物理场强化溶液结晶应用研究进展

结晶是食品和化工分离中的一个重要单元操作。文章阐述了溶液结晶的原理，综述了超声场、微波场、静电场、磁场等物理场在溶液结晶中的应用，分析和探讨了它们对溶液结晶的影响机理，并且对今后的发展进行了展望。     

图像增强技术在安防监控系统中的应用

数字化的图像处理技术里面对于各个综合知识的跨度是相当大的,对于各个知识面的要求也是十分高的。那么图像处理技术在实际的生活应用中也是被广泛运用。随着科技时代的到来,人们对于图像的画质要求更高,所以对于图像处理技术的研发已经是整个行业必须解决的问题。那么在这样一个要求越来越高的情形下,在视频监控行业里面图像处理技术起到了那些作用？是怎么样去应用到安防监控行业里面的？本文针对这些问题作出了一些简单的讨论和研究。     

A minimum variance distortionless response filter based on the bifrequency spectrum for single-channel noise reduction

This paper deals with the problem of single-channel noise reduction in the short-time Fourier transform (STFT) domain. Many algorithms have been developed to solve this important problem, most of which generally assume that the STFT coefficients in different frequency bands are uncorrelated, so the noise reduction is achieved by applying a gain function to the STFT of the noisy speech in each frequency band. However, this assumption is not accurate and the STFT coefficients of speech signals between neighboring frequency bands are correlated in practice due to the use of small lengths of the fast Fourier transform (FFT) and overlap add/save techniques in implementation. This paper formulates the noise reduction problem by taking into account the interband correlation using the so-called bifrequency spectrum. Based on this formulation, a single-channel minimum variance distortionless response (MVDR) filter is derived, which is shown to be able to significantly improve the signal-to-noise ratio (SNR) and meanwhile maintain the desired speech not much distorted. Simulations are presented to justify the claimed merits of the developed MVDR filter.     

视频图像增强关键技术研究

随着社会的飞速发展,采集保存视频/图像已经成为人类日常生活的一部分。视频图像的质量高低,对人类识别图像对象起着非常重要的作用。为了改善图像的视觉效果,有目的地强调图像的某些特征,增加图像的可读性与可识别性,提出采取融合增强术来提高视频图像的对比度与清晰度,提高图像增强质量。     

Ultrasonic defouling of reverse osmosis membranes used to treat wastewater effluents

On-line ultrasonic cleaning was used to remove fouling from a commercially important polyamide based reverse osmosis membrane during cross-flow filtration of CaSO₄, Fe³⁺ and carboxyl cellulose solutions. In each case, the permeate flux of the membrane increased significantly, with virtually no decrease in rejection in the presence of ultrasonication. Membrane surface characterization via scanning electron microscopy (SEM) confirmed the beneficial effect of ultrasonication on the membrane permeate flux. These studies suggest that ultrasonic defouling may be a very useful approach for the future development of reverse membranes, especially as far as fouling with organic materials is concerned.     

Preparation of V doped lanthanum silicate electrolyte ceramics by combustion method and study on conductance mechanism

Vanadium doped La_9.33Si_6−xV_xO_26+0.5x (x = 0.5, 1.0, 1.5) (LSVO) electrolyte powder was prepared by combustion method at 600°C for 5-7 min. The powder was sintered at 1500°C for 3 hours to prepare LSVO ceramics. XPS, IR, XRD, and EIS analysis show that V⁵⁺ doping replaces Si⁴⁺ in [SiO₄] to form [Si(V)O₄] tetrahedron. With the increase in x, the lattice volume increase. When x = 2.0, the LaVO₄ phase was formed, indicating that the limit doping amount of V⁵⁺ replacing Si⁴⁺ is x ≤ 1.5. The conductivity of LSVO increases significantly with the increase in x (x ≤ 1.0), which attributed to the defect reaction caused by V⁵⁺ doping. The addition of the interstitial oxygen Oi* in 6₃ channels and the increase of lattice volume leads to increased conductivity. When x = 1.0, the highest conductivity is 1.46 × 10⁻² S·cm⁻¹ (800°C). The doping enhancement conductivity mechanism is the Interstitial oxygen defect-Lattice volume composite enhancement mechanism.     

大学数学教学团队建设的探索与思考

从目标和定位、队员配备和任务安排、师资培训、课程和资源建设、科研促教等方面对大学数学教学团队建设进行了探讨。     

基于Matlab的数字散斑干涉图像处理

数字散斑干涉技术(DSPI)是一种高精度的光学测量技术,它适用于物体的形变及位移测量。因为其具有较高的测量精度,所以在航空航天、工业检测和生物医学等精度要求较高的领域都得到了广泛的应用。在数字散斑干涉技术中,条纹图像的处理是十分重要的。本文介绍了利用Matlab对散斑图像进行处理的各种方法和实际效果,包括令两幅图灰度值相减得到条纹图,图像的灰度增强处理,滤波处理,二值化处理和条纹的细化处理,最后提取出较清晰的条纹骨架线,为后续处理工作提供了基础。     

一种增加LED照明时序彩色投影系统亮度的方法

基于微型投影显示的色域特性和色彩实现机制,提出了一种提高微型投影系统亮度的方法。在基色子帧中引入其它基色,实现基色坐标的变换,再对微型投影系统亮场白平衡,分析并比较系统在绿色基色校正前后的性能。从理论分析了各色LED的最大工作电流、各基色色坐标和白场色坐标对通过基色校正提高亮度效果的影响。将该方法应用于实验室研发的微型投影系统,在保证系统显示性能的同时,亮度有了25.24%的提升。     

基于神经网络的图像亮度和对比度自适应增强

提出一种高频增强与神经网络相结合的图像亮度和对比度自适应增强方法。利用均值滤波获取原始图像的低频分量,由原始图像与低频分量的差值获取图像的高频分量。同时引入神经网络方法,建立图像的灰度均值、标准偏差与亮度和对比度两个增强系数的非线性映射关系,根据图像本身的均值与标准偏差自动获取增强系数,从而实现图像的亮度和对比度的自适应增强。该方法计算量小,实时性强,对亮度和对比度都较低的图像增强效果较好,可用于图像动态检测系统。为了验证算法的可行性,将所提出的方法应用到货车故障动态图像检测系统(TFDS)所采集的动态图像处理中,获得了好的效果。