重组大肠杆菌发酵生产核酸疫苗的初步研究

初步摸索大肠杆菌DH 5α生产核酸疫苗的发酵条件。通过均匀试验设计确定,当胰蛋白胨与酵母粉的质量比为1∶1.2,并且磷酸盐的加量较大时菌体的质粒产量较高。在菌体生长刚进入对数生长期时采用指数式流加葡萄糖与采用恒速流加葡萄糖,菌体得率相同,而产物收率前者高于后者。在菌体生长进入平稳期时将温度由37°C升高到42°C,在菌体密度没有改变的情况下,质粒产量得到提高,达到75 m g/L。     

Coincidence and reproducibility in the EHT black hole experiment

This paper discusses some philosophical aspects related to the recent publication of the experimental results of the 2017 black hole experiment, namely the first image of the supermassive black hole at the center of galaxy M87. In this paper I present a philosophical analysis of the 2017 Event Horizon Telescope (EHT) black hole experiment. I first present Hacking's philosophy of experimentation. Hacking gives his taxonomy of elements of laboratory science and distinguishes a list of elements. I show that the EHT experiment conforms to major elements from Hacking's list. I then describe with the help of Galison's Philosophy of the Shadow how the EHT Collaboration created the famous black hole image. Galison outlines three stages for the reconstruction of the black hole image: Socio-Epistemology, Mechanical Objectivity, after which there is an additional Socio-Epistemology stage. I subsequently present my own interpretation of the reconstruction of the black hole image and I discuss model fitting to data. I suggest that the main method used by the EHT Collaboration to assure trust in the results of the EHT experiment is what philosophers call the Argument from Coincidence. I show that using this method for the above purpose is problematic. I present two versions of the Argument from Coincidence: Hacking's Coincidence and Cartwright's Reproducibility by which I analyse the EHT experiment. The same estimation of the mass of the black hole is reproduced in four different procedures. The EHT Collaboration concludes: the value we have converged upon is robust. I analyse the mass measurements of the black hole with the help of Cartwright's notion of robustness. I show that the EHT Collaboration construe Coincidence/Reproducibility as Technological Agnosticism and I contrast this interpretation with van Fraassen's scientific agnosticism.     

Cholera toxin structure, gene regulation and pathophysiological and immunological aspects

Many notions regarding the function, structure and regulation of cholera toxin expression have remained essentially unaltered in the last 15 years. At the same time, recent findings have generated additional perspectives. For example, the cholera toxin genes are now known to be carried by a non-lytic bacteriophage, a previously unsuspected condition. Understanding of how the expression of cholera toxin genes is controlled by the bacterium at the molecular level has advanced significantly and relationships with cell-density-associated (quorum-sensing) responses have recently been discovered. Regarding the cell intoxication process, the mode of entry and intracellular transport of cholera toxin are becoming clearer. In the immunological field, the strong oral immunogenicity of the non-toxic B subunit of cholera toxin (CTB) has been exploited in the development of a now widely licensed oral cholera vaccine. Additionally, CTB has been shown to induce tolerance against co-administered (linked) foreign antigens in some autoimmune and allergic diseases. Received 25 October 2007; accepted 12 December 2007     

一种新型多DSP并行计算结构及其应用

传统的雷达信号处理系统的设计方法是针对特定应用的,因此系统的通用性差,而具有超级计算机体系结构的通用高速实时雷达信号处理系统有望解决这一问题。该系统的关键部件为担负具体计算任务的处理结点。首先提出了一种新型的、由5片ADSP-2106x构成的多DSP并行计算结构。它具有运算能力强、I/O带宽大、通信手段多样、能灵活地改变拓扑结构、可扩展、通用性强等特点。并且以此并行计算结构为核心设计实现了通用高速实时雷达信号处理系统的处理结点。     

基于邻域熵的自适应多尺度边缘检测方法

提出了一种基于邻域熵的自适应调整滤波尺度的多尺度边缘检测方法,该方法根据当前像素点所处邻域内像素点的灰度分布的有序性,定义了邻域内灰度分布的邻域熵,以判定该邻域内是否存在边缘。同时分析了后选边缘的宽度,以定量调整边缘检测中的滤波尺度参数。实验结果和抗噪性能分析表明,这种方法可以得到令人满意的结果,特别是对图像中弱边缘的检测效果比较理想。     

计算机网络系统正常工作模式和故障模式分析

提出了考虑网络节点可靠性时,计算机网络系统正常工作模式和故障模式分析方法.通过比较不考虑节点可靠性和考虑节点可靠性条件下,计算机网络系统正常工作模式和故障模式变化,说明在计算机网络系统可靠性与安全性分析时,考虑节点可靠性的必要性.     

一个基于专家系统的入侵检测系统的实现

入侵检测系统是传统被动方式的网络安全检测手段的重要补充,它是一种主动、实时、自动检测入侵行为的工具和手段.本文论述了两种入侵检测方法--异常行为检测方法和比较学习检测方法的基本原理,同时根据这两种网络安全检测方法,采用专家系统技术,构筑了一个实际的网络监控系统的具体实现,并给出了该网络监控系统的结构图.     

基于SolidWorks 渐开线齿轮的三维辅助设计

探讨了基于SolidW orks的二次开发技术,研究如何利用V isual Basic程序语言在SolidW orks中强大的三维绘图功能进行计算机三维辅助设计;并以渐开线齿轮的设计与绘制为例,提出了通过程序计算后利用SolidW orks曲线连接阵列点构建封闭齿廓的方法。实践证明该方法为其它CAD二次开发平台绘画渐开线齿轮提供可借鉴之处。     

电子教鞭软件在计算机实验室管理中的应用研究

电子教鞭软件的作用实际上不止是教学，经过研究和实践，其在计算机实验室的日常管理和维护上同样发挥出色，在实现实验室管理的自动化、提高工作效率和服务满意度等方面都起到一定作用。     

计算机基础课程递进式实训项目与动态评价设计

针对学生个性差异，按照基本操作、高级应用、综合应用的逻辑递进关系设计计算机应用基础课程实训项目序列，以满足不同层次学生的需求．根据项目的设计与划分，设计了由递进序列项目的评价和递进序列任务评价组成的动态评价序列，对学生实施个性化的诊断评价和教学补救．