Vapor-Liquid Equilibrium of 1-butanol-Alkanes System by Molecular Simulation

用Gibbs系综的Monte Carlo法模拟了正丁醇。正己烷和正丁醇-正庚烷体系的气液相平衡。在恒定压力0.496 6 MPa、0.294 0 MPa和0.1 MPa下,分别采用恒温恒压的Gibbs系综(NPT-Gibbs)模拟了不同温度下的气液相平衡。计算结果表明,模拟的数据比较准确,在一定温度范围内与实验结果吻合。The Vapor-Liquid equilibrium of 1-butanol/hexane and 1-butanol/heptane was measured by using Gibbs ensemble.The equilibrium data were obtained by the N-PT-Gibbs at the pressures of 0.4966 MPa,0.2940 MPa and 0.1 MPa.Comparing to the experimental data,the simulation results were quite good in some temperature range.国家自然科学基金(50573063);; 高等学校博士点专项基金(20050384013

Molecular simulation of transport behavior of penetrant through silicon-containing polymers

选择PCFF和COMPASS分子力场对橡胶态聚合物PDMS和玻璃态聚合物PS1体系进行模拟。COMPASS力场模拟得到的体系密度,O2和N2在PDMS与PS1中扩散系数更接近实验值。在模型大小一定时,Group-based求和法中截断距离越长,耗用机时越长,但对计算结果改进不大;截断距离为1.3nm时计算结果最好。Ewald方法耗时多而对计算结果却无明显改进。体系大小对扩散系数的计算值影响甚微。体积越小的分子,在聚合物中运动的范围越大,扩散系数越大。氧气和氮气分子在PDMS与PS1中运动轨迹不同,在PS1中氧气运动范围远大于氮气,而在PDMS中氧气运动范围稍大于氮气。小分子运动轨迹基本与聚合物自由体积分布对应,自由体积分数大,扩散系数也大。PCFF and COMPASS force fields were used to describe PDMS and PS1 polymeric systems and to estimate the diffusion coefficient of N2 and O2 through the PDMS and PS1 matrices at 298 K by molecular dynamics simulation.It was found that the COMPASS force field was better in describing the transport behavior of the penetrants.The calculated densities after refinement were in good agreement with the experimental results.The group-based and Ewald summation skills were used to estimate the non-bonded interaction between atoms.Calculation using the Ewald summation method took much longer time without bringing in obvious improvement in density estimation.Various cut-offs in using the group-based summation method did not produce densities with much difference, and the cut-off of 1.3 nm was the best.Two types of diffusions of the small molecules in the polymers were discussed.The diffusion of O2 and N2 in PDMS could be transformed from anomalous to normal motion in 30 ps; while their diffusion in PS1 would take 300 ps transforming from anomalous to normal state.The trajectories of diffusion of N2 and O2 in PDMS or PS1 were different.The motion area of O2 in the PS1 was much larger than N2; however, the former in the PDMS matrix was only slightly larger than the latter.The diffusions of O2 and N2 in the PDMS and PS1 were consistent with the free volumes of polymers.国家自然科学基金项目(50573063);; 高等学校博士点专项基金项目(20050384013)。~

Design of tracking system for marine moving object

为实现对海上运动目标的实时跟踪,克服跟踪效果易受到严重遮挡影响的缺点,建立了一套实时跟踪系统,并且结合目标的运动信息与新的模型更新策略,对均值漂移与卡尔曼滤波器相结合的跟踪算法做出了改进。当运动船只被遮挡的比例较大时,先用估计出的目标速度矢量更新卡尔曼滤波器,并用相应的模型更新策略更新目标模型以提高模型相似性度量的精确性,再单独利用滤波器进行跟踪,取得了较好的跟踪效果。实验结果表明,该系统可以较好地实现海上运动目标的跟踪,并且改进后的算法具有良好的实时性和鲁棒性。To accomplish the real-time tracking for the marine moving object and overcome the defect of the susceptibility to severe occlusion,a set of real-time tracking system for the moving object at sea is designed.In virtue of the motion information and a new kind of model update strategy,some improvements are made for tracking algorithm combining the mean-shift with Kalman filter.When the moving vessel is largely blocked,Kalman filter is updated by the prior estimated velocity vector,and the accuracy of model similarity measurement is improved by utilizing the model update strategy,then the filter is exploited to implement tracking.The algorithm achieved good tracking effect.Experimental results show that the system implement marine moving object tracking with good real-time performance and robustness

