Investigation of the interaction between acridine orange and bovine serum albumin

The results from the measurement of the fluorescence spectrum showing the binding characteristics of acridine orange (AO) and bovine serum albumin (BSA) are reported. It was found that the equilibrium constant k=4848.64 l mol⁻¹, and the number of binding sites n=0.82. Based on the mechanism of the Forster energy transference, the transfer efficiency of energy and distance between the acceptor AO and BSA were found. The interaction between AO and BSA have been verified as consistent with the static quenching procedure and the quenching mechanism is related to the energy transfer.     

氯酸钾氧化酸性铬深蓝催化光度法测定痕量钒

基于硫酸介质中,酒石酸作活化剂,钒催化氯酸钾氧化酸性铬深蓝,建立了催化光度法测定痕量钒的新方法并讨论了其动力学条件。灵敏度1.47×10~(11)g/ml,测定范围0～9ng/ml。方法简便快速,用于水及食品中痕量钒的测定,结果满意。     

Preparation of Diphenyl Oxalate from Transesterification of Dimethyl Oxalate with Phenol over TS—1 Catalyst

Diphenyl oxalate was synthesized from transesterification of dimethyl oxalate with phenol over TS-1(2.5 wt% Ti)catalyst.TS-1 catalyst,as a beterogeneous catalyst,showed excellent selectivity of diphenyl oxalate and methylphenyl oxalate compared with other homogeneous catalysts.Lewis acid sites on TS-1 catalyst were the active sites for transesterification of dimethyl oxalate with phenol.the high selectivity was closely related to the weak acid sites over TS-1.     

2,6-二甲基吡啶在Y型分子筛的Bronsted和Lewis酸中心上的吸附动力学

２，６—二甲基吡啶在Ｙ型分子筛的Ｂｒｏｎｓｔｅｄ和Ｌｅｗｉｓ酸中心上的吸附动力学董玉林，杨孔章（山东大学胶体与界面化学研究所，济南２５０１００）关键词Ｙ型分子筛，酸中心，Ｌｅｗｉｓ酸中心，２，６—二甲基吡啶，吸附动力学沸石分子筛是一类固体酸催化剂，在...     

Topical Problems in Elemental Analysis of Advanced Ceramic Materials

Selected prominent problems in the analysis of advanced ceramic materials are surveyed. The importance of reliability of results is discussed in the field of elemental trace- and microanalysis in view of its interaction with economy, power of detection, local resolution and speciation selectivity. Particular problems in the analysis of major constituents, trace components and microlocal distributions are based on the striking propertics of ceramics; they are exemplified. Analytical assistance must start from the beginning of the production processing, in the preparation of the powdered base materials. Determination of the stoichiometry requires high accuracy and differentiation of chemical species in bulk and surface analysis of ceramic base powders. Element trace determination by direct instrumental methods requires standard reference materials for calibration; these are currently inavailable in a sufficient variety. For optimum reliability and power of detection, element traces must be prepared in isolated form in a small excitation volume for analysis. A review on the state-of-the-art of wet-chemical combined procedures is presented. Decomposition position procedures are emphasized, due to their risk of contributing severe systematic error. Combustion in elementary fluorine is presented for decomposition of refractory materials. The performance of some direct procedures is discussed. Very efficient methods are available for element trace determinations in ceramic materials, offering high detection power. Several approaches for high-resolution local microanalysis in non-conductive ceramic materials are identified as the most promising development in the analysis of sintered compact ceramic products and devices.     

Specific Sorption Sites for Nitrogen in Zeolites NaLSX and LiLSX

Specific sorption sites for nitrogen, N₂, in NaLSX and LiLSX zeolites were investigated using a DRIFT spectroscopic method. Sorption of molecular hydrogen, H₂, by NaLSX or LiLSX zeolite at 77 K with DRIFT control of perturbation of sorbed molecules allowed to discriminate two or three different types of specific sorption sites in the respective zeolites. Their H–H stretching frequencies are 4077 and 4081 cm^–1 for NaLSX, and 4061, 4084 and 4129 cm^–1 for LiLSX. With reference to an independent investigation by methods of both sorption thermodynamics and molecular modeling for N₂ sorption on LiLSX, the first two of the corresponding bands were ascribed to H₂ sorption on lithium cations, Li⁺, localized in supercages of the faujasite, FAU, zeolite framework at sites SIII and SIII, while the latter band most likely belongs to H₂ sorption on Li⁺ cations at sites SII, and on hydroxyl groups, OH. Sorption of N₂ by Li⁺ cations at sites SIII and SIII is the strongest, resulting in a decrease of intensity of the corresponding DRIFT bands that stem from subsequent H₂ sorption. Nitrogen sorption by Li⁺ cations at sites SII is much weaker. Sorption of N₂ on Na⁺ cations at sites SIII in NaLSX zeolite is also stronger than by Na⁺ cations at sites SII.     

