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991.
A Taguchi and experimental investigation into the optimal processing conditions for the abrasive jet polishing of SKD61 mold steel 总被引:1,自引:0,他引:1
F.C. Tsai B.H. Yan C.Y. Kuan F.Y. Huang 《International Journal of Machine Tools and Manufacture》2008,48(7-8):932-945
This study introduces an abrasive jet polishing (AJP) technique in which the pneumatic air stream carries not only abrasive particles, but also an additive of either pure water or pure water with a specified quantity of machining oil. Taguchi design experiments are performed to identify the optimal AJP parameters when applied to the polishing of electrical discharge machined SKD61 mold steel specimens. A series of experimental trials are then conducted using the optimal AJP parameters to investigate the respective effects of the additive type and the abrasive particle material and diameter in achieving a mirror-like finish of the polished surface. The Taguchi trials indicate that when polishing is performed using pure water as an additive, the optimal processing parameters are as follows: an abrasive material to additive ratio of 1:2, an impact angle of 30°, a gas pressure of 4 kg/cm2, a nozzle-to-workpiece height of 10 mm, a platform rotational velocity of 200 rpm, and a platform travel speed of 150 mm/s. Applying these processing parameters, it is found that the optimal polishing effect is attained using #8000SiC abrasive particles and a 1:1 mixture of water-solvent machining oil and pure water. The experimental results show that under these conditions, the average roughness of the electrical discharge machined SKD61 surface is reduced from an original value of Ra=1.03 μm (Rmax: 7.74 μm) to a final value of Ra=0.13 μm (Rmax: 0.90 μm), corresponding to a surface roughness improvement of approximately 87%. 相似文献
992.
Immersion Ni-P deposition is undoubtedly one of the most important catalytic deposition process, due to its simplicity in operation and low equipment cost. In this study, immersion deposited Ni-P films were used to form Ni-silicide films. Ni-P films with a thickness of 100 nm were fabricated by immersing Si(100) substrates in an aqueous deposition solution. Ni-silicide films were then formed by annealing the samples in a furnace at temperatures ranging from 400 °C to 900 °C for 1 h in an argon ambient. Experimental results indicate that a phosphor addition in Ni films increased the transformation temperature of NiSi to NiSi2 to 900 °C. Moreover, the feasibility of enhancing the thermal stability of NiSi by varying the interface energy at the NiSi2/Si interface and the surface energy of a Ni-P-Si capping layer on the NiSi surface is discussed. 相似文献
993.
V. A. Kalitko Morgan Chun Yao Wu V. A. Zhdanok Benson Ching Tsai Yo 《Journal of Engineering Physics and Thermophysics》2009,82(2):236-245
This paper presents the process of steam thermolysis of shredded used tires for obtaining from them liquid fuel and technical
carbon carried out in a screw reactor with heating due to the partial burning of obtained fuel and burning of the tail combustible
gas. The features and advantages of using steam for safety and stability of the process, including the problem of secondary
waste slime processing, have been considered. The specific fuel consumption and the steam generation per 1 kg of processed
tires and, separately, the gas consumption for power supply (heating) of the process without using fuel, as well as with additional
burning of fuel for processing slime together with tires, have been considered.
Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 82, No. 2, pp. 242–251, March–April, 2009. 相似文献
994.
This study presents a novel numerical method for extracting the tempe -rature-dependent mechanical properties of the gold and aluminum thin-films. In the proposed approach, molecular dynamics (MD) simulations are performed to establish the load-displacement response of the thin substrate nanoindented at temperatures ranging from 300-900 K. A simple but effective procedure involving genetic algorithm (GA) and finite element method (FEM) is implemented to extract the material constants of the gold and aluminum substrates. The material constants are then used to construct the corresponding stress-strain curve, from which the elastic modulus, yield stress and the tangent modulus of the thin film are subsequently derived. Results from high-temperature (900 K) nanoindentation MD simulation show that the value of elastic modulus of the gold and aluminum thin-films could decrease by 63.9% and 73.1%, respectively, as compared with the room temperature values. The resulting temperature-dependent stress-strain curves presented in this paper provide the crucial requirement for quantitative computer simulation of nanofabrication process. 相似文献
995.
