全文获取类型
收费全文 | 470篇 |
免费 | 37篇 |
国内免费 | 232篇 |
专业分类
安全科学 | 7篇 |
废物处理 | 16篇 |
环保管理 | 44篇 |
综合类 | 309篇 |
基础理论 | 187篇 |
污染及防治 | 96篇 |
评价与监测 | 39篇 |
社会与环境 | 28篇 |
灾害及防治 | 13篇 |
出版年
2024年 | 1篇 |
2023年 | 7篇 |
2022年 | 16篇 |
2021年 | 11篇 |
2020年 | 11篇 |
2019年 | 15篇 |
2018年 | 20篇 |
2017年 | 22篇 |
2016年 | 17篇 |
2015年 | 28篇 |
2014年 | 28篇 |
2013年 | 58篇 |
2012年 | 34篇 |
2011年 | 48篇 |
2010年 | 33篇 |
2009年 | 36篇 |
2008年 | 41篇 |
2007年 | 56篇 |
2006年 | 37篇 |
2005年 | 32篇 |
2004年 | 21篇 |
2003年 | 27篇 |
2002年 | 20篇 |
2001年 | 19篇 |
2000年 | 24篇 |
1999年 | 8篇 |
1998年 | 15篇 |
1997年 | 11篇 |
1996年 | 11篇 |
1995年 | 4篇 |
1994年 | 7篇 |
1993年 | 5篇 |
1992年 | 5篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1983年 | 1篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有739条查询结果,搜索用时 546 毫秒
661.
662.
K.M.S. Sundaram 《Journal of environmental science and health. Part. B》2013,48(3):415-442
Abstract Adsorption‐desorption behavior of RH‐5992 [Mimic®, N'‐t‐butyl‐N'‐(3,5‐dimethylbenzoyl)‐N‐(4‐ethylbenzoyl) hydrazine] in sandy and clay loam forest soils was studied using the batch equilibrium method. Adsorption was higher in the clay loam soil than in the sandy loam, and increased linearly with RH‐5992 concentration, but decreased with increasing pH and temperature. The adsorption data fit better to the Freundlich, than to the Langmuir equation. The KD (linear adsorption constant) and KF (Freundlich constant) were similar for each soil at 5, 15 and 25°C and decreased with increase of temperature, indicating that the enthalpy of adsorption was negative. The exponent of the Freundlich equation was close to unity for both soils at all three temperatures. The low Ea (energy of activation) indicated a diffusion‐controlled process during the initial stages of adsorption. The desorption isotherm differed from that of adsorption, and the linear desorption constant, KD(d), was ca 25 times higher than the KD, indicating that adsorption of RH‐5992 was not readily reversible. Evaluation of thermo‐dynamic parameters confirmed the presence of strong bonds between the solute and soil. These findings suggest that RH‐5992 has a limited potential for downward mobility leading to groundwater contamination. 相似文献
663.
M. Kashir K. Zhang G. Achari R. G. Moore S. A. Mehta M. G. Ursenbach 《Environmental Modeling and Assessment》2008,13(2):265-274
A 2-D mathematical model to simulate the temperature distribution, coke formation, and change in residual extractable oil
during remediation by low-temperature oxidation (LTO) process was developed. Simulation results indicate that the spacing
between wells, pressure difference, and air-injection temperature and different well patterns influence the temperature distribution
and consequently the level of remediation in the soil. The model results for coke formation and residual extractable oil distribution
compared well with experimental results. The operating conditions—air-injection temperature of about 200°C, air-injection
pressure of 6 to 10 kPa, air-extraction pressure of −110 Pa, and wells spaced 1 m apart installed in a nine-spot pattern—provide
good remediation of hydrocarbons in soil by LTO process.
相似文献
G. AchariEmail: |
664.
665.
对珠三角两个代表性乡镇工业区的土壤(沉积物)重金属污染现状和来源进行了评价。结果表明,两工业区在主要污染元素类型和综合污染程度上很相似,表层土壤(沉积物)均以Hg、As、Cu的污染为主,且均以Hg的污染最严重;但在某些次要污染元素种类以及某些主要、次要污染元素的单个元素污染程度上存在一些差异。柱样沉积物中重金属的变化特征进一步说明,两工业区土壤(沉积物)中重金属的累积与我国尤其是本地区的工农业发展阶段和发展水平密切相关。文章最后提出了乡镇工业区土壤(沉积物)重金属污染的几点建设性防治对策。 相似文献
666.
667.
