用频域法实现圆环形目标物的计数

研究了用频域法实现圆环形目标物计数的方法。对空域中含有圆环形目标物的二值图像，经傅里叶变换后在频域内进行滤波，再经傅里叶反变换后取一阈值进行处理，则对应于圆环形目标物即变为一个实心体，然后对实心体进行计数即可实现对圆环形目标物的计数。对该方法进行了数学描述，并分别用模拟图像和实际图像进行了实验。结果表明，该方法消除噪声的效果好，对部分封闭圆的检测同样有效，且可用于目标物有粘连的情况。该方法对圆环形目标物的尺寸相差不大的情况更为有效。     

L-型模糊格蕴涵代数

This paper introduced the concept of L-fuzzy sub lattice implication algebra and discussed its properties. Proved that the intersection set of a family of L-fuzzy sub lattice implication algebras is a L-fuzzy sub lattice implication algebra, that a L-fuzzy sub set of a lattice implication algebra is a L-fuzzy sub lattice implication algebra if and only if its every cut set is a sub lattice implication algebra, and that the image and original image of a L-fuzzy sub lattice implication algebra under a lattice implication homomorphism are both L-fuzzy sub lattice implication algebras.     

Efficient Multiparty Quantum Secret Sharing with Greenberger-Horne-Zeilinger States

An effcient multiparty quantum secret sharing scheme is proposed with Greenberger-Horne-Zeilinger （GHZ） states following some ideas in quantum dense coding. The agents take the single-photon measurements on the photons received for eavesdropping check and exploit the four local unitary operations Ⅰ, σx, σx and iσy to code their message. This scheme has the advantage of high capacity as each GHZ state can carry two bits of information. The parties do not need to announce the measuring bases for almost all the photons, which will reduce the classical information exchanged largely. The intrinsic efficiency for qubits and the total effciency both approach the maximal values.     

High-Dimensional Nonlinear Envelope Equations and Nonlinear Localized Excitations in Photonic Crystals

We investigate the nonlinear localized structures of optical pulses propagating in a one-dimensional photonic crystal with a quadratic nonlinearity. Using a method of multiple scales we show that the nonlinear evolution of a wave packet, formed by the superposition of short-wavelength excitations, and long-wavelength mean fields, generated by the self-interaction of the wave packet, are governed by a set of coupled high-dimenslonal nonlinear envelope equations, which can be reduced to Davey-Stewartson equations and thus support dromionlike high-dimensional nonlinear excitations in the system.     

用^60Co放射源检测油垢厚度的初步实验研究

本文用石蜡模拟油垢，用^60Co放射源的1．25MeV平均能量的γ射线垂直入射，以一定的散射角和不同的探测立体角接收散射γ光子敫．发现散射γ计数与被测石蜡厚度之间存在不同的线性关系．结果发现，放射源与探测器之间屏蔽的好坏和合理的探测距离对提高线性度有很大关系．本实验测得最佳线性相关系数平方值为0．9981，平均测量精度为1．26mm．这对研究散射法检测油垢厚度和选择合适的探测距离提供了实验基础．     

Multiband Terahertz Photonic Band Gaps of Subwavelength Planar Fractals

Optical transmission properties of subwavelength planar fractals in terahertz （THz） frequency regime are studied by means of time-domain spectroscopy. The transmission spectra with multiple pass bands and stop bands are observed. The tunable photonic band gaps are realized by changing the angle between the principle axis of planar fractal and the polarization of THz wave. The possible application of the subwavelength optical component is discussed. We attribute the detected transmittance from subwavelength fractals to localized resonances.     

相空间中相互垂直的相干态迭加态以及相应的双模纠缠态研究

相干态是最接近经典态的量子态，而广泛研究的相干迭加态——如奇偶相干态、Schleich的镜像迭加相干态等——则显示更多非经典效应。另外，双模及多模迭加态，特别是所谓的纠缠态，在量子信息处理如量子隐形传态和量子密码术中扮演重要角色。我们就相空间中相互垂直的相干态的迭加态进行讨论，研究其非经典特性，如光子数统计分布、正交分量压缩效应、Wigner分布函数的负性以及由此引入的非经典判别子。结果表明，这一类相干迭加态在满足某种条件下具有亚泊松光子统计分布和正交分量的压缩效应，并且参数变量在一定范围内这两种非经典效应同时存在；这些迭加态的Wigner分布中存在不同程度的负值区域．并与奇偶相干态做出了比较．计算相廊的Wigner函数积分判别子可以定最地分析其负性的深度。     

一维CO2光学晶格中的光子带隙

本文研究了囚禁^85Rb原子的一维CO2光学晶格的光子带隙。由于大失谐CO2聚焦光束（λ=10．6μm）远离Rb原子的共振频率，原子与晶格光场的自恰作用可忽略，Rb原子被囚禁在周期为d=λ／2=5．3μm的周期性格点上，且单个格点上囚禁的原子数目可以达到10^3，整个晶格形成具有空间周期性调制的介电多层膜系。类似于光子晶体，其光学响应将在晶格频率与共振频率之间产生光子带隙。另一方面，