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1.
A relativistic expression has been obtained for the curvature of trajectory of the wave vector of an electromagnetic wave in a moving optically transparent medium. It has been shown that the curvature of the trajectory and angular deviation of rays appear in a homogeneous isotropic medium if the gradient of the velocity field in the medium is nonzero. The bending of the trajectory in the medium with the velocity gradient is a firstorder effect in the ratio u/c. 相似文献
2.
Alan L. Goodman 《Physics letters. [Part B]》1981,103(3):163-164
For a heated rotating nucleus, the angular velocity is equal to one-half the γ-ray transition energy if and only if the band E(I) follows a trajectory of constant entropy. 相似文献
3.
Zhongke Wang Koji Sugioka Katsumi Midorikawa 《Applied Physics A: Materials Science & Processing》2008,93(1):225-229
By the one-continuous fabrication procedure of hollow microstructures using femtosecond (fs) laser direct writing followed
by thermal treatment, successive chemical wet etching and additional annealing, three-dimensional integration of microoptics
with microfluidics, i.e., a planoconvex microlens with a microfluidic chamber, in a single Foturan glass chip was achieved.
Further integration of an optical waveguide was performed through internal refractive index modification by fs laser direct
writing after the fabrication of the microlens and the microchamber. An “all-in-one” microchip that is highly effective for
on-chip photonic biosensing can be manufactured by the present technique with easy assembly of each microcomponent and without
any cumbersome processes for stacking and joining substrates. Experimental demonstration of photonic biosensing using the
integrated microchip has revealed that fluorescence analysis and absorption measurement of liquid samples can be performed
with efficiencies enhanced by factors of 8 and 3, respectively. 相似文献
4.
John C. Tully 《Surface science》1981,111(3):461-478
Three-dimensional stochastic classical trajectory studies have been carried out of the thermal desorption of isolated Ar and Xe atoms from the (111) face of platinum. Realistic interaction potentials that produce quantitative agreement with experimental sticking probabilities and angular and velocity scattering distributions were employed. Energy exchange with lattice phonons was included accurately via empirically chosen friction and fluctuating forces. Application of techniques for the simulation of “infrequent events” allowed studies to be extended to experimentally accessible lifetimes. Atoms were found to desorb preferentially to wide angles, with mean energy considerably lower than 2k times the surface temperature. Significant curvature of the Arrhenius plots was exhibited, and pre-exponential factors were found to be lower than characteristic frequencies. These effects were determined to be mainly dynamical in origin; i.e., they cannot be described by conventional transition-state-theory models. 相似文献
5.
M. Apostol 《Solid State Communications》2012,152(16):1567-1571
Non-inertial electromagnetic effects in matter, i.e. electromagnetic fields created by a non-inertial motion of material bodies, are discussed within the Drude–Lorentz (plasma) model of matter polarization. It is shown that an oscillatory motion of a point-like body, or wavelike motion in an extended body gives rise to electromagnetic fields with the same frequency as the frequency of the original motion, while shock-like movements of a point-like body generate electromagnetic fields with the characteristic (atomic scale) frequency of the bodies. The polarization of a rigid body induced by rotations is discussed in various circumstances. A uniform rotation produces a static electric field in a dielectric and a stationary current (and a static magnetic field) in a conductor. The latter corresponds to the gyromagnetic effect (while the former may be called the gyroelectric effect). Both fields are computed for a sphere and the gyromagnetic coefficient is derived. A non-uniform rotation induces emission of electromagnetic fields. The equations of motion for the polarization are linearized for slight non-uniformities of the angular velocity and solved both for a dielectric and a conducting sphere. The electromagnetic field emitted by a dielectric spherically shaped body in (a slightly) non-uniform rotation has the characteristic (atomic scale) frequency of the body (slightly shifted by the uniform part of the angular frequency). In the same conditions, a conducting sphere emits an electromagnetic field whose frequency is double the uniform part of the angular frequency. 相似文献
6.
The product angular momentum polarization of the reaction of H+NH is calculated via the quasiclassical trajectory method (QCT)
based on the extended London-Eyring-Polanyi-Sato (LEPS) potential energy surface (PES) at a collision energy of 5.1 kcal/mol.
