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大型强子对撞机(LHC)能探测到核子中很小x的动力学区域.在此动力学区域部分子的密度很大,根据高扭度修正过的AP演化方程(MDAP方程),分析了此区域的部分子饱和问题.发现在LHC能区不会出现饱和现象,但部分子分布会由于高扭度效应而明显被抑制,出现部分饱和现象.根据MDAP演化方程,还对LHC能区的部分子分布进行了预言 相似文献
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本文用[1]中方法继续对电子深度非弹散射过程进行讨论.文中给出结构函数中的不可约图的一般表达式,用华德等式将它们与核子电流矩阵元的核、核子的 B-S 方程的核联系起来.文中在不考虑封闭的层子线圈图的贡献和核子方程中的积分核作位势假定的情况下,给出结构函数的表达式和计算方法,用核子方程解出的波函数和方程的积分核可将结构函数算出来. 相似文献
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打破将散度演化分析局限于水平动力学框架内的传统认识思维,针对大气的斜压性与层结特征将对大气运动散度场演化产生显著影响的事实,从湿斜压原始方程出发,将大气的斜压热力作用通过热力学方程引入散度方程,在替换平衡近似(alternative balance)下,导出了显式包含湿非地转Q矢量与垂直风切变耦合强迫作用的新型散度方程.阐明了潮湿大气中非地转斜压强迫激发散度场演化的物理机制,为利用常规观测资料诊断散度场演化提供了一种有效的数学工具.通过对流层中低层气柱内总体辐合增长影响因子的分
关键词:
暴雨天气
散度演变
正压非平衡强迫
湿斜压热动力耦合强迫 相似文献
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《光学学报》2017,(11)
引入一类新的部分相干光束,其谱相干度或关联结构函数具有余弦-洛伦兹的非传统相关函数形式(即非高斯函数形式),这类部分相干光束满足Gori确定的充分条件,是物理上可实现的光束。基于广义惠更斯-菲涅耳衍射的Collins积分公式,获得了余弦-洛伦兹关联结构函数部分相干高斯光束通过近轴ABCD光学系统传输时其交叉谱密度函数的一般解析表达式,并探讨了光束经过薄透镜聚焦时光强分布的演化特性。结果表明:该类光束在合适的参数条件下能呈现自分裂和自整形等奇异传输特性,且这些传输特性与关联结构函数的性质密切相关;这类光束的自分裂和束斑形状变化是由关联结构函数中的不同因子产生的。因此,调控这类部分相干光束的关联结构函数分布可以有效调制其相干长度和非均匀性,从而可操控光束传输行为。该研究结果为实现4个正方形光束提供了可能方案,在工程技术领域具有重要的应用前景。 相似文献
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WANG Yan WU Wenfeng FAN Zhan LIANG Guolong 《声学学报:英文版》2014,(3):267-278
In order to ease the pass-band response distortion of the matrix pre-filter,a simple approach for designing matrix spatial filter is proposed,which minimizes the sum of the k maximal distortion norm(k is the number of the constraint points)within the pass-band,while constraining the filter response within the stop-band.Considering the costly amount of calculation of the high-resolution methods,an algorithm with small amount of calculation based on matrix pre-filtering and subspace fitting using acoustic vector array(MF-VSSF)is proposed.Through joint processing of signal subspace of both pressure and particle velocity,the pre-filtering matrix and the signal subspace is decreased to M-dimensional(M is the number of array-element),hence reduces the time-consumption of the matrix pre-filter design and DOA searching.Simulation results show that,the method offers the same performance as MUSIC with pre-filtering,but has much lesser amount of calculation.Moreover,the designed prefilter can efficiently suppress the interference in the stop-band and improve the estimation and resolution performance of successive DOA estimators. 相似文献
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The formulas of the quantum electrodynamics have been applied to calculate the spontaneous emission rate of excited atom in dielectric microcavity.The results exhibit damping oscillating Patterns which depend sensitively on the scaling parameter and geometrical structure.Compared with the case that the emitting atom is immersed in dielectric,the spontaneous emission rate is depressed obviously and the center or the mean value of the oscillations is intimately related to the real refractive index of the local position where the atom is.In order to explain this phenomenon,we utilize the closed-orbit theory to deal with the classical trajectories of the emitted photon.and extract the corresponding frequencies of the oscillations by Fourier transform.It is found that the oscillations can be represented in terms of the closed-orbits of the photon motion constrained in dielectric microcavity,thus providing another perspective on the spontaneous emission of atom sandwiched by dielectric slabs. 相似文献
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It is demonstrated experimentally that the anharmonic property of the quadrupole trap can be exploited to cool trapped atoms by modulating the trap potential anisotropically.This cooling effect arises from the energy-selective removal of the most energetic trapped atoms and the thermal equilibrium of the remaining atoms.The frequency dependences of the temperature and the fraction of the atoms left in the trap after the modulation are explored.It is also demonstrated that the cooling induced by parametric resonance can also increase the phase space density of the trapped atoms. 相似文献
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According to the equation of motion in the elastic medium and integral equation of target scattering, the sound scattering from the partially water-filled elastic spherical shells with and without an inner plate is studied using the finite element and boundary element method, and the scattering normalized form functions of the shell filled with different volume of water are computed and the mechanism of resonance scattering is analyzed. The results show that the resonance of the shell with partially water-filled and without the plate is mainly related to the volume of water, and the resonance is produced by inner water and the spherical shell. The resonance characteristics of partially water-filled elastic shell with the plate are similar to that of empty structured elastic spherical shell, and the sound field in inner water is weaker which indicates the main resonance characteristics are decided by spherical shell and the plate. In addition, the scattering characteristics of spherical shell with plate and one side full water-filled are greatly different from the partially water-filled ones. 相似文献
