华东地区极端降水动力降尺度模拟及未来预估   总被引：1，自引：1，他引：0  

魏培培  董广涛  史军  张博文 《气候与环境研究》2019,24(1):86-104

利用CMIP5（Coupled Model Intercomparison Project Phase 5）数据集中的全球模式IPSL-CM5A-LR及其嵌套的区域气候模式WRF（Weather Research and Forecasting）,分别评估了模式对1981~2000中国华东区域极端降水指标的模拟能力,并讨论了RCP8.5排放情景下21世纪中期（2041~2060年）中国华东极端降水指标的变化特征。相比驱动场全球气候模式,WRF模式更好地再现了各个极端指数空间分布及各子区域降水年周期变化。在模拟区域气候特点方面,WRF模拟结果有所改进,并在弥补全球模式对小雨日过多模拟的缺陷起到了明显的作用。21世纪中期,华东区域的降水将呈现明显的极端化趋势。WRF模拟结果显示年总降雨量、年大雨日数、平均日降雨强度在华东大部分区域的增幅在20%以上;年极端降雨天数、连续5 d最大降水量的增幅在华东北部部分区域分别超过了50%和35%,同时最长续干旱日在华东区域全面增加;且变化显著的格点主要位于增加幅度较大的区域。未来华东区域会出现强降水事件和干旱事件同时增加的情况,降水呈现明显的极端化趋势,且华东北部极端化强于华东南部。  相似文献   

Differential gene expression in the brain of Sebastiscus marmoratus in response to exposure to polychlorinated biphenyls (PCBs)     

Li B  Wang C  Ye K  Yu A  Chen Y  Zuo Z 《Marine environmental research》2008,66(5):548-552

Effects of exposure to polychlorinated biphenyls (PCBs) on Sebastiscus marmoratus were investigated using a suppression subtractive hybridization method. A total of 108 gene sequences were identified as having the potential for being differentially expressed, and 45 could be identified with homologous database sequences. Functions with which they were associated included long-term potentiation and neurotransmitter release, neuroendocrine, mitosis and cell proliferation, energy-related metabolism, general metabolism, signal protein, hemopoiesis system, immune system, and structure. The expression of 17 of these genes was analyzed in the brain using real time fluorescent quantitative PCR. The present study provided a basis for studying the response of fish to PCB exposure and allowed the characterization of new potential neurotoxicol biomarkers of PCB contamination in seawater.  相似文献   

对岩石学,矿物学与材料科学关系的思考     

李博文 《地质科技情报》1995,14(3):56-60

在综观矿物学、岩石学和材料科学的学科发展的基础上，认为它们在对物质成分、结构、性质或性能、形成机制的研究方法和内容等很多方面相通或相似的，并认为其浙趋融合。淡化学科界线，在物理学和化学水平上发展新的边缘交叉学科，是合理、高效地利用矿产资源和发展新材料的需要，也是学科发展的必然。  相似文献   

致密砂砾岩储层孔隙结构对比及差异机制研究     

孙灵辉  萧汉敏  谭龙  李博文  孙东盟  王鹏威 《地质学报》2022,96(6):2155-2172

致密储层孔隙结构研究对于致密油气的勘探和开发具有重要意义，也是当前致密储层研究的热点。本文以准噶尔盆地三叠系百口泉组致密砾岩和鄂尔多斯盆地三叠系延长组致密砂岩为研究对象，重点开展二维大面积背散射扫描电镜成像技术（Maps）、高压压汞、微米CT和聚焦离子束扫描电镜技术（FIB- SEM）等分析测试，采用定性和定量相结合的方法对致密砾岩和致密砂岩孔隙结构特征进行表征和对比，并进一步揭示了两者的成因机制差异。研究结果表明：百口泉组致密砾岩较延长组致密砂岩储层物性好，前者孔隙度和渗透率平均为9. 29%和1. 65×10-3 μm2，后者孔隙度和渗透率平均为8. 85%和0. 39×10-3 μm2；百口泉组致密砾岩较延长组致密砂岩孔喉尺寸偏大、孔隙连通性较差及孔隙结构更为复杂，前者孔喉半径主要分布在0~200 nm和2~10 μm范围内，平均连通率60. 63%，平均孔喉配位数3. 0446，后者孔喉半径主要分布于0~4 μm范围内，平均连通率73. 60%，平均孔喉配位数2. 7832；差异化沉积作用和成岩作用是导致百口泉组致密砾岩和延长组致密砂岩孔隙结构特征差异的根本原因。  相似文献   

The Pleistocene Succession of the Irish Sea     

D.Q. Bowen 《Proceedings of the Geologists' Association. Geologists' Association》1973,84(3):249-IN2

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油田卤水中短链有机酸的来源,分布及其地球化学意义     

马亭  梅博文 《地质科技情报》1993,12(3):73-77

在几乎所有的油田卤水(地层水)中都含有高浓度的短链有机酸,通常乙酸根是其中最丰富的有机阴离子。大量的模拟实验表明干酪根是有机酸最主要的来源。短链有机酸有着重要的地球化学意义,(1)可以作为石油勘探的近似指示物,(2)它们可能是天然气中某些主要成分的母体,(3)它们是地层水中最主要的弱酸阴离子,因此控制了地层水的pH值的缓冲能力,(4)作为还原剂,它们控制了地层水的Eh值和多价元素的浓度,(5)实验表明,它们还能够与储集岩中的铝、钙、硅等无机离子形成可溶络合物,使长石类矿物的溶解作用增强,从而导致砂岩储层中次生孔隙加大。  相似文献   

