Distribution and source apportionments of polychlorinated biphenyls (PCBs) in mariculture sediments from the Pearl River Delta, South China   总被引：1，自引：0，他引：1  

Wang HS  Du J  Leung HM  Leung AO  Liang P  Giesy JP  Wong CK  Wong MH 《Marine pollution bulletin》2011,63(5-12):516-522

Surface and core sediments collected from six mariculture farms in the Pearl River Delta (PRD) were analyzed to evaluate contamination levels of polychlorinated biphenyls (PCBs). The ∑PCBs (37 congeners) concentrations ranged from 5.10 to 11.0 ng g(-1) (mean 7.96 ng g(-1)) in surface and 3.19 to 22.1 ng g(-1) (mean 7.75 ng g(-1)) in core sediments, respectively. The concentrations were significantly higher than that measured in the sediments of their corresponding reference sites, whereby the average enrichment percentages were 62.0% and 42.7% in surface and core sediments, respectively. Significant correlations (R2=0.77, p<0.05) of PCB homologue group proportions between fish feeds and surface mariculture sediments suggested that fish feed input was probably the main source for the enrichment of PCBs. Due to the fact that PCBs could be transferred along food chains, PCB contamination in fish feeds and mariculture sediments should not be overlooked.  相似文献   

城市大比例尺数字正射影像图制作技术浅析     

李琪  陈春华  孙莉 《地理空间信息》2010,8(5):106-107

数字正射影像图(DOM)是重要的数字产品之一,其应用已相当广泛。结合武汉市东湖技术开发区1:2000真彩色数字正射影像图制作的生产实践,从匹配编辑、匀光处理、影像镶嵌、调色修补几个方面探讨了基于VirtuoZo摄影测量工作站的大比例尺DOM制作的方法和技术。  相似文献   

陕北长城沿线风沙区土地资源研究     

秦其明 《干旱区地理》1988,(1)

本文拟从分析土地资源主要因素入手,通过研究土地结构和功能,划分出四个土地资源区,并对各区土地资源综合开发利用和改造措施作一阐述。  相似文献   

Groundwater quality assessment in urban environment   总被引：1，自引：1，他引：0  

A. M. Oişte 《International Journal of Environmental Science and Technology》2014,11(7):2095-2102

The assessment of environmental effects generated by urban areas (with various activities as agriculture, industry, human activities) on groundwater quality became essential for the use and conservation of the water resources. The main objective was to apply a water quality index to the groundwater sources using the specific methodology, establishing the suitability for drinking for groundwater. Water resources were monitored in October 2011, the samples were collected from 22 points for groundwater, and more parameters were analyzed: pH, electrical conductivity, turbidity, oxygen regime, hardness, alkalinity, nutrients regime (nitrates, ammonium, phosphates) which were considered important and utilized for water quality index computation that reveal poor quality for groundwater. The oxidability should be included in computation formula and the final results used for water management, taking into consideration the limits of the current model. Multivariate statistical analysis was used to indicate the influence of urban area on the quality of groundwater resources. Results of the analysis highlight an influence of geology and a contamination of agricultural origin.  相似文献   

A new flow for Canadian young hydrologists: Key scientific challenges addressed by research cultural shifts     

Caroline Aubry-Wake  Lauren D. Somers  Haley Alcock  Aspen M. Anderson  Amin Azarkhish  Samuel Bansah  Nicole M. Bell  Kelly Biagi  Mariana Castaneda-Gonzalez  Olivier Champagne  Anna Chesnokova  Devin Coone  Tasha-Leigh J. Gauthier  Uttam Ghimire  Nathan Glas  Dylan M. Hrach  Oi Yin Lai  Pierrick Lamontagne-Hallé  Nicolas R. Leroux  Laura Lyon  Sohom Mandal  Bouchra R. Nasri  Nataša Popović  Tracy E. Rankin  Kabir Rasouli  Alexis Robinson  Palash Sanyal  Nadine J. Shatilla  Brandon Van Huizen  Sophie Wilkinson  Jessica Williamson  Majid Zaremehrjardy 《水文研究》2020,34(8):2001-2006

  相似文献   

Food sources of the pearl oyster in coastal ecosystems of Japan: Evidence from diet and stable isotope analysis   总被引：1，自引：0，他引：1  

Kayoko Fukumori  Misa Oi  Hideyuki Doi  Noboru Okuda  Hitomi Yamaguchi  Michinobu Kuwae  Hitoshi Miyasaka  Kenji Yoshino  Yoshitsugu Koizumi  Koji Omori  Hidetaka Takeoka 《Estuarine, Coastal and Shelf Science》2008

