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121.
The need for understanding the factors that trigger human responses to climate change has opened inquiries on the role of indigenous and local ecological knowledge (ILK) in facilitating or constraining social adaptation processes. Answers to the question of how ILK is helping or limiting smallholders to cope with increasing disturbances to the local hydro-climatic regime remain very limited in adaptation and mitigation studies and interventions. Herein, we discuss a case study on ILK as a resource used by expert farmer-fishers (locally known as Caboclos) to cope with the increasing threats on their livelihoods and environments generated by changing flood patterns in the Amazon delta region. While expert farmer-fishers are increasingly exposed to shocks and stresses, their ILK plays a key role in mitigating impacts and in strengthening their adaptive responses that are leading to a process of incremental adaptation (PIA). We argue that ILK is the most valuable resource used by expert farmer-fishers to adapt the spatial configuration and composition of their land-/resource-use systems (agrodiversity) and their produced and managed resources (agrobiodiversity) at landscape, community and household levels. We based our findings on ILK on data recorded for over the last 30 years using detailed ethnographic methodologies and multitemporal landscape mapping. We found that the ILK of expert farmer-fishers and their “tradition of change” have facilitated the PIA to intensify a particular production system to optimize production across a broad range of flood conditions and at the same time to manage or conserve forests to produce resources and services.  相似文献   
122.
本文通过对蒙古高原北部表层沉积物中硅藻属种的鉴定,探讨硅藻属种的分布特征及对水环境变化的响应。Gun Nuur湖泊中共鉴定出2纲7科12属21种硅藻,以羽纹纲为主,Cymbella cistula、Amphora ovalis、Amphora baltica、Amphora ovalis var.pediculus等为相对优势种,且平均相对含量分别为24.4%、23.8%、16.9%、15.6%,其余属种均少于10.0%。优势硅藻种Cymbella cistula表明了Gun Nuur湖泊主要为淡水、偏碱性水体,pH值为8.0左右,距湖岸较近位置有大量的水生生物发育。Anomoeoneis costata和Anomoeoneis sphaerophora var.sphaerophora、Navicula oblonga反映出湖泊由于蒸发作用而导致水体咸化,湖泊矿化度升高,并且湖水属于Na-Ca/Cl-SO4型。在高纬度气候非常寒冷地区的湖泊中,硅藻生长受到严重的抑制作用。偏"胖"的特征有利于硅藻浮游以适应水体温度的变化,湖泊边沿结冰后向湖泊中心游动。湖泊在冰封后可以阻止风浪作用,并且在低于水温的季节中,冰封可以使湖泊水体在阳光照射条件下保持高于外部环境的温度而有利于硅藻的生长。广盐性、真静水性硅藻Epithemia intermedia反映了这种湖泊长期冰封下静水特征。  相似文献   
123.
Efficient use of phosphorus (P) for producing food, preventing water pollution, and managing a dwindling rock P reserve are major challenges for China. We analyzed P stocks and flows in the Chinese food chain to identify where P use efficiency can be improved, where P leaks to the environment, and the research, technologies, and policies needed to improve P use. We found a high degree of inefficiency; of 6652 Gg P entering the food chain, only 1102 Gg P (18%) exit as food for humans. The greatest inefficiencies were a large build-up of soil P (3670 Gg P yr; 52% of P inputs) and high P losses to the environment from animal production (1582 Gg P yr; 60% of excreted P). Improving P use in China must focus on national-scale nutrient management strategies, better animal nutrition, and adoption of technologies and policies to reduce P discharges from the animal sector and recycle P as manures in agriculture.  相似文献   
124.
本文主要介绍了职业应激的概念,以及高温、噪声、辐射、压力这些应激原给炼钢工人健康带来的影响,并提出了预防措施。  相似文献   
125.
Environmental Science and Pollution Research - The zero-valent iron-anaerobic ammonium oxidation (ZVI-anammox) system has received widespread attention due to its excellent nitrogen removal...  相似文献   
126.
手机对人体的电磁生态效应与对策   总被引:1,自引:0,他引:1  
介绍移动通信用便携式收发信机对人体电磁生态效应的原理,研究现状,并就如何减少手机对人体的电磁影响提出几点看法和建议。  相似文献   
127.
