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71.
Berger Ralf G. Drawert Friedrich Kollmannsberger Hubert 《European Food Research and Technology》1989,188(2):122-126
European Food Research and Technology - The volatile constituents of cape gooseberry (Physalis peruviana L.) were characterized using liquid/liquid extraction and fractionation of the flavour... 相似文献
72.
73.
El Mahdi Halim Hubert Perrot Ozlem Sel Catherine Debiemme-Chouvy Khalid Lafdi Mama El Rhazi 《International Journal of Hydrogen Energy》2021,46(38):19926-19938
The development of highly efficient catalysts using inexpensive and earth-abundant metals is a crucial factor in a large-scale commercialization of direct methanol fuel cells (DMFCs). In this study, we explored a new catalyst based on copper nanodendrites (CuNDs) supported on carbon nanofibers/poly (para-phenylenediamine) (CNF/PpPD) nanocomposite for methanol oxidation reaction (MOR). The catalyst support was prepared on a carbon paste electrode by electropolymerization of para-phenylenediamine monomer on a drop-cast carbon nanofibers network. Afterwards, CuNDs were electrodeposited on the nanocomposite through a potentiostatic method. The morphology and the structure of the prepared nanomaterials were characterized by transmission electron microscope, scanning electron microscope, energy dispersive X-ray, X-ray diffraction, and X-ray photoelectron spectroscope. The results suggested that a three-dimensional nanodendritic structure consisting of Cu2O and Cu(OH)2 formed on the hybrid CNF/PpPD nanocomposite. The catalytic performance of CuNDs supported on CNF, PpPD and CNF/PpPD was evaluated for MOR under alkaline conditions. The CNF/PpPD/CuNDs exhibits a highest activity (50 mA cm?2) and stability toward MOR over 6 h, with respect to CNF/CuNDs (40 mA cm?2) and PpPD/CuNDs (36 mA cm?2). This inexpensive catalyst with high catalytic activity and stability is a promising anode catalyst for alkaline DMFC applications. 相似文献
74.
Complex dewetting scenarios captured by thin-film models 总被引:1,自引:0,他引:1
In the course of miniaturization of electronic and microfluidic devices, reliable predictions of the stability of ultrathin films have a strategic role for design purposes. Consequently, efficient computational techniques that allow for a direct comparison with experiment become increasingly important. Here we demonstrate, for the first time, that the full complex spatial and temporal evolution of the rupture of ultrathin films can be modelled in quantitative agreement with experiment. We accomplish this by combining highly controlled experiments on different film-rupture patterns with computer simulations using novel numerical schemes for thin-film equations. For the quantitative comparison of the pattern evolution in both experiment and simulation we introduce a novel pattern analysis method based on Minkowski measures. Our results are fundamental for the development of efficient tools capable of describing essential aspects of thin-film flow in technical systems. 相似文献
75.
D. Hariskos B. Fuchs R. Menner N. Naghavi C. Hubert D. Lincot M. Powalla 《Progress in Photovoltaics: Research and Applications》2009,17(7):479-488
A ZnS/Zn1‐xMgxO buffer combination was developed to replace the CdS/i‐ZnO layers in in‐line co‐evaporated Cu(In,Ga)Se2(CIGS)‐based solar cells. The ZnS was deposited by the chemical bath deposition (CBD) technique and the Zn1‐xMgxO layer by RF magnetron sputtering from ceramic targets. The [Mg]/([Mg] + [Zn]) ratio in the target was varied between x = 0·0 and 0·4. The composition, the crystal structure, and the optical properties of the resulting layers were analyzed. Small laboratory cells and 10 × 10 cm2 modules were realized with high reproducibility and enhanced stability. The transmission is improved in the wavelength region between 330 and 550 nm for the ZnS/Zn1‐xMgxO layers. Therefore, a large gain in the short‐circuit current density up to 12% was obtained, which resulted in higher conversion efficiencies up to 9% relative as compared to cells with the CdS/i‐ZnO buffer system. Peak efficiencies of 18% with small laboratory cells and 15·2% with 10 × 10 cm2 mini‐modules were demonstrated. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
76.
To avoid plasma induced erosion of chamber hardware, the application of remote plasma sources to activate the etch gases was introduced. We present results on the etch behaviour of titanium nitride (TiN) using mixtures of NF3, Cl2 and argon. The gas mixture was excited in a remote plasma source and then routed through a reaction chamber to study the etch behaviour of TiN samples which simulate the situation at the chamber walls. The dependency of the TiN etch rate on temperature, gas flow, composition and pressure was examined. While the temperature (studied in the range 25-300 °C) turned out to be the most sensitive parameter, the general etch rate was mainly dependent on the availability of atomic fluorine. Etch products and NF3/Cl2 dissociation have been monitored by quadrupole mass spectrometry and infrared spectroscopy. While NF3 showed a high decomposition up to 96%, chlorine decomposition was not observed. However the addition of chlorine increased the etch rates up to 260% in the low pressure/low temperature regime. Surface effects of chlorine addition are indicated by X-Ray Photoelectron Spectrometry and REM surface analysis. 相似文献
77.
Hubert Laitko 《NTM》1999,7(1):118-119
Ohne Zusammenfassung 相似文献
78.
L. A. J. Garvie H. Hubert P. Rez P. F. McMillan P. R. Buseck 《Journal of Alloys and Compounds》1999,290(1-2)
Hexagonal boron nitride (hex BN) containing significant amounts of C and O substituting for N (hex BCNO) was synthesized at 75 kbar and 1700°C from mixtures of C, B2O3, and amorphous B contained in a hex BN crucible. Hex BCNO is a minor constituent of the product and occurs as small, <30 nm diameter, rounded pseudohexagonal particles adhering to materials with the α-rhombohedral B structure. Electron energy-loss spectroscopy with a transmission electron microscope was used to quantify their elemental ratios. Up to 50% of the N in hex BN is replaced by C and O, e.g., BN0.49O0.38C0.11. The electron energy-loss near-edge fine structure of the core-loss edges was used to elucidate the possible structures of hex BCNO. The core-loss edges of B, C, N, and O exhibit orientation-dependent intensity changes, which indicates that they occupy similar anisotropic bonding sites in graphite-like BCNO layers. For a composition of BN0.5O0.4C0.1, regions with B–N3, B–N2O, and B–NO2 units predominate. In addition, some grains have significant quantities of B–O3 and B–C3 units. Boron–boron bonding is either absent or infrequent. 相似文献
79.
Yang K. Marshall T. Forman M. Hubert J. Mirth L. Popovic Z. Katehi L.P.B. Whitaker J.F. 《Microwave Theory and Techniques》2001,49(5):849-857
Several Ka-band spatial-amplifier power combiners and their free-space feeds were characterized using a high-resolution extreme-near-field electrooptic measurement technique. The two-dimensional electric-field amplitude and phase maps obtained from several arrays are presented. The usefulness of the technique for diagnostic purposes during the design and prototyping stages of the active arrays is discussed. In particular, the electrooptic maps were shown to be valuable for making improvements in the bias line design in one case, and for isolating faulty unit cells in another case 相似文献
80.