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51.
52.
53.
Miss I. Pratanata L. R. Williams R. N. Williams 《Journal of mass spectrometry : JMS》1974,8(1):175-178
Upon electron-impact aryl methyl sulphones (I) rearranged to form aryl-oxygen bonds. The mode of fragmentation of the intermediate ester (II) to give [aryl O]+ or [aryl OH]+ ions was found to be markedly influenced by the nature of the aryl substituent. 相似文献
54.
Radiolysis of ferrous ammonium sulphate (FAS) dispersed in (a) alkali nitrates [KNO3, NaNO3, Ba(NO3)2, CO(NH3)6(NO3)3] (b) alkali halides [KCl, KBr] and (c) binary mixtures of above [KNO3 + KCl, Ba(NO3)2 + BaCl2) has been extensively investigated. FAS becomes oxidized and Fe3+ formation seems to depend upon the nitrate concentration and gamma dose but is independent of halide concentration. Mossbauer studies confirm these findings and it appears that basic ferric sulphate may be formed during the oxidation process. 相似文献
55.
Summary This note describes a method of preparing, from powders, specimens of intractable polymers for measurement of dynamic mechanical
properties.
The powder, or a mixture of the powder and an inert filler, are compacted at room temperature in a press and if necessary
sintered at an elevated temperature to achieve a low void content.
Good agreement is found between the dynamic mechanical behaviour of specimens prepared by melt and powder pressing.
Zusammenfassung Eine Methode, aus Pulvern von schwer zu behandelnden Polymeren für die Messung der mechanischen Eigenschaften Proben zu bereiten, wird dargelegt. Das Pulver bzw. Mischungen des Pulvers und eines inerten Füllstoffes werden bei Raumtemperatur in einer Presse komprimiert und, falls notwendig, bei h?herer Temperatur gesintert, um Blasen zu vermeiden. Es ergab sich gute übereinstimmung zwischen den so hergestellten und anderen Proben, pr?pariert mit Schmelzverfahren.相似文献
56.
N. Sivaprasad Miss Grace Thomas K. B. Shah R. S. Mani 《Journal of Radioanalytical and Nuclear Chemistry》1979,53(1-2):351-358
A sensitive and specific radioimmunossay procedure (RIA) has been developed for the measurement of Human Placental Lactogen
(HPL). Pure HPL has been labelled with125I and a specific activity of 100 μCi/μgm of HPL has been attained. Dextran-coated charcoal has been employed to separate the
bound from the free hormone in radioimmuno-assay. The sensitivity of this technique has been found to be 0.2 ng of HPL. Intraassay
and inter assay variations have been found to be less than 10%. This procedure has been adopted to establish the normal range
of HPL in pregnant women at different periods of gestation, and to evaluate risk pregnancies. 相似文献
57.
T. N. Srivastava A. K. S. Chauhan Miss Manjula Agarwal 《Transition Metal Chemistry》1978,3(1):378-379
Summary Binuclear complexes of phenyltin(IV) chlorides with transition metal chelates of tetradentate Schiff bases derived from acetylacetone, benzoylacetone oro-hydroxyacetophenone and ethylenediamine or propylenediamine, of the general formula PhnSnCl4-nML (where n = 1 or 2, M = Ni11 or Cu11 and L2–= the Schiff base dianion), have been synthesised and characterized through elemental analysis, conductance and i.r. spectroscopic data. The coordination of metal chelates to tin involves two triply bonded oxygen atoms giving rise to an octahedral environment around SnIV. The molar conductance of the complexes in nitrobenzene shows the presence of the uncoordinated ML and phenyltin(IV) chloride moieties in solution.Author to whom all correspondence should be directed. 相似文献
58.
Summary Complexes ofo-hydroxyacetophenone-2-furoylhydrazone, H2L, of the types M(H2L)C12 · nH2O [Mn = CoII, n=0; NiII, n=2]; Cu(HL)Cl, M(HL)2 [M = VIVO, CoII, NiII or CuII] and M(L)(H2O)n [M = CoII or NiII, n=2; M = CuII, n=0] have been prepared and characterized by elemental analyses, molar conductance, magnetic susceptibility, visible, e.s.r. and i.r. spectral studies. The different modes of ligand chelation and the stereochemistry around the metal ions are discussed. 相似文献
59.
The acid catalysed rearrangement of 8-methyl-pentacyclo(5.4.0.02,6.03,10.05,9)undecan-8-endo-o1 () to 3-methyl-(D3)-trishomocuban-4-o1 () provided the key step to the synthesis of the title compound (). 相似文献
60.
Simran Baweja Bhavika Kalal Prajoy Kumar Mitra Dr. Surajit Maity 《Chemphyschem》2023,24(23):e202300270
Excited state hydrogen (ESHT) and proton (ESPT) transfer reaction pathways in the three and four solvent clusters of 6-azaindole (6AI-S3,4) and 2,6-diazaindole (26DAI-S3,4)(S=H2O, NH3) were computationally investigated to understand the fate of photo-excited biomolecules. The ESHT energy barriers in (H2O)3 complexes (39.6–41.3 kJmol−1) were decreased in (H2O)4 complexes (23.1–20.2 kJmol−1). Lengthening the solvent chain lowered the barrier because of the relaxed transition states geometries with reduced angular strains. Replacing the water molecule with ammonia drastically decreased the energy barriers to 21.4–21.3 kJmol−1 in (NH3)3 complexes and 8.1–9.5 kJ mol−1 in (NH3)4 complexes. The transition states were identified as Ha atom attached to the first solvent molecule. The formation of stronger hydrogen bonds in (NH3)3,4 complexes resulted in facile ESHT reaction than that in the (H2O)3,4 complexes. The ESPT energy barriers in 6AI-S3,4 and 26DAI-S3,4 were found to range between 40–73 kJmol−1. The above values were significantly higher than that of the ESHT processes and hence are considered as a minor channel in the process. The effect of N(2) insertion was explored for the very first time in the isolated solvent clusters using local vibrational mode analysis. In DAI-S4, the higher Ka(Ha⋯Sa) values depicted the increased photoacidity of the N(1)-Ha group which may facilitate the hydrogen transfer reaction. However, the increased N(6)⋯Hb bond length elevated the reaction barriers. Therefore, in the ESHT reaction channel, the co-existence of two competing factors led to a marginal/no change in the overall energy barriers due to the N(2) insertion. In the ESPT reaction pathway, the energy barriers showed notable increase upon N(2) insertion because of the increased N(6)⋯Hb bond length. 相似文献