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991.
Role of carbonate phase in ceria–carbonate composite for low temperature solid oxide fuel cells: A review 下载免费PDF全文
Ceria–salt composites represent one type of promising electrolyte candidates for low temperature solid oxide fuel cells (LT‐SOFCs), in which ceria–carbonate attracts particular attention because of its impressive ionic conductivity and unique hybrid ionic conduction behavior compared with the commonly used single‐phase electrolyte materials. It has been demonstrated that the introduction of carbonate in these new ceria‐based composite materials initiates multi new functionalities over single‐phase oxide, which therefore needs a comprehensive understanding and review focus. In this review, the roles of carbonate in the ceria–carbonate composites and composite electrolyte‐based LT‐SOFCs are analyzed from the aspects of sintering aid, electrolyte densification reagent, electrolyte/electrode interfacial ‘glue’ and sources of super oxygen ionic and proton conduction, as well as the oxygen reduction reaction promoter for the first time. This summary remarks the significance of carbonate in the ceria–carbonate composites for low temperature, 300–600 °C, SOFCs and related highly efficient energy conversion applications. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
992.
993.
994.
G.V.V. SURYA KIRAN K. HARI KRISHNA Sk. SAMEER M. BHARGAVI B. SANTOSH KUMAR G. MOHANA RAO Y. NAIDUBABU RAVIKUMAR DUMPALA B. RATNA SUNIL 《中国有色金属学会会刊》2017,27(4):804-811
AZ91 Mg alloy was considered and friction stir processing (FSP) was adopted to achieve grain refinement to investigate the effect of grain size and secondary phase on machining characteristics during drilling at various speeds and feeds. Super saturated AZ91 Mg alloy was obtained after FSP and the grain refinement was achieved from (166.5±8.7) µm to (21.7±13.5) µm. Surprisingly, hardness reduced for FSP AZ91 Mg alloy (88.95±6.1) compared with AZ91 alloy (108.2±15.6), which was attributed to the reduced secondary phase. However, the mean cutting force for FSP-treated (FSPed) AZ91 Mg alloy was marginally increased. The edge damage of the drilled holes was lower for FSPed AZ91 Mg alloy compared with unprocessed AZ91 Mg alloy. Hence, it can be understood that the grain refinement may slightly increase the cutting forces during drilling but better edge finishing can be achieved in machining of AZ91 Mg alloy. 相似文献
995.
AbstractMagnesium dititanate (MgTi2O5, MT2) has been synthesized since the early 1930s. It has the pseudobrookite structure (general formula Me3O5), corresponding to the Mg-enriched artificial endmember of the Fe2TiO5 (pseudobrookite)–FeTi2O5 (ferropseudobrookite)–Mg0.5Fe0.5Ti2O5 (armalcolite) solid solution. Since MgTi2O5 has relativity high thermal stability among pseudobrookite-type phases, it is expected to be a well-balanced low-thermal-expansion material. Here we review both the historical and recent studies on MgTi2O5, particularly on its crystal structure, cation order–disorder, physical properties and synthesis methods. 相似文献
996.
A Mg-Y-Ca-Ce magnesium alloy was optimized for high ignition-proof property, which did not burn in air at 1233 K up to 30 min. Oxidation behavior of the alloy was investigated by X-ray diffraction (XRD... 相似文献
997.
998.
Seong-Cheol Jang Byung Yong Lee Suk Woo Nam Hyung Chul Ham Jonghee Han Sung Pil Yoon Seong-Geun Oh 《International Journal of Hydrogen Energy》2014
Lump-free Ni-5 wt% Al alloy powder was successfully prepared using an AlCl3 activator at 400 °C under vacuum. The AlCl3 activator served as the catalyst, lowering the fabrication temperature by 1000 °C compared with the temperature required for the conventional process. The Ni–Al alloy was formed by the following steps: the formation of NiAl by the reaction of the Ni surface with AlCl2 or AlCl produced by the reaction between Al and AlCl3, the formation of Ni3Al by Al diffusion and reaction, and the formation of a Ni–Al solid solution by Al diffusion into the Ni matrix until the solubility limitation was reached. Although lowering the alloying temperature lengthens the reaction time, the time could be reduced by controlling the amount of AlCl3. A single cell test and a creep test were also conducted using a green sheet of as-prepared Ni–Al alloy powder as an anode of a molten carbonate fuel cell (MCFC). 相似文献
999.
Lucas E. Wilson 《仪器科学与技术》2013,41(5):457-467
Located at high elevation sites in the Southern Appalachians, the Fraser fir (Abies fraseri) has suffered visible decline in recent years. This study involved the measurement of concentration levels of aluminum, calcium, and magnesium by inductively coupled plasma optical emission spectrometry to determine the contribution of acidic deposition to this decline. Calcium and magnesium are nutrients, and hence one would anticipate relatively high foliar concentrations of these elements in the absence of pollution. Conversely, aluminum is toxic to the trees, and one would expect higher foliar concentrations in polluted locations. Statistical comparisons of the metal concentrations did not demonstrate a causal relationship between the location or elevation of Fraser fir stands. However, compared to previous studies, the foliar concentrations of calcium and magnesium were higher than concentrations previously reported in the 1990s, suggesting pollution controls may have reduced atmospheric deposition. 相似文献
1000.
Jie Song Shou-Mei Xiong Mei Li John Allison 《Materials Science and Engineering: A》2009,520(1-2):197-201
In situ observation of HPDC AM50 alloy in the SEM chamber was performed to study the changes of the micro-voids and the β phase during tensile deformation. The results suggested that micro-voids had little change in the elastic region, opened linearly with increasing load in the plastic region and led to final fracture. The detachment of β phase from the interface was also observed in the plastic region and there was no evidence to suggest that the detachment led to the final fracture. 相似文献