UNIFAC法估算甲烷在常三柴油中的高压溶解度

为满足富氢气氛下,煤直接液化基础数据的需要,选择大港常三柴油做溶剂,用自建的循环法测定气体高压溶解度试验装置,测定甲烷在柴油中的高压溶解度数据(273.45 K-293.75 K,1.79 MPa-8.06 MPa)。根据柴油特点假设其基团构成,用n-d-M-LP法计算柴油的平均结构。用UNIFAC方程估算同条件下的溶解度值,结果估算值与实验值比较,当芳香环和环烷环上有2个取代基时,平均相对误差为3.36%,满足数据缺乏下的估算要求。     

磺胺类药物水溶解度的测定与关联

采用平衡法测定了(298.15～333.15)K温度范围内磺胺嘧啶、磺胺二甲基嘧啶、磺胺二甲氧嘧啶、磺胺对甲氧嘧啶、磺胺间甲氧嘧啶和磺胺甲恶唑6种常见磺胺类药物在水中的溶解度数据,并运用λh方程进行了关联,确定了方程参数,总均方根偏差为0.26×10~(-6)。结果表明,实验范围内磺胺嘧啶、磺胺二甲基嘧啶、磺胺二甲氧嘧啶、磺胺对甲氧嘧啶、磺胺间甲氧嘧啶和磺胺甲恶唑6种常见磺胺类药物的水溶解度均较小,且分别随温度的升高而略有增加,计算值与实验值吻合较好。根据溶解过程热力学,由溶解度实验数据计算出6组磺胺类药物水溶液的超额焓H~E>0,表明其溶解为吸热过程。     

乙醇、异丙醇在超临界二氧化碳中的溶解度及其模型

采用固定体积可视观察法,测定温度313 K～393 K范围内,不同压力下乙醇和异丙醇在超临界CO2中的的溶解度,并应用Chrastil半经验溶解度模型关联这些溶解度.实验结果表明,在相同温度下,随着CO2密度的升高,溶质在气相中的溶解度也升高.且得到了相应于该系统的溶解度方程参数,与实验数据几乎一致.     

超临界二氧化碳与异丁醇二元体系气液相互溶解度模型的研究

采用可变体积可视观察法测量装置,测定CO_2与异丁醇在40℃-80℃温度范围和不同压力下的平衡数据。研究高压状态下CO_2在液相中的溶解度和异丁醇在气相中的溶解度模型,以改进亨利定律和Chrastil半经验溶解度方程,提出适合于高压下CO_2与异丁醇二元体系的相互溶解度模型,其中CO_2在液相中的溶解度可用4次多项式模型关联,其形式为:P_(CO_2)=A+B_1·x~(CO_2)+B_2·x_(CO_2)~2+B_3·x_(CO_2)~3+B_4·x_(CO_2)~4。异丁醇在CO_2中的溶解度可用改进的Chrastil半经验溶解度方程模拟,其形式为C=p~k·exp(α/T)+b。结果:所提出的气相溶解度方程和液相溶解度方程与试验数据非常吻合,拟合相关系数和精度较高。     

基于支持向量机的有机化合物水溶解度的分类和预测的研究

有机化合物的水溶解度是重要的物理化学性质.本文用18个拓扑符去描述1293个化合物的分子结构.先建立1293个有机化合物的分类模型,按照logS的大小,将数据分成三类,通过训练集建立模型,并用测试集检验,分类准确率达92.2%.在此基础上,以上述18个描述符作为输入,losS作为输出,研究水溶解度的定量,建立支持向量机预测模型.比较测试集的结果,以前建立的人工神经网络模型相关系数r2=0.94和标准偏差sd=0.52,而本文建立的支持向量机模型r2=0.95和sd=0.50,显然优于以前建立的模型.     

