共查询到20条相似文献,搜索用时 15 毫秒
1.
Improved column efficiencies and decreased tailing of Eu3+ and Lu3+ elution peaks with 2-hydroxy isobutyric acid, HIBA, were obtained by partial sulfonation of experimental monodisperse 5 and 10 μm, highly (>40%) crosslinked porous beads. Blocking of micropores of such highly crosslinked porous gels with n-dodecane before sulfonation further reduces the extent of sulfonation and improves column efficiency. Simultaneous choice of a smaller particle size and less sulfonation improves the column performance. The normalized performance of a monodisperse 10 μm, highly crosslinked porous resin of 0.058 meq/ml capacity was similar to that of a monodisperse 15 μm, 10% crosslinked surface sulfonated gel type resin of 0.031 meq/ml capacity for Lu3+/HIBA. 相似文献
2.
3.
MOLECULAR THERMODYNAMICS OF GAS SOLUBILITY(Ⅱ)HENRY’S CONSTANTS OF GASES IN POLAR SOLVENTS AND 1-1 TYPE ELECTROLYTE SOLUTIONS
下载免费PDF全文
![点击此处可从《中国化学工程学报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The molecular thermodynamic model established by Hu, Xu and Prausnitz for gas solubility in nonpolar solvents is extended to polar and electrolyte solution systems. The influence of ion charge on the Helmholtz energy of fluid mixtures is taken into account by considering the interactions between the charge of ions located in the first coordination shell and the dipole or induced dipole of the central solute molecules. The contribution of the ions outside the first coordination shell can be neglected owing to the symmetrical distribution of the positive and negative ions with respect to the central solute molecule. The model in this paper includes a correlation equation for the effective hard sphere diameter of ions and the Pauling's crystal diameter, σ=ησ~(crystal), where η=-6.645+747.2511/T+2.95392×10~(-2)T-5.05798×10-~5T~2+3.2431×10~(-8)T~3, for T>453.15 K, η=1.021. Henry's constants of various gases in water, alcohols, ketones, halogenated aromatics and naphthalene substitutes are calculated. For all of the 81 systems with 13 solvents whose maximum dipole moment is 2.83 Debye, satisfactory results are obtained with the use of only one adjustable parameter over a wide temperature range of 193.15—573.15 K. The results of calculations for 78 systems of gas solubility in 1-1 type electrolytic solutions indicate that this model can predict the Henry's constants of gases in electrolytic solutions over a wide temperature range and a wide concentration range for electrolytes with the use of molecular parameters of gases in water only. 相似文献
4.
5.
6.
The solubilities of acetaminophen and ibuprofen in the mixtures of propylene glycol-water, polyethylene glycols 200- and 400-propylene glycol, and polyethylene glycols 200- and 400-propylene glycol-water (122 data points) at 25°C were determined and mathematically represented by the Jouyban-Acree model. The solubilities were measured using the shake flask method, and the model was used to fit the solubility data of each drug in the solvent mixtures. The density of the solute-free solvent mixtures was measured and the density of the drug-saturated solutions was predicted. The obtained overall mean relative deviations (OMRDs) for fitting the solubility data of acetaminophen and ibuprofen in binary mixtures are 1.5% and 11.7%, respectively. The OMRDs for fitting the solubilities in ternary solvent mixtures for acetaminophen and ibuprofen are 16.3% and 42.0%, respectively, and the OMRD values for predicting all solubilities of acetaminophen and ibuprofen by these trained versions of the Jouyban-Acree model were 5.7% and 20.4%, respectively. The prediction OMRD for the density of saturated solutions was 2.5%. 相似文献
7.
W. K. McAfee 《Journal of the American Ceramic Society》1926,9(10):396-399
The rapid development of ceramic technology is necessary to the well-being of our industry. A comprehensive plan should be laid out and the required machinery, responsible to the manufacturers, set up to accomplish this. 相似文献
8.
Solubilities of CO_2 in binary mixtures of n-decane-n-hexadecane and n-heptane-toluenewere measured in a glass apparatus by a synthetic method.Henry's constants at several temperaturesand solvent compositions were reported.While the Henry's constants of CO_2 in mixtures of decaneand hexadecane can be satisfactorily predicted by a simple linear interpolation,prediction of Henry'sconstants for CO_2 in mixtures of heptane and toluene requires excess Gibbs energy of the solvent mix-tures.The standard thermodynamic functions of solution(ΔH~0,ΔG~0,and ΔS~0)were reported. 相似文献
9.
