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1.
假定二元液态混合物分子间的相互作用势能可以表示成多体相互作用势能的和 ,分子间的力为短程力 ,相互作用势能只与分子间的相对距离有关 .利用分布函数理论导出了二元液态混合物的过剩内能和内压的公式 .二元液态混合物的过剩内能和内压可以表示成体积的幂级数形式 ,其中的系数可以用多体相互作用势和多体径向分布函数表出 .讨论了单元液体的内压和过剩内能的表达式 ,在两种特殊情形下 ,过剩内能和内压的表达式分别与Egelstaff的微扰论结果及Frank的实验结果具有相同的形式 .讨论了二元混合物内压和内能的两个特例 ,其一 ,在特殊情形下 ,给出了混合液体过剩内能的混合规则的一个证明 .其二 ,给出的二元混合物的过剩内能和内压的表达式与Frank的实验结果具有相同的形式  相似文献   

2.
低密度溶液中溶剂的重组织性质   总被引:1,自引:0,他引:1       下载免费PDF全文
分析了溶液的微观结构 ,结果表明 ,单个溶质粒子影响其周围的溶剂的结构 ,溶质粒子间的相互作用也将影响溶剂的结构 ,溶质对溶剂结构的影响称作溶剂的重组织 .提出了二阶重组织能及二阶重组织熵等概念 ,可以描述在两个溶质粒子发生碰撞时对其周围溶剂结构的影响 .利用二元系的集团展开理论 ,给出了溶剂的一阶、二阶重组织能和重组织熵的表达式 .统计热力学分析给出了溶剂 溶剂径向分布函数与溶质和溶剂化学势之间的关系 ,给出了无限稀溶液模型是否成立的宏观判据 .提出的理论可用于低密度的二元溶液 .  相似文献   

3.
本文测定了DMF-H_2O和DMF-D_2O体系在全部浓度范围内(摩尔分数为0~1)DMF分子中四极核 ̄(14)N的弛豫时间,讨论了弛豫的溶剂同位素效应和影响四极核弛豫的因素。研究结果表明,体系中 ̄(14)N的弛豫与溶剂水分子的动力学行为有着密切的联系,在无限稀释条件下溶质分子的运动完全受溶剂分子的控制.  相似文献   

4.
液体的内压和内能的统计热力学理论   总被引:2,自引:0,他引:2  
利用分布函数理论导出了液体的内能和内压公式。液体的内压和过剩内能可以表示成体积的幂级数形式,其中的系数可以用多体相互作用势和多体径向分布函数表出,它们仅仅与温度有关。讨论了液体仅存在第n次多体相互作用势情的内压和过剩内能的表达式,结果与Egelstaff的微扰理论结果具有相同的形式,不仅给出了相应参数的表达式而且适用于多体相互作用较强的情形,定义了物性参数α(T)和m,得到的液体过剩内能和内压的表达式与Frank实验结果具有相同的形式,其结果不仅给出了参数α(T)和m的表达式,而且指出了Frank的过剩内能和内压公式只适用于参数α(T)和m与体积无关的液体。  相似文献   

5.
n维理想玻色气体性质的普遍描述   总被引:10,自引:4,他引:6  
给出了在T>Tc和T<Tc情况下能谱为ε=ap^s的n维简并理想玻色色体的内能、熵、状态程和热容量和普遍表达式。指出存在两种类型的玻以-爱因斯坦凝聚。  相似文献   

6.
详细研究了香豆素-1在环己烷-醇、1,4-二氧六环-水二元溶剂及环糊精,表面活性剂溶液体系中的荧光光谱。通过溶剂-溶质分子间氢键作用及对其非荧光性的TICT态形成的影响。讨论了这种荧光探针的荧光光谱对环境极性非常敏感的原因,测定了它与环糊精的包结常数和与表面活性剂胶束的结合常数。  相似文献   

