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941.
P204-煤油萃取剂的生物降解性 总被引:3,自引:0,他引:3
采用测定溶剂饱和溶液 BOD5和 COD的方法对混合溶剂 P204(二-(2-乙基己基 )磷酸 )-煤油的生物降解性进行了研究 .结果表明 ,不同浓度的 P204(煤油)均可降解 .当溶剂中 P204的浓度小于 70%时 ,平衡水相的 COD及 BOD5 与初始溶剂中P204对煤油的体积比成正比 ;当 P204的浓度大于 70%时 ,平衡水相的 COD及 BOD5基本保持不变 .同时 ,建立了 P204(煤油)平衡水相中 P204的浓度的表达式 ,对研究混合溶剂的生物降解性具有一定的指导意义 . 相似文献
942.
A robust and rapid methodology for the determination of iodine by inductively coupled plasma mass spectrometry in environmental
samples is presented. Data were initially obtained for the validation of the analytical measurements, using 17 commercially
available soil reference materials. The methodology was then tested on soil and water samples collected in Afghanistan where
iodine deficiency and its effects are reportedly prevalent. Sample collections were conducted in Greater Kabul; the iodine
in agricultural soils was determined to be in the range of 1.6–4.2 mg/kg and that in water drawn for drinking and irrigation
was found to range from 9.9 to 22.7 μg/L. Samples were also collected in a second region, Nangarhar province, which is located
to the east of Kabul, where goitres in the local population had been reported. The iodine content in soils and water at this
location was 0.5–1.9 mg/kg and 5.4–9.4 μg/L, respectively. The organic content of soils in Kabul was found to be in the range
of 1.9–4.2%; in Nangarhar, organic content ranged from 1.7 to 4.5%. All of the Afghan soils were slightly alkaline at pH 7.6–8.2. 相似文献
943.
以实验室序批式反应器(SBR)为强化生物除磷工艺(EBPR)载体,接种具有初步除磷功能的污泥后,以乙酸∶丙酸=1∶1(按各自折算的COD计)为混合碳源(以下简称混酸),厌氧初始pH 7.6±0.1,富集聚磷菌(PAO)。启动30 d后,EBPR反应器中为PAO和聚糖菌(GAO)的混合菌属,此时从反应器中取泥样进行批式试验,分别考察乙酸、丙酸及混酸对聚磷菌的富集和厌氧释磷的影响。结果表明:在EBPR启动期内,乙酸作为单一碳源时释磷量最大,但混酸碳源释磷效率最高,最有利于PAO富集;丙酸作为单一碳源时降解率最大而释磷量最小,不适合EBPR启动期的PAO富集。 相似文献
944.
Dissolution of raw phosphate (apatite) in sea water of the Gulf of Aqaba was investigated through lab incubation experiments. Three types from three different sources (Al-Hasa, Al-Abyad and Esh-Shydiya) have been used for these experiments. Impact of quantity, grain size, and source (type) of raw phosphate on dissolution rate were studied. Statistical analysis shows significant differences between the results obtained from comparing each two weights; as weight of apatite increased, dissolved inorganic phosphate-phosphorus (DIP) and fluoride in sea water solution increased. The differences between the dissolution rates of raw phosphate from the three sites were not significant while the differences between the different grain size fractions were significant. Dissolution rates were inversely related to particle size. Using a worst-case scenario, a conservative estimate of the maximum increase in DIP in seawater of the Gulf of Aqaba due to the apatite particles lost to the sea during ship loading resulted in DIP concentrations of 0.03 μM per year. As the residence time of the water in the Gulf of Aqaba is about one year, the DIP concentration will not increase by more than 0.03 μM under the estimated annual quantity of exported phosphate. Fluoride will not increase by more than 0.03 mg/l under the same conditions. 相似文献
945.
The effects of alcohol–kola nut interactions on activites of whole brain glucose oxidase, glutamine synthetase, and adenylate deaminase were examined in Wistar rats. Thirty Wistar albino rats were divided into six groups. Control group (1) received a placebo (4 mL of distilled water). Groups 2–6 were treated for a 21-day period with either 10% (v/v) alcohol, kola nut, caffeine, alcohol + kola nut, or alcohol + caffeine at 50 mg per kg in a total volume of 4 mL vehicle via gastric intubation, respectively. One day after the final treatment, the whole brain was harvested and processed to examine for several biochemical parameters, including activities of glucose oxidase, adenylate deaminase, and glutamine synthetase. Results showed that alcohol–kola nut interaction decreased the activities of glucose oxidase, adenylate deaminase, and glutamine synthetase in whole brain, suggesting inhibition of glutamine synthesis, decreased energy (ATP) production, ionic transport and decreased neuronal processes. Data indicates that alcohol–kola nut or alcohol–caffeine interactions modify neuronal processes in rat brain; however, the clinical importance of this is not known. 相似文献
946.
