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941.
The total attenuation cross-sections in elements 6?Z?82 forK α andK β groups of lines of elements Zr, Sn and Ba andL l ,L α,L β andL γ groups of lines of the elements Au, Pb, Th and U have been measured. The experimentally measured attenuation cross-sections have been found in good agreement with the theoretical estimates. 相似文献
942.
943.
Sarangthem Joychandra Singh 《Tetrahedron letters》2008,49(25):3991-3994
Regioselective allylation of enaminones using CuCl2 as the catalyst to give C-allylated products is reported for the first time. The C-allylated products undergo hydrolysis followed by a rearrangement yielding β-keto allyl enamides in excellent yields. 相似文献
944.
945.
Vadapalli Chandrasekhar Palani Sasikumar Puja Singh Ramalingam Thirumoorthi Tapas Senapati 《Journal of Chemical Sciences》2008,120(1):105-113
Organostannoxane cages and aggregates of well-defined composition and structure can be prepared by the reactions of organotin
oxides or organotin oxide-hydroxides with protic acids. The utility of this strategy for the preparation of dendrimer-like
molecules containing a stannoxane core and a functional periphery is described. 相似文献
946.
S. Shylesh Prinson P. Samuel Sheetal Sisodiya A. P. Singh 《Catalysis Surveys from Asia》2008,12(4):266-282
Micelle-templated mesoporous and organic–inorganic hybrid mesoporous materials are important in many fields of material research,
especially for hosting catalysts in confined space. Among this class, the recent discovery of periodic mesoporous organosilicas
(PMOs) represent an exciting new group of organic–inorganic nanocomposites targeted for a broad range of applications ranging
from catalysis to microelectronics. Compared to the earlier generation of organic–inorganic hybrid mesoporous samples, obtained
by the cocondensation reaction or by the grafting reaction, PMOs represent the right combination of organic and inorganic
groups in the frame wall positions. This article reviews the current state of art in organic–inorganic hybrid mesoporous material
research with special emphasis over periodic mesoporous organosilica materials having various redox centers (Ti, V, Cr) suitable
for oxidation reactions as well as acidic sites (Al, –SO3H) for the organic transformation of bulky molecules. 相似文献
947.
An expedient route to tetracyclo[6.5.2.02,7.09,13]pentadec-2(7),11-dien-14-one and tetracyclic framework of conidiogenol have been reported. Cycloaddition of annulated cyclohexa-2,4-dienone with cyclopentadiene, photochemical oxa-di-π-methane reaction and a highly unusual dehalogenation of bridgehead halogen are the key features of our methodology. 相似文献
948.
The data on the excitation functions of20Ne(16O,12C)24Mg,20Ne(16O,12C)24Mg*(1.37, 2+),20Ne(16O,12C)24Mg*(4.12, 4++4.24, 2+) +20Ne(16O,12C*(4.44, 2+))24Mg,20Ne(16O,12C)24Mg*(6.01, 4++6.43, 0+),20Ne(16O,20Ne)16O,20Ne(16O,20Ne*(1.63, 2+))16O, and20Ne(16O,20Ne*(4.25, 4+))16O reactions atθ lab=13° fromE c.m.=22.8 to 38.6 MeV have been subjected to a statistical analysis comprising of the calculations of the distribution of cross sections, deviation functions, cross-correlation functions, summed excitation functions, cross-channel correlation coefficients and coherence widths. The analysis confirms the existence of nonstatistical structures atE c.m.=24.6, 27.8, 31.7 and 35.5 MeV, and identifies a new structure of the same nature atE c.m. =25.6 MeV. 相似文献
949.
950.
Summary The product-limit estimator and its quantile process are represented as i.i.d. mean processes, with a remainder of ordern
–3/4(logn)3/4 a.s. Corresponding bootstrap versions of these representations are given, which can help one visualize how the bootstrap procedure operates in this set up.Research supported by NSF grants MCS-81-02341 and MCS 83-01082 相似文献