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   

DISTRIBUTION OF CCRMP, NIST, AND USGS REFERENCE MATERIAL DATA IN THE LITERATURE (1950 - 1989)     

Ernest S. GLADNEY  Iwan ROELANDTS 《Geostandards and Geoanalytical Research》1996,20(1):45-55

Publication patterns of CCRMP, NIST, and USGS reference materials are traced over the past 40 years by literature source, analytical method employed, and constituents measured. This is the first update to our 1987 paper which covered the period 1951 - 1985.  相似文献   

1988 COMPILATION OF ELEMENTAL CONCENTRATION DATA FOR USGS AGV-1, GSP-1 AND G-2     

Ernest S. GLADNEY  Elizabeth A. JONES  Eric J. NICKELL  Iwan ROELANDTS 《Geostandards and Geoanalytical Research》1992,16(2):111-300

Concentration data on up to 90 individual constituents in USGS AGV-1, GSP-1, and G-2 have been collected from 1270 journal articles and technical reports. These data are summarized in consensus (mean) values with uncertainties expressed as +/- one standard deviation. Mean values are also calculated as a function of analytical procedure and all raw data are given in the tables. Recommended values are proposed based upon data criteria used by NIST (National Institute of Standards and Technology, formerly the National Bureau of Standards or NBS).  相似文献   

An identification methodology for a class of hysteretic structures     

C.-Y. Peng  W. D. Iwan 《地震工程与结构动力学》1992,21(8):695-712

This paper presents a method of identification for determining non-linear dynamic models for certain hysteretic structures. Particular attention is given to modelling and identifying the hysteretic behaviour of structures from strong-motion earthquake data. In this method, the response is separated into mode-like components which are analogous to those of a linear system. Based on modelling of the generalized restoring force of each mode-like component, both non-hysteretic and hysteretic non-linear models are incorporated into the general methodology. A non-hysteretic model provides an initial estimate for a final hysteretic model. The approach is applicable even when data are available from only a small number of locations in the structure. The structural model identified from this method provides a means to predict the response to future events and, ultimately, to examine the damage to a structure as a result of an earthquake.  相似文献   

GeostandaRef Corner*: Geochemical Reference Sample Bibliography for 1979 and 1980     

Iwan ROELANDTS 《Geostandards and Geoanalytical Research》1981,5(2):197-206

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Active interaction control of civil structures. Part 1: SDOF systems     

Yunfeng Zhang  W. D. Iwan 《地震工程与结构动力学》2002,31(1):161-178

This paper presents a family of semi‐active control algorithms termed as active interaction control (AIC) used for seismic response control of civil structures. AIC control algorithms include active interface damping (AID), optimal connection strategy (OCS) and tuned interaction damping (TID). A typical SDOF AIC system consists of a primary structure, an auxiliary structure and an interaction element. The auxiliary structure typically has stiffness comparable to that of the primary structure while its natural frequency is much higher than that of the primary structure. Interactions between the primary and the auxiliary structures are defined by specific AIC control logic such that vibrational energy is extracted from the primary structure into the auxiliary structure during a locking phase and dissipated in the auxiliary structure in the subsequent unlocking phase. The stability of AIC control algorithms is shown using the Lyapunov direct method. The efficacy of AIC control algorithms is demonstrated by the results of numerical simulations of SDOF systems subjected to seismic ground motions. Practical issues such as sampling period and time delay are also investigated in this study. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

Jürgen Remane     

Thierry Adatte  Iwan Stössel-Sittig 《Eclogae Geologicae Helvetiae》2004,97(3):I-II

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1988 Compilation of Elemental Concentration Data for CCRMP Reference Rock Samples SY-2, SY-3 and MRG-1     

Ernest S. GLADNEY  Iwan ROELANDTS 《Geostandards and Geoanalytical Research》1990,14(3):373-458

Concentration data on 80 individual constituents in Canadian Certified Reference Materials Project rock reference materials SY-2, SY-3, and MRG-I have been collected from 382 journal articles and technical reports. These data are summarized as consensus (mean) values with uncertainties expressed as one standard deviation. Mean values are also calculated as a function of analytical procedure and all raw data are given in the tables. Recommended values are proposed based upon data criteria used by NIST (National Institute of Standards and Technology, formerly the National Bureau of Standards or NBS).  相似文献   

The effect of earthquake duration on the damage of structures     

Garrett D. Jeong  Wilfred D. Iwan 《地震工程与结构动力学》1988,16(8):1201-1211

This paper presents a theoretical analysis of the effect of duration on the damage of structures subjected to earthquakes. The earthquake excitation is modelled by a non-stationary random process whose response spectrum is probabilistically consistent with a design response spectrum specified independently of the duration. Damage is assumed to accumulate with the cyclic application of large strains in the structural members. Two types of structure are examined: one representative of a steel structure and the other reprsentative of a reinforced concrete structure. The level of expected damage is found to be a strong function of both the ductility of the response and the duration of the excitation. Results are presented for systems with linear stiffness and a particular form of softening behaviour.  相似文献   

1988 Compilation of Elemental Concentration Data for CCRMP Soils SO-1 to SO-4     

Ernest S. GLADNEY  Iwan ROELANDTS 《Geostandards and Geoanalytical Research》1989,13(2):217-268

Concentration data on 74 individual constituents in CCRMP (Canadian Certified Reference Materials Project) soils SO-1, SO-2, SO-3, and SO-4 have been collected from 83 journal articles and technical reports. These data are summarized in consensus (mean) values with uncertainties expressed as one standard deviation. Mean values are also calculated as a function of analytical procedure and all raw data are given in the tables. Recommended values are proposed based upon data criteria used by NIST (National Institute of Standards and Technology, formerly the National Bureau of Standards or NBS).  相似文献