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31.
Campos-García M Moreno-Oliva VI Díaz-Uribe R Granados-Agustín F Santiago-Alvarado A 《Applied optics》2011,50(19):3101-3109
A method for testing fast aspheric convex surfaces with dynamic null screens using LCDs is shown. A flat null screen is designed and displayed on an LCD monitor with drop-shaped spots in such a way that the image, which is formed by reflection on the test surface, becomes an exactly square array of circular spots if the surface is perfect. Any departure from this geometry is indicative of defects on the surface. Here the whole surface is tested at once. The position of the spots on the LCD can be changed in a dynamic way, to perform point-shifting of the image spots. The proposed procedure improves the dynamic point-shifting method. As has been shown previously, this process reduces the numerical error during the integration procedure, thereby improving the sensitivity of the test. The positioning accuracy for the screen spots is related to the LCD's spatial resolution. Results of the evaluation of a parabolic convex surface with f/#=0.22 are shown. 相似文献
32.
David Pescador Arturo Ibáñez-Fonseca Fermín Sánchez-Guijo Jesús G. Briñón Francisco Javier Arias Sandra Muntión Cristina Hernández Alessandra Girotti Matilde Alonso María Consuelo del Cañizo José Carlos Rodríguez-Cabello Juan Francisco Blanco 《Journal of materials science. Materials in medicine》2017,28(8):115
33.
A Higher-Order Chimera Method for Finite Volume Schemes 总被引:1,自引:0,他引:1
Luis Ramírez Xesús Nogueira Pablo Ouro Fermín Navarrina Sofiane Khelladi Ignasi Colominas 《Archives of Computational Methods in Engineering》2018,25(3):691-706
In this work a higher-order accurate finite volume method for the resolution of the Euler/Navier–Stokes equations using Chimera grid techniques is presented. The formulation is based on the use of Moving Least Squares approximations in order to obtain higher-order accurate reconstruction and connectivity between the overlapped grids. The accuracy and performance of the proposed methodology is demonstrated by solving different benchmark problems. 相似文献
34.
Due to the aperture problem, the only motion measurement in images, whose computation does not require any assumptions about the scene in view, is normal flow—the projection of image motion on the gradient direction. In this paper we show how a monocular observer can estimate its 3D motion relative to the scene by using normal flow measurements in a global and qualitative way. The problem is addressed through a search technique. By checking constraints imposed by 3D motion parameters on the normal flow field, the possible space of solutions is gradually reduced. In the four modules that comprise the solution, constraints of increasing restriction are considered, culminating in testing every single normal flow value for its consistency with a set of motion parameters. The fact that motion is rigid defines geometric relations between certain values of the normal flow field. The selected values form patterns in the image plane that are dependent on only some of the motion parameters. These patterns, which are determined by the signs of the normal flow values, are searched for in order to find the axes of translation and rotation. The third rotational component is computed from normal flow vectors that are only due to rotational motion. Finally, by looking at the complete data set, all solutions that cannot give rise to the given normal flow field are discarded from the solution space.Research supported in part by NSF (Grant IRI-90-57934), ONR (Contract N00014-93-1-0257) and ARPA (Order No. 8459). 相似文献
35.
A synbiotic composed of Lactobacillus fermentum CECT5716 and FOS prevents the development of fatty acid liver and glycemic alterations in rats fed a high fructose diet associated with changes in the microbiota 下载免费PDF全文
Belén Rivero‐Gutiérrez Reyes Gámez‐Belmonte María Dolores Suárez José Luis Lavín Ana María Aransay Mónica Olivares Olga Martínez‐Augustin Fermín Sánchez de Medina Antonio Zarzuelo 《Molecular nutrition & food research》2017,61(8)
We investigated the effect of a high fructose diet (HFD) on Sprague Dawley rats and the impact of a synbiotic composed of Lactobacillus fermentum CECT5716 and fructooligosaccharides. Feeding the HFD for 5 weeks resulted in liver steatosis and insulin resistance but not obesity. These changes were associated with increased production of short‐chain fatty acids and increased Bacteroidetes in feces, with an augmented Bacteroidetes/Firmicutes ratio, among other changes in the microbiota. In addition, barrier function was weakened, with increased LPS plasma levels. These data are consistent with increased fructose availability in the distal gut due to saturation of absorptive mechanisms, leading to dysbiosis, endotoxemia, hepatic steatosis, and insulin resistance. Treatment with the synbiotic prevented some of the pathological effects, so that treated rats did not develop steatosis or systemic inflammation, while dysbiosis and barrier function were greatly ameliorated. In addition, the synbiotic had hypolipidemic effects. The synbiotic composed by L. fermentum CECT5716 and fructooligosaccharides has beneficial effects in a model of metabolic syndrome induced by a HFD, suggesting it might be clinically useful in this type of condition, particularly considering that high fructose intake has been related to metabolic syndrome in humans. 相似文献
36.
