首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Laser-induced excitation spectra of the two bands ?(3)B(1)-;X(1)A(1), 2(1)(0) and 1(1)(0) of (32)SO(2) and (34)SO(2) have been recorded in a supersonic jet at a resolution of 0.015 cm(-1). The rotational and electron-spin fine structure has been analyzed for both isotopic species. Analysis of the rotational and electron-spin fine structure yields precise values of the rotational constants A, B, and C and the spin constants alpha and beta for both (32)SO(2) and (34)SO(2) in the states ?(3)B(1) (010) and (100). No interaction between these two vibrational states with any nearby triplet state is observed for rotational levels with J 相似文献   

2.
本文用通俗的方法介绍了广义相对论的基本思想 ,并得到了史瓦西场时空弯曲的规律及质点在史瓦西场中自由运动的规律 ,从而解决了引力红移 ,CS原子钟环地球飞行后与地面上 CS原子钟的时差 ,行星进动 ,光子经过太阳表面时的偏转角 ,雷达回波延迟等问题 .  相似文献   

3.
We find a mapping between antisymmetric tensormatter fields and the Weinberg 2(2j + 1)-componentbispinor fields. Equations which describethe j = 1 antisymmetric tensor field coincide with the Hammer-Tucker equations entirely and withthe Weinberg ones within a subsidiary condition, theKlein-Gordon equation. A new Lagrangian for the Weinbergtheory is proposed which is scalar and Hermitian. It is built on the basis of the concept ofWeinberg doubles. The origin of acontradiction between the classical theory, the Weinbergtheorem B – A = for quantum relativisticfields, and the claimed longitudity of the antisymmetrictensor field [transformed on the (1, 0) (0, 1)Lorentz group representation] after quantization isclarified. Analogs of the j = 1/2 Feynman–Dysonpropagator are presented in the framework of the j = 1 Weinberg theory.It is then shown that under a definite choice of fieldfunctions and initial and boundary conditions themassless j = 1 Weinberg–Tucker–Hammerequations contain all the information that the Maxwell equationsfor the electromagnetic field have. Thus, the formerappear to be of use in describing some physicalprocesses.  相似文献   

4.
We propose a new model with flavor-dependent gauged U(1)_(B-L_1)×U(1)_(B-L_2-L_3) symmetry in addition to the flavor-blind symmetry in the Standard Model. The model contains three right-handed neutrinos to cancel gauge anomalies and several Higgs bosons to construct the measured fermion masses. We show the generic features of the model and explore its phenomenology. In particular, we discuss the current bounds on the extra gauge bosons from the K and B meson mixings as well as the LEP and LHC data, and focus on their contributions to the lepton flavor violating processes of ?_(i+1) →?_iγ(i=1,2).  相似文献   

5.
《Nuclear Physics B》2002,627(3):403-444
We construct, using harmonic superspace and the quaternionic quotient approach, a quaternionic-Kähler extension of the most general two centres hyper-Kähler metric. It possesses U(1)×U(1) isometry, contains as special cases the quaternionic-Kähler extensions of the Taub-NUT and Eguchi–Hanson metrics and exhibits an extra one-parameter freedom which disappears in the hyper-Kähler limit. Some emphasis is put on the relation between this class of quaternionic-Kähler metrics and self-dual Weyl solutions of the coupled Einstein–Maxwell equations. The relation between our explicit results and the recent general ansatz of Calderbank and Pedersen for quaternionic-Kähler metrics with U(1)×U(1) isometries is traced in detail.  相似文献   

6.
An h-deformation of a (graded) Hopf algebra of functions on supergroup GL(11) is introduced via a contraction of GL q (11). The deformation parameter h is odd (Grassmann). A related differential calculus on h-superplane is presented.  相似文献   

7.
《Nuclear Physics B》2002,644(3):568-584
We investigate the possible regular solutions of the boundary Yang–Baxter equation for the vertex models associated with the An−1(1) affine Lie algebra. We have classified them in two classes of solutions. The first class consists of n(n−1)/2 K-matrix solutions with three free parameters. The second class are solutions that depend on the parity of n. For n odd there exist n reflection K-matrices with 2+[n/2] free parameters. It turns out that for n even there exist n/2 K-matrices with 2+n/2 free parameters and n/2 K-matrices with 1+n/2 free parameters.  相似文献   

