共查询到20条相似文献,搜索用时 15 毫秒
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R. W. Nicholls 《Journal of research of the National Institute of Standards and Technology》1961,(5):451-460
Franck-Condon factor arrays have been computed numerically to high vibrational quantum numbers for the band systems and for the following ionization transitions 相似文献
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Hector E. Lorenzana Magnus J. Lipp William J. Evans Naoki Hemmi 《Journal of Low Temperature Physics》2001,122(3-4):279-290
The molecular analogue of methane CF4 is the most fundamental saturated perfluorocarbon, exhibiting complex optical behavior that is highly unusual for such a simple molecular system. We present Raman measurements in solid CF4 over a wide range in pressure from 1.6 to over 30 GPa at room temperature. The Raman spectra exhibit polarization-dependent intensity variations and history-dependent absence or presence of high pressure modes. Our results compellingly demonstrate that previously identified phase transitions in CF4 based on Raman signatures need to be reconsidered. Though our data suggest possible new high-pressure transitions, we do not identify new phases because of spectral complexity. Finally, we used the measured longitudinal and transverse optical mode splitting to estimate the dipole moment derivative at high pressures and find it close to that of gaseous CF4. 相似文献
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Dagmar Bruß Norbert Lütkenhaus 《Applicable Algebra in Engineering, Communication and Computing》2000,10(4-5):383-399
We review the main protocols for key distribution based on principles of quantum mechanics, describing the general underlying
ideas, discussing implementation requirements and pointing out directions of current experiments. The issue of security is
addressed both from a principal and real-life point of view.
Received: October 15, 1998; revised version: June 8, 1999 相似文献
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Yu. A. Freiman S. M. Tretyak A. Jezowski R. J. Hemley 《Journal of Low Temperature Physics》1998,113(5-6):723-728
The broken symmetry phase (BSP) transition in solid HD has been shown to be an example of quantum orientational melting. Anomalous features observed for the transition are a consequence of the symmetry properties of the system, namely, the fact that in HD all rotational states and transitions between them are allowed, in contrast to the behavior of the homonuclear H2 and D2. 相似文献
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《Nanotechnology, IEEE Transactions on》2006,5(5):568-574
Electrons are bound to the surface of liquid helium by the image potential due to the induced polarization of the helium. The potential varies as the reciprocal of the distance of the electron from the surface so that the energy levels for the electron motion perpendicular to the surface are those of a one-dimensional hydrogen atom with very small charge. In order to make quantum logic elements (qubits) using the ground state and first excited state in this potential, individual electrons must be confined over microelectrodes which are individually connected to variable voltage sources so that the electron energy levels can be shifted in and out of resonance with applied microwave radiation. The electrodes consist of an array of gold columns, about 1.2$muhbox m$ tall and 200 nm in diameter, separated by 500 nm. These are grown by electroplating on the ends of leads deposited on a silicon substrate by e-beam lithography. The leads are covered by a dielectric layer and then a metal ground plane, so that the electric field from the leads is screened. We describe, here, our technique for fabricating this system and present the numerical computations of the electric fields from the electrodes. 相似文献
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超高周疲劳的影响因素及疲劳机理的研究进展 总被引:2,自引:0,他引:2
超高周疲劳的研究可以满足某些特殊零部件极高循环周次的要求。综述了近年来超高周疲劳的研究进展,从S-N曲线的特征、断面上的鱼眼形貌以及裂纹的萌生与扩展特征等方面介绍了超高周疲劳的典型特征。分析了影响超高周疲劳的若干因素,如氢的作用、加载频率、应力比和晶粒尺寸等。进而提出了一些今后超高周疲劳的研究方向:超高周疲劳裂纹扩展的微观机理、扩展速率尤其是微观、宏观上的控制参量的研究以及确定鱼眼与ODA区边缘的应力强度因子范围对内部裂纹扩展门槛值的影响作用。 相似文献
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Misaridis T Jensen JA 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2005,52(2):208-219
This paper, the last from a series of three papers on the application of coded excitation signals in medical ultrasound, investigates the possibility of increasing the frame rate in ultrasound imaging by using modulated excitation signals. Linear array-coded imaging and sparse synthetic transmit aperture imaging are considered, and the trade-offs between frame rate, image quality, and SNR are discussed. It is shown that FM codes can be used to increase the frame rate by a factor of two without a degradation in image quality and by a factor of 5, if a slight decrease in image quality can be accepted. The use of synthetic transmit aperture imaging is also considered, and it is here shown that Hadamard spatial encoding in transmit with FM emission signals can be used to increase the frame rate by 12 to 25 times with either a slight or no reduction in signal-to-noise ratio and image quality. By using these techniques a complete ultrasound-phased array image can be created using only two emissions. 相似文献
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G.F. Cerofolini G.U. Pignatel F. Riva G. Feria F. Nava G. Ottaviani 《Thin solid films》1983,109(2):137-144
To a first approximation, indium diffusion in silicon is characterized by the same diffusion coefficient in an oxidizing atmosphere as in an inert atmosphere.Chemical etching of oxidized wafers has revealed unusual etch patterns and a bimodal stacking fault distribution for samples implanted at 1012 ions cm-2.The segregation between silicon and SiO2 markedly favours silicon. However, in the first stages of oxidation indium can be incorporated in the SiO2 layer because of the high growth rate of the oxide compared with the low indium diffusivity. After that, the “snowplough” effect gives rise to indium accumulation at the silicon surface. 相似文献
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Enhancing Quantum Dots for Bioimaging using Advanced Surface Chemistry and Advanced Optical Microscopy: Application to Silicon Quantum Dots (SiQDs) 下载免费PDF全文
Xiaoyu Cheng Elizabeth Hinde Stuart B. Lowe Peter J. Reece Katharina Gaus J. Justin Gooding 《Advanced materials (Deerfield Beach, Fla.)》2015,27(40):6144-6150
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Yibo Yan Jun Gong Jie Chen Zhiping Zeng Wei Huang Kanyi Pu Jiyang Liu Peng Chen 《Advanced materials (Deerfield Beach, Fla.)》2019,31(21)
Graphene quantum dots (GQDs) that are flat 0D nanomaterials have attracted increasing interest because of their exceptional chemicophysical properties and novel applications in energy conversion and storage, electro/photo/chemical catalysis, flexible devices, sensing, display, imaging, and theranostics. The significant advances in the recent years are summarized with comparative and balanced discussion. The differences between GQDs and other nanomaterials, including their nanocarbon cousins, are emphasized, and the unique advantages of GQDs for specific applications are highlighted. The current challenges and outlook of this growing field are also discussed. 相似文献
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The present final part of this work is devoted to the numerical evaluation of the various effects which were studied, both analytically and qualitatively, in Part II insofar as coupled magnetoelastic waves in ferromagnets are concerned. The case of four typically deformable ferromagnets (Cobalt, Nickel Ferrite, YIG and Iron) is examined. The graphs of practical interest which are obtained provide quantitative results pertaining to the repulsion of coupled modes in crossover regions of the dispersion diagram, the magnetoacoustic resonance effect in the absence of dissipation, the magnetoacoustic Faraday effect and the exchange of relaxation between coupled modes in the neighborhood of the coupling point when viscosity and spin-lattice relaxation are accounted for. The latter effect occurs slightly before, slightly after, or practically at the coupling point, depending on the material considered. 相似文献
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Quantum Dots: Linking Subcellular Disturbance to Physiological Behavior and Toxicity Induced by Quantum Dots in Caenorhabditis elegans (Small 23/2016) 下载免费PDF全文
Qin Wang Yanfeng Zhou Bin Song Yiling Zhong Sicong Wu Rongrong Cui Haixia Cong Yuanyuan Su Huimin Zhang Yao He 《Small (Weinheim an der Bergstrasse, Germany)》2016,12(23):3073-3073