全文获取类型
收费全文 | 36篇 |
免费 | 1篇 |
专业分类
废物处理 | 2篇 |
环保管理 | 3篇 |
综合类 | 13篇 |
基础理论 | 6篇 |
污染及防治 | 9篇 |
评价与监测 | 4篇 |
出版年
2022年 | 1篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2013年 | 5篇 |
2012年 | 1篇 |
2011年 | 2篇 |
2008年 | 1篇 |
2007年 | 1篇 |
2006年 | 1篇 |
2003年 | 2篇 |
1999年 | 1篇 |
1998年 | 4篇 |
1996年 | 1篇 |
1993年 | 1篇 |
1987年 | 1篇 |
1979年 | 1篇 |
1967年 | 1篇 |
1953年 | 1篇 |
1952年 | 1篇 |
1943年 | 1篇 |
1933年 | 1篇 |
1932年 | 1篇 |
1928年 | 2篇 |
1914年 | 1篇 |
1913年 | 3篇 |
排序方式: 共有37条查询结果,搜索用时 78 毫秒
11.
To assist transport modeling in assessments of the radiological impact of a geological repository for radioactive wastes, the mobility of various elements was studied in arable and wetland soils in the Forsmark region, Sweden. Pore water and total element contents were determined for five types of unconsolidated deposits (regolith), spanning a wide range of soil properties with respect to pH and organic matter content. Two soil depths were sampled to capture element mobility in regolith layers affected and unaffected by soil-forming processes. The solid/liquid partition coefficients (K d values) for most elements varied significantly among regolith types. For most elements, the observed variations in K d values could be explained by variations in soil properties. For many elements, mobility increased with decreasing soil pH. The results provide a significant addition of data on radionuclide retention in soils, taking account of soil properties and processes. 相似文献
12.
Urs Baumann Gustav Peter Ernst Pletscher Marcel Wettstein 《Environmental Sciences Europe》2003,15(4):227-233
Before waste-water-relevant organic materials are to be found in large quantities, their specific behavior in sewage treatment plants must be known. With the aid of the OECD simulation test #303 A, an estimation of their elimination in biological clarification stages can be made. In this work, an economical and continuous testing system is presented, which consists of a polyester flies bound to an activated biosludge with a high inoculum density, allowing one to measure no only the elimination of individual substances, but also the specific degree of mineralization. The toxicity of the activated biosludge and the nitrifying substances can also be examined. With the described testing procedure, it is possible to determine the rate of degradation within only a few hours. Finally, it can also be seen that it is possible to reliably and continuously determine the rate of anaerobic, biological degradability through the use of such a modified testing procedure. 相似文献
13.
Mehmet Coelhan Gerda Fingerling Gabriele Christ Harun Parlar 《Environmental Sciences Europe》1998,10(2):109-122
Residue analysis of toxaphene has been difficult because of the complexity of the technical mixture consisting of a high number of compounds with very similar structure and differing chlorine content. Furthermore, the composition of toxaphene in environmental samples varies widely and is normally not related to that of the technical mixture. Therefore, quantification of single components in environmental samples was impossible. After the isolation and identification of a great number of components during the last decade, enough standards are available for the reliable quantification of toxaphene in all environmental compartments. Recently, most research has been performed on the separation of chiral components of toxaphene with a view to identifying the degradation mechanisms and distribution pathways. 相似文献
14.
15.
16.
Historical and Future Stream Temperature Change Predicted by a Lidar‐Based Assessment of Riparian Condition and Channel Width 下载免费PDF全文
Gustav B. Seixas Timothy J. Beechie Caleb Fogel Peter M. Kiffney 《Journal of the American Water Resources Association》2018,54(4):974-991
Riparian forests attenuate solar radiation, thereby mediating an important component of the thermal budget of streams. Here, we investigate the relationship between riparian degradation, stream temperature, and channel width in the Chehalis River Basin, Washington State. We used lidar data to measure canopy opening angle, the angle formed between the channel center and trees on both banks; we assumed historical tree heights and calculated the change in canopy angle relative to historical conditions. We then developed an empirical relationship between canopy angle and water temperature using existing data, and simulated temperatures between 2002 and 2080 by combining a tree growth model with climate change scenarios from the NorWeST regional prediction. The greatest change between historical and current conditions (~7°C) occurred in developed portions of the river network, with the highest values of change predicted at channel widths less than ~40 m. Tree growth lessened climate change increases in maximum temperature and the length of river exceeding biologically critical thresholds by ~50%–60%. Moreover, the maximum temperature of channels with bankfull widths less than ~50 m remained similar to current conditions, despite climate change increases. Our findings are consistent with a possible role for the riparian landscape in explaining the low sensitivity of stream temperatures to air temperatures observed in some small mountain streams. 相似文献
17.
