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891.
Development and application of a two-dimensional water quality model for the
Daqinghe River Mouth of the Dianchi Lake 总被引:1,自引:1,他引:0
Water quality models are important tools to support the optimization of aquatic ecosystem rehabilitation programs and assess their efficiency. Basing on the flow conditions of the Daqinghe River Mouth of the Dianchi Lake, China, two-dimensional water quality model was developed in the research. The hydrodynamics module was numerically solved by the alternating direction iteration (ADI) method. The parameters of the water quality module were obtained through the in situ experiments and the lab analyses that were conducted from 2006 to 2007. The model was calibrated and verified by the observation data in 2007. Among the four modelled key variables that were water level, CODcr, NH3-N and PO4-P, the minimum value of the coefficient of determination (CoD) was 0.69, which mean the model performed reasonably well. The developed model was then applied to simulate the water quality changes at the downstream cross-section assuming that the designed restoration programs were implemented. According to the simulated results, the restoration programs could cut down the loads of CODcr and PO4-P about 15%, however, they would have very little effect on the NH3-N removal. Besides, the water quality at the outlet cross-section would be still in class V (3838-02), indicating more measures should be taken to further reduce the loads. The study demonstrated the capability of water quality models to support aquatic ecosystem restorations. 相似文献
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895.
富营养化水体中微囊藻毒素(MCs)去除技术研究进展 总被引:2,自引:1,他引:1
当前,随着工业的发展水体富营养化程度日益严重。引起富营养化的主要藻类一蓝藻,能够释放对人体及鱼类具有多器官毒性、遗传性和致癌性的毒素——微囊藻毒素(MCs)。MCs治理技术种类繁多,传统的物理法如:混凝沉淀、膜过滤、活性炭吸附、气浮以及直接过滤只能对简单的处理细胞内的MCs;化学氧化法、光催化氧化法以及高级氧化法虽然能有效处理水体中的MCs.但有成本高、易二次污染和操作复杂等缺点,难以满足日益严格的环保要求;生物酶法除了具有生物降解法所具有的廉价、无二次污染、降解彻底和易操作等特点外,还被刺用来监控水体中MCs,它将成为今后重点研究的技术领域. 相似文献
896.
在实验室序批式活性污泥法(SBR)处理系统中以普通活性污泥为接种污泥,采用厌氧-好氧的运行方式提高系统的除磷效果.同时培养颗粒污泥,并对系统中磷的变化和去向进行分析.结果表明,整个试验共运行146 d,成熟颗粒污泥平均粒径为603μm,污泥体积指数(SVI)约为30 mL.g-1,COD去除率可达90%,磷的去除率可达95%左右.颗粒污泥系统除厌氧放磷和好氧聚磷以外,还存在明显的污泥颗粒积磷现象.磷的去除途径主要为:系统排泥(出水悬浮物和专门排泥)和污泥积磷.由厌氧末期颗粒污泥的X射线衍射(XRD)分析结果可知,化学沉淀是污泥积磷的一种重要方式,大量的金属离子会与磷形成无机盐沉积在污泥颗粒上. 相似文献
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898.
Influence of Indian mustard (Brassicajuncea) on rhizosphere soil solution chemistry in long-term contaminated soils: A rhizobox study 总被引:1,自引:0,他引:1
This study investigated the influence of Indian mustard (Brassica juncea) root exudation on soil solution properties (pH, dissolved
organic carbon (DOC), metal solubility) in the rhizosphere using a rhizobox. Measurement was conducted following the cultivation
of Indian mustard in the rhizobox filled four di erent types of heavy metal contaminated soils (two alkaline soils and two acidic
soils). The growth of Indian mustard resulted in a significant increase (by 0.6 pH units) in rhizosphere soil solution pH of acidic
soils and only a slight increase (< 0.1 pH units) in alkaline soils. Furthermore, the DOC concentration increased by 17–156 mg/L
in the rhizosphere regardless of soil type and the extent of contamination, demonstrating the exudation of DOC from root. Ion
chromatographic determination showed a marked increase in the total dissolved organic acids (OAs) in rhizosphere. While root exudates
were observed in all soils, the amount of DOC and OAs in soil solution varied considerably amongst di erent soils, resulting in
significant changes to soil solution metals in the rhizosphere. For example, the soil solution Cd, Cu, Pb, and Zn concentrations increased
in the rhizosphere of alkaline soils compared to bulk soil following plant cultivation. In contrast, the soluble concentrations of Cd, Pb,
and Zn in acidic soils decreased in rhizosphere soil when compared to bulk soils. Besides the influence of pH and DOC on metal
solubility, the increase of heavy metal concentration having high stability constant such as Cu and Pb resulted in a release of Cd and
Zn from solid phase to liquid phase. 相似文献
900.
在热重和红外联用进行等温实验的基础上,探讨了氧体积分数为10%、20%,970-1150℃温度范围内化学链燃烧过程中钙基载氧体再生(cas)的氧化特性-结果显示,CaS氧化的直接产物主要为CaSO4,只有在诱导期生成极少量CaO和SO2;但CaSO4与CaS还可进一步反应,生成更多Can和S02.通过对氧气浓度和温度的实验条件改变,研究了CaS04的转化率、转化速率,并辅以S02析出速率分析,获得了CaSO4相对于CaO的瞬时选择性、Ca.SO4的收率和反应选择率.结果表明,钙基载氧体CaSO.再生过程氧化反应的适宜条件为温度970-1000℃以及较高的氧气气氛.这不仅可以抑制S02的排放量从而得到较高的反应选择率.同时反应过程也具有较高的转化速率. 相似文献