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141.
The contribution from relatively low-K SiON interfacial transition regions (ITRs) between Si and transition metal (TM) gate dielectrics places a significant limitation on equivalent oxide thickness (EOT) scaling for Si complementary metal-oxide-semiconductor (CMOS) devices. This limitation is equally significant and limiting for Ge CMOS devices. Low-K Ge-based ITRs in Ge devices have also been shown to limit performance and reliability, particular for n-MOS field effect transistors. This article identifies the source of significant electron trapping at interfaces between n-Ge or inverted p-Ge, and Ge oxide, nitride and oxynitride ITRs. This is shown to be an interfacial band alignment issue in which native Ge ITRs have conduction band offset energies smaller than those of TM dielectrics, and trap electrons for negative Ge substrate bias. This article also describes a novel remote plasma processing approach for effectively eliminating any significant native Ge ITRs and using a plasma-processing/annealing process sequence for bonding TM gate dielectrics directly to the Ge substrate surface.  相似文献   
142.
A digital holography interference pattern generated by a computer calculation (computer generated hologram, CGH) is one of the most expensive contents and its usage is being expanded. Thus, it is highly necessary to protect the ownership of a digital hologram. This paper introduces a watermarking scheme, a method to protect the ownership of digital holograms using the DCT domain data as the ones to be watermarked. This scheme shows very high imperceptibility and strong robustness against the anticipated attacks. We expect that the conclusions of this paper will be a very useful basis for further work in the area of electronic watermarking schemes for the digital holograms.  相似文献   
143.
A new modulation scheme that improves the bandwidth efficiency of an optical access link is proposed in this paper. It is implemented using non-orthogonal frequency shift keying (FSK) and quadrature amplitude modulation (QAM) simultaneously. We call the proposed technique non-orthogonal frequency quadrature amplitude modulation (NOFQAM). Especially, non-orthogonal FSK based on digital signal processing (DSP) is proposed for the first time. DSP-aided non-orthogonal FSK allows us to select RF carrier frequency irrespective of the channel bandwidth to allocate FSK symbols, unlike the existing orthogonal FSK. The non-orthogonality is implemented using a sequential correlation, where a received NOFQAM signal is correlated with only one RF carrier at a time by using DSP. After the sequential correlation is completed, both the FSK and the QAM symbols are recovered successfully and merged to generate the NOFQAM symbols. For experimental verification, a 20-km optical access link, which can transmit a 64-NOFQAM signal sampled at 10 Gsample/s, is implemented. We observed no increase in occupied channel bandwidth and a power penalty <0.5 dB compared to the 16-QAM scheme. A bit error rate lower than 10?11 was obtained for the frequency spacing considered herein, which corresponds to 3% of the used RF carrier (1.5 GHz) when there are 50 sampling points per 64-NOFQAM symbol.  相似文献   
144.
Among the various cathode materials explored for sodium-ion batteries (SIBs), NaMn0.33Ni0.33Co0.33O2, with a layered oxide structure, is a promising material due to its high theoretical capacity (240 mAhg?1). We have synthesized NaMn0.33Ni0.33Co0.33O2 using two different types of precursors, namely metal acetates and metal nitrates by the sol-gel method. XRD patterns confirm the formation of a stable phase of the material at 900 °C. Coupled TGA-FTIR analysis was used to optimize the calcination conditions and to understand the hydrolysis and condensation mechanism of the sol-gel precursors. FTIR spectra extracted at different temperatures reveal the polymer network-forming tendency of the acetate ligands whereas the polymerization is inhibited in the nitrate precursors. SEM analysis shows spherical and platelet morphologies of samples synthesized from nitrate and acetate precursors, respectively. Using in situ impedance and galvanostatic charge/discharge studies, we observed that the precursors used to synthesize the cathode material influence the electrochemical properties of the material, as in this case, where we observe a 20 % improvement in terms of capacity by using acetate precursors instead of nitrate precursors.  相似文献   
145.
Ryu SY  Choi HY  Na J  Choi ES  Lee BH 《Optics letters》2008,33(20):2347-2349
We report the development of an all-fiber multimodal system, based on a double-cladding fiber (DCF) and related devices, suitable for simultaneous measurements of optical coherence tomography (OCT) and fluorescence spectroscopy (FS). The DCF together with a DCF coupler and a single-body DCF lens has assisted in the realization of a multimodal but single-unit probe for the combined system. The DCF lens allowed simultaneous focusing of input beams for OCT and FS and also the effective collection of both signal beams from a sample. The DCF coupler could extract the OCT signal via the core channel and the FS signal through the cladding channel. The OCT image and the fluorescence spectra of a plant tissue were then simultaneously measured to validate the performance of the proposed multimodal system.  相似文献   
146.
