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The mechanical behavior of nano-scale metallic glasses was investigated by in situ compression tests in a scanning electron microscope. Platinum-based metallic glass nano-pillars were fabricated by thermoplastic forming. The nano-pillars and corresponding bulk substrate were tested in compression over the range of room temperature to glass transition. Stress–strain curves of the nano-pillars were obtained along with in situ observation of their deformation behavior. The bulk substrate as well as nano-pillars showed an increase in elastic modulus with temperature which is explained by diffusive rearrangement of atomic-scale viscoelastic units.  相似文献   
33.
This paper describes our experience in developing techniques for repairing date affected programs using standard compiler technology. Starting with date‐ness information of certain variables based on their declarations, we propagate this information through all possible control paths, using date inference rules to traverse across individual statements. Our approach is fine grained enough to infer the date‐ness of each occurrence of a variable. After detecting date‐ness of variables, we renovate programs by applying a transformation using base year strategy. These techniques have been implemented as a tool set for renovating date affected COBOL programs. Copyright © 1999 John Wiley & Sons, Ltd.  相似文献   
34.
The results of the investigation on the use of polyaniline (PANI) as a cathode material in a battery configuration, having magnesium as anode and a neutral aqueous solution of one of the magnesium salts such as perchlorate, chloride and bromide as an electrolyte, are presented. This system shows a open circuit voltage in the range 1.6-1.8 V. The study indicates that the capacity of the system largely depends upon the anion present in the electrolyte.  相似文献   
35.
Pulsed laser deposition was used to produce thin films of zinc oxysulfide (ZnO x S1−x ) on quartz substrates. The target was a sintered pellet (ZnO0.39S0.61) made of a solution precipitate. The film composition obtained by electron probe microanalysis (EPMA) was ZnO0.41S0.59, ZnO0.44S0.56, and ZnO0.37S0.63 for substrate temperatures of 450°C, 540°C, and 630°C, respectively. X-ray diffraction (XRD) showed that samples deposited at 450°C and at 540°C had a prominent cubic sphalerite phase, whereas samples deposited at 630°C consisted of three phases, viz. hexagonal wurtzite and cubic sphalerite (ZnS), and hexagonal zincite (ZnO). With respect to the tabulated lattice spacings for sphalerite (cell constant 0.5406 nm), distinct shifts were observed for the low temperature samples, yielding cell constants around 0.533 nm. Transmission electron microscopy (TEM)–selected area electron diffraction studies support the XRD data. Patterns of films deposited at 540°C could be indexed as sphalerite, with similar lattice shifts as in XRD, resulting in a cell constant of 0.53. Locally highly resolved chemical analysis by TEM–energy dispersive x-ray analysis revealed a stoichiometry that was consistent with the EPMA results. Ultraviolet (UV)–visible transmission measurements of the films led to bandgap energies around 3.3 eV, which is well below the reported bandgap energies of ZnS.  相似文献   
36.
We have investigated the structure and bonding in phenolic resin-based carbons as a function of heat treatment using a combination of high resolution transmission electron microscopy, electron energy loss spectroscopy, X-ray diffraction, gas adsorption and density measurements. On heat treatment, the initially amorphous material transforms to a micro-porous material containing small graphitic packets enclosing elongated pores, with a relatively small change in density but an appreciable change in planar carbon sp2-content as well as the development of significant curvature in the graphitic layers. The results from the different characterisation techniques are discussed and wherever possible, cross-correlated. They are also compared with proposed models for the microstructural development in non-graphitising carbons and also with the corresponding data obtained from graphitisable carbons. Overall the data provides strong evidence for a fullerene-based model for the microstructural development in non-graphitising carbons and more generally, the interpretation of the current EELS data has important implications for the spatially localised analysis of poorly crystalline carbon materials.  相似文献   
37.
