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排序方式: 共有1139条查询结果,搜索用时 15 毫秒
31.
In this article, we study for the ‐realization of the vector‐valued Schrödinger operator . Using a noncommutative version of the Dore–Venni theorem due to Monniaux and Prüss, we prove that the ‐realization of , defined on the intersection of the natural domains of the differential and multiplication operators which form , generates a strongly continuous contraction semigroup on . We also study additional properties of the semigroup such as extension to L1, positivity, ultracontractivity and prove that the generator has compact resolvent. 相似文献
32.
Yeliz Kara 《代数通讯》2019,47(7):2667-2669
In this corrigendum, we provide correct versions of Theorem 2.8 and Corollary 3.2, retract two consequences of the previous form of the Theorem 2.8. To this end, the main results of the article remain after the aforementioned changes. 相似文献
33.
We study a spin structure that arises in a one‐dimensional quantum dot with zero total spin under the action of a charged tip of a scanning probe microscope in the presence of a weak magnetic field. The evolution of spin structure with changing the probe position is traced to show that the movable probe can be an effective tool to manipulate the spin. The spin structures are formed when the probe is located in certain regions along the dot due to Coulomb interaction of electrons as they are redistributed between the two sections in which the quantum dot is divided by the potential barrier created by the probe. There are two main states: spin‐polarized and non‐polarized ones. The transition between them is accompanied by a spin precession governed by the Rashba spin–orbit interaction induced by the electric field of the probe. In the transition region the spin density changes strongly while charge distribution remains nearly unchanged. (© 2015 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim) 相似文献
34.
To explain the mechanism underlying the adsorption of stevia's polar component rebaudioside A in hydrophilic interaction liquid chromatography mode, the characteristics of rebaudioside A adsorption on various resins in an organic‐solvent‐rich system were studied. Among the tested resins, the strongly acidic cation resin FPC11 showed the best adsorption behavior for rebaudioside A. The factors affecting the adsorption kinetics of the resin for rebaudioside A are discussed. The results showed that the pseudo‐second‐order reaction model and intra‐particle diffusion model best described the adsorption kinetics of rebaudioside A on the resin. The adsorption rate was controlled by physical sorption, mainly via electron sharing or electron transfer between the adsorbent and the adsorbate. The adsorption process with multiple stages involved weak initial adsorption behavior. Thermodynamic studies showed that the adsorption of rebaudioside A on the resin was not an ideal monolayer adsorption, but mutual adsorption effects between the adsorbates. The adsorption was a spontaneous, entropy‐increasing endothermic process. The synergistic effect of hydrogen bonding and ion–dipole was a possible driving force. 相似文献
35.
本文结合次梯度选取技术及割平面法和强次可行方向法的思想,提出了一个求解目标函数非光滑约束优化问题的强次可行方向算法.通过设计一个新的寻找搜索方向子问题和构造新型线搜索,算法不仅能接受不可行的初始点,而且能保持迭代点的强次可行性,同时避免在可行域外目标函数值的不适度增加.算法具备全局收敛性,且初步的数值试验表明算法是稳定有效的. 相似文献
36.
37.
Takashi Noiri 《Acta Mathematica Hungarica》2002,95(4):287-298
We introduce a new class of functions called -preirresolute functions which is contained in the class of quasi preirresolute functions and contains the class of preirresolute functions. It is shown that p-closedness and -connectedness are preserved by -preirresolute surjections. 相似文献
38.
N. G. Khisamiev 《Algebra and Logic》2002,41(4):274-283
Let G be a completely decomposable torsion-free Abelian group and G= Gi, where G
i
is a rank 1 group. If there exists a strongly constructive numbering of G such that (G,) has a recursively enumerable sequence of elements g
i
G
i
, then G is called a strongly decomposable group. Let pi, i, be some sequence of primes whose denominators are degrees of a number p
i
and let
. A characteristic of the group A is the set of all pairs ‹ p,k› of numbers such that
for some numbers i
1,...,i
k
. We bring in the concept of a quasihyperhyperimmune set, and specify a necessary and sufficient condition on the characteristic of A subject to which the group in question is strongly decomposable. Also, it is proved that every hyperhyperimmune set is quasihyperhyperimmune, the converse being not true. 相似文献
39.
Jin-cheng ZHENG 《Frontiers of Physics in China》2008,3(3):269-279
By converting waste heat into electricity through the thermoelectric power of solids without producing greenhouse gas emissions,
thermoelectric generators could be an important part of the solution to today’s energy challenge. There has been a resurgence
in the search for new materials for advanced thermoelectric energy conversion applications. In this paper, we will review
recent efforts on improving thermoelectric efficiency. Particularly, several novel proof-of-principle approaches such as phonon
disorder in phonon-glass-electron crystals, low dimensionality in nanostructured materials and charge-spin-orbital degeneracy
in strongly correlated systems on thermoelectric performance will be discussed.
相似文献
40.
设G是无爪图.对x∈V(G),若G[N(x)]不连通,则存在yi∈V(G)-{x}(i-1,2),使|N(yi)∩Ki(x)|≥2,且|N(yi)∩N(Ki+1(x)){x}|≥2(i模2),那么称无爪图G是强2-阶邻域连通的,其中K1(x),K2(x)分别表示G[N(x)]的两个分支.本文证明了:连通且强2-阶邻域连通的无爪图是Hamilton图. 相似文献