绿巨人继代培养与快繁的培养基筛选

在不同的生长调节剂组合的培养基上 ,取绿巨人的诱导芽进行继代培养 ,以产生大量的丛生芽 ,同时探讨了不同生长激素和浓度对丛生芽和不定根分化的影响 .结果表明MS +BA 0 5～ 1 +IBA/NAA 0 1 (mg/L)有较高的繁殖系数和成苗率以及成本低等优点 ;而BA 1～ 2 +NAA 0 2～ 0 5有利丛生芽分化 ,繁殖系数高 .     

Finite element simulation of stress intensity factors in elastic-plastic crack growth

INTRODUCTION The finite element method (FEM) has been widely employed for solving linear elastic and elas-tic-plastic fracture problems. The evaluation of stress intensity factors in 2D geometries by FEM is a tech-nique widely used for non-standard crack configura-tions. Basically, there are two groups of estimation methods, those based on field extrapolation near the crack tip (Chan et al., 1970; Shih et al., 1976) and those using the energy release when the crack propagates. However…     

水文预报的时间序列神经网络模型

时间序列分析在水文预报中起重要作用 ,其关键是要建立一个合适的预报模型 .文章提出基于 BP算法的单输出和多输出水文预报时间序列神经网络模型 ,克服了以往多种基于随机分析预报模型的缺点 ,不仅能实现快速灵活的信息处理 ,而且具有很强的非线性映射和自学习、自适应能力 ,这为更精确描述复杂非线性水文过程提供了可能 .通过对历史数据的学习 ,模型可对水文径流量时间序列进行预报 ,两个实例分析表明模型的可行性和有效性     

确定主截面内非寻常光传播方向的一种方法

文中用费马原理给出了光沿主截面入射时,非寻常光在各向异性介质中的传播方向,证明了当光轴与法线之间夹角为φ时,入射光的入射角i与非寻常光之折射角θ之间的关系。     

聚合物光纤应力形变区域光强传输情况的研究

基于光束传播法(beam propagation method,BPM),提出了聚合物光纤在受到拉力和压力产生形变的情况下的光传输的理论分析模型,模拟计算了光纤受拉力作用时形变区域的光强传输情况.     

历史记忆与英雄传奇－－“十七年”战争小说论

从“十七年”战争学的生产方式着手,把战争学作为一种精神化现象放置在广阔的社会化语境中加以检视,并且分别对作品与作、本处理、本传播和接受等相互关联的范畴进行整体性的思考。首先从作品与作家的关系上讲,战争学高度的同质性与这个军旅作家群体的构成状况密切相关。其次从本的角度看,战争学通过“转义”和“典型化”之类的叙述策略,来实现抽象与整合历史的目的。最后,战争学在“十七年”形成的广泛而重大的社会影响,并不完全是凭借作品本身获得的,而很大程度上得益于一体化的社会化机制、特殊的时代精神和社会心理。     

正确舆论导向实践论

舆论导向正确，是党和人民之福；新闻宣传报道必须实现正确的舆论导向。在宣传报道的具体运作中既要把握正确舆论导向，又要讲究引导艺术，才能达到实现正确舆论导向的目的。一是通过把握政治导向，规范思想行为导向和匡正价值导向，达到把握舆论导向的目的；二是在作好超前策划的基础上，通过把握报道时机和创新写作手法的引导艺术，实现正确的舆论导向。     

关于20世纪末期编辑传播学研究

20世纪如年代初期，传播学理论已被广泛引入编辑学领域，使编辑传播学研究不断深化，收获颇丰，表现在：对编辑学与传播学的关系的认识更为全面，准确；对编辑主体、编辑功能问题，以编辑传播学的新视野进行了重新审视与定位；对编辑传播原理与规律进行了较为系统的归纳、总结；对编辑传播过程及社会功能进行了更为细致的描述；对于新媒介技术的优势及其带来的编辑模式的变革、编辑主体现念与素质的更新提高问题，作了富有时代特点和现实意义的探讨。可以预料，今后的研究将更加系统化、体系化，研究方法将更加完善和多元，编辑传播学将成为一门重要的分支学科。     

蠕变条件下完整岩石的起裂和扩展准则

The mechanism and criterion of crack initiation and propagation of rocks were investigated by many researchers,And the creep behaviour of rocks was also theoretically and experimentally studied by some scientists and engineers.The characteristics of crack initation and propagation of rocks under creep condition.however,are very improtant for rock engineering and still not paid enough attention by researchers,In this paper,the criterion and mechanism of crack initiation and propagation under creep condition were investigated using specimens collected from sandstone rock formations outcropping in the Emei Mountain,the Sichuan Province of China.Cuboid specimens under three point bending were used in this investigation.All specimens were classified into four sorts and used for Mode-I fracutre of creep frcture tests.The experimental result shows that due to creep deformation.rock crack will inevitably initialt and propagate under a load of KI,which is less than fracture toughness KIC but not less than a constant(marked as KIC2),KIC2 indicates the ability of rock to resist crack initiation and propagation under creep conditions and is less than fracture tough ness KIC.defined as creep fracture toughness in this paper,KIC2 should be considered as an importnat parameter on design and computation of rock engineering.The microstructureal mechanism for crack initiation and propagation of rock materials under creep condition was introduced based on competitive model between softening effect and hardening effect,and the validity of test result was explained.The test result was also verified in rheological theory.When KI is more than KIC2 but less than KIC,rock crack will initiate and propagate after a time interval of sustained loading under creep condition.In order to find the relation between duration of sustained lading.which can lead to crack initiation and propagation,and the initial stress intensity factor KI,an unequal0interval time sequence forecasting and predicting model was introduced,and the relation was obtained for homogeneous and isotropic fine-grained red sandstone.Finally a modified fracture toughness formula was given,in which the influence of fracture process zone(FPZ) was fully considered.     

植物生长调节剂对中国兰花无性繁殖及生长发育影响的试验

用人工合成的植物生长调节剂6-苄基腺嘌呤10～40mg/L和a-萘乙酸1～16mg/L的不同组合的混合液,对春剑、四季兰(彩心建兰)、凤尾素(素心建兰)、墨兰、寒兰5个品系的中国兰花进行盆栽浇灌处理.6个月后对新苗发苗率和新苗平均叶数、平均叶长进行测量和统计,结果各试验组与对照组之间未发现有明显的规律性差异,提示在本试验浓度范围内的6-苄基腺嘌呤和a-萘乙酸两种植物生长调节剂对盆栽中国兰花的无性繁殖率和生长发育无明显影响.