全文获取类型
收费全文 | 220篇 |
免费 | 6篇 |
国内免费 | 3篇 |
专业分类
安全科学 | 8篇 |
废物处理 | 32篇 |
环保管理 | 56篇 |
综合类 | 30篇 |
基础理论 | 34篇 |
污染及防治 | 48篇 |
评价与监测 | 16篇 |
社会与环境 | 3篇 |
灾害及防治 | 2篇 |
出版年
2023年 | 2篇 |
2022年 | 2篇 |
2020年 | 4篇 |
2019年 | 4篇 |
2018年 | 4篇 |
2017年 | 10篇 |
2016年 | 5篇 |
2015年 | 1篇 |
2014年 | 6篇 |
2013年 | 13篇 |
2012年 | 5篇 |
2011年 | 6篇 |
2010年 | 4篇 |
2009年 | 5篇 |
2008年 | 9篇 |
2007年 | 11篇 |
2006年 | 11篇 |
2005年 | 8篇 |
2004年 | 12篇 |
2003年 | 4篇 |
2002年 | 5篇 |
2001年 | 6篇 |
2000年 | 5篇 |
1999年 | 3篇 |
1998年 | 5篇 |
1997年 | 6篇 |
1996年 | 10篇 |
1995年 | 5篇 |
1994年 | 8篇 |
1993年 | 8篇 |
1992年 | 5篇 |
1991年 | 7篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 4篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1973年 | 2篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1969年 | 2篇 |
1968年 | 1篇 |
1964年 | 1篇 |
1962年 | 1篇 |
排序方式: 共有229条查询结果,搜索用时 15 毫秒
51.
The Ala Wai Canal Watershed Model (ALAWAT) is a planning-level watershed model for approximating direct runoff, streamflow,
sediment loads, and loads for up to five pollutants. ALAWAT uses raster GIS data layers including land use, SCS soil hydrologic
groups, annual rainfall, and subwatershed delineations as direct model parameter inputs and can use daily total rainfall from
up to ten rain gauges and streamflow from up to ten stream gauges. ALAWAT uses a daily time step and can simulate flows for
up to ten-year periods and for up to 50 subwatersheds. Pollutant loads are approximated using a user-defined combination of
rating curve relationships, mean event concentrations, and loading/washoff parameters for specific subwatersheds, land uses,
and times of year. Using ALAWAT, annual average streamflow and baseflow relationships and urban suspended sediment loads were
approximated for the Ala Wai Canal watershed (about 10,400 acres) on the island of Oahu, Hawaii. Annual average urban suspended
sediments were approximated using two methods: mean event concentrations and pollutant loading and washoff. Parameters for
the pollutant loading and washoff method were then modified to simulate the effect of various street sweeping intervals on
sediment loads. 相似文献
52.
53.
Dynamite or "blast" fishing is one of the most immediate and destructive threats to coral reefs worldwide. However, little is known about the long-term ecosystem effects of such blasts or the dynamics of recovery. Here, we examine coral reef recovery in the simplest case of acute single blasts of known age, as well as recovery from chronic blasting over greater spatial and temporal scales. Rubble resulting from single blasts slowly stabilized, and craters filled in with surrounding coral and new colonies. After five years, coral cover within craters no longer differed significantly from control plots. In contrast, extensively bombed areas showed no significant recovery over the six years of this study, despite adequate supply of coral larvae. After extensive blasting, the resulting coral rubble shifts in ocean currents, forming unstable "killing fields" for new recruits. While recently tested rehabilitation methods might be feasible on a small scale, human intervention is unlikely to be effective on large spatial scales, highlighting the need for effective management to prevent blast fishing in the first place. 相似文献
54.
