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1.
杜占英 《物理通报》2007,(10):62-63
有些学生平时对相互作用的理解存在一些错误认识,总起来有以下几个方面.  相似文献   

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The equilibrium equation is derived for an ordered phase for various types of superstructures. It is used to analyze the predictions of the Gorskii-Bragg-Williams model regarding the nature of the order-disorder transition. The stability boundaries of the ordered and disordered state are analyzed (for an equiatomic stoichiometry of the superstructure); these boundaries coincide with the lines of a second-order transition.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii Fizika, No. 1, pp. 101–107, January, 1970.  相似文献   

5.
The concentration dependence predicted for the degree of long-range order at constant temperature by the Gor'skii-Bragg-Williams model is analyzed. It is shown why the AB3 superstructure cannot form during equilibrium ordering of a solution with cB < 0.5. It is shown that this model predicts a (usually metastable) equilibrium of two ordered phases (based on the A3B and AB3 superstructures) in a certain concentration range.Translated from Izvestiya VUZ. Fizika, No. 7, pp. 43–47, July, 1970.  相似文献   

6.
In a parameterized three-dimensional system of autonomous differential equations, a T-point is a point of the parameter space where a special kind of codimension-2 heteroclinic cycle occurs. If the parameter space is three-dimensional, such a bifurcation is located generically on a curve. A more degenerate scenario appears when this curve reaches a surface of Hopf bifurcations of one of the equilibria involved in the heteroclinic cycle. We are interested in the analysis of this codimension-3 bifurcation, which we call T-point-Hopf. In this work we propose a model, based on the construction of a Poincaré map, that describes the global behavior close to a T-point-Hopf bifurcation. The existence of certain kinds of homoclinic and heteroclinic connections between equilibria and/or periodic orbits is proved. The predictions deduced from this model strongly agree with the numerical results obtained in a modified van der Pol-Duffing electronic oscillator.  相似文献   

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The state diagrams predicted by the GBW model are analyzed for ordered alloys with fcc and hcp lattices. Features of these state diagrams are discussed.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 118–126, January, 1971.  相似文献   

8.
刘永录  钟鸣  李成飞 《大学物理》2013,(2):22-24,30
大学物理教学中,一些基本概念的讲授不仅对于物理概念本身的深化十分重要,而且对于现代物理学思想的把握和对后续课程的学习也具有十分重要的作用.通过讨论角动量及其在宇称变换下的性质,我们介绍了轴矢量的概念,并在量子力学层次对宇称变换进行了分析,将量子力学层次的态函数和场算符进行了分类,同时说明了在基本粒子物理研究当中对复合粒子进行分类时一个重要的量子数——宇称.  相似文献   

9.
There is a type of nodal surface imposed by symmetry on wavefunctions.These surfaces are crucial to the ordering of low-lying states.Based on an analysis of this type of surface and based on existing theoretical results,the feature of the low-lying spectrum of the He-tetramer is studied,and the candidates of bound states and narrow resonances are suggested.  相似文献   

10.
航天TDI-CCD亚像元相机的MTF研究   总被引:11,自引:4,他引:7  
张毅    李英才  王虎   《光子学报》2005,34(10):1590-1592
讨论了不同步采集和偏流角带来的像移对航天TDI-CCD亚像元相机系统相机调制传递函数的影响.通过对成像工作方式中所产生的速度失配和方向失配的调制传递函数影响的分析,得出了提高相机采集同步精度和消除偏流角的方法.  相似文献   

11.
采用 FI- IR红外光谱仪对德州清陨石的不同部位进行测定 ,确定了清陨石的组分和分类。  相似文献   

12.
The equations of motion of a test particle are integrated for the field of a rotating Kerr black hole (BH) (in accordance with [1]). Due to the lack of analytical transformations for the Carter–Penrose diagrams (CPDs) for the Kerr metric, the topology of the Kerr BH is studied by analytical investigation of the equations of motion. Transformations for the CPDs for the Reisner–Nordström metric are analyzed. The problem of boundary conditions for the Reisner–Nordström topology is analyzed. A solution to this problem of boundary conditions is proposed. It is proved that, in the Reisner–Nordström topology, only one way to go to another universe is possible. For the Kerr topology, the possibility of the existence of an alternative transition to another universe that does not coincide with the universe for the ordinary transition is found. This alternative transition is performed through a surface with a zero radial coordinate (zero radius). Initial conditions for the falling particle are found that correspond to an alternative transition to another universe. The tidal forces acting on a falling body in the Kerr metric are estimated, and the possibility of the transition of the body to other universes without being destroyed by tidal forces is proved.  相似文献   

