Thermal behavior of double salt schoenite

The thermal behavior of synthetic schoenite (K₂SO₄·MgSO₄·6H₂)) during heating has been studied by thermal methods. The temperatures of dehydration and decomposition of schoenite have also been determined by DTA, TG and DSC. The thermal reaction equations and the X-ray power diffraction results of the products have been given and the corresponding kinetic parameters have also been obtained.     

Kinetic Equations for Thermal Dissociation Processes. Part I. KEKAM equation

Relationships have been established between the average conversion degree and the dissociation time for polydisperse granular material, taking its grain size distribution into account. It has been checked in which cases the kinetic curves obtained by a numerical solution can be described in terms of KEKAM equation. This revised version was published online in August 2006 with corrections to the Cover Date.     

9-羟基-芴-9-羧酸双核铜配合物[Cu(C_(14)H_8O_3)(C_9H_7N)(C_2H_5OH)]_2的合成、晶体结构及热稳定性研究

在自然界中,α-羟基羧酸广泛的存在于动植物体内,在羧酸循环、碳水化合物代谢和氨基酸的合成中起到重要的作用。Tapscott等详细总结了有关羟基羧酸及其金属配合物的合成化学[1]。芴的9位上2个氢原子被羟基和羧基取代可生成9-羟基-芴-9-羧酸(简称芴酸),它是α-羟基乙酸的衍生物,是一种具有生理活性的植物生长整形素,它能够延缓植株生长,影响植株根的向地性和茎的向光性[2]。由于芴酸含有羟基和羧基两种不同的氧配位原子,使其又可以作为一种潜在的构筑配合物的组织基元。目前有关芴酸与金属离子的合成与结构化学研究相对较少,仅见铜、镉的单…     

配合物形成的三维超分子体系—[Ni(C_6H_4O_2N)_2(H_2O)_4]的水热法合成、晶体结构及热分析

采用水热法用Ni(NO3)26H2O和异烟酸制备出了一种新的由配合物形成的三维超分子体系—[Ni(C6H4O2N)2(H2O)4],并通过X射线衍射对其晶体结构进行了测定。 该晶体属三斜晶系,空间群为Pī, 所得晶胞参数为: a = 6.9228(4), b = 9.6664(19),c = 6.322(1) , a = 96.86(3), b = 113.33(3), g = 110.35(3)°, V = 347.6(1) 3, Z = 1, Mr = 374.98, Dc = 1.791 g/cm3, F(000) = 194, m = 1.443 mm-1。用1362个可观察的 (I > 2s(I))衍射点,修正123个结构参数, 最终偏离因子R = 0.0444,wR = 0.1271。在组成该化合物的基本结构单元[Ni(C6H4O2N)2(H2O)4]中,Ni处于1个稍微拉长的八面体的中心; 各个结构单元之间通过氢键OH…O相互连接,形成了无限伸展的具有层状结构的三维超分子体系。 另外,从差热及热重曲线可以看出,该化合物加热到154 ℃时开始分解, 首先失去4个H2O,再失去2个异烟酸根,最后残余物为NiO。     

二磺酸掺杂高热稳定性导电聚苯胺的合成及性能

以有机二磺酸作为掺杂剂合成了具有高热稳定性的二磺酸掺杂导电聚苯胺。研究了反应时间、温度、酸/苯胺摩尔比等因素对产率、产物的导电率与分子量的影响。利用微波加热的方法测试有机二磺酸掺杂聚苯胺的热稳定性能，结果表明：有机二磺酸掺杂的导电聚苯胺在微波场中升温速率快，并且具有良好的反复升温性能。     

Thermodynamic and Equilibrium Composition Analysis of Using Iron Oxide as an Oxygen Carrier in Nonflame Combustion Technology

1. Introduction The utilization of fossil fuels causes serious neg- ative impacts on the environment and human life. There are many pollutants such as SOx, NOx and CO2 emission produced from the combustion of coal, oil and natural gas. It has been known for more than 100 years that CO2 is a greenhouse gas and that the release of CO2 from fossil fuel combustion may affect the climate of the earth. In the last years the concern over the aspects of an increased release of greenhouse gases has…     

Investigation of the chemical heterogeneity of polyphenylenes using the condensation of methyl aryl ketones as a model reaction

The chemical heterogeneity of polyphenylenes obtained by trimerization poiycycio-condensation of acetylaromatic compounds has been investigated by GLC-MS analysis of the products of trimerization cyclocondensation of acetophenone. The mechanism for the formation of side products of the reaction is discussed. The presence of dypnone fragments in the polyphenylene structure results in a decrease in the thermal stability of these polymers.Deceased March, 1993.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1595–1601, September, 1993.     

Thermal Decomposition Characteristics of 1,7-Diazido-2,4,6-trinitrazaheptane and its Application in Propellants

The thermal decomposition characteristics of1,7-diazido-2,4,6-trinitrazaheptane (DATH) and multi-component systems containing DATH were studied by using DSC, TG and DTG techniques. Three –NO₂ groups in the DATH molecule break away first from the main chain when DATH is heated up to 200°C. Following this process, the azido groups and the residual molecule decompose rapidly to release a great deal of heat within a short time. In the multi-component systems, DATH undergoes a strong interaction with the binder of the double-base propellant and a weak interaction with RDX. The burning rates of the two propellants were determined by using a Crawford bomb. The results showed that the burning rate rises by about 19–66% when 23.5%DATH is substituted for RDX in a minimum smoke propellant. Meanwhile, the N₂ level in the combustion gases is enhanced, which is valuable for a reduction of the signal level of the solid propellant. This revised version was published online in July 2006 with corrections to the Cover Date.     

Preparation and thermal analysis of synthetic malachite CuCO3·Cu(OH)2

The synthesis of malachite CuCO₃·Cu(OH)₂ or Cu₂CO₃(OH)₂ was studied through titrations of copper(II) salt solutions with a solution of sodium carbonate at different temperatures. The precipitates were characterized by TG, IR and chemical analysis. The composition varies depending on thepH of the solution and the temperature. Purer malachite was synthesized by simple mixing of a solution of copper(II) nitrate or sulfate with a solution of sodium carbonate at 50°C.The kinetics of the thermal decomposition of synthetic malachite was described by eitherR ₃ orA _m(m=1.2–1.4) law, according to TG analysis, both isothermal and nonisothermal. The Arrhenius parameters determined using three different integral methods showed the kinetic compensation effect, which is correlated to the working temperature interval analyzed.The authors thank Mr. H. Takemoto for analyzing kinetics of the thermal decomposition of synthetic malachite.     

Thermodynamic and Equilibrium Composition of Using Iron Oxide as an Oxygen Carrier Nonflame Combustion Technology Analysis in

本文介绍了一种新的燃烧体系--熔融盐循环热载体无烟燃烧技术。这种燃烧体系杜绝环境污染气体NOx和CO2的排放，可以实现真正零排放的目标。计算了以Fe2O3作为氧载体的无烟燃烧体系的热力学参数。用最小吉布斯自由能原则，分析了Fe2O3与CH4的平衡组成。分析表明，如果要想在产物中产生高纯度的CH4完全氧化产物CO2和H2O，Fe2O3与CH4必须达到高摩尔比，如果Fe2O3的量不足，就会产生较多的部分氧化产物如CO，H2甚至C