喷蒸热压法和传统热压法生产杨木刨花板的比较(Ⅰ)喷蒸热压对刨花板力学强度的影响(英文)

该研究以杂种毛白杨无性系（ＰｏｐｕｌｕｓｔｏｍｅｎｔｏｓａＢＬ）４年生幼龄格为原料，应用喷蒸坟和传统热压两种方法来生产杨木刨花板．刨花板内施胶量为１０％的脲醛树脂胶（ＵＦ），目标厚度分别取１０，１５，２０，２５ｍｍ，热压温度固定在１８０℃．喷蒸热压时所用饱和蒸汽的压力为０３～０５ＭＰａ，每种厚度下喷时间一定，取两个压时间；传统热压时每种厚度下各取４个热压时间．然后测定刨花板试件的力学强度和物理性能．在这部分里，主要讨论了责任中热压法生产的刨花板的静曲强度和内结合强度．结论为：相对于传统热压法，喷蒸热压可以明显缩短杨木刨花板生产所需的热压时间，而且使刨花板具有优异的内结合强度；但是，它对饱花板的静曲强度并没有显著影响     

Ethanol and polyphenolic free wine matrix stimulate the differentiation of human intestinal Caco-2 cells. Influence of their association with a procyanidin-rich grape seed extract

The effect of daily contact with ethanol on Caco-2 cell differentiation was investigated. Pure ethanol (1%) and a polyphenolic free wine matrix (polyphenol-free wine containing 1% ethanol) associated or not with a procyanidin-rich grape seed extract (GSE) were added to Caco-2 cells from confluency for 2 h a day after successive incubation in salivary, gastric, and pancreatic media. Treatment with 1% ethanol did not appear to be cytotoxic to cells, but it also stimulated Caco-2 cell differentiation, particularly in the first days following confluency, and this effect was more marked when associated with polyphenolic free wine matrix constituents. This activation resulted in an increase in microvillar density, organization, and elongation (+70%) and was associated with strong stimulation of sucrase-isomaltase (+780%) and a concomitant regular increase in cell protein content (+50-88%). While the presence of GSE in alcoholic solutions did not modify the morphological pattern observed in cells subjected to ethanol and polyphenolic free wine matrix alone, it had a clear reducing effect on their microvillus elongation (-30%). However, these stimulating effects of ethanol on morphological differentiation were attenuated from day 10 postconfluency, which could suggest cell cytoprotection against ethanol. These are the first results in support of the notion that moderate concentration of ethanol may stimulate the differentiation of Caco-2 cells, particularly when integrated with a polyphenolic free wine matrix.     

Genotypic Variation in Maize Shoot Biomass at Different Stages of Development

A diallel cross from nine early-maturing lines of maize was grown in northern Germany during 1981 and 1982 in order to study the genotypic variation of shoot biomass at early and late stages of development. Inbred lines had been chosen from breeding programmes for early and medium early cultivars. Nevertheless, the date of maturity varied between them which can have some influence on the correlation between plant parameters. Plants were harvested at the fourth and sixth leaf stages, at anthesis and at maturity. S.c.a. effects were highly significant for traits during the vegetative stage. G.c.a. effects were highly significant for traits of the mature plant including grain yield components. The ratio of g.c.a. to s.c.a. effects for shoot biomass was dominated throughout the growing season by s.c.a. effects. Hybrids from the diallel cross had a superior growth rate until the fourth leaf stage; thereafter, relative growth rates of lines and hybrids were similar for the average of both groups until maturity. The correlation of g.c.a. effects and s.c.a. effects between shoot biomass throughout the season revealed that no significant relationship existed between early and late stages. G.c.a. and s.c.a. effects for grain yield components, with the exception of hundred kernel weight, were negatively correlated with shoot biomass at an early stage while correlation was positive at maturity. This would probably make it a difficult task to improve shoot growth and grain yield components simultaneously through the season.     

