用于甲烷分解和甲烷二氧化炭重整的碳材料催化剂研究进展

The decomposition and CO2 reforming of methane,respectively,are promising alternatives to industrial steam methane reforming. In recent years,research has been focused on the development of catalysts that can operate without getting deactivated by carbon deposition,where,in particular,carbon catalysts have shown positive results. In this work,the role of carbon materials in heterogeneous catalysis is assessed and publications on methane decomposition and CO2 reforming of methane over carbon materials are reviewed. The influence of textural properties(BET surface area and micropore volume,etc.) and oxygen surface groups on the catalytic activity of carbon materials are discussed. In addition,this review examines how activated carbon and carbon black catalysts,which are the most commonly used carbon catalysts,are deactivated. Characteristics of the carbon deposits from methane are discussed and the influence of the reactivity to CO2 of fresh carbon and carbonaceous deposits for high and steady conversion during CO2 reforming of CH4 are also considered.     

BORONIC ACIDS AS LIGANDS FOR AFFINITY CHROMATOGRAPHY

 A review on the principles and applications of boronic acids as affinity ligands for the chromatographic separation of carbohydrates, nucleic acid components, glycoproteins, and other small biomolecules. The mechanisms of interactions between boronate ligands and analytes are described. Various boronate ligands and supports are discussed. Examples of the use of boronate affinity chromatography for separation of each class of analytes are presented.     

INVESTIGATION OF ELECTRONIC SPECTRA OF AZOCOMPOUNDS——ABSORPTION AND EMISSION SPECTRA OF β-NAPHTHOL AZOBENZENE DERIVATIVES

Absorption and emission spectra of eight naphtholazobenzene derivatives are investigated.Absorption processes of n→π~* and π→π~* transition and emission processes from the excitedstates are studied separately in each compound. Intra- and inter-molecular energy transfersfrom the excited states of different chromophores are discussed. Effects of the molecularstructure and the pH value of the solution on the electronic spectra are discussed also. On thebasis of quantum chemistry theory, the spectral data are analyzed qualitatively.     

SUPERPOSITION OF STRESSES AND COMBINED STRUCTURE

There are two kinds of superposition in the tectonic deformation of the crust, compound superposition and combined superposition. According to the principle of superposition of elastic theory, the tectonic stress field caused by two or more systems of external forces, acting on a block at the same time, equals superposition of the individual tectonic stress-field produced by the action of the forces applied individually. A group of formulas of stress superposition are given, and the superposition of homogeneous and inhomogeneous stress-fields are analysed. The geometric property and features of deformation of combined structures are explained in this paper.     

Fluorescence Signal Amplification Strategies Based on DNA Nanotechnology for miRNA Detection

In this review,the most recent progresses in the field of fluorescence signal amplification strategies based on DNA nanotechnology for miRNA are summarized.The types of signal amplification are given and the principles of amplification strategies are explained,including rolling circle amplification(RCA),catalytic hairpin assembly(CHA),hybridization chain reaction(HCR)and DNA walker.Subsequently,the application of these signal amplification methods in biosensing and bioimaging are covered and described.Finally,the challenges and the outlook of fluorescence signal amplification methods for miRNA detection are briefly commented.     

Synthesis of Iso-condensed Heteroaromatic Pyrroles and Their Application in the Preparation of Conducting Polymers

Iso-condensed heteroaromatic pyrroles 1 are 10π-electron aromatic compounds. They are of interest from both theoretical and synthetic points of view. They are the cyclic analogues of heteroaromatic ortho-quinodimethanes 2, and can react with dienophiles in a Diels-Alder reaction to give the synthetically useful cycloadducts 3. Many of them are also of potential pharmaceutical importance because they are isosteric with indoles. Iso-condensed heteroaromatic pyrroles 1 can be used also as the m…     

STATISTICAL THERMODYNAMICS OF POLYMER MIXTURES

Based on a hole model the equation of state of polymeric liquids, the chemical poten-tial and the spinodal of polymer mixtures are derived. In the model the volume changesof liquids are realized through changing the distance between molecules (size of the cell)and number of holes in liquids. If these two factors are considered one by one, two setsof equations of the above equilibrium properties are obtained but one common chemicalpotential equation. With further simplification all the formulas are reduced to that of theFlory or the Sanchez theory respectively.     

