三维光盘存储系统中双光头同步控制的频域分析与辨识

详细介绍了双光头同步控制原理.对采集的伺服模块聚焦误差跟踪信号及共焦模块读写光头的聚焦线圈驱动信号进行了频域分析,并以此两路信号作为系统输入输出,分别对三种参数模型进行参数优化.根据3种模型的频率响应及阶跃响应,选择双光头同步控制过程的参数模型为[450]阶的ARX模型.实测曲线与模型仿真结果符合度(fit)为78.0259%.     

具有可调紫外滤光性能的富勒烯胺/壳聚糖共混膜的研究

通过溶液共混及流涎成膜法制备了一系列不同C60乙醇胺含量的壳聚糖共混膜。以及含Cu（Ⅱ）的C60乙醇胺/壳聚糖共混膜。研究表明，C60乙醇胺/壳聚糖共混膜具有优异的可调紫外滤光性能，随着C60乙醇胺含量的增加，其紫外滤光波长从200nm红移至400nm左右。在该复合体系中引入Cu（Ⅱ）能有效改善膜的紫外光学性能，同时还初步探讨了这类复合材料的紫外滤光机制。     

Atomic distributions in acetylene-air flame using hydraulic high-pressure nebulization with direct (100%) introduction of solutions Applications to speciation analysis

One of the fundamental factors of the performance of atomic spectrometric methods is the efficiency of sample introduction into flame or plasma. By utilization of the formerly developed hydraulic high-pressure nebulizer, a nebulizer/burner system with solution uptake efficiency of 100% have been worked out. Optimizing operation parameters of nebulizer/burner system, an improvement of 2-12 times was achieved for the signal-to-noise ratio in the flame emission and flame atomic absorption spectrometry, depending on sample flow rate. This nebulizer is especially suitable for development of liquid chromatography-AAS/FES coupled technique for speciation analytical tasks.     

Chlorination of aromatic substrates catalyzed by the phthalocyanine complexes

The chlorination of benzene, toluene, and o-xylene with molecular chlorine in the presence of the phthalocyanine complexes of different structures was studied. The transformations of the catalysts during the reaction were investigated. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1644–1647, August, 2008.     

Electronic Spectra and the Mechanism of Complexing of Uranyl Nitrate in Water–Acetone Solutions

Based on the analysis of electronic absorption and luminescence spectra, the processes of complexing in an aqueous solution of uranyl nitrate hexahydrate (UO₂(NO₃)₂·6H₂O) on gradual addition of small amounts of acetone have been investigated. In a pure aqueous solution, uranyl exists as the UO₂·5H₂O complex. It is shown that addition of acetone to the solution leads to displacement of some water molecules from the first coordination sphere of uranyl and formation of uranyl nitrate dihydrate complexes, UO₂(NO₃)₂·2H₂O. It has been established that the stability of these complexes is determined by the decrease in both the water activity and the degree of hydration of uranyl and nitrate. This is the result of the local increase in the concentration of the molecules of acetone (due to its hydrophobicity) in those regions of the solution in which there are uranyl and nitrate ions. The experimental facts supporting the proposed mechanism are given.     

γ-辐照对纯Y_2SiO_5和Eu~(3+)∶Y_2SiO_5晶体光谱性能的影响

研究了γ-辐照前后纯Y2SiO5和Eu3+掺杂的Y2SiO5晶体吸收光谱的变化,辐照后,未退火和氢气退火的纯Y2SiO5晶体在260~270 nm和320 nm波段产生了附加吸收峰,分别是由F心和O-心的吸收引起的;经过空气退火的纯YSO晶体中,由于消除了氧空位,因此辐照后没有出现色心吸收峰。在Eu3+∶Y2SiO5晶体中,不但有相同的F心和O-心吸收峰,而且还有Eu2+离子在300 nm和390 nm的吸收峰。随着辐照剂量的增加,色心附加吸收峰增强。空气退火能减少Eu3+∶Y2SiO5晶体中的色心,而氢气退火能增加色心。     

Survivability in IP-over-WDM Networks: WDM Lightpath Protection versus IP LSP Protection

This article compares the performance of WDM lightpath protection and IP LSP protection schemes for IP-over-WDM networks. A mathematical formulation of the maximum throughput problem is presented and analytical expressions for recovery time are derived for both schemes. The throughputs and recovery times are analyzed and compared. Results show that the IP LSP protection scheme presents higher throughputs then WDM lightpath protection. The IP LSP protection scheme, providing individual IP LSP protection has, however, scalability problems. This scheme presents high recovery times when a failure affects many lightpaths and many hops are allowed for the primary routes of IP LSPs.     

The spectrum of Nd in rare earth orthoaluminates. The trigonal to orthorhombic transition study of the level

Some structural and spectroscopic features of rare earth orthoaluminates are examined.The trigonal→ orthorhombic transition is studied in a series of Nd_xSm_1−xAlO₃ compounds. The evolution of the crystal structure is followed by X-ray analysis and optical absorption. The free ion and crystal field parameters of Nd³⁺ (4f³ configuration) are determined in LuAlO₃:Nd³⁺.The anomaly of the calculated splitting of the levels is slight, but well characterized in NdAlO₃. The spin correlated crystal field and orbitally correlated crystal field models are tested as well as an empirical correction which was proposed earlier.     

Optical absorption spectra of linear and cyclic thiophenes—selection rules manifestation

We theoretically study the size-dependent relation between absorption spectra of thiophene-based oligomers and the corresponding cyclothiophenes. In our approach based on a Frenkel exciton Hamiltonian, we demonstrate that the geometry and selection rules determine the observed relations between the spectra.     

机载海洋激光测深系统参量设计与最大探测深度能力分析

详细讨论了机载海洋激光测深系统最大测量深度与相关因子之间的关系，并利用最小可探测信噪比为判据，对机载海洋激光测深系统在白天和晚上工作进行了数值模拟，通过比较最大测量深度与激光脉冲峰值功率、接收视场角、接收口径和光谱接收带宽等关系，确定了系统的主要参量。以确定的参量建立的系统具有白天49m和晚上65m的最大测深能力，可完全满足在沿岸带以及岛礁的测量要求。