控制理论中的斜波脉冲函数分析法

所引进的斜波脉冲函数系在Ｌ２空间上具有完备性，与其它常用的正交函数系相比较，它的精度高，适用范围广，特别是在用计算机对控制系统进行分析时，由于所推得的展开与计算公式具有模块结构，使讨论更显示出较强的竞争力。     

一类非线性系统分析的新方法——斜波脉冲函数的应用

利用斜波脉冲函数的线性化特性和简洁的运算规则,本文将一类非线性系统转化为双线性系统然后进行分析和求解。与泰勒展开等其它方法相比较,所提出的方法不仅近似精度高,且不受范围限制,对被近似的函数无可微分的要求。所推导的算法还具有连续递推的功能,很适合用计算机进行求解。     

修正正交分段线性函数及其在线性与时变线性系统中应用

把分段线性函数和斜波脉冲函数进行统一处理，定义成新的函数，使得新的函数既保持了原先两种函数的基本特性，又获得微分和积分递推算法。应用中具有方便，快速计算的优点。     

椭圆三角函数及其在波形发生器中的应用

对普通三角函数进行了推广，给出了椭圆三角函数的定义，指出椭圆三角函数是周期函数，存在最大值和最小值，并在定义域内连续可导．对椭圆正弦函数进行了一系列仿真研究，结果表明，椭圆正弦函数可作为波形发生器的发生函数，可产生方波、普通正弦波、脉冲波、处于普通正弦波和方波之间的波形、处于普通正弦波和脉冲波之间的各种波形，且函数形式是一致的，波形的幅值、频率、初始相位都易于调整．这种波形发生函数能方便地进行数学处理与分析，波形发生原理能应用于各类相关波形发生场合．     

基于随钻测斜技术的井斜预警系统应用

介绍了一种新型的井斜预警系统的地面接收仪器,由井下的机械式井斜预警工具随钻监控井斜,并发生泥浆压力脉冲波,由地面接收仪器测量脉冲波,分析了对信号传递过程中干扰信号的处理方法,经多次现场试验该系统工作良好,可提高工作效率,降低钻井成本。     

雷电电流数学模型的仿真分析

做好雷电流数学模型的分析与仿真,对雷电的研究与防护具有重要意义．章对常见的几种雷电波模型(双指数函数、I-Ieieler函数和脉冲函数模型)进行对比分析,并实现其Matlab仿真．     

耗散弱起伏随机介质中的侧面波脉冲传播：Ⅱ.互相关函数

本文利用Born近似,并矢格林函数,富里埃变换和高频窄带近似等方法得到了耗散弱起伏随机介质中无线电通信相干侧面波脉冲传播的理论公式。瞬态相干侧面波脉冲波的互相关函数解析表达式亦被导出,数字计算表明,本文所得结果与前人的工作一致。     

土-结构共同作用体系的扭转分析

本文对土-基础-非对称结构共同作用体系在斜入射SH波作用下的扭转动力响应进行了研究。从波动理论出发,导出了半空间表面矩形基础位移和力场之间的影响函数阵及表面矩形地基的动力柔度函数和在斜入射SH波作用时刚性矩形基础的输入运动表达式;同时建立了共同作用体系的运动方程。最后讨论了斜入射SH波作用下矩形基础和地基共同作用的动力特性。结果表明,非垂直入射SH波作用时响应显著地不同于通常假设的垂直入射波时的响应,由非垂直入射SH波引起的扭转响应应予以考虑。     

浅水船舶兴波阻力特性的理论分析

运用经典的线性兴波理论对浅水船舶兴波阻力特性进行了研究。针对浅水柯钦函数与深水柯钦函数之间存在的不相容性，通过引入深度影响因子来描述水深对浅水波阻的影响，重新定义了浅水柯钦函数，得到浅水线性波阻的一个新的表达式。借助量级分析和近似处理，导出了简化浅水柯钦函数和相应的浅水线性波阻公式。在上述工作的基础上，对浅水波阻特性进行了分析和讨论，合理地解释了若干实际现象。     

连续气体激光器的自脉冲和混沌

对非旋波近似的Maxwell-Bloch方程进行数值求解。计算结果表明，逐渐增大反转粒子数密度，可以观察连续激光器的自脉冲和混沌。     

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.     

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     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

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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