全文获取类型
收费全文 | 9660篇 |
免费 | 0篇 |
专业分类
安全科学 | 2篇 |
废物处理 | 767篇 |
环保管理 | 1210篇 |
综合类 | 939篇 |
基础理论 | 3108篇 |
污染及防治 | 1728篇 |
评价与监测 | 1008篇 |
社会与环境 | 896篇 |
灾害及防治 | 2篇 |
出版年
2021年 | 2篇 |
2019年 | 1篇 |
2018年 | 1473篇 |
2017年 | 1372篇 |
2016年 | 1193篇 |
2015年 | 124篇 |
2014年 | 14篇 |
2013年 | 8篇 |
2012年 | 462篇 |
2011年 | 1337篇 |
2010年 | 688篇 |
2009年 | 603篇 |
2008年 | 877篇 |
2007年 | 1226篇 |
2006年 | 2篇 |
2005年 | 18篇 |
2004年 | 34篇 |
2003年 | 65篇 |
2002年 | 99篇 |
2001年 | 15篇 |
2000年 | 11篇 |
1999年 | 3篇 |
1998年 | 9篇 |
1997年 | 1篇 |
1994年 | 1篇 |
1988年 | 1篇 |
1984年 | 11篇 |
1983年 | 8篇 |
1935年 | 2篇 |
排序方式: 共有9660条查询结果,搜索用时 546 毫秒
621.
The annual relative mass of storage organs cycle of Bufo gargarizans in southwestern China was studied from December 2005 to November 2006. We described how those organs changed in response to extreme temperatures. Energy reservation dropped to the lowest levels after dormancy for both sexes, and then increased for period of 4.25 month. However, the mass of these organs dropped again rapidly until August (liver) and September (fat bodies) due to the constraint from extreme high temperature occurred during the summer, and then non-significantly increased before hibernation. For ovaries, varied with a different profile to those of liver and fat bodies have a resting period of four months. In addition, the toads’ ovaries kept growing when the mass of liver and fat bodies declining accordingly during hibernation. Therefore, ovarian mass increased during the hibernation and non-hibernation period. 相似文献
622.
D. S. Cardillo Carlos Busso Mariela Ambrosino Leticia Ithurrart Yanina Torres Rosana Palomo 《Russian Journal of Ecology》2018,49(5):413-421
The objectives of this study were to determine the percentage of root colonization by arbuscular mycorrhizal (AM) fungi at various levels of plant species richness and developmental morphology stages in various perennial grass, and herbaceous and woody dicots species using experimental plots during 2013 and 2014. An auger was used to obtain six replicate root + soil samples at each sampling time on each of the study parameters. Roots were washed free of soil, and percentage AM was determined. The shrub Larrea divaricata was the species which showed the lowest percentage of colonization by AM at the vegetative developmental morphology stage at the monocultures and six-species-mixtures on the experimental plots. Dicots, but not grass, species showed a greater percentage colonization by AM fungi at the greatest (i.e., six-species-mixtures) than lowest (i.e., monocultures) species richness. Although at different degrees of species richness and developmental morphology stages, the perennial grasses Nassella longiglumis and N. tenuis, the herbaceous dicot Atriplex semibaccata, and the shrubs L. divaricata and Schinus fasciculatus showed a greater (p < 0.050) percentage colonization by AM fungi during the second than the first study year. Even though it was species- and sampling time-dependent, percentage colonization by AM fungi increased as species richness also increased most of the times. Our results demonstrated that the plant species differences in percentage colonization by AM fungi in the experimental plots were species richness-, developmental morphology stage-, and sampling-time dependents. 相似文献
623.
Azita Farashi 《Russian Journal of Ecology》2018,49(5):449-455
Many factors such as human activities threat brown bears (Ursus arctos) in Southern Asia, and limit it to small populations in remote and rocky mountainous regions. Brown bears are generally studied in North America and Europe, but there is little information about its conditions and requirements for survival in Asia. During the recent years, brown bear populations in Iran have decreased sharply. Therefore, they are now officially listed as a threatened species in local scale. Therefore, we tried to recognize brown bear habitat relationships in northern Iran using species distribution model (SDM). Maxent method was applied using multiscale approach to predict suitable habitats and habitat relationships of the species. Our results revealed that the predictive ability of environment variables and species distribution maps varied across scales strongly. Also, our findings showed that identifying a proper scale is important issue to improve habitat modeling accuracy. Only 17% of the protected areas was found suitable for brown bear and divided to 5.1% poor, 8.8% suitable, and 3.1% high-quality habitat. Consequently, it is suggested that the protected area of northern Iran reconsiders with interventions aimed at maintaining suitable habitats of brown bear. 相似文献
624.
