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21.
Treatment of target cells with IFN induces resistance to NK cell lysis. This process is blocked by expression of E1A gene products in adenovirus (Ad)-infected and Ad-transformed cells. We compared the ability of adenovirus serotype 5 (Ad5) E1A exon 1 mutants to inhibit the induction of cytolytic resistance by IFN and block IFN-stimulated gene expression with their capacity to bind the cellular proteins p105 (retinoblastoma gene product), p107, and p300. E1A mutants that did not express conserved region 3 (CR3; residues 138-184) or contained deletions in the nonconserved regions between residues 26-35 or 86-120, bound p105, p107, and p300 and were not impaired in their capacity to block IFN-stimulated gene expression or IFN's induction of cytolytic resistance. E1A mutants with deletions in CR2 (residues 121-138) could not bind p105 or p107, but blocked IFN-stimulated gene expression and IFN's induction of cytolytic resistance. In contrast, mutants in CR1 or the N-terminal nonconserved region (residues 2, 4-25, and 48-60), which define E1A's binding site for p300, were unable to block either IFN-stimulated gene expression or IFN's induction of cytolytic resistance. We conclude that E1A's capacity to block both IFN-stimulated gene expression and IFN's induction of cytolytic resistance appears to be transduced through a pathway that involves E1A-p300 binding. The capacity of E1A to block IFN's induction of cytolytic resistance is probably secondary to E1A's more general ability to inhibit IFN-stimulated gene expression. 相似文献
22.
E. Thiele R. Klemm L. Hollang C. Holste N. Schell H. Natter R. Hempelmann 《Materials Science and Engineering: A》2005,390(1-2):42-51
Bulk nickel samples, produced by electrodeposition, resulting in different initial structure properties, were experimentally studied by X-ray diffraction, as well as by scanning and transmission electron microscopy. Attempts are made to correlate the mechanical behaviour during cyclic plastic deformation with the response of the microstructure. A special effort is made to examine the influence of grain size and internal stresses on the deformation processes. 相似文献
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The energy release rate G is a measure of the elastic energy causing crack propagation whereas the fracture heat Q indicates the amount of energy dissipated in the fracture zone. As long as any change in structure and energy losts by elastic waves can be neglected, the fracture heat represents the energy consumption of the crack and should be equivalent with G. If this can be proven one could use Q-measurements as an alternative method for investigating running cracks and dynamic fracture criteria, which in some cases may be a more appropriate measurement of the dynamic energy release rate Gdyn or the dynamic stress intensity factor Kdyn. 相似文献
25.
The free-radical addition of 1-octanediol or 3-(trimethoxysilyl)-1-propanethiol on polybutadiene occurs redox-induced with dibenzoylperoxid (DBPO) at room temperature, without any side-reaction. 1,4-trans double bonds do not undergo thiol reactions, similar to the photochemical addition. The molecular weight distribution of the products is comparable with that of the initial polybutadiene. 相似文献
26.
The mineralizing effect of 0.5% F? as CaF2 on the high-temperature reactions in the quaternary system CaOAl2O3Fe2O3SiO2 was studied in the presence of minor amounts of MgO and K2SO4. The partitioning of fluorine between the calcium aluminate and calcium silicate phases was determined in relation to the burning temperature and the presence of MgO. 相似文献
27.
R. Klemm 《Signal processing》1981,3(4):333-344
In shallow water sound propagates in terms of normal modes. The interference between the modes can be utilized to estimate range and depth of an acoustic source in shallow water by applying high resolution power estimators to a hydrophone array. The paper presents results obtained from a theoretical study based on a normal mode model. Various aspects are covered such as depth dependence of resolution, influence of surface fluctuations, comparison of horizontal and vertical line arrays and mismatch between processing and the acoustic field. Conclusions are drawn which give some more insight in the problems. 相似文献
28.
Lars Blankenburg Martin D. Hager Stephan Sell Steffi Sensfuss Elisabeth Klemm 《应用聚合物科学杂志》2009,111(4):1850-1861
A series of phenyleneethynylene copolymers with triphenylamine units as hole‐transporting moieties (TPA‐PPEs) were synthesized by the palladium‐catalyzed cross‐coupling polycondensation of diethynyltriphenylamines and selected dihalogen comonomers, for instance substituted benzene, thiophene, benzothiadiazole, or anthracene. Incorporation of the electron‐rich amino group into the PPE backbone does not interrupt the main chain conjugation. Furthermore, it has a decreasing effect on the oxidation potential, thus makes these polymers interesting as hole‐injection/hole‐transporting materials. The chemical structure of the new alternating copolymers was confirmed by 1H and 13C NMR spectroscopy and elemental analysis and gel‐permeation chromatography (GPC; THF, Mn ≈ 15,000–30,000 g/mol) was conducted. Furthermore, their optical properties were investigated by UV/vis spectroscopy. The TPA‐PPEs exhibit absorption maxima at around 400 nm (π‐π*), except anthracene containing copolymer 3f (λmax = 514 nm in THF) and benzothiadiazole containing one 3g (λmax = 503 nm in THF). The TPA copolymers have oxidation potentials about 1.1 V (Ag/AgCl). They are good photoconducting materials ( 3a : IPhoto = 4 × 10?10 A at 425 nm (400 V), 3g : IPhoto = 1.3 × 10?11 A at λmax = 500 nm (20 V)) and show emission after excitation at around 450 nm (560 nm 3f ). Their application in nonoptimized polymer solar cells (bulk heterojunction) led to power conversion efficiencies of around 1–1.8% after illumination with 100 mW/cm2 of AM1.5. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
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A comparative study of the sorption of benzene and phenol in silicalite, HAlZSM-5 and NaAlZSM-5 by computer simulation 总被引:1,自引:0,他引:1
The sorption of benzene and phenol in silicalite, HAlZSM-5 and NaAlZSM-5 has been studied comparatively with the Cerius2 software from MSI using Monte Carlo simulations. As a test of the simulation method, the well-studied system of benzene–silicalite was simulated first. The results show that the Henry constant and the isosteric heat of adsorption of benzene in silicalite are in good agreement with experimental data from the literature obtained by different methods. The open force field “Burchart–Dreiding” is proved to be suitable for simulation of the adsorption of aromatics in ZSM-5 type zeolites. The Henry constants of the systems mentioned above between 273 and 673 K, the isotherms at temperatures of 473 and 673 K, the sorption sites as well as the interaction energies between the guest molecules and the host zeolite frameworks have been obtained. The differences in the adsorption behavior between benzene and phenol in silicalite, HAlZSM-5 and NaAlZSM-5 are attributed to the differences in Coulomb interactions. 相似文献