Results 91 to 100 of about 18,258 (182)

共线平动点中心流形上的轨道转移问题

open access: yesKongjian kexue xuebao
圆形限制性三体问题共线平动点附近的平动点轨道由于其独特的动力学特性, 在深空探测任务中有着重要价值, 这些轨道间的轨道转移问题值得进行系统性研究. 针对平动点轨道的计算与延拓, 提出了一种基于数值的系统性计算平动点轨道的方法以及状态伴随法的轨道稳定维持策略. 在此基础上, 通过对大量平动点轨道不变流形以及平动点相空间中心流形的研究, 设计了一套通过脉冲机动实现平动点轨道间轨道转移的系统性解决方案. 该方法充分利用平动点动力学特性, 在仿真验证中证实了方案的有效性, 为平动点轨道转移研究提供了新的思路.
杨 富涛, 张 汉清
doaj   +1 more source

Establishment of hydrodynamic model and research on motion simulation of open-frame ROV [PDF]

open access: yes
ObjectiveManeuverability is one of the most important performance characteristics of a Remotely Operated Vehicle (ROV), and is closely related to its dynamics model. To realize the precise control and maneuverability of an open-frame ROV, a dynamic model
Chaohe CHEN   +3 more
core   +1 more source

A Multifunctional Reducing Molecular Dopant for 16% Efficient Tin Perovskite Solar Cells

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT Although lead‐based photovoltaics have seen remarkable progress, tin‐based perovskite solar cells (Sn‐PSCs) continue to face challenges due to their limited power conversion efficiency and insufficient operational stability. The primary cause of this performance gap is the susceptibility of Sn2+ to oxidation, which promotes rapid defect ...
Xianyong Zhou   +12 more
wiley   +1 more source

Numerical Study on the Environment of Shenhu and Quanzhou Bays [PDF]

open access: yes, 2007
本文以福建中部的两个半封闭的海湾——深沪湾和泉州湾为研究对象,通过数值模拟的方法再现了当地的潮汐潮流,浅滩干湿变化,污染物的输运,百年一遇的台风过境引起的增水现象和台风生成的波浪特征,在此基础上进一步探讨了不同动力机制对当地泥沙动力特性的影响。 结果发现:福建沿岸的潮汐潮流以规则半日潮为主,由于潮差较大,一些浅滩、湿地和暗礁在低潮时会露出水面,在高潮时又重新被海水淹没,形成周期性的干湿变化过程。模拟结果还显示:当天文分潮由外海传入海湾时 ...
刘浩
core  

Tailoring Spin States of CuNNi3 via d‐d Orbital Coupling for High Performance Water Splitting

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT Against the backdrop of escalating global energy crises and environmental challenges, the development of clean and sustainable hydrogen energy has become increasingly imperative. Hydrogen production via water electrolysis is widely regarded as a promising approach due to its green and efficient characteristics.
Weigao Zhong   +6 more
wiley   +1 more source

Conservation Status, Decline Factors, and Strategies for Globally Endangered Musk Deer (Moschus spp.) in China 中国境内全球濒危麝属 (Moschus spp.) 物种的保护现状、致危因素及应对策略

open access: yesWildlife Letters, Volume 4, Issue 1, Page 42-55, March 2026.
This review summarizes the status of musk deer in China, highlighting severe population declines due to illegal hunting and habitat loss, and proposes integrated conservation strategies including habitat protection, captive breeding, and law enforcement to support the recovery and sustainable management of this ecologically and economically important ...
Feng Jiang   +8 more
wiley   +1 more source

海底边界对水下管线的水动力影响 [PDF]

open access: yes, 1989
本文叙述了在定常流中,用平板模拟海底平面边界,在雷诺数R_e为4.0×10~3~1.5×10~5范围内,测量了孤立圆柱和离平板不同距离上的单柱的阻力(C_D)、升力(C_L)、上抬力(C_(LO))等水动力系数和响应频率f。研究了管道距平板边界的相对间距H/D(H为圆柱与平板之间的间距;D为圆柱直径 ...
凌国灿, 李战华, 鄂学全
core  

Landscape Composition and Proximity to Water Affect American Badger Occupancy in Shortgrass Prairies 景观组成和与水的距离影响矮草草原中美洲獾的占域率

open access: yesWildlife Letters, Volume 4, Issue 1, Page 23-31, March 2026.
American badgers, a medium‐sized carnivore occurring in much of North America, are important predators in prairie landscapes though our understanding of their habitat use requirements in these areas is unclear. We used a multi‐scale approach to understand American badger habitat use at both local and landscape scales.
Colleen W. Piper   +5 more
wiley   +1 more source

直流断路器快速电磁机构分合特性研究

open access: yesGaoya dianqi, 2016
文中基于某轨道交通直流断路器的总体结构模型,设计了一种快速电磁操动机构,对其结构和工作原理进行了阐述。基于电磁场分析理论,利用有限元分析软件ANSYS对电磁机构的静态特性进行了仿真分析,得出了在合闸状态下磁场分布和动铁心所受电磁吸力情况,并对其影响因素进行了分析。然后对电磁操动机构在不同电流条件下的电磁吸力随气隙变化进行了仿真分析,得出了机构空载条件下的动态输出插值数据。最后建立直流断路器动力学分析模型,借助动力学分析软件ADAMS,将建立的动态离散数据导入其中,对直流断路器动态分合特性进行了仿真 ...
王海燕   +5 more
doaj  

钢塔斜拉桥地震反应特性分析

open access: yesJianzhu Gangjiegou Jinzhan, 2020
针对一个实际钢塔斜拉桥工程,采用有限元软件SAP2000进行了动力特性和地震反应分析,并以主塔为混凝土塔的苏通大桥作为参照,对斜拉桥的动力特性、主塔地震反应和抗震性能等进行了比较分析。结果表明:相对于混凝土塔,钢桥塔的刚度和质量较小,轴压比略大,斜拉桥纵飘和主塔侧弯振型周期较长,主塔重力几何刚度对桥梁动力特性的影响较大,从而显著增大了塔顶及主梁的纵向地震位移,但对主塔及其基础的地震内力影响较小。钢塔斜拉桥的抗震性能较好,在7度地震区,地震作用不会控制钢塔及其基础的结构设计。
朱家豪, 叶爱君, 韩大章, 华新
doaj  

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