以过硫酸铵为引发剂,含不同乙烯氧基重复单元数n的烯丙基聚乙烯氧基硫酸铵(ASn,n=5,10,15,20)和马来酸酐(MA)为单体在水溶液中聚合,合成对循环冷却水系统中磷酸钙垢有显著阻垢效果的共聚物MSn(n=5,10,15,20),并利用红外光谱(FT-IR)和核磁共振氢谱(1H-NMR)对聚合物MS10结构进行了表征。采用静态阻垢方法探讨了共聚物MSn中n值以及聚合物用量、溶液中Fe2+、Ca2+、杀生剂和溶液pH值、溶液温度对共聚物阻磷酸钙垢性能的影响。结果表明MSn用量存在临界值效应,MS10阻磷酸钙垢性能最好,在投加量为6 mg/L时MS10阻磷酸钙垢率达92%,且在高Fe2+浓度、高Ca2+浓度、高pH值以及高温条件下具有优异的阻磷酸钙垢性能,与异噻唑啉酮杀生剂和含氯含溴杀生剂有很好的配伍性。实验表明MS10是一种性能优异的循环水用阻磷酸钙阻垢剂。 相似文献
947.
采用微波Sol-Gel法在石英表面制备了负载型TiO2光催化剂,通过紫外吸收光谱和X衍射分析表征了TiO2溶胶的变化过程及锐钛型TiO2的生成。以活性艳红X-3B为模拟污染物进行光催化降解,探讨了微波功率、反应温度和反应时间对微波Sol-Gel法制备TiO2光催化活性的影响。由因素试验确定了最佳工艺条件:微波功率400W,反应温度90℃,反应时间2min。在此条件下制备的TiO2催化剂对活性艳红X-3B溶液进行光催化降解,反应30 min的脱色率达93%,TOC去除率为55%。采用中空纤维膜三相液相微萃取-毛细管电泳(HF-LLLME-CE)联用技术对降解生成的小分子有机物进行了测定。 相似文献
948.
中国居民生活碳排放的区域差异及影响因素分析 总被引:3,自引:1,他引:2
论文在总结划分居民生活碳排放(HCEs)类别的基础上,以中国HCEs量为测度指标,从时间和空间两个角度对1997-2012年人均HCEs进行分析,同时对2012年人均HCEs的空间格局分布及影响因素进行分析。基本结论如下:根据划分方法,HCEs按照碳排放源可分为直接和间接碳排放;按照基本生活需求可分为基本和发展碳排放;按照人类消费行为可分为交通、居住、食品、商品及服务碳排放五大类。从时间尺度来看,中国各类别人均HCEs均呈现逐年上升趋势。从空间差异来看,1997-2012年,我国各省人均HCEs表现出共同的空间分布特征。从空间格局分布来看,2012年中国人均居民生活碳排放呈现从东到西递减的趋势。从空间计量模型角度看,2012年,人均居民生活基本碳排放比重是影响人均HCEs空间差异的主要驱动因子。此外,各地区人均收入和人均GDP的差异也对人均HCEs的空间差异起到正相关作用。基于对中国人均HCEs的时空格局及影响因素分析,为我国制定碳减排举措提供科学依据并提出有效建议。 相似文献
949.
土壤-水稻系统重金属空间异质性研究——以浙江省嵊州市为例 总被引:3,自引:0,他引:3
在嵊州农产品产地共采集94对土壤-水稻样品,研究重金属在土壤-水稻系统的污染特征及空间异质性.结果表明,土壤重金属Cd、Cu、Ni、Pb和Zn的平均含量分别为0.20、28.64、27.03、38.51和98.74mg/kg,与背景值相比较,这些重金属在研究区均有不同程度的累积,局部污染严重,但是水稻重金属没有超过国家规定的食品安全标准,仍处于安全水平.土壤重金属Cd、Cu、Ni、Pb和Zn都属于中等程度变异,其变异系数分别为45.00%、46.65%、81.54%、18.07%、32.47%.地统计学和局部Moran's I指数结果可识别出这五个重金属的污染分布情况.土壤Cd、Cu、Ni和Zn的空间分布较为相似,基本为东西部含量较低,中部较高,这与工业活动和其他的人为活动有关.土壤-水稻系统重金属的迁移、吸收主要受土壤重金属含量和土壤理化性状的影响.从长远来看,重金属污染对当地生态和居民健康仍有潜在的威胁. 相似文献
950.
Iodine Deficiency Disorders (IDD) are a common health problem prevalent in the wet zone of Sri Lanka with a prevalence of >25 of the population. In comparison, in the dry zone of Sri Lanka IDD occurs in <10 of the population. Seventy soil samples from 14 villages selected on the basis of the incidence of goitre, were collected and analysed for 13 trace elements using ICP-MS. In order to identify any prevailing differences in antecedent chemical environments, soil samples from each pre-selected village were classified into three groups in terms of their geographical location. Among the elements investigated, the total soil concentrations of Rb, Sr, Ba, Mn and Co are lower in the wet zone of Kalutara. In contrast, total soil Rb, Sr, Ba and Mn contents are higher in the dry zone of Anuradhapura. Further soil total Mo and Nb levels are relatively similar in all pre-selected study locations. The high endemic goitre regions (IDD >25 of the population) show low levels of Rb, Sr, Ba, and Mn and higher levels of V, Cr, Co, Ni, Cu, Zn and Pb as compared with moderate and non-goitre areas. Factor analysis was used to exploit the correlation structure present in data and yielded three groups in all cases. This indicated that most transition group elements and iodine are associated with the Mn phase in the low IDD areas whereas iodine shows a high affinity for the organic phase in high IDD regions. The variable distribution of trace elements, therefore, must be due to differences in mobility and capacity for incorporation into the structure of secondary minerals or organic phases. 相似文献