Supramolecular self-assembly of macroscopic tubes

The macroscopic molecular self-assembly of an amphiphilic hyperbranched copolymer in acetone generated multiwalled tubes millimeters in diameter and centimeters in length. The thickness of the tube walls approaches 400 nanometers, and the walls have an inhomogeneous lamella structure that alternates between ordered hydrophilic domains and amorphous, partly irregular hydrophilic domains.     

Predictive self-assembly of polyhedra into complex structures

Predicting structure from the attributes of a material's building blocks remains a challenge and central goal for materials science. Isolating the role of building block shape for self-assembly provides insight into the ordering of molecules and the crystallization of colloids, nanoparticles, proteins, and viruses. We investigated 145 convex polyhedra whose assembly arises solely from their anisotropic shape. Our results demonstrate a remarkably high propensity for thermodynamic self-assembly and structural diversity. We show that from simple measures of particle shape and local order in the fluid, the assembly of a given shape into a liquid crystal, plastic crystal, or crystal can be predicted.     

Reversible optical transcription of supramolecular chirality into molecular chirality

In nature, key molecular processes such as communication, replication, and enzyme catalysis all rely on a delicate balance between molecular and supramolecular chirality. Here we report the design, synthesis, and operation of a reversible, photoresponsive, self-assembling molecular system in which molecular and supramolecular chirality communicate. It shows exceptional stereoselectivity upon aggregation of the molecules during gel formation with the solvent. This chirality is locked by photochemical switching, a process that is subsequently used to induce an inverted chiral supramolecular assembly as revealed by circular dichroism spectroscopy. The optical switching between different chiral aggregated states and the interplay of molecular and supramolecular chirality offer attractive new prospects for the development of molecular memory systems and smart functional materials.     

BA-VAC共聚乳液胶及其对木材的冷胶合

通过对丙烯酸酯－醋酸乙烯酯共聚乳液胶合成工艺研究，分析讨论了各因素对乳液胶质量的影响，选择了最佳工艺条件（聚合温度为85℃，聚合时间4h，引发剂0.4%-0.6%)及木材冷胶合调制配方。结果表明：该乳液胶使用方便，成膜性好，胶合适用范围广，对木材冷压胶合后的板材强度可达I类胶合板要求（＞0.965MPa)。表7参8     

Directed assembly of block copolymer blends into nonregular device-oriented structures

Self-assembly is an effective strategy for the creation of periodic structures at the nanoscale. However, because microelectronic devices use free-form design principles, the insertion point of self-assembling materials into existing nanomanufacturing processes is unclear. We directed ternary blends of diblock copolymers and homopolymers that naturally form periodic arrays to assemble into nonregular device-oriented structures on chemically nanopatterned substrates. Redistribution of homopolymer facilitates the defect-free assembly in locations where the domain dimensions deviate substantially from those formed in the bulk. The ability to pattern nonregular structures using self-assembling materials creates new opportunities for nanoscale manufacturing.     

微波辐射合成纳米Ni粉及其催化性能研究

采用微波协助加热的联氨还原工艺快速合成了纳米Ni粉,并利用X-射线粉末衍射仪(XRD)、透射电子显微镜(TEM)、比表面仪(BET)等测试方法对其结构、形貌和比表面积进行了表征,并用差热分析法(DTA)研究了纳米Ni粉对高氯酸铵(AP)热分解的催化效果。结果表明,微波合成工艺法不仅速度快、反应条件简单、重现性好,而且所得的纳米Ni粉结晶好、分散性好,比表面积大。当其质量分数5%时,可使AP的高温分解峰温度降低了99.25°C,表观分解热增加了960 J/g,表现出对AP热分解具有显著的催化性能,明显优于传统水浴加热法所制得的纳米Ni粉催化剂。     

信息管理与知识管理的演进过程及其关系探讨

章对信息管理与知识管理演进的过程及其关系作了初步探讨，从2产生背景、管理对象、管理目标与功能等方面进行了分析与论述，并得出结论：它们既在上述几方面存在明显差异，同时又具有一定逻辑的和历史的关联。最后，站在管理思想发展的角度，从2关系的研究中揭示了知识管理产生的必然性。     