DEVELOPMENT OF HOLOCENE CORAL REEFS IN CHINA AND THEIR REFLECTION ON SEA LEVEL CHANGES AND TECTONIC MOVEMENT

In this paper the provinces and characteristics of coral reefs in China are described, the formative ages of the Holocene coral reefs and their reflection on sea level changes are discussed, and the rates of vertical tectonic movements of each province of coral reefs since the Holocene are calculated.     

Some problems in adsorption and calorimetric studies of the steps of catalytic processes

Principal side factors as well as technical and procedural peculiarities capable of distorting the results of measurements of adsorbed and desorbed amounts, of falsifying the nature of the processes proceeding in the systems under study, and of promoting artifacts in calorimetric and other studies of gas chemisorption on powders are considered. Modified techniques and procedures allowing the elimination of sources of side phenomena and artifacts and freeing traditional glass static adsorption apparatuses and experimental procedures from undesirable factors and peculiarities are proposed. Some available chemisorption and calorimetric data representing artifacts and also some data that are not artifacts but,due to imperfections of chemisorption techniques, show up as artifacts are presented and discussed. Several applications of the improved techniques and procedures to calorimetric and adsorption studies of the steps of catalytic processes proceeding on the basis of natural gas and of products of its processing are presented and discussed.     

CHINESE JOURNAL OF CHEMISTRY Instructions for Authors

Chinese Journal of Chemistry,a bimonthly journal sponsored by the ChineseChemical Society,is devoted to the publication of research papers in all felds of chemistry.Only contributions that have not been and are not to be publishedelsewhere will be considered.Articles and Communications are published. Articles of high scuebtufuc quality and originality that are of interest to the wideand diverse readership of the Journal will be given priority for publication. Communications are restricted to(usually preliminary)reports of unusual     

Microbial dehalogenation of trichlorophenol by a bacterial consortium: characterization and mechanism

Chlorinated aromatic compounds are a class of widely used, toxic and refractory organic pollutants. Most of them are persistent organic pollutants (POPs). Chlorinated phenols are an im-portant subclass of them. Chlorinated phenolic compounds are generated from a number of indus-trial manufacturing processes. They comprise the bulk of the environmental pollutants. Aqueous effluents from many industrial operations, such as polymeric resin production, oil refining, iron-steel, petroleum, pestic…     

ORGANOMETALLIC FERROELECTRIC LIQUID CRYSTALS Ⅰ. LIQUID CRYSTAL PROPERTIES OF ORTHO—PALLADATED BINUCLEAR COMPLEXES OF AZINE, IMINE AND AZO DERIVATIVES

The mesomorphie properties of title complexes are investigated by means of DSC and polarizing microscopy. The mesophase temperature ranges of complexes are wider than that of corresponding organic ligands. The bridging groups of the complexes have profoand effects on the mesomorphic behavior, When the bridging groups are opticallhy active. the compleve show chiral smectic     

Determination the Total Flavonoids from Stem and Leaf of Artabotrys.haimanensis

The Annonaccac family is a main one of the tropical plants flora and there are totally 127 genus, about 2231 species in the world, wildly distributed in the tropical zone and subtropics areas. China is one of the countries where species of this family are mostly distributed, with 24 genus, 103 species and 6 variant, among which, 45 species and 1 variant are endemic to China. There are about 100 types of plants of Artabotrys genus in the world, among which, 10 species are in China. Scholars f…     

Chemical Modification of Tryptophan Residues in Pullulanase

Tryptophan（Trp）residues in pullulanase have been chemically modified with N-bromossuccinimide（NBS）. The results of ultraviolet spectra indicated that there are 18 Trp residues in pullulanase and nine of them are located on the surface of the enzyme. Three of these Trp residues are none-essential residues which showed the fastest reaction speed by Zhou＇s plot. Two of the seven relative faster reacting residues are essential for the activity of the enzyme. The other eight are none-reactive residues with lowest reaction speed.     

