岩体裂隙扩展过程的有限元仿真

利用1/4奇异元和动态网格调整技术,对岩体裂隙动态扩展过程给出了一较理想的自动跟踪方法。研制并调试完成了具有较强功能及实用性的岩体裂隙扩展过程的动态跟踪仿真程序RCPTP。该程序除能够跟踪仿真裂隙扩张过程以外,还考虑了多种工程因素(如开挖、支护等),能适应于复杂工程岩体结构的稳定性分析及变形特征超前预测。通过算例证明了本研究思想的正确性、有效性和实用性。     

香果树的快速繁殖

以香果树芽外植体在MS+6-BA 0.5mg/L+IBA 0.5mg/L培养基上进行丛芽诱导和继代培养.丛芽分化率达100%,年繁殖系数为6.3×10~5.将单个芽转移到1/2MS无机盐+MS有机物+IBA 0.5mg/L培养基上,生根率为83.1%,移栽成活率达到90%.     

BP神经网络学习算法研究

对日前应用最广的人工神经网络——BP网络的学习算法及各种改进学习算法进行了分类比较和综合分析,并结合作者的研究结果对进一步研究BP网络及算法进行了探讨.     

工程陶瓷材料去除过程研究

用有限元法对增韧氧化锆和低纯度氧化铝陶瓷依靠初始裂纹的形成,扩展和转折而实现的切屑形成和材料去除过程进行理论研究,并分析裂纹扩展路径的影响因素。所得主要结论通过现场观察和高速摄影机拍摄的系列照片得到了验证。     

Bidirectional propagation of lightning leader

The characteristics of initial leader of triggered lightning flashes are studied by use of a highspeed digital camera system with the rate of 1 000 frame per second and simultaneous measurements of current and electric field change with 0.1 μS time resolution. The results show that the altitude-triggered lightning was initiated by bidirectional propagation leader because of "current interruption" by air gap, whereas the grounded-triggered one was not. The onset of downward-moving positive leader was prior to that of the upward-going negative leader for 843 ms in an altitude-triggered lightning under the positive ambient electric field. The downward-moving leader, regardless of its polarity, would produce in-homogeneous distribution of luminosity (current) along the channel on the moment of connection to the ground.     

Feature Extraction and Classification of Echo Signal of Ground Penetrating Radar

0IntroductionGrvoeluonpde dpienne rtercaetinntg y reaardsa r, (wGhiPchR)is i se map lnoeywedte bcyh nsicqieunet idset-and engineers to obtaininformationfromsubsurface and man-made structures .It has advantage of quick,easy and non-de-structive way toi mage the first few meters of the subsurfaceSo,it is widely used in utility location,landmine detectionroad and airport runway inspection,geophysical survey,andarchaeological investigations ,etc[1 ,2]. Conventionally,radaecho signals can be form…     

魔芋组织培养及快繁技术研究

提高魔芋种芋繁殖倍数是魔芋大规模发展的主要方向，通过10个组织培养基培养魔芋试管苗的对比试验，选择出2个较优配方，作为产业化应用的基础，同时研究探讨了1个魔芋试管苗快繁种芋的基本方法。     

何首乌茎段离体培养的研究

用何首乌种子经表面消毒后进行无菌发芽并建立了无菌材料，以无菌实生苗茎段作外植体进行离体快繁研究。试验了不同基本培养基(MS，H，1／2MS，B5和N6)，不同种类外源激素(IBA、NAA、KT)和不同浓度梯度的外源激素(0．0mg／L，0．1mg／L，0．Smg／L，1．0mg／L，2．0mg／L和4．0mg／L)以及不同蔗糖浓度(0．0％，1．0％，2．0％，4．0％，8．0％，16．0％)对茎段离体培养的影响。结果表明：MS基本培养基，0．5mg／L IBA(或0．5mg／LNAA)及3％的蔗糖比较适合于何首乌的茎段离体快繁。推荐用于何首乌茎段离体快繁的最佳培养基配方为：MS 肌醇100mg/L^ 盐酸硫胺素1．0mg／L 盐酸吡哆素0．5mg／L 甘氨酸2．0mg／L IBA0．5mg／L(或NAA0．5mg／L) 蔗糖3．0％ 琼脂0．75％，pH5．9。用该培养基对何首乌进行茎段离体快繁，每次继代培养可增殖4～5倍。     

金钗石斛茎段培养再生绿色植株

报道了用金钗石斛 (DendrobiumnobileLindl)的茎段作离体培养和快速繁殖 ,已诱导出丛生芽并发育形成试管苗 ,试管苗经过“炼苗处理” ,移栽成活。同时还试验了 3种培养基对试管苗生长的影响