基于二维直方图分析的二元子图微光图像增强处理

提出了基于二维直方图分析的二元子图微光图像增强处理算法，根据原始图像的二维直方图分布特征，依据相邻像素的相关性数据，将图像分割成二元子图像，对每个子图像分别进行直方图均衡增强处理，最后合成得到完整的处理图像，通过用信息容量等图像评价参数对实验结果进行分析，表明此算法克服了对整幅图像进行直方图均衡时难以把握局部细节的缺点，得到了具有较好视觉质量的处理后微光图像。     

Application of artificial neural networks to the analysis of two‐dimensional fluorescence spectra in recombinant E coli fermentation processes

A two‐dimensional (2D) spectrofluorometer was used to monitor various fermentation processes with recombinant E coli for the production of 5‐aminolevulinic acid (ALA). The whole fluorescence spectral data obtained during a process were analyzed using artificial neural networks, ie self‐organizing map (SOM) and feedforward backpropagation neural network (BPNN). The SOM‐based classification of the whole spectral data has made it possible to qualitatively associate some process parameters with the normalized weights and variances, and to select some useful combinations of excitation and emission wavelengths. Based on the classified fluorescence spectra a supervised BPNN algorithm was used to predict some of the process parameters. It was also shown that the BPNN models could elucidate some sections of the process's performance, eg forecasting the process's performance. Copyright © 2005 Society of Chemical Industry     

含-NCO双组分水性木器漆的应用研究

介绍了以-NCO交联的双组分水性木器漆常用的树脂、固化剂类型，对其在木器涂装过程中的施工时限、泡沫控制等影响生产应用的因素进行了分析研究，并提出了一些解决方案。     

两相管流工艺计算软件的研制

利用流体力学理论 ,结合目前国内外最新的两相流理论和实验研究成果 ,在描述气液两相流水力计算、热力计算和流型判断的数学物理模型基础上 ,研制出适用于海洋、沙漠、丘陵地区原油与伴生气、凝析天然气与凝液输送工艺的一套新的计算模拟软件TFTCS。介绍TFTCS软件的结构、功能、适用范围。用该软件对锦州 2 0 - 2海底湿天然气管道进行模拟计算 ,并与管线生产数据进行对比 ,用国外同类软件PIPEPHASE进行验算。实例计算分析表明 ,该软件功能完善 ,操作方便 ,计算结果可靠 ,能满足油气混输管道的设计计算和生产管理的需要     

Series resonant ZCS‐PFM DC‐DC power converter with high‐frequency high‐voltage transformer link for high‐power magnetron drive

This paper presents a single lossless inductive snubber‐assisted ZCS‐PFM series resonant DC‐DC power converter with a high‐frequency high‐voltage transformer link for industrial‐use high‐power magnetron drive. The current flowing through the active power switches rises gradually at a turned‐on transient state with the aid of a single lossless snubber inductor, and ZCS turn‐on commutation based on overlapping current can be achieved via the wide range pulse frequency modulation control scheme. The high‐frequency high‐voltage transformer primary side resonant current always becomes continuous operation mode, by electromagnetic loose coupling design of the high‐frequency high‐voltage transformer and the magnetizing inductance of the high‐frequency high‐voltage transformer. As a result, this high‐voltage power converter circuit for the magnetron can achieve a complete zero current soft switching under the condition of broad width gate voltage signals. Furthermore, this high‐voltage DC‐DC power converter circuit can regulate the output power from zero to full over audible frequency range via the two resonant frequency circuit design. Its operating performances are evaluated and discussed on the basis of the power loss analysis simulation and the experimental results from a practical point of view. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 153(3): 79–87, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20126     

高压条件下伴随化学反应两相流动的数值模拟

建立了高装填密度火药床在高压条件下的一维两相流体力学方程组，探讨了两相自由射流边界的处理方法，并对其进行了数值求解．揭示了对流燃烧过程的燃烧机理．数值结果与实验测得的压力曲线和火焰阵面曲线有较好的一致性     

Stability of impulsive stochastic functional differential systems in terms of two measures via comparison approach

Comparison principles for general impulsive stochastic functional differential systems are established.Employing the comparison principles and the theory of differential inequalities,stability and instability,involving two measures,of impulsive stochastic functional differential systems are investigated.Several stability and instability criteria are obtained,and two examples are also given to illustrate our results.     

黄河干流白银市水川段水面线计算方法对比分析

为克服能量方程逐段试算方法在河道水面线计算上存在的不足与局限,本文以黄河干流白银市水川段为例,采用二维水动力数值计算模型,对4种洪水频率工况下黄河干流白银市段的水面线高程进行计算,并将二维数值计算结果与能量方程计算结果进行复核和评价。经计算可知两种计算方法在计算结果上存在偏差,能量方程在河道水面线计算上是一种近似成果,而二维数值计算能够更加真实反映河道的实际情况,因此在水面线计算时推荐二维数值计算方法。     

Optimal Performance in Tracking Stochastic Signal Under Disturbance Rejection

The analysis method of optimal tracking performance is proposed for multiple‐input multiple‐output (MIMO) linear time‐invariant (LTI) systems under disturbance rejection. An H₂ criterion of the error signal between the output of the plant and the reference signal is used as a measure for the tracking performance. Spectral factorization is applied to obtain the optimal solution of the system tracking error. The explicit expressions are derived for this minimal tracking error with respect to random reference signals under disturbance rejection. It is shown that the nonminimum phase zeros, the zero direction, the unstable poles, the pole direction of a given plant, statistical characteristics of the reference input signal, and disturbance signal have a negative effect on a feedback system's ability to reduce the system error with disturbance rejection. The results show that the optimal tracking performance will further be damaged because of disturbance rejection. Some typical examples are given to illustrate the theoretical results.     

建立加气砼直观数理模型的探索

若视加气砼为细观的“两相”材料,则可建立起其细观几何结构的随机直观数理模型,本文应用随机几何的方法探索了加气砼最佳合理内部细观几何结构模型的建立,及其计算机随机模拟,由细观角度讨论了改善加气砼性能的可能性。