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1.
Seasonal measurements of dimethylsulfide(DMS)in surface waters were carried out during 1993-1994 in the Jiaozhou Bay.A seasonal variation is observed for DMS concentrations in seawater,ranging from 0.6 to 8.97 nmol S/L with the highest values in spring.A factor of 4 was measured for DMS concentrations with mean concentrations of 5.85 nmol S/L or 6.58 nmol S/L in spring and 1.40nmol S/L in winter.A sea-to-air flux of DMS also showed a seasonal variation  相似文献   

2.
EcologicalplanningoflanduseinthecentralareaofTianjin,China¥LuYonglong(ResearchCenterforEco-EnvironmentalSciences,ChineseAcade...  相似文献   

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4.
The South pole aera offers one of the best locations on the Earth for studying the composition of the background aerosol. For this purpose, aerosol samples were collected in particle size fractions by 8 stages cascade impactors. Aerosol sampling was begun in Jan. and finished in Dec. 1986 at the St. Great Wall, South Pole. The samples were analysed by Proton Induced X-ray Emission (PIXE) method. In order to learn the enrichment factors of various elements all the results were separated into two groups: coarse (> 10μm) and fine (< 10μm) particles. The correlation coefficients of elements of both coarse and fine particles were discussed. The aerosol levels measured at St. Great Wall were compared to those recently measured at some other locations. It can be concluded the South Pole is a good background area on the Earth.  相似文献   

5.
The U.S. Environmental Protection Agency requested the National Research Council(which is the operating arm of the U.S. National Academy of Sciences and the U.S. National Academy of Engineering) to carry out a critical scientific evaluation of indicators to monitor ecological changes from either natural or anthropogenic causes. More specifically, the National Research Council was asked to identify criteria for evaluating biological indicators, to evaluate methods of indicator development, to provide examples of ndicators that have proven useful, and to identify areas where further research is likely to yield more useful and powerful indicators. In addition, the National Research Council was to examine what aspects of environmental conditions and trends should be monitored.  相似文献   

6.
Human impact recorded in the sediment of Honghu Lake, Hubei, China   总被引:1,自引:0,他引:1  
Vertical profiles of the total organic carbon (TOC), total nitrogen (TN), phosphorus, susceptibilities, elements and partical size were analyzed in a short ^137Cs-dated sediment core collected from Honghu Lake, China. The average sedimentation rate was 1.55 mm/a. The results indicated that trophic status of Honghu Lake in the historical period had experienced three stages. Before 1840 the lake was characterized with lower productivity, TOC was less than 9.92 g/kg; TN was 0.902 to 1.24 g/kg. During about 1840-1950, population increased quickly, there was an obvious change in TOC with an average of 13.0 g/kg. Since 1950, human impacts have accelerated the lake eutrophication and nutrients enriched in the sediment with TOC of 21.7 to 93.1 g/kg, TN of 1.77 to 8.78 g/kg. The heavy metal concentration profiles presented similar distribution trends except Pb .and Mn. The results from elements analyses indicated that Honghu Lake had not been polluted by heavy metals except lead.  相似文献   

7.
Allelochemicals sustained-release microspheres (ACs-SMs) exhibited great inhibition effect on algae,however,few studies have focused on ACs-SMs toxicity on invertebrate.In this study,the effects of single high-concentration ACs (15 mg/L,SH-ACs),repeated low-concentration ACs (3×5 mg/L,RL-ACs) and ACs-SMs containing 15 mg/L ACs exposure on the ingestion,incorporation,and digestion of Daphnia magna Straus (DS) were investigated by stable isotope15N labeling method.Meanwhile,the diversit...  相似文献   

8.
In general, many pollutants co-exist in natural aquatic ecosystems. They affect each other and occur different results, such as synergism, addition and antagonism. So the research at mixtoxicity of contaminants to aquatic organism is more important than monotoxicity. In this paper, 50% effectual inhibition concentration 48h EC50 values of 6 kinds of nitroaromatic compounds to the green algae, Scenedesmus obliquus, were investigated. Mixtoxic experiments, in which any combination of 2,4-DNT and other 6kinds of compounds, indicate: (1) synergisms between 2,4-DNT and 4-NAn, as well as 4-NAnis, 1,4-DNB; (2) antagonisms between 2,4-DNT and 4-NT, as well as 4-NPh, 4-NCB.  相似文献   

9.
IntroductionEnvironmentalcontaminantsmayhavetoxiceffectsonmanydifferentorganismsandaffectbiologicalprocessesatcellular,population ,communityandecosystemlevelsoforganization .Mostrecenthazardevaluationprogramsrecommendalgaetoxicitytestsforevaluationsofc…  相似文献   

10.
DevelopmentoftheprocedureforthestabilizationofrainwatersamplesYuanZhongxin;Chung-ShinYuan(DepartmentofChemicalEngineeringNati...  相似文献   

