形变数字化观测曲线畸变与处理——兼论资料预处理中遇到的一些问题     

黄晓华 《福建地震》2005,(4)

数字化形变台站日常下载、处理直至管理数据,都应用《数字化通讯控制软件》、《形变前兆台站(网)数据处理系统》及《形变前兆数据库服务软件(台站版)》等三个软件交互进行,在实际使用过程中会遇到一些棘手的问题。本文结合我台的观测工作的实践,总结经验,以供台站同行共享。  相似文献   

Geochemistry and occurrence of inorganic gas accumulations in Chinese sedimentary basins   总被引：15，自引：0，他引：15  

Jingxin Dai  Shufeng Yang  Hanlin Chen  Xiaohua Shen 《Organic Geochemistry》2005,36(12):1664

Inorganic gases are commonly seen in eastern China and occasionally in southern China from the shallow water columns above hot and cold springs. The gases contain 68% to nearly 100% CO₂, with δ¹³C_CO2 and δ¹³C₁ values in the range of −1.18‰ to −6.00‰ and −19.48‰ to −24.94‰, respectively. All of the 34 large inorganic CO₂ and one inorganic methane accumulations discovered in China are distributed in eastern parts of the country, from both onshore and continental shelf basins. No commercial inorganic gas accumulation has been found in central and western China. This is a review of the occurrence and geochemical characteristics of inorganic gas accumulations in Chinese sedimentary basins. A detailed study of gas samples collected from four representative inorganic CO₂ pools and one possible inorganic methane pool indicates that inorganic alkane gases typically show δ¹³C₁ values greater than −10‰ versus PDB (mostly −30‰), with a positive stable carbon isotope sequence of δ¹³C₁ < δ ¹³C₂ < δ¹³C₃ < δ ¹³C₄. In contrast, the δ¹³C₁ values of biogenic alkane gases are lighter than −30‰, with a negative isotope sequence (i.e. δ¹³C₁ > δ¹³C₂ > δ ¹³C₃ > δ¹³C₄). Inorganic gases also tend to show less negative δ¹³C_CO2 values (−10‰) than biogenic gases (<−10‰).  相似文献   

Change Analysis of Three Major Antarctic Ice Shelves Based on Multi-source Remote Sensing Data     

Wu Chenxi  Liu Shijie  Tian Yixiang  Tong Xiaohua 《地球科学进展》2016,31(2):206-212

In recent years, melting and calving happen in the Antarctic ice shelves. In this paper, seven periods of coastlines were applied to provide an analysis of the ice front changes of Ross, Filchner-Ronne and Amery ice shelves with the inclusion of 1997 and 2000 Radarsat products, 2003/2004 and 2008/2009 MODIS products and 2006, 2012, 2015 coastline which were extracted from MODIS images. Change area, SCE (Shoreline Change Envelope) and NSM (Net Shoreline Movement) were applied to analyze the variation of the ice shelf front. The results shows that, the ice front of Amery ice shelf has advanced since 1997 and the total outward extension distance of the ice front was about 20 to 25 km while the advance area reached 3.03×10³ km². Ross ice shelf and Filchner-Ronne ice shelf continued to advance after ice calving events under the driver action of glacier. However, the advance area was less than the retreat area and the net change area is respectively -9.39×10³ km² and -5.86×10³ km². The retreat distance of the collapse area were up to 53 km and 39 km in the two biggest ice shelves.  相似文献   

