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821.
为在寒冷地区建立高效的滨岸缓冲带水体工程,选择早熟禾、高羊茅、3种本地耐寒性植物,研究剪股颖构建河流滨岸缓冲带植物的经济性、生长特性、光合作用及其对悬浮物、氮、磷的净化能力。结果表明,3种植物在经济性方面高羊茅与早熟禾差别不大,远低于剪股颖;在生长特性方面,早熟禾与高羊茅的表现相近,高羊茅略好,但比剪股颖表现优秀,早熟禾在净光合作用速率、蒸腾速率以及水分利用效率方面比高羊茅及剪股颖出色;在面源污染物去除率方面,地表径流悬浮物的去除中,早熟禾表现突出;在溶解性磷与总氮的净化中,3种植物表现差异不大,早熟禾略有优势。综合比较各项指标,早熟禾可作为寒冷地区构建滨岸缓冲带较为理想的备选植物。  相似文献   
822.
Characteristics of cadmium (Cd) uptake kinetics and distribution of Cd speciation in the rhizosphere for Cd accumulator and non-accumulator oilseed rape varieties were investigated under nutrient solution and rhizobox soil culture conditions. The results showed that the maximal influx (Vmax) for Cd2+ andKm were significantly different for the two oilseed rape varieties. The value of Vmax for Cd accumulator oilseed rape Zhucang Huazi was two-fold greater than that for oilseed rape Chuan you II-93. The exchangeable Cd concentration in the rhizosphere was significantly lower than in non-rhizospheric soils supplemented with CdSO4 for both the varieties. Carbonate-bound Cd in the rhizosphere of Cd accumulator oilseed rape was significantly higher than that in the rhizosphere of non-accumulator oilseed rape and non-rhizospheric soil. Cd accumulator oilseed rape had a higher Cd2+ affinity and more ability to uptake insoluble Cd in the soil than the non-accumulator oilseed rape.  相似文献   
823.
A case study for water using network of a Starch industry in the state of Gujarat, India, is undertaken with an aim to reduce demineralised water and freshwater flow rates and consequently the wastewater flow rate. The problem was identified as a multi contaminant, reuse and recycle problem. The freshwater consumption and demineralised water consumption were 100 t/h and 51 t/h respectively before modification and the network was dealing with three major contaminants such as total organic content, total dissolved solids and total suspended solids. A program was developed in MATLAB for analysis using Water Pinch. The improved water using network designed for the present work consumed less demineralised and freshwater. The reductions are of the tune of 28% and 64.38% for demineralised and fresh water respectively. Due to alteration in piping, there will be a saving of 406 026 INR per year, which will be utilized for development of efficient environment policy for the company. The entire concept had been implemented on plant level on 1st February-2009 and the reductions are of the tune of 25% and 60% for demineralised and fresh water respectively.  相似文献   
824.
融雪剂对园林植物种子萌发的影响   总被引:1,自引:0,他引:1  
李芳  张俊民 《环境科技》2009,22(5):22-24
使用融雪剂是高纬度城市冬季除雪的主要措施之一,但融雪剂中含有的盐类物质可以对园林植物造成伤害。在此研究了融雪剂对刺(Robinia pseudoacacia)、万寿菊(Tagetes erecta)、矮紫薇(Lagerstroemia indiea’Petite pinkie')、草地早熟禾(Poa pratensis)、侧柏(Platycladus orientalis)种子发芽率和相对受害率的影响。试验结果表明:5种植物种子的发芽率随融雪剂浓度的升高而降低.相对受害率则随融雪剂浓度升高而增大。其中草地早熟禾种子时融雪剂最敏感,可以用草地早熟禾种子萌发为指示,间接检验融雪剂对植物的伤害程度。  相似文献   
825.
陆生经济植物浮床去除富营养化水中氮素研究   总被引:2,自引:0,他引:2  
通过玻璃缸静态培养试验,探讨陆生经济植物芹菜(Apium graveolens L).、茼蒿(Chrysanthemum coronarium L).和大蒜(Alliumsativum L).作为人工生物浮岛栽培植物,去除富营养化水体中氮的可行性和净化效果。采用常规耗竭法进行吸收动力学试验,研究植物根系对不同形态氮的吸收特性,为浮床植物遴选提供理论依据。结果表明:芹菜、茼蒿和大蒜在水中生长状况良好,试验前后生物量相对增长了121.24%~330.12%;三种经济植物浮床系统净化效果显著,对水中TN的去除率为44.94%~82.84%,高于空白对照系统(25.15%)。三种植物浮床系统对TN去除效果差异极显著(P0.05),根据这三种植物根系对不同形态氮在不同浓度水平下的吸收特性研究发现,其吸收规律均符合Michaelis-Menten动力学方程,但不同种类植物根系吸收特性存在差异,从而影响不同形态氮的去除效果。其中芹菜对NH4+-N的吸收潜力最大,对NO3--N的亲和力最大,大蒜对NO3--N的吸收潜力最大,对NH4+-N亲和力最大,茼蒿对两种形态氮的吸收能力较差。  相似文献   
826.
