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281.
基于能值计算的循环农业发展个例分析   总被引:3,自引:0,他引:3  
能值分析能够更好地量化分析和评价循环农业。利用该方法对湖北省武汉银河生态有限公司的循环农业进行了实证分析。结果表明,实施循环农业后的集约养殖场结合农地流转发展起来的“猪-沼(能)肥-地-菜(藕、果、粮)-鱼-村”六位一体的循环农业典型模式,与实施循环农业前当地分离的水稻、小麦、油菜、棉花、蔬菜、柑橘、猪、鱼的农业生产系统相比,在能值转化率、可更新率、能值投资率、能值自给率、净能值产出率、环境负载率、能值交换比率方面均表现出明显优势,并从能值的角度提出了完善循环农业体系的对策建议  相似文献   
282.
Agricultural management affects the movement of atrazine in soil and leaching to groundwater. The objective of this study was to determine atrazine adsorption in a soil after 20 years of atrazine application under agronomic management practices differing in tillage practice (conventional and zero tillage), residue management (with and without residue retention) and crop rotation (wheat-maize rotation and maize monoculture). Atrazine sorption was determined using batch and column experiments. In the batch experiment, the highest distribution coefficient Kd (1.1 L kg?1) at 0–10 cm soil depth was observed under zero tillage, crop rotation and residue retention (conservation agriculture). The key factor in adsorption was soil organic matter content and type. This was confirmed in the column experiment, in which the highest Kd values were observed in treatments with residue retention, under either zero or conventional tillage (0.81 and 0.68 L kg?1, respectively). Under zero tillage, the fact that there was no soil movement helped to increase the Kd. The increased soil organic matter content with conservation agriculture may be more important than preferential flow due to higher pore connectivity in the same system. The soil's capacity to adsorb 2-hydroxyatrazine (HA), an important atrazine metabolite, was more important than its capacity to adsorb atrazine, and was similar under all four management practices (Kd ranged from 30 to 40 L kg?1). The HA adsorption was attributed to the type and amount of clay in the soil, which is unaffected by agronomic management. Soils under conservation agriculture had higher atrazine retention potential than soils under conventional tillage, the system that predominates in the study area.  相似文献   
283.
现代战争中环境监测问题的探讨   总被引:1,自引:0,他引:1  
通过分析在高技术武器装备下的现代战争中环境监测工作的特点,提出要提高仪器设备的科技含量、监测应急机动能力和区域性监测能力,建立高技术环境决策支持系统,积极动员地方监测力量和增强现有技术人员素质,才能够适应战场环境,开展系统完整的环境检测工作,充分发挥环境监测作用,为战争结束后环境和生态恢复提供帮助。  相似文献   
284.
This research aimed at assessing the properties of guinea pig manure digestate from low-cost tubular digesters for crops fertilization in rural Andean communities. To this end, field trials were carried out to evaluate the effect of the digestate on two common Andean crops: potato (Solanum tuberosum) and forage (Lolium multiflorum and Trifolium pratense L.). The potato yield (20-25 tha(-1)) increased by 27.5% with digestate, by 15.1% with pre-compost and by 10.3% with the mixture, compared to the control. The forage yield (20-21 tha(-1)) increased by 1.4% with digestate - 50% dose, and by 8.8% with digestate - 100% dose and digestate - 150% dose, compared to the control. The results suggest that the digestate is an appropriate substitute of manure pre-compost for potato fertilization. The results with forage indicate that it can be applied in a range of doses, according to the amount produced by the digester. Currently, manure is either used for cooking or as fertilizer. With low-cost tubular digesters implementation, it could be used to feed the digester, using the digestate for crops fertilization and biogas for cooking; improving household living conditions and protecting the environment. Since soil properties in rural Andean communities differ from experimental layouts, the effect of fertilizers should be re-evaluated in-situ in future research studies.  相似文献   
285.
基于环境因素的中国农业生产率增长研究   总被引:4,自引:0,他引:4  
考虑环境因素,运用方向性距离函数测算了1999-2008年中国30个省(直辖市、自治区)的农业环境技术效率,采用Malmquist-Luenberger生产率指数测度了28个省(直辖市、自治区)的农业全要素生产率(TFP)增长,并将其进一步分解为技术进步率指数和技术效率变化指数,以分析农业技术进步和农业技术效率变动对中国农业生产率增长的贡献.实证结果表明:东部的农业环境技术效率明显高于中、西部,而中、西部的差别很小,中部略低于西部;1999-2008年间各年的ML指数均值都大于1,表明中国农业每年的生产率都在增长;中国农业生产率的改进来源于技术进步,技术效率变化均值为0.997,农业技术效率在轻微退步;忽略环境因素会高估我国的农业生产率增长.在上述结论基础上,对如何促进中国农业生产率健康发展提出了相应的政策建议.  相似文献   
286.
