基于GPRS无线传感网的大气CO2浓度采集系统研究与设计

针对实现大气中二氧化碳浓度的及时快速采集,设计了基于GPRS无线传感网的大气二氧化碳浓度采集系统,系统分为数据采集终端、GPRS无线传输网络和数据中心3部分.数据采集部分主要由单片机、高精度二氧化碳传感器、GPS模块、GPRS模块和液晶显示模块组成,负责采集二氧化碳浓度和采集点地理定位信息;无线传输网络部分由GPRS模块接入到GPRS网络,再登陆到Intemet网络与检测中心服务器建立TCP网络连接,负责将采集到的数据传输给数据中心;数据中心主要是接受GPRS网路传输过来的数据,并将数据进行处理、显示和录入数据库.采集系统能摆脱数据采集时地理位置和天气条件上的局限性,使检测工作变得更及时方便准确.     

MEMS加速度传感器在强震观测中的应用

提出基于MEMS加速度传感器的强震仪设计方案,并在强震观测中完成了地震加速度数据的采集、触发判断和存储.     

Remote Sensing Retrieval of Optical Character of Cloud and Distribution of Cloud Water in Qilian Mountains

By using MODIS data from Terra and Aqua satellite, 6-h precipitation data of 18 cases from 2002 to 2005, applying 6S model and Mie model, some parameters including optical thickness of cloud, efficient radius of cloud particle, and content of liquid water are retrieved, the interspace of which is also analyzed by combining with GIS software. Then the relation of all those parameters and 6-h precipitation are analyzed.The results show that there is difference between distribution of the optics thickness and efficient radius of cloud particle, which is influenced by terrain. The largest value on the southern mountains is less than 4300 m, which means there is rich cloud water in the region. There is positive correlation between precipitation and three parameters;precipitation probability is large when optical thickness is changed from 8 to 20; efficient radius of cloud particle is changed from 6 to 12 μm and content of liquid water is more than 0.04 g m-3. In Qilian Mountains content of liquid water is higher than 0.15 g-m-3 at 4300 m and it means that there is large potential to exploit cloud water.     

基于CIP-51单片机的温度采集系统

介绍了C8051F系列CIP-51单片机的特点,并使用C8051F330单片机设计了利用单总线技术的温度信息采集系统.     

Mineral aerosol properties observed in the northwest region of China

The aerosol optical depth and Ångström exponent for 2002–2003 were derived from CE_318 sun/sky photometer observations carried out at Tazhong, Hetian, Minqin and Dunhuang, located in the source regions of mineral aerosols in China. The observed aerosol properties, including their diurnal and monthly variations, are given for each of the observation sites. The effects of meteorological parameters, such as wind and relative humidity, on aerosol optical depth are analyzed.     

钙原子束光学Ramsey实验的初步工作

报告了实现钙原子光频标的前期工作—钙原子束的光学Ramsey谱线研究的初步工作,介绍了实验的系统方案、真空和激光器部分的设计以及部分已完成的工作。在得到光学Ramsey线形后,如果把激光器锁定在谱线上,就可以得到一个高精度的光学频率标准。     

基于改进的HD距离的星图识别算法

在基于星敏感器的航天飞行器的自主天文导航中,星图识别是关键技术之一。将改进的HD距离算法用于星图识别,避免了由于个别星体出现较大噪声,以及流星等干扰星出现时发生误匹配的问题。在匹配时利用了星图的全部空间结构信息,具有强的抗星敏感器畸变、噪声和旋转能力,同时也不需要复杂的特征提取算法。仿真实验显示它具有较高的实用价值。     

光纤中的非线性效应对高斯光脉冲传输的影响

非线性效应和色散都是影响光脉冲在光纤中传输的重要因素,在反常色散区,色散和非线性效应的相互平衡可实现光孤子传输;在正常色散区,二者的相互作用可用于光脉冲的压缩.因此,两种效应对光脉冲传输的影响一直受到人们的广泛关注.从光脉冲的非线性薛定谔方程出发,在忽略色散的条件下,推导并模拟了自相位调制(SPM)非线性效应下的高斯光脉冲的非线性相移、频率啁啾;数值模拟了SPM下不同最大相移时无啁啾和有正啁啾时高斯光脉冲的频谱.讨论了SPM效应对高斯光脉冲频谱的影响.     

On the mechanics of contact between a flexible transducer diaphragm located at a rigid boundary and an elastic material

In this paper we examine the mechanics of contact between a flexible elastic diaphragm and an isotropic elastic halfspace region where contact is established through the application of a normal stress. It is shown that a convenient solution for the maximum displacement and maximum flexural moment in the flexible diaphragm can be obtained by employing a variational technique. Copyright © 2006 John Wiley & Sons, Ltd.