Fast and effective method for video mosaic

针对现有的视频图像序列拼接方法处理速度慢的问题,提出一种基于Surf特征的快速有效的拼接算法。该算法用鲁棒性强且计算性能优越的Surf算子取代传统的SIfT算子进行特征点提取;在特征点匹配方面,提出了一种基于哈希映射和双向最近邻距离比的匹配算法,可以快速有效地获得特征点间的对应关系。为了消除由于运动物体干扰带来的误匹配,采用随机采样一致性(rAnSAC)方法来消除外点确保匹配的有效性,再通过最小二乘法估计视频帧之间的全局运动参数,最终拼接形成全景图。实验结果表明,该拼接算法快速有效,鲁棒性强,具有较高的使用价值。As the existing methods for video mosaic take high computational costs,a fast and effective algorithm based on SURF feature for video mosaic is proposed.The algorithm uses SURF method with strong robustness and superior performance to extract feature instead of SIFT.At the aspect of feature matching,a novel matching scheme based on hash mapping and bidirectional nearest neighbor distance ratio is presented,which can quickly and effectively obtain the relationship between the features.In order to exclude the error matchings,a RANSAC technique is applied to eliminate outliers to ensure effectiveness of the matched pairs,and then the global motion parameters are estimated by a least-squares solution,finally panorama from video sequence is achieved using the parameters.Experimental results show that the method with strong robustness performs fast and effectively and has highly valuable in practice

Fast local binary fitting optimization approach for image segmentation

针对灰度不均匀图像难以正确分割和分割结果依赖于初始轮廓的问题,提出一种快速稳定的分割算法,首先通过自适应距离保持水平集演化(AdPlS)算法进行初始分割以获取较好的初始轮廓,然后采用局部二值拟合(lbf)模型进行快速分割。实验表明,改进后的模型有良好的分割效果,较好地解决了分割速度、精度及稳定性之间的矛盾。It is difficult to get the correct segmentation results for the intensity inhomogeneity images,and the segmentation results are very sensitive to the initial contours.Thus,a fast and stable approach was proposed to overcome these disadvantages.First,an Adaptive Distance Preserving Level Set(ADPLS) method was utilized to get a better initial contour.Second,the Local Binary Fitting(LBF) model was used for a further segmentation.The experimental results show that the improved model can achieve good performance and is better to solve the contradiction among the segmentation speed,accuracy and stability.南京军区重点项目(11Z023); 福建省自然科学基金资助项目(2008J0312

Improved Method for Fuzzy C-Means Clustering Algorithm

由于传统的模糊C均值(fuzzy C-MEAnS,fCM)算法没有考虑像素点的空间邻域信息,仅涉及像素的单点灰度,在处理含有噪声的图像时有很大的局限性,因此分割效果较差。针对fCM的缺陷,提出一种新的改进算法,该算法引入gIbbS随机场,将gIbbS随机场先验概率与像素点隶属度的乘积作为新的像素隶属度。实验表明,改进后的算法有良好的分割效果,既可以较为完整地保留图像边界细节,又能较好地去除图像的噪声。The traditional fuzzy C-means (FCM) algorithm has great limitations in dealing with the noisy images owing to not considering the spatial information of the pixels and only involving the pixel gray of a single point,so it's poor in segmenting an image.For the defects of the FCM algorithm,a new improved algorithm is proposed in this article,in which a product of Gibbs priori probability and the membership is regarded as the new pixel membership.Experimental results show that the improved algorithm has a good segmentation result;it can retain more complete edge details of image and can remove the image noise more effectively.南京军区重点项目(项目编号:11Z023); 福建省自然科学基金项目(项目编号:2008J0312

