Simple Chemical Reactions in the Solid State: Towards Elaborating a Conception

In contrast to the conventional homogeneous kinetics, there is no conception of a simple reaction in the solid-state reaction kinetics. The geometric-probabilistic phenomenology currently in use is not adequate for describing the interplay between the chemical mechanism and the observed kinetic behaviour. An attempt is made to formulate a conception of simple reaction in the solid state as a basis for constructing kinetic models of involved reactions.     

Red and near infra-red signaling: Hypothesis and perspectives

The review covers some of the proposed cellular photoreceptors responsible for the effect of red and near infra-red (NIR) light on mammalian cells, including cytochrome-c-oxidase, photoactive porphyrins, flavoproteins, and molecular oxygen. We do not discuss the clinical studies but consider animal models, especially fibroblasts. Several key hypotheses such as mitochondria signaling and free-radical conception of the effects of red light and NIR light based on the changes in redox properties of photoreceptor molecules as well as membrane conception are examined. Special attention is paid to common mechanisms of light signaling in mammalian and plant organisms.     

分离富集技术在形态分析中应用进展

对十年来分离富集技术在形态分析中应用进展进行了评述,引用1991～2001年文献67篇。     

Computer modeling of amorphous silica structures

An algorithm for large cluster construction for quantum-chemical modeling of amorphous silica structures is suggested. The algorithm is based on the conception that different species of disperse amorphous silica, namely aerosil, silica gel and aerogel are different polymorphic forms; that these polymorphic modifications can be classified by Libau's crystallochemical classification of silicates; that each classification mode is determined by the manufacturing method. The structure models presented are obtained in accordance with the algorithm and are in line with the chemical reactions forming the basis of commercial manufacturing of the products.     

Modelisation de la dynamique de fermentation alcoolique

The control of the alcoholic fermentation is necessary to obtain a wine having good organoleptic properties. Our study consists in applying the overall dynamical and phenomenological modelling to this kind of reaction suggesting however hypothesis concerning kinetic laws (order zero and order one). The first proposed models are not perfect but they allowed us to access certain chemical parameters such as the reaction enthalpy. Our aim is to determine a model of simple state (for its application) to allow the conception of the alcoholic fermentation reaction of a real-time command.     

多元线性模型计算基于荧光猝灭原理的膜传感器对分析物的响应参数

根据基于荧光猝灭原理的化学传感膜的结构特征和发光机理,推导并提出量化作用于膜传感器的多种荧光猝灭因素的多元线性模型.结合三杯法,该模型可简便地求出反映不同荧光猝灭机理的特征参数.通过建立的数学模型,测定并计算了芘丁酸膜传感器对应于呋喃妥因等23种药物多种荧光猝灭因素的响应数据和响应参数.结果表明,传感膜对分析物的响应特征往往能得到主要猝灭因素响应模型的近似反映,这为基于荧光猝灭原理的化学传感器定量分析模型的建立提供了可借鉴的思路和方法.     

观念建构为本的化学教学设计研究

以提高学生的科学素养为核心的新课程向以事实为本的课堂教学设计提出了挑战,也为观念建构为本的教学设计提供了展现的平台。在王磊和范晓琼2005年"观念建构为本教学的理论研究"的基础上,提出了观念建构为本的教学设计模型。结合具体教学案例"电离平衡",对如何进行观念建构为本教学设计进行了详细阐述,并提供了电离平衡一节的教学设计。     

A multivariate approach to digital design of items made of textile-composite materials

The conception and structure of a software package providing joint application of different methods of virtual modeling of items made of the textile-composite materials were proposed. Methods of geometrical analysis of multiphysical calculation and averaging subjected to application as complex modules were considered. An electronic database of formalized structural and technological knowledge of technological composites was proposed as a core base of the complex.     

精品课程教材《高分子物理实验》建设的体会——三个及时融入

中国科学技术大学"高分子物理实验"课程是2006年安徽省精品课程,作者结合教学研究和精品课程建设经验,总结出了"三个及时融入"的教材建设理念,本文结合实例对该理念的具体含义进行了阐述.     

Kohlenstoffbestimmung in Silicium — Ein Beispiel für die Problematik analytischer Untersuchungen im ppm-Bereich

Until 1968, analysis of silicon used for semiconductors showed carbon contents between 10 and 500 ppm (w). In the last three years, similar samples, which have been examined in the same manner, have only been found to contain concentrations of between 0.01 and 10 ppm (w). The earlier conception, which has now been proved wrong, was, in itself, plausible and thus gave rise to doubtful conclusions for the development of semiconductors. The various reasons for the incorrect results are discussed. Insufficient knowledge of sample surface purity, mistakes made during the preparation of the samples for analysis and interference reactions are regarded as having contributed most to the misconception.     

