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81.
Ruzicka B Zaccarelli E Zulian L Angelini R Sztucki M Moussaïd A Narayanan T Sciortino F 《Nature materials》2011,10(1):56-60
The relevance of anisotropic interactions in colloidal systems has recently emerged in the context of the rational design of new soft materials. Patchy colloids of different shapes, patterns and functionalities are considered the new building blocks of a bottom-up approach toward the realization of self-assembled bulk materials with predefined properties. The ability to tune the interaction anisotropy will make it possible to recreate molecular structures at the nano- and micro-scales (a case with tremendous technological applications), as well as to generate new unconventional phases, both ordered and disordered. Recent theoretical studies suggest that the phase diagram of patchy colloids can be significantly altered by limiting the particle coordination number (that is, valence). New concepts such as empty liquids—liquid states with vanishing density—and equilibrium gels—arrested networks of bonded particles, which do not require an underlying phase separation to form—have been formulated. Yet no experimental evidence of these predictions has been provided. Here we report the first observation of empty liquids and equilibrium gels in a complex colloidal clay, and support the experimental findings with numerical simulations. 相似文献
82.
Fayçal Hamdaoui Anis Ladgham Anis Sakly Abdellatif Mtibaa 《International journal of imaging systems and technology》2013,23(3):265-271
The partitioning of an image into several constituent components is called image segmentation. Many approaches have been developed; one of them is the particle swarm optimization (PSO) algorithm, which is widely used. PSO algorithm is one of the most recent stochastic optimization strategies. In this article, a new efficient technique for the magnetic resonance imaging (MRI) brain images segmentation thematic based on PSO is proposed. The proposed algorithm presents an improved variant of PSO, which is particularly designed for optimal segmentation and it is called modified particle swarm optimization. The fitness function is used to evaluate all the particle swarm in order to arrange them in a descending order. The algorithm is evaluated by performance measures such as run time execution and the quality of the image after segmentation. The performance of the segmentation process is demonstrated by using a defined set of benchmark images and compared against conventional PSO, genetic algorithm, and PSO with Mahalanobis distance based segmentation methods. Then we applied our method on MRI brain image to determinate normal and pathological tissues. © 2013 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 23, 265–271, 2013 相似文献
83.
Houda Ennaceri Abdellatif Ghennioui Abdelilah Benyoussef Ahmed Ennaoui Asmae Khaldoun 《国际自然能源杂志》2018,39(1):78-86
In this study, potential sites for concentrated solar power (CSP) installations in Morocco are investigated based on direct normal irradiation (DNI). The DNI data of four Moroccan sites (Missour, Erfoud, Zagora and Tantan) were collected from different satellite databases (NASA SSE, PV GIS-Helioclim, Climate-SAF PVGIS and Solar Med Atlas). However, it is required to mitigate the risks resulting from uncertainties of satellite-based irradiation data by combining satellite data to ground measurements of at least 1 year. The ground-measured data reported in this work are collected from MHP and MDI meteorological stations installed by IRESEN in collaboration with DLR and ONEE in the framework of the enerMENA project. The Liu and Jordan and the Collares Pereira and Rabl models were also used to determine the monthly and yearly average hourly DNI values. The results of this study suggest that Missour, Erfoud and Zagora represent potential sites for CSP power plants installations, except for Tantan. 相似文献
84.
A comparative study between Integral and Classical Backstepping IFOC structures of induction motor is proposed in this work. The Integral one is based mainly on a suitable combination of a nonlinear integral backstepping approach and an indirect field orientation control (IFOC). The first part ensures a global system stability using recursive Lyapounov design and increases robustness despite disturbances and model uncertainties. The second part will guarantee flux orientation, decoupling, and current regulation.The effectiveness of the proposed control structure is validated by simulation as well as by experiment under critical disturbance conditions. Obtained results show a fast dynamic response, better load disturbance rejection capability, less parameters sensitivity and better tracking performance. 相似文献
85.
Zubaidi Salah L. Ortega-Martorell Sandra Kot Patryk Alkhaddar Rafid M. Abdellatif Mawada Gharghan Sadik K. Ahmed Maytham S. Hashim Khalid 《Water Resources Management》2020,34(3):1265-1279
Water Resources Management - The accurate forecast of water demand is challenging for water utilities, specifically when considering the implications of climate change. As such, this is the first... 相似文献
86.
Abdellatif GHEDIRA 《粮油食品科技》2022,30(1):83-86
The International Olive Council (IOC) is an international intergovernmental organization dedicated to olive oil and table olives, aiming at modernizing olive production, coordinating olive policies, improving the regulation of international trade, defending the quality of the olive sector and promoting olive oil and table olives to increase their consumption. The IOC grants recognition of laboratories and tasting panels in annual trials when they meet the conditions given in the decisions adopting the IOC certificate for laboratories for the physico–chemical testing of olive oil and laboratories for the sensory analysis of virgin olive oils. The IOC establishes analysis methods applying to olive oils and olive pomace oils for purity, quality and organoleptic assessment. The IOC elaborates guides of storage conditions for olive oils and olive pomace oils, of managing virgin olive oil tasting panels and of sensory testing laboratories. In future works, the IOC includes activities to identify analytical criteria for detecting fraud and guaranteeing the quality of olive oils and olive pomace oils. 相似文献
87.
