深度学习在高分辨率遥感影像冬油菜提取中的应用

近年来,深度学习在基于高分辨率遥感影像的农作物种植信息提取领域应用广泛。本文充分利用油菜在盛花期的光谱特征,提出了基于深度学习理论的单时相高分辨率遥感影像油菜分布提取方法。以2016年湖北省沙洋县作为研究区域,获取油菜盛花时期高分一号(GF-1)影像,并以沙洋县为基础影像,通过手工标记制作油菜训练样本。设计两种深度学习框架模型,一种以卷积神经网络(CNN)为框架,构建一维卷积神经网络(1D-CNN)模型,第二种以循环神经网络(RNN)为框架,组合门控循环单元(GRU)模型,训练标准样本模型,完成油菜分类提取。最后,与传统支持向量机(SVM)、随机森林(RF)方法进行了结果对比。试验结果表明,本文设计的基于深度学习CNN和RNN模型提取的冬油菜空间分布精度和面积精度皆优于其他两种方法,为进一步实现冬油菜提取自动化提供试验基础。     

Periods of rapid environmental change around 12 500 and 10 000 years B.P., as recorded in Swiss lake deposits

In the sediment of three Swiss lakes at a range of altitude from 514 to 2017 m, the Bölling and the Preboreal are recognized as two periods of rapid biotic changes. The main reason is rapid climatic change that triggered shifts in different groups of aquatic and terrestrial organisms. Although these groups would be expected to have very different response times, e.g., to increasing summer temperature, their assemblages responded with surprizing synchroneity. For extracting climatic signals from stratigraphies, the quickly responsive indicators like oxygen isotopes or beetles are useful. For understanding ecological dynamics under a changing climate, the comparison of biota with various response time are important.This is the sixth of a series of papers to be published by this journal that was presented in the paleolimnology sessions organized by R. B. Davis and H. Löffler for the XIIth Congress of the International Union for Quaternary Research (INQUA), which took place in Ottawa, Canada in August 1987. Drs. Davis and Löffler are serving as guest editors of this series.     

Global fits for the spectral index of the cosmological curvature perturbation

Best-fitting values of the spectral index of the curvature perturbation are presented, assuming the ΛCDM cosmology. Apart from the spectral index, the parameters are the Hubble parameter, the total matter density and the baryon density. The data points are intended to represent all measurements that are likely to affect the result significantly. The cosmic microwave anisotropy is represented by the COBE normalization, and heights of the first and second peaks are given by the latest Boomerang and Maxima data. The slope of the galaxy correlation function and the matter density contrast on the 8  h ⁻¹ Mpc scale are each represented by a data point, as are the expected values of the Hubble parameter and matter density. The 'low-deuterium' nucleosynthesis value of the baryon density provides a final data point, the fit giving a value higher by about one standard deviation. The reionization epoch is calculated from the model by assuming that it corresponds to the collapse of a fraction f ≳10⁻⁴ of matter. We consider the case of a scale-independent spectral index, and also the scale-dependent spectral index predicted by running mass models of inflation. In the former case, the result is compared with the prediction of models of inflation based on effective field theory, in which the field value is small on the Planck scale. A detailed comparison is made with other fits, and other approaches to the comparison with theory.     

Late Quaternary deglaciation and climate history of the Larsemann Hills (East Antarctica)

The Late Quaternary climate history of the Larsemann Hills has been reconstructed using siliceous microfossils (diatoms, chrysophytes and silicoflagellates) in sediment cores extracted from three isolation lakes. Results show that the western peninsula, Stornes, and offshore islands were ice‐covered between 30 000 yr BP and 13 500 cal. yr BP. From 13 500 cal. yr BP (shortly after the Antarctic Cold Reversal) the coastal lakes of the Larsemann Hills were deglaciated and biogenic sedimentation commenced. Between 13 500 and 11 500 cal. yr BP conditions were warmer and wetter than during the preceding glacial period, but still colder than today. From 11 500 to 9500 cal. yr BP there is evidence for wet and warm conditions, which probably is related to the early Holocene climate optimum, recorded in Antarctic ice cores. Between 9500 and 7400 cal. yr BP dry and cold conditions are inferred from high lake‐water salinities, and low water levels and an extended duration of nearshore sea‐ice. A second climate optimum occurred between 7400 and 5230 cal. yr BP when stratified, open water conditions during spring and summer characterised the marine coast of Prydz Bay. From 5230 until 2750 cal. yr BP sea‐ice duration in Prydz Bay increased, with conditions similar to the present day. A short return to stratified, open water conditions and a reduction in nearshore winter sea‐ice extent is evident between 2750 and 2200 cal. yr BP. Simultaneously, reconstructions of lake water depth and salinity suggests relatively humid and warm conditions on land between 3000 and 2000 cal. yr BP, which corresponds to a Holocene Hypsithermal reported elsewhere in Antarctica. Finally, dry conditions are recorded around 2000, between 760 and 690, and between 280 and 140 cal. yr BP. These data are consistent with ice‐core records from Antarctica and support the hypothesis that lacustrine and marine sediments on land can be used to evaluate the effect of long‐term climate change on the terrestrial environment. Copyright © 2004 John Wiley & Sons, Ltd.     

