Results 61 to 70 of about 28,511 (200)

不同材料双层结构全瓷冠的三维有限元分析

open access: yesZhongguo shiyan zhenduanxue, 2021
目的研究不同组分的双层结构全瓷冠的应力分布,以指导临床方案设计和选材。方法建立下颌第一磨牙双层结构全瓷冠的三维有限元模型,对下颌第一磨牙沿牙体长轴方向垂直和水平施加401.4N的最大咀嚼力,获得不同组合全瓷冠的应力云图,并分析各个组分的应力分布情况,计算不同材料组合的双层全瓷冠的应力值。结果加载应力主要作用在饰瓷层,基底瓷和基牙受材料弹性模量影响较小;饰瓷-基底瓷界面和粘接剂界面应力受不同材料弹性模量影响较大;受颊向侧向力时应力集中区有向颊侧边缘转移的趋势,且基牙及各界面应力较垂直加压时急剧增加 ...
潘颖菁, 陈振宇, 黄达鸿
doaj  

Biodiversity‐driven spatial conservation planning to delineate temporally stable regions

open access: yesConservation Biology, EarlyView.
Abstract The accelerating loss of biodiversity underscores the critical need for effective conservation strategies, particularly in the face of climate change and anthropogenic pressures. We devised a conservation planning framework that adopts a temporal stacking approach to species distribution models and landscape connectivity analyses. These models
Mattia Iannella   +5 more
wiley   +1 more source

基于混合硬化模型的超高压泵头体自增强研究

open access: yesShiyou jixie, 2015
超高压泵头体自增强分析需要准确描述材料的硬化行为和包辛格效应。在推导出混合硬化弹塑性本构关系的基础上,将开发的子程序UMAT应用于某型超高压泵头体的液压自增强弹塑性有限元分析中。提出了以节点塑性应变增量的变化情况来判断自增强残余应力是否导致反向屈服的方法。通过分析自增强压力与自增强泵头体工作时最大等效应力的关系,得出该型泵头体的最佳自增强压力。泵头体最佳自增强压力的确定应以自增强残余应力不发生反向屈服为前提,以最大工作内压作用下等效应力峰值最小为原则。研究结果表明 ...
李宁   +4 more
doaj  

Defining and identifying relevant stakeholders to advance effective conservation

open access: yesConservation Biology, EarlyView.
The challenge of defining stakeholders in environmental science and an approach for refining existing definitions. Abstract Stakeholder is a contested term that has spawned a multitude of ad hoc definitions. The ambiguity of these definitions has oftentimes impeded transdisciplinary research in environmental governance and conservation science because ...
Milan Büscher   +5 more
wiley   +1 more source

Drivers of bat researchers’ intent to adopt field hygiene practices

open access: yesConservation Biology, EarlyView.
Abstract Infectious disease is a growing threat to wildlife, with zoonotic transmission most likely at the human–wildlife interface. One underappreciated activity at this interface is fieldwork with wild animals, but associated risks can be mitigated through field hygiene (FH) practices, such as using personal protective equipment and other appropriate
Joanna L. Coleman   +6 more
wiley   +1 more source

Spatial identification of areas suitable for other effective area‐based conservation measures in the European Union

open access: yesConservation Biology, EarlyView.
Abstract Although significant biodiversity has been safeguarded by protected areas (PAs), biodiversity trends continue downward. Within the frameworks of the EU Biodiversity Strategy for 2030 and the new EU Restoration Regulation (2024), conserving critical biodiversity areas is essential.
George Kefalas   +14 more
wiley   +1 more source

From Clueless to Confident: How ChatGPT Transforms Academic Writing in Chinese as a Second Language

open access: yesInternational Journal of Applied Linguistics, EarlyView.
ABSTRACT Generative artificial intelligence (GenAI) has demonstrated its potential to enhance the quality of second‐language (L2) academic writing. This study used a qualitative approach comprising analysis of ChatGPT usage‐history screenshots, written assignments, and semi‐structured interview data on students’ use of GenAI in their L2 Chinese ...
Lanfang Sun   +4 more
wiley   +1 more source

Iterative Self‐Branding: Chinese Language Teachers’ Understanding and Rationalization of Working on Online Tutoring Platforms

open access: yesInternational Journal of Applied Linguistics, EarlyView.
ABSTRACT Online tutoring platforms (OTPs) are an increasingly popular way for learners to study languages and for teachers to earn money. On many OTPs, individual teachers are responsible for attracting potential students via self‐branding. While scholarship has examined OTP teachers’ self‐branding practices and identified some of the most popular self‐
Wenjing Zeng, Nate Ming Curran
wiley   +1 more source

双侧沉管在水网地段应力分析及数值模拟

open access: yesShiyou jixie, 2015
为了研究水网地段管道在双侧沉管过程中受力变形的特性,基于有限元软件建立了管道沉沟模型,对不同深度的沉管过程进行力学模拟;同时根据管道下沟过程的受力变形特点,将模型简化成超静定梁,最终推导出不同深度管道最大应力公式。研究结果表明,在下沟过程中,管道上会出现2个应力峰值,当管道的自由端与沟底接触的瞬间管道的应力最大,管道最大应力位于沟上支点附近管道底部的内壁;管道截面上的应力呈8字形分布,截面顶端和底端出现应力峰值,且底端应力大于顶端;管道下沟可以简化超静定梁模型,应力大小与沉沟深度、管道规格密切相关 ...
王付会, 练章华, 林铁军
doaj  

Home - About - Disclaimer - Privacy