葡萄糖酸钙结晶的热力学特性

采用EDTA配位滴定法测定了葡萄糖酸钙在水中293.15-333.15 K的溶解度数据并绘制溶解度曲线,同时采用溶解度模型——λh方程和Apelblat方程对溶解度数据进行了关联.结果表明随着温度升高葡萄糖酸钙在水中的溶解度增大,两方程对于溶解度的关联性相比,Apelblat方程对溶解度的关联效果更好.采用电导率法测定...     

TNAZ溶解度的测定与关联

采用动态法激光检测技术测定了温度为293.15～323.15 K时TNAZ在氯仿、乙醇、乙腈三种溶剂中的溶解度。实验数据采用关联温度和溶解度的apellbat模型[1]、理想溶液模型[2]、多项式经验方程对溶解度数据进行了关联,结果表明上述回归方程均能很好的关联溶解度数据,所得结果可用于工程设计及应用。     

胆甾醇在超临界CO2中的溶解度测定与关联

利用动态法测定了胆甾醇在超临界CO2中的溶解度。在10—30 MPa,313—343 K下,胆甾醇的溶解度摩尔分率为10-6—10-4。引入与密度有关的混合规则,将二元交互参数表示为密度的函数,采用PR状态方程,关联胆甾醇在超临界CO2中的溶解度。改进后的溶解度模型克服了采用经典混合规则的PR方程不能很好地关联胆甾醇大分子物质的缺陷,大大提高了关联精度。     

2，6-二叔丁基对甲酚在甲苯中溶解度的测定及关联

建立了测定固体在液体中溶解度的实验装置.采用合成法测定了常压下2,6-二叔丁基对甲酚在甲苯中的溶解度,并用经验方程、简化的溶解度方程、Apelblat方程对实验数据进行关联,结果表明上述方程均能较好的关联溶解度数据,所得结果对2,6-二叔丁基对甲酚结晶工艺的研究具有较大的指导意义.     

过氧化二异丙苯在不同溶剂中溶解度的测定与关联

冷却结晶法生产过氧化二异丙苯时,溶解度数据至关重要。采用平衡法测定了272.93—307.28 K范围内过氧化二异丙苯在不同比例甲醇-水混合溶剂和不同比例甲醇-异丙苯混合溶剂中的溶解度,并用Apelblat方程对溶解度数据进行关联。结果表明:过氧化二异丙苯在混合溶剂中的溶解度随着温度的升高而显著增加;甲醇是良溶剂,水是不良溶剂,溶解度随着水的比例增加而减小;异丙苯是最优良的溶剂,溶解度随着异丙苯比例的增加而增加。Apelblat方程的关联效果较好,相关系数在0.97以上。实验得到的溶解度数据和关联结果对过氧化二异丙苯结晶分离新工艺的开发具有非常重要的意义。     

氧气在醋酸水溶液中的溶解度估算

将水作为溶剂主体,通过热力学分析导出了氧气在纯水中的溶解度模型。将醋酸作为有机溶剂添加剂,用Stechenov关联式表征了醋酸对氧气在水中的溶解度的影响。模型参数由文献数据回归得到,模型计算得到的溶解度值与文献报导的实验值进行比较吻合良好。建立的氧气在醋酸水溶液中的溶解度机理模型可用于关联和预测不同醋酸浓度下不同温度和压力时氧气在醋酸水溶液中的溶解度。     

纳他霉素在不同溶剂中溶解度的测定与关联

采用平衡法测定了纳他霉素在纯水(278.15 ～ 341.15 K)和异丙醇(278.15 ～ 318.15 K)、甲醇(278.15 ～313.15 K)溶液中的溶解度.在三种溶剂中的溶解度均随温度升高而增大,以在甲醇中溶解效果最好,异丙醇次之,纯水最差.分别用经验模型、理想溶解度方程和Apelblat方程对实验数据进行关联,关联效果令人满意,平均相对误差小于5%,获得了相关模型参数.相对而言,经验模型和Apelblat方程关联的效果较好.实验得到的溶解度数据和关联结果对纳他霉素结晶工艺的研究具有较大的指导意义.     

