The Simulation of Orbit Decay of Double Neutron Star System PSR J1906+0746 by the Gravitational Wave Radiation     

Liu  Peng  Zhang  Cheng-Min  Li  Di  Yang  Yi-Yan  Zhang  Jie  Zhang  Jian-Wei 《Astronomy Reports》2019,63(12):1090-1094

With the discovery of the double neutron star (DNS) merger event GW170817 by LIGO, DNS systems have become one of the important candidates for gravitational wave (GW) observation. There are 19 DNS systems that have been discovered, and PSR J1906+0746 is the youngest DNS system with the age of about 0.1 Myrs. We simulate its orbital decay over its entire life by the GW radiation from the initial stage to the coalescence. For the DNS PSR J1906+0746, we obtain its initial orbital period of 3.99 hrs (3.98 hrs at present) with the nearly circular orbit, and the merger age of 3.18 × 10⁸ yr. At the last minute of coalescence, corresponding to the orbital radius change from 335 to 30 km, we present the GW frequency to be 30 and 1122 Hz, respectively. As a comparison, with the GW frequency from 45 to 450 Hz, the orbital radii of the source GW170817 correspond to 163 and 57 km, respectively.

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南海西缘新生代沉积盆地形成动力学探讨   总被引：8，自引：3，他引：5  

吴世敏  丘学林  周蒂 《大地构造与成矿学》2005,29(3):346-353

通过对南海西缘新生代沉积盆地伸展作用、沉降、构造变形等特征分析,检查印支地块多条近北西向走滑断裂时间、幅度等特征以及与盆地之间联系,结果表明印度-欧亚碰撞引起的逃逸作用与南海西缘新生代盆地没有直接的成因联系;两个与俯冲有关的不同扩张机制与南海西缘新生代盆地有成因联系,即(1)太平洋板块在古新世到始新世的滚动后退,太平洋-欧亚板块汇聚速率的降低驱使这些盆地产生初始伸展作用;(2)渐新世到中中新世古南海南倾俯冲板块的拖曳力,进一步驱使这些盆地的伸展及接着的南海扩张.  相似文献   

Time-Dependent Behaviour and Static Liquefaction Phenomenon of Sand   总被引：1，自引：0，他引：1  

Erdin Ibraim  Herve Di Benedetto  Thiep Doanh 《Geotechnical and Geological Engineering》2009,27(1):181-191

Recent laboratory and field experiments have confirmed that sand does indeed exhibit time-dependent behaviour. Based on these findings, it was considered necessary to revisit some of the published experimental results on the static liquefaction phenomenon of loose anisotropic Hostun RF sand. Time-dependency might have had a significant influence on the observed undrained response of anisotropic consolidated sand specimens. Specific triaxial tests have been performed and a qualitative analysis is presented in this paper. It is shown that, despite the differences on the anisotropic consolidation path employed, different specimens show qualitatively identical undrained responses if creep periods are performed at identical test stages or if the anisotropic consolidation takes place very slowly. With time, the undrained stiffness and strength are considerably improved and this may explain why the static liquefaction phenomenon is not as common in practice as could be predicted based on an instability line concept. Whereas the original instability line concept was developed independently of time-dependency, in field situations, the liquefaction resistance of the sand can increase with time.  相似文献   

基于不同积雪日定义的积雪资料比较分析   总被引：11，自引：4，他引：7  

安迪  李栋梁  袁云  惠英 《冰川冻土》2009,31(6)

利用天气现象定义与积雪深度定义两种方法对全国884个台站的积雪日资料进行统计处理, 分别整理出每一台站各个积雪年的积雪日数、积雪深度、 初终雪间隔日数3个要素的两套数据, 并进行对比分析. 结果表明: 在全国东部大部分地区及新疆地区, 两种数据差别不大, 但在东北及青藏高原两套数据的差别较大. 在积雪日数的比较中, 两种数据在东北及青藏高原的差别基本都在10 d以上, 积雪深度的差别在0.4 cm以上, 初终雪间隔日数的差别以青藏高原最明显, 大部分地区的差别在15 d以上, 甚至有达到30 d以上的区域. 对青藏高原东北边坡代表站的积雪平均值进行M-K突变检验发现, 积雪深度定义的积雪日数与间隔日数减少趋势略大于天气现象定义统计的数值;而在积雪深度的比较中则相反. 两种定义的积雪间隔日数均在1987年出现突变.  相似文献   

振冲碎石桩在龙头石水电站坝基加固中的应用          下载免费PDF全文

彭第  王伟  孟玉红  李静 《地质找矿论丛》2009,24(1):83-86

针对龙头石水电站坝基的深厚砂砾石地层.采用振冲碎石桩处理,通过检测,处理后的地基达到工程要求.并消除了液化,效果较好.  相似文献   

东天山秋格明塔什-黄山韧性剪切带特征与成矿综述     

郑镝  和志军  董少波 《矿产与地质》2009,23(2)

东天山"秋格明塔什-黄山韧性剪切带"是一条多期活动且持续时间很长的韧性剪切变形变质带,介于北部的康古尔塔格-黄山断裂和南部的雅满苏-苦水断裂之间。在研究其空间展布特征、变形组构、演化序列、力学性质、剪切位移量以及变形时代的基础上,对其与成矿的关系进行了初步探讨。  相似文献   