波特假说主要从动态的角度论证了环境规制和农业科技进步之间的正向变亿关系.而在安徽省1990 -2008年的农业生产数据的基础上,选择合适的环境规制和农业科技进步的指标变量,运用Johansen协整分析方法验证了安徽省农业生产中的环境规制和农业科技进步的关系也符合这一假说,Granger因果关系检验说明了安徽省环境规制是农业科技进步产生的原因,脉冲响应分析和方差分析则更深入地从定量的角度分析了环境规制对农业科技进步影响滞后的趋势和影响程度.由实证分析可以看出,只是从静态角度来分析,环境规制是不利于农业的科技进步的;但从长期效益来看,环境规制有利于农业的科技进步.因此,在农业生态环境恶化的形势下,严格对农业废弃物的排放限制,制定较严格的农产品生产标准和产品质量标准,提高农民的环境意识和科技意识,通过强化环境规制来促使农业生产者提高农业生产技术,提高农产品品质和产品的市场竞争力就显得尤为重要.  相似文献   
287.
由于对生态建设的艰巨性和长期性、资金需求、阻力估计不足,生态建设过于口号化,我国生态建设存在诸多问题。从环境承载力的定义入手,分析了生态建设与环境承载力的关系,提出了当前生态建设应采取发展生态农业、生态工业、生态旅游、倡导绿色消费、加强污染综合治理等措施。  相似文献   
288.
Procopio, Nicholas A., 2010. Hydrologic and Morphologic Variability of Streams With Different Cranberry Agriculture Histories, Southern New Jersey, United States. Journal of the American Water Resources Association (JAWRA) 46(3):527-540. DOI: 10.1111/j.1752-1688.2010.00432.x Abstract: The creation of reservoirs and the modification of stream channels are common practices used to facilitate the efficient production of cranberries. The potential impacts to hydrologic and geomorphic aspects of streamflow and channel structure have not been adequately assessed. In this study, the streamflow regime of 12 streams and the channel morphologies of 11 streams were compared for study sites in the Pinelands region of New Jersey with upstream active-cranberry bogs, upstream abandoned-cranberry bogs, and basins with no apparent agricultural history. Flow regime metrics included measures of low-flow, median-flow, and bankfull discharge, two measures of streamflow variability (spread and a modified Richards-Baker Flashiness index), and the frequency of overbank flooding. Stream-channel morphology metrics included average bank slope, average bankfull width, average bankfull depth, average bankfull width-to-depth ratio, and average bankfull area. No significant differences between stream types were apparent for any of the metrics. Basin-area normalized streamflow values of all 12 study sites were highly correlated to each other. Significant relationships existed between some of the flow-regime and channel-morphology metrics. Due to the lack of significant differences between stream types, it appears that neither historic nor current cranberry agricultural practices considerably influence flow regimes or the channel morphology of streams in the New Jersey Pinelands.  相似文献   
289.
The rural economic situation in China-with a living standard mostly at subsistence level-lags far behind the prosperous development in the cities and coastal areas. To balance this disequilibrium, comprehensive concepts and endeavors are necessary keeping in view all-not just economic-interests and needs that contribute to lively rural identities. In this context the role of agriculture, where still 50% of the Chinese population are working, will be newly defined, and sustainability concepts can help to find a readjusted position within the Chinese economy focusing on environmental health and food safety as main targets of political and other supporting measures. Within the SUCCESS project, a Concept of Sustainable Agriculture was developed and it drafts one conceivable relation between the exposure to natural resources and economy and tries to find new answers to the broad range of rural challenges in China. It is a qualitative model and, therefore, not always fully applicable, but in the concrete situation of villages, it shows possible directions of sustainability-oriented development by considering the typical local potentials. In the Chinese context that means identifying the different functions of agriculture-the well-known and the hidden-to make them explicit for the Chinese public and therewith to give them new significance. The article is based on a 3-years study within the EU-China Project SUCCESS with field research in four Chinese rural communities. It analyzes the agricultural sustainability potential of these selected villages against the background of massive structural changes within the next 20 years in rural China. Starting from the current agricultural reality, based on a qualitative analysis of the actual situation, local potentials and needs towards sustainable production and marketing are identified, and possible functions of the Chinese agriculture are formulated for the future.  相似文献   
290.
The introduction of genetically modified organisms (GMOs) in Europe has been characterized by controversy. In 2002, the European Union introduced the concept of “coexistence” as a compromise solution that, through the establishment of science-based technical measures, should allow the market to operate freely while reducing policy conflicts on GMOs. However, the concept remains highly contested and the technical measures difficult to apply. This paper presents qualitative research on the conceptualization and implementation of the coexistence framework in two regions of Spain (Catalonia and Aragon), where 42% and 55% of maize was GM in 2006, respectively. In this context, the concept of coexistence and its proposed implementation both fail to resolve previous conflicts and actually work to generate new ones through the individualization of choice and impacts. Considerations of the social conditions in which the technology and the management measures are implemented were not taken into account. This resulted in the promotion of biotechnological agriculture over other alternatives.  相似文献   
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