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201.
Although invasive alien species (IAS) are a major threat to biodiversity, human health, and economy, our understanding of the factors controlling their distribution and abundance is limited. Here, we determine how environmental factors, land use, life-history traits of the invaders, residence time, origin, and human usage interact to shape the spatial pattern of invasive alien plant species in South Africa. Relationships between the environmental factors and the extrinsic and intrinsic attributes of species were investigated using RLQ analysis, a multivariate method for relating a species-attribute table to an environmental table by way of a species presence/absence table. We then clustered species according to their position on the RLQ axes, and tested these groups for phylogenetic independence. The first three axes of the RLQ explained 99% of the variation and were strongly related to the species attributes. The clustering showed that, after accounting for environmental factors, the spatial pattern of IAS in South Africa was driven by human uses, life forms, and reproductive traits. The seven clusters of species strongly reflected geographical distribution, but also intrinsic species attributes and patterns of human use. Two of the clusters, centered on the genera Acacia and Opuntia, were phylogenetically non-independent. The remaining clusters comprised species of diverse taxonomic affinities, but sharing traits facilitating invasion in particular habitats. This information is useful for assessing the extent to which the potential spread of recent introductions can be predicted by considering the interaction of their biological attributes, region of origin, and human use.  相似文献   
202.
Different solid waste management system scenarios were developed and compared for the Municipal Solid Waste Management System of Ankara by using the life cycle assessment (LCA) methodology. The solid waste management methods considered in the scenarios were collection and transportation of wastes, source reduction, Material Recovery Facility (MRF)/Transfer Stations (TS), incineration, anaerobic digestion and landfilling. The goal of the study was to determine the most environmentally friendly option of MSWM system for Ankara. The functional unit of the study was the amount of solid waste generated in the system area of concern, which are the districts of Ankara. The life cycle inventory analysis was carried out by IWM Model-1. The inputs and outputs of each management stage were defined and the inventory emissions calculated by the model were classified in to impact categories; non-renewable energy sources exhausting potential, final solid waste as hazardous and non-hazardous, global warming, acidification, eutrophication and human toxicity. The impacts were quantified with the weighing factors of each category to develop the environmental profiles of each scenario. In most of the categories, Source Reduction Scenario was found to be the most feasible management method, except the global warming category. The lowest contribution to GWP was calculated for the anaerobic digestion process. In the interpretation and improvement assessment stage, the results were further evaluated and recommendations were made to improve the current solid waste management system of Ankara.  相似文献   
203.
Single, dual and triple mixtures of totally seven different mixture combinations of the metals Al, Ba and Fe were examined in Lemna minor (L) culture, Daphnia magna (D) culture and in a consortium culture consisting of L. minor and D. magna. In this study: (a) differences in removed metal proportions at the end of 24 and 48?h, (b) differences in removed metal amounts due to cultures, (c) differences in the removed proportions of a metal in distinct mediums and (d) removal correlation of the metals due to cultures were investigated. The study results showed that among the metals Al, Ba and Fe, Al has the most toxic effect on organisms involved in this study. Although similar toxicity results of Al and Fe on test groups were observed, Ba gave different toxicity results on test groups. An overview of the bioremediation results indicates that L. minor removes the metals Al and Fe more successfully than Ba. Different mixture combinations of metals performed dissimilar removal results in the same cultures. According to the correlations analysis for the metals Ba and Fe, a high correlation was recorded between the consortium group and test groups containing only D. magna, r?=?0.88, r?=?0.91, respectively.  相似文献   
204.
A Penicillium camemberti strain isolated in our laboratory has been studied for its ability to degrade chlorinated pulping wastes, presumably containing a variety of chlorinated polyphenols. In batch tests, the highest removals (76% AOX, 61% color and 65% TOC) were obtained with 0.2 g/l feed acetate concentration. The tendency of the fungus to dechlorinate bleachery effluents better under non-shaking conditions and to attach onto surfaces suggested the use of immobilized cells rather than freely suspended ones in further exploitation of the process. An upflow glass wool packed column reactor established with this fungus could be operated for nearly two years in the laboratory. At best around 70% AOX could be removed from chlorinated pulping wastes in 7.3 h of contact with no aeration and with a minimal amount of carbon supplement (0.2 g/l). Finally, an asymptotic mathematical formula for determining Michaelis-Menten kinetic rates has been derived. The kinetic rates K(m) (the Michaelis constant or saturation constant for the substrate) and V(m) (the product of maximum rate for the enzymatic reaction and biomass concentration) were then calculated as 126.386 mg/l and 2.83017 mg/lh, respectively.  相似文献   
205.
