全文获取类型
收费全文 | 1485篇 |
免费 | 149篇 |
国内免费 | 90篇 |
专业分类
电工技术 | 44篇 |
综合类 | 73篇 |
化学工业 | 70篇 |
金属工艺 | 27篇 |
机械仪表 | 149篇 |
建筑科学 | 77篇 |
矿业工程 | 37篇 |
能源动力 | 21篇 |
轻工业 | 37篇 |
水利工程 | 33篇 |
石油天然气 | 15篇 |
武器工业 | 6篇 |
无线电 | 180篇 |
一般工业技术 | 95篇 |
冶金工业 | 39篇 |
原子能技术 | 85篇 |
自动化技术 | 736篇 |
出版年
2024年 | 2篇 |
2023年 | 6篇 |
2022年 | 15篇 |
2021年 | 29篇 |
2020年 | 24篇 |
2019年 | 19篇 |
2018年 | 29篇 |
2017年 | 19篇 |
2016年 | 40篇 |
2015年 | 49篇 |
2014年 | 84篇 |
2013年 | 92篇 |
2012年 | 91篇 |
2011年 | 148篇 |
2010年 | 115篇 |
2009年 | 101篇 |
2008年 | 119篇 |
2007年 | 91篇 |
2006年 | 89篇 |
2005年 | 98篇 |
2004年 | 75篇 |
2003年 | 81篇 |
2002年 | 48篇 |
2001年 | 31篇 |
2000年 | 32篇 |
1999年 | 44篇 |
1998年 | 32篇 |
1997年 | 14篇 |
1996年 | 24篇 |
1995年 | 12篇 |
1994年 | 15篇 |
1993年 | 6篇 |
1992年 | 6篇 |
1991年 | 8篇 |
1990年 | 8篇 |
1989年 | 5篇 |
1988年 | 5篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 4篇 |
1983年 | 4篇 |
1978年 | 1篇 |
1975年 | 3篇 |
1971年 | 1篇 |
1955年 | 1篇 |
排序方式: 共有1724条查询结果,搜索用时 15 毫秒
91.
一种抗干扰能力强的频率通道电路的设计 总被引:1,自引:0,他引:1
文中介绍一种抗干扰能力的频率通道电路的设计。该电路突破了传统的斯密特触发器的不足,能根据输入信号幅度自动调节触发电平,工作可靠,通过触发器互锁技术,大大提高了通道抗干扰能力。电路设计简炼,灵敏度高,频率范围宽,具有较高的工程应用价值。 相似文献
92.
93.
本文介绍了通过采用找平装置来控制ISA法铜电解槽槽面水平误差的方法,通过现场测量及工艺操作证明是行之有效的。 相似文献
94.
This paper presents a market-enabling framework where users, content providers and network operators can interact in the seamless, transparent sale and delivery of a wide range of services. The framework allows for dynamic creation, configuration and delivery of services with quality assurance, via automated management of Service Level Agreements (SLAs). We propose an approach relying on a systemic treatment of business, service and network layer issues, which translates into a layered architecture where components belonging to different levels interact on the basis of a mediation paradigm. We use mediation as a generic term for a combination of negotiation, brokerage and state notification, jointly concurring to the realization of the entire life-cycle of a service. 相似文献
95.
In this paper, a fuzzy controller is designed based on parallel distributed compensation (PDC) method and it is implemented in an experimental tank level control system. Firstly, a mathematical model of the system is obtained experimentally. An important feature of the plant is its nonlinearity. To control the level of water in the tank over the whole range, the nonlinear model of the system is linearized around three different operating points. Then, three PI controllers are designed for the operating points, using Skogestad's method. By using the PDC method, an overall fuzzy controller is designed by the fuzzy blending of the three PI-controllers. To evaluate the practical performance of the PDC-based fuzzy controller, the control system is implemented in the experimental system. The evaluation criteria considered are step response and disturbance rejection. The comparison results showed the superiority of the PDC-controller over the classical PI-controller. 相似文献
96.
As the size and complexity of Cloud systems increase, the manual management of these solutions becomes a challenging issue as more personnel, resources and expertise are needed. Service Level Agreement (SLA)-aware autonomic cloud solutions enable managing large scale infrastructure management meanwhile supporting multiple dynamic requirement from users. This paper contributes to these topics by the introduction of Cloudcompaas, a SLA-aware PaaS Cloud platform that manages the complete resource lifecycle. This platform features an extension of the SLA specification WS-Agreement, tailored to the specific needs of Cloud Computing. In particular, Cloudcompaas enables Cloud providers with a generic SLA model to deal with higher-level metrics, closer to end-user perception, and with flexible composition of the requirements of multiple actors in the computational scene. Moreover, Cloudcompaas provides a framework for general Cloud computing applications that could be dynamically adapted to correct the QoS violations by using the elasticity features of Cloud infrastructures. The effectiveness of this solution is demonstrated in this paper through a simulation that considers several realistic workload profiles, where Cloudcompaas achieves minimum cost and maximum efficiency, under highly heterogeneous utilization patterns. 相似文献
97.
T. BurzynskiM. Papini 《Journal of Materials Processing Technology》2012,212(5):1177-1190
A previous implementation of narrow band level set methodology for the modelling of the surface evolution of masked features in abrasive jet micro-machining (AJM) including the effect of mask erosive wear was extended to include the effect of particle second strikes. The model uses a ray tracing/node tracking algorithm to allow the prediction of the effect of particle ricochets from the mask edges and the sidewalls of the machined feature on the resulting surface evolution of high aspect ratio features. Using the model, for the first time, the prediction of the particle second strike effects from inclined masked features is made possible. When compared to previous models that did not account for mask wear and second strike effects, the present model significantly improved the prediction of measured masked micro-channels machined using AJM in glass. When compared to previous particle tracking computer simulations, the present model was found to have a much shorter execution time, and in some cases also showed an improved prediction. The model can be useful in predicting the feature shape in the AJM of brittle targets for aspect ratios greater than 1, and hence for the micro-fabrication of microfluidic and MEMS devices. 相似文献
98.
The aim of the paper is twofold. First, it proposes an original application of the Valuation-Based System (VBS) for the availability assessment of systems under uncertainty in a time-varying fashion. Uncertainties related to failure data of components (data uncertainty) and the system structure (model uncertainty) are analysed in the proposed model. Second, it proposes the application of the VBS for the availability assessment of the European Rail Traffic Management System (ERTMS) Level 2 under uncertainty according to the railway dependability standards. The originality of this work lies in the application of the VBS for the availability assessment of systems under data and model uncertainties, and the proposition of a temporal VBS to evaluate the instantaneous system availability. 相似文献
99.
在混流生产过程中,针对零部件供应不能实现JIT的问题,提出在SPS物料配送模式下,提高零部件消耗平准化程度。在汽车混流装配线中最重要的目标是零部件消耗速率平准化,建立了混流装配线车辆排序模型。结合W公司实际案例,验证了车型排序在平准化物料消耗中的重要意义。 相似文献
100.
In this article, a distributed simulation tool for the feasibility evaluation of multi-site scheduling is proposed. The application areas concern supply chains (SCs) or networks of distributed workshops. The distributed simulation of workshops, called virtual workshops, generates various problems of causality and of tasks execution coordination. These problems are addressed in the proposed distributed architecture by the use of High Level Architecture protocol guaranteeing the synchronisation and the chronology of events occurring in the distributed simulations. An application to a simple case of the SC organising the flow between three workshops shows the effectiveness of the distributed simulation tool. 相似文献