CCD立靶坐标测量系统捕获率研究

介绍了CCD立靶坐标测量系统的坐标测量原理及其目标光学成像特性.在此基础之上从目标特性、相机特性和视频处理能力三方面研究了影响CCD立靶坐标测量系统捕获率的因素,提出了弱化不利因素影响的措施和提高系统捕获率的方法.这些因素在4m×4m的立靶的设计中已被充分考虑,在其后的上千发实弹测试实验中,系统对5.8 mm直径的目标捕获率测试达到了95% 以上,对大于5.8 mm直径的目标捕获率测试达到了更高标准.实验证明这些方法对于提高系统捕获率是非常有效的.     

Improvements to Variable Elimination and Symbolic Probabilistic Inference for evaluating Influence Diagrams

An Influence Diagram is a probabilistic graphical model used to represent and solve decision problems under uncertainty. Its evaluation requires performing several combinations and marginalizations on the potentials attached to the Influence Diagram. Finding an optimal order for these operations, which is NP-hard, is an element of crucial importance for the efficiency of the evaluation. In this paper, two methods for optimizing this order are proposed. The first one is an improvement of the Variable Elimination algorithm while the second is the adaptation of the Symbolic Probabilistic Inference for evaluating Influence Diagrams. Both algorithms can be used for the direct evaluation of IDs but also for the computation of clique-to-clique messages in Lazy Evaluation of Influence Diagrams. In the experimental work, the efficiency of these algorithms is tested with several Influence Diagrams from the literature.     

An upwind finite element scheme for high-Reynolds-number flows

A new upwind finite element scheme for the incompressible Navier-Stokes equations at high Reynolds number is presented. The idea of the upwind technique is based on the choice of upwind and downwind points. This scheme can approximate the convection term to third-order accuracy when these points are located at suitable positions. From the practical viewpoint of computation, the algorithm of the pressure Poisson equation procedure is adopted in the framework of the finite element method. Numerical results of flow problems in a cavity and past a circular cylinder show excellent dependence of the solutions on the Reynolds number. The influence of rounding errors causing Karman vortex shedding is also discussed in the latter problem.     

晶格振动和晶粒尺度对磁记录膜矫顽力的竞争影响研究)

对晶格自旋相互作用的交换积分进行了晶格振动的修正,依此修正,导出了振动对磁记录膜矫顽力的影响关系;分析了磁晶量子尺度效应对磁记录膜矫顽力的影响机制;讨论了振动效应和量子尺度效应相互影响,共同竞争的物理内涵.结果显示:①振动的存在将减小薄膜的矫顽力;②磁晶微粒的量子尺度效应将使薄膜的矫顽力增加;③振动效应和量子尺度效应相互影响,共同竞争,为薄膜提供矫顽力;④要提高薄膜完备系的矫顽力,可将磁记录膜制成纳米级薄膜.     

Influence of temperature on FTIR spectra of various organic compounds analyzed by on-line carbon dioxide SFC/FTIR

The development of an on-line SFC-FTIR method with supercritical carbon dioxide as mobile phase requires information about the nature of the FTIR spectrum of a solute dissolved in supercritical or liquid CO₂. The wavenumber of maximum absorbance of the carbonyl stretching vibration was quantitatively studied versus temperature and CO₂ density. FTIR spectra recorded in supercritical or liquid CO₂ have been compared to their vapor-phase and condensed-phase spectra for various solutes.     

Optical Characterization of 4H-,6H-and 15R-SiC Crystals

The optical absorption of 4H-,6H-and 15R-SiC single crystals has been measured at room temperature. The band gaps were calculated,and the reasons for band gap shrinking were discussed. Influence of free carrier concentration was considered. The first-and second-order Raman spectra of 4H-,6H- and 15R-SiC samples were analyzed. Raman spectra of disorder structure in 6H-SiC grown by Lely method were given and simulated. The low wave-number Raman spectrum is a reliable method to distinguish the SiC polytypes. We analyzed the similarity of the second-order Raman spectra of all polytypes.     

Influences of Triton X-100 micelle on the microstructure of HSA

The effects of Triton X-100 molecule and micelle on the microstructure and properties of HSA are studied by the some methods of UV spectrum, fluorescence spectrum, fluorescence polarization, circular dichroism, conductivity, and zeta potential. With the increase of Triton X-100 concentration, the UV absorbance, fluorescence intensity of HSA, and the system conductivity all first decrease and then increase. The zeta potential of HSA first goes up and then down. The percents of the β-sheet, random, turn structures, and the polarization of HSA increase but the percent of the α-Helix of HSA decreases. When Triton X-100 concentration is more than 1.0×10⁻³ mol l⁻¹, the structure parameters change obviously especially for the percents of random and turn structures.     

Contribution of adsorption to retention data in glass capillary gas chromatography part. I. Polar stationary phases

Summary The influence of the film thickness of Carbowax 20M coated onto glass surfaces (series of columns with different mode of surface treatment) upon the retention indices of solutes which exhibit tendency to hydrogen bonding has been investigated. Limiting values of Kovats indices, I, are calculated for all the columns examined.Presented at the 14th International Symposium on Chromatography London, September, 1982     

Normalkoordinatenanalyse an heteroleptischen Hexahalogenorhenaten(1V) der Punktsymmetrie C4V

Normal Coordinate Analysis on Heteroleptic Hexahalorhenates(1V) with Point Symmetry C_4v Normal coordinate analyses, based on a general valence force field, for 8 complexes [ReX^.Y₄Z′]^2?, C_4v, X^. = F, Cl, Br, I; Y = Cl, Br, I; Z′ = Cl, Br, I, reveal that the force fields may be well approximated by characteristic structural elements: ReY₄ plane, trans-weakened ReX^. and trans-strengthened ReZ′ bonds. For the ReY₄ plane the same valence force constants are valid as for the homoleptic species [ReY₆]^2? (F = 3.23, Cl = 1.67, Br = 1.33, I = 0.80 mdyn/Å). Due to the increasing trans influence F < Cl < Br < I for asymmetric axes X^.ReZ′ the force constants are mutual lowered at ReX^. bonds, up to 10% in case of ReF^., and enhanced at ReZ′ bonds up to 15% for ReI′. Using the data determined for the structural groups the vibrational frequencies of different mixed halorhenates(IV) can be calculated with reliability of a few cm^?1.     

Fast local search methods for solving limited memory influence diagrams

Limited memory influence diagrams are graph-based models that describe decision problems with limited information such as planning with teams and/or agents with imperfect recall. Solving a (limited memory) influence diagram is an NP-hard problem, often approached through local search. In this work we give a closer look at k-neighborhood local search approaches. We show that finding a k-neighboring strategy that improves on the current solution is W[1]-hard and hence unlikely to be polynomial-time tractable. We also show that finding a strategy that resembles an optimal strategy (but may have low expected utility) is NP-hard. We then develop fast schema to perform approximate k-local search; experiments show that our methods improve on current local search algorithms both with respect to time and to accuracy.