We estimated the composition of two food sources for the cultured pearl oyster Pinctada fucata martensii using stable isotopes and stomach content analysis in the coastal areas of the Uwa Sea, Japan. The δ¹³C values of oysters (−17.5 to −16.8‰) were intermediate between that of particulate organic matter (POM, −20.2 to −19.1‰) and attached microalgae on pearl cages (−13.0‰). An isotope mixing model suggested that oysters were consuming 78% POM (mainly phytoplankton) and 22% attached microalgae. The attached microalgal composition of the stomach content showed a strong resemblance to the composition of that estimated through the isotope mixing model, suggesting preferential utilization of specific components is unlikely in this species. These results indicate that P. fucata martensii feed on a mixture of phytoplankton and attached microalgae, and that the attached microalgae on pearl cages can serve as an important additional food source.  相似文献   

Array observation of background atmospheric waves in the seismic band from 1 mHz to 0.5 Hz     

K. Nishida  Y. Fukao  S. Watada  N. Kobayashi  M. Tahira  N. Suda  K. Nawa  T. Oi  T. Kitajima 《Geophysical Journal International》2005,162(3):824-840

  相似文献   

天津蓟县硼矿床锰方硼石矿物的硼同位素研究   总被引：4，自引：0，他引：4  

肖荣阁  大井隆夫  侯万荣  安国英  费红彩 《现代地质》2002,16(3):270-275

天津蓟县硼矿床是世界上唯一的沉积环境特殊的锰方硼石型硼矿床。矿床呈层状产于震旦系碳酸岩泥灰质岩系中 ,矿石呈鲕粒状或球粒状集合体 ,是成因条件极其特殊的矿床类型。含矿岩系为中元古界高于庄组沉积岩系 ,含矿岩性由下而上依次为含锰白云岩、页岩互层→含锰白云岩、泥硅质岩 ,夹锰方硼石矿层→含锰页岩、白云岩→厚层白云岩→薄层白云岩→厚层白云岩 ,锰方硼石矿体在矿层中呈断续相连的团块状或透镜状分布。硼矿物成分简单 ,只有锰方硼石一种矿物 ,锰方硼石矿体呈透镜状断续成层分布 ,东西延长达 30km。东部矿段以锰方硼石为主 ,向西部渐变为菱锰矿。矿石有块状和斑点状。块状矿石全部由球粒状锰方硼石集合体组成 ,w (B2 O3 ) >2 0 % ,最高可达 4 2 %以上。斑点状矿石中锰方硼石集中呈球粒状集合体分布于泥质白云岩中 ,w (B2 O3 ) <7%。首次研究了该硼矿床锰方硼石的硼同位素组成 ,δ11B值为 +6 7‰～ +14 9‰ ,均为正值 ,并且东部大峪矿段的硼同位素值低于西部柏树沟矿段的硼同位素值 ,表明该硼矿床的成矿元素属于海水来源。由于锰方硼石的微量元素组成难以与蒸发岩比较 ,且富含F、Ba、Sn热液富集的元素和Co、Ni、Cr、Ti基性岩浆岩元素以及与Fe、Mn大洋结核有关的元素组分 ,因此锰方硼石应属于  相似文献   

Cartographie du potentiel en eau souterraine du bassin versant de la Lobo (Centre-Ouest,Côte d’Ivoire) : approche par analyse multicritère     

Affoué Berthe Yao  Bi Tié Albert Goula  Alioune Kane  Oi Mangoua Jules Mangoua  Kouamé Auguste Kouassi 《水文科学杂志》2013,58(5):856-867

RÉSUMÉ

Ce travail aborde le problème d’accessibilité en eau potable dans les zones fissurées de la Côte d’Ivoire notamment en saison sèche. Sur le bassin versant de la Lobo, le problème se pose avec plus d’acuité puisque les retenues aménagées pour l’alimentation en eau des populations ne sont pas correctement alimentées ces dernières années et sujettes à une très forte eutrophisation. L’approche pluridisciplinaire (télédétection, analyse multicritère et système d’information hydrogéologique à référence spatiale) a été adoptée. La cartographie des sites potentiels en eau montre que la quasi-totalité du bassin de la Lobo possède une bonne et excellente disponibilité en eau souterraine (93% de la superficie totale). Cette bonne disponibilité en eau souterraine est due à une faible pente et à une bonne densité de fracturation qui entrainent une bonne infiltration des eaux dans l’aquifère. L’identification des sites potentiels montre que près de 72% de la superficie du bassin est favorable à l’implantation d’ouvrages à gros débits. Dans l’ensemble, ces aquifères présentent une bonne accessibilité avec cependant, une exploitabilité médiocre.