全文获取类型
收费全文 | 2963篇 |
免费 | 3篇 |
国内免费 | 33篇 |
专业分类
安全科学 | 68篇 |
废物处理 | 149篇 |
环保管理 | 295篇 |
综合类 | 405篇 |
基础理论 | 1109篇 |
污染及防治 | 594篇 |
评价与监测 | 202篇 |
社会与环境 | 177篇 |
出版年
2023年 | 4篇 |
2022年 | 3篇 |
2021年 | 5篇 |
2020年 | 3篇 |
2019年 | 8篇 |
2018年 | 116篇 |
2017年 | 126篇 |
2016年 | 187篇 |
2015年 | 52篇 |
2014年 | 21篇 |
2013年 | 36篇 |
2012年 | 430篇 |
2011年 | 214篇 |
2010年 | 30篇 |
2009年 | 35篇 |
2008年 | 51篇 |
2007年 | 69篇 |
2006年 | 71篇 |
2005年 | 395篇 |
2004年 | 532篇 |
2003年 | 406篇 |
2002年 | 45篇 |
2001年 | 42篇 |
2000年 | 18篇 |
1999年 | 31篇 |
1998年 | 4篇 |
1997年 | 9篇 |
1996年 | 4篇 |
1995年 | 11篇 |
1994年 | 5篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1991年 | 7篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1972年 | 2篇 |
1971年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1966年 | 2篇 |
1961年 | 2篇 |
1957年 | 1篇 |
排序方式: 共有2999条查询结果,搜索用时 250 毫秒
71.
Janusz Kloskowski Marek Nieoczym Marcin Polak Piotr Pitucha 《Die Naturwissenschaften》2010,97(7):673-682
Fish may significantly affect habitat use by birds, either as their prey or as competitors. Fish communities are often distinctly
size-structured, but the consequences for waterbird assemblages remain poorly understood. We examined the effects of size
structure of common carp (Cyprinus carpio) cohorts together with other biotic and abiotic pond characteristics on the distribution of breeding waterbirds in a seminatural
system of monocultured ponds, where three fish age classes were separately stocked. Fish age corresponded to a distinct fish
size gradient. Fish age and total biomass, macroinvertebrate and amphibian abundance, and emergent vegetation best explained
the differences in bird density between ponds. Abundance of animal prey other than fish (aquatic macroinvertebrates and larval
amphibians) decreased with increasing carp age in the ponds. Densities of ducks and smaller grebes were strongly negatively
associated with fish age/size gradient. The largest of the grebes, the piscivorous great crested grebe (Podiceps cristatus), was the only species that preferred ponds with medium-sized fish and was positively associated with total fish biomass.
Habitat selection by bitterns and most rallids was instead strongly influenced by the relative amount of emergent vegetation
cover in the ponds. Our results show that fish size structure may be an important cue for breeding habitat choice and a factor
affording an opportunity for niche diversification in avian communities. 相似文献
72.
Nowakowski Piotr Wala Mariusz 《Environmental science and pollution research international》2023,30(4):8809-8821
Environmental Science and Pollution Research - Refuse-derived fuel (RDF) can be produced from combustible materials contained in municipal waste. This article investigates energy and material flow... 相似文献
73.
Negative effects of noise on individuals, the inevitable result of urbanization, have become a significant urban problem in our day. Introduction of an approach to the noise problem on an urban-planning scale lightens the burden of measures required to be taken against noise at the stages of regional and developmental planning. Stadiums, which should be also evaluated from the point of noise problem when planning decisions are made on the urban planning scale, may cause very serious problems differing depending on the region they are located in. In this article, various dimensions of the noise problem caused by stadiums have been exemplified by making an assessment on Ali Sami Yen football stadium located in Mecidiyeköy district which is among important residential and commercial centres of ?stanbul or Turkey. When the simulation results obtained for ordinary days and match days are evaluated, it has been found out that the people living in the area are exposed to noise levels substantially exceeding the acceptable values. Results of the survey conducted in the area have clearly revealed the existence of noise problem, too. 相似文献
74.
Stepnowski Piotr Blotevogel Karl-Heinz Jastorff Bernd 《Environmental science and pollution research international》2002,9(1):34-38
In this paper, we present applied methanol recycling technology utilising Chromatographic applications, which has been designed for an academic-size institution. The procedure is combined out of proper recovery technique and the biodegradation method intended for postprocessing residues. Additionally, analytical methods controlling the quality of the process are described in detail in order to enable full transfer of the proposed methodology to the analogous institution. The recovered solvent is of relatively high purity (> 99.92%), containing traces of water and volatile compounds. The spectral purity is sufficient to employ recycled methanol in HPLC applications where low wayelength detection is necessary. Biodegradation of distillation first-cuts and still bottoms is implemented using isolated strains ofMethylobacterium organophilum. During the biodegradation process, a series of carotenoids are biosynthesized, which are of a high commercial value. The proposed application, therefore, offers not only a sustainable, waste-free solution in handling methanol waste, but can also serve as a potential source of value. 相似文献
75.
Hong?ZhengEmail author Yoshitaka?Nitta Isamu?Yokota 《Journal of Material Cycles and Waste Management》2004,6(2):153-161
In this article, the systems for the collection and intermediate processing of used beverage cans (UBCs) are compared and analyzed, focusing on the time taken and the cost of processing, the energy consumption, and the emissions of CO2, SO
x
, and NO
x
, during the process. We found that cases where the UBCs were crushed in the discharging process gave better results, and how the UBCs were collected was the most important factor. It was more desirable to treat UBCs in one place than in two places. When the transportation distance was longer, the pressed form of UBCs was more convenient. When the transportation distance was short, the original form, the crushed form, and the shredded form of UBCs were all suitable. That is, the contribution of the transportation process to the evaluation was large when the transport distance was long, and the contribution of the treatment process was large when the transport distance was short. 相似文献
76.