C60在有机溶剂中溶解度的遗传算法研究

遗传算法是庆适应性和信息交换思想上的随机方法。本文基于遗传算法设计了一种判别分析方法。并用来研究Ｃ６０在有机溶剂中溶解度大小与有机溶剂折光率、介电常数、摩尔体积及Ｈｉｄｅｂｒａｎｄ溶解性参数等物理化学特性参数之 间的关系。     

广义简约梯度增强的遗传算法计算Ca2+-PO43--OH--F--CO32--H2O体系溶解度相图

溶解度曲线图对湿法合成氟取代羟基磷灰石有很重要的指导意义,但是这方面的数据资料很少,本文将描述Ca~(2 )- PO_4~(3-)-OH~--F~--CO_3~(2-)-H_2O体系平衡关系的强非线性方程组求解转变成最优化问题,用广义简约梯度(GRG)增强的遗传算法求解该体系的平衡关系,获得含氟磷灰石-水体系的溶解度相图。结果显示在pH=9附近处,磷灰石溶解度最小,Ca/P和Ca/F增加,磷灰石的溶解度随之增加,温度升高,磷灰石溶解度降低。     

计算液液平衡的基团溶解度参数模型研究

为得到一种简便可靠的计算液液平衡的新方法,利用Delphi语言构建了液液平衡数据库,以此为基础对基团溶解度参数模型(GSP模型)进行了研究。采用的基团溶解度参数具有4维,分别表征基团间4种主要的相互作用。通过建立液液平衡算法,并采用非线性优化方法SIMPLEX作为优化方法,对548个三元体系液液平衡数据进行回归得到模型参数的具体数值。对于这些体系,GSP模型计算的平均R．M．S．为0．07446(mol),计算总体摩尔浓度分数的绝对误差为0．05305(mol)。采用改进的UNIFAC模型进行了同样的关联计算以进行比较。结果表明,对应所收集的平衡数据,GSP模型可以达到与改进的UNIFAC模型同样的关联计算精度,而所需要的参数更少,参数值也更容易得到。     

协溶剂对固体在超临界CO2中溶解度增强效果的关联与预测

为了研究协溶剂对固体在超临界CO2中溶解度增强作用。本文利用PR状态方程,采用拟合两个可调参数(K12和l12)的方法,对酸、芳烃、稠环芳烃、酚、药物和染料六类共27种固体溶质在超临界CO2中的溶解度进行丁关联计算,计算值与实验值的最大平均偏差为9.93％;对超临界CO2／固体／协溶剂三元体系,提出一种直接采用三元系统实验数据拟合3个可调参数(K12,k13,k23)的方法,与Foster和Ting提出的方法相比,计算精度可以大大提高,关联计算的最大平均偏差为4.21％.此外,还提出了一种采用平均可调参数对溶解度进行预测的方法,并对胆固醇和1,4-萘醌的在超临界CO-2中的溶解度进行了成功预测。     

一种估算CO2和SO2在多元胺水溶液体系中溶解度的数学模型

通过离子反应式和亨利定律建立数学模型,在对模型进行适当简化的基础上再借助编程手段可以得到CO₂-SO₂在H₂O-MDEA-活化胺复杂多元溶液体系中溶解度的数值解。研究表明,在MDEA质量分率30%的水溶液中SO₂比CO₂优先溶解,溶液只有在基本上完全吸收SO₂之后才会吸收CO₂;而且其溶解度比较大,常温常压下1 mol的MDEA可吸收超过1.4mol的SO₂气体。在气体分压为（1～100）kPa范围内,SO₂的溶解度受压力参数的影响较大:而在此压力范围之外,温度参数则成为主要影响因素。在MDEA水溶液中添加MEA或DEA活化剂,随着活化剂质量分率的增加,SO₂的溶解度有较大程度的下降;若同时添加MEA-DEA2种活化剂,SO₂的溶解度会随着MEA质量分率的增加而减小,但减少的幅度并不大。     

Correlation of solubilities for the system with the Pitzer model at 15, 25, 50, and

Solubility data of the NaCl+LiCl+H₂O system have been measured at 15 C. These data along with others recorded in the literature, at 25, 50, and 100 C, have been correlated using the Pitzer model and the extended Debye–Hückel model. The latter was used to determine the activity and osmotic coefficients of the binary systems NaCl+H₂O and LiCl+H₂O. The results obtained in this work show that the calculated solubility values are in good agreement with the experimental ones.     

