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101.
We investigate the problem of guessing a random vector X within distortion level D. Our aim is to characterize the best attainable performance in the sense of minimizing, in some probabilistic sense, the number of required guesses G(X) until the error falls below D. The underlying motivation is that G(X) is the number of candidate codewords to be examined by a rate-distortion block encoder until a satisfactory codeword is found. In particular, for memoryless sources, we provide a single-letter characterization of the least achievable exponential growth rate of the ρth moment of G(X) as the dimension of the random vector X grows without bound. In this context, we propose an asymptotically optimal guessing scheme that is universal both with respect to the information source and the value of ρ. We then study some properties of the exponent function E(D, ρ) along with its relation to the source-coding exponents. Finally, we provide extensions of our main results to the Gaussian case, guessing with side information, and sources with memory  相似文献   
102.
Interest in the Build/Operate/Transfer (BOT) scheme for infrastructure projects has been growing rapidly, and numerous projects have been implemented around the world. Through BOT projects, a government reallocates the risks and rewards in the development of large infrastructure projects to the private sector. One key aspect to the successful implementation of the BOT concept in any country is the raising of finance by project sponsors. Financial engineering techniques and capital structuring skills are required to find the proper mix of debt and equity and to achieve successful financing for the proposed project. The objective of this paper is to present a simplified model to determine the optimum equity level for decisionmakers at the evaluation stage of a BOT hydroelectric power plant (HEPP) project in Turkey, which takes place immediately after the completion of the feasibility study. The resulting model is the combination of a financial model and a linear programming model that incorporates an objective of maximizing the return of the project from the equity holder’s point of view. To show versatility of the model, a real case study is conducted. Thus, this research is concerned with the determination of an equity funding level in BOT project finance. There are different equity levels found in BOT HEPP projects, and there is a need for such a model to determine optimal capital structure, which would assist the project sponsors to ensure that the equity level necessary for optimal capital structure is available prior to the project implementation stage.  相似文献   
103.
Historical structures and preserving their cultural values are crucial issues for humanity, not only because of their link to important certain periods in the past, but also their unique architectural features. Although many historical structures continue to offer services while keeping their historical values, some of them are at high risk in seismic prone regions. Therefore, the understanding of their structural performance under strong ground motions has been of significant importance to the civil societies as well as engineering community. The structural systems of historical buildings, generally, consist of masonry walls or piers. The behavior of such walls is controlled by either deformation or force. Seismic performance evaluation of historical structures can be carried out within the framework of performance‐based evaluation principles. This paper mainly discusses the basic principles to be considered in performance‐based seismic evaluation of historical structures. Proposed seismic hazard levels, evaluation of existing seismic hazard, selection of earthquake ground motions as well as site geology, geological and tectonic settings of the area, seismic activity of the region and local soil conditions are needed for a thorough performance evaluation. Seismic performance evaluation of a clock tower located in eastern Turkey was accomplished based on the proposed principles. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
104.
The long-term durability of varnished wooden surfaces used in either indoors or outdoors environments depends on the resistance of varnish layers on these surfaces against potential physical, mechanical and chemical effects to which they may be exposed. In this study, “Nanolacke ultraviolet varnish”, developed by a Turkish dying and varnish industry company and widely accepted as a 21st century technology has been compared to other conventional varnish systems widely used in the industry in terms of dry film resistance properties. In this study, cellulosic, polyurethane, polyester, synthetic and Nanolacke ultraviolet varnish have been applied on beech (Fagus orientalis L.) and oak (Quercus robur L.) wood samples which had been prepared according to the industry standards. Then, the hardness and adhesion resistance of these layers have been determined according to ASTM D 4366 and ASTM D 3359-2 standards, respectively.  相似文献   
105.
Many models have previously been developed for predicting specific cutting energy (SE), being the measure of rock cuttability, from intact rock properties employing conventional multiple linear or nonlinear regression techniques. Artificial neural networks (ANN) also have a great potential in building such models. This paper is concerned with the application of ANN for the prediction of cuttability of rocks from their intact properties. For that purpose, data obtained from three different projects were subjected to statistical analyses using MATLAB. Principal components analysis together with the scatterplots of SE against intact rock properties were employed to select the predictors for SE models. Results of the principal components analysis have shown that the most of the variance in the data set can be explained by three principal components. Principal component with the highest variance is weighted mainly on the uniaxial compressive strength (UCS), Brazilian tensile strength (BTS), static modulus of elasticity (Elasticity), and cone indenter hardness (CI), which were regarded as the independent variables driving the data set. Three predictive models for SE were developed employing above independent variables by multiple nonlinear regression with forward stepwise method and ANN, respectively. Neural networks were developed for two different numbers of hidden neurons in the hidden layer. Goodness of the fit measures revealed that ANN models fitted the data as accurately as multiple nonlinear regression model, indicating the usefulness of artificial neural networks in predicting rock cuttability.  相似文献   
106.