INTRODUCTIONTheBeckmannrearrangementofcyclo hexanoneoximeisanimportantreactionforobtainingε caprolactam ,therawmaterialofnylon 6fibers .Currently ,thewidelyusedtechnologiesfortheproductionofcyclohexanoneoxime producelargeamountsofbyproducts .FortheBeckma… 相似文献
10.
The Beckmann rearrangement of cyclohexanone oxime is an important reaction for obtaining ε-caprolactam, the raw material of nylon 6 fibers. Currently, the widely used technologies for the production of cyclohexanone oxime produce large amounts of byproducts. For the Beckmann rearrangement, many solid acid catalysts such as alumina, boria-alumina, and zeolites including Y, those with MFI-structure and β have been studied. However, no generally accepted understanding about the reaction mechanism has been achieved. 相似文献
11.
The Chinese mathematicians Heping Zhang and Fuji Zhang conceived a combinatorial polynomial associated with benzenoid molecules. This “Zhang–Zhang polynomial” contains information on the Kekulé structure count (K), Clar structure count (C), Clar number (Cl), Hosoya-Yamaguchi sextet polynomial σ(B, x), and several other important characteristics of the underlying benzenoid molecule. We show how one can easily calculate the Zhang-Zhang polynomial, and thus arrive at an algorithm for simultaneous computation of K, C, Cl, and σ(B, x). Some applications of this algorithm are pointed out. 相似文献
12.
13.
INVESTIGATION OF METHINE TYPE DISPERSE DYES OF BENZTHIOPHEN-ONE DERIVATIVES Ⅰ. STUDY ON THE RELATION BETWEEN DYES MOLECULAR STRUCTURES AND THEIR ABSORPTION SPECTRA
下载免费PDF全文
![点击此处可从《中国化学工程学报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
A series of Methine Type Disperse Dyes of Benzthiophen-one derivatives for polyester fiber was devised and prepared. The adsorption spectra of these disperse dyes in solution were measured. The relation between the molecular structures of these dyes and their adsorption spectra was studied and discussed. 相似文献
14.
Willi M. Cohn 《Journal of the American Ceramic Society》1927,10(5):347-352
Due to variation in specific heats obtained by Cohn and MacGee, criticism and comparison of the results is set forth by Cohn. Methods of determination of specific heat, accuracy claimed for the methods, erroneous assumptions, and several other items are taken up in detail in the fourteen sections of the discussion. The reply by MacGee takes up in detail each of the points raised. 相似文献
15.
The macro-kinetics of benzene hydrogenation over porous Ni/γ-Al_2O_3 catalyst was measured with asingle-pellet diffusion reactor.Based on the dusty-gas model,the differential equations by taking into account ofthe variation of effective diffusivities with the composition were derived to describe the diffusion and reactionprocesses of reacting species over porous catalyst.Using the tortuosity factors determined under the condition ofsteady physical diffusion,the global reaction rates were calculated by solving the equations,and the results are ingood agreement with the experimental data obtained. 相似文献
16.
以丙烯酸钾盐和全氟烷基乙烯基加成物(PFOEI)为原料,在反应体系自身产生的压力下,催化合成1H,1H,2H,2H-全氟烷基丙烯酸酯,考察了在原料配比为,n(PFOEI):n(丙烯酸钾):n(叔戊醇):n(PIC):n(阻聚剂)=1:1.5:20:0.06:0.05、反应时间为9 h下,溶剂、相转移催化剂和反应温度对酯... 相似文献
17.
18.
PHYSICAL CHEMISTRY OF ADSORPTION OF COPPER,NICKEL AND COBALT ON LIGNITE FROM AMMONIACAL SOLUTIONS
下载免费PDF全文
![点击此处可从《中国化学工程学报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
夏光祥 《中国化学工程学报》1986,1(1):15-23
The adsorption of Me(metal),NH_3 and CO_2 on lignite from ammoniacal solution containing metallicions such as Cu,Ni,and Co was investigated.Preliminary mechanism studied revealed that active carboxyland phenolic groups of humic acid in lignite as well as surface adsorption were involved.The rate of ap-proach to adsorption equilibrium on lignite was NH_3>Ni>Co>Cu andthe adsorption on lignite is Cu>Co>Ni>NH_3.The order of selective elution was NH_3>>Ni,Co>Cu.All metals were fully stripped and NH,could only be recovered partially.NH_3 adsorbed on lignite fron metal-ammoniacal solution is easily lost by volatilization,only a smallfraction remaining on lignite at a temperature of 120℃.CO_2 adsorbed physically in nature from ammonia-cal solution with a capacity of less then one percent was observed under the practical conditions generallyin hydrometallurgy. 相似文献
19.