栲胶脱硫副产物NaCNS溶解度的测定及关联

采用静态平衡法测定了NaCNS在不同浓度栲胶溶液中的溶解度,并用数学方程对NaCNS的溶解度进行了关联,拟合出了NaCNS溶解度的对数与绝对温度倒数的一元线性方程,用来估算NaCNS在不同温度下的溶解度,为NaCNS的提取回收提供了一定的理论依据。     

邻苯二酚溶解度的测定与关联

采用激光监视技术由合成法测定了邻苯二酚在水、乙酸乙酯、乙酸丁酯和甲基异丁基甲酮中的溶解度,并用溶解度的简化方程对实验数据进行了关联,溶解度的计算值与实验值符合良好。     

溶菌酶在聚电解质溶液中溶解度的测定及关联

用平衡法测定了278～298 K下溶菌酶在不同浓度的PEI、PDDA、PVS、PSS的缓冲溶液(pH=4.5)中的溶解度。结果表明,在一定浓度范围内,PEI、PDDA浓度的增加,溶菌酶的溶解度降低,PSS、PVS浓度增加,溶菌酶溶解度增加。对PEI、PDDA的数据进行模型关联,通过理想溶液模型、Apelblat模型、多项式经验模型的关联结果显示,Apelblat模型的计算值与实验值比较吻合,R2=0.974 2～0.999 8,ARD=0.086%～1.08%。关联溶解度数据可以得到完整的溶解度曲线,为溶菌酶的溶析结晶提供热力学基础。     

流动沸腾传热渐进模型的一种修正形式

在对文献模型进行分析的基础上,提出流动沸腾传热渐进模型的一个修正形式。探讨了该形式的合理性,并对该修正形式与实验数据的吻合情况进行了检测。结果显示,该修正形式能较好地预测窄矩形流道内流动沸腾传热的传热系数     

A percolation threshold model that effectively characterizes the full concentration range for electrical-conducting polymer composites

The new percolation threshold model introduced in this study is a modification of Clingerman's model, which in turn is a modification of the model originally developed by Mamunya et al. Several of the original constants from Clingerman's and Mamunya's were consolidated, and most importantly, the concentration of the percolation threshold is not a required constant in the model. One extraordinary characteristic of this new model is that it is possible to separate this model into two different equations that separately describe the conducting filler component and the insulating matrix component. In general, this new percolation threshold model introduces five new calculated quantities on the S-shaped curve, including the calculated volume fraction of the percolation threshold. The capability of this new model was evaluated with three of Clingerman's polymer composite percolation threshold data sets involving electrical conductivity measurements. This new model did an excellent job of fitting the data extremely well over the whole concentration range. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47184.     

1,2-环己二醇在溶剂中的溶解度

1 INTRODUCTION The solubility of solid in liquids is an excellent tool to investigate solute-solvent intermolecular forces in the liquid state. In this work the solubility of trans-1,2-cyclohexanediol in some polar solvents (wa- ter, methyl acetate, acetic ester, propyl acetate, butyl acetate, methyl acrylate, and ethyl acrylate) was mea- sured at temperatures ranging from about 300 K to 330 K, using a modification of the experimental tech- nique of laser monitoring observation system. So…     

微孔发泡成核理论新进展

运用经典成核理论解释了微孔发泡成核过程，指出在一定条件下，实验数据和运用经典成核理论计算的结果存在明显的偏差。综述了经典成核理论模型以及对该理论进行改进的相关措施，拓展了理论研究领域。     

Model‐based analysis of a gas/vapor–liquid microchannel membrane contactor

A comprehensive numerical investigation on membrane distillation of methanol and water in a microseparator was carried out. The focus was to investigate the impact of the apparatus geometry on the separation performance and to develop alternative designs for process intensification. To describe the process, a computational fluid dynamics‐based model was developed and validated against experimental data from literature. Based on this model, parametric studies were performed to gain a deeper understanding of the microchannel geometry influence. Furthermore, two geometry modifications were suggested and analyzed, a miniaturization of the channel and an implementation of baffles. The modification with baffles was chosen for a new separator design which was studied experimentally, and the obtained experimental data were used for another model validation, this time for the baffle arrangement. Subsequent comprehensive simulations were performed to investigate mass‐transfer enhancement by the modified geometry. Generally, the baffles reveal a considerable potential for the process intensification. © 2015 American Institute of Chemical Engineers AIChE J, 61: 2240–2256, 2015     

三元体系液体混合物粘度的工程应用预测模型

从普遍适用的热力学关系出发，对Eyring模型进行修正，得到一个新的修正Eyring粘度模型。对三元体系液体混合物粘度的预测结果表明，与McAllister二维三体模型相比，修正的Eyring粘度模型预测结果较优，因此其修正更为合理，更具工程应用的前景。     

Some Remarks on the Classification of Water Vapor Sorption Isotherms and Blahovec and Yanniotis Isotherm Equation

Mathematical analysis was performed on equations describing water vapor sorption isotherms. It was shown that an identity exists between the Blahovec and Yanniotis (BY), D'Arcy and Watt (DW), and generalized D'Arcy and Watt (GDW) models. The original BY model has been modified to account for temperature dependence of the model parameters. This modification enables the application of this model to describe sorption data obtained at different temperatures. A new method for classification of sorption isotherms has been proposed that is much simpler than the classification established by Blahovec and Yanniotis.     

