Flow dimension as an indicator of hydraulic behavior in site characterization of fractured rock   总被引：2，自引：0，他引：2  

Kuusela-Lahtinen A  Niemi A  Luukkonen A 《Ground water》2003,41(3):333-341

We examine the possibility of using the flow dimension identified from constant pressure injection tests as a tool for characterizing the hydraulic conditions of fractured media. The data comes from a low-conductivity crystalline rock site, from depths of up to 450 m, and is obtained with 2 m and 10 m measurement scales. In the analysis, the general solution for n-dimensional flow by Barker (1988) is applied. The results show that the most prominent characteristics of the medium can be identified; that is, linear and sublinear flow dimensions as distinguished from dimensions higher than two. In many cases, however, there is significant difficulty in distinguishing the dimensions n = 2, 2.5, and 3 from each other. This is usually because of the experimental difficulties in achieving the ideal conditions required by the theory during the early part of the experiment. In such cases, a full flow curve is not available for the type-curve fitting. In the nonunique cases the higher dimensions typically correspond to higher, sometimes unrealistically high, values of specific storage and to the less reliable and less representative early part of the experiment. Therefore, most of the dimensions in categories n = 3 can be excluded, thus leaving the majority observations in the categories of n = 2 and n = 2-2.5. The dominance of dimension n = 2 is more pronounced for data related to fracture zones in comparison to that related to "average" rock, in particular in the 2 m scale data. The proportion of low (n < 1.5) flow dimensions is small, but for the 10 m scale data it is relatively higher at greater depths and corresponds to lower conductivities. For the smaller 2 m scale data, the low dimensions are not linked to greater depths or systematically smaller conductivities, giving preliminary indication of different flow dimension behavior for the two different scales.  相似文献   

Polycyclic aromatic musk compounds in sewage treatment plant effluents of Canada and Sweden--first results   总被引：8，自引：0，他引：8  

Ricking M  Schwarzbauer J  Hellou J  Svenson A  Zitko V 《Marine pollution bulletin》2003,46(4):410-417

Polycyclic musk fragrances (PMF) are widely used fragrances for cosmetics and other personal and household care products. Quantitative data on PMF (HHCB-Galaxolide, AHTN-Tonalide, ATTI-Traseolide, AHMI-Phantolide, ADBI-Celestolide, and DPMI-Cashmeran) and the most prominent nitro musks (Musk Xylene-MX, and Musk Ketone-MK) in different wastewater treatment effluents in Canada and Sweden are presented to provide preliminary information on the variations within the emission pattern of these compounds. In all samples HHCB and AHTN were detected at concentrations of up to 1300 and 520 ngl(-1), respectively. ADBI, AHMI were also present, but close to the detection limit. The other PMF DPMI, ATTI, and more surprisingly musk ketone and musk xylene were not detected in any sample analysed. In comparison the samples from Canada were contaminated at a higher level than the Swedish samples, by a maximum factor of ca 10 for HHCB and AHTN.  相似文献   

Study of the effect of water-soluble fractions of heavy-oil on coastal marine organisms using enclosed ecosystems,mesocosms   总被引：1，自引：0，他引：1  

Ohwada K  Nishimura M  Wada M  Nomura H  Shibata A  Okamoto K  Toyoda K  Yoshida A  Takada H  Yamada M 《Marine pollution bulletin》2003,47(1-6):78-84

Mesocosm facilities composed of 4 experimental and 2 reservoir tanks (1.5 m in diameter, 3.0 m in depth and 5 tons in capacity) made of FRP plastics, were constructed in the concrete fish rearing pond in the Fisheries Laboratory, The University of Tokyo. The water-soluble fraction of Rank A heavy residual oil was formed by mixing 500 g of the oil with 10 l of seawater, which was introduced to the 5000 l-capacity tanks. Experimental Run 4 was conducted from May 31 to June 7, 2000. Oil concentrations in the tanks were 4.5 microg/l called LOW, and 13.5 microg/l, called HIGH tank. Bacterial growth rates very quickly accelerated in the HIGH tank just after the loading of oil which corresponded with a high increase of bacterial cells in the same tank after 2 days. Later, bacterial numbers in HIGH tank rapidly decreased, corresponding with the rapid increase of heterotrophic nano-flagellates and virus numbers on the same day. Sediment traps were deployed at the bottom of the experimental tanks, and were periodically retrieved. These samples were observed both under light microscope and epi-fluorescent microscope with UV-excitation. It was observed that the main components of the vertical flux were amorphous suspended matter, mostly originating from dead phytoplankton and living diatoms. It was further observed from the pictures that vertical transport of oil emulsions were probably conducted after adsorption to amorphous suspended matter and living diatoms, and were settling in the sediment traps at the bottom of the tanks. This means that the main force which drives the soluble fraction of oil into bottom sediment would be vertical flux of such amorphous suspended particles and phytoplankton. Further incubation of the samples revealed that the oil emulsions were degraded by the activity of autochtonous bacteria in the sediment in aerobic condition.  相似文献   

