Ch解释计算平台在计算机程序设计基础课程中的应用评价

计算机程序设计基础是一门在各学校、各专业都普遍开设的基础课,其中多数以C语言作为入门语言。选择什么样的解释和计算平台能够更有利于学生的学习,从而有效地实现教学目标呢?本文通过一组学生志愿者对不同学习软件的应用体验和评价,说明了Ch解释器可以作为C语言入门课程的一个很好的选择。     

Characterization of bacteriocins produced by two strains of Lactobacillus plantarum isolated from Beloura and Chouriço, traditional pork products from Portugal

Bacteriocins bacST202Ch and bacST216Ch, produced by Lactobacillus plantarum strains isolated from Beloura and Chouriço, respectively, inhibited the growth of a number of Gram-positive and Gram-negative meat spoilage bacteria. According to trycine–SDS–PAGE, bacST202Ch and bacST216Ch are approximately 3.5 and 10.0 kDa in size, respectively. Maximal activity of bacST202Ch (25,600 AU/ml) was recorded after 27 h of and bacST216Ch (102,400 AU/ml) after 22 h of growth. The mode of activity, as determined against Enterococcus faecium HKLHS, is bactericidal. Both peptides adsorb to the surface of the producer cells, but at very low concentrations. Both peptides remained active after 120 min at 100 ^oC and after 2 h of incubation at pH 2.0–12.0. Treatment for 120 min at 121 ^oC did not affect bacST216Ch activity. Activity of bacST202Ch and bacST216Ch was not affected by 1% Triton X-100, Tween 80, Tween 20, SDS, NaCl, urea and EDTA. Bacteriocin ST216Ch was deactivated in the presence of 1% Triton X-114. The nucleotide sequence of a 1044 bp DNA fragment amplified from L. plantarum ST202Ch is identical to the structural gene encoding pediocin PA-1, suggesting that the two bacteriocins are identical. Based on the broad spectrum of antibacterial activity, strains ST202Ch and ST216Ch may be used as starter cultures in the fermentation of meat products.     

Object-oriented cam design through the internet

We have developed a Web-based interactive cam design package under the programming paradigm of the language environment. This package was initially developed as a teaching and learning tool for educational use in an undergraduate Computer-Aided Mechanism Design course. Because the system is Web-based and implemented through a client/server model with the user interface through the Web browser, it is easy to use and maintain. The system can also be used to solve practical engineering cam design problems with flat or roller followers and with translating or oscillating motion types. The system can be used to generate the cam profile, transmission angle, position, velocity, and acceleration of the follower. Once a cam/follower system is designed, animation of the cam/follower system can be performed. At the end of the design, the CNC code for manufacturing the designed cam can also be produced through our Web-based cam design system. The package consists of a number of modules including various Web pages, common gateway interface (CGI) programs, a program called cam.ch, and the CCam class which performs the necessary computation for cam design. Two different versions of the cam design package have been designed and implemented. One runs the cam design program on the client machine as a applet, and the other runs the cam design program on the Web server through CGI. In this paper, details of design and implementation of Web-based cam design package will be described. Two application examples with different motion types for the follower will be used to illustrate features of the applet-based and CGI-based implementation schemes. The ideas of the Web-based software design presented in this paper can be applied to other application areas.     

Growth,Microwave Properties and Microstructure of Ba0.05Sr0.95TiO3 Thin Films

Charged defects were found to have a significant influence over the microwave properties of Ba_0.05Sr_0.95TiO₃ thin films.     

Reproducible tip fabrication and cleaning for UHV STM

Several technical modifications related to the fabrication and ultra-high vacuum (UHV) treatments of the scanning tunneling microscope (STM) tips have been implemented to improve a reliability of the tip preparation for high-resolution STM. Widely used electrochemical etching drop-off technique has been further refined to enable a reproducible fabrication of the tips with a radius 相似文献   

A simple method for AFM tip characterization by polystyrene spheres

An AFM image would not be the true topography of a surface because of the limitation of a finite size of the tip. The true topography of the surface can be deduced if we can know the tip shape. In this paper a simple method has been established to determine the profile of an AFM tip. A geometrical model for the tip and a spherical object has been proposed to show the procedure for deducing the tip shape from AFM images. Isolated spheres and closely packed spheres with different diameters have been observed to confirm the tip shape by this method. It is a non-destructive method to determine the tip shape and the results can be used for future reconstruction of an AFM image.     

Observation and analysis of self-organized surface grain structures in silica films under nonepitaxial growth mode

Silica films under present reactive electron beam deposition conditions have depicted a novel self-organized surface grain structures when probed through atomic force microscopy, 2D fast Fourier transform and glancing incidence X-ray diffraction techniques. The formation of such ordered surface grain structures is observed to be strongly correlated to the nucleation and growth process of the silica films. However, the nature of the substrate (amorphous or crystalline) and multilayer geometries have influenced the shapes, sizes and abundances in the grain structures and the ordering. The strain mediation of such ordered structures when buried under polycrystalline layers like Gd₂O₃ have shown to influence both the grain size as well as roughness. A variety of grain structure evolutions and morphological changes in silica layers were noticed in different multilayer geometries. It is, hence, inferred that by appropriately using combinations of these materials, it is possible to have a control over the multilayer morphology and grain structures, which is a very relevant factor in developing precision ultraviolet laser coatings.     

面向嵌入式通信设备的Ch 自动化测试框架设计

Ch 是一种C/C＋＋脚本语言,用Ch 脚本语言对通信设备进行测试具备简单,快速,可直接嵌入等优点。RobotFramework 是基于Python 语言开发的开源的自动化测试系统,它具有简单明了的上下级结构,可灵活重用的KeyWord,独立于平台和应用,具有很强的扩展性等多种优点。首先介绍构建与实现了一个适合通信设备的Ch 脚本测试新框架,并利用RobotFramework 极强的扩展性,把Ch 测试脚本无缝融合进RobotFramework,融合后的Ch 测试框架同时具备了Ch 脚本和RobotFramework的优点。     

Object-oriented interactive mechanism design and analysis

We have developed a Ch Mechanism Toolkit for analysis and design of mechanisms. The toolkit was developed using Ch, an embeddable C/C++ interpreter with high-level extensions. The toolkit consists of animation program QuickAnimation^TM and a collection of classes for design and analysis of commonly used mechanisms. The Ch Mechanism Toolkit allows users to write simple programs to solve complicated planar mechanism problems. The toolkit can handle mechanisms ranging from the simple fourbar linkage to various sixbar linkages. The Ch Mechanism Toolkit can also be used to design cam-follower systems. It is an effective tool for engineering practice as well as for teaching and learning mechanism design and analysis. This paper describes the design and implementation of the Ch Mechanism Toolkit and its applications.Submitted to Engineering with Computers     

Effects of Li and Fe doping on dielectric relaxation behavior in (Li,Fe)-doped NiO ceramics

High permittivity (Li, Fe)-doped NiO (LFNO) ceramics are prepared by a simple PVA sol–gel route and their dielectric properties are investigated as functions of temperature and frequency. It is found that the concentrations of Li and Fe have strong influences on the microstructure and dielectric properties of the LFNO ceramics. Two thermally activated dielectric relaxations are observed in the Li_0.05Fe_0.10Ni_0.85O ceramic sample with the activation energies of 0.448 and 0.574 eV for the high- and low-frequency relaxations, respectively. By using a complex impedance analysis, it is believed that the high-frequency relaxation is closely related to the transport properties inside the grains, and the low-frequency relaxation might be ascribed to the interfacial polarization at the interface layers of grain boundaries and/or NiFe₂O₄ secondary phase layers.