Results 31 to 40 of about 8,329 (169)

雷电冲击电压下串联双空气球隙击穿现象研究

open access: yesGaoya dianqi, 2021
文中将两个球—球气隙串联,模拟双断口断路器模型,串联的两个气隙承受标准雷电冲击电压(1.2/50μs),空气间隙击穿照片由相机拍摄。实验结果中的击穿现象可分为3种类型,将只有上球隙或下球隙被击穿定义为击穿类型Ⅰ;串联双球隙的非同期击穿定义为击穿类型Ⅱ;串联双球隙的同期击穿定义为击穿类型Ⅲ。进一步研究发现,3种击穿类型的成因与上下间隙的电场强度分布有关,上间隙最大场强与下间隙最大场强之比在6.9~1.52和0.8~0.2之间表现为击穿类型Ⅰ和击穿类型Ⅱ,在1.5~1.52和0.7~0 ...
李秀广   +7 more
doaj  

Anaerobic respiration and its influence on the carbonate system in estuarine sediment [PDF]

open access: yes, 2015
海洋是大气CO2重要的汇。自工业革命以来,海洋吸收的人为CO2已导致表层海水中的自由氢离子浓度升高了26%,海水pH降低了0.1个单位,同时,水体溶解无机碳(DIC)和HCO3-浓度升高,CO32-浓度降低,海水碳酸盐系统对CO2的缓冲能力降低。碱度(TA)的高低是海水对pH变化起缓冲作用的重要因素,一般地说,TA越高,则海水碳酸盐系统的缓冲能力越强。 每年通过河口输入海洋的DIC大致相当于全球海洋吸收大气CO2量的20%,与同时入海的TA一起对海洋碳酸盐系统产生重要影响 ...
胡玲
core  

On the Damage Tolerance of Diffusion Bonded Titanium–Aluminum Phase Biomimetic Composites

open access: yesRare Metals, Volume 45, Issue 2, February 2026.
ABSTRACT The biomimetic design principles of natural structures involve the strategic integration of stiff and compliant phases to synergistically enhance strength and toughness. Its evolutionary refined natural armor, characterized by a specialized microarchitecture, enables superior damage tolerance.
Shuai Tong   +10 more
wiley   +1 more source

220kV绝缘子并联间隙的防雷保护研究和实际应用

open access: yesGaoya dianqi, 2012
绝缘子并联间隙属于新的疏导型防雷措施,能够有效的保护绝缘子串,提高重合闸的成功率。目前,国内对并联间隙的研究主要集中在电弧的运动特性和间隙电极的形状之上,忽略了对并联间隙自身特性的研究,以及并联间隙上的电弧和绝缘子之间的关系等问题。笔者通过大量的试验研究并联间隙对绝缘子的保护特性,认为要想发挥并联间隙良好的保护特性,并联间隙两个电极之间的距离应该不大于绝缘子串结构高度的90%,而且应该和绝缘子之间有足够的距离。
顾铁利   +5 more
doaj  

Investigation of oxygen precipitates and the stability of denuded zone in Czochralski silicon [PDF]

open access: yes, 2016
铜在硅中不仅具有很大的扩散速率,而且随着温度的降低它的固溶度迅速下降,这两个特性使得铜原子很容易在器件制备过程中沉淀下来,严重影响硅片性能。虽然科研工作者们已经提出了多种工艺使硅片近表面处形成洁净区,但却很少对硅中的氧沉淀和洁净区的稳定性进行深入探讨。因此,本文通过实验分析了氧沉淀和洁净区的稳定性,得出以下结论: (1)研究了热处理方式和铜引入温度对洁净区的形成及其稳定性的影响。研究发现,只有Ramping-低-高热处理能使硅片内生成大量氧沉淀的同时有效形成洁净区。引入铜玷污后,RTP-低 ...
吕耀朝
core  

In Situ Uniform Lithium Enrichment for Dense, High‐Performance LLZO Solid Electrolytes

open access: yesRare Metals, Volume 45, Issue 1, January 2026.
ABSTRACT A major challenge in garnet‐type Li7La3Zr2O12 (LLZO) system all‐solid‐state electrolytes is the high porosity that typically remains after sintering, which compromises ionic conductivity and degrades battery cycling performance. To address this, we propose an innovative strategy to achieve uniform lithium enrichment on the surface of ...
Yi‐Yang Xiao   +8 more
wiley   +1 more source

武汉东湖若干种轮虫休眠卵的形态观察 [PDF]

open access: yes, 1997
休眠卵是轮虫在恶劣生态条件下形成的滞育结构。本研究用光学显微镜和扫描电子显微镜对东湖14种轮虫休眠卵形态进行了观察,其中关于尾突臂尾轮虫(Brachionuscaudatus,Barrois&Daday)、方形臂尾轮虫(Bquadridentatus,hermann)、中型晶囊轮虫(Asplanchnaintermedia,Hudson)、顶生三肢轮虫(Filiniaterminalis,Plate)的休眠卵的形态特征尚未见过报道。这些休眠卵一般卵壳较厚,颜色较深,壳表面有纹饰。不同种轮虫的休眠卵形态、
林里,周洁,黄祥飞
core  

Atomic‐scale understanding of interstitial‐strengthened high‐entropy alloys

open access: yesRare Metals, Volume 44, Issue 9, Page 6002-6014, September 2025.
Graphic abstract Abstract Interstitial alloying has emerged as a powerful strategy to tune microstructure and microproperties of high‐entropy alloys (HEAs) due to the strong interaction of interstitials with constituent elements and crystal defects, which enables the development of advanced alloys with superior mechanical and functional properties. The
Qiang Yu, Shi Qiu, Zeng‐Bao Jiao
wiley   +1 more source

The study of AKAP95 and Cx43 protein co-regulating cell G1/S phase transition [PDF]

open access: yes, 2016
本研究分为两部分,第一部分采用免疫组织化学实验,包括肺癌组织中AKAP95和CyclinD3、Akt蛋白表达与临床病理学指标的关系及3种蛋白之间的关联性分析、直肠癌组织中AKAP95、CyclinD1、CyclinE1和Cx43蛋白的关联性分析。通过检测51例肺癌组织和15例癌旁组织中细胞周期蛋白D3(CyclinD3)、蛋白激酶A锚定蛋白95(AKAP95)和丝/苏氨酸激酶(serine/threoninekinase,Akt,亦称蛋白激酶B,PKB)的表达发现,AKAP95 ...
原阳阳
core  

Placental biomarker and fetoplacental Doppler abnormalities are strongly associated with placental pathology in pregnancies with small‐for‐gestational‐age fetus: prospective study

open access: yesUltrasound in Obstetrics &Gynecology, Volume 65, Issue 6, Page 749-760, June 2025.
ABSTRACT Objective Placental dysfunction can result in small‐for‐gestational age (SGA) or fetal growth restriction (FGR). The aim of this prospective cohort study was to assess the association of the cerebroplacental ratio (CPR) and other more conventional fetoplacental Doppler indices, circulating placental growth factor (PlGF) levels and soluble fms ...
J. Hong   +6 more
wiley   +1 more source

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