INTERACTING BOSON-FERMION MODEL AND

A model Hamiltonian of interacting Boson-Fermion system is given and this modelHamiltonian is solved with siniority v≤2. The calculation shows that the back-ben-ding phenomana can be well discribed.     

THREE-DIMENSIONAL POTENTIAL SURFACES FOR BRIDGED MIXED-VALENCE DIMERS

A three-site model for bridged mixed-valence dimers was further developed in this paper.For the Creutz-Taube ion,the complex is delocalized with strong metal-bridge coupling.For deloca-lized complexes,we introduced a new set of bases (b,n,a) and derived a set of simpler, analytical expressions of three-dimens-onal potential sur-faces U_b,U_n and U_a by using the second-orderperturbation theory.The information of the absorption spectrum may be obtained directly from the potential surfaces.     

TWO NEW SOLVABLE DYNAMICAL SYSTEMS OF GOLDFISH TYPE

Two new solvable dynamical systems of goldfish type are identified, as well as their isochronous variants. The equilibrium configurations of these isochronous variants are simply related to the zeros of appropriate Laguerre and Jacobi polynomials.     

THE MOMENT OF INERTIA IN THE INTERACTING BOSON-FERMION MODEL

For a system described by the interacting boson-fermion model (IBFM),we construct the intrinsic states and study the moment of inertia of deformed odd-A nuclei in terms of the selfconsistent cranking calculation.An approximate analytic method for the energy spectrum is presented in the general cases where the IBFM Hamiltonian does not have dynamical symmetry.The rationality of this method is also discussed by taking ^153,155,157Eu isotopes as examples.     

两个严格可解的双原子分子势函数

提出了一个新的势函数，其Ｓｃｈｒ?ｄｉｎｇｅｒ方程严格可解．同时提出一个新的变量变换关系，严格求解了双曲型Ｐ?ｓｃｈｌ-Ｔｅｌｅｒ分子势Ｓｃｈｒ?ｄｉｎｇｅｒ方程的束缚态．得出的能级公式形式封闭、简单，归一化波函数用超几何级数表达．文献中关于Ｈｕｌｔｈéｎ势和修正Ｐ?ｓｃｈｌ-Ｔｅｌｅｒ势及无反射势的结果都作为特例包含在本文更一般的结论之中．最后，还讨论了本文势函数对双原子分子的实际应用． 关键词：     

贴体坐标系下模型加力室的大涡模拟

本文利用贴体网格对带V形槽稳定器模型加力燃烧室素流化学反应流流动进行大涡模拟的研究。采用区域法生成模型加力燃烧室的二维贴体网格,并采用多区域耦合法进行区域之间的数据传递,求解加力室整体流场。采用k方程亚网格尺度模型和亚网格EBU燃烧模型分别估算其亚网格紊流粘性和化学反应速率,用热通量辐射模型估算辐射通量,并用交错网格下SIMPLE算法和混合差分格式求解离散方程,壁面函数处理固壁边界条件。计算结果显示了稳定器后面的回流区气流结构,所得的热态流场模拟结果与实验比较吻合,表明采用贴体网格对模型加力燃烧室进行大涡模拟能真实反映流体流动及燃烧过程。     

复杂系统对流-扩散问题的多尺度关联模式与数值模拟

本文针对一类与时间相关的具有某种周期性的复杂系统对流-扩散方程,初步建立了介观与宏观耦合的多尺度分析的一般框架,并进行了数值实验。     

SOLVABLE SYSTEMS OF ISOCHRONOUS,MULTI-PERIODIC OR ASYMPTOTICALLY ISOCHRONOUS NONLINEAR OSCILLATORS

A simple technique is identified to manufacture solvable nonlinear dynamical systems, and in particular three classes whose generic solutions are, respectively, isochronous, multi-periodic, or asymptotically isochronous.     

