全文获取类型
收费全文 | 957篇 |
免费 | 28篇 |
国内免费 | 15篇 |
专业分类
安全科学 | 76篇 |
废物处理 | 36篇 |
环保管理 | 222篇 |
综合类 | 181篇 |
基础理论 | 231篇 |
环境理论 | 1篇 |
污染及防治 | 168篇 |
评价与监测 | 46篇 |
社会与环境 | 31篇 |
灾害及防治 | 8篇 |
出版年
2023年 | 10篇 |
2022年 | 7篇 |
2021年 | 17篇 |
2020年 | 21篇 |
2019年 | 11篇 |
2018年 | 29篇 |
2017年 | 25篇 |
2016年 | 40篇 |
2015年 | 34篇 |
2014年 | 30篇 |
2013年 | 89篇 |
2012年 | 35篇 |
2011年 | 64篇 |
2010年 | 32篇 |
2009年 | 42篇 |
2008年 | 47篇 |
2007年 | 44篇 |
2006年 | 47篇 |
2005年 | 35篇 |
2004年 | 28篇 |
2003年 | 29篇 |
2002年 | 31篇 |
2001年 | 21篇 |
2000年 | 27篇 |
1999年 | 10篇 |
1998年 | 9篇 |
1997年 | 14篇 |
1996年 | 14篇 |
1995年 | 15篇 |
1994年 | 12篇 |
1993年 | 7篇 |
1992年 | 9篇 |
1991年 | 12篇 |
1990年 | 10篇 |
1989年 | 2篇 |
1988年 | 8篇 |
1987年 | 10篇 |
1986年 | 7篇 |
1985年 | 6篇 |
1984年 | 4篇 |
1983年 | 8篇 |
1982年 | 9篇 |
1981年 | 11篇 |
1980年 | 7篇 |
1979年 | 2篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1966年 | 2篇 |
1956年 | 3篇 |
1941年 | 1篇 |
排序方式: 共有1000条查询结果,搜索用时 46 毫秒
31.
Solid waste is of serious concern in developing countries because of its high rate of generation and the low‐end quality of its management. Inefficient handling of solid wastes may result in deterioration of environmental quality, but it can also result in loss of potential resources. This study reviews current solid waste generation and management in Nigeria and the need for an effective collection, recovery, and recycling policy. Our review is based on literature searches and personal field surveys. Observations showed that uncontrolled electronic waste (e‐waste), agricultural‐waste (agro‐waste), scrap metals, waste polymers, and waste from the transportation sector are prevalent in Nigeria. Recent collection rates were less than 50% of the total solid waste generated (i.e., approximately 40% was collected). With an effective collection system and appropriate policies, the abundance of solid waste in the country could present material recovery and recycling opportunities that would boost the economy and move Nigeria closer to sustainable resource management. 相似文献
32.
Graham Dixon Olivia Bullock Dinah Adams 《Environmental Communication: A Journal of Nature and Culture》2019,13(2):135-143
In 2017, the United States experienced a series of natural hazards (hurricanes, wildfires, and blizzards) that resulted in significant loss of life and property. Emphasizing the role of climate change in these events might offer an important tool for engagement, particularly with skeptical audiences. However, in a survey experiment (N?=?1504) involving three different natural hazards – hurricanes, wildfires, and blizzards – we find that emphasizing the role of climate change in these hazards produced unintended effects for climate change skeptics. In particular, skeptics experienced resistance to the news article, which associated with reduced perceived hazard severity. These backfiring effects likely serve as a defensive mechanism used by skeptics to maintain their prior views of climate change, illustrating the challenges faced in communicating climate change to skeptical audiences. These findings offer additional insight for those attempting to communicate climate-related risk information to skeptical audiences. 相似文献
33.
The concept of time perspective balance has attracted increased attention from scholars in the past decade, reflected in published evidence suggesting positive outcomes ranging from enhanced mood to life satisfaction for those individuals possessing balance among their past, present, and future time perspectives, and assumedly able to shift their time perspective to match situational demands. In this paper, we consider the notion of time perspective balance in an organizational setting within which much consequential adaptation often occurs—the team environment—and explore different configurations of time perspective balance in teams facing dynamic task contexts. Drawing from work on situational awareness, we first consider the mechanism by which time perspective balance likely influences individual adaptation in dynamic task-focused situations. Next, we postulate what types of team configurations—ones with more balanced time perspective uniformity or ones with more time perspective variety—might be more appropriate in dynamic contexts given key team conditions. We illustrate our analysis with examples from healthcare team settings and offer ideas for future research. 相似文献
34.
Maurice Juma Ogada Dianah Muchai Germano Mwabu Mary Mathenge 《Environment, Development and Sustainability》2014,16(5):1065-1076
Smallholder agriculture dominates Kenya’s agricultural landscape, accounting for 75 % of total agricultural output and 70 % of the marketed agricultural produce. As a result, the Government of Kenya, with the support of development partners, has invested in production and dissemination of productivity-enhancing technologies such as high-yielding varieties and inorganic fertilizers targeting the smallholders. Adoption of these technologies has remarkably improved, especially in the maize sub-sector. However, productivity has been declining or, at best, stagnating. Productivity is attributable to not only technological improvements but also technical efficiency. Consequently, this study sought to determine the technical efficiency of the country’s smallholder food crop farmers and establish how it correlates with environmental factors. The study used a two-stage nonparametric approach on household panel data to estimate the efficiency levels of the smallholders and establish the sources of its variation across households. Controlling for endogeneity and incorporating geographic information system-derived measures of environmental factors in the analysis, the study finds that technical efficiency differentials are influenced by environmental factors, production risks and farmer characteristics. The policy implication is that the country has room to improve agricultural productivity by addressing environmental and farm-level constraints. Viable options include switching from rain-fed to irrigated agriculture, entrenching land tenure security, improving transport network among farm communities and setting up smallholder credit schemes. 相似文献
35.
