On the Compensation Effect at the Form of the Differential Conversion Function

From the general form of the rate equation under non-isothermal conditions, some relationships showing the existence of a compensation effect due to the change of the analytical form of the differential conversion function were derived. These relationships were checked for some simulated TG curves, as well as thermogravimetric data corresponding to the degradation of some polymers and to the decomposition of calcium carbonate. This revised version was published online in July 2006 with corrections to the Cover Date.     

Highlights of Spanish chemistry at the time of the chemical revolution of the 18th century

Summary A number of outstanding Spanish chemists and some of their major chemical contributions in the 18th century are briefly considered indicating that Spanish chemistry got a very high level at the end of the century, departing practically from nothing at the beginning of the century. The Vergara School played a very important role as the first national institution for chemistry despite of the fact that it decayed in a few years for a number of reasons. The discovery of three new elements is briefly dealt with (Pt, W, V) and the adoption of the new modern French chemistry in Spain as well as a number of critics against some of Lavoisier's theories and nomenclature posed by some Spanish chemists are considered.     

用分子动力学模拟方法研究层孔与微孔磷酸铝化合 物中有机胺的模板作用: 指 导定向合成的有效途径

用分子动力学方法,研究了有机胺模板剂对二维层孔与三维微孔磷酸铝化合物的模板作用。依据主-客体间的非键相互作用能量,可以有效地预测出适于某一特定结构的有机胺模板剂。通过选择理论预测的有机胺分子作模板剂,在溶剂热体系中可以定向地合成出具有特定结构的化合物。这一工作对于微孔功能体系的分子工程学研究具有一定的指导意义。     

Testing the performance of density functionals for the calculation of energetic properties of complex-forming radical-molecule reactions

The performance of some popular and some more recent density functional methods for the calculation of energies of stationary points on the potential surfaces of radical-molecule reactions was examined. The functionals studied are B3-LYP, BH&H, BH&H-LYP, MPW1K, MPWB1K, TPSS, TPSSh, BB1K, M05 and M05-2X, in conjunction with nine different AO basis sets. The reaction energies, barrier heights and the relative energies of the pre-and post-reaction complexes were compared with those obtained at the CCSD(T)/CBS limit for the reactions of OH radicals with HOOH and CH₃OOH. Very poor barrier heights are provided by the B3-LYP, TPSS and TPSSh functionals. The best overall performance was obtained with the BB1K, MPW1K and MPWB1K functionals. In these reactions all of the studied functionals provide converged results only if they are used with large basis sets like aug-cc-pVTZ and def2-TZVP. The data show that before relying on a functional for a specific reaction, it is desirable to make some test calculations on the performance. The same functional can predict some relative energies very well and some others very poorly even in systems including chemically similar reactants.     

Results obtained from the group study on the clinical efficacy of SPECT of the liver

The influence of SPECT over the detectability of SOL in the liver was evaluated by the Subcommittee on Efficacy Study, which belongs to Medical and Pharmaceutical Committee of Japan Radioisotope Association, under the participation of 9 hospitals including some university hospitals. In this study segmental reading of the SOL was requested. The film reading was performed twice on the different patient-groups and the results from well-experienced doctors (11 doctors) were summarized, indicating a slight increase in sensitivity as a whole although there were some doctors showing a reverse effect in each performance. Sensitivity was determined in the patient-group without SOL, which showed a slight decrease as a whole, indicating that SPECT had some possibility of increasing false positive cases. In the study of SOL detectability based on its segmental location, a marked positive effect of SPECT was noted in the right anterior and right posterior segments whereas a marked negative effect in the left lateral segment. The left medial segment also showed a slight decrease in the detectability of SOL.     

A study of the chemiluminescence of some acidic triphenylmethane dyes

Chemiluminescence was observed when some acidic triphenylmethane dyes were oxidized with hydrogen peroxide in alkaline solution. Trace amounts of Co(II) catalysed this chemiluminescent reaction strongly, especially in the presence of the cationic surfactant cetyltrimethylammonium bromide. The chemiluminescence spectra of some compounds and the absorption spectra of some products of the chemiluminescent reactions were investigated, and some acidic triphenylmethane dyes were studied by the Hückel molecular orbital method. On the basis of these investigations, a possible mechanism for this chemiluminescent reaction, and an initial explanation for the relationship between the structure of the reagents and their chemiluminescent behaviour were proposed. The optimum conditions for use of some of the chemiluminescent reaction systems were selected by means of the modified simplex method, and a chemiluminescent analytical method for determination of ultratrace amounts of cobalt was established, with a detection limit of 5 pg/ml. It was used for analysis of natural water samples, and good results were obtained.     

有机反应中的极性转化方法

极性转换方法是一种重要的有机合成新方法 ,对极性转换的概念和应用作了论述 ,并对一些极性转换的新技术作了简介     

Investigation of the influence of some experimental parameters on the position of the deposition zone in a temperature-gradient tube

An investigation of the influence of some experimental parameters on thermochromatographic separations has been carried out. It is shown that the position of the deposition zone depends on separation time, purity of the inert gas, and on type and amount of the chlorinating agent. The gas flow rate and the amount of the transported compounds have no influence within the limits of experimental conditions. From the experimental results it can be concluded that in some cases the deposited compounds react with the surface or with the excess gas.     

