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331.
Air samples of total suspended particles (TSP, particles less than 30-60 microm), and particles with aerodynamic diameter smaller than 2.5 microm (PM(2.5)) were collected simultaneously at Guiyu (an electronic waste recycling site), three urban sites in Hong Kong and two urban sites in Guangzhou, South China from 16 August to 17 September 2004. Twenty-two PBDE congeners (BDE-3, -7, -15, -17, -28, -49, -71, -47, -66, -77, -100, -119, -99, -85, -126, -154, -153, -138, -156, -184, -183, -191) in TSP and PM(2.5) were measured. The results showed that the overall average concentrations of TSP and PM(2.5) collected at Guiyu were 124 and 62.1 microg m(-3), respectively. The monthly concentrations of the sum of 22 BDE congeners contained in TSP and PM(2.5) at Guiyu were 21.5 and 16.6 ng m(-3), with 74.5 and 84.3%, contributed by nine congeners (BDE-28, -47, -66, -100, -99, -154, -153, -183 and -191 respectively). This pattern was similar to Tsuen Wan site of Hong Kong. Two urban sites of Guangzhou had the same congener pattern, but were different from Yuen Long and Hok Tsui sites of Hong Kong. The results also showed that the amount of mono to penta brominated congeners, which are more toxic, accounted for 79.4-95.6% of Sigma(22)PBDEs from all sites. All congeners tested in Guiyu were up to 58-691 times higher than the other urban sites and more than 100 times higher than other studies reported elsewhere. The higher concentration in the air was due to heating or opening burning of electronic waste since PBDEs are formed when plastics containing brominated flame retardants are heated.  相似文献   
332.
Small- and medium-sized enterprises (SMEs) form the core of societal and economic development. However, most people query on the implementation and performance of environmental management. In this paper, the manufacturing SMEs in Northern China with different pollution levels are studied to explore the main forces (e.g., government, society, market, and enterprise itself) driving SMEs for promoting environmental management. It focuses on the correlation between environmental management and economic performance for SMEs at different pollution levels. The results show that SMEs of different pollution levels have significant differences in the relationship of driving forces and performance. First, for SMEs with high-pollution levels, social and market driving forces and government incentives are revealed having a significant effect on their environmental performance. Driving forces from within the enterprise itself and the market provide a positive effect on the economic performance, while social forces have a negative effect. Second, for SMEs with light pollution, social and market driving forces, and government assistance play a supporting role on corporate environmental performance improvement. It is also found that the driving force of the enterprise itself does not have a significant effect on the environmental performance for SMEs with different pollution levels. In addition, the environmental performance and economic performance for SMEs with high or light-pollution levels are positively correlated. Further, it shows that the environmental performance is moderately correlated with financial indices, but not significantly with the non-financial indices.  相似文献   
333.
Environmental problems are becoming increasingly severe in China with industrial discharges and household sewages being the main sources of water pollution in the country. For example, in the case of Taihu Lake, more than half of the total phosphorus in the lake comes from household sewage. While industrial pollution can be treated through technology innovation and controlled by environmental regulations and laws, decreasing household sewage relies entirely on residents. Raising public environmental awareness therefore is essential for ensuring effective environmental improvement and protection. A quantitative assessment of public awareness can inform policy and decision makers; however, not many such studies have been conducted. Changes in the awareness levels in response to a major environmental pollution incident are of particular interest because of the people’s first-hand experience of the triggered consequences. The present paper establishes a system of indicators for the assessment of public environmental awareness. Combined with a fuzzy matter-element analysis method, a model is set-up to quantitatively assess the public environmental awareness. The model is then applied to assess the environmental awareness of the residents of Wuxi City after its major lake Taihu suffered a severe algae bloom in 2007. This study examines whether this serious environmental incident affected people’s environmental awareness and to what degree. The findings show that the matter-element model is capable to resolve well the fuzziness of the ranking affiliation and classification of subjective perceptions, such as public environmental awareness. They show that this environmental incident has had significant positive impacts on the environmental awareness of Wuxi residents. The paper concludes with recommendations related to raising public environmental awareness.  相似文献   
334.
335.
