不同Web时代个性化信息服务的比较研究

基于Internet的个性化信息服务是根据用户的个性需求，为其提供定向化的信息服务。个性化信息服务在不同Web时代表现有所不同，并从低级形态到高级形态逐渐演变，从个性模糊到用户能参与互动，到最终的网人合一，Web在继承革新的基础上，把人从剥离的场景中融入到网人合一的境界，并最终实现，信息由用户产生，用户有针对性地、特色化地利用信息，并享受信息所带来的财富。     

安徽省皖南地区优质烟叶栽培管理专家系统的研究

以中科院合肥智能所最新研制的智能化农业信息处理开发平台AIP 1.0为系统开发工具 ,科技人员的科研成果、烟农的实际经验和资料知识为基础 ,运用人工智能技术、神经网络技术、多媒体技术、GIS技术、AGENT技术等与专家群经验相结合的方式 ,开发出了适合安徽省皖南地区优质烟叶栽培管理专家系统MESTCM。该系统由知识库、数据库、模型库、信息库、推理机、人机交互等综合而成 ,具有可视化、网络化、知识化、构件化、智能化的特点。该系统的开发可以为科技人员和烟农生产优质烟叶提供一个平台 ,通过该系统还可以帮助烟农做出合理的生产布局和科学决策 ,及时指导烟叶生产 ,进一步提高安徽省烟叶质量     

Effects of vegetation type on soil resistance to erosion: Relationship between aggregate stability and shear strength

Soil water erosion and shallow landslides depend on aggregate stability and soil shear strength. We investigated the effect of vegetation on both soil aggregate stability and shear strength (through direct shear tests) in former croplands converted to vegetated erosion protection areas within the context of China's sloping land conversion programme. Four treatments were analysed in plots comprised of (i) 4 year old crop trees, Vernicia fordii, where understory vegetation was removed; (ii) V. fordii and the dominant understory species Artemisia codonocephala; (iii) only A. codonocephala and (iv) no vegetation. Soil samples were taken at depths of 0–5 cm and 45–50 cm. Root length density (RLD) in five diameter classes was measured, soil organic carbon (SOC), hot water extractable carbon (HWEC), texture and Fe and Al oxides were also measured. We found that mean weight diameter after slow wetting (MWD_SW) in the A-horizon, was significantly greater (0.94–1.01 mm) when A. codonocephala was present compared to plots without A. codonocephala (0.57–0.59 mm). SOC and RLD in the smallest diameter class (< 0.5 mm), were the variables which best explained variability in MWD_SW. A significant positive linear relationship existed between MWD_SW and soil cohesion but not with internal angle of friction. As herbaceous vegetation was more efficient than trees in improving aggregate stability, this result suggests that the mechanisms involved include modifications of the cohesive forces between soil particles adjacent to plant roots and located in the enriched in SOC rhizosphere, thus also affecting shear strength of the corresponding soil volume. Thus, vegetation stabilised soil under different hierarchical levels of aggregate organisation, i.e. intra- and inter-aggregate. Our results have implications for the efficacy of techniques used in land conversion programs dedicated to control of soil erosion and shallow landslides. We suggest that mixtures of different plant functional types would improve soil conservation on slopes, by reducing both surface water erosion and shallow substrate mass movement. Planting trees for cropping or logging, and removing understory vegetation is most likely detrimental to soil conservation.     

实用农业多元统计分析系统的开发与应用

MSA1.0是根据农业科研单位数据处理需要开发的实用农业多元统计分析系统。该系统具有功能实用、操作简单、界面简洁友善、数据处理精度高、稳定性好等特点。本文介绍了MSA1.0的结构特点及其主要功能,并通过应用实例说明了其使用方法。     

北美自由贸易协定中的时效制度浅析——大河六国企业有限公司等诉美利坚合众国案述评

大河六国企业有限公司等诉美利坚合众国案最鲜明的特点是在先置程序中,对是否适用NAFTA(北美自由贸易协定)1116(2)、1117(2)所规定的时效条款的考量。NAFTA规定的时效制度,有利于促使当事人及时行使自己的权利,但它没有规定最长诉讼时效期间,也没有规定时效的中止、中断、延长。     

10种情报学期刊2000～2006年被引统计分析

依据<中国学术期刊文献评价统计分析系统> (V1.0),对10种情报学期刊载文在2000～2006年被引用的情况进行统计分析,客观揭示他们的办刊质量及其影响.     

Effectiveness of SSR molecular markers in evaluating the phylogenetic relationships among eight Actinidia species

The aim of the present study is to evaluate a set of microsatellites and their effectiveness in determining the phylogenetic relationships among Actinidia species. A set of 14 genotypes belonging to eight Actinidia species were subjected to PCR using SSRs as molecular markers. The PCR products were analyzed on denaturing polyacrylamide gels. The discriminating ability of SSRs was based on the number of alleles and the indices DI, I and PIC. All SSR primer pairs were polymorphic and identified a total number of 61 alleles corresponding to an average of 7.8 alleles per locus. Data showed that the di-nucleotide microsatellites were more polymorphic, than the tri-nucleotide and penta-nucleotide, and were more efficient in establishing genetic similarities. The genetic similarity of the genotypes calculated with Jaccard and/or Dice similarity coefficients varied from 0.100 to 0.579, indicating a broad genetic base for the genetic material tested. Both similarity matrices clustered either with UPGMA or NJ, produced similar topology with minor clustering differences among genotypes. Thus, the eight species were clustered in two main groups and each main group in two subgroups. Data showed a close genetic relationship among Actinidia chinensis and Actinidia deliciosa species. The same conclusions were, also, drawn using the principal coordinate analysis.     

粮食检验实践中测量系统分析(MSA)方法的应用

本文尝试采用统计分析工具——测量系统分析(MSA)的方法应用于粮食检测工作,利用计量型测量系统分析方法量具重复性和再现性研究(Gage R&R)的方法,借助MINITAB软件的协助,在实际稻谷脂肪酸值的检测工作中,通过大量实验,对量具的重复性和再现性进行了统计和分析。对测量结果采用测量系统分析中方差分析的数理统计分析方法进行了数据统计分析。通过分析,确定了稻谷脂肪酸值检测系统的精确程度,并进一步分析了脂肪酸值检测系统波动的主要来源;通过在粮食检测行业中尝试使用MSA方法,建议在粮食品质检测中广泛推广测量系统分析方法,同时,建议提高粮食测量系统的自动化程度,以减少人为因素带来的测量系统波动。     

大学图书馆应建立健全第二代学科馆员制度

对大学图书馆学科馆员制度的演变过程,及两代学科馆员制度的不同进行了简要的阐述,重点论述了第二代学科馆员的核心能力,及如何建立健全第二代学科馆员制度。     

利用稻米垩白度分析软件测量叶片相对病斑面积

【目的】提出一种利用稻米垩白度分析软件Chalkiness 1.0测量衡量植物叶片病害综合指标之一叶 片相对病斑面积（RLA）的方法。【方法】通过扫描或拍照获得病害叶片的数字图像;然后利用图像处理软件（如Photoshop）对图像进行处理,最重要的是用肉眼识别病斑并用“画笔工具”涂黑,使叶片中的病斑明晰 化;最后利用Chalkiness 1.0计算出图像中的RLA。【结果】用本方法对稻瘟病叶上病斑的相对面积进行测量。比较5次重复测量的结果,发现该方法重复性好,误差小。【结论】该方法简单、快速、准确,具有广阔的应用前景。