原位担载型煤直接液化催化剂的表征

 通过原位担载法将铁系催化剂担载于煤表面,考察了催化剂前驱体的相态、配位环境以及在载体表面的分散状态．采用X射线吸收精细结构和X射线衍射法对原位担载型铁系催化剂前驱体进行了表征．结果表明,催化剂前驱体在煤表面以非晶态、高分散的形式存在,其化学组成主要为FeOOH,且催化剂前驱体的分散程度与载体煤的物理化学性质有关．     

The idea of simultaneous batch in-situ extraction and arsenic and antimony hydride generation atomic absorption spectrometry determination directly in the solid (tsunami and lake sediments) samples

The article presents the application of in-situ extraction from a solid sample in order to determine metalloids: arsenic and antimony. The reaction vessel, in which hydride generation followed the extraction, was connected with the atomic absorption spectrometer (AAS) in a fast sequential mode. Deionised water, phosphatic buffer (pH?=?6) and hydrochloric acid (2?mol?L^?1) were used as the extractants to determine the concentration of metalloids in the following fractions: easily (water) leachable, exchangeable, and acid leachable. Two different types of sediments were used while developing the application: lake bottom sediments and tsunami deposits. Both types of the sediments samples (5–20?mg) were placed directly in the reaction vessel and after in-situ extraction the determination of the metalloids was conducted, what allowed to assess concentration of arsenic and antimony during single analysis. The results obtained from the analyses of both sediments types were compared with the results from traditional off-line extraction. As a result a good correspondence with both hydrochloric acid and phosphatic buffer was found. The methodology of solid samples analysis was developed with detection limits of 50?ng?g^?1 (for As) and 30?ng?g^?1 (for Sb) for 10?mg of a solid sample.     

P- V- T Data of hexagonal boron nitride h BN and determination of pressure and temperature using thermoelastic equations of state of multiple phases

Abstract

A synchrotron x-ray diffraction study on hexagonal boron-nitride (hBN) was conducted at simultaneous high pressures and temperatures. The pressure applied to the sample is pseudo-hydrostatic up to 9.0 GPa and the temperature was homogeneous in the range of 300 K to 1280 K. A modified Rietveld profile refinement has been applied to these diffraction spectra of low symmetry and multiple phases observed in the energy-dispersive mode. Thermoelastic parameters of hBN were derived by fitting a modified high temperature Birch-Murnaghan equation of state. The results are: bulk modulus K=17.6 GPa, pressure derivative K′=?K/?P=19.5, temperature derivative [kdot]=?K/?T=?0.69 × 10^?2 Gpa/K, volumetric thermal expansivity α=a+bT with values of a=4.38 × 10^?5K^?1 and b=1.75 × 10^?8K^?2, respectively. It is observed that the thermal expansion and compression along different crystal axes are significantly different. The crystal c-axis is much more expandable and compressible than the a-axis. This is attributed to the layered structure of the hBN. Because the thermoelastic equations of state of hBN and NaCl are quite different, the unit cell volumes of these two materials, derived from the same diffraction pattern, can be used to derive the experimental P-T conditions. The large intersection angle of isochoric lines of these phases in P-T space ensures a determination of P-T with satisfactory precision. The application and limitations of this method in obtaining experimental pressure and temperature using diffraction data and thermoelastic equations of state of multiple phases are discussed.     

火烧油层驱油特征的参数敏感性分析

在火烧油层驱油机理的基础上，依据油气层渗流理论，燃烧理论，建立了火烧油层驱油数学模型。用数值解法对干式和湿式两种燃烧进行了比较，得出：湿式燃烧比干式燃烧的驱油效果好。针对湿式燃烧的特点，对火烧油层驱油过程中的参数进行了敏感性分析，取得了有关结论即1）蒸汽带驱油是火烧油层过程中的一个重要机理；2）随着湿式燃烧水气比的增加，发生氧化反应的区域长度扩大，蒸汽带的温度下降，对流前缘速度增加，加速了热对流的传导，驱油效率增大；3）在湿式燃烧过程中，随着氧气利用率的降低，发生氧化反应的区域长度扩大，蒸汽带的温度下降，燃烧1立方米油砂所需空气量增加，燃烧前缘速度减少，驱油效率几乎不变；4）在湿式燃烧过程中，随着注入空气量的增加，发生氧化反应的区域长度扩大，蒸汽带的温度升高，燃烧前缘速度增加，对流前缘速度增加，加速了热对流的传导，驱油效率增大。     

码头动力特性现场测试方法研究

码头的动力特性的变化直接影响到码头的安全运行。实测码头的动力特性具有重要意义。通过四种不同的现场检测方法的研究和分析，确定了不同方法的使用范围。说明现场检测的方法可以有效地确定码头的动力特性。     