债权融资结构与公司业绩实证研究

文章以沪深两市2004年--2007年4 154家A股上市公司的数据对债权融资结构与公司业绩的关系进行了实证研究,将债权融资结构细分为债权融资水平结构、债权融资期限结构和债权融资类型结构,分别与其公司业绩的关系进行实证研究,同时以市净率和净资产收益率两个指标作为公司业绩的替代变量分别对债权融资结构进行研究,得到了不同的结论,说明我国的债权市场还不完善,希望通过研究能够对我国的资本市场提供一些参考意义

24种中药注射剂药品说明书调查与分析

目的调查医院24种中药注射剂药品说明书存在的问题,为确保临床安全用药及完善中药注射剂药品说明书提供参考。方法收集24种中药注射剂药品说明书,根据《药品说明书和标签管理规定》《中药、天然药物处方药说明书内容书写要求》等的要求,统计和分析规格、剂型、警示语、不良反应、药物相互作用等23个项目。结果在收集的24份中药注射剂药品说明书中,规格、成分等必备项目的标注率比较高,不良反应、禁忌、注意事项、药物相互作用等项目,虽标注率比较高,但有的缺乏具体说明内容。孕妇及哺乳期用药、儿童用药、老年患者用药、临床试验、药代动力学、药理毒理等项目,标注率仅为12.50%,4.17%,4.17%,8.33%,37.50%,0。结论中药注射剂药品说明书的完整性和书写规范性应进一步提高

Advances in Structure Controls and Modifications of PIMs Membranes for Gas Separation

自具微孔高分子(POlyMErS Of InTrInSIC MICrOPOrOSITy,PIMS)是近年来出现的一种新型有机微孔材料,由含有扭曲结构的刚性单体聚合而成,具有比表面积高、化学和物理性质稳定、微孔结构可控等优点,在均相催化、氢气储存等方面表现出巨大的应用潜力。因其优越的气体分离性能,PIMS气体分离膜更是吸引了众多研究者的关注,发展迅速。本文总结了PIMS的分类及其在气体分离膜中的应用,重点介绍了PIMS气体分离膜的结构调控与改性方面的研究进展,分析了PIMS的分子结构与气体分离性能间的内在关联,最后提出了目前研究中存在的一些问题并对其发展做出了简要的评述。Polymers of intrinsic microporosity( PIMs),as novel microporous organic polymers polymerized by rigid monomers that have sites of contortion,have great application potential in homogeneous catalysis and hydrogen storage due to their high specific surface,chemical and physical stability and pore size controllability.Particularly,PIMs composed of polymer chains attract more attention in gas separation membranes due to their superior gas separation properties and good solubility.Here,the classification and applications of PIMs as well as the properties including stability,gas permeability and gas selectivity of PIMs gas membrane are introduced.The structure controls and modifications of PIMs gas membrane and the relationship between molecular structures and gas separation properties are described in detail.Finally,the problems existed in the present research are pointed out and a brief comment on the development is given.国家自然科学基金项目(No.21306155); 高等学校博士点专项科研基金(No.20120121120013); 中央高校科研业务费项目(No.2012121029)资助~

国家数字科技文献资源长期保存体系的战略与实践

为解决社会对数字文献资源日益增长的需求和数字文献资源处于多重威胁、&ldquo;濒于损 毁&rdquo;的使用现状之间的突出矛盾，国家科技图书文献中心牵头组织了国家数字科技文献长期保存 体系的建设，在中国大陆本土长期保存对我国具有重要价值的国内外数字文献资源，确立了合理 平衡的长期保存权益管理制度，形成了国家主导、联合参与、可靠管理和公共服务的长期保存体 系，建立了可靠高效的长期保存技术流程和技术系统，提出了公共保存审计和保存机构认证机 制，已经保存了一大批重要的科技数字文献资源，为我国数字知识内容资源的长期保存奠定了坚 实基础。</p