The effect of three-dimensional variational data assimilation of QuikSCAT data on the numerical simulation of typhoon track and intensity   总被引：4，自引：0，他引：4  

ZENG Zhihu  DUAN Yihong  LIANG Xudong  MA Leiming  Johnny Chung-leung CHAN 《大气科学进展》2005,22(4):534-544

In this paper, the three-dimensional variational data assimilation scheme (3DVAR) in the mesoscalemod el version 5 (MM5) of the US Pennsylvania State University/National Center for Atmospheric Research is used to study the effect of assimilating the sea-wind data from QuikSCAT on the prediction of typhoon track and intensity. The case of Typhoon Dujuan (2003) is first tested and the results show appreciable improvements. Twelve other cases in 2003 are then evaluated. The assimilation of the QuikSCAT data produces significant impacts on the structure of Dujuan in terms of the horizontal and vertical winds, sealevel pressure and temperature at the initial time. With the assimilation, the 24-h (48-h) track prediction of 11 (10) out of the 12 typhoons is improved. The 24-h (48-h) prediction of typhoon intensity is also improved in 10 (9) of the 12 cases. These experiments therefore demonstrate that assimilation of the QuikSCAT sea-wind data can increase the accuracy of typhoon track and intensity predictions through modification of the initial fields associated with the typhoon.  相似文献   

塔里木多旋回盆地复合构造样式初步分析   总被引：20，自引：10，他引：10  

何治亮  徐宏节  段铁军 《地质科学》2005,40(2):153-166

塔里木盆地多旋回的演化历史导致了多期次的复合构造变形作用。不同方式的构造运动导致了不同方式的复合,不同等级和不同规模的变形叠加导致了不同级次的复合构造。根据造成复合构造的应力场变化的特征,结合具体实例将塔里木盆地复合构造划分为8种主要类型:继承性挤压、继承性走滑、挤压--走滑、走滑--挤压、拉张--挤压、挤压--拉张、挤压--重力和重力--挤压复合构造。复合构造为油气运移提供了新的运移动力场及高效输导体系。构造复合一方面可能会加大早期构造的幅度并使其更为复杂,另一方面会导致各种圈闭更为复杂的平面组合与纵向叠置方式。构造复合对早期已聚集的油气存在一定的破坏作用,同时,由多油源、多期生烃、多通道、多圈闭类型和多成藏期组成的成藏条件也在复合构造中形成了以塔河--轮南特大型油气田为代表的复式油气聚集带。  相似文献   

塔里木盆地良里塔格地区奥陶系生物礁的沉积特征和成礁模式^*     

孟苗苗  樊太亮  卫端  王珊珊 《古地理学报》2018,20(2):175-190

塔里木盆地奥陶系生物礁储集层受到广泛关注。笔者优选塔里木盆地良里塔格地区奥陶系鹰山组顶部生物礁体(NYG-1)和一间房组底部生物礁体(NYG-2)为研究对象,通过详细的野外观察、实测和薄片鉴定,对生物礁的生物类型、岩性特征和沉积相单元进行分析。结果表明:塔里木盆地良里塔格地区鹰山组和一间房组的造礁生物主要由瓶筐石组成,与生物礁相关的岩性有障积礁灰岩、粘结礁灰岩、生屑粒泥灰岩、生屑泥粒灰岩、内碎屑泥粒灰岩、生屑颗粒灰岩、内碎屑颗粒灰岩和球粒颗粒灰岩。NYG-1礁体发育礁基、礁核、礁顶、礁翼和礁盖5个沉积相单元;NYG-2发育礁基、礁核与礁盖3个沉积相单元。从生物类型来看,鹰山组的礁为托盘—障积礁,为近似圆形的台内点礁,展布无明显的方向性;一间房组的礁为托盘障积—粘结礁,属台缘礁,常呈现出礁体迁移的特征。鹰山组和一间房组成礁模式的共同点是都经历了礁基的形成、礁体的发育和礁体的衰亡3个阶段,而差异主要表现在生物礁体的灭亡阶段: 对鹰山组生物礁而言,海平面的快速下降和高能水动力条件导致了瓶筐石的灭亡和内碎屑灰岩的产生;对一间房组生物礁而言,海平面的上升和浮游藻类生物大量发育造成造礁生物甁筐石的灭亡。以上研究对于建立符合塔里木盆地地区条件的礁体沉积模式和探索露头与井下生物礁对比研究有重要意义。  相似文献   

