Results 41 to 50 of about 7,480 (167)
Using online reports of seahorse seizures to track their illegal trade
Conservation Biology, Volume 39, Issue 5, October 2025.Abstract Illegal wildlife trade (IWT) is a persistent and extensive threat to global biodiversity. Hundreds of marine fish species are subject to regulation under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), but it is unclear how much protection species gain from CITES because information on marine fish ...
Sarah J. Foster +3 more
wiley +1 more source
Automatic Grid Generation of CAD for Gear Reducer Housing
Jixie chuandong, 1994 本文针对齿轮减速机ＣＡＤ过程中箱体类复杂板块组合结构有限元强度分析的特点，提出了基于等参数变换法的三维有限元组合网格自动生成方法，其特点是可将大型复杂结构自动离散为不同单元组成的网格，且可避免过渡单元，特别适用于复杂板块组合结构的有限元分析。
程燕青
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Efficient Quadrature-Based Superconvergent Isogeometric Analysis with Macro-Integration Cells and Applications [PDF]
, 2017 摘要 等几何分析采用计算机辅助几何设计中的非均匀有理B样条(NURBS)基函 数进行几何建模和计算分析，实现了几何建模和有限元分析的无缝衔接。由于 NURBS基函数具有高阶连续性和非负性等性质，在进行动力分析时具有突出优 势，例如基于高阶质量矩阵的超收敛等几何频率分析方法。但是，高阶质量矩阵 虽然能够实现频率超收敛计算，但具有波动方向依赖性，即在进行多维波动问题 分析时不能同时提高各阶频率的收敛率，同时多维情况下其数值实现也不够便捷。 本文基于二次等几何基函数 ...
梁庆文
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Integrative Conservation, Volume 4, Issue 3, Page 322-333, September 2025.A content analysis of 154 nature education lesson plans from China showed that educators designed diverse programs tailored to age‐specific developmental and social needs. Most focused on personal growth, such as cognitive development, mental well‐being, and family bonding, but few explicitly addressed environmental conservation goals.
Yue Li, Danning Lu, Xin Yu, Chuan Liao
wiley +1 more source
Sexuality, Gender &Policy, Volume 8, Issue 3, August 2025.ABSTRACT Spanish universities are currently applying different protocols designed to facilitate name and/or gender changes in the documentation of trans, nonbinary, and intersex individuals in their education communities in compliance with the legislation in force. These policies aim to address the discrimination experienced by these people in everyday
Lucas Platero +3 more
wiley +1 more source
齿轮可靠度计算的概率有限元法——第Ⅰ部分:基于齿根弯曲疲劳强度的计算
Jixie chuandong, 1992 本文结合概率有限元法与齿轮的疲劳强度理论,提出了一种预测齿轮疲劳强度可靠性的新方法。该方法的提出既解决了将概率有限元法应用于复杂结构的疲劳强度可靠性分析问题,又使齿轮的疲劳强度可靠性预测在现有水平上得以提高。本文以齿轮的齿根弯曲疲劳强度可靠性分析为例,给出了概率有限元法计算可靠度的方程与解法。算例的计算结果与实际应用情况十分相近。
吴立言, 刘更, 王步瀛
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Study on pollution incidents backward tracking model [PDF]
, 2017 由于人类活动，近岸海域常出现污染事件，破坏了自然环境。预防和治理海洋污染是可持续发展和生态文明建设必不可少的环节。面对突发性污染事件，找出污染源是根治问题的重要关键。本文尝试利用数值模型方法来解决污染事件的溯源问题。目标模型能够根据污染物当前的浓度分布信息，还原污染物的迁移过程，进而判断出污染源的位置。 有别于研究污染物去向的正问题，污染事件溯源问题是反问题，通过在时间上反向求解对流扩散方程获得数值解。本文中的反问题求解方法采用高斯滤波方法，通过对浓度通量场进行过滤，以消除计算中的不稳定成分 ...
刘迪诗
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Towards a global understanding of tree mortality
New Phytologist, Volume 245, Issue 6, Page 2377-2392, March 2025.Summary Rates of tree mortality are increasing globally, with implications for forests and climate. Yet, how and why these trends vary globally remain unknown. Developing a comprehensive assessment of global tree mortality will require systematically integrating data from ground‐based long‐term forest monitoring with large‐scale remote sensing.
International Tree Mortality Network +114 more
wiley +1 more source
Gaoya dianqi, 2001 本文给出了一种求解悬浮电位的有限元算法 ,并利用它对二维电场 （平面场 ,轴对称场 ）的悬浮电位进行了求解。通过与现有的有限元计算软件相比较 ...
刘春, 李震彪, 张铁, 邹积岩
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Improved NURBS-based Isogeometric Finite Element Analysis with Enhanced Treatment of Essential Boundary Conditions and Strain Smoothing Sub-domain Integration [PDF]
, 2010 几何精确非均匀有理B样条（NURBS）有限元法把计算机辅助几何设计（CAGD）中的NURBS几何构形方法和有限元方法有机结合起来，有效消除了有限元离散模型的几何误差，提高了计算精度。然而在几何精确NURBS有限元分析中，由于NURBS基函数的非插值自然特性，一般强制边界如果采用控制变量直接施加的方法，结果可能产生较大的求解误差且不能达到最佳收敛率。 本文提出了一种改进的几何精确NURBS有限元强制边界条件处理方法，即变换法。与无网格法近似不同 ...
轩军厂
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