散热面积对供热温度的影响

本文通过对集中散热问题的研究,论述了散热面积对供热温度所产生的影响,提出了解决问题的意见和建议。     

在物理实验教学中开发学生的非智力因素

充分发挥学生的主观能动性,变被动教育为主动教育历来是教师面临的一大难题,在大力提倡素质教育的今天这显得尤为重要,本文讨论了如何于物理实验教学中,有效地开发学生的非智力因素,从而使学生“要学”、“乐学”、“会学”。     

基于四叉树分割视频对象的可伸缩编码算法

提出一种利用多级树集合分裂算法(SPIHT:Set Partition In Hierarchical Trees)作为基于四又树分割视频对象(Video object)的编码和解码的核心技术,从而实现了基于对象渐进传输、可伸缩性编码方法。实验结果表明,该算法在相同的比特率下,可以得到比SPIHT更好的主观恢复图像,提高了基于ROI编码的效率。     

参数化的网络状况监控

网络管理的前提是要对网络状况有清楚地认识 ,因此对网络状况的正确评价可以有效地提高网络管理水平 .在利用netflow进行数据采集的基础上 ,为网络的各类状态定义了参数系统 ,并依此为基准来衡量实时网络状况 ,并在此基础上定义了若干指示器为网络异常提供预警     

美丽总令人忧愁——沈从文“湘西人生形式”的审美意蕴

沈从文以“边城”为代表的湘西题材小说,表现了一种“优美、健康、自然而不悖乎人性的人生形式”,具有很高的审美价值。然而,湘西题材创作的审美意蕴,不仅表现这一人生理想上外化的生活、自为的性爱使这一形式获得了定性,而作家对湘西民族历经磨难的历史和生存危机的现实的感叹揉进这一人生形式中,更使作品获得了更耐人寻味的审美效果,达到了作家提出的“美丽总令人忧愁”这一审美境界。     

图书馆藏书中微生物的研究

研究了微生物在图书馆藏书中的基本分布,结果表明:污染图书资料的主要优势菌为霉菌,其次为细菌。楼层不同,人流量不同,微生物的数量相差较大。     

硫酸链霉素的单扫描示波极谱法测定

建立了测定硫酸链霉素的新方法。在0.5mol/L NH_3-NH_4Cl(pH 10.4)缓冲溶液中,硫酸链霉素产生两个还原波,峰电位分别为-1.44V和-1.55V,其中-1.55V处还原波的二阶导数峰电流与硫酸链霉素浓度呈线性,线性范围为250～1100μg/mL,检测下限为200μg/mL。该方法用于注射液中硫酸链霉素含量的测定,结果满意。     

Measurements of leucocyte membrane elasticity based on the optical tweezers

A 1-μm in diameter polystyrene bead coated with lectin is trapped by optical tweezers whics is formed by a focused laser beam (740nm).A leucocyte adhered to the bottom of sample cell is chosen to close to the trapped bead.When their stable combination is confirmed,the leucocyte is displaced by moving the sample stage.A“tether”is then formed between the trapped bead and the membrane.The force acting on the tether is measured by a detector equipped on the optical tweezers system.The deformation of the membrane is diverse in different contact conditions.When the contact area is small,the tether is very thin and the force on it is 7.4pN(10^-12N),while the tether is much thicker under a larger contact area and its corresponding force is about 14pN.It is presumed that the latter is related to the deformation of cytoskeleton.     

Inhibitory effect of the adenovirus type 5 E1A protein expressed in the yeast system

The human adenovirus type 5 E1A, a tumor- suppressor gene[1], codes for two major related proteins of 243 amino acids (12S) and 289 amino acids (13S) by al-ternative splicing in two exons[2]. Studies have been shown that E1A can regulate expression of many genes and cell cycle[3]. Both in vitro and in vivo experiments indicated that E1A could induce tumor cells differentia-tion, convert tumor cells into an epithelial phenotype, in-hibit tumor cell growth and metastasis and strongly en-ha…     

A complete sequence and comparative analysis of a SARS-associated virus(Isolate BJ01)

Severe Acute Respiratory Syndrome (SARS) is a newly identified infectious disease[1—5]. The global outbreak of SARS has been threatening the health of people worldwide and has killed 353 people and infected more than 5462 in 27 countries, as reported by WHO on April 29, 2003 (http://www.who.int/csr/sarscountry/en). Although it has been recognized that a variant of virus from the family of coronavirus might be the candidate pathogen of SARS[1—5], its identity as the unique pathogen sti…