Disi Water Use for Irrigation – a False Decision and Its Consequences          下载免费PDF全文

Elias Salameh  Marwan Alraggad  Arwa Tarawneh 《洁净——土壤、空气、水》2014,42(12):1681-1686

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Recycling of Paper Mill Biosolids: A Review on Current Practices and Emerging Biorefinery Initiatives          下载免费PDF全文

Muhammad Pervaiz  Mohini Sain 《洁净——土壤、空气、水》2015,43(6):919-926

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Late Miocene Pods and Leaves of Albizzia (Leguminosae: Mimosoideae)from Yunnan, SW China and Their Phytogeographic Implications     

LI Binke  XIE Sanping  ZHANG Sihang  CHEN Tianyu  SHAO Yang 《《地质学报》英文版》2017,91(4):1190-1199

Albizzia is a leguminous genus belonging to the subfamily Mimosoideae with approximately150 modern species,widely distributed in the tropical and subtropical regions of Asia,Africa,Australia and America.Among them,17 species are mainly distributed in southern and southwestern China.Abundant fossils of the subfamily Mimosoideae,including leaves,pods,flowers and wood,have been reported from the Cretaceous and Paleogene strata of the Northern Hemisphere.However,Neogene records of Mimosoideae are relatively scarce.In this study,fossil pods and leaves belonging to the genus Albizzia from the Bangmai Formation of Yunnan,China were described.They were assigned to three species,including Albizzia scalpelliformis Guo,Li and Xie Emended,Albizzia cf.kalkora(Roxb.) Prain and Albizzia sp.The occurrence of Albizzia fossils from Lincang not only gives important information on the Neogene plant diversity from Yunnan—a worldwide famous biological hotspot—but also provides additional evidence for its phytogeographic history.  相似文献   

Genesis,distribution, and hydrocarbon implications of ostracod-bearing beds in the Songliao Basin (NE China)     

S. Pan  S. Liang  L. Ma  C. Liu  H. Liu 《Australian Journal of Earth Sciences》2017,64(6):793-806

The Upper Cretaceous Qingshankou Formation (K₂qn) and Nenjiang Formation (K₂n) in the Songliao Basin (SLB), China, contain discrete ostracod-bearing deposits. The ostracod-bearing layers range in thickness from 5 to 380 cm. Based on integrated analysis of seismic, drilling, core and logging data, the sedimentary characteristics, distribution patterns and hydrocarbon implications of the ostracod-bearing beds have been studied. Compared with mudstone and sandstone in lacustrine settings, ostracod-bearing beds have distinctive characteristics in terms of seismic response and logging features. Three types of depositional pattern of ostracod-bearing beds are recognised in different facies: mixed siliciclastic–ostracod deposits in the delta front, sheeted ostracod deposits, and dotted ostracod deposits in shallow or semi-deep lacustrine settings. In plan view, ostracod-bearing beds mainly occur in the Daqing area, the Longhupao–Honggang terraces and the Heidimiao depression, and are relatively less developed in the east of the SLB. Shallow and semi-deep lacustrine settings were favourable environments for the survival of ostracods. In the stratigraphic succession, ostracod-bearing beds mainly occur in the upper K₂qn¹, K₂qn², lower K₂qn³ and K₂n¹ units. High-frequency sequence cycles controlled ostracod reproduction and death, and mass mortalities of ostracods commonly occurred during periods in which the lake base-level fell, leading to water shallowing, increasing salinity and sand intrusion into the shore-shallow lakes. Ostracod mortality was not associated with expansion of the lake area, marine transgression or volcanic eruptions. The ostracod-bearing beds were widely formed in shallow and semi-deep lacustrine settings in the SLB. Tight oil/gas reservoirs can be developed in thick ostracod-bearing beds. In addition, areas containing ostracod can be regarded as sweet spots for mud or shale oil/gas exploration, because extensive ostracods can improve the content of brittle minerals in mudstone.  相似文献   

扬子克拉通崆岭杂岩新太古代花岗片麻岩成因及其构造意义          下载免费PDF全文

邱啸飞  杨红梅  赵小明  卢山松  江拓  段瑞春  刘重芃  彭练红  魏运许 《地球科学》2019,44(2):415-426

以崆岭杂岩中新太古代花岗片麻岩为研究对象,系统研究了其锆石U-Pb年代学和全岩地球化学特征,并对其岩石成因和扬子陆核～3.0～2.6Ga构造演化过程进行了初步探讨.锆石LA-ICP-MS U-Pb同位素测年结果表明,花岗片麻岩形成年龄为2 673±39Ma,且遭受了古元古代(2 042±27Ma)的高压麻粒岩相变质作用.地球化学研究表明,该套花岗片麻岩富Si,贫Mg、Cr、Ni,具有Eu、Sr和高场强元素的负异常.花岗片麻岩的εNd(t)值在-1.9～-0.1之间变化,对应两阶段Nd同位素模式年龄为3.15～3.01Ga,锆石饱和温度为789～825℃,显示岩体可能形成于初生长英质地壳物质在后碰撞伸展构造背景高温条件下部分熔融.结合前人已有的研究成果,认为以崆岭杂岩为代表的扬子陆核可能完整记录了～2.9～2.6Ga板块俯冲-碰撞-后碰撞与造山作用相关的完整过程.  相似文献   

