THE DETERMINATION OF FLUORINE BY PROTON INDUCED GAMMA RAY EMISSION SPECTROMETRY (PIGE) IN EIGHTEEN CHINESE STANDARD REFERENCE SAMPLES OF STREAM SEDIMENTS, SOILS AND ROCKS: GSD 9-12, GSS 1-8 AND GSR 1-6     

Iwan ROELANDTS  Guy ROBAYE  Panagiotis ALOUPOGIANNIS  Georges WEBER  Jeanne-Marie DELBROUCK-HABARU 《Geostandards and Geoanalytical Research》1987,11(1):79-80

Eighteen new Chinese standard reference samples (including stream sediments, soils and rocks) have been analysed by an automated proton induced gamma ray emission (PIGE) method for fluorine. Results of determinations are reported and are generally in good agreement with the "usable values" previously published.  相似文献   

1982 Compilation of Elemental Concentration Data for the United States Geological Survey's Geochemical Exploration Reference Samples GXR -1 to GXR - 6     

Ernest S. GLADNEY  Colleen E. BURNS  Iwan ROELANDTS 《Geostandards and Geoanalytical Research》1984,8(2):119-154

Concentration data for as many as 64 constituents in the six United States Geological Survey's (USGS) Geochemical Exploration Reference Samples (GXR) have been collected from journal articles and technical reports published since these reference materials were issued in 1971. These data are summarized into mean +/- one standard deviation values and compared with our previously calculated concentrations based upon USGS round-robin data published in 1978. All new literature data located are presented in the appendices.  相似文献   

Active interaction control of civil structures. Part 2: MDOF systems     

Yunfeng Zhang  W. D. Iwan 《地震工程与结构动力学》2002,31(1):179-194

In this paper, the performance of active interaction control (AIC) algorithms is assessed within the context of two realistic building models. The AIC control approach is proposed as a semi‐active means of mitigating the structural response during large earthquakes. To implement the AIC control algorithms into MDOF systems, the modal control (MC) approach that directs the control effort to certain dominant response modes is formulated and utilized herein. Two structures, a 3‐storey building and a 9‐storey steel‐framed benchmark building controlled by the AIC algorithms are analysed for two historical earthquake records. The results of numerical simulation verify the efficacy of the AIC control algorithms in controlling vibration of building structures during large earthquakes. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

Characterization of polychlorinated biphenyls and brominated flame retardants in sediments from riverine and coastal waters of Surabaya, Indonesia   总被引：2，自引：0，他引：2  

Muhammad Ilyas  Agus Sudaryanto  Iwan Eka Setiawan  Tomohiko Isobe  Shin Takahashi 《Marine pollution bulletin》2011,62(1):89-98

A total of 33 surficial sediments from riverine and coastal waters from Surabaya, Indonesia were analyzed for PCBs and BFRs. Concentrations of PCBs (62 congeners), PBDEs (14 congeners) and HBCDs (3 isomers) varied from <DL-420, <DL-35 and <DL-5.4 ng g⁻¹ dw, respectively. Higher concentrations of these compounds were found in riverine than coastal sediments. Their levels and distribution were influenced by proximity to the point sources and TOC. The predominant congeners were CB-153, -28, -138, -149, -180, -33 and BDE-209, -207, -206, -197, -196, -183, -99, -47 for PCBs and PBDEs, respectively, and γ-isomer for HBCDs. Debromination of BDE-209 might be taking place producing lower toxic congeners in sediment. Levels of PCBs in riverine sediments were comparable with some polluted areas worldwide, but PBDEs and HBCDs were lower. Hazard assessment of PCBs indicated possible toxic potential, particularly in areas close to point sources.  相似文献   

The use of the distribution of the orbital energy to investigate the evolution of the Perseid meteoroid stream     

Zidian Wu  Iwan P. Williams 《Earth, Moon, and Planets》1995,68(1-3):639-646

Numerical integration of a meteor stream over a long period is a very time consuming process, especially if a number of different models have to be investigated. In this paper we demonstrate that using the distribution of orbital energy as a vector in a Markov process can be a useful tool and that meaningful results can be obtained with far less computation than is normally required.  相似文献   

Periglacial structures within fluvio‐aeolian successions of the end of the Last Glaciation – examples from SE Poland and NW Ukraine     

Paweł Zieliński  Robert J. Sokołowski  Stanisław Fedorowicz  Iwan Zaleski 《Boreas: An International Journal of Quaternary Research》2014,43(3):712-721

The nature of permafrost and related environmental conditions in the Weichselian Late Pleniglacial and Lateglacial are reconstructed based on the assessment of frost structures that are best documented in the Loess Belt and in plateau areas composed of glacial till. Investigations were conducted in the central‐eastern part of the European Sand Belt (SE Poland and NW Ukraine) on a fluvio‐aeolian sedimentary succession and took into account its chronological context given by luminescence dating. Various generations of periglacial structures found in these deposits indicate not only the development of permafrost (ice‐wedge pseudomorphs) and decreased humidity (composite wedge casts) but also the degradation of permafrost (large‐scale involutions) and, finally, the establishment of deep seasonal frost (frost cracks). The diversity of structures in the study region appears to result from local conditions rather than increasing continentality of climate towards the east.  相似文献   

High Inclination Meteorite Streams can Exist     

Daniel C. Jones  Iwan P. Williams 《Earth, Moon, and Planets》2008,102(1-4):35-46

Meteorites represent bodies at the larger end of the meteoroid size spectrum since they are large enough to survive ablation in the Earth’s atmosphere. They are thus far less numerous than normal meteoroids that become meteors. A number of meteorites can arrive at around the same time and location and so in some sense represent a stream, but these are just recent fragmentations. Most meteors, according to their cosmic ray exposure age are at least 10 million years old. This is roughly also the timescale for the onset of chaos in the inner Solar System and so conventional wisdom is that meteorites can not survive on such orbits for such a time span and that they certainly cannot survive as coherent streams. We investigate numerically the survival of streams for this time interval.  相似文献   

Geochemical Reference Sample Bibliography for 1982     

Iwan ROELANDTS 《Geostandards and Geoanalytical Research》1983,7(2):347-347

  相似文献   

GeostandaRef Corner Geochemical Reference Sample Bibliography for 1998     

Iwan Roelandts 《Geostandards and Geoanalytical Research》1999,23(2):261-281

  相似文献   

The impacts of fine sediment on riverine fish   总被引：2，自引：0，他引：2  

Paul Kemp  David Sear  Adrian Collins  Pamela Naden  Iwan Jones 《水文研究》2011,25(11):1800-1821

Elevated fine sediment input from terrestrial and aquatic sources as a result of anthropogenic activity is widely recognized to impact negatively on aquatic ecosystems. In rivers, freshwater fish are exposed to a range of impacts resulting from fine sediment pressures. To date, research on the effects of fine sediments on fish has been concentrated within relatively few families, notably the salmonidae. This paper reviews the literature describing indirect and direct impacts of fine sediment on freshwater fish as a contribution towards enhancing the understanding of the impacts of anthropogenic activities on freshwater ecosystems. We identify the causal mechanisms that underpin the observed negative response exhibited by fish populations to enhanced fine sediment loads, and the variability across different fish species. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献