基于GPU加速的Boussinesq类波浪传播变形数值模型     

孙家文  朱桐  房克照  刘忠波 《海洋工程》2020,38(2):111-119

Boussinesq波浪模型是一类相位解析模型,在时域内求解需要较高的空间和时间分辨率以保证计算精度。为提高计算效率,有必要针对该类模型开展并行算法的研究。与传统的中央处理器(CPU)相比,图形处理器(GPU)有大量的运算器,可显著提高计算效率。基于统一计算设备架构CUDA C语言和图形处理器,实现了Boussinesq模型的并行运算。将本模型的计算结果同CPU数值模拟结果和解析解相比较,发现得到的结果基本一致。同时也比较了CPU端与GPU端的计算效率,结果表明,GPU数值模型的计算效率有明显提升,并且伴随数值网格的增多,提升效果更为明显。  相似文献   

Effect of different registration methods on precision of orientation based on RTK registration/georeferencing mode     

Shengming Hu  Zhijian Chen  Chenghui Wan  Chun Tang  Wen Xiong 《Marine Georesources & Geotechnology》2020,38(4):385-392

Abstract

Compared with traditional methods, the three-dimensional laser-scanning (3D-LS) technique can efficiently acquire many high-quality geometric properties of rock discontinuities. In practice, engineers usually prefer to simplify the processing by using single-station point data and roughly orienting owing to the complexity of registration/georeferencing multi-station point data. However, prior published studies have paid little attention to the accuracy and reliability when determining discontinuity orientations using 3D-LS. We propose a reliable and accurate method with robust on-site applicability. As part of an ongoing effort, we are evaluating the precision of the commonly used coarse registration method and the fine registration method, and promoted the optimized coarse- and fine-registration methods and evaluated their precision. It is found that: (1) the common and the optimized registration method can meet our project’s engineering requirements, and the optimized registration method improved accuracy in the dip direction by approximately 1°; (2) fine registration using an iterative closest point (ICP) algorithm can correct both dip direction and dip angle; and (3) the orientation is of high precision with commonly used coarse and fine registration, whereas the optimization effect to correct the orientation is slightly limited.  相似文献   

NaHSO3对两种微藻生长及胞外多糖和藻胆蛋白含量的影响     

梁英  闫译允  黄徐林  田传远  胡乃霞  王帅 《中国海洋大学学报(自然科学版)》2020,(1):21-29

本文研究了0.25~3 mmol/L浓度的NaHSO3对紫球藻(Porphyridium violaceum)和0.06~0.96 mmol/L浓度的NaHSO3对蓝隐藻(Chroomonas placoidea)的叶绿素荧光参数(PSII最大光能转化效率Fv/Fm、相对电子传递速率rETR、光化学淬灭qP、非光化学淬灭NPQ)、细胞密度、干重、胞外多糖和藻胆蛋白含量的影响。研究表明,较低浓度的NaHSO3对紫球藻和蓝隐藻的生长及活性物质积累有促进作用,2种微藻进行生长和活性物质积累的最适NaHSO3浓度分别为0.5和0.12 mmol/L,此条件下,实验结束时,2种微藻的Fv/Fm、rETR、qP、细胞密度、干重、胞外多糖和藻胆蛋白含量均达到最大值,显著高于对照组。其中,紫球藻的最终细胞密度、干重、胞外多糖和藻胆蛋白含量分别比对照组增加了36.0%、19.1%、71.8%和69.0%。蓝隐藻的上述参数在NaHSO3浓度为0.12 mmol/L时则比对照组增加了60.8%、45.4%、60.0%和53.1%。另一方面,NaHSO3浓度为2~3 mmol/L时显著抑制紫球藻生长及活性物质积累,NaHSO3浓度为0.48~0.96 mmol/L则不利于蓝隐藻生长及活性物质积累。研究结果表明,适合紫球藻和蓝隐藻生长及胞外多糖和藻胆蛋白积累的最佳NaHSO3浓度分别为0.5和0.12 mmol/L,该研究为2种微藻的开发利用提供了理论依据。  相似文献   

厚碳酸盐岩覆盖区RVSP三维地震勘探应用效果分析     

胡小鹏 《山东国土资源》2020,36(5):38-43

该文以中国南方一厚碳酸盐岩覆盖区的RVSP三维地震勘探实例,对RVSP三维地震勘探观测系统和数据采集参数的确定、地面等效处理和波场分离等关键处理技术及地质效果进行了阐述和分析,说明了RVSP在克服表浅层复杂地质条件及环境条件对资料的影响及提高地震资料的分辨率有其特定的优势,同时也提出了RVSP三维地震在采集和处理过程中的难点。  相似文献   