洱海悬浮颗粒物和表层沉积物有机碳氮同位素来源特征及水质指示意义     

季宁宁  刘永  王圣瑞 《湖泊科学》2022,34(1):118-133

为探究湖泊水体悬浮颗粒物和沉积物有机碳、氮来源及水质指示意义,分析了2013-2014年洱海悬浮颗粒物和表层沉积物有机碳同位素(δ13C)、氮同位素(δ15N)和C/N比值时空变化特征及与水质的关系.结果 表明:①洱海悬浮颗粒物δ13C、C/N、δ15N在旱、雨季差异显著(P＜0.05),旱季变化范围分别为-31.75...  相似文献   

基于刷卡数据的公共汽车客流网络复杂性日内变化研究     

赵韶雅  杨星斗  戴特奇  张超 《地球信息科学学报》2020,22(6):1254-1267

大城市公共交通是一个典型的复杂巨系统,采用复杂网络方法分析大城市公共交通网络系统对于城市交通发展具有重要意义。已有大量的研究采用复杂网络理论进行了公共交通线路网络分析,也有研究基于刷卡数据分析了公共交通客流网络的复杂特征,但少有研究探讨客流网络复杂性日内变化特征。鉴于此,本文基于北京市公共汽车刷卡数据识别的不同时间段客流双向邻接矩阵,通过复杂网络指标对比分析公共汽车客流网络的日内变化特征。结果表明：① 各个时间段公共汽车客流分布遵循距离衰减规律,5 km以下的短距离出行约占总出行量的一半左右;② 度中心性和加权度中心性的空间格局在不同时间段整体呈现出明显的核心-边缘特征,但随时间有一定程度的变化,加权度中心性排名前10的节点存在较大变化;③ 累积度分布和累积加权度分布服从指数分布,属于小世界网络。本文还进一步讨论了基于大数据的动态复杂网络研究对城市交通规划建设的启示意义。  相似文献   

Paddy rice multiple cropping index changes in Southern China   总被引：1，自引：0，他引：1  

Jiang  Min  Li  Xiubin  Xin  Liangjie  Tan  Minghong 《地理学报(英文版)》2019,29(11):1773-1787

Journal of Geographical Sciences - Changes in rice production in Southern China are crucial to national food security. This study employed Landsat images to map the distributions of paddy...  相似文献   

Sedimentary filling characteristics of the South China Sea oceanic basin,with links to tectonic activity during and after seafloor spreading     

Shaoru Yin  Weiwei Ding  Derek E. Sawyer  Ziyin Wu  Yong Tang 《International Geology Review》2020,62(7-8):887-907

ABSTRACT

Based on approximately 11,000 km of seismic reflection data collected across the South China Sea oceanic basin, we describe the sedimentary filling characteristics of the basin since its Oligocene opening, as well as connections between this history and contemporaneous regional tectonic events. The seismic lines are spaced ~50 km apart, and the data are tied to International Ocean Discovery Program (IODP) Expedition 349 drilling data. Basin filling occurred in three phases, with basin-wide mean sedimentation rates increasing through time. During the Oligocene to middle Miocene, sediments accumulated primarily in the northern East and Northwest Sub-basins, with a mean basin-wide sedimentation rate of 8 m/m.y. The presence of these deposits over deep basement floor indicates that seafloor spreading initiated in these northern regions. During the late Miocene, deposition occurred primarily in the Northwest Sub-basin and partly in the southern East Sub-basin, with a mean basin-wide sedimentation rate of 30 m/m.y. Basin filling during this time seems to have been linked to slip reversal of the Red River Fault and collision of the North Palawan Block with the Luzon Arc. During the Pliocene and Pleistocene, sediments accumulated rapidly in the northeastern and southern East Sub-basin and the Southwest Sub-basin. The mean basin-wide sedimentation rate was 70 m/m.y. Basin filling during this phase seems to have been associated with the Taiwan and North Palawan collisions, SCS subduction along the Manila Trench, and Tibetan Plateau uplift. Gravity flow deposits predominate throughout the basin fill.  相似文献   

龙镇地区花岗岩锆石U-Pb年龄和Hf同位素及地质意义   总被引：17，自引：8，他引：9  

张彦龙  葛文春  高妍  陈井胜  赵磊 《岩石学报》2010,26(4):1059-1073

龙镇地区花岗岩位于大、小兴安岭的结合部,属于兴安地块与松嫩地块中的A-I型花岗岩带;该区各岩体岩石类型基本相同,主要为花岗闪长岩和二长花岗岩,地球化学特征显示为高钾钙碱性系列的I型花岗岩。花岗岩中锆石的LA-ICP-MSU-Pb年代学分析结果表明,正达山岩体形成于320～315Ma,模拉布山岩体形成于169±3Ma,朝阳林场岩体形成于187～171Ma。这些花岗质岩浆的就位分别与古生代时期古亚洲洋闭合过程中的块体拼合作用及中生代古太平洋的构造演化有关。Hf同位素成分特征表明,两期花岗岩的源岩均为新元古代-显生宙期间亏损地幔来源的火成岩。结合已发表的Sr-Nd-Hf同位素资料,本文认为兴安地块大陆地壳增生的时间主要为新元古代-显生宙,这与松嫩地块一致,而明显晚于额尔古纳地块的地壳增生时间(中-新元古代),从而揭示了它们不同的地壳演化历史。  相似文献