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171.
继近几年来苏联使用的称为“CHIM—10”的野外勘探技术以来,一种基于电化学原理的利用原有设备的方法已用于寻找贱金属硫化物。这个方法利用了金属离子的正电性质,当大片土壤由于输入直流电而被人工电离时,靠近矿化带的潮湿土壤剖面中的金属离子势必会朝大功率大间隔电极系中的阴极运动。首先,进行了实试室模型试验,试验取得了振奋人心的结果。随后,组装了野外试验设备并用于在野外检验它的有效性。试验土壤剖面位于卡纳塔克邦哈桑县Aladahalli地区的贱金属硫化物带上,这里的矿床地质情况是众所周知的。在野外试验中获得的结果相当令人满意,并且与已知的地质情况完全一致。然而,在对该系统不同的可变参数做了必要的改正以后,仍然要对那些数据做细致的评价。以标准化和开发应用为目的,改进方法的工作正在进行,以便定性和定量评价给定地区的隐伏贱金属矿床,尤其是在那些常规地球化学勘查方法不适用的地方。本文论及该方法的细节并讨论在野外试验中所获得的结果。 相似文献
172.
K.Y.Cheng. 《地理学报(英文版)》1935,(3)
During Ching dynasty from 1644 to 1911, an interval of 268 years, there occurred in the lower Yangtze valley 197 floods and 156 droughts. The most serious droughts came in 1785, 1814, and 1856; and the most disastrous floods in 1680, 1823 相似文献
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德国气象学会,每两年举行会议一次,其先已於一九三一年及一九三三年分别在维也纳及汉堡举行。今年八月二十五日至二十七日为第十九次会期,假但泽高等工业学校开会,与会者除德人而外颇多外人。其演讲多属天气与大气之各种现象,兹择要略纪如下。会议开幕时,由主席枢密顾问明兴Schmauss教授演讲“气象学之术语”。略谓:吾人皆知气象界须有统一之国际符号,以为发表工具,使逐日印行之天气图与各处之年报,均有同一之记载。教授继谓气象学上基本术语,应有对外对内之分,前者吾人仅需知其国际简单意义,而後者则更需通晓其文字之说明。此外,吾人更须切实互助, 相似文献
175.
A Visual Basic macro entitled BACKGROUND calculates geochemical background values of chemical parameters and estimates threshold values separating background data from anomalies. The macro uses two statistical methods, the iterative 2-sigma technique and the calculated distribution function, and integrates these model-based objective methods into a widely accessible platform (i.e., MS Excel). The macro offers the possibility for automated processing of geochemical data and enables an automated generation of background range and threshold values for chemical parameters. 相似文献
176.
Ferraro G Bernardini A David M Meyer-Roux S Muellenhoff O Perkovic M Tarchi D Topouzelis K 《Marine pollution bulletin》2007,54(4):403-422
Studies of operational pollution carried out by European commission - Joint Research Centre in the Mediterranean Sea for the years 1999-2004 are briefly introduced. The specific analysis of the Adriatic Sea for the same period demonstrates that this area has been characterized by a relevant number of illegal discharges from ships. After setting the historical background of the project AESOP (aerial and satellite surveillance of operational pollution in the Adriatic Sea), the content, partners and aim of the project are presented. Finally, the results of the first phase of the AESOP project are presented. The results seem very encouraging. For the first time in the Adriatic, real time detection of oil spills in satellite images and an immediate verification by the Coast Guard has been undertaken. An exploratory activity has also been carried out in collaboration with the University of Ljubljana to use automatic information system (AIS) to identify the ships detected in the satellite images. 相似文献
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178.
Sugimoto K Hiraoka K Ohta S Niimura Y Terawaki T Okada M 《Marine pollution bulletin》2007,54(10):1582-1585
The objective of this study is to clarify the effect of ulvoid (Ulva spp.) accumulation on the structure and function of an eelgrass bed by the coast of Iwakuni, Seto Inland Sea, Japan. We monitored eelgrass shoot density and volume of ulvoid accumulation in the study site and evaluated effects of the accumulated ulvoid canopy on the percent survival, seedling density, growth rates, photosynthetic photon flux density (PPFD) and carbon contents of eelgrass. Eelgrass shoot density decreased by the accumulation of ulvoid. Also, seedling density decreased by the increase in the ulvoid volumes. Shoot density, seedling density and leaf elongation were negatively correlated with ulvoid volume. Carbon contents in eelgrass decreased by the accumulation of ulvoid (canopy height: 25cm). These results suggest that accumulation of ulvoid bloom has significant negative impacts on the structure and function of eelgrass bed, i.e. decreases in vegetative shoot density, seedling density, shoot height and growth rate. 相似文献
179.
Bonilla TD Nowosielski K Cuvelier M Hartz A Green M Esiobu N McCorquodale DS Fleisher JM Rogerson A 《Marine pollution bulletin》2007,54(9):1472-1482
Fecal indicator levels in nearshore waters of South Florida are routinely monitored to assess microbial contamination at recreational beaches. However, samples of sand from the surf zone and upper beach are not monitored which is surprising since sand may accumulate and harbor fecal-derived organisms. This study examined the prevalence of fecal indicator organisms in tidally-affected beach sand and in upper beach sand and compared these counts to levels in the water. Since indicator organisms were statistically elevated in sand relative to water, the study also considered the potential health risks associated with beach use and exposure to sand. Fecal coliforms, Escherichia coli, enterococci, somatic coliphages, and F(+)-specific coliphages were enumerated from sand and water at three South Florida beaches (Ft. Lauderdale Beach, Hollywood Beach, and Hobie Beach) over a 2-year period. Bacteria were consistently more concentrated in 100g samples of beach sand (2-23 fold in wet sand and 30-460 fold in dry sand) compared to 100ml samples of water. Somatic coliphages were commonly recovered from both sand and water while F(+)-specific coliphages were less commonly detected. Seeding experiments revealed that a single specimen of gull feces significantly influenced enterococci levels in some 3.1m(2) of beach sand. Examination of beach sand on a micro-spatial scale demonstrated that the variation in enterococci density over short distances was considerable. Results of multiple linear regression analysis showed that the physical and chemical parameters monitored in this study could only minimally account for the variation observed in indicator densities. A pilot epidemiological study was conducted to examine whether the length of exposure to beach water and sand could be correlated with health risk. Logistic regression analysis results provided preliminary evidence that time spent in the wet sand and time spent in the water were associated with a dose-dependent increase in gastrointestinal illness. 相似文献
180.