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101.
Wind energy systems have been considered for Canada's remote communities in order to reduce their costs and dependence on diesel fuel to generate electricity. Given the high capital costs, low-penetration wind–diesel systems have been typically found not to be economic. High-penetration wind–diesel systems have the benefit of increased economies of scale, and displacing significant amounts of diesel fuel, but have the disadvantage of not being able to capture all of the electricity that is generated when the wind turbines operate at rated capacity.Two representative models of typical remote Canadian communities were created using HOMER, an NREL micro-power simulator to model how a generic energy storage system could help improve the economics of a high-penetration wind–diesel system. Key variables that affect the optimum system are average annual wind speed, cost of diesel fuel, installed cost of storage and a storage systems overall efficiency. At an avoided cost of diesel fuel of 0.30 $Cdn/kWh and current installed costs, wind generators are suitable in remote Canadian communities only when an average annual wind speed of at least 6.0 m/s is present. Wind energy storage systems become viable to consider when average annual wind speeds approach 7.0 m/s, if the installed cost of the storage system is less than 1000 $Cdn/kW and it is capable of achieving at least a 75% overall energy conversion efficiency. In such cases, energy storage system can enable an additional 50% of electricity from wind turbines to be delivered. 相似文献
102.
Piotr Długosz Angelika Rączka Adrian Kopeć Rudolf Krzyżak Paweł Darłak Marek Hebda 《Journal of Materials Engineering and Performance》2016,25(6):2261-2266
This paper presents novel opportunities for management of fly ash by synthesizing the material into cordierite ceramics and using it as a reinforcing phase for light metal alloys. Metal matrix composites (based on magnesium alloy and aluminum alloy) were produced by squeeze casting. The magnesium matrix composites with a suitably selected reinforcing phase content (2 wt.%) exhibited much better strength properties than the unmodified alloy (AM60). It was also demonstrated that the wettability (or the lack thereof) in the metal-ceramic system is critical to successful production of the composites based on the AK7 alloy with cordierite. Light alloy matrix composites reinforced with cordierite ceramics particles are innovative materials that combine high strength with low weight, which may be a key factor of merit for numerous applications of the composite in various branches of industries. 相似文献
103.
一种城市主义的批判性实践不应执着于不相干的美学自主性,而应着眼于作为当代城市化主要征象的四种空间类型:位于城市与农村之间界定模糊区域的工厂区;纵横全国的基础设施管线和网络;新型文化聚落、邻里和建筑物;来自农村而在城市工作的新城市主体所形成的心理与社会网络。 相似文献
104.
A major issue in the design and operation of ad hoc networks is sharing the common spectrum among links in the same geographic
area. Bandwidth allocation, to optimize the performance of networks in which each station can converse with at most a single
neighbor at a time, has been recently studied in the context of Bluetooth Personal Area Networks. There, centralized and distributed,
capacity assignment heuristics were developed, with applicability to a variety of ad hoc networks. Yet, no guarantees on the
performance of these heuristics have been provided. In this paper, we extend these heuristics such that they can operate with
general convex objective functions. Then, we present our analytic results regarding these heuristics. Specifically, we show
that they are β-approximation (β<2) algorithms. Moreover, we show that even though the distributed and centralized algorithms
allocate capacity in a different manner, both algorithms converge to the same results. Finally, we present numerical results
that demonstrate the performance of the algorithms.
Randeep Bhatia received the Ph.D. degree in Computer Science from University of Maryland, the M.S. degree in Mathematics and Computer Science
from University of Illinois at Chicago and the B.Tech. degree in Computer Science and Engineering from Indian Institute of
Technology, Delhi. He is currently with the High Speed Networks Research Department at Bell Labs, Lucent technologies, working
on network design, traffic engineering and scheduling algorithms. His current research interests are in the area of QoS for
multimedia services in wireless data networks.
Adrian Segall received the B.Sc. and M.Sc. degrees in electrical engineering from the Technion, Israel Institute of Technology in 1965
and 1971, respectively, and the Ph.D. degree in electrical engineering with a minor in statistics from Stanford University
in 1973. After serving active duty in the Israel Defense Forces, he joined in 1968 the Scientific Department of Israel’s Ministry
of Defense. From 1973 to 1974 he was a Research Engineer at System Control Inc., Palo Alto, CA and a Lecturer at Stanford
University. From 1974 to 1976 he was an Assistant Professor of Electrical Engineering and Computer Science at the Massachusetts
Institute of Technology. From 1987 to 1998 he was on the faculty of the Department of Computer Science at the Technion. He
is presently Benjamin Professor of Computer-Communication Networks in the Department of Electrical Engineering, Technion,
Israel Institute of Technology. From 1982 to 1984 he was on leave with the IBM T.J.Watson Research Center, Yorktown Heights,
NY. He held visiting positions with IBM, AT&T and Lucent Bell Labs. His current research interests are in the area of optical
networks, wireless, sensor and ad-hoc networks. Dr. Segall is an IEEE Fellow and has served in the past as Editor for Computer
Communication Theory of the IEEE Transactions on Communications, Editor for the IEEE Information Theory Society Newsletter
and Senior Editor for the IEEE Journal on Selected Areas in Communications. He was selected as an IEEE delegate to the 1975
IEEE-USSR Information Theory Workshop, and is the recipient of the 1981 Miriam and Ray Klein Award for Outstanding Research
and of the 1990 Taub Award in Computer Science.
