STRUCTURAL ANALYSIS OF PEKEKK（T／I） USING WAXD, IMAGING PLATES AND SAXS

Structures and crystal form transition of the novel aryl ether ketone polymer containing meta-phenylene linkage: PEKEKK(T/I) were investigated by wide angle X-ray diffraction (WAXD), imaging plates (IPs) and small angle X-ray scattering (SAXS). The energy of activation of the decomposition reaction and degree of crystallinity of PEKEKK(T/I) were determined by WAXD and thermo-gravimetric analysis (TGA), respectively. Results obtained fi‘om WAXD and IPs show that crystal forms I and II coexist in the PEKEKK(T/I) samples isothermally cold crystallized in the temperature range from 180℃ to 240℃ and only form I occurs in PEKEKK(T/I) samples isothermally cold crystallized at 270℃. The radius of gyration (Rg), thickness of microregions with electron-density fluctuations (E) and distribution of particle sizes were investigated by SAXS.     

5-{[(4′-正戊基氧-4-联苯基基)羰基]氧}-1-戊炔的相转变与相结构

采用差示扫描量热(DSC)、一维(1D)广角X射线衍射(WAXD)、热台偏光显微镜(PLM-hotstage)等研究手段对含联苯液晶基元的侧链液晶聚炔单体5-{[(4′-正戊基氧-4-联苯基基)羰基]氧}-1-戊炔(A3EO5)的本体相转变和相结构进行了研究.DSC和1D-WAXD实验结果表明,A3EO5在升温和降温过程中均呈现四个相转变过程,形成双向性液晶.样品从各向同性态降温至室温过程中,首先形成近晶A相,随后进入层内排列具有准长程有序的近晶B相,继续降温将形成层内为正交排列的近晶E相,在此之后样品进入晶相.PLM结果指出样品在各向同性态降温过程中分别形成球状织构、角锥织构和同心圆弧织构.     

煤与生物质混烧灰荷电特性研究

对玉米秸分别与两种煤以不同比例混烧生成的混烧灰进行了荷电特性研究。利用法拉第杯荷电量检测系统和静电低压撞击器(ELPI)测量了混烧灰的总体荷质比及分级荷质比,并借助于成分分析及形貌分析结果讨论了其影响机理。结果表明,随着生物质掺入量在混烧燃料中的增加,混烧灰的成分组成发生变化,使得其介电常数变大,比电阻增大,表面吸附能力增强,从而使混烧灰的总体荷质比有一定的上升趋势。对混烧灰的分级荷质比测量结果表明,排除灰样粒径的影响,生物质的掺入使得混烧灰的荷电能力得以增强,但影响相对较小,颗粒粒径是影响混烧灰荷电能力的主要因素。     

半夏淀粉的理化特性

研究了不同产地的4种半夏淀粉的理化特性,包括直链淀粉含量、膨胀度、溶解性、持水性、淀粉粒大小和形貌、结晶类型、热特性和糊化特性等。结果表明,这些半夏淀粉中直链淀粉含量为18.60%～23.91%;膨胀度21.53%～23.09%;溶解度11.5%～32.3%;持水性100.3%～119.0%。淀粉粒单粒球形,卵形或圆半球形,直径2～20μm,复粒由2～3个分粒组成,其结晶类型均为C型,结晶度15.0%～37.9%。用差示扫描量热仪测得的转变温度TO、TP和TC分别为71.58～77.75℃、83.03～83.84℃和89.41～90.99℃,热焓为4.316～5.809 J/g。用快速粘度分析仪测定了4种半夏淀粉的糊化特征值:峰值粘度、热糊粘度、冷糊粘度、稀懈值和回复值分别为149.5～226.2、97.7～127.2、141.8～194.3、50.4～99.0和44.2～67.2 RVU。糊化温度77.8～79.9℃,峰值时间8.3～8.7 min。     

