Synthesis and properties of chitosan-modified poly(vinyl butyrate)

Modification of chitosan by grafting of vinyl butyrate was carried out in homogeneous phase using potassium persulfate as redox initator and 1.5% acetic acid as solvent. The percent grafting and grafting efficiency were analysed and the high grafting efficiency up to 94% was observed. The effects of reaction variables such as monomer concentration, initiator concentration, temperature and reaction time were investigated. It was observed that the solubility of chitosan was markedly reduced after grafting with vinyl butyrate. The grafted product is insoluble in common organic solvents as well in dilute organic and inorganic acids. Characterization of the graft copolymers were carried out by using Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and Scanning Electron Microscopy (SEM) technics. Characteristic signal of carbonyl group was observed at 1,731 cm⁻¹ which belongs to the poly vinyl butyrate segments in the graft copolymer. The melting transition of the chitosan main chain in the copolymer shifted to 124°C from its original value 101°C. In addition to these, we have also studied topology of the graft copolymer and the SEM micrograph showed continuous homogenous matrix which means there is no phase separation.     

莱钢异型坯连铸机控制系统的研究与应用

介绍了莱钢异型坯连铸机的控制系统,并对一级、二级控制系统以及硬件、软件进行了较详细的论述。     

基于函数签名的控制流监控方法

针对恶意篡改程序控制流攻击方式,提出一种监控程序控制流完整性的方法。对程序源代码进行扫描,以函数作为识别程序行为的基本粒子,利用函数调用执行的序列信息,建立表现程序原意的行为轨迹模型,利用该模型在运行期监控程序的执行流程。实验结果表明,该方法对篡改控制流的攻击起到了很好的防御作用。     

Czech project in history of mathematics

The paper describes the Czech project in the history of mathematics which was initiated at the Faculty of Mathematics and Physics of Charles University in Prague at the end of the eighties of the 20th century. Its main aim is to map the development of mathematical research in the Czech lands in the second half of the nineteenth and the first half of the twentieth century. The main result of this project is the production of monographs. These chart out the life and work of some prominent Czech personalities-mathematicians who have had substantial influence on the development of Czech mathematics. The aim of the project, the structure of the monographs and the general method are discussed in the paper.     

地质雷达在铁路桥基无损检测中的应用

详细论述了地质雷达在实际工程中现场探测和分析中的过程和理论，提出了新的应用手段。测试结果达到了预期的目标，证明了地质雷达具有很有价值的应用前景。     

Moisture adsorption isotherms and thermodynamics properties of sucuk (Turkish dry-fermented sausage)

Moisture adsorption isotherms of sucuk were determined using the isopiestic method at 10 °C, 20 °C and 30 °C and within the range of 0.2-0.9 water activity. The isotherms of sucuk exhibited Type II behavior according to BET classification. The adsorption data were analyzed using mathematical equations of Halsey, Caurie, Peleg, Smith, Oswin, Henderson, Modified-BET, GAB, Ferro-Fontan and Harkins-Jura. The best fit of experimental data was obtained with Peleg equation in the range of temperatures and water activities investigated. Thermodynamic properties such as differential enthalpy and entropy, enthalpy-entropy compensation, spreading pressure, net integral enthalpy and entropy were determined from moisture adsorption isotherm data of sucuk. The net isosteric heat of sorption and differential entropy decreased with increasing moisture contents in an exponential function. The spreading pressure increased with increasing water activity, and decreased with increasing temperature. The net integral enthalpy decreased with increased moisture content. The integral entropy increased with moisture content, but it was negative in value. The enthalpy-entropy compensation theory was applied to water adsorption of sucuk.     

Influence of the Interaction Potential on the D↓1 Equation of State

The ground-state properties of spin-polarized deuterium with only one occupied nuclear spin state (D↓₁) at zero temperature are studied by means of the variational Monte Carlo (VMC) method. Influence of the backflow correlations on the ground-state energy of this Fermi system under investigation is also explored. The calculations have been performed using several interatomic potentials and the quantum phase of the D↓₁ system is discussed. Our results are compared with other previously reported variational results.     

Irradiation embrittlement monitoring of WWER-440/213 TYPE RPVs

In the paper the main goals and progress of the surveillance specimen programme for the RPVs WWER-440/213 in Jaslovské Bohunice V-2 and Mochovce NPPs are presented. At Jaslovské Bohunice V-2, the standard surveillance specimen programme (SSSP) was finished and so-called ‘Extended Surveillance Specimen Programme’ (ESSP) was prepared on the base of its critical analysis. For first two units of the Mochovce NPP completely new programmes of irradiation embrittlement monitoring called ‘Modern Surveillance Specimen Programme’ is prepared. It is based on the experience with SSSP and ESSP as well as the recommendations of IAEA experts. This programme will serve for Mochovce NPP during all planned service life. The experience of ESSP application on the 3rd and 4th units in Jaslovské Bohunice V-2 NPP are presented in the paper too.     

复杂三维槽型刀片的断屑性能

对５种国产复杂三维槽型刀片的断屑性能进行了试验研究，并对三维槽型结构要素的断屑机理及断屑特点进行了分析。