Eric Rahn Peter Läderach María Baca Charlotte Cressy Götz Schroth Daniella Malin Henk van Rikxoort Jefferson Shriver 《Mitigation and Adaptation Strategies for Global Change》2014,19(8):1119-1137
There are worldwide approximately 4.3 million coffee (Coffea arabica) producing smallholders generating a large share of tropical developing countries’ gross domestic product, notably in Central America. Their livelihoods and coffee production are facing major challenges due to projected climate change, requiring adaptation decisions that may range from changes in management practices to changes in crops or migration. Since management practices such as shade use and reforestation influence both climate vulnerability and carbon stocks in coffee, there may be synergies between climate change adaptation and mitigation that could make it advantageous to jointly pursue both objectives. In some cases, carbon accounting for mitigation actions might even be used to incentivize and subsidize adaptation actions. To assess potential synergies between climate change mitigation and adaptation in smallholder coffee production systems, we quantified (i) the potential of changes in coffee production and processing practices as well as other livelihood activities to reduce net greenhouse gas emissions, (ii) coffee farmers’ climate change vulnerability and need for adaptation, including the possibility of carbon markets subsidizing adaptation. We worked with smallholder organic coffee farmers in Northern Nicaragua, using workshops, interviews, farm visits and the Cool Farm Tool software to calculate greenhouse gas balances of coffee farms. From the 12 activities found to be relevant for adaptation, two showed strong and five showed modest synergies with mitigation. Afforestation of degraded areas with coffee agroforestry systems and boundary tree plantings resulted in the highest synergies between adaptation and mitigation. Financing possibilities for joint adaptation-mitigation activities could arise through carbon offsetting, carbon insetting, and carbon footprint reductions. Non-monetary benefits such as technical assistance and capacity building could be effective in promoting such synergies at low transaction costs. 相似文献
55.
Fox A Harley W Feigley C Salzberg D Toole C Sebastian A Larsson L 《Journal of environmental monitoring : JEM》2005,7(5):450-456
Muramic acid (Mur) is found in bacterial peptidoglycan (PG) whereas 3-hydroxy fatty acids (3-OH FAs) are found in Gram-negative bacterial lipopolysaccharide (LPS). Thus Mur and 3-OH FAs serve as markers to assess bacterial levels in indoor air. An initial survey, in a school, demonstrated that the levels of dust, PG and LPS (pmol m(-3)) were each much higher in occupied rooms than in the same rooms when unoccupied. In each instance, the Mur content of dust was increased and the hydroxy fatty acid distribution changed similarly suggesting an alteration in the bacterial population. Here, findings are compared with results from two additional schools. Follow-up aerosol monitoring by particle size was also performed for the first time for all 3 schools. The particle size distribution was shown to be quite different in occupied versus unoccupied schoolrooms. Within individual classrooms, concentrations of airborne particles [greater-than-or-equal]0.8 [micro sign]m in diameter, and CO(2) were correlated. This suggests that the increased levels of larger particles are responsible for elevation of bacterial markers during occupation. Release of culturable and non-culturable bacteria or bacterial aggregates from children (e.g. from flaking skin) might explain this phenomenon. 相似文献
56.
57.
58.
59.
Jeff Fox 《Environmental management》1984,8(3):243-249
People's dependence on firewood as a primary source of energy is causing serious deforestation problems in many developing countries. Reliable information on firewood consumption rates is needed to develop afforestation plans and to control deforestation. This study compares three methods used to determine firewood consumption in a Nepali village. Cultural and environmental factors that affect firewood consumption in the village are also examined.Theweight survey proved to be the most accurate method used. The less precisedaily recall andannual recall surveys overestimated actual firewood consumption by factors of 1.76 and 1.95, respectively. Overestimates are attributed to both physical and social factors. In view of the good agreement between daily and annual recall surveys, and the much greater ease of conducting the latter, annual recall surveys are recommended as the most practical method of monitoring firewood consumption rates. Validating the survey with occasional weighed measurements is suggested as a means of improving accuracy. 相似文献
60.
Self‐report measures of job stressors have been criticized for being too subjective, rendering relations with other variables inconclusive. The Factual Autonomy Scale (FAS) was developed to reduce subjectivity by careful choice of fact‐based items. Results of two studies showed that when compared to the Job Diagnostic Survey autonomy scale, the FAS demonstrated superior convergent validity with alternate sources (supervisors in Study 1 and coworkers in Study 2), and discriminant validity when correlated with the remaining JDS core characteristics subscales. In addition, the FAS was correlated to a lesser extent than the JDS autonomy scale with job satisfaction. Incumbent FAS scores and not JDS scores correlated significantly with job performance as assessed by supervisors. It is suggested that it is feasible to develop fact‐based items for scales of the work environment that reduce the degree of subjectivity of responses. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献