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91.
Carbon nanotubes (CNTs) were synthesized through the catalytic decomposition of a ferrocene-xylene mixture in a horizontal chemical va- por deposition reactor. The deposition rate of CNTs along the axial direction was measured. The morphology of CNTs was observed by scan- ning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that the deposition rate of CNTs along the axial direction first increased and later decreased, the position achieving the maximum deposition rate was influenced by the operating conditions. The morphologies of CNTs also changed along the axial direction. 相似文献
92.
Electric Field Assisted Microfluidic Platform for Generation of Tailorable Porous Microbeads as Cell Carriers for Tissue Engineering 下载免费PDF全文
93.
Electric Field Assisted Microfluidic Platform for Generation of Tailorable Porous Microbeads as Cell Carriers for Tissue Engineering 下载免费PDF全文
Marco Costantini Jan Guzowski Paweł J. Żuk Pamela Mozetic Simone De Panfilis Jakub Jaroszewicz Marcin Heljak Mara Massimi Maxime Pierron Marcella Trombetta Mariella Dentini Wojciech Święszkowski Alberto Rainer Piotr Garstecki Andrea Barbetta 《Advanced functional materials》2018,28(20)
Injection of cell‐laden scaffolds in the form of mesoscopic particles directly to the site of treatment is one of the most promising approaches to tissue regeneration. Here, a novel and highly efficient method is presented for preparation of porous microbeads of tailorable dimensions (in the range ≈300–1500 mm) and with a uniform and fully interconnected internal porous texture. The method starts with generation of a monodisperse oil‐in‐water emulsion inside a flow‐focusing microfluidic device. This emulsion is later broken‐up, with the use of electric field, into mesoscopic double droplets, that in turn serve as a template for the porous microbeads. By tuning the amplitude and frequency of the electric pulses, the template droplets and the resulting porous bead scaffolds are precisely produced. Furthermore, a model of pulsed electrodripping is proposed that predicts the size of the template droplets as a function of the applied voltage. To prove the potential of the porous microbeads as cell carries, they are tested with human mesenchymal stem cells and hepatic cells, with their viability and degree of microbead colonization being monitored. Finally, the presented porous microbeads are benchmarked against conventional microparticles with nonhomogenous internal texture, revealing their superior performance. 相似文献
94.
Quentin Baert Anne-Cécile Caron Maxime Morge Jean-Christophe Routier 《Knowledge and Information Systems》2018,54(3):591-615
MapReduce is a design pattern for processing large datasets distributed on a cluster. Its performances are linked to the data structure and the runtime environment. Indeed, data skew can yield an unfair task allocation, but even when the initial allocation produced by the partition function is well balanced, an unfair allocation can occur during the reduce phase due to the heterogeneous performance of nodes. For these reasons, we propose an adaptive multi-agent system. In our approach, the reducer agents interact during the job and the task reallocation is based on negotiation in order to decrease the workload of the most loaded reducer and so the runtime. In this paper, we propose and evaluate two negotiation strategies. Finally, we experiment our multi-agent system with real-world datasets over heterogeneous runtime environment. 相似文献
95.
Maxime Bernaert Geert Poels Monique Snoeck Manu De Backer 《Information Systems Frontiers》2016,18(4):781-818
Enterprise architecture (EA) is a coherent whole of principles, methods, and models that are used in the design and realization of an enterprise’s organizational structure, business processes, information systems, and IT infrastructure. Recent research indicates the need for EA in small and medium-sized enterprises (SMEs), important drivers of the economy, as they struggle with problems related to a lack of structure and overview of their business. However, existing EA frameworks are perceived as too complex and, to date, none of the EA approaches are sufficiently adapted to the SME context. Therefore, this paper presents the CHOOSE metamodel for EA in SMEs that was developed and evaluated through action research in an SME and further refined and validated through case study research in five other SMEs. This metamodel is based on the essential dimensions of EA frameworks and is kept simple so that it may be applied in an SME context. The final CHOOSE metamodel includes only four essential concepts (i.e. goal, actor, operation, object), one for each most frequently used EA focus. As an example, an extract is included from the specific model that was created for the SME used in our action research. Finally, the CHOOSE metamodel is evaluated according to the dimensions essential in EA and the requirements for EA in an SME context. 相似文献
96.
