全文获取类型
收费全文 | 20182篇 |
免费 | 1055篇 |
国内免费 | 489篇 |
专业分类
电工技术 | 841篇 |
综合类 | 894篇 |
化学工业 | 1645篇 |
金属工艺 | 865篇 |
机械仪表 | 1876篇 |
建筑科学 | 1301篇 |
矿业工程 | 432篇 |
能源动力 | 950篇 |
轻工业 | 489篇 |
水利工程 | 350篇 |
石油天然气 | 300篇 |
武器工业 | 170篇 |
无线电 | 877篇 |
一般工业技术 | 2157篇 |
冶金工业 | 368篇 |
原子能技术 | 84篇 |
自动化技术 | 8127篇 |
出版年
2024年 | 58篇 |
2023年 | 168篇 |
2022年 | 236篇 |
2021年 | 311篇 |
2020年 | 364篇 |
2019年 | 444篇 |
2018年 | 423篇 |
2017年 | 614篇 |
2016年 | 699篇 |
2015年 | 723篇 |
2014年 | 925篇 |
2013年 | 1518篇 |
2012年 | 922篇 |
2011年 | 1121篇 |
2010年 | 874篇 |
2009年 | 1138篇 |
2008年 | 1133篇 |
2007年 | 1218篇 |
2006年 | 1210篇 |
2005年 | 1019篇 |
2004年 | 883篇 |
2003年 | 849篇 |
2002年 | 670篇 |
2001年 | 541篇 |
2000年 | 492篇 |
1999年 | 499篇 |
1998年 | 491篇 |
1997年 | 372篇 |
1996年 | 382篇 |
1995年 | 273篇 |
1994年 | 243篇 |
1993年 | 165篇 |
1992年 | 139篇 |
1991年 | 116篇 |
1990年 | 64篇 |
1989年 | 77篇 |
1988年 | 57篇 |
1987年 | 48篇 |
1986年 | 29篇 |
1985年 | 51篇 |
1984年 | 39篇 |
1983年 | 38篇 |
1982年 | 22篇 |
1981年 | 15篇 |
1980年 | 24篇 |
1979年 | 8篇 |
1978年 | 11篇 |
1977年 | 7篇 |
1975年 | 2篇 |
1973年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
31.
以20CrMnTi钢为例,建立了连续冷却渗碳模型;对变温渗碳质量进行了分析计算;对渗碳后的组织情况进行预测,从而对变温渗碳的可行性进行了理论论证. 相似文献
32.
Huan Huang 《Information Sciences》2010,180(19):3806-3813
This paper shows that the Zadeh’s extensions of sendograph-metric-continuous fuzzy-valued functions are sendograph-metric-continuous fuzzy functions. 相似文献
33.
Gyrd Brændeland Author Vitae Atle Refsdal Author Vitae Author Vitae 《Journal of Systems and Software》2010,83(10):1995-2013
The risk analysis of critical infrastructures such as the electric power supply or telecommunications is complicated by the fact that such infrastructures are mutually dependent. We propose a modular approach to the modelling and analysis of risk scenarios with dependencies. Our approach may be used to deduce the risk level of an overall system from previous risk analyses of its constituent systems. A custom made assumption-guarantee style is put forward as a means to describe risk scenarios with external dependencies. We also define a set of deduction rules facilitating various kinds of reasoning, including the analysis of mutual dependencies between risk scenarios expressed in the assumption-guarantee style. 相似文献
34.
Mohamed Sadok Cherif Habib Chabchoub Belaïd Aouni 《International Transactions in Operational Research》2010,17(1):85-102
Quality function deployment (QFD) is a customer-oriented design tool for developing new or improved products to achieve higher customer satisfaction by integrating various functions of an organization. The engineering characteristics (ECs) affecting the product performances are designed to match the customer attributes (CAs). However, from the viewpoint of the QFD team, product design processes are performed in imprecise environments, and more than one factor must be taken into account in determining the target levels of ECs, especially the limited resources and increased market competition. This paper presents an imprecise goal programming (GP) approach to determine the optimum target levels of ECs in QFD for maximizing customer satisfaction under resource limitation and considerations of market competition. Based on benchmarking data of CAs, the concept of satisfaction functions is utilized to formulate explicitly the customer's preferences and to integrate the competitive analysis of target market into the modelling and solution process. In addition, the relationships linking CAs and ECs and the ECs to each other are integrated by functional relationships. The proposed approach will be illustrated through a car door design example. 相似文献
35.