Pathways of liquefied petroleum gas pyrolysis in hydrogen plasma:A density functional theory study

A density functional theory(DFT) study has been conducted in this work to investigate the pyrolysis pathways of propane and n-butane,which are the main components of liquefied petroleum gas(LPG),for better understanding the pyrolysis behavior of LPG in hydrogen thermal plasma. Over 60 possible reactions are considered.The reaction enthalpies and activation energies of these reactions are calculated and analyzed with a Gaussian method of B3LYP and basic set of 6-31G(d,p).A most possible reaction pathway is brought up.According to this reaction pathway, the main products of LPG pyrolysis are acetylene,ethylene,methane,ethane and extra hydrogen.Acetylene mainly comes from the pyrolysis of propylene and ethylene,and hydrogen ion reactions are the main source of extra hydrogen gas.Active H·radicals are found to play a very important role in many reactions,and they can remarkably lower the energies needed for reactions.     

An unexpected Diels-Alder type cycloaddition of cyclic enone ethylene ketals

The ethylene ketal of 2-cyelopentenone and 2-cyelohexenone in acetonitrile in thepresence of a trace of an acid rapidly undergoes the Diels-Alder type dimerization,Theproducts are regiospecific but not stereoselective and are hydrolysed sequentially to affordketo-ketals and diketones whose structures are determined by extensive applications of NMRspectroscopy.     

STUDIES ON STRUCTURAL-OPTICAL MINERALOGY——EFFECTS OF ELECTRON

In this paper, the Gladstone-Dale ionic refractivities (GDIR values) are calculated onthe basis of the K values given by Mandarino and/or the author. The effects of the elec-tron shell configuration of ions on the refractive properties of minerals are discussed. Theconclusions are as follows: (1) The refractive indices of the compounds consisting of Ne-type ions are linearlyrelated with their densities. (2) The ionic refractivities of the inert gas-type ions are different from those of 18electron-type ions in their variation relationship. (3) The ionic refractivities of ⅠA, ⅡA, ⅢA, ⅣA, ⅤA and ⅥA Groups in the periodictable increase linearly with increasing atomic number. (4) The two-humped curves are found for the ionic refractivities of the first transitionelements. (5) Because of the lanthanum series contraction, the ionic refractivities of rare earthelements decrease with increasing atomic number.     

Molecular Replacement Studies of Cucurmosin from Cucurbita Moschata:Structure Homology with Trichosanthin

1 INTRODUCTION Many plants contain proteins that are capable of inactivating ribosomes and therefore are called ribosome-inactivating proteins or RIPs[1]. RIPs are RNA N-glycosidases that inactivate ribosomes through a site-specific deadenylation of the large ribosomal RNA[2, 3]. RIPs are also capable of inactivating many nonribosomal nucleic acid substrates and can be considered as polynucleotide: adenosine glycosidases[4～6]. There are two types of RIPs: type I, single chain pr…     

Synthesis and Re—refinement of Cu3PSe4

1 INTRODUCTION The chemistry of mixed 15/16 main group compounds has attracted great attentions over the last years[1]. The metal chalcogenophosphides synthesized by solid state reactions[2] are the potential candidates for a wide range of applications such as semiconducting properties, two-dimensional magnetic behavior, anisotropy of conductivity and charge density waves. Some of these compounds are of lamellar structure, which are good materials for the investigation of intercalatio…     

Studies on Hydrogen Bonding Network Structures of Konjac Glucomannan

In this paper, the hydrogen bonding network models of konjac glucomannan （KGM） are predicted in the approach of molecular dynamics （MD）. These models have been proved by experiments whose results are consistent with those from simulation. The results show that the hydrogen bonding network structures of KGM are stable and the key linking points of hydrogen bonding network are at the O（6） and O（2） positions on KGM ring. Moreover, acety has significant influence on hydrogen bonding network and hydrogen bonding network structures are more stable after deacetylation.