首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   410篇
  免费   7篇
  国内免费   3篇
安全科学   19篇
废物处理   18篇
环保管理   75篇
综合类   56篇
基础理论   89篇
环境理论   1篇
污染及防治   93篇
评价与监测   26篇
社会与环境   31篇
灾害及防治   12篇
  2023年   4篇
  2022年   7篇
  2021年   4篇
  2020年   5篇
  2019年   8篇
  2018年   14篇
  2017年   10篇
  2016年   22篇
  2015年   6篇
  2014年   15篇
  2013年   32篇
  2012年   21篇
  2011年   19篇
  2010年   18篇
  2009年   23篇
  2008年   32篇
  2007年   18篇
  2006年   17篇
  2005年   15篇
  2004年   15篇
  2003年   16篇
  2002年   5篇
  2001年   12篇
  2000年   8篇
  1999年   3篇
  1998年   5篇
  1997年   4篇
  1996年   2篇
  1995年   5篇
  1994年   3篇
  1993年   2篇
  1992年   6篇
  1991年   8篇
  1990年   2篇
  1989年   3篇
  1987年   3篇
  1986年   2篇
  1985年   2篇
  1982年   2篇
  1980年   3篇
  1979年   3篇
  1978年   1篇
  1977年   1篇
  1975年   2篇
  1972年   2篇
  1970年   1篇
  1961年   1篇
  1958年   3篇
  1955年   3篇
  1954年   1篇
排序方式: 共有420条查询结果,搜索用时 15 毫秒
371.
Objetivo: El objetivo de este estudio era examinar los problemas emocionales y comportamentales de niños refugiados no acompañados que fueron repatriados a Vietnam de los centros de refugiados de Hong-Kong y del Sudeste asiático. Los niños fueron comparados con una muestra emparejada de niños que nunca dejaron Vietnam.Método: La muestra estaba compuesta por un total de 455 niños vietnamitas de edades comprendidas entre los 10 y los 22 años. Un total de 238 niños habían residido previamente sin sus padres en campos de refugiados. Se recogieron datos aplicando la versión de autoinforme para jóvenes del Achenbach (Youth Self-Report), la Escala de Autoeficacia Percibida de Cowen, una escala de Soporte Social y una escala de Exposición al Trauma.Resultados: No se observaron diferencias significativas entre los grupos de niños en la puntuación total del YSR. Los niños previamente refugiados tuvieron puntuaciones más bajas que los niños del grupo control en la escala de “problemas de conducta externalizados”. Se observó una tendencia en los niños refugiados a presentar puntuaciones más altas que los niños del grupo control en la escala de “problemas de conducta internalizados”. No se observaron diferencias entre los dos grupos en la eficacia autopercibida, el número de fuentes de apoyo social y las experiencias de apoyo social. Otros análisis mostraron que una interacción significativa entre la condición de inmigrantes de los niños y su percepción subjetiva del actual nivel de vida explicó las diferencias en las puntuaciones en el YSR.Conclusión: Los resultados sugieren que la experiencia de vivir sin sus padres en un campo de refugiados no conduce a presentar más problemas emocionales y de conducta en los años posteriores inmediatos a la repatriación.
PDF (70 K)
View More Related Articles
 
View Record in Scopus
doi:10.1016/j.envhaz.2007.03.001    
Copyright © 2007 Elsevier Ltd All rights reserved.
Towards an integrated approach of disaster and environment management: A case study of Thua Thien Hue province, central Viet Nam
Phong Tran, a, and Rajib Shaw1, a,
aGraduate School of Global Environmental Studies, Kyoto University, Yoshida Honmachi, Sakyo-ku, Kyoto 606 8501, Japan  相似文献   
372.
