排序方式: 共有59条查询结果,搜索用时 15 毫秒
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Parsons W.M. Ballard E.O. Bartsch R.R. Benage J.F. Bennett G.A. Bowers R.L. Bowman D.W. Brownell J.H. Cochrane J.C. Davis H.A. Ekdahl C.A. Gribble R.F. Griego J.R. Goldstone P.D. Jones M.E. Hinckley W.B. Hosack K.W. Kasik R.J. Lee H. Lopez E.A. Lindemuth I.R. Monroe M.D. Moses R.W. Jr. Ney S.A. Platts D. Reass W.A. Salazar H.R. Sandoval G.M. Scudder D.W. Shlachter J.S. Thompson M.C. Trainor R.J. Valdez G.A. Watt R.G. Wurden G.A. Younger S.M. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1997,25(2):205-211
Atlas is a facility being designed at Los Alamos National Laboratory (LANL) to perform high-energy-density experiments in support of weapon physics and basic research programs. It is designed to be an international user facility, providing experimental opportunities to researchers from national laboratories and academic institutions. For hydrodynamic experiments, it will be capable of achieving a pressure exceeding 30 Mbar in a several cubic centimeter volume. With the development of a suitable opening switch, it will be capable of producing more than 3 MJ of soft X-rays. The capacitor bank design consists of a 36 MJ array of 240 kV Marx modules. The system is designed to deliver a peak current of 45-50 MA with a 4-5-μs rise time. The Marx modules are designed to be reconfigured to a 480-kV configuration for opening switch development. The capacitor bank is resistively damped to limit fault currents and capacitor voltage reversal. An experimental program for testing and certifying prototype components is currently under way. The capacitor bank design contains 300 closing switches. These switches are a modified version of a railgap switch originally designed for the DNA-ACE machines. Because of the large number of switches in the system, individual switch prefire rates must be less than 10-4 to protect the expensive target assemblies. Experiments are under way to determine if the switch-prefire probability can be reduced with rapid capacitor charging 相似文献
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The tandem 1,3-dipolar cycloaddition between sydnones and 1,5-cyclooctadiene provides 9,10-diazatetracyclo[6.3.0.0.4,110.5,9]undecanes (the Weintraub reaction) in modest to good yields. 相似文献
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Honda T Favaloro FG Janosik T Honda Y Suh N Sporn MB Gribble GW 《Organic & biomolecular chemistry》2003,1(24):4384-4391
Novel tricyclic compounds with enone functionalities in rings A and C [tricyclic-bis-enone (TBE) compounds] were designed on the basis of the structure of a synthetic triterpenoid, 2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oic acid (CDDO)(1), which is a promising drug candidate for prevention and/or treatment of cancer and inflammatory diseases whose pathogenesis may involve excessive production of nitric oxide (NO) and/or prostaglandins. A series of TBE compounds in racemic form shows high inhibitory activity against production of NO induced by interferon-[gamma](IFN-[gamma]) in mouse macrophages. One of these compounds, (+/-)-(4a[small beta],8a[small beta],10a[small alpha])-1,2,4a,6,8a,9,10,10a-octahydro-1,1,4a,8a-tetramethyl-2,6-dioxophenanthrene-3,7-dicarbonitrile ((+/-)-3), is orally active at 15 mg kg(-1)(single administration) in a preliminary study using mouse peritoneal inflammation induced by thioglycollate and IFN-[gamma]. Therefore, we desired to synthesize optically active TBE compounds for a comparison of the biological potency of both enantiomers. We now describe the synthesis of both enantiomers of (4a[small beta],8a[small beta],10a[small alpha])-1,2,4a,6,8a,9,10,10a-octahydro-1,1,4a,8a-tetramethyl-2,6-dioxophenanthrene-3-carbonitrile (2) and 3 from commercially available simple compounds. Interestingly, (+)-3 having the same configuration as the CDDO antipode shows about 10 times higher inhibitory activity than (-)-3 on NO production in mouse macrophages. In contrast, (-)-3 inhibits proliferation of MCF-7 breast cancer cells, whereas (+)-3 does not. 相似文献
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J. D. Gribble 《BIT Numerical Mathematics》1977,17(4):392-408
An inner product quadrature formula is of the form $$\int_{ - 1}^1 {w(x)f(x)g(x)dx \cong \sum\limits_{i = 0}^m {\sum\limits_{j = 0}^n {f(x_i )a_{ij} g(y_j ) = f^T Ag.} } } $$ Conditions are established for which these quadrature formulas are exact whenf andg are polynomials of degree not greater thanm+k andn?l (also, analogouslym?k andn+l) respectively. The structure and properties of the matrixA are also considered. 相似文献
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David H. Blank Gordon W. Gribble John S. Schneekloth Jr. Jerry P. Jasinski 《Journal of chemical crystallography》2002,32(12):541-546
Crystal structure determinations of the three title hexahalogenated bipyrroles, (I) C10H6Br6N2, (II) C10H6Br4Cl2N2, and (III) C10H6Cl6N2, reveal essentially planar pyrrole rings having dihedral angles of 64.7, 65.1, and 64.2° between the least-squares planes, favoring in each case a closer methyl–halogen conformation. All three complexes crystallize in the orthorhombic space group Pbcn with the following cell dimensions: (I) a = 12.654(3) Å, b = 8.853(2) Å, c = 13.753(3) Å, = = = 90°, Z = 4; (II) a = 12.438(6) Å, b = 8.753(6) Å, c = 13.696(3) Å, = = = 90°, Z = 4; (III) a = 12.088(6) Å, b = 8.566(4) Å, c = 13.486(8) Å, = = = 90°, Z = 4. 相似文献
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Justin M. Lopchuk William L. Montgomery Jerry P. Jasinski Sayeh Gorjifard Gordon W. Gribble 《Tetrahedron letters》2013
2-Cyanoindole and N-methyl-2-cyanoindole undergo manganese(III)-mediated radical addition with activated methylene and methine compounds. Products of the methylene addition underwent additional oxidation during the course of the reaction to furnish the corresponding acetoxy compounds. Several structures were confirmed by X-ray crystallography. 相似文献
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An efficient one-pot synthesis of pyrrolylamides and pyrrolylimides is described under mild reaction conditions by the catalytic hydrogenation of 2- and 3-nitropyrroles. 相似文献
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Justin M. LopchukGordon W. Gribble 《Tetrahedron letters》2011,52(32):4106-4108
A variety of 2-, 3-, and 4-pyridylpyrroles were synthesized in good to excellent yields via the 1,3-dipolar cycloaddition of symmetrical and unsymmetrical münchnones and nitroalkenes. The unsymmetrical münchnones show moderate to excellent regioselectivity. 相似文献