线列阵甚宽频带恒定束宽的数字实现方法

线性嵌套阵可以很好地在很宽的频率（N个倍频程，N=7）上实现恒定束宽。这种方法设计简单，又节省线阵阵元。本文给出了线性嵌套阵具体的数字化实现方法，解决了FIR滤波器设计，滤波器时间延迟等问题。由于数字化实现过程中使用了很多组FIR滤波器，计算量很大，文章采用了DSP信号处理板实现数字化算法，利用DSP处理板可以多任务同时处理优势，解决了计算量大的问题。经过实验验证，在DSP上实现的数字化的线性嵌套阵宽带恒定束宽方法满足了工程上实时处理的需要。     

用13CNMR研究聚甲基丙烯酸锡酯的立构序列分布

本文测定了自由基型溶液聚合的聚甲基丙烯酸三甲基锡酯(PTMTM),聚甲基丙烯酸三乙基锡酯(PTETM)和聚甲基丙烯酸三丁基锡酯(PTBTM)的¹³C-NMR谱,对其C-2谱扩展分峰,计算立构序列,从定量数据表明,聚合物样品的空间立构富于或稍富于间规立构,随取代基的体积增大而趋于无规分布,作者认为受空间位阻效应和分子内或分子间形成配位键的影响。     

Augmented Spinor Space

In this paper, based on the Pauli matrices, a notion of augmented spinor space is introduced, and a uniqueness of such augmented spinor space of rank n is proved. It may be expected that this new notion of spaces can be used in mathematical physics and geometry.     

某工程地基基坑支护探讨

软土地基中的支护是基础工程的关键，在节约成本的前提下，选择合理的支护结构至关重要．通过对某公司将要开发的2个基坑支护方案的项目进行的相关分析、计算和探讨，总结出了软土地基中的基坑支护方案的选择原则及其相对应的施工措施等．     

Pattern时延差编码四信道水声通信技术研究

本文所研究的是基于Pattern时延差编码（PDS）体制下的水声通信技术.PDS水声编码体制利用Pattern码片出现在码元窗的时延差值进行时延编码,通过码元分割,有效的降低了水声信道的多途干扰;通过频率分割划分四个通信信道,增加通信速率至1000bit/s.在接收端利用带通滤波器来实现通信信道分割,每个信道再应用拷贝相关器实现码元分割并估计出时延差值,完成译码.仿真实验表明,该系统适合于大量不同水声信道高可靠性工作,为水声通信网络化打下坚实基础.     

基于BP网络分类器的交通标志识别

针对中国全部3大类116个交通标志,即禁令标志、指示标志、警告标志,用BP网络实现分类功能.实验中使用了3种测试集,即加高斯噪声、水平扭曲和日本交通标志实景图,对BP网络的分类性能进行了测试.实验结果表明:用BP网络实现交通标志粗分类功能的效果是比较理想的,对交通标志的颜色失真和形状失真均具有较好的容错性和鲁棒性.     

Nuclear Effects in Structure Functions xFa（x, Q^2） from Charge Current Neutrino Deep Inelastic Scattering

By taking advantage of the model-independent nuclear parton distributions, the structure functions xF3（x, Q^2） are calculated, in comparison with the experimental data from CCFR neutrino-nuclei charge current deep inelastic scattering. It is shown that shadowing and anti-shadowing effects occur in valence quark distributions for small and medium x regions, respectively. It is suggested that the neutrino experimental data should be employed in the future for pinning down the nuclear patton distributions.     

Generalized Born scattering in anisotropic media

The Born scattering approximation has been widely used in seismology to study scattered waves, and to linearize the propagation problem for inversion. The standard Born theory requires the model be separated into a smooth, reference model and a perturbation. Scattering occurs from the pertubation. In the distorted Born approximation, when the reference model is inhomogeneous, the reference Green's functions are normally not known exactly, but the error in these Green's functions is rarely quantified. In this paper, we generalize Born scattering theory to include the errors in the Green's functions explicitly, and obtain scattering integrals from these errors. For forward modelling, there is no need to separate the model into a reference and perturbation part - approximate Green's functions in the true model can be used to calculate the scattered signals.

The theory is developed for inhomogeneous, anisotropic media. Asymptotic ray theory results are suitable approximate Green's functions for the generalized Born scattering theory. The error terms are simple, easily calculated and included in the scattering integrals. Various applications of generalized Born scattering theory have already appeared in the literature, e.g. quasi-shear ray coupling, and this paper is restricted to an improved and more complete theoretical development. Further applications will appear elsewhere.     

Use of the Apparent Content Curves for the spectrophotometric identification of substances: identification of amphetamines

The possibility of identification of substances which have similar spectral behaviour by means of Apparent Content Curves has been studied. This study is carried out with absorption, excitation and emission spectra of several amphetamines of widespread pharmaceutical use. Results obtained show that amphetamine, phenylpropanolamine, pseudoephedrine, phenylephrine, epinephrine, dopamine and methoxyamphetamine can be identified with a probability of >95%.     

Determination of glycols by HPLC with refractive index detection

A simple and fast HPLC method for the determination of glycols is described. It is characterized by a reversed-phase separation using water as eluent and a refractive index detection. The method was applied to investigate the biodegradation of glycols in a laboratory activated sludge plant and to determine the content of glycols or alcohols in detergents. The detection limit is 4 mg/l ethylene glycol or propylene glycol in an aqueous sample.