Vapor-Liquid Equilibrium of 1-butanol-Alkanes System by Molecular Simulation

用Gibbs系综的Monte Carlo法模拟了正丁醇。正己烷和正丁醇-正庚烷体系的气液相平衡。在恒定压力0.496 6 MPa、0.294 0 MPa和0.1 MPa下,分别采用恒温恒压的Gibbs系综(NPT-Gibbs)模拟了不同温度下的气液相平衡。计算结果表明,模拟的数据比较准确,在一定温度范围内与实验结果吻合。The Vapor-Liquid equilibrium of 1-butanol/hexane and 1-butanol/heptane was measured by using Gibbs ensemble.The equilibrium data were obtained by the N-PT-Gibbs at the pressures of 0.4966 MPa,0.2940 MPa and 0.1 MPa.Comparing to the experimental data,the simulation results were quite good in some temperature range.国家自然科学基金(50573063);; 高等学校博士点专项基金(20050384013

Molecular simulation of transport behavior of penetrant through silicon-containing polymers

选择PCFF和COMPASS分子力场对橡胶态聚合物PDMS和玻璃态聚合物PS1体系进行模拟。COMPASS力场模拟得到的体系密度,O2和N2在PDMS与PS1中扩散系数更接近实验值。在模型大小一定时,Group-based求和法中截断距离越长,耗用机时越长,但对计算结果改进不大;截断距离为1.3nm时计算结果最好。Ewald方法耗时多而对计算结果却无明显改进。体系大小对扩散系数的计算值影响甚微。体积越小的分子,在聚合物中运动的范围越大,扩散系数越大。氧气和氮气分子在PDMS与PS1中运动轨迹不同,在PS1中氧气运动范围远大于氮气,而在PDMS中氧气运动范围稍大于氮气。小分子运动轨迹基本与聚合物自由体积分布对应,自由体积分数大,扩散系数也大。PCFF and COMPASS force fields were used to describe PDMS and PS1 polymeric systems and to estimate the diffusion coefficient of N2 and O2 through the PDMS and PS1 matrices at 298 K by molecular dynamics simulation.It was found that the COMPASS force field was better in describing the transport behavior of the penetrants.The calculated densities after refinement were in good agreement with the experimental results.The group-based and Ewald summation skills were used to estimate the non-bonded interaction between atoms.Calculation using the Ewald summation method took much longer time without bringing in obvious improvement in density estimation.Various cut-offs in using the group-based summation method did not produce densities with much difference, and the cut-off of 1.3 nm was the best.Two types of diffusions of the small molecules in the polymers were discussed.The diffusion of O2 and N2 in PDMS could be transformed from anomalous to normal motion in 30 ps; while their diffusion in PS1 would take 300 ps transforming from anomalous to normal state.The trajectories of diffusion of N2 and O2 in PDMS or PS1 were different.The motion area of O2 in the PS1 was much larger than N2; however, the former in the PDMS matrix was only slightly larger than the latter.The diffusions of O2 and N2 in the PDMS and PS1 were consistent with the free volumes of polymers.国家自然科学基金项目(50573063);; 高等学校博士点专项基金项目(20050384013)。~

Preparation and permeation characteristics of PVA/PEG/TEOS hybrid membranes

以聚乙烯醇(PVA)与聚乙二醇(PEG)共混,并与正硅酸乙酯(TEOS)进行交联反应制备杂化膜。FTIR证实杂化溶胶液发生交联反应形成共价键Si—O—C,WXRD观察表明加入TEOS改变了膜结晶度,加入PEG提高了PVA膜对乙醇/水溶液的渗透通量,但分离因子下降,随着TEOS的加入,膜的分离因子提高。在TEOS质量分数为10%时,杂化膜的分离因子达到最大。提高退火温度可以提高膜的分离因子,但通量下降。在100℃下退火12 h的杂化膜对乙醇质量分数为85%的乙醇/水溶液的分离性能最佳。Poly(vinyl alcohol)(PVA) was mixed with poly(ethylene glycol)(PEG) and then cross-linked by tetraethoxysilane (TEOS) to prepare organic-inorganic hybrid membranes.Fourier transform infrared spectroscopy(FTIR) proved that covalent bond Si—O—C was formed in the hybrid membranes.Wide-angle X-ray diffraction(WAXD) was used to observe the effect of TEOS and annealing on crystallinity.The hybrid membranes were tested in separation ethanol/water mixture by pervaporation.The effect of PEG,TEOS content and annealing temperature on the PVA hybrid membrane performance was discussed.The addition of PEG increased the PVA membrane flux,but its selectivity decreased.Water permselectivity increased with the addition of TEOS into the PVA/PEG membrane.The hybrid membrane exhibited the highest water permselectivity when TEOS mass fraction was 10%.Water permselectivity increased by increasing the annealing temperature,but permeation flux decreased at the same time.The hybrid membrane separation performance was best for pervaporation of water/ethanol(85%mass fraction of ethanol) mixture when annealing at 100 ℃ for 12 h.国家自然科学基金资助项目(50573063);; 高等学校博士点专项基金资助项目(20050384013

