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41.
Hydrogenation of four bituminous coals impregnated with 5 wt% of either mixtures of ZnCl2-MCln (CuCl, CrCl3 and MoCl5) systems or ZnCl2 was carried out using a batch autoclave system at 400° for 3 h at 9.8 MPa of initial hydrogen pressure. The ZnCl2-MoCl5 system showed the highest yield of the hexane-soluble (HS) fraction compared with the other systems irrespective of the coal used. The difference between the yields of HS fractions using the ZnCl2-MoCl5 and other systems was most marked for coals of fairly low volatile matter content, though the conversion was relatively low (47–66%), whilst for coals of high volatile matter content HS yields with the binary melt systems were high (86–91% conversion). Elemental analyses of the HS fractions indicated that the ZnCl2-MoCl5 system is most favourable in decreasing the average molecular weight and the heteroatom content of HS, this characteristic trend being confirmed also with five HS fractions separated by Chromatographic techniques. Both elemental analyses and molecular weights of asphaltene (benzene-soluble materials, BS) indicated that the ZnCl2-MoCl5 system is also most effective in cracking coal structure. 相似文献
42.
Analysis of the carbon disulphide extracts of nine samples of UK coal-maceral concentrates by 1H highresolution n.m.r. spectroscopy, gas-liquid chromatography and field-desorption mass spectrometry indicates the presence of components with a wide molecular weight range extending up to 1200 amu; these are attributed to n-alkanes up to ≈C50 and highly condensed polynuclear aromatic compounds. 相似文献
43.
44.
David Merrick 《Fuel》1983,62(5):567-570
A mathematical model to predict the strength of a coke manufactured from a blend of coals is proposed. The model operates in terms of ‘bond strengths’ between the constituents. The magnitudes of these bond strengths may be determined from the strengths of cokes manufactured from the individual constituents and from a limited number of binary blends. The model has been applied to predictions of the M10 index of coke strength for binary and ternary blends, and the predictions are in reasonable agreement with the experimental data. In particular, the model is able to account for the behaviour of incompatible coals and bridging coals in blends. 相似文献
45.
The work reported here represents initial attempts to develop a complete kinetic and mechanistic understanding of the reaction chemistry of H2S under coal liquefaction conditions, using both model systems and coal. Hydrogen sulphide was found to promote/catalyse the transfer of hydrogen from tetralin to 2-hydroxyquinoline (2-HOQ). The presence of H2S can increase the rate of hydrogen transfer from tetralin to 2-HOQ by a factor of 10 compared with the same reaction run in the absence of H2S. The energy of activation for hydrogen transfer was found to decrease by ≈5 kcal mol−1 in the presence of H2S. The presence of H2S was also found to promote loss of oxygen from 2-HOQ to form small amounts of quinoline. No evidence of CC or CN bond cleavage in 2-HOQ was noted under any of the reaction conditions studied. These results suggest that the presence of H2S reduces the temperatures necessary to promote effective hydrogen transfer from tetralin by 50–75 °C. Moreover, they imply that similar effects occur in H2S-promoted coal liquefaction. 相似文献
46.
煤岩配煤技术的发展与现状 总被引:3,自引:0,他引:3
煤岩学在炼焦配煤技术上的应用,使炼焦配煤手段更有效,使焦炭质量预测在生产上应用成为可能,为定性的经验配煤技术跃变到定量的科学配煤技术创造了条件。夏皮洛煤岩配煤技术是目前较好的配煤方法,其相关系数可达0.93;国内许多学者在煤岩配煤方面也做了大量研究工作,有些相关系数达0.98。目前虽然各种方法存在一定局限性,但随着计算机和图像处理技术的发展,煤岩学在指导配煤技术方面将有新的突破。 相似文献
47.
David Merrick 《Fuel》1983,62(5):547-552
Mathematical models are proposed to predict the true density of coal, semi-coke and coke and the porosity of a coke oven charge during carbonization. These models are combined in a further model which predicts the hitherto unexplained ‘twin-peaked’ contraction curve observed for semi-coke. It is found that the first contraction peak results from the relatively high rate of mass loss occurring towards the end of the primary devolatilization stage. The second peak occurs because of the increase in true density arising from the elimination of hydrogen from the semi-coke. 相似文献
48.
Philip L. Walker Shiro Matsumoto Tamotsu Hanzawa Takatoshi Muira Ismail M.K. Ismail 《Fuel》1983,62(2):140-149
Calcium is the most important in-situ catalyst for gasification of US coal chars in O2, CO2 and H2O. It is a poor catalyst for gasification of chars by H2. Potassium and sodium added to low-rank coals by ion exchange and high-rank coals by impregnation are excellent catalysts for char gasification in O2, CO2 and H2O. Carbon monoxide inhibits catalysis of the CH2O reaction by calcium, potassium and sodium; H2 inhibits catalysis by calcium. Thus injection of synthesis gas into the gasifier will inhibit the CH2O reaction. Iron is not an important catalyst for the gasification of chars in O2, CO2 and H2O, because it is invariably in the oxidized state. Carbon monoxide disproportionates to deposit carbon from a dry synthesis gas mixture (3 vol H2 + 1 vol CO) over potassium-, sodium- and iron-loaded lignite char and a raw bituminous coal char, high in pyrite, at 1123 K and 0.1 MPa pressure. The carbon is highly reactive, with the injection of 2.7 kPa H2O to the synthesis gas resulting in net carbon gasification. The effect of traces of sulphur in the gas stream on catalysis of gasification or carbon-forming reactions by calcium, potassium, or sodium is not well understood at present. Traces of sulphur do, however, inhibit catalysis by iron. 相似文献
49.
关于煤化工前途的思考 总被引:3,自引:0,他引:3
对煤化工存在的问题做了分析,提出加大科研投入,获取自主知识产权,解决煤化工装置大型化、国产化,坑口气化,煤层气开发利用等煤化工重点问题,适合我国国情的煤化工将有良好的发展前景。 相似文献
50.