Catalytic grafting: A new technique for polymer–fiber composites I. Polyethylene–asbestos composites
In this work we present a new technique to prepare polyolefin-fiber composites. This technique is based on chemical anchoring of a catalyst on reinforcing agents containing OH groups on their surface and then conducting an olefin polymerization on the supported catalyst. This technique offers the possibility to approach the challenging problems encountered in polymer composites, namely, the reinforcement-matrix adhesion, the dispersion, and the wetting of the reinforcement by the resin. As a first part of a systematic research, we report on the procedure of fixation of titanium tetrachloride on the surface of asbestos fibers and the Ziegler-Natta polymerization of ethylene on the surface-modified fibers. The procedure as well as the structure and properties of the composite were investigated by means of FTIR, atomic absorption, SEM, solvent extraction, and tensile testing. The experimental results show that the Ziegler-Natta catalyst can be efficiently anchored on the surface of the fibers to conduct successful polymerization and to “synthesize” a new class of polymer composites. 相似文献
88.
In this paper, the catalytic grafting technique for preparation of polymer/fiber composites is extended to plasma treated ultra-high modulus polyethylene (UHMPE) fiber/high density polyethylene (HDPE) system. The OH groups introduced on the UHMPE fiber surface by oxygen plasma treatment were used to chemically anchor Ziegler-Natta catalyst which then was followed by ethylene polymerization on the fiber surface. The morphology and interfacial behavior, as well as the mechanical properties, of the HDPE composites reinforced by catalytic grafted or ungrafted UHMPE fibers were investigated by SEM, DSC, polarized light optical microscopy, and tensile testing. The experimental results show that the polyethylene grafted on the fibers acted as a transition layer between the reinforcing UHMPE fibers and a commercial HDPE matrix. The interfacial adhesion was also significantly improved. Compared with the composite reinforced by ungrafted UHMPE fibers, the composite reinforced by catalytic grafted UHMPE fibers exhibits much better mechanical properties. 相似文献
89.
A strategy to design intercalated montmorillonite nanocomposites has been explored. A commercial organoclay, 1.34 TCN (Nanocor Inc.), with bis(2‐hydroxylethy1) methy1 tallow ammonium, was modified by tolylene 2,4‐diisocyanate (TDI) and bisphenol A (BA). Thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy and X‐ray diffraction (XRD) results of unmodified and modified 1.34 TCN (1.34‐TDI‐BA) indicate that TDI and BA have reacted with hydroxy1 groups on the surface of 1.34 TCN and hydroxy1 groups in the interlayer of 1.34 TCN. Using a classical two‐stage cure process with diamine as curing agent, intercalated epoxy nanocomposites were prepared for both types of organoclays. XRD and TEM results showed that the basal spacing of clay in nanocomposites was 3.68 and 4.42 nm for 1.34 TCN and 1.34‐TDI‐BA, respectively. Dynamic mechanical analysis (DMA) was performed on both modified and unmodified organoclay composites. Modified organoclay composites were found to have enhanced storage moduli, particularly at temperatures higher than the glass transition, Tg, of the matrix. Glass transition temperatures extracted from linear viscoelastic data are found to be slightly higher for modified organoclay nanocomposites, indicating enhanced interactions between the modified organoclay and the epoxy matrix. These results were also confirmed by independent measurements of Tg using differential scanning calorimetry (DSC). 相似文献
90.
Mohamed Saber Lassoued Abdelmajid Lassoued Salah Ammar Abdellatif Gadri Abdelhamid Ben Salah Santiago García-Granda 《Journal of Materials Science: Materials in Electronics》2018,29(11):8914-8922
The aim of this work was synthesis and investigation of various properties of Co-doped titanium dioxide nanostructures. Synthesis was conducted by the co-precipitation method using cobalt nitrate and titanium isopropoxide as a precursor, followed by thermal treatment at a temperature of 500 °C. The materials were fully characterized using several techniques (X-ray diffraction XRD, SEM, FTIR, TGA/DTA, UV–Vis diffuse reflectance DRS and photoluminescence). However, dopant has no effect on XRD pattern of the host but it can influence on the various characteristics of host such as optical and electrical properties. The scanning electron microscopy was used to detect the morphology of synthesized nanoparticles which sizes changed with the altitude in the doping concentration to 6%. FTIR spectra exhibit broad peaks where anatase phases of TiO2 demonstrate very sharp UV–Vis band gap results showed the reduction in band gap from from 3.21 eV, for undoped TiO2, to 2.74 eV, for Co doped 6% TiO2. The photocatalytic activity of the samples were studied based on the degradation of methyl orange as a model compound, where the results showed that Co doped 6% TiO2 a good photocatalytic activity. 相似文献