THE PREPARATION AND CHARACTERISTICS STUDY OF TiNxOy SPECTRAL SELECTIVE ABSORBING FILM BY MAGNETRON SPUTTERING

Spectral selective absorbent film is a crucial factor for the solar heating device. There are many kinds of spectral selective absorbing film made by different ways. TiNxOy thin film with excellent spectral selecting absobent property were successfully prepared by DC magnetron sputtering with Ar as working gas, N2 and O2 as reactive gas, 99.9% titanium as the target and is copper slice as the substrate. In this article, the optical characteristics and microstructure of TiNxOy thin film were studied. Inputing O2 can decrease the reflection of the visible lights, and double layer film can get good absorption for solar energy.     

Functionalized carbon nanotubes: properties and applications

Carbon nanotubes can be functionalized via amidation and esterification of the nanotube-bound carboxylic acids. The solubility of these functionalized carbon nanotubes makes it possible to characterize and study the properties of carbon nanotubes using solution-based techniques. Representative results concerning the solubility, dispersion, defunctionalization, and optical properties of the functionalized carbon nanotubes are presented. Several examples for the use of functionalized carbon nanotubes in the fabrication of polymeric carbon nanocomposites, the probing of nanotube-molecule interactions, and the conjugation with biological species are highlighted and discussed.     

六六六生产中异构体分配的控制

六六六生产中异构体分配的控制采用下法实验: 实验方法实验使用两种仪器装置:用过量的苯作溶剂时,采用500毫升三口烧瓶,装有搅拌器、温度计、气体进口及取试料口。一或二个100瓦Mazda灯,125瓦Hanovia灯,或400瓦AH-1灯作光源。改变灯与反应器的距离,或在固定的距离下改变电压,以加强或减弱光的照度,进行试验。不含硫茂的苯(熔点5.5℃)200克放入烧瓶中,反应系统用氮充分洗涤。开灯,用水浴调节温度,由少量氮(0.05克分子/小时)稀释的氯通过流量计(0.2～0.4克/分     

Synthetic applications of nonmetal catalysts for homogeneous oxidations

Nonmetal oxidation catalysts have gained much attention in recent years. The reason for this surge in activity is 2-fold: On one hand, a number of such catalysts has become readily accessible; on the other hand, such catalysts are quite resistant toward self-oxidation and compatible under aerobic and aqueous reaction conditions. In this review, we have focused on five nonmetal catalytic systems which have attained prominence in the oxidation field in view of their efficacy and their potential for future development; stoichiometric cases have been mentioned to provide overview and scope. Such nonmetal oxidation catalysts include the alpha-halo carbonyl compounds 1, ketones 2, imines 3, iminium salts 4, and nitroxyl radicals 5. In combination with a suitable oxygen source (H2O2, KHSO5, NaOCl), these catalysts serve as precursors to the corresponding oxidants, namely, the perhydrates I, dioxiranes II, oxaziridines III, oxaziridinium ions IV, and finally oxoammonium ions V. A few of the salient features about these nonmetal, catalytic systems shall be reiterated in this summary. The first class entails the alpha-halo ketones, which catalyze the oxidation of a variety of organic substrates [figure: see text] by hydrogen peroxide as the oxygen source. The perhydrates I, formed in situ by the addition of hydrogen peroxide to the alpha-halo ketones, are quite strong electrophilic oxidants and expectedly transfer an oxygen atom to diverse nucleophilic acceptors. Thus, alpha-halo ketones have been successfully employed for catalytic epoxidation, heteroatom (S, N) oxidation, and arene oxidation. Although high diastereoselectivities have been achieved by these nonmetal catalysts, no enantioselective epoxidation and sulfoxidation have so far been reported. Consequently, it is anticipated that catalytic oxidations by perhydrates hold promise for further development, especially, and should ways be found to transfer the oxygen atom enantioselectively. The second class, namely, the dioxiranes, has been extensively used during the last two decades as a convenient oxidant in organic synthesis. These powerful and versatile oxidizing agents are readily available from the appropriate ketones by their treatment [figure: see text] with potassium monoperoxysulfate. The oxidations may be performed either under stoichiometric or catalytic conditions; the latter mode of operation is featured in this review. In this case, a variety of structurally diverse ketones have been shown to catalyze the dioxirane-mediated epoxidation of alkenes by monoperoxysulfate as the oxygen source. By employing chiral ketones, highly enantioselective (up to 99% ee) epoxidations have been developed, of which the sugar-based ketones are so far the most effective. Reports on catalytic oxidations by dioxiranes other than epoxidations are scarce; nevertheless, fructose-derived ketones have been successfully employed as catalysts for the enantioselective CH oxidation in vic diols to afford the corresponding optically active alpha-hydroxy ketones. To date, no catalytic asymmetric sulfoxidations by dioxiranes appear to have been documented in the literature, an area of catalytic dioxirane chemistry that merits attention. A third class is the imines; their reaction with hydrogen peroxide or monoperoxysulfate affords oxaziridines. These relatively weak electrophilic oxidants only manage to oxidize electron-rich substrates such as enolates, silyl enol ethers, sulfides, selenides, and amines; however, the epoxidation of alkenes has been achieved with activated oxaziridines produced from perfluorinated imines. Most of the oxidations by in-situ-generated oxaziridines have been performed stoichiometrically, with the exception of sulfoxidations. When chiral imines are used as catalysts, optically active sulfoxides are obtained in good ee values, a catalytic asymmetric oxidation by oxaziridines that merits further exploration. The fourth class is made up by the iminium ions, which with monoperoxysulfate lead to the corresponding oxaziridinium ions, structurally similar to the above oxaziridine oxidants except they possess a much more strongly electrophilic oxygen atom due to the positively charged ammonium functionality. Thus, oxaziridinium ions effectively execute besides sulfoxidation and amine oxidation the epoxidation of alkenes under catalytic conditions. As expected, chiral iminium salts catalyze asymmetric epoxidations; however, only moderate enantioselectivities have been obtained so far. Although asymmetric sulfoxidation has been achieved by using stoichiometric amounts of isolated optically active oxaziridinium salts, iminium-ion-catalyzed asymmetric sulf-oxidations have not been reported to date, which offers attractive opportunities for further work. The fifth and final class of nonmetal catalysts concerns the stable nitroxyl-radical derivatives such as TEMPO, which react with the common oxidizing agents (sodium hypochlorite, monoperoxysulfate, peracids) to generate oxoammonium ions. The latter are strong oxidants that chemoselectively and efficiently perform the CH oxidation in alcohols to produce carbonyl compounds rather than engage in the transfer of their oxygen atom to the substrate. Consequently, oxoammonium ions behave quite distinctly compared to the previous four classes of oxidants in that their catalytic activity entails formally a dehydrogenation, one of the few effective nonmetal-based catalytic transformations of alcohols to carbonyl products. Since less than 1 mol% of nitroxyl radical is required to catalyze the alcohol oxidation by the inexpensive sodium hypochlorite as primary oxidant under mild reaction conditions, this catalytic process holds much promise for future practical applications.     

