Sorption,degradation, and transport of methyl iodide and other iodine species in geologic media     

Q.H. Hu  J.E. Moran  J.Y. Gan 《Applied Geochemistry》2012

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Prevalence and risk assessment of antibiotics in riverine estuarine waters of Larut and Sangga Besar River,Perak     

Low  Kyleyoung  Chai  Layching  Lee  Choonweng  Zhang  Gan  Zhang  Ruijie  Vahab  Vaezzadeh  Bong  Chuiwei 《中国海洋湖沼学报》2021,39(1):122-134

Antibiotics released into the environment through anthropogenic activities exert selective pressure,driving bacteria towards increasing antimicrobial resistance.The prevalence of antibiotics and the ecological risks posed in the riverine estuarine of Larut River and Sangga Besar River,which included wastewater effluents from hospital,zoo,and poultry slaughterhouse sources were investigated.Solid phase extraction(SPE) followed by high-performance liquid chromatography tandem mass chromatography(HPLC-MS/MS) were used to extract and quantify the antibiotic residues from 22 antibiotics belonging to six major antibiotic classes(sulfonamide,macrolide,fluoroquinolone,phenicol,trimethoprim,and tetracycline).Sixteen antibiotic residues were detected with concentrations ranging from limit of detection(LOD) to 1 262.3 ng/L.Fluoroquinolones and macrolides were the most frequently detected compounds.Erythromycin,clarithromycin and ofloxacin detected in hospital and zoo effluents posed a high risk to algae while tetracycline had low to medium ecological risks toward all the relevant organisms from aquatic environments(algae,invertebrate Daphnia magna,and fish).  相似文献   

Probability distribution of the Murty‐Loomis tsunami magnitude     

Zi Jun Gan  C. C. Tung 《Marine Geodesy》2013,36(3-4):293-301

Abstract

In 1980, Murty and Loomis proposed a new, objective tsunami magnitude scale based on total tsunami energy. A list of 178 tsunamigenic earthquakes during the period 1815 to 1974 was given along with estimated tsunami magnitudes. In this study, we derived the probability distribution function of tsunami magnitudes based on the assumptions that (1) the occurrences of tsunamigenic earthquakes are a Poisson process, and (2) tsunami energy is a polynomial function of tsunami recurrence time. Using the data given by Murty and Loomis, the parameters of the distribution function are estimated. Comparison with the data shows that the derived distribution is a good representation of the distribution of the Murty‐Loomis tsunami magnitude.  相似文献   

Identification of MgII Absorption Line Systems from SDSS Quasar Catalogue     

W. -R. Huang  Z. -F. Chen  Y. -P. Qin  M. -S. Li  R. -H. Liao  W. -W. He  F. Han  Y. -Q. Zhong  J. -Q. Gan  W. Zhou 《Journal of Astrophysics and Astronomy》2011,32(1-2):277-280

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扫描电镜技术在柴达木盆地昆虫化石潜蝇研究中的应用          下载免费PDF全文

李宏  闫德飞  杜宝霞  温雯雯  邵小阳 《甘肃地质》2010,(4):85-88

近年来应用扫描电子显微镜技术分析现生昆虫微观结构的研究较多,但在化石昆虫的应用方面还比较少见。利用扫描电子显微镜对采自青海省柴达木盆地中新统上干柴沟组的昆虫化石进行了细致分析,并结合光学体视显微镜,观察了该昆虫化石微细构造特征与宏观特征,在此基础上鉴定该化石为潜蝇Agromyza sp.(sp.nov.)。文中对扫描电子显微镜技术在昆虫化石研究中的应用作了较详细的论述。  相似文献   

Sponges (Porifera) as living metazoan witnesses from the Neoproterozoic: biomineralization and the concept of their evolutionary success     

Xiaohong Wang  Shixue Hu  Lu Gan  Matthias Wiens  Werner E.G. Müller 《地学学报》2010,22(1):1-11

