小型平焦场光栅光谱仪的研制

采用名义栅距为 1/12 0 0mm、凹面曲率半径为 5 6 49mm的变栅距凹面光栅 ,研制了一种小型平焦场光栅光谱仪。谱仪入射角为 87.45°,物距为 15 5mm。使用“星光Ⅱ”激光装置对该谱仪进行了测谱实验 ,得到用胶片作时间积分光谱记录时谱分辨率不低于 0 .0 15nm。     

Logistic Map三维耦合格子模型模拟环带球晶

应用Logistic map三维耦合格子模型对环带球晶进行了模拟. 利用数值计算的方法预测了与实验中环带球晶形貌一致的图案. 对于本体体系, 环带球晶形貌的带宽随Logistic map中可调参量μ的增大而变窄, 随耦合模型中的扩散项系数ε的增大而变宽; 对薄膜体系, 环带球晶形貌的带宽随格子厚度的增加而变宽, 模拟结果与实验结果一致. 同时, 还给出了螺旋状环带结构在三维空间中的形貌.     

Bifurcation of collinear crack system under dynamic compression

The evolution pattern of collinear crack array plays a very important role in the final failure pattern of rock and predicting earthquake. Crack interactions lead to the nonhomogeneous pseudo-traction, then result in bifurcation of crack growth pattern. Bifurcation condition of crack growth pattern can be expressed by the crack growth length/spacing ratio. For collinear cracks loaded by dynamic compressive loads, uniform crack growth pattern yields to non-uniform crack growth pattern when the crack growth length/spacing ratio is larger than a critical value. In this paper, crack interactions are studied using stress superposition principle and the Chebyshev polynomials expansion of the pseudo-traction. The analytical solution of the critical value for two collinear cracks and infinite collinear cracks is given out. The critical value is sensitive to pre-existing crack length, the friction coefficient, the orientation of pre-existing crack, crack growth velocity.     

秦山三期核电工程反应堆地段节理裂隙模拟

以秦山三期核电工程反应堆地段作为研究对象 ,针对节理裂隙在岩体中的分布具有随机性的特点 ,运用随机方法对其分布规律进行了研究。根据实测的节理裂隙产状、间距及迹线长度 ,推断节理裂隙概率分布特征。同时充分考虑到节理裂隙分布的不均匀性和方向性等特点 ,采用非平稳态随机过程模拟节理裂隙间距 ,通过 Monte- Carlo方法得到等效的节理裂隙网络。根据统计和拟合的结果 ,对反应堆地段岩体的节理裂隙进行了评价。     

Strong Consistency of the Maximum Product of Spacings Estimates with Applications in Nonparametrics and in Estimation of Unimodal Densities

Distributions with unimodal densities are among the most commonly used in practice. However, for many unimodal distribution families the likelihood functions may be unbounded, thereby leading to inconsistent estimates. The maximum product of spacings (MPS) method, introduced by Cheng and Amin and independently by Ranneby, has been known to give consistent and asymptotically normal estimators in many parametric situations where the maximum likelihood method fails. In this paper, strong consistency theorems for the MPS method are obtained under general conditions which are comparable to the conditions of Bahadur and Wang for the maximum likelihood method. The consistency theorems obtained here apply to both parametric models and some nonparametric models. In particular, in any unimodal distribution family the asymptotic MPS estimator of the underlying unimodal density is shown to be universally L¹ consistent without any further conditions (in parametric or nonparametric settings).     

Calculation of Neutron Resonance Spacing with Microscopic Theory

Nuclear level spacings calculated with a microscopic theory are compared with spacings determined fromneutron resonance experiment. The gross features of the experimental data due to nuclear shells are reproduced with themicroscopic theory. The experimental data for nuclei with statistically deformed nuclei have also been tested with leveldensity formula including low energy rotational levels. The experimental data for the actinide nuclei and the lanthanidenuclei are found to be consistent with the theory which includes collective rotational levels.     

辛烷基苯酚聚氧乙烯醚与正癸醇层状液晶的有序性及层状结构

Order character and lamellar structure of TritonX 100/n C10H21OH/H2O lamellar liquid crystal were investigated. Partial phase diagram of TritonX 100/C10H21OH/H2O was measured at 25℃ by the polarizing microscope, and lamellar structure of the lamellar liquid crystal was verified by the 2H NMR spectra. The ESR spin probe method was used to detect the changes in the lamellar liquid crystal. A stearic acid, 5 doxylstearic acid, was used as the spin probe. The values of hyperfine coupling constant and order parameter of lamellar liquid crystal in the phase diagram were calculated. The values of the hyperfine coupling constant with different composition were almost unchanged. It indicates that the micropolarity of the lamellar liquid crystal is very similar. The order parameter decreases with the increasing water content in lamellar liquid crystal. It can be explained by considering that: First, though the penetration is determined at the given weight ratio of C10H21OH to TritonX 100, the absolute water content penetrated into the amphiphile bilayer increases with the increasing of the water content. Second, the thickness of the solvent also increases, which makes the force between layers weaker. The results also showed that order parameter of lamellar liquid crystal increased with TritonX 100 content, which may be explained from the fact that the water content penetrated into the amphiphile bilayer decreases relatively and the molecules in the amphiphile bilayer are made tighten. The interlayer spacing of lamellar liquid crystal was determined by small angle X ray diffraction. The penetration ratio of water in the lamellar liquid crystal was calculated. It was about 50%.     

Level Spacing Distributions and Quantum Chaos in Hermitian and non-Hermitian Systems

The correspondence between quantum level spacing distribu tions and classical motion of 1-D P T symmetric non-Hermitian systems is investigated using two PT symmetric complex potentials: complex rational power potential V1 (x) = (ix)(2n 1)/m and general polynomial potential V2(x) = x2M ib1x2M-1 b2x2M-2 ... ib2M-1x. The level spacing distribution of V1 has two forms. When 2n 1 - 2m is positive, the level spacing distribution of real eigen values assumes a decreasing power function, while it behaves as an increasing power function when 2n 1 - 2m is negative.The PT symmetry of this system is spontaneously broken as 2n 1 - 2m becomes negative. This change manifests itself in classical mechanics as it is found by Bender et al. However, it was found that the change in the form of level spacing distribution mentioned above is not due to the spontaneous breaking down of PT symmetry. Level spacing distribution of V2 assumes an increasing power function when order of the polynomial is greater than two.     

Energy Level Statistics of SO(5) Limit of Super-symmetry U(6/4) in Interacting Boson-Fermion Model

We study the energy level statistics of the SO(5) limit of super-symmetry U(6/4) in odd-A nucleus using the interacting boson-fermion model. The nearest neighbor spacing distribution (NSD) and the spectral rigidity (△3)are investigated, and the factors that affect the properties of level statistics are also discussed. The results show that the boson number N is a dominant factor. If N is small, both the interaction strengths of subgroups SOB(5) and SOBF(5)and the spin play important roles in the energy level statistics, however, along with the increase of N, the statistics distribution would tend to be in Poisson form.     

新型小分子液晶有机蒙脱土的制备与表征

运用自制的两种新型小分子液晶插层剂对蒙脱土进行有机化修饰,并用IR,XRD,TG及TEM等对有机蒙脱土结构和性能进行了表征与分析。结果表明:有机蒙脱土的层间距由1.00 nm分别增大到2.50 nm和2.88 nm,且能分散均匀,排列疏松,耐热性能也有了显著提高。