海表面温度时空变异特征及对验证误差影响     

蒋锦刚  徐曜  聂晨晖  潘骁骏  周斌 《遥感学报》2019,23(2):336-348

海洋要素的变化存在明显的区域性和季节性的变化特性,本文选择海洋要素中最为突出的海表面温度(SST)要素作为主要分析参数,设计时空变异参数的计算指标,分析时空变异对验证误差影响的关系,通过研究及试验的数据精度验证,证明了时空变异是造成误差的直接原因之一。强烈的时空属性变异,在验证过程中会引入很大的验证误差,处于不同变异等级区划的数据,其验证结果相对误差可达13.08%,变异越剧烈的区域,精度验证效果越差,验证误差就越大,这些误差并非完全是遥感产品的误差,验证结果不具有代表性,不能真实的反映遥感产品的误差特征。对于SST等海洋遥感产品验证时,需要考虑时空变异对验证误差的影响和贡献,合理选择验证试验区域、代表性的评价数据集和科学的评价方法。  相似文献   

A Preliminary Genetic Linkage Map of Sinonovacula constricta(Lamarck, 1818) Based on Microsatellites Derived from RAD Sequencing     

WU Xueping  FENG Yanwei  JIANG Hailin  LIU Xiangquan  PAN Ying 《中国海洋大学学报(英文版)》2018,(4)

Sinonovacula constricta is one of the important economic aquaculture species in China. In this study, we constructed genetic linkage maps of S. constricta based on 300 microsatellite markers derived from RAD-seq using an F1 full-sib family. The female map contained 204 microsatellites assigned to 22 linkage groups, which covered 1529.5 cM with an average interval of 10.3 cM. The male consisted of 187 microsatellites in 19 linkage groups corresponding to the haploid chromosome number(n(28)19), which spanned 1429.3 cM with an average interval of 8.7 cM. The genome coverage was approximately 83.5% and 81.4%, respectively. An integrated map was constructed according to the common markers in parental linkage groups, which had a total length of 1683.8 cM with an average interval of 7.3 cM. The genome coverage of the integrated map was approximately 86.3%. The genetic linkage map would form the foundation for further studies on the quantitative trait loci(QTL), as well as accelerating the breeding process of this species.  相似文献   

Levels of Metabolic Enzymes and Nitrogenous Compounds in the Swimming Crab Portunus trituberculatus Exposed to Elevated Ambient Ammonia-N     

PAN Luqing  SI Lingjun  LIU Shengnan  LIU Maoqi  WANG Guohui 《中国海洋大学学报(英文版)》2018,(4)

This study investigated the effects of ammonia-N(control and 1 and 5 mg L~(-1)) on the changes of metabolic enzymes activities and nitrogenous compounds levels in the gills, hepatopancreas, muscles, and hemolymph of the swimming crab Portunus trituberculatus. Results showed that the levels of hemolymph ammonia increased significantly at 6 h and then decreased to control level at 12 h. The activities of key enzymes involved in biosynthesis pathways of glutamine(Gln) and urea, such as glutamate dehydrogenase(GDH), glutamine synthetase(GS), and arginase(ARG), increased remarkably in different tissues of P. trituberculatus. Gln level was the highest in muscles, while urea content was the largest in hepatopancreas. The m RNA expression level of xanthine dehydrogenase(XDH) was downregulated sharply in gills but upregulated in the hepatopancreas and muscles. A small amount of uric acid was detected in the hemolymph. This result suggests that Gln in muscles may be used as an intermediary nitrogen repository, while urea may be primarily synthesized in the hepatopancreas and then transferred to other tissues via the hemolymph. Uric acid could be synthesized by the anabolism of purine nucleotides, in additon to the inhibitory activities of gills. In addition, the levels of Gln, urea and uric acid exhibited dose-and time-dependent effects with ammonia content. Therefore, P. trituberculatus could possibly convert ammonia into Gln, urea, or uric acid to detoxify ammonia during high ambient ammonia-N stress.  相似文献   

印度尼西亚北苏拉威西蓝碧海峡浮游动物种类组成及分布   总被引：1，自引：0，他引：1  

王彦国  陈小银  邢炳鹏  孙柔鑫  FITRIA Nurul  项鹏  王春光  林茂 《海洋学报(英文版)》2018,37(12):35-44

Based on oceanographic survey data in June 2012 in the Lembeh Strait, the zooplankton ecological characteristics such as species composition, individual abundance, dominant species and distribution were analyzed. The results showed that 183 species(including 4 sp.) had been recognized, most of them belonged to copepoda.Cnidaria followed with 43 species(including 1 sp.) were identified. The average abundance of zooplankton was(150.47±58.91) ind./m~3. As to the horizontal distribution, the abundance of the zooplankton was higher in the southern waters than in the northern waters. The dominant species in the study area were Lensia subtiloides,Sagitta enflata, Lucifer intermedius, Oikopleura rufescens, Diphyes chamissoni, Creseis acicula, Subeucalanus subcrassus, Temora discaudata, Aglaura hemistoma, Doliolum denticulatum, Canthocalanus pauper, Oikopleura longicauda and Nanomia bijuga. Zooplankton biodiversity indexes were higher in study area than previous study in the other regions. The findings from this study provide important baseline information for future research and monitoring programs.  相似文献   

