一维无限深势阱内粒子概率密度演示仪

设计了一维无限深势阱中粒子概率密度演示仪,利用粒子的态函数的驻波图像来演示粒子的概率密度,使学生能直观地观察一维无限深势阱内粒子的概率密度分布规律.     

右半平面上解析的Laplace-Stieltjes变换对数级

本文研究了零级Laplace-Stieltjes变换的增长性问题.利用对数级和对数下级的定义,获得了这类变换具有对数级的特征,即变换的对数级和对数下级与其系数之间的关系,推广了Dirichlet级数的相关结果.     

Perturbation characteristics of ambient sea noise caused by submerged objects

The perturbation characteristics of ambient sea noise field caused by scattering of submerged objects are discussed theoretically. Based on the sea noise source model with Gaussian-correlation amplitude, and applying the integral expressions for arbitrary source distribution and the spherical wave expression of Green function for a monopole in half-infinite space, the expressions of direct-arrival noise fields, scattering fields and total noise fields of a rigid spherical object under the irradiation of monopole and dipole sources, as well as the covariance among those noise fields at two receiving points are obtained. The numerical results of scattering directional patterns of rigid spherical objects and the visibility are given. It is shown that the total noise field is affected by not only the impedance characteristics of the object, the direction of receiver, but also the correlation between surface sources, and the interference between direct-arrival and scattering fields greatly. The results show that the sound visibility of a rigid spherical object is about 4-5 dB in near range and the scattering directivity characteristics of a rigid spherical object under the irradiation of surface sources are different from those of plane wave incidence.     

Bulk工艺气体微网探测器的研究

In this paper, we present a study of a micromegas detector prototype built with bulk technology. Following a short discussion of the micromegas detector＇s structure and working mechanism, the bulk fabrication process is described, and some testing results of the prototype are presented.     

Mean-Field Dynamics of a Two-Mode Bose-Einstein Condensate Subject to Decoherence

We discuss the dynamics of Bose-Einstein condensates in a double-well potential subject to decoherenee （or particle loss）. Starting from the full many-body dynamics described by the master equation, an effective Gross- Pitaevskii-like equation is derived in the mean-field approximation. By numerically solving the GP equation, we find that macroscopic quantum self-trapping disappears for strong decoherence, while generalized self-trapping occurs under weak decoherence. The fixed points have been calculated, and we find that an abrupt change from elliptic to an attractor and a repeller occurs, reflecting the metastable behavior of the system around these points.     

计算最优控制辛数值方法

针对最优控制问题（OCP）的辛数值方法研究及应用进行综述。主要涉及内容包括,动力学系统为常微分方程描述的一般无约束、含不等式约束和状态时滞的最优控制问题,微分代数方程描述的一般无约束、含不等式约束和含切换系统的最优控制问题,以及闭环最优控制问题。从间接法和直接法两个求解框架出发,重点介绍本课题组在保辛算法方面的研究工作。在间接法框架下,首先基于生成函数和变分原理,将OCP保辛离散为非线性方程组,再数值求解方程组。在直接法框架下,将OCP保辛离散为有限维的非线性规划问题（NLP）,再数值求解。针对闭环最优控制问题,提出了保辛模型预测控制、滚动时域估计和瞬时最优控制算法。研究表明,保辛算法具有高精度和高效率的特点,在航空航天和机器人等领域有着广泛应用前景和价值。     

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There're about 10^{11} neurons in the human brain.Through the synaptic junction, neurons have formed a highly complex network.And it is really important to figure out the information expressed in the network, which will contribute to the resolution of the prevention and diagnosis of cognitive disorder of human beings. This paper uses the schizophrenia and healthy controlled subjects' fMRI data to construct the brain network model, in order to explores abnormal topological properties of schizophrenics' brain network based on graph theory. When studying the human brain network information traditionally by the basement of graph theory, it's all assure that the human brain network model has invariance, so it takes the whole period of time series data in constructing human network model, which is a kind static network. However, it's hard to ensure this because of the nonstationarity of fMRI functional time series data. Thus, when constructing human brain network model, we should take its time-variation into consideration, then construct a dynamic brain network. We can explore the brain network information better. In this research, we segment the time series data, using time windows, to constructing dynamic brain network model, then analyze it combined with the knowledge of graph theory, thereby reducing effects that the nonstationarity of fMRI functional time series data will have. Comparing dynamic brain network of the schizophrenic patients with normal controls subjects' in different level, the results show that there are difference in single node property, group network property of schizophrenic patients and normal control subjects' whole brain dynamic functional connectivity network. The discovery of these difference in network topological properties has provide new clues for the further study on the pathological mechanism of schizophrenia.     

综合评价中异常值的识别及无量纲化处理方法

针对综合评价中的异常值现象,讨论了原始数据中是否存在异常值、若存在异常值该如何识别异常值以及对含有异常值的评价数据如何进行无量纲化处理三个问题。关于异常值的判断与识别,给出了以“中位数”为参考点,通过比较排序后两端数据偏离中位数的距离的处理思路。对含有异常值的评价数据的无量纲化处理问题,基于常用的“极值处理法”,通过分别指定异常值和非异常值无量纲化取值区间的方式,提出了一种分段的无量纲化处理方法。最后,通过与已有文献异常值识别及无量纲化处理结果的对比分析,验证了本文方法的有效性,发现本文给出的方法能够实现对异常值的适度筛选,且能够提升无量纲化数据分布均衡性。     

基于期权思想的封闭式基金管理费率的设计研究

针对目前我国证券投资基金单一的管理费率结构,以封闭式基金为研究对象,根据基金投资者的需求不同提出了在不同收益率目标下的管理费率结构,并借用B-S期权定价模型,计算出封闭式基金的管理费率.     

一种基于蒙特卡罗模拟的群体协商评价方法及其应用

针对综合评价中不同专家(或利益相关者)对属性权重看法不一致的情况,提出了一种蒙特卡罗模拟的群体协商评价方法。文章首先给出了一种专家影响力的确定方法;然后对各属性下专家的非一致性意见进行协商集结,得出属性权重的协商区间;最后在权重协商区间确定的基础上,利用蒙特卡罗模拟的方式来计算方案的优先排序概率,据此对方案进行排序,并给出了一个排序可信度的概念。文章最后给出了一个应用例。