X射线衍射定量相分析新方法

在基体清洗法的基础上提出一种新的X射线衍射定量分析方法，该方法是利用混合样品X射线衍射谱图中的全部衍射峰数据，把清洗剂同样品中所包含的所有待测物相的纯相按比例混合，在同一水平下同时测定各物相与清洗剂对应的几个K值，结合JCPDS卡中的各相标准谱峰的相对强度分布数据进行最小二乘方程组的抛弃平均法回归分析，求得混合物样品中各相间的全谱峰匹配强度比，用于混合物样品的X射线衍射定量相分析，有利于提高定量相分析的精度，通过对四组分混合物样品的分析，实验结果和理论完全一致。     

微晶玻璃中物相含量的回归分析计算

提出一种非X射线衍射(X-ray diffraction,XRD)法,仅根据电子探针分析数据和微晶玻璃的化学分析数据,采用回归分析方法确定微晶玻璃材料各物相尤其是玻璃相的物质质量分数.采用该方法研究堇青石微晶玻璃,获得的各物相质量分数与XRD分析结果和Image-Pro Plus图像软件大致吻合,该方法简易可行,准确性满足材料研究的要求.     

铌酸盐Ba3NaBiNb10O30的结构与介电特性

一些铁电铌酸盐具有优良的电光性能和非线性光学性能,因此该类化合物的人工合成,结果与性能的研究受到了人们的重视,其中钨青铜结构的系列晶体（例如SBN,KNSBN,SCNN）在材料制备和器件设计方面都取得了很大进展,它们在实时全息存储,集成光学与光信号处理等领域具有广泛的应用前景[1-4],Ba2NaNb5O145(BNN)是目前认为最好的一种倍频晶体,Geusic[5,6]等人报导了在BNN晶体能实现最优位相匹配,可将1．06um红外光以100％的效率转换为0．53um绿光,我们在BaO-Na2O-Nb2O5体系中通过掺杂Bi3 合成了铌酸盐Ba3NaBiNb10O30,并采用粉晶X射线衍射（XRD）对其结构进行了分析,测试了其烧结体的介电特性。     

铌酸盐Ba_3NaBiNb_(10)O_(30)的结构与介电特性

A niobate was synthesized by doping Bi3＋ in the ternary system BaO Na2O Nb2O5. The crystal structure was determined by X ray powder diffraction,and it belongs to tetragonal tungsten bronze structure at room temperature with unit cell parameters a=1.24777 (2) nm,c=0.39266(1) nm,α =β =γ =90° .Measurements of dielectric properties indicate that phase transitions of Ba3NaBiNb10O30 from paraelectric to ferroelectric occurs at 400℃ ,which is lower than that of Ba2NaNb5O30.     

含过量钛的 BaO·TiO粉末的高温X射线衍射研究

本文采用高温X射线衍射方法研究了含有过量TiO_2的BaTiO_3粉末在不同温度下的物相关系,并对实验结果进行了分析和讨论。     

煤灰中矿物质组成对煤灰熔融温度的影响

选取九种不同灰熔融温度的煤样,利用X射线衍射分析方法,研究了煤灰的矿物质组成及含量对灰熔融温度的影响,以及弱还原性气氛下不同温度煤灰熔融过程中的矿物演变过程及其对灰熔融温度的影响。结果表明,815℃煤灰的主要晶体矿物质组成为石英、硬石膏、赤铁矿、氢氧钙石和石灰等。一般情况下,煤灰中氢氧钙石含量低,硬石膏和赤铁矿含量高的煤,灰熔融温度较低。在还原性气氛下,随着温度的升高,煤灰中的石英、硬石膏、氢氧钙石等结晶矿物含量逐渐减少,生成新的矿物质。莫来石的生成是导致煤灰熔融温度高的主要原因。低灰熔融温度煤灰在加热过程中,在1 100℃时,钙长石和铁钙辉石的生成起到了降低煤灰熔融温度的作用。     

淮南煤灰中晶体矿物组成与煤灰流动温度关系的研究

选取10种不同灰熔融温度的淮南煤,利用典型煤灰化学组成预测煤灰熔融温度的经验公式,对其煤灰流动温度进行了研究,发现预测精度不高;借助X射线衍射K值法分析计算了淮南煤灰的晶体矿物组成,并对晶体矿物组成与淮南煤灰流动温度的关系进行了关联,提出了利用晶体矿物组成预测煤灰流动温度的回归公式,揭示了淮南煤灰中晶体矿物组成与煤灰流动温度的内在关系,利用该公式计算的煤灰流动温度与实测值之差的绝对值小于国标规定的误差值(再现性小于等于80℃)。     

