Infiltration processes and flow rates in developed karst vadose zone using tracers in cave drips   总被引：1，自引：0，他引：1  

Youval Arbel  Noam Greenbaum  Jens Lange  Moshe Inbar 《地球表面变化过程与地形》2010,35(14):1682-1693

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The challenge of environmental law as a tool for balancing environmental and economic interests, in the search for sustainable development     

Cindy L. Halbert  Wilfried Erbguth   《Limnologica》1999,29(3):362

Sustainable development necessitates balancing the interests and concerns of both the environment and the economy. The importance of environmental law as a tool to balance these potentially conflicting interests is increasing. Germany, in particular since reunification, provides a good case study of the challenges inherent in a highly industrialized nation towards achieving sustainable development. Since reunification, the concept of sustainable development, in terms of the protection of the essential basis for the existence of future generations, has been incorporated into the constitution in 1994. Explicit means for how to harmonize the needs of both the economy and the environment, however, remain unclear. This is particularly evident in the implementation of so-called “acceleration” laws, designed to shorten the processing time in the re-development of former east Germany, particularly in the areas of transportation infrastructure, wastewater disposal facilities, and housing construction. The implementation of these acceleration laws is generally at the expense of environmental concerns and public involvement in the decision making process. The effectiveness of environmental law as a tool to balance the needs of the environment and the economy, as is required for sustainable development, remains an unmet challenge.  相似文献   

Plankton prognoses in the North Sea     

Greve  Wulf  Lange  Uwe 《Ocean Dynamics》1999,51(10):155-160

Ocean Dynamics - Our understanding of the marine ecosystem is expressed in our ability to predict ecological processes. Several approaches are compared to make such predictions on plankton...  相似文献   

Variations in phytoplankton development in the eastern Gulf of Finland     

V. N. Nikulina  E. K. Lange 《Water Resources》2008,35(2):220-227

Materials of seasonal observations of phytoplankton at two permanent stations in the inner and outer parts of the Neva estuary. The obtained data demonstrate the changes that took place in the species composition and the quantitative development of phytoplankton during the past two decades. The authors associate these changes with anthropogenic factors, hydrological characteristics, and large-scale cyclic variations in hydrometeorological conditions.  相似文献   

Online First publication     

D. Ganten  R. Lange 《International Journal of Earth Sciences》2000,89(1):1-1

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The production of cosmogenic nuclides in stony meteoroids by galactic cosmic‐ray particles     

Ingo Leya  Hans‐Jürgen Lange  Sonja Neumann  Rainer Wieler  Rolf Michel 《Meteoritics & planetary science》2000,35(2):259-286

Abstract— We present a purely physical model for the calculation of depth‐ and size‐dependent production rates of cosmogenic nuclides by galactic cosmic‐ray (GCR) particles. besides the spectra of primary and secondary particles and the excitation functions of the underlying nuclear reactions, the model is based on only one free parameter—the integral number of gcr particles in the meteoroid orbits. We derived this value from analysis of radionuclide data in Knyahinya. We also show that the mean GCR proton spectrum in the meteoroid orbits has been constant over about the last 10 Ma. For the major target elements in stony meteoroids, we present depth‐ and size‐dependent production rates for ¹⁰Be, ¹⁴C, ²⁶Al, ³⁶Cl, and ⁵³Mn as well as for the rare gas isotopes ³He, ²⁰Ne, ²¹Ne, ²²Ne, ³⁶Ar, and ³⁸Ar. The new data differ from semi‐empirical estimates by up to a factor of 4 but agree within ～20% with results obtained by earlier parametric or physical approaches. The depth and size dependence of the shielding parameter ²²Ne/²¹Ne and the correlations ²⁶Al vs. ¹⁰Be, ²⁶Al vs. ⁵³Mn, ¹⁰Be/²¹Ne vs. ²²Ne/²¹Ne, and ³⁶Ar vs. ³⁶Cl for deciphering preatmospheric sizes, shielding depths, terrestrial residence times, and exposure histories are also discussed.  相似文献   

Characterisation of ground motion recording stations in the Groningen gas field     

Rik Noorlandt  Pauline P. Kruiver  Marco P. E. de Kleine  Marios Karaoulis  Ger de Lange  Antonio Di Matteo  Julius von Ketelhodt  Elmer Ruigrok  Benjamin Edwards  Adrian Rodriguez-Marek  Julian J. Bommer  Jan van Elk  Dirk Doornhof 《Journal of Seismology》2018,22(3):605-623

