全文获取类型
收费全文 | 24131篇 |
免费 | 596篇 |
国内免费 | 5515篇 |
专业分类
安全科学 | 939篇 |
废物处理 | 1672篇 |
环保管理 | 2367篇 |
综合类 | 9160篇 |
基础理论 | 5588篇 |
环境理论 | 2篇 |
污染及防治 | 6999篇 |
评价与监测 | 1509篇 |
社会与环境 | 1382篇 |
灾害及防治 | 624篇 |
出版年
2023年 | 226篇 |
2022年 | 689篇 |
2021年 | 552篇 |
2020年 | 417篇 |
2019年 | 434篇 |
2018年 | 1911篇 |
2017年 | 1934篇 |
2016年 | 1802篇 |
2015年 | 989篇 |
2014年 | 1186篇 |
2013年 | 1635篇 |
2012年 | 1717篇 |
2011年 | 2659篇 |
2010年 | 1630篇 |
2009年 | 1551篇 |
2008年 | 1902篇 |
2007年 | 2130篇 |
2006年 | 835篇 |
2005年 | 624篇 |
2004年 | 459篇 |
2003年 | 615篇 |
2002年 | 583篇 |
2001年 | 427篇 |
2000年 | 444篇 |
1999年 | 475篇 |
1998年 | 432篇 |
1997年 | 352篇 |
1996年 | 342篇 |
1995年 | 286篇 |
1994年 | 236篇 |
1993年 | 189篇 |
1992年 | 155篇 |
1991年 | 89篇 |
1990年 | 70篇 |
1989年 | 54篇 |
1988年 | 47篇 |
1987年 | 30篇 |
1986年 | 25篇 |
1985年 | 13篇 |
1984年 | 26篇 |
1983年 | 26篇 |
1982年 | 11篇 |
1981年 | 12篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1976年 | 2篇 |
1975年 | 4篇 |
1974年 | 2篇 |
1966年 | 1篇 |
1935年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
941.
M. H. Alzawqari A. A. Al-Baddany H. H. Al-Baadani I. A. Alhidary Rifat Ullah Khan G. M. Aqil A. Abdurab 《Environmental science and pollution research international》2016,23(17):17077-17082
The current experiment was conducted to evaluate the effects of feeding dried sweet orange peel (SOP) and lemon grass leaves (LGL) as feed additives on broiler growth performance, serum metabolites, and antioxidant status. A total of 192-day-old (Ross 308) broiler chickens were distributed randomly into 4 dietary treatments with 4 replicates per each treatment. The dietary treatments included a control diet without any feed additive (T1), a diet containing 0.8 % SOP (T2), a diet containing 0.8 % LGL (T3), and a diet containing combination of 0.4 % SOP?+?0.4 % LGL (T4) was fed during the growth period from 22 to 42 days. Feed intake (FI), body weight gain (BWG), feed conversion ratio (FCR), carcass traits, serum components, and antioxidant status were measured. At the end of the experimental period, the results indicated that supplementation of SOP and LGL alone or in combination did not significantly (P?>?0.05) affect BWG, FI, FCR, and carcass characteristics in broiler chickens. Serum total protein was increased significantly (P?<?0.05) in T3 and T4 compared to the other treatments. Also, serum globulin increased significantly (P?<?0.05) in the treated groups. Serum glucose, low density lipoprotein, triglyceride, and very low density lipoprotein decreased significantly (P?<?0.05) in the treatment groups, while cholesterol and high-density lipoprotein decreased in T2 compared to the other groups. Significantly (P?<?0.05) higher total antioxidant status was observed in T2 compared to the other treatments. In conclusion, these results indicate that SOP, LGL, and their combination may positively modify some serum components and the antioxidant status without any beneficial effect on growth performance and carcass traits in broiler chickens. 相似文献
942.
