南海西南次海盆岩石圈结构及其地质意义          下载免费PDF全文

胡立天  张培震  郝天珧  徐亚 《地球物理学报》2019,62(9):3464-3481

南海地区岩石圈资料稀少,阻碍了其形成演化过程的研究.为此,本次研究结合大地热流、空间重力异常、高程、大地水准面和地震数据,在南海西南次海盆反演了两条2.5维岩石圈剖面.本次计算基于三种假设：岩石圈地幔的密度取决于岩石温度;研究区岩石圈处于热稳定状态;研究区处于重力均衡状态.在剖面A-E中,岩石圈底界面从珠江口盆地的105 km迅速抬升到西沙海槽处的50 km,在西沙海槽、西沙-中沙群岛和西南次海盆变化不大,为50~60 km.在剖面F-I中,岩石圈底界面从西沙群岛-中建地块处的88 km向海盆逐渐抬升,在西南次海盆处为46~50 km,到郑和隆起再逐渐变深至64 km.我们比较了西南次海盆岩石圈的冷却模型和热稳定模型,根据冷却模型由水深和热流数据所推断的西南次海盆年龄比实际年龄差很多,说明冷却模型不适用于西南次海盆.通过对比剖面A-E和剖面F-I,说明了剖面A-E经历了更长时间的拉伸,证明南海西南次海盆在形成演化过程中是从北东向南西逐步打开的渐进式扩张.最后,我们综合分析西南次海盆及其大陆边缘的岩石圈结构、减薄陆壳区范围、碳酸盐台地的分布、下地壳韧性流动、流变结构和沉积层特征等多方面资料,认为西南次海盆在形成演化过程中岩石圈地幔首先破裂而地壳后破裂,属于type Ⅱ型非火山型大陆边缘.  相似文献   

浅谈CSS在网站制作中的应用   总被引：3，自引：3，他引：0  

梁苑苑  王佳 《广东气象》2005,(1):46-46,45

随着互联网的蓬勃发展,信息技术的不断更新,各式各样的网站呈现在大家的眼前。但大部分用HTML做网站的人都曾经遇到过这样的问题：原本在自己的机器上排好版的网页,换到另外一台不同分辨率的显示器后就变了样,尤其是一部分字体变得很大,使原先设计的美观页面变了形。这是因为在网页文件中没有统一定义字体的大小。若每个文字都单独定义其大小,  相似文献   

First record of Biecheleria cincta (Dinophyceae) from Chinese coasts, with morphological and molecular characterization of the strains     

罗肇河  杨维东  徐斌  顾海峰 《中国海洋湖沼学报》2013,31(4):835-845

The presence of Biecheleria cincta (=Woloszynskia cincta) in the Chinese coasts is reported for the first time. In scanning electron microscope, three to five series of vesicles and an elongated apical vesicle (EAV) were visible in the epicone, and both the hypocone and the cingulum had three series of vesicles each. Thin sections revealed that B. cincta possesses stalked pyrenoids and an unusual eyespot consisting of a stack of cisternae with brick-like materials (type E), thus supporting its transfer from Woloszynskia to Biecheleria. Spiny cysts formed spontaneously in culture, with an encystment rate of around 20%. Both large subunit ribosomal DNA (LSU rDNA) and internal transcribed spacer region (ITS) sequences in 12 strains from the Chinese coasts were determined. Phylogenetic analyses based on LSU rDNA and ITS sequences using Bayesian inference and maximum likelihood revealed two distinct ribotypes (referred to as ribotype A and B) in B. cincta. ITS region pairwise distances within B. cincta ranged from 0.024 to 0.072, suggesting the existence of a complex of cryptic species.  相似文献   

Bromophenols from marine algae with potential anti-diabetic activities     

LIN Xiukun  LIU Ming 《中国海洋大学学报(英文版)》2012,11(4):533-538

Marine algae contain various bromophenols with a variety of biological activities,including antimicrobial,anticancer,and anti-diabetic effects.Here,we briefly review the recent progress in researches on the biomaterials from marine algae,emphasizing the relationship between the structure and the potential anti-diabetic applications.Bromophenols from marine algae display their hyperglycemic effects by inhibiting the activities of protein tyrosine phosphatase 1B,α-glucosidase,as well as other mechanisms.  相似文献   

Basic Types and Structural Characteristics of Uplifts: An Overview of Sedimentary Basins in China   总被引：4，自引：2，他引：2  