影响中学生化学模糊观念改变的因素及其权重分析

学生模糊观念的产生有着根本原因,且影响其变化的因素主要有 5个维度。我们通过层次分析法得到 5个维度的权重值。这 5个维度的权重值分别为:认知方式:021元认知:018　认识论:022　社会环境 /动机 /情感:013本体论:026。     

Fast neutron induced fission neutron spectra below the incident energy

A fast pneumatic transfer system for an instrumental neutron activation analysis and delayed neutron counting system were reconstructed with new designs of a functional improvement at the HANARO research reactor in 2006. The design, conception, operation and control of these systems are described. Also the experimental characteristic parameters by a functional operation test and an irradiation test of these systems, such as the transfer time, the neutron flux, the temperature of the irradiation position with an irradiation time, the radiation dose rate when the rabbit is returned, etc., are reported to provide a user information as well as for the management and safety of the reactor.     

The problem of recognition in chemistry

A purposeful search for effective biologically active substances with required properties is possible only under the condition that the mechanisms of the chemical reactions taking place in biological systems are understood. The complexity of biochemical processes has forced investigators to devise models for studying and isolating various parameters of these processes. Just such an approach has yielded important results in bioorganic chemistry. One of the most crucial problems in biochemistry and biophysics is the recognition of a specific substrate by a receptor. The theory advanced by E. Fischer at the end of the nineteenth century, that enzymes interact with substrates according to a lock-and-key principle, has been transformed into a fairly rigorous conception of the recognition of molecules of different chemical compounds. The present paper is devoted to a discussion of the problems related to the improvement of the physicochemical model of recognition.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 22, No. 4, pp. 450–463, July–August, 1986.     

Thermodynamic properties of individual ions, calculated in terms of conception of real thermodynamic properties of individual ions in solutions

Real and chemical thermodynamic characteristics for several ions in mixtures of water with organic solvents of different classes are calculated on the basis of the proposed conception of real thermodynamic properties of individual ions in solutions. This conception is an improved and generalized version of the procedure for describing thermodynamic activity of individual ions in aqueous electrolyte solutions, which was successfully exploited for many years. The offered methodology enables one to determine thermodynamic characteristics of individual ions both in aqueous and nonaqueous electrolytes. The use of the Volta potential differences for determining real and chemical thermodynamic characteristics of individual ions in solutions is validated.     

Darken's equation and other diffusion relations in the light of atomistic kinetic concepts

The atomistic kinetic approach of the DOCC sites concept (meaning, very simplified, that the dopant migration in solids progresses via sites which are suitable for occupation by dopant corpuscles summarized as dopant-occupiable sites, i.e. DOCC sites) is here used as a basis on which several diffusion models are thoroughly analysed. Since it is able to cover all effects determining dopant migrations, so that it may be valid in general, it proves other statements on dopant transport to be incorrectly formulated. Following this conception, Darken's equation leads to a link between the Fickian diffusion coefficient of an ideal solution and the activity coefficient of the non-ideal solution, which has up to now been ignored. Contrasting with Darken's hypothesis, Einstein's relation between the Fickian diffusion coefficient and the mobility of dopant particles proves true even in cases of non-ideal solutions. The supposed vacancy wind effect and the diffusion of dopant-defect pairs as molecule-like joined complexes are shown to be physically unrealistic. Orlowski's dopant flux formula proves false. Roth's and Plummer's model on oxidation-enhanced diffusion in silicon is shown to involve incorrectnesses. Received: 27 November 1998 / Accepted: 25 March 1999     

QSAR as a random event: criteria of predictive potential for a chance model

The CORAL software (http://www.insilico.eu/coral) was suggested as a tool to build up quantitative structure–property/activity relationships (QSPRs/QSARs). This software is based on conception “a QSPR/QSAR model should be interpreted as a random event.” This is reflection of fact: different distributions into the training set (substances involved in modeling process) and the validation set (substances, which are not known at the moment of the modeling process) give models with significant dispersion in the statistical quality of the QSPR/QSAR. Results of experiments with the software and possible ways of further improvement of this software are discussed. The most attractive new ways to estimate predictive potential of the CORAL model seem to be the following ones: (i) index of ideality of correlation and (ii) correlation contradiction index. These can be also proposed as criteria of predictive potential for arbitrary QSPR/QSAR.

     

溶剂浓度对PVDF相转换膜大孔结构的影响

提出决定大孔能否发展的初始分相点处溶剂浓度临界点的概念 ,认为初始分相点处较高的溶剂浓度有利于大孔的发展 ,溶剂浓度低于一定的界限后 ,大孔停止发展 ,转为海绵状结构 .实验考察了不同凝胶液组成下制得的PVDF中空膜的结构 ,建立了相应的传质模型 ,模拟不同制膜条件下初生态膜内的组成分布情况 ,根据初始分相点处溶剂浓度临界点的概念 ,预测膜的形态结构 .模拟结果与相应制膜条件下的电镜照片有很好的对应关系 ,证明了上述大孔形成机理的正确性 .