分子光化学贮存太阳能 Ⅲ.双环[2,2,1]-2,5-庚二烯的光诱导电子转移敏化异构化反应

以N,N,N′,N′-四甲基联苯二胺、2,6-二甲氧基萘和2,7-二甲氧基萘为光敏剂,在正己烷溶液中实现了双环[2,2,1]-2,5-庚二烯到四环[2,2,1,0^2,6,0^3,5]庚烷的异构化。测定了反应的量子产率。讨论了反应机理。通过激发态的光敏剂与二烯之间的电子转移反应,形成单重态和三重态处于平衡状态的离子自由基对中间体。处于溶剂笼中的三重态离子自由基对经电子反传,产生激发三重态二烯。最后该激发态二烯经分子内[2+2]环合加成反应异构化为四环烷。     

SOME REPRESENTATIONS FOR TIME-DEPENDENT HARMONIC OSCILLATOR

In terms of the IWOP (integration within ordered product) technique, we construct squeezed state formulatiion for the time-dependent harmonic oscillator.The formulation is based on the Lewis-Riesenfeld quantum theory.Some other representations are also found with the same technique.     

THE GAUGE OPERATORS FOR PSEUDOSCALAR FIELDS AND THE BAKER-HAUSDORFF FORMULA

In this paper, we present the explicit expressions of the gauge operators for pseudoscslar fields in a gauge theory coupled vector and axial-vector fields with the aid of the method of operator algebras.The gauge operators of the pure gauge field theory under the chiral group SU(N)×SU(N) are also presented. P9oreover, the explicit expression of the Baker-Hausdorff formula is obtained for a special case and the general situation is discussed.     

Analytical solution of partial differential equations for radial transport of a solute in double porous media

The mathematical model for radial transport of a solute is summed up in this paper. The action of non-equilibrium linear adsorption, the double property of porous media and the decay of solute are considered. With the first kind of boundary condition, one finds the analytical solution of these equations by Laplace transform and calculates the dimensionless solution by FORTRAN program with DJS-040. The distribution and change of solute are evaluated and the solution under various limit cases is given. By numerical analysis, one obtains some valuable conclusions.     

QUANTUM FIELD THEORY IN EXTERNAL SOURCE:COHERENT STATE AND EIGENSTATES OF FIELDS

The real scalar field and the spinor field with external sources present are studied. The relationship between external sources and coherent states is given. In the case of real scalar field the eigenstates of field and its canonically conjugate field are derived in terms of coherent state and functional integration techniques. For a fermion field, it is demonstrated that Schwinger's external sources technique can lead to the spinor coherent states, with which we can also derive the eigenstates of fie3d operators and their conjugate field operators.The Yang-Feldman equation with the Grassmann sources is also obtained.     

NEW OPERATOR IDENTITIES GAINED VIA COHERENT STATE FORMULATION

By the properties of the coherent state and the technique of performing integrations within ordered products as in Ref. [1], we derive some new useful operator ordering identities. Their applications, especially in studying the Boglyubov transformations both in one and two dimensional cases, are presented. The explicit non-unitary operators which turn the coordinate or momentum eigenstate to the corresponding coherent state are also given. Moreover,by using t h e Schwinger angular momentum theory and the technique mentioned above we f!nd the normal product form of the rotation operator, with which the coefficient of the rotation D-matrix can be easily obtained.     

CALCULATING DENSITY OPERATOR FROM DIAGONAL COHERENT STATE REPRESENTATION

By means of combining normal product's properties we put forward to a formulation for obtaining density operators from Glauber-Suaaishan "P repre-sentation" and other non-diagonal representations directly in the coherent's properties with the quantum optics.     

几种新液晶作固定液分离二元取代苯异构体

Kelker和Dewar等人曾把液晶用作气相色谱固定液分离二元取代苯异构体取得很好的效果,此后很多研究者把近两百种液晶亦都用于气相色谱固定液。在研究和使用的液晶固定液中,芳羧酸酯类液晶被认为具有较好的热稳定性和分离选择性,国内研究较多的也是这一类液晶,而且已有商品。为了进一步研究这类液晶以扩大品种,我们在对苯二酚酯液晶的苯环上引入不同类型和数量的极性基团,并在玻璃毛细柱上考查其对二元取代苯异构体的分离性能。     

疏水-亲脂相互作用对反应性的影响2.长链分子簇集和绕曲的溶剂效应

研究了一系列不同链长的对硝基苯酚羧酸酯在十种有机溶剂和水的二元混合溶剂中的水解反应,有机溶剂的体积含量分别为30％(Φ=0.30)和50％(Φ=0.50).结果表明,在Φ=0.50的各溶剂体系中,只有乙二醇-水和二甲亚砜-水体系,十六酸酯的水解速度才因受物分子的簇集绕曲而减慢.而在Φ=0.30的各溶剂体系中,除t-BuOH-H_2O体系外,十六酸酯全都存在簇集和绕曲现象,水解速度因此而受抑制的程度有如下次序:乙二醇>二甲亚砜>乙二醇单甲醚>二甲基甲酰胺～乙二醇二甲醚>二氧六环>乙醇～丙酮～乙腈>叔丁醇.如以log(k_(C8)/k_(a16))值作为衡量溶剂对受物的疏水-亲脂作用大小的定量标准,则发现各log(k_(C8)/k_(a16))和有机溶剂的介电常数ε,溶剂极性标度Kosower’s Z值,Dimroth’sE_T(30)值及Taft’s π值都不相关,但和Rekker的疏水常数f值却有较好的相关关系.这说明在这些“促簇性”溶剂中,控制长链酯水解的主要因素是疏水-亲脂相互作用,而和溶剂的极性无直接关系.此外,还讨论了不同比例的二元溶剂体系中水解的活化参数△S,△H.本工作首次提供了Rekker疏水常数应用于研究有机化合物反应性的实例.     

自相位调制及群速色散对超短脉冲在准周期LiNbO3 Fibonacci超晶格中传输的影响

从LiNbO₃ Fibonacci超晶格的结构特点出发,数值模拟了超短脉冲在LiNbO₃ Fibonacci超晶格内传输过程中,自相位调制及高阶群速色散效应对脉冲形状和频谱的影响．结果表明,超短脉冲在Fibonacci超晶格中传输时,由于自相位调制(SPM)与群速色散(GVD)耦合效应的影响,脉冲形状畸变和频谱展宽均是不对称的,随着晶格长度的增加,脉冲将会发生分裂,以至成为两个独立的子脉冲,同时也会出现脉冲频谱上的分裂. 关键词：