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101.
RS和GIS技术在新疆地质和矿产资源评价中的应用 总被引:1,自引:0,他引:1
发展宏观、快速、高效地资源管理及评价方法是开展现代地质找矿工作的需要,“3S”技术由于具有上述特点而在地质找矿领域得到越来越广泛的应用。本文针对新疆地质找矿现状,通过对“3S”技术特点的介绍,在以往新疆地质找矿工作的基础之上,系统的提出了在新疆运用RS和GIS技术建立遥感本底数据库及进行矿产资源评价、地质灾害预测的主要内容、方法,同时指出了存在的问题和发展前景。 相似文献
102.
采用低温反应射频溅射法在微晶玻璃上沉积了一层具有择优取向的氮化铝薄膜,再在其上沉积80Ni-20Cr电阻网络。对电阻网络进行了功率老化、高温存贮、热冲击等可靠性试验,结果表明具有AlN薄膜的电阻网络性能得到很大提高 相似文献
103.
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106.
RuO_2厚膜电阻体的阻值与TCR的关系 总被引:3,自引:0,他引:3
RuO_2厚膜电阻体方阻R_s、基片的热膨胀系数a_(sub)与RuO_2厚膜电阻体的电阻温度系数TCR间有一定的关系,讨论了从电阻体的R_s计算其TCR之方法。 相似文献
107.
从热稳定条件出发,对扩散镇流电阻的设计进行了详细的计算和分析,讨论了在保证器件增益前提下提高器件热稳定性的措施,器件应用显示出了良好的结果,最后提出了一种新的没有热崩现象存在的高可靠器件的设想。 相似文献
108.
Base station placement has significant impact on sensor network performance. Despite its significance, results on this problem
remain limited, particularly theoretical results that can provide performance guarantee. This paper proposes a set of procedure
to design (1− ε) approximation algorithms for base station placement problems under any desired small error bound ε > 0. It
offers a general framework to transform infinite search space to a finite-element search space with performance guarantee.
We apply this procedure to solve two practical problems. In the first problem where the objective is to maximize network lifetime,
an approximation algorithm designed through this procedure offers 1/ε2 complexity reduction when compared to a state-of-the-art algorithm. This represents the best known result to this problem.
In the second problem, we apply the design procedure to address base station placement problem when the optimization objective
is to maximize network capacity. Our (1− ε) approximation algorithm is the first theoretical result on this problem.
Yi Shi received his B.S. degree from University of
Science and Technology of China, Hefei, China, in 1998, a M.S. degree from Institute of Software, Chinese Academy of Science,
Beijing, China, in 2001, and a second M.S. degree from Virginia Tech, Blacksburg, VA, in 2003, all in computer science. He
is currently working toward his Ph.D. degree in electrical and computer engineering at Virginia Tech. While in undergraduate,
he was a recipient of Meritorious Award in International Mathematical Contest in Modeling and 1997 and 1998, respectively.
His current research focuses on algorithms and optimizations for wireless sensor networks, wireless ad hoc networks, UWB-based
networks, and SDR-based networks. His work has appeared in journals and highly selective international conferences (ACM Mobicom, ACM Mobihoc, and IEEE Infocom).
Y. Thomas Hou received the B.E. degree from the City College of New York in 1991, the M.S. degree from Columbia University in 1993, and
the Ph.D. degree from Polytechnic University, Brooklyn, New York, in 1998, all in Electrical Engineering.
Since Fall 2002, he has been an Assistant Professor at Virginia Tech, the Bradley Department of Electrical and Computer Engineering,
Blacksburg, VA. His current research interests are radio resource (spectrum) management and networking for software-defined
radio wireless networks, optimization and algorithm design for wireless ad hoc and sensor networks, and video communications
over dynamic ad hoc networks. From 1997 to 2002, Dr. Hou was a Researcher at Fujitsu Laboratories of America, Sunnyvale, CA,
where he worked on scalable architectures, protocols, and implementations for differentiated services Internet, service overlay
networking, video streaming, and network bandwidth allocation policies and distributed flow control algorithms.
Prof. Hou is a recipient of an Office of Naval Research (ONR) Young Investigator Award (2003) and a National Science Foundation
(NSF) CAREER Award (2004). He is a Co-Chair of Technical Program Committee of the Second International Conference on Cognitive
Radio Oriented Wireless Networks and Communications (CROWNCOM 2007), Orlando, FL, August 1–3, 2007. He also was the Chair
of the First IEEE Workshop on Networking Technologies for Software Defined Radio Networks, September 25, 2006, Reston, VA.
Prof. Hou holds two U.S. patents and has three more pending.
Alon Efrat earned his Bachelor in Applied Mathematics from the Technion (Israel’s Institute of Technology) in 1991, his Master in Computer
Science from the Technion in 1993, and his Ph.D in Computer Science from Tel-Aviv University in 1998. During 1998–2000 he
was a Post Doctorate Research Associate at the Computer Science Department of Stanford University, and at IBM Almaden Research
Center. Since 2000, he is an assistant professor at the Computer Science Department of the University of Arizona. His main
research areas are Computational Geometry, and its applications to sensor networks and medical imaging. 相似文献
109.
厚膜电阻的大范围连续可调设计 总被引:1,自引:1,他引:0
介绍了厚膜电阻微调系数和大范围连续可调的基本概念,指出常规厚膜电阻微调系数不超过2,采用帽状电阻可以在一定程度上提高微调系数,但由于受到电阻尺寸的限制,仍不能满足10倍以上的大范围连续可调要求。文中探讨了利用串并联微调来设计大范围连续可调电阻的可行性及基本方法。与单个电阻相比,电阻的串并联微调结构对微调系数具有明显的放大作用,从而使大范围连续可调的实现成为可能。当微调系数超过10时,可通过两个帽状电阻的串并联来实现大范围连续可调,三个矩形电阻的串并联结构可使阻值连续可调范围达30倍以上. 相似文献
110.