Wenli Feng Zhiqiang Wu Liangliang Huang Yang Ding Ruidan Shi 《Russian Journal of Ecology》2018,49(3):260-267
To evaluate the effect of abiotic factors on larval and juvenile fish assemblage in shallow waters of middle reaches of Li River, Guilin, China. Samplings were taken monthly at 7 stations in the mainstream and 2 stations in 3 tributaries from May 2014 to April 2015. Synchronously, temperature, pH, turbidity, conductivity, dissolved oxygen rainfall and discharge were obtained. In all, 11.886 larval and juvenile fish from 18 species belonging to 8 families, 16 genera was captured. Principal Component Analysis (PCA) showed obvious significant difference between the environmental variables across sampling areas and months. The results of Canonical Correspondence Analysis (CCA) indicated that water temperature, turbidity, discharge and rainfall were dominant factors on larval and juvenile fish assemblage. 相似文献
625.
Muhammad Ansori Nasution Dhani S. Wibawa Tofael Ahamed Ryozo Noguchi 《Journal of Material Cycles and Waste Management》2018,20(2):787-799
Palm oil mill effluent (POME) is the liquid waste from palm oil mills, and is generally treated using open lagoon technology. However, open lagoons can also be combined with more environmentally friendly technologies. In this study, the analytic hierarchy process (AHP) was used to determine the best combination open lagoon of technology (COLT) for POME treatment. The selected criteria were benefit, opportunity, risk, and cost, with sub-criteria further determined based on these criteria. The sub-criteria were revenue, greenhouse gas reduction, employment absorption, corporate social responsibility, co-processing, environmental risk, marketing risk, technology reliability, investment cost, operation and maintenance cost, and opportunity cost. The alternatives were COLT-composting for fertilizer purpose and COLT-biogas for energy generation purpose. Calculation and analysis was performed on questionnaire data using Expert Choice®. COLT-composting proved to be the superior COLT using tentative performance of alternative in this research, with advantages in benefit, opportunity, and risk. The priority weight for COLT-composting was 0.636. Sensitivity analysis was performed by changing criteria priorities. For COLT-biogas to be considered better than COLT-composting, the cost would need to be weighted more than 0.954. 相似文献
626.
Inara Amoroso da Silva Stella Thomaz de Lima Marcos Rechi Siqueira Márcia Andreia Mesquita Silva da Veiga Valeria Reginatto 《Journal of Material Cycles and Waste Management》2018,20(2):777-786
Fermentation can use renewable raw materials as substrate, which makes it a sustainable method to obtain H2. This study evaluates H2 production by a mixed culture from substrates such as glucose and derivatives from sugarcane processing (sucrose, molasses, and vinasse) combined with landfill leachate. The leachate alone was not a suitable substrate for biohydrogen production. However, leachate blended with glucose, sucrose, molasses, or vinasse increased the H2 production rate by 2.0-, 2.8-, 4.6-, and 0.5-fold, respectively, as compared with the substrates without the leachate. Determination of metals (Cu, Cd, Pb, Hg, Ni, and Fe) at the beginning and at the end of the fermentative assays showed how they were consumed during the fermentation and demonstrated improved H2 production. During fermentation, Cu, Fe, and Cd were the most consumed leachate metals. The best substrate combination to produce H2 was molasses and leachate, which gave high volumetric productivity—469 ml H2/l h. However, addition of the leachate to the substrates stimulated lactic acid formation pathways, which lowered the H2 yield. The use of leachate combined with sugarcane processing derivatives as substrates could add value to the leachate and reduce its polluting power, generating a clean energy source from renewable raw materials. 相似文献
627.
Klinpratoom Panyaping Phisittapong Moontee 《Journal of Material Cycles and Waste Management》2018,20(2):723-737
Anaerobic digestion of mixed leaf (MLW) and food wastes (FW) was used to explore the potential use of MLW as an accelerator for FW digestion in two parts for biogas production and as a waste management option in a university community. The effects of the single substrate of FW, co-digestion, ratio of MLW and FW (3:2 and 2:3) and ratio of waste feed to inoculum: F/I (0.1 and 0.4), and feeding frequency (every other day and every 2 days) were evaluated in two neutralized anaerobic reactors. The results showed that different mixture ratios with the same F/I ratio were the major factor on biogas (39.87 m3/kg VSadded) and CH4 yield (25.99 m3/kg VSadded), including %COD removal (84.50%). Co-digestion had the same effect as F/I on biogas production. Only FW provided the lowest biogas and CH4 yield. The use of a MLW:FW 2:3, F/I 0.4 mixture with every 2 days feeding provided higher biogas production and %COD removal than with every other day feeding. Two neutralized anaerobic reactors were suitable for digestion with a high F/I, and a wider interval feeding. This finding affirms the possibility of biogas production using MLW as the co-substrate with FW, as opposed to using FW alone. 相似文献
628.
