共查询到20条相似文献,搜索用时 93 毫秒
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给出一种不依赖于具体动量图象求粒子反应中初态粒子的阈能和末态粒子最大能量的方法,并就常见的粒子反应作了讨论。 相似文献
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几类相干态的量子保真度 总被引:1,自引:1,他引:0
在坐标表象下,研究了几类相干态的量子保真度,对于相干态,我们给出了量子保真度的解析表达式,考查了谐振子特征长度 ,平移距离 对保真度的影响;对于相干态 与 的叠加态,考查了初态量子干涉对量子保真度的影响,结论表明:量子保真度呈周期性;与相干态的量子保真度比较而言,当谐振子处于第二类相干态时,量子干涉能抑制量子态失真,当谐振子处于第三类相干态时,量子干涉能抑制量子态失真,也可能加大量子态失真. 相似文献
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使用代数方法给出了粒子质量显含时间的Dirac方程的严格解,解的结构显示了粒子的正负能态与其自旋态具有交换对称性.
关键词: 相似文献
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曹娅 《原子与分子物理学报》2011,28(2):302-308
通过修订的几何纠缠度,讨论一类混态两粒子各项同性态的纠缠,并推广到多粒子高维的情况,给出 -粒子 -能级的各项同性态明确的解析表达式,比较得到关系修订的几何纠缠度小于等于相对熵纠缠度。结果表明修订的几何纠缠度是合理的纠缠度量。 相似文献
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本文推广Martin-Grossc定理到2P,3D态,给出了四个决定2P,3D能级次序的充分条件。 相似文献
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The effective interface potential is derived for a superconducting layer attached to a wall. The expression applies to the neighborhood of a continuous wetting or delocalization transition, which exists for type I superconductors with a negative extrapolation length. From this potential a number of features can be easily derived, such as the locus of the phase transition and the critical exponents. Whereas the order parameter exponent is universal, other exponents, like the susceptibility exponent, are not. 相似文献
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采用数值计算和实验测量相结合的方法, 阐明了高能电子束照射下绝缘厚样品的表面电位和电子产额动态特性. 结果表明: 由于电子在样品内部的散射和输运, 沿着深度方向, 空间电位先缓慢下降到最小值, 然后逐渐升高并趋近于零; 随着电子束照射, 样品的表面电位逐渐下降, 可至负千伏量级, 电子总产额逐渐增大至一个接近于1的稳定值; 电子束停止照射后, 长时间放置下, 表面电位将逐渐升高, 但带电并不会消除; 表面电位随电子束能量的升高近似线性下降, 随入射角的增大而升高, 而随样品厚度的增大仅略有下降. 相似文献
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A new cellular automata model of traffic flow with negative exponential weighted look-ahead potential 下载免费PDF全文
With the development of traffic systems, some issues such as traffic jams become more and more serious. Efficient traffic flow theory is needed to guide the overall controlling, organizing and management of traffic systems. On the basis of the cellular automata model and the traffic flow model with look-ahead potential, a new cellular automata traffic flow model with negative exponential weighted look-ahead potential is presented in this paper. By introducing the negative exponential weighting coefficient into the look-ahead potential and endowing the potential of vehicles closer to the driver with a greater coefficient, the modeling process is more suitable for the driver's random decision-making process which is based on the traffic environment that the driver is facing. The fundamental diagrams for different weighting parameters are obtained by using numerical simulations which show that the negative exponential weighting coefficient has an obvious effect on high density traffic flux. The complex high density non-linear traffic behavior is also reproduced by numerical simulations. 相似文献
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A. V. Melnikov L. G. Eliseev S. A. Grashin A. V. Gudozhnik S. E. Lysenko V. A. Mavrin S. V. Perfilov V. A. Vershkov L. I. Krupnik A. A. Chmyga A. D. Komarov A. S. Kozachok C. Hidalgo A. Alonso J. L. dePablos M. A. Pedrosa 《Czechoslovak Journal of Physics》2005,55(12):1569-1578
Comparison of the plasma electric potential evolution in the T-10 tokamak and TJ-II stellarator was performed. The core potential
was measured by the heavy-ion beam probing and the edge potential was measured by Langmuir probe. The intrinsic potentials
in both devices are different in sign, positive in TJ-II low-density discharge and negative in T-10 higher-density discharges,
but during ECRH they evolve similarly: the potential becomes more positive, and increase of ECRH power leads to stronger rise
of core potential.
Presented at the Workshop “Electric Fields, Structures and Relaxation in Edge Plasmas”, Tarragona, Spain, July 3–4, 2005. 相似文献
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本文从原子间相互作用的物理本质出发,用修正的Tang-Toennies(TT)势模型计算了He-He原子间相互作用的van der Waals势.结果显示修正后的势模型在平衡间距附近及远程部分仍然给出了势能曲线的准确结果,在近程部分则较之TT势给出了与实验符合得更好的结果. 相似文献
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Spectroscopic determination of the cross-membrane electric potential has been used for more than 20 years. This method, which usually employs absorption or fluorescence measurements, allows for a rapid and noninvasive study of the electrical properties of the membranes of cells and liposomes. However, the usual fluorescence techniques preferably allow monitoring changes in the potential on triggerable or excitable membranes, and not the absolute value of the potential. They also do not provide means for measuring the potential on single cells. This paper reviews three methods that solve these issues. Nernstian dyes which partition between intra-and extracompartmental volumes enable a fluorescence microscopic determination of a single cell and even a single organelle. Dual-wavelength ratiometric recording from membrane-staining dyes also provides means for measuring the field on a single cell. Resonance Raman probes provide a spectroscopic method with a natural internal standard for the absolute measurement of membrane potential. 相似文献
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文章分析了重力势能、引力势能、电荷势能、化学势能、热量势能、质量积、动量积等多种势能,发现它们均可表达为一种守恒广延量和对应的强度量的乘积,因此可将其统一定义为"积".基于积这一概念,文章得到了孤立系统内守恒广延量传递过程的积减原理,即孤立系统内进行的守恒广延量传递过程中系统的积总是减小的.进一步,文章还基于积的概念发展了孤立系统和封闭系统的势平衡判据,发现孤立系统达到势平衡状态时,系统的积达到最小值(最小积原理);当封闭系统达到势平衡状态时,系统的准自由积达到最小值(最小准自由积原理).上述结论应用于传热学中即可得到热量传递过程的(火积)减原理及相应的热平衡判据.与热力学中的核心概念熵相对应,由于物理量(火积)可以描述传热过程的不可逆性,作为传热过程的优化准则,度量系统的无序度,并给出系统的热平衡判据,因此(火积)是传热学中的核心概念.
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势能
积
积减原理
平衡判据 相似文献
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A suitable temperature dependence is introduced into the force parameters of the Lennard-Jones potential by taking the free-energy
average of the Rowlinson potential. The resulting temperature-dependent parameters are used to calculate the effective potential,
which is plotted for water vapour at a few different temperatures. The temperature-dependence of the second virial coefficient
is shown for the cases of temperature-independent and temperature-dependent parameters of which the latter agrees very well
with experimental results. 相似文献