基于谷歌地图的地震信息可视化应用     

许进  王晓明  王娟  李健  邱宏茂 《测绘通报》2013,(7):92-94,98

针对禁核试北京国家数据中心地震核查监测数据产品的需求,设计并实现基于Google Maps的动态实时更新的可视化地震信息系统,系统良好的扩展性保证了其可随应用而不断更新变化。  相似文献   

Assessing climate change impacts on the ecohydrology of the Jinghe River basin in the Loess Plateau,China     

Hui Peng  Yangwen Jia  Yaqin Qiu  Cunwen Niu  Xiangyi Ding 《水文科学杂志》2013,58(3):651-670

Abstract

Quantifying the impacts of climate change on the hydrology and ecosystem is important in the study of the Loess Plateau, China, which is well known for its high erosion rates and ecosystem sensitivity to global change. A distributed ecohydrological model was developed and applied in the Jinghe River basin of the Loess Plateau. This model couples the vegetation model, BIOME BioGeochemicalCycles (BIOME-BGC) and the distributed hydrological model, Water and Energy transfer Process in Large river basins (WEP-L). The WEP-L model provided hydro-meteorological data to BIOME-BGC, and the vegetation parameters of WEP-L were updated at a daily time step by BIOME-BGC. The model validation results show good agreement with field observation data and literature values of leaf area index (LAI), net primary productivity (NPP) and river discharge. Average climate projections of 23 global climate models (GCMs), based on three emissions scenarios, were used in simulations to assess future ecohydrological responses in the Jinghe River basin. The results show that global warming impacts would decrease annual discharge and flood season discharge, increase annual NPP and decrease annual net ecosystem productivity (NEP). Increasing evapotranspiration (ET) due to air temperature increase, as well as increases in precipitation and LAI, are the main reasons for the decreasing discharge. The increase in annual NPP is caused by a greater increase in gross primary productivity (GPP) than in plant respiration, whilst the decrease in NEP is caused by a larger increase in heterotrophic respiration than in NPP. Both the air temperature increase and the precipitation increase may affect the changes in NPP and NEP. These results present a serious challenge for water and land management in the basin, where mitigation/adaption measures for climate change are desired.

Editor Z.W. Kundzewicz; Associate editor D. Yang

Citation Peng, H., Jia, Y.W., Qiu, Y.Q., and Niu, C.W., 2013. Assessing climate change impacts on the ecohydrology of the Jinghe River basin in the Loess Plateau, China. Hydrological Sciences Journal, 58 (3), 651–670.  相似文献   

Editorial—The 3rd International Workshop on Modeling the Ocean (IWMO 2011)     

Lie-Yauw Oey  Tal Ezer  Bo Qiu  Jarle Berntsen  Ruoying He 《Ocean Dynamics》2013,63(2-3):307-309

  相似文献   

基于OMR的2．16米望远镜积分视场单元方案   总被引：1，自引：0，他引：1  

高东洋  赵飞  邱鹏  姜晓军 《云南天文台台刊》2012,(2):143-149

基于积分视场单元的三维成像光谱技术日趋成熟,并且与传统的狭缝光谱仪相比有许多明显的优势。2．16m望远镜的OMR光谱仪是采用平面光栅分光的低色散卡焦光谱仪器,可以考虑对其进行积分视场单元的升级优化。在不改变OMR光谱仪自身结构,不影响现有功能的同时,利用“微透镜阵列＋光纤束”的技术可以实现积分视场单元与OMR光谱仪的耦合。设计了两种方案,给出了升级积分视场单元后的空间分辨率和视场。  相似文献   

