Influence of Carbon-doped Content on Formation Conditions of Coesite

The mixtures of α-quartz and graphite powder with different mass ratios were, respectively, high-energetically mechanically milled and then treated under high pressure and high temperature. The influences of carbon content on the synthesis conditions of coesite were investigated. The experimental products were characterized by XRD, TEM, and Raman spectrometry. The results show that the existence of carbon can obviously inhibit the formation of coesite, and the higher the carbon content of the initial material, the higher the pressure for forming coesite.     

高压变质二氧化硅矿物的合成及表征

根据高能机械球磨与地球板块碰撞之间具有的碰撞局域性和剪切应力相似的特点, 采用高能机械球磨和静高温高压技术, 以α-石英与石墨混合粉末为原料, 提出了人工合成地表柯石英的一种新方法. 利用高能机械球磨制备了α-石英和石墨纳米非晶混合粉末, 其高温高压合成柯石英的最低条件是970 K和3.7 GPa. 合成的柯石英有10个Raman峰, 分别位于120, 152, 179, 206, 270, 329, 357, 428, 467和521 cm-1, 是目前最全的柯石英Raman谱.     

金属钾和碳酸钠高压合成金刚石

以金属钾和碳酸钠为反应原料, 在压力为2 GPa, 温度为500 ℃的密封白金坩埚中反应18 h, 所得产物通过粉末X射线衍射和显微拉曼分析进行了表征, 证实合成出了微米级的金刚石. 对金刚石的合成机理进行了研究, 推测其反应过程为碳酸钠在铂和钾的作用下分解出CO2, CO2与钾反应得到金刚石. 研究结果表明金刚石可以在温和的条件下合成.     

聚合物在高压下的结构、形态和性能（下）

聚合物在高压下的结构、形态和性能（下）张雄伟，黄锐（成都科技大学塑料工程系，成都，６１００６５）在上篇中我们介绍了结晶性聚合物在高压下结晶的结构和形态。本篇将介绍聚合物在高压下的结晶动力学和热力学以及聚合物在高压下的退火等方面内容。２高压结晶动力学研...     

High Pressure Study of NH4Pb2Br5 Type Compounds. I Structural Parameters and Their Evolution under High Pressure

We have investigated the nature of the interactions of ns²‐cations and the possible structure‐determining role of the ns²electron pair at ambient and high pressure in several AB₂X₅ (A = K, Rb, Cs, In, Tl; B = Sn, Pb, Sr; X = Cl, Br, I) compounds. Structural parameters are obtained by high pressure x‐ray diffraction as well as by quantum mechanical methods (DFT‐GGA‐calculations). The structural parameters at ambient and high pressure are discussed and compared to those of Tl₅Se₂I crystallising in the antitype structure. Short cation—cation distances in the NH₄Pb₂Br₅ type structure enable direct cation—cation interactions and the existence of an ns²‐cation in the B‐position is crucial for the stability of these structures. The effect of pressure on the structural parameters of these compounds gives new insights into the interactions of lone pair cations. The pronounced decrease of the cation—cation distances with pressure points to strongly increasing bonding interactions between the lone pair cations.     

MCM-48介孔分子筛的高压合成

采用正硅酸乙酯（TEOS）作硅源,十六烷基三甲基溴化铵（CTAB）为模板剂,在高压 （约7 MPa）和373 K下合成了MCM-48介孔分子筛.用XRD、氮气吸附及29Si MAS NMR对样品 进行了表征.与常压合成的相比,高压下合成的MCM-48具有更高的热稳定性和水热稳定性.2 9Si MAS NMR结果表明,高压有利于分子筛孔壁的聚合,导致分子筛结构更加完善,从而使 其具有更高的稳定性.     

High‐Pressure Synthesis and Single‐Crystal Structure Elucidation of the Indium Oxide‐Borate In4O2B2O7

The indium oxide‐borate In₄O₂B₂O₇ was synthesized under high‐pressure/high‐temperature conditions at 12.5 GPa/1420 K using a Walker‐type multianvil apparatus. Single‐crystal X‐ray structure elucidation showed edge‐sharing OIn₄ tetrahedra and B₂O₇ units building up the oxide‐borate. It crystallizes with Z = 8 in the monoclinic space group P2₁/n (no. 14) with a = 1016.54(3), b = 964.55(3), c = 1382.66(4) pm, and β = 109.7(1)°. The compound was also characterized by powder X‐ray diffraction and vibrational spectroscopy.     

