具有相对平坦性的S-系

S－系的相对平坦研究是S－系平坦性理论研究的重要的组成部分，该文利用S－系的相对平坦性的思想，给出了在一些特殊条件下分别满足A－平坦，A－主平坦，条件（PA）的S－系的某些等价刻画。     

齿瓣延胡索细胞悬浮系的建立和延胡索乙素的形成

就各种因素对齿瓣延胡索悬浮细胞生长和延胡索乙素形成的影响做进一步的研究。结果表明：随着接种量的提高，细胞生长加速，培养液浊度增大，齿瓣延胡索细胞悬浮液培养中最适接种量为2g/30ml;pH5.6最有利于细胞生物量的积累；2，4—D与2种细胞分裂素的组合，对于生长量积累和THP含量的作用最显著；在培养基中添加甘露糖和半乳糖，对于提高培养物THP含量是有效的；G1y Phe Lys的作用效果最显著，细胞鲜质量、干质量和THP含量均最高。     

百年诺贝尔物理学奖基本状况的分析

诺贝尔奖是世界近代史上最久负盛誉的一项国际性大奖,从1901年颁发到2000年,已走过了整整一个世纪。百年来,无数科学家在各个学科领域内为人类创造了宝贵的文化和科学财富。了解和研究这段历程,可以使我们获得许多重要的借鉴与启迪。     

《解放军理工大学学报(自然科学版)》2003年(第4卷)第1～6期总目次

(期 -页 )Ad hoc传感网络的体系结构及其相关问题王海涛 ,郑少仁 ( 1-1)………………………………………………………………一种基于马可夫过程统计模型的语音激活检测方法徐筱麟 ,张兴国 ( 1-7)……………………………………………………无线通信系统模块化设计标准体系的研究邱永红 ,王庭昌 ,范建华 ,等 ( 1-11)………………………………………………一种基于自适应模糊滤波的语音增强方法王金明 ,张雄伟 ( 1-17)………………………………………………………………通用分布式仿真环境研究鲍广宇 ,刘晓明 ( 1-2 1)………………………………     

^210Pbex depth distribution in soil and calibration models for assessment of soil erosion rates from ^210Pbex measurements

Throughout the past decade, the potential for using nuclear weapon-produced 137Cs ( half-life 30.2 a) fallout to quantify soil erosion rates on both cultivated and uncul- tivated lands for medium-term timescales (≈ 40 a) has been successfully demonstrated in a wide range of envi- ronments in different regions of the world[1—6]. Because in difficulties of distinguishing Chernobyl-derived compo- nent from total 137Cs input in many parts of Europe, and in measuring low activity samples of…     

Inorganic chemical composition and source signature of PM2.5 in Beijing during ACE-Asia period

Aerosol samples for PM2.5 were collected in Beijing for 38 consecutive days from March to April 2001 using an IMPROVE Sampler. Concentrations of 20 elements in PM2.5 were determined using a PIXE method. Results show that the average mineral dust concentration of PM2.5 was 14.6 Ilg/m3 during the observation period. On the sand-dust event days of March 21 and April 10, dust PM2.5 mass concentrations were 62.4 and 54.1 μg/m^3, respectively.These demonstrate that fine particle pollution by dust event in Beijing was very severe. The enrichment factors of S and Cu reached minimums on the dusty days and were high on the non-dusty days. It is considered that enrichment factors of elements in PM2.5, which are associated with human activities, can probably provide an effective method to distinguish local sources from external sources of dust. Factor analysis on the chemical composition in PM2.5 shows that sources of crustal matters, anthropogenic emission, and oil combustion contributed to PM2.5 levels in air in the springtime of 2001 in Beijing.     

pH Dependence of Chlorophyll States, Protein Structures and Function of the PSII Membranes

IntroductionPhotosystem II ( PSII) is a pigment- proteincomplex in the thylakoid membrane. Its reactioncenter( PSII- RC) ,which is composed of D1 andD2 proteins,generates the highly positive oxidantrequired for the oxidation of water by light- drivencharge separation. Water oxidation occurs at theMn4cluster positioned atthe center of the oxygen-evolving complex on the lumenal surface of PSII.In green plants,the highly reactive Mn4cluster isshielded by a number of extrinsic proteins( 33…     

干湿球法测量相对湿度算法研究及单片机实现

研究基于单片机的干湿球测湿方法．通过对湿度、干球温度、干湿球温差三者关系的分析，提出一种把曲面问题转化成曲线问题的计算方法．本方法不仅计算简便，而且计算准确，如计算结果四舍五入保留整数，则与湿度查算表数值完全吻合．实验表明：应用此方法的单片机测湿系统，其湿度测量精度主要取决于温度测量精度．     

基于图像分析的实验模型变形场量测标点法

在模型观测面上 ,通过设置嵌入式彩色标点 ,在实验各阶段利用数码相机拍摄照片 ,然后应用数字图像处理技术 ,识别并比较每一实验阶段的标点坐标 ,利用有限元中常用的四边形等参变换的方法将测点图像空间坐标转换为模型空间坐标 ,实现了图像校准和变形计算 .开发了一套应用软件系统 ,用于数字图像标点识别分析和结果数据的可视化处理 ,精度检验实验结果表明测点位移识别均方误差为 0 .14～ 0 .5 2个像素 ,相当于模型观测范围的 5 / 10 0 0 0 0～ 1.5 / 10 0 0 0 .最后给出一个在粘土地基承载力模型实验中的应用实例