激光清洗基片表面温度的有限元分析及讨论

采用有限元方法分析了激光清洗过程中基片表面的温度分布，研究了激光清洗过程中清洗阈值和损伤阈值存在的原因，推导出使用波长为３０８ｎｍ，脉宽为２８ｎｓ的准分子激光清洗硅片表面油脂的清洗阈值和损伤阈值，并进行了实验验证，其理论清洗阈值与实验结果是符合的     

小波基下的多分辨率SURE阈值信号估计

根据小波阈值估计理论，通过最小化风险的估计，可计算自适应于数据的阈值，提高估计的信噪比。分析了噪声和信号在小波分解下的特性，提出了小波基下自适应于每一尺度的多分辨率SURE阈值算法，并采用该算法对被噪声污染的信号进行了估计，阈值T选取统一阈值，噪声的标准差由中位公式求出。仿真结果表明，与传统的小波阈值法相比，该算法明显地提高了估计的SNR。     

模拟退火算法在视频序列图像二值化阈值选取中的应用

阈值的选取问题是图像二值化的过程中的一个关键问题，现有的方法主要是利用Otsu算法对分割阈值从0—255的所有灰度值依次遍历，没有考虑视频两帧图像间的相关性。本文利用帧间相关性给出了一个阈值选取算法，该算法在保存上一帧阈值的基础上，运用模拟退火算法对本帧阈值进行一种智能搜索。优化了搜索策略，提高了运行效率。实验表明，该算法提高了阈值选取的效率。     

F阈值浮动的逐步判别法

本文对逐步判别法用固定的Ｆ阈值来选择变量所存在的不足之处进行了分析，提出了将Ｆ阈值浮动的新方法，并用具体例子说明了Ｆ阈值浮动法的优越性。     

小波软阈值算法去除SAR图像中的Speckle噪声

在详细分析了Donoho小波软阈值的基础上，应用小波变换技术对SAP图像进行分析处理。使用“小波局部软阈值算法”来计算阈值，对高频小波系数进行阈值确定。求得估计小波系数，对其取小波反变换后，去除SAP图像中的Speckle噪声。实验结果表明此方法对去除Speckle噪声十分有效，可以在含有Speckle噪声为背景的图像去噪中应用。     

一种改进的随机早期检测算法

针对随机早期检测算法(RED)参数配置困难的问题，提出了一种自适应阈值RED(SATRED)主动队列管理算法．该算法根据网络拥塞状况，周期性地自动调整最大阈值和最小阈值，以便改善RED路由器的性能．在调整周期内，每到达一个数据包，将平均队列长度和阈值进行比较，在周期结束时根据比较结果对阈值进行调整．仿真结果表明，在路由器缓冲区有限的情况下，相对于简单的尾部丢弃(ttail-drop）和RED，该算法能为TCP连接提供更好的公平性．     

图像二值化算法研究及其实现

基于阈值选取对图像分割的基础性，对当前流行的阈值选取算法进行了探讨．并对其算法实现和分割效果进行了比较。     

基于高斯性检验的自适应小波去噪方法

针对软阈值和硬阈值去噪算法存在的缺陷，提出了一种基于高斯性检验的自适应非线性阈值去噪方法。该方法根据信号和噪声的模极大值特性自适应确定分解层数，引入高斯性检验选择软阈值和硬阈值方法对每层小波系数进行降噪处理。仿真结果表明，该自适应滤波方法简单有效、稳定性高，去噪后信号信噪比得到很大提高，且不同仿真信号结果都明显优于经典的小波去噪算法。     

基于灰度最优阈值的图像分割方法及应用

讨论了在对图像进行分割时的一维、二维灰度直方图分割方法，对最优阈值灰度分割方法原理进行了描述，得出了最优阈值灰度分割算法。实验结果表明：利用此算法对图像进行分割能够得到较好的分割效果。     

二进制非线性联为换器的阈值方法

介绍了二进制联合变换器中用于对联合功率谱进行二进制化取阈值的三种方法：固定法、中值方法、子集中值法，并分别对这三种取阈方法的ＪＴＣ以及传统ＪＴＣ的性能进行第二、第三种阈值方法中阈值受目标图象背景噪音的影响，在背景噪音较大的情况下，使用阈值随噪羊而定的后两种方法比第一固定阈方法具有更好的相关性。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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