Lanthanide Complexes for Oligomerization of Phenyl Isocyanate

IntroductionThestudyonthereactivitiesoflanthanidecomplexesto wardisocyanateshasattractedmuchattention .Ithasbeenre portedthatlanthanidealkoxides,1anddivalentdiaza pentadi enyllanthanidecomplexes2 canbeusedasthesinglecompo nentinitiatorsforisocyanatespolymerization .Recentlyourre searchgrouphasalsofoundthatlanthanoceneamide ,3diva lentaryloxideofsamarium4 ,5anddivalentsamarocene6 areallactivefortheoligomerizationofphenylisocyanate,andtheactivespeciesforthesethreesystemswereallsuccessfullyisolat…     

Strong limit-point classification of singular Hamiltonian expressions

Strong limit-point criteria for singular Hamiltonian differential expressions with complex coefficients are obtained. The main results are extensions of the previous results due to Everitt, Giertz, and Weidmann for scalar differential expressions.

     

An algorithm for three-way data analysis that alternatively minimizes coupled vector (COV) resolution error and PARAFAC error.

A novel algorithm, alternatively minimizing coupled vector (COV) resolution error and PARAFAC error algorithm, is proposed in this paper. This algorithm can overcome the problem of slow convergence and is insensitive to the estimation of component number, such problems are unavoidable while using the traditional parallel factors analysis (PARAFAC) algorithm. In other words, this algorithm is capable of improving the computing speed and providing accurate resolutions provided that the number of factors used in the computation is no less than that of the actual underlying ones. The characteristic performances were demonstrated with a novel fluorescence data array.     

The structure of multi-electrode-pair pulse laser and discharge pulse time selection

Applying multi-electrode-pair pulse TEA CO₂ laser to one optical resonance cavity will have several advantages over traditional method, including higher gain, shorter pulse discharge time interval, and in particular, continuous adjustable time interval of multi-pulse laser output can be achieved without high vacuum condition. To improve laser's working stabilization, we proposed new approaches to optimize laser structure design and discharge pulse time interval selection.     

一种新颖的超结构光纤Bragg光栅梳状滤波器的设计

报道一种新颖的用于多波长光纤激光器的超结构光纤Bragg光栅（SFBG）梳状滤波器，其突出特点是仅由单个光栅构成、折射率调制和局部啁啾富于变化、反射峰均匀性好、窄带宽和标准的信道间隔.采用基于LP算法的IS光纤光栅设计技术，将整体加窗切趾法改进为各信道独立加窗切趾，成功地设计出所需的SFBG，同时对SFBG的制作技术也进行了探讨.用传输矩阵法分析反射谱、时延曲线和群时延抖动.结果表明，所设计的SFBG满足各项设计指标要求，在DWDM系统中，这种新颖的SFBG可望成为用于多波长光纤激光器的最理想的高性 能梳 关键词： 超结构光纤Bragg光栅 光栅设计 梳状滤波器     

Classical Limit of Expectation Values in a Wave Packet Involving Few Stationary States

Expectation values of physical quantities in a wave packet involving few stationary states in an infinite square well are calculated. Explicit results show that the expectation values in the classical limit go over to the corresponding classical quantity in the form of the arithmetic mean (in mathematical term, the Fejér's average) of the partial Fourier series converging to the classical quantity. The number of the stationary states is that of the partial Fourer series in the Fejér's average. The quantum uncertainty is then demonstrated to have a classical counterpart.     

Nonparametric estimation of distributions with categorical and continuous data

In this paper we consider the problem of estimating an unknown joint distribution which is defined over mixed discrete and continuous variables. A nonparametric kernel approach is proposed with smoothing parameters obtained from the cross-validated minimization of the estimator's integrated squared error. We derive the rate of convergence of the cross-validated smoothing parameters to their ‘benchmark’ optimal values, and we also establish the asymptotic normality of the resulting nonparametric kernel density estimator. Monte Carlo simulations illustrate that the proposed estimator performs substantially better than the conventional nonparametric frequency estimator in a range of settings. The simulations also demonstrate that the proposed approach does not suffer from known limitations of the likelihood cross-validation method which breaks down with commonly used kernels when the continuous variables are drawn from fat-tailed distributions. An empirical application demonstrates that the proposed method can yield superior predictions relative to commonly used parametric models.     

CRYSTAL AND MOLECULAR STRUCTURE OF A NOVEL Au Ag SUPRACLUSTER COMPOUND [Au_13Ag_12(μ-Br)_4(μ_3-Br)_2(Ph_3P)_10-

<正> [Au13Ag12(μ-Br)1(μ3-Br)2 (Ph3P)10Br2] Br, monoclinic. space group C2/m, a = 36. 496(17). b=16. 878(7), c-=19. 772(9) A , β=99. 87(5)°, V=11998. 9 A3.Z=2. The final R(Rw) is 0. 097(0. 109) for 3779 reflections with I>3σ(I). The structure can he considered as two icosahedral cluster units (AurAg6) sharing one vertex and linked hy six bromine atoms. The Au - Au, Au - Ag. and Ag-Ag distances fall in the ranges of 2. 69-2. 96. 2. 84-3. 02. and 2. 92-3. 26 A, respectively.