全文获取类型
收费全文 | 36527篇 |
免费 | 6002篇 |
国内免费 | 2546篇 |
专业分类
电工技术 | 11523篇 |
技术理论 | 2篇 |
综合类 | 3786篇 |
化学工业 | 1135篇 |
金属工艺 | 511篇 |
机械仪表 | 3653篇 |
建筑科学 | 4091篇 |
矿业工程 | 2866篇 |
能源动力 | 1181篇 |
轻工业 | 328篇 |
水利工程 | 1073篇 |
石油天然气 | 2527篇 |
武器工业 | 589篇 |
无线电 | 2688篇 |
一般工业技术 | 1828篇 |
冶金工业 | 723篇 |
原子能技术 | 169篇 |
自动化技术 | 6402篇 |
出版年
2024年 | 137篇 |
2023年 | 603篇 |
2022年 | 1145篇 |
2021年 | 1378篇 |
2020年 | 1560篇 |
2019年 | 1087篇 |
2018年 | 1043篇 |
2017年 | 1278篇 |
2016年 | 1463篇 |
2015年 | 1656篇 |
2014年 | 2686篇 |
2013年 | 2116篇 |
2012年 | 3058篇 |
2011年 | 3037篇 |
2010年 | 2322篇 |
2009年 | 2429篇 |
2008年 | 2305篇 |
2007年 | 2730篇 |
2006年 | 2340篇 |
2005年 | 2021篇 |
2004年 | 1647篇 |
2003年 | 1446篇 |
2002年 | 1111篇 |
2001年 | 1015篇 |
2000年 | 838篇 |
1999年 | 650篇 |
1998年 | 430篇 |
1997年 | 317篇 |
1996年 | 275篇 |
1995年 | 266篇 |
1994年 | 172篇 |
1993年 | 124篇 |
1992年 | 102篇 |
1991年 | 87篇 |
1990年 | 56篇 |
1989年 | 38篇 |
1988年 | 29篇 |
1987年 | 20篇 |
1986年 | 9篇 |
1985年 | 3篇 |
1984年 | 6篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1980年 | 7篇 |
1979年 | 10篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1959年 | 3篇 |
1955年 | 1篇 |
1951年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 24 毫秒
1.
文章介绍了海外某大型火力发电厂发生的一起发电机定子接地故障的分析和处理过程,对发电厂类似故障的处理和海外发电厂的运行和维护提供了参考。 相似文献
2.
3.
现场可编程门阵列(FPGA)内部资源众多,其中互连资源出现故障的概率远远高于片内其他资源,而在以往许多互连测试研究中,所生成的测试配置存在无法覆盖反馈桥接故障的难题,所以较难有测试配置实现故障列表的100%覆盖。因此通过约束桥接故障只发生在单个查找表(LUT)内的信号线上,并结合单项函数,对反馈桥接故障模型进行优化改进,从根本上解决难题;然后对优化后的反馈桥接故障设置相应的约束条件,再使用布尔可满足性理论(SAT)生成满足约束条件的测试配置。采用优化后的故障模型对ISCAS"89基准电路进行了测试配置生成实验,结果表明生成的测试向量解决了反馈桥接故障的覆盖难题,并且在实现故障列表的100%覆盖下,优化后的故障模型所需要的测试配置数最少。 相似文献
4.
Machine learning algorithms have been widely used in mine fault diagnosis. The correct selection of the suitable algorithms is the key factor that affects the fault diagnosis. However, the impact of machine learning algorithms on the prediction performance of mine fault diagnosis models has not been fully evaluated. In this study, the windage alteration faults (WAFs) diagnosis models, which are based on K-nearest neighbor algorithm (KNN), multi-layer perceptron (MLP), support vector machine (SVM), and decision tree (DT), are constructed. Furthermore, the applicability of these four algorithms in the WAFs diagnosis is explored by a T-type ventilation network simulation experiment and the field empirical application research of Jinchuan No. 2 mine. The accuracy of the fault location diagnosis for the four models in both networks was 100%. In the simulation experiment, the mean absolute percentage error (MAPE) between the predicted values and the real values of the fault volume of the four models was 0.59%, 97.26%, 123.61%, and 8.78%, respectively. The MAPE for the field empirical application was 3.94%, 52.40%, 25.25%, and 7.15%, respectively. The results of the comprehensive evaluation of the fault location and fault volume diagnosis tests showed that the KNN model is the most suitable algorithm for the WAFs diagnosis, whereas the prediction performance of the DT model was the second-best. This study realizes the intelligent diagnosis of WAFs, and provides technical support for the realization of intelligent ventilation. 相似文献
5.
