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31.
Effects of aliphatic alcohols such as ethanol, n-butanol and n-decanol on the formation of cyclodextrin (CD) from soluble starch by Bacillus macerans cyclodextrin glucanotransferase (CGTase) were experimentally studied at 50°C and pH 6.0. The addition of such aliphatic alcohols caused an increase in α-CD yield, which extent was remarkable in n-butanol. From the incubation of α-CD with CGTase, such an increase was found to be due to a restriction on further transglycosylation of α-CD into β-CD by CGTase imposed by the aliphatic alcohols.  相似文献   
32.
In this paper, we investigated the microstructure and electrical properties of Bi2SiO5 (BSO) doped SrBi2Ta2O9 (SBT) films deposited by chemical solution deposition. X-ray diffraction observation indicated that the crystalline structures of all the BSO-doped SBT films are nearly the same as those of a pure SBT film. Through BSO doping, the 2Pr and 2Ec values of SBT films were changed from 15.3 μC/cm2 and 138 kV/cm of pure SBT to 1.45 μC/cm2 and 74 kV/cm of 10 wt.% BSO-doped SBT. The dielectric constant at 1 MHz for SBT varied from 199 of pure SBT to 96 of 10 wt.% BSO-doped SBT. The doped SBT films exhibited higher leakage current than that of non-doped SBT films. Nevertheless, all the doped SBT films still had small dielectric loss and low leakage current. Our present work will provide useful insights into the BSO doping effects to the SBT films, and it will be helpful for the material design in the future nonvolatile ferroelectric memories.  相似文献   
33.
In this paper, a new method is proposed for evaluating the high-cycle fatigue strength of BGA (Ball Grid Array) packages with Pb-free solder and Pb–Sn solder due to vibration. An attached weight induced mixed mode stress in the solder ball of a package was used. To consider the effect of the mixed mode stress that occurred in a solder ball and the frequency to fatigue strength of the solder ball, a test was carried out with the three kinds of weights (σn/τn = 4, 5, and 6) at various frequencies (10–27 Hz). To clarify the effect of frequency, a nonlinear analysis with a viscoplastic model was carried out within the range of 0.001–3450 Hz. From the continuous observation of the cross-section of the package and finite element method (FEM) analysis results, it was revealed that the maximum principal stress is the driving force to package failure. Although an intermetallic compound in both packages and a Pb-rich region in a Pb–Sn solder based package were confirmed by EDX microprobe analysis, they do not contribute to the initiation of a crack in a solder ball. The fatigue strength of the Pb-free solder and Pb solder was evaluated on the basis of the maximum principal stress calculated by FEM and the experimental results.  相似文献   
34.
The system architectures, which allow a high performance fully balanced (FB) system based on ordinary/modified single-ended opamps to be implemented, are investigated and the basic and general requirements are formulated. Two new methods of an FB analog system design, which contribute towards achieving both a high performance IC system implementation and a great reduction of the design time are presented. It is shown that a single-ended system based on any type of opamp (rail-to-rail, constant g m , etc.), realized in any technology (CMOS, bipolar, BiCMOS, GaAs), can be easily and effectively converted to its FB counterpart in a very practical way. Using the proposed rules, any FB system implementation with opamps (data converter, modulator, filter, etc.) requires only a single-ended system version design and the drawbacks related to a conventional FB system design are avoided. The principles of the design are pointed out and they are verified by experimental results.  相似文献   
35.
Ge/Si heterojunctions formed by wet wafer bonding were observed using transmission electron microscopy and energy-dispersive x-ray spectroscopy. For the samples annealed at 880°C, there was a transition layer at the heterointerface with modified regions in the Si and Ge extending 20 nm to 30 nm from the interface. In these modified regions, crystal defects were observed, and a large amount of Ge was detected on the Si side of the junction. For the samples annealed at 250°C or 350°C, the transition layers had an amorphous-like structure with a thickness of about 10 nm. No modified layer or enlargement of lattice spacing was observed.  相似文献   
36.