Gil Zussman received the B.Sc. degree in Industrial Engineering and Management and the B.A. degree in Economics (both summa cum laude) from the Technion—Israel Institute of Technology in 1995. He received the M.Sc. degree (summa cum laude) in Operations Research from Tel-Aviv University in 1999 and the Ph.D. degree in Electrical Engineering from the Technion—Israel
Institute of Technology in 2004. Between 1995 and 1998, he served as an engineer in the Israel Defense Forces. He is currently
a Postdoctoral Associate in the Laboratory for Information and Decision Systems in MIT. His current research interests are
in the area of ad hoc and sensor networks. In particular, he is interested in energy efficient protocols, medium access control
protocols, and personal area networks. Gil received the Knesset (Israeli Parliament) Award for distinguished students, the
Best Student Paper Award at the IFIP-TC6 Networking 2002 Conference, and the IEEE Communications Magazine Best Paper Award
at the OPNETWORK 2002 Conference. In 2004 he received the Marie Curie Outgoing International Fellowship and the Fulbright
Fellowship. 相似文献
105.
Gabriela Buda Lucian Dascalescu Adrian Samuila 《Particulate Science and Technology》2013,31(2):162-167
The control of the triboelectrification factors is the key for a successful application of electrostatic separation to the recycling of mixed plastics waste. This article focuses on the influence of material moisture on the tribocharging process of three granular materials: polyamide (PA), polyvinyl chloride (PVC), and polyethylene terephthalate (PET). Different values of moisture content were obtained by immersing the material in water or drying it in a laboratory oven. Afterward, the granular material was tribocharged on the tray of a vibratory feeder and the accumulated charge was measured by an electrometer. The maximum charge/mass ratio was obtained for the three plastic materials at different values of moisture content: 0.27% for PA, 0.12% for PET 0.1% for PVC. Series of 5 consecutive tribocharging experiments performed on the same sample, show that the first contributes with the greater amount of granules charge while the other four only slightly increment this value. The graphical representation of the evolution of the charge/mass ratio versus number of tribocharging experiment conducts to the conclusion that: i) the charge of the granules tends to saturate; ii) it is useless to excessively increase the duration of the tribocharging process. 相似文献
106.
Tumor Cell Phenotyping: Circulating Tumor Cell Phenotyping via High‐Throughput Acoustic Separation (Small 32/2018) 下载免费PDF全文
107.
This paper proposes a combined method for two-dimensional temperature and velocity measurements in liquid and gas flow using a schlieren system. Temperature measurements are made by relating the intensity level of each pixel in a schlieren image to the corresponding knife-edge position measured at the exit focal plane of the schlieren system. The same schlieren images were also used to measure the velocity of the fluid flow. The measurement is made by using particle image velocimetry (PIV). The PIV software used in this work analyzes motion between consecutive schlieren frames to obtain velocity fields. The proposed technique was applied to measure the temperature and velocity fields in the natural convection of water provoked by a heated rectangular plate. 相似文献
108.
109.
Melanie W. Cole Adrian Podpirka Shriram Ramanathan 《Journal of Materials Science》2009,44(19):5332-5338
Ba0.60Sr0.40TiO3 (BST) thin films, grown via RF-sputtering and the metalorganic solution deposition (MOSD) techniques, were post-growth annealed
via conventional thermal annealing (CTA) and UV-photon irradiation annealing. With respect to the conventional thermal annealed
films the UV-photon irradiation annealed films possessed improved structural properties and dielectric response. The optimization
of the UV-photon irradiation annealing process parameters (using RF-sputtered BST films) was achieved via a detailed set of
iso-thermal/chronal annealing experiments. The optimized UV-process parameters, applied to MOSD synthesized BST films revealed
further enhanced dielectric response, i.e., 23% reduction in tan δ with sustained tunability of 42%. The improvements in the
material properties of the UV-photon irradiation annealed BST thin films are attributed to stoichiometry and structural changes
enabled through the UV-photon irradiation annealing process. 相似文献
110.
This paper describes an integrated surface–subsurface modeling study of the Fuxianhu Lake catchment (southwest China). Pollution
threats to this important water resource have led to the need to evaluate transport pathways and the overall water balance
of the catchment. Catchment inputs to the lake include river inflows, direct overland flow and groundwater discharge, which
are incorporated into a mathematical model of the system. Surface runoff and groundwater recharge are estimated using a parsimonious
soil–vegetation modeling approach, while groundwater flow is based on the MODFLOW-2005 code. Overland flow and stream discharge
are coupled to the groundwater regime through the soil layer and are routed through the catchment to account for surface water
flow pathways. The model is tested using the V-catchment benchmark problem and is compared to existing models to demonstrate
accuracy and capability. Application of the model to the Fuxianhu catchment provides for the first-order approximation of
the average catchment water balance, which comprises such components as evapotranspiration losses (37% of rainfall), surface
runoff to the lake (37% of rainfall), and groundwater discharge to the lake (8% of rainfall), amongst others. The computationally
efficient approach to surface–subsurface modeling adopted in this investigation presents as an alternative to more complex
methods, and allows for the rapid assessment of flow pathways at the catchment scale.
An erratum to this article can be found at 相似文献