Anatomy and dynamics of a supramolecular membrane protein cluster

Most plasmalemmal proteins organize in submicrometer-sized clusters whose architecture and dynamics are still enigmatic. With syntaxin 1 as an example, we applied a combination of far-field optical nanoscopy, biochemistry, fluorescence recovery after photobleaching (FRAP) analysis, and simulations to show that clustering can be explained by self-organization based on simple physical principles. On average, the syntaxin clusters exhibit a diameter of 50 to 60 nanometers and contain 75 densely crowded syntaxins that dynamically exchange with freely diffusing molecules. Self-association depends on weak homophilic protein-protein interactions. Simulations suggest that clustering immobilizes and conformationally constrains the molecules. Moreover, a balance between self-association and crowding-induced steric repulsions is sufficient to explain both the size and dynamics of syntaxin clusters and likely of many oligomerizing membrane proteins that form supramolecular structures.     

DNA-templated self-assembly of protein arrays and highly conductive nanowires

A DNA nanostructure consisting of four four-arm junctions oriented with a square aspect ratio was designed and constructed. Programmable self-assembly of 4 x 4 tiles resulted in two distinct lattice morphologies: uniform-width nanoribbons and two-dimensional nanogrids, which both display periodic square cavities. Periodic protein arrays were achieved by templated self-assembly of streptavidin onto the DNA nanogrids containing biotinylated oligonucleotides. On the basis of a two-step metallization procedure, the 4 x 4 nanoribbons acted as an excellent scaffold for the production of highly conductive, uniform-width, silver nanowires.     

高雅艺术走进农民工生活

在我们传统概念中,高雅艺术和农民工之间并不存在什么联系。但是农民工身上所包 含的积极进取、辛苦耐劳都是高雅艺术,是非常值得尊重的精神。文章以高雅艺术走进农民工 生活为分析对象,首先对相关的概念进行了介绍,接着分析了当前高雅艺术与农民工之间存在 的问题,最后论述了高雅艺术走进农民工生活,以便帮助农民工获得更高的生活质量。     

Plastic and moldable metals by self-assembly of sticky nanoparticle aggregates

Deformable, spherical aggregates of metal nanoparticles connected by long-chain dithiol ligands self-assemble into nanostructured materials of macroscopic dimensions. These materials are plastic and moldable against arbitrarily shaped masters and can be thermally hardened into polycrystalline metal structures of controllable porosity. In addition, in both plastic and hardened states, the assemblies are electrically conductive and exhibit Ohmic characteristics down to approximately 20 volts per meter. The self-assembly method leading to such materials is applicable both to pure metals and to bimetallic structures of various elemental compositions.     

铝塑复合软管的应用与发展

铝塑复合软管是利用铝箔与塑料薄膜复合成片材后，经制管机加工制成的一种软管包装容器。由于它具有阻隔性和抗氧化性好，印刷方式灵活，印刷效果优秀，爆破强度大，手感舒适，防伪效果好等特点，已大量应用于各种膏状产品的包装。应用范围越来越大，发展速度也越来越快。１铝塑复合软管的应用 根据铝塑复合软管的特点，它主要是应用于对卫生性、防氧化性要求较高的产品的包装。按其用量由大到小的顺序排列，主要有牙膏、药膏、化妆品。日用化学品和食品等。 人们在使用牙膏时，每次使用都是从尾部一点点向前挤，并且不希望挤下去的部分又反…     

Interplay of intra- and intermolecular H-bonding in a progressively solvated macrocyclic peptide

Studying solvation of a large molecule on an atomic level is challenging because of the transient character and inhomogeneity of hydrogen bonding in liquid water. We studied water clusters of a protonated macrocyclic decapeptide, gramicidin S, which were prepared in the gas phase and then cooled to cryogenic temperatures. The experiment spectroscopically tracked fine structural changes of the clusters upon increasing the number of attached water molecules from 1 to 50 and distinguished vibrational fingerprints of different conformers. The data indicate that only the first two water molecules induce a substantial change of the gramicidin S structure by breaking two intramolecular noncovalent bonds. The peptide structure remains largely intact upon further solvation, reflecting the interplay between the strong intramolecular and weaker intermolecular hydrogen bonds.     

