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381.
Cyanobacterial blooms have received increasing attention as a public biohazard for human and animal health. To assess the effect of cyanobacteria-dominant lake water on juvenile fish, we measured the responses of specific growth rate, condition factor, body weight and body length, oxidative stress, and related gene expression of juvenile bighead carp Hypophthalmichthys nobilis exposed to in situ eutrophic lake (Chl a was around 7.0 μg L−1). Results showed in situ cyanobacteria-dominant lake water had no effect on the growth performance, but significantly elevated the contents of malondialdehyde, the expression of heat shock protein 70, and the activity of superoxide dismutase, indicating that oxidative stress occurred. Meanwhile in situ lake water significantly decreased the expression of catalase and glutathione S-transferase genes. We conclude that in situ cyanobacteria-dominated lake water was harmful to juvenile bighead carp based on the oxidative stress and changes in the related gene expression levels. 相似文献
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Changjie Cai Fuhai Geng Xuexi Tie Qiong Yu Junlin An 《Atmospheric environment (Oxford, England : 1994)》2010,44(38):5005-5014
Volatile organic compounds (VOCs) were measured from 2007 to 2010 at the center of Shanghai, China. Because VOCs are important precursors for ozone photochemical formation, detailed information of VOC sources needs to be investigated. The results show that the measured VOC concentrations in Shanghai are dominated by alkanes (43%) and aromatics (30%), following by halo-hydrocarbons (14%) and alkenes (6%). Based on the measured VOC concentrations, a receptor model (PMF; positive matrix factorization) coupled with the information related to VOC sources (the distribution of major industrial complex, meteorological conditions, etc.) is applied to identify the major VOC sources in Shanghai. The result shows that seven major VOC sources are identified by the PMF method, including (1) vehicle related source which contributes to 25% of the measured VOC concentrations, (2) solvent based industrial source to 17%, (3) fuel evaporation to 15%, (4) paint solvent usage to 15%, (5) steel related industrial production to 12%, (6) biomass/biofuel burning to 9%, and (7) coal burning to 7%. Furthermore, ozone formation potential related to VOC sources is calculated by the MIR (maximum incremental reactivity) technique. The most significant VOC source for ozone formation potential is solvent based industrial sources (27%), paint solvent usage (24%), vehicle related emissions (17%), steel related industrial productions (14%), fuel evaporations (9%), coal burning (6%), and biomass/biofuel burning (3%). The weekend effect on the VOC concentrations shows that VOC concentrations are generally higher in the weekdays than in the weekends at the sampling site, suggesting that traffic conditions and human activities have important impacts on the VOC emissions in Shanghai. 相似文献
384.
高职食品专业校企合作的问题及对策 总被引:1,自引:0,他引:1
校企合作教育是一种充分利用学校与企业等多种不同的教育环境和资源在培养人才方面的优势,培养适应企业需要的应用性专门人才的教育模式,对高职院校培养应用型人才具有重要的意义。但当前高职院校的校企合作中存在如政策法规不健全、合作机制不完善、企业的热情不高等问题,针对这些问题从政府政策、企业和学校三方面对其解决方法提出了建议。 相似文献
385.
络合脱硝法是近年来新型的脱除氮氧化物的方法之一,其中EDTA金属络合剂受到了广泛关注,而亚铁络合剂又具有很好的脱除氮氧化物的效果。考查了硫酸亚铁铵与EDTA形成的Fe(II)EDTA这种比较常见的EDTA金属络合剂对NO的吸收容量,并考查温度、络合剂浓度等对Fe(II)EDTA吸收NO的影响。研究结果表明:在相同的实验环境和实验条件下,对于影响Fe(II)EDTA吸收NO的因素最重要的是温度,其余依次为络合剂浓度、气体流速、氧含量、吸收液pH,最适宜吸收条件是反应温度50℃、络合剂浓度0.1mol/L、进气流速600mL/min、氧含量2%、吸收液pH=6。 相似文献
386.
The diurnal atmospheric phosphine (PH3) concentrations and fluxes at the water-air interface in Lake Taihu were reported. The results showed that the PH3 flux at the water-air interface ranged from −69.9 ± 29.7 to 121 ± 42 ng m−2 h−1, with a mean flux of 14.4 ± 22.5 ng m−2 h−1. The fluxes were both negative and positive during the diurnal period, indicating that the lake can act as a sink and a source of PH3. In addition, the PH3 fluxes were positively correlated with water temperature, total soluble phosphorus and soluble reactive phosphorus, while they were negatively correlated with water redox potential. A similar diurnal variation curve of atmospheric PH3 concentrations was observed during all four seasons, with the maximum level occurring in early morning and the minimum appearing around midday. These findings suggest that light plays an important role in the elimination of atmospheric PH3. A significant positive correlation was also found between air temperature and atmospheric PH3 concentration. The mean flux of PH3 in Lake Taihu was higher than in other reported wetlands, with an estimated annual emission of PH3 to the atmosphere of 2.94 × 105 g y−1. 相似文献
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Xudong Chen Fengming XiYong Geng Tsuyoshi Fujita 《Waste management (New York, N.Y.)》2011,31(1):168-179
With the increasing attention on developing a low-carbon economy, it is necessary to seek appropriate ways on reducing greenhouse gas (GHG) emissions through innovative municipal solid waste management (MSWM), such as urban symbiosis. However, quantitative assessments on the environmental benefits of urban symbiosis, especially in developing countries, are limited because only a limited number of planned synergistic activities have been successful and it is difficult to acquire detailed inventory data from private companies. This paper modifies and applies a two-step simulation system and used it to assess the potential environmental benefits, including the reduction of GHG emissions and saving of fossil fuels, by employing various Japanese plastics recycling/energy-recovery technologies in Shenyang, China. The results showed that among various recycling/energy-recovery technologies, the mechanical waste plastics recycling technology, which produces concrete formwork boards (NF boards), has the greatest potential in terms of reducing GHG emissions (1.66 kg CO2e/kg plastics), whereas the technology for the production of refuse plastic fuel (RPF) has the greatest potential on saving fossil fuel consumption (0.77 kgce/kg-plastics). Additional benefits can be gained by applying combined technologies that cascade the utilization of waste plastics. Moreover, the development of clean energy in conjunction with the promotion of new waste plastics recycling programs could contribute to additional reductions in GHG emissions and fossil fuel consumption. 相似文献
390.