汽车发动机多模式自动生产输送线控制系统的研发

发动机的制造技术对汽车的质量至关重要。汽车发动机生产输送线采用顺序作业的流水线工艺过程。其自动控制系统采用德国Siemens公司的PLC-300系列控制器作为整个输送线的主体控制器,I/O系统作为控制信号的采集系统,采用Profibus现场总线技术进行通讯,自动完成将发动机部件进行直线移动、旋转、举升,翻转等操作。采用WinCC人机界面软件组建成系统的操作监控站进行产品数量、生产节拍的监视。本项目组成员在此基础之上又根据生产实际制作了相应的适合学校教学自动线实训系统,进行教学设备的开发。     

Measurements of O2-broadening and -shifting parameters of water vapor spectral lines in the second hexad region

Oxygen pressure induced broadening and shifting coefficients for water vapor absorption lines in the 8600–9010 cm⁻¹ region have been measured and calculated. The spectra were recorded with a Bruker IFS 125HR spectrometer at a spectral resolution of 0.01 cm⁻¹ for lines with angular moment of the upper states up to 10. Calculations of line broadening and shifting coefficients are performed using a semi-empirical approach. The method is based on the impact theory of broadening, and includes the correction factors whose parameters can be determined by fitting the broadening or shifting coefficients to the experimental data. The comparison of our calculations with the experimental values argues that the semi-empirical method is quite acceptable for the determination of the water vapor absorption line profile parameters.     

An empirical study on the importance of a speed-dependent Voigt line shape model for tropospheric water vapor profile remote sensing

We use high quality ground-based solar absorption spectra measured in close coincidence with Vaisala RS92 radiosonde in situ water vapor profiles to demonstrate that a Voigt line shape model yields systematic errors in the remotely sensed tropospheric water vapor profiles. We analyse absorption signatures of 4 H₂¹⁶O and 2 HD¹⁶O bands situated between 790 and 4710 cm⁻¹. We find that applying a speed-dependent Voigt line shape model instead of a Voigt line shape model significantly improves the agreement between the water vapor profiles obtained by the radiosondes and by infrared remote-sensing in the different bands. An optimal agreement is obtained for a Γ₂ (relaxation rate for speed-dependence) of 6-21% of Γ₀ (Voigt relaxation rate), which is consistent to the values derived from laboratory experiments. Our study suggests that further extensive laboratory investigations of line shape models are a key for improving the quality of modern water vapor remote sensing products.     

Absolute measurements of intensities, positions and self-broadening coefficients of R branch transitions in the ν2 band of ammonia

A complete spectroscopic study of 22 ammonia transitions belonging to the ν₂ fundamental band has been undertaken using a high-resolution Fourier transform spectrometer. More than 80 spectra of pure ammonia were recorded at different conditions of temperature (235, 264, and 296 K) and pressure (160-2000 Pa). Special attention was paid to the determination of the absolute wavenumber scale and of the ammonia partial pressure, which allowed to determine absolute positions (8×10⁻⁵ cm⁻¹), absolute intensities (<2%) and self-broadening coefficients (<2%) with high accuracy. Measured intensities show a mean difference of more than 13% compared to intensities extracted from the HITRAN (2008) database while absolute positions are in very good agreement (−3.3×10⁻⁵ cm⁻¹) with database values. Self-pressure shift coefficients are also reported.     

A global optimization procedure for the location of a median line in the three-dimensional space

A global optimization procedure is proposed to find a line in the Euclidean three-dimensional space which minimizes the sum of distances to a given finite set of three-dimensional data points.Although we are using similar techniques as for location problems in two dimensions, it is shown that the problem becomes much harder to solve. However, a problem parameterization as well as lower bounds are suggested whereby we succeeded in solving medium-size instances in a reasonable amount of computing time.     

Stabbers of line segments in the plane

The problem of computing a representation of the stabbing lines of a set S of segments in the plane was solved by Edelsbrunner et al. We provide efficient algorithms for the following problems: computing the stabbing wedges for S, finding a stabbing wedge for a set of parallel segments with equal length, and computing other stabbers for S such as a double-wedge and a zigzag. The time and space complexities of the algorithms depend on the number of combinatorially different extreme lines, critical lines, and the number of different slopes that appear in S.     