单季秋茭主要病虫发生规律及防治技术初探

通过定点系统调查，初步明确嘉兴市单季秋茭白主要病虫害有锈病，灰心斑病，胡麻斑病，蚜虫,长绿飞虱，二化螟等。对这些病虫的发生规律进行了调查。根据田间药效试验结果，提出了茭白病虫害无公害防治技术。     

Selection and amplification of hosts from dynamic combinatorial libraries of macrocyclic disulfides

We have discovered two receptors for two different guests from a single dynamic combinatorial library. Each of the two guests amplifies the formation of a tightly binding host at the expense of unfit library members. Small differences in host-guest binding translate into useful differences in amplification. The selected hosts could be readily synthesized using biased dynamic libraries that contain only the right ratio of those building blocks that were selected by the guests. These results establish dynamic combinatorial chemistry as a practical method not only for the discovery but also for the synthesis of new receptors.     

Macroscopic hierarchical surface patterning of porphyrin trimers via self-assembly and dewetting

The use of bottom-up approaches to construct patterned surfaces for technological applications is appealing, but to date is applicable to only relatively small areas (approximately 10 square micrometers). We constructed highly periodic patterns at macroscopic length scales, in the range of square millimeters, by combining self-assembly of disk-like porphyrin dyes with physical dewetting phenomena. The patterns consisted of equidistant 5-nanometer-wide lines spaced 0.5 to 1 micrometers apart, forming single porphyrin stacks containing millions of molecules, and were formed spontaneously upon drop-casting a solution of the molecules onto a mica surface. On glass, thicker lines are formed, which can be used to align liquid crystals in large domains of square millimeter size.     

外源抗氧化剂硫脲基苯甲酰基硫脲衍生物的合成及促植物生长作用

以苯甲酸、芳氨基硫脲或单缩二氨基硫脲为原料,合成得到5个取代硫脲基苯甲酰基硫脲衍生物,经红外、质谱、核磁共振氢谱和元素分析确认了化合物的结构。测定其清除超氧自由基(O_2~-·)、羟自由基(·OH)和2,2-二苯基-1-苦味酰基自由基(DPPH·)的活性及总还原能力,并与维生素C的活性进行比较。以水稻和黄瓜幼苗为试材,用生长测试法、超氧歧化酶(SOD)活性测定法以及过氧化物酶(POD)活性测定法研究这些化合物作为外源抗氧化剂对植物的生长调节作用。结果表明,在测定浓度下,这些化合物均具有清除自由基活性,并对水稻和黄瓜幼苗的生长发育有促进作用,且能激起SOD和POD的活力。     

加入WTO对榕台农业及其合作的影响分析

本文从两地合作的现状出发 ,力求通过对榕台农业的比较 ,分析两地农业的共性与差异、优势与不足 ,阐述入世对两地农业合作的一系列影响。     

杉木种子园病害综合治理的初步探讨

通过长期对尤溪、南平等地杉木种子园的调查研究,结合林木病害综合治理理论,从林业措施等几方面探讨综合治理杉木种子园病害的方法.     

Cylindrical block copolymer micelles and co-micelles of controlled length and architecture

Block copolymers consist of two or more chemically different polymers connected by covalent linkages. In solution, repulsion between the blocks leads to a variety of morphologies, which are thermodynamically driven. Polyferrocenyldimethylsilane block copolymers show an unusual propensity to forming cylindrical micelles in solution. We found that the micelle structure grows epitaxially through the addition of more polymer, producing micelles with a narrow size dispersity, in a process analogous to the growth of living polymer. By adding a different block copolymer, we could form co-micelles. We were also able to selectively functionalize different parts of the micelle. Potential applications for these materials include their use in lithographic etch resists, in redox-active templates, and as catalytically active metal nanoparticle precursors.