液氮冲击压缩特性的理论计算

 用修正的WCA理论计算了液氮冲击压缩至70 GPa的一次冲击Hugoniot数据。计算中引入与体系比容有关的分子离解因子，计算结果表明，在33GPa以上液氮体系发生的相变为分子离解相变，该过程对体系热力学状态有较大影响，分子离解是对冲击能量的吸收过程，导致体系冲击压力和温度增长率下降。     

炸药爆轰产物液氮、液氦和水状态方程研究

 使用修正的WCA状态方程和Ross变分微扰理论研究了炸药爆轰产物（液氮、液氦和水）的冲击压缩特性,并利用exp-6形式的势函数计算分子间相互作用贡献的自由能。研究和计算经验表明,在研究高温高密度条件下液体的冲击压缩特性时,分子间多体相互作用十分重要,多体作用的结果是软化了两体相互作用势。     

液氮与液态一氧化碳混合物的冲击压缩特性研究

 利用二级轻气炮研究了等体积的液态一氧化碳（LCO）与液氮（LN₂）混合物的冲击压缩特性，在10～25 GPa压力范围内获得了5个Hugoniot数据点。混合物冲击绝热线位于单质一氧化碳和液氮Hugoniot拟合线之间，并靠近前者。这意味着混合物的冲击压缩特性不是其中各单质行为的简单平均。     

液态N2、CO冲击压缩特性研究

 介绍利用液氮致冷技术实现低温靶的冷却及样品气体的液化,并通过二级轻气炮对液态气体加载进行平面冲击压缩,实验分别测得10～57 GPa一次冲击压缩下液氮和液态CO的Hugoniot关系数据。这些实验数据结果显示,33 GPa以上比其以下更容易压缩,这种现象本质是氮发生离解相变消耗内能的一种表现形势。液态在20 GPa以下表现为一种稳定的压缩过程,而在其以上则伴随有较为复杂的化学反应现象产生。此外,实验研究还发现,20 GPa以下N₂和CO两种分子液体的冲击压缩特性非常相似。     

利用光分析方法测量液态CO多次冲击Hugoniot状态方程

 结合液氮低温靶技术和光分析方法同时测量液态CO样品的第一、二、三次冲击Hugoniot状态方程，分别在19、60和71 GPa获得3个数据点。样品体积的最大压缩度达到3.5倍，比文献发表的一次冲击最大压缩度提高20%以上。体积测量值比分子流体微扰变分理论的计算结果偏低20%以上，体积发生明显软化现象归因于CO分解反应所致。详述了多次冲击过程的光分析测量方法，该方法应用于其它分子流体可将其物态方程的实验数据点延伸到更高压力和更宽的压缩范围。     

33 GPa压力以下液氩冲击温度的实验测量

 利用液氮冷靶系统制取液氩样品，以二级氢气炮作为加载工具，驱动飞片对液氩样品进行平面冲击压缩，实验测量了33 GPa冲击压力以下液氩的冲击温度。飞片速度由磁测速系统测量，冲击波速度和冲击温度用光纤耦合高温计系统测量，粒子速度采用阻抗匹配法计算得到。实验测得当冲击压力为33 GPa时，液氩的冲击温度超过10 000 K；而当冲击压力超过30 GPa时，冲击温度的上升趋势与理论计算相比明显变缓，该压力点正好与以前测得的冲击波速度-粒子速度曲线的拐点一致。     

自由电子气冲击压缩特性的理论计算

用自由电子气模型对自由电子气(费米能为5 eV)的冲击压缩雨贡纽曲线、冲击温度进行了数值计算.冲击压力、内能和冲击温度被计算为压缩度的函数.计算结果表明,自由电子气(费米能为5eV)的冲击压缩极限近似为初始密度的4倍.     

自由电子气模型计算金属材料冲击压缩极限压缩度

用简单的自由电子气模型对金属铁、铜、铝、铅的冲击压缩特性进行了数值计算,计算结果表明材料并不能无限地被压缩,存在极限压缩度,随着压缩度的增加,在冲击压力增加的同时,冲击温度也急剧上升,限制了材料的进一步压缩,本文计算的这几种材料的极限压缩度为3.9.     

高温高密度条件下氮分子三体关联效应与冲击压缩特性

 基于量子化学从头计算方法，计算了处于高密度条件下氮分子之间的两体排斥势和三体关联势，并采用球面平均近似求得了它们各自的高温平均势能值，得到了包括三体关联效应的等效两体势函数与分子间距的解析关系。借助分子流体微扰变分理论，并考虑van der Waals长程作用，分别采用总平均两体势和总等效两体势，计算了液氮的冲击压缩曲线。计算结果表明，在不需要考虑分子离解的压缩范围内（1～35 GPa），三体关联效应的贡献使分子间总等效两体势函数比单独两个分子间总平均作用势函数明显软化，与实验Hugoniot数据结果一致。     

液氢、液氘冲击压缩特性的理论计算

用液体微扰变分理论,计算了液氢,液氘冲击压缩曲线-计算结果与Nellis实验相一致-计算所得冲击温度比Holmes的实验值明显偏高-对冲击压缩曲线与实验一致,以及冲击温度的计算值明显偏高于实验结果的原因进行了分析- 关键词：     

干涉现象中能量叠加的实验研究

经典的波动理论与量子理论均分别对杨氏双缝干涉实验进行了解释。由于两个解释理论一个简单直观、一个复杂抽象,但两者结果一致,使得学生在学习中容易接受波动理论而排斥量子理论。文中通过实验观测了杨氏双缝干涉光场中能量传递与叠加的实际情况,结果显示实验实际情况与波动理论解释明显不相符合,而与量子理论解释完全相符。通过实验,使学生直观地看到波动理论的局限性,并加深学生对量子力学相关理论的理解。     