8.
本文用密度泛函线性丸盒轨道原子球近似方法(DFT-LMTO-ASA)对(GaAs)_1(AlAs)_1(001)超晶格的电子结构进行了第一原理性计算。利用Lowdin微扰法在矩阵元中计入d态的影响,可使本文方法仅用阶数很小(32×32)的久期方程便可较满意地处理这个超晶格系统。计算并讨论了该超晶格的带隙,导带极小值处各本征态的分波特性以及GaAs和AlAs层间的价电子转移。我们的结果同最近用计算量大得多的从头算赝势法和完整势线性缀加平面波(FLAPW)法所得的结果进行了比较。结果表明,本文方法不仅具有合理的精度,而且有快速高效率的特点,更适于研究层数较多或结构更复杂的半导体超晶格,如(GaAs)m(AlAs)n等系统的电子结构性质。  相似文献   

9.
《Surface science》1987,182(3):L257-L262
The result of a recent study of atomic steps in the (1 × 1) to (1 × 2) surface reconstruction of Pt and Ir (110) planes using ns pulsed-laser heating can only be understood by highly correlated jumps of atoms within a small [110] atom-row. We argue in favor of a simultaneous jump of the entire small [110] row of atoms, possibly stimulated by surface phonon waves propagating in the direction normal to, and also parallel to, the atom-row direction. Surface reconstruction of fcc (110) planes evolves with long-range atomic diffusion, thus the transition occurs relatively slowly. Reconstruction of fcc (001) planes evolves with short-range atomic movements, and the transition occurs very rapidly.  相似文献   

10.
一、量子力学诞生的背景 在十九世纪末,经典物理学理论已经发展到相当完善的阶段。进入廿世纪后,对经典物理理论的研究转移到把这些理论应用于具体问题,因而逐渐脱离基本理论的范围。本世纪初,物理学的基本理论研究已进到近代物理的领域,主要集中在下面三个方面: 1.从经典电动力学的研究进入到相对论的研究。1905年爱因斯坦提出了狭义相对论,1917年又提出广义相对论,从此相对论不单是理论物理学家们竞相钻研的对象,而且为全世界所瞩目。狄拉克曾回忆道[1]:“当时一个奇特的事件发生了。相对论以极大的冲力来到了世界上。骤然间,每个人都谈论…  相似文献   

11.
浪淘沙·文心涨落无欲睹芳容,经典西东。北南风景枉玲珑。正看时光回转后,反演无穷。有意步萍踪,量子匆匆。对角一幕解三重。欲挽本征何处是,简并寒冬。Ⅰ.让声子来存储信息–热导回线在信息领域,热很大程度上是个坏小子。不过,也有时候,热导跟电导一样,是可以利用来存储信息的。与电输运比较,热输运毫无疑问比较慢、比较粗,且热量自由散漫惯了,难以驾驭,也是事实。  相似文献   

12.
正4量纲4.1量纲的明确定义学物理的人都知道量纲,但对它的理解往往若明若暗.何谓量纲?不同作者有不同回答.有书云:"量纲代表物理量的基本属性(终极性质)."述评(1)"属性"多了,量纲代表哪方面的属性?这句话未给出量纲的定义.(2)功和力矩是两个非常不同的物理量类,但在国际制中却有相同量纲.试问什么共同"属性"(或"终极性质")导致它们的量纲相同?你可能会说:"它们毕竟还是有共性  相似文献   

13.
在我们以前的理论研究中,给出了AB(1∏,J)+C(sli)→AB(1∏,J′)+C(slj′)碰撞诱导电子和转动传能的理论模型.为了进一步在理论上研究AB(1∏,J)+C(s1l1j1)→AB(1∏,J′)+C(s1l1j1′)+C(s2l2j2′)的电子和转动传能的电子量子干涉,以波恩奥本海默近似为基础,考虑各项异性Lennard-Jones相互作用势,给出了其理论模型.得出了衡量干涉程度的干涉角,对完全干涉的情况进行了讨论,得出了决定几率比的因素,此理论模型对理解和进行这种类型的实验是很重要的.  相似文献   

