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1

Effect of Sulfur and Acid Soluble Aluminum Content on Precipitate and Microstructure of Grain-Oriented Silicon Steel

Zhou B., Zhu C., Li G., Luo Z., Gao Y., Bao S., Schneider J.

Archives of Metallurgy and Materials

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2018

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Vol. 63, iss. 4

1701--1708

EN

The combined effect of sulfur (S) and acid soluble aluminum (Als ) content on precipitates and microstructures in grain-oriented silicon steel were investigated. The results show that there are dominant AlN and a little amount of MnS-AlN composite in annealed hot-rolled band, and the amount of precipitates increases distinctly with increasing Als content, while S content plays a negligible role. The inhibitors that precipitate during hot band annealing can restrain the grain growth during hot band annealing and primary annealing, and the smaller grains of annealed hot-rolled band can contribute to the formation of {111} <112> texture during primary annealing. Lower S content is conducive to the formation of {111} <112> texture during primary annealing by promoting the formation of Goss texture during hot rolling.

2

Optimized design of a high-power-density PM-assisted synchronous reluctance machine with ferrite magnets for electric vehicles

Liu X., Li Y., Liu Z., Ling T., Luo Z.

Archives of Electrical Engineering

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2017

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Vol. 66, nr 2

279--293

EN

This paper proposes a permanent magnet (PM)-assisted synchronous reluctance machine (PMASynRM) using ferrite magnets with the same power density as rareearth PM synchronous motors employed in Toyota Prius 2010. A suitable rotor structure for high torque density and high power density is discussed with respect to the demagnetization of ferrite magnets, mechanical strength and torque ripple. Some electromagnetic characteristics including torque, output power, loss and efficiency are calculated by 2-D finite element analysis (FEA). The analysis results show that a high power density and high efficiency of PMASynRM are obtained by using ferrite magnets.

3

Dry beneficiation and cleaning of chinese high-ash coarse coal utilizing a dense-medium gas-solid fluidized bed separator

He J., Tan M., Zhu R., Luo Z.

Physicochemical Problems of Mineral Processing

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2016

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Vol. 52, iss. 2

662--675

EN

Dry dense-medium fluidized bed separation provides a new alternative approach for coal beneficiation and cleaning. An indicator of segregation degree Sash was proposed to evaluate the stratified performance of coal samples by bed density. Fluidization stability of the bed was greatly enhanced by mixing a certain amount (21.53%) of fine magnetite powder (< 0.15 mm) into the fluidized media, which indicated a uniform density distribution as well as slight fluctuations in bed. It was found that the favorable density-segregation performance of 3–13 mm coarse coal occurred with a static bed height of 80 mm and a superficial gas velocity of 11.84 cm/s. The optimal segregation degree values of 0.67, 0.74 and 0.76 were obtained for 3–6, 6–10 and 10–13 mm coal samples, respectively. Low-ash clean coal with yields of 50.79, 56.83 and 61.24% were effectively acquired by the dry separation for various coal size fractions, respectively. Probable error values of 0.07, 0.055 and 0.05 g/cm3 were achieved, indicating good separation performance.

4

Influence of Rolling Friction Coefficient on Inter-Particle Percolation in a Packed Bed by Discrete Element Method

Zhou H., Luo Z., Zhang T., You Y., Li H., Zou Z.

Archives of Metallurgy and Materials

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2016

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Vol. 61, iss. 4

1795--1804

EN

Rolling friction representing the energy dissipation mechanism with the elastic deformation at the contact point could act directly on particle percolation. The present investigation intends to elucidate the influence of rolling friction coefficient on inter-particle percolation in a packed bed by discrete element method (DEM). The results show that the vertical velocity of percolating particles decreases with increasing the rolling friction coefficient. With the increase of rolling friction coefficient, the transverse dispersion coefficient decreases, but the longitudinal dispersion coefficient increases. Packing height has a limited effect on the transverse and longitudinal dispersion coefficient. In addition, with the increase of size ratio of bed particles to percolation ones, the percolation velocity increases. The transverse dispersion coefficient increases with the size ratio before D/d<14. And it would keep constant when the size ratio is greater than 14. The longitudinal dispersion coefficient decreases when the size ratio increases up to D/d=14, then increases with the increase of the size ratio. External forces affect the percolation behaviours. Increasing the magnitude of the upward force (e.g. from a gas stream) reduces the percolation velocity, and decreases the dispersion coefficient.

5

Improving separation efficiency of 6-1 mm coal by introducing vibration energy to dense medium gas-solid fluidized bed

He J., Zhao Y., Luo Z., Zhao J., Duan C., He Y.

Physicochemical Problems of Mineral Processing

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2015

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Vol. 51, iss. 1

95--108

EN

Effects of the vibration energy on the fluidization quality and separation performance of dense medium gas-solid fluidized bed were investigated experimentally. The magnetite powder with a wide size range of 0.3-0.074 mm was utilized as the basic medium solids. 6-1 mm fine coal sample from Yongcheng (China) was used to perform the separation experiments. The results indicate that the vibration amplitude A and superficial gas velocity U are greatly significant to the fluidization stability and the density distribution uniformity. Comparing with the bed without vibration, the optimal SP and Sρ values of 0.034 kPa and 0.018 g/cm3 are acquired in vibration bed with the operating factors of A = 1 mm, U = 1.8Umf, f = 15 Hz and Hs = 150 mm. The coal ash content was reduced from 27.84% to 9.50% at a separating density of 1.68 g/cm3 with a probable error E value of 0.505. The separation efficiency of 6-1mm fine coal is effectively improved by introducing vibration energy to dense medium gas-solid fluidized bed. The technology provides a novel approach to achieve high-efficiency separation of 6-1 mm fine coal in the arid and water-shortage areas.