捕捞和气候变化在南海北部湾口鱼类长期种类演替和种群动态的作用   总被引：2，自引：0，他引：2  

王雪辉  邱永松  杜飞雁  刘维达  孙典荣  陈骁  袁蔚文  Chen Yong 《海洋学报(英文版)》2019,38(10):1-8

捕捞压力在改变南海鱼类种类演替和生物量波动方面所起的作用大于气候和环境因素是一个普遍的、有争议的假设。根据1959~2010年南海北部北部湾口底拖网的调查数据，报告了该海域鱼类种类组成、优势类群的丰度比例、生物量的季节和年际变化。建立了鱼类生物量与捕捞压力和气候变化外部因素之间的广义加性模型。结果表明，捕捞压力驱动底层渔业资源急剧下降的主要因素，并随着时间的推移，高值鱼类被低值鱼类所取代。1993年和1998年期间鱼类生物量的突然减少与同期厄尔尼诺事件相对应，气候变化可能是渔业拖网捕捞中中上层鱼类比例变化的主要驱动因素。为了更好地了解鱼类群落动态，需要区分捕捞压力和环境驱动因素对不同生活史策略鱼类物种的影响。  相似文献   

1960—2014年广东省干旱时空演变特征     

王水寒  邱建秀  王大刚 《热带地理》2020,40(2):357-366

利用1960—2014年广东省24个气象站点的逐日降水资料,采用下次降水平均等待时间（Average Waiting Time for Precipitation, AWTP）计算得到的相当干期（Equivalent Dry Period, EDP）指数分析了广东省1960—2014年的干旱时空特性,重点分析其自21世纪以来的干旱时空演变趋势。结果表明：EDP指数能够较好地适用于本研究区。从空间分布上看,广东省干旱大致呈现自西向东、自北向南逐渐加重的空间分布格局,东南部沿海地区干旱程度较粤北和粤西地区更为严重。1960—2014年广东省干旱有明显的年代际的变化特征,且干旱程度存在显著的逐年加重趋势。此外,广东省存在典型的季节性干旱,秋旱和冬旱频发,其次是春旱;各季的干旱中心位置有所不同。21世纪以来广东省干旱的发生频率、强度和影响面积都远超20世纪后半叶。具体而言,进入21世纪,珠三角东部东源站和粤西云浮市罗定站的EDP值明显增高,成为广东省新的干旱中心。从季节性干旱的角度分析,21世纪以来,秋季与冬季的旱情加剧最为严重并向全省蔓延,秋、冬季EDP值在21世纪初期相对20世纪后半叶的增幅都为23%。春旱则是逐年缓慢加重,夏旱在1960—2014年较少,但进入21世纪后广东省夏旱也呈现频发的态势。  相似文献   

Numerical Investigation on Vortex-Induced Rotations of A Triangular Cylinder Using An Immersed Boundary Method     

Wang  Hua-kun  Yan  Yu-hao  Chen  Can-ming  Ji  Chun-ning  Zhai  Qiu 《中国海洋工程》2019,33(6):723-733

A numerical study of vortex-induced rotations(VIRs) of an equivalent triangular cylinder, which is free to rotate in the azimuthal direction in a uniform flow, is presented. Based on an immersed boundary method, the numerical model is established, and is verified through the benchmark problem of flow past a freely rotating rectangular body.The computation is performed for a fixed reduced mass of m~*=2.0 and the structural stiffness and damping ratio are set to zero. The effects of Reynolds number(Re=25-180) on the characteristics of VIR are studied. It is found that the dynamic response of the triangular cylinder exhibits four distinct modes with increasing Re: a rest position,periodic rotational oscillation, random rotation and autorotation. For the rotational oscillation mode, the cylinder undergoes a periodic vibration around an equilibrium position with one side facing the incoming flow. Since the rotation effect, the outset of vortex shedding from cylinder shifts to a much lower Reynolds number. Further increase in Re leads to 2 P and P+S vortex shedding modes besides the typical 2 S pattern. Our simulation results also elucidate that the free rotation significantly changes the drag and lift forces. Inspired by these facts, the effect of free rotation on flow-induced vibration of a triangular cylinder in the in-line and transverse directions is investigated. The results show that when the translational vibration is coupled with rotation, the triangular cylinder presents a galloping response instead of vortex-induced vibration(VIV).  相似文献   

