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1.
There is a potential server bottleneck problem when the Kerberos model is applied in large-scale networks because the model uses centralized management. To enlarge its application scope, researchers must consider how to build a trust relation among those Kerberos servers located on different isolated domains, but have not provided a way to prevent the potential bottleneck that can occur with Kerberos servers. With the development of across-domain authentication techniques, the local server bottleneck problem has not been alleviated; in fact, it has become more serious.Adopting the rigorous binary tree code algorithm, we present an authentication model based on Kerberos. Compared with similar models, our model has several advantages. First, it overcomes the potential server bottleneck problem and can balance the load automatically. Second, it can process across-domain authentication and enlarge the authentication boundary. Finally, its authentication path is short, with no more than two Kerberos servers being involved when authenticating a user. 相似文献
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电动滚筒具有许多独特的优势和特点,但由于存在着制约其发展的技术瓶颈,致使大功率电动滚筒一直未能设计、制造出来,影响了在输送机行业的应用。但随着新技术的发展,现在完全可以应用变频和稀土永磁电机技术、电气启制动技术、新的油冷式技术来设计制造出大功率的电动滚筒,从而推动电动滚筒的广泛应用。 相似文献
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本文通过分析数据包对的分离时间与背景流量之间的关系,提出了一种改进的基于包对模型测量端到端路径有效带宽的方法(ABwPP),可以直接测量路径的有效带宽而不需已知瓶颈带宽。NS-2上的模拟实验结果表明,该方法是准确有效的。 相似文献
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In order to solve the problem that the load of big data stream computing platform fluctuates drastically while the cluster was suffering from the performance bottleneck due to the shortage of computing resources,the load prediction based elastic resource scheduling strategy in Flink (LPERS-Flink) was proposed.Firstly,the load prediction model was set up as the foundation to propose the load prediction algorithm and predict the variation tendency of the processing load.Secondly,the resource judgment model was set up to identify the performance bottleneck and resource redundancy of the cluster while the resource scheduling algorithm was proposed to draw up the resource rescheduling plan.Finally,the online load migration algorithm was proposed to execute the resource rescheduling plan and migrate processing load among nodes efficiently.The experimental results show that the strategy provides better performance promotion in the application with drastically fluctuating processing load.The scale and resource configuration of the cluster responded to the variation of processing load in time and the communication overhead of the load migration was reduced effectively. 相似文献
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Hamidreza Esmaielpour Vincent R. Whiteside Jinfeng Tang Sangeetha Vijeyaragunathan Tetsuya D. Mishima Shayne Cairns Michael B. Santos Bin Wang Ian R. Sellers 《Progress in Photovoltaics: Research and Applications》2016,24(5):591-599
InAs/AlAsxSb1 − x quantum wells are investigated for their potential as hot carrier solar cells. Continuous wave power and temperature‐dependent photoluminescence indicate a transition in the dominant hot carrier relaxation process from conventional phonon‐mediated carrier relaxation below 90 K to a regime where inhibited radiative recombination dominates the hot carrier relaxation at elevated temperatures. At temperatures below 90 K, photoluminescence measurements are consistent with type‐I quantum wells that exhibit hole localization associated with alloy/interface fluctuations. At elevated temperatures, hole delocalization reveals the true type‐II band alignment, where it is observed that inhibited radiative recombination due to the spatial separation of the charge carriers dominates hot carrier relaxation. This decoupling of phonon‐mediated relaxation results in robust hot carriers at higher temperatures, even at lower excitation powers. These results indicate type‐II quantum wells offer potential as practical hot carrier systems. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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随着业务和应用的发展、用户和规模的爆炸性增长,因特网面临许多挑战,如地址空间耗尽、服务质量(QoS)问题等。实质上,QoS问题与网络中存在的一些“瓶颈”是相关的。因特网中存在许多“瓶颈”,本文分析了几个关键“瓶颈”,包括:“最后-公里”、“最初-公里”、“对等点”、IP地址转换等。并且指出,关键“瓶颈”在不同历史阶段是不同的。随着技术进步,接入带宽和路由器目前已不是网络中最关键的“瓶颈”在不同历史阶段是不同的。随着技术进步,接入带宽和路由器目前已不是网络中最关键的“瓶颈”。当前,我们不能再单纯一味地升级网络,要重视对因特网进行优化,通过流量工程和CDN等技术,才能有效地从根本上解决问题。 相似文献
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与有线网络相比,目前移动互联网的带宽普遍较低.这种情况下,如果移动P2P流媒体系统中用户节点上行带宽的利用率不高,将会极大地加重视频源服务器的负载,增加播放延时.为了充分地利用移动节点的上行带宽,缩短播放延时,文中提出了服务感知的视频片调度算法,它由请求算法和服务算法两部分组成.请求节点会根据最近的服务状况动态地调整请求的片数,减少服务拥塞的发生.服务节点会根据请求的优先级合理地安排上传顺序,提高服务的效率.仿真结果表明,该算法很好地适应了移动网络带宽低的情况,能够提高上行带宽的利用率,缩短播放延时. 相似文献