VO(H_2PO_4)_2热分析研究

运用ＴＧ、ＤＴＡ,研究了ＶＯ（Ｈ２ＰＯ４）２在流动空气气氛中的热反应行为、非等温反应动力学和热效应。ＶＯ（Ｈ２ＰＯ４）２从６０９Ｋ开始失重,到６９５Ｋ失重完毕,失重率为１４．０１％,失重后的产物为ＶＯ（ＰＯ３）２。运用Ｓｈａｒｐ法、Ｃｏａｔｓ－Ｒｅｄｆｅｒｎ法和Ｄｏｙｌｅ－Ｚｓａｋｏ法对基础实验数据进行分析,推断出该热分解反应机理为成核和生长（ｎ＝１）,动力学函数为Ａｖｒａｍｉ－Ｅｒｏｆｅｅｖ方程;非等温热分解反应动力学方程：ｄα／ｄＴ＝Ａ／βｅ－Ｅ／ＲＴ（１－α）;动力学补偿方程：ｌｎＡ＝０．１８１Ｅ－４．６８ｂ;热分解反应转变热为０．２９１ｋＪ·ｇ－１。     

马丁—侯状态方程向固相发展

ＭＨ－８１状态方程式经过进一步改进后，其使用范围可扩展到固相。在该方程中增加了三个常数，Ａ６、Ｂ７和ｂｓ后变为：Ｐ＝ＲＴ／Ｖ－ｂ＋Ａ２＋Ｂ２Ｔ＋Ｃ２ｅ－５．４７５Ｔ／Ｔｃ／（Ｖ－ｂ）＾２＋Ａ３＋Ｂ３Ｔ＋Ｃ３ｅ－５．４７５Ｔ／Ｔｃ／（Ｖ－ｂ）＾３＋Ａ４＋Ｂ４Ｔ／（Ｖ－ｂ）＾４＋Ｂ５Ｔ／（Ｖ－ｂ）＾５＋Ａ６／（Ｖ－ｂｓ）＾６＋Ｂ７Ｔ／（Ｖ－ｂ）＾７改进后的状态方程对于一般物质，如二氧化碳、氩、甲烷及氮     

气体P—V—T测定装置

研制了定容法气体Ｐ－Ｖ－Ｔ测定装置,测定过程中所用气体为Ｎ２和ＣＯ２,并在压力０．１￣２．５ＭＰａ、温度２０￣５０℃的范围内进行测定。实验所得数据以ＰＶ＝ｎＺＲＴ、Ｒ－Ｋ、Ｂ－Ｂ方程进行压缩因子计算,将所得结果Ｚ实、ＺＲ－Ｋ、ＺＢ－Ｂ与文献值Ｚ文分别进行比较,平均误差分别为０．６９％、０．４５％、０．１７％,两者基本吻合,达到了设计要求。     

KTa0.55Nb0.45O3薄膜的介电和铁电及热释电性能研究

在ＢＴ／Ｐｔ／Ｔｉ／ＳｉＯ２／Ｓｉ衬底上用溶胶－凝胶法制备了ＫＴａ０．５５Ｎｂ０．４５Ｏ３（ＫＴＮ）薄膜,０．５μｍＫＴＮ－０．０８μｍＢＴ薄膜在２５℃,１．０ｋＨｚ时,其εｒ＝１１１４,ｔａｎδ＝２．５％;１２℃时,其中Ｐｒ＝２．１μＣ／ｃｍ＾２,Ｐｓ＝４．２μｃ／ｃｍ＾２,Ｅｃ＝５．８ｋＶ／ｃｍ,０．５μｍ厚ＫＴＮ膜的Ｃｕｒｉｅ温度为３５℃;１．０ＫＨｚ时,ＫＴＮ膜的εｒ＝１４１２,估算ＫＴＮ     

利用PVT分析仪测定PS的热膨胀系数,等温压缩系数和热压系数

利用实验测得的ＰＶＴ数据直接计算出聚苯乙烯（ＰＳ）的热膨胀系数α，等温压缩系数β和热压系数γ随温度和压力的变化关系，与同样从ＰＶＴ数据获得的Ｔａｉｔ方程计算出的α、β和γ结果比较，说明了Ｔａｉｔ方程在使用上存在一定的局限性。     