Water quantity and quality dynamics of the THC — Tuyamuyun Hydroengineering Complex — And implications for reservoir operation   总被引:2,自引:0,他引:2  
Froebrich J  Bauer M  Ikramova M  Olsson O 《Environmental science and pollution research international》2007,14(6):435-442
Background In the Aral Sea basin, safe water resources are scarce and steadily becoming scarcer. Particularly high quality water is going to become a rare good. The object of the study was the Tuyamuyun Hydroengineering Complex (THC), a complex of artificial water reservoirs located in the lower Amu Darya River, which provides water for irrigation, industry, and drinking for the lower Amu Darya region. The focus was on operation of one of its four reservoirs, the Kaparas, which is mainly used for drinking water supply. The objective includes the investigation of impacts of conventional operation schemes on the reservoir water quality for improving drinking water quality (salinity). Basic operation rules for Kaparas, which can be considered as representative for conventional dam operation under dry year conditions, had to be identified and improved operation schemes derived. Methods Existing data archives were analysed, and further data were acquired from field surveys, data processing and modelling studies. Historical data were identified, which are appropriate to determine representative schemes for the conventional operation. For the simulation of time-dependent and depth-dependent changes of reservoir salinisation, the reservoir water quality model Lac was used and linked with the THC model. Results and Discussion Modelling results for the simulation of temperature dynamics and density stratification showed a sufficient congruence with the measured temperature profiles. The conformity of measured and calculated salt concentration is basically ensured. The reservoir, which fill with higher saline water at the end of the summer, aggravates the entrainment of high saline water in the entire water column. Conclusions The current conventional operation regime mainly leads to filling the Kaparas reservoir with high saline water during the winter months. Even in the event of starting with comparable low salinity levels, the simulation demonstrates the rapid deterioration of the reservoir water quality. Under dry year conditions, the WHO standards for drinking water will be exceeded by 30% after two years, so that the impact of dry years in the context of water stress becomes visible. Recommendations and Outlook Processed data and results are now available to identify enhanced reservoir operation strategies for salinity reduction by changing the period of reservoir filling and release, as well as to initiate a detailed analysis of how water deficits in dry years may be reduced by improved operation regimes. Using adapted and enhanced operation rules for THC reservoirs, the local population within the lower Aral Sea basin might be supplied with more potable water of higher quality in future.  相似文献   
373.
Field monitoring of a LID-BMP treatment train system in China     
Haifeng Jia  Xiangwen Wang  Chaopu Ti  Yanyun Zhai  Richard Field  Anthony N. Tafuri  Huihua Cai  Shaw L. Yu 《Environmental monitoring and assessment》2015,187(6):373
In order to assess the urban runoff control effectiveness of a low-impact development best management practice (LID-BMP) treatment train system, a field test of selected LID-BMPs was conducted in China. The LID-BMPs selected include three grassed swales, a buffer strip, a bioretention cell, two infiltration pits, and a constructed wetland. The test site is in a campus in southern China. The LID-BMPs, connected in a series, received stormwater runoff from four tennis courts with an area of 2808 m2 and eight basketball courts with an area of 4864 m2. Construction of the LID-BMPs was completed in early spring of 2012, and the sampling was conducted during May of 2012 to September of 2013. During the sampling effort, besides the performance evaluations of grassed swales and the bioretention cell in controlling runoff quantity as well as quality, the emphasis was also on determining the performance of the LID-BMP treatment train system. A total of 19 storm events were monitored, with nine producing no runoff and ten producing runoff. Data collected from the ten storm events were analyzed for estimating runoff quantity (peak flow rate and total runoff volume) and quality reduction by the LID-BMPs. The sum of loads (SOL) method was used for calculating the water quality performance of LID-BMPs. Results indicated that, for peak flow rate, a bioretention cell reduction of 50–84 % was obtained, and grassed swale reduction was 17–79 %, with a runoff volume reduction of 47–80 and 9–74 %, respectively. For water quality, the bioretention cell in general showed good removal for zinc (nearly 100 %), copper (69 %), NH3-N (ammonia nitrogen) (51 %), and total nitrogen (TN) (49 %); fair removal for chemical oxygen demand (COD) (18 %); and poor removal for total suspended solids (TSS) (?11 %) and total phosphorus (TP) (?21 %). And its performance effectiveness for pollutant removal increased in the second year after 1 year of stabilizing. When considering the aggregated effect of the LID-BMP treatment train system, it showed excellent removal for NH3-N (73 %), TN (74 %), and TP (95 %) and fair removal for COD (19 %) and TSS (35 %). The assessment results of the LID-BMP treatment train system provide valuable information on how to link the different types of LID-BMP facilities and maximize the integrated effectiveness on urban runoff control.  相似文献   
374.
The role of forest stand density in controlling soil erosion: implications to sediment-related disasters in Japan   总被引:1,自引:0,他引:1  
Bam H. N. Razafindrabe  Bin He  Shoji Inoue  Tsugio Ezaki  Rajib Shaw 《Environmental monitoring and assessment》2010,160(1-4):337-354
The role of forest stand density in controlling soil erosion was investigated in Ehime Prefecture, Japan. The main objective was to compare soil erosion under different forest conditions including forest type, species composition, and stand density as influenced by thinning operations. Relative yield index (Ry) was used as an indicator of stand density to reflect the degree of management operations in the watershed. Eleven treatments were established based on the above forest conditions. Soil loss was collected in each of the 11 treatments after each rainfall event for a period of 1 year. The paper presents summary data on soil loss as affected by forest conditions and rainfall patterns. Findings showed that an appropriate forest management operation, which can be insured by stand density control, is needed to reduce soil loss. The present study plays an important role in clarifying technical processes related to soil erosion, while it helps linking these elements to current Japanese forestry issues and bringing new inputs to reducing sediment-related disasters in Japan.  相似文献   
375.
