全文获取类型
收费全文 | 225篇 |
免费 | 1篇 |
国内免费 | 3篇 |
专业分类
安全科学 | 8篇 |
废物处理 | 10篇 |
环保管理 | 13篇 |
综合类 | 40篇 |
基础理论 | 39篇 |
污染及防治 | 52篇 |
评价与监测 | 15篇 |
社会与环境 | 51篇 |
灾害及防治 | 1篇 |
出版年
2023年 | 5篇 |
2022年 | 9篇 |
2021年 | 4篇 |
2020年 | 3篇 |
2019年 | 6篇 |
2018年 | 13篇 |
2017年 | 8篇 |
2016年 | 18篇 |
2015年 | 16篇 |
2014年 | 12篇 |
2013年 | 18篇 |
2012年 | 10篇 |
2011年 | 18篇 |
2010年 | 15篇 |
2009年 | 8篇 |
2008年 | 11篇 |
2007年 | 8篇 |
2006年 | 8篇 |
2005年 | 4篇 |
2004年 | 6篇 |
2003年 | 3篇 |
2002年 | 4篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1997年 | 2篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1991年 | 1篇 |
排序方式: 共有229条查询结果,搜索用时 15 毫秒
71.
72.
Biodegradable Blends Based on Starch and Poly(Lactic Acid): Comparison of Different Strategies and Estimate of Compatibilization 总被引:1,自引:0,他引:1
Emmanuelle Schwach Jean-Luc Six Luc Avérous 《Journal of Polymers and the Environment》2008,16(4):286-297
Finding plastic substitutes based on sustainability, especially for short-term packaging and disposable applications has aroused
scientific interest for many years. Starch may be a substitute for petroleum based plastics but it shows severe limitations
due to its water sensitivity and rather low mechanical properties. To overcome these weaknesses and to maintain the material
biodegradability, one option is to blend plasticized starch with another biodegradable polymer. To improve both the compatibility
between the main phases and the performance of the final blend, different compatibilization strategies are reported in literature.
However, the relative efficiency of each strategy is not widely reported. This paper presents three different strategies:
in situ (i) formation of urethane linkages; (ii) coupling with peroxide between starch and PLA, and (iiii) the addition of
PLA-grafted amylose (A-g-PLA) which has been elaborated ex situ and carefully analyzed before blending. This study compares
the effect of each compatibilization strategy by investigating mechanical and thermal properties of each blend. Compatibilizing
behavior of the A-g-PLA is demonstrated, with a significant increase (up to 60%) in tensile strength of starch/PLA blend with
no decrease in elongation at failure. 相似文献
73.
Methneni Nosra Anthonissen Roel Van de Maele Jolien Trifa Fatma Verschaeve Luc Mansour Hedi Ben Mertens Birgit 《Environmental science and pollution research international》2020,27(32):40088-40100
Environmental Science and Pollution Research - Due to the complexity and variability of textile wastewater composition, a constant search for new treatment strategies that are efficient,... 相似文献
74.
Frédéric Chivrac Zuzana Kadlecová Eric Pollet Luc Avérous 《Journal of Polymers and the Environment》2006,14(4):393-401
Biodegradable polymers are one of the most promising ways to replace non-degradable polymers. But, to be a real alternative to classical synthetic polymers and find applications, biopolymer (biodegradable polymer) properties have to be enhanced. Nano-biocomposites, which are obtained by incorporation of nanofillers into a biomatrix, are an interesting way to achieve these improvements. Modified and unmodified montmorillonites have been introduced into a biodegradable aromatic copolyester, poly(butylene adipate-co-terephthalate) (PBAT). Structural characterization, thermal and mechanical tests have been carried out to understand better the relations between the nanofillers structuring and the final nano-biocomposite properties. Main results show that clay incorporation and the obtained intercalated structures improve PBAT properties (enhanced thermal stability, increased stiffness) and thus may increase the attractiveness of this biopolymer. 相似文献
75.
