论农学研究的发展     

文新亚  付以彬  王璞 《中国农学通报》2006,22(12):476-476

较为详细地论述了中国传统农学和西方近代农学的哲学基础、方法论及它们各自的不足。中国传统农学思想的阐释借鉴了中国古代哲学的概念和范畴，以朴素的系统、整体观察为特征。西方近代农学则以还原论为基础，以实验、分析方法为特征。系统科学是20世纪兴起的联系社会科学与自然科学的一门横断性学科，是探索整体、演化及其复杂性的科学。现代农学研究应引入系统科学的哲理观和方法论，对于融合中国传统农学与西方近代农学、发展现代农学有重要意义。  相似文献   

Experimental Study on the Extended Length of Negative Reinforcement Cut-in Phases in Continuous Beams     

Zou Zhaowen  Fu Jianping  Bai Shaoliang 《保鲜与加工》1996,(2):10-19

In this paper through the static loading tests of 6 inflexion zones and 2 cantilever zones in full-size constrained R/C beams, the stress performance in rebars cut-in-phases and subjected to negative moment is studied. The stress properties of extended length of rebars with different shear-span ratiosare analysed on basis of the full measurement of strain distributions combined with the investigation on state and regularity of the diagonal cracks development and series of new knowledge are obtained. It is found that current Concrete Design Code provisions on the extended length are inadequate for the high shear-span ratio and superfluous for the low shear-span ratio. The theoretical and experimental foundations are provided for determining proper value of extended length for rebars cut-in-phases.  相似文献   

OPTIMIZATION OF BIPARTITE JOINS WITH GRAPH THGORY     

Zeag Yongning Tong Fu 《保鲜与加工》1989,(2):43-49

An optimization approach for multi-relational joins based on the matching concept in graph theory is introduced. The basic idea lies in constructing a join graph from an expression of N-relation query, and seeking for a maximun matching with minimun total weight. The algorithm for bipartition(X, Y) is proposed in this paper.  相似文献   

The Feasible Control for the Day-operation of the Three-Gorge Cascade Hydropower Station     

Duan Yurong  Fu Li 《保鲜与加工》1995,(1):19-26

The feasible control problem is presented for the day-operation of the Three-Gorge Caseade Hydropower Station. The significance of the problem is explained. Basic propetties ofthe problem and the approaches to study it are discussed. Two methfods are given for solving theproblem. which are calculus of variation and linear programming. In the former. the Euler equationwith time-lag and the generalised two-point boundary conditions are obtained and the correspondingpractical implication is interpreted. In the latter. the rationality for the discrete model is exptainedand the computalional details are given for the implement software. some questions which should bepaid much attentfon and the corresponding propeels are prasented based on the numerical results andtheoretical analysis  相似文献   

New Method to Study In-situ Stress of Rock Mass by AE and Structure Analysis of Rock Mass     

ZHOU Xiao ping  DENG Meng  ZHANG Fu sheng 《保鲜与加工》2001,(6):109-113

In this paper, the authors adopt a method of structural analysis and stereography in combination with acoustic emission Kaiser Effect test in laboratory to find out the main direction of initial stresses. For overcoming the shortcomings of Kaiser effect by comparing it with traditional methods of measuring in-situ stresses, it is shown that this method is simpler, more economical and convenient for a large number of measurements and for studying the law of changes of regional in-situ stresses.  相似文献   

小麦醇溶蛋白电泳分析的新方法   总被引：29，自引：0，他引：29  

傅宾孝  于光华 《作物学报》1993,19(2):185-187

  相似文献   

X射线灭活活体日本沼虾精子的初步研究     

颜跃弟  傅洪拓  梁国霞  乔慧  白鸿坤  蒋速飞  熊贻伟  龚永生  金舒博  张文宜  吕洋  吴滟 《中国农学通报》2015,31(20):35-38

为检测X射线对日本沼虾精子的灭活效果,利用X射线对雄性日本沼虾进行不同时间的照射处理,将处理后的雄虾与刚完成生殖脱壳的雌虾交配。待雌虾产卵后,计数雌虾抱卵天数,并在显微镜下观察卵的畸形情况。X射线管照射强度为100 k V,5 m A,源距10 cm,照射时间为0、30、60、90、120 min。结果发现:照射30 min组的抱卵天数及卵的畸形率较0 min组无变化,卵的畸形率为0,卵能正常发育至孵化出膜。随着照射时间的增加,在30~90 min之间,雌虾抱卵天数逐渐减少,且所抱卵的畸形率呈上升趋势。照射120 min组的抱卵天数较90 min组变化不大,卵的畸形率达100%。在本试验照射时间范围(0~120 min)内,灭活日本沼虾精子遗传物质的最佳照射时间为90~120 min。  相似文献   

喷油泵试验台智能量油系统的研究     

李东民  王会明  傅旭光  何伟宁 《农业装备与车辆工程》2006,(2):39-41

为解决喷油泵试验台量油系统测量误差较大的问题，本研究通过采集喷油器针阀升程、喷油压力、转速等信号精确测得喷油量。  相似文献   

液压自由活塞发动机的节能方式研究   总被引：2，自引：1，他引：2  

夏必忠  周华  傅新  杨华勇  杨开传 《农业机械学报》2001,32(6):8-10,14

液压自由活塞发动机是将内燃机和液压泵集成于一体，实现动力非刚性传输的复合发动机。本文从其内部能量转换及外部能量回收两个方面，详细地分析和阐明了液压自由活塞发动机各种节能方式和实现途径，以液压挖掘机为例，强调液压自由活塞发动机作为中心液压站，结合二次调节及液压变压器技术，简单方便地实现群控节能。  相似文献   

板材多点成形工艺及装备     

崔力生  刘福军 《农业机械学报》1993,24(2):82-85

多点成形法是针对多品种、小批量的三维曲面板材成形的一种柔性加工法。采用这种方法可替代传统的模具,从而节省模具制造费用。本文介绍了有关这一加工方法的基本原理并在自制的简单多点试验机上进行了一系列试验,对4种不同的多点成形法的成形效果进行了讨论。  相似文献