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71.
用透射电子显微镜和正电子湮没等分析手段,研究了CuZnAl形状记忆合金的γ辐照效应,此合金经一定剂量的γ辐照后,马氏体转变温度明显提高,而形状记忆功能仍保持不变。  相似文献   
72.
随着我国汽车工业的迅猛发展,汽车产量不断增多,车速越来越高,对汽车制动性能要求也越来越高。汽车制动器是汽车上的重要设备,其质量的好坏影响着行车的安全。电惯量模拟是近几年兴起的一种比较先进的负载模拟方法,文章就制动器惯性试验台系统结构以及电惯量模拟的方法进行了比较详细的说明。  相似文献   
73.
高速线材轧机锥套故障分析与改进   总被引:1,自引:0,他引:1  
刘峰 《轧钢》2005,22(1):70-71
高速线材生产线精轧机、预精轧机使用的锥套,在材质、结构、处理工艺及生产操作上存在诸多不当之处,为此进行了多项改进,使锥套故障彻底排除,使用寿命达3~5月,而价格仅为进口件的1/3。  相似文献   
74.
彭涛  倪锋  魏世忠  龙锐  张新庄  邵抗振 《铸造技术》2005,26(10):954-956
针对碳化钒的不同形态,设计出定量分析软件,并利用形状因子K,实现了高钒高速钢不同碳化物形态数值化处理,当K介于0.785~1.000之间碳化钒形态为团球状;K≤0.223,碳化钒呈开花状.高钒高速钢当碳含量达到4.2%时,K为0.86和当量直径D为0.78μm,碳化物呈团球状均匀分布.  相似文献   
75.
A novel method was applied to the surface modification of the metal hydride(MH)electrode of MH/Ni batteries.Both sides of the electrode were plated with a thin silver film about 0.1μm thick using vacuum evaporation plating technology,and the effect of the electrode on the performance of MH/Ni batteries was examined.It is found that the surface modification can enhance the electrode conductivity and decrease the battery ohimic resistance.After surface modification,the discharge capacity at 5C(7.5A)is increased by 212 mA.h and the discharge voltage is increased by 0.11 V,the resistance of the batteries is also decreased by 32%.The batteries with modified electrode exhibit satisfactory durability.The remaining capacity of the modified batteries is 89%of the initial capacity even after 500 cycles.The inner pressure of the batteries during overcharging is lowered and the charging efficiency of the batteries is improved.  相似文献   
76.
刘峰  李俊明 《重型机械》2006,(Z1):80-83
详细论述了卷取机动态力矩的数学模型及在控制系统中的实现问题,最后给出了采用CAD计算动态力矩和动态电流、确定相关工艺参数的方法.  相似文献   
77.
The rapid growth of video data demands both effective and efficient video summarization methods so that users are empowered to quickly browse and comprehend a large amount of video content. In this paper, we formulate the video summarization task with a novel minimum sparse reconstruction (MSR) problem. That is, the original video sequence can be best reconstructed with as few selected keyframes as possible. Different from the recently proposed convex relaxation based sparse dictionary selection method, our proposed method utilizes the true sparse constraint L0 norm, instead of the relaxed constraint L2,1L2,1 norm, such that keyframes are directly selected as a sparse dictionary that can well reconstruct all the video frames. An on-line version is further developed owing to the real-time efficiency of the proposed MSR principle. In addition, a percentage of reconstruction (POR) criterion is proposed to intuitively guide users in obtaining a summary with an appropriate length. Experimental results on two benchmark datasets with various types of videos demonstrate that the proposed methods outperform the state of the art.  相似文献   
78.
Feng  Xue  Guoying  Cui  Richang  Hong  Jing  Gu 《Multimedia Systems》2015,21(2):169-175
Multimedia Systems - Camouflage effect evaluation and examination is an important procedure in digital camouflage pattern design as it is helpful in improving the objectivity and effectiveness...  相似文献   
79.
The curvelet transform can represent images at both different scales and different directions. Ripplet transform, as a higher dimensional generalization of the curvelet transform, provides a new tight frame with sparse representation for images with discontinuities along C2 curves. However, the ripplet transform is lack of translation invariance, which causes the pseudo-Gibbs phenomenon on the edges of image. In this paper, the cycle spinning method is adopted to suppress the pseudo-Gibbs phenomena in the multifocus image fusion. On the other hand, a modified sum-modified-laplacian rule based on the threshold is proposed to make the decision map to select the ripplet coefficient. Several experiments are executed to compare the presented approach with other methods based on the curvelet, sharp frequency localized contourlet transform and shearlet transform. The experiments demonstrate that the presented fusion algorithm outperforms these image fusion works.  相似文献   
80.
In this paper, based on the proposed basic implementation of circular projection, a multi-camera setup which can be used for panoramic stereo imaging is presented. Firstly, we get multiple stereo pairs instantly by fixing multiple cameras on the proposed setup, which is an approximate implementation of circular projection. We then prove that the influence on the resultant stereo pairs generated by this approximate setup is slight based on similar triangles and structural similarity (SSIM). With these stereo pairs, the automatic panoramic image stitching algorithm is applied to generate panoramas for both eyes. In addition, with reasonable distance between cameras and the scene, physical dimensions of this setup are given. Finally, experimental results demonstrate that our scheme can be used to generate cylindrical stereo panoramic image with proper scene depth, which can provide viewers with distinguishing stereoscopic experience. The device can be installed on the mobile equipment and captures panoramic stereo image in a moment without stopping. In the future, the proposed setup can be used in the field of network navigation, video monitor and virtual reality.  相似文献   
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