Petrogenesis and tectonic implications of Late Jurassic shoshonitic lamprophyre dikes from the Liaodong Peninsula, NE China

This paper presents detailed mineral chemical, element geochemical and Sr–Nd–Hf isotopic data for the Late Jurassic (155?±?4 Ma) lamprophyre dikes in the Liaodong Peninsula, NE China. The lamprophyres are shoshonitic and geochemically fall into three groups: Group I has relatively high SiO₂ (52.5–57.0 wt.%), low MgO (5.5–8.3 wt.%) and compatible trace element (e.g. Cr?=?128–470 ppm) contents, high initial ⁸⁷Sr/⁸⁶Sr ratios (0.7093–0.7117), and low ε_Nd (T) values (?9.6 to ?12.1); Group II has relatively low SiO₂ (44.8–50.0 wt.%), high MgO (10.8–14.2 wt.%) and compatible trace element (e.g. Cr?=?456–1,041 ppm) contents, low initial ⁸⁷Sr/⁸⁶Sr ratios (0.7073–0.7087), and high ε_Nd (T) values (?1.4 to ?2.9); Group III is transitional between the two in all elemental and isotopic compositions. Interpretation of the elemental and isotopic data suggests that the lamprophyric melts were derived by partial melting of subcontinental lithospheric mantle (SCLM) at a depth of 60–80 km (group I), decompression melting of upwelling asthenosphere at 60–100 km (group II), and mixing between the SCLM-derived and asthenosphere-derived melts (group III). It is assumed that the local SCLM was detached at a depth of 60–80 km by the 155 Ma ago. A continental arc-rifting related to the Palaeo-Pacific plate subduction is favored as a geodynamic force for such a cratonic lithosphere detachment.     

安徽铜陵凤凰山夕卡岩型铜矿床中辉钼矿Re-Os同位素年龄及其地质意义

铜陵矿集区是我国长江中下游Cu-Au-Fe-Mo成矿带中最重要的有色金属基地之一,凤凰山矿床是铜陵矿集区的重要组成部分,为一个典型的夕卡岩型铜矿床。本文利用Re-Os同位素定年方法对凤凰山铜矿床进行了成矿时代测定,获得了辉钼矿的Re-Os同位素模式年龄范围为139.1±2.4～142.0±2.2Ma,等时线年龄为141.1±1.4Ma,与矿区内石英二长闪长岩和花岗闪长岩SHRIMP锆石U-Pb年龄(144.2±2.3Ma)相吻合,也与铜陵地区其他矿田的成矿时代基本一致,可能为岩石圈减薄事件的成矿响应。     

复杂山区小流域径流模拟影响因素分析

为探讨子流域划分与DEM分辨率对于地形和地表状况比较复杂的山区小流域径流模拟的影响,利用分布式水文模型SWAT(Soil and Water Assessment Tool)对复杂山区小流域进行径流模拟,从不同的子流域划分条件下分析了子流域划分对径流模拟的影响及其变化趋势.然后通过对原有的DEM(Digital Elevation Model)进行重采样生成不同格网大小的DEM作为模型输入,研究不同DEM分辨率对复杂山区小流域径流模拟的影响.研究表明:(1)存在一个比较合理的子流域划分方案使径流深比较稳定;(2)存在一个合适的DEM分辨率使模拟得到的径流深比较稳定;(3)山区复杂流域环境,要求更加精细的子流域划分才能获得(1)中的稳定径流深.     

老鹰岩滑坡成因机制与运动特征研究

老鹰岩滑坡是汶川地震触发的大型岩质滑坡,滑坡纵长450 m,最大展宽430 m,体积约1 500×104m3。滑坡掩埋了一座中型水电站,造成20余人死亡,巨大的滑体堆积厚达100余米的滑坡坝,形成了汶川震区库容量仅次于唐家山的第二大堰塞湖。强震触发形成老鹰岩滑坡分为三个阶段,即:①后缘震动拉裂阶段。老鹰岩滑坡后缘为一突兀山脊,地形对地震动力放大效应明显,震动拉裂沿长大结构面形成了一个陡峭、粗糙,与重力作用下呈光滑、有一定弧形的后缘拉裂面迥异的边界。②摩擦阻力降低、滑体溃滑阶段。地震动力的持续作用,地震波不断在滑面处发生反射和折射,使得滑面处摩擦阻力迅速降低,进而岩体内"锁固段"剪断,滑体顺层面高速下滑。③滑体高速流动堆积阶段。规模巨大的滑体,冲入姜巴沟,并对沟两侧的山体产生强烈的铲刮,高速碎屑流受到黄洞子沟左侧山体强力阻挡后折返,并震动堆积形成堰塞湖。     

利用氮氧同位素研究桂林寨底地下河硝酸盐来源

工农业生产的迅速发展使地下水硝酸盐氮(NO3-—N)污染成为世界性的环境问题。地下水中硝酸盐的来源研究在水文地质结构特殊的西南岩溶地区就显得尤为重要。稳定氮同位素和氧同位素在地下水硝酸盐的来源示踪研究中有着广泛的应用。本研究选取岩溶地区典型地下河——广西桂林寨底地下河为研究对象,通过氮氧同位素数据,判断寨底地下河硝酸盐来源是以动物粪便为主的农家肥,为该区地下水的保护和利用提供科学依据。     