INTERRELATION BETWEEN EAST-ASIAN WINTER MONSOON AND INDIAN/PACIFIC SST WITH THE INTERDECADAL VARIATION

Investigated statistically is the interrelation between East Asian winter monsoon(EAWM)and SST over sensitive areas of the Indian and Pacific Oceans.with focus on the relation of EAWMto strong ENSO signal area.i.e.,the equatorial eastern Pacific(EEP)SST.Evidence suggeststhat the EAWM variation is intimately associated not only with the EEP SST but with theequatorial western Pacific“warm pool”and equatorial Indian/northwestern Pacific Kuroshio SSTas well:the EAWM and ENSO interact strongly with each other on the interannual time scales,exhibiting pronounced interdecadal variation mainly under the joint effect of the monsoon QBO andthe monsoon/SST background field features on an interdecadal basis—when both fields are in thesame phase(anti-phase).strong EAWM contributes to EEP SST rise(drop)in the followingwinter,corresponding to a warm(cold)ENSO cycle;the EAWM QBO causes ENSO cycle to bestrong phase-locked with seasonal variation,making the EEP SST rise lasting from April—May toMay—June of the next year,which plays an important role in maintaining a warm ENSO phase.     

GIS支持下的复杂地形区冬小麦长势遥感监测方法

不同的地形,地貌和气候生态系统对小麦生长发育影响很大,也限制了小麦长势卫星遥感监测的精度。在分析豫西半山丘陵区不同地形（河川、丘陵）和气候生态条件（水热条件）对小麦生长影响的基础上,基于ＥＰＰＬ７地理信息系统（ＧＩＳ）,采用扫描、数据格式转化,建立数据库等方法,将ＮＯＡＡ／ＡＶＨＲＲ遥感资料和地形图,土壤图,年降水量图,年平均气温图,政区图等图件集成起来,并进行了监测区分层;根据系统监测和抽样调查     

山西省五台山—恒山地区脉状金矿成矿的地球动力学

０　前　言（代序）该文集命名为“成矿的地球动力学”,表明它只是矿床学中一项较基础性的研究;把脉状金矿作为研究对象,则应属于金矿区域成矿学的范畴。展望２１世纪,资源、环境乃是人类生存与发展之本,因此矿床学所肩负的使命必将更加艰巨。虽然人类利用矿产资源已有数千年的历史,但作为地质科学的重要组成部分—矿床学到１６世纪中叶才萌芽,１９世纪才形成具有较完整理论的学科。如果说矿床学的基本任务是确定这种或那种矿床在地壳中的生成条件和分布规律,矿床的形成又非孤立和偶然的事件,它是一定地质构造背景和地质历史条件下…     

云贵湖泊现代沉积物早期成岩过程中微量重金属地球化学行为研究

云贵湖泊现代沉积物早期成岩过程中微量重金属地球化学行为研究＠马英军￥中国科学院地球化学研究所湖泊沉积物,孔隙水,微量重金属,早期成岩作用,地球化学相云贵湖泊现代沉积物早期成岩过程中微量重金属地球化学行为研究马英军（中国科学院地球化学研究所,贵阳５５０００２...     

高原湖泊沉积物有机元素的早期成岩与湖泊营养演化研究

高原湖泊沉积物有机元素的早期成岩与湖泊营养演化研究＠王浩然￥中国科学院地球化学研究所湖泊,有机质,早期成岩,营养演化,Ｒｅｄｆｉｅｌｄ比值,泸沽湖,洱海高原湖泊沉积物有机元素的早期成岩与湖泊营养演化研究王浩然（中国科学院地球化学研究所,贵阳５５０００２）...     

辽东-吉南地区早元古代变质地体的组成及主要特征

在辽东－吉南地区存在两个性质不同的变质地体：辽北地体和辽南地体,二者之间以断裂带或韧性剪切带相接。辽北地体包括北辽河群和老岭群,辽南地体包括南辽河群和集安群。不同变质地体内的早元古代变质岩系在地层系统及岩石组合、原岩建造及沉积环境、变质作用类型及ｐＴｔ轨迹、区域构造和岩浆活动等方面都存在明显的差别。它们在早元古代时期形成于不同的大陆边缘,具有完全不同的形成条件和演化历史。两个变质地体最晚在早元古代晚期经构造作用拼贴在一起。