Results 71 to 80 of about 247,769 (181)

复合因素导致复发性流产1例

open access: yesZhongguo shiyan zhenduanxue, 2021
复发性流产(RSA)指3次或3次以上在妊娠28周之前的胎儿丢失,包括原发性和继发性[1-2]。目前研究表明反复流产的发生与遗传因素、免疫因素、血栓性疾病、内分泌紊乱有关。而胚胎染色体错误占反复自然流产的50%-60%[3-4]。但具体发病机制尚未完全阐明,可能由多种因素共同导致。妊娠合并全血细胞减少及获得性易栓症临床罕见,现报道反复胎死宫内合并全血细胞减少1例。
黄鲁鑫, 玄志鲁, 李娜
doaj  

Predictive M‐Site Design of MAX‐Derived CoNi Composites: Dual‐Scale TaC + L12 Strengthening Enabled by Rare Metal Ta

open access: yesRare Metals, Volume 45, Issue 9, September 2026.
ABSTRACT In MAX‐phase‐derived metal–matrix composites, the M‐site element simultaneously governs carbide chemistry and matrix precipitate stability, yet it has traditionally been selected empirically rather than from a predictive criterion linking M‐site choice to carbide chemistry, matrix alloying, and L12 stability; moreover, the reaction pathway ...
Wei Yang   +8 more
wiley   +1 more source

一种阻燃的金属盐/聚酰亚胺复合材料

open access: yes, 2001
一种阻燃的金属盐/聚酰亚胺复合材料,其特征在于:该复合材料为副族金属盐或稀土金属盐与聚酰亚胺的组合物,金属盐添加量为聚酰亚胺的1-20%重量。该复合材料能保持原材料的力学性能和热性能,而其阻燃性比原材料提高20%。该法工艺简单,成本低 ...
刘菁   +4 more
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3.0T高分辨磁共振血管壁成像评估颈动脉斑块性质对脑梗死复发的预测价值

open access: yesZhongguo shiyan zhenduanxue
目的分析3.0T高分辨磁共振血管壁成像(HR-MRI) 评估颈动脉斑块性质对脑梗死复发的预测价值。方法选取2019年1月至2024年8月在邯郸市中心医院诊治且行HR-MRI检查的脑梗死患者50例为研究对象,根据既往有无梗死病史将其分为复发组和初发组,分析比较两组患者的基本临床资料、脂质坏死核心、颈动脉斑块负荷参数、斑块稳定性、纤维帽破裂及斑块内出血发生情况。结果复发组不稳定性斑块检出率高于初发组(χ2=4.751,P=0.029);复发组管壁标准化指数(NWI)水平高于初发组(P<0.05 ...
岳志领   +6 more
doaj  

Crisis Leadership Beyond the Flame: A Human‐Centered Crisis Expectations Model and Its Implications for Research, Policy, and Practice

open access: yesRisk, Hazards &Crisis in Public Policy, Volume 17, Issue 3, September 2026.
ABSTRACT Disasters and crises disrupt lives and test the capacities of governments and organizations. While their immediate aftermath is often marked by uncertainty and disruption, recurrent patterns in how individuals are affected give rise to foreseeable hardships.
Michel L. A. Dückers
wiley   +1 more source

基于珠探针复合物分离短散在重复序列的方法

open access: yes, 2009
本发明公开了一种磁珠探针复合物分离短散在重复序列的方法,本发明包括如下步骤:(1)基因组片段富集库的制备。酶切基因组,回收合适大小片段,T4连接酶加接头,少量接头PCR循环放大酶切后的基因组片段库;(2)探针磁珠复合物的制备。通过引物扩增方法实现生物素标记DNA探针,变性后将生物素标记的单链探针绑定到磁珠上;(3)目的片断群的捕获。将磁珠探针复合物与基因组文库杂交,捕获目的片段并将其分离,克隆及阳性选择。该方法简单、高效、快速,缩短了实验周期,降低了成本消耗,极大的提高了效率 ...
何舜平, 童超波
core  

烧伤患者巨细胞病毒复发感染及其对患者预后的评估价值

open access: yesZhongguo shiyan zhenduanxue, 2013
目的观察烧伤病人巨细胞病毒(human cytomegalovirus,HCMV)复发感染情况及对预后的影响。方法对96例烧伤总体表面积(total body surface area,TBSA)>15%的患者进行动态观察。试验分组:(1)按烧伤面积将患者分为三组:Ⅰ组39例(TBSA 15%-49%),Ⅱ组32例(TBSA 50%-69%),Ⅲ组25例(TBSA 70%-99%);(2)根据脓毒血症诊断标准,将患者进一步分为脓毒症组(33例)和非脓毒症组(63例);(3)根据脓毒症组患者的预后情况 ...
龚芳   +5 more
doaj  

复合绝缘子芯棒发热的热传导特性研究

open access: yesDianci bileiqi, 2022
近年来我国复合绝缘子由于芯棒发热导致异常温升的故障时有发生,给电网安全运行带来隐患。为了研究芯棒发热的热传导特性,以及复合绝缘子内外温度的关系,笔者通过理论推导,建立了芯棒发热的热传导模型,并开展仿真与实验研究。结果表明,当复合绝缘子芯棒发热时,硅橡胶护套中径向温度成对数分布,芯棒表面温度与护套表面温度为一次函数关系,并且复合绝缘子内外温差与复合传热系数成正比,与护套导热系数和环境温度成反比,而环境湿度对复合绝缘子芯棒发热的热传导没有明显影响。仿真与实验结果相吻合,验证了热传导模型的准确性。
曾磊磊   +10 more
doaj  

Ecohydrological characteristics of biocrusts explain divergent responses of biocrusts and grasses to rainfall reduction

open access: yesFunctional Ecology, Volume 40, Issue 9, Page 2843-2860, September 2026.
Read the free Plain Language Summary for this article on the Journal blog. Abstract Drylands are mainly structured by both vascular plants and biological soil crusts (biocrusts), the latter often regarded as a self‐organizing component of these ecosystems.
Haoran Luo   +13 more
wiley   +1 more source

一种火箭发射台用热防护涂层的结构及其应用

open access: yes, 2014
本发明公开了一种火箭发射台用热防护涂层材料的结构及其应用。本发明热防护涂层材料由有机底层、耐火砖和有机-无机复合表层三层材料组成。其中,有机底层由环氧树脂、固化剂聚酰胺和增韧剂液态橡胶组成。耐火砖选用黏土质耐火砖,有机-无机复合表层由有机胶环氧树脂、聚氨酯固化剂、沙子和水泥组成。本发明的热防护涂层材料能够承受火箭模拟燃气流冲刷,金属背面温度不超过200 ...
张涛   +11 more
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