6

Study on Thermal Insulation Properties of Aluminised Aramid Fabrics

Cai G., Wang H., Luo Z., Wang Z.

Fibres & Textiles in Eastern Europe

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2015

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Vol. 23, no. 4 (112)

52--56

EN

In order to prevent or minimise skin burn damage resulting from high temperature, a kind of thermal insulation composite fabric, the surface of which is aluminised, was developed. In this study, the thermal insulation properties of aluminised aramid fabrics were investigated. The reflectance of aramid fabrics and aluminised aramid fabrics were measured using a UV–Vis–NIR spectrophotometer. The reflectance of aramid fabric increased from 63.6% to 92.3% as a result of aluminising. The thermal insulation of aluminised fabrics and nonaluminised fabrics was measured using a dry hot plate instrument, where the aluminised fabrics had a higher thermal resistance than those non-aluminised , and the thermal resistance of aramid fabric could be enhanced by almost 45% when aluminised. The aluminised and non-aluminised fabrics were exposed to a hot environment for a few minutes using self-designed apparatus. The results showed that the aluminised aramid fabrics had better thermal insulation performance than the non-aluminised aramid ones. Therefore aluminised aramid fabric exhibits great thermal insulation properties and can be used in the field of thermal protection.

PL

W celu zapobiegania i minimalizowania oparzeń skóry spowodowanych wysoką temperaturą zaproponowano kompozytowe pakiety włókiennicze o aluminiowanej powierzchni. W pracy badano właściwości termicznej izolacji tkanin aramidowych pokrytych aluminium. Mierzono odbicie promieniowania tkanin aramidowych i tkanin pokrytych aluminium za pomocą spektrofotometru UV-Vis-NIR. Odbicie promieniowania od tkanin aramidowych po pokryciu aluminium wzrosło z 63,6% do 92,3%. Izolację termiczną badanych tkanin mierzono stosując przyrząd z suchą gorącą płytą. Stwierdzono, że oporność termiczna tkanin aluminiowanych jest wyższa co najmniej o 45%. W czasie badań tkaniny były poddane działaniu gorącego środowiska przez kilka minut, przy zastosowaniu urządzenia skonstruowanego przez autorów.

7

Regional features analysis of plugged holes of dense phase gas-solid separation fluidized bed

Zhang B., Zhao Y., Luo Z., Song S., Duan C., Dong L.

Physicochemical Problems of Mineral Processing

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2014

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Vol. 50, iss. 2

667--679

EN

In contrast to traditional coal separation, dry separation does not require water and does not cause water pollution. Dense phase gas–solid fluidized beds are used for dry separation. The plugged holes in the air distributor should be tested to ensure the stability of these beds for particle separation. The pressure fluctuation is sensitive to these plugged holes. This sensitivity can be tested and diagnosed by determining the standard deviation of the pressure fluctuation. In areas with partial blockage, that is the areas with weak fluidization, a decrease in the volume fraction of the particles and in the pressure differences in the transverse of the bed results in an increase of the standard deviation of the pressure fluctuation, thereby stimulating the lateral mixing of medium-sized particles. The standard deviation and the mixing intensity decrease axially. The value of sensitivity of the plugged holes in the air distributor decreases as the height of the bed increases. The features of air distributors affect the surrounding areas. The distribution law determining the influence of plugged holes on the beds is symmetrical. As the blockage of the fluidized bed distributor region increases, the mean square error of the pressure fluctuation in the related regions increases. The intensity of the effect is proportional to the distance to the plugged holes.

8

Effects of elevated CO2 and temperature on growth and morphology of fir (Abies faxoniana Rehd. et Wils.) and native herbs in a treeline ecotone : an experimental approach

Hou Y., Luo Z., Kaiyun W., Jenerette G., Qiao Y.

Polish Journal of Ecology

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2010

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Vol. 58, nr 2

311-322

EN

Determining how changes in atmospheric CO2 concentrations and climate affects growth of species is helpful for understanding plant community species shift in response to future environmental changes. In the present study, fir (Abies faxoniana) and native herbs from treeline ecotone of east Qinghai-Tibetan Plateau (altitude: 3230-3300 m) were exposed to ambient CO2 or ambient +350 [mu]mol.mol[^-1] CO2 concentration in combination with ambient or ambient +2[degrees]C air temperature for two years in enclosedtop chambers. The results showed that elevated CO2, elevated temperature and the combination of elevated CO2 and temperature increased biomass, height and diameter of fir compared to the control. Elevated CO2 decreased biomass of Deyeuxia scabrescens, but increased for Fragaria orientalis and Cardamine tangutorum. Except for Fragaria orientalis, herbaceous biomass decreased by elevated temperature. The combination stimulated growth of Fragaria orientalis and Cardamine tangutorum, but suppressed for Deyeuxia scabrescens and Carex kansuensis. The results also demonstrated that elevated CO2 and temperature increased the crown size and altered the morphology of fir, with benefits for resource capture, and did not affect growth of herbs. Larger root to shoot ratio of fir contributed the enhancement of biomass, while negatively influencing the growth of some herbs. This indicates morphological changes of trees may modify their growth responses and species around them to environmental changes. The different effects of elevated CO2 and temperature on the growth of species in treeline ecotone suggest that climate change may alter community composition and structure.