使用DOS批处理文件备份自动气象站数据

从备份自动站数据文件的实际需要出发,通过实例由浅及深地介绍了用DOS批处理文件多目的地、多方式备份自动站数据的方法,包括本机备份、备份到局域网、备份到网络服务器以及自动备份等。     

城市建筑动力学效应对对流边界层影响的敏感性试验

本文将大涡模拟应用于城市对流边界层(CBL)湍流结构和流场特征的研究,在大涡模式中,拖曳系数取与建筑物高度及建筑物高度标准差有关的表达式以考虑次网格建筑物对风速和湍流动能(TKE)的面积平均影响.模拟结果表明,由于城市建筑物对气流的拖曳作用,使建筑物冠层及整个CBL内风速大幅度减小,城市冠层内部风速减小尤为明显,在夹卷层内,风速有一明显的跃变.在边界层中部对流运动已经发展成为较强的热泡,城市建筑物的动力学效应使热泡的水平尺度增大,CBL内平均上升气流速度和下沉气流速度减小,同时使CBL中上升气流所占比例比平坦地面增大.城市建筑物使CBL低层热通量、动量通量、速度方差和位温方差明显增大,但对近地层高度以上的湍流量影响不大.     

1880-2006年中国夏季雨带类型的年代际变化特征

 利用1880-2006年中国东部地区夏季降水量及1951-2006年中国160个站夏季降水量和北半球大气环流资料,在夏季降水分型的基础上,研究了夏季雨型的年代际变化规律,分析了夏季各类雨型所对应的北半球500 hPa环流场的主要特征。结果表明：东部季风区和西部区存在着20～40 a左右的年代际振荡趋势,东北区则表现为明显的15 a左右的年代际变化特点;东部季风区四类雨型东亚大气环流差异显著,西部区二类雨型和东北区二类雨型欧亚大气环流的配置基本都相反。     

1959-2003年中国天山积雪的变化

Mcteorological data at 17 weather stations in the Tianshan Mountains from 1959 to 2003 were analyzed to explore the variations in temperature and snow cover.The abrupt change test for snow depth was performed using Mann-Kendall statistic.The spatial distribution of maximum snow depth was calculated by employing GIDS interpolation and DEM data.The results show that mean temperature in winter had a rising trend at a rate of 0.44℃/10a.The minimum temperature in winter increased more evidently at a rate of 0.79℃/10a.The maximum snow depth has obviously deepened at a rate of 1.15 cm/10 a in the past 45 years,and it was about 16% higher than the average during 1991-2003.The Mann-Kendall statistic test of snow depth indicates that the abrupt change occurred in 1976.The maximum increment for snow cover depth occurred in Zhaoshu(Kunes)(39.3%)and Nilka(39.7%)in the west Tiansban Mountains.In contrast,the snow cover depth reduced by 17% in Barkol in the east Tianshan Mountains.There was a primary change periodicity of about 2.8 years in snow cover.In addition,snow cover days with a depth more than 10 cm increased distinctly,however,there was no obvious advance or delay in snow beginning and ending dates.     

Forecasting the western Pacific subtropical high index during typhoon activity using a hybrid deep learning model

Seasonal location and intensity changes in the western Pacific subtropical high(WPSH) are important factors dominating the synoptic weather and the distribution and magnitude of precipitation in the rain belt over East Asia. Therefore, this article delves into the forecast of the western Pacific subtropical high index during typhoon activity by adopting a hybrid deep learning model. Firstly, the predictors, which are the inputs of the model, are analysed based on three characteristics: the first...     

Instability of seawater pH in the South China Sea during the mid-late Holocene: Evidence from boron isotopic composition of corals

We used positive thermal ionization mass spectrometry (PTIMS) to generate high precision δ¹¹B records in Porites corals of the mid-late Holocene from the South China Sea (SCS). The δ¹¹B values of the Holocene corals vary significantly, ranging from 22.2‰ to 25.5‰. The paleo-pH records of the SCS, reconstructed from the δ¹¹B data, were not stable as previously thought but show a gradual increase from the Holocene thermal optimal and a sharp decrease to modern values. The latter is likely caused by the large amount of anthropogenic CO₂ emissions since the Industrial Revolution but variations of atmospheric pCO₂ cannot explain the pH change of the SCS before the Industrial Revolution. We suggest that variations of monsoon intensity during the mid-late Holocene may have driven the sea surface pH increase from the mid to late Holocene. Results of this study indicate that the impact of anthropogenic atmospheric CO₂ emissions may have reversed the natural pH trend in the SCS since the mid-Holocene. Such ocean pH records in the current interglacial period can help us better understand the physical and biological controls on ocean pH and possibly predict the long-term impact of climate change on future ocean acidification.     

