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1.
Peng Wang Shengqiang Zhu Mihalis Vrekoussis Guy P. Brasseur Shuxiao Wang Hongliang Zhang 《Frontiers of Environmental Science & Engineering》2022,16(5):65
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过渡金属催化剂上CO还原NO反应性能的研究 总被引:3,自引:0,他引:3
在一系列负载型过渡金属催化剂上考察了CO-NO和CO-O2的反应性能。结果表明,催化剂的CO-O2反应活性高于CO-NO反应,催化剂表面NO解离是CO-NO反应的速率控制步骤。低温反庆有利于N2O的生成,高温有利于N2的生成。 相似文献
3.
We performed a screening on 21 Mediterranean sponge species in order to know from which ones primmorphs can be obtained, with a comparison of their formation among the outputs. Thirteen species produced primmorphs, evidencing a high variability among species concerning the number and size of primmorphs, without evidencing any taxonomical specificity. Additionally, the formation process and trend of growth during 1 month of monitoring were studied from a quantitative point of view. The dynamics of primmorphs formation follow different patterns: slow and quick formation, short and long-time survival and in the case of long-time survival, the fission and fusion models are proposed. Besides these patterns, each analysed species showed characteristic trends in the time required for the aggregation of cells, the time required for the production of small primmorphs, growth fluctuation and the acquirement of a final stable size. 相似文献
4.
He NIU Ziwei MO Min SHAO Sihua LU Shaodong XIE 《Frontiers of Environmental Science & Engineering》2016,10(5):1
We develop a multi-effect evaluation method to assess integrated impact of VOCs. Enable policy-makers to identify important emission sources, regions, and key species. Solvent usage and industrial process are the most important anthropogenic sources. Styrene, toluene, ethylene, benzene, and m/p-xylene are key species to be cut. Volatile organic compounds (VOCs) play important roles in the atmosphere via three main pathways: photochemical ozone formation, secondary organic aerosol production, and direct toxicity to humans. Few studies have integrated these effects to prioritize control measures for VOCs sources. In this study, we developed a multi-effects evaluation methodology based on updated emission inventories and source profiles, by combining the ozone formation potential (OFP), secondary organic aerosol potential (SOAP), and VOC toxicity data. We derived species-specific emission inventories for 152 sources. The OFPs, SOAPs, and toxicity of each source were estimated, the contribution and sharing of source to each of these adverse effects were calculated. Weightings were given to the three adverse effects by expert scoring, and then the integrated effect was determined. Taking 2012 as the base year, solvent use and industrial process were found to be the most important anthropogenic sources, accounting for 24.2% and 23.1% of the integrated effect, respectively, followed by biomass burning, transportation, and fossil fuel combustion, each had a similar contribution ranging from 16.7% to 18.6%. The top five industrial sources, including plastic products, rubber products, chemical fiber products, the chemical industry, and oil refining, accounted for nearly 70.0% of industrial emissions. Beijing, Chongqing, Shanghai, Jiangsu, and Guangdong were the five provinces contributing the largest integrated effects. For the VOC species from emissions showed the largest contributions were styrene, toluene, ethylene, benzene, and m/p-xylene. 相似文献
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Anja Widdig Wolf Jürgen Streich Peter Nürnberg Peter J. P. Croucher Fred B. Bercovitch Michael Krawczak 《Behavioral ecology and sociobiology》2006,61(2):205-214
When agonistic interventions are nepotistic, individuals are expected to side more often with kin but less often against kin in comparison with non-kin. As yet, however, few mammal studies have been in a position to test the validity of this assertion with respect to paternal relatedness. We therefore used molecular genetic kinship testing to assess whether adult female rhesus macaques (Macaca mulatta) from the free-ranging colony of Cayo Santiago (Puerto Rico) bias their interventions in ongoing dyadic aggressive interactions towards maternal and paternal half-sisters compared with unrelated females. It turned out that females supported maternal half-sisters significantly more often than paternal half-sisters or non-kin regardless of the costs associated with such interventions. Similarly, females targeted maternal half-sisters significantly less often than non-kin when this was associated with high costs. Unrelated females provided significantly higher mean rates of both high- and low-cost support to each other than did paternal half-sisters. However, females targeted paternal half-sisters significantly less often than non-kin when targeting was at low cost, suggesting that females refrain from intervening against paternal half-sisters. Our data confirm the general view that coalition formation in female mammals is a function of both the level of maternal relatedness and of the costs of intervention. The patterns of coalition formation among paternal kin were found to be more complex, and may also differ across species, but clear evidence for paternal kin discrimination was observed in female rhesus as predicted by kin selection theory. 相似文献
7.
