甜菜黑色焦枯型病毒病原、cDNA合成、光生物素标记及探针制备

从新疆甜菜黑色焦枯型病株上分离到的一种直径为30nm 的球形病毒,在甜菜叶片上初期形成黑褐色小枯斑,后在叶脉间出现黑色焦枯,叶片通常直立向上,内卷;根毛大量坏死,但丛根症状不很明显。病毒经摩擦接种,可侵染4科13种植物,在苋色藜(Chenopodium.amaranticolor)、昆诺藜(C.quinoa)、蔷生藜(C.murale)、菠菜(Spinaciaoleracea)及番杏(Tetragonia expensa)叶片上表现局部坏死斑、一部分茄科植物上形成无     

内蒙古后山地区旱地农业降水利用效率提高途径的探讨

本文分析了内蒙古后山地区降水利用效率低的主要原因是降水量少、土壤肥力水平低和作物布局不合理。其解决途径是,逐步实行体闲轮作制,建立种植业优化结构,增施肥料、以肥调水和改善土壤耕作制度等,通过这些措施,作物的降水利用效率可以从目前的0.14～0.15kg/mm·亩提高到0.25～0.30kg/mm·亩,在正常年降水量的条件下,旱坡地粮食产量可达85～90kg/亩,旱滩地可达100～110kg/亩。     

广东啮虫五新种(啮目:单啮科、叉啮科)

描述了广东省的啮虫五个新种,隶属于2科2属。     

东方对虾饲料不同蛋白源的比较

本试验以鱼粉(F),豆饼(S)和棉籽饼(C)作为东方对虾饲料的主要蛋白源。为适应实际生产的需要,还设计了以混合蛋白源(M)组成的饲料。每种蛋白源的饲料设计了两个粗蛋白水平:前期46%和后期44%。用8种饲料(M-46,F-46,S-46,C-46,M-44,F-44,S-44和C-44)饲喂初重为6.1 g 的东方对虾,观察不同蛋白源对试验对虾的成活率、生长性能和饲料转化率的影响。本试验还以 Cr_2O_3为指示剂,测定东方对虾对不同蛋白源的粗蛋白和主要氨基酸的消化率。为期42 d 的试验结果表明,不同蛋白源对所观察指标有显著影响。     

氯化泥炭对葡萄营养及产量品质的影响

本试验通过盆栽试验研究了氯化泥炭对巨峰葡萄营养及产量品质的影响。试验结果表明:氯化泥炭能够促进葡萄对 N,P,K 养分的吸收,其中对 P 吸收的促进作用比对 N,K 更为显著,对生长前期养分吸收的促进作用比对生长后期养分吸收的促进作用更为明显。另外,氯化泥炭还能提高葡萄浆果的着色率和可溶性固形物的含量,但对葡萄产量的影响不明显。     

模拟二代棉铃虫为害及密度、果枝数对棉花产量影响的综合模型

采用两次回归正交组合设计方法研究了不同密度和果枝数情况下,人工模拟去除早期蕾后对棉花产量的影响,建立了相应的数学模型。明确了以上三因素对产量的单独反响及互作效应。讨论了个体生产力和群体生产力以及不同品种间对环境需求的差异性。     

CONTRIBUTORY MODELS ON SYNTHETICAL EFFECT OF SCIENCE-TECHNOLOGY FROGRESS IN BUILDING ENTERPRISTS

This paper disusses an important component part of the decision support sys- tem of science-technology management in building enterprises.It establishes the increasing degrees and dynamical productive fuctional model in building enterprises,and ayear contribultory models of investing labour and produtive fund,effect of profit-tax and productive total cost ect.     

COMPUTER-AIDED ANALYSIS AND DESIGN FOR THE BASE STRUCTURE OF A MOVABLE TOWER CRANE

This paper is one of the achievements of the researchitem for computer-aided design of tower crane's steel structure.In thepaper,taking the well-base structure as an example,first the method establishing the mechanical model is explained for the base structure ofa movable tower crane.Then the math model of its optimal design andthe N-S figures for the computer program is described and calculatedusing discrete optimal technology.Finally the problems related to thedesign for the base structure of a movable tower crane are briefly illu-strated.     

ANALYSIS OF THE BEHAVIOUR OF HIGH STRENGTH BOLTED SHEAR CONNECTIONS

On the basis of experimental tests,a formula is proposedfor the computation of the load-deformation curves of the single highstrength bolted connections in axial shear forces,which is a piecewisefunction describing three stages of friction,slipping and bearing of theconnections,and is also suitable for the non-slip connections.The limitstate method is used to compute the behaviour of high strength boltedconnections subject to eccentric shear,in which each bolt obeys thenon-linear relationship aforementioned.In this paper,the computer pro-gram is worked out to solve the non-linear problems.Analytical resultsare shown to be in general good agreement with experimental data.     

A SINGULARITY PROPAGATION FOR SEMILINEAR WAVE EQUATIONS

This paper discusses the propagation of singularity forsemilinear wave equations.By use of the theory of para-differentialoperators and the method of microlocal analysis,some results for generalsemilinear wave equations are obtained.