Influence of a coarse interlayer on seawater intrusion and contaminant migration in coastal aquifers          下载免费PDF全文

Yi Liu  Xiaomin Mao  Jian Chen  D. A. Barry 《水文研究》2014,28(20):5162-5175

Vertical 2D slice laboratory experiments were carried out in homogenous and layered sand tanks to elucidate the effects of a highly permeable (coarse‐grained sand) interlayer on seawater intrusion and transport of contaminants to a coastal sea. Tidal fluctuations produced oscillations in the seawater–freshwater transition zone, fluctuations of the contaminant infiltration rate and a zigzag contaminant plume outline. The seawater wedge became discontinuous at the (vertical) edges of the interlayer because of increased lateral movement of the seawater–freshwater interface within the interlayer. The contaminant plume formed a tail within the interlayer depending on the tidal stage, and similar to the wedge, its movement was accentuated. A simple analytical model that neglected vertical flow reliably predicted steady‐state seawater intrusion into the coastal aquifer. Numerical modeling was used to gain insight into the groundwater hydrodynamics and contaminant migration. The numerical results confirmed the experimental findings, i.e. that a highly permeable interlayer can provide a rapid transit path for contaminants to reach the seaward boundary and that the interlayer amplifies the effects of tidal fluctuations, resulting in wider transition zones for the seawater wedge and contaminant plume. Numerical simulations further showed that, with increasing interlayer hydraulic conductivity, the maximum seawater intrusion distance inside the interlayer increases approximately linearly. For the fixed‐head contaminant injection condition used, the model showed that contaminant infiltration increases approximately logarithmically with increasing interlayer hydraulic conductivity (other factors held fixed). Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

Piecewise prediction model for watershed‐scale erosion and sediment yield of individual rainfall events on the Loess Plateau,China          下载免费PDF全文

Yu Guo‐Qiang  Zhang Mao‐Sheng  Li Zhan‐Bin  Li Peng  Zhang Xia  Cheng Sheng‐Dong 《水文研究》2014,28(21):5322-5336

Establishing a universal watershed‐scale erosion and sediment yield prediction model represents a frontier field in erosion and soil/water conservation. The research presented here was conducted on the Chabagou watershed, which is located in the first sub‐region of the hill‐gully area of the Loess Plateau, China. A back‐propagation artificial neural model for watershed‐scale erosion and sediment yield was established, with the accuracy of the model, then compared with that of multiple linear regression. The sensitivity degree of various factors to erosion and sediment yield was quantitatively analysed using the default factor test. On the basis of the sensitive factors and the fractal information dimension, the piecewise prediction model for erosion and sediment yield of individual rainfall events was established and further verified. The results revealed the back‐propagation artificial neural network model to perform better than the multiple linear regression model in terms of predicting the erosion modulus, with the former able to effectively characterize dynamic changes in sediment yield under comprehensive factor conditions. The sensitivity of runoff erosion power and runoff depth to the erosion and sediment yield associated with individual rainfall events was found to be related to the complexity of surface topography. The characteristics of such a hydrological response are thus closely related to topography. When the fractal information dimension is greater than the topographic threshold, the accuracy of prediction using runoff erosion power is higher than that of using runoff depth. In contrast, when the fractal information dimension is smaller than the topographic threshold, the accuracy of prediction using runoff depth is higher than that of using runoff erosion power. The developed piecewise prediction model for watershed‐scale erosion and sediment yield of individual rainfall events, which introduces runoff erosion power and runoff depth using the fractal information dimension as a boundary, can be considered feasible and reliable and has a high prediction accuracy. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

钢管脐带缆扭转平衡设计     

牛学超  祝庆斌  潘盼  邵鹏进  胡明  谢书鸿 《海洋工程》2020,38(6):151-157

钢管脐带缆包含多种螺旋缠绕的功能单元，其在外力载荷下会发生相对运动，而且钢管的刚度较大对扭转平衡有重要影响，因此，相对于普通电缆，钢管脐带缆在扭转平衡设计时更加困难。根据扭转平衡理论公式，采用控制变量法，以第二层铠装钢丝的绞合角度为变量进行扭转平衡设计。首先建立脐带缆缆芯有限元模型，对其施加拉伸载荷，结果显示缆芯出现了扭转，这证明不能将脐带缆缆芯视为一实心圆柱。其次建立不同绞合角度的脐带缆有限元模型，设置各功能单元的材料属性和摩擦系数，分析模型在拉伸载荷下的扭转角度，并将相同拉伸载荷下的扭转角度拟合为直线，从而得到钢管脐带缆在扭转平衡状态时的最优绞合角度。最后，采用试验方法对实物钢管脐带缆进行扭转平衡测试，测试结果显示在拉伸载荷下脐带缆单位长度扭转角度十分微小，这表明缆是扭转平衡的。因此验证了使用的有限元方法在钢管脐带缆扭转平衡设计中的有效性。  相似文献   

