全文获取类型
收费全文 | 178篇 |
免费 | 4篇 |
国内免费 | 51篇 |
专业分类
安全科学 | 3篇 |
废物处理 | 1篇 |
环保管理 | 39篇 |
综合类 | 71篇 |
基础理论 | 51篇 |
污染及防治 | 42篇 |
评价与监测 | 9篇 |
社会与环境 | 8篇 |
灾害及防治 | 9篇 |
出版年
2024年 | 2篇 |
2023年 | 1篇 |
2022年 | 7篇 |
2021年 | 3篇 |
2020年 | 10篇 |
2019年 | 3篇 |
2018年 | 1篇 |
2017年 | 9篇 |
2016年 | 14篇 |
2015年 | 7篇 |
2014年 | 1篇 |
2013年 | 22篇 |
2012年 | 9篇 |
2011年 | 17篇 |
2010年 | 9篇 |
2009年 | 13篇 |
2008年 | 15篇 |
2007年 | 9篇 |
2006年 | 13篇 |
2005年 | 9篇 |
2004年 | 3篇 |
2003年 | 10篇 |
2002年 | 4篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1999年 | 7篇 |
1998年 | 6篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1995年 | 4篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 5篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1978年 | 1篇 |
排序方式: 共有233条查询结果,搜索用时 15 毫秒
101.
Gordon Brent Ingram 《Environmental management》1992,16(5):585-595
Islands with large tracts of primary rain forest constitute a distinct complex of terrestrial and marine ecosystems with global
significance because of high levels of biological richness or, in the case of oceanic islands, the evolutionary distinctiveness
of the organisms that they support. The myriad of small habitat units makes these settings particularly prone to fragmentation
and thus problematic for the conservation of biological diversity. Most of the remaining examples of islands with primary
rain forest are in the Pacific Rim, particularly in Indonesia, and there are threats from intensive timber harvesting, mining,
tourism, and dismemberment of traditional convervation systems. Prospects for inventorying, monitoring, and protecting the
remaining islands with relatively pristine successional mosaics of humid forest and shallow marine habitats within a framework
global monitoring are explored. Recommendations are made for a program of expanded use of the biosphere reserve designation
for rain forest islands and adjacent marine areas. 相似文献
102.
上海地区热带气旋灾情的评估和灾年预测 总被引:12,自引:2,他引:12
本文用数理统计方法,计算了1949 ̄1990年影响上海地区的热带气旋造成的人员伤亡、农田受淹、房屋倒损三方面的灾情指数。在此基础上划分了灾情等级,最后用灰色预测模型预测出在1997年上海将会发生一次中等(含3级)以上热带气旋灾情。 相似文献
103.
No consensus currently exists about how climate change should affect the status of soil organic matter (SOM) in the tropics. In this study, we analyse the impact of climate change on the underlying mechanisms controlling SOM dynamics in a ferralsol under two contrasting tropical crops: maize (C4 plant) and banana (C3 plant). We model the effect of microbial thermal adaptation on carbon (C) mineralisation at the crop system scale and introduce it in the model STICS, which was previously calibrated for the soil-crop systems tested in this study. Microbial thermal adaptation modelling is based on a reported theory for thermal acclimation of plant and soil respiration. The climate is simulated from 1950 to 2099 for the tropical humid conditions of Guadeloupe (French Antilles), using the ARPEGE model and the IPCC emission scenario A1B. The model predicts increases of 3.4 °C for air temperature and 1100 mm yr−1 for rainfall as a response to an increase of 375 ppm for atmospheric carbon dioxide concentration in the 2090-2099 decade compared with the 1950-1959 decade. The results of the STICS model indicate that the crop affects the response of SOM to climate change by controlling the change in several variables involved in C dynamics: C input, soil temperature and soil moisture. SOM content varies little until 2020, and then it decreases faster for maize than for banana. The decrease is weakened under the hypothesis of thermal adaptation, and this effect is greater for maize (−180 kg C ha−1 yr−1 without adaptation and −140 kg C ha−1 yr−1 with adaptation) than for banana (−60 kg C ha−1 yr−1 and −40 kg C ha−1 yr−1, respectively). The greater SOM loss in maize is mainly due to the negative effect of warming on maize growth decreasing C input from residues. Climate change has a small effect on banana growth, and SOM loss is linked to its effect on C mineralisation. For both crops, annual C mineralisation increases until 2040, and then it decreases continuously. Thermal adaptation reduces the initial increase in mineralisation, but its effect is lower on the final decrease, which is mainly controlled by substrate limitation. No stabilisation in SOM status is attained at the end of the analysed period because C mineralisation is always greater than C input. Model predictions indicate that microbial thermal adaptation modifies, but does not fundamentally change the temporal pattern of SOM dynamics. The vegetation type (C3 or C4) plays a major role in SOM dynamics in this tropical soil because of the different impact of climate change on crop growth and then on C inputs. 相似文献
104.