HE Dengf  LI Desheng  WU Xiaozhi  WEN Zhu 《《地质学报》英文版》2009,83(2):321-346

The uplift is a positive structural unit of the crust. It is an important window for continental dynamics owing to its abundant structural phenomena, such as fault, fold, unconformity and denudation of strata. Meanwhile, it is the very place to store important minerals like oil, natural gas, coal and uranium. Giant and large-scale oil and gas fields in China, such as the Daqing Oilfield, Lunnan-Tahe Oilfield, Penglai 19-3 Oilfield, Puguang Gas Field and Jingbian Gas Field, are developed mainly on uplifts. Therefore, it is the main target both for oil and gas exploration and for geological study. The uplift can be either a basement uplift, or one developed only in the sedimentary cover. Extension, compression and wrench or their combined forces may give rise to uplifts. The development process of uplifting, such as formation, development, dwindling and destruction, can be taken as the uplifting cycle. The uplifts on the giant Precambrian cratons are large in scale with less extensive structural deformation. The uplifts on the medium- and small-sized cratons or neo-cratons are formed in various shapes with strong structural deformation and complicated geological structure. Owing to changes in the geodynamic environment, uplift experiences a multi-stage or multi-cycle development process. Its geological structure is characterized in superposition of multi-structural layers. Based on the basement properties, mechanical stratigraphy and development sequence, uplifts can be divided into three basic types ? the succession, superposition and destruction ones. The succession type is subdivided into the maintaining type and the lasting type. The superposition type can be subdivided into the composite anticlinal type, the buried-hill draped type, the faulted uplift type and the migration type according to the different scales and superimposed styles of uplifts in different cycles. The destruction type is subdivided into the tilting type and the negative inverted type. The development history of uplifts and their controlling effects on sedimentation and fluids are quite different from one another, although the uplifts with different structural types store important minerals. Uplifts and their slopes are the main areas for oil and gas accumulation. They usually become the composite oil and gas accumulation zones (belts) with multiple productive formations and various types of oil and gas reservoirs.  相似文献   

科技论文数学公式中字体的用法     

《测绘学报》2013,(4):500

  相似文献   

《新疆地质》征稿简则     

《新疆地质》2012,(Z1):71

2来稿要求(1)论点明确,论据可靠,层次清楚,重点突出,各级标题简明扼要,文、图、表匹配得当,在国内外公开刊物未曾发表过,请勿一稿多投;(2)文稿一般不超过8000字,图幅(含照片)不超过5幅,最好提供彩色图;(3)用1986年10月国务院重新颁布的《简化字总表》规范字体编辑文稿和图表,提供电子  相似文献   

《新疆地质》征稿简则     

《新疆地质》2011,(1):119

1来稿要求(1)论点明确,论据可靠,层次清楚,重点突出,各级标题简明扼要,文、图、表匹配得当,在国内外公开刊物未曾发表过,请勿一稿多投;(2)文稿一般不超过8000字,图幅(含照片)不超过5幅,最好提供彩色图;(3)用1986年10月国务院重新颁布的《简化字总表》规范字体编辑文稿和图表,提  相似文献   

中国陆地海岸线尺度效应研究(英文)   总被引：2，自引：0，他引：2  

苏奋振  高义  周成虎  杨晓梅  费鲜芸 《地理学报(英文版)》2011,21(6):1101-1111

Spatial scale is a fundamental problem in Geography. Scale effect caused by fractal characteristic of coastline becomes a common focus of coastal zone managers and researchers. In this study, based on DEM and remote sensing images, multi-scale continental coastlines of China were extracted and the fractal characteristic was analyzed. The results are shown as follows. (1) The continental coastline of China fits the fractal model, and the fractal dimension is 1.195. (2) The scale effects with fractal dimensions of coastline have significant differences according to uplift and subsidence segments along the continental coastlines of China. (3) The fractal dimension of coastline has significant spatial heterogeneity according to the coastline types. The fractal dimension of sandy coastline located in Luanhe River plain is 1.109. The dimension of muddy coastline located in northern Jiangsu Plain is 1.059, while that of rocky coastline along southeastern Fujian is 1.293. (4) The length of rocky coastline is affected by scale more than that of muddy and sandy coastline. Since coastline is the conjunction of sea, land and air surface, the study of coastline scale effect is one of the scientific bases for the researches on air-sea-land interaction in multi-scales.  相似文献   

Study on scattering wave force of horizontal and vertical plate type breakwaters   总被引：1，自引：0，他引：1  

王科  张犀  高鑫 《中国海洋工程》2011,25(4):699-708

The interaction between wave and horizontal and vertical plates is investigated by the boundary element method,and the relations of wave exciting force with plate thickness,submergence and length are obtained.It is found that:1) The efficient wave exciting force exists while plate submergence is less than 0.5 m,and the plate is very thin with order O(0.005 m).2) The maximum heave wave exciting force exists,and it is the main factor for surface and submerged horizontal plate while the roll force can be ignored.3) The maximum sway wave exciting force exists,it is the main factor for surface or submerged vertical plate,and the roll force is about 20 times of horizontal plate.  相似文献