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22.
In this paper,a strong converse inequality of type B in terms of a new Kfunctional Kλα f,t2(0 < α < 2,0 ≤ λ ≤ 1) for certain mixed Szász-Beta operators is given.By this inequality,the converse theorem can be obtained for the operators. 相似文献
23.
Two novel organic–inorganic hybrid vanadoantimonate compounds, [Zn2(dien)3][{Zn(dien)}2V16Sb4O42(H2O)]·4H2O (1) and [Zn(dien)2]2 [{Zn(dien)}2(V14Sb8O42)2(H2O)]·4H2O (2) (dien = Diethylenetriamine), have been synthesized hydrothermally at different pH value, and structurally characterized
by elemental analyses, FT-IR, XPS, TGA and single crystal X-ray diffraction analysis. Compound 1 is composed of the rare [V16Sb4O42]8− cluster covalently linked by two [Zn(dien)]2+ coordination cations to yield a novel one-dimensional linear chain. Compound 2 exhibits a one-dimensional zigzag chain constructed from the [V14Sb8O42]4− cluster and [Zn(dien)]2+ coordination polymer. The two examples represent the first one-dimensional assemblies based on vanadoantimonate cluster and
the metal–organic complex moieties. 相似文献
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Adaptive lag synchronization and parameter identification of fractional order chaotic systems 下载免费PDF全文
This paper proposes a simple scheme for the lag synchronization and the parameter identification of fractional order chaotic systems based on the new stability theory. The lag synchronization is achieved and the unknown parameters are identified by using the adaptive lag laws. Moreover, the scheme is analytical and is simple to implement in practice. The well-known fractional order chaotic Lü system is used to illustrate the validity of this theoretic method. 相似文献
27.
单分子磁体是指那些在磁场下能够被磁化,当磁场去除后仍能保持磁性的单个分子。由于在信息处理和储存方面具有潜在的广泛应用前景,单分子磁体日益成为化学、材料科学和物理等学科的研究热点。近年来,同时含有镧系金属离子和过渡金属离子的3d-4f单分子磁体更是引起了很多研究者的兴趣。本文阐述了3d-4f单分子磁体的优势,总结了3d-4f单分子磁体的常见合成方法及其磁性,分析了影响3d-4f单分子磁体磁性的因素。 相似文献
28.
Spin Polarization and Andreev Conductance through a Diluted Magnetic Semiconductor Quantum Wire with Spin--Orbit Interaction 下载免费PDF全文
Spin-dependent Andreev reflection and spin polarization through a diluted magnetic semiconductor quantum wire coupled to normal metallic and superconductor electrodes are investigated using scattering theory. When the spin-orbit coupling is considered, more Andreev conductance steps appear at the same Fermi energy. Magnetic semiconductor quantum wire separates the spin-up and spin-down electrons. The Fermi energy, at which different- spin-state electrons begin to separate, becomes lower due to the effect of the spin-orbit interaction. The spin filter effect can be measured more easily by investigating the Andreev conductance than by investigating the normal conductance. 相似文献
29.
The Kondo effect and the Andreev reflection tunneling through a normal (ferromagnet)-double quantum dots-superconductor hybrid system is examined in the low temperature by using the nonequilibrium Green's function technique in combination with the slave-boson mean-field theory. The interplay of the Kondo physics and the Andreev bound state physics can be controlled by varying the interdot hopping strength. The Andreev differential conductance is mainly determined by the competition between Kondo states and Andreev states. The spin-polarization of the ferromagnetic electrode increases the zero-bias Kondo peak. The spin-flip scattering influences the Kondo effect and the Andreev reflection in a nontrivial way. For the ferromagnetic electrode with sufficiently large spin polarization, the negative Andreev differential conductance is found when the spin flip strength in the double quantum dots is sufficiently strong. 相似文献
30.
Xing-Tao An 《Physics letters. A》2008,372(45):6790-6796
Spin polarization in parallel double quantum dots embedded in arms of Aharonov-Bohm interferometer is investigated. The spin-orbit interaction exists in quantum dots. We find that the spin polarization is quite large even with a weak spin-orbit interaction. The direction and the strength of the spin polarization are well controllable and manipulatable by simply varying the strength of spin-orbit interaction or the energy levels in quantum dots. Moreover, electron-electron interaction strengthens the spin accumulation when the energy levels of the two quantum dots are identical. As the energy levels are unequal, electron-electron interaction cannot increase the spin accumulation. It is worth mentioning that the device is free of a magnetic field or a ferromagnetic material and it can be easily realized with present technology. 相似文献