Metacommunity structure of pond macroinvertebrates: effects of dispersal mode and generation time 总被引:1,自引:0,他引:1
A recent challenge in community ecology is to understand under what conditions local and regional processes may be more important in shaping community structure. We investigated the role of dispersal mode and generation time for communities of macroinvertebrates in two sets of connected ponds during three consecutive years. We found no evidence that generation time affected metacommunity structure, possibly because statistical power was limited because the range of generation times present was small. In contrast, we found that the spatial structure of the macroinvertebrate metacommunities differed with dispersal mode in one of two sets of ponds. Passive dispersers showed positive distance-dissimilarity correlations, suggesting mass effects via the pond connections. These correlations did not stretch beyond the first pond downstream suggesting that, in this chain of connected ponds, intervening ponds effectively buffered dispersal. Active dispersers did not show any consistent spatial pattern, possibly because intensive over-land dispersal homogenized the metacommunity. Thus, although pond connections probably equally promoted dispersal of actively and passively dispersing macroinvertebrates, the implications for the structure of their metacommunities may depend on their dispersal mode. We conclude that dispersal mode has the potential to affect the mechanisms that are integral to metacommunity structure. 相似文献
76.
Dormant propagule banks are important reservoirs of biological and genetic diversity of local communities and populations and provide buffering mechanisms against extinction. Although dormant stages of various plant and animal species are known to remain viable for decades and even centuries, little is known about the effective influence of recolonization from such old sources on the genetic continuity of intermittent populations under natural conditions. Using recent and old dormant eggs recovered from a dated lake sediment core in Kenya, we traced the genetic composition of a local population of the planktonic crustacean Daphnia barbata through a sequence of extinction and recolonization events. This was combined with a phylogeographic and population-genetic survey of regional populations. Four successive populations, fully separated in time, inhabited Lake Naivasha from ca. 1330 to 1570 AD, from ca. 1610 to 1720 AD, from ca. 1840 to 1940 AD, and from 1995 to the present (2001 AD). Our results strongly indicate genetic continuity between the 1840-1940 and 1995-2001 populations, which are separated in time by at least 50 years, and close genetic relatedness of them both to the 1330-1580 population. A software tool (Colonize) was developed to find the most likely source population of the refounded 1995-2001 population and to test the number of colonists involved in the recolonization event. The results confirmed that the 1995-2001 population most probably developed out of a limited number of surviving local dormant eggs from the previous population, rather than out of individuals from regional (central and southern Kenya) or more distant (Ethiopia, Zimbabwe) populations that may have immigrated to Lake Naivasha through passive dispersal. These results emphasize the importance of prolonged dormancy for the natural long-term dynamics of crustacean zooplankton in fluctuating environments and suggest an important role of old local dormant egg banks in aquatic habitat restoration. 相似文献
77.
78.
79.
Sophie?GourguetEmail author Olivier?Thébaud Sarah?Jennings L.?Richard?Little Catherine?M.?Dichmont Sean?Pascoe Roy?A.?Deng Luc?Doyen 《Environmental Modeling and Assessment》2016,21(3):371-389
Fisheries management must address multiple, often conflicting objectives in a highly uncertain context. In particular, while the bio-economic performance of trawl fisheries is subject to high levels of biological and economic uncertainty, the impact of trawling on broader biodiversity is also a major concern for their management. The purpose of this study is to propose an analytical framework to formally assess the trade-offs associated with balancing biological, economic and non-target species conservation objectives. We use the Australian Northern Prawn Fishery (NPF), which is one of the most valuable federally managed commercial fisheries in Australia, as a case study. We develop a stochastic co-viability assessment of the fishery under multiple management objectives. Results show that, due to the variability in the interactions between the fishery and the ecosystem, current management strategies are characterized by biological and economic risks. Results highlight the trade-offs between respecting biological, economic and non-target species conservation constraints at each point in time with a high probability and maximizing the net present value of the fishery. 相似文献
80.