全文获取类型
收费全文 | 94349篇 |
免费 | 2336篇 |
国内免费 | 1024篇 |
专业分类
电工技术 | 1583篇 |
综合类 | 3075篇 |
化学工业 | 13081篇 |
金属工艺 | 5267篇 |
机械仪表 | 3613篇 |
建筑科学 | 3077篇 |
矿业工程 | 845篇 |
能源动力 | 1430篇 |
轻工业 | 4718篇 |
水利工程 | 1540篇 |
石油天然气 | 733篇 |
武器工业 | 106篇 |
无线电 | 10590篇 |
一般工业技术 | 17506篇 |
冶金工业 | 3118篇 |
原子能技术 | 373篇 |
自动化技术 | 27054篇 |
出版年
2024年 | 100篇 |
2023年 | 298篇 |
2022年 | 556篇 |
2021年 | 751篇 |
2020年 | 527篇 |
2019年 | 461篇 |
2018年 | 14867篇 |
2017年 | 13793篇 |
2016年 | 10402篇 |
2015年 | 1150篇 |
2014年 | 928篇 |
2013年 | 896篇 |
2012年 | 3879篇 |
2011年 | 10170篇 |
2010年 | 8979篇 |
2009年 | 6195篇 |
2008年 | 7348篇 |
2007年 | 8291篇 |
2006年 | 597篇 |
2005年 | 1571篇 |
2004年 | 1426篇 |
2003年 | 1407篇 |
2002年 | 777篇 |
2001年 | 320篇 |
2000年 | 297篇 |
1999年 | 218篇 |
1998年 | 185篇 |
1997年 | 150篇 |
1996年 | 131篇 |
1995年 | 75篇 |
1994年 | 51篇 |
1993年 | 58篇 |
1992年 | 54篇 |
1991年 | 44篇 |
1990年 | 22篇 |
1988年 | 30篇 |
1969年 | 24篇 |
1968年 | 44篇 |
1967年 | 33篇 |
1966年 | 42篇 |
1965年 | 44篇 |
1963年 | 28篇 |
1962年 | 22篇 |
1960年 | 30篇 |
1959年 | 37篇 |
1958年 | 37篇 |
1957年 | 36篇 |
1956年 | 34篇 |
1955年 | 63篇 |
1954年 | 68篇 |
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
991.
Su-gil Cho Junyong Jang Shinyu Kim Sanghyun Park Tae Hee Lee Minuk Lee Jong-Su Choi Hyung-Woo Kim Sup Hong 《Structural and Multidisciplinary Optimization》2016,54(6):1671-1688
Uncertainty-based multidisciplinary design optimization (UMDO) has been widely acknowledged as an advanced methodology to address competing objectives and reliable constraints of complex systems by coupling relationship of disciplines involved in the system. UMDO process consists of three parts. Two parts are to define the system with uncertainty and to formulate the design optimization problem. The third part is to quantitatively analyze the uncertainty of the system output considering the uncertainty propagation in the multidiscipline analysis. One of the major issues in the UMDO research is that the uncertainty propagation makes uncertainty analysis difficult in the complex system. The conventional methods are based on the parametric approach could possibly cause the error when the parametric approach has ill-estimated distribution because data is often insufficient or limited. Therefore, it is required to develop a nonparametric approach to directly use data. In this work, the nonparametric approach for uncertainty-based multidisciplinary design optimization considering limited data is proposed. To handle limited data, three processes are also adopted. To verify the performance of the proposed method, mathematical and engineering examples are illustrated. 相似文献
992.
993.