广东汕头市农业土壤和蔬菜铅含量及健康风险评估 总被引:2,自引:0,他引:2
重金属元素铅的危害已经引起人们的广泛关注,为了得到汕头市土壤及蔬菜铅污染的状况,选取了该市115个土壤样品及34个蔬菜样品进行铅含量分析.研究发现,汕头市土壤样品铅含量差异较大,最高含量为110mg/kg,最低含量则为12.1mg/kg,极差达到97.9mg/kg.56.52%的土壤样品铅含量超过国家土壤环境质量标准,表明该市土壤铅污染存在普遍性,且各区(县)土壤铅含量极不均匀.汕头市蔬菜样品铅含量全部超过国家食品卫生标准(GB 14935-94),不同蔬菜品种对铅的富集能力均较强,蔬菜样品铅最低含量为5mg/kg,最高含量为85mg/kg,分别为国家标准限值的5倍和425倍.经分析认为,该市铅污染源主要来自工业"三废"排放、大量含铅农药的使用、汽车尾气排放以及大气沉降等.还对汕头市民通过食用蔬菜而导致的铅暴露进行了健康风险评估,结果表明该市居民使用蔬菜存在较大的健康风险. 相似文献
105.
Concentrations of seven metals (Cd, Cr, Mn, Ni, Pb, V, and Zn) were determined in 14 plant species including vegetables and crops from an agricultural area located at the Southern part of the Iranian capital, near the Tehran oil refinery. Different statistical methods, especially multivariate ones, were employed for the analysis of the results. Based on the results of agglomerative hierarchical method for clustering of the grid cells, some similarities between the dendrograms of Pb, Ni, and V and, furthermore, between Mn and Cr were observed that could be attributed to their similar distribution sources in the study area. The principal component analysis showed that with respect to accumulation of all the metals in the plant species, two main groups could be identified. The highest mean concentrations of all metals (except for Pb) were found in onions. In all plants the mean concentrations of Cd and Pb were considerably higher than limits stated in international guidelines for human consumption. The levels of the metals in onions exceeded these limits. Moreover, the Cr concentrations in mint and basil and the Zn concentrations in tarragon and parsley were higher than the established limits. 相似文献
106.
Andrés Vargas Alex Y. Lo Nicholas Rohde Michael Howes 《Journal of Environmental Planning and Management》2017,60(9):1511-1528
Deliberative monetary valuation (DMV) methods can support environmental decision making by enabling the exchange of arguments and information to produce more democratic outcomes. The product of a valuation may be an array of expressions of willingness to pay (WTP) by individuals or a collectively agreed monetary value. Concerns have been raised, however, as to whether this product is an outcome of thoughtful and independent decision-making or influenced by social pressures to conform. Our study examines this issue and addresses concerns about the use of DMV, based on a public deliberation of forest conservation in Colombia. We analyzed the impacts of social conformity on WTP under two different decision scenarios: individual and collective. The results suggest that the impacts of social conformity are greater when a collective decision is required. These findings indicate that tensions between the differing goals of DMV could undermine its democratic promise. 相似文献
107.
