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101.
农药污染地块修复过程中频繁出现异味污染问题,严重影响周边居民日常生活和身体健康。以往报道多集中在场地内有毒有害物质分析,较少关注场地异味污染问题。为预测某有机磷农药场地修复过程异味污染情况,本文以该地块7个潜在异味污染控制区为研究对象,分析了近土壤空气异味污染程度和影响范围,并应用气相色谱-四极杆/静电场轨道阱高分辨质谱技术测定近土壤空气、土壤中挥发性有机物(VOCs)和半挥发性有机物(SVOCs),阐明地块控制区内异味污染排放特征,评估近土壤空气地块污染的人体健康风险。结果表明,7个区域监测点位散发不同程度刺激性气味,臭气浓度值范围为309~72443;生产区异味影响范围最大,达到3.2km;共识别出近土壤环境空气中209种VOCs、土壤样品中246种VOCs和SVOCs,主要包括芳香化合物、卤代物、烷烯烃和含氧有机物;主要异味贡献物质种类包括有机硫化物、芳香化合物和含氧有机物;7个区域近土壤空气均存在致癌风险(>1.0×10-4),5个区域存在非致癌风险,主要致癌物质为1,4-二氯苯、苯、四氯化碳。本文开展的农药场地异味物质组分与致病致癌风险持续研究结果,可为研究区生态环境修复和居民健康保护等提供重要依据。  相似文献   
102.
Atmospheric nitrogen deposition to the Mullica River-Great Bay Estuary   总被引:2,自引:0,他引:2  
Measurements of nitrate and ammonium in precipitation and associated with aerosols were conducted at Rutgers University Marine Field Station in Tuckerton, New Jersey from March 2004 to March 2005 to characterize atmospheric nitrogen deposition to the Mullica River-Great Bay Estuary. The arithmetic means of nitrate and ammonium concentrations for precipitation samples were 2.3mgL(-1) and 0.42mgL(-1), respectively. Nitrate and ammonium concentrations in aerosol samples averaged 3.7microgm(-3) and 1.6microgm(-3), respectively. Wet deposition rates appeared to vary with season; the highest rate of inorganic nitrogen deposition (nitrate+ammonium) occurred in the spring with an average value of 1.33kg-Nha(-2)month(-1). On an annual basis, the total (wet and dry) direct atmospheric deposition fluxes into the Mullica River-Great Bay Estuary were 7.08kg-Nha(-2)year(-1) for nitrate and 4.44kg-Nha(-2)year(-1) for ammonium. The total atmospheric inorganic nitrogen directly deposited to the Mullica River-Great Bay Estuary was estimated to be 4.79x10(4)kg-Nyear(-1), and the total atmospheric inorganic nitrogen deposited to the Mullica River watershed was estimated to be 1.69x10(6)kg-Nyear(-1). Only a fraction of the nitrogen deposited on the watershed will actually reach the estuary; most of the nitrogen will be retained in the watershed due to utilization and denitrification during transport. The amount of N reaching the Mullica River-Great Bay Estuary indirectly is estimated to be 5.07x10(4)kg-Nyear(-1), approximately 97% is retained within the watershed. This atmospheric nitrogen deposition may stimulate phytoplankton productivity in the Mullica River-Great Bay ecosystem.  相似文献   
103.
通过对盐生杜氏藻的热模拟成烃研究,发现其热解产物中含有丰富的咔唑系列化合物,它包括咔唑(CZ)、甲基咔唑(M CZ)、二甲基咔唑(DM CZ)、三甲基咔唑(TM CZ)、四甲基咔唑(TeM CZ)、五甲基咔唑(PM CZ)和六甲基咔唑(HM CZ)。并且在300℃热模拟产物中咔唑系列化合物含量较高,在芳烃馏分中相对含量为30.97%,350℃时产出较低,为15.44%,而250℃时未检出此类化合物。这一方面表明嗜盐杜氏藻很可能是原油和烃源岩中咔唑类化合物的主要母源之一,另一方面表明高盐环境下这种以杜氏藻为主要生烃母质的原油可能富集咔唑类化合物,这为该环境下油源对比提供了有力依据。  相似文献   
104.
