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91.
If is a weakly compactly generated (WCG) Banach space, then X admits an equivalent C1-smooth norm. If a WCG Banach space X admits a Ck-smooth function with bounded support, then X admits Ck-smooth partitions of unity. 相似文献
92.
A general method for calculating the electrochemical availability of a trace metal in a multi-ligand system is illustrated by calculations on lead in artificial seawater. The procedure adopted assumes that the metal is accumulated at a mercury-coated rotating disc electrode during the plating process by the reversible reduction of metal ions. Although uncertainties in the rate constants and stability constants employed prevent the model from being used predictively, qualitative relationships between chemical speciation and electrochemical availability are discussed. The sensitivity of the calculated electrochemical availability to uncertainties in the stability constants and rate constants and variations in diffussion layer thickness and pH is considered in some detail. The results of the calculations are used to formulate recommendations for the electrochemical analysis of untreated natural samples. 相似文献
93.
Lawrence L. Whitfield Eleftherios P. Papadopoulos 《Journal of heterocyclic chemistry》1981,18(6):1197-1201
N-Benzoylthioamides ( 1 ) react with hydrazines and hydroxylamine to form 1H-1,2,4-triazoles and 1,2,4-oxadiazoles, respectively. A similar treatment of the S-methyl derivatives of 1 with amidines leads to 1,3,5-triazines. Ethyl ZV-benzoylthiocarbamate undergoes analogous reactions to yield the corresponding ethoxyheterocycles. 相似文献
94.
Three novel vanadogermanate cluster anions have been synthesized by hydrothermal reactions. The cluster anions are derived from the (V(18)O(42)) Keggin cluster shell by substitution of V=O(2+) "caps" by Ge(2)O(OH)(2)(4+) species. In Cs(8)[Ge(4)V(16)O(42)(OH)(4)].4.7H(2)O, 1, (monoclinic, space group C2/c (No. 15), Z = 8, a = 44.513(2) A, b = 12.7632(7) A, c = 22.923(1) A, beta = 101.376(1) degrees ) and (pipH(2))(4)(pipH)(4)[Ge(8)V(14)O(50).(H(2)O)] (pip = C(4)N(2)H(10)), 2 (tetragonal, space group P4(2)/nnm (No. 134), Z = 2, a = 14.9950(7) A, c = 18.408(1) A), two and four VO(2+) caps are replaced, respectively, and each cluster anion encapsulates a water molecule. In K(5)H(8)Ge(8)V(12)SO(52).10H(2)O, 3, (tetragonal, space group I4/m (No. 87), Z = 2, a = 15.573(1) A, c = 10.963(1) A), four VO(2+) caps are replaced by Ge(2)O(OH)(2)(4+) species, and an additional two are omitted. The cluster ion in 3 contains a sulfate anion disordered over two positions. The cluster anions are analogous to the vanadoarsenate anions [V(18)(-)(n)()As(2)(n)()O(42)(X)](m)(-) (X = SO(3), SO(4), Cl; n = 3, 4) previously reported. 相似文献
95.
Robert J. Whitfield Suzanne E. Battom Miloš Barut David E. Gilham Philip D. Ball 《Journal of chromatography. A》2009,1216(13):2725-2729
To support effective process development there is a requirement for rapid analytical methods that can identify and quantitate adenoviral particles throughout the manufacturing process, from cellular lysate through to purified adenovirus. An anion-exchange high-performance liquid chromatography method for the analysis of adenovirus type 5 (Ad5) particles has been developed using a novel quaternary amine monolithic column (Bio-Monolith QA, Agilent). The developed method separates intact Ad5 from contaminating proteins and DNA, thus allowing analysis of non-purified samples during process development. Regeneration conditions were incorporated to extend the functional life of the column. Once developed, the method was qualified according to performance criteria of repeatability, intermediate precision and linearity. The linear working range of analysis was established between 7.5 × 108 to at least 2.4 × 1010 viral particles (3 × 1010 to 9.6 × 1011 viral particles/mL), with a correlation coefficient of 0.9992. Relative standard deviations (RSDs) for intra- and inter-day repeatability and precision for retention time and peak area were less than 1 and 2.5%, respectively. 相似文献
96.
97.
Chung P Ajitanand NN Alexander JM Anderson M Best D Brady FP Case T Caskey W Cebra D Chance JL Cole B Crowe K Das AC Draper JE Gilkes ML Gushue S Heffner M Hirsch AS Hjort EL Holzmann W Huo L Issah M Justice M Kaplan M Keane D Kintner JC Klay J Krofcheck D Lacey RA Lauret J Lisa MA Liu H Liu YM Milan J McGrath R Milosevich Z Odyniec G Olson DL Panitkin S Porile NT Rai G Ritter HG Romero JL Scharenberg R Srivastava B Stone NT Symons TJ Taranenko A Whitfield J Wienold T Witt R Wood L Zhang WN 《Physical review letters》2003,91(20):202301
The yield for the multistrange Xi(-) hyperon has been measured in 6A GeV Au+Au collisions via reconstruction of its decay products pi(-) and Lambda, the latter also being reconstructed from its daughter tracks of pi(-) and p. The measurement is rather close to the threshold for Xi(-) production and therefore provides an important test of model predictions. The measured yield for Xi(-) and Lambda are compared for several centralities. In central collisions the Xi(-) yield is found to be in excellent agreement with statistical and transport model predictions, suggesting that multistrange hadron production approaches chemical equilibrium in high baryon density nuclear matter. 相似文献
98.
Chung P Ajitanand NN Alexander JM Anderson M Best D Brady FP Case T Caskey W Cebra D Chance JL Cole B Crowe K Das AC Draper JE Gilkes ML Gushue S Heffner M Hirsch AS Hjort EL Holzmann W Huo L Issah M Justice M Kaplan M Keane D Kintner JC Klay J Krofcheck D Lacey RA Lauret J Lisa MA Liu H Liu YM McGrath R Milosevich Z Odyniec G Olson DL Panitkin S Porile NT Rai G Ritter HG Romero JL Scharenberg R Srivastava B Stone NT Symons TJ Taranenko A Whitfield J Witt R Wood L Zhang WN Brown D Pratt S 《Physical review letters》2003,91(16):162301
Source images are extracted from two-particle correlations constructed from strange and nonstrange hadrons produced in 6A GeV Au+Au collisions. Very different source images result from pp vs p Lambda vs pi(-)pi(-) correlations. Scaling by transverse mass can describe the apparent source size ratio for p/pi(-) but not for Lambda/pi(-) or Lambda/p. These observations suggest important differences in the space-time emission histories for protons, pions, and neutral strange baryons produced in the same events. 相似文献
99.
100.
We report observations of 63Cu NQR in CuF2, KCuF3, and RbCuF3 in the paramagnetic state, NQR line widths of 63Cu in CuF2 and CuBr2 and of 81Br in CuBr2, SnBr2 and ZnBr2. The NQR resonances of certain Cu (II) paramagnetic compounds are exchange-narrowed to values commensurate with linewidths of the diamagnetic infinite-lattice compounds. 相似文献