CARAIB陆地碳循环模型研究进展及其应用   总被引：1，自引：0，他引：1  

黄康有  郑卓  Cheddadi R.  Laurent J.M.  Fran 《热带地理》2007,27(6):483-488

陆地生态系统碳循环是全球变化研究中的重要组成部分,多种模型已用于陆地生态系统碳循环的模拟。文中着重论述了陆地生物圈碳循环模型CARAIB的原理、方法及其应用和最新进展。CARAIB模型主要是基于叶面光合作用子模型、冠层子模型和木质呼吸作用3个子模型的耦合,应用大气环流模式气候数据模拟出生态系统碳存储量和生物群区分布。介绍了欧洲利用植物数字化地理配准数据库重新划分植物群组(BAGs)的方法,比较BAGs与传统的植物功能型(PFTs)划分在方法上的差异,根据植物群组应用CARAIB模型进行生物群区分布模拟,并提出利用CARAIB模型模拟我国陆地碳循环和生物群区分布的可行性,为研究中国植被对气候变化的响应模型和预测提供区域尺度的新方法。  相似文献   

湖南瑶岗仙钨矿床流体包裹体特征及其意义   总被引：13，自引：5，他引：13  

王巧云胡瑞忠  彭建堂毕献武  武丽艳刘华 苏本勋 《岩石学报》2007,23(9):2263-2273

对瑶岗仙石英脉型钨矿床的石英、萤石和夕卡岩型钨矿床中石榴石流体包裹体的岩相学特征研究表明,与成矿有关的包裹体主要有三类:富液相、富气相和含子晶的多相包裹体。脉型钨矿床中石英包裹体均一温度范围为180℃～300℃,盐度0.88～6.45 wt%NaCl eqv;矽卡岩型钨矿床中石榴石包裹体的均一温度范围为190℃～300℃,盐度0.1～8.95wt%NaCl eqv;成矿溶液的密度为0.81～0.89g/cm~3,表明形成这两种类型矿床的成矿流体均属于中温、低盐度、低密度的流体;成矿压力为120～160MPa,成矿深度约为7～9km,因此该矿床是在中高压力、中深成条件下形成的。激光拉曼探针分析表明,石英中包裹体的气相成分比石榴石中的更富含 CH_4、CO_4和 H_2O 等挥发份,说明流体是一种介于岩浆与热液之间的过渡性流体,具有上部偏液、下部偏浆的特点。由于该区自燕山期以来软流圈上隆,岩石圈经历了强烈的伸展、减薄作用和壳幔相互作用,而 C-H 还原性组分的增加,指示流体很可能来自于深部的地幔过渡带或者软流圈。  相似文献   

利用SLR数据进行广播星历精度评估     

毛悦  贾小林  孙付平 《测绘学院学报》2007,(4)

论述了利用SLR观测数据进行广播星历精度评估的原理、方法及计算模型。通过理论分析及对比试算,得出该方法所能达到的精度为0.03 m,与微波观测数据计算结果存在近50 mm的系统差,验证了方法的可行性。该方法为广播星历精度评估提供了独立的外部检核条件,克服了利用精密星历评估必须事后进行的缺点,达到了实时处理的效果。采用2005年SLR观测数据对GPS 35卫星广播星历精度进行了实测数据评估,给出了有益的结论。  相似文献   

Palynological assemblages of non-marine rocks at the Permian–Triassic boundary, western Guizhou and eastern Yunnan, South China   总被引：1，自引：0，他引：1  

Yuanqiao Peng  Jianxin Yu  Yongqun Gao  Fengqing Yang 《Journal of Asian Earth Sciences》2006,28(4-6):291-305

Marine and non-marine facies of the Permian–Triassic boundary stratigraphic set (PTBST) are well developed in South China. Palynological assemblages enable subdivision and correlation of the Permian–Triassic boundary (PTB) rocks. Three palynological assemblages are recognized across the PTBST in two terrestrial PTB sections in western Guizhou and eastern Yunnan, South China. Assemblage 1 (Xuanwei Formation) is a Late Permian palynological assemblage dominated by ferns and pteridosperms, with minor gymnosperms. Most taxa are typical long-ranging Paleozoic forms, but the appearance of Lueckisporites confirms a Late Permian age for this assemblage. Assemblage 2 (PTBST) is marked by an abrupt decrease in palynomorph abundance and diversity, and thriving fungal/algal(?) spores. Assemblage 2 is still dominated by ferns and pteridosperms, with a few gymnosperms, but is characterized by a mixed palynoflora containing both Late Permian and Early Triassic elements. Most taxa are typical Late Permian ones also found in Assemblage 1, however, some taxa of Early Triassic aspect, e.g. Lundbladispora and Taeniaesporites, appeared for the first time. In Assemblage 3 (top Xuanwei Formation and Kayitou Formation), the proportion of gymnosperm pollen increases rapidly, exceeding that of ferns and pteridosperms, but the abundance of palynomorphs is still low. Typical Early Triassic taxa (such as Lundbladispora, Aratrisporites and Taeniaesporites) are present in greater abundance and confirms an Early Triassic age for this assemblage.  相似文献   

云南天文台激光测距系统激光特性参数的测量分析   总被引：2，自引：2，他引：0  

伏红林  冯和生  张云成  杨远贵 《天文研究与技术》2004,1(2):112-118

通过激光光腰位置能量分布测量，在已知激光发散角的情况下，直接计算得到光腰半径、光束质量因子等重要参数，更加深入的分析了云台激光束情况，对于测距时激光发散角的控制具有重要意义。从激光能量分布的测量结果看，可把激光的最小发散角压缩到1“，达到大气视宁度水平，从而提高系统的极限测距能力。  相似文献   