马丁－侯状态方程向固相发展

ＭＨ－８１状态方程式经过进一步改进后，其使用范围可扩展到固相。在该方程中增加了三个常数，Ａ６、Ｂ７和ｂｓ后变为：Ｐ＝ＲＴＶ－ｂ＋Ａ２＋Ｂ２Ｔ＋Ｃ２ｅ－５．４７５ＴＴｃ（Ｖ－ｂ）２＋Ａ３＋Ｂ３Ｔ＋Ｃ３ｅ－５．４７５ＴＴｃ（Ｖ－ｂ）３＋Ａ４＋Ｂ４Ｔ（Ｖ－ｂ）４＋Ｂ５Ｔ（Ｖ－ｂ）５＋Ａ６（Ｖ－ｂｓ）６＋Ｂ７Ｔ（Ｖ－ｂｓ）７改进后的状态方程对于一般物质，如二氧化碳、氩、甲烷及氮等，在三相点到临界点温度、计算的饱和液相、汽相摩尔体积与文献值的偏差基本上保持ＭＨ－８１方程的准确度，而固相摩尔体积的偏差在几千大气压下也在１０％左右，一般压力不太高时都在５％以内，需要增加的输入信息仅三相点（Ｐｔ，Ｔｔ）下的Ｖｓｔ数据。     

KSZP陶瓷的烧结和力学性能

研究了ＫＺｒ２Ｐ３（ＫＺＰ）－ＳｒＺｒ４Ｐ６Ｏ２４（ＳＺＰ）系统陶瓷（ＫＳＺＰ）的显微结构和力学性能，添加ＭｇＯ作为烧结助剂，使材料力学性能得到显著的改善，抗弯强度达到１２３ＭＰａ，断裂韧性为２．１ＭＰａ．ｍ＾１／２弹性模量达１１０ＧＰａ，Ｖｉｃｋｅｒｓ硬度为４．５ＧＰａ。     

新试剂糠醛缩7-氨基-8-羟基喹啉-5-磺酸的合成及催化荧光测定超痕量钒(Ⅴ)

合成了新试剂糠醛缩７－氨基－８－羟基喹啉－５－磺酸（简称Ｆ７Ｎ８Ｑ５Ｓ）。试剂在酸性介质中被ＫＢｒＯ３氧化分解，生成强荧光物质，Ｖ（Ⅴ）对该反应具有强烈的催化作用，由此建立了测定痕量钒的催化荧光法。反应在酸性介质中进行，０．０５％Ｆ７Ｎ８Ｑ５Ｓ３．０ｍＬ，５％ＫＢｒＯ３０．６ｍＬ，沸水浴中加热２０ｍｉｎ，λｅｘ／λｅｍ＝３２６ｎｍ／３８６ｎｍ。钒的量在０．０～４．８μｇ／Ｌ范围内呈线性，检测限为０．４μｇ／Ｌ。该方法用于实际样品中痕量钒的测定，结果满意。此外还详细研究了反应机理。     

极谱法测定冷却水中的乙二胺四甲叉膦酸钠

在６．８×１０＾－４ｍｏｌ．Ｌ柠檬酸钠，醋酸－醋酸钠缓冲溶液（ｐＨ＝５．２＋中，Ｃｕ＾２＋可与乙二胺四甲叉膦酸钠（ＥＤＴＭＰＳ）络合，使铜峰降低，峰电位Ｅｐ＝－０．２４Ｖ（银－氯化银电极）。乙二胺四甲叉膦酸钠浓度在３－５０ｍｇ／Ｌ范围内与峰高降低值呈线性关系。采用ＪＰ３－１型示波极谱仪，二次微分，起始电位０．００Ｖ，终止电位－１．２０Ｖ测定，检出银为１ｍｇ／Ｌ，变异系数为３．２％－６．０％，回收率     

导数紫外吸收光谱法测定增效联磺制剂中三组分含量

探讨了导数紫外吸收光谱法测定增效联磺制剂中碘胺噻唑（ＳＤ）、磺胺甲基异哑唑（ＳＭＺ）和甲氧苄氨嘧啶（ＴＭＰ）三组分含量的最佳条件。在０．１ｍｏｌ／ｌ氢氧化钠溶液中，用二阶导数光谱；在２４３．５ｎｍ处测定ＳＤ和ＴＭＰ合量，以示离ＴＭＰ含量，三阶谱导数光谱在２４４．８ｎｍ处测定ＳＤ和ＳＭ合量，以求出ＳＭＺ含量。测定回收率为９８．２－９９．６％，变异系数为０．２６－０．９６％。本法不需分离即可对复方制剂     

