南海琼东南盆地天然气水合物稳定域分布特征及资源预测   总被引：39，自引：14，他引：25       下载免费PDF全文

陈多福  李绪宣  夏斌 《地球物理学报》2004,47(3):483-489

琼东南盆地油气地质显示盆地内具有生物成因和热成因天然气的巨大生成能力和远景. 地震剖面显示盆地内发育有泥底辟和气烟囱、沟通泥底辟和气烟囱与海底的断裂及可能正在活动的天然气冷泉,这些特征非常有利于天然气水合物的发育. 通过天然气水合物热力学稳定域预测,确定了琼东南盆地天然气水合物的平面和剖面分布特征. 生物成因甲烷水合物分布于水深大于约600m的海底,稳定带最大厚度约314m;热成因天然气水合物分布于水深大于约450m的海区,稳定带最大厚度约410m. 盆地内天然气水合物远景总量约10×109m3,水合物天然气远景为1.6×1012m3.  相似文献   

Multi-residues of organic pollutants in surface sediments from littoral areas of the Yellow Sea, China   总被引：1，自引：0，他引：1  

Liu W  Chen J  Hu J  Ling X  Tao S 《Marine pollution bulletin》2008,56(6):1091-1103

Concentrations of all studied organic pollutants, except for DDTs, were greatest at sites in Dalian Bay, where surface sediment concentrations of PHCs, PAHs, PCBs and DDTs exceeded the corresponding ERL values. The sum concentration of DDTs was greatest in Haizhou Bay exceeding the related ERM value. In terms of compositions of PAHs and PAEs, the predominant components were the MMW and HMW compounds, DBP and DEHP, respectively. The main degradation product of p,p'-DDT was p,p'-DDD at most sampling sites. The principal sources of PAHs and DDTs involved various pyrolytic processes (i.e., combustion of biomass and vehicle exhaust), and application of technical DDT (in the form of impurity or raw material), and a mixture of technical DDT and technical dicofol. Moreover, the coastal site with greatest potential ecological risk from total PAHs was located in Dalian Bay, while the littoral areas of Dalian Bay, two harbor cities (Yantai-Weihai), Jiaozhou Bay, and Haizhou Bay, had relatively high potential risk from DDTs, especially in Haizhou Bay.  相似文献   

Selection of Test and Reference Areas for the Indian Deepsea Environment Experiment (INDEX)     

Rahul Sharma  B. Nagender Nath 《Marine Georesources & Geotechnology》2000,18(3):177-187

The Indian Deepsea Environment Experiment (INDEX) was conducted in the Central Indian Ocean Basin, to assess the effects of a simulated disturbance on the marine ecosystem and to collect data to predict the effects of large-scale mining. To select the Test and Reference areas for benthic disturbance, detailed studies were carried out for a better understanding of the topgraphic undulations and nodule distribution in five preselected areas of 10 ×10 nautical miles each. Flat topography was one of the important considerations for selection of the areas, because this would allow further dispersion of sediment plume and offer easier maneuverability of the benthic disturber. Relatively low nodule abundances were also preferred, to prevent clogging of the suction device used for resuspension of sediment. On the basis of morphological analysis and nodule distribution, two areas, T1 and A1, were selected as the best suited pair for the disturbance and monitoring experiment.  相似文献   

Occurrence and seasonal variation of butyltin species along the mediterranean coast of Turkey     

Yemenicioglu S  de Mora S 《Marine pollution bulletin》2009,58(1):163-166

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Distribution of dissolved free amino acids, dissolved inorganic nitrogen and chlorophyll a in the surface microlayer and subsurface water of the Yellow Sea, China   总被引：1，自引：0，他引：1  

Gui-Peng Yang  Yan Chen  Xian-Chi Gao 《Continental Shelf Research》2009,29(14):1737-1747

Concentrations of 14 different dissolved free amino acids (DFAA), dissolved inorganic nitrogen (DIN), and chlorophyll a were determined in the surface microlayer and subsurface waters at 41 stations in the Yellow Sea, China in April 2006. The concentrations of DFAA in the subsurface water ranged from 0.13 to 1.62 μM, with an average of 0.57±0.05 μM, while those in the surface microlayer varied between 0.22 and 2.6 μM, with an average of 0.94±0.08 μM. Major constituents of DFAA present in the study area were glycine, alanine, glutamic acid, serine and histidine. One-way analysis of variance (ANOVA) showed no significant difference in average mol fractions of DFAA between microlayer and subsurface water (F=0.0440, P=0.8355). Hierarchical cluster analysis of the station similarity based on the DFAA composition in both the surface microlayer and subsurface water separated three clusters of stations at the 70% Bray–Curtis similarity level. The average concentrations of chlorophyll a and DIN were 1.18 (0.34–4.44) μg L⁻¹ and 16.57 (3.98–49.59) μM in the subsurface water, and those in the surface microlayer were 1.30 (0.24–3.97) μg L⁻¹ and 18.56 (5.77–48.93) μM, respectively. Our results showed that concentrations of chlorophyll a (r²=0.7940, n=41, p<0.0001), DIN (r²=0.6939, n=41, p<0.0001) and DFAA (r²=0.2416, n=41, P=0.0011) in the microlayer were, respectively, correlated with their subsurface water concentrations, implying that there was a strong exchange effect between the microlayer and subsurface water. The enrichment factor of DFAA in the microlayer ranged from 0.47 to 2.24 with a mean of 1.88±0.16.  相似文献   