Riparian zone vegetation is an important part of the riparian ecosystem and plays an important role in the riparian zone functioning. Herbs, which are one of the main types of riparian vegetation, are extremely sensitive to environmental changes and human activities and have become a hot spot of riparian vegetation research. In this study, the herbaceous communities of four representative rivers (Xiaoyi, Baohe, Fuhe, and Baigouyin River) entering Baiyangdian Lake in China were researched. The herbaceous species in their riparian zones were systematically investigated using the sample plot method. The Shannon-Wiener diversity (H’), Pielou evenness (J), and Patrick richness (R) indices were estimated to examine the species composition and diversity of the herb communities, following which redundancy analysis (RDA) was conducted. The relationship between species diversity, distribution patterns of herbaceous plant communities, and soil environmental factors in the riparian zone of the four rivers is discussed. (1) Eighty-three species of herbaceous plants belonging to 66 genera and 27 families in the riparian zone entering Baiyangdian Lake. Most herbaceous plants, including Poaceae, Compositae, and Chenopodiaceae, were weeds or associated plants. Riparian vegetation was greatly affected by human disturbance. (2) All the three estimated indices of the Xiaoyi, Baigouyin, and Fuhe rivers were better than those of the Baohe River. (3) The vegetation coverage and species diversity of riparian herbaceous communities were positively correlated with soil organic matter and water content but negatively correlated with pH, total nitrogen, and total phosphorus. Therefore, these communities are conducive to the restoration of vegetation and the stability of biodiversity in the riparian core area to reduce the disturbance of human activities and increase humidity. © 2022 Science Press. All rights reserved.  相似文献   
336.
盐基离子随穿透雨和树干茎流的迁移成为森林元素输入的重要组成部分.在迁移过程中,冠层淋溶、树干冲刷等改变了盐基离子含量,而不同林型的林冠特征、树皮性质等存在差异,因此盐基离子含量在不同林型中可能存在差异对米槠次生林和杉木人工林穿透雨、树干茎流进行为期4年的监测,对比研究4种盐基离子(K+、Ca2+、Na+、Mg2+)浓度和输入量的动态特征.结果显示:(1)米槠次生林树干茎流Ca2+、Mg2+浓度显著低于杉木人工林而K+浓度显著高于杉木人工林;穿透雨除Na+浓度外均为米槠次生林显著高于杉木人工林.穿透雨和树干茎流Na+浓度林型差异不显著.(2)两种林型盐基离子季节动态变化基本一致,在雨季旱季各有一个峰值,雨季浓度普遍低于旱季.米槠次生林盐基离子浓度稳定性普遍高于杉木人工林.(3)分析盐基离子浓度与降雨强度的关系发现:Ca2+、K+、Mg2+浓度随雨量级的增加而降低,Na+浓度随雨量级的增加而增加.(4)观测期间米槠次生林穿透雨累计输入Ca2+、K+、Mg2+和Na+总量分别为47.97、35.17、7.15和12.94 kg/hm2,树干茎流累计输入Ca2+、K+、Mg2+和Na+总量分别为11.38、6.21、1.54和3.00 kg/hm2;杉木人工林穿透雨累计输入Ca2+、K+、Mg2+和Na+总量分别为47.24、26.63、6.43和11.55 kg/hm2,树干茎流累计输入Ca2+、K+、Mg2+和Na+总量分别为4.11、1.20、0.50和0.83 kg/hm2.米槠次生林的林内雨盐基离子输入量大于杉木人工林.总体而言,米槠次生林比杉木人工林有更高的养分输入,能更好地维持生态系统养分的供应;上述结果有助于进一步认识森林物质随水文过程的流动,可为人工林经营管理提供一定科学基础数据.(图6表1参36)  相似文献   
337.
Based on community data (2012, 2020) of the Tianlong Mountain evergreen and deciduous broadleaved mixed forest plot in central Guizhou, China, the species composition, importance value index, diversity, and dynamic changes were estimated to explore the renewal and change characteristics of karst secondary forests. The results showed that: (1) the number of individual species in the investigated two hm2 plot encompassing 33 families and 55 genera, totaling 69 species decreased from 10 276 to 7837. Five families, 10 genera, and 18 species were newly added, while seven families, nine genera, and 11 species disappeared. The difference between the importance value indices of the species was obvious; that of Lithocarpus confinis (20.97–23.26) was much higher than that of other species. Except for some species, the overall inter-annual differences were not large, and the status of mesophytic and shaded species has increased. Life forms were dominated by small trees and shrubs or small trees, and the plant number density of different life forms is reduced. (2) The Margalef and Shannon-Wiener indices of shrubs were the largest, and the Pielou indices of shrubs or small trees were the largest. The composition of most life forms has increased; the diversity became richer; and the uniform distribution of individual species has increased, but the change was small. (3) With respect to the spatial distribution pattern, the species were generally clustered, and only a few were randomly distributed. The Cx, I, m*, CA, and G indices of the species were reduced, and those of some species were quite different. A tendency for aggregated distribution was observed over random distribution, but the aggregation degree of Lithocarpus sphaerocephala was still high. The PAI index of most species increased but was not obvious, whereas the K value changed irregularly. Overall, the species composition, importance value index, diversity, and spatial distribution pattern of the main species in this community have changed to some extent but without any significant fluctuations. L. sphaerocephala was still the dominant species in succession, and the species composition of the flora was stable. The restoration of vegetation and the development of the entire community are slow. © 2022 Science Press. All rights reserved.  相似文献   
338.