利用扩展Tao-Mason状态方程预测天然气混合物容积特性(p-V-T)

A statistical-mechanical-based equation of state(EOS)for pure substances,the Tao-Mason equation of state,is successfully extended to prediction of the(p-v-T)properties of fourteen natural gas mixtures at temperatures from 225 K to 483 K and pressures up to 60.5 MPa.This work shows that the Tao-Mason equation of state for multicomponent natural gas is predictable with minimal input information,namely critical temperature,critical pressure,and the Pitzer acentric factor.The calculated results agree well with the experimental data.From a total of 963 data of density and 330 data of compressibility factor for natural gases examined in this work,the average absolute deviations(AAD)are 1.704%and 1.344%,respectively.The present EOS is further assessed through the comparisons with Peng-Robinson(PR)equation of state.For the all of mixtures Tao-Mason(TM)EOS outperforms the PR EOS.     

含(CH4+CO2+H2S)酸性天然气水合物形成条件实验与计算

采用高压全透明蓝宝石水合物相平衡装置,测定了(CH₄+CO₂+H₂S)三元酸性天然气在纯水条件下的水合物生成条件数据.实验温度范围为274.2～299.7 K,压力范围为0.58～8.68 MPa.混合物气体中H₂S和CO₂的浓度分别为 4.95%（mol）～26.62％（mol）和6.81%（mol）～10.77%（mol）.采用Chen-Guo水合物模型对实验数据进行了计算,结果表明,在不同的H₂S浓度下,Chen-Guo水合物模型的预测精度优于CSMHYD 模型.随着H₂S浓度的增加,计算的绝对偏差增大.针对H₂S浓度较高［＞10％（mol）］的体系,该两种水合物模型均有待改进.     

液体导热系数的自由体积模型

本文用统一的自由体积模型描述温度，压力和组成对稠密流体，尤其是液体的导热系数的影响。首先，在低压下纯液体的导热系数提出了简单的三参数关联式，对４３种纯物质，４４３个数据点的总平均误差仅为０．２６％，在此基础上，提出了液体混合的模型，其参数可视与温度无关，对４３个二元体系，包括含水体系，计８６９个点的计算误差仅为２．３１％，优于被认为成功的Ｔｅｊａ－Ｒｉｃｅ模型，最后，提出了适用于高压下，包括气液两     

Prediction of equilibrium liquid compositions from dew-point measurements for ternary systems

A simple calculation procedure is developed which permits the prediction of bubble-point compositions from dew-point measurements for ternary systems at low pressures.The proposed method is equally applicable to isothermal and isobaric data. It does not require any calculation of liquid activity coefficients and their correlation by means of an integrated Gibbs-Dubem equation, nor does it require any supporting physical properties of the pure components constituting the ternary system.Calculation of the bubble-point compositions from the dew-point data for the ternary system methyl ethyl ketone-n-heptane-toluene at 760 torr is carried out to serve as an illustration of the proposed method.     

Implementation of electrolyte CPA EoS to model solubility of CO_2 and CO_2+ H_2S mixtures in aqueous MDEA solutions

The electrolyte version of SRK plus association equation of state(e SRK-CPA Eo S) was employed to correlate CO_2 solubility in MDEA aqueous solutions. The applied model comprises the classic form of CPA Eo S including SRK Eo S plus Wertheim association term in addition to MSA theory and Born terms so that the two last terms are responsible for the long-range interactions. A reaction-containing bubble pressure computation technique comprising two nested loops was utilized to model the systems. The internal loop, calculates the liquid phase concentrations via reaction, mass and charge balance equation solving, whereas, the vapor phase concentrations will be obtained in the external one. 470 experimental data were used to correlate binary subsystems and the H_2O + MDEA + CO_2 ternary system. Since, there not exist any binary VLE data for MDEA + CO_2 subsystem, two fitting scenarios were applied. At the first scenario, the binary interaction parameter was assumed equal to zero, while, in second approach the parameter was obtained through ternary system correlation. Both scenarios show very good accuracy in that the Absolute Average Deviation percentages(AAD) obtained were 19.12% and 18.85%, respectively. Also, to show the efficiency of the used model, a comparison between our results and those of the best-known models was made.Finally, having model parameters for H_2S solubility from our previous work [A. Afsharpour, Petroleum Science and Technology 35(3)(2017) 292-298], simultaneous solubility of CO_2+ H_2S mixtures in MDEA solutions was predicted using the e SRK-CPA Eo S with no new optimizable parameters. As the results show,the applied model has a good performance for correlation and prediction of acid gas solubility in a wide range of pressures, temperatures, acid gas loadings, and MDEA concentrations.     

