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推导出了势垒贯穿问题中当∪0=E时的透射系数表达式,并利用该公式圆满解释了《大学物理》刊出的一篇题为《从一道习题看量子力学中的势垒》文章中提出的问题. 相似文献
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粒子在经过一个势垒时,无论粒子能量和势垒高度存在怎样的关系,理论上都有一定的透射.本文用Matlab软件探讨了粒子对于宽度为n*a的势垒和n重宽度为a的势垒进行贯穿时的透射系数.研究结果说明:在E/U1情况下,宽度为na的势垒的贯穿透射系数较n重宽度为a的势垒的贯穿系数大;当E/U1时,情况则相反. 相似文献
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本文报道关于内部电势对低频交流电压介观电子输运的影响.内部电势的典型特征是保证电荷守恒和规范不变性.在大多数情况下,内部电势很快达到自身平衡,并且系统响应为外部变量.然而,在一些特殊情况下,内势变得自发振荡和随机涨落,在这种情况下系统将变得不稳定. 相似文献
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普通物理学中有这样一道习题:如图所示,一质量为m,半径为R的刚性圆柱,在水平外力F作用下,在一刚性水平面上作无滑滚动,力的作用线与圆柱中心轴线的垂直距离为r,求圆柱所受的静摩擦力. 相似文献
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电磁感应教学中有教师会让学生记忆电荷量与磁通量变化量、导体棒切割运动的位移成正比的结论.以一道含容电路试题为例,分析指出电磁感应含容电路问题中该结论的错误,并提供了正确的设问范例. 相似文献
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We show that the width for thermal barrier penetration (Γout) of a classically trapped (complete-fusion) trajectory can be important and that this decay mode may explain the enhanced fusion-fission yield observed in some systems. 相似文献
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N. I. Zhirnov 《Russian Physics Journal》1966,9(6):56-60
The approximation method, discussed in [1], of calculating the coefficients of penetration through one-dimensional potential barriers is unsuitable at small values of the energy. In the present work this insufficiency is removed by applying some additional conditions to the basic potential W(S). A new solution is given for the problem of particle penetration through a symmetric barrier. 相似文献
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研究闪光照相中影响材料有效吸收系数的两个主要因素,即X光的能谱效应和散射影响。用Monte-Carlo方法对闪光照相系统的客体各种组成材料的有效吸收系数进行数值模拟;求出不考虑散射而仅受能谱影响的有效吸收系数及其空间分布,发现该分布类似于医学CT数的分布规律,在高光程数对应的位置上该吸收系数较低;也得到了在20MeV闪光机情况下,客体各种组成材料的单个平均吸收系数。结果表明:钨、铝和铁的平均等效吸收系数分别近似为0.830,0.080和0.265cm
-1。 相似文献
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P. Zeyen B. Ackermann U. Dämmrich K. Euler V. Grafen C. Günther P. Herzog M. Marten-Tölle B. Prillwitz R. Tölle Ch. Lauterbach H. J. Maier 《Zeitschrift für Physik A Hadrons and Nuclei》1987,328(4):399-407
TheK π=0? bands in even uranium nuclei were studied in the compound reactions231Pa(p, 2n)230U,230, 232Th(α,2n)232, 234U and236U(d, pn)236U. In-beamγ-rays were measured in coincidence with conversion-electrons, which were detected with an iron-free orange spectrometer. The negative-parity levels are observed up to intermediate spins (I<13?). In addition, the 1? and 3? levels in230U were confirmed by a decay study with an isotope separated230Pa source. For the heavier isotopes (A≥232) the properties of theK π=0? bands (energies andγ-branchings) are consistent with a vibrational character of these bands. For230U theK π=0? band lies at rather low energy (E(1?)=367 keV), and the level spacings within this band are very similar to those of the isotones228Th and226Ra, which might indicate the onset of a stable octupole deformation. 相似文献
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Recently the replica limit n = 0 of the U(n) and
models have attracted interest since they describe the Anderson localization behaviour in the band-centre of a two-sublattice model. For n ≠ 0 the theories can be decomposed into one with symmetry U(1) and one for SU(n) and
. This does not no longer hold for n = 0. We show how the beta-functions and zeta-functions for operators without derivatives can be obtained in this limit from those of SU(n) and
and draw consequences for these functions in this limit. 相似文献
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The relevance of tunneling in determining the cross section for complete fusion is explored. The classical model with frictional forces is used for the determination of the trajectory of two heavy ions up to the classical turning point. The penetrability of the barrier is calculated quantum mechanically. It is shown that the so calculated transmission coefficient differ from the sharp cut-off approximation, but yield cross section for complete fusion which are not significantly different from the cross section neglecting quantum mechanical effects. 相似文献
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《Nuclear Physics A》1988,485(1):136-160
A decay scheme for the 130±20 ns high-spin isomer in 182Os has been established. The excitation energy of the isomer is 7049±1 keV and it has Iπ = 25(+). A 2.4% decay directly to the yrast 24+ level at 5988 keV is observed. In 184Os a 20±5 ns isomer is observed at 2366±1 keV excitation energy with Iπ = 10+. Again, direct transitions into the yrast 8+ and 10+ levels are observed. Contrary to previous speculations, there is no compelling evidence for stable triaxial shapes in the structure of the levels through which the isomers decay. The abnormally short half-lives observed, as well as the unusual decay patterns, are best understood in terms of a γ-soft nuclear potential. Motion in the γ-direction allows the isomer to decay via barrier penetration from an axially symmetric prolate shape with the angular momentum along the nuclear symmetry axis (deformation aligned state) via oblate shapes to another prolate shape with the angular momentum perpendicular to the nuclear symmetry axis (rotation-aligned state). 相似文献
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The least action principle is used to determine the semiclassical path in the penetration of a multidimensional fission barrier using the gap parameter as a dynamical variable. An increase in the gap parameter, the larger the deeper the penetration of the barrier is predicted. 相似文献