Results 21 to 30 of about 18,386 (242)
Abstract Prior disaster experiences often provide lessons for communities to respond to new disasters. In informal communities prone to disasters but conditioned within reactive disaster management regimes, residents and Community‐Based Organizations (CBOs) play immense roles in disaster risk reduction and response.
Stephen Kofi Diko+5 more
wiley +1 more source
Research on Force Transmission of the Artificial Hip Prosthesis and Osseointegration [PDF]
随着中国社会老龄化进程不断推进,由股骨头坏死、关节病变、骨折等原因产生的全髋关节置换手术量呈现逐年上升的趋势。 全髋关节置换手术利用人工髋关节假体置换病变的髋关节,假体一端与股骨髓腔装配,另一端与髋臼连接。人工髋关节假体置换失败的主要因素是影响假体近端骨整合的应力遮蔽,直柄假体与髓腔远端匹配度较低导致的假体无菌松动。 人工髋关节假体置换中的应力遮蔽、无菌松动等问题与假体的力传递特性密切相关。当假体上的力无法传导到股骨近端时,股骨近端将产生骨溶解,无法使假体与股骨形成良好的整合,假体在髓腔中的稳定性不足 ...
王爱民
core
Abstract The fifth edition of “Theories of the Policy Process” represents a further step in consolidating these theories. However, four of them—Advocacy Coalition Framework, Multiple Streams Framework, Narrative Policy Framework, and Punctuated Equilibrium Theory—exhibit a few limitations in light of the characteristics of implementation and policy ...
Giliberto Capano
wiley +1 more source
利用有限元的思想并结合有限谱法提出求解偏微分方程的有限谱有限元方法,在元素内部基函数使用有限谱基函数。将此方法应用于求解不可压缩Navier-Stokes方程,具体求解了二维方腔流顶盖驱动流,并与基准解对比获得了比较好的结果。A finite element method combined with the idea of finite spectral method was represented to solve the partial differential equations. In each
健 王
semanticscholar +1 more source
Towards a global understanding of tree mortality
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
与传统有限元不同,非均匀有理B样条(NURBS)几何精确有限元有机结合了计算机辅助几何设计和有限元分析方法,不仅可以有效消除几何离散误差,还非常容易构造整体高阶连续近似。本文利用NURBS有限元这一优点将其应用于对近似函数有C1连续性要求的薄梁板问题。文中详细讨论了NURBS基函数的构造和梁板结构的等效积分弱形式,并采用罚函数法将强制边界条件作为约束条件引入梁板弱形式,建立了NURBS有限元离散方程。该方法不引入额外变量,易于编程实现 ...
张汉杰, 王东东, 轩军厂
core
本文基于静力学原理,对系泊系统中的六个大部件进行了局部与整体的受力分析。列出了一系列物理学方程。并最终推导出了系泊系统的非线性微分方程模型。方程采用迭代法进行求解。根据锚链的结构,采用有限元方法中对应的结构方法。运用了非线性有限元方法进行计算,得出系泊系统的锚链方程。计算出锚链系统无抬升角限制的边界条件。对锚链进行了受力分析。使锚不会被轻易拖移,并且使钢桶尽量保持竖直的条件。找到了在风力、水流力的影响下,钢桶、钢管的倾斜角度、锚链形状、浮标的吃水深度和游动区域,以确保使系统稳定的条件。 Based on
苗帅, 吴健宇, 张荣荣, 张卓
semanticscholar +1 more source
Abstract Metacognitive regulation refers to learners’ ability to use a repertoire of metacognitive strategies to guide, observe, and manage thoughts, actions, and emotions in learning activities. It has been widely acknowledged as a significant predictor of language learning success, including writing.
Wandong Xu, Xinhua Zhu
wiley +1 more source
Finite Element Analysis for Maxwell's Eigenvalue Problems [PDF]
在微波工程中,波导和谐振腔都是十分重要的微波器件,这些微波器件广泛地用于 我们的现实生活中.在波导问题中,如果电磁波的频率给定,那么传播常数就是一个非常重要的物理参数.在谐振腔问题中,谐振频率是一个十分重要的物理参数.当波导横截面不规则或者填充有非均匀介质时,此时波导问题的解析解是很难找到的;当腔体的几何结构十分复杂或者填充有非均匀介质时,此时谐振腔问题的谐振频率的精确解也是很难找到的.但是我们往往需要知道这些微波工程器件的这些物理参数,所以通常采用数值方法去近似求解它们 ...
姜威
core
由于拉索内部的力学性能比较复杂,采用有限元方法进行拉索分析。对于钢绞线的有限元模型,目前多采用Solid164单元来进行建模,而对于半平行钢丝束拉索的有限元模型,目前多采用Pipe16单元来进行建模。该模型的特点是由短梁单元和弹簧单元组成。分别采用Pipe16单元和Solid164单元来建立拉索模型,分析了两种有限元模型的弯曲荷载-挠度曲线和拉索的有效弯曲刚度,并与试验数据进行了对比分析。结果表明,对于无预应力条件下,Pipe16单元的模型结果与试验数值误差比Solid164模型的要大 ...
马红旭+3 more
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