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1.
Pimchaya Luangaramvej Peeranuch Poungsripong Stephan Thierry Dubas 《Polymer International》2022,71(1):139-145
Polyelectrolyte complex (PEC) membranes prepared from poly(styrene sulfonate) (PSS) and poly(diallyldimethylammonium chloride) (PDADMAC) were modified by crossflow polymerization of aniline (ANI). The PEC membranes were used as separators in a two-compartment setup where ANI monomer and ammonium persulfate (APS) oxidant diffused through the membranes to form polyaniline (PANI). APS and ANI having different distributions throughout the membranes, the reaction led to the asymmetric polymerization of PANI on one face of each PEC membrane thus producing Janus membranes. Due to the excess PANI content, the membrane displayed distinct asymmetric electrical conductivities on each face. Interestingly, very different ANI polymerizations were obtained when nonstoichiometric PEC membranes having different molar ratio of cationic and anionic polyelectrolytes (P+:P? represents PDADMAC:PSS) were used and transport of APS was fastest through the 2:1 PEC when compared to the 1:2 PEC. In all experiments, the polymerization was most intense on the ANI side of the membranes. Also, the influence of NaCl both during PEC fabrication and during polymerization was studied and found to have some effect on the solute permeability. Results showed that a higher content of PANI was formed on PEC membranes having excess P+ and with no NaCl added during PEC fabrication. Although X-ray diffraction confirmed the presence of PANI on both sides of each membrane, scanning electron microscopy images demonstrated that both sides of each membrane had different PANI content deposited. Electrical conductivity measurements using a four-point probe setup also showed that the PEC–PANI exhibits asymmetric electrical property on different sides. © 2021 Society of Industrial Chemistry. 相似文献
2.
《Ceramics International》2022,48(24):36835-36844
Molybdate and tungstate with scheelite-type structure are excellent self-luminescent materials, which can be used as ideal hosts for the doping of rare-earth ions. In this study, a series of Eu3+-activated SrAO4 (A = Mo and W) phosphors were successfully synthesized, and their crystal structures, photoluminescence properties, and temperature measurement performance were analyzed in detail. These phosphors were excited by UV light (291 nm and 247 nm, respectively), with clear energy transfer (ET) (MoO42?→Eu3+ or WO42?→Eu3+). According to fluorescence intensity ratio (FIR) and Judd–Ofelt (J–O) theory, compared to SrWO4:0.01Eu3+ phosphor, SrMoO4:0.01Eu3+ phosphor exhibited better thermal stability, with relatively low Sa value (maximum values were 5.082 %K?1 and 20.74 %K?1, respectively), and their Sr values were not significantly different (maximum values were 0.864 %K?1 and 0.83 %K?1, respectively). Sa value was negatively correlated to central asymmetry of Eu3+, but the optimal Sr value tended to be more suitable for central asymmetry of Eu3+. In addition, Eu3+ exhibited stronger central asymmetry as well as covalency of Eu–O bond in SrMoO4. Results reveal that SrMoO4:xEu3+ and SrWO4:xEu3+ can be used for luminescent thermometers. 相似文献
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Intermetallic materials are bestowed by diverse ordered superlattice structures together with many unusual properties. In particular, the advent of chemically complex intermetallic alloys (CCIMAs) has received considerable attention in recent years and offers a new paradigm to develop novel metallic materials for advanced structural applications. These newly emerged CCIMAs exhibit synergistic modulations of structural and chemical features, such as self-assembled long-range close-packed ordering, complex sublattice occupancy, and interfacial disordered nanoscale layer, potentially allowing for superb physical and mechanical properties that are unmatched in conventional metallic materials. In this paper, we critically review the historical developments and recent advances in ordered intermetallic materials from the simple binary to chemically complex alloy systems. We are focused on the unique multicomponent superlattice microstructures, nanoscale grain-boundary segregation, and disordering, as well as the various extraordinary mechanical and functional properties of these newly developed CCIMAs. Finally, perspectives on the future research orientation, challenges, and opportunities of this new frontier are provided. 相似文献
5.