稀醋酸共沸精馏脱水工艺的模拟

醋酸是一种重要的化工原料,其水溶液广泛存在于各类工业过程中。由于醋酸与水会缔合使得两者的相对挥发度不大,生产中用于分离醋酸/水的工艺能耗较高,因此研究者和工业界都在寻求更好的分离方法。本文以醋酸正丙酯做挟带剂,应用Aspen Plus流程模拟软件,汽相逸度采用Hayden-O’Connell方程,液相活度系数采用NRTL方程计算,实现了稀醋酸共沸精馏脱水工艺的模拟。本文详细讨论了全塔理论板数、进料位置、回流比等因素对脱水塔性能的影响。结果表明,在理论板数50块,回流比3.2,醋酸进30块板,挟带剂与进料比0.15条件下,塔釜得到醋酸浓度高于95%。模拟结果对醋酸脱水工艺的设计和改造具有重要的指导意义。     

“3+1”应用型人才培养模式的研究与探索

"3+1"人才培养模式是目前高校培养应用型人才的成功模式。建立基于校企合作的"3+1"人才培养,是高校发展的必然趋势,本文将以信息管理与信息系统专业为例从"3+1"的教学体系、双师型师资队伍、先进的教学方法及手段、多元化的校企合作模式等方面研究"3+1"应用型人才培养模式。     

计算机模拟在间歇精馏法富集C9芳烃混合物中均三甲苯上的应用

为考察以间歇精馏法富集C9芳烃混合物中的均三甲苯的适宜工艺条件,借助三对角矩阵法,建立间歇精馏模型对该过程进行了计算机模拟。以少量实验验证计算机模拟的可靠性,所得结果与预测值符合较好,表明计算机模拟方法可用于C9芳烃间歇精馏分离过程分析。利用此模拟方法分析了操作条件的变化对于间歇精馏分离情况的影响,并优选出最佳工艺条件。     

3-取代4-氧-3H-咪唑并[5,1-d][1,2,3,5]四嗪-8-羧酸衍生物抗肿瘤活性的定量构效关系研究

目的:研究3-取代4-氧-3H-咪唑并[5,1-d][1,2,3,5]四嗪-8-羧酸衍生物分子结构与抗肿瘤活性的关系.方法:采用量子化学和分子力学方法计算分子结构参数,利用Cram-Schmidt正交化法筛选参数,利用偏最小二乘法建立QsAR模型.结果:建立合理的3-取代-4.氧-3H-咪唑并[5,1-d][1,2,3,5]四嗪-8-羧酸衍生物抗肿瘤活性模型.结论:3-取代-4-氧-3H-咪唑并[5,1-d][1,2,3,5]四嗪-8-羧酸衍生物抗肿瘤活性与分子油水分配系数LogP和8位取代基R1上的非氢原子净电荷Q1相关,研究结果可为同类抗肿瘤药物的分子设计提供参考.     

甲苯与异戊二烯合成2,6-二甲基萘的热力学计算

2，6-二甲基萘是合成聚2，6-萘二甲酸乙二酯的重要起始原料。本文讨论了以大宗化工原料甲苯与异戊二烯为起始原料合成2，6-二甲基萘的可能性，并对各种可能化学反应的热力学过程进行了分析，通过分析发现以甲苯与异戊二烯为起始原料经过烷基化、环化及异构化反应可以合成2，6-二甲基萘。同时指出了只有控制异戊二烯合适位置上的碳原子参与烷基化反应才能最终得到目标产物。     

Alpha(1) adrenoceptor subtype selectivity. 3D-QSAR models for a new class of alpha(1) adrenoceptor antagonists derived from the novel antipsychotic sertindole