Efficient Synthesis of Highly Functionalized Thiazolidine-4-ones Under Solvent-Free Conditions

Summary. 4-Phenylthiosemicarbazide reacts smoothly with dimethyl acetylenedicarboxylate in the presence of aldehydes or ketones under solvent free conditions to produce highly functionalized thiazolidine-4-ones.     

无胺体系高硅铝比丝光沸石的合成

Mordenite has two kinds of pore channels. The main straight channels of 0.67 nm ×0.70 nm (12-membered ring) parallel to the caxis are interconnected with small side-channels of 0.29 nm×0.57 nm (8-membered ring) parallel to the baxis.     

A High Pressure Study on NH4Pb2Br5 Type Compounds Part II: Electronic Structure and Changes under High Pressure

In this work, we present a theoretical study (based on DFT‐calculations) of the electronic properties of compounds crystallising in a NH₄Pb₂Br₅ type structure in a wide pressure range. The main focus of this study is to elucidate the nature of bonding of the ns²‐cations at ambient and elevated pressure. For a better understanding of the structure and bonding, the DOS of these compounds are evaluated and discussed on the basis of a simple model assuming mainly ionic interactions. The calculations are complemented by an orbital analysis using the crystal orbital Hamilton population (COHP) and an analysis of the electronic density topology with the electron localisation function (ELF). Structural and theoretical investigations give results that are in excellent agreement: The DFT‐calculations confirm the existence of bonding interactions between the ns²‐cations at elevated pressure. Our study indicates that the “character” of the additional electron pair changes with increasing pressure from nonbonding to bonding in agreement with a simple model system of two interacting ns²‐cations.     

单相Ce0.5Zr0.5O2立方固溶体的高压高温合成

以化学沉淀法制备的 Ce O2 和 Zr O2 纳米微粒为前驱体 ,首次在高压高温 (3 .1 GPa,1 0 73 K)下合成了单相 Ce0 .5Zr0 .5O2 面心立方固溶体 .使用 X射线衍射、TG-DTA、XPS、Raman、电子自旋共振谱和交流阻抗谱等对样品的结构、Ce离子的价态和导电性进行了表征 .实验结果表明 ,纳米 Ce O2 -50 % Zr O2 混合物在高压 (0 .9GPa以上 )高温 (1 0 73 K以上 )条件下可以发生固态反应 ,高压下固溶温度明显降低 .Ce0 .5Zr0 .5O2 面心立方固溶体在 773 K以下是热稳定的 ,不发生结构转变 ,固溶体中 Ce离子完全以 Ce4 + 形式存在 ,773 K退火也不引起 Ce4 + 向 Ce3 + 转变 ,晶格中氧缺位非常少 .Ce0 .5Zr0 .5O2 面心立方固溶体是离子导电 ,82 3 K时电导率 σ=1 .2× 1 0 -5S/cm,与纯 Ce O2 在同温度下的电导率同数量级 ;1 1 2 3 K时 σ=2 .1× 1 0 -3 S/cm,小于掺入稀土或碱土氧化物的氧化锆和氧化铈基电解质的电导率 .在高温区和低温区 ln(σT)与 1 /T的关系满足斜率不同的二条直线 ,低温活化能小于高温活化能 .固溶体的显微硬度 (50 g载荷 )为 572 HV.     

2-溴-4-甲基苯酚的合成

2-溴-4-甲基苯酚是合成许多药物及广谱型香料香兰素的重要中间体。常温下,以对甲基苯酚为原料加溴易生成2,6-二溴-4-甲基苯酚,本文在原来工作的基础上,在低温下,通过溴化氧化一步直接合成了2-溴-4-甲基苯酚,产率可达93％并通过红外光谱和核磁共振谱对产物结构进行确证。反应的最佳条件是：反应温度为-5～-10℃,反应时间为4h,搅拌速度为1000r／min,对甲基苯酚与双氧水物质的量比为1：0．85。反应方程式如下：     

Determination of High Pressure Phase Diagrams of the Ternary Alloy System

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Rapid Determination of Propranolol and 4-Hydroxypropranolol in Plasma by High Pressure Liquid Chromatography

Abstract

The resolving power of high pressure liquid chromatography has been combined with the sensitivity of fluorescence detection to develop a method for the determination of propranolol and 4-hydroxypropranolol in plasma. A single selective extraction step precedes chromatography on a high efficiency bonded phase column. The limits of quantitation are approximately 2 ng/ml of plasma for each drug. The analysis of a number of clinical samples has demonstrated the application of the method in pharmacokinetic studies, but the possible interference of other drugs and their metabolites is still under investigation.     

