基于成像算子优化的微震逆时定位方法

针对目前微震逆时定位成像存在的问题,提出一种优化后的成像算子,对模型数据进行抗噪性、误差速度以及检波器分布和数量进行测试,并提出采用峰度值作为定位成像结果的评价标准。结果表明,优化后的成像条件在定位能量聚焦程度和成像分辨率上都得到了提升,对含速度误差和含噪微震数据都有较好的成像结果,并且对检波器的分布和数量有较好的适应性,取得了较为理想的定位效果。     

基于ICP算法的非合作目标特征点云配准优化

针对视觉测量中非合作目标无法提供合作信息从而引起的位姿测量问题,采用ICP(Iterative Closest Point)算法配准不同时刻获取的点云降采样数据来完成目标的相对位姿测量。利用运动恢复结构算法获取了目标当前时刻的点云数据并比较了基于阈值匹配与光流匹配的特征点匹配算法,利用三角测量法对提取到的特征点进行重建,同时将点云数据进行降采样处理,根据降采样后的点云数据计算出不同时刻目标的相对位姿关系。实验表明当物体发生旋转运动时,对降采样数据利用ICP算法计算得到的目标绕坐标轴旋转角度最大误差不超过0.11º。     

Multifractal analysis of resting state fMRI series in default mode network: age and gender effects

Age-related changes of resting state in default mode network （DMN） may provide new clues to the developing mechanism of normal brain as well as early diagnosis and therapy of some neuropsychiatric disorders. The application of multifractal theory to functional magnetic resonance imaging （fMRI） signals has recently raised increasing attention. We aim to explore the multifractal characteristics underlying the resting state functional magnetic resonance imaging （rs-fMRI） series extracted from DMN, and two issues are mainly discussed： （1） whether there exist multifractals in rs-fMRI series; （2） whether it is possible to distinguish between the different ages or genders by means of multifractal characteristics. Results demon- strated the existence of multifractals in rs-fMRI series in DMN. In addition, slight differences between young subjects and middle-aged or elderly subjects can be successfully detected by △asα, a modified measure we proposed. Furthermore, it is revealed that the rs-fMRI series from young subjects possess smaller averaged scale index and weaker long range correlation, while those from middle-aged or elderly people present increasing averaged scale index andstronger long range correlation. Whereas no significant statistical differences has been found between male and female group. Our results, therefore, highlight the potential useful- ness of multifractal analysis in fMRI series of a certain brain region, and provide important insights into healthy aging in DMN.     

A 65-nm 1-Gb NOR floating-gate flash memory with less than 50-ns access time

This paper presents a 65-nm 1-Gb NOR-type floating-gate flash memory, in which the cell device and chip circuit are developed and optimized. In order to solve the speed problem of giga-level NOR flash in the deep submicron process, the models of long bit-line and word-line are first given, by which the capacitive and resistive loads could be estimated. Based on that, the read path and key modules are optimized to enhance the chip access property and reliability. With the measurement results, the flash memory cell presents good endurance and retention properties, and the macro is operated with 1-las/byte program speed and less than 50-ns read time under 3.3 V supply.     

接触网作业车基础制动装置设计

接触网作业车基础制动装置是作业车制动系统的重要组成部分,文章介绍了其结构特点及主要构成,详细说明了基础制动装置的工作原理及制动方式,以及设计作业车基础制动装置。     

济宁市农村社会养老服务供需的实证研究

本文通过抽样调研,对济宁市农村人口老龄化现状以及社会养老服务供需进行分析,从而对实现该地区农村社会养老服务供需均衡提出相应对策,以促进济宁市养老保障事业发展.     

高氯氧化锌烟尘微波介电特性及温升特性

为了研究微波焙烧处理氧化锌烟尘脱氯的可行性,采用谐振腔微扰法测量锌浸出渣经回转窑挥发产氧化锌烟尘的微波介电特性,并考查其在不同物料量和不同微波功率条件下的温升特性。研究结果表明:氧化锌烟尘的介电常数、介电损耗与表观密度呈正比,同时拟合得到氧化锌烟尘表观密度与介电参数、微波穿透深度的线性函数关系式;氧化锌烟尘具有良好的吸波性能,在微波场加热条件下,物料温度迅速升高,在6 min左右可达到800℃,其表观升温速率随微波焙烧功率的增加而增大,随物料质量的增加而减小。     

《世界遗产公约》中两个重要概念的解析与引申--论世界遗产的"真实性"和"完整性"

从实际问题出发,引入<保护世界文化与自然遗产公约>中"真实性"和"完整性"两个重要概念加以论述.通过分析指出,<公约>中的"真实性"和"完整性"原则分别单向对应于文化遗产、自然遗产,而这一关系已在中国世界遗产地、文物保护单位以及风景名胜区的实际问题中显示出局限性.结论是:无论从当今世界遗产事业发展趋势看,还是从中国的世界遗产往往兼具历史文化积淀和自然山水之胜的鲜明特点看,中国当前的世界遗产申报、文物保护和风景名胜区规划与利用等重要问题,都需用"真实性"和"完整性"的双重原则来面对.     

朝鲜鹌鹑耳蜗的组织发生

以朝鲜鹌鹑胚胎和幼体的内耳为材料，用组织学方法对内耳的发育过程进行研究。孵化３６ｈ，听基板已形成；孵化７２ｈ，听泡形成；孵化４ｄ，基乳突形成；孵化６ｄ，毛细胞分化出来；孵化１６ｄ，内耳结构基本发育完成；出壳后，其结构继续发育完善。 发育结果显示：螺旋神经节细胞和毛细胞优先发育，附属结构在其后发育。