Results 61 to 70 of about 12,629 (167)

An integrated DIC and CPG investigation of the model-I fracture features for granites after cyclic heating-cooling treatments [PDF]

open access: yes
The thermo-mechanical properties of deep reservoir rocks, especially the damage and failure characteristics under heating-cooling cycles, are of great importance to the stability analysis of well wall and the evaluation of geothermal extraction ...
Gan FENG   +5 more
core   +1 more source

Realizing the Enhanced Electromagnetic Wave Absorption and Self‐Cleaning Pollution in BaFe12O19 Composite

open access: yesRare Metals, Volume 45, Issue 1, January 2026.
ABSTRACT With increasing complex requirement in organic pollution environment, the development of actual electromagnetic wave (EMW) absorbers with high EMW absorption performance and self‐cleaning pollution function is becoming a significant challenge.
Shou‐Hang Lv   +8 more
wiley   +1 more source

棒形悬式复合绝缘子压接结构耐温特性研究

open access: yesDianci bileiqi, 2012
复合绝缘子端部金具和芯棒装配的压接式工艺是靠金具和芯棒间的形变应力产生的静摩擦力承担机械强度。金具和芯棒二者之间的材质不同,热膨胀系数也不同,当受热后金具和芯棒的形变也随之改变,因此,理论上说受热对压接强度有一定的影响。笔者通过对比试验得出:一定范围内的温度变化对压接式复合绝缘子的性能没有影响。
侯建峰, 马西武, 金强
doaj  

土壤渗透性的区域变化规律及因子分析

open access: yesShuitu Baochi Xuebao, 2019
通过应用数据挖掘和数据整合方法,以建立我国土壤渗透性数据库,并对影响土壤渗透性的各因子综合分析,揭示土壤渗透性的区域变化规律。结果表明:(1)土壤渗透性呈现明显的区域性变化,表现为西南地区 < 华北地区 < 东北地区。西南地区土壤渗透力最差,稳渗速率对数值为-0.5~-2.0;华北、东北地区整体数值均在0.5以上,土壤渗透力较强。(2)在影响土壤渗透力的各因子中,气候类型及林龄通过影响植被来间接改善土壤渗透力;植被能有效提升土壤渗透力,但不同植被类型间土壤渗透力并无显著差异;随土层深度的增加 ...
丁海晶, 姜姜, 张金池
doaj  

Study on induced mechanism of slurry splitting deviation and diffusion in long hole grouting near faults [PDF]

open access: yes
Affected by complex hydro-geological conditions, mine production is facing serious water hazards, with water inrush and sudden water accidents occurring from time to time.
Lianchong LI   +4 more
core   +1 more source

复合绝缘子伞套间粘接结构性能

open access: yesDianci bileiqi, 2005
为了确保伞套间粘接性能,选用特制的粘合剂,采用半机械化套粘伞裙装置,把自动打磨好内口表面的,与护套采用过盈配合的,按内外绝缘强度差1倍所确定内口长度的伞裙套粘在护套上以保证伞套间粘接部位实现硅氧烷分子交链完全,补强剂颗粒表面羟基及分子间范德华力利用充分,没有较大的填充剂颗粒存在的界面,使界面具有较高的机械强度和良好的绝缘性能。伞套间的过盈配合在相应部位所出现的弹变,因其体形网状分子结构中和硅氧烷分子螺旋状态的存在,其蠕变性能极为缓慢,应力松弛现象几乎不存在,伞套间粘接性能是可靠的。
张福林, 段旻
doaj  

硅橡胶绝缘高压电缆附件的老化特性研究

open access: yesGaoya dianqi, 2023
为研究高压电缆附件绝缘在电、热和环境等多因素作用下的老化特性,文中以6种退役硅橡胶绝缘高压电缆附件样品为研究对象开展工作。采用SEM、FTIR和XRD分析了不同运行环境下样品的理化特性和微观分子结构变化,通过介电测试和表面电位衰减测试获得了样品宏观介电性能和微观电荷特性,采用拉伸实验获得了绝缘样品的力学性能数据,最后结合上述表征对电缆附件的绝缘和老化状态进行评估。结果表明硅橡胶附件老化过程中以Si-O主链降解为小分子为主,小分子物质进一步发生氧化和重结晶反应,导致分子的交联度下降和极性增强 ...
景巍巍   +7 more
doaj  

Experimental study on the effect of the angle of the shaped charge tube on the penetration enhancement of coal seam blasting [PDF]

open access: yes
In order to solve the problem of poor permeability enhancement effect caused by disorderly expansion of coal cracks in traditional presplitting blasting, the influence of different opening angles of shaped charge blasting cartridge on permeability ...
Guodong QIAO   +5 more
core   +1 more source

考虑偏心的发电机绕组振动与绝缘损伤研究

open access: yesZhendong Ceshi yu Zhenduan
针对振动作用下发电机绕组绝缘断裂损伤机理与偏心故障影响机制尚未明确的问题,提出考虑静态偏心故障的绕组绝缘损伤分析方法。首先,建立理论模型,对偏心前后的绕组电磁力与绝缘断裂情况进行解析;其次,构建有限元分析模型并进行电磁场分析,验证偏心前后的电磁力分布、幅值及频率变化;然后,进行结构场仿真,揭示绝缘应力分布与裂纹扩展情况;最后,通过实验来验证理论模型与有限元分析结果。结果表明:在正常情况下,各绕组所受电磁力基本相同;发生偏心故障后,气隙减小(增大)处绕组电磁力增大(减小 ...
doaj   +1 more source

影响福建省水土流失导因子的研究

open access: yesShuitu Baochi Xuebao, 2000
影响水土流失的因素众则复杂,以福建省为研究区域,在闽西北,闽中,闽东,闽西南和闽东南5个地区共建立了442个样区,应用数量化理论Ⅰ,分析样区的土壤侵蚀强度与植被覆盖度,植被结构,土地利用类型,坡度,母岩类型和工程措施及有机质,质地,分用率和降雨侵蚀力R值等的关系,结果表明:影响福建省水土流失的主导因子为植被覆盖度、工程措施、降雨侵蚀力R值、土地利用类型,坡度和有机质6个主导因子,另外 ...
黄炎和 蔡志发
doaj  

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