全文获取类型
收费全文 | 736篇 |
免费 | 17篇 |
国内免费 | 7篇 |
专业分类
安全科学 | 20篇 |
废物处理 | 60篇 |
环保管理 | 80篇 |
综合类 | 106篇 |
基础理论 | 149篇 |
环境理论 | 1篇 |
污染及防治 | 231篇 |
评价与监测 | 66篇 |
社会与环境 | 44篇 |
灾害及防治 | 3篇 |
出版年
2023年 | 10篇 |
2022年 | 20篇 |
2021年 | 23篇 |
2020年 | 17篇 |
2019年 | 16篇 |
2018年 | 22篇 |
2017年 | 31篇 |
2016年 | 42篇 |
2015年 | 23篇 |
2014年 | 47篇 |
2013年 | 55篇 |
2012年 | 43篇 |
2011年 | 65篇 |
2010年 | 59篇 |
2009年 | 35篇 |
2008年 | 39篇 |
2007年 | 34篇 |
2006年 | 30篇 |
2005年 | 22篇 |
2004年 | 27篇 |
2003年 | 22篇 |
2002年 | 16篇 |
2001年 | 10篇 |
2000年 | 9篇 |
1999年 | 10篇 |
1998年 | 6篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1988年 | 1篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1978年 | 1篇 |
1975年 | 1篇 |
1963年 | 1篇 |
1955年 | 1篇 |
排序方式: 共有760条查询结果,搜索用时 312 毫秒
531.
532.
Claudia Gutirrez Huete 《Journal of the American Water Resources Association》1987,23(1):121-126
ABSTRACT: The water resources of Nicaragua are largely undeveloped and distributed unequally throughout the nation. In addition, there is a significant geographical imbalance between the abundant water supply in the Atlantic Basin and the less abundant supply in the Pacific Basin which accounts for most of the water demand. The Lakes Basin, comprising Lakes Managua and Nicaragua, could be manipulated to solve the imbalance. Specifically, this paper presents a scheme to transfer water from Lake Nicaragua to Lake Managua and, subsequently, direct water from each lake for irrigation and hydroelectric generation. The scheme has been designed to maximize economic benefits and requires environmental impact analysis. 相似文献
533.
The chlorinated solvent stabilizer 1,4‐dioxane (DX) has become an unexpected and recalcitrant groundwater contaminant at many sites across the United States. Chemical characteristics of DX, such as miscibility and low sorption potential, enable it to migrate at least as far as the chlorinated solvent from which it often originates. This mobility and recalcitrance has challenged remediation professionals to redesign existing treatment systems and monitoring networks to accommodate widespread contamination. Furthermore, remediation technologies commonly applied to chlorinated solvent co‐contaminants, such as extraction and air stripping or in situ enhanced reductive dechlorination, are relatively ineffective on DX removal. These difficulties in treatment have required the industry to identify, develop, and demonstrate new and innovative technologies and approaches for both ex situ and in situ treatment of this emerging contaminant. Great strides have been made over the past decade in the development and testing of remediation technologies for removal or destruction of DX in groundwater. This article briefly summarizes the fate and transport characteristics of DX that make it difficult to treat, and presents technologies that have been demonstrated to be applicable to groundwater treatment at the field scale. ©2016 Wiley Periodicals, Inc. 相似文献
534.
The challenge of being a young manager: The effects of contingent reward and participative leadership on team‐level turnover depend on leader age
下载免费PDF全文
![点击此处可从《组织行为杂志》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Effective leadership requires a leader claiming as well as team members granting the leadership position. Contingent reward and participative leadership may both facilitate this mutual process. However, these behaviors differ in the degree to which they require a leader to have status and be prototypical. Their effectiveness might thus depend on the status‐related characteristics of the leader. In this respect, we propose that younger leaders, by deviating from the leader prototype in terms of age, lack a natural status cue, which will determine the effectiveness of these two leadership behaviors in shaping turnover. Two pilot studies (N = 113 and 121 individuals) confirm that younger leaders are perceived as less prototypical and to have lower status than older leaders. Examining 83 work teams, we show that leader age differently moderates the effects of contingent reward and participative leadership on time‐lagged team turnover. For younger (compared with older) leaders, contingent reward was effective as illustrated by decreased voluntary turnover and increased involuntary turnover, whereas participative leadership, which was associated with increased voluntary turnover and decreased involuntary turnover, was ineffective. These findings point to the importance of incorporating natural status cues of leaders for understanding the effectiveness of different leadership behaviors. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
535.
