关于拟常曲率空间中具有常平均曲率超曲面

设(Nn 1,g)是n 1维单连通完备的黎曼流形,其黎曼曲率张量取如下形式KABCD=a(gACgBD-gADgBC) b(gACλBλD gBDλAλC-gADλBλC-gBCλAλD), ∑gABλAλB=1,称Nn 1为拟常曲率空间.本文讨论了这类空间中具有常平均曲率的紧致超曲面,给出了关于其第二基本形式模长平方S的积分不等式.     

常系数非齐次线性微分方程组特解公式的新推导及其应用

首先利用推广的分部积分法导出一阶线性方程组的两个特解公式,然后将有关的结果应用到高阶线性方程(组),得出了特解的一些新公式。     

光纤Bragg光栅横向负载敏感特性的实验研究

对光纤Bragg光栅的横向负载敏感特性进行了实验研究 .利用光纤中的应力双折射效应 ,使光纤光栅横向受压 ,产生谐振波长分裂 .通过实验研究得到了良好的谐振波长分裂与横向负载的关系曲线 ;在此基础上 ,进行了波长寻址的多点横向负载分布测量的初步探索 ,完成了两光栅同时传感的实验研究 .     

Determination of Henry''s Law constant for methyl hydroperoxide by long path FTIR

Methyl hydroperoxide (MHP, CH3OOH) is one of the main organic peroxides in the atmosphere. In order to understand how MHP partitions in atmospheric gas and liquid phases, the Henry's Law constant for its aqueous solution is determined. A novel technique is established for measuring gas-phase MHP concentration, I.e. The gas phase is collected by a gas-bag and then analyzed by long path Fourier transform infrared (LP-FTIR) spectrometry. At 283 K～303 K, the temperature dependence of the Henry's Law constant for MHP can be expressed as lnKH= a/T - b, a = 4386 ± 140, b = 9.19 ± 0.48, where KH is in unit of molar concentration per atm,and T is in degrees Kelvin. The standard heat of solution is 36.45 ± 1.16 kJ? K- 1? mol-1.     

基于双层符号常数模的多径水声信道盲均衡算法

针对常数模算法(CMA)及符号常数模算法(SCMA)迭代中的大量乘法运算会产生延时的不足，提出了双层符号常数模算法(DSCMA)。该算法采用逐级取符号的办法，将迭代过程中的大量乘法运算转化为比较运算，大大减少了计算量。而基于双层符号常数模的多径水声信道盲均衡器，具有收敛速度快，超量均方误差和计算复杂度小等特点。用负声速梯度信道及深海信道对该盲均衡器性能进行的仿真研究表明：该盲均衡器对多径干扰有良好的抑制作用，对水下数据通信有很强的实用价值。     

一种用于多径衰落水声信道的盲均衡算法仿真研究

在水声数字通信中，严重的多径衰落和多普勒频移是影响通信性能的两个主要因素。研究了一种分数间隔判决反馈盲均衡结构，以有效地克服水声信道多径衰落的不利影响。同时，针对水声信道的时变多普勒特性，在分数间隔判决反馈结构的基础上，提出了一种修正常数模分数间隔判决反馈盲均衡与二阶数字锁相环相结合的盲均衡算法，以纠正信道引入的载波相位旋转。最后通过计算机仿真，将该算法与常数模波特间隔判决反馈盲均衡算法进行了性能对比，仿真结果证明了该算法的有效性。因此，该算法具有良好的实用性和应用前景。     

倍频光栅的莫尔条纹研究

用傅里叶频谱分析方法研究了横向莫尔条纹中一个光栅倍频时莫尔条纹的变化，论证了倍频光栅形成的莫尔条纹方向与等周期两RoncK光栅形成的莫尔条纹方向相同，其周期与两小周期光栅的莫尔条纹周期相同，其对比度随倍率的增加而减小的特点，呈现莫尔条纹效应的主要是等栅距光栅和二倍频光栅，介绍了产生倍频光栅的一些方法，如采用滤波的方法，消去光栅的0级衍射波，形成倍频光栅；采用球面波照明光栅，形成倍频的光栅的自成像等，举例说明了其应用，这些应用表明二倍频光栅莫尔条纹可使结构紧凑，测量简单，或使分辨率提高一倍。     

应变式传感器恒压源间歇供电

分析了恒压源供电下的桥路输出特性以及影响电桥电压灵敏度的各种因素.供电电压的增加会受到桥臂允许功耗的限制,从而制约了电桥电压灵敏度的提高,并产生电阻"温升"和热噪声.针对电桥存在的上述问题提出的恒压源间歇供电方式,不仅可以提高传感器的灵敏度,还有效地降低了应变片电阻的"温升"和热噪声,提高了传感器的精度.     

The Application of Similarity Theory in Designing Large Deflection Buckling Spring-Piece

Large Deflection Buckling Spring-Piece (LDBSP) refers to the deformation of an end-fixed flat spring-piece under normal loadings. Plastic deformation usually appears in LDBSP.The static characteristic curve is very particular, because within its linear deflection region, the spring constant can be designed to be any value from minus to plus. With its obvious advantages of large liner deflection range, low spring constant, etc., the LDBSP has now been extensively applied to the exciting device, low-frequency shock absorbers and so on. The static characteristic curve of LDBSP belongs to the nonlinear problem of an arch with varying section. Therefore, it is difficult to obtain it theoretically. The formulae for designing LDBSP have not been set up yet. In this study,the authors apply similarity theory to analyze the liner deflection range A and the spring constant K, and derive the relationship of similarity criterion, finally obtain a set of formulae for designing LDBSP by model test and the least square method, which can be applied in engineering design.Through the research, it is proved that it is unnecessary to keep geometrical similarity of spring-piece shape. This fact extends the application scope of the formulae. The proposed formulae for designing LDBSP thereby can be applied for any dimensions within the range allowed.     

具有齐次核的Hilbert型积分不等式的构造特征及应用

利用实分析技巧,研究具有齐次核的Hilbert型积分不等式的构造特征及取最佳常数因子的充要条件,得到了最佳常数因子的解析表达式.