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991.
Policy and research issues in the framing and qualities of uncertainties in risks are analyzed, based on the assessments of
dioxin-like compounds (DLCs) and other ingredients in Baltic Sea fish, a high-profile case of governance. Risks are framed
broadly, to then focus on dioxins and beneficial fatty acids, fish consumption, human health, and science-management links.
Hierarchies of uncertainty (data, model, decision rule, and epistemic) and ambiguity (of values) are used to identify issues
of scientific and policy contestation and opportunities for resolving them. The associated complexity of risks is illustrated
by risk–benefit analyses of fish consumption and by evaluations of guideline values, highlighting value contents and policy
factors in presumably scientific decision criteria, and arguments used in multi-dimensional risk and benefit comparisons.
These comparisons pose challenges to narrow assessments centered, for e.g., on toxicants or on food benefits, and to more
many-sided and balanced risk communication and management. It is shown that structured and contextualized treatment of uncertainties
and ambiguities in a reflexive approach can inform balances between wide and narrow focus, detail and generality, and evidence
and precaution. 相似文献
992.
Zhou ZF Zheng YM Shen JP Zhang LM He JZ 《Environmental science and pollution research international》2011,18(9):1644-1652
Purpose
Denitrification is an important biochemical process in global nitrogen cycle, with a potent greenhouse gas product N2O. Wastewater irrigation can result in the changes of soil properties and microbial communities of agricultural soils. The purpose of this study was to examine how the soil denitrification genes responded to different irrigation regimes. 相似文献993.
Cruceru I Iancu V Petre J Badea IA Vladescu L 《Environmental monitoring and assessment》2012,184(5):2783-2795
A simple, sensitive and reliable HPLC-FLD method for the routine determination of 4-nonylphenol, 4-NP and 4-tert-octylphenol, 4-t-OP content in water samples was developed. The method consists in a liquid–liquid extraction of the target analytes with dichloromethane at pH 3.0–3.5 followed by the HPLC-FLD analysis of the organic extract using a Zorbax Eclipse XDB C8 column, isocratic elution with a mixed solvent acetonitrile/water 65:35, at a flow rate of 1.0 mL/min and applying a column temperature of 40°C. The method was validated and then applied with good results for the determination of 4-NP and 4-t-OP in Ialomi?a River water samples collected each month during 2006. The concentration levels of 4-NP and 4-t-OP vary between 0.08–0.17 μg/L with higher values of 0.24–0.37 μg/L in the summer months for 4-NP, and frequently <0.05 μg/L but also between 0.06–0.09 μg/L with higher values of 0.12–0.16 μg/L in July and August for 4-t-OP and were strongly influenced by sesonial and anthropic factors. The method was also applied on samples collected over 2 years 2007 and 2008 from urban wastewaters discharged into sewage or directly into the rivers by economic agents located in 30 Romanian towns. Good results were obtained when the method was used for analysis of effluents discharged into surface waters by 16 municipal wastewater treatment plants, during the year 2008. 相似文献
994.
Research into national innovation systems (NISs) has received extensive academic and policy attention, and is especially relevant
with latecomer countries seeking to innovate in challenging industrial environments. In playing catch up with their early
industrializing counterparts, methods of learning take on increased importance in determining industrial success for latecomers.
The wind turbine technology innovation system is one that is highly dependent on both the extent of the national learning
processes and the strength of the national social-institutional setting. This research investigates the case of Taiwan, a
country which has embarked on a program to build its national innovative capacity in wind turbine technologies with specific
emphasis on Taiwan’s social sector. Within this system, the spotlight will be on four types of learning processes that interplay
during wind turbine development: learning by searching, learning by doing, learning by using, and learning by interacting. Through a case study of the emergence of Taiwan’s burgeoning large-scale wind power technology initiatives, the paper aims
to add to the understanding on how methods of learning impact upon the success of innovation systems. The findings show that
the industry’s future prospects are constrained because of the limited learning by interacting processes between turbine component producers, turbine owners, and researchers and because of weaknesses in the institutional
framework. This research also recognizes the importance that culture has on dominant forms of learning. 相似文献
995.
The presence of natural estrogen hormones as trace concentrations in the environment has been reported by many researchers
and is of growing concern due to its possible adverse effects on the ecosystem. In this study, municipal biosolids, poultry
manure (PM) and cow manure (CM), and spent mushroom compost (SMC) were analyzed for the presence of seven estrogen hormones.
17α-estradiol, 17β-estradiol, 17α-dihydroequilin, and estrone were detected in the sampled biosolids and manures at concentrations
ranging from 6 to 462 ng/g of dry solids. 17α-estradiol, 17β-estradiol, and estrone were also detected in SMC at concentrations
ranging from 4 to 28 ng/g of dry solids. Desorption experiments were simulated in the laboratory using deionized water (milli-Q),
and the aqueous phase was examined for the presence of estrogen hormones to determine their desorption potential. Very low
desorption of 0.4% and 0.2% estrogen hormones was observed from municipal biosolids and SMC, respectively. An estimate of
total estrogen contribution from different solid waste sources is reported. Animal manures (PM and CM) contribute to a significant
load of estrogen hormones in the natural environment. 相似文献
996.
