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131.
Conventional iris recognition requires a high-resolution camera equipped with a zoom lens and a near-infrared illuminator to observe iris patterns. Moreover, with a zoom lens, the viewing angle is small, restricting the user’s head movement. To address these limitations, periocular recognition has recently been studied as biometrics. Because the larger surrounding area of the eye is used instead of iris region, the camera having the high-resolution sensor and zoom lens is not necessary for the periocular recognition. In addition, the image of user’s eye can be captured by using the camera having wide viewing angle, which reduces the constraints to the head movement of user’s head during the image acquisition. Previous periocular recognition methods extract features in Cartesian coordinates sensitive to the rotation (roll) of the eye region caused by in-plane rotation of the head, degrading the matching accuracy. Thus, we propose a novel periocular recognition method that is robust to eye rotation (roll) based on polar coordinates. Experimental results with open database of CASIA-Iris-Distance database (CASIA-IrisV4) show that the proposed method outperformed the others.  相似文献   
132.
Resistive tactile sensors based on changes in contact area have been extensively explored for a variety of applications due to their outstanding pressure sensitivity compared to conventional tactile sensors. However, the development of tactile sensors with high sensitivity in a wide pressure range still remains a major challenge due to the trade‐off between sensitivity and linear detection range. Here, a tactile sensor comprising stacked carbon nanotubes and Ni‐fabrics is presented. The hierarchical structure of the fabrics facilitates a significant increase in contact area between them under pressure. Additionally, a multi‐layered structure that can provide more contact area and distribute stress to each layer further improves the sensitivity and linearity. Given these advantages, the sensor presents high sensitivity (26.13 kPa?1) over a wide pressure range (0.2–982 kPa), which is a significant enhancement compared with the results obtained in previous studies. The sensor also exhibits outstanding performances in terms of response time, repeatability, reproducibility, and flexibility. Furthermore, meaningful applications of the sensor, including wrist‐pulse‐signal analysis, flexible keyboards, and tactile interface, are successfully demonstrated. Based on the facile and scalable fabrication technique, the conceptually simple but powerful approach provides a promising strategy to realize next‐generation electronics.  相似文献   
133.
Dense and adhesive WO3 films were prepared on a silicon substrate by the cold gas dynamic spray process (or cold spray). In contrast to standard metallic coatings, there was no sizable crater formation and plastic deformation. However, the aggregation of raw powder particles of a relatively large size was found to be destroyed upon impact on the substrate, forming a highly irregular surface with very fine secondary particles and providing good interlocking powder and void reduction among the particles in the coating. High-resolution images of the substrate interface showed that particles at the interface were more densely packed and that good adhesion was obtained. There fore, the particle bombardment onto the first layer of the coating could provide enhanced adhesion to the substrate mechanically and/or chemically.  相似文献   
134.
Food Science and Biotechnology - The potential nutricosmetic activities and compositional changes of 80% ethanol extracts of white soybean (MFWS) and black soybean (MFBS) fermented with Monascus...  相似文献   
135.
136.
Hydrogen usually penetrates metals through defects such as dislocations, vacancies, and crystalline imperfections and causes embrittlement, leading to cleavage fracture and intergranular fracture. Synthetic natural gas produced by coal gasification, biogas, and landfill gas inevitably contain hydrogen. Therefore, hydrogen embrittlement of pipeline materials should be considered when they are mixed with conventional natural gas and supplied to customers. To analyze hydrogen embrittlement of base metals and girth weld metals of API 5L X70 and X65 gas pipelines, a specimen was treated in 100 % hydrogen environment at 10 MPa to determine the hydrogen concentration in it. Small punch (SP) tests were performed under various gaseous components and pressures. When SP tests were performed at very low speed, hydrogen embrittlement could be observed. Specimens became very susceptible to hydrogen embrittlement with increasing hydrogen partial pressure in the hydrogen/methane gas mixture, and the SP energy also decreased dramatically.  相似文献   
137.
