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1.
《国际环境与污染杂志》2011,10(2):304-314
This paper investigates some of the reflectivity characteristics that clouds (when modelled as solid bodies) must exhibit to be compatible with observations that the reflecting surface of a cloud (i) appears almost equally bright across its face, (ii) is brightest when the cloud is opposite to the Sun but decreases in brightness as the cloud moves to other positions and (iii) increases in brightness with increasing optical thickness of the cloud in the observer's line of sight. These observations, respectively, are shown to imply that the peak value of the bidirectional total reflectivity from a cloud surface (i) increases in inverse proportion to the cosine of the angle between the Sun and the normal to the cloud surface, as the incident angle increases, (ii) appears to be directed back in the direction of the incident radiation, and (iii) increases as optical thickness of the cloud in the observer's line of sight increases. The results could have application in many fields (e.g. modelling diffuse radiance distributions for cloudy skies). 相似文献
2.
Árpád Ambrus 《Journal of environmental science and health. Part. B》2013,48(3):435-442
Abstract A computer model was used to take random samples from primary sample populations obtained from field trials to simulate the uncertainty of sampling for residue analysis of plant commodities and soil. The results indicate about 40%, 30% and 20% relative uncertainty when random samples of size 5, 10 and 25 are taken respectively, from a single lot. Therefore the sample size should be the same for establishing and enforcing legal limits. 相似文献
3.
India has a very extensive coastline of about 7515 km, rich in diverse living resources. These resources continue to deteriorate with rampant harvesting or are altered for other uses such as aquaculture and fisheries. The present paper deals with degrading coastal habitats in northeastern India, and projects the intensity of the stress arising from the collection of tiger prawn seeds (Penaeus monodon) for aquacultural farms and molluskan shells for poultry feed and edible lime. Indiscriminate exploitation of these resources leads to a heavy reduction of the species concerned and other associated marine communities. The magnitude of such destruction has been quantified. The impacts of biodiversity loss and their after-effects on the ecobalance of this coastal system have become a matter of great concern to ecologists to maintain security and sustainability. The authors propose a public awareness program on themes relating to the importance of biodiversity for human livelihoods. 相似文献
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Philip W. West J. Jaime Chiang 《Journal of the Air & Waste Management Association (1995)》2013,63(7):671-673
A method is described for determining acidity by means of the spectrophotometric determination of the displacement of the equilibrium of açid-base indicators. The method is simple, sensitive and free of known interferences. There is no dependence on costly or sophisticated equipment and the results obtained are reliable and reproducible. 相似文献
6.
J. P. Franey T. E. Graedel 《Journal of the Air & Waste Management Association (1995)》2013,63(6):644-648
The corrosion films that form on metals and alloys during field exposure are generally chemical mixtures. It is clear that the formation of such films requires the presence of mixtures of atmospheric corrosive gases, or of a combination of corrosive gases and atmospheric aerosol particles. Thus, laboratory experiments designed to reproduce field effects must involve mixtures of corrosive constituents. In this paper we review the mixed corrodent experiments of ourselves and others, describe the synergistic effects of mixtures of pollutants on a variety of metals, and present the necessary ingredients for experiments designed to simulate the interactive effects of atmospheric corrosive constituents. 相似文献
7.
Volker Berding Stefan Schwartz Michael Matthies 《Environmental science and pollution research international》1999,6(1):37-43
The interdependencies of parameters applied in the models of EUSES are visualised in a directed connectivity graph. The parameters
(inputs, defaults, state variables, outputs) are represented by boxes (nodes) and their relations by lines (edges). The visualisation,
on the one hand, clarifies the complexity of the models in EUSES and, on the other hand, creates an overview and transparency.
The parameters’ relations to each other can be recognised faster, and the models can be better understood. The complexity
was quantified by the number (variety), kind (substance parameter, physico-chemical parameter, concentration, other parameters),
and depth (dimension) of the parameter and the number of relations (connectivity). The variety of EUSES (without the modelsSimple Treat andSimple Box whose interior structure is not documented and without the effect and risk characterisation) amounts to 466, the connectivity
to 961, and the maximal dimension is 21. 相似文献
8.
