关于Dedekind和的一个均值公式

利用ＤｉｒｉｃｈｌｅｔＬ－函数的均值定理研究Ｄｅｄｅｋｉｎｄ和的一类均值问题,并给出一个较为精确的渐近公式。     

Testing relative evolutionary rates and estimating divergence times among six genera of Rhizophoraceae using cpDNA and nrDNA sequences

The molecular phylogenetic trees of 10 species representing 6 genera of the family Rhizophoraceae have been constructed using the sequences of chloroplast genesmatK andrbcL as well as the ITS regions of nuclear ribosomal DNA. Relative-rate tests between lineages in these phylogenetic trees have been performed. On the basis of the results of the relative-rate tests and related molecular evolutionary rate data, the divergence times between the lineages are estimated as follows: (i) the first divergence time in these genera is 132.25 million years ago (mya); (ii) the average divergence time between two tribes, i.e. inland Legnotideae (exceptCarallia brachiata) and mangrove Rhizophoreae, is 64.13 mya; and (iii) the average divergence time between two inland species,C. garciniaefolia andC. pectinifolia, is 19.92 mya.     

Biological mechanism of controlling cotton aphid (Homoptera: aphididae) by the marginal alfalfa zone surrounding cotton field

At the beginning stage of cotton aphids (Aphis gossypii Glover) invading the cotton field, large numbers of insects have accumulated in the marginal alfalfa (Medicago sativa L.) zone surrounding it. They are 6.94 times (excluded natural enemies) as many as the aphids in cotton field. Most of these insects areTherioaphid maculata (Buckton), and occur in fields 10–15 d earlier than cotton aphids. Consequently, abundant natural enemies have bred in alfalfa zone when cotton aphids increase rapidly in cotton fields in the middle of June in Xinhe County, Xinjiang Autonomous Region. The total number of the major natural enemies, including Coccinellids, Chrysopids and Syphid flies in alfalfa zone, is 13.65 times that in cotton field within the same acreage of fields. At this period, it is very effective to force the natural enemies from the alfalfa zone into the nearby cotton field to control the rapid increase of cotton aphid population by cutting the alfalfa stands.     

利用两种反应器发酵米根霉生产L-乳酸的研究

介绍了采用米根霉产L-乳酸的反应器发酵。以摇瓶发酵为基础,建立了两种反应器模型,探讨了间歇式发酵的产酸速率、周期和发酵次数等因素。     

外部平面图的L(p,q)-标号

对于正整数p,q,n与图G,如果函数φ:V(G)→｛0,1,2, ,n｝满足如下关系:若distG(u,v)=1,则|φ(u)-φ(v)|≥p;若distG(u,v)=2则|φ(u)-φ(v)|≥q,那么称函数φ为图G的L(p,q) 标号.在所有L(p,q) 标号中最小的n称为(p,q) 跨度,记作λ(G;p,q).本文证明了如下结论:设图G是一个最大度为Δ的外部平面图,那么λ(G;p,q)≤qΔ+4p+2q-4.     

L.C振子超混沌系统的参数辨析

对于L.C振子超混沌系统的未知参数提出一种简单的辨析方法,首先通过对系统实行反馈控制使其到达任意不动点,其次通过求解不动点的平衡方程,解析得到系统未知参数的表达式,当超混沌系统参数发生阶跃变化时也能实现准确辨析,数值计算结果和理论分析一致。该方法对于研究其他超混沌系统结构具有一定的理论意义。     

不同化学因子对银杏发根悬浮培养生长效应的研究

以银杏幼叶、幼芽为材料,诱导银杏外植体产生发根,在建立发根悬浮培养体系的基础上,探讨不同种类植物生长调节物质、不同类型培养基以及蔗糖浓度对银杏发根悬浮培养生长的影响.以便获得银杏悬浮发根快速增殖的最适培养条件,为银杏发根大规模工业化生产提供必要的理论基础.实验结果表明:添加外源植物生长调节物质,对发根的生长是有利的,其中以NAA效果最好,其最佳浓度为1.0 m g/L,发根生长速度为8.59 m g.L-1.-d 1.B5培养基有利于发根的生长,其最佳生长速度为8.58 m g.L-1.d-1.培养基蔗糖的最佳浓度为15 g/L,银杏发根生长速度为7.36 m g.L-1.d-1.     

霜霉菌侵染对三裂叶豚草叶绿体和木质素作用的影响

采用光学显微镜和透射电子显微镜技术,对苍耳轴霜霉菌(Plasmopara angustiterminalis Novotelnova)侵染三裂叶豚草( Ambrosia trifida L. )叶片木质素沉积变化和叶绿体结构影响进行了初步研究。结果表明,苍耳轴霜霉菌能够导致寄主叶绿体膜破损,内含物外流,从而影响叶片光和能力,抑制豚草生长。叶片中木质素因霜霉菌的侵染其沉积量明显增加。     

带有混合约束的特殊三次规划问题的全局最优性充分条件

利用拉格朗日函数和L-次微分的方法,研究了带有双值和不等式约束的特殊三次规划问题的全局最优性充分条件;首先刻画出该类三次规划问题的拉格朗日函数的抽象次微分,得到了特殊三次规划问题的全局最优性充分条件;然后,举例说明利用所给出的全局最优性充分条件判定当前可行解就是全局最优解是有效的.     

小菜蛾的抗药性研究

小菜蛾是十字花科蔬菜上最主要的害虫,也是目前产生抗药性最严重的害虫之一.本文采用浸叶法测定了常用6种农药对福安市小菜蛾的毒力,比较研究了福安市不同菜区的小菜蛾对其中3种常用农药的和抗药性差异,为小菜蛾的抗药性治理提供理论依据.