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   22824篇
  免费   3466篇
  国内免费   2710篇
电工技术   1999篇
技术理论   6篇
综合类   2056篇
化学工业   388篇
金属工艺   266篇
机械仪表   1853篇
建筑科学   460篇
矿业工程   272篇
能源动力   237篇
轻工业   120篇
水利工程   221篇
石油天然气   229篇
武器工业   156篇
无线电   3901篇
一般工业技术   1161篇
冶金工业   167篇
原子能技术   153篇
自动化技术   15355篇
  2024年   57篇
  2023年   436篇
  2022年   646篇
  2021年   804篇
  2020年   891篇
  2019年   690篇
  2018年   703篇
  2017年   924篇
  2016年   1109篇
  2015年   1347篇
  2014年   1966篇
  2013年   1827篇
  2012年   2097篇
  2011年   2020篇
  2010年   1357篇
  2009年   1346篇
  2008年   1458篇
  2007年   1596篇
  2006年   1250篇
  2005年   1165篇
  2004年   980篇
  2003年   821篇
  2002年   626篇
  2001年   526篇
  2000年   415篇
  1999年   335篇
  1998年   245篇
  1997年   226篇
  1996年   193篇
  1995年   178篇
  1994年   163篇
  1993年   114篇
  1992年   122篇
  1991年   58篇
  1990年   51篇
  1989年   50篇
  1988年   45篇
  1987年   30篇
  1986年   22篇
  1985年   24篇
  1984年   19篇
  1983年   14篇
  1982年   7篇
  1981年   6篇
  1980年   9篇
  1979年   8篇
  1977年   8篇
  1976年   5篇
  1975年   3篇
  1972年   2篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
随着医疗服务体系的发展和进步,越来越多的医院开始将云计算技术引入信息服务系统,使医院信息化建设得到了迅速发展。文章分析了云计算技术的特点及其在智能医院信息服务中的应用和影响,以期促进该技术在未来的发展和推广。  相似文献   
12.
The alternating direction multiplier method (ADMM) is widely used in computer graphics for solving optimization problems that can be nonsmooth and nonconvex. It converges quickly to an approximate solution, but can take a long time to converge to a solution of high-accuracy. Previously, Anderson acceleration has been applied to ADMM, by treating it as a fixed-point iteration for the concatenation of the dual variables and a subset of the primal variables. In this paper, we note that the equivalence between ADMM and Douglas-Rachford splitting reveals that ADMM is in fact a fixed-point iteration in a lower-dimensional space. By applying Anderson acceleration to such lower-dimensional fixed-point iteration, we obtain a more effective approach for accelerating ADMM. We analyze the convergence of the proposed acceleration method on nonconvex problems, and verify its effectiveness on a variety of computer graphics including geometry processing and physical simulation.  相似文献   
13.
Investigations were performed on a group utilizing (General Purpose Unit) GPU and executions were evaluated for the utilization of the created parallel usages to process satellite pictures from satellite Landsat7.The usage on a realistic group gives execution change from 2 to 18 times. The nature of the considered techniques was assessed by relative dimensionless global error in synthesis (ERGAS) and Quality Without Reference (QNR) measurements. The outcomes demonstrate execution picks ups and holding of value with the bunch of GPU contrasted with the outcomes and different analysts for a CPU and single GPU. The errand of upgrading the view of a scene by combining data caught from various picture sensors is usually known as multisensor picture combination. This paper displays a territory based picture combination calculation to consolidate SAR (Synthetic Aperture Radar) and optical pictures. The co-enlistment of the two images is first led utilizing the proposed enrollment method prior to picture combination. The paper displays a parallel execution of existing picture combination techniques on a graphical group. Parallel executions of techniques in view of discrete wavelet changes are created. Division into dynamic and motionless regions is then executed on the SAR surface picture for particular injection of the SAR picture into panchromatic (PAN) picture. An integrated image in view of these two pictures is produced by the novel region based combination plot, which forces diverse combination rules for each fragmented region. At long last, this picture is melded into a multispectral(MS) picture through the half breed skillet honing technique proposed in past research. Exploratory outcomes exhibit that the proposed strategy demonstrates preferred execution over different fusion algorithms and can possibly be connected to the multisensory combination of SAR and optical pictures.  相似文献   
14.
Deep learning has gained a significant popularity in recent years thanks to its tremendous success across a wide range of relevant fields of applications, including medical image analysis domain in particular. Although convolutional neural networks (CNNs) based medical applications have been providing powerful solutions and revolutionizing medicine, efficiently training of CNNs models is a tedious and challenging task. It is a computationally intensive process taking long time and rare system resources, which represents a significant hindrance to scientific research progress. In order to address this challenge, we propose in this article, R2D2, a scalable intuitive deep learning toolkit for medical imaging semantic segmentation. To the best of our knowledge, the present work is the first that aims to tackle this issue by offering a novel distributed versions of two well-known and widely used CNN segmentation architectures [ie, fully convolutional network (FCN) and U-Net]. We introduce the design and the core building blocks of R2D2. We further present and analyze its experimental evaluation results on two different concrete medical imaging segmentation use cases. R2D2 achieves up to 17.5× and 10.4× speedup than single-node based training of U-Net and FCN, respectively, with a negligible, though still unexpected segmentation accuracy loss. R2D2 offers not only an empirical evidence and investigates in-depth the latest published works but also it facilitates and significantly reduces the effort required by researchers to quickly prototype and easily discover cutting-edge CNN configurations and architectures.  相似文献   
15.