The paper presents the electrostatic charge dissipative performance of conducting polymer nanocomposite impregnated fabric based on polyaniline (PANI) and zinc oxide nanoparticles (ZnO NPs). Conducting polymer nanocomposites (PANI‐ZnO NPs) were synthesized by in situ chemical oxidative polymerization of aniline by using sodium dodecyl sulfate as surfactant and HCl as dopant. Coating of PANI‐ZnO nanocomposites on the cotton fabric was carried out during polymerization. The interaction of ZnO NPs with the PANI matrix was determined by Fourier transform infrared spectra (FTIR), TGA, XRD, scanning electron Microscopy (SEM), high resolution transmission electron microscopy (HRTEM) and conductivity measurements. The conductivity of PANI‐ZnO NP coated fabric was found to be in the range 10?3 ? 10?6 S cm?1 depending on the loading concentration of ZnO NPs in the polymer matrix. TEM and HRTEM images showed that the PANI‐ZnO nanocomposites had an average diameter of 25–30 nm and were nicely dispersed in the polymer matrix. Antistatic performance of the nanocomposite impregnated fabric was investigated by static decay meter and John Chubb instrument. The static decay time of the film was in the range 0.5 ? 3.4 s on recording the decay time from 5000 V to 500 V. This indicated that the nanocomposite based on PANI‐ZnO nanocomposites has great potential to be used as an effective antistatic material. © 2015 Society of Chemical Industry  相似文献   
38.
Organic coating approaches for corrosion protection with inherently conducting polymers have become important because of restriction on the use of heavy metals and chromates in coatings due to their environmental problems. The present work is directed towards the synthesis of polyaniline (PANI) and polyaniline–SiO2 composites (PSCs) by chemical oxidation polymerization in the presence of phosphoric acid and evaluation of synthesized PANI and PSCs for protection of mild steel from corrosion in a strong aggressive medium (i.e. 1.0 mol L–1 HCl). A suitable coating with PSC was formed on mild steel using epoxy resin by the powder coating technique. A comparative study of the corrosion protection efficiency of mild steel coated with PANI and PSC in 1.0 mol L–1 HCl solution was evaluated using the Tafel extrapolation, chrono‐amperometry and weight loss methods. The PSC coating showed that a significant reduction in the corrosion current density reflects the better protection of mild steel in an acidic environment. Higher protection efficiency up to 99% was achieved by using PSC‐coated mild steel at 6.0 wt% loading of PSC in epoxy resin. The coating performance and corrosion rate of mild steel were investigated by using immersion of polymer‐coated mild steel in 1.0 mol L–1 HCl for 60 days and indicated that PSC‐coated mild steel showed better performance from corrosion than PANI in an acidic medium.© 2012 Society of Chemical Industry  相似文献   
39.
Cultivars with efficient root systems play a major role in enhancing resource use efficiency, particularly water absorption, and thus in drought tolerance. In this study, a diverse wheat association panel of 136 wheat accessions including mini core subset was genotyped using Axiom 35k Breeders’ Array to identify genomic regions associated with seedling stage root architecture and shoot traits using multi-locus genome-wide association studies (ML-GWAS). The association panel revealed a wide variation of 1.5- to 50-fold and were grouped into six clusters based on 15 traits. Six different ML-GWAS models revealed 456 significant quantitative trait nucleotides (QTNs) for various traits with phenotypic variance in the range of 0.12–38.60%. Of these, 87 QTNs were repeatedly detected by two or more models and were considered reliable genomic regions for the respective traits. Among these QTNs, eleven were associated with average diameter and nine each for second order lateral root number (SOLRN), root volume (RV) and root length density (RLD). A total of eleven genomic regions were pleiotropic and each controlled two or three traits. Some important candidate genes such as Formin homology 1, Ubiquitin-like domain superfamily and ATP-dependent 6-phosphofructokinase were identified from the associated genomic regions. The genomic regions/genes identified in this study could potentially be targeted for improving root traits and drought tolerance in wheat.  相似文献   
40.
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