To remove cesium ions from water and soil, a novel adsorbent was synthesized by following a one-step co-precipitation method and using non-toxic raw materials. By combining ammonium-pillared montmorillonite (MMT) and magnetic nanoparticles (Fe3O4), an MMT/Fe3O4 composite was prepared and characterized. The adsorbent exhibited high selectivity of Cs+ and could be rapidly separated from the mixed solution under an external magnetic field. Above all, the adsorbent had high removal efficiency in cesium-contaminated samples (water and soil) and also showed good recycling performance, indicating that the MMT/Fe3O4 composite could be widely applied to the remediation of cesium-contaminated environments. It was observed that the pH, solid/liquid ratio and initial concentration affected adsorption capacity. In the presence of coexisting ions, the adsorption capacity decreased in the order of Ca2 + > Mg2 + > K+ > Na+, which is consistent with our theoretical prediction. The adsorption behavior of this new adsorbent could be expressed by the pseudo-second-order model and Freundlich isotherm. In addition, the adsorption mechanism of Cs+ was NH4+ ion exchange and surface hydroxyl group coordination, with the former being more predominant.  相似文献   
128.
利用粘结挤压法将Fe-Al-Ce复合氧化物粉末材料制备成颗粒材料(GFAC),进行表征、静态和动态吸附除氟性能评价和现场应用.结果显示,优选GFAC颗粒直径为1.6 mm,具有较高的压缩破坏强度33.80 N和除氟性能.GFAC颗粒对氟的吸附过程符合准二级反应动力学方程,吸附速率受膜扩散和内扩散共同控制;在pH 7.0±0.2条件下,GFAC颗粒对氟的饱和吸附容量达到51.28 mg/g(25℃,Langmuir等温吸附模型).不同空间流速(SV)下动态实验出水穿透(1mg/L)时对氟的累积吸附量分别为5.69mg/g (SV=1 h-1)、5.61mg/g (SV=2h-1)、2.83 mg/g (SV=5 h-1),高于常见活性氧化铝除氟剂(AA,1.77 mg/g,SV=1 h-1)及其他报道的颗粒除氟剂.GFAC颗粒在河北现场成功用于实际高氟地下水的处理,在原水氟浓度(3.7±0.3)mg/L和pH 8.0±0.2条件下,对氟的累计吸附量为3.16 mg/g,明显高于AA(0.83mg/g),具有较好的应用前景.  相似文献   
129.
Effects of excessive fertilizer and manure applications on the soil environment were compared in greenhouse vegetable systems shifted from wheat-maize rotations 5-15years previously and in wheat-maize rotations. N, P and K surpluses to the greenhouses were 4328, 1337 and 1466kgha(-1)year(-1), respectively compared to 346, 65 and -163kgha(-1)year(-1) to wheat-maize fields. Subsequently, substantial mineral N and available P and K accumulated in the soil and leaching occurred down the soil profile in the greenhouses. Soil pH under vegetables was significantly lower than in the wheat-maize fields, while the EC was significantly higher in the vegetable soils. The mean Cd concentration in the vegetable soils was 2.8 times that in the wheat-maize rotations. Due to excessive fertilizer application in greenhouse vegetable production in northeast China, excessive salt and nitrate concentrations may accumulate and soil quality may deteriorate faster than in conventional wheat-maize rotations.  相似文献   
130.
Liu YN  Tao S  Dou H  Zhang TW  Zhang XL  Dawson R 《Chemosphere》2007,66(10):1922-1928
Exposure of on-duty traffic police in Beijing to polycyclic aromatic hydrocarbons (PAHs) was investigated during the summer, 2004 using a personal sampling technique in measuring both particulate and gaseous phase PAHs. The results were then compared with those from two control sites away from the street. Exposure levels to gaseous and particulate PAHs for the traffic police were found to be 1525 +/- 759 ngm(-3) and 148 +/- 118 ngm(-3), respectively, representing 2-2.5 times higher levels than those at the control sites. The daily inhalation exposure of the police was estimated to be 277 ngkg(-1)d(-1). Most of the PAHs exposure came from the vapor phase, particularly NAP, FLO and PHE. Based on calculated PAH diagnostic ratios, the major source of PAHs exposure was from vehicle exhaust. The effects of temperature, humidity and atmospheric stability on exposure levels are also discussed.  相似文献   
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