二阶随圆组广义解的高阶可微性

本文讨论了二阶椭圆型方程组在ｐ次多项增长情形Ｗ￣（１，Ｐ）∩Ｌ￣ｑ广义解的高阶可微性．     

线性规划摄动的一点注记

本文是根据旋转运算的单纯形法，得到现行决策能够继续适用参数的摄动范围，这是公式性的一航结论，而在有关书籍中，只是以例子说明。     

包膜肥生产工艺初探

本文主要采用医药上常用的滚转包衣机来进行肥料的包膜,其工作原理与生产肥料时所使用的圆盘造粒机一致,在实验室,通过两种包膜材料,对其生产过程中的一些参数,如包衣机倾角、转速、包膜时间、包膜材料细度、用量等进行了确定。     

高层框筒结构正交各向异性等效模型的解析解

基于正交各划性连续化等效模型，将高层框筒结构转换成弹性力学平面应力平板组合结构，并采用应力函数法获得了解析解。     

二阶中立型微分差分方程有界解的振动性

建立了一类二阶中立型微分差分方程有界解振动的充分条件，且当变系数都是常数时，该条件也是必要的；同时，根据该方程的“极限”方程建立了它自身的一个有界振动准则。     

蛋白质分解不定方程的三层分解法

本文研究了蛋白质分解不定方程,提出方程解的个数估计式,并主要给出一种适宜应用微机编程求解方程的三层分解法。     

青蒿素母液体外抗真菌试验

用5%青蒿素母液、苯甲酸、水杨酸、6%青蒿素渣煎剂和青蒿素渣粉剂对3种霉菌及酵母菌进行体外生长抑制试验;再用2%、1%、0.5%、0.25%、0.125%的青蒿素母液及苯甲酸,采用平皿纸片扩散法对3种霉菌及酵母进行体外抑菌试验,并与空白和溶剂对照。结果表明青蒿素渣粉剂和煎剂对部分真菌有不同程度的抑制作用,5%母液对所试真菌抑制作用均很强,与5%苯甲酸和水杨酸相当。青蒿素毒母液在浓度高于20%时对所试真菌有较强抗菌作用,其作用苯甲酸相当(P>0.05),而低于20%时抑菌效果不明显。     

油菜花期高浓度尿素叶面喷施效应

油菜花期高浓度（10％～20％）低液量（150kg／hm2）喷施尿素，具有较好的生物学效应。中部叶片叶绿素含量比对照增加6．5％～27．9％，水势提高3．8％～13．3％；叶片长宽厚以及每角长宽、干重和单株角果数、每角粒数都有明显提高，产量增加5．1％～13．5％。适宜尿素浓度为15％。     

发酵液体饲料的研究进展

发酵液体饲料在欧洲已广泛使用 ,并成为当前人们研究的新热点。本文仅从发酵液体饲料对猪的生产性能、胃中酸度及肠道菌群的影响、发酵液体饲料的发酵控制 ( p H、温度、水料比及日粮组成、发酵促进剂 )和发酵液体饲料的应用现状及存在的问题几个方面的研究进展进行论述     

Rice-soil interactions in Vietnamese acid sulphate soils: impacts of submergence depth on soil solution chemistry and yields

Abstract. The aim of this study was to investigate the effects of water submergence depth on radial oxygen loss (ROL), soil solution chemistry and rice growth performance in acid sulphate soils in southern Vietnam. ROL was measured in a solution culture. In a separate pot experiment the impact of water submergence depth on rice growth and soil solution chemistry was studied. Three submergence depths were used in the two experiments (5, 10 and 15 cm). ROL declined with submergence depth and was significantly greater in young roots (with no root hairs) than in older roots. In the pot experiment rice growth and soil solution chemistry were clearly affected by the submergence depth. During the first crop at 5 cm submergence, there was a significantly higher yield and a higher oxidation state (pe+pH) compared to 10 or 15 cm submergence. The Fe concentration was significantly greater at the 5 cm depth compared to the 10 or 15 cm depth. SO₄^2– reduction was delayed at the 5 cm depth. Rice yield was c. 25% less at the 15 cm than at the 5 cm depth. During a second crop, there was a substantial SO₄^2- reduction and H₂S formation and almost no significant effects of submergence depth on either soil solution chemistry or crop yield. In a field experiment with a dry-season rice crop, yield and Fe, Al and SO₄^2– concentrations were higher at a shallow submergence depth than at greater depths in the same field, showing similar depth trends to those found during the first crop in the pot experiment. Farmers should be advised to use a shallow submergence depth and, if possible, avoid deep-rooted rice varieties. A conceptual model is suggested, which summarizes the relationships between ROL and soil solution chemistry.