基于客观分析的多源卫星叶绿素a浓度产品融合方法研究     

施英妮  张亭禄  石立坚  胡晓华  南明星 《海洋学报》2016,38(3):82-87

本文基于Aqua/MODIS、Terra/MODIS和Envisat/MERIS多源卫星叶绿素a浓度产品,研究了客观分析融合方法,制作了西北太平洋海域(0°~50°N,100°~150°E)叶绿素a浓度融合产品,并从有效数据空间覆盖率和产品精度两个方面对融合方法进行了评价。与单传感器以及欧洲太空局发布的GSM模型业务化融合产品相比,客观分析融合产品空间覆盖率明显提高;与收集的2002-2012年间叶绿素a浓度实测数据比较,GSM模型业务化融合产品的匹配数据点为578个,偏差为-0.20 mg/m3,均方根误差为0.37 mg/m3,客观分析法融合产品的匹配数据点为1432个,偏差为-0.21 mg/m3,均方根误差为0.36 mg/m3。结果表明:本文研究的客观分析融合方法在保证融合产品精度的同时可显著提高产品的空间覆盖率,在海洋水色融合应用前景广阔。  相似文献   

伊犁盆地伊昭井田煤层煤质特征研究          下载免费PDF全文

裴重举  秦守萍  仇晓华 《山东国土资源》2016,32(2)

伊昭井田位于伊犁盆地中西部,煤层资源储量36亿t。赋煤层位为侏罗世水西沟群西山窑组,共含煤12层,其中可采煤层6层,3号煤层和5号煤层为井田主采煤层。对各煤层特征进行了研究,总结了各煤层特征及赋存规律及各煤层煤质特征及工业利用方向。对指导伊犁盆地的煤炭勘查、开发利用及生产布局具有积极意义。  相似文献   

Dynamic land use change simulation using cellular automata with spatially nonstationary transition rules   总被引：2，自引：0，他引：2  

Yongjiu Feng  Xiaohua Tong 《地理信息系统科学与遥感》2018,55(5):678-698

The dynamic relationships between land use change and its driving forces vary spatially and can be identified by geographically weighted regression (GWR). We present a novel cellular automata (GWR-CA) model that incorporates GWR-derived spatially varying relationships to simulate land use change. Our GWR-CA model is characterized by spatially nonstationary transition rules that fully address local interactions in land use change. More importantly, each driving factor in our GWR model contains effects that both promote and resist land use change. We applied GWR-CA to simulate rapid land use change in Suzhou City on the Yangtze River Delta from 2000 to 2015. The GWR coefficients were visualized to highlight their spatial patterns and local variation, which are closely associated with their effects on land use change. The transition rules indicate low land conversion potential in the city’s center and outer suburbs, but higher land conversion potential in the inner near suburbs along the belt expressway. Residual statistics show that GWR fits the input data better than logistic regression (LR). Compared with an LR-based CA model, GWR-CA improves overall accuracy by 4.1% and captures 5.5% more urban growth, suggesting that GWR-CA may be superior in modeling land use change. Our results demonstrate that the GWR-CA model is effective in capturing spatially varying land transition rules to produce more realistic results, and is suitable for simulating land use change and urban expansion in rapidly urbanizing regions.  相似文献   

新时代北京市地质灾害综合防控工作现状与建议     

孙小华 《城市地质》2021,16(3):248-253

20世纪70年代以来,北京地区陆续开展的地质灾害防治工作为首都防灾减灾提供了重要保障,如何满足新时代地质灾害防治的新要求,成为当前地灾防治面临的首要任务.回顾40年来北京地质灾害调查评价、监测、预警与防治工作,分析了当前极端气候条件下人类对地质灾害隐蔽性规律认识不清,人类工程活动引发地质灾害等环境地质问题,以及地质灾害防治工作与新时代具体要求的差距,结合北京具体情况,提出了"十四五"时期北京地质灾害综合防控工作思路,包括强化地质灾害调查评价体系、完善地质灾害监测预警体系、巩固综合治理体系、建强应急防治体系和深化科技创新体系5个方面.  相似文献   

固体潮观测数据预处理中的常用方法及计算机实现   总被引：1，自引：0，他引：1  

熊先保  黄晓华  牛其寿  徐智明  张远城 《地震地磁观测与研究》2006,27(4):98-101

从地震台站产出的原始地形变前兆数据出发,提出实际操作性较强的预处理方法,从已编制好的软件中给出处理实例,从而提高地震台站观测人员的科研能力,填补资料预处理方面的某些空白,对于地震台站人员集观测、科研于一体有着十分重要的意义。从95-01-02项目厦门地震台前兆数据预处理的实践表明:这些方法取得了明显的实效,直到今天仍然具有很大的使用价值。  相似文献   

