稀土元素异硫氰酸盐水合物的低温热容和热力学性质研究——Ⅲ.Sm(NCS)_3·6H_2O,Gd(NCS)_3·6H_2O,Yb(NCS)_3·6H_2O和Y(NCS)_3·6H_2O

用全自动绝热量热计测定了4种稀土异硫氰酸盐六水合物,Sm(NCS)_3·6H_2O,Gd(NCS)_3·6H_2O,Yb(NCS)_3·6H_2O和Y(NCS)_3·6H_2O在13～300 K间的热容,在实验温区上述化合物均未发现反常热容.根据实验热容数据用最小二乘拟合方法得出了计算这4种化合物在13～300 K温区内的热容多项式方程.13K以下的热容用 Debye-Einstein热容函数估算而得.计算了这些化合物在0～300 K间的标准热力学函数及其标准生成Gibbs能.     

PBT-PA6嵌段共聚物中嵌段间的相容性

用热分析、动态粘弹谱、红外光谱和小角X光散射的实验结果,证实了在聚对苯二甲酸丁二酯-聚己内酰胺嵌段共聚物(简称PBT-PA_6)的无定形区中,两嵌段间具有良好的相容性,两嵌段间有氢键生成。     

α-氨基-α-甲基,1,3-丙二醇从280K到其熔点间的热容和相变

本文用绝热量热计测量了α-氨基-α-甲基-1,3丙二醇从280K到其熔点间的热容和相变, 首次发现该物质在352,89和353,72K处有一个双叉型固-固相变, 并准确测定其熔点为384,08k。双叉型固-固相变和固液相变的相变焓经测定分别为(23,46±0.29)和(2.78±0.05)KJ,mol^-^1提出了"比例分配法", 用以解释两个相变温度极其接运的一级相变的相变焓, 并据此估算组成双叉型相变的两个固-固相变的相变焓分别为(5.00±0.75)和18.46±0.75)KJ,mol-1, 讨论了形成双叉型固一固相变的原因。     

ON A DIFFERENTIAL EQUATION FOR KINETICS OF NON- ISOTHERMAL CRYSTALLIZATION

A new differential equation was derived from the modified first-order kinetic model to describe the polymer crystallization processes. The crystallization experiments were carried out by means of DSC. Poly (ethylene terephthalate) resins were selected as the samples containing different catalysts. The relationships between the parameters obtained from the known Avrami equation and from one in the present paper were discussed. A method for applying the equation to determine the kinetic parameters from a constant heating and a constant cooling curve was proposed.     

高聚物的非等温结晶动力学——从不同速率的升温或降温DSC曲线解析结晶动力学参数

The differential equation, which was proposed by us in previous paper, was applied to analysis of the DSC curves of poly (etkylene terephthalate) with several constant heating or cooling rates. The parameters characterizing the rate and the mechanism of crystallization can be derived by using present method. The results of the isothermal and the constant heating and cooling rate tests were illustrated.     

三甲醇丙烷—季戊四醇固体溶液的热容和相变焓

前曾报道季戊四醇在461.60K有一个固-固相变,其相交含为41.37kJmol~(-1)。但是,作为低温储能材料,该物质的相变温度偏高。从有关固-固相变储能材料的热力学研究中,我们发现三甲醇丙烷-季戊四醇固体溶液具有较低的固-固相变温度。本文测定了三甲醇丙烷-季戊四醇(摩尔比60:40)固体溶液的相变热参数和热容。     

页岩气吸附解吸规律研究

页岩中天然气的吸附解吸规律是页岩气开发的基础。根据物质平衡原理,自行设计了页岩气吸附解吸实验装置。用该装置对取自鄂尔多斯盆地的三个页岩岩样在不同温度(30～90℃)、不同压力(0.1～10MPa)条件下,进行页岩气吸附及解吸规律研究。实验结果表明,吸附量随有机碳含量的增加而增大;随压力的增加吸附量增大,而随温度的增大吸附量减小。同一温度压力条件下,相对吸附过程而言,解吸过程有滞后现象,解吸不够彻底。对粘土含量较大的页岩,朗格缪尔模型拟合效果较差,而利用修正的双朗格缪尔模型可以得到较好的拟合结果。     

筼筜湖CDOM的三维荧光光谱及其污染示踪研究

测定了2008年4～5月厦门筼筜湖52个CDOM样的三维荧光及吸收光谱,以探讨利用其光谱特征示踪高污染近海浅水湿地生物修复过程中有机污染程度的可行性。利用平行因子分析对三维荧光光谱进行解谱。结果表明,筼筜湖CDOM可识别出3类5个荧光组分,包括类腐殖质荧光组分C1(240,325/422 nm)和C5(260,380/474 nm)、类蛋白质荧光组分C2(225,275/350 nm)和C4(240,300/354 nm)以及有机污染组分C3(225/342 nm),其中C3可作为外来有机污染物输入的指纹特征。松柏湖干渠及污水处理厂排放口C3组分及DOC浓度很高,表明周边污水输入是筼筜湖有机污染的主要来源。类腐殖质荧光组分C1及吸收系数a(280)与COD之间、类蛋白质荧光组分C2与BOD₅之间均具有很好的线性相关关系,表明CDOM的光谱特性可很好地指示有机污染程度,对评价有机污染严重水域生物修复作用机理及效果有重要的参考价值。     

KINETICS OF NON-ISOTHERMAL CRYSTALLIZATION

A kinetic equation of non-isothermal crystamzation was derived by extending Avrami's equation to the non-isothermal situation. More crystallization information can be obtained from this kinetic equation. The curves of non-isothermal and isothermal crystallizations were analysed and compared for poly (ethylene terephthalate) (PET), and the results were discussed.     

稀土化合物晶格熵的估算

考虑到化合物的阳离子质量和摩尔体积对其晶格熵的影响,提出一个估算同构同阴离子稀土化合物晶格熵的公式:S_(298.15)~0=S_(ref)~0 (3/2)n_1R·lnM/M_(ref) (3/2)n_2R·lnV/V_(ref)计算结果能满意地与实验值相吻合.