一种新型微型空速计的研制

微型飞行器是应用MEMS技术的一种智能微系统,针对微型飞行器的要求,利用微型螺旋浆带动编码盘,采用单片机解码,研制了一种微型空速计,并制作了其演示系统。     

NSRL-U7C双晶单色器热载影响与计算分析

在测试合肥国家同步辐射实验室(NSRL)U7C X射线吸收精细结构(XAFS)光束线双晶单色器(DCM)热载影响基础上,进行了单色器在无水冷却、辐射散热条件下热平衡动态过程分析,并运用有限元方法对第一晶体作了热-结构耦合计算,得到晶体热平衡所需时间、温度梯度分布及由此产生的热应力形变与面形误差等;同时对拟增设的普通底面水冷方式作了比较分析.     

微型飞行器数据集成的硬件实现

为了实现微型飞行器的自主飞行控制,需要将多种传感器的数据集成起来,这些传感器包括摄像系统、GPS、高度计、加速度计、风速计、陀螺等.本文兼顾微型飞行器体积小、重量轻的要求,使用LM331作为关键器件使数据易于处理,提高了数据处理的速度和控制的反应速度,并给出了具体的方案和处理结果,证明了方案的可行件和有效性.另外,在研究微型飞行器的动力特性时,利用LM331的F/V转换特性,设计并研制了微型动力测试仪.     

社会城市思想对中国城市化进程的启示

1城市规划的社会思想根源及其演变历程 自城市规划产生至今,从理性的综合规划模式到多元规划模式,再到合作性规划模式,城市规划的每一步发展都蕴含着深刻的社会思想,并深受其影响。可以说,研究城市规划的人首先一定是研究社会的人。如果对社会问题没有敏锐的思辨能力,则不可能规划好城市。城市规划绝不仅仅是美学意义上的物质形态规划,而是一项关于生存形式、社会状态的人类生存空间的规划。     

广州市南沙区农业区域 海平面上升应对策略

It envinces that sea level rise aggravates low-lying terrain inundation, storm surges, beach erosion, and other ecological damages. The developed agricultural system in the Pearl River Delta is at a high risk to floods; and, in light of the tactical significance of the Guangdong-Hong Kong-Macao Greater Bay Area and its high vulnerability to sea level rise and storm surges, it urgently requires to study their impacts on the agricultural areas in this region. Taking Nansha District, Guangzhou City, Guangdong Province, China as the study area, this study builds a vulnerability evaluation model of agricultural areas with the Source-Pathway-Receptor-Consequence framework using an indicator system upon exposure, sensibility, and adaptation, and quantitatively predicts the inundation risk level, financial loss, and vulnerability patterns of varied scenarios of sea level rise superimposed with storm surges with the ArcGIS. The main findings include 1) the stimulated proportion of inundated areas in minimum-risk and maximum-risk scenarios is 73.38% and 87.96% respectively, and the estimated financial loss in both scenarios is RMB 3,897.3855 million and 7,140.4979 million, respectively; 2) the central Nansha will suffer from a higher inundation risk, and the northern and southern agriculatural parts within the study area have a higher vulnerability to flood disasters. Resilience strategies—through defense, adaptation, or relocation—for each vulnerable zone are then proposed accordingly.     

Molecular Insight into Gut Microbiota and Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a systemic, inflammatory, and autoimmune disorder. Gut microbiota play an important role in the etiology of RA. With the considerable progress made in next-generation sequencing techniques, the identified gut microbiota difference between RA patients and healthy individuals provides an updated overview of the association between gut microbiota and RA. We reviewed the reported correlation and underlying molecular mechanisms among gut microbiota, the immune system, and RA. It has become known that gut microbiota contribute to the pathogenesis of RA via multiple molecular mechanisms. The progressive understanding of the dynamic interaction between gut microbiota and their host will help in establishing a highly individualized management for each RA patient, and achieve a better efficacy in clinical practice, or even discovering new drugs for RA.     

一种带约束的电压空间矢量脉宽调制方法

为解决传统调制方法中的最小脉宽问题,提出了一种带约束的电压空间矢量脉宽调制(space vector pulse width modulation,SVPWM)方法。首先,建立新的三相桥臂坐标,取消了扇区的划分和判断;其次,将基本电压空间矢量由8个减小为3个,并将其作用时间与三相桥臂的导通时间一一对应;再次,通过增加约束条件,将传统SVPWM方法的调制过程及其结果离散化,从而避免了窄脉宽的出现;最后,给出了一种快速的计算策略,其计算量仅与SVPWM方法一个扇区的计算量基本相同。相对于SVPWM方法,所提方法调制的基波与杂波在频谱上的分布更清晰,低次谐波较少,有利于进行低通滤波处理,更适合较高电压和较大电流的逆变要求。仿真及实验结果均验证了该方法的可行性。     

基于聚类神经网络的机场拥挤等级预测

对机场拥挤机理进行分析;从后果类指标入手,提出基于饱和度的拥挤等级评价方法,建立机场拥挤5色预警等级,从原因类指标入手,提取出分别刻画机场容量和需求的5个拥挤特征指标;提出了基于聚类的神经网络分类算法;利用ATL机场实际航班数据进行实例验证,拥挤等级预测的准确度达到80%,预测效果优于BP神经网络。结果表明,提出的方法预测效果较好,具有一定的实用性。     

氯化镁制备碱式碳酸镁研究

采用某钛冶炼厂副产品氯化镁为原料,进行了碱式碳酸镁的制备研究。通过正交设计,考察了氯化镁浓度、结晶时间及结晶温度对Mg转化率的影响程度,得出了利用氧化镁制备碱式碳酸镁的较优条件值,所得碱式碳酸镁达到行标优等品标准。