分形理论在分子动力学模拟中的应用

本文基于分形理论提出了一个假说,认为实际流体分子的无规运动可以用分数布朗函数作为概率密度函数来描写,而其分数维数可根据分子运动的图像确定。本文以流体Ar作为对象进行了分子动力学模拟,根据分子动力学模拟的结果提取了运动的分数维数,构造了描述分子无规运动的分数布朗函数,并对所提出的假说进行了验证。     

On Perfectly Generating Projective Classes in Triangulated Categories

We say that a projective class in a triangulated category with coproducts is perfect if the corresponding ideal is closed under coproducts of maps. We study perfect projective classes and the associated phantom and cellular towers. Given a perfect generating projective class, we show that every object is isomorphic to the homotopy colimit of a cellular tower associated to that object. Using this result and the Neeman's Freyd-style representability theorem, we give a new proof of Brown Representability Theorem.     

In-situ observation of the combustion of air-dried and wet Victorian brown coal

This work investigates the fundamental and practical implications of the application of drying technologies to Victorian brown coal combustion. The base case of 60% moisture content coal preheated prior to combustion is compared with partially dried coal (with or without pre-heating) and coal dried to equilibrium moisture content (10–15%). Pulverised coal was combusted in a drop tube furnace and in-situ observations of combustion phenomena, particle temperature and gas temperature were made. An ignition delay was found to occur when partially dried coal was combusted without pre-heating. Flame stability was also decreased when wet coal was combusted without pre-heating. No ignition delay was observed when the water in coal was heated prior to entering the furnace, as in current boilers. The peak particle temperature was found to be higher than the wall temperature by around 130 °C for dried coal, 80 °C for preheated wet coal and 40 °C for non-preheated partially dried coal. The gas temperature profile in the furnace was measured and found to lag behind the particle temperature peak. It was concluded that the evolution and evaporation of water in the wet case lead to an ignition delay, cooler peak particle temperatures and prolonged char combustion. The difference in particle temperatures between preheated wet coal and dried coal and the gas temperature behaviour was attributed to the steam gasification reaction, although studies to elucidate reasons for the differences are ongoing. The quantified results on ignition delay and particle temperatures have important implications for the design of new technologies, in particular the boilers and feed size preparation, for power generation from high-moisture brown coals.     

GARCH模型参数变化的残量检验

本文研究GARCH模型参数变化的检验问题. 给出残量累积和统计量, 在原假设下得到了统计量的极限分布; 模拟结果表明残量检验可以弥补Kim, Cho和Lee (2000)\ucite{1}提出的平方累积和检验的某些不足, 比如经验势函数值过低的问题.     

A New Sesquiterpene-substituted Benzoic Acid from the Brown Alga Dictyopteris divaricata

A new sesquiterpene-substituted benzoic acid has been isolated from the brown Alga Dictyopteris divaricata Okam.Its structure was elucidated as 3-[(2-hydroxy-2,5,5,8a-tetramethyldecahydro-1-naphthalenyl)methyl]-4-hydroxybenzoic acid, named dictyvaric acid on the basis of spectroscopic methods including IR, HRFABMS, 1D and 2D NMR techniques.     

Electrochemical studies of the interaction of Basic Brown G with DNA and determination of DNA

A new method of electrochemical probe has been proposed for the determination of Herring Sperm DNA (DNA) based on its interaction with Basic Brown G (BBG). The electrochemical behavior of interaction of BBG with DNA was investigated on Hg electrode. In 0.1 mol L⁻¹ NH₃-NH₄Cl buffer solution (pH 8.0), BBG can be reduced on Hg electrode with a well-defined voltammetric peak at −0.67 V (versus SCE). In the presence of DNA, the reduction peak current of BBG decreases and the peak potential shifts to a more positive potential without the appearance of new peak. The study shows that a new BBG-DNA complex is formed by linear sweep voltammetry (LSV) and spectrophotometry. The decrease of the second order derivative of reductive peak current (Δi^″p) of BBG is proportional to the concentration of DNA in the range of 0.10-36 μg mL⁻¹. Limit of detection of DNA is 0.04 μg mL⁻¹. DNA of Hepatitis B Virus in serum samples was determined satisfactorily. Additionally, the binding mechanism was preliminarily discussed. The mode of interaction between BBG and DNA was found to be intercalation binding.     

A Method Based on FBM Self similar Image Model for Digital Hologram SynthesisSupported by National Natural Science Foundation of China.

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俾士麦棕与核酸相互作用的吸收光谱行为

利用分光光度法研究了俾士麦棕与核酸的结合作用。当pH在6．9—7．6时,体系在446nm处有最大吸收峰,且在室温下2min达到稳定且吸光度在3h之内保持不变。在最佳显色条件下,小牛胸腺脱氧核糖核酸（et DNA）和鲱鱼脱氧核糖核酸（fs DNA）的线性范围分别为0．1—18mg／L和0．1～28mg／L;检出限分别为0．019mg／L和0．028mg／L。采用摩尔比法和Rosenthanl作图法测定了俾士麦棕与核酸的结合数,且利用Rosenthanl作图法获得了俾士麦棕与核酸的结合常数。两种方法所得结合数基本一致,即核酸分子中的一个核苷酸可与3个染料分子结合。该方法灵敏度高,稳定性好,操作简便,重现性好以及抗干扰能力强,用于合成样品的分析,回收率在95．2％-102％之间;相对标准偏差低于4．9％,结果令人满意。     

棕青铜单晶低温电阻—温度特性研究

我们利用ＥＨＴＳ方法首次制备了棕青铜单晶，经ＥＤＳ谱分析，其分子式为Ｋ０．０１ＭｏＯ３研究表明，棕青铜在７７～３００Ｋ温区呈金属导电性，室温电阻率为４．２×１０－４Ω·ｃｍ，电阻－温度系数为３．６×１０－３／Ｋ；真空退火后其电阻率减小，氧退火后电阻车增大两个数量级，且在２５０￣３００Ｋ出现负温度系数。