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1.
N. V. Vostokov Yu. N. Drozdov Z. F. Krasil’nik O. A. Kuznetsov A. V. Novikov V. A. Perevoshchikov M. V. Shaleev 《Russian Microelectronics》2005,34(4):203-209
The results are presented of the fabrication of strain-relaxed graded Si1 − x
Gex/Si(001) buffer layers with a maximum Ge fraction of about 0.25 that have a low density of threading dislocations (<106 cm−2) and low surface roughness. The buffer layers are grown by atmospheric-pressure hydride CVD. It is found that chemical mechanical polishing can reduce their surface roughness to a level comparable with that of the original Si(001) substrates. It is shown that the polished buffer layers can serve as substrates for MBE-grown SiGe/Si heterostructures.__________Translated from Mikroelektronika, Vol. 34, No. 4, 2005, pp. 243–250.Original Russian Text Copyright © 2005 by Vostokov, Drozdov, Krasil’nik, Kuznetsov, Novikov, Perevoshchikov, Shaleev. 相似文献
2.
aneta Polkowska Jacek Namienik Jacek Czerwiski & Bogdan Zygmunt 《International Journal of Food Science & Technology》1996,31(5):387-395
Applicability of thin-layer headspace (TLHS) procedure giving an aqueous concentrate and also classical purge and trap (PT) in off-line mode to isolate and enrich volatile organohalogen compounds in common beverages was tested. Both enrichment tech-niques were used in combination with gas chromatography – electron capture detection (GC-ECD). TLHS, combined with direct aqueous injection (DAI)-GC-ECD, proved applicable in the determination of volatile organohalogen compounds in all studied beverages, while the PT in a version with no preliminary sample pre-treatment was of limited applicability. Detection limits of the TLHS-based procedure were in the order of 1 ppt. Content of volatile organohalogen compounds in a number of beverages available on the Polish market including mineral waters, beers, juices, carbonated and non-carbonated soft drinks, etc. was determined by means of TLHS-DAI-GC-ECD. 相似文献
3.
Non-specific antitumoral activity of staphylococcal enterotoxins 总被引:2,自引:0,他引:2
O N Shcheglovitova A D Voskobo?nik M N Solov'eva M K Fan'kovskaia Iu V Ezepchuk 《Eksperimental?nai?a onkologii?a》1987,9(1):28-30
St. aureus enterotoxins A and B possess an antitumour effect. After intraperitoneal inoculation they decrease the size and in some cases prevent the development of the human hypernephroma in the cheek pouch of golden hamsters. The effect of enterotoxins may possibly consist in inducing the production of endogenous immune interferon which activates the host immune system and enhances the rejection of heterologous tumour cells. 相似文献
4.
V. P. Kuznetsov D. Yu. Remizov V. B. Shmagin K. E. Kudryavtsev V. N. Shabanov S. V. Obolensky O. V. Belova M. V. Kuznetsov A. V. Kornaukhov B. A. Andreev Z. F. Krasil’nik 《Semiconductors》2007,41(11):1312-1314
Results of experimental studies of erbium ion electroluminescence in p ++/n +/n-Si:Er/n ++ silicon diode structures grown by sublimation molecular-beam epitaxy are discussed. The distinctive feature of these structures is that the regions of electron flux formation of (n +-Si) and impact excitation of erbium ions (n-Si:Er) are spaced. The influence of the n +-Si layer thickness on electrical and electroluminescent properties of diodes was studied. It was shown that n +-Si layer thinning causes the transformation of the structure breakdown mechanism from tunneling to avalanche. The dependence of the Er3+ ion electroluminescence on the thickness of the heavily doped n +-Si region is bell-shaped. At the n +-Si-layer doping level n ≈ 2 × 1018 cm?3, the maximum electroluminescence intensity is attained at an n +-Si layer thickness of ~23 nm. 相似文献
5.
