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381.
382.
Curtis T. Mcmullen 《Acta Mathematica》2003,191(2):191-223
383.
We will prove a result concerning the inclusion of non-trivial invariant ideals inside non-trivial ideals of a twisted crossed
product. We will also give results concerning the primeness and simplicity of crossed products of twisted actions of locally
compact groups on -algebras.
Received: 25 January 2002; in final form: 22 May 2002/Published online: 2 December 2002
This work is partially supported by Hong Kong RGC Direct Grant. 相似文献
384.
Determination of electronic structure of ozone related geometry is the main subject in this research. The proposed electronic structure must satisfy the experimental geometry, explain the excellent oxidizing properties of ozone, and can also explain the capability of additional reaction with unsaturated hydrocarbons. The potential energy surface of singlet and triplet state of ozone has been studied in order to check the correctness of the proposed structure. The proposed electronic structure of ozone is capable of explaining the oxidizing behavior of ozone in visible wavelength (daylight) 430–700 nm. For comparison, the other proposed structure of ozone in literature such as Pauling, Linnett and Weinhold has also been discussed. The main method used in this research is well-known density functional procedure, B3LYP, which takes the electron correlation aspect into consideration. The polarization and diffused functions are included in the basis set, 6-311++G**. The obtained geometry is a bent and cumulated double bond with inter-bond angle 118.42° (1.39%), and bond length 1.256 Å (1.72%). The obtained results revealed that frontier orbital theory is a proper tool for explaining the addition reaction. 相似文献
385.
Kukharev B. F. Stankevich V. K. Klimenko G. R. 《Russian Journal of Organic Chemistry》2003,39(5):625-629
Russian Journal of Organic Chemistry - 相似文献
386.
A hybrid heuristic method for combinatorial optimization problems is proposed that combines different classical techniques such as tree search procedures, bounding schemes and local search. The proposed method enhances the classic beam search approach by applying to each partial solution corresponding to a node selected by the beam, a further test that checks whether the current partial solution is dominated by another partial solution at the same level of the search tree. If this is the case, the latter solution becomes the new current partial solution. This step allows to partially recover from previous wrong decisions of the beam search procedure and can be seen as a local search step on the partial solution. We present here the application to two well known combinatorial optimization problems: the two-machine total completion time flow shop scheduling problem and the uncapacitated p-median location problem. In both cases the method strongly improves the performances with respect to the basic beam search approach and is competitive with the state of the art heuristics. 相似文献
387.
Alvim Adriana C.F. Ribeiro Celso C. Glover Fred Aloise Dario J. 《Journal of Heuristics》2004,10(2):205-229
We propose in this work a hybrid improvement procedure for the bin packing problem. This heuristic has several features: the use of lower bounding strategies; the generation of initial solutions by reference to the dual min-max problem; the use of load redistribution based on dominance, differencing, and unbalancing; and the inclusion of an improvement process utilizing tabu search. Encouraging results have been obtained for a very wide range of benchmark instances, illustrating the robustness of the algorithm. The hybrid improvement procedure compares favourably with all other heuristics in the literature. It improved the best known solutions for many of the benchmark instances and found the largest number of optimal solutions with respect to the other available approximate algorithms. 相似文献
388.
The influence of the sample orientation on the effective value of the hydrostatic piezoelectric coefficients d
h
(i)
of Sn2P2S6 crystals has been studied. The hydrostatic piezoelectric coefficients d
h
(1)
and d′
h
(3)
, were measured, d
h
(1)
=(244±3) pC/N and d′
h
(3)
=(92±1) pC/N. The hydrostatic piezoelectric coefficient d
h
(3)
for orthogonal axis system was calculated to be d
h
(3)
=(87±2) pC/N. The, optimal orientation of the sample has been found as (Xy l)−20°-cut. Maximal value of the effective hydrostatic piezoelectric coefficient d
h
(1)
equals 260 pC/N. Double rotated samples were also studied. The orientation of the samples insensitive to the pressure has
been found. The theoretical mean value of hydrostatic piezoelectric coefficient (d
h
)
mean
corresponding to randomly oriented Sn2P2S6 grains in a poled composite has been calculated to be (d
h
)
mean
=136 pC/N. 相似文献
389.
390.
Lev Buhovsky 《Israel Journal of Mathematics》2004,143(1):181-187
In this paper we find homological restrictions on Lagrangians in cotangent bundles of spheres and Lens spaces.
This research was supported by the Israel Science Foundation (grand No. 205/02). 相似文献