Boris Škorić Sebastiaan J. A. de Hoogh Nicola Zannone 《International Journal of Information Security》2016,15(4):381-402
The concept of reputation is widely used as a measure of trustworthiness based on ratings from members in a community. The adoption of reputation systems, however, relies on their ability to capture the actual trustworthiness of a target. Several reputation models for aggregating trust information have been proposed in the literature. The choice of model has an impact on the reliability of the aggregated trust information as well as on the procedure used to compute reputations. Two prominent models are flow-based reputation (e.g., EigenTrust, PageRank) and subjective logic-based reputation. Flow-based models provide an automated method to aggregate trust information, but they are not able to express the level of uncertainty in the information. In contrast, subjective logic extends probabilistic models with an explicit notion of uncertainty, but the calculation of reputation depends on the structure of the trust network and often requires information to be discarded. These are severe drawbacks. In this work, we observe that the ‘opinion discounting’ operation in subjective logic has a number of basic problems. We resolve these problems by providing a new discounting operator that describes the flow of evidence from one party to another. The adoption of our discounting rule results in a consistent subjective logic algebra that is entirely based on the handling of evidence. We show that the new algebra enables the construction of an automated reputation assessment procedure for arbitrary trust networks, where the calculation no longer depends on the structure of the network, and does not need to throw away any information. Thus, we obtain the best of both worlds: flow-based reputation and consistent handling of uncertainties. 相似文献
994.
Michael Filhol Mohamed N. Hadjadj Benoît Testu 《Universal Access in the Information Society》2016,15(4):487-498
The topic of this paper is machine translation (MT) from French text into French sign language (LSF). After arguing in favour of a rule-based method, it presents the architecture of an original MT system, built on two distinct efforts: formalising LSF production rules and triggering them with text processing. The former is made without any concern for text or translation and involves corpus analysis to link LSF form features to linguistic functions. It produces a set of production rules which may constitute a full LSF production grammar. The latter is an information extraction task from text, broken down in as many subtasks as there are rules in the grammar. After discussing this architecture, comparing it to the traditional methods and presenting the methodology for each task, the paper present the set of production rules found to govern event precedence and duration in LSF and gives a progress report on the implementation of the rule triggering system. With this proposal, it is also hoped to show how MT can benefit today from sign language processing. 相似文献
995.
João Tavares Jorge Barbosa Ismael Cardoso Cristiano Costa Adenauer Yamin Rodrigo Real 《Universal Access in the Information Society》2016,15(4):589-607
This article proposes Hefestos, an intelligent system applied to ubiquitous accessibility. This model uses ubiquitous computing concepts to manage accessibility resources for people with disabilities. Among the concepts employed, context awareness, user profiles and trails management can be highlighted. The paper proposes an ontology for accessibility and delineates scenarios of its application in everyday life of people with disabilities. Moreover, the implementation of a smart wheelchair prototype and its application in a practical experiment is described. Ten users with a range of disability degrees tried the system and filled out a survey based on the technology acceptance model. This experiment demonstrated the main functionalities and the acceptance of the system. The results showed 96 % of acceptance regarding perceived easy of use and 98 % in perceived usefulness. These results were encouraging and show the potential for implementing Hefestos in real life situations. 相似文献
996.
Kavita Krishnaswamy Ravi Kuber Tim Oates 《Universal Access in the Information Society》2016,15(4):609-627
Limb repositioning is necessary for individuals with severe physical disabilities to sustain muscle strength and prevent pressure sores. As robotic technologies become ubiquitous, these tools offer promise to support the repositioning process. However, research has yet to focus on ways in which individuals with severe physical disabilities can control robots for these tasks. This paper presents a study that examines the needs and attitudes of potential users with physical disabilities to control a robotic aid for limb repositioning. Subjects expressed interest in using brain–computer interface (BCI) and speech recognition technologies for purposes of executing robotic tasks. The performance of four subjects controlling arm movements on an avatar through the keyboard, mouse, BCI, and Dragon NaturallySpeaking speech recognition was evaluated. Although BCI and speech technologies may limit physical fatigue, more challenges were faced using BCI and speech conditions compared to the keyboard and mouse. This research promotes accessibility into mainstream robotic technologies and represents the first step in the development of a robotic prototype using a BCI and speech recognition technologies for limb repositioning. 相似文献
997.