东秦岭东段新发现的沙坡岭细脉浸染型钼矿地质特征、Re-Os同位素年龄及其地质意义

豫西洛宁沙坡岭钼矿床位于华北克拉通南缘东秦岭钼矿带东段,是新近发现的赋存于太古宙太华群变质岩中的细脉浸染型钼矿床。本文对其地质特征进行了研究,并初步测定了1个辉钼矿样品的Re－Os同位素年龄,获得模式年龄为126.8±1.7Ma,表明沙坡岭钼矿形成于燕山期,接近金堆城、雷门沟钼矿的形成时代,Re同位素含量显示其地幔来源的特征。沙坡岭钼矿形成机制错综复杂,有待进一步研究,特别是深部钻孔工程验证工作,对于验证深部是否隐伏着与成矿相关的斑岩体、储量更大的斑岩型钼矿有着重要作用,找矿潜力巨大。     

Geochemical, Sr–Nd and zircon U–Pb–Hf isotopic studies of Late Carboniferous magmatism in the West Junggar, Xinjiang: Implications for ridge subduction?

Voluminous granitic intrusions are distributed in the West Junggar, NW China, and they can be classified as the dioritic rocks, charnockite and alkali-feldspar granite groups. The dioritic rocks (SiO₂ = 50.4–63.8 wt.%) are calc-alkaline and Mg enriched (average MgO = 4.54 wt.%, Mg^# = 0.39–0.64), with high Sr/Y ratios (average = 21.2), weak negative Eu (average Eu/Eu = 0.80) and pronounced negative Nb–Ta anomalies. Their Sr–Nd and zircon Hf isotopic compositions ((⁸⁷Sr/⁸⁶Sr)_i = 0.7035–0.7042, ε_Nd(t) = 4.5–7.9, ε_Hf(t) = 14.1–14.5) show a depleted mantle-like signature. These features are compatible with adakites derived from partial melting of subducted oceanic crust that interacted with mantle materials. The charnockites (SiO₂ = 60.0–65.3 wt.%) show transitional geochemical characteristics from calc-alkaline to alkaline, with weak negative Eu (average Eu/Eu = 0.75) but pronounced negative Nb–Ta anomalies. Sr–Nd and zircon Hf isotopic compositions ((⁸⁷Sr/⁸⁶Sr)_i = 0.7037–0.7039, ε_Nd(t) = 5.2–8.0, ε_Hf(t) = 13.9–14.7) also indicate a depleted source, suggesting melts from a hot, juvenile lower crust. Alkali-feldspar granites (SiO₂ = 70.0–78.4 wt.%) are alkali and Fe-enriched, and have distinct negative Eu and Nb–Ta anomalies (average Eu/Eu = 0.26), low Sr/Y ratios (average = 2.11), and depleted Sr–Nd and zircon Hf isotopic compositions ((⁸⁷Sr/⁸⁶Sr)_i = 0.7024–0.7045, ε_Nd(t) = 5.1–8.9, ε_Hf(t) = 13.7–14.2). These characteristics are also comparable with those of rocks derived from juvenile lower crust. Despite of the differences in petrology, geochemistry and possibly different origins, zircon ages indicate that these three groups of rocks were coevally emplaced at ~ 305 Ma.A ridge subduction model can account for the geochemical characteristics of these granitoids and coeval mafic rocks. As the “slab window” opened, upwelling asthenosphere provided enhanced heat flux and triggered voluminous magmatisms: partial melting of the subducting slab formed the dioritic rocks; partial melting of the hot juvenile lower crust produced charnockite and alkali-feldspar granite, and partial melting in the mantle wedge generated mafic rocks in the region. These results suggest that subduction was ongoing in the Late Carboniferous and, thus support that the accretion and collision in the Central Asian Orogenic Belt took place in North Xinjiang after 305 Ma, and possibly in the Permian.     

复杂储层识别的地震反演方法及其在塔木察格盆地的应用

随着油气藏勘探开发程度的加深,准确识别复杂储层变得愈发重要,地震反演已成为储层预测的核心技术.本文对蒙占国塔木察格盆地南部凹陷1 800 km²地震资料进行波阻抗反演研究,研究工作包括测井曲线的标准化校正、地质框架模型的准确建立及其它反演参数的正确选取.波阻抗反演结果为研究沉积相划分、砂体空问展布的认识提供了可靠依据,在一定程度上解决了该区主要日的层南屯组沉积物源多、相变快和在地震剖面上无法追踪的问题.