Discriminating Bio-Induced and Detrital Sedimentary Processes from Particle Size Distribution of Carbonates and Non-Carbonates in Hard Water Lake Sediments     

F.?ArnaudEmail author 《Journal of Paleolimnology》2005,34(4):519-526

Particle size distribution (PSD) and carbonate content are two of the most frequently used parameters for describing lake sediments. This paper presents a method for rapidly measuring both these parameters using a laser particle-sizer, as well as an original way in which to separately interpret the PSD of the carbonate and non-carbonate fractions. Differential particle size analyses are produced by measuring the PSD of each sample twice. The first PSD is measured using the bulk sample. The second PSD is measured after the carbonate fraction has been completely dissolved by adding hydrochloric acid to the sample. As well as particle size analyses, laser particle-sizers automatically give obscuration values for the samples being analysed. By comparing the obscuration value for the bulk sample with the value for the de-carbonated fraction, the carbonate content of the sediment can be determined. In order to test the accuracy of the method, the results were compared with chemical analyses of carbonate content. This comparison showed that when applied to diatom-rich samples the method underestimates the carbonate content. This is due to the fact that the differential particle size method measures the volume concentrations of the carbonate and non-carbonate fractions, whereas chemical analysis measures the weight concentrations. As diatoms are hollow and have relatively low-densities, differential particle size analyses of diatom-rich samples overestimate the non-carbonate fraction. Despite this limitation, and bearing in mind that laser particle-sizer distributions are expressed in terms of volume percent for each size class and not weight percent, PSDs can provide useful data for interpreting sedimentary processes. One of the main advantages of this method is that it can be used to separate the PSDs of the carbonate (autochthonous) fraction and the non-carbonate (allochthonous) fraction from the PSD of the bulk sample. The value of such an approach was demonstrated by the analysis and interpretation of a 9 m-long core from Lake Bourget in France. An analysis of the bulk sample PSDs plotted as a function of depth showed the consistency of sedimentary processes over the last 7200 years. Amongst these processes, it was possible to identify two modes of clastic material deposition: river-borne fine sedimentation during major floods and gravity reworking of sandy sediment from the lakeshore.  相似文献   

应用人卫激光测距技术测定潮汐形变勒夫数   总被引：2，自引：0，他引：2  

彭碧波  吴斌  许厚泽 《测绘学报》2000,29(4):305-309

本文讨论了利用人卫激光测距（ＳＬＲ）资料确定分潮波形式的地球固体潮汐形变勒夫数的可能性,并用１１年的Ｌａｇｅｏｓ－１的人卫激光测跨资料直接解算了四个周日波Ｑ、,Ｏ１,Ｐ１,Ｋ１和四个半日波Ｓ２,Ｋ２,Ｎ２,Ｍ２的弹性和粘弹性地球状态下的地球潮汐形变勒夫数ｈ２ｓ,ｌ２ｓ,结果与ＶＬＢＩ结果相符,与ＩＥＲＳ及Ｗａｈｒ的模型值的潮汐响应趋势相符,这证明了利用ＳＬＲ技术确定潮汐形变勒失数是可行的,从而为传统技术和空间技术提供了一种新的有意义的方法和选择。  相似文献   

光电测深和激光投点技术在矿井联系测量中的试验研究     

徐乃忠  侯公羽  朱广斌  王玉君  蒋正钦 《测绘工程》2000,9(3):41-43

介绍了光电测距仪直接在井筒中测定井深导入高程和激光投点代替钢丝投点的试验研究,并和传统方法进行比较,结果令人十分满意。  相似文献   

陆相碳酸钙沉积特征及水能量分类   总被引：1，自引：1，他引：0  

程星  李大勇 《中国岩溶》2002,21(2):84-88

以野外观察及室内试验分析为基础,讨论了陆相碳酸钙沉积类型与水能量条件的相关关系,并定量和定性地讨论了各类型之间的水能量界线;指出陆相碳酸钙沉积包括超高能、高能、低能及超低能四种沉积类型;根据其位置它们又可划分为地表和地下两种类型。这些陆相碳酸钙的相应的沉积水能量条件分别为超高能水、高能水、低能水及超低能水。此外,还描述了各类陆相碳酸钙的各自的发育特征。   相似文献   

Cosmogenic 10Be and 26Al Chronology of the Last Glaciation of the Palaeo-Daocheng Ice Cap, Southeastern Qinghai-Tibetan Plateau     

ZHANG Zhigang  WANG Jian  XU Xiaobin  BAI Shibiao  CHANG ZhiYang 《《地质学报》英文版》2015,89(2):575-584

The glacial landforms of the Qinghai-Tibetan Plateau(QTP) provide a unique opportunity to research hemispheric and global environmental changes. In this study,we focus on the glacial history of the palaeo-Daocheng Ice Cap(p-DIC) in the southeastern QTP during the last glacial cycle. Based on field investigations,morphostratigraphy,and surface exposure dating of roche moutonnée,polished surface and moraine debris through the terrestrial cosmogenic nuclides(TCN) 10 Be and 26 Al. We identify glacial deposits of the last deglaciation,with minimum ages of 14.9±1.3–18.7±1.7 ka,the Last Glacial Maximum(LGM) of 24.7±2.2 ka,and the early part of the last glacial period(marine oxygen isotope stage(MIS) 3) of 37.1±3.4–45.2±3.9 ka. Our results show that in this region,the extent of the glacial advance during MIS 3 was larger than that during the traditional LGM(MIS 2). These ages are consistent with prior chronologies,and the 10 Be age is consistent with the 26 Al age for the same sample. Thus,these data provide reliable constraints on climate change in the QTP,during the last glaciation.  相似文献