全文获取类型
收费全文 | 21286篇 |
免费 | 1654篇 |
国内免费 | 888篇 |
专业分类
电工技术 | 1087篇 |
综合类 | 1379篇 |
化学工业 | 3715篇 |
金属工艺 | 1440篇 |
机械仪表 | 1198篇 |
建筑科学 | 1555篇 |
矿业工程 | 777篇 |
能源动力 | 509篇 |
轻工业 | 1401篇 |
水利工程 | 367篇 |
石油天然气 | 1540篇 |
武器工业 | 202篇 |
无线电 | 2221篇 |
一般工业技术 | 2814篇 |
冶金工业 | 1162篇 |
原子能技术 | 192篇 |
自动化技术 | 2269篇 |
出版年
2024年 | 107篇 |
2023年 | 364篇 |
2022年 | 666篇 |
2021年 | 927篇 |
2020年 | 725篇 |
2019年 | 600篇 |
2018年 | 625篇 |
2017年 | 732篇 |
2016年 | 618篇 |
2015年 | 880篇 |
2014年 | 1099篇 |
2013年 | 1212篇 |
2012年 | 1318篇 |
2011年 | 1508篇 |
2010年 | 1266篇 |
2009年 | 1224篇 |
2008年 | 1096篇 |
2007年 | 1192篇 |
2006年 | 1146篇 |
2005年 | 979篇 |
2004年 | 614篇 |
2003年 | 555篇 |
2002年 | 554篇 |
2001年 | 470篇 |
2000年 | 475篇 |
1999年 | 556篇 |
1998年 | 411篇 |
1997年 | 377篇 |
1996年 | 327篇 |
1995年 | 294篇 |
1994年 | 250篇 |
1993年 | 173篇 |
1992年 | 133篇 |
1991年 | 83篇 |
1990年 | 63篇 |
1989年 | 48篇 |
1988年 | 54篇 |
1987年 | 31篇 |
1986年 | 23篇 |
1985年 | 11篇 |
1984年 | 12篇 |
1983年 | 12篇 |
1982年 | 10篇 |
1981年 | 5篇 |
1980年 | 1篇 |
1959年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
21.
Cui‐Zhen Yao 《Asian journal of control》2013,15(5):1531-1537
This article considers stabilization of a one‐dimensional Schrödinger equation with variable coefficient and boundary observation which suffers from an arbitrary given time delay. We design an observer and predictor to stabilize the system. The state is estimated in the time span where the observation is available, and also predicted in the time interval where the observation is not available. It is shown that the estimated state feedback stabilizes the system exponentially. A numerical simulation is presented to illustrate the effect of the stabilizing controller. 相似文献
22.
SoC测试访问机制和测试壳的蚁群联合优化 总被引:2,自引:0,他引:2
针对系统级芯片(SoC)测试壳优化和测试访问机制的测试总线划分问题,提出了基于蚁群算法的SoC Wrapper/TAM联合优化方法.构造蚁群算法时首先进行IP核的测试壳优化,用于缩短最长扫描链长度,减少单个IP核的测试时间;在此基础上进行TAM结构的蚁群优化,通过算法迭代逼近测试总线的最优划分,从而缩短SoC测试时间.对ITC2002基准SoC电路进行实验的结果表明,该方法能有效地解决SoC测试优化问题. 相似文献
23.
实现全面资源共享、充分提高资源利用率是教育资源网格的主要研究目标,为了实现该目标,设计了ERGM(educa-tion resource grid monitor)监控模型,它具有采集的信息全面、良好的可扩展性和容错性等优点.通过它可以及时采集资源的状态信息为资源调度系统提供依据,使资源的利用更加合理,很好地满足了教育资源网格监控的需求. 相似文献
24.
变分问题是一个研究泛函极值的经典数学问题,寻求变分问题的直接解法具有重要的理论和现实意义.鉴于PSO算法在极值问题中的广泛应用,利用分段Hermite插值.建立了求解含一阶导数的变分问题优化模型,构造出了适应度函数,从而使得PSO算法成功应用到变分问题的求解当中.数值实验结果表明了方法的可行性,同时也拓展了PSO算法的应用领域. 相似文献
25.
