In this paper, we establish nonlinear GP model between impact factor of sci-tech journal and related indexes based on genetic programming approach. The proposed GP model utilizes average authors, number of district, n...
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In this paper, we establish nonlinear GP model between impact factor of sci-tech journal and related indexes based on genetic programming approach. The proposed GP model utilizes average authors, number of district, number of affiliation, international paper ratio and foundation paper ratio as the inputs, and uses impact factor as the output. The journals data from Chinese S&T Journal Citation Reports in 2005 are used as experimental data. The experimental results show that impact factor is mainly related to average authors and foundation paper ratio, and nearly has nothing to do with number of district, number of affiliation and international paper ratio. Therefore, increasing the average authors and foundation paper ratio of sci-tech journal will help to promote the impact factor of journal and improve the quality of journal to some extent.
In real life, people always move according to a certain paths, for example, walking from one side of corridor to the other side of it, but not passing through the wall, and so on. Therefore, all kinds of possible path...
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In real life, people always move according to a certain paths, for example, walking from one side of corridor to the other side of it, but not passing through the wall, and so on. Therefore, all kinds of possible paths could be predefined, then the indoor positioning systems can make full use of these paths to further improve the positioning accuracy. In this paper, an indoor positioning algorithm based on path tracking assistance is presented which makes the most of path information in indoor environment to optimize the searched subspaces of positioning algorithm. Experimental results demonstrated that the proposed path tracking assistance algorithm can improve the 73% accuracy in 3 meters of traditional kNN algorithm to 92% in a typical office building testbed when the subspaces are defined rationally.
Very uniform and well shaped Mn 3 O 4 nano-octahedra are synthesized using a simple hydrothermal method under the help of polyethylene glycol (PEG200) as a reductant and shape-directing agent. The nano-octahedra forma...
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Very uniform and well shaped Mn 3 O 4 nano-octahedra are synthesized using a simple hydrothermal method under the help of polyethylene glycol (PEG200) as a reductant and shape-directing agent. The nano-octahedra formation mechanism is monitored. The shape and crystal orientation of the nanoparticles is reconstructed by scanning electron microscopy and electron tomography, which reveals that the nano-octahedra only selectively expose {101} facets at the external surfaces. The magnetic testing demonstrates that the Mn 3 O 4 nano-octahedra exhibit anomalous magnetic properties: the Mn 3 O 4 nano-octahedra around 150 nm show a similar Curie temperature and blocking temperature to Mn 3 O 4 nanoparticles with 10 nm size because of the vertical axis of [001] plane and the exposed {101} facets. With these Mn 3 O 4 nano-octahedra as a catalyst, the photodecomposition of rhodamine B is evaluated and it is found that the photodecomposition activity of Mn 3 O 4 nano-octahedra is much superior to that of commercial Mn 3 O 4 powders. The anomalous magnetic properties and high superior photodecomposition activity of well shaped Mn 3 O 4 nano-octahedra should be related to the special shape of the nanoparticles and the abundantly exposed {101} facets at the external surfaces. Therefore, the shape preference can largely broaden the application of the Mn 3 O 4 nano-octahedra.
This paper reports that the nanostructured β-FeSi2 bulk materials are prepared by a new synthesis process by combining melt spinning （MS） and subsequent spark plasma sintering （SPS）. It investigates the influence...
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This paper reports that the nanostructured β-FeSi2 bulk materials are prepared by a new synthesis process by combining melt spinning （MS） and subsequent spark plasma sintering （SPS）. It investigates the influence of linear speed of the rolling copper wheel, injection pressure and SPS regime on microstructure and phase composition of the rapidly solidified ribbons after MS and bulk production respectively, and discusses the effects of the microstructure on thermal transport properties. There are two crystalline phases （α-Fe2Si5 and ε-FeSi） in the rapidly solidified ribbons; the crystal grains become smaller when the cooling rate increases （the 20 nm minimum crystal of ε-FeSi is obtained）. Having been sintered for 1 min above 1123K and annealed for 5min at 923K, the single-phase nanostructured β- FeSi2 bulk materials with 200-500 nm grain size and 98% relative density are obtained. The microstructure of β-FeSi2 has great effect on thermal transport properties. With decreasing sintering temperature, the grain size decreases, the thermal conductivity of β-FeSi2 is reduced remarkably. The thermal conductivity of β-FeSi2 decreases notably （reduced 72% at room temperature） in comparison with the β-FeSi2 prepared by traditional casting method.
A solution method was developed for fabricating ZnO nanostructures using （NH4）2CO3 as starting material SEM analysis shows that ZnO nanostructures exhibit nanorod, branch and flower-like morphologies. The crystal ph...
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A solution method was developed for fabricating ZnO nanostructures using （NH4）2CO3 as starting material SEM analysis shows that ZnO nanostructures exhibit nanorod, branch and flower-like morphologies. The crystal phase of as-synthesized products was characterized by X-ray diffraction （XRD）. The growth process, formation mechanism and optical property were also discussed by means of transmission electronic microscopy （TEM）, high resolution transmission microscopy （HRTEM） and photoluminescence （PL）. The growth direction of ZnO nanostructures was investigated based on the results of HRTEM. The PL spectrum shows two strong peaks （centered at around -387 and -470 nm） and a broad Deak （centered at around -580 nm）.
Ordered microporous carbon molecular sieves with high specific area and well-dispersed Pt nanoparticles have been prepared by chemical vapour deposition method. Electrochemical properties were measured, showing the ni...
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ISBN:
(纸本)9781424435432;9781424435449
Ordered microporous carbon molecular sieves with high specific area and well-dispersed Pt nanoparticles have been prepared by chemical vapour deposition method. Electrochemical properties were measured, showing the nitrogen-doped carbons exhibited excellent performance as an electrochemical supercapacitor.
Preparation and thermoelectric properties of nanostructured n-type Mg2Si bulk materials were reported. Nanosized Mg2Si powder was obtained by mechanical milling of the microsized Mg2Si powder prepared by solid-state r...
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Preparation and thermoelectric properties of nanostructured n-type Mg2Si bulk materials were reported. Nanosized Mg2Si powder was obtained by mechanical milling of the microsized Mg2Si powder prepared by solid-state reaction. The bulk materials with 30 nm and 5 μm were prepared by spark plasma sintering of the nanosized and microsized Mg2Si powder, respectively. Both the samples show n-type conduction and the Seebeck coefficient of the sintered samples increase determinately with the grain size decrease from 5 μm to 30 nm. On the other hand, the electrical and thermal conductivity decrease with the decrease of grain size. Accordingly, decreasing their grain size increases their thermoelectric-figure-of-merit. A maximum thermoelectric figure of merit of 0.36 has been obtained for the nanostuctured Mg2Si sample at 823 K, which is 38% higher than that of microsized Mg2Si bulk materials and higher than results of other literatures. It could be expected that the properties of the nanocomposites could be further improved by doping optimization.
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