Receptor-binding affinities for the alpha(1) adrenoceptor subtypes alpha(1a), alpha(1b) and alpha(1d) for a series of 39 alpha(1) adrenoceptor antagonists derived from the antipsychotic sertindole are reported. The SAR of the compounds with respect to affinity for the alpha(1a), alpha(1b) and alpha(1d) adrenoceptor subtypes as well as affinity obtained by an alpha(1) assay (rat brain membranes) were investigated using a 3D-QSAR approach based on the GRID/GOLPE methodology. Good statistics (r(2)=0.91-0.96; q(2)=0.65-0.73) were obtained with the combination of the water (OH2) and methyl (C3) probes. The combination of steric repulsion and electrostatic attractions explain the affinities of the included molecules. The adrenergic alpha(1a) receptor seems to be more tolerant to large substituents in the area between the indole 5- and 6-positions compared to the adrenergic alpha(1b) and alpha(1d) receptor subtypes. There seems to be minor differences in the position of areas in the alpha(1b) receptor compared to alpha(1a) and alpha(1d) receptors where electrostatic interaction between the molecules and the receptor (OH2 probe) contribute to increased affinity. These observations may be used in the design of new subtype selective compounds. In addition, the model based on biological data from an alpha(1) assay (rat brain membranes) resembles the model for the alpha(1b) adrenoceptor subtype.     

3D-QSAR analysis of TRPV1 inhibitors reveals a pharmacophore applicable to diverse scaffolds and clinical candidates

TRPV1 (Transient Receptor Potential Vanilloid Type 1) receptor, a member of Transient Receptor Potential Vanilloid subfamily of ion channels, occurs in the peripheral and central nervous system, and plays a key role in transmission of pain. Consequently, this has been the target for discovery of several pain relieving agents which have undergone clinical trials. Though several TRPV1 antagonists have progressed to become clinical candidates, many are known to cause temperature elevation in humans, halting their further advancement, and signifying the need for new chemotypes. Different chemical classes of TRPV1 antagonists share three important features: an amide or an isostere flanked by an aromatic (or fused aromatic) ring with polar substitutions on one side, and a hydrophobic group on the other. Recent work identified new series of compounds with these and additional features, leading to improvement of properties, and development of clinical candidates. Herein, we describe a 3D-QSAR model (n = 62; R² = 0.9 and Q² = 0.75) developed from the piperazinyl-aryl series of compounds and a novel 5-point pharmacophore model is shown to fit several diverse scaffolds, six clinical candidates, five pre-clinical candidates and three lead compounds. The pharmacophore model can aid in finding new chemotypes as starting points that can be developed further.     

A disposable electrochemical immunofiltration test strip for rapid detection of α-fetoprotein

A disposable electrochemical immunofiltration test strip for the rapid detection of α-fetoprotein (AFP) was developed. The test strip was constructed by assembly of screen-printed carbon electrodes, absorption-water pad, nitrocellulose membrane modified by anti-AFP antibody and glass fiber membrane conjugated with ferrocene monocarboxylic acid (FC) labeling AFP. The analytical system utilizes flow-through immunofiltration and competitive immunoassay techniques in combination with an amperometric sensor. The parameters affecting the immunoassay such as selection of filter membrane, membrane pore-size, and antibody binding capacity were investigated and optimized. The immunofiltration system allows us to specifically and directly detect AFP in serum with a low detection limit of 6 ng/mL. The working range is from 6 to 500 ng/mL with an overall analysis time of 5 min for one sample. This electrochemical immunoassay system enabled us to construct a novel point-of-care testing device for the monitoring of biomarker including AFP.     

Comparison of 2-D and 3-D computer models for the M. Salta rock fall, Vajont Valley, northern Italy

A rock fall occurs when a fragment of rock is detached from a cliff and travels down-slope at high speed. Rock falls are a constant hazard in mountainous regions and pose a significant threat to the population. In this paper, a comparison of software designed to model rock falls is presented. The computer codes selected for the experiment are STONE and RocFall®. STONE is a research code for the 3-dimensional simulation of rock falls. RocFall® is commercial software widely used for the 2-dimensional simulation of rock falls along user defined topographic profiles. The two computer programs require similar input and provide comparable outputs, allowing for a quantitative evaluation of their modelling results. To compare the software, the Monte Salta rock fall, in northern Italy, was selected. Specific tests were designed to compare the ability of the software to predict the maximum travel distance of the falling boulders, and the distance from the ground of the computed rock fall trajectories. Results indicate that the two rock fall modelling codes provide similar—but not identical—results. In general, STONE computes higher and longer rock fall trajectories than RocFall®, and allows identifying a larger area as potentially affected by falling boulders.