M. Iaconelli M. Divizia S. Della Libera P. Di Bonito Giuseppina La Rosa 《Food and environmental virology》2016,8(4):289-295
The prevalence and genetic diversity of human bocaviruses (HBoVs) in sewage water samples are largely unknown. In this study, 134 raw sewage samples from 25 wastewater treatment plants (WTPs) in Italy were analyzed by nested PCR and sequencing using species-specific primer pairs and broad-range primer pairs targeting the capsid proteins VP1/VP2. A large number of samples (106, 79.1 %) were positive for HBoV. Out of these, 49 were classified as HBoV species 2, and 27 as species 3. For the remaining 30 samples, sequencing results showed mixed electropherograms. By cloning PCR amplicons and sequencing, we confirmed the copresence of species 2 and 3 in 29 samples and species 2 and 4 in only one sample. A real-time PCR assay was also performed, using a newly designed TaqMan assay, for quantification of HBoVs in sewage water samples. Viral load quantification ranged from 5.51E+03 to 1.84E+05 GC/L (mean value 4.70E+04 GC/L) for bocavirus 2 and from 1.89E+03 to 1.02E+05 GC/L (mean value 2.27E+04 GC/L) for bocavirus 3. The wide distribution of HBoV in sewages suggests that this virus is common in the population, and the most prevalent are the species 2 and 3. HBoV-4 was also found, representing the first detection of this species in Italy. Although there is no indication of waterborne transmission for HBoV, the significant presence in sewage waters suggests that HBoV may spread to other water environments, and therefore, a potential role of water in the HBoV transmission should not be neglected. 相似文献
536.
Treatment of effluent from re‐refined lubricating oils by combined processes of coagulation,flocculation, and Fenton process
下载免费PDF全文
![点击此处可从《环境质量管理》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Lucas Pisoni da Silva Silvio Roberto Taffarel Fernanda Rosa da Silveira Fagner Tafarel Campos de Sá Luís Felipe Silva Oliveira 《环境质量管理》2018,27(4):135-141
This work examines the possibility and the potential application of physicochemical processes (coagulation and flocculation) and advanced oxidative processes (Fenton Process) in the treatment of effluents from the re‐refining of used lubricating oils. 相似文献
537.
Ivan B. T. Lima Fernando M. Ramos Luis A. W. Bambace Reinaldo R. Rosa 《Mitigation and Adaptation Strategies for Global Change》2008,13(2):193-206
By means of a theoretical model, bootstrap resampling and data provided by the International Commission On Large Dams (ICOLD
(2003) World register of dams. http://www.icold-cigb.org) we found that global large dams might annually release about 104 ± 7.2 Tg
CH4 to the atmosphere through reservoir surfaces, turbines and spillways. Engineering technologies can be implemented to avoid
these emissions, and to recover the non-emitted CH4 for power generation. The immediate benefit of recovering non-emitted CH4 from large dams for renewable energy production is the mitigation of anthropogenic impacts like the construction of new large
dams, the actual CH4 emissions from large dams, and the use of unsustainable fossil fuels and natural gas reserves. Under the Clean Development
Mechanism of the Kyoto Protocol, such technologies can be recognized as promising alternatives for human adaptations to climate
change concerning sustainable power generation, particularly in developing nations owning a considerable number of large dams.
In view of novel technologies to extract CH4 from large dams, we estimate that roughly 23 ± 2.6, 2.6 ± 0.2 and 32 ± 5.1 Tg CH4 could be used as an environmentally sound option for power generation in Brazil, China and India, respectively. For the whole
world this number may increase to around 100 ± 6.9 Tg CH4. 相似文献
538.