The emergence of the Metazoa can be dated back to the Neoproterozoic Era which comprises the Cryogenian Period during which two major glaciations occurred, the Sturtian and the Varanger-Marinoan. At that time, the phylum Porifera (sponges) evolved as the first animals and developed a hard skeleton. The two classes of siliceous sponges, the Hexactinellida and the Demospongiae, are already provided with the major genetic repertoire and gene regulatory networks that also exist in modern multicellular animals. Besides these metazoan innovations, the siliceous sponges display one autapomorphic character, silicatein, an enzyme which mediates bio-silica formation. Well preserved siliceous sponge fossils have been excavated from the Cambrian Burgess Shale- and Chengjiang deposits. It is concluded that it was the hard skeleton of the siliceous sponges that contributed to the successful evolution and survival of the Porifera during the last 500 Ma.  相似文献   

阿拉善地块南缘构造活动特征与青藏高原东北缘向外扩展的最新边界     

郑文俊  张博譞  袁道阳  陈干  张逸鹏  俞晶星  张冬丽  毕海芸  刘炳旭  杨敬钧 《地球科学与环境学报》2021,(2):224-236

青藏高原向北东方向扩展的方式及最新扩展边界的位置,是目前青藏高原东北缘构造变形研究的热点.基于近年来对阿拉善地块南缘及邻区活动构造运动特征调查和定量研究结果,重点总结了阿拉善地块南缘活动断裂几何图像及运动特征,指出以前普遍认为的稳定阿拉善地块内部在新生代晚期发育了一系列规模不等、运动性质各异的活动断裂,这些活动断裂是青...  相似文献   

宜昌附近第四纪断层研究的新进展     

甘家思  刘锁旺 《大地测量与地球动力学》1995,(4)

通过野外地震地质调查，发现：（１）北东向新场—古老背断裂带的地表形迹和更新世多期活动的地层、构造岩证据；（２）近南北向虎牙第四纪断层及其粘滑快速断错的剩余形变特征；（３）北西向天阳坪断裂带南支早第四纪粘滑快速断错的剩余形变特征及其上覆晚更新世末期堆积（１４Ｃ１６４００±４３９年）未受断错所揭示的时间上限约束。  相似文献   

Seasonal variability of eddy characteristics and energetics in the Kuroshio Extension     

Yang  Chen  Yang  Haiyuan  Chen  Zhaohui  Gan  Bolan  Liu  Yongzheng  Wu  Lixin 《Ocean Dynamics》2023,73(8):531-544

Ocean Dynamics - Based on the eddy-resolving Four-dimensional variational Ocean Re-Analysis for the Western North Pacific over 30 years (FORA-WNP30) product, this study investigates the...  相似文献   

2020年1月24—25日贵州冰雹、雨雪共存天气机理分析          下载免费PDF全文

王芬  唐浩鹏  杨帆  罗旋  王兴菊  杨春艳  张淦 《沙漠与绿洲气象(新疆气象)》2021,15(4):17-25

利用常规观测、NCEP再分析及FY-2G TBB等资料,对贵州2020年1月24—25日的冰雹、雨雪共存天气进行分析,结果表明:(1)此次复杂天气主要由南支槽前强上升运动把低空急流带来的充沛水汽强迫抬升至-10℃以上,前期能量集聚使得大气不稳定度迅速加大,滇黔静止锋触发贵州南部不稳定能量释放,共同造成了此次天气。(2)冰雹是由高架雷暴造成的,暖湿逆温层、强垂直风切变、强不稳定层结和合适的温度垂直分布是发生强对流的主要原因。(3)冷锋及深厚南支槽是降雪发生的主要环流形势,中层水汽辐合的强度及厚度不断增长、槽前动力抬升使得水汽伸展到-10℃以上,配合气温不断下降共同造成了暴雪天气。(4)贵州西部较充沛的外部水汽输送为降雨提供有利条件,高低空急流的有效叠加及典型的低层辐合、高层辐散加大降水强度。(5)强上升运动在降雪前8 h出现、涡度平流在降雪前24 h出现跃增,低层辐合的强度大于高层辐散;较之冰雹、暴雪区,大暴雪区饱和区伸展更高、上升运动更强、涡度平流更强,但水汽辐合稍弱;大暴雪区表现为稳定的低冷高暖,冰雹区、暴雪区则表现为由低到高的"冷—暖—冷"结构。(6)降雪区TBB纹理较均匀,大部在-20～-32℃,TBB低值区对应降雪强度较大,降雪最强时段TBB达-52℃。  相似文献