频率域海洋可控源电磁垂直各向异性三维反演   总被引：1，自引：0，他引：1       下载免费PDF全文

彭荣华  胡祥云  李建慧  刘亚军 《地球物理学报》2019,62(6):2165-2175

地层宏观电性各向异性会对可控源电磁响应产生重要影响.由于海底地层电性结构常表现为电导率各向异性，若仅对海洋可控源电磁（MCSEM）数据进行常规各向同性反演，有可能无法获得准确的反演解释结果，从而削弱MCSEM技术的可靠性.本文实现了电导率垂直各向异性（VTI）条件下频率域海洋可控源电磁数据三维反演算法.其中，三维正演采用基于二次场控制方程的交错网格有限体积法，并利用直接矩阵分解技术来求解离散所得的大型线性方程组，有利于快速计算多场源的响应.反演采用具有近似二次收敛性的高斯牛顿算法对目标函数进行最优化.最后，对具有VTI电性各向异性特征的盐丘构造模型的MCSEM合成数据分别进行了电导率各向同性和垂直各向异性三维反演，结果表明：各向同性三维反演算法无法对受VTI介质影响的MCSEM数据进行正确的反演解释，而垂直各向异性三维反演能够获得更为可靠的地下电阻率结构和异常体分布，展现出对海底电性各向异性结构更为优良的反演解释能力.  相似文献   

利用接收函数方法研究中国东北东南部地区不同构造体的地壳特征   总被引：3，自引：0，他引：3       下载免费PDF全文

李天觉  陈棋福 《地球物理学报》2019,62(8):2899-2917

基于我们布设的探测深俯冲的中国东北地震台阵NECsaids台阵和固定地震台长时段的观测记录及NECESSArray流动台阵共计152个台站数据提取得到的33752条P波接收函数，采用H-κ叠加分析和共转换点（CCP）叠加成像等方法进行统一分析处理，并汇集他人接收函数研究结果得到中国东北东南部地区迄今为止最高分辨率的地壳厚度和平均波速比分布图像.对中国东北东南部地区不同构造体的地壳特征综合分析研究表明：研究区不同陆块的地壳属性存在明显差别，张广才岭地块中南部的地壳厚度和波速比与华北克拉通东北缘相当，地壳厚度同地表地形之间显示有明显的正相关关系；松辽地块东南缘地壳最薄、波速比最高，地壳厚度同壳内波速比之间显示出明显的负相关关系；兴凯地块西部地区的地壳结构表现为稍厚的地壳厚度和研究区内最低的壳内波速比，其地壳厚度同壳内波速比之间亦显示出明显的负相关关系；佳木斯地块西南缘在具有"正常"的壳内波速比同时地壳最厚.研究区内的郯庐断裂带北延段在切穿其下Moho面的同时表现出南北分段的特征：北段（44.4°N—47°N）两分支之下的Moho面整体下凹，而南段（41.5°N—43.3°N）两分支之下的Moho面则整体上隆.长白山天池火山下方表现为Moho面下凹沉落及高壳内波速比特征，推测其壳内岩浆囊很可能存在于火山口东北隅至少10 km的范围内.  相似文献   

APPLYING 3D INVERSION OF SINGLE-PROFILE MAGNETOTELLURIC DATA TO IDENTIFY THE SHADE AND YUNONGXI FAULTS          下载免费PDF全文

JIANG Feng  CHEN Xiao-bin  DONG Ze-yi  CUI Teng-fa  LIU Zhong-yin  WANG Pei-jie 《地震地质》2019,41(6):1444-1463

