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71.
72.
We consider global solutions of the nonlinear Schrödinger equation
相似文献
73.
The thermally stable solids Re2(CO)8[μ-InRe(CO)5]2 and Re4(CO)12[μ3-InRe(CO)5]4 could be obtained by treatment of In with Re2(CO)10 in a bomb tube. A mechanism of the formation of the latter cluster from the first one is proposed. Compared with Re2(CO)8[μ-InRe(CO)5]2, Re4(CO)12[μ3_InRe(CO)5]4 shows in polar solvents an unusual high stability, which can be explained by the higher coordination number of In with rhenium carbonyl ligands. Re4(CO)12-[μ3-InRe(CO)5]4 dissolves monomerically in acetone, where as Re2(CO)8[μ-InRe(CO)5]2 dissociates yielding Re(CO)5? anions. Single-crystal X-ray analyses of Re4(CO)12[μ3-InRe(CO)5]4 establish the metal skeleton. The central molecular fragment Re4(CO)12 contains a tetrahedral arrangement of four bonded Re atoms [ReRe 302.8 (5) pm]. The triangles of this fragment are capped with a μ3-InRe(CO)5 group each [InRe(terminal) 273.5 (7) pm; InRe (polyhedral) 281.8 (7) pm]. The bridging type of In atoms with the Re4 tetrahedron and the metal skeleton was realized for the first time. By treating Re4(CO)12[μ3-InRe(CO)5]4 with Br2 the existence of Re(CO)5 ligands could be proved by isolating BrRe(CO)5. 相似文献
74.
The effects of gamma irradiation on the microbiological, physical and sensory qualities of diced tomatoes 总被引:1,自引:0,他引:1
Anuradha Prakash Jacqueline Manley Suresh DeCosta Fred Caporaso Denise Foley 《Radiation Physics and Chemistry》2002,63(3-6):387-390
Diced Roma tomatoes were treated with gamma irradiation and evaluated for changes in microbial, physical, chemical and sensory properties. Dosages for Trial 1 were 0.0, 0.39, 0.56 and 1.82 kGy and in Trial 2, 0.0, 0.50, 1.24 and 3.70 kGy. Irradiation at 3.70 kGy resulted in no aerobic populations through day 12 and significantly fewer colonies through day 15 whereas yeast and mold populations experienced a 2 log reduction through day 12. Color, titratable acidity, and °Brix were not significantly affected by irradiation. Tissue firmness decreased with increasing dose but not with storage time. Treatment with 3.7 kGy decreased firmness by 50% and 20% with 0.5 kGy, however, the reduced firmness induced by 0.50 kGy was undetected by a 9 member trained sensory panel. A significant (p0.05) inverse correlation between changes in texture and water-soluble pectin (WSP) was determined while total pectin remained relatively constant and oxalate soluble pectin content decreased slightly with irradiation dose. The significant inverse correlation between the loss of firmness and WSP indicates that the changes in WSP play an important role in the tissue softening of tomatoes, This study indicates that irradiation at 0.5 kGy can reduce microbial counts substantially to improve microbial shelf life without adverse effects on sensory qualities. 相似文献
75.
Joseph Glover 《Probability Theory and Related Fields》1981,56(1):133-144
Summary Let X be a strong Markov process. Let M be an optional set with the property that 1MoT
(S)=1
M
(s+T) whenever s>0 and T is an optional time with [T]M. If L=sup{t>0 tM}M, we show that L is a splitting time of X: the pre-L events and the post-L events are conditionally independent given X
L
. To prove this, we extend work of Sharpe's to show that the big shift operators
T
and
commute with optional projection and dual optional projection, respectively, whenever T is an optional time. Examples are given which are not contained within previous work of Millar and Getoor. 相似文献
76.
Andrzej Chmura Sven Rustler Monica Paravidino Fred van Rantwijk Andreas Stolz Roger A. Sheldon 《Tetrahedron: Asymmetry》2013,24(19):1225-1232
Enantiomerically pure (S)-mandelic acid was synthesised from benzaldehyde by sequential hydrocyanation and hydrolysis in a bienzymatic cascade at starting concentrations up to 0.25 M. A cross-linked enzyme aggregate (CLEA) composed of the (S)-selective oxynitrilase from Manihot esculenta and the non-selective nitrilase from Pseudomonas fluorescens EBC 191 was employed as the biocatalyst. The nitrilase produces approx. equal amounts of (S)-mandelic acid and (S)-mandelic amide from (S)-mandelonitrile under standard conditions, but we surprisingly found that high (up to 0.5 M) concentrations of HCN induced a marked drift towards amide production. By including the amidase from Rhodococcus erythopolis in the CLEA we obtained (S)-mandelic acid as the sole product in 90% yield and >99% enantiomeric purity. 相似文献
77.
M. Fred Hoover 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(6):1327-1418
This paper is a literature survey of quaternary ammonium, sulfonium, and phosphonium polymers. 相似文献
78.
79.
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