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黄壤颗粒表面离子吸附动力学中的离子特异性效应 被引量:5
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作者 吴英博 刘新敏 +3 位作者 李睿 杜伟 田锐 李航 《土壤学报》 CAS CSCD 北大核心 2018年第6期1450-1459,共10页
基于考虑离子非经典极化作用的离子吸附动力学模型,以可变电荷黄壤颗粒为代表材料,研究了锂离子(Li+)、钠离子(Na+)和铯离子(Cs+)在黄壤颗粒表面的吸附动力学特征,进一步计算了离子在土壤/水界面的扩散距离与表面电化学参数。结果表明:(... 基于考虑离子非经典极化作用的离子吸附动力学模型,以可变电荷黄壤颗粒为代表材料,研究了锂离子(Li+)、钠离子(Na+)和铯离子(Cs+)在黄壤颗粒表面的吸附动力学特征,进一步计算了离子在土壤/水界面的扩散距离与表面电化学参数。结果表明:(1)Li+、Na+和Cs+在黄壤颗粒表面吸附仅存在一级动力学过程并存在明显的离子特异性差异,这种差异随着电解质浓度降低而增大;(2)离子非经典极化与体积效应的共同作用决定了离子在固/液界面的扩散距离,在较高浓度电解质中,Na+和Li+的离子体积和极化效应基本平衡,导致Na+和Li+离子间差异不显著,但Cs+由于强烈的非经典极化作用,扩散距离表现为:Cs+>Na+≈Li+;在低浓度电解质中,离子非经典极化作用占主导,扩散距离表现为:Cs+> Na+> Li+,表明离子扩散距离在低浓度下差异大,而高浓度下差异不显著;(3)离子扩散距离的差异导致固/液界面电位的不同,Stern电位、电荷密度和电场强度均受到离子扩散距离的影响,表面电位(绝对值)在各个浓度下均表现为:Li+> Na+> Cs+,说明表面电位仅受非经典极化作用的影响。本研究将对土壤/水界面反应理论的完善提供新思路。 展开更多
关键词 离子吸附 极化 表面电位 离子特异性效应 电场
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Ideal Cardiovascular Health Metrics and Coronary Artery Calcification in Northern Chinese Population:A Cross-sectional Study 被引量:2
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作者 LUO Tai Yang liu Xiao Hui +3 位作者 DAI Tian Yi liu xin min ZHANG Qian DONG Jian Zeng 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2016年第7期475-483,共9页
Objective Coronary artery calcification(CAC) is a well-established risk predictor of coronary heart disease events and is recognized as an indicator of subclinical atherosclerosis.Methods A cross-sectional study con... Objective Coronary artery calcification(CAC) is a well-established risk predictor of coronary heart disease events and is recognized as an indicator of subclinical atherosclerosis.Methods A cross-sectional study consisting of 2999 participants aged ≥40 years from the Jidong community of Tangshan City,an industrial and modern city of China,was conducted between 2013 and 2014 to examine the association between the ideal cardiovascular health(CVH) metrics and CAC.The ideal CVH metrics were determined based on the definition of the American Heart Association(AHA).The participants were then grouped into 4 categories according to the quartiles of their CVH metric scores as follows:first quartile(0-2),second quartile(3),third quartile(4),and fourth quartile(5-7).CAC was assessed by using high-pitch dual-source CT,and patients were identified based on thresholds of 0,10,100,or 400 Agatston units,as per common practice.Results The prevalence of subclinical atherosclerosis was 15.92%,13.85%,6.76%,and 1.93%,determined by using the CAC scores at thresholds of 0,10,100,and 400 Agatston units,respectively.Compared with the group in the first quartile,the other three CVH groups had a lower odds ratio of CAC 0 after adjusting for age,sex,income level,education level,and alcohol use in the logistic regression analysis.The odds ratios in these groups were 0.86 [95% confidence interval(CI),0.63-1.17;P0.05],0.75(95% CI,0.55-1.02;P0.05),and 0.49(95% CI,0.35-0.69;P0.05),respectively.These associations of CAC with the CVH metrics were consistent when different CAC cutoff scores were used(0,10,100,or 400).Conclusion The participants with more-ideal cardiovascular metrics had a lower prevalence of subclinical atherosclerosis determined according to CAC score.Maintaining an ideal cardiovascular health may be valuable in the prevention of atherosclerosis in the general population. 展开更多
关键词 Ideal cardiovascular health Coronary artery calcification ATHEROSCLEROSIS
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