全文获取类型
收费全文 | 3278篇 |
免费 | 9篇 |
国内免费 | 35篇 |
专业分类
安全科学 | 67篇 |
废物处理 | 142篇 |
环保管理 | 402篇 |
综合类 | 416篇 |
基础理论 | 1227篇 |
污染及防治 | 648篇 |
评价与监测 | 233篇 |
社会与环境 | 179篇 |
灾害及防治 | 8篇 |
出版年
2022年 | 5篇 |
2021年 | 7篇 |
2020年 | 3篇 |
2019年 | 7篇 |
2018年 | 113篇 |
2017年 | 125篇 |
2016年 | 196篇 |
2015年 | 53篇 |
2014年 | 19篇 |
2013年 | 67篇 |
2012年 | 438篇 |
2011年 | 231篇 |
2010年 | 38篇 |
2009年 | 49篇 |
2008年 | 69篇 |
2007年 | 81篇 |
2006年 | 89篇 |
2005年 | 402篇 |
2004年 | 553篇 |
2003年 | 418篇 |
2002年 | 53篇 |
2001年 | 48篇 |
2000年 | 25篇 |
1999年 | 37篇 |
1998年 | 14篇 |
1997年 | 18篇 |
1996年 | 6篇 |
1995年 | 15篇 |
1994年 | 15篇 |
1993年 | 10篇 |
1992年 | 9篇 |
1991年 | 11篇 |
1990年 | 8篇 |
1989年 | 9篇 |
1988年 | 10篇 |
1987年 | 5篇 |
1985年 | 3篇 |
1984年 | 7篇 |
1983年 | 7篇 |
1982年 | 8篇 |
1981年 | 3篇 |
1980年 | 7篇 |
1979年 | 4篇 |
1975年 | 2篇 |
1974年 | 4篇 |
1973年 | 2篇 |
1972年 | 3篇 |
1971年 | 2篇 |
1968年 | 2篇 |
1966年 | 2篇 |
排序方式: 共有3322条查询结果,搜索用时 15 毫秒
71.
Ohne Zusammenfassung
Original erschienen in UWSF – Z Umweltchem ?kotox 20(2):133–144 (2008) DOI:
Herausgeber: Martin Pehnt und Eckard Helmers 相似文献
72.
This work examines the performance of a hydrous ferric oxide (HFO) reactive filtration (RF) process with coupled chemically enhanced secondary treatment (RECYCLE) for phosphorus removal from municipal wastewater (HFO-RF-RECYCLE). A 3-month, 0.95-ML/d (0.25-mgd) demonstration of HFO-RF-RECYCLE was performed at a municipal wastewater treatment plant equipped with oxidation ditches and secondary clarifiers. Influent to the plant averaged 6.0 mg/L phosphorus, with a tertiary effluent average of 0.011 mg/L phosphorus. Iron doses to the plant were low, at 5 mg/L. Inline recycling of HFO solution rejects to the plant influent resulted in a maximum 90.3%, dose-dependent reduction of phosphorus in the secondary effluent at 4.5 ML/d (1.2 mgd). Other results included reduction of total suspended solids and turbidity. A mass balance analysis was performed. We conclude that HFO-RF-RECYCLE may allow very low levels of phosphorus discharge from municipal wastewater treatment plants with a ferric-iron-based tertiary filtration process and residual recycling. 相似文献
73.
Asbj?rn Haaning Nielsen Jes Vollertsen Henriette Stokbro Jensen Heidi Ina Madsen Thorkild Hvitved-Jacobsen 《Water environment research》2008,80(1):16-25
The formation and fate of sulfide in a force main and a downstream-located gravity sewer were investigated in an extensive field study. Sulfide formation in the force main was significant. However, during 14 minutes of transport in the gravity sewer, the sulfide concentration decreased 30%, on average. An application of a conceptual sewer process model for simulating the formation and fate of sulfide was demonstrated. Overall, the model predicted that approximately 90% of the decrease of the sulfide concentration in the gravity sewer was the result of sulfide oxidation and that only a small fraction entered the sewer atmosphere, causing odor and corrosion. Even so, the model predicted concrete corrosion rates of up to 1.2 mm/y in the gravity sewer section. 相似文献
74.