砾质辫状河型冲积扇沉积微相及沉积模式:以准噶尔盆地西北缘现代白杨河冲积扇为例^*          下载免费PDF全文

刘大卫  纪友亮  高崇龙  靳军  杨召  段小兵  桓芝俊  罗妮娜 《古地理学报》2018,20(3):435-452

冲积扇砂砾岩储集层具有相变快、连续性差等特点,显示冲积扇内部沉积环境的复杂性。本次研究以准噶尔盆地西北缘现代白杨河冲积扇为例,在丰富的野外露头资料基础上,结合区域水文资料以及冲积扇文献资料,对白杨河冲积扇沉积演化特征及沉积模式进行探讨。按其沉积机制,白杨河冲积扇属于辫状河型冲积扇,具有规模大(扇体总面积约327.6km²)、坡度平缓(约4‰~7‰)、沉积粒度粗和漫洪细粒沉积物不发育的典型特征。在白杨河冲积扇内共可识别出16种岩相类型,并根据岩相形成的流体动力差异划归为5类成因,即重力流成因、高流态牵引流成因、低流态牵引流成因、静水沉积成因以及风成沉积成因。白杨河冲积扇扇体建造过程可划分为洪水期和间洪期2个时期,洪水期以沉积作用为主,从扇根至扇缘依次发育扇根补给水道沉积、扇根片流沉积、扇中片流沉积、扇中辫状水道沉积、扇缘径流水道沉积和扇缘湿地沉积6种沉积微相类型;间洪期以改造作用为主,从扇根至扇缘依次发育扇根主槽沉积、扇中辫状沟槽沉积和扇缘湿地沉积3种沉积微相类型。最后,依据白杨河冲积扇建立了砾质辫状河型冲积扇洪水期和间洪期的沉积模式。  相似文献   

基于Poynting矢量的地震照明分析     

杨弘宇  刘继承  段玉波 《吉林大学学报(地球科学版)》2017,47(1)

地震照明分析能够定量分析影响逆时偏移成像质量的因素。文章基于Poynting矢量方法进行地震定向照明分析及成像补偿方法研究,利用Poynting矢量进行波场传播角度分解,通过计算不同入射及散射波方向的部分照明建立局部照明矩阵。该矩阵包含了照明分析中波与地质结构相互作用所涉及的所有角度信息,可以方便地分析目标附近所有可能的入射波和散射波对局部照明的贡献。根据局部照明矩阵可以获得对地下结构的照明描述、采集倾角响应,并依此进行成像补偿计算。以SEG/EAGE模型作为数值计算实例,进行基于Poynting矢量的照明分析及成像补偿,有效地提高了成像质量。该方法为角度域逆时偏移成像校正及分辨率分析等提供了高效的处理手段。  相似文献   

Coagulation performance and microstructural morphology of a novel magnetic composite coagulant for pre-treating landfill leachate     

Z. Liu  X. Duan  P. Zhan  R. Liu  F. Nie 《International Journal of Environmental Science and Technology》2017,14(11):2507-2518

A novel magnetic composite coagulant, prepared from nano-Fe₃O₄ and poly-aluminum chloride, was introduced to pre-treat mature landfill leachate. The coagulation performance of the coagulant as well as its microstructural morphology was discussed. Coagulation experimental results revealed that the coagulation performance of the landfill leachate using the new coagulant was better than that using poly-aluminum chloride alone, with COD and color removals above 60 and 68%, respectively. Based on the analysis of three-dimensional excitation–emission matrix spectrum, the fluorescence signals of treated leachate are totally reduced by the magnetic composite coagulant. The components of dissolved organic matters in the wastewater are removed in different degrees. Fourier transform infrared spectra analysis shows that the magnetic composite coagulant, which is a multi-core polymer with hydroxyl ligands and nano-Fe₃O₄, has a complex valence and crystal structure. Besides, X-ray diffraction pattern analysis indicates that the chemical composition of the magnetic composite coagulant is not changed significantly, which has comprehensively combined the chemical characteristics of both nano-Fe₃O₄ and poly-aluminum chloride, whereas the specific surface area of the novel magnetic composite coagulant effectively increased by nano-Fe₃O₄ particles under the analysis of scanning electron microscope spectral. The specific surface area analysis indicates that the magnetic composite coagulant is interconnected by narrow cracks and holes and has a high specific surface area and developed pore structure, which is also similar to the typical porous-type materials. Therefore, the nano-Fe₃O₄ compounded with poly-aluminum chloride leads to a larger specific surface, smaller average pore diameter, and more pore volume of the novel coagulant.  相似文献   

Combined spheropolyhedral discrete element (DE)–finite element (FE) computational modeling of vertical plate loading on cohesionless soil     

Christopher T. Senseney  Zheng Duan  Boning Zhang  Richard A. Regueiro 《Acta Geotechnica》2017,12(3):593-603

This paper presents a combined spheropolyhedral discrete element (DE)–finite element (FE) computational approach to simulating vertical plate loading on cohesionless soils such as gravels. The gravel particles are modeled as discrete elements, and the plate is modeled as a deformable FE continuum. The simulations provide a meaningful step toward better understanding how deformable bodies transmit loads to granular materials. The DE–FE contact algorithm is verified through comparison with an analytical solution for impact between two symmetric bars. A parametric study is conducted to ensure boundary effects are not significantly influencing the simulations. Numerical simulations are compared to experimental test results of lightweight deflectometer loading on a gravel base course with satisfactory agreement. Future developments of the approach intend to simulate wheel loading of military aircraft on unsurfaced airfields.  相似文献   

