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101.
L. Rodríguez‐Tembleque R. Abascal 《International journal for numerical methods in engineering》2013,94(7):687-707
This paper presents a new and efficient methodology for solving 3D frictional contact problems considering an orthotropic friction law. The contact methodology is based on a proposed augmented Lagrangian formulation for orthotropic frictional contact problems, and a new discrete contact operator, which allows to reduce the number of unknowns in a Newton‐like algorithm that accelerates the attainment of the solution. A fast Uzawa scheme is also proposed on the basis of the Steffensen's method. Both algorithms prove to be very robust and efficient to solve orthotropic frictional contact problems. The proposed formalism has the advantage of being very compact and valid for both the FEM and the BEM. Numerical results are given to demonstrate the validity of the formulation and algorithms proposed. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
102.
Pablo Ares Miriam Jaafar Adriana Gil Julio Gómez‐Herrero Agustina Asenjo 《Small (Weinheim an der Bergstrasse, Germany)》2015,11(36):4731-4736
In this work, the use of magnetic force microscopy (MFM) to acquire images of magnetic nanostructures in liquid environments is presented. Optimization of the MFM signal acquisition in liquid media is performed and it is applied to characterize the magnetic signal of magnetite nanoparticles. The ability for detecting magnetic nanostructures along with the well‐known capabilities of atomic force microscopy in liquids suggests potential applications in fields such as nanomedicine, nanobiotechnology, or nanocatalysis. 相似文献
103.
Edgardo D. Castronuovo Julio Usaola Ricardo Bessa Manuel Matos I.C. Costa L. Bremermann Jesus Lugaro George Kariniotakis 《风能》2014,17(6):829-852
The increasing wind power penetration in power systems represents a techno‐economic challenge for power producers and system operators. Because of the variability and uncertainty of wind power, system operators require new solutions to increase the controllability of wind farm output. On the other hand, producers that include wind farms in their portfolio need to find new ways to boost their profits in electricity markets. This can be done by optimizing the combination of wind farms and storage so as to make larger profits when selling power (trading) and reduce penalties from imbalances in the operation. The present work describes a new integrated approach for analysing wind‐storage solutions that make use of probabilistic forecasts and optimization techniques to aid decision making on operating such systems. The approach includes a set of three complementary functions suitable for use in current systems. A real‐life system is studied, comprising two wind farms and a large hydro station with pumping capacity. Economic profits and better operational features can be obtained from the proposed cooperation between the wind farms and storage. The revenues are function of the type of hydro storage used and the market characteristics, and several options are compared in this study. The results show that the use of a storage device can lead to a significant increase in revenue, up to 11% (2010 data, Iberian market). Also, the coordinated action improves the operational features of the integrated system. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
104.
In the framework of the I-series of Recommendations, layer 1 specifications for ISDN user-network interfaces are given in Recommendation I.430 for the basic access(2B + D) at 144 kbits/s, and in Recommendation I.431 for the primary access at 1544 and 2048 kbits/s. The former Recommendation contains a completely new set of procedural, functional, and electrical characteristics whose definition was started during the last CCITT Study Period and is expected to be completed by the end of the present CCITT Study Period. Moreover, the latter Recommendation is largely based on functional and electrical characteristics of existing Recommendation G.703, which gives specifications for the physical/electrical characteristics of the hierarchical digital interface. 相似文献
105.
Julio C. Minotas Hocine Djellab Edward Ghali 《Journal of Applied Electrochemistry》1989,19(5):777-783
The anodic behaviour of three different copper electrodes in sulphuric acid medium was investigated using cyclic voltammetry in the potential range between the rest potentialE
i=0=–0.34 V and +0.80 V vs the Hg, Hg2SO4/K2SO4 saturated (MSE) reference electrode. Arsenic dissolved in the electrode matrix as well as oxygen dissolved in solution were found to delay passivation. The anodic peak current density was proportional to the square root of the potential sweep rate in two consecutive domains. An unusual break was observed for high scan rates (>50 m V s–1) and was attributed to an increase of the medium viscosity because of the large gradient of concentration near the electrode surface. On the other hand, current oscillations, usually observed in the anodic processes of metallic electrodes, have been studied as a function of the electrode vertical/horizontal positions. Gravity has been found to affect both the frequency and the amplitude of the oscillations. X-ray diffraction measurements conducted on galvanostatically electrolyzed samples revealed, besides copper metal, the presence of copper sulfate pentahydrate and trihydrate for Cu–As and Cu–Sb, respectively. SEM analysis showed the existence of preferential domains of white product on a darker background of metallic copper or copper oxides. 相似文献
106.