观测安徽吉阳核电厂址近地面层的气象数据,对该厂址近地面层温度梯度及风廓线规律的适用性进行了分析,通过散点图的形式寻找风速比随稳定度参数的变化特征。结果表明,本区气温日变化符合一般观测规律,四季平均气温有较大差异、温差偏大,春夏两季多易出现逆温,春冬逆温强度较夏季偏大;非中性层结条件下风速比值随稳定度的增强而离散增大。  相似文献   
827.
Mercury (Hg) contents in ten chemical fertilizers were determined, and the e ect of calcium superphosphate (CSP) on the uptake and translocation of Hg in corn seedlings was investigated by pot experiments. CSP was applied at the levels of 0, 66.7, and 133.4 mg P2O5/kg to Hg-treated (2 mg/kg) and untreated soils. CSP had the highest Hg content (5.1 mg/kg), followed by the NPK compound fertilizer 15-5-5 (15% N, 5% P2O5, 5% K2O) (1.2 mg/kg), then by nitrogen fertilizers (except for ammonia sulfate) and potassium fertilizers. Application of CSP did not obviously influence the biomass of corn roots, but it significantly increased the biomass of corn shoots in Hg-treated soil. Application of CSP at the levels of 66.7 and 133.4 mg P2O5/kg did not obviously influence the uptake of Hg by corn seedlings on soils without Hg treatment, but it decreased the Hg uptake of corn seedlings significantly on Hg-treated soils. The transfer coe cient of Hg in corn seedlings improved slightly on soils without Hg treatment, but decreased slightly on Hg-treated soils with the application of CSP. These results implied that CSP could ameliorate Hg toxicity to corn seedlings by inhibiting the uptake and the translocation of Hg in plants on Hg-polluted soils.  相似文献   
828.
Propolis is a natural resinous product collected by honeybees from certain plants. It has gained popularity as a food and alternative medicine. Poplar and Baccharis are well known as the source plants of European and Brazilian propolis, respectively. However, the propolis from Okinawa, Japan, contains some prenylflavonoids not seen in other regions such as Europe and Brazil, suggesting that the plant origin of Okinawan propolis is a particular plant that grows in Okinawa. To identify the plant origin of Okinawan propolis, we observed the behavior of honeybees as they collected material from plants and caulked it inside the hive. Honeybees scraped resinous material from the surface of plant fruits of Macaranga tanarius and brought it back to their hive to use it as propolis. We collected samples of the plant and propolis, and compared their constituents by high-performance liquid chromatography with a photo-diode array detector. We also compared their 1,1-diphenyl-2-picryl-hydrazyl radical scavenging activity. The chemical constituents and biological activity of the ethanol extracts of the plant did not differ from those of propolis. This indicates directly that the plant origin of Okinawan propolis is M. tanarius. S. K. and J. N. contributed equally to this work.  相似文献   
829.
孔石莼(Ulva pertusa)对铅、铜、镉的吸收   总被引:1,自引:0,他引:1  
研究了大型藻孔石莼对铅、铜和镉的吸收动力学和热力学过程。结果表明,暴露于不同浓度的重金属体系中的孔石莼对铅、铜和镉的积累量随着水相中的游离态浓度的增加而增加,可以用Langmuir吸附等温式从热力学平衡角度加以描述,铅和镉饱和结合量分别为:0.715mg/g干重,Cd^2+为0.037mg/g干重;在孔石莼对铜(0.056mg/L)吸收动力学浓度的实验中,第4天达到了吸收平衡,蓄积量为对照组的9.01倍;在镉暴露浓度为0.028mg/L的实验中,第5天达吸收平衡,蓄积量为对照组的5.06倍。  相似文献   
830.
史建君  林明明 《环境科学》2007,28(8):1806-1809
为了探明14CO2在环境中的行为,采用同位素示踪技术研究了青菜对14CO2的吸收和积累动态.结果显示,通过叶片光合作用从空气中吸收的14CO2会向青菜其他部位组织输送并形成积累趋势,各部位组织中14C比活度随时间呈线性增长,增长速率介于95.3~270.2 Bq/(g·d)范围内, 大小次序为:菜心>叶>叶柄>茎盘>根.青菜对14CO2(14C)具有强烈的富集作用,各部位的富集系数随时间呈快速增加,积累效应十分明显,其中菜心中的富集系数最大(48 d时高达156.4),叶片次之(48 d时为135.6). 青菜各部位14C比活度均随14CO2引入次数的增加而递增,回归分析表明:各部位组织中14C比活度C的变化与引入次数N间呈线性正相关.青菜对空气中14CO2的高富集特性可用来作为监测大气14CO2污染的指示作物.  相似文献   
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