基于网络药理学及分子对接探讨八珍汤抗疲劳的作用机制

目的：运用网络药理学方法探讨八珍汤抗疲劳的药理机制,为八珍汤抗疲劳的临床应用提供理论依据。方法：筛选八珍汤药物的活性成分及靶点,查找疲劳相关基因,确定八珍汤抗疲劳靶点,进行基因本体（GO）功能和京都基因与基因组百科全书（KEGG）通路富集分析,将预测靶点最多的活性成分与蛋白质-蛋白质相互作用（PPI）网络中节点最大的靶点进行分子对接。结果：共筛选出143个有效活性成分,作用于133个疲劳靶点,八珍汤抗疲劳的核心基因主要有白细胞介素-1β（IL-1β）、趋化因子8（CXCL8）等47个。中药-疾病靶点涉及的GO功能分析中,生物过程主要集中在对无机物的反应、脂多糖的反应、炎症反应等;分子功能主要集中在激酶结合、DNA 结合转录因子结合、蛋白质结构域特异性结合等;细胞组分主要集中在膜筏、细胞周期蛋白依赖性蛋白激酶全酶复合物、囊腔等。KEGG通路富集分析主要富集在包括癌症通路、糖尿病并发症晚期糖基化终产物及其受体信号通路、白细胞介素-17（IL-17）信号通路等。分子对接结果显示槲皮素、山柰酚、甘草酮a和β谷甾醇与核心靶点结合性较好,结合能均<0 kcal/mol。结论：八珍汤抗疲劳的机制是多靶点、多通路的,为后续的基础研究提供了思路,并为临床运用八珍汤抗疲劳提供了理论支持。     

中国西北地区城市网络体系分析——基于民营企业布局

从民营企业视角对中国西北地区的城市网络体系进行实证分析,透视民营企业对其城市网络形成的作用。利用民营企业的分布数据,借鉴城市网络分析方法,从服务值、连通性、网络性3个方面对西北地区的城市网络体系进行了分析。基于民营企业视角,西北地区的城市构成了以西安和乌鲁木齐为主副双核、省会城市为核心节点、其他城市可作为其辐射区域的网络系统,且基于民营企业的城市网络体系尚处于初级发展阶段。     

A new insight into land use classification based on aggregated mobile phone data

Land-use classification is essential for urban planning. Urban land-use types can be differentiated either by their physical characteristics (such as reflectivity and texture) or social functions. Remote sensing techniques have been recognized as a vital method for urban land-use classification because of their ability to capture the physical characteristics of land use. Although significant progress has been achieved in remote sensing methods designed for urban land-use classification, most techniques focus on physical characteristics, whereas knowledge of social functions is not adequately used. Owing to the wide usage of mobile phones, the activities of residents, which can be retrieved from the mobile phone data, can be determined in order to indicate the social function of land use. This could bring about the opportunity to derive land-use information from mobile phone data. To verify the application of this new data source to urban land-use classification, we first construct a vector of aggregated mobile phone data to characterize land-use types. This vector is composed of two aspects: the normalized hourly call volume and the total call volume. A semi-supervised fuzzy c-means clustering approach is then applied to infer the land-use types. The method is validated using mobile phone data collected in Singapore. Land use is determined with a detection rate of 58.03%. An analysis of the land-use classification results shows that the detection rate decreases as the heterogeneity of land use increases, and increases as the density of cell phone towers increases.     

The Second Decadal Leading Mode of East Asian Summer Monsoon Rainfall

The first decadal leading mode of East Asian summer rainfall （EASR） is characterized by rainfall anomalies along the East Asian subtropical rain belt. This study focuses on the second decadal leading mode （2DLM）, accounting for 17.3% of rainfall decadal vari- ance, as distinct from the other two neighboring modes of EAMR, based on the state-of-the-art in-situ rainfall data. This mode is characterized by a South-China-wet-Huaihe- River-dry pattern, and is dominated by a quasi-30-yr pe- riod. Further analysis reveals the 2DLM corresponds to an enhanced lower-level monsoon jet, an eastward extension of the western North Pacific subtropical high, and a weakened East Asian upper-level westerly jet flow. The Tibetan Plateau surface temperature and Pacific Decadal Oscillation （PDO） are closely linked with the 2DLM. The regressed SST pattern indicates the PDO-like pattern of sea surface temperature anomalies may have a telecon- nection relationship with the 2DLM of EASR.     

沁水盆地煤层气成藏主控因素与成藏模式分析

沁水盆地石炭-二叠系煤层厚度大、分布稳定、演化程度高,具有良好的煤层气勘探潜力,是目前国内首个成功商业化开发的煤层气盆地。基于研究区已有地质成果,对影响沁水盆地煤层气富集成藏的主控地质因素与成藏模式进行分析,认为构造运动、水动力条件、煤层埋深、煤岩组成及热演化程度是控制沁水盆地煤层气成藏的主要地质因素,高镜质组含量、高热演化程度、弱水动力条件和较大的埋深是煤层气成藏的有利条件,向斜是煤层气富集成藏的有利部位。