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排序方式: 共有4743条查询结果,搜索用时 15 毫秒
41.
介绍了混炼硅橡胶的基本配合过程和硫化体系,着重比较了间歇法和连续法两种混炼工艺的生产效率及对硅橡胶硫化胶性能的影响,讨论了6种过氧化物硫化剂的特点及适应范围。 相似文献
42.
The effect of pH on the decomposition of peracetic acid in an aqueous solution was studied. It was found that three potential reactions, namely i) the spontaneous decomposition, ii) the hydrolysis and iii) the transition metal catalysed decomposition, are responsible for the consumption of peracetic acid. The spontaneous decomposition reaches its maximum at pH 8.2, while both the hydrolysis and metal ion catalysed decomposition increase as the pH increases. At pH 10.5 and higher, the hydrolysis becomes dominant when the metal ion catalysed decomposition is minimized by the addition of DTMPA. The kinetics of the peracetic acid hydrolysis was developed, which can very well predict the development of peracetic acid and hydrogen peroxide during the decomposition reaction. 相似文献
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J. F. Toro-Vazquez Alejandro Rocha-Uribe 《Journal of the American Oil Chemists' Society》1993,70(6):589-594
The adsorption of peroxides, unsaturated carbonyls, free fatty acids and carotenoids from unrefined sesame oil on vegetable
carbon (5%, w/w) in a miscella system was studied. Three different solvent conditions (hexane/ethanol, 100:0, 95:5 and 75:25,
vol/vol), combined in a factorial design with five levels of solvent (0, 10, 20, 30 and 40%, w/w), were used to develop the
miscella. Equilibrium adsorption was not achieved during the 100 min of adsorption, mainly because the oil components were
involved in oxidation reactions during the adsorption process. However, for a given solvent concentration, adsorption of the
oil components showed a significant linear regression on their respective initial concentration in the miscella (Ci). Peroxides and carbonyls showed, at all solvent levels investigated, an affinity for the carbon more independent of their
Ci than free fatty acids and carotenoids. In general, at the same Ci, a higher adsorption was achieved as solvent concentration increased. The results indicated that free fatty acid adsorption
may depend on competitive adsorption based on molecule hydrophobicity. However, in spite of the higher hydrophobicity of carotenoids,
compared with free fatty acids, they might not be competing for the same adsorbing sites. Ethanol showed a prooxidant effect
that increased peroxide production during adsorption but did not affect the reaction involved in carbonyl production. 相似文献
45.
46.
J.L. Rodríguez E. Pastor C.F. Zinola V.M. Schmidt 《Journal of Applied Electrochemistry》2006,36(11):1271-1279
The influence of hydrogen peroxide on the adsorption and oxidation of carbon monoxide, methanol and ethanol adlayers on porous Pt electrodes were studied in 2 M sulphuric acid solution by means of cyclic voltammetry and differential electrochemical mass spectrometry (DEMS). The oxidation of adsorbed species is observed at electrode potentials far less negative than those required for electrochemical adsorbate oxidation. The oxidation by H2O2 is dependent on its concentration in solution, as well as on the adsorbates and their coverages. In all cases the isolated adlayers are oxidised by dissolved H2O2. However, the presence of H2O2 during adsorption partially inhibits adlayer formation from CH3OH and C2H5OH, but avoids almost completely the adsorption of carbon monoxide. The removal of the residues from the surface by dissolved hydrogen peroxide probably occurs through Oad species formed during the heterogeneous decomposition reaction of H2O2 on Pt. 相似文献
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49.
G. R. Agladze G. S. Tsurtsumia B. -I. Jung J. -S. Kim G. Gorelishvili 《Journal of Applied Electrochemistry》2007,37(9):985-990
The technological and economic aspects of using the Fenton process to treat industrial wastewater containing morpholyne and
diethylethanolamine, as well as sodium salts of naphthalene sulfonic acid and of ethylenediaminetetraacetic acid based on
data obtained in pilot tests are discussed. Chemical Fenton technology was tested using commercial 30–35% solutions of H2O2 and iron (II) salts, which was followed by the additional electrochemical destruction of organic pollutants in an undivided
reactor with catalytic stable anodes (CSA) and 1 g L−1 NaCl as a supporting electrolyte and a source of active chlorine. An alternative electrochemical method involving the electrogeneration
of hydrogen peroxide in polluted water at the gas
-diffusion cathode was studied both with the addition of ferrous salt to the electrolyte prior to electrolysis (in-cell electro-Fenton)
as well as with the post-electrolysis addition of Fe2+ in another reactor (ex-cell electro-Fenton). The accumulation of hydrogen peroxide in concentrations sufficient for the mineralization
of organic pollutants was achieved in both cases with near 100% current efficiency. In comparison with wastewater treatment
processes which use a purchased hydrogen peroxide reagent, the Fenton-like processes achieved an economic savings of as much
as 64.5% in running costs due to the on-site electrochemical generation of H2O2. Preparative electrolysis in the membrane reactor showed higher current efficiencies and lower specific energy consumptions
for H2O2 electrogeneration in comparison with the results of tests carried out in an undivided cell. 相似文献
50.