In accelerated weathering tests, specimens are exposed to higher radiation intensity, temperature and humidity than is likely under natural weathering in order to achieve rapid degradation of the polymer in a convenient short time. In the current work, a correlation between the two environments is attempted so that a prediction of lifetimes in the natural environment can be achieved. During aging, surface flaws are created due to the chain scission process. This is initiated by the absorption of ultra-violet light and directly affects visual appearance and impact strength. After natural weathering, the material shows only plastic deformation in an impact test. However, after artificial weathering to 5000 h of UV exposure, there is a decrease of 85% in impact strength. Colour change occurs at a high rate in the early stages of UV exposure. Beyond 2000 h of exposure, the colour change approaches a steady state and a correlation between the changes under natural and artificial weathering becomes apparent for a potential prediction of lifetimes. From the analysis including the specular component (SCI), taking surface roughening into account, 1 year under natural weathering was found to be equivalent to 25 days under accelerated weathering. 相似文献
943.
944.
945.
Tran Quang Tuyen 《Environment, Development and Sustainability》2016,18(4):1239-1254
This study analyzes the sources of income inequality among ethnic minorities in the Northwest region—the poorest and highest inequality region of Vietnam. Using an analysis of Gini decomposition by income source, the results show that while agricultural income, notably crop income, considerably decreases income inequality, off-farm income sources (wage and non-farm self-employment incomes) are found to increase inequality. This can be explained that in comparison with other income sources, agricultural income is more equally distributed and the main income source for most poor households. However, off-farm income sources are more unequally distributed and flow disproportionately toward the better-off. The findings support the hypothesis that income diversification in non-farm activities results in either greater inequality if opportunities for these activities are skewed toward to the better-off or less inequality if such opportunities are accessible to the poorer part of the population. 相似文献
946.
Suman Mor Manchanda K. Chhavi Kansal K. Sushil Khaiwal Ravindra 《Environment, Development and Sustainability》2018,20(2):625-639
Dyes and pigments are one of the major water pollutants and if not discharged properly cause ecological disturbance. Considering this, the current study investigates the application of thermal power plant by-product, i.e., fly ash for the elimination of a hazardous methylene blue dye from its synthetic aqueous solution. Experiments were conducted in batch mode to study the effect of pH, temperature, adsorbent dose and contact time. Highest dye removal (94.3%) was achieved at pH 10 using adsorbent dose of 10 g/L in 90 min of contact time at 40 °C. However, for cost-effective operation at neutral pH and room temperature (30 °C), it yields 89.3% dye removal having similar dose and contact time. Equilibrium isotherms for adsorption were analyzed by Langmuir and Freundlich, Temkin and Dubinin–Radushkevich isotherm equations. The results revealed that the best fit model of adsorption closely followed Langmuir adsorption. Based on adsorption isotherm models, thermodynamics parameters ΔG, ΔH and ΔS were calculated. The negative value of ΔG and ΔH revealed that adsorption process was exothermic, spontaneous and physical. The present work suggests that through simple process hydrothermally modified fly ash has the potential to be used as cost-effective and efficient adsorbent for the treatment of wastewater from textile industries. 相似文献
947.
Jonathan N. Hogarh Nobuyasu Seike Yuso Kobara Derick Carboo Julius N. Fobil Shigeki Masunaga 《Environmental science and pollution research international》2018,25(17):16316-16324
With recent evidence that persistent organic pollutants (POPs) such as polychlorinated biphenyls (PCBs) are emerging in environmental media in some developing countries that otherwise have sparing production and usage history, it has become important to identify such contemporary source factors of PCBs and the risks this may pose, in line with the global consensus on POP management and elimination. The present study investigated contaminations from atmospheric PCBs in Ghana, deciphered source factors, and accessed risk of exposure to dioxin-like PCBs (DL-PCBs). Atmospheric PCBs were monitored by deployment of PUF-disk passive air samplers (PAS) at several sites across Ghana for 56 days. Atmospheric ∑190PCB concentration in Ghana ranged from 0.28 ng/m3 in Kumasi to 4.64 ng/m3 at Agbogbloshie, a suburb in Accra noted for informal electronic waste (e-waste) recycling activities. As high as 11.10 ng/m3 of PCB concentration was measured in plumes from uncontrolled open burning of e-wastes at Agbogbloshie. Applying statistical source characterization tools, it emerged that e-wastes were a major contributor to the environmental burden of atmospheric PCBs in Ghana. The risk of DL-PCB toxicity via inhalation in the Agbogbloshie area was 4.2 pg TEQ/day, within similar order of magnitude of an estimated risk of 3.85 pg TEQ/day faced by e-waste workers working averagely for 8 h per day. It is suggested that elimination of e-waste sites would help to significantly reduce PCB-related toxicity issues in Ghana. 相似文献
948.
