Study of Underwater Target Recognition for Torpedo Electromagnetic Fuse with High Detecting Precision

鱼雷武器系统的主动电磁引信回波信号中蕴含着雷目交会过程重要特征信息。针对回波信号能量比较法受到直达场耦合成分和噪声影响的问题,提出了基于数字信号处理技术的目标特征提取算法。对接收天线的回波信号进行全相位二次补偿处理;采用短时傅里叶变换对目标回波信号进行包络解调;再利用改进的三次多项式最小二乘拟合方法,以抑制数据波动影响并提高计算效率;提出一种基于钟型脉冲的参数识别算法对回波包络极大值点进行估计。仿真和试验数据验证表明所提出方法具有一定的工程实用性。Characteristic information is hidden in the received signal of active torpedo electromagnetic fuse.The conventional burst controlling strategies based on energy-comparison are affected by ambient and electromechanical noises.The improved algorithms based on digital signal processing techniques are proposed.The received signals are first processed by all-phase compensation method to eliminate the direct coupling component,and then the residual signal is demodulated using STFT.An improved polynomial least mean square approximation method,which reduces the computation time,is presented for eliminating the side-effects brought by noise.A parametric estimation model base on bell-shape impulse is used to estimate the maximum of echo envelope.Simulation and trial data show that the proposed algorithm is effective and practical.国家自然科学基金项目(51275384、51275382); 国家科技重大专项(2010ZX04014-016

Simple Combustion Production and Characterization of Octahydro[60]fullerene with a Non-IPR C-60 Cage

1. Xiamen Univ, State Key Lab Phys Chem Solid Surface, Xiamen 361005, Peoples R China 2. Xiamen Univ, Dept Chem, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China 3. Xiamen Univ, Sch Life Sci, Xiamen 361005, Peoples R ChinaFor the first time an easier, operable combustion method is employed for the synthesis of non-IPR fullerene, and an octahydro[60)fullerene with a non-IPA C-60 cage (C-60 isomer C-#1809(60)) produced by combustion is isolated and characterized by MS, UV vis, IR, and NMR spectroscopies in combination with DFT calculations. This finding shows that, in addition to chlorine, hydrogen can be an ample cataloreactant for the production of non-IPR fullerene derivatives under such conditions as arc-burning and diffusion combustion.NSFC 20525103 20673088 20973137 20721001 20423002 21031004 973 projects 2007CB815301 2007CB81530

Combustion Synthesis and Electrochemical Properties of the Small Hydrofullerene C50H10

通讯作者地址: Xie, SY (通讯作者),Xiamen Univ, Coll Chem & Chem Engn, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, Coll Chem & Chem Engn, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 2. Xiamen Univ, Coll Chem & Chem Engn, Dept Chem, Xiamen 361005, Peoples R China 3. Xiamen Univ, Sch Life Sci, Xiamen 361005, Peoples R China 电子邮件地址: [email protected]; [email protected] hydrofullerene C50H10 is synthesized by low-pressure benzeneoxygen diffusion combustion. The structure of C50H10 is identified through NMR, mass spectrometry, and IR and Raman spectroscopy as a D5h symmetric closed-cage molecule with five pairs of fused pentagons stabilized by ten hydrogen atoms. UV/Vis and fluorescence spectrometric analyses disclose its optical properties as comparable with those of its chloride cousin (C50Cl10). Cyclic and square-wave voltammograms reveal that the first reduction potential of C50H10 is more negative than that of C50Cl10 as well as C60, with implications for the utilization of C50H10 as a promising electron acceptor for photovoltaic applications.973 projects 2011CB935901 NSFC 21031004 21021061 2077310

The Establishment and Technical Approach of PC Cluster

[中文文摘]以RedHat 6.2为操作系统建立基于DQS(Distributed Queueing System,分布式队列管理系统)的计算集群系统(Pc Cluster)。该系统提供Gaussian98、GAMESS2000、Xiamen99给用户进行的量子化学计算,用户根据作业的大小选择所要使用的CPU的个数,如单CPU计算、双CPU并行计算、四CPU并行计算(由2台服务器来完成)。本文主要对构建过程中出现的有关技术和解决方法进行深入的探讨。整个PC Cluster有良好的性价比,且安全可靠、运算速度快,它有望发展成为一个重要的科学计算系统。[英文文摘]A PC Cluster based on DQS (Distributed Queueing System) for scientific computation has been established with Red-Hat6.2 operation system. Gaussian98, GAMESS2000, Xiamen99 are provided for quantum chemistry calculation. Users can choose the number of CPU in terms of their tasks, such as single,, dual, quadruple CPUs. The technical aspect for the PC Cluster was discussed in details. The whole system which costs little and has good quality is reliable and safe. It is anticipated that it would be an important system for scientific computation

Study on One Part Blocked Polyurethane-Ag Conductive Adhesive

通讯作者: [email protected][中文文摘]以封闭型聚氨酯为基体、三羟甲基丙烷(TMP)为固化剂,制备了单组份银粉导电胶,并研究其性能.该聚氨酯基体由2,4-甲苯二异氰酸酯(TDI)、TMP和少量聚乙二醇进行缩聚,并与己内酰胺反应而得.在基体中添加TMP固化剂、银粉和二氧化硅并充分搅拌后制得单组份导电胶.通过红外光谱、剪切强度和电阻率的测定对产物进行了表征,结果表明,70℃下TMP、TDI的加成反应需要时间为4~4.5 h,与己内酰胺的封闭反应时间为3~4 h;银粉的质量分数为75%时产物性能最好;加入少量二氧化硅能够提高导电胶的剪切强度,但电阻率会随之升高.[英文文摘]The preparation and properties of one-component Ag powder conductive adhesive which consisted of TMP-TDI adduct as matrix and TMP as hardener were studied.TMP-TDI adduct was synthesized by TMP,TDI and PEG.Then the prepolymer was blocked by caprolactam to get blocked polyurethane.Hardener,Ag powder and fumed silica were added to the polyurethane to prepare one-component conductive adhesive through agitating well.The products were characterized by FTIR,moreover,their shear strength and electrical resistivity were measured respectively. The results demonstrated that the addition reaction of TMP and TDI needed 4~4.5 h, while the blocked reaction needed 3~ 4 h. The optimum mass fraction of Ag powder was 75%. Employing fumed silica to the conductive adhesive reinforced the shear strength and elect rical resistivity

Application of Green Ampt Equation During Infiltration in Layered Soil

通过对GreenAmpt 入渗模型特点的进一步分析和总结,概述了目前对GreenAmpt 入渗模式的发展情况,特别在沙层阻水、浑水入渗、间歇入渗和降雨入渗方面的应用进行分析,并对GreenAmpt 公式在这些方面应用中参数确定方法进行了进一步探讨,为在黄土区的应用提供指导

Power system abnormal data identification method

本发明涉及一种电力系统异常数据辨识方法，包括将电力系统正常数据作为训练样本，训练神经网络；将待检测数据输入训练后的神经网络，获得残差序列；基于仿射传播聚类算法对残差训练进行聚类；根据各个类别的特征和类内距离进行异常数据判断。本发明利用混沌粒子群算法来进行神经网络训练，同时采用仿射传播聚类算法来实现数据聚类，能够显著降低计算量，同时不依赖采样分布，有效地提高了电力系统异常数据辨识的准确性

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel