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介绍MIMO技术的定义和历史,从空间复用、传输分集技术、波束成型等方面对MIMO技术进行说明,并对MIMO在3G(HSPA+)中的应用做了简单的描述。 相似文献
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A pair of E/Z-isomers of 2-phenyl-6,7-dihydrobenzofuran-4(5H)-one O-cyanomethyl oxime,C16H14N2O2,as potential drugs for treating peptic ulcer and other acid-related diseases have been synthesized and characterized by IR,MS and NMR spectra.Meanwhile,the crystal of IIIa was obtained and determined by X-ray single-crystal diffraction.Crystal data: monoclinic system,space group P21 /c,a = 8.423(8),b = 19.596(16),c = 8.770(8),β = 107.750(12)°,V = 1379(2)3,Z = 4,F(000) = 560,Dc = 1.283 g/cm3,μ = 0.086 mm 1,R = 0.0681 and wR = 0.2029 for 14472 independent reflections(Rint = 0.0782) and 2428 observed ones(I 2σ(I)). 相似文献
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Using the Bs meson wave function extracted from non-leptonic Bs decays, we reevaluate the rare decays Bs→l+l- γ,(l=e,μ) in the Standard Model, including two kinds of contributions from the magnetic-penguin operator with virtual and real photons. We find that contributions to the exclusive decays from the magnetic-penguin operator b→sγ with real photons, which were regarded as negligible in the previous literature, are large and the branching ratios Bs→l+l-γ are enhanced by a factor of almost 2. With the predicted branching ratios of the order of 10-8, it is expected that these radiative dileptonic decays will be detected in LHC-b and B factories in the near future. 相似文献
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掺铥光纤激光器输出的2 μm波段在医疗、激光雷达、遥感测控和光参量振荡方面有着广泛应用,目前已实现千瓦级的激光输出。文中主要介绍了掺铥光纤激光器的基本结构及工作原理,并综述和分析了国内外掺铥光纤激光器的研究进展,并展望了掺铥光纤激光器的发展。 相似文献
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多线性分离变量法已成功地应用于诸多(2+1)维非线性可积系统.将该方法拓展运用于(3+1)维破碎孤子方程中,获得了含任意函数的变量分离解.通过适当地设定任意函数的形式,得到了(3+1)维破碎孤子方程丰富的局域激发模式. 相似文献
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Ab initio MRCI+Q study on potential energy curves and spectroscopic parameters of low-lying electronic states of CS+ 下载免费PDF全文
Carbon monosulfide molecular ion (CS+), which plays an important role in various research fields, has long been attracting much interest. Because of the unstable and transient nature of CS+, its electronic states have not been well investigated. In this paper, the electronic states of CS+ are studied by employing the internally contracted multireference configuration interaction method, and taking into account relativistic effects (scalar plus spin–orbit coupling). The spin–orbit coupling effects are considered via the state-interacting method with the full Breit–Pauli Hamiltonian. The potential energy curves of 18 Λ–S states correlated with the two lowest dissociation limits of CS+ molecular ion are calculated, and those of 10 lowest Ω states generated from the 6 lowest Λ–S states are also worked out. The spectroscopic constants of the bound states are evaluated, and they are in good agreement with available experimental results and theoretical values. With the aid of analysis of Λ–S composition of Ω states at different bond lengths, the avoided crossing phenomena in the electronic states of CS+ are illuminated. Finally, the single ionization spectra of CS (X1Σ+) populating the CS+(X2Σ1/2+, A2Π3/2, A2Π1/2, and B2Σ1/2+) states are simulated. The vertical ionization potentials for X2Σ1/2+, A2Π3/2, A2Π1/2, and B2Σ1/2+ states are calculated to be 11.257, 12.787, 12.827, and 15.860 eV, respectively, which are accurate compared with previous experimental results, within an error margin of 0.08 eV~0.2 eV. 相似文献