Adriana Caione Anna Lisa Guido Angelo Martella Roberto Paiano Andrea Pandurino 《Information Systems and E-Business Management》2016,14(3):533-576
Enterprise activities are governed by regulations and laws that are multiple, heterogeneous and not always easy to understand. The arising and/or the modification of these regulations and laws can cause a significant impact in the business context, especially in terms of enterprise information systems adaptation. Currently, there are many methodological and technological tools that facilitate the application of regulations and procedures, but they are not integrated enough to ensure a complete problem management. Therefore, they are not sufficient to support organizations and companies in the management of their business processes. In this paper we propose a methodological and technological solution, able to model, manage, execute and monitor business processes of complex domains. The system allows both the design of an information system and its prototyping as a web application, by the extension of an appropriately selected Business Process Management suite. During both the design and the usage phases of the prototyped information system, it is possible to interface with a knowledge base that contains information about regulations and aspects that characterize the enterprise (organizational chart, tasks, etc.). 相似文献
998.
Norbert Koppenhagen Benjamin Mueller Alexander Maedche Ye Li Stephanie Hiller 《Information Systems and E-Business Management》2016,14(3):613-636
E-procurement and supplier-relationship management systems have helped to substantially advance process execution in supply management. However, current supply network systems still face challenges of high data integration efforts, as well as the decoupling of structured data and processes from the growing amount of digitalized unstructured interactions of supply management professionals. Inspired by the room for improvement posed by this challenges, our research proposes a design for a supply network artifact in supplier qualification that addresses these problems by enabling holistic integration of data, processes, and people. The artifact is developed following an action design research approach. Building on a set of meta-requirements derived from literature and practice explorations, we conceptualize two design principles and derive corresponding design decisions that have been implemented in an software artifact. Finally, we formulate testable hypotheses and evaluate the artifact and its design in the context of supplier qualification. Our results show that the proposed design reduces mental effort of supply management professionals and significantly increases efficiency when performing typical supply network tasks such as supplier qualification. 相似文献
999.
Nadiya Slobodenyuk 《Personal and Ubiquitous Computing》2016,20(6):1035-1047
Gaze-controlled interfaces have become a viable alternative to hand-input-based displays and present a particular value to the field of assistive technologies, allowing people with motor disabilities to partake in activities that otherwise would have been inaccessible to them. The present paper gives an overview of the key problems associated with the user experience in gaze-controlled human–computer interfaces and introduces two areas of psychological research that could contribute to the development of gaze-controlled interfaces that give a more intuitive sense of control and are less likely to interfere with ongoing cognitive processes. Such interfaces are referred to as cognitively grounded. The two areas of psychological research that lead to the design of cognitively grounded gaze-controlled interfaces are the sense of agency and the cognitive embodiment. This overview builds on findings within these areas and outlines research questions essential to the design of cognitively grounded gaze-controlled interfaces. 相似文献
1000.
Ugljesa Marjanovic Milan Delić Bojan Lalic 《Information Systems and E-Business Management》2016,14(2):253-272
This paper examines the success of an e-learning system in a company from the perspective of employees by using a multimethod approach. For this purpose Moodle learning management system was used. The success of e-learning as an information system was evaluated using four constructs of the updated DeLone and McLean IS success model—system quality, use, user satisfaction and net benefits, and adding one more construct—user performance. In this research a combination of observation and survey as two different research methods was used, which allowed the new measure to be incorporated into the model. Empirical assessment was carried out by exploratory factor analysis, confirmatory factor analysis and structural equation modeling. The research model was found to be valid and reliable. The results provide an expanded understanding of the constructs that measure the success of an e-learning system, helping to more deeply understand the key success dimensions and their interrelationships. The implications of our work were discussed. The DeLone and McLean IS success model applied equally well. However, the use of observation as a method of data collection revealed the weaknesses of the original model. 相似文献