Upasna Sharma Anand Patwardhan 《Mitigation and Adaptation Strategies for Global Change》2008,13(7):703-717
Vulnerability indices are commonly used for characterizing the impacts on a region or comparing relative vulnerability across
regions. Such indices are usually computed as a composite/aggregate across different components of vulnerability. Though such
a single numerical value can be useful in many situations, a major disadvantage is that it leads to loss of information about
how the different factors that went into making the composite index interact with each other, and contribute to making a place
vulnerable. In this paper we develop an alternative approach for identifying hotspots, based on cluster analysis that seeks
to address this problem by considering the different components of vulnerability separately. We compute different indices
for each of the components of vulnerability. Cluster analysis helps in identifying the most vulnerable districts based on
different combinations of the components of vulnerability. In addition to being methodologically more robust than the index
approach, the clustering approach may have greater policy-relevance as it provides information about which aspects of vulnerability,
policy needs to address in the most vulnerable districts.
An erratum to this article can be found at 相似文献
108.
Akira Watanabe Benito H. Purwanto Ho Ando Ken-ichi Kakuda Foh-Shoon Jong 《Agriculture, ecosystems & environment》2009,134(1-2):14-18
Tropical peatland is a vast potential land source for biological production, but peatland is a major natural source of greenhouse gases, especially methane (CH4). It is important to evaluate the changes in greenhouse gas emissions induced by cultivation practices for sustainable agricultural use of tropical peatland. We investigated the effects of fertilizer application and the groundwater level on CH4 and carbon dioxide (CO2) fluxes in an Indonesian peat soil. The crop cultivated was sago palm (Metroxylon sagu Rottb.), which can grow on tropical peat soil without drainage and yield great amounts of starch. CH4 emission through sago palm plants was first estimated by collecting gas samples immediately after cutting sago suckers using the closed chamber method. The CH4 fluxes ranged from negative values to 1.0 mg C m−2 h−1. The mean CH4 flux from treatment with macroelements (N, P, and K) and microelements (B, Cu, Fe, and Zn) applied at normal rates did not differ significantly from that of the No fertilizer treatment, although increasing the application rates of macroelements or microelements by 10-fold increased the CH4 flux by a factor of two or three. The relationship between CH4 flux and the groundwater table was regressed to a logarithmic equation, which indicated that to maintain a small CH4 flux, the groundwater table should be maintained at <−45 cm. The CO2 fluxes ranged between 24 and 150 mg C m−2 h−1, and were not significantly affected by either fertilizer treatments or the groundwater level. The inclusion of sago palm suckers in a chamber increased CH4 emission from the peat soil significantly. Thus, gas emissions mediated by certain kinds of palm plants should not be disregarded. 相似文献
109.
It is an important approach to use the Cd-contaminated soils properly by growing low accumulator or excluder plants for Cd to
produce safe foods. To find the suitable vegetable species for growing in Cd-contaminated soils, in the present study the variations in
the Cd accumulation for twenty eight vegetable species and several cultivars of five common vegetables (cowpea, kidney pea, bitter
gourd, cucumber and squash) were investigated in two soil Cd levels (1 and 2 mg/kg Cd). Experimental results showed that highly
significant di erences in Cd concentration were evident among 28 vegetables. For example, spinach Cd concentrations were 110-fold
and 175-fold higher than that of sweet pea under the 1 and 2 mg/kg Cd exposures, respectively. For Cd accumulation, the order of
vegetable species was: leafy vegetables > solanaceous vegetables > kale vegetables > root vegetables > allimus > melon vegetables >
legumes. Distinctive di erences were also identified when comparing di erent cultivars of the five common vegetables with an average
range of 0.003–0.094 mg/kg Cd. Our results indicated that a large genotypic variation existed among vegetable species or cultivars
when subjected to Cd exposure. Therefore, it is important and feasible to elect/breed vegetable species/cultivars with low accumulation
of Cd, especially in mildly Cd-contaminated soils. 相似文献
110.