胆红素LB膜的电化学行为研究

胆红素（BR）是存在于动物体内的一种重要生物物质，也是人和绝大多数哺乳动物体内血红蛋白等含铁卟啉化合物分解代谢的产物和代谢中间体。它是一种内源性抗氧化剂，对肝细胞的再生具有积极的作用，BR常以线状四吡咯或类卟啉结构的形式存在。胆红素及其金属配合物在水溶液犤１～６犦与有机介质（如DMF和DMSO）犤７～９犦中的电化学行为，文献上已有较多报道。前文犤１０～１２犦我们报道了胆红素可在不同亚相（酸性、中性及部分金属离子）表面形成Langmuir－Blodgett（LB膜）；在有磷脂存在时，其成膜性能更佳犤１３犦。由于LB膜同生…     

球形氯化镁载体与四氯化钛反应的载钛过程研究

球形氯化镁载体型齐格勒-纳塔催化剂是目前常用的工业聚烯烃催化剂,由于制备工艺对催化剂性能影响很大,因此对此类催化剂制备过程的研究具有重要意义。本文利用自制球形氯化镁载体与四氯化钛反应制备球形聚烯烃催化剂,分析了载钛反应过程的中间产物。对球形氯化镁载体载钛过程中钛含量、比表面、比孔容、晶型等发生的变化进行分析,并研究了邻苯二甲酸二丁酯作为内给电子体在球形氯化镁载体载钛过程中的作用,为球形氯化镁载体型催化剂制备工艺的改进提供了重要参考依据。     

岩石抽提物中极性化合物超高分辨质谱识别

采用具有超高分辨率的负离子电喷雾-傅立叶变换离子回旋共振质谱(ESI FT-ICR MS)分析了储层岩石抽提物中的石油酸及中性氮化物的分子组成,得到了抽提物中杂原子化合物类型分布、等效双键数(Double bonds equivalent,DBE)及碳数分布特征。研究结果表明,储层抽提物中含有多达16种不同杂原子类型的化合物,包括N1、N1O1、N1O2、N1O3、N1S1、N1S2、N2、N2S1、O1、O1S1、O2、O2S1、O1S2、O2S2、O3和O4,其中N1、N1S1、O2及O2S1类具有较高的相对丰度。抽提物中的N1类化合物以咔唑和苯并咔唑类化合物为主;N1S1类化合物以C2~C8烷基取代的咔唑并苯并噻吩类化合物为主;O2类化合物主要为1~2环环烷酸,其次还在抽提物中鉴别出具有较高相对丰度的DBE为5和6的O2类化合物;而O2S1类化合物中以DBE为7和8的O2S1具有最高的相对丰度。     

绿色安全染发剂的研究进展及展望

染发已成为人们的日常需要与时尚选择。目前广泛使用的化学染发剂主要成分为对苯二胺类物质,其引起的致敏性、致癌性与致突变性等问题日益凸显。生物质染发剂及仿生染发剂与化学合成染发剂相比具有安全低毒、资源可再生、环境友好等优点。本文以近年来国内外对绿色安全染发剂的研究为基础,从头发的组成结构和显色机理出发,从生物质染发剂以及仿生染发剂两个方面总结了绿色安全染发剂的研究现状与发展瓶颈,并对其应用前景进行了展望,旨在为安全无毒、绿色健康染发剂的研发提供参考。     

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HL-2A装置实验高性能计算系统共有130个CPU,配置了多种工具软件和程序编译器;系统峰值性能为每秒7680亿次浮点运算,并且具有很好的可管理性与可扩展性。以此为基础开展了程序调优研究,HL-2A装置实验应用研究,并取得了进展。     

ECRH过程中电子速率分布的变化和加热效果分析

本实验利用两台高性能的硅漂移探测器（SDD）、高速波形A／D和虚拟多道分析器组成探测系统，可获得高时间分辨的软X射线辐射能谱，可以非常直观地观察电子回旋共振加热（ECRH）的效果以及电子速率分布的改变。由于SDD探测器的光峰计数／本底计数比率≥400-3000，因此X射线在探测器中仅有光-空穴和电子对效。     

二甲酸二脂系玻璃化转变的力学谱研究

本文用最近发明的液态低频力学谱方法对二甲酸二脂系列样品进行了测量，验证了该方法的可信性与有效性。并且表明它能够提供物质变化的丰富信息。研究结果还表明，随着分子内部自由度的增加、二甲酸三脂系列的玻璃化转变温度表现出先减小然后又增加、但脆性是先增加后减小的有趣又难以理解反常趋势。     

Enhanced MgB2 Superconductivity Under High Pressure

We report on in situ high-pressure studies up to 1.0GPa on the MgB2 superconductor which was high-pressure synthesized.The as-prepared sample is of high quality in terms of sharp superconducting transition (Tc) at 39K from the magnetic measurements.The in situ high-pressure measurements were carried out using a Be-Cu piston-cylinder-type instrument with mixed oil as the pressure transmitting medium which warrants a quasihydrostatic pressure environment at low temperature.The superconducting transitions were measured using the electrical conductance method.It is found that Tc increases by more than 1K with pressure in the low-pressure range,before the Tc valus decreases with the further increase of the pressure.     

Effects of oxygen concentration and irradiation defects on the oxidation corrosion of body-centered-cubic iron surfaces: A first-principles study

Oxidation corrosion of steels usually occurs in contact with the oxygen-contained environment, which is accelerated by high oxygen concentration and irradiation. The oxidation mechanism of steels is investigated by the adsorption/solution of oxygen atoms on/under body-centered-cubic (bcc) iron surfaces, and diffusion of oxygen atoms on the surface and in the near-surface region. Energetic results indicate that oxygen atoms prefer to adsorb at hollow and long-bridge positions on the Fe(100) and (110) surfaces, respectively. As the coverage of oxygen atoms increases, oxygen atoms would repel each other and gradually dissolve in the near-surface and bulk region. As vacancies exist, oxygen atoms are attracted by vacancies, especially in the near-surface and bulk region. Dynamic results indicate that the diffusion of O atoms on surfaces is easier than that into near-surface, which is affected by oxygen coverage and vacancies. Moreover, the effects of oxygen concentration and irradiation on oxygen density in the near-surface and bulk region are estimated by the McLean's model with a simple hypothesis.     

Avalanche Phenomenon of Superthermal Electrons Measured by SDD with New SPHA during ECRH

Two high performance silicon drift detectors （SDD） are installed at the equatorial port with z = 0 and z = -16.4 cm on HL-2A tokamak, respectively. These SDDs combine with the new and non-conventional software pulse height analyser （SPHA ） successfully developed more recently by us to measure the time evolution of soft x-rays spectra, the thermal and superthermal electron temperatures. The high-quality three-dimensional figure of time evolution for soft x-rays energy spectra is easily obtained by combination of a new SPHA and computer. Therefore, the measurement accuracies and the time resolutions of thermal and superthermal electron temperatures are also improved. The enhancement phenomenon of superthermal electron during electron cyclotron resonance heating （ECRH） can be explained by the combination of superthermal electron avalanche theory and experimental parameters.