7.
本文研究了N,N-二甲基苯胺分子在环已烷和苯混合溶剂中的^1HNRM谱的溶剂效应,观察到N,N-二甲基苯胺分子内的两个甲基和混合溶剂的苯-环已烷的化学位移随苯的摩尔分数增加而逐渐移向高场,ASIS值随苯的摩尔分数增加而增加。得到了所有化学位移植和ASIS值与苯的摩尔分数呈线性关系,尝试用溶剂化作用解释了苯对N,N-二甲基苯胺的ASIS效应。  相似文献   

8.
本文研究了N,N-二甲基苯胺分子在环已烷和苯混合溶剂中的1HNMR谱的溶剂效应,观察到N,N-二甲基苯胺分子内的两个甲基和混合溶剂中的苯、环己烷的化学位移随苯的摩尔分数增加而逐渐移向高场,ASIS值随苯的摩尔分数增加而增加。得到了所有化学位移值和ASIS值与苯的摩尔分数呈线性关系;尝试用溶剂化作用解释了苯对N,N-二甲基苯胺的ASIS效应。  相似文献   

9.
飞秒荧光亏蚀光谱技术研究液相体系取向弛豫   总被引:1,自引:0,他引:1  
溶液中分子的快速弛豫过程直接反映了溶液中溶质和周围溶剂分子间的相互作用[1- 3 ] .在液相体系中分子取向通常是随机分布的 .当溶质分子被线偏振光激发至激发态时 ,其分子取向将由原来各向同性的球形分布瞬间变成各向异性的椭球分布 .由于溶质分子周围大量溶剂分子的存在 ,通过二者之间相互作用 ,激发态溶质分子在一定方向上的取向优势将很快弛豫掉 .这种溶液中的取向弛豫过程通常是几个到几百皮秒[1- 3 ] .飞秒分辨荧光亏蚀光谱原理和实验方法见文献[4 - 7] .当溶液中的溶质分子被线偏振飞秒激光脉冲激发至电子激发态时 ,经过一定的延迟…  相似文献   

10.
附加克尔介质Jaynes-Cummings模型的场熵演化   总被引:8,自引:0,他引:8  
方卯发  刘惠恩 《光学学报》1994,14(5):475-479
研究了附加克尔(Kerr)介质Jaynes-Cummings(J-C)模型场熵演化的动力学特性,讨论了克尔介质非线性相互作用以及失谐量对场熵演化的影响.  相似文献   

11.
We investigate self-diffusion in a classical fluid composed of two species which are distinguished through the color of their particles, either black or white, but are identical as regards their mechanical properties. Disregarding color the fluid is in thermal equilibrium. We show that if a single test particle in the one-component fluid moves asymptotically as Brownian motion, then the color density and current in certain classes of nonequilibrium states are related, on the appropriate macroscopic scale, through Fick's law, and the former is governed by the diffusion equation. If in addition several test particles move asymptotically as independent Brownian motions, then the colored fluid is, on a macroscopic scale, in local equilibrium with parameters governed by the solution of the diffusion equation.Part of this work was done while both authors were at IHES, Bures-sur-Yvette, France.Supported in part by NSF Grant No. PHY 78-15920-02.Supported by a Heisenberg fellowship of the Deutsche Forschungsgemeinschaft.  相似文献   

12.
We present identities relating the equations of motion of various quasiprobabilities for quantum oscillators. These identities turn out useful for checking the consistency of approximations made in constructing the equations of motion with the basic Bose commutator. Moreover, our identities allow to identify the quasiprobability distributions which have the easiest-to-solve equations of motion.  相似文献   

13.
14.
Currently, there are many types of virtual displays and new types arise every year. However, their vast majority appear technically inapplicable because they are inconsistent with a number of key factors related to the eye physiology. In this paper, we present the general requirements for optical systems of virtual displays, taking into account human eye physiology.  相似文献   