一种格网树与KD树组合的水深数据索引方法     

陈秋  贾帅东  刘现鹏 《海洋测绘》2019,39(5):18-20

针对当前构建高精度数字水深模型中常用的格网数据索引方法,在海量数据管理中存在因树的规模限制而导致检索效率低的问题,提出了一种格网树与KD树(K-Dimension,KD)组合的水深数据索引方法。首先,利用格网将水深源数据分割为网状的数据块,构建出数据块的格网树;其次,构建各数据块的KD树,实现对数据块中任意数据的快速索引;最后,通过快速定位数据块,查找其所在KD树的位置,实现对海量数据的快速检索。实验结果表明:①与格网树相比,本文所提组合检索方法的检索效率随检索树规模的变化不明显;②在相同的数据量下,组合树的检索效率要普遍高于格网树方法。  相似文献   

A Method of Estimating the [α/Fe] Ratios from Low-resolution Stellar Spectratwo     

Lu Yu  Li Xiang-ru  Lin Yang-tao  Qiu Kai-bin 《Chinese Astronomy and Astrophysics》2019,43(2):237-251

A method for the determination of [α/Fe] from low-resolution stellar spectra is presented. The proposed scheme includes the following three steps: firstly, the spectrum is decomposed by the multi-scale Haar wavelet, and the high-frequency components are removed to suppress the high-frequency noise; then, based on the correlation of the spectral data component with [α/Fe], the spectral features are selected by the LASSO (Least Absolute Shrinkage and Selection Operator) algorithm; finally, [α/Fe] is measured by the multiple linear regression method based on the MARCS stellar spectrum library. The effectiveness of the method is verified with the low-resolution stellar spectra of ELODIE, SDSS (Sloan Digital Sky Survey), LAMOST (Large Sky Area Multi-Object Fibre Spectroscopic Telescope), and four star clusters. The systematic deviations and accuracies are as follows: (0.04 dex, 0.064 dex) for the 317 ELODIE spectra; (0.16 dex, 0.065 dex) for the 412 SDSS spectra; (0.05 dex, 0.062 dex) for the 1276 LAMOST spectra (with the signal-noise ratio in the g band (SNRG) greater than 20). The averages of [α/Fe] obtained for the likely members of the globular star clusters (M13, M15) and open star clusters (NGC2420, M67) are in agreement with the literature values.  相似文献   

Preservation of Lipid Molecular Fossils in the Sediments from an Oil-Gas Releasing Zone in the South China Sea     

Hong Qiu  Li Zou  Minsheng Zhang  Chaoqi Zhu  Yonggang Jia 《中国海洋大学学报(英文版)》2018,17(6):1336-1342

In order to explore the standing stock and preservation of organic carbon, different forms of compound specific lipids were analyzed, based on a 1.8 m sediment core collected in the northern continental shelf of South China Sea in May, 2016. In the core sediments, 21 species of fatty acids, 6 species of alcohols, 8 species of sterols and phytol were detected. Fatty acids were dominated components with the percent of 67%–91% in the total lipids, in which saturated fatty acid C16:0 accounted for about 50%. The contents of lipid species generally decreased from the sediments at surface to those deep, except alcohols waving in a certain range at the same time. Fatty acids primarily existed in free form, followed by base hydrolytic form, and then acid hydrolytic form. Free alcohols were obviously dominated, while base and acid hydrolytic forms contributed small comparably. Phytol gave a significant priority to base hydrolytic form, while acid hydrolytic form could be neglected. Similar to phytol, sterols mostly presented in base hydrolytic form, and then in free form. The compositions of lipids and their forms suggested that organic carbon basically originated from primary production in upper waters in studying area, and were well preserved in the sediments.  相似文献