6.
针对常见泥石流防治结构被冲击破坏的问题,基于“柔性消能”理念,结合张弦梁结构和竖向预应力锚杆技术,提出一种既能改善结构受力性能、增加结构整体抗冲击能力、保证结构安全可靠,又能减小结构构件截面尺寸、节约成本、便于现场施工组装和后期运营维护的新型地锚张弦梁式泥石流格栅坝,并阐述其技术原理。根据泥石流荷载分布和新型地锚张弦梁式泥石流格栅坝的受力特征,给出其简化的内力计算方法;并利用SAP2000建立新结构有限元模型,分析了结构的整体受力,验证了构件简化计算方法的合理性;结合Python语言和Qt De? signer软件开发了相应的设计计算软件,对新型地锚张弦梁式泥石流格栅坝的内力进行求解。结果表明:提出的新结构抗冲击性能好,构件受力均匀;以后设计中应关注竖杆的剪切脆性破坏和立柱偏心受力情况,保证结构安全;变形协调仅使底层张弦梁与竖杆内力偏大,实际工程应用时,应着重验算底层构件,防止其破坏;文中提出的简化计算方法能较准确的反映结构的受力特性,具有一定的合理性,研究可为新型地锚张弦梁式泥石流格栅坝的设计计算和推广应用提供理论依据和技术支持。 相似文献
7.
One of the major challenges in wireless body area networks (WBANs) is sensor fault detection. This paper reports a method for the precise identification of faulty sensors, which should help users identify true medical conditions and reduce the rate of false alarms, thereby improving the quality of services offered by WBANs. The proposed sensor fault detection (SFD) algorithm is based on Pearson correlation coefficients and simple statistical methods. The proposed method identifies strongly correlated parameters using Pearson correlation coefficients, and the proposed SFD algorithm detects faulty sensors. We validated the proposed SFD algorithm using two datasets from the Multiparameter Intelligent Monitoring in Intensive Care database and compared the results to those of existing methods. The time complexity of the proposed algorithm was also compared to that of existing methods. The proposed algorithm achieved high detection rates and low false alarm rates with accuracies of 97.23% and 93.99% for Dataset 1 and Dataset 2, respectively. 相似文献
8.
Leo H. Chiang Birgit Braun Zhenyu Wang Ivan Castillo 《American Institute of Chemical Engineers》2022,68(6):e17644
In the Industry 4.0 era, the chemical industry is embracing broad adoption of artificial intelligence (AI) and machine learning (ML) methods. This article provides a holistic view of how the industry is transforming digitally towards AI at scale. First, a historical perspective on how the industry used AI to aid humans in better decision-making is shown. Then state-of-the-art AI research addressing industrial needs on reliability and safety, process optimization, supply chain, material discovery, and reaction engineering is highlighted. Finally, a vision of the plant of the future is illustrated with critical components of AI-ready culture, model life cycle management, and renewed role of humans in chemical manufacturing. 相似文献
9.
10.
The present study proposes an algorithm for fault detection in terms of condition‐based maintenance with data mining techniques. The proposed algorithm is applied on an aircraft turbofan engine using flight data and consists of two main sections. In the first section, the relationship between engine exhaust gas temperature (EGT) as the main engine health monitoring criterion and other operational and environmental parameters of the engine was modelled using the data‐driven models. In the second section, a data set including EGT residuals, that is, the difference between the actual EGT of the system and the EGT estimated by the developed model in the health conditions of the engine, was created. Finally, faults occurring in each flight were detected based on the identification of abnormal events by a one‐class support vector machine trained by the health condition EGT residual data set. The results indicated that the proposed algorithm was an effective approach for inspecting aircraft engine conditions and detecting faults, with no need for technical knowledge on the interior characteristics of the aircraft engine. 相似文献