全文获取类型
收费全文 | 635篇 |
免费 | 79篇 |
国内免费 | 109篇 |
专业分类
电工技术 | 18篇 |
综合类 | 38篇 |
化学工业 | 101篇 |
金属工艺 | 8篇 |
机械仪表 | 20篇 |
建筑科学 | 50篇 |
矿业工程 | 42篇 |
能源动力 | 23篇 |
轻工业 | 13篇 |
水利工程 | 2篇 |
石油天然气 | 10篇 |
武器工业 | 1篇 |
无线电 | 112篇 |
一般工业技术 | 55篇 |
冶金工业 | 6篇 |
原子能技术 | 4篇 |
自动化技术 | 320篇 |
出版年
2024年 | 3篇 |
2023年 | 27篇 |
2022年 | 46篇 |
2021年 | 48篇 |
2020年 | 53篇 |
2019年 | 55篇 |
2018年 | 30篇 |
2017年 | 28篇 |
2016年 | 33篇 |
2015年 | 33篇 |
2014年 | 40篇 |
2013年 | 52篇 |
2012年 | 44篇 |
2011年 | 47篇 |
2010年 | 23篇 |
2009年 | 29篇 |
2008年 | 32篇 |
2007年 | 36篇 |
2006年 | 28篇 |
2005年 | 28篇 |
2004年 | 15篇 |
2003年 | 21篇 |
2002年 | 19篇 |
2001年 | 6篇 |
2000年 | 6篇 |
1999年 | 11篇 |
1998年 | 6篇 |
1997年 | 2篇 |
1996年 | 5篇 |
1995年 | 5篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1988年 | 2篇 |
排序方式: 共有823条查询结果,搜索用时 15 毫秒
1.
David Mills 《Granular Matter》2004,6(2-3):173-177
For fine powdered materials, capable of being conveyed in dense phase, a conveying region exists in which instability in flow and pipeline blockage can occur if the pressure gradient available is insufficient to maintain a minimum value of solids loading ratio. A reduction in material flow rate can also lead to pipeline blockage in this region. Conveying trials under-taken with cement are used to illustrate the nature of the problem. 相似文献
2.
Discretization of boundary integral equations leads, in general, to fully populated non-symmetric linear systems of equations. An inherent drawback of boundary element method (BEM) is that, the non-symmetric dense linear systems must be solved. For large-scale problems, the direct methods require expensive computational cost and therefore the iterative methods are perhaps more preferable. This paper studies the comparative performances of preconditioned Krylov subspace solvers as bi-conjugate gradient (Bi-CG), generalized minimal residual (GMRES), conjugate gradient squared (CGS), quasi-minimal residual (QMR) and bi-conjugate gradient stabilized (Bi-CGStab) for the solution of dense non-symmetric systems. Several general preconditioners are also considered and assessed. The results of numerical experiments suggest that the preconditioned Krylov subspace methods are effective approaches solving the large-scale dense non-symmetric linear systems arising from BEM. 相似文献
3.
The rate of filtration and the water content of cake are influenced by the existence of a dense skin in a highly compressible
cake. The phenomenon of the dense skin has been rarely studied, and its existence has not been verified experimentally. In
this study, the porosity variation in a very compressible cake is measured by using a new experimental apparatus, and with
this the existence of dense skin has been established experimentally. ‘Unified theory on solid-liquid separation’, a recently
developed theory, is utilized for calculating the porosity variation in a very compressible cake. 相似文献
4.
Herbert J. Bernstein 《Quantum Information Processing》2006,5(6):451-461
Recent advances in experimental technique make SuperDense Teleportation (SDT) possible only now, ten years after my first proposal at an ISI Torino summer conference on Quantum Computing. The effect uses remote state preparation to send more state-specifying parameters per bit than ordinary quantum teleportation (QT) can transmit. The SDT uses a maximally entangled state to teleport the relative phases of an n-dimensional state with equal amplitudes on every standard basis vector. For n greater than or equal to 3, the SDT sends more of these state-specifying parameters than QT. In the limit of large n the ratio is 2 to 1, hence the nomenclature by analogy with Super Dense Coding. Alice’s measurements and Bob’s transformations are far simpler than their corresponding operations in QT. The roles of Charles who chooses the state and Diana who deploys it are different than in QT. My discussion includes a brief review of the progress and possibilities of realization for several different experimental approaches around the world. This paper is the write-up of my remarks at the Festschrift conference for Anton Zeilinger, for many years a close collaborator in the Hampshire College NSF grant continuing our work with Mike Horne and Danny Greenberger started under Cliff Shull at MIT in the late 20th century. 相似文献
5.
一种基于多Agent的人群仿真多机并行平台研究 总被引:1,自引:0,他引:1
本文提出了一种针对多Agent人群仿真模型的多机并行平台,该平台利用MPI作为节点间的通讯软件,采用主从模式设计多机并行执行环境。在主控节点中设置结果回收模块与监控模块,通过K-means算法保证执行节点之间的负载均衡,同时以此作为任务分发与调度的依据;在执行节点(从节点)中,则根据主控节点的任务调度执行相关Agent模型,并执行仿真同步与状态信息汇报等任务。实验结果表明,该多机并行平台能够执行基于多Agent的人群仿真模型,能有效地提高仿真的性能,同时具有良好的可扩展性。 相似文献
6.
超低碳不锈钢316L管-管板的焊接采用手工钨极氩弧焊,对316L不锈钢的焊接性进行了分析和研究,通过工艺试验,证明了焊接工艺的可靠性,并在不锈钢浓H2SO4冷却器阳极保护(管壳式)设备的焊接中取得了满意的效果. 相似文献
7.
8.
9.
研究图像在频域中的纹理特性,实现了在频域中的人群密度估计.首先,对视频的每一帧进行离散余弦变换(DCT),将视频图像的空域性质转化到频域中;其次,统计分析视频图像DCT变换矩阵的纹理特性,提取能描述不同密度等级的纹理描述子作为特征向量;最后,用提取出的特征向量训练概率神经网络,并进行人群密度等级估计.实验表明,该方法可以很好地进行密度估计,获得了较高识别效率. 相似文献
10.