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排序方式: 共有2697条查询结果,搜索用时 15 毫秒
101.
提出了一种基于非乘积型小波的纹理分析方法:首先利用非乘积型小波分解原始图象,然后对高频部分的子图分别进行像素能量计算、纹理滤波以及直方图分割,从而得到粗分类的结果图;再把所有子图合并,并进行适当的后处理;最后利用小波的多尺度特性,决定分析是否终止,从而得到纹理分析结果。本方法是一种无监督分类,精确度高且计算复杂度低。 相似文献
102.
有真实感图形的纹理映射算法 总被引:2,自引:0,他引:2
本文讨论了计算机生成真实感图形的纹理映射技术,根据模拟现实物体的表面细节特征提出了三种纹理映射方法。 相似文献
103.
构造一个基于Web的虚拟室内图案效果展示的机制。引入一种适应于网络应用的、针对3D场景的图案纹理映射算法。 相似文献
104.
Unsupervised image segmentation using a simple MRF model with a new implementation scheme 总被引:7,自引:0,他引:7
A simple Markov random field model with a new implementation scheme is proposed for unsupervised image segmentation based on image features. The traditional two-component MRF model for segmentation requires training data to estimate necessary model parameters and is thus unsuitable for unsupervised segmentation. The new implementation scheme solves this problem by introducing a function-based weighting parameter between the two components. Using this method, the simple MRF model is able to automatically estimate model parameters and produce accurate unsupervised segmentation results. Experiments demonstrate that the proposed algorithm is able to segment various types of images (gray scale, color, texture) and achieves an improvement over the traditional method. 相似文献
105.
We provide analytical forms for the plastic deformation and velocity gradients associated with a single pass of equal channel angular extrusion (ECAE). Three cases of plastic deformation are considered: ideal simple shear, a plastic deformation zone (PDZ) in the shape of a central fan of angle βm, and a two-part PDZ consisting of a central fan in the ‘upper’ region and a low intensity shear deformation in the ‘lower’ region. The analysis for simple shear considers a general die angle Φ, whereas the other two cases only consider Φ=90°. The tensors for deformation and velocity gradients completely describe the deformation, such as the directions and magnitudes of material stretching and rotations. From this analysis, one can calculate deformation and texture evolution. Texture evolution during flow through the central fan zone involves continuous rotation of the texture components causing the texture developed at the end of the extrusion to be rotated relative to the ideal simple shear case. The analysis of the two-part zone suggests inhomogeneity in texture evolution, in which features of the initial texture are retained and rotated in the lower region, while they are nearly erased in the upper region. These analytical flow patterns for a single pass can be repeatedly applied for any number of passes of any ECAE route. 相似文献
106.
Continuous cast (CC) AA5182 Al alloy with the precipitation of Mg2Al3 and of MnAl6 was cold rolled to 70% reduction and then isothermally annealed in a salt bath at three temperatures (316, 343, and 371 °C) for different times. Texture evolution during recrystallization was investigated. It was found that the recrystallization textures of the material with intense Mg2Al3 precipitation along the grain boundaries exhibited weaker Cube, Goss and R/β fiber components than those of the material with the more uniform fine MnAl6 precipitates. The opposite was true in the cold rolled condition, i.e. the material with MnAl6 precipitation had weaker Cube, Goss, and R/β fiber components in the cold rolled condition than the material with intense Mg2Al3 precipitation. Thus, recrystallization textures of material with Mg2Al3 precipitation were weaker than material with MnAl6 precipitation. This is due to the fact that large Mg2Al3 particles favor the nucleation of randomly oriented grains. When subjected to formability tests, the material with prior Mg2Al3 precipitation displayed a lower anisotropy in tensile yield strength, ultimate tensile strength, elongation, and strain hardening exponent than material with prior MnAl6 precipitation. This is in accord with the texture results which indicated that the recrystallization textures of material with an initial Mg2Al3 precipitation were closer to those of a perfectly random sample than those of material with an initial MnAl6 precipitation. On the other hand, the elongation and Olsen values were lower and the surface quality after bending tests was worse for material with Mg2Al3 precipitation. This is due to the non-uniform distribution of Mg2Al3 particles which precipitated primarily along the grain boundaries and caused an earlier formation and coalescence of the microvoids around the grain boundary precipitates. The forming limit diagrams (FLD) correlated well with the tensile, Olsen and bending results. 相似文献
107.
A.A. Kassim Author Vitae Zhu Mian Author Vitae Author Vitae 《Pattern recognition》2004,37(9):1925-1933
Tool wear monitoring can be achieved by analyzing the texture of machined surfaces. In this paper, we present the new connectivity oriented fast Hough transform, which easily detects all line segments in binary edge images of textures of machined surfaces. The features extracted from line segments are found to be highly correlated to the level of tool wear. A multilayer perceptron neural network is applied to estimate the flank wear in various machining processes. Our experiments show that this Hough transform based approach is effective in analyzing the quality of machined surfaces and could be used to monitor tool wear. A performance analysis of our Hough transform is also provided. 相似文献
108.
109.
《Journal of the European Ceramic Society》2014,34(16):4247-4256
Pure ZnO and single Al-doped ZnO compounds without secondary phase have been obtained by SPS process. Starting powders prepared by co-precipitation have been synthesized. The sintered pellets exhibit different texture degree but similar isotropic shaped grains. Sintering mechanisms are proposed for both powders, explaining the different texture and grain size evolutions as a direct consequence of the differences observed in both compounds. The influence of texture and grain morphology on the thermoelectric properties is studied. 相似文献
110.
This paper proposes a novel technique for texture image retrieval based on tetrolet transforms. Tetrolets provide fine texture information due to its different way of analysis. Tetrominoes are applied at each decomposition level of an image and best combination of tetrominoes is selected, which better shows the geometry of an image at each level. All three high pass components of the decomposed image at each level are used as input values for feature extraction. A feature vector is created by taking standard deviation in combination with energy at each subband. Retrieval performance in terms of accuracy is tested on group of texture images taken from benchmark databases: Brodatz and VisTex. Experimental results indicate that the proposed method achieves 78.80% retrieval accuracy on group of texture images D1 (taken from Brodatz), 84.41% on group D2 (taken from VisTex) and 77.41% on rotated texture image group D3 (rotated images from Brodatz). 相似文献