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71.
We propose a fast and effective technique to improve sub‐grid visual details of the grid based fluid simulation. Our method procedurally synthesizes the flow fields coming from the incompressible Navier‐Stokes solver and the vorticity fields generated by vortex particle method for sub‐grid turbulence. We are able to efficiently animate smoke which is highly turbulent and swirling with small scale details. Since this technique does not solve the linear system in high‐resolution grids, it can perform fluid simulation more rapidly. We can easily estimate the influence of turbulent and swirling effect to the fluid flow.  相似文献   
72.
On social Web sites   总被引:1,自引:0,他引:1  
Today hundreds of millions of Internet users are using thousands of social Web sites to stay connected with their friends, discover new “friends,” and to share user-created contents, such as photos, videos, social bookmarks, and blogs. There are so many social Web sites, and their features are evolving rapidly. There is controversy about the benefits of these sites, and there are social issues these sites have given rise to. There are lots of press articles, Wikipedia articles, and blogs—in varying degrees of authoritativeness, clarity and accuracy—about some of the social Web sites, uses of the sites, and some social problems, and business challenges faced by the sites. In this paper, we attempt to organize the status, uses, and issues of social Web sites into a comprehensive framework for discussing, understanding, using, building, and forecasting the future of social Web sites.  相似文献   
73.
Different nanostructures of TiO2 play an important role in the photocatalytic and photoelectronic applications. TiO2 nanotubes (TNTs) have received increasing attention for these applications due to their unique physicochemical properties. Focusing on highly functional TNTs (HF‐TNTs) for photocatalytic and photoelectronic applications, this study describes the facile hydrothermal synthesis of HF‐TNTs by using commercial and cheaper materials for cost‐effective manufacturing. To prove the functionality and applicability, these TNTs are used as scattering structure in dye‐sensitized solar cells (DSSCs). Photocatalytic, optical, Brunauer‐Emmett‐Teller (BET), electrochemical impedance spectrum, incident‐photon‐to‐current efficiency, and intensity‐modulated photocurrent spectroscopy/intensity‐modulated photovoltage spectroscopy characterizations are proving the functionality of HF‐TNTs for DSSCs. HF‐TNTs show 50% higher photocatalytic degradation rate and also 68% higher dye loading ability than conventional TNTs (C‐TNTs). The DSSCs having HF‐TNT and its composite‐based multifunctional overlayer show effective light absorption, outstanding light scattering, lower interfacial resistance, longer electron lifetime, rapid electron transfer, and improved diffusion length, and consequently, J SC, quantum efficiency, and record photoconversion efficiency of 10.1% using commercial N‐719 dye is achieved, for 1D‐based DSSCs. These new and highly functional TNTs will be a concrete fundamental background toward the development of more functional applications in fuel cells, dye‐sensitized solar cells, Li‐ion batteries, photocatalysis process, ion‐exchange/adsorption process, and photoelectrochemical devices.  相似文献   
74.
Novel and low‐cost batteries are of considerable interest for application in large‐scale energy storage systems, for which the cost per cycle becomes critical. Here, this study proposes K0.5MnO2 as a potential cathode material for K‐ion batteries as an alternative to Li technology. K0.5MnO2 has a P3‐type layered structure and delivers a reversible specific capacity of ≈100 mAh g?1 with good capacity retention. In situ X‐ray diffraction analysis reveals that the material undergoes a reversible phase transition upon K extraction and insertion. In addition, first‐principles calculations indicate that this phase transition is driven by the relative phase stability of different oxygen stackings with respect to the K content.  相似文献   
75.
76.
Quantitative estimation of the specific contact resistivity and energy barrier at the interface between transparent conducting oxide (TCO) and hydrogenated p-type amorphous silicon carbide (a-Si1 − xCx:H(p)) was carried out by inserting an interfacial buffer layer of hydrogenated p-type microcrystalline silicon (μc-Si:H(p)) or hydrogenated p-type amorphous silicon (a-Si:H(p)). In addition, superstrate configuration p-i-n hydrogenated amorphous silicon (a-Si:H) solar cells were fabricated by plasma enhanced chemical vapor deposition to investigate the effect of the inserted buffer layer on the solar cell device. Ultraviolet photoelectron spectroscopy was employed to measure the work functions of the TCO and a-Si1 − xCx:H(p) layers and to allow direct calculations of the energy barriers at the interfaces. Especially interface structures were compared with/without a buffer which is either highly doped μc-Si:H(p) layer or low doped a-Si:H(p) layer, to improve the contact properties of aluminum-doped zinc oxide and a-Si1 − xCx:H(p). Out of the two buffers, the superior contact properties of μc-Si:H(p) buffer could be expected due to its higher conductivity and slightly lower specific contact resistivity. However, the overall solar cell conversion efficiencies were almost the same for both of the buffered structures and the resultant similar efficiencies were attributed to the difference between the fill factors of the solar cells. The effects of the energy barrier heights of the two buffered structures and their influence on solar cell device performances were intensively investigated and discussed with comparisons.  相似文献   
77.