The calculated results of the vector correlations are denoted by using the angular distribution functions. The polarization-dependent
differential cross sections (PDDCSs) demonstrate that the rotational angular momentum of the product H2 is aligned and oriented
along the direction perpendicular to the scattering plane. Vector correlation shows that the angular momentum of the product
H2 is aligned in the plane perpendicular to the velocity vector. It suggests that the reaction proceeds preferentially when
the reactant velocity vector lies in a plane containing all three atoms. The orientation and alignment of the product angular
momentum affects the scattering direction of the product molecules. The polarization-dependent differential cross sections
(PDDCSs) reveal that scattering is predominantly in the backward hemisphere.
相似文献
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8.
水下移动观测平台的机动航路对纯方位目标运动分析方法的使用性能具有重要的影响。针对此问题,提出了一种利用信号自相关函数warping变换的浅海水下移动观测平台机动优化方法。该方法利用warping变换从接收信号自相关函数中提取与目标距离相关的简正波相干项的特征频率,进而估计距离特征量,再根据预估的目标初始距离范围估计目标运动态势范围。针对观测平台机动方式为匀速转弯运动的情况,以目标方位变化率为评价指标得到了观测平台在所估计的目标运动态势范围下的最优转弯角速率。在浅海Pekeris波导环境下的数值仿真结果和实验数据处理结果表明:方位变化率与纯方位扩展卡尔曼滤波算法的性能密切相关;利用warping变换可以有效地估计距离特征量;观测平台根据以方位变化率为评价指标得到的最优转弯角速率进行机动可以获得较好的目标跟踪性能,收敛时间较短,目标位置估计误差较小。 相似文献
9.
10.
The optical properties of a silver-doped phosphate glass have been monitored during thermal processing at several fixed temperatures by in situ optical microspectroscopy. Silver nanoparticle (NP) formation and growth processes were assessed by analysis of surface plasmon resonance spectral features. Nucleation and growth processes were distinguished, which appeared temperature and time dependent. While nucleation was favored at low temperatures, relatively high temperatures promoted NP growth by silver diffusion. Photoluminescence spectra acquired along with optical absorption data indicated a continuous reduction of Ag+-Ag0 pairs concomitant with NP precipitation, suggesting their role as nucleation centers. The work of Ag NP formation and the activation energy for silver diffusion were estimated. 相似文献
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12.
Zimmermann R Gasteuil Y Bourgoin M Volk R Pumir A Pinton JF 《Physical review letters》2011,106(15):154501
The motion of a large, neutrally buoyant, particle freely advected by a turbulent flow is determined experimentally. We demonstrate that both the translational and angular accelerations exhibit very wide probability distributions, a manifestation of intermittency. The orientation of the angular velocity with respect to the trajectory, as well as the translational acceleration conditioned on the spinning velocity, provides evidence of a lift force acting on the particle. 相似文献
13.
The product angular momentum polarization of the reaction of H+NH is calculated via the quasiclassical trajectory method (QCT) based on the extended London-Eyring-Polanyi-Sato (LEPS) potential energy surface (PES) at a collision energy of 5.1 kcal/mol. The calculated results of the vector correlations are denoted by using the angular distribution functions. The polarization-dependent differential cross sections (PDDCSs) demonstrate that the rotational angular momentum of the product H2 is aligned and oriented along the direction perpendicular to the scattering plane. Vector correlation shows that the angular momentum of the product H2 is aligned in the plane perpendicular to the velocity vector. It suggests that the reaction proceeds preferentially when the reactant velocity vector lies in a plane containing all three atoms. The orientation and alignment of the product angular momentum affects the scattering direction of the product molecules. The polarization-dependent differential cross sections (PDD-CSs) reveal that scattering is predominantly in the backward hemisphere. 相似文献
14.
