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排序方式: 共有479条查询结果,搜索用时 15 毫秒
81.
82.
In this paper, we describe a simplified version of the Advanced Encryption Standard algorithm. This version can be used in the classroom for explaining the Advanced Encryption Standard. After presentation of the simplified version, it is easier for students to understand the real version. This simplified version has the advantage that examples can be worked by hand. We also describe attacks on this version using both linear and differential cryptanalysis. These too can be used in the classroom as a way of explaining those kinds of attacks. 相似文献
83.
Mohammed I. A. Ibrahim Musa Zakariah Reneilwe A. Molele Mohamed A. A. Mahdy June H. Williams Christo J. Botha 《Microscopy research and technique》2022,85(3):1160-1170
The testicular excurrent duct system undergoes several physiological and morphological changes during the reproductive stage or breeding season in mammals, birds, and reptiles. Studies on normal age-related histomorphological changes in the excurrent duct system of Japanese quails (Coturnix japonica) remain unreported, despite the extensive use of this bird as an avian model in research studies. The current study investigated the histological, ultrastructural, and histometric changes in the testicular excurrent duct system of the Japanese quail during three reproductive stages, namely prepubertal, pubertal, and adult. Simple squamous to low cuboidal cells formed the epithelia of the rete testis in prepubertal and pubertal birds, while in adult birds the lining was low cuboidal to cuboidal. In pubertal and adult birds, the nonciliated Type I epithelial cells of the proximal efferent duct displayed a subapical endocytotic apparatus comprising coated pits, coated apical tubules, and endosomes. There was a significant increase (p ≤ .001) in epithelial heights of all ducts of the excurrent duct system in the mature, sexually active, adult birds when compared to the other age groups. The luminal and tubular diameters, and the cross-sectional areas of efferent ducts and the epididymal duct unit increased significantly (p ≤ .001) with age. It is concluded that the morphology and morphometry of the excurrent ducts of the testis of the Japanese quail change as birds mature. 相似文献
84.
Tan Chee Hau Yap Hwa Jen Musa Siti Nurmaya Chang Siow Wee Sivadas Chandra Sekaran Hisaburi Ahmad Syazwan Liew Kan Ern Ismail Ahmad Humaizi Baharudin Luqman Hakim 《Journal of Mechanical Science and Technology》2021,35(9):4115-4123
Journal of Mechanical Science and Technology - Facility layout planning (FLP) has an important role in manufacturing industries. There are few approaches to solve FLP such as procedural,... 相似文献
85.
Musa Gögebakan 《Journal of Materials Engineering and Performance》2003,12(5):521-523
The crystallization behavior of melt-spun A85Y10Fe5−xNx (x=0, 2.5, 5) amorphous alloys has been investigated by a combination of differential scanning calorimetry (DSC) and x-ray
diffractometry (XRD). XRD traces of these alloys consisted of a single broad peak corresponding to fully amorphous structure.
Continuous DSC results showed that, the first crystallization peak temperature of Al85Y10Fe5 amorphous alloy was about 60 K higher than that of Al85Y10Ni5. The activation energies for the first crystallization peak increased from 210 kJ/mol for Al85Y10Ni5 to 280 for Al85Y10Fe5. These results indicate that 5 at.% substitutions Ni by Fe increases the stability of the amorphous phase. 相似文献
86.
Musa Yildirim Dursun Özyürek Metin Gürü 《Fullerenes, Nanotubes and Carbon Nanostructures》2016,24(7):467-473
In this study, the effect of CNT amount in Al-CNT composites produced by adding carbon nanotube (CNT) to 7075 Al alloy in various amounts on microstructure and wear behaviors of aluminum matrix composites was investigated. CNT was added to 7075 Al alloy powder at five different amounts. The powders were mechanically milled for 2 hours. Mechanical milled powders were cold pressed and then pre-shaped by hot pressing. Pre-shaped samples were sintered for 1 hour under 10?6 millibar in 580°C. Microstructure examinations, hardness measurements, and wear tests were carried out. The results show that CNT's in the microstructure were agglomerated as nanotube amount increases and there was no uniform distribution. The highest hardness value was obtained in AMC reinforced with 1% CNT while it is seen that hardness of the composite decreases and weight loss increases as CNT amount increases. 相似文献
87.
