力控组态软件在双电机交流变频调速实验系统中的应用

介绍了力控组态软件,并以双电机交流变频调速实验系统为例,阐述了该双电机变频调速系统的构成、工作原理及力控组态软件在该系统中的应用。通过引入力控组态软件,使该系统更具实用性。     

聚丙烯／玻璃纤维的界面改性研究（Ⅰ）：不同界面改性方法的比较

玻璃纤维增强聚丙烯复合材料的关键是提高非极性的聚丙烯和极性的玻璃纤维的界面粘结强度,本文比较了以双马来酰亚胺,聚丙烯－马来酸酐接枝共聚物,硅烷偶联剂作为界面剂的几种最为常见的界面改性方法对聚丙烯／玻璃纤维的界面改性效果,指出以聚丙烯－马来酸酐接枝共聚物作用面剂是最经济,最有效的聚丙烯／玻璃纤维的界面改性方法。     

A New Quality Improving Scheme for VQ Decompressed Images Based on DWT

The better compression rate can be achieved by the traditional vector quantization (VQ) method, and the quality of the recovered image can also be accepted. But the decompressed image quality can not be promoted efficiently, so how to balance the image compression rate and image recovering quality is an important issue. In this paper, an image is transformed by discrete wavelet transform (DWT) to generate its DWT transformed image which can be compressed by the VQ method further. Besides, we compute the values between the DWT transformed image and decompressed DWT transformed image as the difference matrix which is the adjustable basis of the decompressed image quality. By controlling the deviation of the difference matrix, there can be nearly lossless compression for the VQ method. Experimental results show that when the number of compressed bits by our method is equal to the number of those bits compressed by the VQ method, the quality of our recovered image is better. Moreover, the proposed method has more compression capability comparing with the VQ scheme.     

室外型自动扶梯检测应注意的问题

随着城市建设的高速发展，自动扶梯的拥有量与日俱增，而室外型自动扶梯以其独特的设计和建筑物完美的结合成为城市交通的一道靓丽风景线。目前，室外型自动扶梯设计制造参照的是室内自动扶梯的有关标准。但由于我国幅员辽阔，各个地区的气候特点不同，由此带来一系列因设计制造不完善，造成自动扶梯使用过程中故障频发、安全隐患严重等问题。因此，设计出适合地区气候特点，满足室外条件安全运行的自动扶梯对每个生产厂家显得尤其重要。