利用样本成分耗散物的非线性化学指纹图谱的检测方法、条件、特点和应用

分析了适用于测定样本非线性化学指纹图谱的热力学体系和动力学模型,结果表明,在远离平衡的封闭体系和无耗散物补充的敞开体系中,阻尼非线性化学反应对样本化学成分的群集表征和整体含量分析具有重要作用．以丙酮和葡萄糖等为耗散物的阻尼B—Z振荡非线性化学反应为例,研究了反应物种及其浓度、电极类型、温度、搅拌速率、样本种类及用量等影响非线性化学指纹图谱的因素,并对指纹图谱中样本化学成分的定量信息、指纹图谱的特点和应用等进行了研究．成功提出了用于鉴别和评价样本的非线性化学指纹图谱的检测条件和方法．     

Decomposition of reaction networks: the initial phase of the permanganate/oxalic acid reaction

The determination of all chemical reaction networks composed of elementary reactions for a given net chemical reaction is one of the fundamental problems in chemistry, since the decomposition elucidates the reaction mechanism. It is essential in a wide range of applications: from the derivation of rate laws in physical chemistry to the design of large-scale reactors in process engineering where presence of unexpected side products can disturb operation. As an example we consider the well-known permanganate/oxalic acid reaction. We characterize all intermediate substances that can in principle act (auto-)catalytic, list all possible additional intermediate substances that would suffice to start the reaction without assuming presence of any autocatalyst. In particular, we propose for the first time a minimal network in which the well-known autocatalyst Mn²⁺ is produced. To derive our results we present an automatic method to determine whether a net chemical reaction can be explained by some reaction network with a given list of intermediate substances, how to generate all such networks, and how to suggest more intermediate substances if no network with the initially given substances exists.     

Methodology for Developing a Specialized Ontology for Chemical Technology of Reagents and Special-Purity Substances

Two methodologies for developing a specialized ontology for chemical technology of reagents and special-purity substances were proposed. One of them is a methodology for developing the structure and conceptual content of a specialized ontology for the chemistry and technology of production of reagents and special- purity substances. The other is a methodology for using the specialized ontology in interactive intelligent systems for semantic processing of science and technology texts.     

Determining method, conditional factors, traits and applications of nonlinear chemical fingerprint by using dissipative components in samples

The thermodynamic systems and dynamic model suitable for determining the nonlinear chemical fingerprints of samples were analyzed.The results indicated that the damp nonlinear chemical reactions in close systems away from the equilibrium and open systems without the complementarity of the dissipation substances have important significance for the throng characterization and whole content analysis of chemical components in samples.Various factors influencing on nonlinear chemical fingerprint,such as reactant species and their concentrations,electrode types,temperature,stir rate,the sort,dosage and granularity of the sample,etc.were amply researched by a nonlinear chemistry reaction,namely,damp B-Z oscillation which used acetone and glucose as the main dissipative substances.In addition,the quantitative information on the whole of chemical components in samples and the traits and applications of the fingerprint were investigated.The method and its important conditions for determining nonlinear chemistry fingerprint used in distinguishing and evaluating complex samples were successfully put forward.     

A Comparative Study on HCN Polymers Synthesized by Polymerization of NH4CN or Diaminomaleonitrile in Aqueous Media: New Perspectives for Prebiotic Chemistry and Materials Science

HCN polymers are a group of complex and heterogeneous substances that are widely known in the fields of astrobiology and prebiotic chemistry. In addition, they have recently received considerable attention as potential functional material coatings. However, the real nature and pathways of formation of HCN polymers remain open questions. It is well established that the tuning of macromolecular structures determines the properties and practical applications of a polymeric material. Herein, different synthetic conditions were explored for the production of HCN polymers from NH₄CN or diaminomaleonitrile in aqueous media with different concentrations of the starting reactants and several reaction times. By using a systematic methodology, both series of polymers were shown to exhibit similar, but not identical, spectroscopic and thermal fingerprints, which resulted in a clear differentiation of their morphological and electrochemical properties. New macrostructures are proposed for HCN polymers, and promising insights are discussed for prebiotic chemistry and materials science on the basis of the experimental results.     

Analytical methods for monitoring contaminants in food—An industrial perspective

Incoming legislation on the registration, evaluation, authorisation and restriction of chemical substances places responsibility on the chemical industry, including downstream users of chemicals, to provide appropriate safety information with which to improve the protection of human health and the environment through the better and earlier identification of the intrinsic properties of chemical substances. Food consumption is only one of several potential exposure routes, but if industrial chemicals enter the food chain, the diet may be a significant pathway of human exposure. Consequently strong measures are taken to protect the integrity of the human food chain and these are constantly revised to address perceived chemical safety threats. In order to understand the risk presented by the possible presence of a chemical residue in food, knowledge is required of its toxicology and of the level of exposure. Reliable exposure assessment requires robust analytical methodology. Existing standards for the validation and performance evaluation of methods have led to improved analytical capability and better inter-laboratory agreement of results. However, increasing the availability of robust, cost-effective methodology should be the benchmark for future developments in the field of food chemical residue analysis. Chromatography meets the needs of target analyses well and largely provides the selectivity of measurement needed to assess compliance with food regulatory limits. However, to keep pace with the increased need for expanded analytical capability – faster throughput, more analytes per sample – chromatographic separation capability still needs to grow. In this respect, orthogonal separation techniques and multi-dimensional chromatography are key tools for the future.     