基于吸力量测确定膨胀土活动带和裂隙深度   总被引：7，自引：2，他引：5  

潘宗俊  谢永利  杨晓华  李志峰 《工程地质学报》2006,14(2):206-211

采用M itchell公式和裂隙扩展深度方程两种吸力法确定安康地区膨胀土大气影响深度和裂隙开展深度。其一通过对安康地区两处天然边坡开挖观测井,利用张力计进行不同深度处吸力值的现场量测,根据M itchell提出公式计算大气影响深度;其二根据非饱和土抗拉强度公式,建立膨胀土裂隙扩展深度方程,利用基质吸力量测结果求其理论解。结果表明,安康地区膨胀土吸力变化曲线随深度增加变幅减小,呈波浪式推移。M itchell公式确定安康地区膨胀土的大气影响深度为3.35m以内,裂隙深度方程确定裂隙开展深度为3.063.14m。利用M itchell公式计算大气影响深度与膨胀土断裂理论公式确定的裂隙开展深度结果接近。  相似文献   

再探温跃层有孔虫B/Ca与温度和[CO₃^2-]的依赖性及其在24 ka以来热带西太平洋次表层碳酸盐系统重建中的应用     

郭景腾  李铁刚  熊志方  仇晓华  常凤鸣 《海洋学报(英文版)》2019,38(9):71-86

The B/Ca ratio of planktonic foraminifer shells has been used as a proxy for reconstructing past ocean carbonate chemistry. However, recent studies have revealed significant uncertainties associated with this proxy, such as whether seawater temperature or [ CO_3~(2-)] is the dominant control on the partition coefficient(K_D) of planktonic foraminiferal B/Ca. To address these uncertainties and thus improve our understanding of the planktonic foraminiferal B/Ca proxy, we analysed B/Ca ratios in the tests of Neogloboquadrina dutertrei(300–355 μm) and Pulleniatina obliquiloculata(355–400 μm) in surface sediment samples from the tropical western Pacific and South China Sea. The relationship between these B/Ca ratios and bottom water calcite saturation states(Δ[ CO_3~(2-)]) is weak, thus suggesting only a small dissolution effect on the B/Ca of the two species. The correlation coefficients(R~2) between the B/Ca ratios of N. dutertrei and P. obliquiloculata and environmental parameters(e.g., temperature, salinity, phosphate, DIC and ALK) in the tropical western Pacific and South China Sea are not high enough to justify using B/Ca ratios as a palaeoenvironmental proxy in the study areas. The significant correlation between K_D values of N. dutertrei and P. obliquiloculata and carbonate system parameters(e.g.,[ CO_3~(2-)], DIC, ALK, pH and [ HCO_3~-]) in the study area reflect chemical links between the K_D denominator and these variables. Based on our surface sediment calibration, an empirical relationship between the K_D of N.dutertrei and temperature is proposed in the tropical western Pacific. We also generated a record of B/Ca ratios in N. dutertrei(300–355 μm) from Core MD06-3052 in the tropical western Pacific over the past 24 ka to evaluate the application of the revised B/Ca proxy method. Based on the reconstructed empirical relationship for B/Ca and subsurface seawater ALK, we estimated subsurface seawater carbonate system parameters in the tropical western Pacific since 24 ka. In general, the estimated subsurface seawater pH and [ CO_3~(2-)] show an increase with time, and the record of subsurface seawater pCO_2 shows a decrease with time, in the tropical western Pacific over the past 24 ka. The consistent trends in subsurface seawater pCO_2 and opal flux during deglaciation may imply that the reported increase in subsurface water pCO_2 in the study area was promoted by enhanced upwelling in the Southern Ocean.  相似文献