Results 51 to 60 of about 24,432 (139)
Zhongguo shiyan zhenduanxue, 2023 目的 研究人体成分分析对血液透析患者心功能的影响及相关性。方法 以30例规律血液透析患者为研究对象，通过自身对照研究方法，检测基线期及3个月时的透析前血红蛋白(HB)、白蛋白(Alb)、总胆固醇(CHO)、甘油三酯(TG)、B型利钠肽(BNP)、钾、钠、钙、磷、甲状旁腺激素(PTH)、射血分数(EF)、收缩压(SBP)、舒张压(DBP)、细胞内水分(ICW)、细胞外水分(ECW)、身体总水分(TBW)、脂肪组织(FM)、去脂体重(FFM)、体质指数(BMI)等。结果 与基线相比，入组3个月时患者的ECW/
王欢欢 +7 more
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Politics &Policy, Volume 54, Issue 2, April 2026.ABSTRACT The Great Depression was a turning point in the development of social programming in North America. This paper explores the politics of social policy expansion during the Great Depression in the United States and Canada through an analytical lens that combines the insights of historical institutionalism and the analysis of transnational ...
Daniel Béland +2 more
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Gaoya dianqi, 2020 高压断路器分合闸过程中的触头行程曲线蕴含着反映其内部机构机械状态的丰富信息,是实现其状态识别和故障诊断的重要依据。文中提出了一种基于主成分分析和支持向量机的高压断路器机械状态识别方法,基于奇异值分解计算特征量的主成分,降低特征量的维度,筛选出包含主要信息的特征矩阵,然后基于特征矩阵构建支持向量机,结合交叉验证网格搜索确定最优参数,进而确定最优分类模型。对实验数据的分析结果表明,该方法可以有效提取触头行程曲线中蕴含的特征信息,准确度高达99%,可以实现对高压断路器机械状态的识别。
刘伟鹏 +5 more
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Zhejiang Daxue xuebao. Lixue ban, 2018 互联网的飞速发展，产生了大量的图像信息.为了减少图片占用的存储空间，提高图像质量，提出了一种将主成分分析(PCA)和分层树集合划分(SPIHT)压缩算法相结合的有损图像压缩算法.首先对图像进行主成分分解，选取主要特征值进行压缩，再利用SPIHT算法将图像分解成不同子带的小波系数进行压缩，对SPIHT压缩系数进行哈夫曼编码，实现图像二级压缩.将本文提出的算法与SPIHT、SPIHT的哈夫曼编码、JEPG2000、PCA压缩算法进行了比较，结果表明本算法较其他压缩算法具有更好的性能 ...
FANGXiansu(方炫苏) +2 more
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People and Nature, Volume 8, Issue 3, Page 741-753, March 2026.Abstract Currently, scholarship on education to foster connectedness with nature primarily focuses on children. As adults likewise face the disconnection from nature and play a key role in influencing children, it is important to understand how they perceive, engage in, and benefit from relevant programmes.
Xiaoxue Chen, Zuyi Lyu, Junxi Qian
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Dianci bileiqi, 2013 为今后实现自然积污规律研究和防污的差异化,对污秽颗粒等效简化模型、大气总悬浮颗粒物（TSP）的粒径分布函数、绝缘表面污秽主要化学成分对应TSP的粒径分布进行了综述和分析,认为可以污秽颗粒可等效简化为球体,使用空气动力学粒径衡量其粒径;建立TSP粒径分布函数拟合模型;分析认为化学成分Ca2+、SO42-、Cl-、SiO2、Al2O3在TSP中的粒径主要分布在1.810μm,010μm,1.810μm,30-40μm,40μm50μm的范围内,最后对自然积污规律研究和防污的差异化进行了展望。
李恒真 +5 more
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Policy &Internet, Volume 18, Issue 1, March 2026.ABSTRACT This article investigates how TikTok Shop reproduces the e‐commerce model of Douyin Shop against a backdrop of divergent regulatory challenges and geopolitical distrust. One of the strategic changes we observe in TikTok Shop is the shift of consumer goods suppliers from local merchants to China‐based sellers.
Shuaishuai Wang, Jing Meng, Yitong Li
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Policy &Internet, Volume 18, Issue 1, March 2026.ABSTRACT Over the past two decades, Voting Advice Applications (VAAs) have become widely used tools that provide personalized political information to help voters make informed choices and strengthen democratic processes. However, little research has examined their potential unintended effects.
Marius Fröhle +4 more
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Rare Metals, Volume 45, Issue 3, March 2026.ABSTRACT Proton exchange membrane fuel cells (PEMFCs) require advanced bipolar plate coatings to enhance efficiency, durability, and commercialization potential. This review presents a systematic framework for evaluating and designing bipolar plate coatings, integrating material selection, performance metrics, deposition techniques, and future ...
Shijie Li +12 more
wiley +1 more source
Zhongguo shiyan zhenduanxue, 2006 目的研究乳腺磁共振成像（Magnetic resonance imaging,MRI）弥散加权像（diffusion-weighted image,DWI）中表观弥散系数（apparent diffusion coefficient,ADC）的影响因素。方法对照病理分析32例乳腺疾病患者的42个ADC值异常的感兴趣区,分析ADC的相关影响因素。结果乳腺间质成分百分比与ADC值呈正比趋势,随间质百分比的增加ADC值增加。肿瘤组织内出血、坏死及间质成分中纤维细胞排列的疏密对ADC有明显影响 ...
赵继红 +5 more
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