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51.
Secondary ion mass spectrometry (SIMS) and glow discharge mass spectrometry (GDMS) were used to determine the impurity concentrations
of hydrogen, carbon, nitrogen, and oxygen elements in Cu films, and the results of SIMS and GDMS were carefully interpreted.
The Cu films were deposited on Si (100) substrates at substrate bias voltages ranging from 0 V to −150 V using a non-mass
separated ion beam deposition method. From the results of SIMS using a Cs− ion beam, as a whole, many high intensity peaks were observed in the Cu films deposited without substrate bias voltage. From
the quantitative GDMS results, these peaks were determined to be signals detected as a cluster state such as CxHx, OxHx, CxOxHx. Therefore, using a combination of these dominant impurities, all the unknown peaks observed in the SIMS results could be
interpreted. Moreover, it was found that the dominant impurities having a great influence on the film purity were hydrogen,
carbon, nitrogen, and oxygen. 相似文献
52.
Tetsuo Suga Yasuoa Murai Taizo Kobashi Kunika Ueno Minoru Shindo Katsunori Kanno 《Welding International》2016,30(3):166-174
In many industries, there are applications that require the joining of stainless steel and copper components; therefore, the welding of dissimilar stainless steel/copper joints is a common process. For this investigation, the optimal brazing conditions and suitable filler metals for laser brazing of stainless steel/copper lap joints were studied. Tensile shear force increases with increases in the laser spot diameter or in the laser irradiation angle, which is associated with increased bonding width; however, as bonding width approaches 2 mm, tensile shear force reaches a saturated value due to fracturing at the HAZ of the Cu base plate. In order to obtain joints with high tensile shear strength, laser brazing was optimized by using Cu–Si-based filler metal under the following conditions: laser power, 4 kW; spot diameter, 3 mm; laser irradiation angle, 80°; irradiation position shift, 0.6 mm; brazing speed, 0.30 m/min; and filler metal feed speed, 0.30 min. Concerning filler metals, it was found that the Ni–Cu type showed relatively large tensile shear force even at high welding speeds in comparison with those of the Cu–Si, Cu, Cu–Ni, Ni–Cu and Ni types, respectively. 相似文献
53.
The precipitation characteristics and mechanism of vanadium carbides during isothermal transformation at 650 ℃ in a V-microalloyed medium-carbon steel were investigated through scanning electron microscopy and transmission electron microscopy as well as dilatometry test. Five morphologies of vanadium carbides were found to precipitate at different nucleation sites during the transformation. Two kinds of interphase precipitation form simultaneously in both pro-eutectoid and pearlitic ferrites. The linear arrays of fine interphase precipitates are parallel to the c/a interface, and the fine needles of interphase precipitates are perpendicular to the c/a interface. The vanadium carbides of long or short fibers, coarse particles and fine particles form in both pro-eutectoid and pearlitic ferrites, displaying different precipitation distributions and orientation relationships with ferrite. The precipitation mechanisms of vanadium carbide precipitates with different modes were proposed, and the precipitation sequence of various vanadium carbide precipitates was finally ascertained. 相似文献
54.
To model the molten globule structure of -lactalbumin, moleculardynamics (MD) simulations were carried out for the protein inexplicit water at high temperature. In these simulations, long-rangeCoulomb interactions were evaluated explicitly with an originalmethod (particleparticle and particlecell: PPPC)to avoid artifacts caused by the cut-off. The MD simulationswere started from two initial conditions to verify that similarresults would be obtained. From the last 150 ps trajectoriesof the two MD simulations, two partially unfolded average structureswere obtained. These structures had the following common structuralfeatures which are characteristic of the molten globule state.The radii of gyration for these conformations were 7.4 and 9.6%larger than that of the native state. These values were almostthe same as the experimental value (9.6%) observed recentlyby small-angle X-ray scattering (Kataoka,M., Kuwajima,K., Tokunaga,F.and Goto,Y., 1997, Protein Sci., 6, 422430). Furthermore,aromatic residues of clusters I and II in these structures werefar apart from each other except for Try103Trp104. Thisresult is in good agreement with NMR experimental results forthe acid-denatured molten globule state (Alexandrescu et al.,1992, 1993); that is, NOE signals between the aromatic residueswere not observed, except for that of Try103Trp104 inthe molten globule state. Other structural features of thesemodels for the molten globule state are discussed with referenceto native state structures. 相似文献
55.
