全文获取类型
收费全文 | 6233篇 |
免费 | 425篇 |
国内免费 | 285篇 |
专业分类
电工技术 | 229篇 |
综合类 | 653篇 |
化学工业 | 361篇 |
金属工艺 | 141篇 |
机械仪表 | 264篇 |
建筑科学 | 413篇 |
矿业工程 | 135篇 |
能源动力 | 243篇 |
轻工业 | 721篇 |
水利工程 | 210篇 |
石油天然气 | 75篇 |
武器工业 | 61篇 |
无线电 | 263篇 |
一般工业技术 | 481篇 |
冶金工业 | 965篇 |
原子能技术 | 40篇 |
自动化技术 | 1688篇 |
出版年
2024年 | 15篇 |
2023年 | 53篇 |
2022年 | 111篇 |
2021年 | 121篇 |
2020年 | 188篇 |
2019年 | 184篇 |
2018年 | 149篇 |
2017年 | 146篇 |
2016年 | 168篇 |
2015年 | 207篇 |
2014年 | 297篇 |
2013年 | 414篇 |
2012年 | 324篇 |
2011年 | 403篇 |
2010年 | 339篇 |
2009年 | 376篇 |
2008年 | 313篇 |
2007年 | 428篇 |
2006年 | 395篇 |
2005年 | 324篇 |
2004年 | 279篇 |
2003年 | 286篇 |
2002年 | 259篇 |
2001年 | 245篇 |
2000年 | 172篇 |
1999年 | 144篇 |
1998年 | 101篇 |
1997年 | 83篇 |
1996年 | 75篇 |
1995年 | 56篇 |
1994年 | 74篇 |
1993年 | 39篇 |
1992年 | 21篇 |
1991年 | 17篇 |
1990年 | 17篇 |
1989年 | 11篇 |
1988年 | 11篇 |
1987年 | 11篇 |
1986年 | 7篇 |
1985年 | 7篇 |
1984年 | 13篇 |
1983年 | 9篇 |
1982年 | 7篇 |
1980年 | 5篇 |
1979年 | 3篇 |
1966年 | 5篇 |
1963年 | 3篇 |
1959年 | 3篇 |
1958年 | 4篇 |
1954年 | 4篇 |
排序方式: 共有6943条查询结果,搜索用时 15 毫秒
81.
A confidence-based framework for business to consumer (B2C) mobile commerce adoption 总被引:1,自引:0,他引:1
The Technology Acceptance Model (TAM) has been considered to be fundamental in determining the acceptance of new technology
in the past decades. The two beliefs, ease of use and usefulness, in the model may not, however, fully explain the consumers’
behavior in an emerging environment, such as mobile commerce (m-commerce). This paper aims to develop a framework for m-commerce
adoption in consumer decision-making processes. In this paper TAM has been adopted and extended to analyze successful m-commerce
adoption. The key elements of the proposed confidence-based framework for B2C m-commerce adoption include psychological and
behavioral factors. Psychological factors include history-based confidence, institution-based confidence and personality-based
confidence. Behavioral factors include perceived ease of use and perceived usefulness of the mobile application and technology. 相似文献
82.
广西钦州坭兴陶是中国"四大名陶"之一,其制陶工艺历史悠久,坭兴陶的土质洁净细腻、制作工艺精湛,在烧制过程中还可以产生丰富的色彩变化,形成稀有独特的"窑变"效果,这种效果的陶制品非常珍贵,被称作"窑宝"。广西钦州坭兴陶独特的民族文化装饰图案赋予了它独特的地域特征,凝聚了钦州陶艺师们智慧结晶和艺术表现力,为钦州的文化产业做出突出的贡献。 相似文献
83.
The paper describes a combinatorial scheme for the analysis and synthesis of product life cycle on the basis of a typical compressed structure: design of materials and manufacturing process. In addition, the following problems are studied: system refinement, series-parallel production process, and multistage design (design of product trajectories). Hierarchical combinatorial morphological approach is proposed. The solving process is based on ordinal expert knowledge. The following phases are examined: design of a basic system morphology, generation of local design alternatives, knowledge acquisition as ordinal estimates for local design alternatives and their compatibility, and synthesis of the best compositions.A realistic numerical example for concrete-macrotechnology (composing of concrete from constituents and selection of manufacturing alternatives) illustrates the approach. 相似文献
84.
Marian J. Patrick 《国际水》2013,38(1):63-80
Managing for social and environmental justice in water allocation is a necessary yet challenging goal. Often, what can appear as a just or equitable outcome for a specific location or group of stakeholders can also result in injustices at other locations or for other stakeholders. This paper describes a conceptual framework, The Cycles and Spirals of Justice, that helps make sense of the relationship between justice and injustice in the context of water-allocation decision making by explicitly utilizing a landscape-ecology understanding of scale and levels. The framework is illustrated using a case study from the Murray-Darling Basin in Australia and describes how justice and injustice are part of a cycling continuum of “justice for whom” and how this plays out in a multi-level system where the problem of scale can surface. 相似文献
85.
