Neo-lignans in the Seed Crusts of Trewia nudiflora

Four new neo-lignans were isolated from the chloroform portion of 70% ethanol extract of the seed crusts of Trewia nudiflora L., and were determined to be 9′-methoxy-7′-en-3′,8:4′,7-diepoxyneolignan-3,4,9-triol 1, 9′-methoxy-7′-en-3′,7:4′,8-diepoxyneolignan-3,4,9-triol 2, 9′- ethoxy-7′-en-3′,8:4′,7-diepoxyneolignan-3,4,9-triol 3, 9′-butoxy-7′-en-3′,8:4′,7-diepoxy-neolignan -3,4,9-triol 4, respectively, on the basis of spectral data. The antimicrobial bioassays showed that 4 had evident inhibitory activity against Mycobacterium tuberculosis.     

多谱线耦合系统辐射束缚问题的理论处理

提出一种处理多荧光谱线耦合系统辐射束缚问题的理论方法．这里的耦合包括激发态间的碰撞传能和当谱线重叠时对荧光的交叉吸收．首先将描述辐射束缚的Ｈｏｌｓｔｅｉｎ方程扩展为适用于描述多个激发能级且包括交叉耦合项的微分积分方程组，并将其纳入矢量、矩阵的形式．然后直接通过算符运算求解，给出按算符展开的级数解式．最后对级数解进行约化，导出一个只用有限项便可对系统行为进行完整描述的、远较简单截断近似优越的结果．还给出了一个双激发能级系统的计算实例     

薯蓣皂素对油菜幼苗生长及内源IAA和GA含量的影响

油菜幼苗在二叶一心期经，0．5mg／L的薯蓣皂素喷施处理后，幼苗生长受到促进，苗高增加、叶片增大，用酶联免疫吸附技术(ELISA)检测叶片内源激素含量，结果表明，经适当浓度的薯蓣皂素处理，油菜叶片生长素(IAA)、赤霉素(GA)含量增加．薯蓣皂素处理可能通过提高油菜体内生长素和赤霉素的含量，进而促进油菜生长，     

CULTURE AND REGENERATION OF POPLAR MESOPHYLL PROTOPLASTS

Populus tomentosa is one special species of poplar growing in North China. Mesophyllprotoplasts were isolated from the axenic shoots and cultured in the modified KM8p liquidmedium. Protoplast-derived cells started to divide after 7 days of culture. The frequencyof cell division reached about 20% in 10 days. The yellowish green calli grew compact andnodular after the hormone concentration of medium was adjusted. Shoot formation occurredwhen the protoplast--derived calli were transferred onto MS medium containing zeatin andIAA or NAA. The shoots rooted readily on 1/2 MS hormone--free medium.     

Picosecond flat-top pulse generation using dual-mode fiber Mach-Zehnder interferometers

We report on an optical fiber Mach-Zehnder interferometer made by offset splicing a dual-mode fiber with two single-mode fibers. The extinction ratio can be tuned from less than 1 dB to greater than 28 dB by rotating the dual-mode fiber along its axial direction. The interferometer is utilized as a pulse shaper to convert a 2.5 ps Gaussian pulse to a 5.2 ps flat-top pulse.     

OPTIMAL STRATEGY FOR ERADICATION OF MULTIPLE POPULATIONS USING THE STERILE INSECT TECHNIQUE

Sterile insect technique (SIT) provides an attractive alternative to chemical pesticides for insect pest eradication. Because mass rearing facilities are expensive both to construct and to maintain, project managers have a limited number of sterile insects to use in any single eradication campaign. The problem of availability of sufficient numbers of sterile insects can be magnified when two or more independent pest infestations occur at the same time. In this paper we present the results of a modeling study in which dynamic programming is used to compute the optimal allocation strategy for release of sterile insects to control two independent infestations of Mediterranean fruit fly, Ceratitis capitata (Wied.) (medfly). We assume that a fixed number of sterile flies are available per week. Both deterministic and stochastic analyses are presented.     

薯蓣皂素免疫原的合成及其免疫效果分析

采用二环己基碳二亚胺(dicyclohexyIcarbodiimide，DCC)法和水溶性碳二亚胺[1-ethyl-3-(3-dimethy-laminopropyl)carbodiimide hydrochloride，EDC]法，分别将琥珀酸酐化的薯蓣皂素与牛血清白蛋白(bovine serurmalbumin，BSA)偶联，得到不同的免疫原，通过免疫获得兔多克隆抗体，用间接竞争性Dot-ELISA方法分析比较量两种免疫原的免疫效果，结果表明，DCC法合成的薯蓣皂素免疫原免疫效果优于EDC法。