Zielvorgaben für Pflanzenschutzmittelwirkstoffe und andere Schadstoffe in Oberflächengewässern     

Jutta Jahnel  Christian Zwiener  Thomas J. Gremm  Gudrun Abbt‐Braun  Fritz H. Frimmel  Carola Kussatz  Dieter Schudoma  Werner Rocker 《洁净——土壤、空气、水》2001,29(4):246-253

Quality Targets for Pesticides and Other Pollutants in Surface Waters Surface waters are not only adversely affected by industrial and municipal wastewaters but also by diffuse sources. For the control of the ecological water quality, so‐called quality targets are set. The quality targets are threshold concentrations for hazardous substances related to the protected goods like water ecosystems, drinking water supply, sediments, or fishing. In this paper, quality targets for the protection of aquatic life in surface waters were derived on the basis of a concept developed by the International Commission for the Protection of the Rhine (Internationale Kommission zum Schutze des Rheins – IKSR). The quality targets for the selected hazardous substances, which mainly belong to the chemical class of pesticides, were calculated using ecotoxicological results for species of bacteria, algae, fish, and small crustaceans, as the four trophic standards of the water ecosystem. In cooperation with the Federal Environmental Agency (Umweltbundesamt – UBA) the effect data were taken from ecotoxicological data bases. According to the concept of the IKSR, the lowest test result for the most sensitive species was multiplied by an assessment factor. This proceeding concerns the difficulty in describing the complex interactions in water ecosystems with toxicity data of single laboratory experiments for a few organisms. For seven pesticides quality targets below 0.1 μg/L were proposed. These results show that the ecotoxicologically based quality targets might be even lower than the limit values for pesticides in drinking water of 0.1 μg/L. But for most of the substances the determined values are significantly higher. The great concentration range of quality targets demonstrates distinctly that one standard concentration for all pesticides could not be given with regard to the different effects on aquatic organisms.  相似文献   

国外政治地理学边界理论研究进展与评述     

廖开怀  何金廖  蔡云楠  WernerBreitung 《世界地理研究》2020,29(2):264-274

边界研究是政治地理学的一个经典议题。受“冷战”结束和全球化的影响,边界研究在20世纪90年代初期以来步入一个复兴时期,产生了新的理论视角和概念转变。本文通过梳理国外文献,归纳总结了边界理论的内涵、研究内容和方法的演变。边界研究进入复兴时期后呈现出明显的多学科交叉和综合性特征,对边界的理解超越了传统意义上把边界单纯看作是国家空间分隔的理解,强调边界内涵的动态性、多尺度性、空间性和多样性,更多地关注不断创造和重新创造出来的符号性边界,以及不同空间尺度的社会实践。研究呼吁加强边界理论向城市内部空间尺度的边界延伸与拓展,以及加强边界理论与地缘政治学说的融合。  相似文献   

Basement-controlled deformation of sedimentary sequences,Anadarko Shelf,Oklahoma     

Folarin Kolawole  Molly Simpson Turko  Brett M. Carpenter 《Basin Research》2020,32(6):1365-1387

Structures rooted in the crystalline basement frequently control the deformation of the host bedrock and the overlying sedimentary sequences. Here, we elucidate the structure of the c. 2-km deep Precambrian granitic basement in the Anadarko Shelf, Oklahoma, and how the propagation of basement faults deformed the sedimentary cover. Although the basin is foreland in origin, the gently dipping shelf sequences experienced transpressional deformation in the Late Palaeozoic. We analyse a 3-D seismic reflection data set and basement penetrating well data in an area of 824 km². We observe: (a) pervasive deformation of the basement by basement-bounded interconnected mafic sills, and a system of subvertical discontinuity planes (interpreted as faults) of which some penetrate the overlying sedimentary cover; (b) three large (>10 km-long) through-going faults, with relatively small (<100 m) vertical separation (Vsep) of the deformed stratigraphic surfaces; (c) upward propagation of the large faults characterized by faulted-blocks near the basement, and faulted-monoclines in the deeper sedimentary units that transition into open monoclinal flexures up-section; (d) cumulative along-fault deformation of the stratigraphy exhibits systematic trends that varies with offset accrual; (e) two styles of Vsep—Depth distribution which include a unidirectional decrease of Vsep from the basement through the cover rocks (Style-1) and a bidirectional decrease of Vsep from a deep sedimentary unit towards the basement and shallower sequences (Style-2). We find that the basement-driven propagation (Style-1) shows greater efficiency of driving the fault deformation to shallower depths compared to the intrasedimentary-driven fault nucleation and propagation (Style-2). Our study demonstrates an evolution of cumulative Vsep trends with offset accrual on the faults, and the partial inheritance of the heterogeneous intra-basement deformation by the sedimentary cover. This contribution provides important insight into the upward propagation of basement-driven faulting associated with structural inheritance in contractional sedimentary basins.  相似文献   