The carbonate radical (CO 3 ?· ) is a photoinduced transient species occurring in surface waters. The carbonate radical can transform both natural compounds and xenobiotics. For instance, it can react with electron-rich substrates such as anilines, phenols and organic sulfur compounds. Here we used the APEX software to assess photochemical reactions, including the formation rates of transient species, based on water chemistry and depth, under summertime irradiation conditions. We found that the reaction between peroxynitrite and carbon dioxide is a potentially significant source of CO 3 ?· in sunlit surface waters, and could account for up to 10–15 % of the total CO 3 ?· formation. The peroxynitrite pathway to CO 3 ?· would be most significant at pH 7–8 and would be enhanced in waters with elevated nitrate and low alkalinity. Therefore, the proposed process could add to the known photochemical sources of CO 3 ?· in surface-water environments. 相似文献
8.
Marine bryozoans have a variety of behavioural reactions that are associated with different functions: feeding, cleaning, removal of filtered water, gamete release, avoidance reactions and, probably, sensation. Coordinated activities of polypides are regulated neurophysiologically, physiologically, structurally and, possibly, hormonally. Several group reactions are supposedly non-coordinated. Group autozooidal reactions and different types of colonial behaviour were observed and recorded for 17 bryozoan species and subspecies from the White and Barents Seas. Three local collective reactions (synchronised scanning, repeated particle transfer by circular water currents, and feeding and cleaning of the colony surface by "chains" of inclined lophophores) are described for the first time. The formation of water outlets (chimneys) was observed in four species with encrusting colonies. A new type of chimney was discovered in large colonies of Tegella armifera, in which chimneys are formed by temporary retraction of 10-12 neighbouring polypides. The space thus formed is surrounded by equitentacled lophophores standing vertically. Chimneys associated with elevated areas on the colony surface (monticules) were found in two species. In contrast to all previously published speculations and observations, the monticules were often places of incurrent rather than excurrent flow, and water outlets were formed in depressions between monticules. In Schizomavella lineata, monticules change their function from incurrent to excurrent after polypide degeneration. Conditions for the origin of various types of water outlets are discussed. 相似文献
9.
由文辉 《生态与农村环境学报》1997,(3)
淀山湖是上海市唯一的淡水湖泊,面积约62km2。淀山湖湿地的形成主要是地质、地貌、气候、水文等自然因素和人类活动影响长期相互作用的结果。本文着重讨论了淀山湖湿地的生产功能和环境生态功能,并对湖泊湿地的利用与保护提供了建议。 相似文献
10.
Lexi Journey Jonathan P. Drury Michael Haymer Kate Rose Daniel T. Blumstein 《Behavioral ecology and sociobiology》2013,67(8):1285-1293
Because conspicuous morphology such as colorful plumage may increase predation risk, we aimed to see if variation in plumage coloration could explain variation in avian anti-predator behavior. We included several measures of plumage coloration: human perception of vividness from images in field guides, total intensity from reflectance spectra of museum skins, contrasts calculated from physiological models of these spectra parameterized for both raptors and humans, chroma, and spectral saturation. We investigated how well these measurements predicted risk assessment in ten species of birds in St. John, U.S. Virgin Islands. We quantified how each species responded to playbacks of a predator’s calls and compared this response to that elicited by songs from a non-predatory, sympatric bird. We found that human-determined measures of vividness best predicted anti-predator responses of birds—more vividly colored species responded more to predators than duller species. No spectrophotometric variable explained variation in species reactions to a predator call. Our results suggest that vivid birds may compensate for their conspicuousness by being more responsive to the sound of predators and that more work is needed to better evaluate how animal coloration is quantified in comparative studies. 相似文献
11.
