综合地震勘探方法在陕北煤田采空区探测中的应用

基于陕北黄土塬煤层采空区地震勘探方法研究项目,在该类复杂地质背景和地震地质条件下进行了煤层采空区多种地震探测方法的应用。探测中依据不同的地震勘探方法原理,针对同一目标地质体,提取了识别其地震波场的响应特征:①在地震反射时间剖面上呈现反射波组中断缺失、不连续特征;②在折射层析速度剖面上反射为低速异常;③面波记录出现强能量基阶面波传播中止(波散),面波速度剖面呈现为低速异常,频散曲线发生畸变(呈"之"字型回折);④煤层采空区边界显现出散射波特征。这些地震波场特征在鄂尔多斯等地的煤层采空区探测中也已得到验证。陕北煤田采空区探测实例表明,采用综合地震勘探方法探测可有效解决单一方法的多解性问题,提高其成果的准确性和可靠性。     

华南扬子陆块成冰纪冰川作用的启动时限及其全球对比*

江口冰期和南沱冰期是华南地区引人注目的2次成冰纪冰川事件,但其确切启动时间及其全球对比关系仍未有定论。为此,对桂北地区成冰系(南华系)长安组底部和南沱组底部冰成杂砾岩开展了碎屑锆石U-Pb年代学研究。长安组碎屑锆石U-Pb年龄集中分布于958—717 Ma,显著峰值为720、753、805及848 Ma,最年轻一组 ²⁰⁶Pb/²³⁸U 年龄的加权平均值为719.6±6.1 Ma,可解释为长安组最大沉积年龄;南沱组碎屑锆石U-Pb 年龄集中分布于987—649 Ma,显著峰值为650、720、753、779、803、823及848 Ma,最年轻一组 ²⁰⁶Pb/²³⁸U 年龄的加权平均值为649.3±6.2 Ma,可解释为南沱组最大沉积年龄。结合已发表的相关年龄数据可知,江口冰期很可能启动于ca.715 Ma,与塔里木、阿拉伯—努比亚、劳伦等陆块的Sturtian冰川作用高度同步;南沱冰期的启动应晚于650 Ma,与西伯利亚、澳大利亚、劳伦等陆块的Marinoan冰川作用基本同步。另外,碎屑锆石U-Pb年龄谱与CL图像显示,长安组和南沱组的物质来源主要为下伏新元古界岩浆—沉积记录,揭示出冰川对下伏地层的强烈刨蚀作用和华南新元古代幕式构造岩浆热事件。扬子陆块成冰纪冰川刨蚀作用可能与Rodinia 超大陆“裂离”有关的强烈伸展活动存在联系,并可能持续至Marinoan 冰期结束。     

城市青年群体住房产权获得的区域差异——以上海和南京为例

从城市异质性视角,以一线城市上海和二线城市南京为例,基于2013年长三角地区社会变迁调查和南京市住房调查数据,利用Logistic模型,剖析了两地青年住房产权获得的影响因素及其差异。研究发现,两个城市青年住房产权获得的影响因素存在较大差异。与南京相比,上海青年居民的住房获得存在更大的区位和制度壁垒,受城市区位、户口、制度因素影响更大,而受教育水平、工作流动性等市场因素以及年龄、是否育有子女等生命历程因素的影响较小。上海,作为一线城市,户口制度仍然处于精准严控阶段,落户门槛相对较高,另外住房价格高企,上海的青年群体在住房产权获得中同时面临着制度层面和市场层面的双重严苛考验。而在二线城市南京,户口政策相对较为宽松,青年群体的住房产权获得所面临的制度性障碍较小,而市场因素更加主导。     

Comparison of the Ability of ARIMA,WNN and SVM Models for Drought Forecasting in the Sanjiang Plain,China

Natural Resources Research - Drought is a natural disaster that profoundly impacts all parts of the environment. Drought forecasting could provide technical support for drought risk prevention....     

