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991.
Real-world data are often prepared for purposes other than data mining and machine learning and, therefore, are represented by primitive attributes. When data representation is primitive, preprocessing data before looking for patterns becomes necessary. The low-level primitive representation of real-world problems facilitates the existence of complex interactions among attributes. If lack of domain experts prevents traditional methods to uncover patterns in data due to complex attribute interactions, then the use of soft computing techniques such as genetic algorithms becomes necessary. This article introduces MFE3/GADR, a data reduction method derived from the learning preprocessing system MFE3/GA. The method restructures the primitive data representation by capturing and compacting hidden information into new features in order to highlight regularities to the learner. We thoroughly analyze the empirical results obtained on the poker hand data set. The results show that this approach successfully compacts the set of low-level primitive attributes into a smaller set of highly informative features which outline patterns to the learner; thus, the new approach provides data reduction and yields learning a smaller and more accurate classifier. 相似文献
992.
Since the 1970s, nighttime fatal crashes have been used as a surrogate measure for alcohol-related fatalities for crashes for which more direct measures were absent. The validity of this approach was confirmed in 1985 but has not been re-evaluated since. Although this measure has also been applied to identify alcohol involvement in nonfatal crashes, its validity when applied to nonfatal cases has never been determined.The objective of this study was to evaluate the appropriateness of using nighttime crashes as surrogate measures for alcohol impairment when applied to fatal and nonfatal injury and property damage only (PDO) crashes. To do so, we used data from a crash-control design study collected at the roadside in two U.S. states between 1997 and 1999, as well as from the 1997-1999 and 2004-2006 Fatality Analysis Reporting System.The outcome of this study confirms the validity of using nighttime crashes as a surrogate measure for alcohol-related fatalities and supports the use of after-midnight crashes for measuring alcohol involvement in nonfatal and PDO crashes when the number of late-night crashes permits. 相似文献
993.
Antonio Vega-Gálvez Eduardo Notte-Cuello Roberto Lemus-Mondaca Liliana Zura Margarita Miranda 《Food and Bioproducts Processing》2009,87(4):254-260
Aloe vera (Aloe barbadensis Miller) slabs dried at 60 °C were rehydrated at three temperatures (20, 40 and 60 °C) in order to study the influence of temperature on the kinetics of mass transfer during rehydration phenomenon. Fick, Peleg and Weibull models were applied for rehydration modelling, as well as one new proposed model. All kinetic parameters of the models showed positive dependence on temperature, according to the Arrhenius-type equation. Weibull model and the new proposed model provided the best fit quality for each rehydration curve based on the statistical tests RMS, SSE and Chi-square. In accordance with the results, both models may be used to estimate the rehydration time of A. vera. Furthermore, two rehydration indices (RR and WHC) were analysed, which decreased as temperature increased. These indices confirm that drying process modifies the cell structure of A. vera, reducing the rehydration ability due to cellular and structural disruption that takes place during dehydration. 相似文献
994.
995.
This volume is a recent addition to the Camacho and Bordons' book ‘Model Predictive Control in the Process Industry’, edited by Springer Verlag. The book presents a complete review of the theory and applications of Model Predictive Control MPC, from the simple unconstrained SISO case to the more complex constrained MIMO situations. Special attention is given to the Generalized Predictive Controller that is one of the most known and cited MPC strategies. In all the chapters the results are illustrated with simulation examples and also with some experimental results that validated the controllers and tuning rules analyzed in the book. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
996.
Eduardo N. Dvorkin Rita G. Toscano 《International journal for numerical methods in engineering》2003,58(12):1803-1816
A new rigid‐viscoplastic model that includes the effect of thermal strains when modelling steady‐state metal‐forming processes was developed. A symmetric approximation to the resulting non‐symmetric stiffness matrix was derived. The thermo‐mechanical flow formulation was implemented using the pseudo‐concentrations technique. The new formulation was numerically tested showing that it provides reliable results. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
997.