As a special ecosystem, an urban forest park, which is different from a regular “forest park”, is one of the key elements involved in improving the urban ecological environment and promoting the sustainable development of a city. The “urban forest park” can also significantly improve living conditions by acting as a greenbelt. The Chengdu Longquan Mountain Urban Forest Park is a rare mountain urban forest park located in the center of the city. This “urban forest park” not only provides more ecological products and maintains ecological security but also meets the growing needs of people for food, environmental quality, and spirituality. To comprehensively assess the ecological value of the Chengdu Longquan Mountain Urban Forest Park, this study used the literature analogy and questionnaire survey methods to establish a targeted ecosystem service assessment system in this study area. In addition, combined with the hierarchical analysis method, the indicator system was tested, and the specific evaluation index was determined. In the Longquan Mountain Urban Forest Park Ecosystem Service Value Index System, three first-level indicators, such as ecological material products (with a weight of 0.412 6), ecological regulation (0.327 5), and dwelling culture (0.259 9); eight secondary indicators, such as product production (0.206 3), resource supply (0.206 3), and biodiversity (0.194 4); and twenty-three tertiary indicators, such as air negative oxygen ion (0.154 7), habitat quality (0.095 9), and ecological health benefit (0.075 5), were identified. From the weights of the first and second indicators, it was clear that the supply of ecological material products is the main service function in the Longquan Mountain Urban Forest Park ecosystem. Moreover, from the weights of the third indicator, the public’s cognition and concept of the ecosystem service value of the “urban forest park” gradually shifted from the supply service of products and resources to cultural services. In summary, the ecosystem service value assessment system designed for the Longquan Mountain Urban Forest Park in this study has certain feasibility and extensibility that lays a theoretical foundation for the scientific assessment of ecological value and ecological value realization mechanism for other “forest parks” worldwide. © 2022 Authors. All rights reserved.  相似文献   
339.
Based on observation data of daily sunshine duration from 1961 to 2020 at 175 meteorological observation stations over Qinghai-Tibet Plateau and its surrounding areas, spatial transformation analysis, climate trend analysis and M-K mutation test were used to analyze the temporal and spatial variation characteristics of the seasonal and annual sunshine duration in the region in the last 60 years. The results show that (1) annual average sunshine duration was 2 323 h, the maximum was 3 487 h in Gaer, Tibet, and the minimum was 771 h in Ya'an, Sichuan. The high-value areas were mostly located in western Tibet, northern Qinghai, western Gansu, and Xinjiang, and the low-value areas were mostly located in Nyingchi in Tibet, the mountainous area on the western edge of the Sichuan Basin, and northwestern Yunnan. The highest sunshine duration was recorded in winter (631 h), and the lowest was recorded in autumn (555 h) among the four seasons. (2) The average decrease in annual sunshine duration was 10.27 h/10 a. The largest rates of decrease were mainly in Gannan of Gansu and Ganzi of Sichuan, with the largest rate of decrease of 130 h/10 a. The areas with large rates of increase were mainly in Hotan area of Xinjiang, Liangshan of Sichuan and Lhasa of Tibet, with the largest increase of 61 h/10 a. Among the four seasons, spring exhibited an upward trend, and the remainder exhibited a downward trend. (3) Before 2017, the annual sunshine duration increased but declined after 2017. Spring sunshine duration had the largest number of mutation years, and the earliest mutation time was 1963. Winter had the fewest number of mutation years and the latest mutation time occurred in 2015. In summary, the annual and seasonal sunshine duration of Qinghai-Tibet Plateau vary greatly in space, but with the general characteristics of more sunshine in the northwest and less in the southeast, and sunshine hours were mainly decreasing, with 2017 as a mutation point of annual sunshine duration. Most areas of Qinghai-Tibet Plateau have great potential for photosynthetic production and are suitable for the development of light-loving plants and high-density planting. Shade-loving or shade-tolerant plants, including tea, are suitable for development in remote mountainous areas with low sunshine values in the western part of the basin, including Ya’an, Sichuan, and other areas, such as Medog, Tibet. © 2022 Science Press. All rights reserved.  相似文献   
340.
Environmental Science and Pollution Research - The increasing discrepancy between a regional economy and transportation imposes higher requirements for their coordinated development. This paper...  相似文献   
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