13.
We present results of a spin-parity analysis of the system from threshold to 1.52 MeV based on 12 500 events of the type K?p→K?π+π?πop at 7.3 GeV/c. We also present evidence for a possible resonant state decaying into at a mass 1710 ± 15 MeV and width 110 ± 50 MeV.  相似文献   

14.
We perform a frequency analysis of the EPR-Bell argumentation. One of the main consequences of our investigation is that the existence of probability distributions of the Kolmogorov-type which was supposed by some authors is a mathematical assumption which may not be supported by actual physical quantum processes. In fact, frequencies for hidden variables for quantum particles and measurement devices may fluctuate from run to run of an experiment. These fluctuations of frequencies for micro-parameters need not contradict to the stabilization of frequencies for physical observables. If, nevertheless, micro-parameters are also statistically stable, then violations of Bell's inequality and its generalizations may be a consequence of dependence of collectives corresponding to two different measurement devices. Such a dependence implies the violation of the factorization rule for the simultaneous probability distribution. Formally this rule coincides with the well known BCHS locality condition (or outcome independence condition). However, the frequency approach implies totally different interpretation of dependence. It is not dependence of events, but it is dependence of collectives. Such a dependence may be induced by the same preparation procedure.  相似文献   

15.
快慢Lorenz-Stenflo系统分析   总被引:1,自引:0,他引:1       下载免费PDF全文
韩修静  江波  毕勤胜 《物理学报》2009,58(7):4408-4414
通过对系统的重新标度,得到了气流旋转缓慢变化时的Lorenz-Stenflo系统;基于Routh-Hurwitz准则,分析了平衡点的稳定性问题,得到了参数平面上的分岔集,这些分岔集将参数平面划分为不同的区域,在各个不同的区域对应于系统不同的解.随着参数的变化,从平衡点分岔出不同的解.此外,展示了系统的对称簇发解和对称混沌吸引子,并用快慢分析法给出了对称簇发解的产生机理. 关键词: Lorenz-Stenflo系统 快慢分析法 分岔 对称簇发  相似文献   

16.
The Karmarkar-Karp differencing algorithm is the best known polynomial time heuristic for the number partitioning problem, fundamental in both theoretical computer science and statistical physics. We analyze the performance of the differencing algorithm on random instances by mapping it to a nonlinear rate equation. Our analysis reveals strong finite size effects that explain why the precise asymptotics of the differencing solution is hard to establish by simulations. The asymptotic series emerging from the rate equation satisfies all known bounds on the Karmarkar-Karp algorithm and projects a scaling n c ln n , where c = 1/(2 ln 2) = 0.7213 .... Our calculations reveal subtle relations between the algorithm and Fibonacci-like sequences, and we establish an explicit identity to that effect.  相似文献   

17.
Korenblit  S. E.  Lovtsov  S. V.  Sinitskaya  A. V. 《JETP Letters》2019,110(5):307-312
JETP Letters - The pre-asymptotic analysis of the multichannel scattering problem for particles with an arbitrary spin and short-range interactions has been presented. The complete operator-valued...  相似文献   

18.
An implementation of algorithms for constructing and analyzing the cluster structure for a square quadruply connected lattice in the uncorrelated percolation problem is considered. Subsets of the complete superior hull and the skeleton of a percolation cluster are singled out using a modification of the Hoshen—Kopelman relabeling algorithm and the Bellman principle of optimality. The critical nature of the percolation process is demonstrated using the method for statistical tests, and the behavior of mass dimension is analyzed for various subsets of a percolation cluster.  相似文献   

19.
近红外定性分析模型的稳健性与适应性分析   总被引:1,自引:0,他引:1  
研究了近红外定性分析中模型的稳健性与适应性问题。讨论了单独建模延长建模周期对模型性能的影响,结果显示这种方法可以显著提高模型的稳健性,同时对模型的台间适应性也有所提升,但提升作用有限;研究了不同仪器联合建模的方法对模型性能的影响,该方法不仅可以显著提高模型的适应性,而且可以有效提高模型的稳健性。对比单独建模,可以缩短建模时间,减少模型建立的工作量;延长模型的适用期限,提高建模效率。结果表明,对模型适应性的测试,单独建模其正确识别率较低,不能满足应用的要求,而多台仪器联合建模可以达到90%以上,提升效果明显;对模型稳健性的测试,联合建模也能得到相比单独建模更好的模型识别效果,具有很好的应用价值。  相似文献   

20.
Summary The room temperature phosphorescence of crystalline thianthren in the 1.6–3.3 eV energy region has been measured using time delays going from 0.03 to 9.5 ms. The time dependence of the emission spectra which show the presence of three resolved bands, was analysed by means of a numerical best-fitting procedure, and the results obtained have been compared with those predicted by means ofab initio and semiempirical molecular orbital calculations.  相似文献   

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