Oxidation behaviour of precipitation hardened steel TG,X-Ray,XRD and SEM study

In the present work the oxidation behavior of ageing treated steel was examined up to 1000°C in different environments (O₂ and CO₂) and with different heating rates. The examination was conducted by means of thermogravimetric analysis, scanning electron microscopy and X-ray diffraction. In this study it was deduced that in the case of O₂ an oxide scale is formed on top of the steel. The oxidation is uniform and the growth of the scale is more intent at low heating rate. It consist of different Fe, Mn, Mo and Cr oxides which are adjusted in the form of layers. This phenomenon was explained by the different diffusion coefficients of each metal in the already formed scale. Regarding the oxidation in CO₂, the scale formation takes place at a lower temperature than in the case of O₂. Hence the examined substrate is more vulnerable in CO₂.     

Characterization of some new alkali metal molybdate hydrates by thermal and X-ray methods

Preparation and characterization of four new hydrated alkali metal molybdates Na₂Mo₄O₁₃·6H₂O, K₂Mo₄O₁₃·3H₂O, Rb₂Mo₄O₁₃·2H₂O and Cs₂Mo₄O₁₃·2H₂O are described. The compounds were prepared by crystallizing the solution obtained by dissolving MoO₃ and corresponding alkali metal carbonates A₂CO₃ or molybdate A₂MoO₄ in stoichiometric amount in distilled water. The hydrated molybdates were characterized by thermal (TG/DTA) and X-ray diffraction (XRD) methods. The number of water molecules in the compounds were determined from their TG /DTA curves recorded in air and identification of their dehydration products was done by XRD. The cell parameters of the compounds were obtained by indexing their XRD patterns. Attempt to prepare the corresponding hydrated compound of lithium was not successful. This revised version was published online in July 2006 with corrections to the Cover Date.     

生物质与煤混燃灰的比电阻特性实验研究

以玉米秸、麦秸、锯末纯燃并以不同比例与煤混燃,利用DR型高压粉尘比电阻实验台对灰样比电阻R进行测量, 以AAS对灰样化学成分进行分析。结果表明,纯生物质燃料灰R值为10⁸Ω·cm~10¹0Ω·cm,属于中比电阻。混燃灰样的R值均为10⁸Ω·cm~10¹2Ω·cm。麦秸与煤的混燃灰中,掺混率R_t对比电阻R的影响不明显;玉米秸与煤的混燃灰中,在110℃以下,R_t越高,R越低;在110℃以上,R_t越高,R越大。生物质与煤的混燃改变了燃料的燃烧特性及熔融特性,使灰的物理特性和化学成分、含量发生变化,造成混燃灰比电阻与煤灰比电阻的规律存在一定的差异。     

X-Ray Diffraction Studies of Sol-Gel Derived ORMOSILs Based on Combinations of Tetramethoxysilane and Trimethoxysilane

ORMOSILs have been prepared in the series TMOSx·MTMS(100 – x) (where TMOS is tetramethoxysilane; MTMS is methyltrimethoxysilane; x is mol% silane with respect to total silane for 0 x 100) by means of acid catalyzed, sol-gel processing. After drying at 60°C, small bulk samples were obtained of excellent optical clarity. Powder X-ray diffraction (XRD) patterns, in the range of 5 to 60°2, were compared with that of fused silica. All the prepared samples were amorphous. Fused silica exhibits one broad peak, d2 centered at d-spacing 4.12 Å. For the TMOS100 silica xerogel, the analogous broad peak had shifted slightly, to be centered at 3.88 Å; and remained in about the same position as x was decreased for the series TMOSx·MTMS(100 – x). In addition, a second, broad peak, d1, was observed for the ORMOSIL series centered at the d-spacing 8.7 Å for MTMS100 (i.e., x = 0) and increasing smoothly as x was increased, reaching 11.3 Å for x = 70, and >11.3 Å for x > 70. The intensity of d1 was found to have trebled, relative to the intensity of d2, on increasing the organic character of the matrix from TMOS70·MTMS30 to MTMS100.The d2 peak appearing at about 4 Å for both fused silica and the ORMOSILs is assumed to be associated with the spacing between silicon atoms connected by means of an oxygen bridge. The Si–O–Si angle for silica xerogels is known to depend upon the nature of the sol-gel processing and is bigger than that of fused silica.The d1 peak may be associated with the spacing between silicons attached to methyl groups and indicative of channels of methyl groups in the structure. Alternatively, the d1 peak may have its origin in a preferred, discrete structural unit in the matrix for instance cubane based on a octameric silicon arrangement.     