Khan AT Graham TC Ogden L Ali S Salwa Thompson SJ Shireen KF Mahboob M 《Journal of environmental science and health. Part. B》2007,42(4):403-415
A two-generation reproductive toxicity study of zinc chloride (ZnCl(2)) was conducted in rats. F(o) male and female rats were administered 0.00 (control), 7.50 (low), 15.00 (mid) and 30.00 (high) mg/kg/day of ZnCl(2). Selected F(1) male and female rats were exposed to the same doses received by their parents (F(o)). Exposure of F(0) parental rats to ZnCl(2) showed significant reduction in fertility, viability (days 0 and 4), and the body weight of F(1) pups from the high-dose group but caused no effects on litter size, weaning index, and sex ratio. Similarly, the continued exposure of F(1) parental rats to ZnCl(2) also reduced fertility, liter size, viability (day 0), and the body weight of F(2) pups within the high-dose group but caused no effects on weaning index and sex ratio. Exposure of ZnCl(2) to F(0) and F(1) parental males resulted in a significant reduction in their body weights, and the F(0) and F(1) parental females did not show any significant difference in their body weights compared to their control groups. However, the postpartum dam weights of both F(0) and F(1) female rats were significantly reduced compared to their controls. Exposure of ZnCl(2) to F(o) and F(1) generation parental rats did not produce any significant change of their clinical signs as well as their clinical pathology parameters, except the alkaline phosphotase (ALK) level, which showed an upward trend in both sexes of both generations. Exposure of ZnCl(2) to F(0) rats resulted in a reduction of brain, liver, kidney, spleen and seminal vesicles weights of males and in the spleen and uterus of females. Similarly, exposure of F(1) rats to ZnCl(2) also resulted in reduction of brain, liver, kidney, adrenal, spleen, prostate and seminal vesicles weights of males and in spleen and uterus of females. ZnCl(2) exposure resulted in grossly observed gastro-intestianla (GI) tract, lymphoreticular/hematopoietic, and reproductive tract lesions in parental rats in both generations. Reduced body fat was also recorded in F(1) parental rats. 相似文献
75.
76.
77.
The theory of space accessibility analysis, space syntax, has been considered for capturing trip-makers’ route-choice decisions with an understanding that, while selecting routes, trip-makers tend to follow forward-facing fields traditionally represented by axial lines. But the idea of treating axial lines as a set of roadway segments representing an urban texture has remained under scrutiny when distinct procedures have been tested without much success. Nor has the axial-line theory seemed to gain much popularity within the orthodox transportation planning community. Studies show that a long axial line is found gaining configurational centrality, in general, for being well connected to its incident lines. Fragmenting a long axial line results in weakening it (in centrality terms), but also in generating a locally oriented model. Recent investigations, dealing with this problem, have resulted in the emergence of the unit-segment theory, which has turned out to be more sensitive to the local structures located within a large urban texture than the axial counterpart for the purpose of modeling vehicular movement networks without using origin–destination trip-counts. Essentially, the question now is: Is the unit-segment analysis also capable of generating syntax configurations that are equally sensitive to large and complex urban textures? What should be the methodology of such an analysis? This paper throws deeper insights into these questions by producing theoretical and empirical research findings and seeks to develop a common ground for both transportation planning and space syntax communities to work together for gaining a better understanding of how urban configurations relate to urban vehicular movement networks. 相似文献
78.
