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11.
Conductance data for sodium nitrite, chloride, and acetate in water andN,N-dimethylformamide (DMF)-water mixtures (74.82D42.48) for the concentration range 0.001–0.04N, as well as the densities, viscosities, and dielectric constants of the solvent mixtures at 35°C, are reported. The data have been analyzed by the Fuoss (1975) equation. The existence of a maximum in the viscosity at a 13 mole ratio of DMF and water is indicated. The Walden products for all the three salts pass through a maximum while the equivalent conductances show a minimum with increasing DMF content. The maxima in the Walden product are attributed to the dehydration of ions by the cosolvent (DMF).Part I:Indian J. Chem.
14A, 1015 (1976).Deceased. 相似文献
12.
Adamovich MI Aggarwal MM Alexandrov YA Andreeva NP Anson ZV Arora R Avetyan FA Badyal SK Basova E Bazarov IK Bhalla KB Bhasin A Bhatia VS Bogdanov VG Bubnov VI Burnett TH Cai X Carshiev DA Chasnicov IY Chernova LP Chernyavski MM Eligbaeva GZ Eremenko LE Gaitinov AS Ganssauge ER Garpman S Gerassimov SG Grote JG Gulamov KG Gupta SK Gupta VK Heckman HH Huang H Jacobsson B Judek B Kachroo S Kalyachkina GS Kanygina EK Karabova M Kharlamov SP Kitroo S Koss T Krasnov SA Kumar V Lal P Larionova VG 《Physical review D: Particles and fields》1993,47(9):3726-3732
13.
Microwave-activated solvent-free Michael addition of 3-imino-1,4,2-dithiazoles to 4-arylidene-5(4H)-oxazolones furnished isolable adducts regio- and diastereoselectively, which underwent ring transformation to yield the target dithiazolopyrimidines. Alternatively, the similar conjugate addition of methanesulfinylmethylisothioureas to 4-arylidene-5(4H)-oxazolones diastereoselectively afforded Michael adducts, which underwent ring transformation followed by heterocyclization via deoxygenative demethylation with thionyl chloride to yield the same products dithiazolopyrimidines regio- and diastereoselectively. 相似文献
14.
Densities,ρ, ultrasonic speeds, u, viscosities,η, and refractive indices, n, of pure benzene, benzyl alcohol (BA), benzonitrile (BN), benzoyl chloride (BC), chlorobenzene (CB) and their thirty six binary mixtures, with benzene as common component, were measured at 303.15 K over the entire mole fraction range. From these experimental data the values of deviations in ultrasonic speed, △u, isentropic compressibility, △ks,excess acoustic impedance, ZE, deviation in viscosity, Dh, and excess Gibbs free energy of activation of viscous flow, G*E, and partial molar isentropic compressibility, Kφ,20 of BA, BN, BC and CB in benzene were computed. The variation of these derived functions with composition of the mixtures suggested the increased cohesion
(molecular order) in the solution and that interaction (A-B)>(A-A) or (B-B).Moreover, theoretical prediction of ultrasonic speed, viscosity and refractive index of all the four binary mixtures was made on the basis of empirical and semi-empirical relations by using the experimental values of the pure components. Comparison of theoretical results with the experimental values was made in order to assess the suitability of these relations in reproducing the
experimental values of u, η and n. Also, molecular radii of pure liquids and the average molecular radii of binary mixtures were evaluated using the corresponding refractive indices of pure liquids and binary mixtures. The average molecular radii of binary mixtures were found to be additive with respect to mole fraction of the pure component. 相似文献
15.
Dr. S. Lal 《Monatshefte für Chemie / Chemical Monthly》1974,105(5):974-976
Study of europium(III)-l-histidine complex has been made in sodium perchlorate at μ=0.1 by tast polarography. The reduction process appears to be quasi irreversible. The apparent rate constants have been determined byGellings method1. With the knowledge ofE 1 2/r and use ofLingane's method, one complex Eu(Histd)2+ with the instability constant 6.77×10?5 is reported. 相似文献
16.
Kanchan Kothari Ramji Lal M. R. A. Pillai 《Journal of Radioanalytical and Nuclear Chemistry》1995,196(2):331-338
A direct radioimmunoassay for the measurement of progesterone in human serum is described. Progesterone 11-hemisuccinate was conjugated to tyrosine methyl ester (TME) by the mix anhydride method and then iodinated using chloramine-T. The radiochemical purity of different batches of125I-progesterone was greater than 95% and showed 70–75% binding with excess antibody. Progesterone 11-hemisuccinate was coupled with BSA and injected to rabits. Antisera collected after three booster injections and having aK value of 1·1091/M was selected for the assay. Significant reduction in binding with antibody was seen when hormone free serum was used in the assay system. Various blocking agents were tried to reduce the serum effects and none of them were found satisfactory. From a series of optimization experiments, an assay was developed without the use of blocking agents. This assay used a much higher concentration of antibody along with lower amount of serum sample (50 l). The optimized assay has a sensitivity of 0.5 nj/ml and a working range of 0.5 to 100 ng/ml. Serum samples were analyzed analysis showed good correlation between the results obtained from the present system and the DPC kit. (Y=0.93X+0.5,r=0.93, forn=25). 相似文献
17.