Marco Muccino Carlo Luciano Bianco Luca Izzo Yu Wang Maxime Enderli Milos Kovacevic Giovanni Battista Pisani Ana Virginia Penacchioni Remo Ruffini 《Gravitation and Cosmology》2014,20(3):197-202
GRB 090227B and GRB 090510, traditionally classified as short gamma-ray Bursts (GRBs), indeed originate from different systems. For GRB 090227B we inferred a total energy of the e + e ? plasma \(E_{e^ + e^ - }^{tot} \) = (2.83 ± 0.15) × 1053 erg, a baryon load of B = (4.1 ± 0.05) × 10?5, and a CircumBurstMedium (CBM) average density 〈n CBM〉 = (1.90 ± 0.20) × 10?5 cm?3. From these results we have assumed the progenitor of this burst to be a symmetric neutron stars (NSs) merger with masses m = 1.34 M⊙, radii R = 12.24 km. GRB 090510, instead, has \(E_{e^ + e^ - }^{tot} \) = (1.10 ± 0.06) × 1053 erg, B = (1.45 ± 0.28) × 10?3, implying a Lorentz factor at transparency of Γ = (6.7 ± 1.7) × 102, which are characteristic of the long GRB class, and a very high CBM density, 〈n CBM〉 = (1.85 ± 0.14) × 103 cm?3. The joint effect of the high values of Γ and of 〈n CBM〉 compresses in time and “inflates” in intensity in an extended afterglow, making appear GRB 090510 as a short burst, which we here define as “disguised short GRB by excess” occurring an overdense region with 103 cm?3. 相似文献
97.
Geometric and electronic structures of some aniline derivatives have been obtained, aimed at a microscopic explanation of the observed electropolymerizability of these compounds. Monomers, dimers and their corresponding free radicals and ionic species, with the sulfonic acid group substituent located at various positions on the benzenoid ring, are considered. In this work we present an ab initio post-Hartree-Fock and density functional study of the ortho-, meta- and para-isomer of aminobenzenesulfonic acid (ortho-, meta-, and para-ABSA). To envisage a possible coupling scheme between ABSA molecules, we have obtained the equilibrium geometry and the electronic structure for monomers and dimers of ABSA as well as for the corresponding free radicals and ions.Based on the monomer-optimized geometries, atomic charges, bond orders and spin densities, a coupling scheme in the electrochemical polymerization is suggested. We have also calculated band gaps and ionization potentials. Some comments concerning the different theoretical methods used are made. 相似文献
98.
M. Lépinay N. Djourelov H. Marinov L. Broussous K. Courouble C. Licitra F. Bertin V. Rouessac A. Ayral 《Journal of Porous Materials》2014,21(4):475-484
The impact of plasma etching and chemical wet cleaning on solvent diffusion in porous network of a SiOCH low-k dielectric material is studied. Characterization of porosity and pore size distribution by means of ellipso-porosimetry and positron annihilation lifetime spectroscopy are presented. The results are compared with solvent diffusion kinetics, measured using probe molecules of different polarity, surface energies and molecular sizes. Infrared spectroscopy, Doppler broadening of annihilation radiation and time-of-flight secondary ion mass spectrometry measurements are also performed to investigate material modifications causing variations of diffusion kinetics. 相似文献
99.
100.
The majority of methods for the automatic surface reconstruction of an environment from an image sequence have two steps: Structure-from-Motion and dense stereo. From the computational standpoint, it would be interesting to avoid dense stereo and to generate a surface directly from the sparse cloud of 3D points and their visibility information provided by Structure-from-Motion. The previous attempts to solve this problem are currently very limited: the surface is non-manifold or has zero genus, the experiments are done on small scenes or objects using a few dozens of images. Our solution does not have these limitations. Furthermore, we experiment with hand-held or helmet-held catadioptric cameras moving in a city and generate 3D models such that the camera trajectory can be longer than one kilometer. 相似文献