Using provenance to disambiguate locational references in social network posts     

Thomas Hervey  Werner Kuhn 《International journal of geographical information science》2019,33(8):1594-1611

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Experimental hydrothermal alteration of basaltic glass with relevance to Mars     

C. Stre  H. Hellevang  L. Riu  H. Dypvik  C. Pilorget  F. Poulet  S. C. Werner 《Meteoritics & planetary science》2019,54(2):357-378

Phyllosilicates, carbonates, zeolites, and sulfates on Mars give clues about the planet's past environmental conditions, but little is known about the specific conditions in which these minerals formed within the crust and at the surface. The aim of the present study was to gain increased understanding on the formation of secondary phases by hydrothermal alteration of basaltic glass. The reaction processes were studied under varying conditions (temperature, pCO₂, water:rock ratio, and fluid composition) with relevance to aqueous hydrothermal alteration in fully and partly saturated Martian basalt deposits. Analyses made on reaction products using X‐ray diffraction (XRD) and scanning electron microscope (SEM) were compared with near infrared spectroscopy (NIR) to establish relative detectability and spectral signatures. This study demonstrates that comparable alteration minerals (phyllosilicates, carbonates, zeolites) form from vapor condensing on mineral surfaces in unsaturated sediments and not only in fully water‐saturated sediments. In certain environments where water vapor might be present, it can alter the basaltic bedrock to a suite of authigenic phases similar to those observed on the Martian surface. For the detection of the secondary phases, XRD and SEM‐EDS were found to be superior to NIR for detecting and characterizing zeolites. The discrepancy in detectability of zeolites between NIR and XRD/SEM‐EDS might indicate that zeolites on Mars are more abundant than previously thought.  相似文献   

Oxidative stress response of European flounder (Platichthys flesus) to cadmium determined by a custom cDNA microarray     

Sheader DL  Williams TD  Lyons BP  Chipman JK 《Marine environmental research》2006,62(1):33-44

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Exposure of sticklebacks (Gasterosteus aculeatus) to cadmium sulfide nanoparticles: biological effects and the importance of experimental design.   总被引：1，自引：0，他引：1  

Matthew B Sanders  Marion Sebire  Joachim Sturve  Paul Christian  Ioanna Katsiadaki  Brett P Lyons  Dave Sheahan  Jason M Weeks  Stephen W Feist 《Marine environmental research》2008,66(1):161-163

Effects of nanoparticles on aquatic organisms have been little studied to date and toxicological data are urgently needed for development of regulatory frameworks for these substances. Here, we report the findings of a study exposing sticklebacks to cadmium sulfide (CdS) as bulk material and quantum dots. Fish were exposed for 21 d in a flow through test system to 5, 50 or 500 microg l(-1) CdS nanoparticles (nCdS) coated in thiol terminated methyl polyethylene glycol (MPEG), bulk CdS or MPEG at 500 microg l(-1) (nominal concentrations). With the exception of the highest nCdS exposure, measured concentrations were approximately one order of magnitude below nominal. A single fish from each group (excluding MPEG) was examined using energy dispersive X-ray analysis (EDX) to localise cadmium, however, cadmium could not be detected in whole body sections. Elevated levels of oxidized glutathione were measured in the gills of fish exposed to 50 and 500 microg l(-1) nCdS. Induction of vitellogenin synthesis was not detected in any of the treatment groups. The number of males engaged in nest-building behaviour following exposure to 500 microg l(-1) nCdS was reduced and livers of 4/6 fish in the same treatment displayed hepatocellular nuclear pleomorphism. The results are discussed emphasising the fundamental importance of experimental design and the need to understand the behaviour of nanoparticles in the aqueous phase.  相似文献   

Alto Bkachner (Hrsg.): G. F. Brander 1713- 1783. Wissenschaftliche Instrumente aus seiner Werkstatt. Deutsches Mu-seum München. München 1983. 395 Seiten     

Werner Bronkalla 《Astronomische Nachrichten》1985,306(5):282-282

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