基于被动微波遥感反演雪深的时间序列分析我国积雪时空变化特征

利用1978-2005年逐日中国积雪深度数据集,分析了我国积雪空间分布特征和季节时空分布特征,并运用趋势线分析方法和均方根差模拟了积雪深度和积雪日数的变化趋势及异常空间变化特征.结果表明:青藏高原东南、青藏高原西部和南部、新疆北部和东北山区为我国积雪空间分布四大高值区.近28 a来,积雪深度和积雪日数呈增加趋势,20世纪80年代青藏高原明显增加和明显减少趋势并存,90年代整体明显增加,2000-2005年整体基本不变.青藏高原中东部、新疆北部以及东北山区为积雪深度异常变化敏感区,而青藏高原西部则为积雪日数异常变化敏感区.     

基于重心-GTWR模型的京津冀城市群研究

Research into urban expansion patterns and their driving forces is of great significance for urban agglomeration development planning and decision-making.In this paper,we reveal the multi-dimensional characteristics of urban expansion patterns,based on the intensity index of the urban expansion,the differentiation index of the urban expansion,the fractal dimension index,the land urbanization rate,and the center of gravity model,by taking the Beijing-Tianjin-Hebei(Jing-Jin-Ji)urban agglomeration as an example.We then build the center of gravity-geographically and temporally weighted regression(GTWR)model by coupling the center of gravity model with the GTWR model.Through the analysis of the temporal and spatial patterns and by using the center of gravity-GTWR model,we analyze the driving forces of the urban land expansion and summarize the dominant development modes and core driving forces of the Jing-Jin-Ji urban agglomeration.The results show that:1)Between 1990 and 2015,the expansion intensity of the Jing-Jin-Ji urban agglomeration showed a down-up-down trend,and the peak period was in 2005-2010.Before 2005,high-speed development took place in Beijing,Tianjin,Baoding,and Langfang;after 2005,rapid development was seen in Xingtai and Handan.2)Although the barycenter of cities in the Jing-Jin-Ji urban agglomeration has shown a divergent trend,the local interaction between cities has been enhanced,and the driving forces of urban land expansion have shown a characteristic of spatial spillover.3)The spatial development mode of the Jing-Jin-Ji urban agglomeration has changed from a dual-core development mode to a multi-core development mode,which is made up of three functional cores:the transportation core in the northern part,the economic development core in the central part,and the investment core in the southern part.The synergistic development between each functional core has led to the multi-core development mode.4)The center of gravity-GTWR model combines the analysis of spatial and temporal nonstationarity with urban spatial interaction,and analyzes the urban land expansion as a space-time dynamic system.The results of this study show that the model is a feasible approach in the analysis of the driving forces of urban land expansion.     

长江三峡地区宜昌、巴东短历时极值降水特征分析

利用长江三峡库首宜昌站及库区巴东站1955—2008年分钟降水强度资料,采用广义极值分布和线性矩参数估计方法,拟合两站7个短历时(60min以内)年最大降水量概率分布,推断各历时有关重现期降水极值,计算各历时暴雨频次及年最大降水量气候倾向率,分析各历时降水广义极值分布的参数随时间变化规律。结果表明:宜昌、巴东两站7个短历时年最大降水量采用广义极值分布拟合,其效果较好;两站短历时降水平均值趋势变化不明显,而不同百分位数降水量变化趋势差异较大,其中中位数的降水量呈下降趋势,较高百分位数的降水量增加趋势显著,达20%～30%。     

Automatic spikes detection in seismogram

Data processing for seismic network is very complex and fussy, because a lot of data is recorded in seismic network every day, which make it impossible to process these data all by manual work. Therefore, seismic data should be processed automatically to produce a initial results about events detection and location. Afterwards, these results are reviewed and modified by analyst. In automatic processing data quality checking is important. There are three main problem data thatexist in real seismic records, which include: spike, repeated data and dropouts. Spike is defined as isolated large amplitude point; the other two problem datahave the same features that amplitude of sample points are uniform in a interval. In data quality checking, the first step is to detect and statistic problem data in a data segment, if percent of problem data exceed a threshold, then the whole data segment is masked and not be processed in the later process.     

资源经济政策密集出台为的是什么?

进入本世纪以来,中国经济一直保持快速增长局面,取得了很大的成绩,同时也产生了一些问题。其中一个重要的方面就是大宗矿产品供需规     

Windows XP下3机4网卡共享上网的设置

许多台站对多台微机共享上网都有需求，然而仅仅为两三台微机组网而购买1个HUB又显得不太合算。既然在传统组网中每块网卡只能引出1根网线用来连接另1台微机，那么如果给其中1台微机装上2块网卡，就可以引出2根网线。这样就可以将这台微机与另外2台微机连接。本文就Window XP下3机4网卡互联网中服务器端的安装设置作以介绍。     

河道信息系统关键技术的研究

介绍了长江河道信息系统研制背景、系统主要功能，对断面计算、槽蓄量计算及分析过程可视化等关键技术问题进行了研究。     

FTP的多文件传输和Leapftp软件

以传输全省各站天气报文为例,利用FTP服务器进行多文件传输。     

中国地面月气候资料质量控制方法的研究

针对湿度质量控制中的主要问题,利用3种温湿关系,设计了温湿跳变一致性检查、湿度传感器僵死现象检查、温湿空间质量控制参数一致性检查3种检测方法,对全国2 428站相对湿度资料的质量检测。结果表明：在检测的42个月内,平均每站每年未通过跳变一致性检查为1.2次,且大都集中出现在少部分台站;出现湿度传感器僵死现象共22站次,僵死过程平均持续时间为17 d,最长超过了65 d;温湿空间质量控制参数一致性检查方法,降低了相对湿度空间一致性检查方法的误检率。

     

“海鳐”波浪滑翔器在水下定位与通信中的应用

“海鳐”波浪滑翔器是我国自主研制的第 1 代波浪滑翔器产品,性能优异,可靠性高,已完成包括海洋环境观测、水下目标探测、跨域通信及信息传递等应用研究。在国家重点研发计划“无人无缆潜水器组网作业技术与应用示范”等领域项目的支持下,“海鳐”波浪滑翔器平台技术成熟度及应用研究上均得到进一步提升,为在我国在军事、海洋环境监测及海洋资源开发利用等领域的应用推广奠定了坚实的基础。介绍了“海鳐”波浪滑翔器在水下声学定位与跨域组网通信中的最新应用进展,总结了应用中的主要技术问题, 对波浪滑翔器装备未来的发展给出了新的研究方向。