多尺度空间分析技术遥感影像去雾方法

基于多尺度空间分析技术构建了两种影像去雾方法。多时相参考影像去雾方法利用同一地区没有雾的影像作为参考,运用多尺度空间分析技术获取地面低频信息将雾去除。自动影像去雾方法是基于拓扑分析的多尺度空间分析技术,分析影像的纹理和特征信息,将同一场景中的雾和地面信息分离,从而获得去雾后影像。通过青岛地区大量遥感影像数据测试,证明该方法是非常有效的。     

Carbon and Noble Gas Isotopes in the Tengchong Volcanic Geothermal Area, Yunnan, Southwestern China

Carbon and noble gas isotope analyses are reported for bubbling gas samples from the Tengchong volcanic geothermal area near the Indo-Eurasian suture zone. All samples contain a resolvable component of mantle-derived 3He. Occurrence of mantle-derived 3He coincides with surface volcanism. However, 3He occurs over a larger geographic areathan do surface volcanics. δ13C values for CO2 and CH4 vary from -33.4‰ to 1.6 ‰ and from -52.8‰ to -2.8‰, respectively. He and C isotope systematics indicate that CO2 and CH4 in the CO2-rich gases originated predominantly from magmatic component mixed with crustal CO2 produced from carbonate. However, breakdown of organic matter and near-surface processes accounts for the CH4 and CO2 in N2-rich gases. 3He/4He ratio distribution pattern suggests that mantle-derived He and heat sources of high-temperature system in central Tengchong originate from a hidden magma reservoir at subsurface. CO2-rich gases with the highest 3He/4He ratio (5.2 Ra) may be representative of the     

Experimental constraints on ultrapotassic magmatism from the Bohemian Massif (durbachite series, Czech Republic)

The equilibrium phase relations of a mafic durbachite (53 wt.% SiO₂) from the Třebíč pluton, representative of the Variscan ultrapotassic magmatism of the Bohemian Massif (338–335 Ma), have been determined as a function of temperature (900–1,100°C), pressure (100–200 MPa), and H₂O activity (1.1–6.1 wt.% H₂O in the melt). Two oxygen fugacity ranges were investigated: close to the Ni–NiO (NNO) buffer and 2.6 log unit above NNO buffer (∆NNO + 2.6). At 1,100°C, olivine is the liquidus phase and co-crystallized with phlogopite and augite at 1,000°C for the whole range of investigated pressure and water content in the melt. At 900°C, the mineral assemblage consists of augite and phlogopite, whereas olivine is not stable. The stability field of both alkali feldspar and plagioclase is restricted to low pressure (100 MPa) at nearly water-saturated conditions (<3–4 wt.% H₂O) and T < 900°C. A comparison between experimental products and natural minerals indicates that mafic durbachites have a near-liquidus assemblage of olivine, augite, Ti-rich phlogopite, apatite and zircon, followed by alkali feldspar and plagioclase, similar to the mineral assemblage of minette magma. Natural amphibole, diopside and orthopyroxene were not reproduced experimentally and probably result from sub-solidus reactions, whereas biotite re-equilibrated at low temperature. The crystallization sequence olivine followed by phlogopite and augite reproduces the sequence inferred in many mica-lamprophyre rocks. The similar fractionation trends observed for durbachites and minettes indicate that mafic durbachites are probably the plutonic equivalents of minettes and that K- and Mg-rich magmas in the Bohemian Massif may have been generated from partial melting of a phlogopite–clinopyroxene-bearing metasomatized peridotite. Experimental melt compositions also suggest that felsic durbachites can be generated by simple fractionation of a more mafic parent and mixing with mantle-derived components at mid crustal pressures.     

Errors and correction of precipitation measurements in China

In order to discover the range of various errors in Chinese precipitation measurements and seek a correction method, 30 precipitation evaluation stations were set up countrywide before 1993. All the stations are reference stations in China. To seek a correction method for wind-induced error, a precipitation correction instrument called the ＂horizontal precipitation gauge＂ was devised beforehand. Field intercomparison observations regarding 29,000 precipitation events have been conducted using one pit gauge, two elevated operational gauges and one horizontal gauge at the above 30 stations. The range of precipitation measurement errors in China is obtained by analysis of intercomparison measurement results. The distribution of random errors and systematic errors in precipitation measurements are studied in this paper. A correction method, especially for wind-induced errors, is developed. The results prove that a correlation of power function exists between the precipitation amount caught by the horizontal gauge and the absolute difference of observations implemented by the operational gauge and pit gauge. The correlation coefficient is 0.99. For operational observations, precipitation correction can be carried out only by parallel observation with a horizontal precipitation gauge. The precipitation accuracy after correction approaches that of the pit gauge. The correction method developed is simple and feasible.     

