三大区域村庄类型分布的刻画：历史移民解读

中国农村存在巨大的区域差异,从社会结构上看,可以分为华南宗族团结型地区、中部原子化分散型地区和华北小亲族分裂型地区三大区域.通过数据挖掘和分析,发现我国出生性别比的分布极具规律性,显示出区域上的差异.结合中国南方方言形成及南方宗族型文化发育的共同历史移民根源,笔者将南方方言分布图与出生性别比地图及三大区域划分进行比较研究,具体分析了三者间高度关联性的共同历史移民根源.     

路桥过渡段施工问题研究

在路桥过渡段施工时，会因基础不同、防水措施不足、施工质量等问题产生显著的沉降差异，从而引起桥头跳车现象。路桥过渡段的施工，应做好施工勘察设计工作、处理好软性地基、选好台后填筑材料、做好台背排水、压实填土，减少台后路基的沉降，提高路基的刚度，尽力实现路桥刚柔平稳过渡，达到防治桥台跳车的目的。     

枣花发育过程中糖类物质的分布与变化

以壶瓶枣为试材,通过组织学制片,运用PAS-苏木精复染和汞-溴酚蓝法对材料进行染色,用显微镜观察了花芽形态分化过程及其花器官中的糖类物质分布。结果表明,从枣吊萌动到花开,淀粉粒在各个分生组织分裂最旺盛的细胞中逐渐积累;随着花器官的发育,在萼片中形成囊状特化大细胞,到花粉粒成熟时布满萼片、花瓣和花托,标志着糖类物质积累达到高峰;但是当花开时,这些囊状特化大细胞中的糖类物质消失,变成空腔。     

Ein allgemeiner Ansatz zur Quantifizierung des Einflusses der Güte der Sätechnik auf den Flächenertrag

A general approach to determine the effect of accuracy of sowing technique on yield per area
Caused by nonperfect seed placement accuracy of sowing machines as well as by many other abiotic and biotic factors the resulting plant stands exhibit nonregular plant distributions. Based on several simplifying assumptions a stochastic approach provides a quantitative determination of the effects of accuracy of sowing technique on yield per area. In this approach, two random variables are assigned to each individual plant: single plant yield E and single plant area A, which is calculated in this paper by the construction and quadrature of the so-called Thiessen-polygons. The yield per area F is calculated as the expectation of the ratio E/A. By assuming a deterministic mathematical relationship between E and A, the calculation of F reduces to the calculation of the expectation of a function of only one random variable A. A simple approximation with sufficient accuracy for many applications only depends on the mean and on the variance of the areas of the individual plants. For demonstration purposes, the theoretical approaches and results have been finally applied to three data sets for drilled seeds of winter oilseed rape (plant density: 60 plants/m² and distance between rows: 10 cm). These data sets exhibit different accuracies of the longitudinal distributions within rows which have been quantitatively measured by the coefficient of variation for the distances between plants within rows: Yield depression increases with an increasing variability of plant distances within rows.     

丰产素在兰州大接杏上的应用

1990～1992年我们对丰州牌丰产素在兰州大接杏上的应用进行了研究，采用的浓度分别为2000信液，4000倍液，6000信液，进行全树喷洒，3a的试验结果表明，3种不同浓度的丰产素对兰州大接否新消生长量，枝条成熟度和产量均有影响，其中以4000信液对新消生长量影响最大，新稍长度比对照长8．44cm，粗度比对照粗0．14cm，而且枝条成熟度比对照好，对产量的影响以2000倍波增产幅度最大，单株平均产量比对照增产47.07％。     

麦套春棉麦棉共生期水分变化动态研究

１９９２～１９９３年对麦套春棉麦棉共生期水分变化动态进行了研究。两年试验结果表明，４种套种方式共生期田间持水量变化动态均表现为：棉行间＞棉株间＞麦棉行间＞麦行间；在试验范围内麦棉间距≥０３０ｍ时，无论麦收前有无自然降雨，棉行间、棉株间持水量与纯作棉田（ＣＫ）差异不显著，而麦棉行间、麦行间持水量显著低于ＣＫ；３—２式和４—２式用水较为经济；套种田与ＣＫ持水量等同点分布区集中在距小麦边行０３０～０４０ｍ处，各套种方式麦棉间距以０３０ｍ为宜。     

利用塑料大棚延长对虾交尾期的研究

为提高对虾交尾率，１９９３，１９９４年进行了塑料大棚延长对虾交尾期试验，通过大棚控制交尾水温，采取合理安排雌雄比，调节水质，投喂沙蚕，防治疾病等综合技术措施，２年共出棚交尾虾１２３５２尾，未交尾虾５９２２尾，雄虾５２５２尾，平均交尾率６７．５９％，雌雄虾成活率分别为８７．５４％，６３．００％，共获产值６２６１００元，纯利４４２６００元，平均每尾入棚雌虾净协效益２１．２３元，专家鉴定认为，本研究达国     

西藏“一江两河”中部流域河谷沙化草地及其恢复途径探讨

“一江两河”中部流域是西藏沙漠化最为严重的地区之一，草地的沙化对于生态环境的恶化和畜牧业生产造成很大的不利影响。通过对这一地区草地的现状分析，划分了沙化草地类型，并通过示范试验结果分析，探讨了沙化草地恢复的主要措施。     

In vitro effects of malathion and O,O,S-trimethyl phosphorothioate on cytotoxic T-lymphocyte responses

Oral administration of O,O,S-trimethyl phosphorothioate (OOS), an impurity present in technical formulations of malathion, has been shown to be associated with a high incidence of pneumonia in rats and to be highly immunosuppressive in mice. Based on these findings, an in vitro model was established to study the effect of this and other organophosphorus compounds on murine cytotoxic T-lymphocyte (CTL) responses. The organophosphorus compounds were tested for their ability to block in vitro generation of CTL responses to alloantigen and/or the expression of these cytotoxic responses. Responses were generated in C57Bl/6 (H-2^b) spleen cells to mitomycin C-blocked P815 (H-2^d) tumor cells. The cytotoxicity of the cultured splenocytes to P815 target was measured using a 4-hr chromium release assay. These data demonstrated that malathion was able to block the ability of splenocytes to sensitize to P815 at concentrations as low as 25 μg/ml, but was not able to block the expression of cytotoxicity by mature killer T cells. The same was true for OOS which had been activated by preincubation with rat liver postmitochondrial supernatant (PMS). Activated OOS blocked the generation of CTL responses at concentrations as low as 75 μg/ml while having no effect on mature cytotoxic cells. In fact, both malathion and activated OOS were no longer able to suppress CTL responses if treatment was performed as early as 24 hr after exposure to antigen. Additionally, it was demonstrated that when malathion was preincubated with PMS it was no longer suppressive and that OOS without activation failed to suppress CTL responses.     

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。