C Fermé 《Canadian Metallurgical Quarterly》1998,48(10):1082-1086
Treatment strategy is based on prognosis groups although there is no consensus on their definition. In stages IIIA with unfavorable factors and stages IIIB or IV without high risk factors, chemotherapy alone or followed by irradiation is used. To reduce toxicity, radiation therapy on bulky disease and residual masses is preferred to extended fields. Indications for intensive chemotherapy with autograft of hematopoietic stem cells as initial treatment for high-risk patients must be determined with therapeutic trials. 相似文献
37.
This paper proposes a framework for the identification, assessment and analysis of the water–energy–food nexus at a basin scale. This methodology is applied to the Duero river basin in Spain to detect the most important conflicts derived from water, food and energy interdependencies. Some of the most important issues are the limitations posed by rising energy prices for irrigated agriculture due to modernization, limitations to water treatment, and the possible emergence of new water demands for energy by hydraulic fracturing for oil and gas and enhanced bioenergy. 相似文献
38.
Maurício D. L. Reis Pavlos Peppas Eduardo Fermé 《Annals of Mathematics and Artificial Intelligence》2016,78(3-4):181-203
In some recent works (Reis 2011, Fermé and Reis, J. Philos. Log. 41, 29–52, 2012, Fermé and Reis, Rev. Symb. Log. 6, 460–487, 2013) two new kinds of multiple contraction functions have been proposed, namely the system of spheres-based multiple contractions and the epistemic entrenchment-based multiple contractions, as generalizations (to the case of multiple contraction) of the well-known classes of systems of spheres-based and of epistemic entrenchment-based (singleton) contractions. Additionally, a representation theorem for the class of epistemic entrenchment-based multiple contraction has been proposed, and it has been shown that the two newly proposed constructions are equivalent, in the sense that a multiple contraction function is a system of spheres-based multiple contraction if and only if it is an epistemic entrenchment-based multiple contraction. In this paper we present two axiomatic characterizations for those multiple contraction functions which differ from the one mentioned above and, in particular, make use of some more intuitive postulates. 相似文献
39.
Martín-del-Campo Angelina Fermín-Jiménez José Antonio Fernández-Escamilla Víctor Vladimir Escalante-García Zazil Yadel Macías-Rodríguez María Esther Estrada-Girón Yokiushirdhilgilmara 《Food science and biotechnology》2021,30(7):901-910
Food Science and Biotechnology - Red seaweed Chondracanthus canaliculatus, an underexploited algae species, was used as a potential source for the obtaining of carrageenan. Seaweed was treated... 相似文献
40.
Kejun Tu Diana Tranca Fermín Rodríguez-Hernández Kaiyue Jiang Senhe Huang Qi Zheng Ming-Xi Chen Chenbao Lu Yuezeng Su Zhenying Chen Haiyan Mao Chongqing Yang Jinyang Jiang Hai-Wei Liang Xiaodong Zhuang 《Advanced materials (Deerfield Beach, Fla.)》2020,32(46):2005433
Heterostructures exhibit considerable potential in the field of energy conversion due to their excellent interfacial charge states in tuning the electronic properties of different components to promote catalytic activity. However, the rational preparation of heterostructures with highly active heterosurfaces remains a challenge because of the difficulty in component tuning, morphology control, and active site determination. Herein, a novel heterostructure based on a combination of RuMo nanoalloys and hexagonal N-doped carbon nanosheets is designed and synthesized. In this protocol, metal-containing anions and layered double hydroxides are employed to control the components and morphology of heterostructures, respectively. Accordingly, the as-made RuMo-nanoalloys-embedded hexagonal porous carbon nanosheets are promising for the hydrogen evolution reaction (HER), resulting in an extremely small overpotential (18 mV), an ultralow Tafel slope (25 mV dec−1), and a high turnover frequency (3.57 H2 s−1) in alkaline media, outperforming current Ru-based electrocatalysts. First-principle calculations based on typical 2D N-doped carbon/RuMo nanoalloys heterostructures demonstrate that introducing N and Mo atoms into C and Ru lattices, respectively, triggers electron accumulation/depletion regions at the heterosurface and consequently reduces the energy barrier for the HER. This work presents a convenient method for rational fabrication of carbon–metal heterostructures for highly efficient electrocatalysis. 相似文献