Specific features of adsorption of azo dyes on fly ash

A possibility to utilize fly ash (FA) formed at coal-fired power plants as a cheap adsorbent for the purification of wastewater containing azo dyes methylene blue (MB) and methyl red (MR) was considered. The effect of an FA additive on the adsorption capacity of active carbon was studied. The efficiency of FA as an adsorbent for the purification of aqueous solutions from MB and MR was shown. The adsorption is also fairly efficient when active carbon is partially replaced by FA. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 545–548, March, 2007.     

X-Ray Analysis of Multi-Films for Electrochromic Device Application

Multilayer films based on tungsten oxide (WO₃), ITO (indium tin oxide) and CdS were deposited mainly by reactive dc magnetron sputtering onto glass substrates for electrochromic application. The thin films were analyzed by means of XPS (X-ray photoelectron spectroscopy), GIXD (grazing incidence X-ray diffraction) and XRD (X-ray diffraction). XRD and XPS results confirmed that the films were WO₃, CdS and ITO, respectively. The surface and interface of the CdS/ITO bi-layered film was studied by GIXD in different incidence angles. Detailed results about the amorphous characterization of the films during room temperature growth and post annealing are given.     

Heteropolyacid/saponite-like clay complexes and their blends in amphiphilic SEBS

A synthetic saponite-like clay, Sumecton SA (SSA), was self-assembled with 12-phosphotungstic acid (PTA) heteropolyacid for the preparation of new hybrid nanocomposites for proton exchange membranes. Thermogravimetric analysis (TGA) and Fourier transformed diffuse reflectance spectroscopy (DRIFT) measurements indicate the formation of robust PTA-SSA complexes. The Keggin structure of PTA is preserved within the complexes and is thermally stable up to 450 °C. The amount of PTA incorporated into the clay depends on the PTA-SSA weight ratio used for the complex preparation. PTA incorporation achieved is approximately 2-3 times the PTA content of most reported literature. However, higher PTA incorporation is accompanied by a significant loss of structural clay integrity. Low PTA-SSA weight ratios tend to preserve clay structure, but do not preclude its general amorphization generated by the PTA acidic treatment. PTA-SSA complexes present a low degree of order. Inorganic complexes were blended by melt extrusion with chemically-modified styrene/ethylene-co-butylene/styrene block copolymer (SEBS). Poly(oxyethylene/oxypropylene)-grafted-SEBS is more efficient than maleic anhydride-grafted-SEBS at dispersing PTA-SSA complexes. For both nanocomposite systems, nanoparticles’ size varies between 30 and 300 nm.     

Remediation of Wastewater with Ultraviolet Irradiation Using a Novel Titanium (IV) Oxide Photocatalyst

Photocatalysis has become common and nanomaterials having photocatalytic functions have been widely characterized. At present, among the many candidates for photocatalysis, TiO₂ is almost the only material suitable for industrial use. In this paper, we present a TiO₂ synthesis starting from Ti sheets put in contact with a mixture of 0.1 N NaOH and acetone for 72?hours under ambient conditions. The obtained sheets were washed with distilled water and ethanol, and the surface was analyzed for its structural and morphological properties. Thus, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) investigations indicated the formation of TiO₂ on the edges of nanometer circles on the surface of the Ti sheets. For characterizing the photocatalytic capacity for wastewater treatment, Ti sheets with TiO₂ on the surface contacted with methylene blue solutions at room temperature under ultraviolet light. The degradation of the methylene blue concentration was measured by ultraviolet–visible spectroscopy, demonstrating 99.94% efficiency for wastewater treatment using the obtained material.