测度链上一类时滞微分方程组的振动准则

考虑如下时滞微分方程组y^△i（t）=fi（t,y1（τ1（t））,y2（τ1（t））,y1（τ2（t））,t≥t0,i=1,2其中（i）fi（t,u1,u2,v1,v2）对参数都是连续的;（ii）τi（t）∈Crd[t0,R^＋],τi（t）≤t,且τi（t）≤t,且τi（t）单调不减,lim t→∞τi（t）=∞,获得了该方程组所有解振动的充分条件．     

多维交替型脉冲微分系统的稳定性

研究了一类多维交替型脉冲微分系统的稳定性,给出了系统的平凡解渐近稳定的充分条件。     

Floating-roof steel tanks under harmonic settlement：FE parametric study and design criterion

INTRODUCTION Vertical cylindrical steel tanks widely used for fluid storage generally consist of a thin bottom plate, a cylindrical shell, and a fixed or floating roof. Large tanks constructed on soft foundations are susceptible to various types of settlement deflections. The set-tlement components are: uniform settlement, planar tilt and differential settlement. The uniform settle-ment and planar tilt cause rigid-body deflection or rotation of the tank, and so, are of relatively little i…     

简谐振动运动方程的推导

本文从不同的物理角度 ,导出了简谐振动的运动方程     

丁二酮肟修饰玻碳电极差分脉冲溶出伏安法测定痕量铅

提出了一种用丁二酮肟修饰玻碳电极,以差分脉冲溶出伏安法测定水中痕量铅离子的方法.在实验过程中,对各种实验参数如电解质种类及酸度、丁二酮肟用量、富集电位和时间、扫描速度等进行一定的优化.在pH=5.6的HAc-NaAc缓冲溶液中,铅离子与丁二酮肟生成螯合物富集在电极表面,然后在-0.8V被还原成零价的铅,在向阳极电位扫描的过程中,还原的铅被氧化而从电极表面溶出,于-0.60V形成阳极溶出峰,且峰电流与待测物浓度成正比,据此溶出峰电流可定量测定痕量铅离子.实验测得铅的线性范围为1×10-7 mol/L至5×10-5 mol/L,检测限为1×10-9 mol/L.在同一含量的体系中平行测定6次1×10-7 mol/L Pb2+的溶液,其标准偏差为2.9%.用丁二酮肟修饰玻碳电极测定水样中的铅离子,取得满意结果.     

一类复高阶非线性代数微分方程解的研究

利用亚纯函数的Nevanlinna值分布理论,研究一类复代数微分方程的亚纯解的问题,得到一个结论,推广和改进了高凌云等人的结论。     

一类含参变量的广义积分的计算

本文讨论一类舍参变量的广义积分计算问题,利用Fourier变换和Laplace变换的定义和性质,总结出计算该问题的一般方法,并举出了例子说明。     

LDPC based differential unitary space-frequency coding for MIMO-OFDM systems

INTRODUCTION Unitary space-time modulation (USTM) (Hochwald and Marzetta, 2000) has been shown to be ideally suited for Rayleigh flat fading channels when there is no CSI. And for continuously changing fading channels, differential unitary space-time modulation (DUSTM) was proposed in Hochwald and Sweldens (2000). However, the performance of DUSTM de-grades considerably in frequency-selective fading channels often encountered in broadband wireless communications. Hence concatena…     

Construction of a hepatic stellate cells subtracted cDNA library of differentially expressed genes in normal mice and mice with Schistosomiasis japonica

To construct a hepatic stellate cells (HSCs) subtracted cDNA library to find differentially expressed genes in normal mice and mice infected with Schistosomajaponicum (S. japonicum). Suppression subtractive hybridization (SSH) was used. The cDNA fragments of normal mouse were compared to those of schistosoma-infected mice to find differentially expressed genes. Then differentially expressed cDNA fragments were directly inserted into T/A cloning vector to set up the subtractive library. Amplification of the library was carried out with transformation of DH5α. The amplified library contained more than 400 positive bacterial clones, which were then hybridized with forward and backward subtracted probes for differential screening, One hundred positive bacterial clones were randomly selected for sequencing and BLAST analysis, Finally, virtual Northern Blot confirmed such differential expression. The subtracted cDNA library of differentially expressed genes of HSCs was constructed successfully, the library is efficient and lays foundation for screening and cloning new and specific genes of schistosomiasis.     

浅谈微积分在初等数学中的应用

本文通过对微分在解决一些初等函数单调性、求曲线的切线以及几个初等数学命题的积分证明等问题的讨论,为我们解决一些初等数学问题提供了一些新的思想,使微积分对初等数学的指导作用得到具体体现。