Amination of biochar surface from watermelon peel for toxic chromium removal enhancement

Watermelon peel residues were used to produce a new biochar by dehydration method. The new biochar has undergone two methods of chemical modification and the effect of this chemical modification on its ability to adsorb Cr(VI) ions from aqueous solution has been investigated. Three biochars, Melon-B, Melon-BO-NH_2 and Melon-BO-TETA, were made from watermelon peel via dehydration with 50% sulfuric acid to give Melon-B followed by oxidation with ozone and amination using ammonium hydroxide to give Melon-BO-NH_2 or Triethylenetetramine(TETA) to give Melon-BO-TETA. The prepared biochars were characterized by BET, BJH,SEM, FT-IR, TGA, DSC and EDAX analyses. The highest removal percentage of Cr(VI) ions was 69% for Melon-B,98% for Melon-BO-NH_2 and 99% for Melon-BO-TETA biochars of 100 mg·L~(-1) Cr(VI) ions initial concentration and 1.0 g·L~(-1) adsorbents dose. The unmodified biochar(Melon-B) and modified biochars(Melon-BO-NH_2 and Melon-BO-TETA) had maximum adsorption capacities(Qm) of 72.46, 123.46, and 333.33 mg·g~(-1), respectively.The amination of biochar reduced the pore size of modified biochar, whereas the surface area was enhanced.The obtained data of isotherm models were tested using different error function equations. The Freundlich,Tempkin and Langmuir isotherm models were best fitted to the experimental data of Melon-B, Melon-BO-NH_2 and Melon-BO-TETA, respectively. The adsorption rate was primarily controlled by pseudo-second–order rate model. Conclusively, the functional groups interactions are important for adsorption mechanisms and expected to control the adsorption process. The adsorption for the Melon-B, Melon-BO-NH_2 and Melon-BO-TETA could be explained for acid–base interaction and hydrogen bonding interaction.     

Synthesis of functionalized PET fibers by grafting and modification and their application for Cr(VI) ion removal

A new fiber adsorbent for removing Cr(VI) ions from aqueous solution was prepared by grafting and modification. The grafted fiber and modified fiber were characterized by SEM, FTIR, and TGA. FTIR analysis indicated that acrylonitrile monomer was grafted onto the PET surface and that new groups were present on the surface after the modification. Scanning electron microscopy showed that the PET fiber was wider after grafting and especially modification. The TGA results showed that the degradation steps and the thermal behavior of the PET fiber changed after modification. The effects of the pH, ion concentration, and temperature on the amount of Cr(VI) adsorbed were investigated. The fiber showed its maximum adsorption capacity in acidic medium. Isotherm studies indicated that the experimental results were best fitted to the Langmuir isotherm. The adsorption capacity of the modified fiber was found to be 25.77, 38.17, and 44.84 mg/g fiber at 25, 35, and 45 °C, respectively. Kinetic results indicated that the adsorption of Cr(VI) onto the modified fiber followed a pseudo-second-order kinetic model. Calculated thermodynamic parameters demonstrated that the adsorption of Cr(VI) ions on the modified fiber is an endothermic, feasible, and spontaneous process.     

Modifying the inter‐phase drag via solid volume fraction gradient for CFD simulation of fast fluidized beds

The conventional drag model in two‐fluid simulation, which assumes uniform particle distribution in a computational grid, overestimates the drag force, thus failed in capturing the subgrid‐scale strands and resolvable‐scale clusters. This work proposed a new modification to the conventional drag model through considering the heterogeneous distribution of solid volume fraction (SVF), especially, in the inter‐phase boundary (i.e., cluster boundary). The resulting drag model is a function of particle Reynolds number, SVF and the gradient of SVF. This straightforward modification is consistent with the elaborately filtered‐approach‐based modification method in nature. A CFD simulation for a two‐dimensional riser was conducted to validate the new drag model. The outlet solid mass flux, axial and radial time‐averaged voidages from the new drag model agreed well with the experimental measurements, and these results were far better than those from the conventional homogeneous drag models. © 2017 American Institute of Chemical Engineers AIChE J, 63: 2588–2598, 2017