Results 41 to 50 of about 173,503 (241)
Research on the structure and properties of SiC ceramic containing titanium and boron [PDF]
, 2016 碳化硅（SiC）陶瓷具有高强度、高硬度、耐高温、抗氧化、抗化学腐蚀、低热膨胀系数、高热传导率等众多特点，不仅被广泛应用在功能陶瓷、高级耐火材料、磨料及冶金原料等民用领域，还应用于航空航天领域，用作发动机的热端部件。为了提高先驱体转化法制备碳化硅陶瓷的耐高温性和吸波性能，本文将钛、硼元素引入陶瓷先驱体中，利用二者高温下生成的二硼化钛作为SiC陶瓷的烧结助剂，提高SiC陶瓷的耐高温性能，并利用钛元素提高陶瓷的吸波性能，系统研究了钛硼的引入，陶瓷结构与性能的演变规律。 首先，固定先驱体中硼元素的含量 ...
李风萍
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Effects of parachute science on local research capacity 降落伞科学对当地研究能力的影响
Conservation 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
Zhongguo shiyan zhenduanxue, 2017 目前处于分娩期的女性和妇产科的医生们都把重心放在围生期女性盆底功能状态的研究上,尤其是怎么样才能快捷有效的对盆底功能障碍性疾病进行诊断[1]。盆底功能障碍性疾病主要包括压力性尿失禁、大便失禁、盆腔器官脱垂、性功能异常、便秘及慢性盆腔疼痛等。多种因素如肥胖、年龄、妊娠等都能导致女性盆底功能异常,其中妊娠和分娩造成的肛提肌组织破坏是最主要的因素[2]。
薛丹 +4 more
doaj
A link between increased temperature and avian body condition in a logged tropical forest
Conservation 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
Jianzhu Gangjiegou Jinzhan, 2010 设计钢管混凝土梁柱长圆孔变型性高强螺栓节点,上下节点板通过高强螺栓拼接连接钢管混凝土柱与钢筋混凝土梁,并引入长圆形螺栓孔以提高节点的延性变形性能。本文通过两个长圆孔变型性高强螺栓节点试件及两个传统焊接节点试件的低周反复加载试验,对不同连接方式节点在地震作用下的承载力、延性变形能力、耗能能力、滞回性能进行研究与对比。试验结果表明,螺栓节点满足节点承载能力,同时其延性性能好于传统焊接节点,节点的延性变形能力通过螺栓在长圆孔中的滑移有明显提高。与焊接节点相比较,最终两个长圆孔变型性螺栓节点发生延性破坏 ...
马人乐 +4 more
doaj
Surface Functionalization of Polymer Substrates through Radiation-Induced Graft Polymerization: Conventional and Controlled Polymerization Techniques [PDF]
, 2018 学位記番号 ...
Jordan F., Madrid +1 more
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Comprehensive framework for assessing and optimizing existing research networks
Conservation 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
Design and Implementation of Adaptive Optimization System for Web Server Resources [PDF]
, 2015 经研究发现目前Web服务器面临的数据处理在不断的叠加，但是自身的资源优化存在较大的问题和漏洞，本文提出了Web服务器资源自适应优化机制，该机制首先对影响Web服务器性能的相关因素进行分析。在此基础上确定性能评价指标，对这些指标进行实时监控，并根据监控数据对Web服务器性能做出评价。最后依据评价结果对系统资源做自适应调整，从而实现在各种工作负载条件下，Web服务器资源自适应优化功能，保证Web服务器高性能运行。 基于前面的工作，建立了Web服务器资源优化模型，该模型实现了三大功能：一是运行状态监控管理功能；
胡奎
core
Representation of obligate groundwater‐dwelling copepod diversity in European protected areas
Conservation 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
基于不同构造形式半刚性节点的人字形中心支撑钢框架低周往复荷载试验研究
Jianzhu Gangjiegou Jinzhan, 2021 为研究装配式中心支撑半刚接钢框架结构的抗震性能,选取三种便于装配化施工的半刚性梁柱螺栓节点,即带腹板耳板的顶底角钢连接、外伸端板连接和T形钢连接,设计了3榀人字形中心支撑半刚接钢框架试件,进行低周往复荷载试验,对结构的滞回曲线、承载能力、耗能性能和刚度退化进行了研究,并对比分析不同半刚性节点钢框架的性能优劣。试验结果表明:试件滞回曲线饱满,抗侧承载力高,具有稳定可靠的耗能性能和塑性变形能力;结构在水平往复荷载作用下有明显的屈服和破坏过程,整体呈现延性破坏的特征;结构的塑性变形和损伤破坏主要集中在支撑体系,
杨融谦, 周学军
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