Mechanism of interaction between urbanization and resource environment in Central Asia

Journal of Geographical Sciences - Central Asia features an arid and semi-arid climate, and the region is undergoing urbanization in the context of a fragile eco-environment. The influence of...     

孔石莼净化高盐废水海藻叶表微生态分析

孔石莼是一种大型潮间带绿藻,在去除氮磷营养盐方面已发挥显著作用,但目前尚不清楚其在净化高盐废水时的叶表微生态情况。本研究利用孔石莼处理高盐废水,通过高通量测序技术分析了孔石莼表面和废水中的微生物群落分布特征。研究结果表明：孔石莼表面的微生物多样性和微生物丰度均高于废水。孔石莼叶表优势菌属包括芽孢杆菌属Bacillus、微小杆菌属Exiguobacterium、虚构芽孢杆菌属Fictibacillus和短芽孢杆菌属Brevibacillus,其中芽孢杆菌属Bacillus最为丰富,占比超过整体的70%。废水中微生物以芽孢杆菌属Bacillus与微小杆菌属Exiguobacterium为主,二者占比总和超过整体的99%。相较于水体的流动性,孔石莼表面更利于微生物的生长与分布。     

Interdecadal oscillations in the Japan Sea proper water related to the arctic oscillation

The time series of dissolved oxygen (DO) concentration in the Japan Sea Proper Water (JSPW) shows clear interdecadal oscillation with about 20-year periodicity since the 1970s. This interdecadal variation in the DO concentration is positively correlated with the Arctic Oscillation (AO) index; the DO concentration tends to be high during a positive AO phase when the East Asian winter monsoon (EAWM) is relatively weak, which is considered to be an unfavorable condition for the JSPW formation. To clarify the discrepancy, the cause of the interdecadal oscillation was investigated using the wind at Wajima and sea surface temperature (SST) in the JSPW formation area. The cold-air outbreaks determined from the wind at Wajima are synchronized with the interdecadal oscillation of the AO; during a positive AO phase the cold-air outbreaks over the Japan Sea are more active, as reported by Isobe and Beardsley (2007). Since the SST in the JSPW formation area is negatively correlated with cold-air outbreaks, the activity of cold-air outbreaks is more important to the JSPW formation than the EAWM, at least on an interdecadal timescale. Significant correlations of the indicator of low pressure migration with the AO and cold-air outbreaks confirm that atmospheric disturbances move frequently into the Japan Sea from the East China Sea in a positive AO phase. A detailed examination of cold-air outbreaks revealed that the passing of atmospheric low pressures temporarily enhances the east-west pressure gradient over the Japan Sea and effectively brings cold air into the JSPW formation area.     

应用FMI成像测井识别钙质结核及意义

结核属于一种矿物集合体,对于查明所赋存沉积物的沉积环境、沉积特征及演化历史等方面有重要意义,以往对于露头中出现的结核研究较为成熟。而对于井下发育的结核,缺乏有效手段对其形态、形成阶段及数量进行全面认识,致使结核理论在地质分析应用中受到极大限制。充分利用FMI成像测井纵、横向分辨率高、井眼覆盖率高、图像清晰等特点,对珠江口盆地琼海凸起珠江组大量发育的钙质结核形态及形成阶段做了详细研究,为认识研究区沉积环境及演化规律起到积极意义,同时也证明FMI成像测井资料为识别井下地层中发育的结核提供了一种有效手段。     

κ-卡拉胶固相酸降解及其寡糖结构分析

以κ-卡拉胶为原料,采用正交实验法建立了1种固相酸降解制备κ-卡拉胶寡糖方法。结果表明,当阳离子交换树脂(732#)用量为100 mg/mL、κ-卡拉胶的质量浓度为3%时,在60℃下降解3 h后,寡糖分布宽度较窄,经PAGE和电喷雾离子化质谱(ESI-MS)分析,表明所得寡糖为聚合度小于25的系列奇数寡糖。