全文获取类型
收费全文 | 14504篇 |
免费 | 1143篇 |
国内免费 | 110篇 |
专业分类
电工技术 | 247篇 |
技术理论 | 1篇 |
综合类 | 98篇 |
化学工业 | 3346篇 |
金属工艺 | 560篇 |
机械仪表 | 999篇 |
建筑科学 | 307篇 |
矿业工程 | 45篇 |
能源动力 | 671篇 |
轻工业 | 1093篇 |
水利工程 | 71篇 |
石油天然气 | 133篇 |
武器工业 | 10篇 |
无线电 | 2648篇 |
一般工业技术 | 3023篇 |
冶金工业 | 827篇 |
原子能技术 | 211篇 |
自动化技术 | 1467篇 |
出版年
2024年 | 20篇 |
2023年 | 191篇 |
2022年 | 265篇 |
2021年 | 495篇 |
2020年 | 389篇 |
2019年 | 363篇 |
2018年 | 457篇 |
2017年 | 493篇 |
2016年 | 551篇 |
2015年 | 442篇 |
2014年 | 673篇 |
2013年 | 952篇 |
2012年 | 957篇 |
2011年 | 1147篇 |
2010年 | 870篇 |
2009年 | 871篇 |
2008年 | 824篇 |
2007年 | 595篇 |
2006年 | 561篇 |
2005年 | 538篇 |
2004年 | 482篇 |
2003年 | 422篇 |
2002年 | 390篇 |
2001年 | 335篇 |
2000年 | 305篇 |
1999年 | 331篇 |
1998年 | 412篇 |
1997年 | 259篇 |
1996年 | 228篇 |
1995年 | 144篇 |
1994年 | 155篇 |
1993年 | 111篇 |
1992年 | 68篇 |
1991年 | 83篇 |
1990年 | 57篇 |
1989年 | 56篇 |
1988年 | 36篇 |
1987年 | 39篇 |
1986年 | 23篇 |
1985年 | 19篇 |
1984年 | 23篇 |
1983年 | 23篇 |
1982年 | 13篇 |
1981年 | 20篇 |
1980年 | 9篇 |
1979年 | 10篇 |
1978年 | 5篇 |
1977年 | 13篇 |
1976年 | 11篇 |
1974年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Jeong‐Doo Yi Joon‐Yeon Kim Tae‐Woo Kim Hak‐Cheol Yang Jeong‐Nam Kim Yoon‐Hyoung Cho 《Journal of the Society for Information Display》2005,13(11):883-888
Abstract— We propose a PDP having a new structure and driving scheme. An auxiliary electrode was inserted between X and Y electrodes. Driving and discharge stability was determined using a test panel. A 42‐in. SD (852 × 480) panel and a 42‐in. HD (1366 × 768) panel were also made having this new structure, and we verified the increase in luminous efficacy and the reduction of ionic losses. We achieved a luminous efficacy of 2.35 lm/W in an SD panel and 1.97 lm/W in a HD panel. Finally, we investigated the characteristics and merits of the new structure. 相似文献
992.
Moon Gi Cho Kyung Wook Paik Hyuck Mo Lee Seong Woon Booh Tae-Gyu Kim 《Journal of Electronic Materials》2006,35(1):35-40
The interfacial reaction between 42Sn-58Bi solder (in wt.% unless specified otherwise) and electroless Ni-P/immersion Au was
investigated before and after thermal aging, with a focus on the formation and growth of an intermetallic compound layer,
consumption of under bump metallurgy (UBM), and bump shear strength. The immersion Au layer with thicknesses of 0 μm (bare
Ni), 0.1 μm, and 1 μm was plated on a 5-μm-thick layer of electroless Ni-P (with 14–15 at.% P). The 42Sn-58Bi solder balls
were then fabricated on three different UBM structures by using screen printing and pre-reflow. A Ni3Sn4 layer formed at the joint interface after the pre-reflow for all three UBM structures. On aging at 125°C, a quaternary phase,
identified as Sn77Ni15Bi6Au2, was observed above the Ni3Sn4 layer in the UBM structures that contain Au. The thick Sn77Ni15Bi6Au2 layer degraded the integrity of the solder joint, and the shear strength of the solder bump was about 40% less than the nonaged
joints. 相似文献
993.
994.