Bozhi Ren Yalin Zhou Hongpu Ma Renjian Deng Peng Zhang Baolin Hou 《Journal of Material Cycles and Waste Management》2018,20(1):193-200
Sb release characteristics of blast furnace slag, mining waste rock and tailing sand were investigated in static immersion and dynamic leaching test. These three kinds of waste samples were collected from the antimony mine in Lengshuijiang, China, produced in mining smelting process. Effects of solid/liquid ratio, sample size and pH of leaching solution on Sb release characteristics were inspected based on the analysis of scanning electron microscope, pH and EC of leachate. The optimal parameters for Sb leaching of each sample were analyzed. For blast furnace slag and mining waste rock, Sb release contents increased along with the decline of solid/liquid ratio. The maximum accumulative release contents were 42.13, 34.26 mg/kg at the solid/liquid ratio of 1:20. While Sb release content for tailing sand decreased first and then increased with the reduction of solid/liquid ratio. When the solid/liquid ratio was 1:5, the accumulative Sb release content reached the most (24.30 mg/kg). Sb release content of mining waste rock increased with the drop of leaching solution pH, with the highest accumulative release content of 26.01 mg/kg at pH 2.0. Sb release contents of blast furnace slag and tailing sand showed positive correlation with the variation of leaching solution pH. The maximum accumulative release contents of these two samples were 215.91 and 147.83 mg/kg, respectively, when leaching solution pH was 7.0. In summary, Sb release capacity of the three samples in descending order was tailing sand, blast furnace slag and mining waste rock. pH and EC of the leachate in dynamic test varied independently with the initial pH of leaching solution while showing close relationship with mineral hydrolysis in the waste. 相似文献
629.
Wen-Jun Hong Hongliang Jia Yongsheng Ding Wen-Long Li Yi-Fan Li 《Journal of Material Cycles and Waste Management》2018,20(1):80-90
The present study investigated the occurrence of polychlorinated biphenyls (PCBs) and halogenated flame retardants (HFRs) in soil, water, reed, air and dust samples collected from the e-waste recycling region in Ziya Town, Northern China. The results showed that the concentrations of PCBs reached relative high level in environmental matrices in the study area. HFRs including polybrominated diphenyl ethers (PBDEs), dechlorane plus (DP), allyl 2,4,6-tribromophenyl ether (ATE), tetrabromoethylcyclohexane (TBECH), pentabromotoluene (PBT), pentabromoethylbenzene (PBEB), 2,3-dibromopropyl 2,4,6-tribromophenyl ether (DPTE), 1,2-bis-(2,4,6-tribromophenoxy) ethane (BTBPE) and so on were also widely detected in multi-matrices. Long-range atmospheric transport (LRAT) potentials of non-BDE HFRs were assessed to address the LRAR abilities of these compounds. Analysis of soil–air exchange of PCBs and HFRs showed that soil acted as a secondary source to the atmosphere only for a few low molecular weight compounds, while the direction of the flux of most detected chemicals was from air to soil. 相似文献
630.
Chung Duc Tran Stefan Petrus Salhofer 《Journal of Material Cycles and Waste Management》2018,20(1):110-126
E-waste management in Vietnam poses real challenges such as the lack of specific e-waste legislation, the strong involvement of “craft villages” and the missing of monitoring data. Many issues (e.g., pollution level, generated waste, health of workers and resident living at recycling sites) lead to the limited access to these craft villages. Thus, there is no comprehensive picture on e-waste management in Vietnam available today. This research focuses on the current situation of e-waste management. Sources of e-waste, collection and treatment in Vietnam are investigated by utilizing most available sources of information (published journals, unpublished works from projects and reports from institutes, ministry) together with the interviewed data from experts, collectors, workers and especially, biggest traders in the field. Based on this information, the processes applied in Vietnam, both in the formal and informal sector, have been analyzed systematically in terms of inputs, outputs, potential emissions and related risks for workers. From these aspects, a comparison in terms of legal frameworks, collection and treatment at both formal and informal sector between Vietnam and other countries in Asian region was undertaken. Thus, major challenges of e-waste management and relatively comprehensive image of e-waste management and treatment in Vietnam have been identified. 相似文献