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1.
Recent progress in road and lane detection: a survey   总被引:2,自引:0,他引:2  
The problem of road or lane perception is a crucial enabler for advanced driver assistance systems. As such, it has been an active field of research for the past two decades with considerable progress made in the past few years. The problem was confronted under various scenarios, with different task definitions, leading to usage of diverse sensing modalities and approaches. In this paper we survey the approaches and the algorithmic techniques devised for the various modalities over the last 5 years. We present a generic break down of the problem into its functional building blocks and elaborate the wide range of proposed methods within this scheme. For each functional block, we describe the possible implementations suggested and analyze their underlying assumptions. While impressive advancements were demonstrated at limited scenarios, inspection into the needs of next generation systems reveals significant gaps. We identify these gaps and suggest research directions that may bridge them.  相似文献   
2.
We present an efficient method for learning part-based object class models from unsegmented images represented as sets of salient features. A model includes parts’ appearance, as well as location and scale relations between parts. The object class is generatively modeled using a simple Bayesian network with a central hidden node containing location and scale information, and nodes describing object parts. The model’s parameters, however, are optimized to reduce a loss function of the training error, as in discriminative methods. We show how boosting techniques can be extended to optimize the relational model proposed, with complexity linear in the number of parts and the number of features per image. This efficiency allows our method to learn relational models with many parts and features. The method has an advantage over purely generative and purely discriminative approaches for learning from sets of salient features, since generative method often use a small number of parts and features, while discriminative methods tend to ignore geometrical relations between parts. Experimental results are described, using some bench-mark data sets and three sets of newly collected data, showing the relative merits of our method in recognition and localization tasks.  相似文献   
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We present a family of nonlocal games in which the inputs the players receive are continuous. We study three representative members of the family. For the first two a team sharing quantum correlations (entanglement) has an advantage over any team restricted to classical correlations. We conjecture that this is true for the third member of the family as well.  相似文献   
5.
Ultrasonic irradiation of molten gallium in organic liquids (decane, dodecane, etc.) results in dispersion of the gallium into nanometric spheres. These were examined by several analytical methods XRD, DSC, Raman and IR spectroscopy) as well as electron microscopy (SEM, TEM) and found to be composed of Ga and C. The DSC analysis indicates that the Ga has possibly reacted with carbon, while the Raman spectrum of the product demonstrates a strong additional peak that could not be identified. This work explores the possibility that the product is gallium carbide or another gallium‐carbon complex. To investigate the nature of the product, we performed detailed extended X‐ray absorption fine structure (EXAFS) and X‐ray absorption near‐edge structure (XANES) analyses. On the basis of DSC, IR, and Raman it appear to be formation of GaC, whereas the analysis by EXAFS and XANES demonstrated that the gallium is found to be in a higher reduced state (almost metallic), supported by carbon. The question that remains open in addition to the one related to the formation of galium carbide is whether a complex structure, including oxygen contamination is involved in the layers surrounding the Ga as indicated by the EXAFS results.  相似文献   
6.
A composite material made of zinc oxide and polyvinyl alcohol was prepared by a sonochemical method. Annealing of the composite under air removed the polymer, leaving porous spheres of ZnO. This change was accompanied by a change of the surface area from 2 m2/g to 34 m2/g. The porous ZnO particles were used as the electrode material for dye-sensitized solar cells (DSSCs). It was tested by forming a film of the doped porous ZnO on a conductive glass support. The performance of the solar cell is reported.  相似文献   
7.
Poly(para-xylylene)(PPX)/carbon fiber towpregs were produced by two different in-situ polymerization processes: Electrochemcal polymerization (ECP) and vapor deposition polymerization (VDP). The monomer used for the ECP process was α, α′ -dibromo-para-xylylene and di-para-xylylene was the starting material for the VDP process. A series of tests, including FTIR, WAXD, DSC, TG, and SEM were carried out to identify and compare these two composite towpregs. It has been confirmed that the PPX samples obtained by the two different polymerization processes were basically chemically identical. However, the polymer coating on the fiber surface produced by the VDP process was much smoother than that produced by the ECP process, which produced a porous coating.  相似文献   
8.
A model of a repetitive multiproject management is introduced that includes uncertainties in activity durations, and the corresponding quantities of resources needed. Following the convention, a project is viewed here as a network of related activities aimed at the accomplishment of a predetermined objective at a given deadline. A project has a starting point in time and a preplanned completion point and so does each activity within it. The structural and operational characteristics described here are drawn from organization and management theories and used to describe project organization. This is demonstrated by means of field data gathered from a sample of ‘bloodmobile projects’ - an organized effort for the collection of blood donations in support of medical needs.  相似文献   
9.
The criticality of modern software applications, the pervasiveness of malicious code concerns, the emergence of third-party software development, and the preponderance of program inspection as a quality assurance method all place a great premium on the ability to analyze programs and derive their function in all circumstances of use and all its functional detail. For C-like programming languages, one of the most challenging tasks in this endeavor is the derivation of loop functions. In this paper, we outline the premises of our approach to this problem, present some mathematical results, and discuss how these results can be used as a basis for building an automated tool that derives the function of while loops under some conditions.  相似文献   
10.
Crystalline helical carbon nanotubes (HCNTs) are synthesized as the main products in the pyrolysis of acetylene at 450 °C over Fe nanoparticles generated by means of a combined sol–gel/reduction method. Transmission electron microscopy (TEM) images reveal that there are two HCNTs attached to each Fe3C nanoparticle, and that the two HCNTs are mirror images of each other. Annealing in Ar at 750 °C and purification by immersion in hot (90 °C) HCl solution do not significantly change the structure of the HCNTs, despite the partial removal of Fe nanoparticles by the latter treatment. The magnetic properties of the as‐prepared, annealed, and purified HCNTs have been systematically examined. The annealed sample shows relatively high magnetization due to the ferromagnetic α‐Fe nanoparticles encapsulated in the HCNT nodes. In the case of HCl treatment, relatively pure HCNTs are obtained by the removal of ferromagnetic nanoparticles from the double‐HCNT nodes. The effects of the amount of catalyst used in the synthesis process on the morphology and yield of the carbon products have also been investigated.  相似文献   
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