全文获取类型
收费全文 | 93篇 |
免费 | 6篇 |
国内免费 | 2篇 |
专业分类
安全科学 | 3篇 |
废物处理 | 4篇 |
环保管理 | 11篇 |
综合类 | 12篇 |
基础理论 | 35篇 |
环境理论 | 1篇 |
污染及防治 | 18篇 |
评价与监测 | 5篇 |
社会与环境 | 8篇 |
灾害及防治 | 4篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 2篇 |
2020年 | 2篇 |
2018年 | 6篇 |
2017年 | 8篇 |
2016年 | 6篇 |
2015年 | 1篇 |
2014年 | 4篇 |
2013年 | 6篇 |
2012年 | 9篇 |
2011年 | 8篇 |
2010年 | 5篇 |
2009年 | 3篇 |
2008年 | 5篇 |
2007年 | 6篇 |
2006年 | 5篇 |
2005年 | 1篇 |
2003年 | 4篇 |
2002年 | 4篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1995年 | 1篇 |
1988年 | 2篇 |
1986年 | 1篇 |
1982年 | 1篇 |
1977年 | 1篇 |
1953年 | 1篇 |
排序方式: 共有101条查询结果,搜索用时 31 毫秒
51.
Erica von Essen Michael P. Allen 《Environmental Communication: A Journal of Nature and Culture》2017,11(5):654-666
Two obstructionist ways of doing politics on contentious wildlife management issues currently reflect a legitimacy deficit in official channels for public engagement. The first is that of a pernicious “direct-action” politics, in the form of resort by hunters in rural Sweden to illegal killings of protected wolves over whose policy they contest. The second obstruction is when environmental non-governmental organizations routinely file appeals in higher-level courtrooms contesting democratically mandated wolf cull decisions. Although markedly different when it comes to their categorically deliberative values as well as fidelity to the law, we argue both extra-legal and the litigative phenomena reflect disenfranchisement with the participation channels in which such controversies may be resolved through a public dialogue. We also argue that both possess negative systemic deliberative value inasmuch as they frustrate goals of reaching deliberative consensus, by contributing to a stalled public communication on wolf management. We address this deficit by appeal to recent developments in the theory and practice of mini-publics that promote both the categorical and systemic deliberative value of channeling contestation. In particular, we appeal to a novel conception of hunter-initiated, but citizen controlled, mini-publics as a vehicle for re-starting stalled public communication on wolf conservation. 相似文献
52.
Gregory S. Lepak Bryan R. Moser Erica L. Bakota Julia Sharp C. David Thornton Terry Walker 《International Journal of Sustainable Engineering》2017,10(2):105-114
Biodiesel from waste cooking oil (WCO) requires antioxidants to meet oxidation stability specifications set forth in ASTM D6751 or EN 14214. In contrast, unrefined cottonseed oil (CSO), containing tocopherols and gossypol, produces biodiesel of higher oxidation stability. However, only a portion of these CSO endogenous antioxidants are suspected to be retained in biodiesel. Because the economics of biodiesel manufacturing rely upon inexpensive sources of triglycerides, emphasis was placed on developing improved alternative processing methods where WCO was the main source of methyl esters (WCOME) and CSO was used as a supplemental source of triglycerides and antioxidants in a 4:1 ratio. This study compared four processing methods for their ability to produce biodiesel of increased oxidative stability prepared from a 4:1 ratio of WCO:CSO. Two novel processing methods developed for this study utilise solvent properties of fatty acid methyl esters and glycerol to avoid additional chemical inventory for biodiesel processors. This study concludes that the two new processing methods resulted in biodiesel that had statistically significant improved oxidation stability when compared to two common industrial processing methods. Another significant finding is that high-shear homogenisation during transesterification reduced reaction time from the published one hour to 16 minutes. 相似文献
53.
Although Brazil is well endowed with natural resources, some of these are unexploited due to poor communications and political instability. The authors review present government policy and the situation with regard to oil and gas, iron ore, manganese and steel and other minerals, and conclude that Brazil has a bright economic future. 相似文献
54.
Erica H. Dunn 《Conservation biology》2002,16(6):1632-1637
55.
56.
57.
