OYZ不等式的初等证明

设Euclid空间n元点集,及其度量和所构成的单形的外接球半径分别为R_1,R_2,R.我们用完全初等的方法证明了OYZ不等式:R~2≤R_1~2+R_2~2.     

STRATIGRAPHICAL CLASSIFICATION OF JURASSIC AND CRETACEOUS IN CHINA

The stratigraphical provinces, subdivisions and correlations of the Early and MiddleJurassic, Late Jurassic, Early Cretaceous and Late Cretaceous are separately discussed accordingto their characteristics of palaeogeography, biogeography and sedimentation. The names forthe typical formations of each stratigraphical province or subprovince are also proposed inthis paper.     

GLOBAL EXISTENCE OF CLASSICAL SOLUTION FOR A VISCOUS LIQUID-GAS TWO-PHASE MODEL WITH MASS-DEPENDENT VISCOSITY AND VACUUM

In this work, we obtain the global existence and uniqueness of classical solu-tions to a viscous liquid-gas two-phase model with mass-dependent viscosity and vacuum in one dimension, where the initial vacuum is allowed. We get the upper and lower bounds of gas and liquid masses n and m by the continuity methods which we use to study the compressible Navier-Stokes equations.     

Quantum-chemical Investigations of Structures and Stabilities of Ethynyl-or Ethenyl-expanded [n]-Prismanes

Quantum-chemical calculations on some derivatives of [n]-prismanes expanded by ethynyl or ethenyl groups have been performed using density functional theory (DFT) method.Their geometric structures,electronic structures,vertical ionization potentials and vertical electron affinities have been obtained at the B3LYP/6-31G** level of theory.Meanwhile,the total strain energy has been investigated in detail and compared with [n]-prismane and other derivatives.The present paper has also computed the enthalpies of formation for different isomers so as to evaluate their thermal stabilities.     

FREE BOUNDARY VALUE PROBLEM OF ONE DIMENSIONAL TWO-PHASE LIQUID-GAS MODEL

n this paper,we study a free boundary value problem for two-phase liquidgas model with mass-depcndent viscosity coefficient when both the initial liquid and gas masses connect to vacuum continuously.Th...     

An Extension of the Mitrinovi c-Djokovi e Inequality

A certain generalization of the Mitrinovi c-Djokovi c inequality is proved by means of elementary calculus.     

L-S耦合中原子基态诸量子数的计算

由原子基态的电子组态所形成的可能状态中,能级最低的为原子的基态.在LS耦合中,利用原子中电子的壳层分布,应用洪特定则,可以推导出几个公式计算各种原子基态的总轨道角动量量子数L、总自旋角动量量子数S和总角动量量子数J.一、原子基态(L,S,J)的计算 大多数元素的原子中只有一个次壳层未被电子占满,计算时只需计及这一个次壳层中的电子,其他已占满的次壳层无需考虑.下面先讨论这种情形. 根据洪特定则,由同一电子组态所形成的原子状态中,S最大的态能级最低;具有相同S的态中,L最大的态能级最低.所以,由原子基态电子组态所形成的状态中,S…     

半量子群U≥0

设U^≥0表示一个固定单李代数的半量子群,给出了U^≥0的性质和表示. 证明了Hopf代数U^≥0不是拟余交换的,因此左U^≥0模范畴不是辫子monoidal范畴. 在权模范畴W中,给出了所有单对象和投射对象. 最后描述了所有单的Yetter-Drinfel'd U^≥0权模.