介绍了电解法生产次氯酸钠的原理 ,并在原有生产工艺的基础上进行了重新设计和对设备的重新选择、改造 ,得出了各个工艺参数的最佳值 ,生产出高品质的次氯酸钠 相似文献
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Morten E. Simonsen Martin B. S?rensen Erik G. S?gaard 《Environmental science and pollution research international》2012,19(9):3772-3781
Objective
This work aims to investigate the correlation between the photocatalytic activity determined by methylene blue bleaching (DIN 52980), stearic acid degradation, and degradation of acetone in gas phase.Method
The photocatalytic TiO2 coatings included in this investigation ranged from thin commercially available coatings (ActivTM and BioCleanTM) and ready to use suspensions (Nano-X PK1245) to lab-produced PVD and sol?Cgel coatings. XRD analysis of the photocatalytic coatings showed that all the coatings consisted of nanocrystalline anatase, although the thickness and porosity varied considerably.Results
The study showed that the reproducibility of the activity measurements was good. However, more importantly, the investigation showed that there is a good correlation between the activities determined by the different methods even though the characteristics of the photocatalytic coatings and the organic probe molecules varied considerably.Conclusion
The overall findings of this work suggest that there is a good correlation between the investigated methods. These results are promising for the future work concerning standardization of methods for determination of the activity of photocatalytic films. 相似文献10.
Changes of BOD/TOD and DOC with time were obtained for solutions of 9 synthetic surfactants and 2 fatty acid salts under various conditions. The cationic surfactants, ABM and ABDM, were not biodegraded at all and inhibited the biodegradation of a synthetic sewage. LAS was not biodegraded at concentration of 30 mg/l and higher and inhibited the biodegradation of the sewage. 相似文献
11.
Marrs RH Williams CT Frost AJ Plant RA 《Environmental pollution (Barking, Essex : 1987)》1989,59(1):71-86
With increasing use of herbicides there has been growing concern that spray drift from treated land will affect vegetation on adjacent nature reserves and other areas of high conservation interest. A preliminary attempt was made to assess this risk by placing a range of native plant species at different distances downwind from standardised drift events and assessing lethal effects and sublethal damage. Five herbicides were tested: asulam, 'Finesse' (chlorsulfuron + metsulfuron-methyl), glyphosate, MCPA and mecoprop. Applications were made at the appropriate time of years for each herbicide (autumn, spring and summer), and at both low and high wind speeds. The maximum safe distance at which no lethal effects were found was 6 m from the sprayer, but for most herbicides the distance was 2 m or less. Generally, damage symptoms were found at greater distances than lethal effects, but in most cases there was rapid recovery by the end of the growing season. These observations are consistent with drift-deposition models, in which the fallout of herbicide droplets has been measured. It is suggested that buffer zones surrounding nature reserves should be in the order of 5-10 m for ground sprayers to minimise the risk of herbicide impacts on these habitats. 相似文献
12.
造纸废水混凝处理中SFT助凝替代性研究 总被引:1,自引:0,他引:1
中小造纸厂废水处理常用PAC作混凝剂 ,PAM作助凝剂。由于PAM成本很高 ,影响了处理设备的投运率。用超细滑石粉 (SFT)替代PAM助凝 ,与混凝剂PAC配合 ,其混凝处理效果基本相当 ,但是处理成本降低 0 .10元 /m3 。由于SFT属环境无害材料 ,不会给排泥带来二次污染 相似文献
13.
