液相体系芳香卤化物催化加氢降解研究

芳香卤化物是应用非常广泛的重要化工原料，多数具有强毒性和难以生物降解特性，对人类健康和自然环境造成了严重的威胁。催化加氢是一种先进、绿色处理技术，安全无毒物排放，降解产物还可以回收利用，受到研究者广泛关注。用催化加氢技术降解芳香卤化物具有应用价值和科学意义。 本文主要以Raney Ni为催化剂，氢气为氢源，研究了液相条件下，以氯苯为模型分子的催化加氢脱氯反应。详细讨论了在有机溶剂/水混合体系中溶剂、碱和温度等因素对催化剂活性和氯苯加氢脱氯的影响；探讨了催化剂失活的主要原因以及水促进催化剂活性和稳定性的原因；完善了一种适合降解氯代有机物的体系，并将其应用到了多氯代苯和持久性有机污染物

高稳定度大功率可控整流稳流电源

本实用新型涉及一种高稳定度大功率可控整流稳流电源，该电源是采用十二相全桥可控硅整流，两桥并联，平衡电抗器，带有自动平衡的数字触发板，ＬＣ无源滤波，并加有滤波电路对非特征谐波进行特殊处理，电流检测单元采用ＤＣＣＴ，负载为电感性负载，整个系统反馈调节包括一个电压纹波环和一个电流环，保护采用了ＰＬＣ部件，本实用新型的长期电流稳定度达到±１×１０↑［－５］，电源效率达到９０％，功率因素大于０．９。

精神分裂症易感基因GULP1与中国人群大脑容量的相关性研究

精神分裂症是一种复杂的精神疾病,全世界约有1%的人患有这种疾病.以往的研究发现精神分裂症患者的脑容量比正常人小,且一些精神分裂症易感的DNA序列多态性也同时与脑的结构异常有关,这与精神分裂症的神经发育假说是吻合的.最近研究发现人的GULP1基因的两个SNP(rs2004888和rs4522565)与精神分裂症显著相关.为了研究这两个精神分裂症易感的SNP是否也符合神绎发育假说,我们检测了791个正常人的这两个SNP的基因型并测量它们的脑容量,相关性分析发现这两个SNP和脑容量无关,说明GULP1的精神分裂症易感性存在更加复杂的机制.

氨酰-tRNA合成酶专一性识别的进化

氨酰-tRNA合成酶(AARS)是一类在蛋白质合成过程中起着重要作用的酶,它通过与tRNA及其相应氨基酸的专一性识别作用,使得基因序列能够被精确地翻译成蛋白质序列。然而,氨酰-tRNA合成酶的这种识别作用既有专一性,也具有“兼容性”。氨酰-tRNA合成酶的这种双重性质不仅与其结构的进化有关,而且还与其所处的各类生物的不同进化阶段有关。AARS似乎经历了一个由“模糊专一性”(多重专一性)到“精确专一性”(单一专一性)的演变历程。

Evolution of structures and specific recognitions in aminoacyl-tRNA synthetases

The aminoacyl-tRNA synthetases (AARS) are very important during the protein biosynthesis, which can make the gene sequence be accurately translated into the protein sequence by the specific recognition between AARS and tRNA/amino acids. However, the recog

Fabrication of excitonic luminescent inorganic-organic hybrid nano- and microcrystals

Inorganic-organic (IO) hybrid nano- and microcrystals are fabricated by a low-cost, environmentally friendly and easily scaled-up route. Lead(II) iodide (PbI 2) nano/microcrystals are obtained by solvothermal techniques and subsequent IO hybrid (C 12H 25NH 3) 2PbI 4 crystals are produced by intercalation of the organic moiety. The hexagonally shaped crystals obtained range in size from 20 nm to ∼7 μm. Sequential stacking of inorganic/organic layers in these IO hybrid crystals results in strong room-temperature exciton photoluminescence, wherein the excitons are confined within the inorganic sheets. © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Liquid crystalline chromophores for photonic band-edge laser devices

We present results on laser action from liquid crystal compounds whereby one sub-unit of the molecular structure consists of the cyano-substituted chromophore, {phenylene-bis (2-cyanopropene)}, similar to the basic unit of the semiconducting polymer structure poly(cyanoterephthalylidene). These compounds were found to exhibit nematic liquid crystal phases. In addition, by virtue of the liquid crystalline properties, the compounds were found to be highly miscible in wide temperature range commercial nematogen mixtures. When optically excited at λ = 355 nm, laser emission was observed in the blue/green region of the visible spectrum (480-530 nm) and at larger concentrations by weight than is achievable using conventional laser dyes. Upon increasing the concentration of dye from 2 to 5 wt.% the threshold was found to increase from Eth = 0.42 ± 0.02 μJ/pulse (≈20 mJ/cm2) to Eth = 0.66 ± 0.03 μJ/pulse (≈34 mJ/cm2). Laser emission was also observed at concentrations of 10 wt.% but was less stable than that observed for lower concentrations of the chromophore. © 2012 Elsevier B.V. All rights reserved.

Detection reliability analysis of passive DAS RFID system

Recently, it has been shown that improved wireless communication coverage can be achieved by employing distributed antenna system (DAS). The DAS RFID system is based on a novel technique whereby two or more spatially separated transmit and receive antennas are used to enable greatly enhanced tag detection performance over longer distances using antenna diversity combined with frequency and phase hopping. In this paper, we present a detection reliability evaluation of the DAS RFID in a typical lab environment. We conduct an extensive experimental analysis of passive RFID tag detection with different locations and orientations. The tag received signal strengths corresponding to various tag locations on one of the six different sides of a cube, and for different reader transmit power are collected and analyzed in this study.

Si-based optoelectronic devices and their attractive applications

The semiconductor photonics and optoelectronics which have a great significance in the development of advanced high technology of information systems will be discussed in this paper. The emphasis will be put on the recent research carried out in our laboratory in enhanced luminescence from low dimensional materials such as SiGe/Si and Er-doped Si-rich SiO2/Si and Er-doped SixNy/Si. A ring shape waveguide structure, used to promote the effective absorption coefficient in PIN photodetector for 1.3 mu m wavelength and a resonant cavity enhanced structure, used to improve the quantum efficiency and response in heterostructure photo-transistor (HPT), are also proposed in this paper.

开放式实时环境中的集成调度框架

开放式实时环境中的多类型实时任务并存的情况给实时调度机制带来了新的需求和挑战 提出了一种适用于开放式实时环境的 3层集成调度框架 ,它基于服务器方式的实时调度理论 ,把 5种既有相关性又有功能互补特征的服务器有机的集成到统一的调度机制中 可支持多种类型的实时任务及非实时任务共存于同一系统的混合调度 ,并且根据它们的属性自动选择最合适的服务器与之搭配 相对于现有方法 ,该调度框架可支持的调度对象类型更广泛 ,易于进行服务质量控制 ,并且有良好的可扩展性 因此 ,更适合于开放式实时环境