A reduced Hessian algorithm with line search filter method for nonlinear programming

This paper proposes a line search filter reduced Hessian method for nonlinear equality constrained optimization. The feature of the presented algorithm is that the reduced Hessian method is used to produce a search direction, a backtracking line search procedure to generate step size, some filtered rules to determine step acceptance, second order correction technique to reduce infeasibility and overcome the Maratos effects. It is shown that this algorithm does not suffer from the Maratos effects by using second order correction step, and under mild assumptions fast convergence to second order sufficient local solutions is achieved. The numerical experiment is reported to show the effectiveness of the proposed algorithm.     

6038～6052cm~(-1)附近CH_4低温吸收光谱研究

在CH4吸收光谱测量中,特别是低温吸收光谱测量中,分子吸收谱线的准确性测量十分重要,尤其是将所得的测量参数运用到地球大气以及外星球的遥感探测和模拟。HITRAN数据库中CH4给出的参数并不完整,同时还很不准确。为了对6 038～6 052cm-1波段的CH4低温吸收光谱进行测量,该文采用窄线宽的二极管激光器作为光源,结合自主设计的低温装置,测量了CH4的低能级能量和转动量子数,并与HITRAN 2008进行了对比,同时模拟了线强随温度的变化。     

A high-speed particle-detection in a large area using line-laser light scattering

We study the optical characteristics of a home-built line-laser surface light scattering system that detects sub-micron scale irregularities on a large area in high speeds. The sensitivity of the detection system, i.e. signal to noise (STN) ratio, is found to depend strongly on the detection angle. We find an optimal detection angle at 30°, at which STN ratio is maximized for 2500 nm silica particles on wafer surface. Experimental results of scattering intensity measurements from a smooth surface and from surfaces with spherical irregularities are in excellent agreement with corresponding theoretical model calculations. The line scan speed can be as high as ∼17 mm/s, while identifying the presence of a particle as small as 700 nm in a pixel area (∼15 μm × ∼17 μm). The presence of irregularities found by the line scan system is confirmed by confocal laser-scanning microscopy imaging. Due to unique advantages such as non-disruptiveness, high-speed over large area, and high sensitivity, this line scan system may be used as a surface inspection system that meets the requirements of recent flat panel display manufacturing environments.     

Enhancing time-suspension sequences for the measurement of weak perturbations

We detail key features for implementation of time-suspension multiple-pulse line-narrowing sequences. This sequence class is designed to null the average Hamiltonian (Hˉ(?)) over the period of the multiple-pulse cycle, typically to provide for high-resolution isolation of evolution from a switched interaction, such as field gradients for imaging or small sample perturbations. Sequence designs to further ensure null contributions from correction terms (Hˉ((1)) and Hˉ(2)) of the Magnus expansion are also well known, as are a variety of approaches to second averaging, the process by which diagonal content is incorporated in Hˉ(?) to truncate unwanted terms. In spite of such designs, we observed spin evolution not explicable by Hˉ(?) using 16-, 24- and 48-pulse time-suspension sequences. We found three approaches to effectively remove artifacts that included splitting of the lineshape into unexpected multiplets as well as chirped evolution. The noted approaches are simultaneously compatible for combination of their benefits. The first ensures constant power deposition from RF excitation as the evolution period is incremented. This removes chirping and allows more effective 2nd averaging. Two schemes for the latter are evaluated: the noted introduction of a diagonal term in Hˉ(?), and phase-stepping the line-narrowing sequence on successive instances during the evolution period. Either of these was sufficient to remove artifactual splittings and to further enhance resolution, while in combination enhancements were maintained. Finally, numerical simulations provide evidence that our experimental line-narrowing results with ??As in crystalline GaAs approach performance limits of idealized sequences (e.g., with ideal square pulses, etc.). The three noted experimental techniques should likewise benefit ultimate implementation with switched interactions and corresponding new error contributions, which place further demand on sequence performance.