Brígido Flores O Montalván Estrada A Rosa Suárez R Tomás Zerquera J Hernández Pérez A 《Journal of environmental radioactivity》2008,99(12):1834-1837
An extensive research project to investigate the radioactive properties of Cuban building materials was carried out because there is a lack of information on the radioactivity of such materials in Cuba. In the framework of this project 44 samples of commonly used raw materials and building products were collected in five Cuban provinces. The activity concentrations of natural radionuclides were determined by gamma ray spectrometry using a p-type coaxial high purity germanium detector and their mean values were in the ranges: 9-857Bqkg(-1) for (40)K; 6-57Bqkg(-1) for (226)Ra; and 1.2-22Bqkg(-1) for (232)Th. The radium equivalent activity in the 44 samples varied from 4Bqkg(-1) (wood) to 272Bqkg(-1) (brick). A high pressure ionisation chamber was used to measure the indoor absorbed dose rate in 543 dwellings and workplaces in five Cuban provinces. The average absorbed dose rates in air ranged from 43nGyh(-1) (Holguín) to 73nGyh(-1) (Camagüey) and the corresponding population-weighted annual effective dose due to external gamma radiation was estimated to be 145+/-40microSv. This value is 51% lower than the effective dose due to internal exposure from inhalation of decay products of (222)Rn and (220)Rn and it is 16% higher than the calculated value for the typical room geometry of a Cuban house. 相似文献
539.
Footdrumming and other anti-predator responses in the bannertail kangaroo rat (Dipodomys spectabilis) 总被引:1,自引:0,他引:1
Summary Anti-predator behaviors of the bannertail kangaroo rat (Dipodomys spectabilis) toward snake predators were investigated. We induced responses by presenting a live (tethered) snake and an inflatable snake decoy to rats of known ages and sex in their territories. Comparisons of behaviors during spontaneous activity (baseline), naturally occurring snake-rat interactions, and experimental procedures further clarified anti-predator behaviors. The tethered snake immediately induced high rates of footdrumming (the repeated striking of the hind feet on the ground) in all rats (n=24) (Table 2), and individuals of both sexes and all ages footdrummed significantly more at the tethered snake than at the decoy. Other antipredator behaviors included alert postures, jumpback, kicking sand and avoidance. Juvenile rats exhibited more avoidance behavior and alert postures than adults and footdrummed at the decoy only if they experienced the snake first. We conclude that footdrumming functions as an individual alarm signal against predation by snakes in D. spectabilis. The drumming probably informs a snake that it has been detected and may cause it to leave. Because rats did not footdrum in response to aerial predators (owls), we suggest that kangaroo rats use different anti-predator strategies that depend on the kind of threat and the type of predator. 相似文献
540.
Summary. We adapted a four-arm olfactometer (55 × 55 × 5.5 cm) for bioassays of large insects and its usefulness was evaluated by testing
the responses of three beetles, the palm weevil Rhynchophorus palmarum (L.) (Coleoptera: Curculionidea) and two Dynast scarabs Strategus aloeus (L.) and Oryctes rhinoceros (L.) (Coleoptera: Scarabaeidae) to plant odours and aggregation pheromones. This olfactometer was coupled to a volatile delivery
system dispensing highly volatile semiochemicals at constant concentrations. We materialized airflows in the olfactometer
by discolouring sensitive papers with acid vapours under various conditions (air straighten by stainless steel grids in inputs
and output, 500 ml/min per arm) to visualize air turbulence and to test air-tightness. The volatile delivery system can be
used to mix and dispense a broad range of concentrations of semiochemicals in air from diluted aqueous solutions. It was calibrated
by measuring the release of the pheromone using solid phase-microextraction (SPME). Dose-response curves to synthetic pheromone
were obtained for O. rhinoceros of both sexes. Coupling the volatile delivery system to the fourarm olfactometer provided a system with which the responses
of R. palmarum and S. aloeus to their synthetic aggregation pheromones and to natural plant volatiles could be readily observed and studied. 相似文献