In this paper, we address the problem of estimating the parameters of an electrophysiological model of the heart from a set of electrical recordings. The chosen model is the reaction-diffusion model on the transmembrane potential proposed by Aliev and Panfilov. For this model of the transmembrane, we estimate a local apparent two-dimensional conductivity from a measured depolarization time distribution. First, we perform an initial adjustment including the choice of initial conditions and of a set of global parameters. We then propose a local estimation by minimizing the quadratic error between the depolarization time computed by the model and the measures. As a first step we address the problem on the epicardial surface in the case of an isotropic version of the Aliev and Panfilov model. The minimization is performed using Brent method without computing the derivative of the error. The feasibility of the approach is demonstrated on synthetic electrophysiological measurements. A proof of concept is obtained on real electrophysiological measures of normal and infarcted canine hearts.  相似文献   
37.
Uncooled 25 Gbit/s direct modulation of 1.3 mum DFB lasers is demonstrated. The 150 mum-long semi-insulating buried-heterostructure AIGalnAs quantum-well DFB lasers show clear eye-openings with dynamic extinction ratio of 5 dB up to 70degC. 13 km singlemode-fibre transmission experiments using the devices show low power penalty within 1.3 dB between 25 and 70degC. These characteristics are the first achievement by 1.3 mum directly modulated lasers.  相似文献   
38.
A major concern is to locate manufacturing plants and/or distribution centers to serve the needs of consumers widely and rapidly with reasonably distributive cost and flexible delivery time. The purpose of this research is to help enhance a decision support for three distribution center locations with different ranges of area in order that the distributors are able to serve appropriately the retailers in twelve large cities or capitals of the nine countries in Asia-Pacific region. The researcher applies the theory of supply chain and logistics management systems with Excel, Visual Basic and Genetic Algorithms programs to find the research results. The research results revealed that the interfaces of Excel, Visual Basic, and Genetic Algorithms programs helped decision support in distribution range selection for 3 distribution center locations. Each of which had different ranges of area for distribution with a rapidly, flexibly distributed time. However, variables resulting in a decision-making should be adjusted under certain circumstances for more reliable, specific needs.  相似文献   
39.
The objective of this study was to develop a model of ocular damage induced by 40, 75, and 95 GHz continuous millimeter waves (MMW), thereby allowing assessment of the clinical course of ocular damage resulting from exposure to thermal damage-inducing MMW. This study also examined the dependence of ocular damage on incident power density. Pigmented rabbit eyes were exposed to 40, 75, and 95 GHz MMW from a spot-focus-type lens antenna. Slight ocular damage was observed 10 min after MMW exposure, including reduced cornea thickness and reduced transparency. Diffuse fluorescein staining around the pupillary area indicated corneal epithelial injury. Slit-lamp examination 1 day after MMW exposure revealed a round area of opacity, accompanied by fluorescence staining, in the central pupillary zone. Corneal edema, indicative of corneal stromal damage, peaked 1 day after MMW exposure, with thickness gradually subsiding to normal. Three days after exposure, ocular conditions had almost normalized, though corneal thickness was slightly greater than that before exposure. The 50% probability of ocular damage (DD50) was in the order 40?>?95?≈?75 GHz at the same incident power densities.  相似文献   
40.
Protein affinity reagents (e.g., antibodies) are often used for basic research, diagnostics, separations, and disease therapy. Although a lot of “synthetic” protein affinity reagents have been developed as a cost-effective alternative to antibodies, their low biocompatibility is a considerable problem for clinical application. Lipid nanoparticles (LNP) represent a highly biocompatible drug delivery agent. However, little has been reported that LNP itself works as a protein affinity reagent in living animals. Here, LNP is engineered for binding to and neutralizing a target toxic peptide in living animals by multifunctionalization with amino acid derivatives. Multifunctionalized LNP (MF-LNP) is prepared using amino acid derivative-conjugated lipids. Optimized MF-LNP exhibits nanomolar affinity to the target toxic peptide and inhibits toxic peptide-dependent hemolysis and cytotoxicity. In addition, MF-LNP captures and neutralizes the toxic peptide after intravenous injection in the bloodstream; in addition, MF-LNP does not release the toxic peptide in the accumulated organ. These results reveal the potential of using LNP as a highly biocompatible protein affinity reagent such as an antidote.  相似文献   
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