Summary Electroosmosis of acetone, water and their binary mixtures through thorium oxide (ThO2) plug membrane has been studied and the data analysed using non-equilibrium thermodynamics. The phenomenological coefficients,L
11 andL
12 have been found to vary nonlinearly with composition. Excess phenomenological coefficients have therefore been evaluated and the results explained in terms of the membrane permeant and permeant-permeant interactions. The results on the measurement of electrophoretic velocity of ThO2 particles dispersed in acetone-water mixtures also lead to the conclusion that the components of the mixture interact appreciably.
With 8 figures and 1 table 相似文献
Zusammenfassung Die Elektroosmose von Aceton, Wasser and deren binären Gemische durch eine ThO2-Pflock-Membran wurde untersucht; die Daten wurden mit Hilfe der Nichtgleich-gewichts-Thermodynamik analysiert. Die phänomenologischen KoeffizientenL 11 undL 12 ändern sich hiernach nichtlinear mit der Zusammensetzung. Es wurden daher Exzess-L 11-und -L 12-Werte berechnet; die Ergebnisse wurden auf Grund der Membran-Permeant- und Permeant-Permeant-Wechselwirkungen diskutiert. Aus der Messung der elektrophoretischen Geschwindigkeit von ThO2-Teilchen, die in Aceton-Wasser-Gemischen dispergiert sind, folgt, daß eine merkliche Wechselwirkung zwischen den Komponenten der Mischung vorliegt.
With 8 figures and 1 table 相似文献
18.
Earlier work by Lindenbaum and Boyd has demonstrated the important role of hydrophobic interactions involving the water solvent in determining the osmotic coefficients and properties of aqueous solutions of the tetraalkylammonium halides. Osmotic coefficients of solutions of tetramethyl-, tetraethyl-, tetrapropyl-, and tetrabutylammonium bromides in the more highly structured solvent D2O have now been determined by the gravimetric isopiestic method, using reference solutions of NaCl in D2O. The data were fitted to the Rush-Johnson and Pitzer equations. Satisfactory agreement with the results for aqueous solutions at comparable concentrations indicates that the solution chemistry of these quaternary ammonium bromides is not highly dependent on the degree of structure of the pure solvents. Supplementary data for mixtures of Me4NBr with Et4NBr, Pr4NBr, or Bu4NBr in both H2O and D2O are consistent with this conclusion.On leave 1980–82 from Banaras Hindu University, India 相似文献
19.
Even with the emergence of advanced techniques of separation and identification, it is rarely possible to analyse food without manipulation. The traditional techniques for sample preparation are time consuming and require large amount of reagents, which are expensive, generate considerable waste, contaminate the sample and can enrich it for analytes. The more analytical techniques have become highly developed, the more has sample clean-up become important in order to fully take advantage of them. Due to the multiplicity of food matrices, it is not possible to use one sample preparation technique, so many methods have been proposed for meeting all the requirements. The newest variations of wet digestion, solvent and sorbent extraction and membrane separation are summarised and their most recent applications to food analysis are provided. 相似文献
20.
Summary A nitrate-selective electrode based on precipitated nitron nitrate in an epoxy resin matrix has been prepared. The lower detection limit is 10–5
M, the optimum pH range is 2.0–8.5, and the response time is 1 min. The electrode is selective in presence of CH3COO–, SO4
2–, C2O4
2–, PO4
3–, NO2
–, Cl– and Br–, but I– interferes. Results for nitrate in soil samples were in agreement with values obtained spectrophotometrically.
Presented at the 8th International Microchemical Symposium, Graz, August 25–30, 1980. 相似文献
Eine neue nitrat-spezifische Elektrode auf der Basis gefällten Nitronnitrats
Zusammenfassung Eine nitrat-spezifische Elektrode auf der Basis gefällten Nitronnitrats in einer Epoxyharz-Matrix wurde hergestellt. Die untere Nachweisgrenze ist 10–5 M, das pH-Optimum liegt zwischen 2,0 und 8,5, die Reaktionszeit beträgt 1 Minute. Die Elektrode ist selektiv in Gegenwart von Acetat, Sulfat, Oxalat, Phosphat, Nitrit, Chlorid und Bromid; aber Jodid stört. Ergebnisse der Nitratbestimmung in Bodenproben stimmen mit spektrophotometrischen Resultaten überein.
Presented at the 8th International Microchemical Symposium, Graz, August 25–30, 1980. 相似文献