In hybrid electric vehicles (HEVs), there are usually several different DC-buses of different voltage levels to handle different loads. DC–DC converters are used to transfer energy between different DC-buses. This paper proposed a double-ended converter for two different DC-buses with large voltage ratio. The high-voltage DC-bus is 600 V for the traction motor drive, while the low-voltage DC-bus is 48 V for the electronic devices on the vehicle. By using the proposed system configuration, energy could be transferred freely between the generator and the two loads, forming a very flexible powertrain. In addition, the weight, volume, and cost of power electronics components could be reduced. This paper introduced the operation principal and control algorithm of the proposed system. Simulations verified the functionality of the proposed system. The proposed system configuration is not only suitable for automotive applications, but can also be implemented in other applications, such as aerospace, marine, and industrial, where multiple DC-bus voltage levels are required.  相似文献   
107.
Forty lambs were used to investigate effects of suckling length and rearing type (single and twin) on welfare parameters, carcass and meat quality characteristics. SC-45 and SC-75 lambs were weaned at 45-d and 75-d of age, respectively, whereas SC-120 lambs were not weaned until slaughter age of 120-d. The elevated cortisol concentration due to weaning stress returned to pre-weaning level at 2-d after weaning. SC-120 lambs had higher daily gain, plasma cortisol and glucose levels at exsanguination, hot carcass weight, dressing percentage and fatness score than weaned lambs. Suckling length did not influence instrumental meat quality characteristics, except shear force. SC-45 lambs had tougher meat than other groups according to instrumental and sensory analyses. SC-75 and SC-120 lambs had similar meat shear force value and sensory scores. Single lambs had higher daily gain, and greater scores for carcass characteristics and sensory evaluation, and lower pH(24) and shear force than twin lambs.  相似文献   
108.
The response of glass–epoxy composites to repeated impact for various impact energies ranging from 5 to 15 J was investigated. Specimens with two different stacking sequences were studied; [0/90/0/90]S and [0/90/+45/−45]S. In addition to the room temperature, impact tests were also performed at −40°C environmental test temperature for impact energy of 15 J. Contact force‐deflection and energy‐time curves at each test and the number of impacts to failure (Nf) were obtained for each experiment. Compression after impact (CAI) tests were also conducted to determine the residual load carrying capacity of the damaged specimens. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers  相似文献   
109.
Shock recovery experiments have been conducted to assess the role of shock stress and orientation dependence on substructure evolution and deformation twinning of a [1 0 0]/[011¯] copper bicrystal. Transmission electron microscopy of the post-shock specimens revealed that well-defined dislocation cell structures developed in both grains and the average cell size decreased with increasing shock pressure from 5 to 10 GPa. Twinning occurred in the [1 0 0] grain, but not the [011¯] grain, at the 10 GPa shock pressure. The stress and orientation dependence of incipient twinning can be predicted by the stress and orientation conditions required to dissociate slip dislocations into glissile twinning dislocations. The dynamic widths between the two partials are calculated considering the three-dimensional deviatoric stress state induced by the shock as calculated using plane-strain plate impact simulations and the relativistic and drag effects on dislocations moving at high speeds.  相似文献   
110.
Poly[(maleic anhydride)‐co‐(vinyl acetate)] (MAVA) copolymer was synthesized by free radical polymerization reaction, in methyl ethyl ketone at 80 °C, using benzoyl peroxide as the initiator. The copolymer was then modified with a biomolecule, noradrenaline (NA). The modification reaction was performed at 70 °C in dimethylformamide containing triethylamine as the catalyst. The modified polymer was named MAVA/NA. Structural characterization of the copolymer and the modified product was carried out by Fourier transform infrared (FTIR) and 1H NMR and 13C NMR spectroscopy. The FTIR, 1H NMR and 13C NMR spectra confirmed that NA was successfully covalently bound to the MAVA copolymer backbone. Surface morphology was visualized by atomic force microscopy. The cumulative release of NA from MAVA/NA was determined in phosphate buffered saline solution for 7 days at 37 °C and compared with MAVA. Cytotoxicity of the MAVA/NA was evaluated by using a mouse fibroblast cell line (L929). Results obtained indicated that MAVA/NA had almost no toxicity and no negative effect on cell viability at 250 µg mL?1 concentration. © 2012 Society of Chemical Industry  相似文献   
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