9 research outputs found
基于切向超滤技术的胶体有机碳和无机氮分离及物源初探
利用切向超滤技术对九龙江口天然水体中胶体相(1 kDa~0. 45μm)、真溶解相(<1 kDa)和\"溶解相\"(<0. 45μm)的溶解有机碳和无机氮进行了分离与提取,初步探讨了水环境因子对其理化特性的影响机制,进而探讨了它们的来源和转化.结果表明,切向超滤过程的膜空白和质量平衡符合技术要求;溶解有机碳、亚硝酸盐氮、氨氮、硝酸盐氮和无机氮存在形式以真溶液相(<1 kDa)为主,其在胶体相中的质量浓度分别为0. 207~0. 810 mg/dm3、0. 001~1. 870μg/dm3、ND~2. 08μg/dm3、0. 62~79. 30μg/dm3和1. 07~81. 10μg/dm3;胶体态溶解有机碳(COC)含量主要受陆源输入控制.国家海洋局海洋公益性行业科研专项资助项目(201505034-4);;福建省科学技术厅公益专项资助项目(2015R1003-12
The Study of Magnetics Properties and AIREs of Nanostructured Materials
纳米材料具有许多不同于常规材料的特性,特别是其特殊的热、力、光、 磁等性质,引起了物理、化学、材料等众多学科的兴趣,也是材料科学家们一直在努力探索的核心问题。纳米材料的特殊性质与其微观结果有着密切的关系,因此研究纳米材料的微观结构与纳米材料的特性之间的关系十分重要。 计算机模拟技术正逐渐被广泛应用,它具有传统手工运算不可替代的优势,快速高效的优点可以节省大量的人力,运用模拟技术可以预见一些未知的结果,帮助人们认识事物的新性质,指导实验实施。为了了解纳米结构材料性质,本文运用MonteCarlo方法对二维磁性纳米结构材料进行了模拟计算,发现其与单晶粒子材料之间有重要差别,这有助于从结构上理解...Nano-material has a great number of properties different from those of traditional bulk materials, especially in mechanical, electric, optical and magnetic features. They have attracted many researchers and scientists’ interests. These distinctive properties mostly originate from the microstructure of nano-materials. So it is very important to obtain a deep insight into the relationship between na...学位:理学硕士院系专业:物理与机电工程学院物理学系_理论物理学号:20012401
Monte Carlo Simulation of Two-dimensional Magnetic Nanostructured Materials
【中文文摘】运用MonteCarlo模拟方法,通过分析系统自旋序参数与温度的变化关系了解纳米结构材料磁性的特征.计算模拟结果表明,磁性纳米材料具有比同等大小和平均密度的单晶低的居里温度,且在相变过程中往往会出现一些亚稳态.研究结果提供了一种解析金属纳米结构材料特性的重要方法.
【英文文摘】In this article, Monte Carlo simulation is applied to analyze the characteristics of twodimensional magnetic nanostructured materials. It is shown that nanostructured materials possess lower Curie temperature in comparison with crystalline materials with the same size and average densities. In addition, some mesoscopic states tend to appear in the transition processes of nanostructured materials. The result presented here gives an important approach to analyze nanostructured metal materials.国家自然科学基金纳米科技基础研究重大研究计划(90602039);; 中科院创新工程(K81045)资助项
Studies on the abnormal IR effects for CO adsorption on nanostructured Pt thin films
CO吸附在经方波电势处理后的纳米结构Pt金属膜电极上可观察到异常红外效应 (AIREs) .在实验基础上用粒子间的相互作用和电子 空穴衰减机理分析、模拟了AIREs ,表明Pt金属表面的纳米岛状结构增强了CO分子间及CO分子与纳米结构表面的相互作用 ,电子 空穴衰减引起的能量转移和粒子间相互作用的增强可以导致异常红外吸收谱线变化特征的出现 .国家自然科学基金 (批准号 :10 2 2 5 42 0 ,90 2 0 60 3 9,2 0 0 2 10 0 2 ); 福建省自然科学基金 (批准号:A0 2 10 0 19)资助的课
Research of nitrification in coastal water of Meizhou Bay—— [~(15)N]ammonium oxidation method
本文利用15n-nH4+氧化法对湄洲湾近岸水体的硝化作用进行深入研究。结果表明,湄洲湾近岸水体硝化速率范围在0.51~4.60μMOl·l-1·d-1。养殖区附近较高的硝化速率,有利于海水对nH4+-n污染物的自净作用,当水体硝化作用强烈时,水中的nO-3的浓度也随之升高,表明海水中nO-3主要来自于细菌的硝化作用。湄洲湾海水nH4+-n的周转时间在1~9 d,表层水体的nH4+-n转化时间高于底层水。硝化作用转化nH4+为nO-2,并最终转化为nO-3,减少了nH3-n及nH4+-n对近岸养殖系统中生物的危害。These studies were conducted to estimate nitrification in coastal water of Meizhou Bay by [15N]ammonium oxidation method.The nitrification rate of 0.51 ~ 4.60 μmol·L-1·d-1were recorded,and the higher nitrification rate in water close to aquaculture area were propitious to ammonium self-purification.Higher nitrification rate was observed at high NO-3concentration water column,which showed NO-3 produced mostly from nitrification.The biological turnover times for NH+4 were short( 1 ~ 9 d) in coastal water of Meizhou Bay with the longer turnover times in surface seawater.Nitrification transformed NH+4 to NO-2,final to NO-3,reducing the harm to organisms of coastal aquaculture system resulted from NH3-N and NH+4-N.福建省专项基金(2005021477); 福建省自然科学基金(D0610020
Monte Carlo simulation of magnetic nanostructured thin films
Using Monte Carlo simulation, we have compared the magnetic properties between nanostructured thin films and two-dimensional crystalline solids. The dependence of nanostructured properties on the interaction between particles that constitute the nanostructured thin films is also studied. The result shows that the parameters in the interaction potential have an important effect on the properties of nanostructured thin films at the transition temperatures
Studies on the abnormal IR effects for CO adsorption on nanostructured Pt thin films
The abnormal IR effects(AIREs) of the adsorption of CO on electrodes made of Pt nanostructured thin films generated in square wave potential treatment were observed. Based on the experimental results, the AIREs were analysed and simulated by taking into consideration of the interparticle interaction and the electron - hole damping. The results illustrate that the islanded narrostructured Pt surfaces give rise to the interactions between CO molecules as well as between CO molecules and nanostructured Pt surface. The energy transfer due to electron-hole damping and the enhancement of interparticle interaction are the important cause of the changes of IR absorption spectra
中国脑血管病临床管理指南(第2版)(节选)——第3章 脑血管病高危人群管理 Chinese Stroke Association Guidelines for Clinical Management of Cerebrovascular Diseases (Second Edition) (Except) ——Chapter Three Management of Patients at Hige-risk of Cerebrovascular Diseases
针对脑血管病的危险因素积极进行早期干预管理是减少脑血管病危害最有效的方法。本章节介绍脑血管病高危人群管理的推荐意见,包括对不可干预和可干预血管危险因素的控制,阿司匹林在缺血性卒中一级预防中的应用以及首次卒中风险评估等方面。
Abstract: Early intervention to manage the risk factors of cerebrovascular disease is the most effective way to reduce the harm of cerebrovascular diseases. This chapter presents recommendations for the management of populations at high risk for cerebrovascular disease, including control of non-interventionable and interventionable vascular risk factors, the use of aspirin in the primary prevention of ischaemic stroke, and the risk assessment of first-time stroke