Advances in inorganic particle filled polymeric membranes

[中文文摘]根据有机、无机组分间相互作用类型对有机-无机杂化膜进行了分类,重点论述了无机粒子填充型有机-无机杂化膜的最新研究进展,归纳了此类杂化膜的优异性能,总结了无机粒子的物理化学性能、含量、尺寸及其与聚合物的相容性等因素对此类杂化膜结构和性能的主要影响。最后提出了目前研究中存在的一些问题,并对其发展做出了简要的述评。[英文文摘]Hybrid organic-inorganic membranes are being classified according to the links between the organic and inorganic components ,the advances in inorganic particles filled polymeric membranes are reviewed emphatically. The superior properties of this kind of hybrid membranes are briefly discussed and some influencing factors such as physical and chemical properties ,content ,size of inorganic particles and its compatibility with polymers on the morphology and characteristics of the hybrid membranes are illustrated. Finally , some problems which existed in the present research are pointed out and a brief comment on their development is given.国家自然科学基金项目(50573063);高等学校博士点专项基金项目(20050384013

三聚氰胺包合法分离不饱和脂肪酸

采用三聚氰胺包合法从混合脂肪酸中分离不饱和脂肪酸(UFAs),探讨了三聚氰胺/脂肪酸质量比、晶化包合温度、包合时间对包合效果的影响,并采用傅里叶变换红外光谱(FT-IR)、X射线衍射(XRD)和核磁...国家重点研发计划资助(2016YFD0600802);; 云南省重大科技专项计划(2018ZG003);; 云南省教育厅科学研究基金项目资助(2018Y119

载银介孔SBA-15吸附剂的制备及其对脂肪酸甲酯的吸附研究

以介孔分子筛SBA-15作为载体,在3-氨基丙基三乙氧基硅烷(APTS)对SBA-15表面修饰的基础上负载银离子制备Ag~+-APTS/SBA-15吸附剂,采用氮气吸附-脱附、X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)、透射电镜(TEM)、扫描电镜-能谱(SEM-EDS)对吸附剂进行表征,并将吸附剂应用于混合脂肪酸甲酯的分离以考察其吸附性能。氮气吸附-脱附、XRD和TEM分析结果可以看出,制备的吸附剂具有规则有序孔道结构;FT-IR数据显示,介孔SBA-15表面被APTS成功修饰;SEM-EDS结果表明,银离子成功负载到载体SBA-15上;对混合脂肪酸甲酯吸附研究表明,该吸附剂对不饱和脂肪酸甲酯(UFAMEs)吸附效果较好,且随着银离子负载量的增加以及UFAMEs双键数的增多,吸附效果增强;当银离子负载量为25%时,吸附剂对亚麻酸甲酯吸附率高达53.47%。国家重点研发计划项目(2016YFD0600802);;\n厦门大学闽江学者特聘教授科研启动项目(无编号);;\n云南省重大科技专项计划(2018ZG003

A Fully Flexible Potential Model for Carbon Dioxide

A fully flexible potential model for carbon dioxide has been developed to predict the vapor-liquid coexistence properties using the NVT-Gibbs ensemble Monte Carlo technique (GEMC). The average absolute deviation between our simulation and the literature experimental data for saturated liquid and vapor densities is 0.3% and 2.0%, respectively. Compared with the experimental data, our calculated results of critical properties (7.39 Mpa, 304.04 K, and 0.4679 g.cm(-3)) are acceptable and are better than those from the resealing the potential parameters of elementary physical model (EPM2). The agreement of our simulated densities of supercritical carbon dioxide with the experimental data is acceptable in a wide range of pressure and temperature. The radial distribution function estimated at the supercritical conditions suggests that the carbon dioxide is a nonlinear molecule with the C=O bond length of 0.117 nm and the O=C=O bond angle of 176.4 degrees, which are consistent with Car-Parrinello molecular-dynamics (CPMD), whereas the EPM2 model shows large deviation at supercritical state. The predicted self-diffusion coefficients are in agreement with the experiments.National Natural Science Foundation of China [50573063]; Program for New Century Excellent Talents in University of the State Ministry of Education [NCET-05-0566]; Specialized Research Fund for the Doctoral Program of Higher Education of China [2005038401

中国物理海洋学研究70年：发展历程、学术成就概览

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本文主要介绍了结构动力反应分析中的四种显式积分算法和四种常规的时域逐步积分算法,针对其精度与稳定性进行了对比分析。通过理论分析与算例对比清楚地了解了不同积分算法的特点,为在实际计算中选择一种合适的积分算法提供了参考