期权定价的局部线性预测法

在为期权定价时,使用B-S公式算得的结果和市场交易值存在一定偏差.本文针对这一问题,给出了一种新的期权定价数值方法,即局部线性预测法.并用股票期权的实际交易数据对这一方法进行了数值验证,表明这一方法是有效的.     

基于高阶累计量的大气光通信自适应信号处理

针对强湍流信道下信号衰落的特点,分析了对数正态分布模型与K分布模型的适用范围.基于K分布模型建立大气光通信接收信号模型,并给出了自适应最优门限检测方法.采用四阶和六阶累计量对强湍流信道参量进行估计,采用二阶累计量对其它高斯噪音进行估计,得到K分布参量及高斯噪音统计量的预测值,实现自适应门限更新.基于Monte Calro算法进行仿真,给出了门限更新算法对通信系统误码率的影响,同时分析了信号采样率对估计参量偏差的影响.计算表明,在强湍流情况下,大气光通信系统的误码率性能得到极大的改善,优于基于MLSD检测的接收机.     

阿累尼乌斯方程探讨

用微分法对k=Aexp[-(Ea)/(RT)]、A和Ea均不随温度变化且Ea>0的基元反应进行了讨论。结论为:在一定温度下,(dlnk)/(dT)总是Ea的增函数,当EaRT时,(dk)/(dT)是Ea的减函数。在一定活化能下,(dlnk)/(dT)总是T的减函数,当T<(Ea)/(2R)时,(dk)/(dT)是T的增函数,当T>2ERa时,(dk)/(dT)是T的减函数。     

Molecular Simulation on Competitive Adsorption Differences of Gas with Different Pore Sizes in Coal

Micropores are the primary sites for methane occurrence in coal. Studying the regularity of methane occurrence in micropores is significant for targeted displacement and other yield-increasing measures in the future. This study used simplified graphene sheets as pore walls to construct coal-structural models with pore sizes of 1 nm, 2 nm, and 4 nm. Based on the Grand Canonical Monte Carlo (GCMC) and molecular dynamics theory, we simulated the adsorption characteristics of methane in pores of different sizes. The results showed that the adsorption capacity was positively correlated with the pore size for pure gas adsorption. The adsorption capacity increased with pressure and pore size for competitive adsorption of binary mixtures in pores. As the average isosteric heat decreased, the interaction between the gas and the pore wall weakened, and the desorption amount of CH₄ decreased. In ultramicropores, the high concentration of CO₂ (50–70%) is more conducive to CH₄ desorption; however, when the CO₂ concentration is greater than 70%, the corresponding CH₄ adsorption amount is meager, and the selected adsorption coefficient S_CO2/CH4 is small. Therefore, to achieve effective desorption of methane in coal micropores, relatively low pressure (4–6 MPa) and a relatively low CO₂ concentration (50–70%) should be selected in the process of increasing methane production by CO₂ injection in later stages. These research results provide theoretical support for gas injection to promote CH₄ desorption in coal pores and to increase yield.     

Discussion of the protein characterization techniques used in the identification of membrane protein targets corresponding to tumor cell aptamers

Aptamer is an oligonucleotide chain with specific binding ability to protein and other targets,which is widely used in ma ny fields.Because of its ability to screen the premise of unknown targets,it can be used to discover some novel tumor markers,i.e.,membrane proteins that are specifically highly expressed on the surface of tumor cells.Tumor markers can be used in many fields such as early diagnosis and treatment,and a new type of tumor marker proved to be effective can significantly improve the therapeutic effect of such tumors.However,further characterization of newly acquired membrane proteins is essential for their clinical use as tumor markers.This review first briefly introduced the process of obtaining novel tumor markers from nucleic acid aptamers.Next,the commonly used protein characterization methods could be used as a technical means to identify membrane protein targets corresponding to tumor cell aptamers,to clarify the principles,advantages and disadvantages of various means,and to analyze the most suitable situations for various experimental methods.Finally,the outlook was made and the characterization methods that should be used in such experiments were summarized.     

氮杂环丙烷化合物在直链淀粉柱上的拆分

在自制的直链淀粉-三(3,5-二甲基苯基氨基甲酸酯)(ADMPC)手性固定相上,对2种氮杂环丙烷对映体进行了手性拆分研究.系统选用了不同种类及不同含量的醇改性剂,详细考察了样品的保留时间和立体选择性.     

光度分析法测定痕量硒的研究与应用

就目前研究较多的测定痕量硒的光度分析法进行了综述,着重介绍了分光光度法、荧光光度法、散射光谱法、原子吸收光谱法、电感耦合等离子体发射光谱等方法.     

卤键在化学传感和分子识别中的应用

卤键是一种新的分子间非共价作用力,它存在于卤素原子(路易斯酸)和具有孤电子对的原子或π-电子体系(路易斯碱)之间,在超分子化学、材料科学、生物识别和药物设计等领域已经显示出独特的优势。本文主要从卤键的特征和在化学传感和分子识别中的应用以及发展前景等几方面进行了介绍,期望引起人们对卤键的更多关注。     

钪与氧空位共掺杂锐钛矿相TiO2的形成能与电子结构的第一性原理研究

采用基于密度泛函理论的第一性原理研究了钪(Sc)、氧空位(O_V)单/共掺杂锐钛矿相TiO₂,对晶体结构、形成能以及电子结构进行了对比分析.研究结果表明,Sc-TiO₂在富氧环境下缺陷形成能为负值,富钛环境下缺陷形成能为正值,表明Sc-TiO₂只能在富氧环境下制备;O_V-TiO₂、Sc-O_V-TiO₂在富氧或富钛环境下缺陷形成能均为负值,但富氧环境下形成能更低;O_V-TiO₂的0/1-缺陷电荷转变能级为深能级,而Sc-TiO₂的0/1-缺陷电荷转变能级则属于相对较浅能级;与纯锐钛矿相TiO₂相比,Sc-TiO₂的禁带宽度略有减小,但O_V-TiO₂、Sc-O_V-TiO₂禁带宽度变宽.     

荧光法猝灭测定木槿叶中混合氨基酸的总量

在乙酸-乙酸钠缓冲介质中,氨基酸能猝灭壳聚糖-茚三酮体系荧光,基于此,对木槿叶中混合氨基酸进行测定,并对该方法的测定条件进行了讨论.线性范围为0.5～3.0 mmol/L,检出限为0.1 mmol/L.木槿叶干粉中游离氨基酸的质量分数为10.18%,相对标准偏差为1.3%,回收率为102.5%～94.3%.