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881.
M. Shepherd E. R. Weaver P. G. Ledig Aktiebolaget Carba K. Melanby H. L. Harden P. Borinski H. Murschhauser R. Staufer R. Krais H. Markert H. Mogilnickij H. Heinicke K. Heimberger L. C. Mc Nair H. C. Gull St. Hediger E. Lieber R. Rosen K. M. Watson N. H. Ceaglske 《Analytical and bioanalytical chemistry》1933,94(1-2):34-42
882.
An Efficient “One Pot” Synthesis of Isoflavones 总被引:1,自引:0,他引:1
Initial formation of deoxybenzoin 3 from phenyl acetic acid 1 and phenol 2 in the presence of BF3.Et2O followed by its treatment at room temperature with N, N'-dimethyl (chloromethylene) ammonium chloride, generated by reacting PCl5 with DMF provides a mild and efficient route for a “one pot” synthesis of Isoflavones in high yields. 相似文献
883.
S. V. Thakare A. G. C. Nair S. Chakrabarty B. S. Tomar 《Journal of Radioanalytical and Nuclear Chemistry》1999,242(2):537-539
An alternative reaction route for the production of111In from rhodium target bombarded with a12C beam has been developed. Sulfate fusion was adapted for dissolution of the irradiated rhodium metal target. Indium was coprecipitated
with La(OH)3 and purified by solvent extraction of the InBr3 complex into di-isopropyl ether and back extraction in 6M HCl. The chemical yield of the separation, determined using105Rh as tracer, was found to be above 90%. The radionuclidic purity of the separated111In satisfies the requirement prescribed for radiopharmaceutical preparations. The radioactivity yield achieved using this
route was about 0.2 MBq/μAh. 相似文献
884.
885.
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887.
Sharanya Nair 《Combustion Theory and Modelling》2020,24(2):279-306
Due to recent interest in methanol economy, it is seen that a numerical study of combustion of methanol in a comprehensive manner is necessary. Motivated from this interest and based on the studies from literature, a numerical study on prediction of structures of non-premixed methanol-air flames in laminar forced convective environment is reported. Two-dimensional, planar and axisymmetric, computational domains are considered. Corresponding governing equations for conservation of mass, momentum, species and energy have been solved using Ansys FLUENT. The numerical model incorporates multi-component diffusion, variable thermal and physical properties, a short chemical kinetics mechanism with 18 species and 38 elementary reactions, and a non-luminous thermal radiation model. Homogeneous flames in opposed flow and heterogeneous flames in cross-flow and co-flow configurations are studied. For heterogeneous flames, interface conditions at the liquid methanol surface are defined systematically using a user-defined function. Numerical results are validated against the experimental results available in literature. Results in terms of mass burning rates, flow, species and temperature fields have been presented to describe the flame characteristics. 相似文献
888.
A new class of hydrogels made from poly(vinyl alcohol) (PVA) and amino acid was formed into porous tissue engineering scaffolds by the colloidal gas aphron (CGA) method. CGA microfoams are formed using high speed stirring to generate uniform, micrometer scale bubbles. CGAs offer several advantages over conventional scaffold fabrication techniques including room temperature processing, aqueous conditions and utilization of air bubbles to create uniform pores. This technique eliminates the need for toxic solvents and salt templates. In addition, the novel poly(vinyl alcohol) hydrogels are inherently strong, eliminating the need for crosslinkers. 相似文献
889.
T. Balaji R. N. Acharya A. G. C. Nair A. V. R. Reddy K. S. Rao G. R. K. Naidu S. B. Manohar 《Journal of Radioanalytical and Nuclear Chemistry》2000,243(3):783-788
Elemental concentrations of a few medicinal leaves are determined by instrumental neutron activation analysis using the single comparator (k
0) method. Data obtained for neem leaves, collected from two different places, have been used to see the effect of soil condition. The applicability of the method particularly for the simultaneous determination of Ca, Mg, V and Al in biological matrices has been evaluated in terms of the detection limit, precision and accuracy. The method was validated by analysing the NIST Standard Reference Material (SRM-1571) and it was found that the elemental concentrations measured in SRM-1571 are within ±10% of the reported values. 相似文献
890.
A. G. C. Nair A. V. R. Reddy R. N. Acharya P. P. Burte S. B. Manohar 《Journal of Radioanalytical and Nuclear Chemistry》1999,240(3):877-881
A chemical neutron activation analysis method to determine trace amounts of palladium present in the uranium ores has been
developed. Palladium was concentrated on an anionic exchanger to purify from large amounts of uranium, iron and copper that
were present in the ore. The resin in which Pd was adsorbed was neutron irradiated and the activation product109Pd was assayed through its daughter109mAg by low energy photon spectrometry to estimate palladium. Both the 88 keV gamma-line and the 22 keV X-ray line (arising
out of the internal transition of109mAg) were used to arrive at the concentration values by a standard comparison technique. A thin window Si(Li) detector and
an HPGe detector were used for the radioactive assay. Detection limits and the advantage of using the X-ray line of Ag over
that of the gamma-line were discussed. An absolute detection limit of 0.12·10−9 g could be arrived at by the use of the 22.10 keV X-ray line in an interference-free condition. 相似文献