Kishore?Kumar?MahatoEmail author Krishna?Dutta Bankim?Chandra?Ray 《Journal of Polymers and the Environment》2018,26(3):1024-1050
The study of static and dynamic behavior of environmentally conditioned fibre reinforced polymeric (FRP) composites is necessary and crucial to examine the durability, reliability and sustainability of these noble materials. FRP composites are being used all around the globe and substituting the conventional materials, starting from mini toys to large aerospace components. Present review has introduced to accumulate and understand the disseminate literature in concentrating the significance of understanding the static and dynamic behavior of FRPs with changing environmental conditionings (hygrothermal, low and high temperature, salt solution, freeze thaw, UV light) and with the interaction of different nano-fillers. Their stability and integrity in diverse service environments may be reformed by their reactions against different nature of loadings i.e. static or dynamic and the components such as fibre, matrix and fibre/matrix interfaces in those environments. The static and dynamic states of loading may come with a possible weaker region to encounter the durability and integrity of the composites. To understand the exact failure modes that correlates the position of environmentally conditioned interfaces and dynamic state of loadings, thus confusing the estimation of its overall performance and mechanical behavior. Interface reliability and durability is vital since in-service environments the degradation in the interfacial region leads to complete composite failure. Therefore, the study of combined effects of various in-service environmental conditions and the role of static and dynamic behavior on the interface will be a crucial part related to the multiaxial dynamic states of failures occurring in FRP’s. 相似文献
79.
Oili?TarvainenEmail author Anne?Tolvanen 《Environmental science and pollution research international》2016,23(14):13732-13744
Reclaiming abandoned and unmaintained roads, built originally for forestry and mineral extraction, is an important part of ecological restoration, because the roads running through natural habitats cause fragmentation. The roads can be reclaimed in a passive way by blocking access to the road, but successful seedling recruitment may require additional management due to the physical constraints present at the road. We established a full factorial study to compare the effects of three road reclaiming measures, namely ripping, creation of safe sites by adding mulch and pine seed addition, on soil processes, recovery of understorey vegetation and seedling recruitment in three conservation areas in eastern Finland. We surveyed soil organic matter, frequency and cover of plant functional types, litter and mineral soil, and number of tree seedlings. The soil organic matter was, on average, 1.3-fold in the 50-cm-deep ripping treatment relative to unripped and 20-cm-deep ripping treatments. The germination and survival of deciduous seedlings and grass establishment were promoted by adding mulch. The addition of pine seeds counteracted the seed limitation and enhanced the regeneration of trees. The treatment combination consisting of ripping, adding mulch and pine seed addition enhanced the vegetation succession and tree-seedling recruitment most: the cover of grasses, herbs and ericaceous dwarf shrubs was 1.3–7.6-fold and the number of coniferous tree seedlings was 3.4–7.1-fold relative to the other treatment combinations. Differences between short-term (1–3 years) and longer-term (6 years) results indicate the need for a sufficient observation period in road reclamation studies. 相似文献
80.
Francesca?De?PascalisEmail author Antonio?Petrizzo Michol?Ghezzo Giuliano?Lorenzetti Giorgia?Manfè Giorgio?Alabiso Luca?Zaggia 《Environmental science and pollution research international》2016,23(13):12515-12534
The Taranto basin is a shallow water marine system in the South of Italy characterized by the presence of a lagoon environment together with a semi-enclosed bay connected to the Ionian Sea. This marine system experienced over the last few decades strong biochemical pollution and environmental degradation, and it is considered a hotspot study site for economic, ecological and scientific reasons. The aim of this study was to examine, on an annual temporal scale and with high spatial resolution, the main hydrodynamical processes and transport scales of the system by means of a 3D finite element numerical model application, adopting the most realistic forcing available. The model allowed us to assess the role played by baroclinic terms in the basin circulation, describing its estuarine nature. In particular, the main features of water circulation, salinity and temperature distribution, water renewal time and bottom stress were investigated. Our results allowed us to equate this system dynamic to that of a weakly stratified estuary, identifying the main driving sources of this mechanism. The vertical stratification over the whole year was proved to be stable, leading to a dual circulation flowing out on the surface, mainly through Porta Napoli channel, and inflowing on the bottom mainly through Navigabile channel. This process was responsible also for the renewal time faster on the bottom of the Mar Piccolo basin than the surface. Due to the great importance of the Taranto basin for what concerns sediment pollution, also the effect of currents in terms of bottom stress was investigated, leading to the conclusion that only in the inlets area the values of bottom stress can be high enough to cause erosion. 相似文献