36.
Bumhwi KimAuthor Vitae 《Neurocomputing》2011,74(4):646-655
A new incrementally growing neural network model, called the growing fuzzy topology ART (GFTART) model, is proposed based on integrating the conventional fuzzy ART model with the incremental topology-preserving mechanism of the growing cell structure (GCS) model. This is in addition, to a new training algorithm, called the push-pull learning algorithm. The proposed GFTART model has two purposes: First, to reduce the proliferation of incrementally generated nodes in the F2 layer by the conventional fuzzy ART model based on replacing each F2 node with a GCS. Second, to enhance the class-dependent clustering representation ability of the GCS model by including the categorization property of the conventional fuzzy ART model. In addition, the proposed push-pull training algorithm enhances the cluster discriminating property and partially improves the forgetting problem of the training algorithm in the GCS model. 相似文献
37.
Abstract: The concept of linked oscillators in biological control systems has long been established. Frequency entrainment is a predominant explanation behind many biological rhythms. In this paper a preliminary examination of electroencephalographic entrainment is made to survey the possibility and methods of achieving signal entrainment at the highest level of neurological organization and function. A model of the thalamocortical system is employed to generate simulated electroencephalographic signals and is tested in various configurations in the search for entrainment under very simple conditions. Additionally, an analysis of the coupled Van der Pol model of the circadian rhythm controller is performed to identify the possibility of affecting that system with a drastically different coupling input signal. We were able to conclude that overall signal shape can have a significant impact on the entrainment characteristics of the system. Due to the nature of the underlying mathematical structure of the model, by examining the circadian rhythm controller, we found that it is unsuitable for entrainment to an incident entraining signal of much higher frequency. 相似文献
38.
In sensor networks, a compromised node can either generate fabricated reports with false votes or inject false votes into real reports, which causes severe damage such as false alarms, energy drain and information loss. An interleaved hop-by-hop authentication (IHA) scheme addresses the former attack by detecting and filtering false reports in a deterministic and hop-by-hop fashion. Unfortunately, in IHA, all en-route nodes must join to verify reports while only a few are necessary to the authentication procedure. In this paper, we propose a fuzzy-based interleaved multi-hop authentication scheme based on IHA. In our scheme, the fuzzy logic system only selects some nodes for verification based on the network characteristics. Moreover, we apply a voting method and a hash-based key assignment mechanism to improve network security. Through performance evaluation, the proposed scheme is found to save up to 13% of the energy consumption and to provide more network protection compared to IHA. 相似文献
39.
Loss and gain functions for CBR retrieval 总被引:2,自引:0,他引:2
The method described in this article evaluates case similarity in the retrieval stage of case-based reasoning (CBR). It thus plays a key role in deciding which case to select, and therefore, in deciding which solution will be eventually applied. In CBR, there are many retrieval techniques. One feature shared by most is that case retrieval is based on attribute similarity and importance. However, there are other crucial factors that should be considered, such as the possible consequences of a given solution, in other words its potential loss and gain. As their name clearly implies, these concepts are defined as functions measuring loss and gain when a given retrieval case solution is applied. Moreover, these functions help the user to choose the best solution so that when a mistake is made the resulting loss is minimal. In this way, the highest benefit is always obtained. 相似文献
40.
This paper presents a systematic approach for decreasing conservativeness in stability analysis and control design for Takagi-Sugeno (TS) systems. This approach is based on the idea of multiple Lyapunov functions together with simple techniques for introducing slack matrices. Unlike some previous approaches based on multiple Lyapunov functions, both the stability and the stabilization conditions are written as linear matrix inequality (LMI) problems. The proposed approach reduces the number of inequalities and guarantees extra degrees of freedom to the LMI problems. Numeric examples illustrate the effectiveness of this method. 相似文献