Darryn McEvoy Piotr Matczak Ilona Banaszak Adam Chorynski 《Mitigation and Adaptation Strategies for Global Change》2010,15(7):779-795
Whilst mitigation has dominated policy and research agendas in recent years there is an increasing recognition that communities
also need to be preparing for change that is unavoidable, partially a consequence of anthropogenic greenhouse gases already
emitted to the atmosphere. The perceived need for adaptation has also received additional impetus through the high public
profile now given to the impacts of current day weather variability, particularly the significant economic and social costs
associated with recent extreme events. However, being a relatively new focus for both research and policy communities; practical
evidence of the extent, feasibility, efficiency, and cost effectiveness of potential adaptation options remains largely lacking.
In response, this paper seeks to make a contribution to this embryonic but evolving knowledge base by considering the theoretical
underpinnings of adaptation and ultimately how this translates into practice ‘in the real world’. The analytical commentary,
based on a bottom-up approach involving iterative engagement with key stakeholders and experts, reflects on the identification
of measures that are either innovative or examples of good practice in reducing or transferring climate risks, as well as
considering those ‘enabling’ institutional structures and processes that act to support implementation on the ground. The
paper concludes by synthesising the key findings to date in order to highlight some of the opportunities for, and barriers
to, adaptation activity. 相似文献
997.
Abel Duarte Alonso 《The Environmentalist》2009,29(4):388-397
Despite aquaculture’s contribution providing an additional food source or employment in rural areas, this industry is often
presented in a controversial way, including its impact on the environment. However, an argument can also be made in favour
of aquaculture operators and their efforts to follow environmentally sound practices. Along these lines, the present study
investigates operators’ stance on environmental sustainability from a group of 26 Western Australian marron growers. Overall,
the findings demonstrate growers’ commitment to grow marron environmentally, for instance, without the use of fertilisers
or feeding. Furthermore, respondents are in agreement with the potential effects of environmentally unfriendly practices,
especially as in many cases marron growing is a complement to rural activities such as horticulture and cattle farming. At
the other end, some operators voice concerns on a different environmental issue, namely, the challenge that increasing droughts
and lack of sufficient rain is posing to their industry. 相似文献
998.
Hegetschweiler KT van Loon N Ryser A Rusterholz HP Baur B 《Environmental management》2009,43(2):299-310
Urban forests are popular recreation areas in Europe. Several of these temperate broad-leaved forests also have a high conservation
value due to sustainable management over many centuries. Recreational activities, particularly the use of fireplaces, can
cause extensive damage to soil, ground vegetation, shrubs, and trees. Firewood collection depletes woody debris, leading to
a loss of habitat for specialized organisms. We examined the effects of fireplace use on forest vegetation and the amount
of woody debris by comparing disturbed and control plots in suburban forests in northwestern Switzerland. At frequently used
fireplaces, we found reduced species densities in the ground vegetation and shrub layer and changes in plant species composition
due to human trampling within an area of 150–200 m2. Picnicking and grilling also reduced the height and changed the age structure of shrubs and young trees. The amount of woody
debris was lower in disturbed plots than in control plots. Pieces of wood with a diameter of 0.6–7.6 cm were preferentially
collected by fireplace users. The reduction in woody debris volume extended up to a distance of 16 m from the fire ring, covering
an area of 800 m2 at each picnic site. In order to preserve the ecological integrity of urban forests and to maintain their attractiveness
as important recreation areas, we suggest depositing logging residues to be used as firewood and to restrict visitor movements
near picnic sites. 相似文献
999.
The photovoltaic conversion efficiency for near-infrared (NIR) sunlight is improved successfully by dye sensitization of bulk heterojunction polymer solar cells, in which the active layer was prepared by a ternary blend of poly(3-hexylthiophene), a fullerene derivative (1-(3-methoxycarbonyl)propyl-1-phenyl-[6,6]-methanofullerene), and an NIR dye, silicon phthalocyanine bis(trihexylsilyl oxide). The mechanism of the NIR-dye sensitization is studied by femtosecond transient absorption spectroscopy. 相似文献
1000.
The Effect of Water Harvesting Techniques on Runoff,Sedimentation, and Soil Properties 总被引:1,自引:0,他引:1
This study addressed the hydrological processes of runoff and sedimentation, soil moisture content, and properties under the
effect of different water harvesting techniques (treatments). The study was conducted at three sites, representing environmental
condition gradients, located in the southern part of the West Bank. For each treatment, the study evaluated soil chemical
and physical properties, soil moisture at 30 cm depth, surface runoff and sedimentation at each site. Results showed that
runoff is reduced by 65–85% and sedimentation by 58–69% in stone terraces and semi-circle bunds compared to the control at
the semi-humid site. In addition, stone terraces and contour ridges significantly reduced the amount of total runoff by 80%
and 73%, respectively, at the arid site. Soil moisture content was significantly increased by water harvesting techniques
compared to the control in all treatments at the three study sites. In addition, the difference between the control and the
water harvesting structures were higher in the arid and semi-arid areas than in the semi-humid area. Soil and water conservation,
via utilization of water harvesting structures, is an effective principle for reducing the negative impact of high runoff
intensity and subsequently increasing soil moisture storage from rainfall. Jessour systems in the valley and stone terraces
were effective in increasing soil moisture storage, prolonging the growing season for natural vegetation, and decreasing the
amount of supplemental irrigation required for growing fruit trees. 相似文献