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991.
Whasley F. Duarte Disney R. Dias José M. Oliveira José A. Teixeira João B. de Almeida e Silva Rosane F. Schwan 《LWT》2010,43(10):1564-1572
The main aim of this work was to produce fruit wines from pulp of gabiroba, cacao, umbu, cupuassu and jaboticaba and characterize them using gas chromatography–mass spectrometry for determination of minor compounds and gas chromatography-flame ionization detection for major compounds. Ninety-nine compounds (C6 compounds, alcohols, monoterpenic alcohols, monoterpenic oxides, ethyl esters, acetates, volatile phenols, acids, carbonyl compounds, sulfur compounds and sugars) were identified in fruit wines. The typical composition for each fruit wine was evidenced by principal component analysis and Tukey test. The yeast UFLA CA 1162 was efficient in the fermentation of the fruit pulp used in this work. The identification and quantification of the compounds allowed a good characterization of the fruit wines. With our results, we conclude that the use of tropical fruits in the production of fruit wines is a viable alternative that allows the use of harvest surpluses and other underused fruits, resulting in the introduction of new products into the market. 相似文献
992.
Mezadri T Fernández-Pachón MS Villaño D García-Parrilla MC Troncoso AM 《Archivos latinoamericanos de nutrición》2006,56(2):101-109
The acerola (Malpighia emarginata Sessé y Moci?o ex DC) is a wild plant grown in zones of tropical and subtropical climate. Acerola is origin from South of Mexico, Central America and Septentrional area of South America. Its scientific name was adopted in 1986 by the International Council of Vegetable Genetic Resources. Malpighia emarginata has a subglobulose drupa fruit with three seeds which account between the 19 - 25% of the total weight. The diameter and weight of the fruit varies between 1 - 4 cm and 2 - 15 g, respectively. The fruit shows green color when it is developing, which changes to yellow and red tones when it is mature. Each plant produces annually 20 - 30 kg of fruits. This fruit contents macro and micronutrients: proteins (0.21-0.80 g/100 g), fats (0.23-0.80 g/100 g), carbohydrates (3.6-7.80 g/100 g), mineral salts (iron 0.24, calcium 11.7, phosphorus 17.1 mg/100 g) and vitamins (thiamine 0.02, riboflavine 0.07, piridoxine 8.7 mg/100 g). Its high content in vitamin C (695 a 4827 mg/100 g) is remarkable, therefore acerola has an increasing economic value by its great consume during last years. Acerola also presents carotenoids and bioflavonoids which provide important nutritive value and its potential use as antioxidant. Brazil has a climate and soil appropriate for the culture of acerola, thus this country is the main mundial productor. Acerola is commercialised as juices, jams, ices, gelatins, sweets or liquors. Bibliographical data have been mainly supplied by Electronic Resources of the University of Seville and the University do Vale do Itajaí (Santa Catarina, Brazil). 相似文献
993.
Tatiana V. Magdesieva Magdalena Graczyk Oleg M. Nikitin Kim P. Butin 《Electrochimica acta》2006,52(3):1265-1280
We have studied a reaction between the reduced form of titanocene dichloride (Cp2TiCl2) and a group of organic halides: benzyl derivatives (4-XC6H4CH2Cl, X = H, NO2, CH3; 4-XC6H4CH2Br, X = H, NO2, PhC(O); 4-XC6H4CH2SCN, X = H, NO2) as well as three aryl halides (4-NO2C6H4Hal, Hal = Cl, Br; 4-CH3O-C6H4Cl). It has been shown that the electrochemical reduction of Cp2TiCl2 in the presence of these benzyl halides leads to a catalytic cycle resulting in the reductive dehalogenation of these organic substrates to yield mostly corresponding toluene derivatives as the main product. No dehalogenation has been observed for aryl derivatives. Based on electrochemical data and digital simulation, possible schemes of the catalytic process have been outlined. For non-substituted benzyl halides halogen atom abstraction is a key step. For the reaction of nitrobenzyl halides the complexation of Ti(III) species with the nitro group takes place, with the electron transfer from Ti(III) to this group (owing to its highest coefficient in LUMO of the nitro benzyl halide) followed by an intramolecular dissociative electron redistribution in the course of the heterolytic CHal bond cleavage.The results for reduced titanocene dichloride centers immobilized inside a polymer film showed that the catalytic reductive dehalogenation of the p-nitrobenzyl chloride does occur but with a low efficiency because of the partial deactivation of the film due to the blocking of the electron charge transport between the electrode and catalytic centers. 相似文献
994.