11.
In this paper it was reported that PbCl2 , CdCl2 , HgCl2, and aquatic environmental samples containing Al, Cd, Cu, Pb, Sr, Zn and other heavy metal ions as well as organic chemicals suppressed thegrowth of E. coli only at higher exposed concentrations. The stimulative effects of PbCl2 and HgCl2 on thegrowth of E. coli were clearly showed at lower concentrations and longer time. It suggested that the toxic effects of heavy metal ions and other pollutants on the growth of E. coli are variable according to the differentexposed levels.  相似文献   

12.
Atmospheric carbonyls were measured at a semi-urban site in Orléans, France, from October 2010to July2011. Formaldehyde, acetaldehyde and acetone were found to be the most abundant carbonyls, with average concentrations of 3.1, 1.0, 2.0 ppb, respectively in summer, 2.3, 0.7, 2.2 ppb, respectively in autumn, 2.2, 1.0, 2.1 ppb, respectively in spring,and 1.5, 0.7, 1.1 ppb, respectively in winter. Photo-oxidation of volatile organic compounds(VOCs) was found to make a remarkable contribution to atmospheric carbonyls in the semi-urban site based on the distinct seasonal and diurnal variations of the carbonyls, as well as the significantly positive correlations between the carbonyls and ozone. The significantly negative correlations between NO x and O_3 as well as the carbonyls and the positive correlations between wind speed and O_3 as well as the carbonyls implied that the carbonyls and O_3 at the semi-urban site were probably formed during air mass transport from neighboring cities.  相似文献   

13.
EcologyoftherehabilitationofvegetationontropicalcoastalerodedlandinGuangdong,ChinaYuZuoyue;WangZhuhaoSouthChinaInstituteofBot...  相似文献   

14.
Sincetheinternationalgeophysicalyear(IGY,1957—1958),Antarcticahasbeentheobjectofintensivescientificinvestigationbyteamsofscientists...  相似文献   

15.
A wide range of wastes can potentially be used to generate thermal and electrical energy.The co-combustion of several types of waste as part of water-containing waste-derived fuels is a promising method for their recovery. In this research, we use thermogravimetric analysis and differential scanning calorimetry to study the thermal behavior and kinetics of coal slime, biomass, waste oils, and blends on their basis. We also analyze the concentrations of gaseous emissions. The results show that bi...  相似文献   

16.
SO2 Pollution; rape plant (Brassica chinensis); turnip moth (Agrotis segetum); growth and developmental parameters.  相似文献   

17.
On the study of ecosystem health:state of the art   总被引:2,自引:0,他引:2  
IntroductionDuringlastdecades,theterm“ecosystemhealth”isusedwithincreasingfrequencyintheliterature.Thegrowinginterestsinthestu...  相似文献   

18.
Fossilization in amber is unique in preserving specimens with microscopic fidelity; however, arthropod inclusions are rarely examined beyond the exoskeleton as this requires destructive sampling when traditional techniques are used. We report the first complete, digital 3D, non-destructive reconstruction of the anatomy of an insect fossil, a specimen of †Mengea tertiaria embedded in a 42-Ma Baltic amber. This was made possible using Synchrotron μ-CT. The species belongs to the stem group of the phylogenetically enigmatic and extremely specialized Strepsiptera. Most internal structures of the fossil are preserved, but small parts of the lumen had decayed due to incomplete infiltration of the resin. Data on internal organs provided additional information for resolving phylogenetic relationships. A sister group relationship between †Mengea and all extant lineages of the group was confirmed with characters previously not accessible. The newly gained information also yielded some insights in the biology of †Mengea and the early evolutionary history of Strepsiptera. The technique has a tremendous potential for a more accurate interpretation of diverse fossil arthropods preserved in ambers from 130 Ma to the present.  相似文献   

19.
The fluxes of heavy metals and magnetite, a fly-ash component, from coal burning, to sediments of the Kunming Lake in Beijing have increased measurably over the last fifty years. Ages were introduced to the sediment strata through Pb-210 geochronologies. Even with a doubling of coal usage by the year 2000, the anthropogenic metal fluxes will still be less than those recorded in metropolitan Tokyo and U.S. lakes.  相似文献   

20.
Eleven organophosphate esters (OPEs) in the air and seawater were investigated from the northwestern Pacific Ocean to the Southern Ocean during the 2018 Chinese 34th Antarctic Scientific Expedition.The concentration of total OPEs ranged from 164.82 to 3501.79 pg/m3in air and from 4.54 to 70.09 ng/L in seawater.Two halogenated OPEs,tri(chloropropyl) phosphate (TCPP) and tri (2-chloroethyl) phosphate (TCEP),were generally more abundant than the non-halogenated OPEs.A level Ⅲ fugacity mo...  相似文献   

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