平台钢在海洋环境中腐蚀因子的灰色关联分析     

兰志刚  侯保荣  宋积文  陈胜利  张杰 《海洋科学》2010,34(11):69-71

结合海洋平台实测的pH值、温度、溶解氧、盐度、生物附着等数据,通过灰色关联算法分析了海水腐蚀因子对平台钢腐蚀的影响,并按实际影响大小进行了排序。结果表明海水腐蚀因子对于A537-1钢和SM50B-ZC钢平均腐蚀速率的影响主次顺序不同。对平台钢的腐蚀规律研究及现场应用提供了可参考的依据。  相似文献   

Characteristics of bottom dissolved oxygen in Long Island Sound,New York     

Younjoo J. Lee  Kamazima M.M. Lwiza 《Estuarine, Coastal and Shelf Science》2008

The variability of bottom dissolved oxygen (DO) in Long Island Sound, New York, is examined using water quality monitoring data collected by the Connecticut Department of Environmental Protection from 1995 to 2004. Self-organizing map analysis indicates that hypoxia always occurs in the Narrows during summer and less frequently in the Western and the Central Basins. The primary factor controlling the bottom DO, changes spatially and temporally. For non-summer seasons, the levels of bottom DO are strongly associated with water temperature, which means DO availability is primarily driven by solubility. During summer, stratification intensifies under weak wind conditions and bottom DO starts to decrease and deviate from the saturation level except for stations in the Eastern Basin. For the westernmost and shallow (<15 m) stations, bottom DO is correlated with the density stratification (represented by difference between surface and bottom density). In contrast, at deep stations (>20 m), the relationship between oxygen depletion and stratification is not significant. For stations located west of the Central Basin, bottom DO continues to decrease during summer until it reaches its minimum when bottom temperature is around 19–20 °C. In most cases the recovery to saturation levels at the beginning of fall is fast, but not necessarily associated with increased wind mixing. Therefore, we propose that the DO recovery may be a manifestation of either the reduced microbial activity combined with the depletion of organic matter or horizontal exchange. Hypoxic volume is weakly correlated to the summer wind speed, spring total nitrogen, spring chlorophyll a, and maximum river discharge. When all variables are combined in a multiple regression, the coefficient of determination (r²) is 0.92. Surprisingly, the weakest variable is the total nitrogen, because when it is excluded the coefficient r² only drops to 0.84. Spring bloom seems to be an important source of organic carbon pool and biological uptake of oxygen plays a more crucial role in the seasonal evolution of bottom DO than previously thought. Our results indicate that the reassessment phase of the Long Island Sound Total Maximum Daily Load policy on nitrogen loading will most likely fail, because it ignores the contributions of the spring organic carbon pool and river discharge. Also, it is questionable whether the goal of 58.5% anthropogenic nitrogen load reduction is enough.  相似文献   

塔北西部一间房组碳酸盐岩礁滩体同生期暴露溶蚀作用模式          下载免费PDF全文

赵学钦  杨海军马 青周成刚  孙崇浩蔡 泉 孙仕勇 《中国地质》2015,(6):1811-1811

在详细的钻井资料和岩心的宏观及微观特征研究的基础上,通过对塔北隆起西部奥陶系中统一间房组礁滩体沉积相特征及展布规律的分析,结合礁滩体储层同生期溶蚀作用特征研究,按照古沉积地貌单元结合岩相的方法建立了一间房组礁滩体同生期溶蚀作用模式。研究认为一间房组开阔台地相包括台内滩、滩间海和台内点礁3个亚相,沉积相平面分布稳定;一间房组的同生期暴露溶蚀作用明显,普遍反映出滩体的间歇性暴露的特征:生物钻孔和溶蚀孔洞内充填礁滩体暴露形成的古土壤泥;发育潮间带的化石碎片堆积和软体生物活动遗迹;岩心观察和成像测井可以识别出渗流-潜流带溶蚀作用旋回。按照礁滩相沉积地貌结合岩相的模式,将一间房组开阔台地的浅滩和点礁沉积划分出潮上长期暴露滩、潮间间歇暴露滩、潮下高能滩、瓶筐石障积礁、潮汐水道等地貌单元。  相似文献   

Quasi-static modelling of stress histories during the earthquake cycle: precursory seismic and aseismic stress release     

Ian G. Main 《Geophysical Journal International》1990,102(1):195-203

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ELECTROCHEMICAL STUDY ON CORROSION BEHAVIOUR OF STEELS IN SAND WITH WATER     

王佳 《中国海洋湖沼学报》1997,15(4):369-372

ImooUcr0NCormsinnofsodinconatisnowrognindasaseriousproblemwithlargeere-nondconSequenas.Thecormsionproducofondatthesurfaeeofrenfontin-dutaltenSioninthernaterial,resultinginfraCtureandspillingoftheconcretefromtherenfoot(Madrinaldetal.,l99l).Asaasult,theconCretestructure'sIneCanhalstwthisgreatiytalued.0wingtothephyShaldfultyofconduCtingforchdricalexperiInentsinconare,muCoftheworkintheaasofndanisticdCtendnationsforcormsionofstalincon-~wereconduedinalkalinesolution,generallyofporewatCr(Romirz…  相似文献   

