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151.
Sorption of aniline by montmorillonite was studied by infra-red, X-ray diffraction and differential thermal analysis methods. The amount of aniline sorbed and the type of bonding depend upon the interlayer cations: anilinium, H+- and Al3+- give anilinium aniline ions, NH44-ammonium aniline ions, alkalis and alkaline earths except Cs are bonded to aniline through water bridges and transition metal cations are coordinated to aniline partly directly and partly through water bridges. Sorption does not occur in the complete absence of water. 相似文献
152.
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154.
A comparative investigation on the wettability and tensile strength of a Sn–2Ag, a Sn–40Bi and the traditional eutectic Sn–Pb solder alloys was carried out. The wettability is represented by thickness of covered layer (TCL) and spread area (SA) while the mechanical behaviour by the ultimate tensile strength (UTS). It is shown that the TCL of studied alloys decreased with the increase in the dipping temperature. It is also shown that TCL and SA have opposite behaviour with respect to the cooling rate. The Sn–Bi solder alloy has lower SA when compared with those of the Sn–Ag solder when similar cooling rates are considered. The Sn–Bi solder exhibits the best UTS/SA combination for dendritic spacings between 25 and 27?µm, associated with cooling rates ~2°C?s?1, 2× lower than those of the Sn–Ag alloy. Besides, the Sn–Bi alloy has shown SA >70~80% associated with higher UTS (~80?MPa) as compared with the other alloys examined. 相似文献
155.
Pang L. Zhang Z. W. Zhao Y. Huang S. Q. Hu Q. R. Zhao J. J. Yang K. Sun S. H. 《Combustion, Explosion, and Shock Waves》2021,57(5):597-606
Combustion, Explosion, and Shock Waves - Explosion venting experiments of corn starch are carried out in a small-scale container. With the help of a high-speed camera and a pressure sensor, an... 相似文献
156.
Incontinentia pigmenti is an uncommon genodermatosis that occurs in female infants. The characteristic dental defects are partial anodontia and the presence of some peg-shaped teeth. This report describes a patient with incontinentia pigmenti who exhibited multiple missing teeth in both arches. The patient had malpositioned teeth and decreased occlusal vertical dimension associated with the missing teeth. Orthodontic treatment was required for prosthetic purposes. The dental anomalies of incontinentia pigmenti and the treatment procedure are presented. 相似文献
157.
Edwin Yesid Gómez-Pachón Francisco Manuel Sánchez-Arévalo Federico J. Sabina Alfredo Maciel-Cerda Raúl Montiel Campos Nikola Batina Israel Morales-Reyes Ricardo Vera-Graziano 《Journal of Materials Science》2013,48(23):8308-8319
The aim of this study is to predict the elastic response of poly(lactic acid) (PLA) electrospun nanofibre scaffolds through mathematical models based on homogenisation and the differential replacement method (DRM). These models principally seek to determine and analyse the effects of the internal morphology of the nanofibres on the effective Young’s modulus of polymer nanofibre scaffolds. The microstructure of the nanofibres was first characterised by SEM, XRD, DSC, AFM, and TEM techniques. From this characterisation, strong evidence of a hierarchical core–shell structure was found. With the experimental data, it was possible to design and validate better models than those currently used. In addition, the effects of the electrospinning parameters, such as take-up velocity and thermal treatment, were analysed and correlated with the morphology and the elastic properties of the nanofibres and their scaffolds. To validate the models’ results, we conducted a series of uniaxial tensile tests on the PLA nanofibre scaffolds. Using the data from the nanofibre measurements, the homogenisation approximations and the model based on the DRM predicted an effective Young’s modulus of 667 and 835 MPa, respectively. The predicted data were in excellent agreement with the experimental results (685–880 MPa). These models will be useful in understanding and evaluating the structure–property relationships of oriented nanofibre scaffolds for medical or biological applications. 相似文献
158.
The regulation of would healing is one of the most important fields of research in ophthalmology today. Rabbit corneal fibroblast cultures were used to study the effects of interleukin-1 (IL-1) blockers on the proliferation of fibroblasts which is closely related to the wound healing. It was found that IL-1 blockers, such as CK-17, CK-101A, CK-2 and CK-103A, suppress fibroblast proliferation in a concentration-dependent manner. DNA synthesis was significantly inhibited by CK-17 and CK-103A but not by CK-101A and CK1-102. Although the synthesis of mRNA was reduced by all CK-compounds at most concentration tested, the synthesis of protein was only slightly reduced or unaffected. These results indicate that CK-compounds are potent fibroblast inhibitors but not cytolytic agents. 相似文献
159.
Nuno M. Garrido Ioannis G. Economou António J. Queimada Miguel Jorge Eugénia A. Macedo 《American Institute of Chemical Engineers》2012,58(6):1929-1938
In recent years molecular simulation has emerged as a useful tool to predict physical properties of complex chemical systems. A methodology to estimate the n‐hexane/water and 1‐octanol/water partition coefficients of environmentally relevant solutes, namely substituted alkyl‐aromatic molecules, chlorobenzenes, polychlorinated biphenyls (PCBs) and polychlorinated diphenyl ethers (PCDEs) using molecular simulation is elucidated here. The partition coefficients are calculated based on the absolute solvation Gibbs energies in each phase which are estimated from molecular dynamics simulations employing the thermodynamic integration approach. Very encouraging results, with average absolute deviations of 0.4 log P units are presented. Consequently, this molecular‐based approach with a strong physical background can provide reliable prediction of the partition coefficients in different solvent pairs without the a priori knowledge of experimental data. © 2011 American Institute of Chemical Engineers AIChE J, 58: 1929–1938, 2012 相似文献
160.
A. N. Tynnyi Z. A. Bazilevich S. I. Mikitishin Ya. I. Lavrentovich G. V. Karpenko 《Materials Science》1972,5(3):242-244
Time-to-rupture and creep of polymethyl methacrylate (PMM) under the combined influence of stress, active liquid media, and -radiation were studied. It was shown that time-to-rupture of PMM under these conditions is determined mainly by the influence of the working medium when the absorbed radiation dose is less than about 10 Mrads and that -radiation increases the creep rate of PMM in active liquid media. 相似文献