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121.
反渗透(Reverse Osmosis,RO)因出水水质好、运行成本低等优势常用于垃圾渗滤液的处理,但产生的RO浓缩液具有COD高、色度高、盐分高、难降解等特点,其处理存在效果差、能耗和成本均较高等问题.本工作采用氧化钌/氧化铱涂层电极(RuO2/IrO2-Ti)的钛网为阳极,以304不锈钢电极为阴极,设计制作了6通道的电化学反应器,通过电化学氧化处理RO浓缩液,研究考查了电流密度、循环流速、比电极面积等参数对COD去除效果的影响,分析了电化学氧化去除难降解有机物并同时脱盐的过程机理与能耗.结果表明,在电流密度32.89 mA·cm-2,循环流速0.46 cm·s-1,比电极面积65.10 m2·m-3的条件下,电化学氧化处理RO浓缩液3 h,COD去除率可达68.0%,TOC去除率可达40.6%,脱盐率可达72.1%,去除单位质量COD能耗仅为常规的板状电极电化学反应器的25.5%.本工作可为垃圾渗滤液RO浓缩液的预处理提供新思路.  相似文献   
122.
对九龙江流域规模化养猪场猪饲料、沼气出液和猪粪中砷的含量进行了测定。猪饲料中砷的含量范围为0.50~7.72mg·kg-1,平均值为3.49mg·kg-1;沼气出液中砷的含量范围为0.47~56.13μg·L-1,平均值为13.45μg·L-1;猪粪中砷的含量范围为0.32~114.46mg·kg-1,平均值为13.45mg·kg-1。同一养猪场,小猪猪粪中的砷含量一般高于大猪和母猪猪粪;沼气出液和猪粪中的砷含量具有一定的相关性。由估算知,养猪场向九龙江流域年排放的砷总量约为821kg。9家养猪场中有2家猪粪和1家沼气出液中砷的含量相对较高,生态风险等级较高,已超过国家相应标准。总之,应该加强养猪业的管理,以防止养猪场对九龙江流域造成砷污染。  相似文献   
123.
国土空间规划监测评估预警是监督规划实施管理、保障规划实施成效的重要手段,也是实现“可感知、能学习、善治理、自适应”智慧规划转型的关键支撑。针对当前国土空间规划监测评估预警研究重机制、轻理论,以及缺乏一套科学可用的监测评估预警技术方法支撑的不足,在系统分析国土空间规划监测评估预警目标与内涵的基础上,构建以人工智能(Artificial Intelligence)、大数据(Big Data)、云计算(Cloud Computing)等新型信息技术(“ABC”技术)为支撑,覆盖国土空间规划“监测—评估—预警”业务全生命周期的应用模型体系,并结合信息系统建设案例,介绍了基于“ABC”技术的国土空间规划监测评估预警模型体系对实现各地国土空间规划“动态监测、精准评估、及时预警”的重要支撑作用。  相似文献   
124.
    
•Harbin showed relatively high threshold RH (80%) for apparent increase of SOR. •The observed SOR were at the lower end of the ratios from Beijing’s winter. •Temperature-dependent increase of NOR was sharper than that of SOR. • NOR increased with stronger biomass burning impact but SOR was largely unchanged. Formation of secondary inorganic aerosol (SIA) was investigated during a six-month long heating season in Harbin, China. Enhanced sulfate formation was observed at high relative humidity (RH), with the same threshold RH (80%) for both colder and warmer measurement periods. Compared to wintertime results from Beijing, the threshold RH was considerably higher in Harbin, whereas the RH-dependent enhancement of sulfur oxidation ratio (SOR) was less significant. In addition, the high RH events were rarely encountered, and for other periods, the SOR were typically as low as ~0.1. Therefore, the sulfate formation was considered inefficient in this study. After excluding the several cases with high RH, both SOR and the nitrogen oxidation ratio (NOR) exhibited increasing trends as the temperature increased, with the increase of NOR being sharper. The nitrate to sulfate ratio tended to increase with increasing temperature as well. Based on a semi-quantitative approach, this trend was attributed primarily to the temperature-dependent variations of precursors including SO2 and NO2. The influence of biomass burning emissions on SIA formation was also evident. With stronger impact of biomass burning, an enhancement in NOR was observed whereas SOR was largely unchanged. The different patterns were identified as the dominant driver of the larger nitrate to sulfate ratios measured at higher concentrations of fine particulate matter.  相似文献   
125.