《International Journal of Hydrogen Energy》2022,47(33):15084-15093
The effect of ammonia (NH3) contained in hydrogen (H2) gas on hydrogen environment embrittlement (HEE) of SCM440 low-alloy steel was studied in association with the NH3 concentration, loading rate, and gas pressure. NH3 worked as both mitigator of the HEE and inducer of hydrogen embrittlement (HE) depending on the testing conditions. The mitigation of the HEE was achieved by the deactivation of the iron (Fe) surface for H2 dissociation caused by the preferential adsorption of NH3 on the Fe surface, which is enhanced by the increase in the NH3 concentration and decrease in the H2 gas pressure. NH3 induced HE was caused due to creating hydrogen by the NH3 decomposition. Since the NH3 decomposition rate is low, the induction effect was observed when the loading rate was low. The effect of NH3 was determined by the competition of the mitigation and induction effects. 相似文献
6.
Juan José Burbano He/him Darío Marcelino Cabezas María Jimena Correa 《International Journal of Food Science & Technology》2022,57(8):4772-4781
Walnut flour (WF), a by-product of walnut oil production, is characterised by high polyunsaturated fatty acids, proteins, and fibre contents and presents suitability for bakery products. However, when using non-traditional ingredients, it is essential to evaluate the effect on the quality properties of the final product. So, this work aimed to assess the impact of WF on the technological, physicochemical, and sensory properties of gluten-free (GF) cakes. WF was added at a flour blend (cassava (CS) and maize (MS) starches and rice flour) at 0, 10%, 15%, and 20%. The results showed that WF modified starch gelatinisation, increased amylose–lipid complex (ALC) content, and made crumbs easier to chew. Besides, the total dietary fibre (TDF) and protein content significantly increased. Cakes with 15% WF presented the highest specific volume (SV) and no differences in overall acceptability with respect to control. Hence, WF is a suitable ingredient for gluten-free bakery products. 相似文献
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Maxim Stolyarchuk Julie Ledoux Elodie Maignant Alain Trouv Luba Tchertanov 《International journal of molecular sciences》2021,22(2)
Redox (reduction–oxidation) reactions control many important biological processes in all organisms, both prokaryotes and eukaryotes. This reaction is usually accomplished by canonical disulphide-based pathways involving a donor enzyme that reduces the oxidised cysteine residues of a target protein, resulting in the cleavage of its disulphide bonds. Focusing on human vitamin K epoxide reductase (hVKORC1) as a target and on four redoxins (protein disulphide isomerase (PDI), endoplasmic reticulum oxidoreductase (ERp18), thioredoxin-related transmembrane protein 1 (Tmx1) and thioredoxin-related transmembrane protein 4 (Tmx4)) as the most probable reducers of VKORC1, a comparative in-silico analysis that concentrates on the similarity and divergence of redoxins in their sequence, secondary and tertiary structure, dynamics, intraprotein interactions and composition of the surface exposed to the target is provided. Similarly, hVKORC1 is analysed in its native state, where two pairs of cysteine residues are covalently linked, forming two disulphide bridges, as a target for Trx-fold proteins. Such analysis is used to derive the putative recognition/binding sites on each isolated protein, and PDI is suggested as the most probable hVKORC1 partner. By probing the alternative orientation of PDI with respect to hVKORC1, the functionally related noncovalent complex formed by hVKORC1 and PDI was found, which is proposed to be a first precursor to probe thiol–disulphide exchange reactions between PDI and hVKORC1. 相似文献
10.
The micro-arc oxidation (MAO) coatings were prepared in four different electrolyte systems, including mixed acid, phosphate, phosphate-aluminate and phosphate-silicate electrolytes. The friction and wear properties of MAO coatings in ambient air, seawater and four groups of saline solutions related to seawater were investigated. The results showed that the addition of silicate to phosphate could increase the density of the coating. The phosphate-aluminate ceramic layer exhibited the lowest wear rate in various environments. Additionally, the friction coefficient and wear rate of MAO coating in seawater were lower than those in ambient air, which was due to the boundary lubrication effect of seawater. Meanwhile, the presence of divalent metal salts in seawater made its lubricity better than other salt solutions. 相似文献