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991.
992.
993.
Sample preparation methods and data acquisition protocols were optimized for the application of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) to high-throughput quantitative analysis of low molecular mass substrates and products of an enzyme-catalyzed reaction. Using a deuterlum-labeled internal standard, precise standard curves were obtained (r(2) = 0.9998) over two orders of magnitude of concentration of rac-1-phenylethylamine (PEA), which is converted to 2-methoxy-N-[(1R)-1-phenylethyl]acetamide (MET) by a lipase-catalyzed reaction with ethylmethoxyacetate (EMA) as second substrate. Reliable relative standard deviations were achieved (< or =5%) using automated analysis with peak intensity ratios between 0.2 and 5 of analyte to internal standard. This method permitted quantitative analysis of the lipase reaction, producing results comparable to those from gas chromatographic (GC) analysis in the dynamic range of GC. This work shows that MALDI-TOFMS can be applied for the high-throughput screening of enzymes. 相似文献
994.
In this paper we give a realization of crystal bases for quantumaffine algebras using some new combinatorial objects which wecall the Young walls. The Young walls consist of colored blockswith various shapes that are built on a given ground-state walland can be viewed as generalizations of Young diagrams. Therules for building Young walls and the action of Kashiwara operatorsare given explicitly in terms of combinatorics of Young walls.The crystal graph of a basic representation is characterizedas the set of all reduced proper Young walls. The characterof a basic representation can be computed easily by countingthe number of colored blocks that have been added to the ground-statewall. 2000 Mathematical Subject Classification: 17B37, 17B65,81R50, 82B23. 相似文献
995.
LongGuangHE DeShouZHONG 《数学学报(英文版)》2003,19(4):745-756
In this paper,some properties of reduction for symplectic F-spaces are discussed.The properties of stable subgroups are discussed.We find that the symplectic action of a symplectic groupoid on a symplectic manifold can induce a symplectic map between reduced symplectic manifolds.This symplectic action can be characterized by the action of its induced symplectic groupoid on a symplectic manifold.Lastly,we shall discuss Poisson reduction and give a Poisson reduction theorem. 相似文献
996.
We have tuned the whispering-gallery modes of a fused-silica microresonator over nearly 1 nm at 800 nm, i.e., over half a free spectral range, or 10(6) linewidths of the resonator. This result has been achieved by use of a new method based on the stretching of a two-stem microsphere. We describe devices that will permit new cavity QED experiments with this high- Q optical resonator when it is desirable to optimize its coupling to emitters with given transition frequencies. The demonstrated tuning capability is compatible with both UHV and low-temperature operation, which should be useful for future experiments with laser-cooled atoms or single quantum dots. 相似文献
997.
Baryon rapidity loss in relativistic Au + Au collisions 总被引:4,自引:0,他引:4
Back BB Betts RR Chang J Chang WC Chi CY Chu YY Cumming JB Dunlop JC Eldredge W Fung SY Ganz R Garcia E Gillitzer A Heintzelman G Henning WF Hofman DJ Holzman B Kang JH Kim EJ Kim SY Kwon Y McLeod D Mignerey AC Moulson M Nanal V Ogilvie CA Pak R Ruangma A Russ DE Seto RK Stanskas PJ Stephans GS Wang HQ Wolfs FL Wuosmaa AH Xiang H Xu GH Yao HB Zou CM 《Physical review letters》2001,86(10):1970-1973
An excitation function of proton rapidity distributions for different centralities is reported from AGS Experiment E917 for Au+Au collisions at 6, 8, and 10.8 GeV/nucleon. The rapidity distributions from peripheral collisions have a valley at midrapidity which smoothly change to distributions that display a broad peak at midrapidity for central collisions. The mean rapidity loss increases with increasing beam energy, whereas the fraction of protons consistent with isotropic emission from a stationary source at midrapidity decreases with increasing beam energy. The data suggest that the stopping is substantially less than complete at these energies. 相似文献
998.
We studied the mutual information between a stimulus and a system consisting of stochastic, statistically independent elements that respond to a stimulus. Using statistical mechanical methods the properties of the mutual information (MI) in the limit of a large system size N are calculated. For continuous valued stimuli, the MI increases logarithmically with N and is related to the log of the Fisher information of the system. For discrete stimuli the MI saturates exponentially with N. We find that the exponent of saturation of the MI is the Chernoff distance between response probabilities that are induced by different stimuli. 相似文献
999.
Georgia Benkart Seok-Jin Kang Masaki Kashiwara 《Journal of the American Mathematical Society》2000,13(2):295-331
A crystal base theory is introduced for the quantized enveloping algebra of the general linear Lie superalgebra , and an explicit realization of the crystal base is given in terms of semistandard tableaux. 相似文献
1000.