    
● An approach for assessing the transport of benzene on the beach was proposed. ● The behavior of benzene in the subsurface of the beach was impacted by tide. ● Tidal amplitude influenced the travel speed and the benzene biodegradation. ● Hydraulic conductivity had the impact on plume residence time and biodegradation. ● Plume dispersed and concentration decreased due to high longitudinal dispersivity. The release and transport of benzene in coastal aquifers were investigated in the present study. Numerical simulations were implemented using the SEAM3D, coupled with GMS, to study the behavior of benzene in the subsurface of tidally influenced beaches. The transport and fate of the benzene plume were simulated, considering advection, dispersion, sorption, biodegradation, and dissolution on the beach. Different tide amplitudes, aquifer characteristics, and pollutant release locations were studied. It was found that the tide amplitude, hydraulic conductivity, and longitudinal dispersivity were the primary factors affecting the fate and transport of benzene. The tidal amplitude influenced the transport speed and percentage of biodegradation of benzene plume in the beach. A high tidal range reduced the spreading area and enhanced the rate of benzene biodegradation. Hydraulic conductivity had an impact on plume residence time and the percentage of contaminant biodegradation. Lower hydraulic conductivity induced longer residence time in each beach portion and a higher percentage of biodegradation on the beach. The plume dispersed and the concentration decreased due to high longitudinal dispersivity. The results can be used to support future risk assessment and management for the shorelines impacted by spill and leaking accidents. Modeling the heterogeneous beach aquifer subjected to tides can also be further explored in the future study.  相似文献   
126.
加快渔业产业结构调整、刺激渔业经济增长,是辽宁省渔业经济发展的现实需要。从2000—2012年的经济数据分析来看,辽宁省渔业产业结构现状是支柱产业稳定、主导产业发展潜力小、潜导产业向主导产业转移。采用Gompertz曲线预测,得出2015年辽宁省渔业经济总产值年均增长速度为9.5%,与农业部发布的《全国渔业发展"十二五"规划》中2015年渔业经济总产值年均增速10.2%的发展目标存在一定的差距,以此为基础提出辽宁省渔业产业结构优化的具体路径选择。  相似文献   
127.
The circular economy (CE) concept was introduced in China to address environmental degradation and resource scarcity associated with rapid economic development. Chosen as a demonstration city, Dalian has implemented the CE strategy as a means of conserving water, materials, energy and land. This paper outlines some of the regional CE initiatives that have been successful to date in Dalian, including those focusing on conserving energy and water resources and others focusing on reduced industrial emissions. The paper details the approach used in implementing the CE concept in Dalian, tracing the foci and goals of the program, and the sectoral approach used to implement a CE. Although Dalian municipality has achieved many successes in implementing a CE, our paper identifies several challenges that, until recently, have held back complete implementation. These include: the lack of incentives for older industries to 'green' their operations, the lack of financial support to expand the CE concept, and a broad-based need for heightened public awareness and participation in CE initiatives. Our paper then identifies several responses by Dalian municipality to overcome these challenges, including pricing and tax reforms that serve as conservation incentives, the provision of financial support for CE promotion through budget reorganization, and the organization of CE training programs. Our paper concludes that, although CE initiatives have been successful in Dalian, more is possible and more is needed before Dalian can be designated a true 'eco-city'. The approach used by Dalian can provide guidance for other Chinese cities, although it is recognized that each city must tailor its own approach for differing contexts and conditions.  相似文献   
128.
若尔盖高原是黄河上游主要的水源补给地,也是我国重要的生态安全屏障区,但近年来由于超载过牧、气候变化、鼠害等原因出现了严重的沙化问题.通过比较分析合理放牧、围封禁牧以及自然恢复3种恢复措施对若尔盖典型沙化草地植物群落结构、生物量和土壤理化性质的恢复效果.结果显示,恢复6年后,自然恢复草地恢复效果不明显,而合理放牧草地恢复效果最好.与自然恢复和围封禁牧恢复草地相比,(1)合理放牧使得草地植物群落盖度、物种丰富度、地上生物量和地下生物量显著增加,分别为93%、9、396.41 g/m~2和693.4 g/m~2;(2)合理放牧恢复草地土壤容重、pH显著降低;含水量、最大持水量、可溶性全氮、硝态氮、可溶性有机氮和可溶性有机碳显著增加.本研究表明合理放牧有利于沙化草地更快恢复,建议制定相关标准在适当区域进行应用和推广.  相似文献   
129.
为了研究室内环境中热、湿以及挥发性有机化合物(VOCs)的分布特征,根据不可逆过程热力学基本原理,考虑交叉耦合扩散效应的影响,采用数值模拟方法研究了室内环境中同时存在温度梯度、水蒸气浓度梯度和VOCs浓度梯度时的自然对流传热传质现象,展示了流场、温度场和浓度场随浮力比的变化状况,着重讨论了热扩散效应、扩散热效应和质附加扩散效应对无量纲传热努谢尔特数和传质舍伍德数的影响特性.研究表明,多物理场中交叉耦合扩散效应对自然对流传热传质具有一定的影响.  相似文献   
130.
周家珍  王丽萍  王玉明  李江  耿彪 《环境工程》2012,30(5):61-63,95
以塔山电厂SO3烟气调质运行实测数据为基础条件,通过分析SO3烟气调质后的除尘效率与飞灰比电阻、飞灰粒径、飞灰含湿量等理化性质,揭示SO3烟气调质对燃用高灰分劣质煤电厂除尘性能改善机制。为期一年测试结果表明:调质后比电阻降低3个数量级,2μm以下粒径粉尘比例提高了近6%,含湿量提高14%,从而提高表面导电机制,改善电除尘器电气参数,使电除尘效率由原来98.82%稳定提高至99.91%。  相似文献   
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