华北地区一次强灰霾污染的天气学效应   总被引:2,自引:1,他引:1  
利用在线耦合的大气化学模式WRF-Chem V3.6(Weather Research Forecasting Model with Chemistry Version 3.6)及环境、气象观测数据,在完成大气化学方案优选的基础上,研究了华北地区一次重霾污染过程(2013年2月15~17日)对气象条件的反馈作用。重点关注一次颗粒物、无机气态成分和挥发性有机污染物的人为排放对PM2.5(空气动力学当量直径小于等于2.5μm的颗粒物,即细颗粒物)生成的贡献,探讨了由此引发的气象条件的变化。模拟结果显示,上述3种人为源的综合排放对华北地区PM2.5浓度的平均贡献率为91.27%,其中对北京、秦皇岛和沧州的贡献率分别达96.9%、95.9%和97.2%。这使区域地面太阳向下短波辐射降低近15.99%,区域平均地面辐射强迫达-26.51 W m-2,由此导致地面温度下降0.14°C(3.68%),逆温增强,垂直温度梯度(?T/?z)升高0.026 K km-1,边界层高度降低18.92 m(8.77%),平均风速减少约0.014 m s-1(0.35%),相对湿度绝对值升高0.51%,地面平均气压降低0.86 Pa。对于15~17日污染过程,人为源综合排放的气溶胶对短波辐射的影响在天气过程中占主导地位,对边界层高度的影响较大,但不起主导作用,对温度、风速、相对湿度、气压的作用则远小于天气系统本身。挥发性有机污染物(Volatile Organic Compounds,VOCs)作为二次有机气溶胶(Secondary Organic Aerosol,SOA)的前体物,其人为排放对SOA浓度的贡献率约为99.6%。同时,VOCs通过调整大气反应活性促进无机气态成分向无机盐转化,它对硫酸盐和硝酸盐浓度的贡献达50%以上。然而,VOCs对整个PM2.5浓度的贡献不及各种源综合贡献的1/4。人为排放的VOCs对气象场的反馈与综合排放的作用基本一致,但对地面气压的影响VOCs排放时以热力因子为主,而人为源综合排放时以动力因子为主。上述结果暗示,灰霾污染过程所引发的气象条件向不利于污染物扩散方向改变,这可能促进污染物的局地累积、增强污染程度并延长区域内重污染的持续时间。因此,在探讨区域性灰霾污染成因时,灰霾自身通过辐射强迫作用对大气的调节是不可忽视的重要影响因素。  相似文献   
105.
海马齿是一种热带和亚热带盐生植物, 既是传统野生菜蔬, 也在海岸带生态修复中发挥重要作用。北移种植海马齿进行生态修复时, 越冬低温的影响是成功与否的首要关注问题, 其机制尚待解明。脂肪酸在生物耐受低温中发挥作用, 挥发性有机物与脂肪酸代谢关系密切。本研究利用海湾环境中生态修复浮床上的海马齿样品, 重点解析北移种植环境下, 海马齿植株不同部位受越冬影响前后的脂肪酸和挥发性有机物的组成、差异及变化特征。结果显示, 海马齿的花、叶、茎和根样本中, 共检出14种脂肪酸, 根中的脂肪酸种类数相对最多; 多不饱和脂肪酸在花和叶中的含量(平均分别为56.46%和60.23%)总体大于茎和根(平均分别为41.56%和44.45%)。茎、叶中共检出86种挥发性有机物, 蘑菇醇为优势种类。越冬后脂肪酸和挥发性有机物种类数量显著降低, 多不饱和脂肪酸比例在冻伤植株中显著升高; 就植株脂质营养指数而言, 耐受越冬低温的植株其脂质营养品质提高。越冬造成海马齿两类化合物发生显著变化, 其中C18脂肪酸代谢响应有重要贡献, C18: 3(n-3)和蘑菇醇分别是脂肪酸与挥发性物质中最为重要的两个代谢产物, 可能与抗冻应激有密切关系。本研究为推广海马齿种植以构建可持续近海生态修复体系提供了参考。  相似文献   
106.
107.