The use of a non-lethal tool for evaluating toxicological hazard of organochlorine contaminants in Mediterranean cetaceans: new data 10 years after the first paper published in MPB     

Fossi MC  Marsili L  Neri G  Natoli A  Politi E  Panigada S 《Marine pollution bulletin》2003,46(8):972-982

In the Mediterranean Sea, top predators, and particularly cetacean odontocetes, accumulate high concentrations of organochlorine contaminants and toxic metals, incurring high toxicological risk. In this paper we investigate the use of the skin biopsies as a non-lethal tool for evaluating toxicological hazard of organochlorines in Mediterranean cetaceans, presenting new data 10 years after the paper published by Fossi and co-workers [Mar. Poll. Bull. 24 (9) (1992) 459] in which this new methodology was first presented. Some organochlorine compounds, now with worldwide distribution, are known as endocrine disrupting chemicals (EDCs). Here the unexplored hypothesis that Mediterranean cetaceans are potentially at risk due to organochlorines with endocrine disrupting capacity is investigated. High concentrations of DDT metabolites and PCB congeners (known as EDCs) were found in the different Mediterranean species (Stenella coeruleoalba, Delphinus delphis, Tursiops truncatus and Balaenoptera physalus). In this paper we also propose benzo(a)pyrene monooxygenase (BPMO) activity in marine mammal skin biopsies (non-lethal biomarker) as a potential indicator of exposure to organochlorines, with special reference to the compounds with endocrine disrupting capacity. A statistically significant correlation was found between BPMO activity and organochlorine levels (DDTs, pp(')DDT, op(')DDT, PCBs and PCB99) in skin biopsies of males of B. physalus. Moreover a statistical correlation was also found between BPMO activity and DDT levels in skin biopsies of the endangered Mediterranean population of D. delphis. These results suggest that BPMO induction may be an early sign of exposure to organochlorine EDCs and can be used for periodic monitoring of Mediterranean marine mammal toxicological status.  相似文献   

煤田火区遥感四层空间探测方法   总被引：4，自引：0，他引：4  

张建民  管海晏  A.Rosema 《国土资源遥感》2004,15(4):50-53,62

煤层自燃是一个动态变化的过程,随着自燃向不同方向扩大或缩小,其热场随着燃烧过程而发生空间变化。本文在研究煤田煤层自燃现象及其火区灾害特征的基础上,基于宁夏汝箕沟地区的四层空间遥感探测试验,总结了不同平台遥感方法的探测效果,提出了利用遥感方法实现地下煤田火区监测的有效方法。  相似文献   

参考数据集的数据质量管理     

Jakobsson A  Marttinen J  赵园春 《测绘文摘》2004,(1)

地理信息团体习惯于使用现有的数据集,元数据(关于数据的数据)也随之日渐重要,数据质量正是元数据的一个重要方面。为广泛使用地理信息,出现了包括全球空间基础设施、欧洲的 INSPIRE以及国家空间数据基础设施(澳大利亚、美国)等项目。开放地理信息系统联盟 (OGC)已推出在不同应用程序间的数据转换方  相似文献   

