首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   84709篇
  免费   8010篇
  国内免费   4588篇
电工技术   6383篇
技术理论   2篇
综合类   6018篇
化学工业   12514篇
金属工艺   5226篇
机械仪表   5959篇
建筑科学   5632篇
矿业工程   2220篇
能源动力   2724篇
轻工业   5893篇
水利工程   1967篇
石油天然气   3478篇
武器工业   1015篇
无线电   10852篇
一般工业技术   9961篇
冶金工业   4033篇
原子能技术   1078篇
自动化技术   12352篇
  2024年   278篇
  2023年   1006篇
  2022年   2070篇
  2021年   3121篇
  2020年   2291篇
  2019年   1885篇
  2018年   2112篇
  2017年   2588篇
  2016年   2523篇
  2015年   3314篇
  2014年   4357篇
  2013年   5219篇
  2012年   6431篇
  2011年   6870篇
  2010年   6351篇
  2009年   6180篇
  2008年   6020篇
  2007年   5568篇
  2006年   5081篇
  2005年   4211篇
  2004年   3345篇
  2003年   3070篇
  2002年   3242篇
  2001年   2784篇
  2000年   1778篇
  1999年   1322篇
  1998年   934篇
  1997年   753篇
  1996年   597篇
  1995年   440篇
  1994年   358篇
  1993年   258篇
  1992年   182篇
  1991年   150篇
  1990年   130篇
  1989年   121篇
  1988年   70篇
  1987年   73篇
  1986年   45篇
  1985年   36篇
  1984年   26篇
  1983年   20篇
  1982年   18篇
  1981年   20篇
  1980年   11篇
  1979年   7篇
  1978年   6篇
  1977年   6篇
  1975年   6篇
  1959年   5篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
Pythagorean fuzzy sets (PFSs), originally proposed by Yager (Yager, Abbasov. Int J Intell Syst 2013;28:436–452), are a new tool to deal with vagueness considering the membership grades are pairs satisfying the condition . As a generalized set, PFSs have close relationship with intuitionistic fuzzy sets (IFSs). PFSs can be reduced to IFSs satisfying the condition . However, the related operations of PFSs do not take different conditions into consideration. To better understand PFSs, we propose two operations: division and subtraction, and discuss their properties in detail. Then, based on Pythagorean fuzzy aggregation operators, their properties such as boundedness, idempotency, and monotonicity are investigated. Later, we develop a Pythagorean fuzzy superiority and inferiority ranking method to solve uncertainty multiple attribute group decision making problem. Finally, an illustrative example for evaluating the Internet stocks performance is given to verify the developed approach and to demonstrate its practicality and effectiveness.  相似文献   
63.
Generalized evidence theory   总被引:3,自引:0,他引:3  
  相似文献   
64.
分组加工模式的应用是特色工艺研究和精细化加工的结合,目前被应用在了很多企业中。为了解决计划制订到生产调度指挥这一过程中的问题,企业采用了MES技术来优化这一模式下的工艺过程。分析了MES技术的应用。  相似文献   
65.
66.

Visual tracking is one of the most important problems considered in computer vision. To improve the performance of the visual tracking, a part-based approach will be a good solution. In this paper, a novel method of visual tracking algorithm named part-based mean-shift (PBMS) algorithm is presented. In the proposed PBMS, unlike the standard mean-shift (MS), the target object is divided into multiple parts and the target is tracked by tracking each individual part and combining the results. For the part-based visual tracking, the objective function in the MS is modified such that the target object is represented as a combination of the parts and iterative optimization solution is presented. Further, the proposed PBMS provides a systematic and analytic way to determine the scale of the bounding box for the target from the perspective of the objective function optimization. Simulation is conducted with several benchmark problems and the result shows that the proposed PBMS outperforms the standard MS.

  相似文献   
67.
A noteworthy thing in desktop PCs is that they can provide a great opportunity to increase the performance of processing multimedia data by exploiting task- and data-parallelism with multi-core CPU and many-core GPU. This paper presents a high performance parallel implementation of 2D DCT on this heterogeneous computing environment. For this purpose, Intel TBB (threading building blocks) and OpenCL (Open Compute Language) are utilized for task- and data-parallelism, respectively. The simulation result shows that the parallel DCT implementations far the serial ones in processing speed. Especially, OpenCL implementation shows a linear speedup, a typical SIMD characteristic as the increase of 2D data sets.  相似文献   
68.
Registration of range scans is commonly required in many localization and mapping algorithms. In this paper, we introduce a novel approach called Polar-Cartesian Hybrid Transforms for pair-wise registration of range scans. The proposed algorithm iteratively establishes correspondences by searching the points with closest polar angles in the polar coordinate frame. An angular look-up table is constructed based on the properties of the laser range finder to accelerate the searching procedure. In order to speed up the convergence, we compute the difference of polar range of every matched point pair to select the most contributing correspondences. After the correspondences are determined, the transformation is computed in Cartesian coordinate frame using a point-to-line metric. Combining the advantages of the polar and Cartesian coordinate frames, both robustness and efficiency are greatly improved compared with an up-to-date ICP algorithm.  相似文献   
69.
针对片状颗粒厚度检测的实际需求,结合机器视觉、图像处理和嵌入式技术,设计与实现了一套基于高性能ARM11的微片状颗粒厚度检测系统。该系统以QT和S3C6410为软硬件平台,提出了利用轮廓提取和最小矩形边界框相结合的方法计算片状颗粒厚度。结果表明,该检测系统具有处理速度快,测量精度高和成本低廉等优点,满足了对颗粒厚度测量的需求。  相似文献   
70.
Image mosaic construction is about stitching together a number of images about the same scene to construct a single image with a larger field of view. The majority of the previous work was rooted at the use of a single image-to-image mapping termed planar homography for representing the imaged scene. However, the mapping is applicable only to cases where the imaged scene is either a single planar surface, or very distant from the cameras, or imaged under a pure rotation of the camera, and that greatly limits the range of applications of the mosaicking methods. This paper presents a novel mosaicking solution for scenes that are polyhedral (thus consisting of multiple surfaces) and that are pictured possibly in closed range of the camera. The solution has two major advantages. First, it requires only a few correspondences over the entire scene, not correspondences over every surface patch in it to work. Second, it conquers a seemingly impossible task—warping image data of surfaces that are visible in only one of the input images, which we refer to as the singly visible surfaces, to another viewpoint to constitute the mosaic there. We also provide a detail analysis of what determines whether a singly visible surface could be mosaicked or not. Experimental results on real image data are presented to illustrate the performance of the method.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号