Results 31 to 40 of about 13,315 (169)

渤海海峡跨海通道地壳稳定性调查评价研究进展 [PDF]

open access: yes, 2016
中国地质调查局立项开展的渤海海峡跨海通道地壳稳定性的调查评价是重大涉海工程前期的基础性工作,该项目在收集已有成果资料的基础上,对渤海海峡区域进行了系统的地球物理勘测与研究,分析了灾害地质类型, 甄别出了主要的活动断裂,开展了渤海海峡及邻区的外围地震活动性和地壳层析成像研究,并进行了地应力、微震实地长期监测 ...
赵铁虎, 赵铁虎 齐君
core  

Assessing differences among elasmobranch nurseries to aid conservation based on a genomics framework

open access: yesConservation Biology, EarlyView.
Abstract Elasmobranch nurseries often differ in environmental conditions, demographics, and use patterns. These differences affect the distribution of genetic variation among nurseries. However, conservation and management strategies often fail to account for such differences because they are difficult to characterize.
Dominic G. Swift   +8 more
wiley   +1 more source

Q460高强钢焊接H形柱轴心受压力学性能数值分析

open access: yesJianzhu Gangjiegou Jinzhan, 2013
为了考察国产Q460高强钢焊接H形柱的轴心受压力学性能,对6个已有焊接H形柱的轴心受压试验进行了数值分析。数值分析采用作者编制的数值积分法电算程序和通用有限元软件ANSYS。以考虑了实测初始挠度、初始偏心及简化残余应力分布的数值模型,计算Q460高强钢焊接H形柱轴心受压的极限承载力与荷载-挠度曲线。发现数值积分法与有限单元法所计算试件的荷载-挠度曲线基本重合。为了验证数值模型的准确性,将数值分析结果与已有试验结果进行对比;并通过对比简化残余应力分布模型与实测残余应力分布对试件极限承载力、荷载 ...
王彦博   +3 more
doaj  

基于多物理场的预置式(插拔式)海底电缆终端电场优化研究

open access: yesGaoya dianqi, 2020
电缆终端电场分布优化研究是海底电缆安全运行和试验迫切需要解决的问题,为提高其运行的安全性与可靠性,可对电缆终端电场分布进行优化。文中基于有限元法对海底电缆终端电场进行多物理场耦合研究分析,综合考虑终端实际运行环境及实际生产情况,采用电流—温度—电压仿真法对电缆主绝缘及应力锥绝缘部分材料进行优化分析,同时对应力锥金属部分曲率及应力锥金属与绝缘部分比例分配进行优化,寻求终端电场分布的最优化。结果表明:采用与电场、温度相关的非线性材料对终端电场分布很大改善,应力交界点电场强度降低幅度为25.83 ...
谢晨   +5 more
doaj  

A FEM-DEM Coupled Multiscale Analysis Method for Study of Mechanical Behaviors of Concrete [PDF]

open access: yes, 2017
混凝土是一种多相复合材料,由于材料非均匀各向异性的特点,其力学性能十分复杂,但作为建筑结构中最广泛使用的材料之一,研究能够可靠高效分析其力学行为的数值模拟方法有非常重要的意义。有限元法(FEM)目前主要集中于对混凝土宏观力学行为的模拟,但是由于基于连续介质力学假设,对混凝土开裂后细观力学性能的分析较为困难。离散元法(DEM)虽然对于混凝土的细观开裂和局部破坏有较好的模拟效果,但是由于计算耗时过大,限制了其在工程问题的应用范围。因此,本文想开发一种结合两者优点的数值模拟方法 ...
刘轲奇
core  

Analysis on characteristics of coal-rock gas dynamic disasters based on stress grading action mechanism [PDF]

open access: yes
With the gradual depletion of shallow coal resources, coal mining in China gradually extends to the deep. With the increase of buried depth, the stress state will change and the type of stress field will also change, which makes the internal stress ...
Aitao ZHOU   +5 more
core   +1 more source

Emerging applications of large language models in ecology and conservation science

open access: yesConservation Biology, EarlyView.
Abstract Large language models (LLMs) mark a major development in artificial intelligence, with potentially transformative implications for ecology and conservation science. Built on advanced deep‐learning architectures, these models can support a wide range of tasks. We reviewed emerging applications of LLMs, drawing on the wider scientific literature
Christos Mammides   +5 more
wiley   +1 more source

内压作用卧式采油树油管挂承载能力研究

open access: yesShiyou jixie, 2014
利用ABAQUS有限元软件建立了油管挂三维简化模型,研究开口对应力分布及承载能力的影响,将出油口直径与壁厚进行比较,分析不同出油口直径和壁厚配置对应力分布的影响。建模时将油管挂简化为具有大尺寸侧开口的内压圆筒,采用20节点2阶六面体单元划分网格。分析结果表明,开口内径比对承载性能的影响呈先降低后回升的趋势,其作用机理在于小直径开口对局部应力突变影响较大;侧向开口增加局部应力,导致应力分布不均匀。
唐彪   +5 more
doaj  

高压大截面电缆和金具短路电动力的电磁——结构耦合有限元分析

open access: yesGaoya dianqi, 2023
高压大截面电缆运行电流大,发生短路故障时产生的短路电动力大大高于普通电缆,更容易造成缆体和固定金具的损伤,威胁输配电安全。为了分析高压大截面电缆短路电动力对缆体和金具的影响,文中建立了330 kV高压大截面品型垂直蛇形敷设电缆的电磁—结构耦合有限元模型,使用Maxwell瞬态电磁场分析法计算出电缆的短路电动力体密度分布;采用顺序耦合法将电动力体密度耦合至结构场计算出电缆金具的应力分布;对缆体磁场分布、受力时变特性及金具的应力分布进行了分析。结果表明,缆体短路电动力的幅值随时间周期性衰减 ...
牛冲宣   +5 more
doaj  

A Systematic Scoping Review of Self‐Regulated Learning With AI in Language Education

open access: yesInternational Journal of Applied Linguistics, EarlyView.
ABSTRACT The rapid development of artificial intelligence (AI) technology has brought new opportunities for second/foreign language (L2) education while also raising concerns about the use of AI tools. This systematic scoping review provides a snapshot of the current state of research situated at the intersection of self‐regulated learning (SRL) and AI
Zheng Zhang, Sihan Zhou, Barry Bai
wiley   +1 more source

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