慢启动半导体激光器驱动电源的设计

根据半导体激光器的光功率与电流的关系,通过慢启动电路、纹波调零电路、功率稳恒电路等解决了使用中的电源在工作温度范围内其输出功率不稳定的问题。设计的电路稳定度达到4×10-4。     

阿尔兹海默症患者的语义记忆损伤:表现、理论及展望

图片命名、范畴流畅性等神经心理学测验表明,阿尔兹海默症(AD)患者普遍存在语义记忆的损伤,并随着病程的发展表现出进行性与弥散性特点。AD患者语义记忆的损伤既可能由语义知识的存储障碍造成,也可能由语义知识的提取障碍引发,还可能由存储与提取的双重损伤造成。未来研究应开发出对早期AD检测更为敏感的语义记忆测验,并采用横向与纵向多种研究技术与手段,考虑不同语言文化背景下AD患者语义损伤的情况,以综合分析AD患者语义记忆损伤的实质及其发展趋势。     

3-(6-溴吡啶-2)-2-(2-氟-6-氯苯)-噻唑酮-4的电子结构与抗HIV活性间关系的量子化学研究

采用AM1方法,对3-(6-溴吡啶-2)-2-(2-氟-6-氯苯)-噻唑酮-4(BPFCTZO)进行了量子化学计算,给出了分子的几何构型、原子的净电荷、键级、前沿分子轨道组成与能级、前沿轨道电子密度等参数.结果表明BPFCTZO分子的稳定构型呈蝴蝶状,噻唑酮环为主活性区,其上的2位C、4位N和6位O等原子很可能是其与RT酶作用的活性位点.     

On-line estimation of concentration parameters in fermentation processes

INTRODUCTION Saccharomycete, closely linked with human life, is the only microbe that has been utilized to the extent of over a million tons in the world, and is one of the modelled biological bacteria mostly used in modern genetic engineering. Since there are no effective online instruments for measuring the production or resultant concentration, which is a very important quality index in fermentation process, soft sensors (Martin, 1997; Tham et al., 1991; Assis and Filho, 2000; Salgad…     

Active changes of lignification-related enzymes in pepper response to Glomus intraradices and/or Phytophthora capsici

INTRODUCTION Plants have defense mechanisms against patho-gen infection by inducing systemic resistance in re-sponse to localized pretreatment with biological cotrol agents, thus making them resistant to subsequpathogen infection (Caruso et al., 1999; Hammschmidt, 1999; Mohammadi and Kazemi, 2002; yada et al., 1995; Pozo et al., 2002; Ray et al., 199Biological control of plant pathogens has receivmuch more attention. It is well known that plants amicroorganisms symbiosis is a defense m…     

近期中国风水文化争议综述

近日随着建设部中国建筑文化中心和国际易学联合会主办的“首届中国建筑风水文化与健康地产发展国际论坛”在人民大会堂开幕和以建设部中国建筑文化中心与南京大学易学研究所名义开办的国内首个“建筑风水文化培训班”的开张,什么是风水,风水究竟是科学还是迷信,以及如何看待风水的影响与作用等,又成了学术界争议的热门话题。这一争议热潮有利于人们如何正确认识和对待风水。     

大学英语中个性化教学的探索与实践

个性化教学不是一种学习方式或方法,而是一种教育理念。在每个学生接受传授的同时,以学生为中心,目的是让学生按自己的进度,用自己的方法来学习他们所需要的内容,计算机和网络技术是必要的硬件保证。文章探讨了使用计算机进行个性化教学的利与弊以及如何进行个性化教学。最后,作者以一次教学尝试说明了个性化教学的可行性和效果。     

The Use and Misuse of Standardized Testing: A Whiteheadian Point of View

First an overview is given about the actual national and international situation concerning standardized testing. Then two major reasons are presented why accountability systems based on standardized testing have become so widespread: (a) the missing validity and reliability of teachers’ assessment of students’ achievement, and (b) the important role standardized testing plays for out-put management in educational systems.On the basis of these considerations Alfred North Whitehead’s critical remarks on external standardized testing are presented. Whitehead’s main point is that external standardized testing limits the freedom of teachers to adapt to the complex, situation specific circumstances in order to obtain a maximum of the creative learning process for students who are conceived as specialists. Instead external testings lead to “teaching to the test.” As a consequence, the attitude of creative, adventurous exploration is undermined and substituted by simple pattern recognition, narrow visions, and even boredom. Finally, the question is raised whether there is any possibility of developing a measurement tool which on the one side meets scientific test criteria, and on the other side is still flexible enough to do justice to needs of individual schools – which according to Whitehead are the essential educational unit – and not vice versa, as it is the case at present with external standardized testing. That such a flexible approach to evaluation is possible is demonstrated by the presentation of the basic ideas of the MSS (Module Approach to Self-Evaluation of School Development Projects) which has been developed and examined in ten schools by the author and his collaborators.     

三个代表"重要思想:马克思主义理论发展的新境界

"三个代表"重要思想以高度浓缩的形式体现着唯物主义历史观和科学社会主义的基本原理,蕴含着马克思主义关于共产主义社会经济、政治和文化基本特征的规定,包含着毛泽东、邓小平的一系列重要思想,因而是马克思主义本质的体现,与马克思列宁主义、毛泽东思想、邓小平理论一脉相承。同时,"三个代表"重要思想又是对新的历史条件、新的历史任务和党的建设面临的新问题的新概括,它本身就是一个理论整体,体现了卓越的理论创造性,并以一系列新思想、新观点和新论断发展了马克思主义。"三个代表"重要思想本身就是发展着的马克思主义,是党在新世纪的新的理论武装。     

科举的公正诉求与乡土中国的社会流动

公正是贯穿科举考试中的一条红线。科举考试对官宦庶民一视同仁,从考场专门设置、糊名誊录、双重定等第、别头试和锁厅试等方法的采用,都力图给中小地主阶级和平民百姓通过科举入仕实现向上社会流动提供了一个公平竞争的平台。公平竞争、择优录取是科举制得以长期存在的重要原因,科举制度使封建社会通过选纳社会精英进入政治权力中心而不时迸发出活力。