永磁直线同步电机位置系统的模糊IP控制研究

针对具有电磁推力大、响应快、易于矢量解耦控制的永磁直线同步电机PMLSM,研究高精度位置伺服控制系统的设计,以满足高速加工与高精度微进给加工的需求。考虑被控对象的变化和外界扰动,控制器的参数难于在线修订,设计了一种模糊/积分-比例IP位置控制器。它将具有并联反馈环节的IP控制器与模糊控制器有效结合,根据位置偏差的变化率进行切换,即存在较大输入指令与系统输出偏差较大时采用模糊控制,而系统输出接近于输入指令时则采用IP控制器,从而发挥模糊控制器对变参数系统的自适应性和IP控制器的快速和准确性优势。仿真实验结果表明模糊/IP控制器在稳态精度和动态性能方面优于单纯的IP控制器和模糊控制器,能够满足变参数控制系统的性能指标。     

R-L-C串联谐振在船舶同步发电机自励恒压装置中的应用

从同步发电机自励建压过程中存在的问题入手,分析了R—L—C串联谐振在同步发电机自励恒压装置中,如何改变自励回路的阻抗、励磁冲击电流的产生和对建压的作用．同时从实际应用角度出发对谐振参数的调节与谐振频率的整定也作了阐述．     

Synchronization in a Mutualism Ecosystem Induced by Noise Correlation

Understanding the cause of the synchronization of population evolution is an important issue for ecological improvement. Here we present a Lotka-Volterra-type model driven by two correlated environmental noises and show, via theoretical analysis and direct simulation, that noise correlation can induce a synchronization of the mutualists. The time series of mutual species exhibit a chaotic-like fluctuation, which is independent of the noise correlation, however, the chaotic fluctuation of mutual species ratio decreases with the noise correlation. A quantitative parameter defined for characterizing chaotic fluctuation provides a good approach to measure when the complete synchronization happens.     

A new quantitative Raman measurement scheme using Teflon as a novel intensity correction standard as well as the sample container

A novel and reliable quantitative Raman measurement scheme has been proposed for the analyses of ethanol and isopropanol solutions. Teflon tubing was employed as an effective intensity correction standard as well as the sample cell. This allowed for the synchronous collection of the mixed Raman spectrum from the Teflon standard and the sample without any extra optical configuration. A non‐overlapping Teflon band was used as the standard peak to correct the Raman intensity changes resulting from laser power variations. In addition to the use of Teflon tubing,a wide area illumination (WAI) scheme was employed, which made the laser illumination into a circle of 6 mm diameter (area: 28.7 mm²), to cover a wide sample area. The WAI scheme improved the reliability of the Raman measurement by significantly increasing the reproducibility of the sampling owing to a decreased sensitivity to sample placement with respect to the focal plane as well as a wider sample coverage area. The resulting Raman spectra were more reproducible and more representative of the correct sample composition. Overall, a superior prediction performance was achieved using the WAI scheme compared to the conventional Raman collection method. The proposed system has great potential for use in the quantitative analysis of diverse liquid samples with good reproducibility. Copyright © 2006 John Wiley & Sons, Ltd.     

多环芳烃混合物的快速导数-恒能量同步荧光光谱分析

多环芳烃混合物的快速导数-恒能量同步荧光光谱分析;导数技术     

同步荧光光谱法测定十二烷基苯磺酸钠的临界胶束浓度

采用表面张力、电导率、紫外可见吸收光谱、恒波长同步荧光光谱法分析了典型阴离子表面活性剂十二烷基苯磺酸钠在水溶液中的临界胶束浓度（CMC）。 结果表明,同步荧光光谱法测定CMC时的样品用量少,检测灵敏度高,具有较高的准确性;测定的十二烷基苯磺酸钠的第一临界胶束浓度和第二临界胶束浓度分别为1.48和6.90 mmol/L,与传统的表面张力法和电导率法的测定结果一致。 验证了同步荧光光谱法测定表面活性剂CMC的可靠性。     

二维相关光谱探测荧光能量转移现象

以EuCl₃和NdCl₃混合水溶液为研究对象,按正交浓度序列以浓度为外部扰动构建紫外可见-荧光二维相关光谱。在混合溶液的二维相关光谱中,观察到了Eu3+的荧光发射谱峰与Nd^{3+的吸收谱峰之间存在交叉峰。交叉峰的出现表明Eu3+和Nd3+的荧光发射与吸收之间存在能量传递。二维相关光谱中交叉峰的产生并非由于溶剂水分子与溶质(Eu3+或Nd3+)之间相互作用;若以单一溶质的EuCl₃和NdCl₃的水溶液构造模拟的“混合溶液”的拟合光谱构建二维紫外可见-荧光相关光谱,由于Eu3+和Nd3+在空间上相互分离,无相互作用发生,交叉峰并不存在。二维相关光谱的交叉峰可为从光谱学角度探测复杂体系能量传递及其相关机制提供一条新思路。}     

Parallel Synchronous and Asynchronous Space-Decomposition Algorithms for Large-Scale Minimization Problems

Three parallel space-decomposition minimization (PSDM) algorithms, based on the parallel variable transformation (PVT) and the parallel gradient distribution (PGD) algorithms (O.L. Mangasarian, SIMA Journal on Control and Optimization, vol. 33, no. 6, pp. 1916–1925.), are presented for solving convex or nonconvex unconstrained minimization problems. The PSDM algorithms decompose the variable space into subspaces and distribute these decomposed subproblems among parallel processors. It is shown that if all decomposed subproblems are uncoupled of each other, they can be solved independently. Otherwise, the parallel algorithms presented in this paper can be used. Numerical experiments show that these parallel algorithms can save processor time, particularly for medium and large-scale problems. Up to six parallel processors are connected by Ethernet networks to solve four large-scale minimization problems. The results are compared with those obtained by using sequential algorithms run on a single processor. An application of the PSDM algorithms to the training of multilayer Adaptive Linear Neurons (Madaline) and a new parallel architecture for such parallel training are also presented.     

γ模拟器与EMP模拟器同步运行可行性研究

 γ-EMP组合模拟器的关键问题是实现γ模拟器与EMP模拟器的准确同步运行。分析了组合模拟器对γ模拟器同步性能的要求,指出γ模拟器动作时间的抖动ΔTγ至少应达到γ脉冲半幅值宽度的1/2的水平。分析研究了选择闪光Ⅰ作为γ模拟器时存在的困难和改进同步性能的途径。讨论了选择闪光ⅠA 作为γ模拟器时的同步性能和可行性。     

司帕沙星金属络合物在胶束体系中的荧光特性研究及应用

研究了在金属离子存在下司帕沙星在胶束体系中的荧光特性,首次发现锌（Ⅱ）和阴离子表面活性剂十二烷基硫酸钠对司帕沙星的荧光有显著的协同增敏作用,据引建立了测定人体尿液中司帕沙星含量的同步－导数荧光光谱法,定量线性范围为０．０４～４．０ｍｇ／Ｌ,检测限为０．０４ｍｇ／Ｌ。相对标准偏差为１．６％～３．９％。探讨了锌（Ⅱ）和十二烷基硫酸钠对司帕沙星荧光的增敏机理。