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排序方式: 共有313条查询结果,搜索用时 15 毫秒
51.
R. Brunner O. Sandfuchs C. Pacholski C. Morhard J. Spatz 《Laser \u0026amp; Photonics Reviews》2012,6(5):641-659
In nature, optical structures in the subwavelength range have been evolved over millions of years. For example, in the form of ‘moth‐eye’ structures they show a strong anti‐reflective effect on the compound eyes of night‐active insects and therefore offer a successful protection over predators. In this contribution the advantages and challenges to transfer this natural concept of subwavelength structured optical interfaces to high‐end optical systems are discussed. Here, in comparison to alternative conventional multilayer systems, the bioinspired anti‐reflective structures offer a wide wavelength range and a broad angle dependency. Additionally, adhesion problems are reduced drastically. Simultaneously to the theoretical consideration of the best profile form of the subwavelength structures, appropriate realization technologies have been developed in recent years, where both top‐down and bottom‐up approaches have been investigated. Depending on the choice of the structuring technique, anti‐reflective subwavelength structures are applicable to a wide spectrum of optical elements ranging from micro‐optical components to aspheres for applications in imaging and also illumination setups of high‐end optical instruments. 相似文献
52.
The littlest Higgs model with T-parity, which is called LHT model,
predicts the existence of the new particles, such as heavy top
quarks, heavy gauge bosons, and mirror fermions. We calculate the
one-loop contributions of these new particles to the top quark
chromomagnetic dipole moment (CMDM)
ΔK. We find that the
contribution of the LHT model is one order of magnitude smaller
than the standard model prediction value. 相似文献
53.
We study the one-loop contribution of the effective flavor changing neutral couplings (FCNC) tcZ on the charm quark electric dipole moment. Using the known limits on the top and charm quarks electric dipole moments, we place limits on these FCNC anomalous couplings. 相似文献
54.
Spectroscopic analysis of asymmetric top free radicals 总被引:1,自引:0,他引:1
Yuyan Liu Xiaoyong Liu Hongping Liu Yuanqing Guo Guangming Huang Jieli Lin Hui Gao Chuanxi Duan 《中国科学B辑(英文版)》2001,44(1):7-16
Several key problems involved in the analyses of spectra of asymmetric top molecules, i.e., the effective Hamiltonian, the
representation and basis vector, identification of energy levels, the selection rules, the relative intensity, and Zeeman
tuning rate, were elucidated systematically. Introducing the high-order centrifugal distortion terms into the effective Hamiltonian,
the precision for calculation has been improved substantially, which allows us to analyze the high-lying rotational transitions.
A global analysis of all available spectra of14N16O2 in the ground vibronic state has been made to obtain a set of molecular constants of14N16O2 in the ground vibronic state which is the most precise and extensive so far. Using the improved parameters, some FIR LMR
lines left unassigned hitherto have been identified successfully. 相似文献
55.
This paper reports that the organic field-effect transistors with
hybrid contact geometry were fabricated, in which the top electrodes
and the bottom electrodes were combined in parallel resistances
within one transistor. With the facility of the novel structure, the
difference of contact resistance between the top contact geometry
and the bottom contact geometry was studied. The hybrid contact
devices showed similar characteristics with the top contact
configuration devices, which provide helpful evidence on the lower
contact resistance of the top contact configuration device. The
origin of the different contact resistance between the top contact
device and the bottom contact device was discussed. 相似文献
56.
Distribution of active earth pressure of retaining wall with wall movement of rotation about top 总被引:5,自引:0,他引:5
Based on the Coulomb‘s theory that the earth pressure against the back of a retaining wall is due to the thrust exerted by the sliding wedge of soil from the back of the wall to a plane which passes through the bottom edge of the wall and has an inclination equal to the angle of O, the theoretical answers to the unit earth pressure, the resultant earth pressure and the point of application of the resultant earth pressure on a retaining wall were obtained for the wall movement mode of rotation about top. The comparisons were made among the formula presented here, the formula for the wall movement mode of translation, the Coulomb‘ s formula and some experimental observations. It is demonstrated that the magnitudes of the resultant earth pressures for the wall movement mode of rotation about top is equal to that determined by the formula for the wall movement mode of translation and the Coulomb‘s theory. But the distribution of the earth pressure and the points of application of the resultant earth pressures have significant difference. 相似文献
57.
58.
ZHANGQing-Jun LIChong-Sheng LIUJian-Jun JINLi-Gang 《理论物理通讯》2003,40(6):687-692
We investigate the spin correlations in top quark pair production near the threshold at the e^ e^- linear collider. Comparing with the results above the threshold region, we find that near the threshold region the off-diagonal basis, the optimized decomposition of the top quark spins above the threshold region, does not exist, and the beamline basis is the optimal basis, in which there are the dominant spin components: the up-down (UD) component for e^-le^ scattering and the down-up (DU) component for eR^-e^ scattering can make up more than 50% of the total cross section,respectively. 相似文献
59.
60.
Dynamics of the tippe top via Routhian reduction 总被引:1,自引:1,他引:0
We consider a tippe top modeled as an eccentric sphere, spinning on a horizontal table and subject to a sliding friction.
Ignoring translational effects, we show that the system is reducible using a Routhian reduction technique. The reduced system
is a two dimensional system of second order differential equations, that allows an elegant and compact way to retrieve the
classification of tippe tops in six groups as proposed in [1] according to the existence and stability type of the steady
states.
相似文献