Rietveld Analysis of a High Pressure Modification of Monocalcium Oxogallate (CaGa2O4)

A high‐pressure modification of monocalcium gallate (CaGa₂O₄) has been prepared in a piston‐cylinder apparatus at 700 °C and 4.0 GPa. The compound is orthorhombic (space group Pnam, a = 9.12476(15) Å, b = 10.56093(18) Å, c = 2.98547(4) Å, V = 287.70(1) ų, Z = 4, D_calc = 5.62 g/cm³) and belongs to the CaFe₂O₄‐type structure family. The structure was refined by the Rietveld method using laboratory X‐ray powder diffraction data. Two crystallographically independent GaO₆‐octahedra forming edge‐sharing double chains can be distinguished. The shared edges exhibit a considerable shortening. The chains are running parallel to the c‐axis and are linked by corner‐sharing. They enclose tunnels in which the calcium atoms are located for charge compensation. Each calcium cation has eight nearest oxygen neighbors. The coordination environment can be described as a bicapped trigonal prism.     

2-烷硫基-5-苯基亚甲基-4H-咪唑啉-4-酮的合成与表征

用2-硫代-3-正丁基-5-苯基亚甲基4-咪唑啉二酮的-S-烷基化反应合成了2-烷硫基-3-正丁基-5-苯基亚甲基-4H-咪唑啉-4-酮衍生物。探讨了S-烷基化反应的反应条件和所合成化合物的波谱性质。目标产物均为新的化合物，其结构经元素分析，IR，1H NMR和MS确正。     

Synthesis,Crystal Structure and Properties of Ag4CuTeO6

The new quaternary oxide Ag₄CuTeO₆ has been obtained by solid state reaction starting from stoichiometric amounts of the binary oxides at elevated temperatures and oxygen pressures. Ag₄CuTeO₆ crystallises in space group C2/c with a = 11.3021(8), b = 9.6875(6), c = 5.7082(5) Å, β = 99.301(7)°, V = 616.77(8) ų, Z = 4; the structure refinement was based on 747 independent reflections and resulted in R₁ = 3.26 %, wR₂ = 7.29 %. The crystal structure consists of isolated TeO₆ octahedra which are connected by distorted CuO₄ squares, thus forming one‐dimensional, infinite heteropolyanions, extending along the c axis. According to the approximately fcc packing and a distorted octahedral oxygen environment of all the cations, the structure may be regarded a derivative of the NaCl structure type. Ag₄CuTeO₆ is paramagnetic between 300 K and 7 K, where it develops antiferromagnetic ordering. An evaluation according to the Curie‐Weiss law yielded a magnetic moment of 1.86 μ_B per copper ion. The electronic conductivity shows a maximum at ～ 75 K, below a temperature characteristic of a semiconductor, above of a metal.     

High Pressure Behavior of Mercury Cyanamide HgCN2

Using the diamond anvil cell technique, angle‐dispersive X‐ray diffraction and Raman spectroscopy were employed to study the high pressure behavior of mercury cyanamide. Its decomposition under pressure starts at 1.9 GPa and is not completed even up to 10 GPa. The decomposition product α‐Hg transforms to β‐Hg during 7–10 GPa, while the C/N residual is not detectable by X‐ray diffraction. The zero pressure bulk modulus of mercury cyanamide is estimated as 38.5 GPa.     

Synthesis of 4-azacyclopent-2-enones and 5,5-dialkyl-4-azacyclopent-2-enones

Three different methods are reported for the preparation of 4-azacyclo-2-enones 1, two of which allow the preparation of the compounds in optically active form. In addition, a facile route to 4-aza-5,5-dimethylcyclopent-2-enones 2 is disclosed.     

含镧金属富勒烯不同溶剂的高温高压提取

将金属原子或离子置于以Ｃ６０、Ｃ８２为代表的富勒烯笼内形成金属富勒烯包合物是目前富勒烯研究的热点课题［１～３］．合成的金属富勒烯常伴随生成较难分离的空心富勒烯,传统的索氏提取法效率又较低,使得金属富勒烯的深入研究受到限制［１,２］．本文采用改进的高温...