Results 11 to 20 of about 36,289 (215)

Experimental study on mix proportion of transparent similar materials for rock mass [PDF]

open access: yes, 2023
Traditional rock mass is opaque and the internal deformation and fracture process cannot be observed directly, using transparent materials to make similar models is an effective solution.
Binyu LUO   +4 more
core   +1 more source

Comprehensive Error Model and Experimental Research of Large Aperture Optics Measurement Platform [PDF]

open access: yes, 2015
大口径高精度光学元件,特别是非球面光学元件,已经广泛应用于航空航天、天文及惯性约束聚变(ICF)激光装置等国家重大工程中,特殊的工作环境对光学元件的面形精度和表面质量均提出了很高的要求。在制造过程中,为了达到各项技术参数的要求,非球面光学元件必须经过反复检测,并将检测得到的面形精度信息反馈到加工系统中,以指导下一步加工工序的修正和补偿。为了使大口径光学元件检测平台的测量信息能够准确地指导加工,对大口径光学元件检测平台的精度提出了更高的要求。 本文以所在课题组自行研发设计的“大口径光学元件检测平台 ...
王詹帅
core  

PARAMETER OPTIMIZATION AND EXPERIMENTAL RESEARCH ON THE HAMMER MILL 锤片式粉碎机参数优化与试验研究

open access: yesINMATEH Agricultural Engineering, 2020
Low productivity and high electricity consumption are considered problems of the hammer mill, which is widely used in current feed production. In this paper, the mechanical properties of corn grain ground by a hammer mill were analysed, and the key ...
Di Wang   +5 more
semanticscholar   +1 more source

When and why to give shorebirds a head start

open access: yesConservation Biology, EarlyView.
Abstract Headstarting is a translocation technique involving the hatching or rearing of wild eggs or young in captivity and the release of those individuals back to the wild at or before independence. It has been trialed as a conservation intervention for shorebirds over recent decades to improve the population trend of target populations by increasing
Lynda Donaldson   +4 more
wiley   +1 more source

Tianshui's Three Treasures: Water and Soil Conservation in Wartime Northwest China [PDF]

open access: yes, 2019
In addition to examining how wartime imperatives shaped the agricultural research, demonstration, and extension programs undertaken by the Nationalist government’s Tianshui Water and Soil Conservation Experiment Area (the Experiment Area) after its ...
Muscolino, Micah S
core  

Effects of political identity activation and inaccurate metaperceptions on attitudes toward wolves

open access: yesConservation Biology, EarlyView.
Abstract Polarization between groups can undermine durable conservation outcomes. Activating group identities (i.e., an individual's sense of self derived from membership in a group) can exacerbate differences, especially when people hold inaccurate perceptions of their peers and rivals.
Alexander L. Metcalf, Justin W. Angle
wiley   +1 more source

Nonlinear finite element analysis for seismic performance of high-strength concrete beam-column joints with new reinforcement details [PDF]

open access: yes, 2006
Because the factors that affect the behavior of the beam-column joints are complicated, an experimental study alone is not sufficient. Therefore, a nonlinear finite element analysis was conducted to provide better understanding of the performance of the ...
Gan, L, Li, J, Pam, HJ
core  

Using incentive payments to promote human–carnivore coexistence

open access: yesConservation Biology, EarlyView.
Abstract For many large carnivores, minimizing the financial burden they impose on local people is critical to their conservation. Incentive‐based programs that provide people with financial benefits for taking pro‐conservation actions or achieving conservation goals are a promising tool for promoting human–carnivore coexistence. Although the number of
Adam Pekor   +9 more
wiley   +1 more source

Key Techniques and Applied Research on Engineering Vehicles' Noise Reduction, Energy Saving and Acoustic Comfort [PDF]

open access: yes, 2016
当前,噪声已经成为衡量工程机械装备性能的一个重要指标。市场要求越来越高,相关的国家标准、国际标准日益严格。随着大功率产品的不断发展,整机噪声随之增加和热流密度不断提高,过低的冷却空气流量已满足不了发动机的热平衡要求,整机工作热流密度与逐渐降低的噪声限值的矛盾日益突出。同时,随着人们生活质量和品质追求的提高,整机声学舒适性也逐渐备受关注,对噪声的控制由最初的满足限值要求将转向声学舒适性的研究。因此,我国工程机械要发展并跻身世界市场,必须解决整机存在噪声偏大、热流密度高和声学舒适性差的共性问题 ...
张恩来
core  

岩样水力射流孔眼轨迹特性试验研究

open access: yes工程技术与管理, 2020
针对在水射流孔工艺过程中孔眼轨迹特性不明确的问题,搭建试验流程,采用不同岩样和多种水泥石开展水力喷射试验。根据经济钻速和试验结果,测试相关岩样的抗压强度和可钻性级值,确定水射流工艺适用岩样抗压强度范围和可钻级值范围。通过测量井眼轨迹,分析孔眼在水平和竖直方向的轨迹特性,提供轨迹特性曲线,为该技术的进一步研究和水射流井身设计提供依据。
勇 陈, 辉 张
semanticscholar   +1 more source

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