扁刺栲-华木荷群系次生林林下物种多样性分析 总被引:6,自引:0,他引:6
对四川中亚热带扁刺栲(Castanopsis platyacantha)—华木荷(Schima sinensis)群系人工杉木林、水杉林、日本落叶松林和天然次生林林下植物进行了群落调查和物种多样性分析。结果表明:(1)杉木林、水杉林、日本落叶松林和次生扁刺栲—华木荷林(20a)的物种丰富度分别为62,59,53和32;Simpson多样性指数分别为7.95,7.08,9.24和5.38;Shannon—Wiener多样性指数分别为3.67,3.3l,3.64和2.46。(2)人工林林下植物群落之间的群落系数和相似度系数分别为0.45~0.60和0.62~0.82;人工林林下植物群落与次生阔叶林林下植物群落之间的群落系数和相似度系数分别为0.19~0.53和0.55~0.77。(3)人工林林下物种多样性比次生林高的主要原因可能是风倒木和站干死木导致人工林乔木层郁闭度减小,增加了林下的光照,从而改蛮了林下的微生境。表6参19。 相似文献
12.
Dongjie Shang Jianfei Peng Song Guo Zhijun Wu Min Hu 《Frontiers of Environmental Science & Engineering》2021,15(2):34
13.
Lei Chen Stephan Küppers Zheng Wang Xinyi Xiang Shiwei Cao 《Environmental Chemistry Letters》2014,12(2):329-334
Electrochemistry–mass spectrometry is used to simulate redox reactions in many research disciplines because this technique is fast and provides information on compound metabolites. However, the analysis of the degradation of refractory organic pollutants by reactive oxygen species is difficult to achieve by the electrochemistry step. Therefore, here we use online electro-Fenton-mass spectrometry to study for the first time the oxidation of 2,4′,5-trichlorobiphenyl [polychlorinated biphenyl (PCB) 31] by reactive oxygen species and the binding reactions of PCB degradation products with model substances of natural organic matter. The degradation products were identified by coupled Q Trap mass spectrometry. We observed a binding of a degradation product with γ-l-glutamyl-l-cysteinyl-glycine. We propose a transformation pathway. We conclude that online electro-Fenton-mass spectrometry is a promising technique to study the oxidation of refractory organic pollutants and further binding of degradation products with natural organic matter. 相似文献
14.
Size-resolved aerosol ionic composition and secondary formation at Mount Heng in South Central China
Xinfeng WANG Wenxing WANG Likun XUE Xiaomei GAO Wei NIE Yangchun YU Yang ZHOU Lingxiao YANG Qingzhu ZHANG Tao WANG 《Frontiers of Environmental Science & Engineering》2013,7(6):815-826
To understand the size-resolved aerosol ionic composition and the factors influencing secondary aerosol formation in the upper boundary layer in South Central China, size-segregated aerosol samples were collected using a micro-orifice uniform deposit irnpactor (MOUDI) in spring 2009 at the summit of Mount Heng (1269 m asl), followed by subsequent laboratory analyses of 13 inorganic and organic water-soluble ions. During non- dust-storm periods, the average PM1.8 concentration was 41.8 μg·m^-3, contributing to 55% of the PM10. Sulfates, nitrates, and ammonium, the dominant ions in the fine particles, amounted to 46.8% of the PM1.8. Compared with Mount Tai in the North China Plain, the concentrations of both fine and coarse particles and the ions contained therein were substantially lower. When the air masses from Southeast Asia prevailed, intensive biomass burning there led to elevated concentrations of sulfates, nitrates, ammonium, potassium, and chloride in the fine particles at Mount Heng. The air masses originating from the north Gobi brought heavy dust storms that resulted in the remarkable production of sulfates, ammonium, methane sulfonic acid, and oxalates in the coarse particles. Generally, the sulfates were primarily produced in the form of (NH4)2SO4 in the droplet mode via heterogeneous aqueous reactions. Only approximately one-third of the nitrates were distributed in the fine mode, and high humidity facilitated the secondary formation of fine nitrates. The heterogeneous formation of coarse nitrates and ammonium on dry alkaline dust surfaces was found to be less efficient than that on the coarse particles during non-dust-storm periods. 相似文献
15.
We augment the standard cartel formation game from non-cooperative coalition theory, often applied in the context of international environmental agreements, with the possibility that singletons support coalition formation without becoming coalition members themselves. We assume their support takes the form of a monetary transfer to the coalition, in order to induce larger coalitions, higher levels of public good provision and higher payoffs. We show that, under mild conditions on the costs and benefits of contributing to the public good (e.g. abatement of greenhouse gas emissions), there exist equilibria with support. Allowing for support increases payoffs to each of three types of agents: members, supporters and free-riders. 相似文献
16.