将废PFT转变成有用的聚氨酯多元醇

将这种芳族多元醇用在聚氨酯和聚异氰脲酸酯配方中能制得含少量阻燃剂、性能达到规定火焰扩散速率的泡沫系统。通过应用证明:回收 PET 作原料是可靠而稳定的。将处理后的 PET 废料再作为原料。最初是出于生态学角度考虑,只要经济效益明显,回收 PET 作为聚氨酯多元醇的新原料是完全符合逻辑的。     

Olfactory Responses of Banana Weevil Predators to Volatiles from Banana Pseudostem Tissue and Synthetic Pheromone

As a response to attack by herbivores, plants can emit a variety of volatile substances that attract natural enemies of these insect pests. Predators of the banana weevil, Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae) such as Dactylosternum abdominale (Coleoptera: Hydrophilidae) and Pheidole megacephala (Hymenoptera: Formicidae), are normally found in association with weevil-infested rotten pseudostems and harvested stumps. We investigated whether these predators are attracted to such environments in response to volatiles produced by the host plant, by the weevil, or by the weevil–plant complex. We evaluated predator responses towards volatiles from banana pseudostem tissue (synomones) and the synthetic banana weevil aggregation pheromone Cosmolure+ in a two-choice olfactometer. The beetle D. abdominale was attracted to fermenting banana pseudostem tissue and Cosmolure+, whereas the ant P. megacephala was attracted only to fermented pseudostem tissue. Both predators were attracted to banana pseudostem tissue that had been damaged by weevil larvae irrespective of weevil presence. Adding pheromone did not enhance predator response to volatiles from pseudostem tissue fed on by weevils. The numbers of both predators recovered with pseudostem traps in the field from banana mats with a pheromone trap were similar to those in pseudostem traps at different distance ranges from the pheromone. Our study shows that the generalist predators D. abdominale and P. megacephala use volatiles from fermented banana pseudostem tissue as the major chemical cue when searching for prey.     

子午线轮胎的部件和性能

子午线轮胎的部件和性能Ｓ．Ｗ．Ｈｏｎｇ著胡尧生译涂学忠校轿车子午线轮胎结构需要有几种不同的部件，每个部件都提供规定的使用性能。然而，轮胎公司一直在努力简化结构、减轻重量并降低加工成本。各轮胎部件都有与使用性能相关的关键特性。轮胎配方人员在不断努力通过...     

Protein design to understand peptide ligand recognition by tetratricopeptide repeat proteins

Protein design aims to understand the fundamentals of protein structure by creating novel proteins with pre-specified folds. An equally important goal is to understand protein function by creating novel proteins with pre-specified activities. Here we describe the design and characterization of a tetratricopeptide (TPR) protein, which binds to the C-terminal peptide of the eukaryotic chaperone Hsp90. The design emphasizes the importance of both direct, short-range protein-peptide interactions and of long-range electrostatic optimization. We demonstrate that the designed protein binds specifically to the desired peptide and discriminates between it and the similar C-terminal peptide of Hsp70.     

杀虫脒对夜蛾科害虫(Spodoptera littoralis)各个发育阶段的毒性机制

杀虫脒是一个防治几种重要的鳞翅目害虫很有希望的杀卵剂。Streibert和Dittrich(1977)总结了三种夜蛾科大害虫(Spodoptera bittoralis及二种Heliothis属的害虫)的卵和幼虫对杀虫脒的敏感度资料,除杀卵作用外还发现杀虫脒对棉铃虫、烟芽夜蛾成虫产卵行为有高度的活性。本文目的是详细分析杀虫脒对夜蛾科害虫的毒性机制,测定S.littoralis卵     

Fluor SOx净化工艺——为俄罗斯绿色环境开发的将SOx转化为元素硫的经济技术

Fluor公司开发的Fluor SOx净化工艺具有广泛多样的工艺布局，可以通过经济的方式定制脱除烟气中的有害组成。该工艺几乎能去除全部SOx并减少CO排放。Fluor SOx净化工艺的主要步骤已在多套工业装置中得到成功的证实。除技术可行、经济合理之外，Fluor SOx净化工艺不会产生任何有害副产物，也不会遇到与SOx有关的腐蚀问题。此外，该工艺生产高纯度可市售的元素硫。论述了Fluor SOx净化工艺的特征、技术和成本优势、设计和操作的简易性以及实施的便利性。