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241.
The viscosities of Sr(NO3)2 and Cd(NO3)2 have been determined in dioxane, glycol and methyl alcohol+water mixtures at 10, 20 and 30% by weight. The B values have been computed at different temperatures both from the Jones—Dole and Das's equation. From the B values, the effective rigid molar volume, its change with % of organic solvent, temperature and the ion—solvent interaction have been inferred. Activation parameters have also been calculated and the structure breaking effect has been deduced. 相似文献
242.
U.N. Dash 《Thermochimica Acta》1975,11(1):25-33
The ionization constants of iodic and bromic acids in formamide have been determined at 25, 30, and 35°C from solubility measurements. The ionization constants of iodic acid are found to be 9.83 × 10?2, 12.02 × 10?2 and 12.14 × 10?2, respectively, and those of bromic acid, 9.56 × 10?2, 9.70 × 10?2, and 10.15 × 10?2, respectively, at 25, 30 and 35°C. Thermodynamic parameters associated with the ionization processes have also been determined. 相似文献
243.
The tricyclic alpha-keto hemiacetals 3a,b and 8a-d obtained from ruthenium-catalyzed oxidation of tetrahalonorbornyl derivatives possessing a pendant hydroxymethyl group were cleaved using Pb(OAc)(4) or alkaline H(2)O(2) to give gamma-lactone-fused cyclopentane derivatives 5a,b and 9a-d. The alpha-keto hemiacetal 3b has also been elaborated to spiroepoxide derivative 25. The stable hydrate 4 formed from ruthenium-catalyzed oxidation of acrolein adduct 10 furnished an intramolecular hemiacetal 11 upon cleavage with Pb(OAc)(4). The alpha-halo ester moiety in 5a was transformed smoothly in a highly regio- and stereoselective manner to alpha-hydroxy esters through a lactone-assisted intermediate to furnish 18. 相似文献
244.
S.C. ParidaSmruti Dash Ziley SinghR. Prasad K.T. JacobV. Venugopal 《Journal of solid state chemistry》2002,164(1):34-41
The enthalpy increments and the standard molar Gibbs energy of formation of NdFeO3(s) have been measured using a high-temperature Calvet microcalorimeter and a solid oxide galvanic cell, respectively. A λ-type transition, related to magnetic order-disorder transformation (antiferromagnetic to paramagnetic), is apparent from the heat capacity data at ∼687 K. Enthalpy increments, except in the vicinity of transition, can be represented by a polynomial expression: {H°m(T)−H°m(298.15 K)}/J·mol−1 (±0.7%)=−53625.6+146.0(T/K) +1.150×10−4(T/K)2 +3.007×106(T/K)−1; (298.15≤T/K ≤1000). The heat capacity, the first differential of {H°m(T)−H°m(298.15 K)} with respect to temperature, is given by Cop, m/J·K−1·mol−1=146.0+2.30×10−4(T/K)−3.007×106(T/K)−2. The reversible emf's of the cell, (−) Pt/{NdFeO3(s) +Nd2O3(s)+Fe(s)}//YDT/CSZ//{Fe(s)‘FeO’(s)}/Pt(+), were measured in the temperature range from 1004 to 1208 K. It can be represented within experimental error by a linear equation: E/V:(0.1418±0.0003)−(3.890±0.023)×10−5(T/K). The Gibbs energy of formation of solid NdFeO3 calculated by the least-squares regression analysis of the data obtained in the present study, and data for Fe0.95O and Nd2O3 from the literature, is given by ΔfG°m(NdFeO3, s)/kJ·mol−1(±2.0)=−1345.9+0.2542(T/K); (1000≤T/K ≤1650). The error in ΔfG°m(NdFeO3, s, T) includes the standard deviation in emf and the uncertainty in the data taken from the literature. Values of ΔfH°m(NdFeO3, s, 298.15 K) and S°m(NdFeO3, s, 298.15 K) calculated by the second law method are −1362.5 (±6) kJ·mol−1 and 123.9 (±2.5) J·K−1·mol−1, respectively. Based on the thermodynamic information, an oxygen potential diagram for the system Nd-Fe-O was developed at 1350 K. 相似文献
245.
246.
247.
Kumar Manoj Shaikh Samina Gandhi Shyamala Pandey Usha Kumar Sanjukta Dash Ashutosh 《Journal of Radioanalytical and Nuclear Chemistry》2020,324(2):879-885
Journal of Radioanalytical and Nuclear Chemistry - This study describes the fabrication of 57Co point sources utilizing the metal sorption properties of amidoxime functionalized PAN-PVDF beads.... 相似文献
248.
