极地锚碇潜标系统回收探索与研究     

袁东方  朱兵  夏寅月  陈清满  崔丽娜  吴浩宇 《极地研究》2022,34(1):130-138

随着南北极考察的深入开展,锚碇观测系统的布放和回收已经成为科考破冰船常态化作业内容.在极地考察作业过程中,锚碇系统的布放作业相对比较简单,但是回收作业往往受天气、海况、浮冰等条件影响,经常发生各种突发问题,造成无法顺利回收.本文根据多年南北极科学考察锚碇系统科考船回收作业经验,分析了大船、小艇回收方式的优缺点以及影响锚...  相似文献   

Development of a dynamic load direct shear apparatus for the study of permafrost     

YingHui Cui  JianKun Liu  Peng Lv 《寒旱区科学》2013,5(4):0399-0403

The dynamic parameters of permafrost are crucial to and directly affect the accuracy of engineering design and numerical simulation. This paper describes a new dynamic load direct shear apparatus that was developed to measure these parameters. The power systems and measurement and control systems of the device are described, as is a successful validation experiment. The results show that this dynamic load direct shearing device can accurately derive dynamic shear parameters within a certain range of frequencies and amplitudes of shear load.  相似文献   

Radio Observation of the 11-Month Fermi-AGN at Urumqi Observatory     

Zhen Ding  Xiang Liu  Jun Liu  Lang Cui  H. G. Song 《Journal of Astrophysics and Astronomy》2011,32(1-2):47-48

We carry out flux observation at 5 GHz for 124 sources from the ‘clean’ sample of Fermi catalog 1LAC (The First LAT AGN Catalog) with Urumqi 25 m telescope. We find that it is obvious that there is a correlation between the γ-ray and the radio flux density for blazars. For the subclasses, the correlation for FSRQs is strong, but the correlation for BL Lacs is weak.  相似文献   

Variability of GPS Radio Sources at 5 GHz     

Lang Cui  Xiang Liu  Jun Liu 《Journal of Astrophysics and Astronomy》2011,32(1-2):281-283

We carry out flux monitoring on a sample of 169 Gigahertz Peaked Spectrum (GPS) radio sources at 5 GHz and find that about one-third of them show considerable Inter-Month Variability (IMV), and these IMV phenomena are likely to be caused by interstellar scintillation (ISS). Furthermore, we find that those showing IMV tend to be point-like or core-jet structures at VLBI scale.  相似文献   

用MapReduce框架构建虚拟天文台数据节点     

宋烜  周薇  韩冀中  崔辰州 《云南天文台台刊》2012,(2):150-156

MapReduce是一种大规模分布式并行处理框架,最初被用于互联网服务中的海量数据处理,并逐渐扩展到各个行业领域。目前,虚拟天文台面临着越来越多的地面及空间望远镜观测到的海量天文数据。为了提高中国虚拟天文台数据节点处理海量天文数据的能力,首次提出基于MapReduce框架构建中国虚拟天文台数据节点的方法,并以批量星表交叉认证为例描述了具体实现过程,性能评估结果证明基于MapReduce框架构建虚拟天文台数据节点,可以在性能、扩展性与成本等多方面获得收益。  相似文献   

An improved map-symbol model to facilitate sharing of heterogeneous qualitative map symbols     

Mingguang Wu  Axing Zhu  Peibei Zheng  Lili Cui  Xueying Zhang 《制图学和地理信息科学》2013,40(1):62-75

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武汉地区植被NPP动态监测研究     

王伦澈  龚威  张淼  马盈盈 《武汉大学学报(信息科学版)》2013,38(5):548-552

通过建立、比较多种区域性光合有效辐射(PAR)估算模型,对比分析了NDVI、EVI与光合有效辐射吸收系数(fPAR)之间的关系,根据不同植被最大光能利用率的不同,改进了植被净初级生产力(NPP)模拟算法。利用MODIS、气象辐射数据等,研究了武汉市2001～2011年间植被NPP季节、年际变化特征。结果表明,NPP季节变化明显,夏季高,春秋次之,冬季低,七月中旬最高,达到85gCm-2 month-1;年平均NPP呈现出一定的增长趋势,2008年最高562gCm-2a-1;不同类型植被NPP差异较大,常绿阔叶植被年平均值最大1 028gCm-2a-1,每年生阔叶植被NPP最低410gCm-2a-1。  相似文献   

A method to estimate concentrations of surface-level particulate matter using satellite-based aerosol optical thickness   总被引：3，自引：0，他引：3  

TAO JinHua  ZHANG MeiGen  CHEN LiangFu  WANG ZiFeng  SU Lin  GE Cui  HAN Xiao  ZOU MingMin 《中国科学:地球科学(英文版)》2013,(8):1422-1433

We propose a new method to estimate surface-level particulate matter(PM)concentrations by using satellite-retrieved Aerosol Optical Thickness(AOT).This method considers the distribution and variation of Planetary Boundary Layer(PBL)height and relative humidity(RH)at the regional scale.The method estimates surface-level particulate matter concentrations using the data simulated by an atmospheric boundary layer model RAMS and satellite-retrieved AOT.By incorporation MODIS AOT,PBL height and RH simulated by RAMS,this method is applied to estimate the surface-level PM 2.5 concentrations in North China region.The result is evaluated by using 16 ground-based observations deployed in the research region,and the result shows a good agreement between estimated PM 2.5 concentrations and observations,and the coefficient of determination R2 is 0.61 between the estimated PM 2.5 concentrations and the observations.In addition,surface-level PM 2.5 concentrations are also estimated by using MODIS AOT,ground-based LIDAR observations and RH measurements.A comparison between the two estimated PM 2.5 concentrations shows that the new method proposed in this paper is better than the traditional method.The coefficient of determination R2 is improved from 0.32 to 0.62.  相似文献   

GIS-based method of delimitating trade area for retail chains     

Can Cui  Yingxia Pu  Jinsong Ma  Gang Chen 《International journal of geographical information science》2013,27(10):1863-1879

Delimitating trade area with accuracy is a major concern for retail and service companies who want to adapt their marketing strategy to be competitive in today's highly competitive chain industry. A collection of methods have been proposed to delimitating trade area, but either some are too simple or the necessary data are not available. In this article, a geographic information system-based method for precisely delimitating trade area is proposed. It is based on the fact that the social and economic activities are actualized along the street networks. The trade area can be delineated in terms of time distance with high precision taking the practical traffic situations into account. In addition, centered on this method of delimitating trade area, a wide array of functions can be extended to support both operational day-to-day and long-term strategic decision making for retailers.  相似文献   

水准测量网监测在德州市地面沉降中的应用     

何国荣  冯在敏  冯克印  任翠爱  商婷婷  谭现锋 《山东地质》2012,(6):28-30

山东地面沉降灾害以鲁北平原最为严重,在德州地区的地面沉降已对当地人民的正常生产和生活构成了威胁,并制约了当地经济的可持续发展。通过建立水准测量网络及监测运行,查明了德州市地面沉降的规模和范围,研究成果表明工作区均存在地面沉降现象,截至2010年,德城区由于地下水开采强度大,地面沉降幅度最大,目前地面累计沉降量为-1186．9～-636．9mm,多年平均沉降速率为59．35mm／a,形成了以市区西北部为中心的地面沉降盆地。超量开采深层地下水是造成大规模地面沉降的重要因素。  相似文献