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991.
The effect of metal-to-oxide grain boundary layer in $ {\text{Ni}} - {\text{BaCe}}_{{0.8}} {\text{Y}}_{{0.2}} {\text{O}}_{{3 - \delta }} $ (BCY) cermet membrane on hydrogen permeation was studied by applying the different size of oxide grain on Ni-BCY membranes. Two types of cermet membranes having different grain size of oxide were prepared by using different starting particle size of oxide powder. The hydrogen flux of coarse-oxide-grain membrane showed higher flux than that of small-oxide-grain membrane. It was understood that the negative potential at metal-to-oxide grain boundary, reference to the bulk oxide ( $ \phi _{0} < \phi _{\infty } = 0 $ ), was developed, and the accumulation of the effectively positively charged protons may occur at the grain boundary layer (space charge layer), which may result in providing highly conductive proton path by shifting the charge neutrality condition from $ {\left[ {OH^{ \bullet }_{O} } \right]} = {\left[ {Y^{/}_{{Ce}} } \right]} $ to $ {\left[ {OH^{ \bullet }_{O} } \right]} = n $ .  相似文献   
992.
Zn–Sn–O (ZTO) thin film transistors (TFTs) were fabricated with a Cu source/drain electrode. Although a reasonably high mobility (μFE) of 13.2 cm2/Vs was obtained for the ZTO TFTs, the subthreshold gate swing (SS) and threshold voltage (Vth) of 1.1 V/decade and 9.1 V, respectively, were inferior. However, ZTO TFTs with Ta film inserted as a diffusion barrier, exhibited improved SS and Vth values of 0.48 V/decade and 3.0 V, respectively as well as a high μFE value of 18.7 cm2/Vs. The improvement in the Ta‐inserted device was attributed to the suppression of Cu lateral diffusion into the ZTO channel region. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   
993.
Park J  Kim Y 《The Analyst》2012,137(14):3246-3248
A new colorimetric molecular probe based on a 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) dye selectively binds Pb(II) ions in aqueous solutions, allowing for highly sensitive naked-eye detection.  相似文献   
994.
Reductive coupling of 1-chloro-2-iodoperfluorocyclobutene (I), cyclopentene (III) and cyclohexene (VI) has been carried out with copper powder and a trace amount of dimethylformamide to give the corresponding 2,2′-dichloroperfluoro-(bi-1-cycloalken-1-yl) derivatives in 69%, 36% and 73% yield, respectively. A reduced by-product, 2H,2′H-dodecafluoro-(bi-1-cyclopenten-1-yl) was also obtained in the copper coupling of (III). Coupling of 1,2-di-iodoperfluorocyclobutene (IX) and cyclopentene (XII) under similar conditions gave good yields of cyclic trimers and tetramers. Mass spectra, infrared and 19F NMR data are discussed.  相似文献   
995.
Backbone–backbone hydrogen bonds (BBHBs) are one of the most abundant interactions at the interface of protein–protein complex. Here, we propose an angle‐dependent potential energy function for BBHB based on density functional theory (DFT) calculations and the operation of a genetic algorithm to find the optimal parameters in the potential energy function. The angular part of the energy funtion is assumed to be the product of the power series of sine and cosine functions with respect to the two angles associated with BBHB. Two radial functions are taken into account in this study: Morse and Leonard‐Jones 12‐10 potential functions. Of these two functions under consideration, the former is found to be more accurate than the latter in terms of predicting the binding energies obtained from DFT calculations. The new HB potential function also compares well with the knowledge‐based potential derived by applying Boltzmann statistics for a variety of protein–protein complexes in protein data bank. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010  相似文献   
996.
The phase‐transfer catalyzed graft copolymerization of methyl methacrylate onto polychloroprene was carried out using tricaprylylmethylammonium chloride as a phase‐transfer catalyst in a two‐phase system of an aqueous Na2S2O8 solution and toluene at 55 °C under a nitrogen atmosphere. The initial rate of graft copolymerization was expressed as the combined terms of quaternary onium cation and peroxydisulfate anion in the aqueous phase rather than the fed concentrations of catalyst and Na2S2O8. The observed initial rate of graft copolymerization was used to analyze the graft copolymerization mechanism with a cycle phase‐transfer initiation step in the heterogeneous liquid–liquid system. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 3543–3549, 2000  相似文献   
997.
Plasmonic off axis beaming and focusing of light by the use of asymmetric or non-periodic dielectric gratings around a metallic slit are experimentally demonstrated. The far-field probing was done by holographic microscopy. While the conventional near-field microscopes can probe only near-fields, our four-step phase-shift interferometer provides an efficient way of probing and reconstructing light paths coming out from the plasmonic devices. We hope our experimental work contributes to the practical applications of plasmonics such as optical interconnection and optical data storage.   相似文献   
998.
Cross layer handover schemes are expected to provide seamless services to users on the move. To achieve this goal, a link layer must timely trigger handover protocols of upper layers so that they can finish necessary handover procedures before current wireless link terminates. Therefore, a mobile node needs an appropriate model to predict impending handover to generate link layer triggers in time. In this paper, we propose a mobility model that does not assume any radio propagation environments and movement patterns of a mobile node. Through statistical analysis of the received signal strength index (RSSI) datasets measured in various radio propagation environments, we validate that an adaptive autoregressive process can be used as a handover prediction model. With the proposed model, we also propose a link layer triggering scheme. Since the prediction process inevitably introduces errors, we devise a statistical compensation method to initiate link layer triggers in a timely manner considering the given handover signaling delay bound. Simulation results show that the error compensation method can significantly decrease the rate of late link layer triggers with the reasonable increase in the false alarm rate.  相似文献   
999.
1000.
Recently, Huang and Cao proposed a novel and efficient unlinkable secret handshakes scheme with several security features including the affiliation-hiding property and the AKE-security. In this paper, we examine the security of the Huang-Cao scheme and show that the scheme fails to achieve two fundamental security requirements, the affiliation-hiding property and the AKE-security.  相似文献   
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