The seismic hazard and risk analysis for the onshore Groningen gas field requires information about local soil properties, in particular shear-wave velocity (V_S). A fieldwork campaign was conducted at 18 surface accelerograph stations of the monitoring network. The subsurface in the region consists of unconsolidated sediments and is heterogeneous in composition and properties. A range of different methods was applied to acquire in situ V_S values to a target depth of at least 30 m. The techniques include seismic cone penetration tests (SCPT) with varying source offsets, multichannel analysis of surface waves (MASW) on Rayleigh waves with different processing approaches, microtremor array, cross-hole tomography and suspension P-S logging. The offset SCPT, cross-hole tomography and common midpoint cross-correlation (CMPcc) processing of MASW data all revealed lateral variations on length scales of several to tens of metres in this geological setting. SCPTs resulted in very detailed V_S profiles with depth, but represent point measurements in a heterogeneous environment. The MASW results represent V_S information on a larger spatial scale and smooth some of the heterogeneity encountered at the sites. The combination of MASW and SCPT proved to be a powerful and cost-effective approach in determining representative V_S profiles at the accelerograph station sites. The measured V_S profiles correspond well with the modelled profiles and they significantly enhance the ground motion model derivation. The similarity between the theoretical transfer function from the V_S profile and the observed amplification from vertical array stations is also excellent.  相似文献   

A Method to Create a Horizontal Resistance Layer by Injection of a Viscous Fluid: PLAID          下载免费PDF全文

W.J. de Lange  J.P.M. Vink 《Ground water》2018,56(4):541-546

We present a method to create a horizontal resistance layer at desired depth below soil surface to decrease seepage over a relatively large area. The layer is produced in a continuous process by means of numerous temporary screens of wells. Between each pair of screens groundwater flow is forced in horizontal direction. In the center of such flow, along virtual parallel flow lines, a chemical, viscous and dense fluid is injected that produces a clogging substance within several hours. The impact of density is overcome by the forced flow between screens. The impact of viscosity on the flow distribution is handled by adaptation of the fluxes and heads at the filters in the screens. The resulting procedure includes multistep injection and is supported by model simulations. Though a small‐scale proof of concept has been successful, the composition of the optimal chemical mixture needs further research.  相似文献   

The biology,ecology and history of toheroa (Paphies ventricosa): a review of scientific,local and customary knowledge     

P. M. Ross  M. P. Beentjes  J. Cope  W. P. de Lange  B. G. McFadgen  P. Redfearn 《新西兰海洋与淡水研究杂志》2018,52(2):196-231

Toheroa (Paphies ventricosa) were formerly abundant on west and south-facing New Zealand surf beaches. Harvesting of this surf clam was intense during the early to mid-1900s, and populations declined to levels where harvesting was no longer viable. Despite having now been protected for 35–45 years, toheroa have failed to recover. This paper reviews the history of human interactions with toheroa and our understanding of their ecology, with a view to identifying knowledge requirements for management and restoration. Historical and legal documents pertaining to the use of marine resources are reviewed and scientific understanding compared with customary and local knowledge. We consider the factors that may be preventing toheroa recovery and make recommendations for research into life history, habitat requirements and the ecological consequences of changing land use. Management options are suggested to address the effects of vehicle use on beaches, poaching and the failings of the customary harvest system.  相似文献   

Cathodoluminescence of moldavites          下载免费PDF全文

B. Fritzke  J. Götze  J.‐M. Lange 《Meteoritics & planetary science》2017,52(7):1428-1436

A systematic study of a large set of moldavites and the application of cathodoluminescence (CL)‐spectroscopy with a detailed discussion of spectral features is presented. Optical CL microscopy and spectroscopy (OM‐CL) were performed on 57 moldavite samples from different substrewn‐fields in Germany and the Czech Republic. The extracted CL data were supported by SEM‐EDX analysis. In general, two different kinds of CL colors can be distinguished: different shades of green in the matrix of the tektite glasses and a variation of blue color for lechatelierite inclusions (a pure silica‐glass phase). Spectral analysis of these colors shows three CL emission bands for green and five bands for blue c. Most CL activators are structural defects of the local glass network, influenced by the crystal field. The visible green CL emission is caused by defects related to strong local disorder as well as Al‐O^?‐Al defects. The blue CL emission is activated by different types of lattice defects such as nonbridging oxygen‐hole center (NBOHC), self‐trapped excitons (STE), and oxygen deficiency centers (ODC). Intensity variations of the CL emissions were observed for samples from the different localities, but there is no direct correlation between substrewn‐fields and CL characteristics. Nevertheless, CL microscopy is a powerful tool for the high‐contrast visualization of internal textures such as streaks and lechatelierite in the tektite matrix due to the luminescence properties of the defect structures in the glassy network.  相似文献