塔里木盆地流体与油气藏   总被引:6,自引:0,他引:6       下载免费PDF全文
本文以塔里木盆地为例,通过流体势分析,油田水化学分析,包裹体测温和原油中含氮化合物的丰度及比值研究,确定塔中地区晚海西期油气主要来自东北和西北两个方向,在中段形成塔中4油藏,并通过流体运移方向分析,认为塔中4油藏在喜马拉雅期受淡水冲洗破坏,使油所储量大大减少,轮南地区的油气主要来自南部的满加尔凹陷和两侧的哈拉哈塘凹陷和草湖凹陷,其中草湖凹陷两次供油气,而其他两个凹陷三次供油气,流体运移方向的研究有助于认识油气的分布规律,对确定勘探的有利区带和目标具有重要意义。  相似文献   
108.
A geographic information system (GIS) raster technique has been developed and used interactively with remediation designers to evaluate the optimum extent of excavating soil contaminated by chlorinated solvents. The technique and the results of its application are presented. The site was a former chemical storage plant for acids and solvents. Two distinct solvent plumes were detected within the ground using a photo-ionisation detector. The solvents were found to be dissolved in the groundwater and migrating in the general direction of groundwater flow. A remediation strategy was proposed involving the localised excavation of contamination ‘hot spots’ followed by the implementation of a groundwater remediation system. A number of excavation options were discussed and the GIS raster technique was developed to evaluate these options in terms of contaminant removed and excavation cost.

The plumes were initially mapped using a triangular irregular network (TIN). These TIN models were rasterised to produce a regular grid of rectangular cells, each cell having a value relating to the concentration of contaminant at that spatial point. The proposed excavation zones were then overlaid on to the raster models as masks. The relationship between the value of contaminant concentration of cells within the mask (or excavation zone) and the total value of contaminant concentration of cells within the solvent plume was used to determine the efficiency of the excavation.

The excavation options were compared taking into account the percentage of the contaminant plume removed, the excavation area (soil volumes) and related costs. Once the GIS raster technique had been developed, it proved very quick to rerun the analysis for the other excavation zones. The optimum excavation zone, based upon cost and contaminant recovery, was found for the site. The technique helped by targeting the worst area of contamination and provided the client with a cost-benefit analysis of the different remediation options.  相似文献   

109.
庞燕波  王文兴 《大气科学》1993,17(4):499-505
全球和区域大气环境研究的重要任务之一是查明各种气态物质自然源释放通量,含硫化合物是其中的一种,它在阐明生物圈硫循环和环境酸化中起重要作用.迄今为止,我国尚无有关研究报道.本文参考文献资料和实测数据用类比法进行了我国两广地区自然源硫化物释放量的计算.结果表明,天然源硫化物中主要是来自树木和土壤,释放的硫化物为COS(49%),DMS(32%)和H_2S(14%).两广地区全年自然源硫释放量3325吨(以硫计).  相似文献   
110.
Inorganic ions, organic carbon (OC), elemental carbon (EC) and a variety of organic single species in airborne particles have been determined at the research station of the Leibniz – Institut für Troposphärenforschung (IfT) in Melpitz (Germany) in autumn 1997.Samples of eight selected measurement events were divided in two groups in order to investigate differences in the chemical composition of particles originating from southwesterly (SW – developed EU countries) or from easterly directions (E – less developed eastern countries). Differences between these two groups were tested statistically by Student's t-test.Five stage cascade impactor samples show nitrate as most abundant in the accumulation mode in the SW group. EC and sulphate show the most abundant mass fractions in the E group. That can be considered as a consequence of domestic coal heating and coal-fired power plant emissions in the region of westerly Poland, northern Czech Republic and easterly Germany. Higher nitrate concentrations in the SW group can be explained by stronger NO x emissions caused by the leeward plume of the conurbation of Leipzig, as well as by the still higher traffic density in western Germany.The methane sulphonic acid (MSA) mass fraction was higher for SW air masses in accumulation mode particles, probably indicating marine origin. Succinic acid also showed higher mass fractions for the SW group. This could be caused by primary emission in automobile exhaust gases and photochemical formation during transport from SW. Indeed, during SW sampling, solar radiation intensity was higher than during E sampling.The observed differences in the particle composition are an expression of the still existing technology gradient in Europe. Future campaigns could show the development to a joint economy with smaller differences in anthropogenic emissions.  相似文献   
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