Silva AP Guimarães DE Mizurini DM Maia IC Ortiz-Costa S Sardinha FL do Carmo MG 《Lipids》2006,41(6):535-541
The purpose of this study was to evaluate the effects of four isoenergetic diets of differing fat composition on blood lipid
profile and adiposity in young rats. Diets containing different lipid sources—partially hydrogenated vegetable oil (PHVO),
palm oil (PO), canola oil (CO), and soy oil (SO)—were fed to lactating rats during the 21 days of lactation, and then fed
to young males following weaning until the 45th, day of life. In vivo lipogenesis rate (LR), lipid content (LC), relative level of FA, and the activity of lipoprotein lipase (LPL) enzyme were
measured in epididymal adipose tissue (EPI). Fasting blood lipoproteins and LC in the carcass were also appraised. Body weight
of PO and PHVO groups was significantly higher than CO and SO groups from day 14 of lactation to day 45, despite the lower
food intake in the PHVO group. PO and PHVO groups presented higher LR and LC in EPI than SO and CO groups. Carcass fat content
was significantly higher in PHVO and PO groups than in CO and SO groups. The LPL activity in EPI was unaffected by dietary
lipids. PHVO group had increased total cholesterol and TAG concentrations in comparison with the PO group, and significantly
lower HDL level compared with the other groups. These results show that the kind of FA in the dietary lipid offered early
in life can affect lipid metabolism and adiposity. 相似文献
995.
Simulation of reflectometry Bragg backscattering spectral responses in the absence of a cutoff layer
da Silva F da Graça S Heuraux S Conway GD;ASDEX Upgrade Team 《The Review of scientific instruments》2010,81(10):10D927
Experimental reflectometry signals obtained in the absence of a cutoff layer, with the possibility of interferometric operation excluded, show a coherent and recurrent frequency spectrum signature similar to an Alfvén cascade signature. A possible explanation resides in the modulation of a resonant Bragg backscattering response by an Alfvén mode structure located at the center of the plasma whose frequency of oscillation modulates the backscattered signal in a conformable way. This situation is modeled and simulated using an O-mode full-wave Maxwell finite-difference time-domain code and the resulting signatures are discussed. 相似文献
996.
Maíra Martins da Silva Olivier Brüls Wim Desmet Hendrik Van Brussel 《Mechatronics》2009,19(6):1016-1025
This paper considers the optimal design of mechatronic systems with configuration-dependent dynamics. An optimal mechatronic design requires that, among the structural and control parameters, an optimal choice has to be made with respect to design specifications in the different domains. Two main challenges are treated in this paper: the non-convex nature of the optimization problem and the difficulty in modeling serial machines with flexible components and their embedded controllers. The optimization problem is treated using the direct design strategy which considers simultaneously structural and control parameters as variables and adopts non-convex optimization algorithms. Linear time-invariant and gain-scheduling PID controllers are addressed. This methodology is exploited for the multi-objective optimization of a pick-and-place assembly robot with a gripper carried by a variable-length flexible beam. The resulting design tradeoffs between system accuracy and control efforts demonstrate the advantage of an integrated design approach for mechatronic systems with configuration-dependent dynamics. 相似文献
997.
de Souza M. e Silva F. de Melo M.T. Novo L.R.G.S.L. 《Microwave Theory and Techniques》2009,57(9):2224-2231
The authors have studied a new way to design an instantaneous frequency measurement subsystem (IFMS). The method is based on bandstop filters. The device uses rectangular open-loop resonators instead of delay lines. The resonance frequency is adjusted by a resonator perimeter that must be approximately a half-wavelength long, and also by coupling distance between the resonators and the main transmission line. Simulated and experimental results are presented for a 5-bit IFMS. 相似文献
998.
