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Sidney Coleman 《Communications in Mathematical Physics》1977,55(2):113-116
I show that there are no finite-energy non-singular solutions of classical Yang-Mills theory in four-dimensional Minkowski space that do not radiate energy out to spatial infinity. Finite-energy non-singular solutions that are either static or periodic in time, are a fortiori non-radiant; thus this generalizes earlier theorems that state that there are no such solutions.Research supported in part by the National Science Foundation under Grant No. PHY75-20427 相似文献
54.
Sidney W. Benson 《国际化学动力学杂志》1992,24(3):217-237
The literature on the pyrolysis of acetylene below 1000 K is reviewed and it is shown that the reaction is a radical chain polymerization initiated by H atoms. The induction period is examined and shown to arise from a rapid autocatalysis produced by the very first product, vinyl acetylene. Data from studies of acetylene polymerization induced by vinyl acetylene and styrene are examined and shown to be in good qualitative agreement with the radical chain process presented. Measured and where needed, estimated rate constants are given to produce numerical estimates of chain length, rates of polymerization, induction period, and rates of initiation. It is further shown that all the products of the polymerization are capable of efficiently initiating chains in the system. An examination of the possible kinetics of vinylidene shows that it does not play any role in acetylene chemistry. 相似文献
55.
Pier Luigi Stanghellini Livio Cognolato György Bor Sidney F. A. Kettle 《Journal of chemical crystallography》1983,13(2):127-133
13C-enriched carbido carbonyl clusters of the type [M6C(CO) n ] z? (M=Fe,n=16,z=2; M=Ru,n=16 ifz=2 andn=17 ifz=0) have been prepared and their IR spectra observed in the 900?600 cm?1 region; the band shifts occurring upon13 C substitution enable the assignment to the stretching modes of the interstitial C atom. Band patterns reflect the symmetry of the M6C core, but the frequencies seem dependent on other molecular features. 相似文献
56.
Data on the kinetics of S2F10 pyrolysis, which gives SF4 + SF6, have been reinterpreted to give a value for the equilibrium constant of S2F10 ? SF4 + SF6. This, together with statistical estimates of the entropy and heat capacity of S2F10, can be used to give for this reaction values of ΔH = 19.7 ± 1.0 kcal/mole and ΔS = 47.6 ± 2 gibbs/mole. ΔH(S2F10) = –494 kcal/mole. A compatible mechanism is shown to be S2F10 ? 2SF5 (fast); 2SF5 ? SF6 + SF4 (slow) with step 2 rate-determining. The overall, best first order rate constant is proposed as kmeas = 1017.42–43.0/θ sec?1 = K1k2, where θ = 2.303RT in kcal/mole. Independent measurements of δH and S° for the SF5 radical, permits the evaluation of the equilibrium constant K1 = 108.92–(27.1 ± 6)/θ l./mole-sec and yields k2 = 108.50–15.9/θ l./mole-sec. The observed homogeneous catalysis by NO and CHCl ? CHCl can be explained in terms of a direct abstraction of F from S2F10 : C + S2F10 → CF + S2F9, followed by S2F9 → SF5 + SF4 and SF5 + CF ? SF6 + C (C ? NO or C2H2Cl2). 相似文献
57.
Limit theory for multivariate sample extremes 总被引:4,自引:0,他引:4
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The sign of the single-particle exchange nucleon force due to ρ°-ω mixing is shown on experimental and theoretical grounds to make the resulting charge asymmetric potential, Vnn ? Vpp in the 1S0 state, attractive. The sign agrees quite well with the binding energy difference in the A = 3 mirror nuclei and is not inconsistent with present knowledge of NN scattering lengths, predicting . 相似文献
60.
Numerical results for the density and current correlation functions in dense hard-sphere fluids are obtained from a kinetic equation which is the extension of the linearized Enskog equation to finite wavelengths in order to demonstrate the convergence of the method of solution. Comparison is made to a previously proposed approximate solution.This work was performed in part under the auspices of the U.S. Department of Energy by the Lawrence Livermore Laboratory under contract number W-7405-ENG-48 and in part supported by the National Science Foundation. 相似文献