Sparse asymptotic minimum variance based bearing estimation algorithm for a single vector hydrophone

For underwater target detection using a single vector hydrophone, sparse asymptotic minimum variance(SAMV) method is used to estimate the target bearing. The SAMV discretizes the entire scanning space and the target bearing is located at the position of the discrete direction. The SAMV algorithm utilizes the sparsity of the spatial signal to improve the estimation performance of the target bearing. Background noise level(BNL) of the bearing estimation of SAMV algorithm is lower than those of the conventional beam forming(CBF)method and minimum variance distortionless response(MVDR) method for different signal noise ratios(SNRs). When the SNR is higher than 0 d B, the direction-finding error of this algorithm is less than 2°. Moreover, the SAMV algorithm has a better dimensional orientation resolution capability. The experimental results show that the SAMV algorithm gives a bearing and time recording map with a lower BNL, which effectively verifies the effectiveness of SAMV algorithm in terms of underwater target detection.     

A Model System for the Study of Competitive Coordination in Aminoheterocyclic Complexes. Molecular and Crystal Structure of 2-Amino-1-methyl-Benzoimidazolium Chloride Hydrate

2-Amino-1-methyl-benzoimidazolium chloride hydrate was structurally characterized by X-ray diffraction analysis. Its crystal is built from organic cations, chloride anions, and molecules of crystallization water, which are united through a related system of hydrogen bonds. In the organic cation, the proton is localized at the N atom of the pyridine type.     

离子交换色谱法分离测定磷霉素的研究

分别采用全多孔型硅胶基键合强阴离子交换柱与氨丙基键合硅胶柱，在低波长 ２００ ｎｍ 处检测，分离测定了磷霉素 探讨了流动相条件，如ｐ Ｈ 值、离子强度等对磷霉素保留及分离选择性的影响，优化分离条件，建立了一种测定磷霉素的高效液相色谱新方法方法简便、快速     

New Ambidentate Ligands—Azomethin Derivatives of 1-Amino-3-methylbenzimidazoline-2-thion

Metal chelates ML₂ (M = Co²⁺, Ni²⁺, Cu²⁺, Cd²⁺) are synthesized from azomethin derivative of amino-3-methyl-benzimidazoline-2-thion and 2-N-tosylaminobenzaldehyde (HL) and their compositions and structures are determined from the electronic mass spectrometry, IR and electronic spectroscopy and magnetochemistry data.     

利用提升小波的蛋白质相互作用特征提取

利用提升小波从蛋白质序列中提取出它们相互作用的频谱特征,经支持向量机训练学习后,用于预测蛋白质间的相互作用.模拟计算结果表明,在阳性数据和阴性数据平衡的前提下,利用提升小波获取的低维蛋白质相互作用特征向量可以得到较高预测精度.进一步阐述了不同物种的蛋白质相互作用网络有着不同特征,为了得到更准确的预测结果,需要利用不同的方法提取蛋白质相互作用的特征.     

一种新的自动调焦方法—离轴探测法

本文提出了的种新的自动调焦方法——离轴探测法,此法没用任何附加元件,结构简单、装调容易、线性度好、灵敏度高、调焦范围大、实用性强;介绍了此法的原理、理论计算结果及实验结果;给出了应用实例.     

C_0复杂度的改进及其在证券市场中的应用

系统地分析了Lemple-Ziv复杂性度量方法的应用过程中,将实际信号(时间序列)转变成符号序列的诸多方法中存在的一些问题,提出了更合理兼容法.该方法可以有效地刻划各种时间序列的复杂度.文章最后动态地分析了中国证券市场的复杂性.     

Novel tribochemically active metal chelates of aromatic azo ligands

Novel Cu(II) and Pd(II) complexes with o-phenylaminoazo compounds were synthesized and studied by X-ray diffraction. Distorted tetrahedral chelate complex of Cu contains two six-membered CuN₃C₂ metal cycles. The complexes under study can be used as industrial lubricant additives.     

交通流非参数回归模型

交通流宏观参数流量、速度和占有率在交通工程和管理中具有非常重要的作用 ,对这三者关系的刻划反映了道路本身特性和交通流的规律。到目前为止 ,基本上采用线性或非线性的参数模型来描述 ,此类模型在应用中具有一定的局限性 ,并交通变量时间序列进行预测 ,数据拟合表明 ,选择适当的核函数或邻近数以及窗宽 ,可以达到比较满意的效果