全文获取类型
收费全文 | 85406篇 |
免费 | 8894篇 |
国内免费 | 5231篇 |
专业分类
电工技术 | 6355篇 |
技术理论 | 4篇 |
综合类 | 7006篇 |
化学工业 | 12127篇 |
金属工艺 | 5452篇 |
机械仪表 | 5987篇 |
建筑科学 | 6559篇 |
矿业工程 | 2836篇 |
能源动力 | 2424篇 |
轻工业 | 7843篇 |
水利工程 | 2265篇 |
石油天然气 | 3698篇 |
武器工业 | 1071篇 |
无线电 | 9272篇 |
一般工业技术 | 9146篇 |
冶金工业 | 3701篇 |
原子能技术 | 1269篇 |
自动化技术 | 12516篇 |
出版年
2024年 | 471篇 |
2023年 | 1529篇 |
2022年 | 3019篇 |
2021年 | 3996篇 |
2020年 | 2936篇 |
2019年 | 2373篇 |
2018年 | 2510篇 |
2017年 | 2815篇 |
2016年 | 2548篇 |
2015年 | 3721篇 |
2014年 | 4584篇 |
2013年 | 5467篇 |
2012年 | 6414篇 |
2011年 | 6725篇 |
2010年 | 6180篇 |
2009年 | 5874篇 |
2008年 | 5727篇 |
2007年 | 5596篇 |
2006年 | 4913篇 |
2005年 | 4115篇 |
2004年 | 3033篇 |
2003年 | 2488篇 |
2002年 | 2501篇 |
2001年 | 2250篇 |
2000年 | 1814篇 |
1999年 | 1391篇 |
1998年 | 850篇 |
1997年 | 681篇 |
1996年 | 617篇 |
1995年 | 532篇 |
1994年 | 385篇 |
1993年 | 333篇 |
1992年 | 262篇 |
1991年 | 191篇 |
1990年 | 156篇 |
1989年 | 103篇 |
1988年 | 111篇 |
1987年 | 54篇 |
1986年 | 69篇 |
1985年 | 34篇 |
1984年 | 28篇 |
1983年 | 21篇 |
1982年 | 14篇 |
1981年 | 23篇 |
1980年 | 13篇 |
1979年 | 15篇 |
1977年 | 8篇 |
1970年 | 6篇 |
1959年 | 5篇 |
1951年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
93.
PAN Yi 《数字社区&智能家居》2008,(29)
在网络管理系统中CORBA技术被广泛应用在北向接口模块中,在测试这类模块时通常会针对不同的规范开发专门的测试程序,费时费力,且没有通用性。该文介绍了一个基于idl语法分析的动态测试工具,可动态测试不同规范的CORBA接口,大大提高了生产效率。 相似文献
94.
Group interaction analysis in dynamic context. 总被引:1,自引:0,他引:1
Peng Dai Huijun Di Ligeng Dong Linmi Tao Guangyou Xu 《IEEE transactions on systems, man, and cybernetics. Part B, Cybernetics》2008,38(1):275-282
Computer understanding of human actions and interactions is one of the key research issues in human computing. In this regard, context plays an essential role in semantic understanding of human behavioral and social signals from sensor data. This paper put forward an event-based dynamic context model to address the problems of context awareness in the analysis of group interaction scenarios. Event-driven multilevel dynamic Bayesian network is correspondingly proposed to detect multilevel events, which underlies the context awareness mechanism. Online analysis can be achieved, which is superior over previous works. Experiments in our smart meeting room demonstrate the effectiveness of our approach. 相似文献
95.
A unicast-based fault-tolerant multicasting method is proposed for hypercubes, which can still work well when the system contains enough faults. A multicast message may be unable to reach a destination if Hamming distance between the destination and the multicast source is large enough. A multicast message fails if any one of the destinations is unreachable from the source. An effective destination ordering scheme of the destinations is proposed for one-port systems first, it is extended to all-port systems for unicast-based fault-tolerant multicasting. Unreachable destinations from the source based on the local safety information are forwarded to a reachable destination, where the multicast message can be routed reliably. Destination ordering is completed based on Hamming distance. A multiple round p-cube routing scheme is presented for a deadlock-free fault-tolerant routing for each unicast step in hypercubes, where the same virtual channel is used for each round of p-cube routing. Sufficient simulation results are presented by comparing with the previous methods. 相似文献
96.
Dong RG Welcome DE Wu JZ 《Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine》2007,221(8):847-861
This study generally hypothesized that the vibration-induced biodynamic stress and number of its cycles in a substructure of the hand-arm system play an important role in the development of vibration-induced disorders in the substructure. As the first step to test this hypothesis, the specific aims of this study were to develop a practical method to quantify the biodynamic stress-cycle measure, to compare it with ISO-weighted and unweighted accelerations, and to assess its potential for applications. A mechanical-equivalent model of the system was established using reported experimental data. The model was used to estimate the average stresses in the fingers and palm. The frequency weightings of the stresses in these substructures were derived using the proposed stress-cycle measure. This study found the frequency dependence of the average stress distributed in the fingers is different from that in the palm. Therefore, this study predicted that the frequency dependencies of finger disorders could also be different from those of the disorders in the palm, wrist, and arms. If vibration-induced white finger (VWF) is correlated better with unweighted acceleration than with ISO-weighted acceleration, the biodynamic stress distributed in the fingers is likely to play a more important role in the development of VWF than is th e biodynamic stressdistributed in the other substructures of the hand-arm system. The results of this study also suggest that the ISO weighting underestimates the high-frequency effect on the finger disorder development but it may provide a reasonable risk assessment of the disorders in the wrist and arm. 相似文献
97.
98.
给出了AutoCAD环境下的木工成型铣刀CAD系统中 ,用户输入的工件截形曲线通过坐标变换生成木工成型铣刀前刀面截形曲线的方法 ,并进一步讨论了样条曲线最值点的求法 相似文献
99.
简述了色彩形成的物理过程,建立一较有效的材料光谱特性仿真与色彩预测模型.采用密度泛函理论,计算了纤锌矿ZnO的复折射率,计算结果与实验结果相符.计算并分析了ZnO薄膜的反射光谱性质,预测了ZnO薄膜颜色为黄色,与实际样品相符.研究了薄膜厚度对ZnO薄膜色彩的影响,结果表明,在相干长度范围内(<1300 nm),膜厚对ZnO薄膜颜色调制作用显著,膜较厚时(>1300 nm),色彩及明度趋于稳定. 相似文献
100.
介绍了大气污染控制工程课程教学改革研究的内容,提出了由教学内容、教学形式、教学平台与教学评价等4方面组成的立体化课程教学模式,并讨论了该模式下教学资源平台的建设,给出了大气污染控制工程课程的评价和考核方法.该模式在实践教学中取得了比较好的成效. 相似文献