空气主要组分在Ag表面的吸附行为研究

空气中熔融的Ag能够溶解自身体积的22倍氧气,冷却固化过程中其他气体(N₂、CO₂等)几乎为零。吸附是气体溶解的第一步,本文基于量子化学和簇模型的方法建立空气主要组分N₂、O₂、CO₂于Ag表面的吸附模型,研究Ag表面对空气主要组分的吸附行为。结果显示,O₂在Ag(100)、Ag(110)、Ag(111)上的吸附能都为最大,空气中Ag的周围主要吸附O₂,且几乎不产生与其他非氧组分的直接接触;Ag表面上N₂、O₂、CO₂的解离都需要一定的热激活条件,O₂在Ag表面的解离能垒低于N₂和CO₂,更容易解离成O吸附在表面。因此,Ag对空气中的O₂具有选择性吸附的功能。     

Investigation of the interaction of the components in the Y–Si–Sb system at 670 K

Phase equilibria were established in the Y–Si–Sb ternary system at 670 K. The investigation of the phase relations was based on X-ray diffraction experiments made on arc-melted alloys, which were annealed up to 720 h. The 670 K isothermal section consists of 8 three-phase, 12 two-phase and 11 single-phase regions. The formation of a solid solution of Si in the binary YSb compound (8 at.% Si) has been observed. In the Y–Si–Sb system solid solutions between the isostructural binary compounds Y₅Si₃–Y₅Sb₃ form a continuous series. One ternary compound was observed: Y₅Si₂Sb₂ (Tm₅Si₂Sb₂ str. type, Cmca space group, a=1.4971(2), b=0.7855(2) and c=0.7820(2) nm).     

Equilibrium adsorption of stilbenoids at metal oxides

The isotherms of adsorption of trans-hydroxystilbenes (stilbenoids) and hydroxybenzenes (phenols) from n-hexane-ethyl acetate (1: 1) at nanodispersed aerogels of aluminum and titanium oxides were measured under static conditions. The adsorption isotherms can be approximated well by the Freundlich equation for the model of localized adsorption at energetically heterogeneous solids. It was found that the adsorption value of both stilbenoids and phenols is improved with an increase in the number of OH groups in their molecules, being sensitive to the chemistry of the adsorbent surface. trans-Hydroxystilbenes adsorb at TiO₂ better than do the corresponding phenols. The opposite pattern was observed for Al₂ O₃. The adsorption of trans-hydroxystilbenes at TiO₂ is irreversible and accompanied by the formation of colored surface compounds.     

分子药理学中吸附层析模拟系统的研究

目的 建立用于分子药理学研究的药物分离吸附层析模拟系统并初步应用。方法 提出吸附层析 的多室解吸理论模型, 推导相关公式, 编制计算机程序。结果与结论 该模型可根据实验需要拟合出最佳分离效果的吸附层析解吸曲线, 并准确描述系统各室浓度随时间的变化规律。介绍了数例有应用价值的特殊解吸曲线, 并利用此系统对膜整合蛋白进行了分离, 取得了较传统两室线性解吸法明显好的分离效果。     

焊接结构件装配CAAP软件应用系统开发

针对焊接结构件装配工艺设计自动化程度低．影响产品制造周期和质量的问题，设计了CAAP(计算机捕助装配工艺规划)装配自动化系统，包括确立焊接结构件装配顺序的设计方法、明确其装配过程的工艺基准和建立零件间的信息与约束模型3个过程。并利用VC 编程语言，完成其应用软件开发，该系统已实用化。     

Krypton adsorption on microporous adsorbents at higher pressures

The xenon adsorption isotherms were measured on AUK microporous carbon adsorbent in the range of pressures from 1 Pa to 6 MPa and temperatures of 177.7—393 K. With the adsorption isotherms in the same range of pressures and temperatures, the xenon adsorption isosteres were calculated. The derived curves are well approximated with linear functions. With the adsorption isosteres, differential molar isosteric adsorption heat curves were plotted vs. adsorption and temperature. The obtained results were compared with the reference data of the xenon adsorption on PAU-10 active carbon.     

