新兴的边缘学科——粒子天体物理学的现状及发展前景

天体物理学和基本粒子物理学之间正在形成一种互相促进、共同发展的关系：天体物理学的观测结果有助于阐明基本粒子的性质，而粒子理论及其实验技术又可用于研究宇宙的各个组成部分并探讨宇宙的起源。     

Discussion On the Semantics and Culture

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Botany: specialized bird perch aids cross-pollination

Birds may hover over or perch on flowers when feeding on nectar, and this assists cross-pollination if they then visit other plants. Here we investigate the curious sterile inflorescence axis of the South African Cape endemic 'rat's tail' plant (Babiana ringens, Iridaceae), whose function--unlike in other bird-pollinated plants--is exclusively to provide a perch for foraging birds. We find that this structure promotes the plant's mating success by causing the malachite sunbird (Nectarinia famosa), its main pollinator, to adopt a position ideal for the cross-pollination of its unusual ground-level flowers.     

Macromolecules Mimicking Backbones of Nucleic and Teichoic Acids.Synthesis,Some Properties and Applications

1 Results Several methods have been elaborated in this laboratory allowing preparation of macromolecules with phosphodiester bonds,and having sequence of atoms similar as in the chains of biomacromolecules - nucleic or teichoic acids (TA),namely:-(C)n-O-PO-,where n=2 (for teichoic acids) or 3.These methods,to be discussed in the lecture,are based on the ring-opening polymerization,transesterification,and recently elaborated direct addition of phosphoric acid to diepoxides.For the first time an attempt has been made to directly reacting phosphoric acid with diols in the presence and absence of catalysts.The major side reaction,preventing high molar mass polymers formation,results from dealkylation,i.e.nucleophilic attack of the OH groups on the C atom,instead attack on the P atom.The other two methods allowed reaching high molar mass macromolecules,with Mn up to 105.Following these studies phosphorylation of polymers with side groups containing -OH groups were studied and a series of diblock copolymers with ionic and nonionic blocks were prepared.     

核磁共振研究Ⅰ——乙醛烯醇锂的溶液结构

在-80℃至0℃温度范围内,测定了乙醛烯醇锂1在四氢呋喃(THF)中的~(13)C核磁共振自旋—晶格弛豫时间T_1。亚甲碳的弛豫比次甲碳快近七倍,两个碳核均有完全的核Overhauer效应(NOF),这些结果表明烯醇锂1在溶液中的运动是高度各向导性的。对这种典型烯醇锂的溶液结构提出了一种具有立方构型的,非刚性溶剂化四聚体模型,并就这个模型及其对反应机理的影响进行了讨论。     

Preface

Energy is stored and transported most easily as chemical energy. The fossil fuels represent solar energy captured and stored as chemical energy by plants over many millions of years. Modern economies depend on this finite, non-renewable energy store. The inexorable march to a global economy and the rising expectations of an expanding world population place ever greater demands on the finite resources of planet