Local magnetic behaviour of Rh implanted into Ni-Rh alloys near the critical Rh compositionx=0.37 has been studied using the TDPAC method. The observed Curie-Weiss type local susceptibility reflects the presence of large d spin polarization around Rh yielding a total moment of 4.7 B. Our results show that the magnetism of Rh in the alloys depends strongly on the number of Ni near neighbour atoms. 相似文献
A less labour-intensive method, involving a mixture of 1.0 g MnO2 + 20 mL HCl (11), is proposed for decomposing seven ores and six metallurgical products for accurate and precise estimation of copper, lead, zinc, cobalt and nickel for quality control assessment. Twentyone international reference materials were also analysed. Results of regression analyses are presented and intermethod comparison studies reveal that the probability of results being different compared with a reference method was less than 1%. Sample decomposition is straightforward and the method has been found to be very simple, rapid and easily adaptable, as it involves no separation of the analyte from the matrix elements. 相似文献
N-Hydroxy-N-m-tolyl-N′-(2-methyl-5-chloro)phenyl-p-toluamidine hydrochloride (HTMCPTH), a monobasic and bidentate chelating agent which reacts with vanadium(V) in carboxylic acid media to develop a blue-violet complex, has been employed as a highly selective reagent for extraction and direct photometric determination of the metal. Solvent extraction experiments indicate that from aqueous acetic acid (1.0–10.0 M), monochloroacetic acid (0.1–10.0 M), and phenylacetic acid (at pH 0.5–6.0) vanadium(V) is quantitatively extracted into chloroform. Almost all common ions including Fe3+, Cu2+, Ni2+, Co2+, Mn2+, Cr3+, Ti4+, Zr4+, and Mo6+ do not interfere with the proposed method. The procedure has been utilized for accurate determination of vanadium in standard steels. 相似文献
Surface tension measurements can be used to investigate molecular complex formation in liquid solutions for strong and weak
complexes. The association constant and epthalpy for triethylamine-iodine, hexamethylbenzene-tetracyanoethylene and ethanol-iodine
in cyclohexane are 4·55×103, 218 and 0.93M−1 at 25° C and 12·5, 7·7 and 5·1 kcal/mol respectively. These values compare well with those reported in the literature by
other methods. 相似文献
The use of fenugreek mucilage, a natural polysaccharide and a direct food additive, as a flocculating agent for removal of suspended and dissolved solids from sewage effluent has been reported. A flocculation study has been done by the standard jar test method. The percent removal of suspended solid (SS) and dissolved solid (TDS) was determined by varying the polymer dose, pH and contact time. X-ray diffraction patterns of the solid waste material of mucilage and flocs (so obtained after treatment) were used to suggest the incorporation of the crystalline waste material in the mucilage. The optimal mucilage concentration was found to be 0.16 mg/l. The suitable pH range for maximum solid removal (SS and TDS) was alkaline and the time required for treatment was 1-3 h. 相似文献
In the present paper, we report the standard molar Gibbs energy of formation for CaThF6 measured by gas equilibration and e.m.f. methods. The HF(g) vapour pressure over the equilibrium reaction: \({\text{CaThF}}_{6} \left( {\text{cr}} \right) + 2 {\text{H}}_{ 2} {\text{O}}\left( {\text{g}} \right) = {\text{CaF}}_{2} \left( {\text{cr}} \right) + {\text{ThO}}_{2} \left( {\text{cr}} \right) + 4{\text{HF}}\left( {\text{g}} \right)\) has been measured using transpiration technique. The above reaction mechanism has been established employing TG and XRD techniques. A fluoride e.m.f. cell: (−)Pt, CaF2(cr) + ThOF2(cr) + CaThF6(cr) |CaF2(cr)| NiO(cr) + NiF2(cr), Pt(+) has been constructed to measure Gibbs energy of formation of CaThF6 (cr) using CaF2 (cr) as a solid electrolyte. The isobaric heat capacity \({\text{Cp}}_{\text{m}}^{{\circ }} \left( T \right)\) of the compound has been measured using differential scanning calorimetric technique. Based on the experimental results, thermodynamic functions for CaThF6 have been generated.
Enthalpies of formation of 1,10-phenanthrolinium ion and ferrous-1,10-phenanthroline (tris) complex in dioxane—water and ethanol—water media at 25°C have been determined by calorimetry. Results are discussed in the light of ion—solvent and solvent—solvent interactions. 相似文献
Dissolution effect on recoil128I retention in the form of IO
4–
ion following /n,/ process in potassium periodate target has been studied. A remarkable variation in retention is found both in solid and solution phase with the pH of dissolution. A suitable mechanism is suggested to explain the observed results. 相似文献
The ion exchange and sorption properties of crystalline Tin bis(monohydrogen orthophosphate) monohydrate of composition Sn(HPO(4))(2).H(2)O were studied in an aqueous solution of KCl over the temperature range 300-320 K, varying the pH and metal ion concentration in the solution. The data were explained on the basis of the law of chemical equilibrium. The metal ion sorption data were fitted to the Langmuir adsorption equation to evaluate the Langmuir parameters. The extent of adsorption was found to increase with an increase in temperature and metal ion concentration in the selectivity order Cu(2+)>Co(2+)>Ni(2+). The Langmuir parameters were used to calculate the thermodynamic functions like standard entropy, enthalpy, and free energy changes during the process of sorption. Copyright 2000 Academic Press. 相似文献