图像重构中估计基础矩阵的线性迭代算法

基础矩阵给出了图像间对极几何关系的代数描述,对其精确估计一直是未标定图像序列重构中的一个非常关键的问题.本文在8点算法的基础上,通过引入与对极距离有关的权因子,给出了一种高精度估计基础矩阵的线性迭代算法.实验结果表明,与归一化8点算法相比,此算法具有更强的抗噪声能力,更小的计算误差,从而提高了所估计基础矩阵的精度.     

调制和编码对超宽带接收机性能改善的比较

1 INTRODUCTION Ultra- wideband (UWB) technology can achieve 100Mbps high- speed wireless communications by use of GHz bandwidth short pulses. Because it has some merits such as very low radio power, difficult to be detected, good penetration and centimeter level location ability, it can be used in secret communications, target detection, personnel search and so on military applications. Since the large bandwidth of UWB signal cause the channel to be extreme frequency selectivity, a con…     

Translation Surfaces with Zero Mean Curvature in （2+p）-Dimensional Pseudo-Euclidean Space E22+p or Ep2+p

Let Ep^2＋p（resp.E2^2＋p） be a （2＋p）-dimensional pseudo-Euclidean space with the index p （resp.2）. The maximal spacelike or minimal timelike translation surfaces M^2 in Ep^2＋p or E2^2＋p are considered and a complete classification is given.     

Fractal character of lenticles and its influence on sediment state in tailings dam

1INTRODUCTION Undertheinfluenceofthevariousfactors,suchasaseriesoftailingswithdifferentparticle sdiametersandtailingsdisposal,theprocessoftail ingssedimentisverycomplicated.Thearsenicdis posalpracticeofthemetallurgicalindustryandthesedimentofthedisposedarseniccompoundswerereviewedbyRiverosetal[1].Wind wave induced suspensionofminetailingsindisposalpondwasstudiedbyLawrenceetal[2]withimplicitfinitedifference.Samadetal[3]usedlinearwavetheoryandcountercurrentflowprofilestoobtainthetotalbotto…     

Parameters Relevant to Bubble Detachment when Gas-injecting into Polymer Melt Flow Field

The bubble deformation processes were reported when gas was injected into polymer melt flow field in another paper, the experiments showed that the deformation was severely affected by the volume of the bubble, and in turn, for the different bubbles, several different deformation processes were presented during their movement along the flow channel. In addition, we could find that the magnitude of the bubble volume was dependent upon the pressure difference of the gas injection pressure and the melt pressure, In this paper, more experimental conditions were changed to investigate the parameters relevant to the detachment of bubbles from the injection nozzle. The experimental results show that the pressure difference, the melt flow velocity as well as the melt pressure were all critical for the purameters, such as the bubble detachment time, the maximum bubble diometers and the magnitude of the bubble volume. The morphology changes of bubble were very large when the flow field was abruptly changed, and the situations were more complicated.     

微波辐射在联氨还原法制备金属Co纳米微粒中的应用

采用次亚磷酸钠为辅助还原剂,联氨为主还原剂,在微波辐射下还原钴盐制备六方结构o纳米粒子.采用透射电子显微镜和激光散射仪观察并测定纳米Co粒子的形貌、粒径大小及分布,确认Co纳米粒子为类球形,粒径为10～15nm.在正己烷中存在软团聚,团聚体平均尺寸约30nm.采用XPS考察产物的表面价态,证明金属Co纳米晶是以零价态存在的.     

转炉吊挂机构拉杆座有限元分析及结构优化

通过对转炉吊挂机构的有限元分析，分析了构件受载后的应力分布及危险点，并对构件的几何结构进行了修正及优化，保证了设备的可靠性和安全性。     

平均应变对0Cr18Ni10Ti钢随机循环应力-应变关系的影响规律

试验研究了平均应变对0Cr18Ni10Ti管道钢随机循环应力．应变关系的影响规律从节约试样和试验费用角度，提出了改进的极大似然疲劳试验法，以应变比分别为-1、-0．52、-0．22、0．029．0．18和0．48完成了104个试样的应变控制疲劳试验。揭示出材料具有Masing行为和完全平均应力松弛特征，现有平均应变理论无法表征其影响。因此．首先基于Ramberg-Osgood方程，应用广义极大似然法有效地测定出各应变比的材料随机循环应力-应变关系。通过比较各应变比的循环应力幅均值、循环应力幅均方差和概率循环应力幅，揭示出高可靠性管理时．平均应变具有降低循环应力幅作用，应变比接近0时最显著．偏离逐渐减弱，说明了研究平均应变效应．仅考虑均值．可能给出错误评价；必须综合考虑均值、均方差和样本量3因素才能给出合理评价。     

21 在БФC-101-1（钚堆芯）上用小型裂变室测量轴向和径向平均裂变截面比σf^9/σf^5

本工作是在БФC-101-1（钚堆芯）临界装置上采用带富集铀（^235U的富集度为90％）和钚（^239Pu富集度为99.5％）涂层的小型裂变室方法测量平均裂变截面比σf^9/σf^5。     

上肢伸展姿势预测研究进展

对上肢伸展姿势进行实时预测是工效学领域人体模型需完成的重要功能之一。迄今尚无公认的最优方法。该文主要介绍了启发式算法、非线性优化方法、伪逆方法、几何算法和行为的逆向运动学方法等预测方法及其特点。最后作者指出了目前上肢伸展姿势预测方法存在的不足以及研究方向。