949.
Magnus Bengtsson Eva Alfredsson Maurie Cohen Sylvia Lorek Patrick Schroeder 《Sustainability Science》2018,13(6):1533-1547
The United Nations formulated the sustainable development goals (SDGs) in 2015 as a comprehensive global policy framework for addressing the most pressing social and environmental challenges currently facing humanity. In this paper, we analyse SDG 12, which aims to “ensure sustainable consumption and production patterns.” Despite long-standing political recognition of this objective, and ample scientific evidence both on its importance and on the efficacy of various ways of promoting it, the SDGs do not provide clear goals or effective guidance on how to accomplish this urgently needed transformation. Drawing from the growing body of research on sustainable consumption and production (SCP), the paper identifies two dominant vantage points—one focused on promoting more efficient production methods and products (mainly through technological improvement and informed consumer choice) and the other stressing the need to consider also overall volumes of consumption, distributional issues, and related social and institutional changes. We label these two approaches efficiency and systemic. Research shows that while the efficiency approach contains essential elements of a transition to sustainability, it is by itself highly unlikely to bring about sustainable outcomes. Concomitantly, research also finds that volumes of consumption and production are closely associated with environmental impacts, indicating a need to curtail these volumes in ways that safeguard social sustainability, which is unlikely to be possible without a restructuring of existing socioeconomic arrangements. Analysing how these two perspectives are reflected in the SDGs framework, we find that in its current conception, it mainly relies on the efficiency approach. On the basis of this assessment, we conclude that the SDGs represent a partial and inadequate conceptualisation of SCP which will hamper implementation. Based on this determination, this paper provides some suggestions on how governments and other actors involved in SDGs operationalisation could more effectively pursue SCP from a systemic standpoint and use the transformation of systems of consumption and production as a lever for achieving multiple sustainability objectives. 相似文献
950.
Kristine B. Pedersen Pernille E. Jensen Beata Sternal Lisbeth M. Ottosen Mie Vesterskov Henning Manja Marie Kudahl Juho Junttila Kari Skirbekk Marianne Frantzen 《Environmental science and pollution research international》2018,25(33):32901-32912
Mining of Cu took place in Kvalsund in the Arctic part of Norway in the 1970s, and mine tailings were discharged to the inner part of the fjord, Repparfjorden. Metal speciation analysis was used to assess the historical dispersion of metals as well as their potential bioavailability from the area of the mine tailing disposal. It was revealed that the dispersion of Ba, Cr, Ni, Pb and Zn from the mine tailings has been limited. Dispersion of Cu to the outer fjord has, however, occurred; the amounts released and dispersed from the mine tailing disposal area quantified to be 2.5–10 t, less than 5% of Cu in the original mine tailings. An estimated 80–390 t of Cu still remains in the disposal area from the surface to a depth of 16 cm. Metal partitioning showed that 56–95% of the Cu is bound in the potential bioavailable fractions (exchangeable, reducible and oxidisable) of the sediments, totalling approximately 70–340 t, with potential for continuous release to the pore water and re-precipitation in over- and underlying sediments. Surface sediments in the deposit area were affected by elevated Cu concentrations just above the probable effect level according to the Norwegian sediment quality criteria, with 50–80% Cu bound in the exchangeable, reducible and oxidisable fractions, potentially available for release to the water column and/or for uptake in benthic organisms. 相似文献