Xenon adsorption on microporous adsorbents at higher pressures

The xenon adsorption isotherms were measured on AUK microporous carbon adsorbent in the range of pressures from 1 Pa to 6 MPa and temperatures of 177.7—393 K. With the adsorption isotherms in the same range of pressures and temperatures, the xenon adsorption isosteres were calculated. The derived curves are well approximated with linear functions. With the adsorption isosteres, differential molar isosteric adsorption heat curves were plotted vs. adsorption and temperature. The obtained results were compared with the reference data of the xenon adsorption on PAU-10 active carbon.     

机-电-液元件及系统的对应分析

文章分析探讨了机械、电气、液压元件及系统的结构功能对应、数学模型对应、物理对应等内在对应关系,用以指导控制元件和系统的研究和开发.     

Influence of desorption conditions on the state of components in the cellulose-water system

We studied the processes of spin-spin and spin-lattice relaxations in the cellulose-water system upon varying the conditions of water desorption; the rate of moisture evaporation and the mobility of components in this system depend on one another.     

储气库Y型井口携砂采气临界冲蚀模拟研究

目的 研究储气库携砂采气过程中储气库生产通道冲蚀磨损的主要影响因素及规律。方法 在辽河油田双6储气库注采井管柱结构和生产工况条件下,开展室内冲蚀模拟实验和生产通道冲蚀数值模拟研究,通过数值分析,明确采气速度、生产压力、出砂速率、出砂粒径对管柱冲蚀速率的影响规律。结合临界冲蚀理论计算结果,设计适用于出砂工况条件下储气库生产通道临界冲蚀系数取值的图版。结果 出砂速度、采气速度、生产压力在管柱冲蚀中起着主要作用,实验数据与预测结果的一致性较高,管柱最大冲蚀速率与日产气量的二次幂、井筒内压力的负二次幂、出砂速率的一次幂成正比。此外,管柱变径部位的冲蚀速率随着服役时间的延长呈下降趋势,最终与管壁的冲蚀速率基本保持在相同数量级。根据构建的临界冲蚀系数取值图版,在当前储气库出砂工况条件下,为了保证储气库满足服役年限,将临界冲蚀系数(C)取值为180,进一步考虑到储气库的最大产能情况,推荐C介于175~200之间。结论 通过储气库管柱冲蚀的实验模拟和数值模拟研究,建立了储气库注采井管柱的冲蚀速率模型,构建了储气库注采管柱临界冲蚀系数设计图版,有利于工程技术人员准确判断实时生产工况条件下储气库注采管柱的生产工况负荷、服役安全工况条件等,可以提供关键的实时性、安全性基础数据。     

气路组件钎缝的漏气原因及银钎焊工艺试验

介绍了气路组件的结构和对钎焊接头的技术要求,分析了气路组件采用锡铅钎料钎焊钎缝漏气的原因,重点介绍了采用氧乙炔焰钎焊方法和银钎抖进行的工艺试验,确定了接头尺寸,选择了钎剂和钎料,探索出了合理的工艺流程及操作要点,制定出了焊前、钎接和钎后等全过程的钎焊质量保证措施.钎缝在经过高温、低温、振动、水平与垂直冲击、高压密封性等一系列试验后,气密性合格,所确定的钎焊工艺经过了多个批次的生产,质量稳定,再没有发生漏气现象.     

On the formation of supramolecular systems in the adsorption of aromatic compounds at porous adsorbents

Competitive adsorption of anisole, benzaldehyde, benzoic acid, benzene, toluene, and phenol from dilute solutions in n-heptane at three chemically different porous adsorbents was studied by high-performance liquid chromatography (HPLC). The retention times of these compounds were used to calculate the equilibrium constants of the adsorption isotherms, the partition coefficients, and the Gibbs energy changes. The results obtained made it possible to estimate the Gibbs energy changes in the competitive adsorption of arenes leading to the formation of supramolecular surface compounds at cellulose and silica and the formation of arene clusters at the pyrocarbon surface from dilute solutions in n-heptane. Original Russian Text ? N.A. Eltekova, Yu.A. Eltekov, 2008, published in Zashchita Metallov, 2008, Vol. 44, No. 2, pp. 193–196.     

