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991.
992.
Placement is a critical step in VLSI design because it dominates overall speed and quality of design flow.In this paper,a new fast and stable placement algorithm called FaSa is proposed.It uses quadratic programming model and Lagrange multiplier method to solve placement problems.And an incremental LU factorization method is used to solve equations for speeding up.The experimental results show that FaSa is very stable,much faster than previous algorithms and its total wire length is comparable with other algorithms. 相似文献
993.
S?ren?Emil?S?rensenEmail author Michael?R.?Hansen Morten?K.?Ebbesen Ole??.?Mouritsen 《Structural and Multidisciplinary Optimization》2012,45(6):907-916
Poor dynamics owing to polygon action is a known concern in mechanical applications of closed articulated chains. In this
paper a kinematic model of the polygon action in large chains of loop-sorting-systems is proposed. Through optimization techniques
the chain dynamics is improved by minimizing the polygon action using a parametric model of the track layout as design variables.
Three formulations of the kinematic polygon action are tested on an average sized planer tracks layout to find a superior
model. Verification of the proposed optimization method is performed using a state-of-the-art multi-body simulation model
of the chain dynamics. 相似文献
994.
Since opening sizable bandgaps in bilayer graphene (BLG) was proven possible, BLG has attracted considerable attention as a promising high-mobility candidate material for many electronic and optoelectronic applications. However, the bandgaps observed in the transport experiments reported in the literature are far smaller than both the theoretical predictions and the bandgaps extracted from optical measurements. In this study, we investigate the factors preventing the formation of large bandgaps and demonstrate that a ~200-meV transport bandgap can be opened in BLG by scaling the gate dielectric and employing a ribbon channel to suppress the percolative transport. This is the largest transport bandgap that has been achieved in BLG to date. 相似文献
995.
This article reports on the characterization and preparation of N-doped titanium dioxide (TiO2) films by reactive magnetron sputtering from Ti(99.5) targets in a mixture of Ar/O2/N2 atmosphere on unheated glass substrates. A dual magnetron system supplied by a dc bipolar pulsed power source was used to sputter the TiOxNy films. The amount of N in the TiOxNy film ranges from 5 to 40 at%. Its structure was measured using X-ray diffraction (XRD), the optical band gap was calculated from Tauc plots and the decrease of the water contact angle αir after the film activation by UV irradiation was investigated as a function of at% of N in the TiOxNy film. The yellow-coloured TiOxNy films with high (≈8 at%) amount of N exhibited a strong decrease of the band gap Eg down to 2.7 eV. A significant decrease of the water contact angle αir after UV irradiation has been observed for 2 μm thick transparent nanocrystalline (anatase+rutile) N-doped TiO2 films containing less than 6 at% of N. 相似文献
996.
Raquel P. RochaAdrián M.T. Silva Goran Dra?i?Manuel F.R. Pereira José L. Figueiredo 《Materials Letters》2012,66(1):64-67
Multi-walled carbon nanotubes (MWCNTs) were functionalized by HNO3 hydrothermal oxidation at 200 °C. The degree of surface functionalization was described by an exponential function in terms of HNO3 concentration. Very small Pt particles, with mean particle size of 1.7 ± 0.3 nm, could be supported on the surface of pristine MWCNTs and also on MWCNTs treated with HNO3 concentrations up to 0.20 mol L− 1, while a broader range of particle sizes, and larger Pt particles (3.4 ± 1.3 nm) were obtained on the MWCNTs treated with a higher HNO3 concentration (0.30 mol L− 1). Therefore, the amounts of surface groups and Pt particle sizes can be selected by tuning the HNO3 concentration used in the hydrothermal treatment. 相似文献
997.
A time-domain boundary element method (BEM) together with the sub-domain technique is applied to study transient response
of interfacial cracks in piecewise homogeneous, anisotropic and linear piezoelectric bi-materials under electrical and mechanical
impacts. The present time-domain BEM uses a quadrature formula for the temporal discretization to approximate the convolution
integrals and a collocation method for the spatial discretization. Quadratic quarter-point elements are implemented at the
tips of the interface cracks. To determine the real or complex dynamic stress intensity factors and the dynamic electrical
displacement intensity factor of the interfacial cracks, an explicit extrapolating formula in a typical state of the crack
plane perpendicular to the poling direction is presented in this paper. Numerical examples are presented; and the effects
of the load combination and material combination on dynamic intensity factors and dynamic energy release rate are discussed. 相似文献
998.
Ch.?Venkata ReddyEmail author S.?V.?Prabhakar Vattikuti Jaesool?ShimEmail author 《Journal of Materials Science: Materials in Electronics》2016,27(8):7799-7808
CdS nanoparticles (NPs) were synthesized using co-precipitation method. X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were used to confirm the structures and morphologies of CdS NPs. X-ray diffraction data confirmed the crystal structure of the CdS NPs. Raman spectrum exhibited the Raman modes of LO and 2LO of CdS at 290 and 595 cm?1 respectively. The evaluated band gap was 3.15 eV, this value was shifted compared with the bulk value and this could be a significance of a size quantization effect in the sample. The CdS nanoparticles showed higher photocatalytic activity for the discoloration of methyl orange (MO) under UV light irradiation for 90 min. The highest photocatalytic activity was obtained with the sample containing 0.3 wt % CdS nanoparticles, in which more than 98 % of the MO was discolored within 90 min. 相似文献
999.
Anca Hermenean Daniela Oatis Hildegard Herman Alina Ciceu Giovanbattista DAmico Maria Consiglia Trotta 《International journal of molecular sciences》2022,23(10)
Galectins are ten family members of carbohydrate-binding proteins with a high affinity for β galactose-containing oligosaccharides. Galectin-1 (Gal-1) is the first protein discovered in the family, expressed in many sites under normal and pathological conditions. In the first part of the review article, we described recent advances in the Gal-1 modulatory role on wound healing, by focusing on the different phases triggered by Gal-1, such as inflammation, proliferation, tissue repair and re-epithelialization. On the contrary, Gal-1 persistent over-expression enhances angiogenesis and extracellular matrix (ECM) production via PI3K/Akt pathway activation and leads to keloid tissue. Therefore, the targeted Gal-1 modulation should be considered a method of choice to treat wound healing and avoid keloid formation. In the second part of the review article, we discuss studies clarifying the role of Gal-1 in the pathogenesis of proliferative diabetic retinopathy, liver, renal, pancreatic and pulmonary fibrosis. This evidence suggests that Gal-1 may become a biomarker for the diagnosis and prognosis of tissue fibrosis and a promising molecular target for the development of new and original therapeutic tools to treat fibrosis in different chronic diseases. 相似文献
1000.
Ali?YassineEmail author Nitin?Joglekar Dan?Braha Steven?Eppinger Daniel?Whitney 《Research in Engineering Design》2003,14(3):145-161
Execution of a complex product development project is facilitated through its decomposition into an interrelated set of localized development tasks. When a local task is completed, its output is integrated through an iterative cycle of system-wide integration activities. Integration is often accompanied by inadvertent information hiding due to the asynchronous information exchanges. We show that information hiding leads to persistent recurrence of problems (termed the design churn effect) such that progress oscillates between being on schedule and falling behind. The oscillatory nature of the PD process confounds progress measurement and makes it difficult to judge whether the project is on schedule or slipping. We develop a dynamic model of work transformation to derive conditions under which churn is observed as an unintended consequence of information hiding due to local and system task decomposition. We illustrate these conditions with a case example from an automotive development project and discuss strategies to mitigate design churn.
相似文献
Ali YassineEmail: Phone: 217-333-8765Fax: 217-244-6165 |