Green Chemistry and Modern Technology

The basic principles, approaches, and early achievements of green chemistry are considered. The definition of green chemistry as a branch of chemistry that studies the laws of passing of chemical reactions and the properties of substances participating in such reactions, with the aim of acquiring basic knowledge that provides a basis for designing chemical technologies that eliminate (sharply curtail) the use and production of materials that pose a risk to the environment.     

利用样本成分耗散物的非线性化学指纹图谱原理及相似度计算与评价

在恒温恒压条件下,以丙酮和样本中底物作为主要耗散物的不同成分的样本对非线性化学反应机理产生不同影响,从而引起反应体系电位-时间曲线形状不同变化为特征的B-Z化学振荡体系为例,就非线性化学指纹图谱原理进行了详细研究和讨论,并提出了计算非线性化学指纹图谱系统相似度的通用方法.利用系统相似度和欧氏距离、相关系数及夹角余弦对不同生产批次古汉养生精和18种其他样本的非线性化学指纹图谱的相似度进行了计算与分析.结果表明,相关系数和夹角余弦都不能用来作为评价非线性化指纹图谱相似度的指标.利用欧氏距离公式计算指纹图谱的非参数型相似度时,能正确反映指纹图谱的特征差异,但用其计算参数型相似度时,则有时不能正确反映样本非线性化学指纹图谱特征差异的相对程度.系统相似度能最真实反映样本指纹图谱之间差异程度,是4种相似度计算方法中最好的,可用于非线性化学指纹图谱相似度计算与评价.成功提出了一种经济、简便、易行和有效的鉴别样本真伪与评价其质量的科学方法.     

论中学生化学元素观的建构

化学元素观是中学化学学习中的核心观念。化学元素观的建构有利于中学生对物质世界形成有序的认识,有利于中学生形成化学的思维方法。化学元素观建构的基本策略是:(1)在元素概念基础上形成物质的基本分类;(2)在原子结构认识的基础上理解元素是如何形成物质的;(3)在元素周期律学习的基础上形成元素性质研究的基本模型;(4)在专题性学习中建构化学元素观;(5)在元素观指导下的应用性学习中丰富元素观;(6)利用概念图技术帮助化学元素观的建构。     

2-羟基-1-萘甲醛缩邻苯二胺席夫碱及其铜(Ⅱ)配合物的合成及组成测定——介绍一个大学化学综合实验

设计开发了一个大学化学综合性实验,合成了2-羟基-1-萘甲醛缩邻苯二胺席夫碱及其铜(Ⅱ)配合物,分别采用化学分析法和仪器分析法对配合物的组成进行了测定,并结合红外光谱、核磁共振氢谱对产物的结构进行了表征,取得了满意的实验结果。该实验一定程度上弥补了大学化学教学实验中合成有机金属配位化合物教学资源的匮乏。通过该实验的实施,可使学生进一步巩固回流、纯化、离心等基本操作技能,掌握摩尔比法测定配合物配位数及稳定常数的原理和方法,同时掌握运用有机波谱技术推断和鉴定分子结构的方法。本实验有利于培养学生综合运用有机化学、无机化学、化学分析及仪器分析等知识解决具体问题的能力,同时有利于学生了解席夫碱及其金属配合物的性质、研究动态等,激发学生对科学研究的热情,培养学生系统的科学思维和研究能力。     

Ceramics and Nanostructures from Molecular Precursors

The elaboration of solids from the molecular scale by a kinetically controlled methodology is one of the main challenges of molecular chemistry. In the long term, this should permit the design of solids with desired properties. Here, some examples are given which show a few methods that have been used for the preparation of solids from molecular precursors. The one-pot synthesis of rheologically controlled SiC is described. Access to a new kind of ceramic is obtained by the same methodology using molecular precursors. Mixed ceramics with interpenetrating networks are not accessible by the chemical thermodynamic route. The chemistry of hybrid materials obtained from molecular precursors through inorganic polymerization is presented. This class of materials offers wide perspectives because of 1) the large possibilities opened by the organic unit, 2) the kinetic control, which permits any kind of texture for the solid, and 3) the aptitude of these solids to become nanostructured.     