国审小麦新品种小偃22的研究与利用

国审小麦新品种小偃22是常规育种和远缘杂交有机结合而育成的,通过远缘杂交技术,导入长穗偃麦草的优质、抗病、抗逆多个优异基因,实现了种属间优异性状的有效结合,在一定程度上成功地解决了高产与稳产、高产与优质之间的矛盾,将高产、优质、多抗、广适几个主要目标性状结合起来,具有多穗多粒、结实性突出、品质优良、增产潜力大、抗逆性强、适应性广等突出优点,产量三因素在较高水平上达到协调。小偃22从2000年以来长期是陕西省主栽品种,是陕西省第六次更新换代的骨干品种。笔者对小偃22来源、特征特性、创新点,应用情况,优质高产栽培规程进行了系统研究和总结,并对更新换代大品种的特点和培育和产业化推广经验进行了探讨。     

In-field development of a conceptual crop functioning and management model: A case study on cotton in southern Mali

West African cotton production has increased rapidly in recent years. Cotton is being cropped under new ecological conditions by new cotton-producing farmers, but the cropping techniques recommended by developers have essentially remained the same. Methodologies are needed to generate a broad scope of recommendations on cropping techniques to deal with the increasing diversity concerning farmers and cropping conditions.

A conceptual model of a cotton field was developed that approaches a crop field as a biophysical system under the influence of a “technical system” (i.e. the combination of farmers’ practices implemented in the field). The system outputs were restricted to yield and the main yield components. A theoretical model was first designed on the basis of published data and expert knowledge on cotton physiology, local soil–climate conditions and farmers’ practices. It was based on five specific hypotheses on links between technical and biophysical systems. The hypotheses were tested in a local farmers’ network. Thirty “cropping situations” (soil–crop–technique combinations) were selected in farmers’ fields around Katogo village (Mali), a village that had been previously selected for a cotton crop management prototyping program. Homogeneous groups of situations were drawn up on the basis of the dynamics of crop aerial biomass accumulation. They were compared for their management and environment features. The initial conceptual model was then simplified, while taking the measured variability in its components and the sensitivity of the outputs to these components into account. This conceptual model is being evaluated in other villages, where we have partnerships with farmers, in order to develop a version adapted to a broad range of situations.     

无角道塞特羊胚胎移植技术研究

（西北农林科技大学生物工程研究所,陕西杨凌712100）     

水泵优化选型的整数规划法

水泵选型合理与否,不仅关系到水泵的安装与安全运行,而且也直接影响到泵站的工程投资和运行费用。本文用整数规划法进行水泵优化选型。这种方法是在现有水泵产品范围内,以装机容量最小作为水泵优化选型的目标函数,比较适合于初步设计的规划阶段。由于本法主要考虑的是工程投资和运行费用问题,因此,在利用本方法获得水泵优化选型结果后,还应进行工况校核,并考虑其安装管理因素后,再作出综合决策。     

牡丹江林区林产工业产品结构优化研究

合理的产品结构是影响一个地区林产工业经济效益的重要因素之一。为确定牡丹江林区林产工业合理的产品结构，首先以定性方法（或定性方法数量化处理）得出一般的定性结论，在此基础上再使用定量方法求得比较精确的数量化结果以达成结论的正确性和准确性。     

水生美人蕉组培快繁技术研究

以水生美人蕉带有芽苞的根茎为外植体进行组培快繁技术研究,结果表明：MS＋BA1.0~4.0mg/L+NAA0.2mg/L培养基能较好地诱导分化出不定芽;MS+BA6.0~8.0mg/L+NAA0.2mg/L培养基增殖效果最好;在MS不加激素和MS＋NAA0.2mg/L培养基上进行生根培养都有不同程度的根分化。株高6~8cm出瓶用苔藓炼苗,成活率达95%以上。     

保康蜡梅盆景的技艺在参展中学习提高

自1997年第五届全国梅花蜡梅展在武汉市举办以来,湖北省保康县连续参加了五届全国梅花蜡梅展览。通过向来自各地的参展梅花、蜡梅盆景作品的学习及当地技术人员的努力,保康蜡梅盆景的技艺得到不断提高,不仅获得了全国梅展的奖励,也促进了当地蜡梅盆景的生产和销售。