新生二氧化锰吸附法去除水中直接大红染料   总被引:10,自引:0,他引:10  
研究了影响新生MnO2对直接大红4B染料废水脱附脱色的有关因素,结果表明,pH是影响脱色效果的关键因素,吸附脱色存在佳化pH范围,其上限随染料浓度的提高和MnO2投加量的增加而增大。投加0.3g/L的MnO2可使染料废水的脱色率达到98.2%,升高温度可提高脱色率。  相似文献   
206.
振动与冲击试验中单自由度线性系统损坏可能性的比较   总被引:1,自引:0,他引:1  
比较了单自由度线性机械系统在稳态振动,随机振,运输试验以及冲击试验中响应的大小。  相似文献   
207.
In this study, a comparative thermodynamic performance analysis of cascade system (CCS) for cooling and heating applications is presented and compared for different refrigerant couples. The CCS consists of the low-temperature cycle (LTC) and high-temperature cycle (HTC). The CO2 was used as working fluid in LTC, whereas the HFE 7000, R134a, R152a, R32, R1234yf, and R365mfc refrigerants were used in HTC. The heating and cooling coefficients of performance (COPht, COPcl) and exergy efficiency of CCS are investigated parametrically according to various factors such as the evaporator, condenser, and reference temperatures. After thermodynamic analyses are completed, the COPcl of CCS is obtained as 1.802, 1.806, 1.826, 1.769, 1.777, and 1.835 for CO2-HFE7000, CO2-R134a, CO2-R152a, CO2-R32, CO2-R1234yf, and CO2-365mfc refrigerant couples, respectively. Furthermore, the heat exchanger has the highest exergy destruction rate, whereas the expansion valves have the lowest of exergy destruction rate.  相似文献   
208.
ABSTRACT

Deltamethrin is a widely used pyrethroits worldwide. Although the chemical is used to combat insects, it has effects on other non-target organisms. Deltamethrin is extensively used in agriculture, animal husbandry, and domestic areas in the Lake Van basin. The aim of this study was to determine the cytotoxic, genotoxic, and oxidative damage from deltamethrin on the primary hepatocyte culture of Lake Van fish (Alburnus tarichi). In this study, the toxic effects of different concentrations (0.01, 0.1, 1, and 10?µM) of deltamethrin in the primary hepatocyte culture of Lake Van fish were investigated via liver enzymes aspartase aminotransferase (AST) and alanine aminotransferase (ALT), and the total antioxidant status (TAS), total oxidant status (TOS), lipid peroxidation (MDA), and DNA damage (8-OHdG).

Deltamethrin caused an increase in the AST and ALT levels dependent on the dosage and time. The TAS and TOS levels increased at the end of 24?h and there was no difference at the end of 48?h. Deltamethrin did not affect the MDA level, but increased the 8-OHdG (P?<?0.05). In conclusion, it can be said that high doses of deltamethrin (1 and 10?µM) have a toxic effect on the primary hepatocyte culture of Lake Van fish.  相似文献   
209.
三维植被网喷播植草技术在高速公路边坡上的应用   总被引:7,自引:0,他引:7  
顾晶 《生态环境》2003,12(2):155-156
三维网喷播植草是一种能在纯石质边坡上进行绿化的新工艺。文章介绍了该技术的施工工艺和质量检验标准,并在广惠高速公路边坡进行应用试验。试验结果表明,该技术绿化防护效果较好,适应当地气候条件。  相似文献   
210.
Nitrification and carbon removal are investigated in aerobicbatch digestion of various sludges. The experiments arecarried out with activated sludge (Test 1) and with amixture of activated and primary settling sludge (Test2). The nitrification rate was monitored, measuring theNO2 - concentration. At the 3rd day of thedigestion 40.7 mgNO2-N/l and 3.89 mgNO2-N/l werefound in Tests 1 and 2 respectively. In a digestion process,the degradation of biomass indicates the beginning of theendogenous phase. Our measure for biomass content of thesludge was protein analysis. In Test 1, the first day valuesof 50.93 mgTOC/ gdry matter/day and 138.53mgprotein-C/gdry matter/day for specific TOC andprotein-C removal rates showed, that the digestion processbegan in the endogenous phase. For Test 2, since theendogenous phase began after removal of raw organic matter inprimary settling sludge, specific TOC and protein-C removalrates were observed to be 60.12 mgTOC/gdry matter/dayand 26.72 mgprotein-C/gdry matter/day,respectively.  相似文献   
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