改进的小波阈值函数对变形监测数据的去噪研究     

甘若  陈天伟  郑旭东  段青达  潘梅 《大地测量与地球动力学》2020,40(1):17-22

基于小波分析中传统的阈值函数,结合其他学者提出的小波阈值函数,提出一种改进的小波阈值函数,并将其应用于变形监测数据的去噪处理。理论分析和算例表明,新的小波阈值去噪函数能够有效去除噪声。  相似文献   

GBW10010a大米标准物质复(研)制及数据特征     

杨榕  顾铁新  潘含江  刘妹  周国华 《岩矿测试》2020,39(6):866-877

随着我国对生态文明建设的重视，自然资源综合调查势在必行，对生物标准物质亦提出了新的需求。当前相关调研工作已经大面积开展，自然资源综合调查、农产品与食品安全评价都需要对生物样品元素组成进行准确测试，需要以生物标准物质作为生物成分测试量值比对和溯源的基础，因此对生物基体标准物质的需求量大幅增加。大米作为主要粮食之一，其食品安全日益受到重视，对大米中的化学成分进行准确的分析测试具有重要的现实意义，因而对大米标准物质的需求量尤为突出，但目前大米成分分析标准物质已供不应求。本文严格按照《标准物质定值的通用原则及统计学原理》（JJF 1343—2012）和《地质分析标准物质的研制》（JJF 1646—2017）等相关规范要求，开展了GBW10010a大米成分分析标准物质的复（研）制工作，包括样品采集、加工制备、均匀性检验、稳定性检验、多家实验室协作定值测试及不确定度评定等关键环节。结果表明：本次复（研）制的大米标准物质定值成分多样、量值准确可靠，符合国家一级标准物质的要求。GBW10010a共定值54项主微量元素，包括Ag、Al、As、B、Ba、Be、Bi、Ca、Cd、Ce、Co、Cr、Cs、Cu、Dy、Er、Eu、Fe、Gd、Ge、Hg、Ho、K、La、Li、Ho、Mg、Mn、Mo、N、Na、Nb、Nd、Ni、P、Pb、Pr、Rb、S、Sb、Sc、Se、Si、Sm、Sr、Tb、Th、Tl、Tm、U、V、Y、Yb、Zn，其中的39项元素给出了标准值及不确定度，包括Ag、Al、As、B、Ba、Ca、Cd、Ce、Co、Cs、Cu、Dy、Er、Fe、Hg、K、Li、Mg、Mn、Mo、N、Na、Nd、Ni、P、Pb、Pr、Rb、S、Sb、Se、Si、Sm、Sr、Tb、Tl、Y、Yb、Zn；15项元素提供参考值，包括Be、Bi、Cr、Eu、Gd、Ge、Ho、Ho、La、Nb、Sc、Th、Tm、U、V。与原有GBW10010大米标准物质相比较，GBW10010a中As、Cd、Co、Cr、Cu、Hg、Mn、Mo、Ni、Zn等重金属元素含量显著下降，其中Cd、Cu、Zn降幅较大，分别下降约39%、43%、38.7%，一定程度上反映了农田生态环境的改善。本批标准物质定值元素总数量增加了6项，新增定值元素Ag、Nb（Nb给出参考值），并且各项元素不确定度范围整体上有所缩小，如Al、Cd、Cu、Fe、K、Mg、Mo、Na、P、Pb、Se、Zn等对生物易有影响的重要元素，表明了地质分析测试方法技术的进步及定值水平的提高。本批标准物质定值元素涵盖了具有生物效应的大部分主微量元素，适用于农业生态环境地球化学调查与评价、生物样品测试、农产品质量与食品安全评价样品测试时的分析仪器校正、分析方法评价和分析质量监控等多个领域。  相似文献   

机载多光谱LiDAR的随机森林地物分类   总被引：1，自引：0，他引：1  

曹爽  潘锁艳  管海燕 《测绘通报》2019,(11):79-84

机载多光谱LiDAR技术利用激光进行探测和测距，不仅可以快速获取地面物体的三维坐标，还可以获得多个波段的地物光谱信息，可广泛用于地形测绘、土地覆盖分类、环境建模、森林资源调查等。本文提出了多光谱LiDAR的随机森林地物分类方法。该方法通过对LiDAR强度数据和高程数据提取分类特征，完成多光谱LiDAR的随机森林地物分类；并分析随机森林的特征贡献度特性，采用后向特征选择方法实现分类特征选择。通过对加拿大Optech Titan多光谱LiDAR数据的试验表明：随机森林方法可以获得较好的地物分类精度，而且可以适当地去除部分冗余和相关的特征，从而有效提高分类精度。  相似文献