驻极体对大肠杆菌的影响研究

为了有效防止空气中的大肠杆菌附着在食物等表面对人和动物造成腹泻等肠道疾病。以聚四氟乙烯制作的驻极体薄膜为试材,用控制变量法与理论分析和试验研究相结合的方法测得带负电和带正电的驻极体薄膜对大肠杆菌的影响数据。结果表明：带负电的驻极体薄膜对大肠杆菌的正常生长具有抑制作用,最高抑制率达到70.82%;带正电的驻极体薄膜促进了大肠杆菌的生长,最高促进率达到54.65%。进一步用光学显微镜观察到在带正电的驻极体薄膜下处理后的大肠杆菌菌落生长密集,带负电的驻极体薄膜处理后的菌落生长稀疏。驻极体薄膜对大肠杆菌生长造成影响的机制主要是静电场影响了大肠杆菌分子的膜电位,进而影响大肠杆菌的生长。带负电的驻极体薄膜对大肠杆菌具有良好的抑制作用,可为生产与驻极体灭菌有关的材料提供理论依据。     

渔业资源中两个变量之间的关系

本文根据已发表的资料讨论了渔业资源中两个变量之间的关系，认为变量对目标的影响约有三类，可用与此相应的三类表达式描绘两者之间的关系。     

Shell-shape variation along the latitudinal range of the Chilean blue mussel Mytilus chilensis (Hupe 1854)

Shell‐shape variation in the Chilean blue mussel Mytilus chilensis was examined in eight populations covering the totality of its distribution range, which represents over 1800 km of latitudinal gradient in the southeastern Pacific. The shell outline shapes were assessed using elliptic Fourier analysis followed by canonical variates analysis. Fourier coefficients showed a highly significant morphological variation between the populations studied. Canonical variates analysis showed a visual association of the First canonical with convexity of ventral edge and umbo shape, while the second axis was associated with shell elongation. Previously described genetic patterns were marginally congruent with our morphometric pattern, though geographic distance had a stronger effect on morphology. Shape change (elongation) was correlated with latitudinal clinal variation. The morphometrical analysis proved to be an important tool for evaluating the components of shell‐shape variation in mussels and to document association patterns with geographical and ecological variables. Such patterns are useful to establish a wide field of work, including sexing, stock recognition, traceability studies and productive management in general.     

非参数度量在小麦品种区试资料中的应用

运用秩次变量nij和n′ij，非参数统计量Pi、P′i、Si和Dj描述2002年国区东北春小麦早熟旱地组区试资料的基本特征。分析结果表明：赤94-5号为丰产性和稳定性最佳品种，沈免96085、铁90010、哲麦7号和丰强7号为丰产性和稳定性优良的品种。对品种差异有较高分辨力的试点有7个，分辨力最高的试点为L8，有69．1％的差数为显著。     

西南玉米杂交种区试资料的非参数统计

应用秩次变量nij和n′ij,非参数统计量Pi,P′i,Si 和Dj 描述 1999年四川省玉米品种区试资料的基本特征。研究结果表明 ,SAU97 1是丰产性最佳品种 ,产量稳定性最好的品种为川单 9号 ,2 738为丰产性与稳定性优良的品种 ;对品种差异具有较高分辨力的试点有 10个 ,分辨力最高的试点为沐川县种子公司 ,发现了 81%的差数为显著     

Recovery of soil microbial community structure after fire in a sagebrush‐grassland ecosystem

Recovery of the soil microbial community after fire in a sagebrush‐grassland ecosystem was examined using a chronosequence of four sites ranging in time since fire from 3–39 years. The successional stage communities examined included Recent Burn (3 years since fire, ysf), Establishment (7 ysf), Expansion (21 ysf), and Mature (39 ysf). Aboveground standing plant biomass increased with time since disturbance to the Mature stage where sagebrush became dominant over herbaceous species. Phospholipid fatty acid (PLFA) analysis was used to characterize the microbial community structure. Soil microbial community productivity generally appeared to be similar to the Mature site soil (39 ysf) within 7 years of fire. Diversity of PLFAs detected in soils, at both depths, increased from a low value of 29 at the Recent site to a high of 37 at the Establishment site and then decreased again to 31 at the Mature stage site. Canonical variates analysis indicated important disparities in microbial community structure at the four sites. Greatest disparities were observed in microbial community structure between the Recent and Establishment stages but greater similarity between the Recent stage and the sagebrush dominated Mature stage. This study emphasizes both short‐term and long‐term changes in the belowground community and suggests that soil microbial communities are highly resilient to disturbances after prescribed fire. Copyright © 2010 John Wiley & Sons, Ltd.     

玉米品种区试资料的非参数度量

应用秩次变量n_ij和n′_ij，非参数统计量P_i、P′_i，S_i和D_j描述1999年四川省玉米品种区试资料的基本特征。研究结果表明，V₅是丰产性最佳品种，产量稳定性最好的品种为V₇，V₁为丰产性与稳定性优良的品种；对品种差异具有较高分辨力的试点有10个，分辨力最高的试点为L₈，发现了81%的差数为显著。     

Data recording for agroforestry experiments

Examples of typical data-sets from agroforestry trials are considered and difficulties with the recording of such data are discussed. Suggestions for efficient data recording for a number of agroforestry trials are made so that easy data-checking, efficient computer entry and accurate analysis can be produced without the need for excessive data manipulation at each stage. General recommendations for data-recording from agroforestry trials are given.     

非参数统计法在绿豆区试中的应用及其分析

应用秩次变量 nij和 n′ij,非参数统计量 Pi,P′i,Si 和 Dj描述了 2 0 0 1年国家绿豆品种区试资料的基本特征 ,并对参试品种进行综合评判。结果表明 :绿豆区试品种间丰产性和稳定性存在显著差异 ,92 39- 8和 930 9- 2 2是丰产性和稳定性较好的品种。2 0个试点中有 14个试点对品种差异具有较高的分辨力 ,其中分辨力最高的试点为山西长治 ,发现 80 .0 %的差数显著。