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1.
In this work three H2S scavengers were prepared by reacting monoethanolamine with formaldehyde in different ratios (1:1, 2:1 and 2:3) to give MF1, MF2 and MF3, respectively. The chemical structures of the prepared scavengers were confirmed by FT-IR spectroscopy. The effect of reaction time (the time required for completing the reaction between the scavenger and the H2S gas) has been studied for the three prepared scavengers. The effects of concentration and temperature have been studied on the scavenging efficiency of H2S using three prepared products and two commercial products EPRI-710 and EPRI-730. The surface and thermodynamic parameters of the prepared scavengers were determined at 25 °C including, surface tension (γ), and effectiveness, maximum surface excess (Γmax) and minimum surface area (Amin). Also, the standard free energy of micellization and adsorption was recorded. The results show that the efficiency of scavengers increased with increasing reaction time up to 50 min. Also, as concentration of scavengers and temperature increased, the removal efficiency of the scavengers increased. By comparing the efficiency of the prepared products with the commercial products EPRI-710 and EPRI 730, it was found that, MF3 exhibited a similar efficiency comparing with the commercial scavenger EPRI 730 (currently used in the field) at different concentrations and temperatures.  相似文献   
2.
The long term variation of the mean dose due to natural radiation in Japan received by an individual person was investigated. The mean exposure rate in each prefecture obtained by in-situ measurements was adopted as a basis of the radiation level. Population data were taken from both the resident registration and the census taking into account the essential difference of their meanings. It was revealed that the per capita dose due to outdoor natural radiaiton in Japan has been decreasing in the last approximate 30 yr. It will be due to the population movement from countrysides towards urban areas. That is because countrysides generally consist of stable mountainlands where granitic rocks distribute though urban areas generally consist of alluvial plains where volcanic ash or humus dominates. Although the contribution of low radiation level (below 9.0μR/h) areas to the nation-wide collective dose still remains under 50%, its relative importance has certainly been increasing in the last three decades. It is expected that human population will be the dominating factor which eventually controls the mean dose due to natural radiation in Japan.  相似文献   
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4.
高LET的7Li离子致DNA损伤的直接和间接作用研究   总被引:1,自引:0,他引:1  
在HI-13串列加速器加速的具有高LET值的7Li离子辐照不同浓度的pUC19质粒DNA水溶液、加自由基清除剂(甘露醇)的DNA水溶液以及干状DNA样品,利用高分辨的原子力显微镜技术,研究7Li致DNA损伤的直接作用和间接作用.结果显示,在相同剂量下,7Li离子比低LET辐射能诱发更多的双链断裂,形成更多的集团损伤,使DSB的分布更局部和更密集.对于水溶液DNA,7Li离子的水辐解产生的自由基的间接作用在DNA分子链断裂的产生方面发挥着重要作用,而且自由基清除剂甘露醇能有效地保护DNA分子.  相似文献   
5.
Radical scavenger, radical anion scavenger, and peroxide decomposer were added to aromatic hydrocarbons and phosphates in aromatic rings with and without side chain, and the effect of these inhibitors on tribopolymerisation and the lubrication characteristics of the aromatic compounds were investigated, in various atmospheres, in order to clarify the reaction mechanism. The aromatics of both hydrocarbons and phosphates with a methyl group in aromatic rings react readily at the rubbing surfaces to form polymer or polymer-like products, improving the lubricating characteristics. The tribochemical reactions of alkylaromatic compounds is shown to differ from those of trialkyl or triarylphosphates. It was concluded that the reaction proceeds through the radical or radicalanion and via peroxide to cause polymerisation.  相似文献   
6.
酚型抗氧剂和胺型抗氧剂作为自由基捕捉剂型抗氧剂,已被广泛地应用于各类润滑油中。分析研究了自由基捕捉剂型抗氧剂的作用机理,对于有效地改善润滑油的氧化安定性能、延长润滑油的使用寿命以及研制新型润滑油抗氧剂具有重要意义。  相似文献   
7.
在BL-甲醛消除剂A中加入一定量的分子筛和光触媒后,可制成新型甲醛消除剂B。研究结果表明:胶合板表面经甲醛消除剂B处理后,其甲醛释放量明显降低;当甲醛消除剂B的双面喷涂量为1.2~3.5 g/m2时,胶合板的甲醛消除率为73.5%~98.7%,其再胶接强度基本不变,并且其甲醛消除持久性较长(60 d内甲醛消除率仍不低于86.7%)。  相似文献   
8.
对表面活性剂和硫化物去除剂协同处理含硫化亚铁颗粒污油的可行性进行了研究。通过将污油混入游离水脱除器进液中,并在游离水脱除器和电脱水器进液中分别投加0·012kg/m3污油破乳剂和0·607kg/m3硫化物去除剂,回收处理了2150m3大庆油田北二联合站内的含硫化亚铁颗粒污油,污油回收处理过程中的药剂费用为61·40元/m3。  相似文献   
9.
钻井液中在循环过程中,有大量氧气溶解其中,溶解氧对钻具产生腐蚀。通过大量实验,室内研制出新型钻井液用除氧剂。在静态和动态的条件下,对不同的除氧剂浓度下除氧效率100%所需时间和溶氧浓度0.1 mg/L的持续时间进行测试实验,并根据现场实际工况制作出模拟井筒实验装置,进行除氧评价实验。最终确定此除氧剂具有除氧效率高、作用时间长、配伍性好等特点。  相似文献   
10.
Lu RL  Hu FL  Xia T 《Journal of food science》2010,75(8):H239-H243
Gao-Cha is a traditional Chinese health tea made from Acer ginnala. We performed a components and radical scavenging activity analysis to identify any medicinal components in this tea. High performance thin layer chromatography (HPTLC)-1,1-Diphenyl-2-picryhydrazyl (HPTLC-DPPH) assay showed that the methanolic extract contained strong radical scavengers. Quantitative analysis revealed that the IC(50) of the extract against 1 mM DPPH was 52.7 ± 0.6 μg/mL. Bioactive-guided isolations led to procurement of 3 radical scavengers with IC(50)s of 17.5 ± 2.1, 29.3 ± 2.5, and 21.6 ± 1.7 μg/mL, respectively. Analysis of the high resolution-electric spray ionization-mass spectrometer and (1)H, (13)C, distortionless enhancement by polarization transfer at 135°, heteronuclear quantum coherence, correlating spectroscopy coupling, and heteronuclear multiple bond coherence (HMBC) data revealed that the compounds were methyl 3, 4, 5-trihydroxybenzoate (1), quercetin-3-O-α-rhamnopyranoside (2), and 2,6-bis (3,4,5-trihydroxybenzoyl)-aceritol (3). Bioactive combined components analysis revealed that, apart from compounds 1, 2, and 3, the tea possibly contained radical scavengers: ginnalin A (4) and B (5), 2″-O-Galloylquercitrin (6) and 3″-O-Galloyl-quercitrin (7). Compounds 2, 6, and 7 were isolated from Acer ginnala for the first time. The positions of the 2 galloyl moieties in compound 3 were unambiguously established by the HMBC spectrum for the first time.  相似文献   
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