Alfredo Aires Eduardo Rosa Rosa Carvalho 《Journal of the science of food and agriculture》2006,86(10):1512-1516
Broccoli (Brassica oleracea L. var. italica cv. Marathon) sprouts are a rich source of glucosinolates, particularly 4‐methylsulfinylbutyl glucosinolate (glucoraphanin), the precursor of the chemoprotective isothiocyanate, sulforaphane. Sulfur and nitrogen fertilization have been shown to influence the pattern and levels of glucosinolates in mature broccoli, but little information is available on the fertilization of sprouts, a transient stage of broccoli growth, which have been recommended for salads. Therefore, an experiment was set up to evaluate the effect of N and S fertilization on the glucosinolate content of the aerial part and roots of broccoli sprouts. Nitrogen was tested at 0, 45.5, 91.0 mg L?1 and sulfur at 0, 14.6 and 29.2 mg L?1. The results showed that total glucosinolates in the aerial part were significantly higher (P < 0.001) than in the roots. The major glucosinolates in the aerial part were 4‐methylsulfinylbutyl and 3‐methylsulfinylpropyl whereas in the roots they were 2‐phenylethyl and 4‐methylthiobutyl. Fertilization of broccoli sprouts had a significant (P < 0.001) detrimental effect on the levels of aliphatic glucosinolates whereas the opposite was noted for indole and aromatic glucosinolates, for some of the fertilization combinations tested. Overall, the results indicate that broccoli sprouts do not benefit from fertilization. Copyright © 2006 Society of Chemical Industry 相似文献
998.
Eduardo Javier Huerta Yero Marco Aurélio Amaral Henriques 《Journal of Parallel and Distributed Computing》2007
Although cluster environments have an enormous potential processing power, real applications that take advantage of this power remain an elusive goal. This is due, in part, to the lack of understanding about the characteristics of the applications best suited for these environments. This paper focuses on Master/Slave applications for large heterogeneous clusters. It defines application, cluster and execution models to derive an analytic expression for the execution time. It defines speedup and derives speedup bounds based on the inherent parallelism of the application and the aggregated computing power of the cluster. The paper derives an analytical expression for efficiency and uses it to define scalability of the algorithm–cluster combination based on the isoefficiency metric. Furthermore, the paper establishes necessary and sufficient conditions for an algorithm–cluster combination to be scalable which are easy to verify and use in practice. Finally, it covers the impact of network contention as the number of processors grow. 相似文献
999.
João Eduardo Borges 《Computers & Fluids》2007,36(2):480-483
This paper describes an inverse method that applies to two-dimensional, irrotational and incompressible flow, based on a transformation of variables from the physical plane defined by (x, y), to a computational plane defined by the stream function ψ, and the velocity potential, ?. In this new plane, the resulting differential equation describing the flow is relatively simple, and should be solved in a domain that presents always a rectangular shape, facilitating the generation of a numerical grid appropriate to the problem. The solution of this equation gives the distribution of the x coordinate throughout the flow field, while the values of the y coordinate are calculated by integration of the previous result. Some of the numerical details of the procedure will be discussed, with special emphasis on the numerical treatment of the boundary conditions. The application of the described method to the design of a curved duct with an overall deflection of around 90° will be presented, with the aim of showing the potentialities of the method, which is computationally quite simple. 相似文献
1000.
Armando Escobar Keith A Schimmel Josefina de Gyves Eduardo Rodríguez de San Miguel 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2004,79(9):961-973
Lead(II) and cadmium(II) solvent extraction (SX) with D2EHPA dissolved in heptane and kerosene from aqueous chloride media was studied. Extraction reaction stoichiometries and extraction equilibrium constants were evaluated. Application of a dispersion‐free membrane‐based extraction and stripping technique with two hollow‐fiber contactors under recirculating operation mode allowed a quantitative (>97%) removal of lead from the aqueous solution in the extraction module with a separation factor of 19 and a 62% recovery in the back‐extraction module with a separation factor of 6.3 after 7 h under optimum conditions. Mass‐transfer coefficients for the system were evaluated. Optimal conditions for transport and separation are reported and compared using SX and the membrane‐based technique. Copyright © 2004 Society of Chemical Industry 相似文献