The refined theory of deep rectangular beams based on general solutions of elasticity

The problem of deducing one-dimensional theory from two-dimensional theory for a homogeneous isotropic beam is investigated. Based on elasticity theory, the refined theory of rectangular beams is derived by using Papkovich-Neuber solution and Lur’e method without ad hoc assumptions. It is shown that the displacements and stresses of the beam can be represented by the angle of rotation and the deflection of the neutral surface. Based on the refined beam theory, the exact equations for the beam without transverse surface loadings are derived and consist of two governing differential equations: the fourth-order equation and the transcendental equation. The approximate equations for the beam under transverse loadings are derived directly from the refined beam theory and are almost the same as the governing equations of Timoshenko beam theory. In two examples, it is shown that the new theory provides better results than Levinson’s beam theory when compared with those obtained from the linear theory of elasticity.     

Dynamic non-linear response of beams subjected to impact loads

A non-linear theory is presented for plane deformation of beams which allows for longitudinal stretching as well as for cross-sectional stretching and shearing. The exact strain measures for this theory are also deduced. The longitudinal and flexural motions are coupled in the theory. If the cross section is constrained from stretching, the resulting theory may be classified as a non-linear Timoshenko beam theory. The equations of the latter theory are used to study the motion of beams under impact loads.     

Geometric Formulation of Gauge Theory of Gravity

Differential geometric formulation of quantum gauge theory of gravity is studied in this paper. The quantumgauge theory of gravity is formulated completely in the framework of traditional quantum field theory. In order to studythe relationship between quantum gauge theory of gravity and traditional quantum gravity which is formulated in curvedspace, it is important to set up the geometry picture of quantum gauge theory of gravity. The correspondence betweenquantum gauge theory of gravity and differential geometry is discussed and the geometry picture of quantum gaugetheory of gravity is studied.     

Associating fluids with four bonding sites against a hard wall: density functional theory

We present two new perturbation density functional theories to investigate non-uniform fluids of associating molecules. Each fluid molecule is modelled as a spherical hard core with four highly anisotropic square well sites placed in tetrahedral symmetry on the hard core surface. In one theory we apply the weighting from Tarazona's hard sphere density functional theory to Wertheim's bulk first-order perturbation theory. The other theory uses the inhomogeneous form of Wertheim's theory as a perturbation to Tarazona's hard-sphere density functional theory. Each theory approaches Tarazona's theory in the limit of zero association. We compare results from theory and simulation for density profiles, fraction of monomers, and adsorption of an associating fluid against a hard, smooth wall over a range of temperatures and densities. The non-uniform fluid theory which uses Tarazona's weighting of Wertheim's theory in the bulk is in good agreement with computer simulation results.     

Stability and vibration of isotropic,orthotropic and laminated plates according to a higher-order shear deformation theory

A higher-order shear deformation theory is used to determine the natural frequencies and buckling loads of elastic plates. The theory accounts for parabolic distribution of the transverse shear strains through the thickness of the plate and rotary inertia. Exact solutions of simply supported plates are obtained and the results are compared with the exact solutions of three-dimensional elasticity theory, the first-order shear deformation theory, and the classical plate theory. The present theory predicts the frequencies and buckling loads more accurately when compared to the first-order and classical plate theories.     

分子和金表面相互作用的DFT和HF研究之比较

从第一性原理出发,分别利用密度泛函理论和哈特利-福克方法优化了4 ,4-二巯基联苯分子的几何结构,计算了电子结构,讨论了分子与金表面的相互作用.结果表明,在描述分子的电子结构以及分子与金表面的相互作用时,密度泛函理论可以给出更好的结果.     

Simplicial vs. continuum string theory and loop equations

We derive loop equations in a scalar matrix field theory. We discuss their solutions in terms of simplicial string theory—the theory describing embeddings of two-dimensional simplicial complexes into the spacetime of the matrix field theory. This relation between the loop equations and the simplicial string theory gives further arguments that favor one of the statements of the paper hep-th/0407018. The statement is that there is an equivalence between the partition function of the simplicial string theory and the functional integral in a continuum string theory—the theory describing embeddings of smooth two-dimensional world-sheets into the spacetime of the matrix field theory in question.     

Derivation of the Bosonic Part of the Electroweak Chiral Lagrangian from a General Underlying Technicolor Theory

Bosonic part of SU(2)L U(1)Y effective chiral Lagrangian for electroweak symmetry breaking is derived from an underlying technicolor theory with no approximation. The underlying theory is assumed to be the most general gauge theory without fundamental scalars. A condensate is required to exist in the theory which breaks SU(2)L U(1)Y dynamically to U(1)em and the anomaly of the theory caused by gauge interaction must be cancelled. The formulation offers general definitions in terms of underlying theory for the low energy constants in effective chiral Lagrangian.``     

Scalar-tensor theories of gravitation: Foundations and prospects

A generalization of Einstein's theory is discussed in which the gravitation is described by a tensor and a scalar field. The theory is more consistent with Mach's principle and less reliant on absolute properties of space. The modification involves a violation of the “strong principle of equivalence” on which Einstein's theory is based. In the original version of this new theory, the “constant” of gravitationG is varying and particle masses are fixed. Later on another version of the theory was given in whichG is truly a constant and the particle masses vary. The two versions are related by a conformal transformation. The physical and mathematical foundations of this theory have been discussed and the field equations have been derived. The astrophysical and cosmological consequences of the theory have been elaborately reviewed.