中国古代牧业社会骨制品的初步考察:以新疆巴里坤石人子沟遗址为例

考古遗址出土骨制品的研究对于揭示古代社会的动物资源获取和利用、手工业生产、社会组织结构等问题具有重要意义。国内骨制品研究目前多集中在农业区域,这些研究为探讨新石器时代至青铜时代的动物使用及其与社会发展、早期国家形成的关系等问题作出了重要贡献。然而,针对牧业社会骨制品的考察十分缺乏。新疆哈密地区巴里坤草原分布有大量古代牧业文化遗址,石人子沟遗址（43°31'12.8"~43°34'28.9"N,93°13'44.8"~93°16'49.1"E）是其中一处青铜时代晚期至铁器时代早期的大型聚落。本文从动物考古学视角研究该遗址2006年至2011年发掘出土的426件骨制品。结果显示,石人子沟遗址骨制品的原料主要为以羊（Ovis aries/Capra hircus）、马（Equus caballus）为主的家养动物和以鹿（Cervidae）为主的野生动物,其中羊的比例最高（69.7%）,鹿（13.8%）、马（2.3%）次之,这与中原地区青铜时代农业文化遗址的骨制品多以牛为原料的情况明显不同。羊在骨制品原料中占绝对多数且大量使用羊距骨制品的现象是对石人子沟遗址以牧业为主的生业经济方式的直接反映。石人子沟遗址不同类型骨制品的制作各具特点,但整体表现出"省时省力"的特点,即对使用部位细致打磨,对非使用部位仅做简单处理。与中原地区商周时期大型制骨作坊规范化、规模化、产业化的骨器生产不同,石人子沟遗址未见专门的制骨场所,骨制品生产的操作链条也并不完整。遗址的骨制品生产可能是以家庭为单元进行的,产品的专业化、精细化程度也相对较低。该研究填补了我国古代牧业文化遗址出土骨制品动物考古学专门研究的空白,为进一步探究我国古代不同区域、不同生业经济基础下的制骨手工业面貌提供了重要资料。

     

Lateral extrusion along the Altyn Tagh Fault,Qilian Shan (NE Tibet): insight from a 3D crustal budget

The lithospheric strike‐slip Altyn Tagh Fault has accommodated hundreds of kilometres of displacement between the Qaidam and Tarim blocks since its Eocene reactivation. However, the way the deformation is accommodated in the Qilian Shan and further east remains uncertain. Based on 360 km of north‐eastward migration of the relatively rigid Qaidam block along the Altyn Tagh Fault and 3D isovolumetric balancing of the crustal deformation within the Altyn Tagh Fault–Qilian Shan system, we demonstrate that 250 ± 28 km (43.8–49.4%) of N20E directed crustal shortening and an additional ~250–370 km of eastward motion of the Qilian Shan crust must be accounted for by strike‐slip faulting in the Qilian Shan and crustal thickening in the Qinling area, as well as by extension in the adjoining North China block graben systems.     

S频段用于卫星导航的电磁环境研究

结合不同的信号调制方式,在满足一定伪距误差的条件下,从所需信号发射功率小和与北斗一代相互干扰小的角度论证了RNSS应用BOC（6,1）和BOC（6,2）两种调制方式的优势。并且对2 483.5~2 500 MHz频段中导航系统与其他通信系统之间的干扰作出估计,论证了GNSS系统与其他无线电业务的兼容性。     

The limits of validity of the Frequency Ratio Method: The particular case of γ Doradus stars

This work provides a general vision of the limits of validity of the Frequency Ratio Method applied to the g‐mode pulsators in asymptotic regime, the γ Doradus stars. In particular, the work is mainly focused on the role of rotation which is found one of the most important source of uncertainty of the method. The particular case of the moderately rotating γ Doradus star HD48501 is discussed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Controls on sediment evacuation from glacially modified and unmodified catchments in the eastern Sierra Nevada,California

The degree of glacial modification in small catchments along the eastern Sierra Nevada, California, controls the timing and pattern of sediment flux to the adjacent fans. There is a close relationship between the depth of fan‐head incision and the pattern and degree of Late Pleistocene catchment erosion by valley glaciers; catchments with significant glacial activity are associated with deeply incised fan heads, whereas fans emerging from glacially unmodified catchments are unincised. We suggest that the depth of fan‐head incision is controlled by the potential for sediment storage during relatively dry ice‐free periods, which in turn is related to the downstream length of the glacially modified valley and creation of accommodation through valley floor slope lowering and glacial valley overdeepening and widening. Significant storage in glacially modified basins during ice‐free periods leads to sediment supply‐limited conditions at the fan head and causes deep incision. In contrast, a lack of sediment trapping allows quasi‐continuous sediment supply to the fan and prevents incision of the fan head. Sediment evacuation rates should thus show large variations in glacially modified basins, with major peaks during glacial and lows during interglacial or ice‐free periods, respectively. In contrast, sediment removal from glacially unmodified catchments in this type of setting should be free of this effect, and will be dominated instead by short‐term variations, modulated for example by changes in vegetation cover or storm frequency. This distinction may help improve our understanding of long‐term sediment yields as a measure of erosional efficiency. Copyright © 2008 John Wiley & Sons, Ltd.     

山西临汾中心地震台石英摆倾斜仪前驱波特征分析

文章对山西临汾中心地震台石英摆倾斜仪记录到的2008至2009年3月全球MS≥7.0、中国大陆MS≥6.0地震前前驱波进行了统计,结果表明,全球50%的大于7.0级地震震前有前驱波记录,而对于中国大陆大于6.0级地震震前也有前驱波记录;前驱波出现的时间多为震前几小时到7 d左右,存在有形态和幅度的差异,且对应的地震具有地区性的特点.