Statistic characteristics of thermal structure in the southern Yellow Sea in summer   总被引：1，自引：0，他引：1  

白虹  胡敦欣  陈永利  王庆业 《中国海洋湖沼学报》2004,22(3):237-243

Based on the temperature data along 34°N, 35°N and 36°N sections in August from 1977 to 2003, the structure and formation of the Southern Yellow Sea Cold Water Mass (SYSCWM) and its responses to El Nino events are analyzed. Results show that: (1) There exist double cold cores under the main thermocline along the 35°N and 36°N sections. Also, double warm cores exist above the main thermocline along the 36°N section. (2) Thermocline dome by upwelling separates the upper warm water into two parts, the eastern and western warm waters. Additionally, the circulation structure caused by upwelling along the cold front and northeastward current along the coast in summer is the main reasons of double warm cores along the 36°N section. The intermediate cold water is formed in early spring and moves eastward slowly, which results in the formation of the western one of double cold cores. (3) Position of the thermocline dome and its intensity vary interannually, which is related to El Nino events. However, the  相似文献   

Land consolidation and eco-environmental sustainability in Loess Plateau: A study of Baota district,Shaanxi province,China     

Bai  Yu  Liu  Yansui  Li  Yuheng  Wang  Yongsheng  Yuan  Xuefeng 《地理学报(英文版)》2022,32(9):1724-1744

Journal of Geographical Sciences - Eco-environmental sustainability is the basis for sustainable development in ecologically fragile areas. Land consolidation plays an important role in...  相似文献   

PET FRP与混凝土界面黏结行为试验研究     

秦思颖  朱铮  白玉磊 《震灾防御技术》2021,16(4):717-727

通过双面剪切试验对24个试件进行高延性纤维增强复合材料（PET FRP）与混凝土界面黏结性能研究,研究参数包括FRP种类、FRP黏结厚度、黏结长度和黏结宽度;分析各参数对PET FRP与混凝土黏结性能的影响,基于试验结果评估现有黏结滑移关系模型,并进行模型修正。研究结果表明,在有效黏结长度内,随着黏结长度的增加,PET FRP与混凝土界面黏结强度增大;当超过有效黏结长度后,增加PET FRP黏结长度不能明显增加界面黏结强度,但可提高试件破坏的延性;增加PET FRP黏结宽度可提高界面黏结强度,但会受PET FRP黏结宽度和混凝土宽度比值的影响;当界面刚度接近时,碳纤维增强复合材料（CFRP）与混凝土界面黏结强度远小于PET FRP与混凝土界面黏结强度。  相似文献   

氯化物中锂离子存在时EDTA质量滴定锶离子含量     

孙柏  ;李海军  ;赵静  ;丁秀萍  ;宋彭生 《盐湖研究》2014,(3):29-37

锂共存时对EDTA络合滴定Sr2+离子产生较强的干扰,使分析结果偏高。根据被测液中氯化锂的大约含量,通过加入适量混合醇,可消除Li+离子的干扰,质量滴定法相对误差<0.3%。在锂锶质量比为0.100¹4.5范围内,被测样中LiCl质量与加入混合醇体积呈线性关系。混合醇掩蔽体积范围为314.5范围内,被测样中LiCl质量与加入混合醇体积呈线性关系。混合醇掩蔽体积范围为3⁵ mL。根据锂离子与水分子、短链醇形成蔟合物的键能,对消除Li+离子干扰络合滴定的机理进行探讨。  相似文献   

建库与制图数据一体化生产与管理技术的研究与实践     

吴燕平  田超  谢露蓉  夏宏威  陈白 《测绘科学》2011,36(6):224-226,181

本文通过对目前建库与制图数据生产与管理的现状,以及这两种数据特点的分析,阐明了建库与制图数据生产与管理一体化的真正含义和一体化空间数据模型的内容,通过在建库与制图数据一体化软件平台--Map-Store基础测绘版上的实践,总结了建库与制图数据一体化工艺方法和质量控制,在建库与制图数据一体化数据管理的基础上实现两种数据快...  相似文献   

Contamination characteristics of heavy metals in wetland soils along a tidal ditch of the Yellow River Estuary, China   总被引：3，自引：0，他引：3  

Junhong Bai  Laibin Huang  Denghua Yan  Qinggai Wang  Haifeng Gao  Rong Xiao  Chen Huang 《Stochastic Environmental Research and Risk Assessment (SERRA)》2011,25(5):671-676

Surface soils (0–20 cm) were collected from along a tidal ditch of the Yellow River Estuary in August of 2007. Samples were subjected to a total digestion technique before they were analyzed for total concentrations of As, Cr, Cd, Cu, Ni, Pb, Zn, P and S in order to investigate heavy metal contamination levels in wetland soils nearby the tidal ditches and their main sources. Results showed that the mean concentrations of these heavy metals except for As and Cd were lower than the Class I criteria. Nearly all sampling sites showed lower contamination levels for As and Cd, while no contamination levels for other heavy metals. Cr, Cu, and Ni mainly originated from parent rocks, and Pb and As might originate from tidal seawater and oil field pollution, respectively; while Cd and Zn mainly originated from parent rocks and tidal seawater. Most of heavy metals showed significant correlations with total concentrations of P and S, however, no significant correlations were observed between them and soil pH, slat and soil organic matter.  相似文献   