普遍化的基于LJ流体的自扩散系数预测模型

引　言扩散系数由于在实验测定上存在一定的困难 ,其预测就显得非常重要 .近年来 ,随着计算机技术的发展 ,分子动力学 (ＭＤ)模拟成为一种新的有效的扩散系数预测工具[1] .目前在预测有机物扩散系数的ＭＤ研究中主要采用的势能模型为Ｈａｒｄ -Ｓｐｈｅｒｅ(ＨＳ)模型和Ｌｅｎｎａｒｄ -Ｊｏｎｅｓ(ＬＪ)模型 .然而 ,由于ＭＤ模拟需要较长的计算时间 ,从工程应用的角度出发 ,半经验的扩散系数预测模型还是显得比较方便 .对于自扩散系数的研究 ,以前主要有刘洪勤等[2 ] 、于养信等[3] 采用ＬＪ模型进行了探讨 .然而 ,他们都是对每一种物质的…     

二氧化碳在CH4+CO2+N2/C2H6三元系中的结霜温度计算

含CO₂的天然气体系在历经低温工艺时,由于CO₂的三相点温度(216.55 K)较高,容易凝华结霜产生固体CO₂,因而有必要对CO₂在天然气中的结霜温度进行计算。根据气固相平衡原理,分别采用道尔顿分压定律、PR状态方程对CO₂在CH₄-CO₂-N₂和CH₄-CO₂-C₂H₆三元系中的结霜温度进行了计算。此外,还采用HYSYS软件对CO₂的结霜温度做了相应的计算。将3种方法的计算结果和实验结果进行了比较,结果表明3种方法在预测三元系中CO₂的结霜温度时,都具有良好的精度。其中,PR状态方程法和HYSYS法的精度略高于道尔顿分压定律法;道尔顿分压定律法虽精度最低,但计算最简单,且也能获得满意的精度,可做工程快速估算使用。     

Evolving an accurate model based on machine learning approach for prediction of dew-point pressure in gas condensate reservoirs

Over the years, accurate prediction of dew-point pressure of gas condensate has been a vital importance in reservoir evaluation. Although various scientists and researchers have proposed correlations for this purpose since 1942, but most of these models fail to provide the desired accuracy in prediction of dew-point pressure. Therefore, further improvement is still needed. The objective of this study is to present an improved artificial neural network (ANN) method to predict dew-point pressures in gas condensate reservoirs. The model was developed and tested using a total set of 562 experimental data point from different gas condensate fluids covering a wide range of variables. After a series of optimization processes by monitoring the networks performance, the best network structure was selected. This study also presents a detailed comparison between the results predicted by this ANN model and those of other universal empirical correlations for estimation dew-point pressure. The results showed that the developed model outperforms all the existing methods and provides predictions in acceptable agreement with experimental data. Also it is shown that the improved ANN model is capable of simulating the actual physical trend of the dew-point pressure versus temperature between the cricondenbar and cricondenterm on the phase envelope. Finally, an outlier diagnosis was performed on the whole data set to detect the erroneous measurements from experimental data.     

Vapour-liquid equilibria of hydrogen/coal liquid and methane/coal liquid systems at elevated temperatures and pressures

A cubic equation of state is modified in such a way that prediction of PVT data from 40 model compounds, typical of coal oil, becomes possible with an absolute mean deviation of less than 2% for saturated liquid volumes and vapour pressures > 1 bar. Additional correlations for binary interaction parameters are obtained by an optimization procedure using vapour-liquid euilibrium (VLE) data from known heavy hydrocarbon liquid/light gas systems. When the modified equation is applied to coal-derived liquids, only specific gravity and boiling analysis data of the coal liquids are required, primarily in order to determine the equation-of-state parameters. The proposed equation is shown to allow a good prediction of VLE data for systems consisting of wide-boiling-range coal oils and light gases. Experimental values were obtained at elevated temperatures and pressures with a circulation flow apparatus.