全文获取类型
收费全文 | 14859篇 |
免费 | 1957篇 |
国内免费 | 1540篇 |
专业分类
电工技术 | 712篇 |
技术理论 | 4篇 |
综合类 | 1914篇 |
化学工业 | 387篇 |
金属工艺 | 296篇 |
机械仪表 | 1036篇 |
建筑科学 | 798篇 |
矿业工程 | 171篇 |
能源动力 | 180篇 |
轻工业 | 287篇 |
水利工程 | 241篇 |
石油天然气 | 342篇 |
武器工业 | 202篇 |
无线电 | 1296篇 |
一般工业技术 | 1543篇 |
冶金工业 | 682篇 |
原子能技术 | 109篇 |
自动化技术 | 8156篇 |
出版年
2024年 | 107篇 |
2023年 | 340篇 |
2022年 | 515篇 |
2021年 | 540篇 |
2020年 | 496篇 |
2019年 | 444篇 |
2018年 | 369篇 |
2017年 | 420篇 |
2016年 | 552篇 |
2015年 | 548篇 |
2014年 | 760篇 |
2013年 | 973篇 |
2012年 | 878篇 |
2011年 | 1025篇 |
2010年 | 871篇 |
2009年 | 955篇 |
2008年 | 977篇 |
2007年 | 1125篇 |
2006年 | 995篇 |
2005年 | 819篇 |
2004年 | 739篇 |
2003年 | 692篇 |
2002年 | 538篇 |
2001年 | 461篇 |
2000年 | 406篇 |
1999年 | 328篇 |
1998年 | 228篇 |
1997年 | 161篇 |
1996年 | 163篇 |
1995年 | 178篇 |
1994年 | 129篇 |
1993年 | 118篇 |
1992年 | 95篇 |
1991年 | 85篇 |
1990年 | 64篇 |
1989年 | 67篇 |
1988年 | 53篇 |
1987年 | 22篇 |
1986年 | 24篇 |
1985年 | 17篇 |
1984年 | 8篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1981年 | 5篇 |
1980年 | 10篇 |
1979年 | 7篇 |
1963年 | 4篇 |
1960年 | 3篇 |
1959年 | 3篇 |
1958年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 18 毫秒
1.
Topic modeling is a popular analytical tool for evaluating data. Numerous methods of topic modeling have been developed which consider many kinds of relationships and restrictions within datasets; however, these methods are not frequently employed. Instead many researchers gravitate to Latent Dirichlet Analysis, which although flexible and adaptive, is not always suited for modeling more complex data relationships. We present different topic modeling approaches capable of dealing with correlation between topics, the changes of topics over time, as well as the ability to handle short texts such as encountered in social media or sparse text data. We also briefly review the algorithms which are used to optimize and infer parameters in topic modeling, which is essential to producing meaningful results regardless of method. We believe this review will encourage more diversity when performing topic modeling and help determine what topic modeling method best suits the user needs. 相似文献
2.
AbstractIndustry 4.0 aims at providing a digital representation of a production landscape, but the challenges in building, maintaining, optimizing, and evolving digital models in inter-organizational production chains have not been identified yet in a systematic manner. In this paper, various Industry 4.0 research and technical challenges are addressed, and their present scenario is discussed. Moreover, in this article, the novel concept of developing experience-based virtual models of engineering entities, process, and the factory is presented. These models of production units, processes, and procedures are accomplished by virtual engineering object (VEO), virtual engineering process (VEP), and virtual engineering factory (VEF), using the knowledge representation technique of Decisional DNA. This blend of the virtual and physical domains permits monitoring of systems and analysis of data to foresee problems before they occur, develop new opportunities, prevent downtime, and even plan for the future by using simulations. Furthermore, the proposed virtual model concept not only has the capability of Query Processing and Data Integration for Industrial Data but also real-time visualization of data stream processing. 相似文献
3.
Aditi Chatterjee Jayabrata Biswas Kiranmoy Das 《International Journal of Communication Systems》2020,33(9)
In recent years, Internet of Things (IoT) devices are used for remote health monitoring. For remotely monitoring a patient, only the health information at different time points are not sufficient; predicted values of biomarkers (for some future time points) are also important. In this article, we propose a powerful statistical model for an efficient dynamic patient monitoring using wireless sensor nodes through Bayesian Learning (BL). We consider the setting where a set of correlated biomarkers are measured from a patient through wireless sensors, but the sensors only report the ordinal outcomes (say, good, fair, high, or very high) to the sink based on some prefixed thresholds. The challenge is to use the ordinal outcomes for monitoring and predicting the health status of the patient under consideration. We propose a linear mixed model where interbiomarker correlations and intrabiomarker dependence are modeled simultaneously. The estimated and the predicted values of the biomarkers are transferred over the internet so that health care providers and the family members of the patient can remotely monitor the patient. Extensive simulation studies are performed to assess practical usefulness of our proposed joint model, and the performance of the proposed joint model is compared to that of some other traditional models used in the literature. 相似文献
4.
5.
6.
7.
ABSTRACT Contact tracing is widely considered as an effective procedure in the fight against epidemic diseases. However, one of the challenges for technology based contact tracing is the high number of false positives, questioning its trust-worthiness and efficiency amongst the wider population for mass adoption. To this end, this paper proposes a novel, yet practical smartphone-based contact tracing approach, employing WiFi and acoustic sound for relative distance estimate, in addition to the air pressure and the magnetic field for ambient environment matching. We present a model combining six smartphone sensors, prioritising some of them when certain conditions are met. We empirically verified our approach in various realistic environments to demonstrate an achievement of up to 95% fewer false positives, and 62% more accurate than Bluetooth-only system. To the best of our knowledge, this paper was one of the first work to propose a combination of smartphone sensors for contact tracing. 相似文献
8.
9.
10.
Computer‐Interpretable Guidelines (CIGs) are the dominant medium for the delivery of clinical decision support, given the evidence‐based nature of their source material. Therefore, these machine‐readable versions have the ability to improve practitioner performance and conformance to standards, with availability at the point and time of care. The formalisation of Clinical Practice Guideline knowledge in a machine‐readable format is a crucial task to make it suitable for the integration in Clinical Decision Support Systems. However, the current tools for this purpose reveal shortcomings with respect to their ease of use and the support offered during CIG acquisition and editing. In this work, we characterise the current landscape of CIG acquisition tools based on the properties of guideline visualisation, organisation, simplicity, automation, manipulation of knowledge elements, and guideline storage and dissemination. Additionally, we describe the CompGuide Editor, a tool for the acquisition of CIGs in the CompGuide model for Clinical Practice Guidelines that also allows the editing of previously encoded guidelines. The Editor guides the users throughout the process of guideline encoding and does not require proficiency in any programming language. The features of the CIG encoding process are revealed through a comparison with already established tools for CIG acquisition. 相似文献