14.
Non-minimalSU(5) supergravity GUTs are analyzed in order to obtain theSU(5) andSU(2)×U(1) breakings à la Coleman-Weinberg as dynamical effects generated by the soft breaking terms, residues of supergravityN=1 (minimally coupled). Solutions are found that predict the existence ofSU(2)-triplets andSU(3)-octets as heavy asO(1 TeV). Supersymmetric Higgs masses, of the same order than the gravitino mass, must be introduced for the heavy, Σ(24), and lightH 1 (2),H 2 (2) sectors. Imposing the experimental bound \(m_{\tilde g} \gtrsim 60GeV\) , the lower boundsm 3/2?30 GeV, \(m_{\bar e} > 140GeV\) \(m_{\bar u} > 133GeV\) are obtained.  相似文献   

15.
本文研究了金属玻璃(Cu_(1-x)Ni_x)_(33)Zr_(67)的超导电性.测量了超导转变温度T_c、上临界磁场H_c_2和其它重要物理量.结果分析表明:这些金属玻璃属于弱耦合超导体.随着Ni含量增多,T_c提高.由(dH_c_2/dT)_(T_c)的测量得到费米面上电子态密度N(0).Varma-Dynes参数δ粗略地是常数.较高的N(0)相应于较高的T_c.N(0)是支配超导行为的基本参量.  相似文献   

16.
《Physics letters. [Part B]》1988,207(4):451-456
We supplement a previous discussion of baryosynthesis in flipped SU(5)×U(1) GUTs by including (1) the large incoherent field energy density which is likely SU(5) is broken, and (2) the possibility of additional Higgs triplet fields suggested by four dimensional string model-building. We consider strong (weak) reheating scenarios in which the Universe is (is not) SU(5) symmetric after inflation. We find an adequate baryon asymmetry subsequent to strong reheating, whatever the number of Higgs triplets (although beware of possible difficulties with quasi-stable relic particles), whereas weak reheating requires at least two Higgs triplets.  相似文献   

17.
We derive a class of inequalities for detecting entanglement in the mixed SU(2) and SU(1,?1) systems based on the Schrödinger-Robertson indeterminacy relations in conjugation with the partial transposition. These inequalities are in general stronger than those based on the usual Heisenberg uncertainty relations for detecting entanglement. Furthermore, based on the complete reduction from SU(2) and SU(1,?1) systems to bosonic systems, we derive some entanglement conditions for two-mode systems. We also use the partial reduction to obtain some inequalities in the mixed SU(2) (or SU(1,?1)) and bosonic systems.  相似文献   

18.
用四端引线法测量了Fe_(100-x)B_x(12≤x≤24)、(Fe_(1-x)Co_x)_(84)B_(16)(0.02≤x≤0.08)和(Fe_(1-x)Ni_x)_(84)B_(16)(0.02≤x≤0.08)非晶态合金的电阻率与温度的关系。实验结果得到,这三个非晶态合金系列在低温区都呈现出电阻率极小,极小值的温度T_(min)都在20K以下。电阻率极小的出现认为是类Kondo效应的贡献。在T>T_(min)温区,电阻率与温度的关系用推广的Ziman理论作了解释。  相似文献   

19.
本文研究了金属玻璃(Fe_(1-x)CO_x)_(78)Si_(10)B_(12)的磁化感生各向异性、应变感生各向异性随成分和温度的变化。磁化感生各向异性常数K_(um)为正值,x=0.7时为最大;不可逆的应变感生各向异性常数K_(usi)为正值,x=0.5时为最大;可逆的应变感生各向异性常数K_(usr)除了x>0.975区均为负值,在x=0.7时为最大;感生各向异性常数在温度变化时与M_s~α成正比,α在3.4和7.5之间随成分和退火工艺而变化。用短程有序模型解释了部分实验结果。  相似文献   

20.
本文为了进一步在理论上对AB(~1∑,J) C(~(S_1)l_(1i_1))→AB(~1∑,J′) C(~(S_1)l_((1j_1)′)) C(~(S_2)l_((2j_2)′))的转动传能量子干涉进行研究,提出了理论模型,此模型对理解和进行实验是非常重要的.在含时一级波恩近似的基础上,考虑各向异性相互作用势,推导出衡量干涉程度的干涉角,并讨论完全干涉的情况,得到影响几率比的因素.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号