Organic nitrogen and caloric content of detritus: II. Microbial biomass and activity     

Roger B. Hanson 《Estuarine, Coastal and Shelf Science》1982,14(3):325-336

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地下水NO -3污染的微生物修复实验研究   总被引：5，自引：0，他引：5  

张胜  张云  张凤娥  荆继红  张明 《水文地质工程地质》2005,32(2):25-30

随着农业的发展,尤其是化肥和农药的超量施用,产生了一系列的环境问题,已危及地下水的质量安全。大量的氮素没有被农作物吸收,经微生物硝化作用后,以硝态氮的形式进入土体和地下水。浅层地下水已普遍受到氮素不同程度的污染。本文以硝态氮污染为例,在实验室探索了硝态氮污染地下水微生物修复的实验方法,通过室内模拟含水层地下水静止条件和流动条件下,利用优选的菌群制剂和少量营养碳源,对试验区高含NO-3地下水的修复试验效果是显著的,去除率可达90%～100%。其作用还是持续的,静止条件下试验进行到256d时,其去除率仍达89 74%;流动条件下试验进行到112d时,试验主孔下游的观测孔3#、4#中的去除率也还有16 22%和27 26%。试验结果为野外现场原位微生物修复提供了技术支撑。  相似文献   

Middle and Late Devonian microbial carbonates,reefs and mounds in Guilin,South China and their sequence stratigraphic,paleoenvironmental and paleoclimatic significance   总被引：2，自引：0，他引：2  

Pedoja Kevin 《中国科学D辑(英文版)》2005,48(11):1900-1912

The importance of calcimicrobes and microbialite in carbonate platform and reefal environments has been stressed in recent literature. Burne and Moore[1] introduced the term microbialite to describe the clotted, laminated and undifferentiated fabrics formed by mi-crobial communities. Microbialites are organosedi-mentary deposits that have accreted as a result of ben-thic (prokaryotic or eukaryotic) communities, trapping and binding detrital sediment[1]. Microbial organisms and microbialite are…  相似文献   

开垦对内蒙古温带草地土壤不同有机碳组分的影响(英文)   总被引：3，自引：2，他引：1  

齐玉春  董云社  彭琴  肖胜生  何亚婷  刘欣超  孙良杰  贾军强  杨智杰 《地理学报(英文版)》2012,22(2):315-328

Cultivation is one of the most important human activities affecting the grassland ecosystem besides grazing, but its impacts on soil total organic carbon (C), especially on the liable organic C fractions have not been fully understood yet. In this paper, the role of cropping in soil organic C pool of different fractions was investigated in a meadow steppe region in Inner Mongolia of China, and the relationships between different C fractions were also discussed. The results indicated that the concentrations of different C fractions at steppe and cultivated land all decreased progressively with soil depth. After the conversion from steppe to spring wheat field for 36 years, total organic carbon (TOC) concentration at the 0 to 100 cm soil depth has decreased by 12.3% to 28.2%, and TOC of the surface soil horizon, especially those of 0-30 cm decreased more significantly (p<0.01). The dissolved organic carbon (DOC) and microbial biomass carbon (MBC) at the depth of 0-40 cm were found to have decreased by 66.7% to 77.1% and 36.5% to 42.4%, respectively. In the S.baicalensis steppe, the ratios of soil DOC to TOC varied between 0.52% and 0.60%, and those in the spring wheat field were only in the range of 0.18%-0.20%. The microbial quotients (qMBs) in the spring wheat field, varying from 1.11% to 1.40%, were also lower than those in the S. baicalensis steppe, which were in the range of 1.50%-1.63%. The change of DOC was much more sensitive to cultivation disturbance. Soil TOC, DOC, and MBC were significantly positive correlated with each other in the S. baicalensis steppe, but in the spring wheat field, the correlativity between DOC and TOC and that between DOC and MBC did not reach the significance level of 0.05.  相似文献   

石油污染湿地土壤生物修复研究进展   总被引：3，自引：1，他引：2  

阚兴艳  于君宝  王雪宏  谢文军  韩广轩  马向明  陈景春  林乾欣 《湿地科学》2012,10(2):250-256

从石油污染湿地土壤生物修复的植物修复、微生物修复和植物—微生物联合修复3方面综合阐述了国内外该领域的研究现状。在采用植物进行石油污染湿地修复时,选择湿地环境下典型植物或者能适应湿地特殊环境的植物品种是常用的也是有效的方法之一。在采用微生物进行石油污染湿地修复时,主要通过投加外源微生物和改变环境因素或施加营养元素刺激土著微生物等方式。植物—微生物联合修复石油污染湿地的方法,则是利用微生物自身作用促进植物生长,从而增加植物吸收、降解污染物的能力。由于植物或微生物的生长对污染物浓度有一个耐受极限,植物和微生物修复的效果主要取决于石油污染物浓度。为此,将湿地的石油污染浓度降到植物—微生物可降解范围内,并提高联合修复的降解效率,将是今后石油污染湿地土壤生物修复研究的重点。  相似文献