188 research outputs found

    A Kind of Web Spreadsheets Based on POI

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    互联网技术的飞速发展使得基于Web的应用越来越普遍,同时也更加复杂。基于Web的动态Excel表格就是一个典型的实例。随着开发技术的不断发展,一些开源项目凭借其公开、自由以及免费等众多优势产生了越来越大的影响,很多项目都采用了开源技术。文中介绍了一种开源的基于Java的Excel报表开发组件POI引擎,阐述了其表格显示原理。通过在Web上实现动态Excel表格,给出了一种典型应用,并结合一个实际项目中的例子进行了分析,探索出了一种开发Web动态Excel表格的方法。With the development of Internet,Web application has been more popular and complicated.Dynamic Web spreadsheets is a typical case.With the development of developing technology,some open source projects become more infective for open and free,and are implemented in many projects.This paper introduces a kind of open source implementing dynamic spreadsheets on Web based on POI engine,describes the display theory of POI.This paper gives a typical application,analyses with an example in a practical project and finds a way to develop dynamic spreadsheets.国家985二期信息创新平台项目(0000-X07204

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

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    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

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    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)。~

    蚕丝和蜘蛛丝多级结构对力学性能的影响

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    家蚕丝和蜘蛛丝具有力学性能优异、生物可相容和生物可降解等诸多优点。本文阐述了蚕丝和蜘蛛丝的一级结构、二级结构、β-折叠晶体网络(纳米纤维)结构及其形成过程,综述了丝蛋白亲疏水域、分子量和晶体网络结构对力学性能的影响。其中,晶体网络结构的强度是影响力学性能的关键,由拓扑结构、相关长度、取向度和连接(或者相互作用的强度)这4个因素决定。本文为力学性能的控制及提高提供了指导。高等学校学科创新引智计划(B16029);;国家自然科学基金(51773171,U1405226);;福建省科技厅自然科学基金(2017J06019);;中央高校基本科研业务费专项资金(20720160088,20720150218

    Research on Image Recognition Basd on BP Neural Network

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    BP神经网络具有较强的容错性和自适应学习能力,因而在数字图像识别领域有着广泛的应用。本文在经典BP神经网络的基本算法的基础上,对BP算法的参数设置进行了优化,实现了一种基于分类的改进BP神经网络算法。通过探讨BP神经网络在数字图像分类识别中的应用,详细考察了各种参数对识别效果的影响。实验结果证明改进后的算法有很好的实用价值。Back-propagation neural network with high fault-tolerance and good adaptive learning ability,is found great applications in digital image recognition.This paper presents an improved algorithm through setting new parameters based on traditional BP algorithm,applies it to digital image recognition and analyzes the influence produced by improved parameters.The experimental result shows that the improved algorithm has a certain practical value.国家985二期信息创新平台项目(0000-X07204

    Fast local binary fitting optimization approach for image segmentation

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    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

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    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

    非离子态氨对转“全鱼”生长激素基因鲤鱼的急性毒性和慢性毒性

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    在自然水体和人工水体中氨氮对鱼类是有毒的.利用静水更新式生物测试研究了非离子态氨对转基因鲤鱼和对照鱼的96h急性毒性实验和21d慢性毒性实验.通过96h非离子态氨急性毒性实验发现,转基因鲤鱼的非离子态氨氮24,48,72和96h半数致死浓度(LC50)(2.64,2.44,2.28和2.16mg/L)分别比对照鲤鱼相应的24,48,72和96h半数致死浓度(LC50)(2.70,2.64,2.52和2.33mg/L)略低,没有显著性差异;但在不同非离子态氨氮(3.86,3.29和2.09mg/L)胁迫下
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