环境中植酸的分布、形态及界面反应行为 总被引:2,自引:0,他引:2
肌-肌醇六磷酸(myo-inositol-1,2,3,4,5,6-hexakisphosphate,IHP,myo-IP6)简称植酸(Phytic acid或phytate),是大多数土壤中最为丰富的有机磷,它在环境中的界面反应影响着磷素的迁移、循环、转化、生物有效性以及环境效应.本文简要总结了环境中植酸的分布与形态,并综述了其界面反应,包括铁铝氧化物、粘土矿物、碳酸钙等对植酸的吸附解吸,多价阳离子与植酸的络合反应以及沉淀作用.土壤矿物对植酸的吸附影响其转化和生物有效性,矿物对植酸磷的吸附量一般远高于正磷酸盐.其中,弱晶质铁铝(氢)氧化物对植酸的吸附能力一般较晶形铁铝(氢)氧化物大很多.同时,分析了矿物类型、介质pH、温度、共存离子等环境条件对植酸界面反应的影响,植酸吸附对矿物表面电荷性质、颗粒大小和分散稳定性等的作用,以及植酸在金属污染土壤修复中的应用前景.最后讨论了环境中植酸的主要研究热点和方向. 相似文献
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18.
James Franklin 《毒物与环境化学》2013,95(3):169-182
The present paper reviews the existing literature on the atmospheric degradation and impact of perchloro‐ethylene (PER). Topics covered are: assessment of the relative importance of primary reactions of PER with OH, Cl, O3 and other reactive species; other tropospheric sinks for PER; estimated tropospheric lifetime, observed concentrations and atmospheric budget calculations; breakdown mechanisms leading to the formation of phosgene, and possibly trichloroacetyl chloride and carbon tetrachloride; contribution of PER to atmospheric chlorine loading; impact of PER on tropospheric ozone formation; uptake and hydrolysis of degradation products by clouds, rainwater and the oceans; contribution of PER to chloride and acidity in rainwater; potential contribution of PER to trichloroacetic acid in the hydrosphere, soil and the biosphere. 相似文献
19.
利用量子化学计算气相中锌离子各种水合和水解形态的几何结构、电荷分布以及水合和水解反应的Gibbs自由能变和焓变.结果表明,除了水合锌离子外,锌离子各种水解络合物的配位数均小于6;对于深度水解产物Zn(OH)3^-和Zn(OH)4^2-,内层无水分子的键合.水合作用和水解作用互相抑制,水合作用阻碍了水解产物进一步水解(Zn(OH)2除外),水解作用使得水合变得困难.内层键合水分子数的增加降低了水合形态中Zn上的电荷,使得水解形态Zn上的电荷升高. 相似文献
20.
Usefulness of the Umbrella Species Concept as a Conservation Tool 总被引:20,自引:0,他引:20
Abstract: In the face of limited funding, knowledge, and time for action, conservation efforts often rely on shortcuts for the maintenance of biodiversity. The umbrella species concept—proposed as a way to use species requirements as a basis for conservation planning—has recently received growing attention. We reviewed the literature to evaluate the concept's general usefulness. An umbrella species is defined as a species whose conservation is expected to confer protection to a large number of naturally co-occurring species. This concept has been proposed as a tool for determining the minimum size for conservation areas, selecting sites to be included in reserve networks, and setting minimum standards for the composition, structure, and processes of ecosystems. Among the species suggested as potential umbrellas, most are large mammals and birds, but invertebrates are increasingly being considered. Eighteen research papers, most of which were based on hypothetical reserves or conservation networks, have provided evaluations of umbrella species schemes. These show that single-species umbrellas cannot ensure the conservation of all co-occurring species because some species are inevitably limited by ecological factors that are not relevant to the umbrella species. Moreover, they provide evidence that umbrella species from a given higher taxon may not necessarily confer protection to assemblages from other taxa. On the other hand, multi-species strategies based on systematic selection procedures (e.g., the focal species approach) offer more compelling evidence of the usefulness of the concept. Evaluations of umbrella species schemes could be improved by including measures of population viability and data from many years, as well as by comparing the efficiency of the proposed scheme with alternative management strategies. 相似文献