Many synthetic model studies suggested that the best way to obtain good 3D interpretation results is to distribute the MT sites at a 2D grid array with regular site spacing over the target area. However, MT 3D inversion was very difficult about 10 years ago. A lot of MT data were collected along one profile and then interpreted with 2D inversion. How to apply the state-of-the-art 3D inversion technique to interpret the accumulated mass MT profiles data is an important topic. Some studies on 3D inversion of measured MT profile data suggested that 2D inversions usually had higher resolution for the subsurface than 3D inversions. Meanwhile, they often made their interpretation based on 2D inversion results, and 3D inversion results were only used to evaluate whether the overall resistivity structures were correct. Some researchers thought that 3D inversions could not resolute the local structure well, while 2D inversion results could agree with the surface geologic features much well and interpret the geologic structures easily. But in the present paper, we find that the result of 3D inversion is better than that of 2D inversion in identifying the location of the two local faults, the Shade Fault(SDF)and the Yunongxi Fault(YNXF), and the deep structures. In this paper, we first studied the electrical structure of SDF and YNXF based on a measured magnetotelluric(MT) profile data. Besides, from the point of identifying active faults, we compared the capacity of identifying deep existing faults between 2D inversion models and 3D models with different inversion parameters. The results show that both 2D and 3D inversion of the single-profile data could obtain reasonable and reliable electrical structures on a regional scale. Combining 2D and 3D models, and according to our present data, we find that both SDF and YNXF probably have cut completely the high resistivity layer in the upper crust and extended to the high conductivity layer in the middle crust. In terms of the deep geometry of the faults, at the profile's location, the SDF dips nearly vertically or dips southeast with high dip angle, and the YNXF dips southeast at depth. In addition, according to the results from our measured MT profile, we find that the 3D inversion of single-profile MT data has the capacity of identifying the location and deep geometry of local faults under present computing ability. Finally, this research suggests that appropriate cell size and reasonable smoothing parameters are important factors for the 3D inversion of single-profile MT data, more specifically, too coarse meshes or too large smoothing parameters on horizontal direction of 3D inversion may result in low resolution of 3D inversions that cannot identify the structure of faults. While, for vertical mesh size and data error thresholds, they have limited effect on identifying shallow tectonics as long as their changes are within a reasonable range. 3D inversion results also indicate that, to some extent, adding tippers to the 3D inversion of a MT profile can improve the model's constraint on the deep geometry of the outcropped faults.  相似文献   

CTS-1E、CMG-3ESPC-120型地震计工作参数对比分析     

段绍鑫  乌尼尔  李晓东  张森  张小飞 《地震地磁观测与研究》2019,40(4):120-124

CTS-1E型、CMG-3ESPC-120型地震计安装架设在库尔勒地震台小泉沟观测点同一台基上，均使用EDAS-24GN型数据采集器进行实时数据采集，对比分析观测数据波形特征、地动噪声功率谱及动态范围等，明确2套地震计在实际观测中的性能差异，以便为地震监测数据分析及相关研究提供参考。  相似文献   

Global Statistical Assessment and Cross-Calibration with Jason-2 for Reprocessed HY-2 A Altimeter Data     

Maofei Jiang  Ke Xu  Yalong Liu 《Marine Geodesy》2018,41(3):289-312

HY-2 A (Haiyang-2 A) satellite was launched on August 16, 2011 and radar altimeter is one of its main payloads. We reprocessed two years of HY-2 A altimeter sensor geophysical dataset records (SGDR) data. This paper presents the main results in terms of reprocessed HY-2 A altimeter data quality: verification of data availability and validity, monitoring several relevant altimeter parameters, and assessment of the HY-2 A altimeter system performances. A cross-calibration analysis of reprocessed HY-2 A altimeter data with Jason-2 was conducted. The reprocessed HY-2 A altimeter data show good quality and have a low level of noise with respect to Jason-2. The same geophysical correction methods were used to calculate the sea surface height (SSH) for the two missions. The mean standard deviations of the crossover differences for HY-2 A and Jason-2 are 5.24 cm and 5.34 cm, respectively. The mean standard deviation of the crossover differences between HY-2 A and Jason-2 is 5.37 cm. These show that HY-2 A can provide SSH measurements at almost the same level of accuracy as Jason-2. The relative SSH bias between HY-2 A and Jason-2 due to the Ultra Stable Oscillator (USO) drift is obviously observed, and it can affect the calculation of mean sea level and should be further studied and corrected.  相似文献   

两种造礁石珊瑚对海水酸化和溶解有机碳加富的响应*     

郭亚娟  周伟华  袁翔城  廖健祖  江雷  黄晖 《热带海洋学报》2018,37(1):57-63

文章选择鹿回头近岸海域常见的板叶角蜂巢珊瑚(Favites complanata)和十字牡丹珊瑚(Pavona decussata)为研究对象, 采用室内连续培养的方法, 探究两种不同造礁石珊瑚对酸化和溶解有机碳(DOC)加富的响应。结果表明: 酸化(pH 7.6)并不会影响两种珊瑚的钙化速率和生长速率; 但DOC加富(524.03±78.42μmol•L^-1)使两种珊瑚的钙化速率分别降低67%和47%、生长速率降低59%和40%。当二者共同作用时, 两种珊瑚的钙化速率降低30%和11%、生长速率降低46%和59%, 大多没有DOC单独作用时强烈, 表现出一定的拮抗作用。两种珊瑚共生虫黄藻叶绿素荧光指数(F_v/F_m)均升高后降低, 板叶角蜂巢珊瑚F_v/F_m最先降低。实验表明, 这两种珊瑚虽然对海洋酸化的敏感度不高, 但是对有机物加富有不同的响应, 板叶角蜂巢珊瑚更为敏感, 可能导致这两种珊瑚在未来环境变化中有不同命运。  相似文献