2,6-二羟基改性PBO的AB型新单体的合成

研究了以2,6-二羟基-1-甲酯-1,4-苯二酸(α酯)与4-氨基-6-硝基间苯二酚盐酸盐(ANR·HCl)为原料经酰氯化、N-酰化、环合和催化加氢还原等一系列反应合成得到中间体4-[(2,4-二羟基-5-硝基苯基)氨甲酰基]-2,6-苯甲酸甲酯(2,6-DH-MNC)和4-(6-羟基-5-硝基-2-苯并 唑基)-2,6-苯甲酸甲酯(2,6-DH-MNB)及2,6-二羟基改性PBO的AB型新单体4-(5-氨基-6-羟基-2-苯并 唑基)-2,6-二羟基苯甲酸甲酯(2,6-DH-MAB),并对环合和催化还原加氢的反应条件进行了优化。结果表明:对于环合反应,以二乙二醇二甲醚为溶剂,多聚磷酸(PPA)为脱水剂,PPA中P₂O₅质量分数83%,w(2,6-DH-MNC):w(PPA)=1:6,反应温度140℃,反应时间8h,2,6-DH-MNB收率74.15%,HPLC纯度98.76%;催化加氢还原反应,以N,N-二甲基甲酰胺(DMF)为溶剂,w(5%Pd/C):w(2,6-DH-MNB)=1:20,氢气压力0.5~1MPa和温度60℃下反应3h得到2,6-DH-MAB,HPLC纯度99.69%,收率81.42%。中间体和产物结构经FT-IR、13C NMR、¹H NMR和ESI-MS表征确认。     

响应面优化改进硫脲法浸出炼锌渣中银的工艺

采用改进硫脲法浸出含硫铁矿炼锌渣中银,用响应面方法研究了双氧水浓度［X1/（mol·L-1）］、硝酸浓度［X2/（mol·L-1）］、硫脲浓度［X3/（mol·L-1）］和浸出温度（X4/℃）对银浸出率（Y/%）的影响,并优化了浸出工艺。银浸出率与工艺因素之间的关系符合二次模型：Y=-476.0-40.17X1+58.20X2+82.15X3+12.30X4-22.65X1X3+5.03X1X4-0.51X2X4-1.08X3X4-81.47X12-3.65X22-1.30X32- 0.11X42。双氧水浓度和硫脲浓度的一次项对浸出率的影响不显著,浸出温度的一次项、双氧水浓度和硫脲浓度的二次项对浸出率有着显著影响,硝酸初始浓度的一次项和二次项对浸出率有着高度显著影响。双氧水浓度与硫脲浓度,温度与双氧水浓度、硝酸浓度、硫脲浓度之间均存在高度显著的交互作用。模型拟合所得最优的浸出条件为：双氧水浓度为0.96 mol/L、硝酸浓度为4.12 mol/L、硫脲浓度为2.17 mol/L、浸出温度为55 ℃。此条件下,银浸出率为91.3%,接近模型预测值（92.7%）。与单因素实验相比,银浸出率提高近10%。     

量子化学方法应用于分子筛上苯与短链烯烃反应机理的研究进展

对近年来基于量子化学方法研究苯与短链烯烃烷基化反应机理的进展进行了综述。简要介绍了量子化学方法的相关软件及其应用。对于苯与短链烯烃发生烷基化时存在争议的协同机理和分步机理, 详细阐述了采用大小不同模型和计算方法对其进行研究的进展;由此可以展望量子力学/分子动力学(QM/MM)组合方法综合了量子化学理论和分子动力学理论的优点, 将成为研究化学反应机理的更有效方法。     

物理化学实验教学中自主学习模式的探索

随着高校改革的不断深化,高校实验室的各项整改势在必行,笔者提出的物理化学中自主学习型教学模式,是以培养学生实际动手操作能力和自我创造能力为中心进行试验教学,并以设计实验考试作为物理化学实验考试成绩评定方法的教学模式,旨在培养学生自主学习及独立完成实验、分析实验结果的能力,激发学生学习的兴趣和潜能,能有效克服传统教学模式中难以发挥学生主体作用的弊端.     

