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201.
The aqueous mobility and potential bioavailability of metals and metalloids in road runoff in a ‘wet–dry’ tropical location
were assessed by analysing metal and metalloid concentrations in particulate, total dissolved and labile dissolved phases
in runoff waters. Road-derived Al, Cu, Pb, Sb and Zn concentrations were substantially elevated in runoff when compared to
receiving creek waters. Median dissolved concentrations in road runoff exceeded those in creek waters by up to an order of
magnitude. Leaching experiments of road sediments confirmed that several metals and metalloids were released in high concentrations
from road sediments. Labile Zn and Cu concentrations measured by diffusion gradients in thin films (DGT) showed that almost
all dissolved Zn and up to half of dissolved Cu in runoff waters and in road sediment leachate were potentially bioavailable.
Comparisons of dissolved metal concentrations in receiving waters affected by road runoff with ecosystem guideline levels,
indicated a risk of reaching toxic levels of Cu and Zn in the receiving waters in the absence of adequate treatment or dilution.
Low dilution rates of road runoff are likely to occur during late ‘dry’ season/early ‘wet’ season storms which have the potential
to produce high metal concentrations derived from long periods of accumulation of road sediment at a time when creek flow
rates are at their annual minimum. 相似文献
202.
Niels B. Christensen 《Geophysical Prospecting》2000,48(1):1-19
Surface electrical and electromagnetic methods have a limited resolution capability for determining the conductivity structure of the earth. In one-dimensional modelling a collection of many thin layers is frequently considered as one composite layer, which is then macro-anisotropic. Neither galvanic methods nor inductive methods alone can resolve the anisotropy of the ground, but a joint inversion of galvanic and inductive data may do so. The necessity of including the coefficient of anisotropy in the joint inversion of galvanic and inductive sounding data is demonstrated. An analysis is made of the combined use of geoelectrical and transient soundings to resolve the coefficient of anisotropy of a subsurface layer for varying thickness, resistivity and coefficient of anisotropy. It is found that the coefficient of anisotropy is well resolved only for layers that are many times thicker than the overburden and for coefficients of anisotropy that are not too small. The ability of the joint inversion of geoelectrical and transient sounding data to resolve macro-anisotropic layers is tested using realistic earth models determined from electrical logs. 相似文献
203.
At the Delft University of Technology (DUT), data of six stations participating in the first international GLONASS tracking
campaign, IGEX-98, were analyzed with integrity monitoring software. The software was developed at the Department of Mathematical
Geodesy and Positioning of DUT. The main function of the software is to detect slips and outliers in phase and code observations
in real time. In addition, the software also allows the validation of the information contained in the broadcast navigation
messages.
The results of the IGEX-98 data analyses are presented in a three part series. In this third and final part of the series,
GLONASS and GPS navigation message validation results will be discussed in detail. The first part was concerned with the availability
of GLONASS observations (Jonkman & de Jong, 2000a), while in the second part, GLONASS slip and outlier statistics were considered
(Jonkman & de Jong, 2000b).
The discussion of the navigation message validation results concentrates on anomalies detected in the data of an IGEX-98 station
in Switzerland. Data collected at this station from September 1998 to December 1999 was analyized. In all, 19 anomalies were
detected by the integrity monitoring software, 8 in GLONASS messages and 11 in GPS messages. The cause of the anomalies was
established by evaluating the original data files, studying official bulletins of the GLONASS and GPS ground segments, and
in some cases tracing the anomaly through the complete IGEX-98 network. ? 2000 John Wiley & Sons, Inc. 相似文献
204.
Niels Fold 《Singapore journal of tropical geography》2000,21(3):263-278
Palm oil from Malaysia and soybean meal from Brazil are of major importance in the world market. State regulation in both countries has played a crucial role in agro-industrial upgrading, i.e. the establishment, consolidation and diversification of manufacturing capacity in the oil seed chains. In particular, sufficient volumes of raw materials for local processing have been secured through systems of differential export taxes. This core set of regulatory mechanisms has been used in both countries, despite structural differences between the two chains related to the properties of the crops (oil palms and soybeans), the previous organisation of agricultural production, and the size and nature of the local markets. Globalisation in its present neoliberal form, institutionalised within the World Trade Organisation, gradually erodes the opportunity for other developing country states to upgrade agro-industries by adapting similar forms of regulatory mechanisms. 相似文献
205.
206.
Biodiversity Conservation in the REDD 总被引:1,自引:0,他引:1
Gary D Paoli Philip L Wells Erik Meijaard Matthew J Struebig Andrew J Marshall Krystof Obidzinski Aseng Tan Andjar Rafiastanto Betsy Yaap JW Ferry Slik Alexandra Morel Balu Perumal Niels Wielaard Simon Husson Laura D'Arcy 《Carbon balance and management》2010,5(1):1-9