N.A. Mohd Zahri N.E. Sahira Shafee F. Yusof S. Nurmaya Musa N. Liana Sukiman A.S.M.A. Haseeb Y. Miyashita T. Ariga 《Materialwissenschaft und Werkstofftechnik》2021,52(6):655-663
The porous copper foam was sandwiched between two coppers plate and then brazed using copper-tin (9.7 %)-nickel (5.7 %)-phosphorus (7 %) filler foil. Brazing process was conducted to joint copper/porous copper foam by evaluating the effect of porous copper foam pore densities [pore per inch (PPI)] and brazing holding times. The brazed joint interface of copper and porous copper foam was characterised using Field emission scanning electron microscopy and Energy-dispersive x-ray spectroscopy for the microstructure and elemental composition analysis, respectively. X-ray diffraction analysis was carried out on the shear fractured surfaces of brazed copper and porous copper foam for phase determination. The results exhibited distinct phases of copper (Cu), copper phosphide (Cu3P), nickel phosphide (Ni3P), and copper compound with tin (6 : 5) (Cu6Sn5). The filler layer was formed as an island-shaped that consists of copper phosphide and nickel phosphide. Prolong brazing holding time causes a thinner filler layer in brazing seam. While the non-uniform thickness of the filler layer was observed at different pore densities of porous copper foam. The shear strength of brazed copper/porous copper foam 15 PPI with a 10 min brazing holding time yield a maximum shear strength of 2.9 MPa. 相似文献
88.
Shahad Alyousif Mohammed Dauwed Rafal Nader Mohammed Hasan Ali Mustafa Musa Jabar Ahmed Alkhayyat 《计算机、材料和连续体(英文)》2023,75(1):531-546
The number of mobile devices accessing wireless networks is skyrocketing due to the rapid advancement of sensors and wireless communication technology. In the upcoming years, it is anticipated that mobile data traffic would rise even more. The development of a new cellular network paradigm is being driven by the Internet of Things, smart homes, and more sophisticated applications with greater data rates and latency requirements. Resources are being used up quickly due to the steady growth of smartphone devices and multimedia apps. Computation offloading to either several distant clouds or close mobile devices has consistently improved the performance of mobile devices. The computation latency can also be decreased by offloading computing duties to edge servers with a specific level of computing power. Device-to-device (D2D) collaboration can assist in processing small-scale activities that are time-sensitive in order to further reduce task delays. The task offloading performance is drastically reduced due to the variation of different performance capabilities of edge nodes. Therefore, this paper addressed this problem and proposed a new method for D2D communication. In this method, the time delay is reduced by enabling the edge nodes to exchange data samples. Simulation results show that the proposed algorithm has better performance than traditional algorithm. 相似文献
89.
In the discrete part manufacturing industry, engineers develop process plans by selecting appropriate machining processes and production equipment to ensure the quality of finished components. The decisions in process planning are usually made based on personal experience and the verification of process plans is based on physical trial-and-error runs, which is costly and time-consuming. This paper proposes to verify process plans by predicting machining tolerances via Monte Carlo simulation. The basic idea is to use a set of discrete sample points to represent workpiece geometry. The changes of their spatial position are simulated and tracked as the workpiece undergoes a series of machining processes. Virtual inspections are then conducted to determine the dimensional and geometric tolerances of the machined component. Machining tolerance prediction is completed through: (1) manufacturing error synthesis, and (2) error propagation in multiple operations. In this way, engineers can quickly screen alternative process plans, spot the root error causes, and improve their decisions. Therefore, physical trial-and-error runs can be reduced, if not eliminated, resulting in significant savings in both time and costs. 相似文献
90.
Musa E 《Applied optics》2008,47(19):3415-3422
Design methods of a light barrier consisting of a reciprocally placed transmitter-receiver system with a continuous directional light beam are considered. An optical diagram is designed. Usage of multiple lasers in the transmitter is proposed to form a rectangular detection area. A sequential pulsed driving method is used. A detection method to find the detectors blocked by an object existing in the detection area is proposed. Light barrier detection area determination, line laser placements, photodetector array design principles, a common operation principle of sequentially pulsed lasers, reaction time obtainment, a simplified diagram, the structure of the light barrier using two line lasers, and the time diagrams explaining the operation principle are given. 相似文献