Atsushi?TerazonoEmail author Aya?Yoshida Jianxin?Yang Yuichi?Moriguchi Shin-ichi?Sakai 《Journal of Material Cycles and Waste Management》2004,6(2):82-96
In this article, we clarify the current status of Japanese exports and Chinese imports of secondary resources. A total of around 10 million metric tons (t) of secondary resources are exported annually from Japan to China, Hong Kong, and Korea. Hong Kong plays the role of a transshipment point, especially regarding the trade in plastic waste, and China imports much from the USA and Japan, often through Hong Kong. The secondary resources exported from Japan include both byproducts from manufacturing processes and end-of-life products or materials. The great demand in China, and the difference in prices between countries, drive this transboundary shipment, although Japan has enacted various recycling laws that were implicitly intended to promote domestic recycling. In China, the imported secondary resources are recycled, usually by means of primitive and low-cost hand labor. The greatest concern is whether there are still improper (illegal or polluting) recycling activities in China. International material cycles should prevent environmental pollution and ensure efficient resource utilization. To that end, the following measures are needed: cooperative control of the trade of secondary resources between countries, the alignment of domestic laws with the regulations in other countries based on the actual trade activities, and the realization of sound practices for global resources management. 相似文献
77.
Bulent?InancEmail author Azni?Idris Atsushi?Terazono Shin-ichi?Sakai 《Journal of Material Cycles and Waste Management》2004,6(2):97-103
This article briefly summarizes the limited landfill/dump information available for developing Asian countries, and introduces a database that aims to close the information gap through collecting and sharing data. Developing nations usually try to adapt the systems and technologies of developed countries. However, this approach may not be appropriate because of differences in socioeconomic, cultural, and political backgrounds. Many waste management projects fail after operations are transferred to local authorities owing to a lack of funds to cover the high operational expenses. Some successful projects have been adapted to local conditions, although the information on these successes is not often available for others. Nevertheless, only a few developing countries even have a national inventory of their dumps/landfills, and decision-makers have little awareness of the dumps and their impacts. The database introduced here will gather landfill/dump information from each country and organize it in a comparable format, and it will then be published on the Internet. 相似文献
78.
Utilization of red mud as catalyst in conversion of waste oil and waste plastics to fuel 总被引:4,自引:0,他引:4
A. Ihsan?Cakici Jale?YanikEmail author Suat?U?ar Tamer?Karayildirim Huseyin?Anil 《Journal of Material Cycles and Waste Management》2004,6(1):20-26
The aim of this study was to investigate the possibilities of using a by-product (red mud) from alumina production as a catalyst for recovery of waste. The conversion of waste mineral oil (WMO) and waste mineral oil/municipal waste plastic (WMO/MWP) blends over red mud (RM), a commercial hydrocracking catalyst (silica–alumina), and a commercial hydrotreating catalyst (Ni–Mo/alumina) to fuel has been studied. The effect of the catalyst and the temperature on the product distribution (gas, liquid, and wax) and the properties of liquid products were investigated. In the case of hydrotreatment of WMO, the liquids obtained over RM at both 400° and 425°C had larger amounts of low-boiling hydrocarbons than that of thermal or catalytic treatment with hydrotreating catalyst. Gas chromatography and nuclear magnetic resonance analysis of the liquid products showed that RM had hydrogenation and cracking activity in hydrotreatment of WMO. In coprocessing of WMO with municipal waste plastics, temperature had an important effect as well as the amount of MWP in the blend and the catalyst type. The hydrocracking at 400°C produced no liquid product. In hydrocracking at 425°C, the product distribution varied with catalyst type and MWP amount. The commercial hydrocracking catalyst had more cracking ability in the conversion of WMO/MWP to liquid and gas fuel than RM. In the case of hydrocracking over RM, the largest amount of liquid having satisfactory quality was obtained only from the blend containing 20% MWP. 相似文献
79.
Seung-Hwan?LeeEmail author Tsutomu?Ohkita 《Journal of Polymers and the Environment》2004,12(4):203-210
Ring-opening polymerization of cyclic esters (-caprolactone, -valerolactone, and l-lactide) onto liquefied biomass (LB) was conducted to obtain the polyester-type polyol and to regulate the characteristics of LB. IR and 1H-NMR spectra of the obtained polyol showed that the polymerization was successfully conducted in the presence of acid catalyst, which is used in liquefaction. The molecular weight (Mw), hydroxyl value, and viscosity were controllable by changing the reaction conditions. Polyester-type polyurethane foams with a wide range of properties were prepared from the obtained polyol with the appropriate combinations of foaming agents. 相似文献
80.
Abdul G.?LiewEmail author Azni?Idris Abdul A.?Samad Calvin H.K.?Wong Mohd S.?Jaafar Aminuddin M.?Baki 《Journal of Material Cycles and Waste Management》2004,6(1):41-47
Bricks produced from sewage sludge in different compositions were investigated. Results of the tests indicated that the sludge proportion is a key factor in determining the brick quality. Increasing the sludge content results in a decrease in brick shrinkage, bulk density, and compressive strength. Brick weight loss on ignition was mainly due to the contribution of the contained organic matter from the sludge being burnt off during the firing process, as well as inorganic substances found in both clay and sludge. The physical, mechanical, and chemical properties of the bricks that were supplemented with various proportions of dried sludge from 10 to 40wt% and generally complied with the General Specification for Brick as per the Malaysian Standard MS 7.6:1972, which dictates the requirements for clay bricks used in walling in general. A standard leaching test method also showed that the leaching of metals from the bricks is very low. 相似文献