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Short, simple and enantioselective syntheses of the natural product (+)-streptol, the non-peptide apoptosis inhibitor ent-RKTS-33 and the putative structure of ‘parasitenone’ have been accomplished from the readily available chiral building block. ‘Parasitenone’ has been shown to be identical with the known natural product epoxydon.  相似文献   
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JPC – Journal of Planar Chromatography – Modern TLC - Use of an internal standard is proposed in this thin-layer chromatographic determination of fluconazole in tablet and capsule...  相似文献   
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This report summarises the activities of the working group on ‘Physics beyond the Standard Model’. The results of investigations in incorporatingR-parity in grand unification, the possibility of a light charged Higgs boson in extension of MSSM and radiative generation of neutral vector boson self-couplings within the MSSM are described. Also given is an account of activities in neutrino physics, namely a proposal for a study of the atmospheric muon anomaly in deep underground mines, a field theoretic study of neutrino oscillations and a mechanism to generate appropriate masses of three active plus one sterile neutrino species.  相似文献   
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 The extraction behavior of platinum(IV) was studied with N-n-octylaniline as a function of different parameters, such as pH, concentrations of weak acids, mineral acids, reagents and elution time. A selective method was developed for the extraction chromatographic studies of platinum(IV) and its separation from several metal ions with N-n-octylaniline (liquid anion exchanger) as a stationary phase on silica gel. The quantitative extraction of platinum(IV) was observed with 0.067 mol/L N-n-octylaniline and 0.015 mol/L ascorbic acid at pH 1.0. Metal ion was stripped from the column with water and determined spectrophotometrically with stannous chloride method. The proposed method is free from the interference of a large number of cations and anions. Platinum(IV) was separated from pharmaceutical preparations, alloys and synthetic mixtures. Mutual separation scheme was developed for platinum(IV), palladium(II) and gold(III). The log-log plot of N-n-octylaniline concentration versus the distribution ratio indicates that the probable extracted species is [RR′NH+2 ]· Pt(C6H7O6)-3.  相似文献   
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We find a general explicit formula for all sequences satisfying a two-term recurrence of a certain kind. This generalizes familiar formulas for the Stirling and Lah numbers.  相似文献   
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We consider the spectral problem resulting from the Schrödinger equation for a quantum system ofn2 indistinguishable, spinless, hard-core particles on a domain in two dimensional Euclidian space. For particles obeying fractional statistics, and interacting via a repulsive hard core potential, we provide a rigorous framework for analysing the spectral problem with its multi-valued wave functions.Partially supported by the Mathematical Sciences Research Institute, Berkeley California, under NSF Grant # DMS 8505550Partially supported under NSF Grant no. DMR-9101542  相似文献   
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A tetrabutylammonium hydrogen sulfate (TBA-HS) mediated procedure for one pot synthesis of novel benzopyran-annulated pyrano[2,3-c]pyrazoles via domino/Knoevenagel-hetero-Diels-Alder reaction has been demonstrated.  相似文献   
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