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991.
The temperature independent esr spectrum of di-i-Propyl-t-butylmethyl radical, derived from photolysis of oxalate ester, indicates a frozen “cogwhell” conformation for this specie. The neo-pentyl substituted oxalate esters are suggested to qive β-hydrogen abstraction on presence of di-t-butylperoxide on photolysis. 相似文献
992.
993.
994.
Stochastic integer programs are notoriously difficult. Very few properties are known and solution algorithms are very scarce. In this paper, we introduce the class of stochastic programs with simple integer recourse, a natural extension of the simple recourse case extensively studied in stochastic continuous programs.Analytical as well as computational properties of the expected recourse function of simple integer recourse problems are studied. This includes sharp bounds on this function and the study of the convex hull. Finally, a finite termination algorithm is obtained that solves two classes of stochastic simple integer recourse problems.Supported by the National Operations Research Network in the Netherlands (LNMB). 相似文献
995.
关于两类污染数据回归分析的参数估计 总被引:21,自引:0,他引:21
研究简单回归模型:yj=a+βxj+εj,j=1,2,…,n,其中Eεj=0,Eε^2j=σ^2j;但y1,y2,…,yn受到另一独立同分布随机变量序列t,t2,…,tn两种不同方式的污染,tj与yj独立。本文给出了两种污染方式下的a、β和污染参数的估计。 相似文献
996.
997.
V. Devesa M. A. Súer V. W.‐M. Lai S. C. R. Granchinho J. M. Martínez D. Vlez W. R. Cullen R. Montoro 《应用有机金属化学》2002,16(3):123-132
The arsenic species present in samples of the crayfish Procambarus clarkii caught in the area affected by the toxic mine‐tailing spill at Aznalcóllar (Seville, Southern Spain) were analyzed. The total arsenic contents ranged between 1.2 and 8.5 µg g?1 dry mass (DM). With regard to the different species of arsenic, the highest concentrations were for inorganic arsenic (0.34–5.4 µg g?1 DM), whereas arsenobetaine, unlike the situation found in marine fish products, was not the major arsenic species (0.16 ± 0.09 µg g?1 DM). Smaller concentrations were found of arsenosugars 1a (0.18 ± 0.11 µg g?1 DM), 1b (0.077 ± 0.049 µg g?1 DM), 1c (0.080 ± 0.089 µg g?1 DM), and 1d (0.14 ± 0.13 µg g?1 DM). The presence of two unknown arsenic species was revealed (U1: 0.058 ± 0.058 µg g?1 DM; U2: 0.12 ± 0.12 µg g?1 DM). No significant differences were seen with respect to the total arsenic contents between the sexes. However, significant differences in the total arsenic contents were revealed between the area affected by the spill and the area not affected, the contents being greater in the affected area. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
998.
In this first part a straight general wave-guide with a perfectly conducting outer wall and several dielectrics, excited by an electrically generally polarized matter is considered and the electromagnetic field is determined. 相似文献
999.
François Pierrot 《Comptes Rendus Mathematique》2006,342(9):661-663
We study the unbounded KK-theory of S. Baaj and P. Julg in the equivariant framework concerning the action of locally compact groups and groupoids, and give some geometrical examples. To cite this article: F. Pierrot, C. R. Acad. Sci. Paris, Ser. I 342 (2006). 相似文献
1000.
We classify the ergodic invariant Radon measures for the horocycle flow on geometrically infinite regular covers of compact
hyperbolic surfaces. The method is to establish a bijection between these measures and the positive minimal eigenfunctions
of the Laplacian of the surface. Two consequences arise: if the group of deck transformations G is of polynomial growth, then these measures are classified by the homomorphisms from G
0 to ℝ where G
0 ≤ G is a nilpotent subgroup of finite index; if the group is of exponential growth, then there may be more than one Radon measure
which is invariant under the geodesic flow and the horocycle flow. We also treat regular covers of finite volume surfaces.
The first author was supported by NSF grant 0500630.
The second author was supported by NSF grant 0400687. 相似文献