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941.
A total of 105 fresh pork sausages were packaged in atmospheres varying in oxygen concentration, using the following mixtures (%O2/%CO2/%N2): 0/20/80, 0/20/80 + O2 scavenger, 20/20/60, 40/20/40, 60/20/20, and 80/20/0. In addition, two batches were subjected to vacuum packaging or over-wrap with O2-permeable film. They were stored for 20 days at 2 ± 1 °C in the dark. Values of pH, CIE L*, a* and b* color parameters, surface metmyoglobin percentage, TBA-reactive substances, psychrotroph aerobe bacterial numbers and sensory discoloration and off-odor were assessed throughout storage. Packaging in the absence of O2, either under vacuum or in atmosphere with O2 scavenger, led to extension of shelf-life in terms of both color and odor stability due to low oxidation rates. Increase of O2 caused a significant enhancement of oxidation, decrease of shelf-life due to discoloration and off-odor development. The highest O2 concentration gave rise to a significant color improvement, though only for a limited period of 8 days. 相似文献
942.
Impact of Commercial Precooking of Common Bean (Phaseolus vulgaris) on the Generation of Peptides,After Pepsin–Pancreatin Hydrolysis,Capable to Inhibit Dipeptidyl Peptidase‐IV 下载免费PDF全文
The objective of this research was to determine the bioactive properties of the released peptides from commercially available precook common beans (Phaseolus vulgaris). Bioactive properties and peptide profiles were evaluated in protein hydrolysates of raw and commercially precooked common beans. Five varieties (Black, Pinto, Red, Navy, and Great Northern) were selected for protein extraction, protein and peptide molecular mass profiles, and peptide sequences. Potential bioactivities of hydrolysates, including antioxidant capacity and inhibition of α‐amylase, α‐glucosidase, dipeptidyl peptidase‐IV (DPP‐IV), and angiotensin converting enzyme I (ACE) were analyzed after digestion with pepsin/pancreatin. Hydrolysates from Navy beans were the most potent inhibitors of DPP‐IV with no statistical differences between precooked and raw (IC50 = 0.093 and 0.095 mg protein/mL, respectively). α‐Amylase inhibition was higher for raw Red, Navy and Great Northern beans (36%, 31%, 27% relative to acarbose (rel ac)/mg protein, respectively). α‐Glucosidase inhibition among all bean hydrolysates did not show significant differences; however, inhibition values were above 40% rel ac/mg protein. IC50 values for ACE were not significantly different among all bean hydrolysates (range 0.20 to 0.34 mg protein/mL), except for Red bean that presented higher IC50 values. Peptide molecular mass profile ranged from 500 to 3000 Da. A total of 11 and 17 biologically active peptide sequences were identified in raw and precooked beans, respectively. Peptide sequences YAGGS and YAAGS from raw Great Northern and precooked Pinto showed similar amino acid sequences and same potential ACE inhibition activity. Processing did not affect the bioactive properties of released peptides from precooked beans. Commercially precooked beans could contribute to the intake of bioactive peptides and promote health. 相似文献
943.
Medina-Torres L Vernon-Carter EJ Gallegos-Infante JA Rocha-Guzman NE Herrera-Valencia EE Calderas F Jiménez-Alvarado R 《Journal of the science of food and agriculture》2011,91(6):1001-1005
BACKGROUND: The process of convective drying was evaluated in terms of the bioactive compounds contained in nopal samples before and after dehydration. Total polyphenol, flavonoid, flavonol, carotene and ascorbic acid contents were determined in undehydrated and dehydrated samples. Two drying temperatures (45 and 65 °C) and two air flow rates (3 and 5 m s?1) were evaluated. The rheology of samples under the best drying conditions was also studied, since it provides important information regarding processing (mixing, flow processing) as well as the sensory attributes (texture) of rehydrated samples. RESULTS: Non‐Newtonian shear‐thinning behaviour was observed for samples dried at 45 °C, while samples dried at 65 °C showed shear‐thickening behaviour, possibly caused by thermal chain scission of high‐molecular‐weight components. CONCLUSION: The best conditions for bioactive compound preservation were a drying temperature of 45 °C and an air flow rate of 3 m s?1, resulting in 40.97 g phenols, 23.41 g flavonoids, 0.543 g β‐carotene and 0.2815 g ascorbic acid kg?1 sample as shown in table 3. Copyright © 2011 Society of Chemical Industry 相似文献
944.
Ana Fernndez Estela Fabuel Estefnia Alves Carmen Rodriguez Luis Sili Cristina
vilo 《Journal of the science of food and agriculture》2004,84(14):1855-1860
Traceability in the meat supply chain depends on systems based on electronic identification, but DNA tests would be suitable to audit the genetic origin of some labelled meat products. Differentiated labelling is required for highly prized meat products from purebred Iberian pigs and from animals crossbred with the Duroc breed. A panel of breed specific markers based on polymorphisms found in two coat colour genes was investigated in the present study. The genotyping of the G/C or A/G polymorphisms at nucleotide positions ?160 and 727 bp of the melanocortin receptor 1 (MC1R) gene can be indistinctly used to discriminate the Duroc specific allele (MC1R*4) from all the alleles (MC1R*3, MC1R*6 and MC1R*7) found in the Iberian breed. It allows one to differentiate unambiguously samples from purebred Iberian and Duroc crossbred genotypes. The additional genotyping of the A/G polymorphism at position 2462 of the pink‐eyed dilution (OCA2) gene, four microsatellites (SW24, SW413, SW874 and SW1057) and nine amplified fragment length polymorphism (AFLP) markers would allow one to detect Duroc crossbred genotypes with a probability of exclusion of the pure Iberian origin greater than 0.968. The validation of batches of marketed products may be achieved with more single tests on pooled DNA samples. Copyright © 2004 Society of Chemical Industry 相似文献
945.
