土地开发整理对区域环境潜在影响估算——以河北省为例   总被引：1，自引：0，他引：1  

刘浩杰  刘宏娟  元媛  刘慧涛  谭莉梅  刘金铜 《地域研究与开发》2013,32(1):117-122

土地开发整理在提高区域经济产出及保障水平的同时也必将对区域生态环境造成影响。以河北省耕地后备潜力为基础,运用市场收益法和修正后的生态系统服务功能价值评估法,从区域角度对河北省各类型区(坝上高原区、山地丘陵区、平原区、滨海区)土地开发整理的潜在经济、生态环境影响进行了估算。结果表明:全部开发河北省耕地后备潜力,需投资432.7亿元,经济收益58.4亿元/a,静态投资回收期为7.4 a;而生态系统服务功能损失9.4亿元/a。耕地潜力全部开发,坝上高原区、山地丘陵区、平原区、滨海区将分别产生经济和生态效益0.7亿元/a,8.7亿元/a,33.4亿元/a,6.2亿元/a。其中,生态系统服务功能价值坝上高原区增加0.2亿元/a,山地丘陵区、平原区、滨海区分别损失0.7亿元/a,8.5亿元/a,0.4亿元/a。因此,河北省未来土地开发整理的重点方向是平原区和山地丘陵区,并且需要大力加强生态环境建设。  相似文献   

中国大陆及边邻地区6 级以上地震序列的最大余震统计特征     

任雪梅  谭俊林  马禾青  曾宪伟 《中国地震》2013,29(4):480-488

依据1966 年以来中国大陆及边邻地区记录相对完备的6 级以上地震序列资料,统计研究了地震的破裂类型和不同破裂类型下余震序列特征等,得到了不同破裂类型下不同余震序列比例和优势分布、主震震级与最大余震震级差的经验关系。主震与最大余震的震级关系线性较好,得到的经验公式可以为中国大陆及边邻地区同类地震的最大余震震级判定提供参考;最大余震发生在主震后10 天内的比例为43. 8% ～ 81. 8% ,正断型和走滑型中的孤立型的最大余震发生在主震后10 天内的比例高达80% 。  相似文献   

新疆地震烈度衰减关系模型参数拟合   总被引：1，自引：0，他引：1  

谭明  李帅  孙静  王伟  唐丽华  吴传勇 《中国地震研究》2013,27(2):261-268

By using the existing historical earthquake investigation data in Xinjiang,this paper obtained the envelope curves of isoseismal maps of 103 destructive earthquakes occurring from 1716 to 2010 after digitization of the data. The author summarized the seismic intensity attenuation laws in the Xinjiang region with the multiple regression fitting method. The intensity attenuation function of the elliptical model was provided and the fitting results in different periods and areas were compared. Finally, the intensity attenuation relationship in the Xinjiang region was obtained by the method of constraining the start and end of the attenuation curves.  相似文献   

Thorium(IV) removal from aqueous medium by citric acid treated mangrove endophytic fungus Fusarium sp. #ZZF51     

S.K. Yang  N. Tan  X.M. Yan  F. Chen  W. Long  Y.C. Lin 《Marine pollution bulletin》2013

Thorium(IV) biosorption is investigated by citric acid treated mangrove endophytic fungus Fussarium sp. #ZZF51 (CA-ZZF51) from South China Sea. The biosorption process was optimized at pH 4.5, equilibrium time 90 min, initial thorium(IV) concentration 50 mg L⁻¹ and adsorbent dose 0.6 g L⁻¹ with 90.87% of removal efficiency and 75.47 mg g⁻¹ of adsorption capacity, which is obviously greater than that (11.35 mg g⁻¹) of the untreated fungus Fussarium sp. #ZZF51 for thorium(IV) biosorption under the condition of optimization. The experimental data are analyzed by using isotherm and kinetic models. Kinetic data follow the pseudo-second-order model and equilibrium data agree very well with the Langmuir model. In addition, FTIR analysis indicates that hydroxyl, amino, and carbonyl groups act as the important roles in the adsorption process.  相似文献   

汶川M_S8.0、 海地M_W7.0地震 电磁信号小波能谱分析   总被引：2，自引：0，他引：2       下载免费PDF全文

解滔  杜学彬  刘君  范莹莹  安张辉  陈军营  谭大诚 《地震学报》2013,35(1):61-71

应用小波变换方法处理了2008年汶川M_S8.0地震前后成都、 江油台地电阻率观测数据及汶川地震、 2010年海地M_W7.0地震前后DEMETER卫星记录的电离层磁场观测数据, 研究了地电阻率和电离层磁场的小波能谱及其相对变化.结果表明: ① 对应汶川大震前成都台N58°E测道地电阻率中期下降变化和短期上升变化的时段, 地电阻率小波能谱相对变化显著增大, 江油台N10°E测道地电阻率在主震前记录到了临震异常, 在临近主震前后, 电离层磁场特别是x分量的能谱及相对变化显著增大, 展现了与汶川大震明显对应的地电阻率、 电离层磁场变化的似同步异常; ② 在海地地震前夕, 电离层磁场x, z分量的能谱也出现了显著增大的现象, 类似于汶川大震前后电离层磁场的能谱增大变化.   相似文献   

An individual cognitive evacuation behaviour model for agent-based simulation: a case study of a large outdoor event     