云南鸡街碱性超基性岩杂岩体中橄榄石的化学成分分带现象     

吴静  黄智龙  A.McCaig  E.Condliffe  颜以彬 《矿物学报》2004,24(1):7-13

云南鸡街碱性超基性岩杂岩体的主体岩石为岩浆结晶分异作用的产物，形成顺序为霞霓钠辉岩→霓霞岩→磷霞岩。在杂岩体的霓霞岩中发现了1粒具分带现象的橄榄石，从中心到边缘，SiO2、MgO和NiO逐渐降低，而FeO和MnO逐渐升高。MgO与SiO2和NiO之间呈正相关关系，与FeO和MnO之间呈负相关关系，中心的Fo值(最高为86．91)略高于霞霓钠辉岩中斑晶橄榄石(Fo值：85．66～86．02)，而边缘的Fo值(最低为73．82)与霓霞岩中无分带现象橄榄石(Fo值：72．18～74．72)相近。各种证据表明，发现的具分带现象橄榄石可能不是霓霞岩熔体结晶分异作用的产物，而可能是霓霞岩熔体捕获的Fo值相对较高(高于霓霞岩橄榄石的Fo值)的橄榄石晶体内部MgO和FeO等成分扩散作用的结果。  相似文献   

加利福尼亚帕克菲尔德米德尔山圣安德烈斯断层带的高分辨率地震速度和浅层结构     

R.D.Catchings  M.J.Rymer  M.R.Goldman  J.A.Hole  R.Huggins  C.Lippus  谢汝一 《世界地震译丛》2004,(1)

加利福尼亚帕克菲尔德附近横跨圣安德烈斯断层(SAF)带5 km长高分辨率地震成像测量和建议中的圣安德烈斯断层深孔观测(SAFOD)表明,速度在横向及垂向上均有变化。速度从地表附近的<1.0 km/s变化到750m深度的4.8 km/s。最低的速度(<1.0～3.0 km/s)对应于地表附近的未固结的沉积岩、泥岩和砂岩,而较高的速度(>4.0 km/s)可能对应于萨林断块的花岗岩,该岩出露在圣安德烈斯断层西南数千米处。沿地震剖面可能的花岗岩顶部的埋深存在横向变化,但是在建议中的SAFOD场址处约为600m深。在圣安德烈斯断层地表迹线的西南部之下,我们观测到一个优势的横向低速层(LVZ),低速层在300m深度上宽约1.5km,但是在750m深度上逐渐减少到约600m宽。在速度模型的最大深度(750m)上,低速层集中在圣安德烈斯断层地表迹线西南大约400m处。在低速层两侧差不多的深度上观测到了相似的速度及速度梯度,说明低速层相对其任何一侧的岩石都是异常的。低速层内的速度低于圣安德烈斯断层断层泥的速度,而且,相对于重力、地磁、电阻率测量值,低速层也是异常的。由于低速层接近圣安德烈斯断层的地表迹线,使人认为它代表了深部破碎的结晶岩地层。然而,低速层也可能代表了现在仍然与圣安德烈斯断层邻接或包围圣安德烈斯断层的沉积岩的构造破碎带。这种沉积岩的破碎带意味着断层横跨两侧并可能位于破碎带中,说明断层带在300m深处上至少为1.5 km宽,在750m深度上逐渐减小到约600m宽。沉积破碎带内的流体可能是造成观测到的低电阻率值的原因。  相似文献   

Focal mechanism study of north Potwar dformed zone, Pakistan     

Mona Lisa  Shahid A Khan  Azam A Khwaja 《地震学报(英文版)》2004,17(3):255-261

Introduction Northern Pakistan is one of the seismically active regions in the world. Numerous studies have been undertaken to highlight and understand the ongoing collisional process of the Indo-Pakistan plate with the Kohistan island arc. Besides the N-S compression, as a result of the con-vergence, transpressional features have also been recognized. However, in the studied area pres-ence of evaporites (Eocambrian) has led to the development of duplex type models with the basal decollemen…  相似文献   

Paleomagnetic age and palaeobiological significance of hominoid fossil strata of Yuanmou Basin in Yunnan   总被引：4，自引：0，他引：4  

Friedrich A. Heller 《中国科学D辑(英文版)》2004,47(5)

The Yuanmou area in Yunnan Province is a fa-mous place for origin of mankind. Qian Fang et al. found tooth fossils of Yuanmou man in Shangnabang Village of Yuanmou in 1965. Jiang Nengren et al. identified the hominoid teeth from animal fossils un-earthed near Zhupeng Village in the Xiaohe Basin which were delivered by the local peasants. Hominoid fossils were also found in Leilao Village of Yuanmou afterward. These great discoveries have aroused ex-tensive concern in academic circle[1,2…  相似文献