全文获取类型
收费全文 | 7211篇 |
免费 | 612篇 |
国内免费 | 614篇 |
专业分类
电工技术 | 84篇 |
综合类 | 307篇 |
化学工业 | 1506篇 |
金属工艺 | 208篇 |
机械仪表 | 205篇 |
建筑科学 | 240篇 |
矿业工程 | 51篇 |
能源动力 | 437篇 |
轻工业 | 250篇 |
水利工程 | 118篇 |
石油天然气 | 40篇 |
武器工业 | 1篇 |
无线电 | 1169篇 |
一般工业技术 | 1085篇 |
冶金工业 | 109篇 |
原子能技术 | 63篇 |
自动化技术 | 2564篇 |
出版年
2024年 | 25篇 |
2023年 | 311篇 |
2022年 | 220篇 |
2021年 | 337篇 |
2020年 | 372篇 |
2019年 | 348篇 |
2018年 | 211篇 |
2017年 | 414篇 |
2016年 | 383篇 |
2015年 | 311篇 |
2014年 | 456篇 |
2013年 | 464篇 |
2012年 | 506篇 |
2011年 | 640篇 |
2010年 | 488篇 |
2009年 | 565篇 |
2008年 | 393篇 |
2007年 | 487篇 |
2006年 | 449篇 |
2005年 | 197篇 |
2004年 | 83篇 |
2003年 | 83篇 |
2002年 | 84篇 |
2001年 | 64篇 |
2000年 | 52篇 |
1999年 | 69篇 |
1998年 | 31篇 |
1997年 | 19篇 |
1996年 | 31篇 |
1995年 | 25篇 |
1994年 | 15篇 |
1993年 | 25篇 |
1992年 | 18篇 |
1991年 | 28篇 |
1990年 | 19篇 |
1989年 | 13篇 |
1988年 | 28篇 |
1987年 | 58篇 |
1986年 | 50篇 |
1985年 | 12篇 |
1984年 | 13篇 |
1983年 | 10篇 |
1982年 | 2篇 |
1981年 | 7篇 |
1980年 | 4篇 |
1979年 | 12篇 |
1978年 | 1篇 |
1976年 | 4篇 |
排序方式: 共有8437条查询结果,搜索用时 0 毫秒
21.
压缩技术被广泛应用于数据存储和传输中,然而由于其内在的串行特性,大多数已有的基于字典的压缩与解压缩算法被设计在CPU上串行执行。为了探究使用图形处理器(graphic processing unit,GPU)对压缩与解压缩过程潜在性能的提升,结合合并内存访问与并行组装的技术,基于CUDA(compute unified device archi-tecture)平台研究了两种并行压缩与解压缩方法:基于字典的无状态压缩和基于字典的LZW压缩。实验结果表明,与传统的单核实现比较,所提方法能够显著改善已有的基于字典的串行压缩与解压缩算法的性能。 相似文献
22.
Hao Lili Zhan Xisheng Wu Jie Han Tao Yan Huaicheng 《International Journal of Control, Automation and Systems》2021,19(1):200-208
This paper deals with the fixed-time group consensus problem for multi-agent systems (MASs) subjected to exogenous disturbances. Firstly, two pinning control algorithms are constructed for MASs, which not only reduce the number of controllers but also achieve expected tracking consensus. Secondly, fixed-time group consensus is ensured by utilizing the algebraic graph theory, Lyapunov stability and fixed-time control technique. Finally, simulations are finally given for demonstrate the availability of the derived results.
相似文献23.
Modern database systems desperate for the ability to support highly scalable transactions and efficient queries simultaneously for real-time applications. One solution is to utilize query optimization techniques on the on-line transaction processing (OLTP) systems. The materialized view is considered as a panacea to decrease query latency. However, it also involves the significant cost of maintenance which trades away transaction performance. In this paper, we examine the design space and conclude several design features for the implementation of a view on a distributed log-structured merge-tree (LSMtree), which is a well-known structure for improving data write performance. As a result, we develop two incremental view maintenance (IVM) approaches on LSM-tree. One avoids join computation in view maintenance transactions. Another with two optimizations is proposed to decouple the view maintenance with the transaction process. Under the asynchronous update, we also provide consistency queries for views. Experiments on TPC-H benchmark show our methods achieve better performance than straightforward methods on different workloads. 相似文献
24.
A dynamic pushdown network (DPN) is a set of pushdown systems (PDSs) where each process can dynamically create new instances of PDSs. DPNs are a natural model of multi-threaded programs with (possibly recursive) procedure calls and thread creation. Thus, it is important to have model checking algorithms for DPNs. We consider in this work model checking DPNs against single-indexed LTL and CTL properties of the form \({\bigwedge f_i}\) such that f i is a LTL/CTL formula over the PDS i. We consider the model checking problems w.r.t. simple valuations (i.e., whether a configuration satisfies an atomic proposition depends only on its control location) and w.r.t. regular valuations (i.e., the set of the configurations satisfying an atomic proposition is a regular set of configurations). We show that these model checking problems are decidable. We propose automata-based approaches for computing the set of configurations of a DPN that satisfy the corresponding single-indexed LTL/CTL formula. 相似文献
25.
26.
核反应堆中需要实时精确地计算堆芯和增殖材料的有效共振积分或群截面来实现反应堆的安全控制。整个计算过程因为涉及大量的积分运算和庞大的核素截面数据,采用常规的计算方法,计算时耗相当大。基于统一计算设备架构(CUDA)平台,利用图形处理器(GPU)的计算能力,对整个计算过程进行并行化分解,多线程同时运算,大幅度提升计算速度,降低时耗。实验结果表明,在GPU上并行计算所得结果与原始数据没有明显差异,且加速效果显著。 相似文献
27.
28.
美国Nova科学出版公司自2009年起出版以评介化学各分支领域的进展和应用前景为重点的《化学研究与应用》(Chemical Research and Applications)系列丛书,涵盖了化学的各个分支领域。预计到2012年底共出版125卷。目前已列 相似文献
29.
朱贇 《数字社区&智能家居》2013,(23):5326-5327
该文对C语言教学中两种不同的教学思路做了举例、分析和比较,偏重算法的教学有助于培养学生研究算法编制程序的能力,但对初学者培养兴趣、树立信心方面没有益处,在这方面偏重语法的教学更有效率,建议在教学实践中注重两者的结合。 相似文献
30.
This paper proposes a discrete-time nonsmooth internal model control (NSIMC) approach for mechanical transmission systems described by so-called sandwich system with backlash. In this method, a dynamic compensator is introduced to compensate for the effect of the input linear subsystem. Thus, the sandwich systems with backlash can be simplified as a pseudo-Hammerstein system with backlash. The corresponding NSIMC strategy is designed to control this system. The design procedure of the controller is presented based on the analysis on the robust stability by considering the model errors involved with the effect of backlash as well as the compensated error of the input linear subsystem. Moreover, as the model is switched among the different operating zones, the robust filters are proposed to guarantee the robust stability and satisfactory control performance of the system. 相似文献