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Iodine release in potassium iodide solution has been investigated under the irradiations of ultrasound and visible light respectively and simultaneously. We have observed that the amount of iodine liberated under the combined irradiation of ultrasound and visible light is larger than the sum of that under the respective irradiations of ultrasound and visible light, indicating a synergistic effect of ultrasound and visible light irradiations. Based on the investigation of the reaction kinetics of iodine liberated, we have ascribed the synergistic effect to the perfect stirring of the photochemical reactor induced by the applying simultaneous ultrasound. The ideal stirring can result in the homogenization of the primary light effect in the whole reaction medium, which induces the acceleration of the photochemical reaction. On behavior of our knowledge, there are few reports on the investigations of utilizing the combination of ultrasonic energy and light energy to accelerate the reaction yield and rate as well as the kinetics of the reaction. 相似文献
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During the evolution of the binary system,many physical processes occur,which can influence the orbital angular velocity and the spin angular velocities of the two components,and influence the non-synchronous or synchronous rotation of the system.These processes include the transfer of masses and angular momentums between the component stars,the loss of mass and angular momentum via stellar winds,and the deformation of the structure of component stars.A study of these processes indicates that they are closely related to the combined effects of tide and rotation.This means,to study the synchronous or non-synchronous rotation of binary systems,one has to consider the contributions of different physical processes simultaneously,instead of the tidal effect alone.A way to know whether the rotation of a binary system is synchronous or non-synchronous is to calculate the orbital angular velocity and the spin angular velocities of the component stars.If all of these angular velocities are equal,the rotation of the system is synchronous.If not,the rotation of the system is non-synchronous.For this aim,a series of equations are developed to calculate the orbital and spin angular velocities.The evolutionary calculation of a binary system with masses of 10M⊙+6M⊙shows that the transfer of masses and angular momentums between the two components,and the deformation of the components structure in the semidetached or in the contact phase can change the rotation of the system from synchronous into non-synchronous rotation. 相似文献
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《Comptes Rendus Physique》2015,16(4):368-378
To present knowledge, all the physics at the Large Hadron Collider (LHC) can be described in the framework of the Standard Model (SM) of particle physics. Indeed the newly discovered Higgs boson with a mass close to 125 GeV seems to confirm the predictions of the SM. Thus, besides looking for direct manifestations of the physics beyond the SM, one of the primary missions of the LHC is to perform ever more stringent tests of the SM. This requires not only improved theoretical developments to produce testable predictions and provide experiments with reliable event generators, but also sophisticated analyses techniques to overcome the formidable experimental environment of the LHC and perform precision measurements. The present article proposes an overview of the present theoretical tools and of the experimental results in the field of strong and electroweak interactions. 相似文献
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Frequency-selective surface (FSS) is a two-dimensional periodic structure consisting of a dielectric substrate and the metal units (or apertures) arranged periodically on it. When manufacturing the substrate, its thickness and dielectric constant suffer process tolerances. This may induce the center frequency of the FSS to shift, and consequently influence its characteristics. In this paper, a bandpass FSS structure is designed. The units are the Jerusalem crosses arranged squarely. The mode-matching technique is used for simulation. The influence of the tolerances of the substrate's thickness and dielectric constant on the center frequency is analyzed. Results show that the tolerances of thickness and dielectric constant have different influences on the center frequency of the FSS. It is necessary to ensure the process tolerance of the dielectric constant in the design and manufacturing of the substrate in order to stabilize the center frequency. 相似文献
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Algirdas Audzijonis Gediminas Gaigalas Leonardas Žigas Audrius Pauliukas Raimundas Žaltauskas Aurimas Čerškus Jurgis Narusis 《Central European Journal of Physics》2005,3(3):382-394
This paper presents the theoretical investigation of energy levels of valence bands (VB) and core levels (CL) of the ferroelectric
SbSl single crystals in antiferroelectric and ferroelectric phases. Since the best approximation for the deep VB levels is
a calculation by the Hartree-Fock method, the molecular model of a SbSI crystal was used for calculations. This model of the
crystal was also used for calculations of the total density of states. It was found that the VB and CL of this ferroelectric
semiconductor are sensitive to the small lattice distortion at the phase transition, and that an average of the total density
of states, when all atoms participate in oscillations of all normal modes, are more similar to the experimental X-ray photoelectron
spectra (XPS). The experimental splitting of CL obtained by XPS was compared with the theoretically calculated one by two
different methods. The cluster model calculations showed that the splitting of the CL in SbSI might be caused by photoelectron
emission from the atoms, which have different valence state, at the surface. 相似文献