The paper presents a computational approach and numerical data which facilitate the use of the smeared-tip method for cohesive fracture in large enough structures. In the recently developed K-version of the smeared tip method, the large-size asymptotic profile of the stress intensity factor density along a cohesive crack is considered as a material characteristic, which is uniquely related to the softening stress-displacement law of the cohesive crack. After reviewing the K-version, an accurate and efficient numerical algorithm for the computation of this asymptotic profile is presented. The algorithm is based on solving a singular Abel's integral equation. The profiles corresponding to various typical softening stress-displacement laws of the cohesive crack model are computed, tabulated and plotted. The profiles for a certain range of other typical softening laws can be approximately obtained by interpolation from the tables. Knowing the profile, one can obtain with the smeared-tip method an analytical expression for the large-size solution to fracture problems, including the first two asymptotic terms of the size effect law. Consequently, numerical solutions of the integral equations of the cohesive crack model as well as finite element simulations of the cohesive crack are made superfluous. However, when the fracture process zone is attached to a notch or to the body surface and the cohesive zone ends with a stress jump, the solution is expected to be accurate only for large-enough structures. 相似文献
6.
V. V. Artamanov M. Ya. Valakh N. I. Klyui V. P. Mel’nik A. B. Romanyuk B. N. Romanyuk V. A. Yukhimchuk 《Semiconductors》1998,32(12):1261-1265
The properties of silicon structures with silicon carbide (SiC) buried layers produced by high-dose carbon implantation followed
by a high-temperature anneal are investigated by Raman and infrared spectroscopy. The influence of the coimplantation of oxygen
on the features of SiC buried layer formation is also studied. It is shown that in identical implantation and post-implantation
annealing regimes a SiC buried layer forms more efficiently in CZ Si wafers or in Si (CZ or FZ) subjected to the coimplantation
of oxygen. Thus, oxygen promotes SiC layer formation as a result of the formation of SiOx precipitates and accommodation of the volume change in the region where the SiC phase forms. Carbon segregation and the formation
of an amorphous carbon film on the SiC grain boundaries are also discovered.
Fiz. Tekh. Poluprovodn. 32, 1414–1419 (December 1998) 相似文献
7.
P. Lobotka I. Vávra Š. Gaži A. Plecenik J. Dérer 《Journal of Low Temperature Physics》1997,106(3-4):381-386
A Josephson junction Nb/Si/Nb with a 10 nm thick amorphous silicon barrier is studied. The upper electrode contains a 2 nm
thick sublayer of amorphous phase adjacent to the barrier, as revealed by cross-sectional TEM. Thus, the junction can be considered
as a S-I-N-S system with the N layer represented by amorphous niobium. Peculiarities in the I–V and Δ(T) dependencies are
observed and explained as a consequence of a proximity effect present in the upper electrode. 相似文献
8.
9.
L M Iakushina Iu P Arkhapchev S I Ale?nik N V Blazheevich V A Isaeva I A Alekseeva E Iu Glinka N L Grishchenko L S Evert E I Prakhin 《Voprosy pitaniia》1992,(3):59-62
The effect of the prophylactic use of multivitamin "Undevitum" on parameters of vitamin providing of schoolchildren in Norilsk was studied. The results of the investigation showed a positive effect of the prophylactic vitamin administration on providing with vitamins of schoolchildren in Norilsk and proved the necessity of conducting mass vitamin administration to schoolchildren. 相似文献
10.
Electropolymerization of phenol and mono-, di-, tri-, pentachlorophenols was studied using EQCM on a Pt electrode at 0.78 V (SHE) in 1 M NaOH solution containing 0.1 M of the corresponding phenol. The highest electropolymerization rate was found for ortho-substituted chlorophenols indicating a weak fouling of the electrode. Low electropolymerization rates for para-substituted chlorophenols suggest a low permeability of the polymer film, resulting in rapid electrode fouling. The EQCM data suggest that electropolymerization of chlorophenols occurs without Cl-elimination for the monomers with unsubstituted ortho and para positions. Dechlorination is most pronounced for electropolymerization of para-substituted isomers. The mechanism of electropolymerization of chlorophenols is discussed. 相似文献