Silicone–acrylic resins were synthesized to prepare superweatherable paints for building materials. The raw materials used were n‐butyl acrylate, methyl methacrylate, and n‐butyl methacrylate as acrylic monomers and 3‐methacryloxypropyltrimethoxysilane (MPTS) as a silicone monomer reactive with the acrylic monomers. Acrylic copolymers were synthesized such that their glass‐transition temperatures were adjusted to 30°C and their MPTS contents were varied to 10, 20, and 30 wt %. As the content of silicone and MPTS increased, average molecular weight and viscosity increased, and thermal stability at high temperatures improved. When we tested the properties of coatings by blending the synthesized silicone–acrylic resins with a white pigment, adhesion was superior with various substrates, and their properties were suitable on the whole. Weatherability was tested by an outdoor exposure test with a weather‐ometer and an accelerated weathering tester, and their results showed that silicone–acrylic resin composed of 30 wt % MPTS was a superweatherable coating. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1614–1623, 2001  相似文献   
138.
Caffeoyl shikimate esterase (CSE) has been shown to play an important role in lignin biosynthesis in plants and is, therefore, a promising target for generating improved lignocellulosic biomass crops for sustainable biofuel production. Populus spp. has two CSE genes (CSE1 and CSE2) and, thus, the hybrid poplar (Populus alba × P. glandulosa) investigated in this study has four CSE genes. Here, we present transgenic hybrid poplars with knockouts of each CSE gene achieved by CRISPR/Cas9. To knockout the CSE genes of the hybrid poplar, we designed three single guide RNAs (sg1–sg3), and produced three different transgenic poplars with either CSE1 (CSE1-sg2), CSE2 (CSE2-sg3), or both genes (CSE1/2-sg1) mutated. CSE1-sg2 and CSE2-sg3 poplars showed up to 29.1% reduction in lignin deposition with irregularly shaped xylem vessels. However, CSE1-sg2 and CSE2-sg3 poplars were morphologically indistinguishable from WT and showed no significant differences in growth in a long-term living modified organism (LMO) field-test covering four seasons. Gene expression analysis revealed that many lignin biosynthetic genes were downregulated in CSE1-sg2 and CSE2-sg3 poplars. Indeed, the CSE1-sg2 and CSE2-sg3 poplars had up to 25% higher saccharification efficiency than the WT control. Our results demonstrate that precise editing of CSE by CRISPR/Cas9 technology can improve lignocellulosic biomass without a growth penalty.  相似文献   
139.
The gas-aerosol equilibrium model, SCAPE, presented in Part I is used to evaluate the sensitivity of thermodynamic calculations of aerosol composition to common approximations and the choice of activity coefficient estimation method. The treatment of weak electrolytes, associated ammonia, NH3(aq), and bisulfate ion, HSO4 ?, is analyzed. Comparisons of the three multi-component activity coefficient estimation methods are carried out with a variety of data. On the basis of the sensitivity analysis results, recommendations are provided for treating these electrolytes and for selecting an activity coefficient estimation method in atmospheric gas-aerosol equilibrium calculations. The two gas-aerosol equilibrium models, SCAPE and AIM, are compared. Remaining questions in gas-aerosol equilibrium are highlighted.  相似文献   
140.
Digital watermarking is already used to establish the copyright of graphics, audio and text, and is now increasingly important for the protection of geometric data as well. Watermarking polygonal models in the spectral domain gives protection against similarity transformation, mesh smoothing, and additive random noise attacks. However, drawbacks exist in analyzing the eigenspace of Laplacian matrices. In this paper we generalize an existing spectral decomposition and propose a new spatial watermarking technique based on this generalization. While inserting the watermark, we avoid the cost of finding the eigenvalues and eigenvectors of a Laplacian matrix in spectral decomposition; instead we use linear operators derived from scaling functions that are generated from Chebyshev polynomials. Experimental results show how the cost of inserting and detecting watermarks can be traded off against robustness under attacks like additive random noise and affine transformation.  相似文献   
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