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211.
A vinyl‐modified anthraquinone (AQ) derivative (Vinyl‐AQ) is synthesized through a palladium‐mediated Suzuki coupling reaction between vinylphenylboronic acid and 2‐chloromethylanthraquinone and, subsequently, copolymerized with N,N‐dimethylacrylamide (DMAM) through free radical copolymerization in organic solvent. The chemical structure of the resulting water‐soluble copolymer, P(DMAM‐co‐AQ), is verified using techniques such as proton nuclear magnetic resonance, attenuated total reflection‐infrared spectroscopy, thermogravimetric analysis, and UV–vis spectroscopy. The evolution of the oxygen scavenging abilities of aqueous P(DMAM‐co‐AQ) solutions after UV irradiation is monitored as a function of UV irradiation time, concentration of AQ moieties, and pH. The copolymer is proved an effective UV‐triggered oxygen scavenger, leading to dissolved oxygen contents below 1 ppm for the optimized experimental conditions. This behavior is related with the appearance of novel chemical species with interesting optical properties, as suggested by the respective evolution of the UV–vis absorption and photoluminescence spectra after UV irradiation.  相似文献   
212.
风电输出功率具有强随机性和波动性的特点,因此风电高占比带来的输入电能波动给多区负荷频率控制带来更大挑战。计及风功率预测误差对负荷频率控制的影响,且考虑到未来开放式通信环境对区域控制误差信号传输的影响,文中提出了一种基于事件驱动通信下的鲁棒负荷频率控制策略,以保证含风电电力系统频率稳定性的同时尽可能地减少网络通信传输量。以典型含风电的两区域负荷频率控制为例进行了仿真研究,仿真结果表明,文中所提出的基于事件驱动通信的鲁棒控制器相对于常规比例—积分控制器而言,不仅能够有效保证风功率波动下的频率输出的l2增益性能,还能减少系统平稳态的通信次数,具有良好的频率控制性能。  相似文献   
213.
Social network communities are involving millions of users, representing one of the main reasons why people log on the Internet from their home computers. Part of this success is certainly due to the possibility for end users to reverse the traditional publisher/consumer model, achieving control over service consumption, and gaining the opportunity to produce multimedia contents instantaneously available worldwide. Social network communities are not destined to be confined in traditional wired networks. Indeed, mobile users could greatly benefit from applications that combine social networks and location-based multimedia services. It is hence of particular interest to consider the next frontier in wireless networking, i.e., vehicular networks, and imagine how community-based services could be provided in this highly variable context, enabling the sprouting of communities on the road. To this aim, we address here one of the specific challenges in this scenario, i.e., the fast delivery of service triggering messages generated by a user to a certain area where another user can provide the requested multimedia service (e.g., live video streaming, traffic updates, friends finder, status messages of social network applications). We discuss the state-of-art for this technical challenge and compare it against our solution, which is able to dynamically adapt to different transmission conditions as those featuring a vehicular network. In essence, the main innovation of our contribution amounts to a transmission range estimator that enables vehicles to know their current transmission range, independently from changes in the vehicular network topology, and use it to maximize the efficiency in transmitting service-triggering messages.
Marco Roccetti (Corresponding author)Email:
  相似文献   
214.
无线传感器网络中由最大连通度生成簇算法得到的簇结构,各簇头节点间负载不均衡,能量消耗较快。对止,用剩余能量和发射功率构建综合权值来决定节点竞选簇头的可能性,并通过设计的拓扑维护概率适当性的对网络拓扑进行局部调整,形成了基于概率触发的负载均衡区域竞选分簇算法,有效地延长了网络生命期。  相似文献   
215.
This paper considers the distributed event‐triggered consensus problem for multi‐agent systems with general linear dynamics under a directed graph. We propose a novel distributed event‐triggered consensus controller with state‐dependent threshold for each agent to achieve consensus. In this strategy, continuous communication in both controller update and triggering condition monitoring is not required, which means the proposed strategy is fully continuous communication free. Each agent only needs to monitor its own state continuously to determine if the event is triggered. Additionally, the approach shown here provides consensus with guaranteed positive inter‐event time intervals. Therefore, there is no Zeno behavior under the proposed consensus control algorithm. Finally, numerical simulations are given to illustrate the theoretical results.  相似文献   
216.
This paper investigates decentralized control for a class of interconnected system. Different from the traditional systems, the considered system has the following features: (i) its subsystems are connected through a communication network subject to transmission delays and packet losses; (ii) the subsystems' multi‐actuators are subjected to random faults; and (iii) the subsystems are subject to probabilistic nonlinear disturbances, the inner variation information of the nonlinearities, as well as their bounds information, is utilized to analyze the nonlinearities. Furthermore, in order to reduce the network bandwidth burden, a decentralized state‐dependent triggering scheme is proposed. Considering aforementioned characteristics and using the state‐dependent triggering scheme, new type of network‐based interconnected system model is built. By using the Lyapunov functional approach, sufficient conditions for the mean square stability and stabilization of the network‐based interconnected systems are obtained. Then reliable controllers, as well as the triggering matrices of the local subsystems, can be co‐designed by using a cone complementary linearization algorithm. Two simulation examples are given to illustrate the effectiveness and application of the proposed method. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
217.
一维触发元胞自动机加密系统的缺点是密钥空间小[1],二维触发元胞自动机在几乎不增加计算量及复杂度的同时,极大地扩张了密钥空间。简述二维触发元胞自动机的基本理论,应用其触发规则建立动态密码系统,完成加密解密,并根据程序的最终测试数据,进行性能分析。  相似文献   
218.
为了解决智能网中存在无法申请和触发多个智能业务的问题,即多业务触发问题。分析和比较了当前国际上各种智能网标准的业务触发方式,并针对该问题指出了现有解决方案和标准的不足,提出了对智能网实施功能分离,建立业务交互状态模型来实现签约用户业务个人化的方法。  相似文献   
219.
基于ARENE软件的TCSC特殊触发方式研究   总被引:1,自引:0,他引:1  
可控串补(TCSC)相对于固定串补的优势在于它可以快速灵活地调整线路阻抗以响应系统运行变化且不会引起次同步谐振(SSR),而能否准确地触发TCSC则是实现其阻抗控制的关键所在.研究表明,对TCSC采用常规的相控触发方式无法实现正常的旁路及闭锁工作模式,因此有必要对TCSC的触发方式进行研究.在研究前人成果的基础上提出一种适合于软件仿真的实现TCSC旁路及闭锁的特殊触发控制方式.仿真结果表明,该触发方式不依赖于同步信号,可靠稳定,能够准确实现旁路及闭锁工作模式.这对系统的暂态稳定控制至关重要.  相似文献   
220.
多跳无线传感器网络中,部分节点由于担当数据转发任务,能量消耗较快,缩短了网络的生命期。充分考虑节点承担数据转发任务时负载过大的特点,用剩余能量和发射功率构建综合权值来决定节点担当数据转发任务的可能性,并通过设计的拓扑维护概率周期性的对网络拓扑进行局部调整,形成了基于概率触发的负载均衡拓扑控制算法,有效地解决了节点由于担当转发任务而造成能量过早耗尽的问题在一定程度上均衡了节点负载,延长了网络生命期。  相似文献   
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