ABSTRACT Irrigation-water-delivery systems are designed and managed to receive water from a source and to distribute it among farmers in order to meet their agricultural requirements. High system performance can be achieved through rehabilitation of deteriorating and inadequate physical facilities and through improved system management. Various design decisions must be made in order to rehabilitate or develop irrigation-water-delivery systems, including those related to specification of the characteristics of hydraulic structures used to convey regulate, or divert water This study develops and applies a response surface methodology (RSM) for achieving optimal design for hydraulic structures in irrigation-water-delivery systems in canal networks. This approach provides a means of understanding system behavior through developing a response surface in terms of a mathematical expression representing system performance as affected by design decisions. Design decisions include pipe diameters for diversion and regulating structures. Simulation of steady spatially varied flow was incorporated into the response surface methodology to determine high-performance low-cost solutions. Objectives of adequacy, efficiency dependability, and equity of water delivery were considered in defining water delivery performance. Fuzzy membership functions were used to address subjectivity associated with interpreting expected values of performance measures associated with each of the prescribed objectives. This study is an extension of a previous study by Alshaikh [1]. That study reported the application of RSM on a single canal case while herein RSM was used for the case of a canal network. Though, in general, RSMs for large-scale branched systems are computationally intensive, this proposed methodology overcomes this drawback. The approach constitutes a significant easy-to-use step forward in the development of comprehensive systems-scale techniques for the design of structural components of irrigation-water-delivery systems. 相似文献
86.
The purpose of competence set expansion is to find an optimal expansion process at the minimal cost and then obtain the required competence set from the acquired competence set to solve a problem. Several models have been proposed to address the competence set expansion problem of only a single decision maker or multiple decision makers without considering multilevel skills. However, a practical competence set expansion model should involve multiple decision makers and multilevel skills. This study discusses an optimal expansion model of incorporating competence sets of group decision makers with multilevel skills. The proposed method not only obtains the optimal competence set expansion of all decision makers with the maximal total benefit but finds all optimal alternatives of the competence set expansion model. A cooperative alliance problem is solved to illustrate the usefulness of the proposed method. 相似文献
87.
In this paper, a new method for aggregating the opinions of experts in a preferential voting system is proposed. The method, which uses fuzzy concept in handling crisp data, is computationally efficient and is able to completely rank the alternatives. Through this method, the number of votes for certain rank position that each alternative receives are first grouped together to form fuzzy numbers. The nearest point to a fuzzy number concept is then used to introduce an artificial ideal alternative. Data envelopment analysis is next used to find the efficiency scores of the alternatives in a pair-wise comparison with the artificial ideal alternative. Alternatives are rank based on these efficiency scores. If the alternatives are not completely ranked, a weight restriction method also based on fuzzy concept is used on the un-discriminated alternatives until they are completely ranked. Two examples are given for illustration of the method. 相似文献
88.
This paper considers the problem of multirobot coordination in pick-and-place tasks on a conveyor band. The robot team is composed of identical robots with mutually exclusive, but neighboring workspaces. The products are fed in at one end of the band, move through each workspace sequentially until being picked up and are collected at the other end—if not picked up interim. Each robot has the same task—that is picking up and packaging as many products as possible. We propose an approach based on noncooperative game theory where each robot uses local observations of the conveyor band and their neighbors' actions in order to decide on its actions. The developed algorithm has been implemented and tested in a simulated manufacturing environment using Webots. Results obtained from the simulations are analyzed using a variety of statistical performance measures. 相似文献
89.
José María Moreno-Jiménez Juan Aguarón Jesús Cardeñosa María Teresa Escobar José Luis Salazar Adrián Toncovich Alberto Turón 《Computers in human behavior》2012
Two key aspects of the Knowledge Society are the interconnection between the actors involved in the decision making processes and the importance of the human factor, particularly the citizen’s continuous learning and education. This paper presents a new module devoted to knowledge extraction and diffusion that has been incorporated into a previously developed decision making tool concerning the Internet and related with the multicriteria selection of a discrete number of alternatives (PRIOR-Web). Quantitative and qualitative procedures using data and text mining methods have been employed in the extraction of knowledge. Graphical visualisation tools have been incorporated in the diffusion stage of the methodological approach suggested when dealing with decision making in the Knowledge Society. The resulting collaborative platform is being used as the methodological support for the cognitive democracy known as e-cognocracy. 相似文献
90.
A consistency and consensus based decision support model for group decision making with multiplicative preference relations 总被引:1,自引:0,他引:1
Zhibin Wu Author VitaeJiuping XuAuthor Vitae 《Decision Support Systems》2012,52(3):757-767
In group decision making (GDM) with multiplicative preference relations (also known as pairwise comparison matrices in the Analytical Hierarchy Process), to come to a meaningful and reliable solution, it is preferable to consider individual consistency and group consensus in the decision process. This paper provides a decision support model to aid the group consensus process while keeping an acceptable individual consistency for each decision maker. The concept of an individual consistency index and a group consensus index is introduced based on the Hadamard product of two matrices. Two algorithms are presented in the designed support model. The first algorithm is utilized to convert an unacceptable preference relation to an acceptable one. The second algorithm is designed to assist the group in achieving a predefined consensus level. The main characteristics of our model are that: (1) it is independent of the prioritization method used in the consensus process; (2) it ensures that each individual multiplicative preference relation is of acceptable consistency when the predefined consensus level is achieved. Finally, some numerical examples are given to verify the effectiveness of our model. 相似文献