Fallout radionuclides in the Pacific Ocean: Vertical and horizontal distributions,largely from GEOSECS stations     

Vaughan T. Bowen  Victor E. Noshkin  Hugh D. Livingston  Herbert L. Volchok 《Earth and Planetary Science Letters》1980,49(2):411-434

From GEOSECS stations, largely, the 1974 distributions of Pu and of¹³⁷Cs are described in the Pacific Ocean north of about 20°S latitude. Changes in some of these distributions are described from 1978 cruises by the authors.The Pacific exhibited, everywhere, a shallow subsurface layer of Pu-rich water with its concentration maximum at about 465 m in 1974; over a large portion of the central North Pacific a second layer of Pu-labelled water, less concentrated than the shallow layer, lay just above the bottom. Similar features were not observed in the case of¹³⁷Cs.The inventories of both Pu and¹³⁷Cs in the water column at most 1974 stations are substantially greater than those to be expected from world-wide fallout alone; these inventory excesses appear to be attributable to close-in fallout, but only if the ratio Pu/¹³⁷Cs in this source was much higher than in world-wide fallout. The North Pacific mean ratio of the inventories is 2.2 times that observed in world-wide fallout.Resolubilization of Pu both from sinking particles and from sediments explains peculiarities of its depth distributions.There is little evidence for tracer movement by sliding downward along density surfaces;¹³⁷Cs appears to have moved to depth by downmixing at the edge of the Kuroshio, and then moved horizontally and upward alongσ_t contours. The shallow Pu-rich layer shows no coordination with density, salinity or O₂ isopleths. The deep Pu-rich layer is restricted to a narrow range of O₂ concentrations that confirm its origin in the Aleutian Trench and rapid spread southward and laterally. Near-bottom circulation processes have been much more active than here-to-fore described.  相似文献   

Vertical coherence and phase delay between wind components in strong winds below 20 m     

A. J. Bowen  R. G. J. Flay  H. A. Panofsky 《Boundary-Layer Meteorology》1983,26(4):313-324

Vertical coherence and phase delay between wind components in strong winds in the lowest 20 m over uniform terrain in New Zealand have been analysed. The vertical decay constants and slopes for the horizontal wind components could be described as linear functions of the ratio of vertical spacing to mean height (δz/z), with relatively little scatter. The decay constants for the lateral were smaller than for the longitudinal components, the slopes larger for the lateral components, as found previously. The coherence of vertical velocity is best described by exponential decay functions multiplied by a parameter which decreases linearly from 1 (for δz/z=0) to 0.5 (for δz/z=1). The decay constants increased linearly with δz/z, as in the case of the horizontal components. There were no significant phase differences for the vertical components. Lateral and vertical decay constants for the longitudinal wind component could be fitted to identical functions of δy/z and δz/z, respectively.  相似文献   

Stratigraphic Framework of the Cryogenian in China     

YU Yang  YE Qin  ZHANG Kexin  HE Weihong  SONG Bowen  XU Yadong  KOU Xiaohu  WANG Jiaxuan  YANG Fengli 《《地质学报》英文版》2020,94(4):942-971

The Cryogenian is a critical period in the history of the Earth. It is marked by multiple extreme climate changes that caused alternating global glacial and interglacial intervals. These dramatically changed the sedimentary system, and metal ores and source rocks distributed widely during this period. Therefore, studying the Cryogenian stratigraphic framework and sedimentary basins is important to improve the stratigraphic resolution for metal mineral and hydrocarbon prospecting and exploration in China. This review paper firstly divides three tectonic-stratigraphic regions in China in the Cryogenian, including the tectonic-stratigraphic regions of Great South China, Xingmeng-Tarim, and North China. Secondly, geochronologic data and geological records are combined to clearly depict the Cryogenian sedimentary sequence of continental blocks and micro-continental blocks in different tectonic-stratigraphic regions. The results were used to propose a new comparison scheme of stratigraphy for the Cryogenian in China. Finally, according to differences of sedimentary evolution and tectonic evolvement, sedimentary basins and their lithofacies paleogeography are identified and summarized, respectively.  相似文献   

大火成岩省的类型、成因及其地球系统意义     

张招崇  朱江  程志国  魏博雯  侯通  张宏罗  谢秋红 《地质学报》2022,96(12):4057-4090

大火成岩省指的是板块内部在相对短的时间间隔内(通常＜3 Ma)巨量的岩浆喷发和侵入形成的火成岩省(面积超过10. 5 km. 2，体积超过10. 5 km. 3)。自此概念提出至今，在许多方面都取得了重要进展，但对于其成因以及对大陆裂解、物质循环、环境效应、生物灭绝等方面还存在着诸多争论。本文在回顾大火成岩省定义及其演变的基础上，对上述问题进行了全面的讨论，内容包括：① 镁铁质大火成岩省(MLIP)成因的地幔柱模型及其存在的问题；② 水在MLIP形成过程中的作用；③ MLIP成因的其他替代模型；④ 硅质大火成岩省(SLIP)的成因及其与MLIP之间的关系；⑤ 大火成岩省和超大陆裂解之间的耦合关系；⑥ 大火成岩省与碳、硫循环及其对全球环境和生物大规模绝灭的影响；⑦ 大火成岩省与全球海平面升高、温室效应以及大洋缺氧事件的关系；⑧ 大火成岩省的地表地形效应。最后提出了大火成岩省研究中有待解决的几个重要问题和可能的解决思路。  相似文献