Comparison of carbon footprints of steel versus concrete pipelines for water transmission     
Lalit Chilana  Arpita H. Bhatt  Mohammad Najafi  Melanie Sattler 《Journal of the Air & Waste Management Association (1995)》2016,66(5):518-527
The global demand for water transmission and service pipelines is expected to more than double between 2012 and 2022. This study compared the carbon footprint of the two most common materials used for large-diameter water transmission pipelines, steel pipe (SP) and prestressed concrete cylinder pipe (PCCP). A planned water transmission pipeline in Texas was used as a case study. Four life-cycle phases for each material were considered: material production and pipeline fabrication, pipe transportation to the job site, pipe installation in the trench, and operation of the pipeline. In each phase, the energy consumed and the CO2-equivalent emissions were quantified. It was found that pipe manufacturing consumed a large amount of energy, and thus contributed more than 90% of life cycle carbon emissions for both kinds of pipe. Steel pipe had 64% larger CO2-eq emissions from manufacturing compared to PCCP. For the transportation phase, PCCP consumed more fuel due to its heavy weight, and therefore had larger CO2-eq emissions. Fuel consumption by construction equipment for installation of pipe was found to be similar for steel pipe and PCCP. Overall, steel had a 32% larger footprint due to greater energy used during manufacturing.

Implications: This study compared the carbon footprint of two large-diameter water transmission pipeline materials, steel and prestressed concrete cylinder, considering four life-cycle phases for each. The study provides information that project managers can incorporate into their decision-making process concerning pipeline materials. It also provides information concerning the most important phases of the pipeline life cycle to target for emission reductions.  相似文献   

376.
Anaerobic degradation of nonylphenol in soil     
Bea V. Chang  Bei W. Chiang  Shaw Y. Yuan 《Journal of environmental science and health. Part. B》2013,48(4):387-392
This study investigated the effects of various factors on the anaerobic degradation of nonylphenol (NP) in soil. The results show that the optimal pH for NP degradation was 7.0 and that the degradation rate was enhanced when the temperature was increased. The addition of compost enhanced NP degradation. The individual addition of the electron donors lactate, acetate, and pyruvate inhibited NP degradation. The high-to-low order of NP degradation rates under three anaerobic conditions was sulfate-reducing conditions > methanogenic conditions > nitrate-reducing conditions. The results show that sulfate-reducing bacteria, methanogen, and eubacteria are involved in the anaerobic degradation of NP, with sulfate-reducing bacteria being a major component of the soil. Of the anaerobic strains isolated from the soil samples, strain AT3 expressed the best ability to biodegrade NP.  相似文献   
377.
Balance Corrections for Buoyancy     
Robert W. Shaw 《Journal of the Air & Waste Management Association (1995)》2013,63(8):908-909
This paper describes a versatile experimental facility for evaluating the collection of high resistivity fly ash by advanced electrostatic precipitator designs at near full scale. The unit will operate on a slipstream of up to 424 m3/min (15,000 acfm) from a boiler firing pulverized low sulfur Western coal with an ash resistivity of 1013 ohm-cm at 149°C (300°F). The test unit is designed so that if can be configured as either a single-stage or a two-stage unit and allows for easy installation of different charger and collector components for evaluation. A dampered heat exchanger provides control over the gas temperature from 93°C (200°F) to 370°C (700°F) so that tests can be run at either hot-side or cold-side conditions. Support equipment includes a gas circulating fan, venturi meter for measurement and control of the flow, an instrumentation trailer housing a computerized system for data collection and control of the ESP, and a gas analysis trailer and particulate sampling station for a comprehensive evaluation of the system.  相似文献   
378.