Relationship between mass-flux reduction and source-zone mass removal: analysis of field data 总被引:1,自引:1,他引:0
The magnitude of contaminant mass-flux reduction associated with a specific amount of contaminant mass removed is a key consideration for evaluating the effectiveness of a source-zone remediation effort. Thus, there is great interest in characterizing, estimating, and predicting relationships between mass-flux reduction and mass removal. Published data collected for several field studies were examined to evaluate relationships between mass-flux reduction and source-zone mass removal. The studies analyzed herein represent a variety of source-zone architectures, immiscible-liquid compositions, and implemented remediation technologies. There are two general approaches to characterizing the mass-flux-reduction/mass-removal relationship, end-point analysis and time-continuous analysis. End-point analysis, based on comparing masses and mass fluxes measured before and after a source-zone remediation effort, was conducted for 21 remediation projects. Mass removals were greater than 60% for all but three of the studies. Mass-flux reductions ranging from slightly less than to slightly greater than one-to-one were observed for the majority of the sites. However, these single-snapshot characterizations are limited in that the antecedent behavior is indeterminate. Time-continuous analysis, based on continuous monitoring of mass removal and mass flux, was performed for two sites, both for which data were obtained under water-flushing conditions. The reductions in mass flux were significantly different for the two sites (90% vs. approximately 8%) for similar mass removals ( approximately 40%). These results illustrate the dependence of the mass-flux-reduction/mass-removal relationship on source-zone architecture and associated mass-transfer processes. Minimal mass-flux reduction was observed for a system wherein mass removal was relatively efficient (ideal mass-transfer and displacement). Conversely, a significant degree of mass-flux reduction was observed for a site wherein mass removal was inefficient (non-ideal mass-transfer and displacement). The mass-flux-reduction/mass-removal relationship for the latter site exhibited a multi-step behavior, which cannot be predicted using some of the available simple estimation functions. 相似文献
58.
59.
Erica L. Seubert Alyssa G. Gellene Meredith D. A. Howard Paige Connell Matthew Ragan Burton H. Jones Jennifer Runyan David A. Caron 《Environmental science and pollution research international》2013,20(10):6878-6895
Reports of toxic harmful algal blooms (HABs) attributed to the diatom Pseudo-nitzschia spp. have been increasing in California during the last several decades. Whether this increase can be attributed to enhanced awareness and monitoring or to a dramatic upswing in the development of HAB events remains unresolved. Given these uncertainties, the ability to accurately and rapidly identify an emerging HAB event is of high importance. Monitoring of HAB species and other pertinent chemical/physical parameters at two piers in southern California, Newport and Redondo Beach, was used to investigate the development of a site-specific bloom definition for identifying emerging domoic acid (DA) events. Emphasis was given to abundances of the Pseudo-nitzschia seriata size category of Pseudo-nitzschia due to the prevalence of this size class in the region. P. seriata bloom thresholds were established for each location based on deviations from their respective long-term mean abundances, allowing the identification of major and minor blooms. Sixty-five percent of blooms identified at Newport Beach coincided with measurable DA concentrations, while 36 % of blooms at Redondo Beach coincided with measurable DA. Bloom definitions allowed for increased specificity in multiple regression analysis of environmental forcing factors significant to the presence of DA and P. seriata. The strongest relationship identified was between P. seriata abundances 2 weeks following upwelling events at Newport Beach. 相似文献
60.
The efficacy of a simple mass-removal function for characterizing mass-flux-reduction/mass-removal behavior for organic-liquid contaminated source zones was evaluated using the data obtained from a series of flow-cell experiments. The standard function, which employs a constant exponent, could not adequately reproduce the non-singular (multi-step) behavior exhibited by the measured data. Allowing the exponent to change as a function of mass removal (as the organic-liquid distribution and relative permeability change) produced non-singular relationships similar to those exhibited by the measured data. Four methods were developed to dynamically inform the exponent through use of measurable system-indicator parameters. Key factors that mediate the magnitude of mass flux (dilution and source accessibility) were accounted for using measures of source zone cross-sectional area, ganglia-to-pool (GTP) ratio, and relative permeability. The two methods that incorporated only the ganglia-to-pool ratio produced adequate simulations of the observed behavior for early stages of mass removal, but not for later stages. The method that incorporated parameters accounting for the source zone cross-sectional area (i.e., measure of system dilution) and source accessibility (GTP ratio and relative permeability) provided the most representative simulations of the observed data. 相似文献