DYYZⅡ型自动站风向风速故障实例分析与处理     

乔卫平  杨晓芳  王瑞  白金凤  朱新民 《山西气象》2011,(4):43-44

本文对DYYZⅡ型自动气象站三例不同的风向、风速仪器故障进行了分析处理,总结出在风的观测中两点建议：一是观测中要注意观察自动站数据与室外风向标及风杯转动是否相一致;二是要注意自动站数据与人工观测数据（即风的显示器）进行对比,遇有仪器故障能够及时发现排除。同时要注意风仪器的定期维护,保障风杯、风标板不变形,轴承转动灵活,信号传输线路畅通。  相似文献   

Prestack Kirchhoff time migration of 3D coal seismic data from mining zones     

Yijun Yuan  Yuan Gao  Liying Bai  Zhanzu Liu 《Geophysical Prospecting》2011,59(3):455-463

Conventional seismic data processing methods based on post‐stack time migration have been playing an important role in coal exploration for decades. However, post‐stack time migration processing often results in low‐quality images in complex geological environments. In order to obtain high‐quality images, we present a strategy that applies the Kirchhoff prestack time migration (PSTM) method to coal seismic data. In this paper, we describe the implementation of Kirchhoff PSTM to a 3D coal seam. Meanwhile we derive the workflow of 3D Kirchhoff PSTM processing based on coal seismic data. The processing sequence of 3D Kirchhoff PSTM includes two major steps: 1) the estimation of the 3D root‐mean‐square (RMS) velocity field; 2) Kirchhoff prestack time migration processing. During the construction of a 3D velocity model, dip moveout velocity is served as an initial migration velocity field. We combine 3D Kirchhoff PSTM with the continuous adjustment of a 3D RMS velocity field by the criteria of flattened common reflection point gathers. In comparison with post‐stack time migration, the application of 3D Kirchhoff PSTM to coal seismic data produces better images of the coal seam reflections.  相似文献   

锡林郭勒草原不同生态地理区气候干燥度周期变化的小波分析     

王海梅  白殿奎  闫军  刘建成 《内蒙古气象》2011,(3):20-22,47

以锡林郭勒盟及其周边地区17个气象站点1960年以来的月气温和降水量数据为基础,利用气象学与生态学知识,按照荒漠草原区、典型草原区、草甸草原区和农牧交错区4个生态地理区对锡林郭勒盟及其周边地区的气象站点进行分区归并,统计各区的De Martonne干燥度指数,在Matlab等软件的支持下,用小波分析的方法,研究各区年平均气温的周期性变化规律及各区之间的异同点。研究结果表明,在25-32a时间尺度上,随着时间的推移,锡林郭勒盟4个生态地理区年干燥度均呈现明显的周期变化,形成正负相间的震荡中心;草甸草原区和农牧交错区表现出干燥程度增加的趋势。总体上推测,2007年以后的15a左右时间,锡林郭勒盟的4个生态地理区的气候均将呈现比较干燥的状态。  相似文献   

Multielemental contents of foodstuffs from the Wanshan (China) mercury mining area and the potential health risks     

Xiaoyan Wang  Yu-Feng Li  Bai LiZeqin Dong  Liya QuYuxi Gao  Zhifang ChaiChunying Chen 《Applied Geochemistry》2011,26(2):182-187

Potentially harmful element contamination from mining and smelting raises concerns due to possible health risks. For most people, diet is the main route of exposure to potentially harmful elements, so determination of the concentrations of these elements in foodstuffs and assessment of their possible risk for humans via dietary intake is very important. This study was designed to investigate the concentrations of different elements, including Hg, Pb, Cd, Mn and Se in foodstuffs and to estimate the potential health risk of these elements via consumption of polluted foodstuffs in the Wanshan Hg mine area, Guizhou province, SW China. The multielemental concentrations were determined by inductively coupled plasma-mass spectrometry (ICP-MS). The target hazard quotient (THQ) and hazard index (HI) were calculated to evaluate the potential health risk from individual and combined potentially harmful elements due to dietary intake. The average contents of Hg, Pb, Cd, Mn and Se in the most frequently consumed foodstuffs were: 31, 248, 121, 1035 and 32 μg/kg respectively. Among them, Cd and Hg were the most important contributors to potentially harmful elements contamination in Wanshan. Eight of 10 kinds of vegetables were contaminated to various levels by different elements but the samples of rice, pork, radish and potato were below the stipulated limits for toxic elements. In this study, the average dietary intakes of Hg, Pb, Cd, Mn, Se by an adult man of 60 kg living in Wanshan were: 27, 167, 86, 1061, 42 μg/day, respectively. The HIs for multielement dietary intake was 3.11, with the relative contributions of Hg, Pb, Cd, Mn and Se being 22.3%, 24.3%, 45.0%, 3.9% and 4.4%, respectively, which indicated that consumption of food poses a potential health risk. Vegetables were found to be the main source of potentially harmful element dietary intake.  相似文献