Cognitive Radio and Networking Research at Virginia Tech 总被引:1,自引:0,他引:1
MacKenzie A.B. Reed J.H. Athanas P. Bostian C.W. Buehrer R.M. DaSilva L.A. Ellingson S.W. Hou Y.T. Hsiao M. Jung-Min Park Patterson C. Raman S. da Silva C. 《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》2009,97(4):660-688
More than a dozen Wireless @ Virginia Tech faculty are working to address the broad research agenda of cognitive radio and cognitive networks. Our core research team spans the protocol stack from radio and reconfigurable hardware to communications theory to the networking layer. Our work includes new analysis methods and the development of new software architectures and applications, in addition to work on the core concepts and architectures underlying cognitive radios and cognitive networks. This paper describes these contributions and points towards critical future work that remains to fulfill the promise of cognitive radio. We briefly describe the history of work on cognitive radios and networks at Virginia Tech and then discuss our contributions to the core cognitive processing underlying these systems, focusing on our cognitive engine. We also describe developments that support the cognitive engine and advances in radio technology that provide the flexibility desired in a cognitive radio node. We consider securing and verifying cognitive systems and examine the challenges of expanding the cognitive paradigm up the protocol stack to optimize end-to-end network performance. Lastly, we consider the analysis of cognitive systems using game theory and the application of cognitive techniques to problems in dynamic spectrum sharing and control of multiple-input multiple-output radios. 相似文献
999.
In this paper, we consider MC-CDM schemes (MultiCarrier Code Division Multiplexing) where clipping techniques are employed to reduce the envelope fluctuations of the transmitted signals. Both CP-assisted (Cyclic Prefix) and ZP (Zero- Padded) MC-CDM schemes are studied. We develop frequencydomain turbo equalizers combined with an iterative estimation and cancelation of nonlinear distortion effects, with relatively low complexity since they allow FFT-based (Fast Fourier Transform), frequency-domain implementations. Our performance results show that the proposed receivers allow significant performance improvements at low and moderate SNR (Signal-to-Noise Ratio), even when strongly nonlinear transmitters are employed. The receiver for ZP MC-CDM is of special interest for systems where the duration of the channel impulse response is not a small fraction of the duration of the MC-CDM blocks, being suitable to MC-CDM systems with very large blocks (hundreds or even thousands of subcarriers), since they do not require the inversion nor the multiplication of large matrixes. 相似文献
1000.
Jovani L. Favero Paulo Laranjeira da Cunha Lage Flávio da Silva Francisco Tatiane F. Machado Luiz Fernando L. R. Silva Fábio P. Santos 《加拿大化工杂志》2024,102(2):941-964
An analysis was conducted on the displacement of a heavy fluid by a miscible light fluid in the flow assurance operation of injecting diesel oil to displace heavy oil in an insulated offshore production line. A three-dimensional computational fluid dynamics model was developed and implemented in OpenFOAM®. It stimulates the production stages, no-touch time, and oil displacement, considering heat transfer through natural convection and conjugated heat transfer through the solid layers of the pipeline. The specific test case focused on the first 180 m of an existing offshore production line. The simulations revealed two primary mechanisms of mixing: turbulence and secondary flows generated by the pipeline curves. Remarkably, the results demonstrate that by injecting a volume of lighter oil 1.3 times the pipeline volume, approximately 90%–95% of the heavy oil can be effectively removed. 相似文献