(Y1-xGdx)2O3:Eu phosphor particles with dense morphology were prepared by flame spray pyrolysis and the effect of LiCl flux on the crystallinity, morphology, and photoluminescence characteristics of the particles was investigated. All as-prepared particles had monoclinic phase regardless of flux and had different luminescence characteristics from those of commercial Y2O3:Eu particles of cubic phase. The addition of LiCl flux reduced the post-treatment temperature by 300 °C for phase transformation from the monoclinic phase to the cubic phase. The post-treatment temperature of (Y0.75Gd0.25)2O3:Eu particles for phase transformation decreased from 1100 °C to 700 °C when LiCl flux was used. The morphology of the particles was also influenced by the Y/Gd ratio and the LiCl flux. The as-prepared particles had spherical shape and non-aggregation characteristics regardless of Y/Gd ratio and flux. The sphericity of the as-prepared particles prepared without flux was maintained after post-treatment for phase transformation in all Y/Gd ratios. However, LiCl addition promoted the aggregation between product particles. The prepared particles had high photoluminescence intensities comparable to that of the commercial product. PACS 64.70.Kb; 78.55.-m; 81.20.Rg; 75.50.Tt  相似文献   
147.
Herein, we design and synthesized new fluorescein based derivatives by insitu formation of fluorescein ester and further treated with corresponding hydrazide and amine to yield respective compounds i.e. FB1, FB2, FB3 and FB4. The spectral purity and characterization was done by using IR, NMR and Mass spectroscopies. The synthesized derivatives were examined for their photophysical properties by using variety of organic solvents and results were discussed in details. The structural diversity of synthesized compounds motivate us to evaluate these compounds for urease inhibition. The compound FB3 (IC50?=?0.0456 μM) shows 100 fold more active against Jack bean urease than standard drug thiourea (IC50?=?4.7455 μM). Other synthesized compounds showed potent activity. Free radical percentage scavenging assay further supported the capacity of compounds to urease inhibition. While, molecular docking simulations helps to examine the molecular interactions of active compounds FB1, FB2, FB3 and FB4 within the binding site of urease enzyme.  相似文献   
148.
We report the synthesis of Li2CoSiO4 by the sol-gel method and the preparation of a composite electrode by incorporating functionalized multi-walled carbon nanotubes (fn. MWCNTs) as conductive additive. XRD pattern of the composite confirms the structural stability of Li2CoSiO4 even after the addition of fn. MWCNTs. SEM images of the composite reveal the presence of conductive bridges formed by MWCNTs between the submicron-sized particles of Li2CoSiO4. The cyclic voltammograms of the composite cathode show redox peaks with higher current density than pure Li2CoSiO4 and the current density increases with increase in sweep rate. The diffusion coefficient of lithium has been improved by the addition of fn. MWCNTs from 1 × 10?14 to 8 × 10?14 cm2/s as calculated using Randles-Sevcik equation. The charge-discharge cycling performance of both pure Li2CoSiO4 and composite cathode has been discussed.  相似文献   
149.
Summary A sequential sampling rule is given for selecting the most probable event from a multinomial distribution withk cells. A random number of observations is taken from the given multinomial distribution at each stage of sampling, where the number is distributed according to a Poisson distribution with mean λ. The sampling is stopped when the count in any cell is greater than or equal to a given positive integerN. The cell with the highest count is selected for the most probable event. The mathematical analysis of the problem is simplified as a result of the statistical independence of the cell frequencies due to the randomization of the sample number. The expected value of the stage when the sampling terminates is decreasing in λ. The sequential sampling scheme in which one observation is taken at a time until the highest cell count is equal toN, corresponds to λ→0. A table is given showing some properties of the given selection procedure.  相似文献   
150.
By combined investigation of STM and synchrotron PES on Ge/Si(5 5 12)-2 × 1 at 530 °C, it has been found that, in addition to the upward-relaxed surface Si atoms, a subsurface Si atom is also readily replaced by an arriving Ge atom at the initial adsorption stage. Such enhanced interdiffusion is due to a unique character of one-dimensional chain structures of the reconstructed substrate, such as π-bonded and honeycomb chains not existing on other low-index Si surfaces such as Si(001)-c(4 × 2) and Si(111)-7 × 7, applying a tensile surface stress to the neighbouring subsurface atoms. Interdiffusion of Ge having lower surface energy induces adsorption of the displaced Si atoms on the surface to form sawtooth-like facets composed of (113)/(335) and (113)/(112) with arriving Ge atoms until the surface is filled with those facets. Such displacive adsorption is the origin of high Si concentration of formed facets.  相似文献   
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