Hung‐Jen Yen Shan‐hui Hsu Ching‐Lin Tsai 《Small (Weinheim an der Bergstrasse, Germany)》2009,5(13):1553-1561
The immunological response of macrophages to physically produced pure Au and Ag nanoparticles (NPs) (in three different sizes) is investigated in vitro. The treatment of either type of NP at ≥10 ppm dramatically decreases the population and increases the size of the macrophages. Both NPs enter the cells but only AuNPs (especially those with smaller diamter) up‐regulate the expressions of proinflammatory genes interlukin‐1 (IL‐1), interlukin‐6 (IL‐6), and tumor necrosis factor (TNF‐α). Transmission electron microscopy images show that AuNPs and AgNPs are both trapped in vesicles in the cytoplasma, but only AuNPs are organized into a circular pattern. It is speculated that part of the negatively charged AuNPs might adsorb serum protein and enter cells via the more complicated endocytotic pathway, which results in higher cytotoxicity and immunological response of AuNPs as compared to AgNPS. 相似文献
996.
In this study, a single-stage, non-catalytic, dry methane plasmalysis process for producing mainly hydrogen and carbon powders using an atmospheric-pressure microwave plasma reactor is demonstrated. A high selectivity of H2 and carbon powders (C1), and a low required energy consumption of H2 could be obtained simultaneously at a low-applied power and a high inlet concentration of CH4 ([CH4]in), reaching 86.0% (selectivity of H2), 50.7% (selectivity of C1), and 6.7 eV/molecule–H2, respectively, at 0.8 kW, [CH4]in = 20%, and 12 slpm when CH4 gas was fed from the downstream of the cavity resonator. In addition, large amounts of nano carbon powders, which consisted of C atoms and had a graphite–rhombohedral structure with a particle size of about 50 nm, were produced. These particles had potential for using as a support for platinum catalysts in fuel cells. 相似文献
997.
Conjunctive Management of Large-Scale Pressurized Water Distribution and Groundwater Systems in Semi-Arid Area with Parallel Genetic Algorithm 总被引:2,自引:2,他引:0
Frank T.-C. Tsai Vineet Katiyar Doug Toy Robert A. Goff 《Water Resources Management》2009,23(8):1497-1517
This study develops a production well management model for the conjunctive management of water resources in semi-arid areas.
The management model integrates a large-scale pressurized water distribution system and a three-dimensional groundwater model
under an optimization framework. The well pump operations optimization problem is formulated as a Boolean integer nonlinear
programming (BINLP) problem to optimize the periodic 24-h pump on/off operations over a 1-week operation horizon. The management
model considers multiple objectives and is solved by a parallel genetic algorithm (PGA) to overcome the difficulty of solving
the BINLP problem. The PGA significantly reduces computation time for a case study in Chandler, Arizona. The Chandler water
distribution model is built based on EPANET, and the Chandler three-dimension groundwater model is developed using MODFLOW.
The high performance computing (HPC) of the genetic algorithm makes it possible to obtain 24-h real-time operations in the
7-day forecast model. The tank reliability, resilience, and vulnerability (R-R-V) are evaluated to infer the system reliability.
The Pareto curve provides compromise solutions between the two competing objectives of energy reduction and pressure violation
reduction. 相似文献
998.
999.
Chen C.-J. Ye J. Wong W.S. Lu Y.-W. Ho M.-C. Cao Y. Gassner M.J. Pease J.S. Tsai H.-S. Lee H.K. Cabot S. Sun Y. 《Electronics letters》2001,37(21):1304-1305
A robust control scheme for suppressing transients in both lumped and distributed Raman amplifiers is demonstrated. The control method uses only output power monitoring and holds gain fluctuations on surviving channels to <±0.06 dB in an experiment 相似文献
1000.
Parametric studies of passive Q-switching and mode-locking in a Nd 3+:YVO4-Cr4+:YAG laser were theoretically carried out. Simultaneous mode-locking and Q-switching was also experimentally studied. It was found that over 90% of the output power could be mode-locked in a diode-pumped passively Q-switched Nd3+:YVO4-Cr4+:YAG laser. The average pulse duration of the mode-locked pulse train was estimated to he around 110~150 ps. The highest peak power of a single pulse near the maximum of the Q-switched envelope was greater than 100 kW 相似文献