香蕉茎秆纤维提取机刀片的分析和优化设计—基于SolidWorks

为减小香蕉茎秆纤维提取机刀片工作时的最大应力,增大其安全系数,利用SolidWorks软件对刀片进行三维建模,运用软件的Simulation插件分析刀片的应力、应变云图,并对刀片相关尺寸进行优化设计。优化结果显示,刀片的最大应力由68.58MPa下降到49.33MPa,下降约28%;刀片的最小安全系数由3.21上升到4.47,增加了约1.4倍;刀片的质量由0.702kg下降到0.698kg,达到了优化的目标。     

育种咨询系统中的水稻杂交后代性状预测

杂交育种是一个很复杂的组合过程。由于指导育种的遗传学原理还远不够完善,因此,在实践中更多的是依赖育种家的经验和技巧,从而造成了育种工作中一定程度上的盲目性。为了提高育种效率,有必要发展一套为育种工作服务的咨询系统。利用它协助育种家收集数据、分析育种过程。本文重点阐述水稻杂交咨询系统研制中的杂交后代性状预测方法及原理。     

麦草畏、水杨酸对西洋参成熟种胚体细胞胚发生的影响

以西洋参成熟种胚为试材,以不加激素和添加0.5mg/L 2,4-D的MS培养基为对照,研究了不同浓度(0.05~2.00mg/L)麦草畏、水杨酸对西洋参体胚发生的影响。结果表明:未添加激素的空白培养基没有愈伤和体胚发生;在附加2,4-D的培养基中愈伤和体胚发生率为100%;5个浓度的麦草畏和水杨酸均能诱导出体胚,其中1.00mg/L麦草畏的效果最佳,体胚发生率为56.60%,水杨酸处理下体胚发生率最高为7.50%;在各种浓度的水杨酸中种胚生长量比对照小且褐化严重。说明麦草畏、水杨酸均可诱导西洋参成熟种胚体细胞胚发生,诱导能力2,4-D麦草畏水杨酸;水杨酸对种胚生长有抑制作用。     

花生转基因研究进展

同多数豆科作物一样，花生的基因转化技术难度大，且与主要粮食和经济作物相比起步晚，因此进展较慢。本文收集近几年的中外资料，时花生基因转化研究中植抹再生体系的完善过程及存在问题、目前用于转化的目的基因、主要转化方法的改进及转化基因的表达方面的研究进展进行了综述，并指出在花生基因转育中急待解决的问题或需要努力的方向，为进一步进行花生转育研究提供理论基础。     

炭疽菌附着胞的研究进展

摘 要：炭疽菌属Colletotrichum Corda 是一类重要的植物病原菌，寄主范围广，对农林生产危害很大。炭疽菌能产生特殊的侵染结构附着胞穿透寄主组织，附着胞的形成对炭疽菌确立侵染非常关键。综述了炭疽菌分生孢子在寄主表面的附着、附着胞的形成、附着胞对环境影响因素的应答和附着胞的穿透。影响炭疽菌附着胞形态发育的因素很多，其中硬质疏水表面在短时间内通常是有利于附着胞的形成。并简要概述了炭疽菌附着胞的基因克隆研究情况。     

浅析中国种业的基本特征

本文从我国特殊的国情、特殊的消费群体、特殊的产品、特殊的产业四个方面揭示了中国种业的基本特征.     

Study on Modeling for Pretreatment and Cyclic Control Stream

The characteristics of pretreatment and cyclic control stream are analysed:the form of cyclic embedded hardware circuit,the idea for designing the pretreatment program.The chart model of the system is established preliminarily.     

Reuolution and Research of Green Automobile

The green is as a symbol of no pollution,no public harm and environmental protection. The green automobile is the inevitable results that the automobile technique continuously developes. A new style vehicle--the green automobile is the urgent solicit of environmental protection is developed. The automobile industry can develop continuously. This article mainly discusses the importance of the green auto_mobile's research and development,the development status in quo and prospect of the green auto_mobile technique in the world,and states the relationship between the green automobile technique and environmental protection from green technical system theoretically clarify the study of green automobile,including its design and the system,the manufacture and its technology,the energy,the rebuild engineering and a series of subjects. How to evaluate the cycle and the evaluable mark of the green automobile,the prospect of green automobile are pointed out.     

AMETHOD OF COMPREHENSIVE EVALUATION TO DEVELOPMENT PROJECT ALTERNATIVES

In view of the complication of compreliensive evaluation to development projectplanning alternatives,an AHP model for comprehensive evaluation to the alternatives is advanced,the way of determinating the weight of each index affecting the aIternatives' quality is expounded,and the general methods of evaluating the alternatives with the indexes are given.     

Simulation of the penetration rate (ROP) of the air percussion drilling

It is difficult to calculate the penetration rate (ROP) of percussion drilling. In the early research, the empirical or semiempirical formulae of the ROP are derived from the laboratory or field data collected by the researchers. However, the ROP value of the formulae is not as accurate as that in the field. Benefiting from the dynamic model, the geometric structure model and the theory of the roller cone bit, the mathematical model of the hammer bit, the mathematical model of the true bottom hole and the mathematical model between the tooth and the rock of the hammer bit are established. Hence the ROP of the air percussion drilling can be predicted by simulation. Field tests show the models are reliable and the results are coincident with that in the field. The research can help to redesign the hammer bit and optimize the drilling parameters.