活性位高度暴露的钴/氮/碳电催化剂的构建及氧还原性能研究

金属/氮/碳催化剂（M/N/C，M=Fe、Co等）是最有发展前景的非贵金属电催化剂之一，其性能依赖于催化剂表面的活性物种密度.通过常规的热解含氮前驱物与金属盐的方法制得的催化剂往往存在金属活性物种被包埋而不能有效利用的缺点.考虑到石墨相氮化碳（g-C₃N₄）富含类吡啶氮和亚纳米孔腔结构，将g-C₃N₄包覆在高导电性碳纳米笼（hCNC）表面，进而利用表层g-C₃N₄的配位和限域作用锚定大量Co²⁺离子，获得的Co/g-C₃N₄/hCNC复合物经热解后形成了活性位高度暴露、导电性好、孔结构丰富的Co/N/C催化剂.800℃热解得到的最优化催化剂在碱性介质中展现出优异氧还原活性，其起始电位（0.97 V）与商业Pt/C催化剂相当，且抗甲醇干扰性能和稳定性优异.此项研究提供了一种构建具有高度暴露活性位的M/N/C催化剂的有效策略.     

DFT Study of Metal Atoms Adsorbed at Low-coordinated Sites of MgO （001） Surface

1 INTRODUCTION The interfaces between metals and oxide play a vital role in many industrial applications: hetero- geneous catalysis, microelectronics, thermal barriers, corrosion protection, metal processing and so on[1]. In catalysis, the choice of metal and oxide support is critical in order to obtain a desired reactivity and selectivity[2]. This is due in part to the inherent reac- tivity of the two components. Also the size and shape of the metal particle, which depend on the choice…     

Synthesis and Crystal Structure of Isonicotinic Acid [1-（3,5-Dibromo-2- hydroxyphenyl）methylidene]hydrazide Methanol

A new Schiff base compound, C13H9Br2N3O2·CH3OH, isonicotinic acid [1-(3,5- dibromo-2-hydroxyphenyl)methylidene]hydrazide methanol, has been synthesized and characterized by elemental analysis, IR spectra, and single-crystal X-ray diffraction. The compound comprises a Schiff base moiety isonicotinic acid [1-(3,5-dibromo-2-hydroxyphenyl) methylidene]hydrazide and a methanol molecule. The crystal belongs to the triclinic system, space group P1 with a = 8.464(1), b = 9.511(2), c = 10.901(2) , α = 92.940(2), β = 110.456(2), γ = 96.040(2)o, Z = 2, V = 814.0(2) 3, Dc = 1.759 g/cm3, Mr = 431.09, λ(MoKα) = 0.71073 , μ = 4.994 mm-1, F(000) = 424, R = 0.0440 and wR = 0.1061. A total of 3284 unique reflections were collected, of which 2197 with I > 2σ(I) were observed. The molecule adopts a trans configuration about the C=N double bond. The dihedral angle between the benzene and pyridine rings is 22.0(4)o. The crystal structure is stabilized by intermolecular O-H···N and C-H···O hydrogen bonds, forming layers parallel to the ac plane. The preliminary biological tests show that the compound has potential antibacterial activities.     

Zur Reaktion von 1,3-Oxazolidinen mit Dicarbonsäureanhydriden

Reaction of 3-methyl-1,3-oxazolidine with phthalic anhydride in chloroform leads to ring opening and higher oligomers2 are formed. These are cleaved by addition of protic solvents and 2-methylaminoethyl hydrogenphthalate3 a is obtained. Other 1,3-oxazolidines and succinic anhydride behave similarly.

Herrn Prof. Dr. Dr. h. c.Karl Kratzl mit den besten Wünschen zum 70. Geburtstag gewidmet.