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981.
SMBus协议分析及其在双MCU通讯中的应用 总被引:2,自引:0,他引:2
SMBus是一种高效率的同步串行总线。本文在分析其通讯协议的基础上.认为采用SMBus通讯协议作为双MCU间的通讯协议可以达到既节省引脚又减少时钟周期的效果。最后.以C8051F310为例,给出了具体实现方案和程序流程。 相似文献
982.
983.
Lu Y. Abdelzaher T.F. Avneesh Saxena 《Parallel and Distributed Systems, IEEE Transactions on》2004,15(5):440-452
With the dramatic explosion of online information, the Internet is undergoing a transition from a data communication infrastructure to a global information utility. PDAs, wireless phones, Web-enabled vehicles, modem PCs, and high-end workstations can be viewed as appliances that "plug-in" to this utility for information. The increasing diversity of such appliances calls for an architecture for performance differentiation of information access. The key performance accelerator on the Internet is the caching and content distribution infrastructure. While many research efforts addressed performance differentiation in the network and on Web servers, providing multiple levels of service in the caching system has received much less attention. It has two main contributions. First, we describe, implement, and evaluate an architecture for differentiated content caching services as a key element of the Internet content distribution architecture. Second, we describe a control-theoretical approach that lays well-understood theoretical foundations for resource management to achieve performance differentiation in proxy caches. An experimental study using the Squid proxy cache shows that differentiated caching services provide significantly better performance to the premium content classes. 相似文献
984.
Multimedia proxy plays an important role in multimedia streaming over wireless Internet. Since wireless network exhibits different characteristics from the Internet, multimedia proxy caching over wireless Internet faces additional challenges. In this paper, we present a study of cache replacement for a single server and server selection for multiple servers across wireless Internet. By considering multiple objectives of multimedia proxy, we design a unified cost metric to measure proxy performance in wireless Internet. Based on the defined unified cost metric, we propose a novel replacement algorithm for single-server and a new server-selection policy for multiple servers to improve the end-to-end performance such as throughput, media quality, and start-up latency. To effectively handle errors occurred on wireless link, channel-adaptive unequal error protection is deployed according to distinct quality of service requirements of layered or scalable media. Simulation results demonstrate that our approaches achieve significantly better performance than the known cache-replacement algorithms and sever selection schemes, respectively. 相似文献
985.
An Accumulation Algorithm for Video Shot Boundary Detection 总被引:5,自引:0,他引:5
In this paper, an accumulation algorithm for video shot detection is introduced. The algorithm considers the properties of gradual transition. In a gradual transition, there is only a small difference between consecutive frames. The algorithm remembers the differences between consecutive frames and accumulates them. When the accumulation difference exceeds a threshold, an occurrence of shot transition is declared. Our main contributions are to introduce a frame C that remembers the changes from the beginning of a shot and detect the different types of boundaries (cut, fade, dissolve) at one process. We tested our algorithm with clips extracted from MPEG VCDs. The algorithm showed a good performance in detecting the gradual transitions as well as the abrupt cuts and has the ability to identify different types of boundaries. 相似文献
986.
In this paper, a new saturation control technique in the framework of anti-windup compensation is developed for exponentially unstable linear time-invariant systems subject to input nonlinearities. The proposed control algorithm guarantees regional stability in the existence of input saturation, and provides less conservative performance than most existing anti-windup schemes. Moreover, an explicit form of anti-windup controller with its order no more than the order of the plant is derived. An inverted pendulum example is used to demonstrate the advantages of the newly proposed anti-windup control technique. 相似文献
987.
Lixin ZHANG Chengmin WANG Shiyu HELaboratory of Space Materials Environment Engineering Harbin Institute of Technology Harbin ChinaElectric Engineering Department Shanghai Jiao Tong Unirersity Shanghai China 《材料科学技术学报》2004,20(6):751-754
The damage effects and mechanisms of proton irradiation with 50-200 keV energy to space-grade methyl silicone rubber was performed using a ground-based simulator for space irradiation environment. The changes in surface morphology, mechanicai properties, cross-linking density, glass temperature, infrared attenuated total reflection spectrum, mass spectrum and pyrolysis gas chromatography-mass spectrum indicated that, under lower energy, the proton irradiation would induce cross-linking effect, resulting in an increase in tensile strengths and hardness of the methyl silicon rubber. However, after the irradiation of protons for more than 150 keV, the irradiation induced degradation, which decreased the tensile strengths and hardness, became a dominant effect. A macromolecular network destruction modei for the silicone rubber radiated vvith the protons was proposed. 相似文献
988.
989.
Dai Hong-lian Li Shi-pu Lu Xu-hui Wang Xin-yu Yan Yu-hua Fang fang 《武汉理工大学学报(材料科学英文版)》2004,19(3):14-17
To study the new bone formation in the bone defect area after implantation, the tetracycline tracing method was used. The
results show that new bone formed in 1 month, and the formation rate of new bone was very high (8. 164 μm/day), considerably
faster than that of control groups (3.219 μm/day). The new bone grew up quickly and β_TCP particles were surrounded by double
fluorescence bands which became more obvious. The new bone formation rate was maximal at 2 months, and then gradually reduced.
The rate was steady at 4 months, and then reduced to resembling as the normal physiologic metabolism of bone, which indicated
the implanted materials were completely replaced by bone. Calcium phosphate materials had the ability of osteoconduction. 相似文献
990.