Isothermal crystallization and spherulite structure of partially miscible polypropylene–linear low-density polyethylene blends

Polypropylene (PP) was blended with a linear low-density polyethylene (LLDPE, containing 5% hexene comonomer) over a composition range of 10–90% of PP. The crystallization and morphology of the PP–LLDPE blends were studied by differential scanning calorimetry (DSC), polarized optical microscopy with a hot stage (HSOM), and scanning electron microscopy (SEM). In particular, the isothermal crystallization of PP in molten LLDPE was investigated. It was observed that the crystallization and melting behavior of PP and LLDPE changed in the blends, indicating that there was some degree of miscibility between the PP and the LLDPE. A depression of the equilibrium melting temperature (T) of PP in the blends with no more than 15% of PP confirmed that PP was miscible with LLDPE at and below 15% of PP. In addition, a drastic decrease in T from the 25% PP blend to the 20% blend led us to conclude that the miscible behavior between PP and LLDPE became favorable at a PP concentration of 20%. The optical microscopic images showed that, in the blends with 10 and 15% of PP, the PP crystallized as open-armed diffuse spherulites, similar to those in the miscible blends. In contrast, the PP crystallized in a phase-separated matrix or droplets with more than 25% of PP, when obvious phase separation occurred. The SEM image revealed that the PP lamella was able to penetrate the PP and LLDPE phase boundary and grow in the LLDPE phase. The above results displayed that the PP dissolved in the LLDPE, and, particularly, when the PP concentration was below 20%, the dissolution was substantial. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 628–639, 2001     

基于同轴相位法含水率的实验研究

随着油田的不断开发和开采,油井的数量逐步上升,产出液的含水率也不断升高,因此准确的测量各个产层的流量和含水率对于确定油井出水、出油层位,计算原油产量,预测油井的开发寿命具有重要意义。根据油田对生产测井的要求研制的同轴相位含水率计应用于油田测试工作,可以根据该仪器在某一产液量给出的不同响应值求得相应的含水率。通过在模拟井筒内对仪器进行反复的测量与校正从理论上分析了仪器对油水混合介质的反映规律。研制的仪器不但提高了测量精度,还实现了油井含水率以往难实现的连续测量。利用该仪器进行现场测试,并与模拟井资料进行对比,结果表明该仪器可很好地应用于该地区的油井测试工作。     

Application of Dispersed Particle Gel to Inhibit Surfactant Adsorption on Sand

This article highlights an efficient and cost-effective additive-dispersed particle gel (DPG) to reduce surfactant adsorption on sand. Indoor experiments were conducted to study the effect of DPG on static adsorption and dynamic adsorption of the surfactant. The static adsorption data were evaluated using different isotherm models and the Redlich–Peterson isotherm matched the best. Results showed a significant inhibition of surfactant adsorption in the presence of DPG. The dynamic adsorption of SDS on sand decreased to 0.78, 0.68 and 0.61 mg/g compared with original value of 1.17 mg/g by adding 0.1, 0.2 and 0.3 wt% DPG particles, respectively. This study suggests that DPG can inhibit the adsorption of surfactant on sand effectively.     

Experimental study of the relationship between separation performance and lengths of vortex finder of a novel de-foulant hydrocyclone with continuous underflow and reflux function

To solve the blockage and defer the fouling of sewage heat exchanger, a novel de-foulant hydrocyclone with continuous underflow and reflux function was proposed. Experimental results demonstrated that the novel hydrocyclone had a remarkable behavior on separating the sand (75–250 μm) and foulant (<4 mm). The continuous underflow and reflux function could significantly improve the separation efficiency by relieving the particle re-entrainment and eliminating the air core without increasing energy consumption (<17 kPa) and split ratio (<10%) considerably. Besides, the range of optimum vortex finder length was proportional to the particle density.