The on-going introduction of non-native species to Antarctica due to expanding human activity presents an increasing threat to biodiversity. Under the Protocol on Environmental Protection to the Antarctic Treaty, all introduced non-native species should be removed from the Antarctic Treaty area. The non-native grass Poa pratensis was first introduced to Cierva Point (Danco Coast, Antarctic Peninsula), along with substantial quantities of non-Antarctic soil, in the mid-1950s. Consistent with the Protocol, in January 2015 an internationally coordinated team undertook the eradication of the grass. Immediately prior to removal of P. pratensis, factors affecting its establishment, persistence and impacts upon local indigenous species was examined within the international management framework of the Antarctic Treaty System. The underlying soil had a high organic content of 15.5%, which may have contributed to the successful establishment of P. pratensis and restricted, at least initially, its vegetative growth to the enriched area. Examination of P. pratensis expansion from the original introduction sites showed that the plant colony intricate root system facilitated little or no coexistence of other native plants within its extent. The non-native plant colony also constituted a novel habitat for soil fauna within Antarctic terrestrial environments. The P. pratensis plant colony provided an unfavorable habitat for two of the locally endemic soil invertebrates, Cryptopygus antarcticus and Belgica antarctica. These observations led to the selection of an appropriate eradication approach, where the plants were targeted for physical extraction along with all underlying soil. During the eradication, c. 500 kg of soil and plant material from the P. pratensis colony was removed from the site. Monitoring one year later showed no evidence of re-establishment. Consistent with the Committee for Environmental Protection ‘Non-native Species Manual’, we recommend development and implementation of rapid response protocols following the discovery of a non-native plant colony to limit future impacts on indigenous species and local habitats. 相似文献
668.
669.
Watmough SA 《Environmental geochemistry and health》2008,30(5):431-444
The potential environmental risk posed by metals in forest soils is typically evaluated by modeling metal mobility using soil-solution partitioning coefficients (K(d)), although such information is generally restricted to a few well-studied metals. Soil-solution partitioning coefficients were determined for 17 mineral elements (Al, As, Be, Ba, Ca, Cr, Cu, Fe, Ga, K, Li, Mg, Rb, Sr, Tl, U and V) in A-horizon (0-5 cm) soil at 46 forested sites that border the Precambrian Shield in central Ontario, where soil pH(aq) varied from 3.9 to 8.1. Sites were dominated by mature sugar maple (Acer saccharum Marsh.), white birch (Betula papyrifera Marsh.), balsam fir (Abies balsamea (L.) Mill.) or white pine (Pinus strobus L.). Log K(d) values for all elements could be predicted by empirical linear regression with soil pH (r (2) = 0.17-0.77) independent of forest type, although this relationship was greatly affected by positive relationships between acid-extractable metal concentration and pH(aq) for 13 of the 17 elements. Elements that exhibited strong or moderate (r (2)> 0.29; p < 0.001) relationships with soil pH(aq) in soil water extracts include Al, Ba, Fe, Ga, K, Li, Rb, Tl, V (negative) and Ca (positive). Elemental partitioning in mineral soil was independent of forest type; tree species differed in their response to chemical differences in mineral soil. For example, Rb, Ba, and Sr concentrations in foliage of sugar maple and white birch significantly increased with increasing soil acidity, whereas Rb, Ba, and Sr concentrations in balsam fir and white pine foliage exhibited no response to soil pH(aq). While K(d) values can provide useful information on the potential mobility and bioavailability of mineral elements in forest soils, care must be used when interpreting the relative contribution of solid and aqueous phases to this relationship and the differing responses of vegetation in elemental cycling in forests must also be considered. 相似文献
670.
Holmberg Maria Mulder Jan Posch Maximilian Starr Michael Forsius Martin Johansson Matti Bak Jesper Ilvesniemi Hannu Sverdrup Harald 《Water, Air, & Soil Pollution: Focus》2001,1(1-2):91-101
We reviewed the current methods for calculatingcritical loads of acidity for forest soils. The consequencesof four sets of assumptions concerning the soil modelstructure, parameter values and the critical loads criterionwere explored by comparing the values of the averageaccumulated exceedance (AAE) calculated for Finland withdeposition values for the year 1995. The AAE index is given inthe unit of deposition and is a measure of how far a region isfrom being protected in terms of fulfilling a certaincriterion, taking into account the size of the ecosystem areas.Using a critical limit for the molar ratio of theconcentrations of base cations to aluminium in soil solutiongave the lowest average accumulated exceedance. Assumingorgano-aluminium complexes and leaching of organic anions gaveAAE = 4 eq ha-1 a-1, which was close to the valueobtained with the standard approach used in Finland, assuminggibbsite equilibrium and no leaching of organic anions,yielding AAE = 5 eq ha-1 a-1. With a critical basesaturation limit, instead of the concentrations criterion, theAAE index was 17 eq ha-1 a-1. The highest averageaccumulated exceedance (AAE = 25 eq ha-1 a-1),corresponding to the lowest critical load, was obtained whenthe effects-based criterion (critical concentration or criticalbase saturation) was substituted with one restricting thedeterioration of the neutralizing capacity of the soil, ANC
le(crit) = 0. These tests illustrate the variabilityof the critical load values for acidity that can be introducedby changing the criterion or by varying the calculation method,without, however, representing the extreme values of criticalloads that could be derived. 相似文献