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61.
62.
Xiaoqiang Li Jie Xu Lipeng Zhou Feng Wang Jin Gao Chen Chen Jianbo Ning Hong Ma 《Catalysis Letters》2006,110(1-2):149-154
Copper manganese oxides (Cu–Mn oxides) were prepared by coprecipitation method and characterized by several techniques, such
as X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and Temperature-programmed reduction (TPR).
Catalytic activities of the Cu–Mn oxides were tested by the oxidation of toluene with molecular oxygen in liquid phase and
solvent-free conditions. The molar ratio of Cu:Mn in catalyst was optimized to be 1:1 and thus the corresponding crystalline
material was designated as Cu1.5Mn1.5O4. 相似文献
63.
Preparation and characterization of porous carbon beads and their application in dispersing small metal crystallites 总被引:2,自引:0,他引:2
Porous carbon beads were prepared by the pyrolysis of poly(vinylidene chloride) beads that were synthesized by suspension polymerization. After prolysis treatment at 180–300 °C under argon stream, the polymeric beads were further carbonized at 1000 °C for 3 h under argon stream to acquire porous carbon beads, of which the specific surface area was about 1000 m2/g, and pore size was mainly in the width range of 0.8–1.2 nm. The carbon structure and surface chemical composition characterized by X-ray diffraction and X-ray photoelectron spectroscopy, depended on the preparation temperature and the relations between them were examined. The characterization of the carbon beads by scanning electron microscopy, atomic force microscopy presented the morphological structure of the carbon beads surface and a global view of pores. The dispersion of nickel crystallites on the carbon beads surface was characterized by electron microprobe analysis. This study reveals that uniform surface morphological structure leads to the fine dispersion of metal crystallites. 相似文献
64.
Qin Zou Yu Cao Qingquan Li Qingzhou Mao Song Wang 《Machine Vision and Applications》2014,25(7):1841-1858
Recent inpainting techniques usually require human interactions which are labor intensive and dependent on the user experiences. In this paper, we introduce an automatic inpainting technique to remove undesired fence-like structures from images. Specifically, the proposed technique works on the RGBD images which have recently become cheaper and easier to obtain using the Microsoft Kinect. The basic idea is to segment and remove the undesired fence-like structures by using both depth and color information, and then adapt an existing inpainting algorithm to fill the holes resulting from the structure removal. We found that it is difficult to achieve a satisfactory segmentation of such structures by only using the depth channel. In this paper, we use the depth information to help identify a set of foreground and background strokes, with which we apply a graph-cut algorithm on the color channels to obtain a more accurate segmentation for inpainting. We demonstrate the effectiveness of the proposed technique by experiments on a set of Kinect images. 相似文献
65.
本文主要介绍了该项目在湖南省铜官陶瓷总公司推广应用实例,论述本技术改革传统隧道窑预热带及冷却带的结构.开发利用隧道密的烟气度热.进一步挖掘冷却带余热的潜力.使隧道窑余热利用率由30%左右提高到50%以上。用来烘干陶瓷半成品、石膏模、匣体取代锅炉蒸汽干燥,节能显著。 相似文献
66.
Shen TJ; Ho NT; Zou M; Sun DP; Cottam PF; Simplaceanu V; Tam MF; Bell DA Jr; Ho C 《Protein engineering, design & selection : PEDS》1997,10(9):1085-1097
A hemoglobin expression system in Escherichia coli is described. In order
to produce authentic human hemoglobin, we need to co-express both
methionine aminopeptidase and globin genes under the control of a strong
promoter. We have constructed three plasmids, pHE2, pHE4 and pHE7, for the
expression of human normal adult hemoglobin and a plasmid, pHE9, for the
expression of human fetal hemoglobin, in high yields. The globin genes can
be derived from either synthetic genes or human globin cDNAs. The extra
amino-terminal methionine residues of the expressed globins can be removed
by the co-expressed methionine aminopeptidase. The heme is inserted
correctly into the expressed alpha- globin from our expression plasmids. A
fraction (approximately 25%) of the heme is not inserted correctly into the
expressed beta- or gamma- globin. However, the incorrectly inserted hemes
can be converted into the correct conformation by carrying out a simple
oxidation-reduction process on the purified hemoglobin molecule. We have
investigated the functional properties of the expressed hemoglobins by
measuring their oxygen-binding properties and their structural features by
obtaining their 1H-NMR spectra. Our results show that authentic human
normal adult and fetal hemoglobins can be produced from our expression
plasmids in E. coli and in high yields. Our expression system allows us to
design and to produce any recombinant hemoglobins needed for our research
on the structure-function relationship in hemoglobin.
相似文献
67.
介绍了在PKM气化炉中弱粘结性双阳煤的试烧情况,并给出了主要工艺参数控制范围。试烧结果表明:依兰煤中配入50%双阳煤,汽氧比6.0:1时,气化炉工况良好。 相似文献
68.
69.
We present an interactive method for mesh segmentation that is inspired by the classical live‐wire interaction for image segmentation. The core contribution of the work is the definition and computation of wires on surfaces that are likely to lie at segment boundaries. We define wires as geodesics in a new tensor‐based anisotropic metric, which improves upon previous metrics in stability and feature‐awareness. We further introduce a simple but effective mesh embedding approach that allows geodesic paths in an anisotropic path to be computed efficiently using existing algorithms designed for Euclidean geodesics. Our tool is particularly suited for delineating segmentation boundaries that are aligned with features or curvature directions, and we demonstrate its use in creating artist‐guided segmentations. 相似文献
70.