The concept of critical loads has been generally accepted throughout Europe, and increasingly in Asian countries and the rest of the world, as providing the data which forms the basis for international negotiations on abatement strategies for emissions of acidifying pollutants. Central to the determination of quantitative critical loads of acidity for forests (and other ecosystems) is the rate at which the minerals in the soil weather or dissolve. Seven methods for determining these rates on a regional basis for the production of critical load maps have been suggested by the official bodies which are responsible for co-ordinating the European critical load mapping efforts. These methods are largely correlations which require a knowledge of the soil parent material and/or the soil mineralogy. The purpose of this paper is to review these weathering rate calculation methods and to assess whether it is currently possible to calculate numerically accurate critical loads for the production of regional critical load maps. A consideration of the data used to generate these methods and comparisons of the weathering rates calculated using various methods leads to the conclusion that at present it is not. Further work is needed to develop and maintain the initial credibility of critical loads both scientifically and as an aid to policy decisions. 相似文献
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讨论了以河道底泥和生活污泥为原料烧制陶粒比表面的测定原理、方法和结果,并对生活污泥添加量、粘结刑添加量和烧结温度对陶粒比表面的影响作了进一步分析。 相似文献
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Saeki K Nakajima M Loughlin TR Calkins DC Baba N Kiyota M Tatsukawa R 《Environmental pollution (Barking, Essex : 1987)》2001,112(1):19-25
Silver in the three species of pinnipeds [northern fur seal (Callorhinus ursinus), Steller sea lion (Eumetopias jubatus), and harbor seal (Phoca vitulina)] caught in the North Pacific Ocean were analyzed using inductively coupled plasma-mass spectrometry, in order to understand accumulation and distribution of silver in pinnipeds. In northern fur seals, relatively high concentrations of silver were observed in the liver and body hair. Some 70% of the silver burden was concentrated in the liver. Hepatic silver concentrations were significantly correlated to age in northern fur seals (r = 0.766, P < 0.001, n = 49) and Steller sea lions (r = 0.496, P < 0.01, n = 28). Levels of silver concentrations per wet weight (microgram g-1) in the three pinnipeds ranged from 0.04 to 0.55 for northern fur seals, from 0.1 to 1.04 for Steller sea lions and from 0.03 to 0.83 for harbor seals. Silver concentrations in liver for all pinnipeds were significantly correlated with mercury, and selenium (P < 0.001). Molar ratios between silver to selenium approximated 1:180 in northern fur seals, 1:120 in Steller sea lions, and 1:60 in harbor seals. The silver-mercury molar ratios were approximately 1:170 in northern fur seals, and 1:80 both in the other species. Increase in silver accumulation in the liver was caused by the retention in nuclei and mitochondria fraction together with mercury and selenium in the cells of northern fur seals. 相似文献
18.
Interactions of micro-contaminants with soil may play a crucial role in their environmental fate and possible harmful effects. Major goals of our investigations were to model the availability of widely used pesticides and characterize adsorption capabilities of distinctive soil types by the accomplishment of extensive comparative studies and application of several extraction methods. Environmental and biological relevance of these examinations is enhanced by the fact that intrinsic features and specific details of pesticide accessibility have not been revealed so far by a comparative approach. Five different experimental methods were assessed for modelling accessibility of five selected pesticides. The applied models for regaining the pesticides showed diverse efficiency in extraction capability in cases of the different soil types (sandy, brown forest and alluvial soils). The amounts of the obtained pesticides were determined by using gas-chromatography coupled to mass spectrometry (GC-MS) and high pressure liquid chromatography coupled to mass spectrometry (HPLC-MS). Accessibility of pesticides was also compared in cases of sterilized and real soil samples in order to estimate the extent of the influence of microflora. Aqueous extraction solvents proved to be suitable for accurate assessment of the accessible amounts of pesticides, as their effectivity was at least as high as that of the applied organic solvents. In our studies pesticide-soil interactions have comprehensively been characterized, and possible influences of environmental factors on the accessibility have also been revealed. Our study might be regarded as a tentative approach to model some significant circumstances playing key roles in pesticides' possible bioavailability. 相似文献
19.
有机螯合剂的存在能促进土壤中的固相Ni向水溶态转化 ,提高Ni的生物可利用性。本文讨论了土壤中镍的存在形态以及有机螯合剂对土壤中镍形态的影响 ,并从植物吸收Ni的机制出发 ,阐述有机螯合剂对植物吸收Ni和植物生物量的影响 ,分析了植物修复的螯合诱导技术的一些局限性 ,并对植物修复螯合诱导技术提出展望 相似文献