首页 | 官方网站   微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1162篇
  免费   31篇
  国内免费   23篇
工业技术   1216篇
  2024年   3篇
  2023年   13篇
  2022年   9篇
  2021年   20篇
  2020年   30篇
  2019年   17篇
  2018年   29篇
  2017年   23篇
  2016年   31篇
  2015年   35篇
  2014年   55篇
  2013年   77篇
  2012年   44篇
  2011年   78篇
  2010年   66篇
  2009年   88篇
  2008年   73篇
  2007年   76篇
  2006年   71篇
  2005年   68篇
  2004年   44篇
  2003年   45篇
  2002年   29篇
  2001年   19篇
  2000年   26篇
  1999年   30篇
  1998年   20篇
  1997年   15篇
  1996年   12篇
  1995年   13篇
  1994年   12篇
  1993年   9篇
  1992年   5篇
  1991年   9篇
  1990年   4篇
  1989年   5篇
  1988年   4篇
  1987年   2篇
  1986年   2篇
  1985年   2篇
  1983年   1篇
  1982年   1篇
  1979年   1篇
排序方式: 共有1216条查询结果,搜索用时 390 毫秒
71.
The paper describes the results of treatment of soil samples, deriving from a dismissed industrial site, contaminated with several metals: Hg, Ni, Co, Zn, Pb, Cu, Cr, As and organic substances. The soil was subjected to remediation based on a process in which an oxidising leaching agent was produced electrochemically in-line in an undivided electrochemical cell reactor equipped with a Ti/Pt-Ir anode and a stainless steel cathode. Leaching of the soil samples was performed under dynamic conditions using a leaching column. A subsequent regeneration of the leaching solution, which consisted in electrodeposition of metals and electro-oxidation of organic substances, was carried out in a packed-bed reactor equipped with a centrally positioned graphite rod, serving as an anode, and stainless steel three-dimensional filling as a cathode. The study was focused on how and to which extent the metals present in the soil, as organic complexes, can be solubilised and how the process rates are impacted by the solution pH and other process variables. Data obtained under non-oxidising conditions, typically adopted for leaching of metals, are compared with the performance of chlorine-enriched leaching solutions. The results obtained under various conditions are also discussed in terms of the total organic carbon (TOC) removal from the water phase.  相似文献   
72.
探讨纺织空调系统滤料应用现状与性能要求.分析了在纺织空调系统滤料应用中存在的问题.针对除尘滤料的开发,认为滤料应具备除尘效率高、永久阻燃性强、耐用性能好、尘体在滤料表面的静电吸附性低、滤料表面的疏水性能好等性能要求,方能满足纺织空调除尘对滤料性能的要求.  相似文献   
73.
74.
针对农药厂高、中、低浓度的三类废水,测定其COD与TOC,并对测定值进行一元线性回归分析。结果表明,有机物成分稳定的废水不管浓度高低其COD与TOC均具有显著的相关性,可以建立相应的回归模型,模型计算值与测定值相对偏差小于5%。  相似文献   
75.
煤系地层富含有机岩石,导致测井响应特征复杂。以实测TOC含量数据为基础,分析了煤系烃源岩中煤岩、炭质泥岩和泥岩有机碳含量的测井响应特征,发现电阻率、声波时差、自然伽马、密度和中子孔隙度等测井参数与有机碳含量相关性较高,并基于此建立了针对不同岩性煤系烃源岩有机碳含量计算模型,即多元回归模型和Δlog R模型。结合研究层段,分别建立了一元、二元、五元线性回归模型及重叠法模型,进行TOC含量计算并做了误差分析。结果表明:五元回归模型的计算误差最小,但在没有实测TOC含量数据层段计算误差较大;重叠法计算误差最大,但其整个层段的TOC含量预测值更符合岩性特征。煤系地层有机碳预测研究旨在为后续煤系烃源岩综合评价提供参考。  相似文献   
76.