典型飞机构件焊接数值模拟系统研制

针对典型飞机焊接构件,研制焊接热过程、应力应变以及变形的模拟系统.提出并利用面向网格划分的数据抽象造型方法,实现模拟过程的自动化.解决一般有限元软件模拟飞机构件焊接温度场和应力/应变场过程中操作繁琐的问题.系统采用面向对象方法设计.利用文中系统,用户只需输入构件模型几何参数,网格尺寸、热源参数、装夹位置和焊接顺序.这些参数经过系统核心类计算,生成温度和应力/应变模拟的自动化信息.自动化信息由系统转化为Marc的命令流文件,自动被导入到后台运行的Marc中计算,并对结果分析,实现对典型飞机构件焊接温度、应力/应变以及变形预测和分析.     

Adsorption deformation of AUK microporous carbon adsorbent at adsorption of n-heptane

Isotherms of relative linear adsorption deformation are measured on an AUK microporous carbon adsorbent for adsorption of @n-heptane in the pressure range of from 1 Pa to 5 kPa and the temperatures of 273, 293, 313, 353, and 393 K. The curves of adsorption deformation behave in a similar way in the whole range of studied temperatures: the adsorbent is practically not deformed in the range of small and medium fillings and its drastic expansion is observed in the range of high fillings. Numeric simulation of n-heptane adsorption in AUK pores is carried out using the model of slit-shaped pores equivalent to porosity parameters determined on the basis of the Dubinin’s bulk micropore filling theory for AUK. The relationship has been established between adsorption deformation of the adsorbent and adsorbate structure variation in micropores.     

Comparative analysis of the adsorption of the stereoisomers of hydroxy- and dihydroxyproline at graphitized thermal soot

The thermodynamic characteristics of the adsorption of proline and its derivatives at graphitized thermal soot (GTS) were determined. It was found that the arrangement of the hydroxy groups in the amino acid molecule influences its adsorption at GTS. The thermodynamic characteristics of the adsorption of the stereoisomers of hydroxy- and dihydroxyproline at GTS were calculated. The influence of the internal rotation angles in the molecules of proline and its derivatives on their adsorption at GTS was studied.     

Redistribution of concentration of components during interdiffusion in Cu-Fe-Ni system

Interdiffusion in a Cu-Ni-Fe system was studied at a temperature of 1000°C for three different diffusion couples. It has been shown that, in the studied diffusion couples, the distributions of some components of the system have a distinctly nonmonotonous character and, apart from the local extremes of the concentration curves, there are also zero flux planes in five diffusion zones. Special features of the behavior of the concentration curves and diffusion paths are discussed using thermodynamic data for the system. It has been found that diffusion fluxes of the components are unambiguously associated with a derivative of thermodynamic activity by the concentration taken along the diffusion path. There are experimental data in the appendix concerning the concentration profiles for all of the studied components of the diffusion couples.     

Thermodynamics of methane adsorption on X type zeolites at supercritical temperatures

Methods describing isotherms and thermodynamic properties of methane adsorption on various cationic forms of X-type zeolite at temperatures above critical ones are considered.     

Influence of the structures of hydrogen-bonded dimeric molecules on their adsorption at graphitized thermal carbon

This study is devoted to the influence of the structures of hydrogen-bonded dimeric molecules on their adsorption at graphitized thermal carbon (GTC). The thermodynamic adsorption characteristics (TACs) of amino acid dimers and dimers of amino acids with acetic acid and formamide at GTC were determined. The results obtained for the adsorption of dimeric molecules at the carbon sorbent were compared with the calculated data for the molecules of the corresponding amino acids at GTC. The geometric parameters of dimeric molecules were varied to analyze the influence of the hydrogen bond lengths on the TACs of the compounds under study.