北阿尔金西段正长花岗岩和闪长岩地球化学、锆石U-Pb定年及Hf同位素特征     

郑坤  吴才来  魏春景  郜源红  郭文峰  陈红杰  吴迪  高栋 《岩石学报》2019,35(2):541-557

北阿尔金西段出露大量中酸性侵入岩,为探讨西段地区花岗质岩石的成因、形成环境以及北阿尔金地区岩浆活动特点,本文选取北阿尔金西段的正长花岗岩体和闪长岩体作为研究对象,进行了岩石学、地球化学、锆石U-Pb年代学及Hf同位素等方面的研究。研究结果表明,正长花岗岩体形成时代为495.7～502.0Ma,铝饱和指数A/CNK为0.86～1.09小于1.1,P_2O_5与Si O_2含量呈负相关,具I型花岗岩特征。轻稀土富集而重稀土亏损,具有明显的负Eu异常,微量元素特征显示富集Rb、Ba、Th、U、K等元素,相对亏损Nb、Ta、P、Ti等元素。岩石地球化学及锆石Hf同位素特征暗示其源区物质成分不均一,源岩主要为0.95～1.4Ga的新生地壳(变中基性岩),并有1.42～1.83Ga的古老地壳物质的参与。闪长岩体的侵位时代为497.1±3Ma,轻稀土富集而重稀土亏损,较弱的负Eu异常,相对富集Rb、Ba、Th、U、K等元素,而亏损Nb、Ta、P、Ti。锆石ε_(Hf)(t)值为-1.61～+2.16,二阶段模式年龄t_(DM2)为1.34～1.56Ga,暗示其源岩可能主要为新生地壳,并有古老地壳物质参与成岩。北阿尔金西段正长花岗岩、闪长岩均形成于早古生代,具弧型花岗岩特点,结合区域构造背景,认为其形成可能与北阿尔金洋壳俯冲有关,产于陆弧环境。  相似文献   

Late Cretaceous Adakitic Granites of the Southeastern Tibetan Plateau: Garnet Fractional Crystallization of Arc‐Like Magmas at the Thickened Neo‐Tethyan Continental Margin     

XIANG Kun  XUE Chuandong  YANG Tiannan  XIE Zhipeng  XIN Di  JIANG Lili  LAI Ruijuan 《《地质学报》英文版》2019,93(4):857-873

The tectonic setting of Cretaceous granitoids in the southeastern Tibet Plateau, east of the Eastern Himalaya Syntax, is debated. Exploration and mining of the Laba Mo–Cu porphyry-type deposit in the area has revealed Late Cretaceous granites. New and previously published zircon U–Pb dating indicate that the Laba granite crystallized at 89–85 Ma. Bulk-rock geochemistry, Sr–Nd isotopic data and in situ zircon Hf isotopic data indicate that the granite is adakitic and was formed by partial melting of thickened lower crust. The Ca, Fe, and Al contents decrease with increasing SiO2 content.These and other geochemical characteristics indicate that fractional crystallization of garnet under high-pressure conditions resulted in the adakitic nature of the Laba granite. Cretaceous granitoids are widespread throughout the Tibetan Plateau including its southeastern area, forming an intact curved belt along the southern margin of Eurasia. This belt is curved due to indenting by the Indian continent during Cenozoic, but strikes parallel to both the Indus–Yarlung suture zone and the Main Frontal Thrust belt. It is therefore likely that Cretaceous granitoids in both the Gangdese and southeastern Tibetan Plateau areas resulted from subduction of Neo-Tethyan lithosphere.  相似文献   

北阿尔金喀孜萨依二长花岗岩成因及其构造意义     

郑坤  吴才来  吴迪  高栋  陈红杰  徐楠 《地质学报》2019,93(10):2531-2541

喀孜萨依二长花岗岩出露于北阿尔金蛇绿混杂岩带北缘,为探讨其成因、源区特征及构造环境,本文对其进行了岩石学、锆石U-Pb定年、Hf同位素及岩石地球化学等方面的研究。研究结果表明,喀孜萨依二长花岗岩主要由石英、斜长石、钾长石、角闪石、黑云母等矿物组成,岩体侵位时代为425～423 Ma,铝饱和指数A/CNK为0.97～1.07,属弱过铝质钙碱性-高钾钙碱性岩石,P2O5与SiO2含量呈负相关,具I型花岗岩特征。轻稀土富集而重稀土亏损,Eu异常不明显,岩石富集Rb、Ba、Th、U、K等元素,相对亏损Nb、Ta、P、Ti等元素。锆石εHf(t)值为+2.65～+6.23,二阶段模式年龄tDM2为1015～1243Ma,其源岩主要来自新生地壳。结合区域构造背景,喀孜萨依二长花岗岩体可能形成于碰撞后伸展环境。  相似文献   

城市文化地图集设计的理论框架与实践案例     

苏世亮  吴林颖  杜清运  亢孟军  翁敏 《测绘科学》2021,46(7):145-152

针对当前学术界对城市文化地图集设计方法关注不足的局限性,该文以主题内容和表达策略为具体突破点,首先对城市文化地图集的概念进行了界定;进而提出了"意象"—"漫游"—"行走"的理论框架,并据此形成了城市文化地图集的设计理念和逻辑思路;以《漫步江城地图集》为实践案例,说明了主题内容选取和表达策略设置的原则、方法与过程,以期为城市文化地图集设计提供理论依据与实践参考.  相似文献