Results 71 to 80 of about 18,258 (182)

Dynamic characteristics and damage model of freezing thawing red sandstone under impact load [PDF]

open access: yes
To study the dynamic mechanical properties and damage evolution characteristics of freeze-thaw rocks under impact loads, 0, 15, 30, 45, and 60 freeze-thaw cycle tests and dynamic impact tests were conducted on red sandstone in cold regions.
Huiming ZENG   +5 more
core   +1 more source

Laser‐Driven Halide Exchange and High‐Resolution Multicolor Patterning of Perovskite Films

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT Translating the excellent properties of metal halide perovskites (MHPs) into practical flexible optoelectronic devices requires high‐resolution multicolor patterning techniques that are compatible with post‐fabrication processing. However, such a capability has remained elusive.
Shu Yang   +6 more
wiley   +1 more source

126kV真空断路器新型磁力操动机构研究与设计

open access: yesGaoya dianqi, 2017
对比永磁操动机构,磁力机构具有出力大、行程长等优点,可用于中高压等级。在126 kV真空灭弧室研制成功的基础上,文中提出一种适用于126 kV单断口真空断路器的新型长行程磁力操动机构。利用Ansys仿真软件对126 kV磁力机构静态特性进行仿真设计,通过改变辅助永磁体排列方式、端盖封装方式增大了机构合闸保持力,采用增大合闸保持力的方法使机构分闸速度得到提高。分析了充电电容、线圈匝数等电气参数对磁力机构动态特性的影响,并在此基础上进行了参数优化。仿真结果表明,文中设计的126 ...
许家源   +6 more
doaj  

THE ANALYSIS OF FLOOR RESPONSE SPECTRUM IN EQUIPMENT-STRUCTURE INTERACTION FORM IN FREQUENCY DOMAIN [PDF]

open access: yes, 2006
直接从由建筑物和设备组成的主次结构耦合系统各自的动力特性出发,考虑主次结构间调谐、干扰、非经典阻尼等因素的影响,推导出频率传递函数和次结构的加速度均方根响应,并由此进一步得到楼层的加速度均方根反应谱。这一方法避免了求解联合系统的复特征值和动力方程出现病态等问题,大大简化了计算过程。最后在算例中就次结构的阻尼比、质量比、安装楼层及场地土等因素对楼层加速度均方根反应谱的影响进行了讨论,算例表明,质量比是决定能否采用古典谱的关键因素,场地土对反应谱的影响也不容忽视。Based on the dynamic ...
张建霖, 张灿辉, 杨安钦
core  

Current status and developing recommendations of tailings dam failure [PDF]

open access: yes, 2018
This is the final version of the article. Available from Hindawi Publishing Corporation via the DOI in this record.Tailings dam failure accidents with limited emergency response time and huge potential threats, can often lead to heavy casualties and ...
Bu, L   +4 more
core   +1 more source

Electronegativity‐Driven Frontier Orbital Engineering in B‐Ti Diatomic Synergy Enables Selective Li2C2O4 Conversion in Li‐CO2 Batteries

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT As a promising alternative to sluggish Li2CO3‐based Li‐CO2 electrochemistry, Li2C2O4 offers a favorable 2e− discharge pathway, yet its selective formation and reversible decomposition remain debated. Herein, we propose a nonmetal‐metal synergistic catalyst—B‐Ti coregulated layered transition metal boride Ti18B18O9/graphene (B‐Ti/TiBOG)—to ...
Qiong Peng   +8 more
wiley   +1 more source

短路冲击下低频风电变压器机械特性研究

open access: yesGaoya dianqi
低频风电变压器是海上风电用柔性低频交流输电系统的关键设备。为进一步了解低频变压器在短路冲击下的振动特性和受力特性,采用镜像法计算变压器绕组漏磁场,并建立了绕组轴向振动的非线性动力学模型,对一台5 000 kVA低频变压器在17 Hz和50 Hz下的短路冲击振动特性和受力进行了分析。研究结果表明,17 Hz下变压器绕组中的短路冲击电流、振动位移、轴向受力和辐向受力均小于50 Hz时的结果,但绕组振动特性基本相同;17 Hz下绕组垫块面积减小32.5%时垫块的最大压缩力应力与50 Hz时相同;17 ...
吴鹏   +4 more
doaj  

高压断路器运动特性仿真

open access: yesGaoya dianqi, 2003
根据高压断路器分闸运动原理,建立了高压断路器液压机构与压气室的联合运动方程。通过仿真,分析了运动方程中各种力参数对分闸运动特性的影响和操作功特性,并且从理论上提出了调节分闸运动特性的两种途径。
孙弋   +4 more
doaj  

按输出力特性曲线设计凸轮轮廓曲线

open access: yesGaoya dianqi, 2020
针对以往设计断路器弹簧操动机构均是先确定满足动触头速度特性的输出力特性;再根据所需输出特性按照功或功率相等的等效原则计算动触头各行程下的凸轮轮廓半径;最后拟合出凸轮轮廓曲线。文中以设计真空断路器弹簧操动机构上配备的摆动滚子从动件盘形凸轮合闸行程中的轮廓曲线为模型,在以往的设计方法上提出了利用速度瞬心和微积分原理求得凸轮轮廓曲线的方法,该方法解决了传统设计方法繁琐的重复计算,不仅能方便的得到满足输出力特性曲线的凸轮轮廓,并能快速得到凸轮上各行程的压力角 ...
程俊文   +4 more
doaj  

湍流度对二分裂新月形覆冰绞股导线气动力特性的影响研究

open access: yesGaoya dianqi, 2023
在研究覆冰输电导线风致舞动及其气动力特性时,必须考虑实际风场中的湍流强度。文中选取湿雪天气中易起舞的二分裂新月形覆冰绞股导线作为研究对象,通过风洞试验探究了湍流度变化对其气动力特性的影响。首先探讨了试验模型的绞股外形设计对于获取准确的气动力参数的重要性,然后制作了二分裂新月形覆冰绞股导线的刚性节段模型,并在不同湍流度下测量了该模型的气动三分力系数,并基于Den Hartog以及Nigol舞动机理对该模型的驰振稳定性进行了分析。结果表明:制作覆冰导线模型时设计绞股外形对于结果的准确性非常重要 ...
邹建章, 张丹丹, 张宇, 万智渝
doaj  

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