15.
How should one select the best detector for a particular measurement in energy dispersive X‐ray fluorescence (EDXRF)? How should one select the optimum system configuration, i.e. the best shaping time and beam current? Manufacturers provide a variety of specifications, such as energy resolution and maximum count rate, but these are indirectly related to the end use of an EDXRF instrument, the measurement and detection limit of the measured elemental concentrations. We suggest in this paper using the time required to achieve a given statistical uncertainty as a figure of merit. We derive scaling rules for this figure of merit based on conventional specifications, including energy resolution, peaking time, maximum count rate, detector area, and intrinsic efficiency. These scaling rules also include the peak to background ratio of a photopeak and the number of overlapping peaks. We then show how this figure of merit can be used to select the optimum detector and spectrometer configuration for specific applications and compare the results to data obtained with typical systems. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

16.
《光学技术》2013,(6):517-521
为了解决具有大畸变内窥镜标定的标志点提取困难和人工参与较多等问题,提出了一种简单快速准确的棋盘格标志点提取方法。该方法是采用粗提取和优化来完成棋盘格标志点的提取的:首先利用高斯滤波去除图像噪声,并计算两次图像的梯度特征,利用梯度极值约束得到粗提取的角点;然后利用棋盘格标志点的对称特点消除噪声点的影响,并得到优化的角点位置。实验结果表明,该方法简单易行,计算量小,不需要人工干预即可获得全部标志点,反投影误差小于0.2pixel。  相似文献   

17.
Memory for pitch versus memory for loudness   总被引:5,自引:0,他引:5  
The decays of pitch traces and loudness traces in short-term auditory memory were compared in forced-choice discrimination experiments. The two stimuli presented on each trial were separated by a variable delay (D); they consisted of pure tones, series of resolved harmonics, or series of unresolved harmonics mixed with lowpass noise. A roving procedure was employed in order to minimize the influence of context coding. During an initial phase of each experiment, frequency and intensity discrimination thresholds [P(C) = 0.80] were measured with an adaptive staircase method while D was fixed at 0.5 s. The corresponding physical differences (in cents or dB) were then constantly presented at four values of D: 0.5, 2, 5, and 10 s. In the case of intensity discrimination, performance (d') markedly decreased when D increased from 0.5 to 2 s, but was not further reduced when D was longer. In the case of frequency discrimination, the decline of performance as a function of D was significantly less abrupt. This divergence suggests that pitch and loudness are processed in separate modules of auditory memory.  相似文献   

18.
Expressions for third-order aberration in the reconstructed wave front of point objects are established by Meier. But Smith, Neil Mohon, Sweatt independently reported that their results differ from that of Meier. We found that coefficients for spherical aberration, astigmatism, tally with Meier’s while coefficients for distortion and coma differ.  相似文献   

19.
In this paper we will study a function of simultaneous measurements for quantum events (s-map) which will be compared with the conditional states on an orthomodular lattice as a basic structure for quantum logic. We will show the connection between s-map and a conditional state. On the basis of the Rényi approach to the conditioning, conditional states, and the independence of events with respect to a state are discussed. Observe that their relation of independence of events is not more symmetric contrary to the standard probabilistic case. Some illustrative examples are included.  相似文献   

20.
In this paper we obtain the differential equations which describe the rotating rod and precession of the spin of a gyroscope moving along a curved trajectory. Several examples of such motion are considered. The obtained equations differ from the traditional Thomas expression, interpreted as a rotation of the noninertial frame relative to the fixed one. The cause of this disagreement is the fact that, in general, the axes of the moving frame are not orthogonal for the fixed observers. When the velocity changes, the axes’ direction changes, due to both Wigner rotation and Lorentz contraction. In the present paper we take into account both of these factors. It is shown that the vectors representing various physical quantities transform in different ways in the moving reference frame. Thus, the kinematic equations describing the motion of these quantities in a fixed frame are different as well.  相似文献   

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