Circadian rhythmicity plays an important role for many aspects of honey bees’ lives. However, the question whether it also
affects learning and memory remained unanswered. To address this question, we studied the effect of circadian timing on olfactory
learning and memory in honey bees Apis mellifera using the olfactory conditioning of the proboscis extension reflex paradigm. Bees were differentially conditioned to odours
and tested for their odour learning at four different “Zeitgeber” time points. We show that learning behaviour is influenced
by circadian timing. Honey bees perform best in the morning compared to the other times of day. Additionally, we found influences
of the light condition bees were trained at on the olfactory learning. This circadian-mediated learning is independent from
feeding times bees were entrained to, indicating an inherited and not acquired mechanism. We hypothesise that a co-evolutionary
mechanism between the honey bee as a pollinator and plants might be the driving force for the evolution of the time-dependent
learning abilities of bees. 相似文献
18.
Predation is often thought of as an unforgiving and strong selective force, quickly selecting against maladaptive behaviour in the prey. It is argued that experience is likely to have low influence on the phenotypic response to predation, as failing to react correctly to a predator may mean death to the prey and no second chance to learn and correct the behaviour. Individuals from different populations of Eurasian perch are known to differ in risk-taking behaviour. Variation in predation pressure has been suggested as a key factor causing these differences, but little is known about the underlying mechanism by which predation generates risk-taking phenotypes in perch. We compared the degree of boldness between two natural populations of Eurasian perch, living under different predation regimes, and the same populations hatched and reared under identical conditions, free from predation. By this common-garden approach, we sought to investigate patterns in the influence of inheritance and experience on boldness phenotype. The wild fish differed in risk taking, with fish from the low predation-risk population acting bolder than fish from the high-risk environment. In the reared fish, both populations behaved equally bold. Only the fish originating from the high predation population showed different behaviour when comparing wild and reared ecotypes. Our results suggest that experience has an important impact on the response to predators and that geographic variation in risk taking between populations of Eurasian perch to a high degree is shaped by adjustments to the current environment. Habituation had an effect of risk-taking behaviour over the experimental period, but consistent differences between individuals were also found. Furthermore, we also show, by the estimation of variance components, that the behaviour we observe is affected by a range of random effects, such as aquaria and group membership, that in concert shapes the behaviour of an individual perch. 相似文献
19.
Gustav Richnau Per Angelstam Sviataslau Valasiuk Lyudmyla Zahvoyska Robert Axelsson Marine Elbakidze Joshua Farley Ingemar Jönsson Ihor Soloviy 《Ambio》2013,42(2):188-200
Forest landscapes provide benefits from a wide range of goods, function and intangible values. But what are different forest owner categories’ profiles of economic use and non-use values? This study focuses on the complex forest ownership pattern of the River Helge å catchment including the Kristianstad Vattenrike Biosphere Reserve in southern Sweden. We made 89 telephone interviews with informants representing the four main forest owner categories. Our mapping included consumptive and non-consumptive direct use values, indirect use values, and non-use values such as natural and cultural heritage. While the value profiles of non-industrial forest land owners and municipalities included all value categories, the forest companies focused on wood production, and the Swedish Environmental Protection Agency on nature protection. We discuss the challenges of communicating different forest owners’ economic value profiles among stakeholders, the need for a broader suite of forest management systems, and fora for collaborative planning.
Electronic supplementary material
The online version of this article (doi:10.1007/s13280-012-0374-2) contains supplementary material, which is available to authorized users. 相似文献20.
Leif G. Salford Henrietta Nittby Arne Brun Gustav Grafström Jacob L. Eberhardt Lars Malmgren Bertil R. R. Persson 《The Environmentalist》2007,27(4):493-500
The environment in which biology exists has dramatically changed during the last decades. Life was formed during billions of years, exposed to, and shaped by the original physical forces such as gravitation, cosmic irradiation and the terrestrial magnetism. The existing organisms are created to function in harmony with these forces. However, in the late 19th century mankind introduced the use of electricity and during the very last decades, microwaves of the modern communication society spread around the world. Today one third of the world’s population is owner of the microwave-producing mobile phones. The question is: to what extent are living organisms affected by these ubiquitous radio frequency fields? Since 1988 our group has studied the effects upon the mammalian blood-brain barrier (BBB) by non-thermal radio frequency electromagnetic fields (RF-EMF). These have been revealed to cause significantly increased leakage of albumin through the BBB of exposed rats as compared to non-exposed animals—in a total series of about two thousand animals. One remarkable observation is the fact that the lowest energy levels give rise to the most pronounced albumin leakage. If mobile communication, even at extremely low energy levels, causes the users’ own albumin to leak out through the BBB, also other unwanted and toxic molecules in the blood, may leak into the brain tissue and concentrate in and damage the neurons and glial cells of the brain. In later studies we have shown that a 2-h exposure to GSM 915 MHz at non-thermal levels, gives rise to significant neuronal damage, seen 28 and 50 days after the exposure. In our continued research, the non-thermal effects (histology, memory functions) of long-term exposure for 13 months are studied as well as the effects of short term GSM 1,800 MHz upon gene expression. Most of our findings support that living organisms are affected by the non-thermal radio frequency fields. Studies from other laboratories in some cases find effects, while in other cases effects are not seen. Our conclusion is that all researchers involved in this field have the obligation to intensify this research in order to reduce, or avoid, the possible negative effects of the man made microwaves! 相似文献