Serdeczny Olivia Adams Sophie Baarsch Florent Coumou Dim Robinson Alexander Hare William Schaeffer Michiel Perrette Mahé Reinhardt Julia 《Regional Environmental Change》2017,17(6):1585-1600
Regional Environmental Change - The repercussions of climate change will be felt in various ways throughout both natural and human systems in Sub-Saharan Africa. Climate change projections for this... 相似文献
36.
37.
K.R. Renjith V. Sudheesh Anu Shaji Ejin George Manju Mary Joseph C.S. Ratheesh Kumar 《毒物与环境化学》2016,98(1):36-52
The spatial and temporal variations of some trace metals in the surface sediments of Cochin Estuary were analyzed along with their geochemical associations to identify the possible sources, bioavailability and the health risks posed by them. The dominance of kaolinite and suggested that clay minerals distribution is influenced by sediment sorting. Total metal analysis revealed enrichment for Cd, Pb and Zn due to anthropogenic activities. The speciation analysis established that notwithstanding the large availability, carbonate as well as organic and sulfides bound fractions showed negligible associations with most of the metals. Hydrous Fe–Mn oxides appeared to play a major role in controlling the fate and transport of these metals in the sediments of Cochin Estuary. Lower contribution of the residual fractions for Cd (21%–26%), Pb (<60%) and Zn (24%–42%) indicated an obvious increase of other geochemical fractions. Risk assessment analysis revealed that regardless of total concentration, none of the analyzed metals were at safe levels in the estuary as appreciable percentages were found to be associated with mobile geochemical forms. The speciation study conspicuously established that the metals originating from non-geogenic sources are largely associated with the labile fractions and hence are more detrimental to the aquatic biota. 相似文献
38.
Polychlorinated biphenyls in vacuum dust and blood of residents in 20 Wisconsin households 总被引:1,自引:0,他引:1
Human exposure to PCBs is nearly universal in North America. While most exposure can be linked to consumption of contaminated fish, detection of PCBs in non-fish eating populations suggests that other routes of exposure including inhalation of PCB-laden particles or volatile congeners, ingestion of contaminated soil or dust, or dermal absorption following direct contact are also important. In an effort to assess the role of the residential environment as a source of exposure, vacuum dust was collected from the homes of 26 Wisconsin residents whose serum PCB levels had been measured approximately 2 years earlier. More than 60 congeners were detected in dust with all of the samples containing congeners 101, 110, 138 and 153. Total PCB levels ranged from 8.8 to 1186 ng g−1 with levels being highest in vacuum dust from homes built between 1959 and 1970. Total PCB levels ranged from 0.05 to 8.34 μg L−1 in serum collected from the adults living in these households, with congeners 138, 153 and 180 predominating. Hexa- and hepta-chlorinated biphenyls comprised 73% of the total residues detected in serum. However, most of the residues found in dust were lower chlorinated congeners with tetra- and penta-chlorinated biphenyls being dominant. Following log transformation, a positive association was found between serum and house dust PCB levels. This association was stronger among infrequent consumers of Great Lake fish, but of borderline statistical significance. This exploratory study suggests that house dust may be a significant source of exposure to PCBs and supports the need for further investigations. 相似文献
39.
The initial step in the analysis of contaminant transport in fractured rock requires the consideration of groundwater velocity. Practical methods for estimating the average linear groundwater velocity (vˉ) in fractured rock require determination of hydraulic apertures which are commonly calculated by applying the cubic law using transmissivity (T) values and the number of hydraulically active fractures in the test interval. High-resolution, constant-head step injection testing of cored boreholes in a 100 m thick fractured dolostone aquifer was conducted using inflatable packers to isolate specific test intervals from the rest of the borehole. The steps in each test interval were gradually increased from very low to much higher injection rates. At smaller injection rates, the flow rate vs. applied pressure graph projects through the origin and indicates Darcian flow; non Darcian flow is evident at higher injection rates. Non-Darcian flow results in significantly lower calculated T values, which translates to smaller hydraulic aperture values. Further error in the calculated hydraulic aperture stems from uncertainty in the number of hydraulically active fractures in each test interval. This estimate can be inferred from borehole image and core logs, however, all of the fractures identified are not necessarily hydraulically active. This study proposes a method based on Reynolds number calculations aimed at improving confidence in the selection of the number of active fractures in each test interval. 相似文献
40.
Vega-Millán Christian B. Dévora-Figueroa Ana G. Burgess Jefferey L. Beamer Paloma I. Furlong Melissa Lantz R. Clark Meza-Figueroa Diana O´Rourke Mary Kay García-Rico Leticia Meza-Escalante Edna R. Balderas-Cortés José J. Meza-Montenegro Maria M. 《Environmental science and pollution research international》2021,28(26):34355-34366
Environmental Science and Pollution Research - Environmental arsenic exposure in adults and children has been associated with a reduction in the expression of club cell secretory protein (CC16) and... 相似文献