双阱势Fokker-Planck方程准确解模型

采用Darboux变换和一个积分变换,获得了两类双阱势Fokker-Planck方程准确解模型。严格解的结果同Kranmers近似作了比较。 关键词：     

量子双阱势准确解模型

Darboux变换和一个积分变换用于变换Poschl-Teller势和改型Poschl-Teller势的薛定谔型方程,求得了两类双阱势可解模型。 关键词：     

严格可解四参数双原子分子势函数

提出一个四参数双原子分子势函数,对s波Schrdinger方程进行了严格求解,并采用一个简便的方法考虑了转动修正.该势函数对实验Rydberg-Klein-Rees曲线及振动-转动能级的计算精度远优于常用的Morse势,且将Morse势等势函数作为特例包括于其中. 关键词：     

FREQUENCY DOMAIN ARX MODEL AND MULTI-HARMONIC FRF ESTIMATORS FOR NON-LINEAR DYNAMIC SYSTEMS

Non-linear dynamic systems respond at frequencies other than the excitation frequency; however, standard frequency response function estimators for linear systems do not accommodate this harmonic distortion. A new multi-harmonic frequency response function estimator that utilizes discrete frequency models for non-linear systems is introduced here. The multi-harmonic estimator relates the frequency response at each frequency to the input and output spectra within a given frequency band in the same way that autoregressive exogenous input models relate inputs and outputs at particular samples in the time domain. Overdetermined, least-mean-squares calculations are used to minimize model error throughout a frequency band rather than at a single frequency as in the corresponding linear estimators. The resulting multi-harmonic frequency response function models are non-parametric (e.g., vary with amplitude) when linear functions are used and parametric when non-linear functions are used. A new sensitive indicator for experimentally characterizing non-linearity is introduced.     

A BOSON-FERMION DESCIPTION OF THE NUCLEAR MANY-BODY PROBLEM

A new formalism of the nuclear many-body problem is established in which one ean work with various physical state vector spaces consisting of both Fermions and Bosons, all being equivalent to the original one consisting only of Fermions.With the help of the usual commutation relations and anticommutation relations between the annihilation and creation operators of Boson and Fermion, a generalized state vector space is established, which contains all the physical spaces each being equivalent to the original physical space in terms of pure Fermion operators. Transformation between the state vectors in various equivalent physical spaces are constructed. Basic operators in the original state space are transformed into effective operators in the new physical spaces.     

MASTER EQUATION FOR QUANTUM SYSTEMS

The Master equation for quantum systems with strong interaction is derived, and the condition for its validity is discussed.     

吡嗪桥接混合价二聚体中的光吸收

本文提出一个包括吡嗪环内部结构的多模模型来研究吡嗪桥接含Ru混合价二聚体(即C-T离子)。在C-T离子中,两个Ru离子的4d_xz电子轨道经过吡嗪环的π^*轨道相互耦台,把这些轨道重新组合成键合(B)、非键合(N)和反键合(A)三种类型;构成三个多维势表面,而把有关的光吸收归于电子在相应的势表面之间的跃迁,所得的结果更接近实验事实。 关键词：     

NEW EXACTLY SOLVABLE SUPERSYMMETRIC PERIODIC POTENTIALS

Using the formalism of supersymmetric quantum mechanics, we give an exact solution for a family of one-dimensional periodic potentials, which are the supersymmetric partners of the potential proportional to the trigonometric function cos(2x) such that the Schr?dinger equation for this potential is named the Mathieu equation mathematically. We show that the new potentials are distinctly different from their original ones. However, both have the same energy band structure. All the potentials obtained in this paper are free of singularities.     

冰箱系统毛细管计算模型

冰箱系统毛细管计算模型赵晓宇，韩礼钟，朱明善（清华大学热能工程系北京１０００８４）关键词：计算模型，毛细管，冰箱１研究背景毛细管是普遍使用于小型制冷设备中的节流装置，它对制冷系统的连续运行起着重要作用，又有结构简单、价格低廉、无运动部件、系统充液量少...