Use of the beta-phase of poly(9,9-dioctylfluorene) as a probe into the interfacial interplay for the mixed bilayer films formed by sequential spin-coating

Spin-coating one polymer solution on another spin-cast polymer film is believed to result in unfavorable interfacial mixing. Here, we show some results to demonstrate that some interesting properties will be obtained in such mixed bilayer films formed by sequential spin-coating. Poly(9-vinylcarbazole) and poly(9,9-dioctylfluorene-2,7-diyl) were chosen as the first and second polymer layers, respectively. By varying the initial thickness of the first layer, some interesting variations were observed. The spectroscopic features of beta-phase polyfluorene were utilized to reflect the variations at the complicated interface. Morphologies were also presented to illustrate that the variations of spectroscopic features were accompanied with some interesting morphological changes. On the basis of these results, a schematic model was proposed to gain insight into the mixed interface formed by sequential spin-coating. Polymer light-emitting devices based on such films were also investigated.     

On the chronicle of high-T c oxide superconductors

After briefly noting some development records in phase diagrams, the stoichiometry is dealt with in more details showing the structural layer ordering in the superconducting cuprates and mentioning some correlation between thermodynamics and BSC theory of superconductivity. This revised version was published online in July 2006 with corrections to the Cover Date.     

Note of the INDO geometry optimization of biphenyl

Recently published results of Rayez and Dannenberg concerning the biphenyl molecule show some inadequacies. Our recalculation gives contrary results, which are in qualitatively good agreement with some CNDO/2 calculations presented recently. Consequently, implictions discussed by Rayez and Dannenberg are not justified and they are in contrast to our experience with CNDO/2 geometry optimizations.     

我国化学课程标准中的建构主义评析

我国的化学课程标准在某种程度上反映了建构主义的一些思想,具体表现在对科学探究、学习情景及合作学习的强调上。同时,建构主义自身也有不足之处,课程的实施者对此要有清醒的认识。     

Analysis of the Vorontsova equation for calculation of vicinal coupling constants: Criticism of the criticism of the Karplus equation

Analysis of the Vorontsova calculation of vicinal coupling constants in terms of angular and chemical shift dependence indicates some serious inconsistencies in this equation.     

艾滋病（AIDS）病毒抗体检测方法研究进展

对艾滋病(A IDS) 病毒抗体检测方法的研究进展作了较系统的评述。从抗原试剂的构成及样品的来源等方面对各种检测方法进行归纳分类。论述了病毒抗体检测方法研究发展的三个阶段, 分析比较了各种艾滋病毒抗体检测方法的优缺点。给出125 篇参考文献。     

Energy dispersive X-ray fluorescence and neutron activation analysis of surficial sediments of the Sea of Marmara and the Black Sea around Istanbul

Surficial sediment samples, collected from 27 sampling sites of the Sea of Marmara and the Black Sea nearby Istanbul area in 1996 and 1999 years, were analyzed quantitatively for some heavy metals and some other elements by using radioisotope excited energy dispersive X-ray fluorescence (EDXRF). The U and Th concentrations of the samples were determined by instrumental neutron activation (INAA). The results were compared with those from other contaminated and uncontaminated sedimentary materials. It is found that some elemental concentrations of the Sea of Marmara and the Black Sea sediments are comparable with those in most other sea sediments in the vicinity of densely populated regions.     

On the Thermal Behaviour of some Polyimide Membranes

The authors present their results concerning the influence of the nature and amount of plasticizer on the thermal stability of some polyimide membranes. A non-isothermal kinetic investigation of some thermal decomposition workable steps was performed too. This revised version was published online in July 2006 with corrections to the Cover Date.     

蛋白质在疏水作用色谱上的保留模型及其模型参数间关系的研究

在优先水化作用和相关作用原理的基础上,从热力学出发推导出蛋白质在高效疏水作用色谱(HIC)上的保留模型,建立了模型参数间的关系式,使过去观察到的经验规律有了理论依据,并利用上述模型解释了一些蛋白质在HIC上的重要色谱特性。     

On the origin of the peaks of some substituted ions in the mass spectra of lecithins

Preliminary results concerning the origin of the peaks of some substituted ions in the mass spectra of lecithins, obtained under electron impact and chemical ionization conditions, are reported.     

Mixing in the sample loop of the loop-type interface in coupled LC-GC

During introduction of an LC fraction into the sample loop of the loop-type interface mixing occurs between the fraction of interest and the material previously eluted from the LC. Such mixing may not only result in losses of the solute material of interest, but also in contamination of the fraction of interest with material from which it was supposed to have been isolated. Experimental determination of the extent of mixing has led to the conclusion that whereas the effects are negligible under some conditions, in some circumstances the mixing can cause severe problems.