毛细管X光透镜共聚焦微束X射线荧光技术在胶囊类药品分析中的应用

为了对胶囊类药品进行无损分析鉴别,利用两个多毛细管X光透镜搭建了共聚焦微束X射线荧光谱仪,两个处在共聚焦状态的透镜形成共聚焦微元,探测器只能探测到来自该共聚焦微元中的X射线信号,这有利于分别对胶囊壳和其内部药物进行原位无损元素分析,从而辨别它们的种类。分析了4种胶囊类药品对应的X射线荧光谱特征,从荧光谱图上可以看出不同胶囊类药品有不同的X射线荧光谱,对应不同的元素组成,所以可以利用胶囊内部药物对应的X射线荧光谱鉴别胶囊类药品的种类。实验证明,利用共聚焦微束X射线荧光技术可以在不破坏胶囊壳的情况下对胶囊类样品进行无损原位分析,该技术在胶囊类药品种类和真伪鉴别中具有潜在应用价值。     

基于微芯片的透射电子显微镜的低温纳米精度电子束刻蚀与原位电学输运性质测量

利用微芯片制备技术制备了带有电极的原位电学薄膜芯片,并结合自制的原位透射电镜样品台,实现了低温下透射电子显微镜聚焦电子束对InAs纳米线的精细刻蚀以及不同温度下的原位电学性能测量.研究发现,随着刻蚀区域截面积的减小,纳米线的电导率也随之减小.当纳米线的截面积从大于10000 nm2刻蚀至约800 nm2时,纳米线电导的减小速率与截面积的减小具有线性关系.同时利用低温聚焦电子束刻蚀,在InAs纳米线上原位制备了一个10 nm的纳米点,并在77与300 K下对该纳米点进行了电学性能测量.通过测量发现在77 K时出现库仑阻塞效应,发生了电子隧穿现象;而300 K时,热扰动提供的能量使这种现象消失.     

Impact of co-doping concentration in copolymer network liquid crystals

ABSTRACT

The impact of varying the co-doping concentration of a mesogenic and a non-mesogenic monomer in the reactive mixtures used to create a copolymer network LCs was investigated. Use of copolymer has been found to improve the response properties in the obtained liquid crystal composites. The polymer network in the studied copolymer network LCs was examined by scanning electron microscopy and the response times in various samples were investigated. Samples were prepared with various reactive mixtures, each of which had a constant concentration of mesogenic monomer, various concentrations of non-mesogenic monomer, and the same amount of photoinitiator. These reactive mixtures were filled in home assembled test cells with planar alignment and then exposed to UV light. With increasing concentration of the non-mesogenic monomer, the response properties of the resulting copolymer network LC were improved. Usually, if the overall polymer content in a polymer network LC is increased, the threshold voltage is also increased. However, both threshold voltages and response times were lowered and the response properties were thus improved in the studied copolymer network LCs. This unexpected behavior could be traced back to inducing a grainy polymer morphology of the copolymer network by using a non-mesogenic monomer.     

碳纳米管/聚氨酯杂化膜的原位聚合构建及气体渗透性能

采用H₂SO₄/HNO₃混酸处理得到不同氧化程度的多壁碳纳米管（MWCNT-COOH）,再通过与4,4’-二苯基甲烷二异氰酸酯（MDI）、1,4-丁二醇（BDO）的预聚和扩链反应构建碳纳米管/聚氨酯（MWCNT-COOH/PU）杂化膜。利用傅里叶红外光谱（FTIR）、拉曼光谱（Raman）和透射电子显微镜（TEM）等分析表征多壁碳纳米管结构;探讨了多壁碳纳米管氧化程度和填充量对MWCNT-COOH/PU杂化膜的形貌和CO₂、N₂渗透性能的影响。结果表明,混酸处理后的多壁碳纳米管带有一定的含氧基团,并随氧化程度的提高,多壁碳纳米管的拉曼光谱G峰和D峰的强度之比（I_D/I_G）有所增大;氧化程度对多壁碳纳米管在溶剂和杂化膜中的分散性有较大影响,氧化程度越高,分散性越好;杂化膜的CO₂、N₂渗透性及CO₂/N₂渗透选择性随多壁碳纳米管氧化程度的增加有所增大,而随多壁碳纳米管填充量的增加表现出先增大后减小的趋势,当氧化程度较高的多壁碳纳米管（H-MWCNT-COOH）填充量为1.0wt%时,H-MWCNT-COOH/PU杂化膜的CO₂渗透系数为67.8Barrer,CO₂/N₂渗透选择性可达45,表明适量填充MWCNT-COOH能显著提高MWCNT/PU杂化膜的CO₂渗透性及CO₂/N₂的渗透选择性。     

碳酸二甲酯在锌铝复合氧化物上分解行为的红外研究

采用尿素热分解法制备锌铝水滑石,1 073 K下煅烧得到相应的锌铝复合氧化物催化剂。通过XRD谱图确定锌铝复合氧化物ZAO-3(1 073 K)催化剂的组分为ZnO相和ZnAl2O4尖晶石相。NH3(CO2)-TPD结果表明,当向ZnO中引入Al后,催化剂的酸碱性位和酸碱性强度都发生改变。采用原位红外(in-situ FT-IR)手段,研究了碳酸二甲酯(DMC)分别在ZAO-3(1 073 K)、ZnAl2O4、ZnO上随着温度变化的分解行为。结果表明,ZAO-3(1 073 K)催化剂上大量的弱酸碱性位协同稳定DMC,抑制DMC的分解。