Luis Alcides Brandini De Boni Isaac Newton Lima da Silva 《Fuel Processing Technology》2011,92(5):1001-1006
The production of biodiesel is rapidly expanding around the world, making it more important to produce this fuel with more energy efficiency. In this paper, we observed a series of transesterification reactions of soy bean oil and methyl alcohol catalyzed by potassium hydroxide. The observations were made using a non-invasive optical technique. This technique is useful to indicate the endpoint of a transesterification reaction or to determine when this reaction is reaching the state of chemical equilibrium. This study made it possible to improve the follow-up of the transesterification reaction, by optimizing the reaction time with a better monitoring system. 相似文献
946.
Samantilleke AP Rebouta LM Garim V Rubio-Peña L Lanceros-Mendez S Alpuim P Carvalho S Kudrin AV Danilov YA 《Nanoscale research letters》2011,6(1):309
In this study, transparent conducting nanocrystalline ZnO:Ga (GZO) films were deposited by dc magnetron sputtering at room temperature on polymers (and glass for comparison). Electrical resistivities of 8.8 × 10-4 and 2.2 × 10-3 Ω cm were obtained for films deposited on glass and polymers, respectively. The crack onset strain (COS) and the cohesive strength of the coatings were investigated by means of tensile testing. The COS is similar for different GZO coatings and occurs for nominal strains approx. 1%. The cohesive strength of coatings, which was evaluated from the initial part of the crack density evolution, was found to be between 1.3 and 1.4 GPa. For these calculations, a Young's modulus of 112 GPa was used, evaluated by nanoindentation. 相似文献
947.
Benedicto M Galiana B Molina-Aldareguia JM Monaghan S Hurley PK Cherkaoui K Vazquez L Tejedor P 《Nanoscale research letters》2011,6(1):400
Nanostructuring of ultrathin HfO2 films deposited on GaAs (001) substrates by high-resolution Lloyd's mirror laser interference nanolithography is described. Pattern transfer to the HfO2 film was carried out by reactive ion beam etching using CF4 and O2 plasmas. A combination of atomic force microscopy, high-resolution scanning electron microscopy, high-resolution transmission electron microscopy, and energy-dispersive X-ray spectroscopy microanalysis was used to characterise the various etching steps of the process and the resulting HfO2/GaAs pattern morphology, structure, and chemical composition. We show that the patterning process can be applied to fabricate uniform arrays of HfO2 mesa stripes with tapered sidewalls and linewidths of 100 nm. The exposed GaAs trenches were found to be residue-free and atomically smooth with a root-mean-square line roughness of 0.18 nm after plasma etching.PACS: Dielectric oxides 77.84.Bw, Nanoscale pattern formation 81.16.Rf, Plasma etching 52.77.Bn, Fabrication of III-V semiconductors 81.05.Ea. 相似文献
948.
Jaafar M Serrano-Ramón L Iglesias-Freire O Fernández-Pacheco A Ibarra MR De Teresa JM Asenjo A 《Nanoscale research letters》2011,6(1):407
High-resolution magnetic imaging is of utmost importance to understand magnetism at the nanoscale. In the present work, we use a magnetic force microscope (MFM) operating under in-plane magnetic field in order to observe with high accuracy the domain configuration changes in Co nanowires as a function of the externally applied magnetic field. The main result is the quantitative evaluation of the coercive field of the individual nanostructures. Such characterization is performed by using an MFM-based technique in which a map of the magnetic signal is obtained as a function of both the lateral displacement and the magnetic field. 相似文献
949.
Fuentes N Martín-Lasanta A Alvarez de Cienfuegos L Ribagorda M Parra A Cuerva JM 《Nanoscale》2011,3(10):4003-4014
In a general sense, molecular electronics (ME) is the branch of nanotechnology which studies the application of molecular building blocks for the fabrication of electronic components. Among the different types of molecules, organic compounds have been revealed as promising candidates for ME, due to the easy access, great structural diversity and suitable electronic and mechanical properties. Thanks to these useful capabilities, organic molecules have been used to emulate electronic devices at the nanoscopic scale. In this feature article, we present the diverse strategies used to develop organic switches towards ME with special attention to non-volatile systems. 相似文献
950.
Sáez-Ayala M Sánchez-del-Campo L Montenegro MF Chazarra S Tárraga A Cabezas-Herrera J Rodríguez-López JN 《ChemMedChem》2011,6(3):440-449
Despite bioavailability issues, tea catechins have emerged as promising chemopreventive agents because of their efficacy in various animal models. We synthesized two catechin-derived compounds, 3-O-(3,4,5-trimethoxybenzoyl)-(-)-catechin (TMCG) and 3-O-(3,4,5-trimethoxybenzoyl)-(-)-epicatechin (TMECG), in an attempt to improve the stability and cellular absorption of tea polyphenols. The antiproliferative and pro-apoptotic activities of both compounds were analyzed with various cancer cell systems, and TMCG, which was easily synthesized in excellent yield, was more active than TMECG in both melanoma and non-melanoma cell lines. TMCG was also a better inhibitor of dihydrofolate reductase and was more efficiently oxidized by tyrosinase, potentially explaining the difference in activity between these epimers. 相似文献