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881.
It is pointed out that the citation to the work of the originators of the basic circuit investigated in a recent paper [1] published in this journal is missing. 相似文献
882.
Venkatesan T. Wu X. Inam A. Chang C.C. Hegde M.S. Dutta B. 《Quantum Electronics, IEEE Journal of》1989,25(11):2388-2393
High-T c superconducting thin films can be deposited and processed by pulsed and CW lasers, and a respectable materials technology for the Y-Ba-Cu-O superconductor is rapidly emerging. The pulsed laser deposition technique is simple because it produces films with compositions nearly identical to those of the target pellets. A larger variety of substrates can be used, compared to other deposition technologies, because of the relatively low temperature requirements. The laser deposition mechanism has been investigated. As-deposited superconducting films, epitaxial films with smooth surfaces, and multilayer structures with abrupt interfaces have been produced. The electrical transport properties can be changed locally using a focused argon-ion laser by modifying the oxygen stoichiometry. This laser writing can be erased by room-temperature exposure to an oxygen plasma. Other laser patterning methods such as material removal, melt-quench, and direct pattern transfer are being developed 相似文献
883.
The magnitude and delay responses of a multiplexed charge-transfer delay line are shown to be equal ripple. While the magnitude ripple decreases with increase in the number of parallel channels, the delay ripple is independent of this number and is determined only by the charge-transfer inefficiency. 相似文献
884.
Tushar Kanti Chakraborty N. V. Suresh Kumar Saumya Roy Samit Kumar Dutta Ajit Chand Kunwar Balasubramanian Sridhar Harjinder Singh 《Journal of Physical Organic Chemistry》2011,24(8):720-731
Structural and electronic properties of diastereomers of tetrahydrofuran amino acids (TAA) derived tripeptide, Boc‐TAA‐Leu‐Val‐OMe, are studied using density functional theory. Predicted secondary folding patterns with hydrogen bonded pseudocycles of different sizes in peptides containing (2R,5S)‐cis‐TAA and (2S,5R)‐cis‐TAA are confirmed by detailed NMR studies of both, and single crystal X‐ray analysis of the former. A novel unusual folding pattern emanating from three‐centered hydrogen bond is found in peptide with (2R,5S)‐cis relationship. Stereochemical control on the orientation of interacting sites is substantiated by structural analysis of the peptides. Using natural bonding orbital and atoms in molecules analyses, charge transfer interactions are analyzed. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
885.
Ayan Kar Michael A. Stroscio Mitra Dutta M. Meyyappan 《physica status solidi b》2011,248(12):2848-2852
Growth conditions leading to kinking and branching in SnO2 nanowires have been investigated. Lower temperature growth at 750 °C leads to Y‐junctions as seen previously in carbon nanotubes, whereas straight nanowires are obtained at 880 °C. Photoemission valence band spectroscopy is used to show that the carrier concentration and Fermi level position vary with diameter. Thus, the stem and branches in a Y‐junction can have completely different semiconducting properties, leading to opportunities in novel device construction. 相似文献
886.
Polycrystalline samples of [Pb0.92(La1–zGaz)0.08][Zr0.65Ti0.35]0.98O3 (PLGZT) for z = 0.0, 0.3, 0.6, 0.9, and 1.0 were prepared by a solid‐state reaction technique. The single‐phase formation of the new compounds with tetragonal crystal structures was established by the room‐temperature X‐ray analysis. The occupancy of Ga ion in the La site has been confirmed by FTIR analysis. Complex impedance spectroscopy (CIS) has provided a convincing evidence for the existence of both grain (bulk) and grain boundary effects in the materials, which is also evident from the microstructures, comprise grains separated by well‐defined boundaries. The electrical processes in the sample have been modeled in the form of an electrical equivalent circuit made up of a series combination of two parallel RC circuits attributed to grains and grain boundaries. The real and imaginary parts of dielectric constants have been separated from impedance spectrum results and expressed in terms of loss tangent (tan δ). The ferroelectric transition temperature (Tc) of the materials is evaluated from the plot of real permittivity versus temperature and found to be shifted to higher temperature side with increasing Ga‐ion concentration. A sharp rise in conductivity is observed in the nature of temperature variation of the bulk electrical conductivity (σdc) at higher temperature for all the Ga‐modified PLZT samples. This type of behavior is typical to dielectric ceramics having conductive grain boundary arising out of a relaxation process of the Maxwell–Wagner type. At higher temperature a substantial increase in conductivity ∼10–3 S cm–1 is achieved for complete replacement of the La ion by Ga (z = 1.0). (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
887.
888.
889.
The phase diagrams of the Si Sn and Ge Sn systems are investigated using the previous electronic theory based on pseudopotentials. The calculated results negate the presence of the Si1−xSnx and Ge1−xSnx solid solutions. The obtained curves near the melting point show reasonable agreement with experimental data. 相似文献
890.
Structural and electrical properties of crystalline Ge films deposited at 723 K on glass substratee and crystallized Ge films obtained by crystallizing the amorphous films by heating at 723 K ars investigated. The films are polycrystalline with small grain size (≈ 620 Å in crystalline films and ≈ 100 Å in crystallized films). Both the films show p-type behaviour. The observed temperature dependence of the carrier concentration is theoretically analyzed which shows the existence of an acceptor level at about 0.05 eV above the valence band. The mobility of charge carriers is analyzed in terms of various scattering mechanisms. Grain boundary scattering is found to be the dominant scattering mechanism in these films. The potential barrier associated with grain boundary scattering is calculated to be 1.0 × 10−2 eV in crystalline and 2 × 10−2 eV in crystallized films. 相似文献