关于氮族元素教学改革的几点建议

Based on the knowledge characteristics of the chapter on nitrogen group elements, and combined with the teaching experience of our excellent video open course, this paper has probed the teaching reform of inorganic elements chemistry from the following aspects:using the principle of chemistry to explain the structure and properties of substances, designing problems to guide students to think and cultivate their learning ability, instructing students to be good at inducing the changing laws of material properties, paying attention to the relationship between the elements and compounds and practices of production and life. It aims to guide students to learn, memorize and master the knowledge of element chemistry effectively, and improve the quality of classroom teaching.     

Supramolecular Inorganic Chemistry: Small Guests in Small and Large Hosts

A key reaction in the biological and material world is the controlled linking of simple (molecular) building blocks, a reaction with which one can create mesoscopic structures, which, for example, contain cavities and display specifically desired properties, but also compounds that exhibit typical solid-state structures. The best example in this context is the chemistry of host–guest interactions, which spans the entire range from three- and two-dimensional to one- and “zero-dimensional”, discrete host structures. Members of the class of multidimensional compounds have been classified as such for a long time, for example, clathrates and intercalation compounds. Thus far, however, there are no classifications for discrete inorganic host–guest compounds. The first systematic approach can be applied to novel polyoxometalates, a class of compounds which has only recently become known. Molecular recognition; tailor-made, molecular engineering; control of fragment linkage of spin organization and crystallization; cryptands and coronands as “cages” for cations, anions or anion–cation aggregates as sections of ionic lattices; anions within anions, receptors; host–guest interactions; complementarity, as well as the dialectic terms reduction and emergence are important terms and concepts of supramolecular inorganic chemistry. Of particular importance for future research is the comprehension of the mesoscopic area (molècular assemblies)—that between individual molecules and solids (“substances”)—which acts in the biological world as carrier of function and information and for which interesting material properties are expected. This area is accessible through certain variations of “controlled” self-organization processes, which can be demonstrated by using examples from the chemistry of polyoxometalates. The comprehension of the laws that rule the linking of simple polyhedra to give complex systems enables one to deal with numerous interdisciplinary areas of research: crystal physics and chemistry, heterogeneous catalysis, bioinorganic chemistry (biomineralization), and materials science. In addition, conservative self-organization processes, for example template-directed syntheses, are of importance for natural philosophy in the context of the question about the inherent properties of material systems.     

A Robust and Efficient Method for the Computation of Equilibrium Composition in Gaseous Mixtures

This paper presents in detail a robust, efficient and accurate methodology for the computation of equilibrium composition in gaseous mixtures. The methodology is founded on the concept of the chemical basis, which is defined and formalized using a powerful matricial approach. The method is specially designed to be general, thus providing basic thermodynamic data in several areas, such as combustion, plasma chemistry and, more generally speaking, computational fluid dynamics. The performance of the method is given in terms of CPU usage and the computed results are compared with those in the published literature. The method is shown to yield results of very high quality in terms of accuracy and smoothness.     

计算机模拟在化学理论与实验教学中的应用

With the help of PHREEQC program,we introduced the application of computer simulation in theoretical and laboratory teaching of chemistry.Accordingly,reaction models for the chemical process of acid-base neutralization,complexation reaction,precipitation-dissolution equilibrium,and chemical kinetics were established.These models can greatly help the students understand chemistry,improve the teaching quality,enrich modern teaching methodology,develop students' creativity,and establish a scientific and efficient research method.     

土壤腐殖质的分析化学研究进展

对土壤腐殖质的分析化学研究进展作了综述。具体包含如下几个方面的内容；土壤腐殖质的组成和结构的研究，土壤腐殖质的起源和形成的研究，土壤腐殖质与土壤中有机，无机物质的相互作用的研究以及有机物料的分解，转化及其对腐殖质影响的研究，同时，对土壤腐殖质的研究中有待进一步用分析化学方法解决的几个问题进行了探讨。     

SOME PRESUPPOSITIONS IN THE METAPHYSICS OF CHEMICAL REACTIONS

The project of chemistry to classify substances and develop techniques for their transformation into other substances rests on assumptions about the means by which compounds are constituted and reconstituted. Robert Boyle not only proposed empirical tests for a metaphysics of material corpuscules, but also a principle for designing experimental procedures in line with that metaphysics. Later chemists added activity concepts to the repertoire. The logic of activity explanations in modern times involves hierarchies of activity concepts, transitions between levels through non-dispositional groundings. Such hierarchies terminate in powerful particulars, such as elementary charged particles. Do these have a fundamental place in the most recent accounts of molecular architecture, stabilities and transformations? However, a close study of the contemporary chemistry of substances transforming reactions discloses a hybrid metaphysics, making use of both the Boylean corpuscles and Faradayan fields. This is illustrated by an analysis of the metaphysics inherent in John Polanyi’s use of “chemoluminescence” to follow the formation of products in chemical reactions. A brief sketch of a resolution of the tension between the two metaphysical schemes is drawn from Niels Bohr’s radical metaphysics extended from the quantum realm proper to chemistry (and perhaps beyond).