针对异构计算节点组成的大规模多状态计算系统的容错性能分析问题,提出了一种计算系统容错性能的评估方法。该方法采用自定义的两级容错性能形式化描述框架进行系统描述,通过构造多值决策图(Multi-value Decision Diagram,MDD)模型对系统进行容错性能建模,并基于构造的模型高效地计算出部件故障的条件下计算系统在特定性能水平上运行的概率,减少了计算的冗余性。实验结果表明,该方法在模型的大小和构建时间上均优于传统方法。该方法的提出将对系统操作员或程序设计者具有重要意义,使其确保系统适合预期应用。  相似文献   
16.
A model for the simulation of geothermal systems with parallel- and series-connected boreholes is presented. Mass and heat balance problems are formulated for each component in the system and are assembled into system-level problems. A third problem is formulated to account for heat transfer in the bore field, using the finite line source solution. This third problem is coupled to the system-level heat balance problem by an analytical solution of the heat transfer inside boreholes with multiple U-tubes. The simulation model allows for any number of independent fluid loops within the bore field or within individual boreholes and allows for combinations of specified inlet fluid temperatures and heat extraction rates in independent fluid loops. The model accounts for the axial variation of the fluid and borehole wall temperatures and heat extraction rates. The capabilities of the model are demonstrated through three example simulations.  相似文献   
17.
Efficient energy and temperature management techniques are essential elements for operators of cloud data centers. Dynamic virtual machine (VM) consolidation using live migration techniques presents a great opportunity for cloud service providers to adaptively reduce energy consumption and optimize their resource utilization. In recent studies, power consumption readings of individual physical hosts were chosen as the main monitoring parameters in their allocation policies, whereas very few have considered host temperature, which has shown to have a negative impact on server reliability, as a migration criterion. In this work, a thermal-aware VM consolidation mechanism is proposed for resource allocation optimization and server reliability assurance. We consider the variability in host temperature as a migration criterion to avoid outage incidents via having better VM consolidations. Extensive simulation results obtained from CloudSim show the promising performance of the proposed mechanism in energy saving while reducing the number of server outage incidents due to fluctuations in host temperature.  相似文献   
18.
在高性能计算领域,数据流是一类重要的计算结构,也在很多实际场景表现出很好的性能和适用性。在数据流计算模式中,程序是以数据流图来表示的,数据流计算中一个关键的问题是如何将数据流图映射到多个执行单元上。通过分析现有数据流结构的指令映射方法及其不足,提出了基于数据流结构的新型指令映射优化方法。主要是根据多地址共享数据包的特性对指令映射方法进行优化,延迟多地址共享数据路由包的拆分,减少网络拥堵。  相似文献   
19.
徐雅斌  彭宏恩 《计算机应用》2019,39(6):1583-1588
针对缺乏PaaS平台下资源需求的有效预测与优化分配的问题,提出一种资源需求预测模型和分配方法。首先,根据PaaS平台中应用对资源需求的周期性来对资源序列进行切分,并在短期预测的基础上结合应用的多周期性特征,利用多元回归算法建立综合的预测模型。然后,基于MapReduce架构设计实现了一个Master-Slave模式的PaaS平台资源分配系统。最后,结合当前任务请求和资源需求预测结果进行资源分配。实验结果表明,采用该资源需求预测模型和分配方法后,相比于自回归模型和指数平滑算法,平均绝对百分比误差分别下降8.71个百分点和2.07个百分点,均方根误差分别下降2.01个百分点和0.46个百分点。所提预测模型的预测结果不仅误差小,与真实值的拟合程度也较高,而且利用较小的时间开销就可以获得较高的准确度。此外,使用该预测模型的PaaS平台的资源请求的平均等待时间有了明显的下降。  相似文献   
20.
In this study, the analysis of nonlinear stability with viscoelastic ferromagnetic fluids as working media is performed by finite-amplitude perturbations. The solution of the resulting nonautonomous system of the Lorenz model (generalized Khayat–Lorenz model of four modes) is obtained numerically to measure the amount of heat transport. The effects of elastic parameters, Prandtl number, modulation parameters, buoyancy magnetic parameter, and nonbuoyancy magnetic parameter on heat transport are studied. Heat transport is quantified through the average Nusselt number, which is determined by solving the scaled Lorenz model. As limiting cases of the study, the results of Newtonian, Maxwell, Rivlin–Ericksen fluids are determined. The results obtained have been presented graphically.  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