介绍某型号合成孔径雷达系统的1553B总线通信接口设计方案与工程实现;方案采用国内自主研发的4M/s速率1553B总线接口芯片,PC/104工控机与FPGA结合,通过硬件系统设计和软件编程,实现对1553B总线数据收发和雷达部分辅助数据的提供,实现项目总体对1553B总线通信接口的要求。实际应用情况表明,该通信接口运行稳定、可靠,具有一定的实用性和良好的应用前景。 相似文献
26.
Afify M. Cui X. Gao Y. 《IEEE transactions on audio, speech, and language processing》2009,17(7):1325-1334
We present a stochastic mapping technique for robust speech recognition that uses stereo data. The idea is based on constructing a Gaussian mixture model for the joint distribution of the clean and noisy features and using this distribution to predict the clean speech during testing. The proposed mapping is called stereo-based stochastic mapping (SSM). Two different estimators are considered. One is iterative and is based on the maximum a posteriori (MAP) criterion while the other uses the minimum mean square error (MMSE) criterion. The resulting estimators are effectively a mixture of linear transforms weighted by component posteriors, and the parameters of the linear transformations are derived from the joint distribution. Compared to the uncompensated result, the proposed method results in 45% relative improvement in word error rate (WER) for digit recognition in the car. In the same setting, SSM outperforms SPLICE and gives similar results to MMSE compensation of Huang A 66% relative improvement in word error rate (WER) is observed when applied in conjunction with multistyle training (MST) for large vocabulary English speech recognition in a real environment. Also, the combination of the proposed mapping with CMLLR leads to about 38% relative improvement in performance compared to CMLLR alone for real field data. 相似文献
27.
Li Shibao Wang Mingyu Wang Xiaoli Li Chen Liu Jianhang Cui Xuerong 《Wireless Networks》2022,28(6):2519-2531
Wireless Networks - In the unmanned ship networking scenario, the position of the unmanned ship changes continuously, leading to the result that the desired transmitters and the interference... 相似文献
28.
Cui Ying Guo Dongyan Shao Yanyan Wang Zhenhua Shen Chunhua Zhang Liyan Chen Shengyong 《International Journal of Computer Vision》2022,130(2):550-566
International Journal of Computer Vision - Visual tracking of generic objects is one of the fundamental but challenging problems in computer vision. Here, we propose a novel fully convolutional... 相似文献
29.
The issues of hydrogen generation and storage have hindered the widespread use and commercialization of hydrogen fuel cell vehicles.It is thus highly attractive,but the design and development of highly active non-noble-metal catalysts for on-demand hydrogen release from alkaline NaBH4 solution under mild conditions remains a key challenge.Herein,we describe the use of CoP nanowire array integrated on a Ti mesh (CoP NA/Ti) as a three-dimensional (3D) monolithic catalyst for efficient hydrolytic dehydrogenation of NaBH4 in basic solutions.The CoP NA/Ti works as an on/off switch for on-demand hydrogen generation at a rate of 6,500 mL/(min.g) and a low activation energy of 41 kJ/mol.It is highly robust for repeated usage after recycling,without sacrificing catalytic performance.Remarkably,this catalyst also performs efficiently for the hydrolysis of NH3BH3. 相似文献
30.
Molecular dynamic model of nanofluid between flat plates under shear flow conditions was built. The nanofluid model consisted
of 12 spherical copper nanoparticles with each particle diameter of 4 nm and argon atoms as base liquid. The Lennard–Jones
(LJ) potential function was adopted to deal with the interactions between atoms. Thus, the motion states of nanoparticles
during the process of flowing were obtained and the flow behaviors of nanofluid between flat plates at different moments could
be analyzed. The simulation results showed that an absorption layer of argon atoms existed surrounding each nanoparticle and
would accompany with the particle to move. The absorption layer contributed little to the flow of nanoparticles but much to
the heat transferring in nanofluids. Another phenomenon observed during shear flowing process was that the nanoparticles would
vibrate and rotate besides main flowing with liquid argon and these micro-motions could strengthen partial flowing in nanofluids. 相似文献