Fabiane Ferreira Martins Bruna Cadete Martins Ananda Vitoria Silva Teixeira Matheus Ajackson Vanessa Souza-Mello Julio Beltrame Daleprane 《Molecular nutrition & food research》2024,68(6):2300634
The discovery of metabolically active brown adipose tissue (BAT) in human adults and the worldwide increase in obesity and obesity-related chronic noncommunicable diseases (NCDs) has made BAT a therapeutic target in the last two decades. The potential of BAT to oxidize fatty acids rapidly and increase energy expenditure inversely correlates with adiposity, insulin and glucose resistance, and cardiovascular and metabolic diseases. Currently, BAT is recognized by a new molecular signature; several BAT-derived molecules that act positively on target tissues have been identified and collectively called batokines. Bioactive compounds present in foods are endowed with thermogenic properties that increase BAT activation signaling. Understanding the mechanisms that lead to BAT activation and the batokines secreted by it within the thermogenic state is fundamental for its recruitment and management of obesity and NCDs. This review contributes to recent updates on the morphophysiology of BAT, its endocrine role in obesity, and the main bioactive compounds present in foods involved in classical and nonclassical thermogenic pathways activation. 相似文献
107.
Meng Li Clara Seinsche Samuel Jansson Julio Hernandez Jadranka Rota Eric Warrant Mikkel Brydegaard 《Journal of the Royal Society Interface》2022,19(191)
There are hundreds of thousands of moth species with crucial ecological roles that are often obscured by their nocturnal lifestyles. The pigmentation and appearance of moths are dominated by cryptic diffuse shades of brown. In this study, 82 specimens representing 26 moth species were analysed using infrared polarimetric hyperspectral imaging in the range of 0.95–2.5 µm. Contrary to previous studies, we demonstrate that since infrared light does not resolve the surface roughness, wings appear glossy and specular at longer wavelengths. Such properties provide unique reflectance spectra between species. The reflectance of the majority of our species could be explained by comprehensive models, and a complete parametrization of the spectral, polarimetric and angular optical properties was reduced to just 11 parameters with physical units. These parameters are complementary and, compared with the within-species variation, were significantly distinct between species. Counterintuitively to the aperture-limited resolution criterion, we could deduce microscopic features along the surface from their infrared properties. These features were confirmed by electron microscopy. Finally, we show how our findings could greatly enhance opportunities for remote identification of free-flying moth species, and we hypothesize that such flat specular wing targets could be expected to be sensed over considerable distances. 相似文献
108.
Supply chain networks need to respond efficiently to operation disruptions, as one of their aims is to guarantee the on time delivery of products. Hence, robustness has become one of the important issues to consider when designing supply networks. There are alternative ways to measure what robustness means in this context. In this paper, we propose a new metric based on the effect on service level of the collapse of active transportation links. Numerical experiments are carried out to understand how different design factors affect robustness. Robustness under a targeted attack is compared with robustness to random failures. Results show that flow complexity (i.e. the number of potential transportation links between supply network nodes) is the most influential factor affecting supply network and its robustness, as well as the service level that can be maintained after disruptions. Thus, diversification both in supply sources and transportation routes seems to be key to robustness. 相似文献
109.
The mechanical reinforcement of nanocomposites containing nanorods‐like fillers such as cellulose nanocrystals (CNCs) is often interpreted by adapting the classical parallel–series model, assuming a simple hyperbolic dependence between the percolation threshold and aspect ratio. However, such assumptions are valid only for nanorods with high aspect ratio and often are misinterpreting the reinforcement obtained at low volume fraction of filler loading. To elucidate this intriguing scenario, we proposed a new approach and validated it by compiling and reinterpreting some of available literature that represent the experimental reinforcement with CNCs. Our approach showed better accuracy, specifically for the cases of CNC nanorods with lower aspect ratio. We conclude that this route permits a more realistic evaluation of the mechanical reinforcement, where a physical parameter accounting the polymer filler association is introduced. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45254. 相似文献
110.