Lu Tan  Lei Wu 《International journal of geographical information science》2013,27(9):1552-1568

Route selection is a complex issue in simulating the pedestrian’s walking behaviour during the evacuation. In many current studies, the agent-based model has been widely used to simulate the individualized behaviour, and growing concern is given to the cognitive aspects in route selection. However, the influence of incomplete spatial knowledge and the preferences for different routing strategies has not been fully considered. To represent more reliable route choice by different pedestrians, this study presents an individual cognitive evacuation behaviour model which is mainly focusing on the individual differences in routing strategy and spatial knowledge. The model consists of two major components, namely the multiple routing strategies and personalized spatial cognitive road network. Based on a review of the previous studies, the potential factors that may affect the evacuation behaviour were discussed. The quantitative relationships between these potential factors and the pedestrian’s routing preference, as well as the possibilities of recognizing different roads, were explored using the regression method. As a case study, the proposed model was implemented using the data collected from a field survey of a real outdoor event. When applied in an agent-based simulation, the implemented model will support more reliable simulation of route choices corresponding to the pedestrians’ behaviour in the real event.  相似文献   

Study of Flare Energy Release Using Events with Numerous Type III-like Bursts in Microwaves     

N. S. Meshalkina  A. T. Altyntsev  D. A. Zhdanov  S. V. Lesovoi  A. A. Kochanov  Y. H. Yan  C. M. Tan 《Solar physics》2012,280(2):537-549

The analysis of narrowband drifting of type III-like structures in radio bursts dynamic spectra allows one to obtain unique information about the primary energy release mechanisms in solar flares. The SSRT (Siberian Solar Radio Telescope) spatially resolved images and its high spectral and temporal resolution allow for direct determination not only of the source positions but also of the exciter velocities along the flare loop. Practically, such measurements are possible during some special time intervals when SSRT is observing the flare region in two high-order fringes near 5.7?GHz; thus, two 1D brightness distributions are recorded simultaneously at two frequency bands. The analysis of type III-like bursts recorded during the flare 14?April 2002 is presented. Using multiwavelength radio observations recorded by the SSRT, the Huairou Solar Broadband Radio Spectrometer (SBRS), the Nobeyama Radio Polarimeters (NoRP), and the Radio Solar Telescope Network (RSTN), we study an event with series of several tens of drifting microwave pulses with drift rates in the range from ?7 to 13?GHz?s^?1. The sources of the fast-drifting bursts were located near the top of a flare loop in a volume of a few Mm in size. The slow drift of the exciters along the flare loop suggests a high pitch anisotropy of the emitting electrons.  相似文献   

The impact of global cropland changes on terrestrial ecosystem services value, 1992–2015     

Li  Yuanyuan  Tan  Minghong  Hao  Haiguang 《地理学报(英文版)》2019,29(3):323-333

Journal of Geographical Sciences - From 1992 to 2015, ecological environment has been threatened by the changes of cropland around the world. In order to evaluate the impact of cropland changes on...  相似文献   

不同状态浒苔对东海原甲藻生长的影响     

林锟  杨雪  谭丽菊  王江涛 《海洋学报》2020,42(8):69-75

近年来富营养化等海洋污染现象日益加重，我国近海每年都会暴发浒苔绿潮和微藻赤潮现象。本文在实验室模拟条件下，研究了不同状态不同含量的浒苔（Ulva prolifera），即浒苔新鲜藻体、浒苔培养液和浒苔干粉末与东海原甲藻（Prorocentrum donghaiense）共培养时产生的竞争抑制作用。结果表明，浒苔新鲜藻体、浒苔培养液和浒苔干粉末在初始质量含量大于1 g/L的条件下都会对东海原甲藻产生抑制作用，浒苔干粉末的抑制强度远远超过浒苔培养滤液和浒苔新鲜藻体。在二者共培养时，出现了“低促高抑”的现象，即浒苔含量较低时会促进东海原甲藻的生长，而高含量的浒苔则抑制东海原甲藻的生长，且抑制作用随浒苔含量的升高而增大。浒苔对东海原甲藻的这种抑制作用，一方面可能来自于营养物质的竞争和消耗，另一方面可能来自于浒苔释放的化感物质对东海原甲藻产生的影响。利用浒苔对东海原甲藻的抑制作用，可为东海原甲藻赤潮的生物防治提供一种思路与方法。  相似文献   

Implementation of the parallel mean shift-based image segmentation algorithm on a GPU cluster     

Fang Huang  Yinjie Chen  Li Li  Ji Zhou  Xicheng Tan 《International Journal of Digital Earth》2019,12(3):328-353

The mean shift image segmentation algorithm is very computation-intensive. To address the need to deal with a large number of remote sensing (RS) image segmentations in real-world applications, this study has investigated the parallelization of the mean shift algorithm on a single graphics processing unit (GPU) and a task-scheduling method with message passing interface (MPI)+OpenCL programming model on a GPU cluster platform. This paper presents the test results of the parallel mean shift image segmentation algorithm on Shelob, a GPU cluster platform at Louisiana State University, with different datasets and parameters. The experimental results show that the proposed parallel algorithm can achieve good speedups with different configurations and RS data and can provide an effective solution for RS image processing on a GPU cluster.  相似文献