Upendra N. Dash Banka B. Das Uttam K. Biswal Tapodhan Panda Narendra K. Purohit Dushmanta K. Rath Subhankar Bhattacharya 《Thermochimica Acta》1983,61(3):379-387
The hydration kinetics of tricalcium aluminate, C3A, with gypsum or anhydrite at 1:3 mole ratio were studied using hydration periods of 5 min up to 7 days. These studies were assessed with the aid of differential thermal analysis, thermogravimetric analysis and X-ray diffractometry as well as chemical analysis.The results revealed that hydration periods of up to 7 days of tricalcium aluminate with gypsum in paste form and in suspension, forms ettringite with unhydrated components of C3A and gypsum. On the other hand, the only hydration product of the slurry of C3A with anhydrite is ettringite after 7 days of hydration. The kinetics of hydration were studied by the quantitative determination of ettringite from the TG analysis. The results also illustrate that the rate of ettringite formation is slower in the presence of gypsum than in the presence of anhydrite and also that hydration of the slurry gives more ettringite than the hydration of the paste. 相似文献
249.
Lee YJ Wang MZ Abe K Abe K Aihara H Asano Y Aulchenko V Aushev T Bahinipati S Bakich AM Bedny I Bitenc U Bizjak I Bondar A Bozek A Bracko M Brodzicka J Browder TE Chang MC Chang P Chao Y Chen A Chen KF Chen WT Cheon BG Chistov R Choi SK Chuvikov A Cole S Dalseno J Danilov M Dash M Drutskoy A Eidelman S Enari Y Fang F Fratina S Gabyshev N Garmash A Gershon T Gokhroo G Golob B Gorisek A Haba J Hayasaka K Hazumi M Hinz L Hokuue T Hoshi Y Hou S Hou WS Hsiung YB Iijima T Imoto A Inami K Ishikawa A 《Physical review letters》2005,95(6):061802
We report the first observation of the radiative hyperonic B decay B+ --> plambdagamma, using a 140 fb(-1) data sample recorded on upsilom(4S) resonance with the Belle detector at the KEKB asymmetric energy e+e- collider. The measured branching fraction is [symbol: see text](B+ --> plambdagamma) = (2.16(+0.58)(-0.53) +/- 0.20) x 10(-6). We examine its M(plambda) distribution and observe a peak near threshold. This feature is expected by the short-distance b --> sgamma transition. A search for B+ --> pepsilon0gamma yields no significant signal, and we set a 90% confidence-level upper limit on the branching fraction of [symbol: see textB+ --> pepsilon0gamma <4.6 x 10(-6). 相似文献
250.
Mizuk R Abe K Abe K Aihara H Akatsu M Asano Y Aulchenko V Aushev T Bakich AM Balagura V Ban Y Banerjee S Bedny I Bitenc U Bizjak I Blyth S Bondar A Bozek A Bracko M Brodzicka J Browder TE Chao Y Chen A Cheon BG Chistov R Choi SK Choi Y Chuvikov A Cole S Dalseno J Danilov M Dash M Dragic J Drutskoy A Eidelman S Fratina S Gabyshev N Garmash A Gershon T Gokhroo G Haba J Hastings NC Hayasaka K Hayashii H Hazumi M Hokuue T Hoshi Y Hou S Hou WS Hsiung YB Iijima T Imoto A Inami K Ishikawa A Itoh R 《Physical review letters》2005,94(12):122002
We report the observation of an isotriplet of excited charmed baryons, decaying into Lambda(+)(c)pi(-), Lambda(+)(c)pi(0), and Lambda(+)(c)pi(+). We measure the mass differences M(Lambda(+)(c)pi)-M(Lambda(+)(c)) and widths to be 515.4(+3.2+2.1)(-3.1-6.0) MeV/c(2), 61(+18+22)(-13-13) MeV for the neutral state; 505.4(+5.8+12.4)(-4.6-2.0) MeV/c(2), 62(+37+52)(-23-38) MeV for the charged state; and 514.5(+3.4+2.8)(-3.1-4.9) MeV/c(2), 75(+18+12)(-13-11) MeV for the doubly charged state, where the uncertainties are statistical and systematic, respectively. These results are obtained from a 281 fb(-1) data sample collected with the Belle detector near the Upsilon(4S) resonance, at the KEKB asymmetric energy e(+)e(-) collider. 相似文献