广义sine-Gordon和广义sinh-Gordon方程的显式精确解

利用平面动力系统理论将四类广义sine-Gordon和广义sinh-Gordon方程的行波解进行分类.在一个四参数空间上,得到了不同区域的所有可能的边界行波和它们的精确的显性参数表示.     

关于等价无穷小替换求极限方法的推广

将求极限时无穷小的因子可用其等价无穷小代替的结论推广到幂指函数的情形,给出了“和或差中的项”可用等价无穷小代替的条件。     

文化缺省视角下英汉对应词的研究与翻译

语言是文化的载体,文化则是某一社团的各种信仰和生活实践的总和.语言只有浸透在文化语境中才能生存.不同文化之间虽然存在不可译性,但也存在意义相近的对应词.文章主要通过对英汉对应词的认识, 对照和分析了对应词与对应词之间、对应词与文化之间的关系.     

宽阻带小型化低通滤波器的设计

This paper presents a novel low-pass filter （LPF） with sharp rejection, wide stopband and compact size, which are realized by the defected ground structure （DGS） and the defected microstrip structure （DMS）. The equivalent circuit model is proposed and the circuit parameters are extracted by the circuit simulation software. The parameters measured are 3 dB cutoff frequency fc of 5.2 GHz, the insertion loss less than 0.5 dB from DC to 4.0 GHz and S21 less than -20 dB within the wide stopband from 6 GHz to 16 GHz. The results of the circuit optimization agree well with those of the full wave simulation and the measured ones, which validate the effectiveness of the equivalent circuit model. The size of the proposed LPF is decreased compared with normal LPF. This LPF can be applied in rectennas to eliminate high order harmonics.     

Evaluation of the optimum pre-stressing pressure and wall thickness determination of thick-walled spherical vessels under internal pressure

In the present study, in the first part for a spherical vessel with known dimensions and working pressure, two methods of hoop and equivalent stress optimization across the wall thickness are employed to determine the best autofrettage pressure. In the next part for a predefined working pressure the minimum wall thickness of the vessel is calculated using two other design criteria i.e. (A) optimizing the hoop stress, and (B) assuming a suitable percent for the penetration of yielding within the wall thickness. Finally, the optimum thickness and the necessary strengthening pressure are extracted and different plots are introduced for different types of structural materials under different internal pressures.     

广义(3+1)维KPB方程的对称约化、精确解和守恒律

运用李对称方法得到了(3+1)维Kadomtsev Petviashvili Boussinesq(KPB)方程的对称和约化方程。进而,利用齐次平衡原理和椭圆函数方法得到了方程的精确解。最后,给出了该方程的守恒律。     

整数规划中精确罚函数的一般形式

In this paper, the general exact penalty functions in integer programming were studied. The conditions which ensure the exact penalty property for the general penalty function with one penalty parameter were given and a general penalty function with two parameters was proposed.     

压缩映像原理的简单应用——Banach空间等价范数与Lipschitz条件

观察Lipschitz条件与范数等价的命题在形式上的一致性,证明推导了结论:范数可以成为一个压缩映像,并利用这一思想来讨论范数一致收敛的问题.     

单片机等效采样示波器的设计

介绍了基于单片机系统的精密时钟发生电路对高频信号（1MHz～80MHz）进行等效采样的方法，设计并实现一个模拟带宽为1Hz～80MHz的简易数字示波器。     

综采工作面斜长等长的控制方法

为克服传统综采工作面上下风巷平行布量时，因煤层倾角变化大而造成工作面倾斜长度不断变化给工作面回采带来的不利影响，通过对三维地震资料的分析，在顺槽掘进过程中运输顺槽按设计方位且超前轨道顺槽施工，并不断对两顺槽标高进行测量调整轨道顺槽的方位，使工作面斜长变化值控制在一定范围内；回采过程中不增减设备，实现综采工作面安全、高效的顺利回采。