南秦岭竹溪县天宝乡粗面岩地球化学特征与铌成矿     

杨成  刘成新  刘万亮  万俊  段先锋  张众 《岩石矿物学杂志》2017,36(5):605-618

南秦岭造山带北大巴山东段大面积出露早志留世粗面岩,夹于早志留世梅子垭组(S_1m)下部层位含炭粉砂质板岩之中,整体呈北西-南东向展布。这套粗面质火山岩与铌矿关系密切。竹溪县天宝铌矿床产出于火山喷发沉积韵律的中下部层位,赋矿岩石以粗面质熔结凝灰岩为主。粗面质熔岩地球化学数据显示其富碱质,稀土元素总量高且轻稀土元素明显富集,高场强元素Nb、Ta、Zr、Hf等富集,Sr、P、Ti等亏损,具有类似于OIB的地球化学性质,来源于幔源玄武质岩浆的演化,是形成于大陆裂谷环境的低压型粗面岩。矿体粗面岩类(熔结凝灰岩)与非矿体粗面岩(粗面质熔岩)相比,具有略低的SiO_2含量,高的Al_2O_3、K_2O、CaO含量,低的P_2O_5含量,更为富集的高场强元素(Nb、Ta、Zr、Hf)和轻稀土元素(La、Ce),更强的负Eu异常、正Ce异常,略强的P、Ti负异常以及更高的挥发分(F、CO_2)含量。天宝铌矿含铌矿物为易解石,产出于早期矿物的边缘、裂隙或晚期细脉中,成矿阶段处于岩浆作用的晚期。铌的富集与挥发分(F、CO_2等)的运移、保存条件密切相关。该铌矿为火山岩型稀有金属矿床,兼具岩浆型和岩浆热液型矿床特征,与庙垭和杀熊洞铌-稀土矿床属同一成矿系列的不同类型矿床。  相似文献   

In situ major and trace element analysis of amphiboles in quartz monzodiorite porphyry from the Tonglvshan Cu–Fe (Au) deposit,Hubei Province,China: insights into magma evolution and related mineralization     

Deng-Fei?Duan  Shao-Yong?JiangEmail authorView author&#;s OrcID profile 《Contributions to Mineralogy and Petrology》2017,172(5):36

The Tonglvshan deposit is the largest Cu–Fe (Au) skarn deposit in the Edong district, which is located in the westernmost part of the Middle and Lower Yangtze River metallogenic belt, China. In this study, we performed a detailed in situ analysis of major and trace elements in amphiboles from the ore-related Tonglvshan quartz monzodiorite porphyry using electron microprobe (EMPA) analysis and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Two distinct populations of amphiboles, which can be distinguished by their aluminum content, are found in the quartz monzodiorite porphyry. The low-aluminum (Low-Al) amphiboles are subhedral or anhedral and formed at 46.3–73.5 MPa and 713–763 °C. In contrast, the high-aluminum (High-Al) amphiboles are euhedral and formed at 88–165 MPa and 778–854 °C. Some euhedral amphiboles are partially or completely replaced by Low-Al amphibole. The compositions of parental melts in equilibrium with the High-Al amphibole (Melt 1) and Low-Al amphibole (Melt 2) were computed by applying solid/liquid partition coefficients. This modeling shows that magma in equilibrium with High-Al amphibole (Melt 1) underwent 40% fractional crystallization of amphibole, plagioclase and apatite at a depth of ~5 km to evolve to magma in equilibrium with Low-Al amphibole (Melt 2). Copper enrichment occurred in the magma after undergoing fractional crystallization. The magma had a high oxygen fugacity, increasing from NNO + 1 (Melt 1) through NNO + 2 to HM (Melt 2), which could have prevented the loss of Cu (and possibly Au) to sulfide minerals during crystallization. Finally, the evolved magma intruded to shallower depths, where it presumably exsolved aqueous ore-forming fluids. Therefore, the large Cu–Fe–Au reserves of the Tonglvshan deposit can likely be attributed to a combination of controlling factors, including high oxygen fugacity, fractional crystallization, fluid exsolution, and a shallow emplacement depth.  相似文献   

The assessment of traffic accident risk based on grey relational analysis and fuzzy comprehensive evaluation method   总被引：1，自引：1，他引：0  

Yaolong Liu  Xiaoli Huang  Jin Duan  Huaming Zhang 《Natural Hazards》2017,88(3):1409-1422

The traffic accident risk includes three aspects, traffic accident probability, traffic accident severity, and traffic accident trend respectively. In this paper, nine indicators are selected to evaluate the traffic accident risk. The grey relational analysis method was used to determine the weights, and the fuzzy comprehensive evaluation method was used to calculate the risk. These methods were applied to assess the comprehensive risk of traffic accident in 31 provinces in China. The results show that the average value of traffic accident risk is 55.17. Nine provinces which are located in the northwest area and southeast area belong to the high-risk level. The medium-risk areas are widely distributed in the central, northeast, and southwest regions. The low-risk areas are Jilin, Neimenggu, Guizhou, and Beijing. The results have great significance for the measurement and management of regional traffic accident risk.  相似文献