A shared disks (SD) cluster couples multiple computing nodes for high performance transaction processing, and all nodes share
a common database at the disk level. In the SD cluster, a front-end router selects a node for an incoming transaction to be
executed. An affinity-based routing can increase the buffer hit ratio of each node by clustering transactions referencing
similar data to be executed on the same node. However, the affinity-based routing is non-adaptive to the changes of the system
load. This means that a specific node would be overloaded if corresponding transactions rush into the system. In this paper,
we propose a new transaction routing algorithm, named Dynamic Affinity Cluster Allocation (DACA). DACA can make an optimal balance between the affinity-based routing and indiscriminate sharing of load in the SD
cluster. As a result, DACA can increase the buffer hit ratio and reduce the frequency of inter-node buffer invalidations while
achieving the dynamic load balancing. 相似文献
995.
Doo-Yeoun Cho Author Vitae Author Vitae Tae-Wan Kim Author Vitae 《Computer aided design》2006,38(6):641-660
We propose a local method of constructing piecewise G1 Bézier patches to span an irregular curve network, without modifying the given curves at odd- and 4-valent node points. Topologically irregular regions of the network are approximated by implicit surfaces, which are used to generate split curves, which subdivide the regions into triangular and/or rectangular sub-regions. The subdivided regions are then interpolated with Bézier patches. We analyze various singular cases of the G1 condition that is to be met by the interpolation and propose a new G1 continuity condition using linear and quartic scalar weight functions. Using this condition, a curve network can be interpolated without modification at 4-valent nodes with two collinear tangent vectors, even in the presence of singularities. We demonstrate our approach in a ship hull. 相似文献
996.
997.
This paper presents a segmentation algorithm for 3D triangular mesh data. The proposed algorithm uses iterative merging of adjacent triangle pairs based on their orientations. The oversegmented regions are merged again in an iterative region merging process. Finally, the noisy boundaries of each region are refined. The boundaries of each region contain perceptually important geometric information of the entire mesh model. According to the purpose of the segmentation, the proposed mesh-segmentation algorithm supports various types of segmentation by controlling parameters. 相似文献
998.
To avoid the state–space explosion by including tick events in timed discrete event systems (DESs) under partial observation, a notion of eligible time bounds is introduced and based on the notion, controllability and observability conditions of languages are presented. In particular, this paper shows that these controllability and observability conditions are necessary and sufficient for the existence of a supervisor to achieve the given language specification. 相似文献
999.
对于粘性绕流的数值模拟,在直角叉树切割网格的基础上,结合三角形非结构网格和矩形结构化网格,利用其各自的优势和特点,提出了一种生成混合染交网格的思路和方法,在物面附近生成了适合粘性流计算的大长宽比矩形网格,地远场分布直角叉树切割网格,快速离散计算空间。对于复杂的多体问题,采用三角形网格来连接 各体网格,并运用网格合并的方法,保证了各网格之间的光滑过渡过连接,提高了网格的质量,针对复杂多段翼型绕流问题,在上述网格基础上,采用B-L代数湍流模型和中心有限体积法,完成了Navier-Stokes方程(N-S方程)的数值模拟,计算结果表明,网格生成和流场计算都是正确的。 相似文献
1000.
Integrated position estimation using aerial image sequences 总被引:10,自引:0,他引:10
Dong-Gyu Sim Rae-Hong Park Rin-Chul Kim Sang Uk Lee Ihn-Cheol Kim 《IEEE transactions on pattern analysis and machine intelligence》2002,24(1):1-18
Presents an integrated system for navigation parameter estimation using sequential aerial images, where the navigation parameters represent the positional and velocity information of an aircraft for autonomous navigation. The proposed integrated system is composed of two parts: relative position estimation and absolute position estimation. Relative position estimation recursively computes the current position of an aircraft by accumulating relative displacement estimates extracted from two successive aerial images. Simple accumulation of parameter values reduces the reliability of the extracted parameter estimates as an aircraft goes on navigating, resulting in a large positional error. Therefore, absolute position estimation is required to compensate for the positional error generated by the relative position estimation. Absolute position estimation algorithms using image matching and digital elevation model (DEM) matching are presented. In the image matching, a robust-oriented Hausdorff measure (ROHM) is employed, whereas in the DEM matching, an algorithm using multiple image pairs is used. Experiments with four real aerial image sequences show the effectiveness of the proposed integrated position estimation algorithm 相似文献