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21.
自复式电路保护器件可以用来进行过热、过电流及过电压保护,用于先进设备中的电动机和风扇、控制器、触按元件、显示器和接口电路的保护.  相似文献   
22.
The Mn–Cu nanoferrites of composition Mn0.5Cu0.5Fe2−2x Ni x Zr x O4 (0.00≤x≤0.80) were synthesized by incorporating dopant Zr4+ and Ni2+ cations via a chemical coprecipitation technique. The single phase of the prepared spinel nanoferrites with particle sizes 15–31 nm was confirmed by XRD. Both electrical and magnetic properties are found to depend on the x contents and explained by considering the Zr4+ and Ni2+ cations distribution, displacement of the Fe3+ ions by dopants, changes in magnetic moment at tetrahedral A site and octahedral B site, Fe3+(A)–O2–Fe3+ [B] linkages and extent of the primary superexchange interactions (A)–O–[B] of the Fe3+ ions on the A and B-sites. DC resistivity, saturation magnetization (M s), remanence (M r) and Bohr magneton (n B) are observed to increase up to x≤0.40, while these parameters fall at relatively higher value of x≥0.60.  相似文献   
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Highly dispersible, uniform size (~7 nm) single-phase Cu2ZnSnS4 nanoparticles have been synthesized by hydrothermal method using non-toxic surfactant (oleic acid). High resolution transmission electron microscopy image indicates good crystallinity of the Cu2ZnSnS4 nanoparticles with the growth along (1 1 2) plane. X-ray photoelectron spectroscopy analyses suggested that the formation of with Cu, Zn, and Sn in +1, +2 and +4 oxidation states. The optical absorption spectrum of Cu2ZnSnS4 nanoparticles exhibits an absorption in the visible region and its optical band gap was found to be ~1.72 eV, which could be much more appropriate for photocatalytic application under visible light irradiation. These Cu2ZnSnS4 nanoparticles have been shown high photocatalytic degradation activity of methylene blue (MB) dye in the presence of visible light irradiation. The rate constant (k) value of Cu2ZnSnS4 nanoparticles is found to be 0.0144 min?1. We have discussed the mechanism of dye degradation process that drives the photocatalytic degradation process. The reusability of the Cu2ZnSnS4 nanoparticles for the dye degradation is also demonstrated.  相似文献   
25.
Periodicity detection has been used extensively in predicting the behavior and trends of time series databases. In this paper, we present a noise resilient algorithm for periodicity detection using suffix trees as an underlying data structure. The algorithm not only calculates symbol and segment periodicity, but also detects the partial (or sequence) periodicity in time series. Most of the existing algorithms fail to perform efficiently in presence of noise; although noise is an inevitable constituent of real world data. The conducted experiments demonstrate that our algorithm performs more efficiently compared to other algorithms in presence of replacement, insertion, deletion or a mixture of any of these types of noise.  相似文献   
26.
Nanotechnology is an emerging field of science that applies particles between 1 and 100 nm in size for a range of practical uses. Nano‐technological discoveries have opened novel applications in biotechnology and agriculture. Many reactions involving nanoparticles (NPs) are more efficient compared to those of their respective bulk materials. NPs obtained from plant material, denoted as biogenic or phytosynthesised NPs, are preferred over chemically synthesised NPs due to their low toxicity, rapid reactions and cost‐effective production. NPs impart both positive and negative impacts on plant growth and development. NPs exhibit their unique actions as a function of their size, reactivity, surface area and concentration. An insight into NP biosynthesis and translocation within the plant system will shed some light on the roles and mechanisms of NP‐mediated regulation of plant metabolism. This review is a step towards that goal.Inspec keywords: nanofabrication, nanoparticles, nanobiotechnology, particle size, reviews, botany, biochemistryOther keywords: chemically synthesised NPs, low toxicity, rapid reactions, cost‐effective production, positive impacts, plant growth, translocation, plant system, plant metabolism, nanotechnological discoveries, biotechnology, agriculture, plant material, biogenic NPs, phytosynthesised NPs, bulk materials, nanoparticles, biosynthesis, surface area, review, size 1.0 nm to 100.0 nm  相似文献   
27.
In this paper the electromechanical behavior of a torsional micromirror was investigated using of a static model with considering torsion and bending characteristics of micro-beams. A set of nonlinear equations based on the parallel plate capacitor model was derived to represent the relationships between the applied voltage, torsion angle, and vertical displacement of the torsional micromirror. Step by step linearization method (Newton’s method) was used to calculate the rotation angle and vertical displacement of the micromirror due to the applied voltage. This method is fast and gave acceptable and accurate results which were in good agreement with the experimental data.  相似文献   
28.
In this paper, we have developed a method to enhance the Al-N co-dopant solubility in bulk ZnO prepared by solid state reaction method. Reactive donor Al and acceptor N were mobilized by annealing the samples at various temperatures from 650 to 850?°C with a step of 50?°C in a programmable furnace. The solubility enhancement argument was verified by the conductivity measurements which showed that the conductivity of annealed films increases as the annealing temperature increases. The activation energy was calculated by the Arrhenius plot and was found to be (0.08?eV) very close to activation energy of shallow acceptor (nitrogen). To further strengthened our argument, we have also performed XRD, FTIR, Raman Spectroscopy and SEM measurements. XRD data suggested that only ZnO phases were present and no evidence for the presence of AlN, Al2O3 or Zn3N2 phases. We have also observed weakening and peak shifting of (002) with annealing temperature that suggested the incorporation of more acceptor defects in the crystal of ZnO. FTIR results verified the presence of Zn-O bond (437?cm?1) along with week vibration of Al-N bond at 917?cm?1. Raman spectroscopy data consists of 2E2, A1 (LO) and E2(high) modes of ZnO but sample annealed at 800?°C has additional nitrogen related mode at 507?cm?1. SEM images demonstrated the crystalline nature of samples having smooth surface but sample annealed at 800?°C has rough surface which indicated the enhancement of acceptor defects density.  相似文献   
29.
The purpose of this paper was to propose a new method to solve partial differential equations arising in the field of science and engineering. In this new method, we have reduced the multiple integrals into a single integral and expressed it in terms of a difference kernel. To make the calculation easy and convenient, we have used the Laplace transformation to solve the difference kernel. The method is very simple, easy to understand and calculation minimizing as compared to the Adomian decomposition method and the variational iteration method. Some examples are given to verify the reliability and efficiency of the method.  相似文献   
30.
In this work, the effective parameters in liquid polysulfide curing system were optimized by D ‐optimal design method. Five main components in the formulation, carbon black, vulcanizing agents (MnO2, Na2Cr2O7, and PbO2), CaCO3, fumed silica, and chlorinated paraffin, were selected. Mechanical and chemical properties of the samples were investigated. The results showed that tensile strength, hardness, viscosity, and optimum cure time (t90) presented a suitable coordination with reduced quadratic model. For elongation at break and swelling tests, reduced two‐factor interaction (2FI), and for peel strength, a linear model showed the best correlation. To achieve the desirable properties for liquid polysulfide sealants used in fuel tanks, an optimized amount of the above components in the formulation were used. Finally, MnO2 curing system, compared with Na2Cr2O7 and PbO2, was selected as the best choice. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011  相似文献   
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