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31.
Richard E Norton 《Annals of Physics》1980,130(1):14-69
By extending methods previously used to study the equations of state at low temperature, it is shown that the entropy density and the statistical average of a conserved, non-spontaneously violated, charge density can be expanded in terms of integrals over products of many body n-point amplitudes defined for real, continuous frequencies. The general structure of the expansions is described, and it is demonstrated that essentially the same spectral function determines the entropy density and the average charge densities. Certain classes of terms are worked out in detail, and the formal sum of one such class is shown to provide the contributions to the equations of state arising from composite quasiparticles associated with the poles of the n-point amplitudes. [Another term, discussed in many previous works, involves the logarithms of the elementary propagators and yields the contributions to the equations of state coming from elementary quasiparticles.]The Appendices include an extensive study of the analytic properties of many body amplitudes in the frequencies of the external and internal lines. Specialized to zero temperature, these considerations apply to the Feynman diagrams for elementary particle amplitudes. 相似文献
32.
Salluzzo M Palomba F Pica G Andreone A Maggio-Aprile I Fischer O Cantoni C Norton DP 《Physical review letters》2000,85(5):1116-1119
We report on a study on the effect of Nd/Ba disorder on the ab-plane penetration depth of epitaxial Nd(1+x)Ba(2-x)Cu(3)O(7-delta) thin films. While in stoichiometric samples lambda(T) at low temperature is linear, Nd-rich films exhibit a quadratic law. For low Nd excess (x<0.04), a satisfying fit is obtained using the "dirty" d-wave model assuming that Nd ions at Ba sites act as strong scattering centers. At high x (x>0.15) the data are explained if Nd/Ba disorder becomes less effective as a source of scattering. The effect of localization has been discussed to account for the experimental results. 相似文献
33.
Ice nucleating-active Pseudomonas fluorescens F264C was fed to Colorado potato beetles to determine bacterial retentioin in the beetle gut and its effect on the cold hardiness of this insect pest. The bacrterium was present in beetles recovered after overwintering in the field, seven months after their exposure to P. fluorescens. Retention was evident not only in the detection of the P. fluorescens ice nucleating gene, inaW, in bacterial cultures from beetle guts but also in the elevated supercooling points of some treated beetles. 相似文献
34.
This paper presents a simulation and an analytical modeling of the machine interference problem in manufacturing cells. Each machine experiences two types of stoppage which are to be served by a robot. Several combinations of the distributions of the stoppages, service distributions, and service disciplines are studied. We determine the optimal number of machines assigned to the robot under different operating conditions such that the expected total cost of the manufacturing cell is minimized.This research is based on Mr. Norton's M.S. thesis, which was conducted at Rutgers. 相似文献
35.
Norton P. Peet 《Journal of heterocyclic chemistry》1989,26(3):713-716
A synthetic route to 5-substituted 3-(1H-tetrazol-5-yl)pyrazolo[1, 5-a]quinazolines is described. An unexpected displacement of a 4-morpholinyl group from the 5-position of this system occurred during tetrazole formation by the ammonia produced by in situ generation of hydrazoic acid from ammonium chloride and sodium azide. 相似文献
36.
G. W. Pearce L. B. Norton und P. J. Chapman 《Fresenius' Journal of Analytical Chemistry》1938,112(5-6):235-236
Ohne Zusammenfassung 相似文献
37.
38.
E. Nihoul G. Vortmann C. Meineke G. Lunge P. Naef Th. Salzer E. Kock W. Younger L. M. Norton M. Rosenbaum W. Spring Ed. Bourgeois N. Sokolow P. Maltschewski R. Otto C. Friedheim Fr. Stolba G. Linossier M. Lignon W. Gathorne Young R. Kayser H. Offermann A. Carnot V. Gasselin Th Petersen 《Analytical and bioanalytical chemistry》1896,35(1):200-211
39.
Yao S Hinds MG Murphy JM Norton RS 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2011,211(2):243-247
Conformational or chemical exchange can cause significant sensitivity loss in NMR spectroscopy through resonance broadening for nuclear spins involved in these processes. While this effect may sometimes be alleviated by manipulating experimental conditions such as temperature, pH, and buffers, conditions optimal for all resonances are not always achievable. As a consequence, any means of recovering or minimizing this exchange-induced sensitivity loss is potentially of significant value in regaining information otherwise lost. We report the experimental observation of significant sensitivity gain for nuclear spins undergoing chemical exchange with solvent (water) at exchange rates ca 1-10 s(-1) in (1)H-(15)N correlation spectra of proteins acquired with band-selective pulses (the SOFAST-HMQC sequence). 相似文献
40.
A single kinetic mechanism for methanol pyrolysis is tested against multiple sets of experimental data for the first time. Data are considered from static, flow, and shock tube reactors, covering temperatures of 973 to 2000 K and pressures of 0.3 to 1 atmosphere. The model results are highly sensitive to the rates of unimolecular fuel decomposition and of various chain termination reactions that remove CH2OH and H radicals, as well as to experimental temperature uncertainties. The secondary fuel decomposition reaction CH3OH = CH2OH + H, which has previously been included only in mechanisms for high temperature conditions, is found to have a significant effect at low temperatures as well, through radical recombination. The reaction CH3O + C = CH3 + CO2, rather than CH3OH + H = CH3 + H2O, is found to be the dominant source of CH3 at low temperatures. The reverse of CH3 + OH = CH2OH + H is important to CH3 production at high temperatures. 相似文献