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111.
Video assessment of environmental impacts of salmon farms 总被引:1,自引:0,他引:1
112.
113.
辽东湾北部海域营养状况与趋势评价 总被引:3,自引:0,他引:3
根据 1999-2006 年 6-8 月的调查数据,分析辽东湾北部海域的营养水平及变化趋势,以了解辽东湾北部海域营养水平的分布特点及污染状况.由 E 值和 CN/CP 值的总体评价结果来看,辽河口、双台子河口和大凌河口海域的富营养化程度较高,属于磷中等限制潜在性富营养区,而锦州湾海域污染相对较轻,属于中度营养区;在时空分布上,辽东湾北部海域 1999 年与 2006 年污染较为严重,中间年份污染相对较轻.针对辽东湾的具体环境用 CN/CP 值的评价模式更能揭示出营养盐限制对富营养化的影响. 相似文献
114.
本文根据胜利二号极浅海步行坐底钻井平台的作业和工作环境特点,进行了防腐措施研究,设计了切合实际的防腐措施。该平台在海上作业近四年进坞修理,经观测防腐情况良好。 相似文献
115.
如何计算整个系统的运转效率,特别是受不确定因素影响的系统(如过驳系统),仍然是一个非常重要的研究课题。文章提出基于模糊综合评判方法的效率计算方法,是一种新的尝试,这种方法较好的避免了人的主观随意性,更符合实际情况,同时又可以弥补统计方法的不足。文章对某沿海地区的一过驳系统进行了效率计算,取得比较好的效果。 相似文献
116.
Shane M. Ohline Malcolm R. Reid Shamus L.G. Husheer Kim I. Currie Keith A. Hunter 《Marine Chemistry》2007
Accurate measurement of seawater pH has long been sought by marine chemists (for example: [Dickson, A.G. 1993a. The measurement of sea water pH. Marine Chemistry, 44, 131–142, Dickson, A.G. 1993b. pH buffers for sea water media based on the total hydrogen ion concentration scale. Deep-Sea Research, 40, 107–118; Zhang, 1996; Tapp, M., Hunter, K.A., Currie, K. and Macaskill, B. 2000. Apparatus of continuous-flow underway spectrophotometric measurement of surface water pH. Marine Chemistry 72(2–4), 193–202; Friis, K., Koetzinger, A., Wallace, D.W.R. 2004. Spectrophotometric pH measurement in the ocean: Requirements, design and testing of an autonomous charge-coupled device detector system. Limnology and Oceanography: Methods 2, 126–136]. Recently, such attempts have taken on greater significance as anthropogenic carbon dioxide emissions may create rapidly changing oceanic pH. Spectrophotometric techniques have been accepted generally as the best for determination of seawater pH. Here we report a new technique using thymol blue as the indicator dye and fitting the entire spectrum from 400 to 900 nm rather than measuring the absorbance values at only two or three points in the spectrum. This full-spectrum modelling enables a reduction in signal to noise over other techniques. In the laboratory, we find with seawater samples a pH precision increase of five-fold “within” a sample and seven-fold “between” samples when comparing the full spectrum to the three-point method of analysis [Zhang, H., Byrne, R.H. 1996. Spectrophotometric pH measurements of surface seawater at in-situ conditions: absorbance and protonation behaviour of thymol blue. Marine Chemistry 52, 17–25]. 相似文献
117.
In recent years, bulk carriers have been identified with high risks of catastrophic structural failure and foundering, and with heavy loss of human life. This study, based upon Lloyd's of London casualty records, identified four risk factors that had significant, independent effect upon the likelihood of a bulk carrier foundering. The risk of foundering increased with the age of the ship, and was related to the ship's flag of registration. Most importantly, however, increased risks were found for heavy cargoes of iron ore and scrap steel or iron, and for trading routes to the Far East and from Europe to North America. Additional safety measures, in particular regarding ship design and high-risk trades, may well be necessary to reduce the high casualty rates. 相似文献
118.
解决山东水资源短缺的对策 总被引:1,自引:0,他引:1
分析了山东省水资源现状和存在的主要问题,针对山东省水资源的严重短缺,提出了在传统用水、治水的基础上,实施人工增雨工程,直接利用海水和海水淡化与节约用水,建立节水型社会,调整水源结构,更新用水观念,开发新水源,综合用水,综合治水的路子,只有这样才能长久解决水危机。 相似文献
119.
A study on the curves of the exchange ratio E(%)-pH on the liquid-solid interface of the systems Zn(II) with clay minerals (Kaolinite , illite and montmorillonite), Zn(II) with hydrous ferric oxides (amorphous ferric oxide, goethite and hematite). Zn(II) with hydrous manganese oxide (y-MnOOH, manganite and 5-MnO2) etc . in seawater resulted in the discovery of new plateau type exchange ratio ?%)-pH curves not yet reported in literature. The two factors that decide the growth , decline and the change of the " plateau type " curve are : (1) the inherent characteristics of systems , which can be explained by the exchange constants i(i=1 ,2 , 3 . etc .) of interfacial stepwise ion / coordination particle exchange between liquid and solid ; and (2)The theory of interfacial stepwise ion/coordination(the amount of solid exchange reagent)particle exchange in seawater was applied to explain the experimental results of the above study and a general formula was derived for the plateau type exchange ratio E(%)-pH c 相似文献
120.
The working group Mathematical Geology of the Freie Universität Berlin was formed in 1971. We review quantitative methods used by the working group since 1983 to treat mineral exploration problems. The methods applied vary from elementary statistical analysis of multivariate exploration data to optimal strategies for selecting favorable targets, and from multiobjective decision-making for additional drill hole locations to expert systems in exploration.The methods applied are directly related to the level of information at each stage of the exploration process. Special emphasis was placed on the relationship between and evaluation of subjective and objective data. Case studies illustrating the various methods are presented for different kinds of mineral deposits and exploration environments. 相似文献