Influence of the deposition parameters on the properties of SnS2 films prepared by PECVD method combined with solid sources

We report a simple and rapid biological approach to synthesize water-soluble and highly roughened “meatball”-like Au nanoparticles using green tea extract under microwave irradiation. The synthesized Au meatball-like nanoparticles possess excellent monodispersity and uniform size (250 nm in diameter). Raman measurements show that these tea-generated meatball-like gold nanostructures with high active surface areas exhibit a high enhancement of surface-enhanced Raman scattering. In addition, the Au meatball-like nanoparticles demonstrate good biocompatibility and remarkable in vitro stability at the biological temperature. Meanwhile, the factors that influence the Au meatball-like nanoparticles morphology are investigated, and the mechanisms behind the nonspherical shape evolution are discussed.     

One-pot approach to installing eight-membered rings onto indoles

Ring fusion: The Pd(0)-catalyzed reaction of 2-allyl-3-iodo-1-tosyl-1H-indoles and propargylic bromides affords dihydrocycloocta[b]indoles (see scheme; M.S. = molecular sieves, TFP = tris(2-furyl)phosphine, Ts = 4-toluenemethanesulfonyl), and proceeds by carbon-carbon coupling, [1,5]-hydrogen migration, and electrocyclization. The newly established method was used to efficiently access iprindole.     

Allenes in catalytic asymmetric synthesis and natural product syntheses

Allenes are the simplest class of cumulenes, with two contiguous C=C bonds, and show unique physical and chemical properties. These features make allenes particularly attractive in modern organic chemistry. In this Review, attention is paid to the advances made in catalytic asymmetric synthesis and natural product syntheses based on well-established reactions of allenes, such as propargylation, addition, cycloaddition, cycloisomerization, cyclization, etc., with or without catalysts. Their versatile reactivity, substituent-loading ability, axial to center chirality transfer, and controllable selectivity allow access to target molecules by unique and efficient approaches. The main topics in this Review are presented with selected examples from 2003 to 2011.     

K(2)CO(3)-catalyzed Michael addition-lactonization reaction of 1,2-allenyl ketones with electron-withdrawing group substituted acetates. An efficient synthesis of alpha-pyrone derivatives

[reaction: see text] Alpha-pyrone derivatives were synthesized via the base catalyzed or promoted reaction of 1,2-allenyl ketones and electron-withdrawing group substituted acetates. The reaction was believed to proceed through a Michael addition C-C double-bond migration-lactonization process.     

Palladium-catalyzed highly regio- and stereoselective addition of organoboronic acids to allenes in the presence of AcOH

The Pd(0)-catalyzed regio- and stereoselective addition of organoboronic acids to allenes leads to stereodefined tri- or tetrasubstituted alkenes. Furthermore, this method shows high substitutent-loading capability and tolerance of various substitutents. A hydropalladation-Suzuki coupling mechanism, which may account for the regio- and stereoselectivity, is proposed.     

超临界流体萃取气相色谱法测定粮谷中拟除虫菊酯残留量

本文建立了一种离线超临界流体萃取、气相色谱法快速测定粮谷（大米、小米、玉米）中的二氯苯醚菊酯、氯氰菊酯、速灭杀丁、溴氰菊酯等４种拟除虫菊酯残留量的方法。在优化条件下，菊酯被提取并收集于正己烷中，定容后直接进行气相色谱测定。整个分析时间小于１ｈ。     

LiGaO2衬底上ZnO外延膜的结构与光学特性

采用磁控溅射法在(001),(100)及(010)LiGaO2衬底上制备了ZnO薄膜,通过X射线衍射(XRD)、原子力显微镜(AFM)、透过光谱以及光致发光谱(PL)对薄膜的结构、形貌及光学性质进行了表征.结果表明LiGaO2衬底不同晶面上制备的ZnO薄膜具有不同的择优取向,在(001)、(100)及(010)LiGaO2上分别获得了[001]、[1100]及[1120]取向的ZnO薄膜;不同取向的ZnO薄膜表面形貌差异较大;薄膜在可见光波段具有较高的透过率;在ZnO薄膜的光致发光谱中只观察到了位于378 nm的紫外发射峰,而深能级发射几乎观察不到,(1100)取向的薄膜紫外发射峰强度最大,半高宽也最小,薄膜光致发光件质的差异丰要和晶粒尺寸有关.     

轻型反射镜研究与发展

应用有限元分析方法研究了自重对轻型反射镜变形的影响，反射镜轻量化技术及关键材料，并研制出Φ６３０ｍｍ轻型熔石英反射镜；高温２００℃、低温－４０℃及５年时效对面形稳定性影响；轻型熔石英反射镜加工技术；轻型反射镜宽带高反射膜系及镀膜技术。利用上述技术研制出Φ３００ｍｍ、Φ４１０ｍｍ、Φ４７０ｍｍ及Φ６３０ｍｍ球面及非球面熔石英轻型反射镜及平面反射镜。轻型反射镜减重达７０％，Φ６３０ｍｍ轻型非球面反射镜仅重２０．２ｋｇ。Φ４７０ｍｍ球面轻型反射镜加工后面形ＰＶ值０．１１７λ，ＲＭＳ值０．０２４λ（λ∶６３２．８ｎｍ）。