56.
Minoru Watanabe Takenori Shiki Fuminori Kobayashi 《Analog Integrated Circuits and Signal Processing》2009,60(1-2):137-143
Dynamic reconfigurable devices present new computational paradigms because programmable devices’ activity and performance can be improved dramatically by increasing its reconfiguration frequency. Therefore, this paper presents designs of optically differential reconfigurable gate array (ODRGA) VLSIs using 0.18 μm and 0.35 μm CMOS process technologies. Although they are a type of programmable gate array, they can be reconfigured optically in nanoseconds. This paper also discusses future scaling prospects of ODRGA-VLSIs. 相似文献
57.
Matsui T Matsumura K Hagisawa K Ishihara M Ishizuka T Suzuki M Kurita A Kikuchi M 《IEEE transactions on bio-medical engineering》2002,49(6):621-623
The purpose of this study is to investigate the vascular wall with a thermally self-regulating, cylindrical stent made of a low Curie temperature ferromagnetic alloy. Physiologic saline was circulated in the silicone model vessel implanted with the stent. The stent-temperature remained nearly constant for variable saline flows, saline temperatures, and magnetic flux densities. Stent implants of this type in human blood vessels could potentially enable thermotherapy and temperature determination without catheterization. 相似文献
58.
Numerical prediction of fraction of eutectic phase in Sn−Ag−Cu soldring using the phase-field method
Machiko Ode Minoru Ueshima Taichi Abe Hideyuki Murakami Hidehiro Onodera 《Journal of Electronic Materials》2006,35(11):1969-1974
A combination of macroscale solidification simulation and phase-field calculation is employed to predict the volume fraction
of the eutectic phase in Sn-4.0 mass% Ag-XCu solder alloys (X=0.5–1.1 mass%). The solidification simulation incorporates the
cooling rate in the phase-field simulation. We assume the residual liquid solidifies as eutectic phase when the driving force
for the nucleation of Cu6Sn5 amounts to a critical value, which is determined based on the experimental data. Though the calculation results depend on
the experimental data, the obtained fractions are about 40% for 0.5 mass% Cu and more than 90% for 1.1 mass% Cu alloy, which
shows good agreement with the experimental data. 相似文献
59.
A new process for electrolytic production of a perfluorinated compound, (CF3)3N, using lanthanum nickel oxide-coated Ni sheet anode in the (CH3)4NF·4.0HF melt at room temperature, was developed. Thin films of the lanthanum nickel oxides were prepared on Ni sheets by sol-gel coating method using polyvinlylpyrrolidone(PVP). The main components of the thin films were La2O3, LaNiO3, and La2NiO4 at 500, 750 and 1000 °C, respectively. The anode performance in the (CH3)4NF·4.0HF melt depends greatly on the main component of the thin film, and the LaNiO3-coated Ni sheet anode gives the best anode performance. The potential of LaNiO3-coated Ni sheet anode remains constant at 5.9 V during electrolysis at 20 mA·cm−2 in the (CH3)4NF·4.0HF melt for 100 h. This is because LaNiO3 and NiF3, and/or Ni2F5, the latter of which was formed during electrolysis, in the film give a high electronic conductivity to the surface film during electrolysis. The maximum mole fraction of (CF3)3N (21.4%) was obtained at 20 mA·cm−2 in (CH3)4NF·4.0HF melt using the LaNiO3-coated Ni sheet. 相似文献
60.
A version of structured FORTRAN named STAR is introduced. STAR allows recursive subroutines. Implementation problems such as parameter passing by value and local variable stacking are discussed. The major difficulty in the preprocessor approach is debugging. We claim that execution profiles are strong debugging aids, and demonstrate how to debug a STAR program at source language level with the clue in the profiles plus assertion statements. We make use of a quicksort program as an example. 相似文献