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161.
162.
Recent Gaussian-effective-potential results for “autonomous”λΦ 4 theory, an apparently nontrivial, positive-λ, 3+1 dimensional theory, are extended to include a Yukawa coupling to fermions. The formerly massless bosons of the symmetric phase acquire a mass. 相似文献
163.
P.M. Stevenson 《Physics letters. [Part B]》1981,100(1):61-64
Next-to-leading-order QCD predictions depend on the arbitrary choice of renormalisation scheme. I resolve this ambiguity and show how to find the unique, optimum prediction, given the result in some arbitrary, initial scheme. 相似文献
164.
The rates of gas-phase thermolysis reactions of 2-acetylcyclopentanone 1,2-acetylcyclohexanone 2, N-acetylcaprolactam 3,2-acetylbutyrolactone 4,2-acetyl-2-methylbutyrolactone 5, and 3-acetyl-2-oxazolidinone 6 have been measured over a temperature range of 50 K. They undergo unimolecular first-order elimination reactions for which log A = 11.7, 11.7, 11.2, 11.4, 11.5, and 11.1 s?1 and Ea = 193.4, 189.5, 153.2, 201.0, 206.8, and 176.1 kJ mol?1, respectively. The effect of the ring size together with the effect of a heteroatom in the ring on the rate of thermolysis reactions for compound 1–6 is the subject of this work. © 1995 John Wiley & Sons, Inc. 相似文献
165.
A stereoselective synthesis procedure for lignans of the all-trans αα'-diaryl-ββ'-dimethyltetrahydrofurans is described. The lignans, galbelgin (4) and grandisin (37) were synthesized by routine reduction of the tetrahydrofuran dicarboxylic esters (24 and 34), obtained by mild acid treatment of the readily available diaryl dilactones (23 and 33). 相似文献
166.
D.J. Stevenson 《Physics letters. A》1976,58(4):282-284
Binary alloys in which all the electrons form a uniform, degenerate, non-relativistic gas are predicted to exhibit miscibility gaps. Approximate analytical formulae are given for the critical temperatures and compositions. Astrophysical implications are mentioned. 相似文献
167.
Rob Stevenson 《Numerische Mathematik》1993,66(1):373-398
Summary We analyse multi-grid applied to anisotropic equations within the framework of smoothing and approximation-properties developed by Hack busch. For a model anisotropic equation on a square, we give an up-till-now missing proof of an estimate concerning the approximation property which is essential to show robustness. Furthermore, we show a corresponding estimate for a model anisotropic equation on an L-shaped domain. The existing estimates for the smoothing property are not suitable to prove robustness for either 2-cyclic Gauss-Seidel smoothers or for less regular problems such as our second model equation. For both cases, we give sharper estimates. By combination of our results concerning smoothing- and approximation-properties, robustness of W-cycle multi-grid applied to both our model equations will follow for a number of smoothers. 相似文献
168.
A relationship is derived between CN concentration and atomization efficiency in the C2H2-N2O flame. The relationship is examined under various experimental conditions and β values are estimated for a number of elements. The possibility of complex vapour phase oxide formation by U is considered. 相似文献
169.
An artefact caused by the binding of protein to dextran gel 总被引:1,自引:0,他引:1
G T Stevenson 《Journal of chromatography. A》1968,37(1):116-117
170.
The crystallization behavior of two Cu60Ti40 amorphous alloys, one prepared by a vapor-quench (VQ) process and one by a liquid-quench (LQ) process, has been studied using differential scanning calorimetry, X-ray diffraction, and transmission electron microscopy. Microstructural studies show that the two alloys have the same transformation sequence under similar annealing conditions. However DSC measurements of the crystallization temperature during isochronal annealing and of the incubation time for crystallization during isothermal annealing show that the LQ alloy is more thermally stable and therefore more structurally relaxed. TEM analysis of the partially annealed microstructures gives some insight into the mode of crystal nucleation and growth as a function of temperature. During isothermal annealing significant differences are observed for the two alloys in the shape and orientation of the crystals and in the crystal structure formed. Whereas the VQ alloy transforms polymorphicaly into the intermetallic Cu3Ti2, the LQ alloy forms the Ti-rich phase, Cu4Ti3. The two phases are closely related in structure and composition. The differences observed for the two alloys are discussed in terms of greater structural relaxation and short range order in the LQ alloy resulting from the mode of synthesis. 相似文献