发展了可用于速度谱诊断的角色散Fabry-Perot干涉测量技术,使不同频移探测激光形成的干涉条纹在空间分离,从而可对单一或混合运动源引起的多普勒频移成分进行检测,并给出物体速度谱分布。利用Fabry-Perot干涉测量技术,开展了激光驱动铝箔飞片实验。随着驱动激光能量的变化,观察到了铝箔飞片的不同速度谱分布,包括没有速度空间分散的速度谱、分裂成几片并以不同速度飞行的离散速度谱、碎片云或射流状态下的连续速度谱分布,此外还观测到了冲击下铝箔/玻璃界面分离引起的条纹分裂现象。 相似文献
15.
Inelastic collisions between the hydrogen molecule ion and the hydrogen molecule leading to dissociation are investigated experimentally in the energy range between 3 and 20 keV. The velocity distributions of the protons produced in these processes are compared with calculated distributions using a Born approximation formula. The calculation takes into account the excitation of the 2pσ u state of the H 2 + and a possible simultaneous excitation of the target. It can be shown, that the quantitative knowledge of these processes makes possible a satisfying explanation of the measured distributions. In general a good agreement is obtained between theory and experiment concerning both energy and angular dependence of the velocity distributions. 相似文献
16.
R. F. Rodríguez J. A. Reyes J. Fujioka E. Cortés J. A. Olivares F. L.S. Cuppo 《The European Physical Journal B - Condensed Matter and Complex Systems》2007,55(4):411-418
We investigate the effects produced on the diffraction pattern of a dyed
nematic thin film under the action of an optical field and a low frequency
AC electric field. For a homeotropically aligned mixture of the nematic E7
doped with a dichroic dye, a sequence of dynamical regimes of the far field
diffraction pattern is observed. For specific values of the beam's power,
frequency and amplitude of the AC field, a uniform steady rotational
motion (SR) of the pattern sets in with a measured angular velocity
νexp =2.58 Hz. To account for this and other observed features of the
diffraction pattern an analytical model is proposed. This allows us to
describe quantitatively the reorientation of the film, to calculate some
specific structural features of the diffraction pattern, as well as its
angular velocity. We find that the predicted angular velocity νtheor=5.7 Hz, is in quite good agreement with the measured value. 相似文献
17.
Barbara Korzeniowska Micaella P. Fonseca Vladimir Gorshkov Lilian Skytte Kaare L. Rasmussen Henrik D. Schrøder Frank Kjeldsen 《Particle & Particle Systems Characterization》2020,37(8):2000135
With a steady growth in use of engineered nanoparticles (NPs) in consumer products the unintended exposure to humans has increased. The risks associated with introduction of NPs in the environment have been widely investigated, but mostly for single type of NPs. Herein, a single NP and NP co-exposure study is reported: the cellular effects of silver and platinum NPs on the main components of the blood–brain barrier, human cerebral microvascular endothelial cells, and human primary astrocytes. The synergy is quantitatively evaluated as per the Chou–Talalay method. NP co-exposure synergistically inhibits proliferation of both cell types, to a greater extent for endothelial cells. In addition, astrocytes are more tolerant to NPs. The mechanism of synergy with short-duration incubation time points (up to 30 min) is further explored. Although intracellular trafficking studies and quantitative assessments of NP uptake does not explain the mechanisms of synergistic cytotoxicity, a proteomics analysis suggests that it arises from activation of an immune modulating response and deregulation of the extracellular matrix organization. The substantial synergetic effects in the co-exposure studies highlight the importance of this work in relation to assessment of the health risks associated with nanomaterials. 相似文献
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19.
从(1+2)维非局域非线性薛定谔方程出发, 通过坐标变换得到了旋转坐标系下的非局域非线性薛定谔方程. 假设响应函数为高斯型, 用虚时间法数值求解了旋转坐标系下的非局域非线性薛定谔方程的静态孤子解, 迭代出了不同非局域程度条件下的静态椭圆孤子数值解. 最后采用分步傅里叶算法, 以迭代的孤子解作为初始输入波形, 模拟了在不同的非局域程度条件下, (1+2)维椭圆空间光孤子的旋转传输特性. 强非局域时, 椭圆光孤子的长轴方向和短轴方向波形都是高斯型, 其他的非局域程度下, 不是高斯型. 由此表明:(1+2)维椭圆光孤子对非局域程度依赖性很强. 旋转角速度和功率均与非局域程度以及孤子的椭圆度有关. 相似文献