Genesis of the Late Mesozoic Great Xing’an Range Large Igneous Province in eastern central Asia: A Mongol–Okhotsk slab window model     

《International Geology Review》2012,54(13):1557-1583

The late Mesozoic Great Xing’an Range Large Igneous Province (XRLIP), with an area of >3 × 10⁵ km², is a prominent, enigmatic feature in eastern central Asia. The province is characterized by extensive within-plate magmatism, including a >4 km-thick sequence of volcanic rocks and voluminous plutons emplaced during an interval of ~40 million years from Late Jurassic through Early Cretaceous times (~150–110 Ma). The igneous activities are characterized by widespread adakitic rocks, alkalic basalts, and A-type granitoids with largely intraplate geochemical signatures, emplaced in a normal continental crustal setting. A Mongol–Okhotsk ridge subduction model is proposed for petrogenesis of the igneous rocks. Partial melting of young, hot, subducting oceanic slabs close to the ridge formed the adakitic rocks. A slab window that opened during ridge subduction triggered alkalic basaltic to A-type granitic and minor calc-alkaline magmas, as well as large-scale, metallogenic mineralization and subsequent basin formation.  相似文献   

海上高效侧钻小井眼水平井钻完井技术研究及应用          下载免费PDF全文

赵少伟  范白涛  岳文凯  李长林 《探矿工程》2016,43(3):13-18

通过对常规侧钻小井眼方案的分析对比,结合钻机作业能力提出了高效侧钻小井眼水平井钻完井技术,包括小井眼水平井钻进、防砂方式优选、油水层的封隔等技术。通过在QHD32-6F平台4口调整井的钻完井实施证明,该技术能有效降低小尺寸套管侧钻井作业难度,大大降低了钻完井的综合成本,为海上钻完井提速增效发挥了重要作用。该技术具有很好的应用前景。  相似文献   

羌塘盆地天然气水合物钻探试验井工程井壁稳定性分析   总被引：2，自引：0，他引：2       下载免费PDF全文

吴纪修  张永勤  梁健  李宽  李鑫淼  王汉宝 《探矿工程》2014,41(6):8-13

基于三维快速拉格朗日有限差分法多孔介质流固耦合理论及弹塑性极限平衡理论,根据羌塘盆地天然气水合物钻探试验井工程QK-2井实钻资料,分析在渗流条件下井壁失稳机理,并对失稳段井壁稳定性进行了数值模拟分析,研究在不同钻井液密度下井径周围围岩应力分布和井眼坍塌或拉裂变形规律,为羌塘盆地天然气水合物钻探试验井工程确定地层不坍塌（不缩径）、不压漏的钻井液安全密度窗口,以便为钻井井身结构设计及合理钻井液密度的确定提供依据。  相似文献   

东海黑潮上下游不同的涡动能季节变化特征及其产生机制     

王思雯  杨洋  梁湘三  赵宇慧  王长友 《海洋与湖沼》2022,53(2):278-294

用一种新的泛函工具——多尺度子空间变换(multiscale window transform,MWT),得到如实的东海涡动能分布,发现东海黑潮上下游区域的涡动能有着完全不同的季节变化特征.根据功率谱分析,东海黑潮流系可正交地重构到背景流尺度子空间(大于64 d)与涡旋尺度子空间(小于64 d),并用MWT得出相应子空...  相似文献   

Bounding the time delay between high-energy neutrinos and gravitational-wave transients from gamma-ray bursts     

Bruny Baret  Imre Bartos  Boutayeb Bouhou  Alessandra Corsi  Irene Di Palma  Corinne Donzaud  Vronique Van Elewyck  Chad Finley  Gareth Jones  Antoine Kouchner  Szabolcs Mrka  Zsuzsa Mrka  Luciano Moscoso  Eric Chassande-Mottin  Maria Alessandra Papa  Thierry Pradier  Peter Raffai  Jameson Rollins  Patrick Sutton 《Astroparticle Physics》2011,35(1):1-7

We derive a conservative coincidence time window for joint searches of gravitational-wave (GW) transients and high-energy neutrinos (HENs, with energies ?100 GeV), emitted by gamma-ray bursts (GRBs). The last are among the most interesting astrophysical sources for coincident detections with current and near-future detectors. We take into account a broad range of emission mechanisms. We take the upper limit of GRB durations as the 95% quantile of the T₉₀’s of GRBs observed by BATSE, obtaining a GRB duration upper limit of ∼150 s. Using published results on high-energy (>100 MeV) photon light curves for 8 GRBs detected by Fermi LAT, we verify that most high-energy photons are expected to be observed within the first ∼150 s of the GRB. Taking into account the breakout-time of the relativistic jet produced by the central engine, we allow GW and HEN emission to begin up to 100 s before the onset of observable gamma photon production. Using published precursor time differences, we calculate a time upper bound for precursor activity, obtaining that 95% of precursors occur within ∼250 s prior to the onset of the GRB. Taking the above different processes into account, we arrive at a time window of t_HEN − t_GW ∈ [−500 s, +500 s]. Considering the above processes, an upper bound can also be determined for the expected time window of GW and/or HEN signals coincident with a detected GRB, t_GW − t_GRB ≈ t_HEN − t_GRB ∈ [−350 s, +150 s]. These upper bounds can be used to limit the coincidence time window in multimessenger searches, as well as aiding the interpretation of the times of arrival of measured signals.  相似文献   

基于Landsat和Sentinel-2时间序列影像的海南西部橡胶林龙卷风灾情评估   总被引：1，自引：0，他引：1  

陈帮乾  云挺  安锋  寇卫利  李海亮  罗红霞  杨川  王琴飞  孙瑞  吴志祥 《遥感学报》2021,25(3):816-829

风害是影响中国天然橡胶产业发展最严重的自然灾害之一,它短时间内对橡胶林造成严重的物理伤害(大量落叶、枝条和主干折断等),严重影响后期生长和产量.传统地面调查虽然精度高,但耗时费力、经济成本高,利用遥感快速评估对指导灾后生产恢复、保险赔付和科学研究等具有重要意义.本研究以2019年8月1912号热带风暴“杨柳”在海南西部...  相似文献   

不同计算形式的相关分析在气象中的应用综述     

朱玉祥  江剑民  赵亮  刘海文  侯美亭  李宏毅  万文龙  赵翠光 《热带气象学报》2021,37(1):1-13

相关分析在气象科研和业务中具有广泛应用,是定量分析气象变量之间关系的重要工具.首先系统综述了气象科研与业务中不同计算形式的相关分析算法,然后重点阐述了相关分析在气象领域应用的最新进展,特别是全窗口滑动相关和相关系数的扫描式多尺度突变检测算法.接着介绍了大数据研究领域中新发展的相关分析算法,简析了其对气象相关分析的启示....  相似文献   

基于背景匀质性双边滤波的SAR图像斑点噪声抑制算法     

艾加秋  王非凡  杨兴明  史骏  刘凡 《遥感学报》2021,25(5):1071-1084

针对双边滤波在抑制SAR图像相干斑噪声的不足,本文提出了一种基于背景匀质性的改进双边滤波算法BH-IBF(Improved Bilateral Filtering algorithm based on Background Homogeneity),并将其应用于SAR 图像斑点噪声抑制.BH-IBF以传统双边滤波作为基...  相似文献