患者 ...
李鑫阳   +4 more
doaj  

Effects of landscape context on avian specialist response to increased surface temperature in protected areas

open access: yesConservation Biology, EarlyView.
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

ENERGY SAVING TECHNOLOGY STUDY ON EXISTENT DWELLINGS IN NANJING AREA [PDF]

open access: yes, 2002
高校博士点资金资助项目 ,编号 :1999028622;; 江苏省建设委员会和江苏省墙体改革办公室资助项目 ,批文号 :苏建科(1998 ...
彭小云, 彭昌海, 王波, 邰惠新
core  

Perceived costs as drivers of wildlife management preferences in rural Tanzanian communities

open access: yesConservation Biology, EarlyView.
Abstract Effectively managing human–wildlife interactions is crucial for fostering coexistence on shared landscapes. Management options are most effective when aligned with the preferences of people directly affected by wildlife, yet little is known about how socioecological factors influence these preferences.
Christian Kiffner   +10 more
wiley   +1 more source

混合式风电塔架的强度折减系数概率谱模型

open access: yesJianzhu Gangjiegou Jinzhan, 2023
为提高风电塔架的抗震性能,提出了考虑耗能时序的混合式风电塔架的概念,重点研究了结构抗震设计与评估的关键指标——强度折减系数。利用等效单自由度体系表征具有三线性滞回特征的新型塔架,并基于不同周期和滞回参数组成的变量矩阵,以320条近场地震动作为激励对等效单自由度体系进行了大量非线性动力分析,获取了3 600万个强度折减系数。强度折减系数均值对结构周期及滞回参数敏感,故基于对比研究选取的对数正态分布概率模型,通过多轮非线性回归分析建立了一系列预测方程,从而实现强度折减系数概率谱模型的建立 ...
李红, 柯珂
doaj  

Gallery structure design of one instructional laboratory building in one high school [PDF]

open access: yes, 2007
通过对某中学教学实验楼连廊结构设计的介绍,重点讨论了连廊屋盖结构选型和优化分析以及特殊的支座处理方式,为同类建筑结构设计提供参考借鉴。According to the introduction of gallery structure design of one instructional laboratory building in one high school,it discusses the roof structure selection,optimum analysis and the ...
郭娟娟
core  

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