本文以柴油和石蜡混合物为碳源,利用液体培养基富集培养石油烃类降解菌。得到的菌液通过DCIP显色实验和原油模拟降解实验初步筛选出13株降解菌菌株,并经过分子生物学的鉴定大部分为不动杆菌属和假单胞菌属。经过摇瓶培养后,HY-3、G6和8号菌对于COD和TOC的去除效果较好,并通过和活性污泥复配后发现8号菌能够有效提升SBR系统的生物处理能力,COD去除率达到90%以上。  相似文献   
77.
Amino acids and peptides may form potentially harmful disinfection byproducts during the conventional treatment of water and wastewater. Removal of these parent compounds by the use of the environmental-friendly oxidant, ferrate(VI) (FeVIO42−, Fe(VI)) was assessed by studying the kinetics of the oxidation of glycine (NH3+CH2COOH, Gly) and glycylglycine (NH3+CH2CONHCH2COOH, Gly-Gly) as a function of pH (4.0-12.4) at 25 °C. This study with Gly-Gly represents an initial investigation of oxidation of peptides by Fe(VI). Generally, the second-order rate constant (k) increased with decreased pH in the basic pH region, but this trend was reversed in the acidic pH range. Consideration of the reactivity of three oxidants (H2FeO4, HFeO4, and FeO42−) with three species of Gly and Gly-Gly (positive, neutral, and negative) reasonably explained the pH dependence of the rates. At pH 9.0, the molar consumption of Fe(VI) was nearly equal to that of Gly. The reaction of Fe(VI) with Gly at molar ratios of 1.0 and 2.0 ([Fe(VI)]:[Gly]) produced ammonia, carbon dioxide, and acetate. A reaction scheme is proposed which explains the formation of these products. The values of k for oxidation of iminodiacetate and nitriloacetate at pH 7.0 were also determined in order to compare oxidation of amines by Fe(VI). The calculated half-lives at neutral pH for the oxidation of primary and secondary amines were in seconds while decomposition of tertiary amines would occur in minutes. Overall, the reactivity of Fe(VI) with Gly and Gly-Gly indicates the significant potential of Fe(VI) to remove amine- and peptide-containing pollutants in water and wastewater.  相似文献   
78.
张光斌  肖立川  吕宏伟 《化工机械》2010,37(6):693-696,701
介绍了整体煤气化联合循环系统(IGCC)的两种净化系统——常温湿法净化系统和高温干法净化系统的结构和除尘脱硫的原理,并基于净化流程结构与热力学定律对两种净化系统进行了比较,指出在采用高温干法净化系统的IGCC整体效率要高于采用常温湿法净化系统的。  相似文献   
79.
The use of chemically modified silica gel N-(1-carboxy-6-hydroxy) benzylidenepropylamine (SiG-CHBPA), ion exchanger for removal and preconcentration of Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd and Pb in natural water samples collected from River Nile, Mediterranean Sea and other locations followed by their consecutive AAS determination was described. The effects on the percentage of recovered metal ions including mass change of ion exchanger, stirring time, pH of sample solutions and eluent concentration were studied. The distribution coefficient Kd, ml g− 1 and the percentage concentration of the studied metal ions on the ion exchanger at equilibrium, CM,eqm ,% (Recovery, %) were studied as a function of experimental parameters. The logarithmic values of the distribution coefficients, log Kd are 3-6.3. The interfering effects of some foreign ions on the removal, preconcentration and determination of the investigated metal ions were described. The metal-chelates formed between the ion exchanger and the studied metal ions were characterized by IR (absorption and reflectance), UV spectrometry, potentiometric titration and thermal analysis (TG and DTG). The reliability of the present method was confirmed by the comparison with a standard solvent extraction method. The present method is simple and rapidly applicable for the determination of the studied metal ions, ng ml− 1 in different natural water samples.  相似文献   
80.
黄宪升  白晓琳  吴昊 《辽宁化工》2010,39(10):1027-1029
采用絮凝法降低炼油厂循环水中油含量。分别选取聚合氯化铝、聚合硫酸铁等单一絮凝剂和自制复合絮凝剂,研究各种絮凝剂除油效果。通过对絮凝剂加入量的改变,观察其絮凝状况及除油效果,筛选出除油效果最佳的絮凝剂。试验结果表明常规无机絮凝剂与自制接枝淀粉复配其除油效果最佳,除油效率可达80%以上。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号