Dry-processed wastepaper (magazine) fibers possess desirable mechanical characteristics as reinforcing fibers in cement-based matrices; up to 50% of virgin wood fibers have been replaced with wastepaper fibers in cement composites without any significant change in short-term performance characteristics. The large volumes of fibrous cement board used in building construction promise to provide wastepaper with a large-volume and high-value application. In this study, the effects of weathering on the performance of recycled wastepaper fiber-cement composites were investigated through accelerated aging tests simulating natural aging conditions. Microstructural studies were conducted in order to establish the mechanisms of aging in the composite material. These mechanisms provided the basis for the selection of certain refinements in the matrix composition, which were successfully evaluated for the control of weathering effects on the composite material structure and properties. The effects of aging and moisture on composites were best controlled by measures which reduced the calcium hydroxide content of hydration products and improved the watertightness and the structure of interface zones; these refinements were made using relatively high levels of cement replacement with silica fume or through full substitution of Portland cement with a special cement.  相似文献   
78.
Charge carrier transport in multilayer van der Waals (vdW) materials, which comprise multiple conducting layers, is well described using Thomas–Fermi charge screening (λTF) and interlayer resistance (Rint). When both effects occur in carrier transport, a channel centroid migrates along the c‐axis according to a vertical electrostatic force, causing redistribution of the conduction centroid in a multilayer system, unlike a conventional bulk material. Thus far, numerous unique properties of vdW materials are discovered, but direct evidence for distinctive charge transport behavior in 2D layered materials is not demonstrated. Herein, the distinctive electron conduction features are reported in a multilayer rhenium disulfide (ReS2), which provides decoupled vdW interaction between adjacent layers and much high interlayer resistivity in comparison with other transition‐metal dichalcogenides materials. The existence of two plateaus in its transconductance curve clearly reveals the relocation of conduction paths with respect to the top and bottom surfaces, which is rationalized by a theoretical resistor network model by accounting of λTF and Rint coupling. The effective tunneling distance probed via low‐frequency noise spectroscopy further supports the shift of electron conduction channel along the thickness of ReS2.  相似文献   
79.
Prostate cancer (PCa) is the most commonly diagnosed malignancy among men in developed countries. The five-year survival rate for men diagnosed with early-stage PCa is approximately 100%, while it is less than 30% for castration-resistant PCa (CRPC). Currently, the detection of prostate-specific antigens as biomarkers for the prognosis of CRPC is criticized because of its low accuracy, high invasiveness, and high false-positive rate. Therefore, it is important to identify new biomarkers for prediction of CRPC progression. Extracellular vesicles (EVs) derived from tumors have been highlighted as potential markers for cancer diagnosis and prognosis. Specifically, urinary EVs directly reflect changes in the pathophysiological conditions of the urogenital system because it is exposed to prostatic secretions. Thus, detecting biomarkers in urinary EVs provides a promising approach for performing an accurate and non-invasive liquid biopsy for CPRC. In this study, we effectively isolated urinary EVs with low protein impurities using size-exclusion chromatography combined with ultrafiltration. After EV isolation and characterization, we evaluated the miRNAs in urinary EVs from healthy donors and patients with CRPC. The results indicated that miRNAs (miR-21-5p, miR-574-3p, and miR-6880-5p) could be used as potential biomarkers for the prognosis of CRPC. This analysis of urinary EVs contributes to the fast and convenient prognosis of diseases, including CRPC, in the clinical setting.  相似文献   
80.
As smoking has emerged as a health-risk behavior, communication scholars and practitioners have put many efforts into finding out ways to achieve smoking cessation. In this research, participants (N = 57) were randomly assigned to a spatial augmented reality (SAR) condition (3D projection mapping) and 2D flat screen to be exposed to an anti-smoking message. This research provides insightful evidence that the effects of SAR on people’s behavioral intention to spread anti-smoking messages online could be explained by spatial presence and negative emotions. Implications for research on the potential of SAR in terms of emotions and online viral behavioral intentions are discussed.  相似文献   
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