Results 11 to 20 of about 10,712 (195)
Dianci bileiqi, 2022 特高压直流输电工程中,避雷器组在限制过电压过程中要吸收大量的能量,部分位置避雷器组的吸收能量设计容量达到30 MJ,需要大量电阻片组成上百柱并联进行分流,随之出现了部分电阻片老化较快率先损坏导致避雷器组故障的问题。为提升大规模多柱并联避雷器组运行可靠性,提出了基于避雷器组中各电阻片吸收能量均衡的配组算法。首先探讨了ZnO电阻片伏安特性分散性机理及统计规律,提出了配组算法流程,并根据实际避雷器组案例进行模拟计算。结果显示,经过迭代计算配组后的避雷器组在限制过电压过程中吸收能量分布更加均衡 ...
刘志远 +6 more
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Evaluation on crashworthiness and energy absorption of composite light airplane [PDF]
[[abstract]]The main aim of this study was to explore the safety differences when using aluminum alloy and three different fiber reinforced composites as material for the cockpit and fuselage of light aircraft under crash landing.
Pu-Woei Chen
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Research of Image Acquisition and Data Management System in Tooth Cleaning Laser Machine [PDF]
, 2006 随着生活水平的提高，口腔健康教育宣传的开展，越来越多的人意识到洁牙的重要性。目前，临床上大多数医院采用超声波洁牙，但它工作时所发出刺耳的声音，会给患者造成一种心理上的恐惧感。激光清洗技术作为一项新兴清洗技术，已成为传统清洗方法的补充和延伸，因其固有的优点，而在工农业生产、科研、医疗、国防建设等方面得到广泛的应用，激光洁牙设备将成为现代牙科必不可少的工具。与超声波洁牙等技术相比，激光洁牙属于非机械接触，不存在超声波洁牙所具有的振动噪声，不易损伤牙齿表面釉质，不损伤周边组织。按现有的牙科医疗器械 ...
陈春华
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Dianci bileiqi, 2021 110 kV并联电容器装置具有单组容量大、电压等级高的特点,而其结构形式和运行工况又与传统并联电容器装置有所区别,因此研究其避雷器参数合理选取原则对于提高其经济性和安全可靠性具有重要意义。以特高压工程110 kV/240 MVA并联电容器装置为研究对象,对其正常分闸重击穿以及单相接地故障情况下单相重击穿时出现的过电压水平进行了理论分析,并在此基础上建立了避雷器吸收能量仿真模型,仿真分析了各种重击穿情况下避雷器的吸收能量以及运行工况对避雷系吸收能量的影响规律,最终提出了最严重工况下避雷器吸收能量的选取建议:
何慧雯, 尹婷, 马跃, 王子建
doaj
Experimental study on dynamic response and residual compressive strength of composite sandwich panel with PVC foam core under single-point low-velocity impact [PDF]
ObjectivesIn this paper, an orthogonal braided glass fiber composite sandwich panel with a PVC foam core and dimensions of 150 mm×100 mm×26 mm is selected as the research object in order to study the impact mechanical properties of composite sandwich ...
Chongyi CHEN +6 more
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Impact resistance performance of rockbolt system with(out) rubber cushion energy absorbing and buffering components [PDF]
The practice of impact resistance support in dangerous roadways has shown that energy absorbing and buffering components can improve the impact resistance performance of rockbolt support systems. A rubber cushion layer was used as an energy absorbing and
Fuqiang GAO +8 more
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Rare Metals, EarlyView.ABSTRACT Rare earth elements (REEs) play an irreplaceable role in modern technology and industry. However, due to the highly similar physicochemical properties among REEs, their separation remains a significant challenge. Additionally, REEs often exist in low‐concentration solutions, making efficient REE recovery an urgent task.
Miao‐Miao Huang +6 more
wiley +1 more source
, 2018 为摩托车头盔的安全性设计,需要研究在冲击载荷下内衬泡沫的能量吸收能力对摩托车头盔防护性能的影响。该文建立了有限元数值分析头盔模型,依据欧洲经济委员会(ECE)的法规ECE R22.05的动态测试方法,验证该模型的有效性。改变头盔不同测试点下的泡沫密度,进行了12个跌落的仿真试验。结果表明:在头盔的前部、冠部和后部测试点区泡沫密度由40 kg/m3增加到80 kg/m~3时,泡沫的能量吸收能力逐渐增大,头部冲击能量衰减得更快,导致3个测试点头部颅骨骨折的风险从25%、55%、39%分别增大至53%、96%、
何伟 +4 more
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Rare Metals, EarlyView.ABSTRACT The development of high‐performance electromagnetic protection materials integrating broadband absorption and effective shielding capabilities is hindered by challenges in simultaneously optimizing multiple electromagnetic properties through conventional material designs.
Changlong Du +9 more
wiley +1 more source
Shuitu Baochi Xuebao, 2006 采用^15N-尿素进行盆栽和田间试验，研究了复合氮肥增效剂用量、尿素与复合氮肥增效剂配施对水稻生长、籽粒产量和氮素吸收利用的影响。结果表明，适宜用量（施氮量的20％）的复合氮肥增效剂能显著促进水稻幼苗生长发育；尿素全量配施复合氮肥增效剂不影响水稻生长，能显著提高水稻植株Ndff％、氮吸收总量，氮素利用率和^15N的吸收量,尿素减量5％～15％（即减少施氮7．8～23．7kg／hm^2）配施复合氮肥增效剂基本上不影响水稻生长、籽粒产量和吸氮总量，能显著提高氮素的农学效率、生理效率和氮素利用率；植株吸氮总量、
田秀英, 王正银
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