辽宁冬季城市空气质量分布状况综合研究   总被引：5，自引：0，他引：5       下载免费PDF全文

马雁军  刘宁微  王扬锋 《气象与环境学报》2007,23(3):15-18

利用2006年12月辽宁14个城市的大气环境现状监测资料和沈阳、鞍山、抚顺、本溪4城市可吸收入颗粒物(PM10,PM2.5和PM1)的监测资料,对辽宁冬季各城市的空气质量分布状况进行了综合研究。结果表明:辽宁14个城市的冬季空气质量分布状况为优、良和轻微污染3个等级,其中铁岭、营口和辽阳的空气质量有28 d为良及以上等级;空气质量级别为轻微污染日数最多的城市是本溪,共计12 d;其次是葫芦岛、沈阳、鞍山、抚顺、盘锦、阜新,共计7—10 d。各城市的首要污染物是PM10。由于冬季燃煤量的增加,沈阳、鞍山、抚顺和本溪4城市PM2.5日平均浓度值的超标率为77.4%—90.3%。  相似文献   

多环芳烃来源与分布及迁移规律研究概述   总被引：14，自引：0，他引：14  

韩菲 《气象与环境学报》2007,23(4):57-61

概述了多环芳烃的来源,就近年来多环芳烃(PAHs)在大气、土壤、植被和水体沉积物中分布与迁移规律的研究成果进行了综述,并展望了未来PAHs研究方向。  相似文献   

广东红层形成及其发育规律研究   总被引：1，自引：0，他引：1  

吴志才  彭华 《热带地理》2006,26(3):207-210

在一定的地质构造、岩性特征和气候与时间等因素的作用下,广东的红层都分布在白垩-第三纪的红色盆地中,在全省108个红层盆地中,各盆地红层的总面积为28 283 km2,约占全省陆地面积的16%.文中总结出了红层的地层特征、岩性特征和地貌特征,并得出广东省红层分布规律为:红层空间分布:主要受深、大断裂控制呈带状和串珠状分布;红层时代分布:中生代中期后.其中部分红层中的丹霞地貌区给地方经济发展起到了重要作用.  相似文献   

关于香港人口的分布与其土地利用问题的意见   总被引：2，自引：0，他引：2  

叶汇  林慧玲 《热带地理》2000,20(1):12-15

概述了香港人口分布和土地利用现状的特点 ,根据香港的土地利用特点 ,结合香港地势图分析 ,全区的土地利用以城市用地为主 ,主要利用沿海冲积 -海积平原和坡地。文中针对高台地和斜坡地利用提出一些新意见 ,务求全体香港市民不受滑坡的威胁。  相似文献   

Effect of environmental gradients on the quantity and quality of fallen logs in Tsuga longibracteata forest in Tianbaoyan National Nature Reserve, Fujian province, China   总被引：1，自引：0，他引：1  

Hui-ming You  Dong-jin He  Wei-bin You  Jin-shan Liu  Chang-tang Cai 《山地科学学报》2013,10(6):1118-1124

We investigated the quantity and quality 0f fallen l0gs in different Tsuga l0ngibracteata f0rest c0mmunities in the Tianba0yan Nati0nal Nature Reserve. We used redundancy analysis t0 determine the spatial distributi0n 0f fallen l0gs in the different f0rest c0mmunities and t0 analyze the relati0nships am0ng stand structure, t0p0graphic fact0rs and human disturbance. The v0lume, c0vered area, mean l0g length and number 0f fallen l0gs differed significantly am0ng f0rest types （P 〈 0.05）, but mean diameter at breast height sh0wed n0 significant difference （P 〉 0.05）. The l0g v0lume and c0vered area in different f0rest types sh0wed the f0ll0wing trend： T. l0ngibracteata pure f0rest 〈 T. l0ngibracteata ＋ Olig0staehyum scabrifl0rur 〈 T. l0ngibraeteata ＋ hardw00d 〈 Rh0d0dendr0n simiarum ＋ T. l0ngibraeteata 〈 T. l0ngibraeteata ＋ Phyll0stachys heter0cycla pubescens. The spatial distributi0n patterns 0f l0gs quantity and quality indicated that l0g v0lume and c0vered area were str0ngly affected by envir0nmental fact0rs in the f0ll0wing 0rder： human disturbance 〉 elevati0n 〉 sl0pe p0siti0n 〉 b0le height 〉 tree height 〉 sl0pe aspect 〉 density 〉 basal area 〉 sl0pe gradient. The relative c0ntributi0n 0f envir0nmental variables 0n the t0tal variance was t0p0graphy （76%） 〉 disturbance （42%） 〉 stand structure （35%）. T0p0graphy and disturbance c0mbined explained 8.2% 0f the variance. Fallen l0~s auantitv and aualitvwere negatively related t0 elevati0n and sl0pe p0siti0n, and p0sitively ass0ciated t0 human disturbance. The l0g v0lume decreased fr0m n0rthern t0 s0uthern sl0pes. Envir0nmental fact0rs had the highest impact 0n class I （slightly decayed）, and l0west impact 0n class V （highly decayed）.  相似文献