Removal of propylene and butylene as individual compounds with compost and wood chip biofilters     
Rani M  Sattler ML 《Journal of the Air & Waste Management Association (1995)》2011,61(5):527-534
Propylene and butylene are highly reactive volatile organic compounds (HRVOCs) in terms of ground-level ozone formation. This study examined the effectiveness of biofiltration in removing propylene and butylene as separate compounds. Specific objectives were (1) to measure maximum removal efficiencies for propylene and butylene and the corresponding microbial acclimation times, which will be useful in the design of future biofilters for removal of these compounds; (2) to compare removal efficiencies of propylene and butylene for different ratios of compost/hard wood-chip media; and (3) to identify the microorganisms responsible for propylene and butylene degradation. Two laboratory-scale polyvinyl chloride biofilter columns were filled with 28 in. of biofilter media (compost/wood-chip mixtures of 80:20 and 50:50 ratios). Close to 100% removal efficiency was obtained for propylene for inlet concentrations ranging from 2.9 x 10(4) to 6.3 x 10(4) parts per million (ppm) (232-602 g/m3-hr) and for butylene for inlet concentrations ranging from 91 to 643 ppm (1.7-13.6 g/m3-hr). The microbial acclimation period to attain 100% removal efficiency was 12-13 weeks for both compounds. The lack of similar microbial species in the fresh and used media likely accounts for the long acclimation time required. Both ratios of compost/wood chips (80:20 and 50:50) gave similar results. During the testing, media pH increased slightly from 7.1 to 7.5-7.7. None of the species in the used media that treated butylene were the same as those in the used media that treated propylene, indicating that different microbes are adept at degrading the two compounds.  相似文献   
379.
Stakeholder perceptions of grassland ecosystem services in relation to knowledge on soil fertility and biodiversity     
P��n��lope Lamarque  Ulrike Tappeiner  Catherine Turner  Melanie Steinbacher  Richard D. Bardgett  Ute Szukics  Markus Schermer  Sandra Lavorel 《Regional Environmental Change》2011,11(4):791-804
The concept of ecosystem services is increasingly being used by scientists and policy makers. However, most studies in this area have focussed on factors that regulate ecosystem functions (i.e. the potential to deliver ecosystem services) or the supply of ecosystem services. In contrast, demand for ecosystem services (i.e. the needs of beneficiaries) or understanding of the concept and the relative ranking of different ecosystem services by beneficiaries has received limited attention. The aim of this study was to identify in three European mountain regions the ecosystem services of grassland that different stakeholders identify (which ecosystem services for whom), the relative rankings of these ecosystem services, and how stakeholders perceive the provision of these ecosystem services to be related to agricultural activities. We found differences: (1) between farmers?? perceptions of ecosystem services across regions and (2) within regions, between knowledge of ecosystem services gained by regional experts through education and farmers?? local field-based knowledge. Nevertheless, we identified a common set of ecosystem services that were considered important by stakeholders across the three regions, including soil stability, water quantity and quality, forage quality, conservation of botanical diversity, aesthetics and recreation (for regional experts), and forage quantity and aesthetic (for local farmers). We observed two contrasting stakeholder representations of the effects of agricultural management on ecosystem services delivery, one negative and the other positive (considering low to medium management intensity). These representations were determined by stakeholders?? perceptions of the relationships between soil fertility and biodiversity. Overall, differences in perceptions highlighted in this study show that practitioners, policy makers and researchers should be more explicit in their uses of the ecosystem services concept in order to be correctly understood and to foster improved communication among stakeholders.  相似文献   
380.
Linking life history to landscape for threatened species conservation in a multiuse region     
Robyn E. Shaw  Peter B. Spencer  Lesley A. Gibson  Judy A. Dunlop  Janine E. Kinloch  Karel Mokany  Margaret Byrne  Craig Moritz  Harriet Davie  Kenny J. Travouillon  Kym M. Ottewell 《Conservation biology》2023,37(1):e13989
Landscape-scale conservation that considers metapopulation dynamics will be essential for preventing declines of species facing multiple threats to their survival. Toward this end, we developed a novel approach that combines occurrence records, spatial–environmental data, and genetic information to model habitat, connectivity, and patterns of genetic structure and link spatial attributes to underlying ecological mechanisms. Using the threatened northern quoll (Dasyurus hallucatus) as a case study, we applied this approach to address the need for conservation decision-making tools that promote resilient metapopulations of this threatened species in the Pilbara, Western Australia, a multiuse landscape that is a hotspot for biodiversity and mining. Habitat and connectivity were predicted by different landscape characteristics. Whereas habitat suitability was overwhelmingly driven by terrain ruggedness, dispersal was facilitated by proximity to watercourses. Although there is limited evidence for major physical barriers in the Pilbara, areas with high silt and clay content (i.e., alluvial and hardpan plains) showed high resistance to dispersal. Climate subtlety shaped distributions and patterns of genetic turnover, suggesting the potential for local adaptation. By understanding these spatial–environmental associations and linking them to life-history and metapopulation dynamics, we highlight opportunities to provide targeted species management. To support this, we have created habitat, connectivity, and genetic uniqueness maps for conservation decision-making in the region. These tools have the potential to provide a more holistic approach to conservation in multiuse landscapes globally.  相似文献   
[首页] « 上一页 [33] [34] [35] [36] [37] 38 [39] [40] [41] [42] 下一页 » 末  页»
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号