多级旋转式倒立摆的建模与分析

运用刚体的动力学知识对多级旋转式倒立摆系统进行了动力学分析,归纳其规律性,并推导出旋臂及各级摆杆的运动微分方程,从而获得任意级旋转式倒立摆的非线性数学模型。文中还对旋转式倒立摆系统进行了能控性分析。最后利用MATLAB对一级、二级旋转式倒立摆的控制进行了仿真,并得到较好的仿真结果。     

Romberg integration using systolic arrays

A systolic array is presented to improve numerical approximations to integrals using Richardson's extrapolation procedure in the form of Romberg integration. Two designs are presented, the first is an intuitive linear systolic array, the second, a systolic ring using approximately 1/3 of the cells of the first array. Both systolic arrays have a computation time of 3n cycles, which is a significant improvement on the O(n²) steps required to construct the extrapolation table sequentially.     

Approximating a composite cubic curve by one with fewer pieces

A basic algorithm for merging two adjacent cubic pieces of a given composite cubic curve is suggested here. As a typical application, it is combined with a standard interpolating scheme to approximate a sequence of data points by a composite cubic of few pieces.     

Correlation between structural and optical properties of 30 nm and 60 nm lead sulfide nanowires

PbS nanowires with 30 nm and 60 nm diameter fabricated under the same condition of electrochemical deposition with sulfuric and oxalic anodic alumina membranes (AAM), respectively, have been successfully prepared in order to study their optical properties in relation to their size. Scanning electron microscopy indicates that the 60 nm PbS nanowire arrays have the same shape with the 30 nm. X-ray diffraction result shows that 60 nm PbS nanowires are crystalline and have a highly (200) preferential orientation like 30 nm ones. UV spectrum considers the nanowire size decrease as the absorption peak shifts to the blue. The quantum confinement effects compared between 30 nm and 60 nm PbS nanowire arrays were observed by the measurements of ultraviolet-visible absorption spectroscopy (UV-vis).     

无人飞艇低空数码影像多视摄影测量

针对大比例尺测图的精度要求,研究低空数码影像多视摄影测量的方法.根据计算机视觉的多视几何原理建立匹配的约束条件,实现多视匹配;利用低空数码影像的重叠度大的特点,建立多基线立体,进行多片空间前方交会.不同重叠度的立体像对空间前方交会和多片空间前方交会的实验结果证明,多视摄影测量能够提高有效低空数码影像的摄影测量精度.     

A Review of Microfluidic Experimental Designs for Nanoparticle Synthesis

Microfluidics is defined as emerging science and technology based on precisely manipulating fluids through miniaturized devices with micro-scale channels and chambers. Such microfluidic systems can be used for numerous applications, including reactions, separations, or detection of various compounds. Therefore, due to their potential as microreactors, a particular research focus was noted in exploring various microchannel configurations for on-chip chemical syntheses of materials with tailored properties. Given the significant number of studies in the field, this paper aims to review the recently developed microfluidic devices based on their geometry particularities, starting from a brief presentation of nanoparticle synthesis and mixing within microchannels, further moving to a more detailed discussion of different chip configurations with potential use in nanomaterial fabrication.     

安藤忠雄的几何方法论

安藤以其执着的信念,具有标识性的几何手法,抵达了“纯粹空间”的彼岸,成功营造了人类精神的乌托邦.就安藤如何将几何学提升为方法论,使其作品具有一种超越国界、超越时间的魅力,结合最新实例做出简要分析.