Space symmetry of prehnite, which occurs in cavities and veins within Skarn from the Tieshan iron mineral deposit,Daye,Hubei province,Central China,has been determined using selected area electron diffraction (SAED) a...
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Space symmetry of prehnite, which occurs in cavities and veins within Skarn from the Tieshan iron mineral deposit,Daye,Hubei province,Central China,has been determined using selected area electron diffraction (SAED) and convergent-beam electron diffraction (CBED) on the submicrometer *** results confirm that the natural prehnite may have the structure with symmetry *** unit-cell parameters of investigated prehnite (a=0.458nm,b=0.555nm,and c=1.853nm) have been calculated by using the multicrystal diffraction rings of gold,the internal standard.
This paper studies the temperature distribution of BN, an insulating material, sintered in the Spark Plasma Sintering ( SPS) system. The temperature distributions of BN at different heating rates were measured , which...
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This paper studies the temperature distribution of BN, an insulating material, sintered in the Spark Plasma Sintering ( SPS) system. The temperature distributions of BN at different heating rates were measured , which showed that seeking for an over high heating rate in SPS is not as desirable as controlling of a suitable heating rate in order to have a fast sintering with a uniform temperature distribution.
The texture of interfacial zone between cement paste and quartz in the cement-based composites containing polyvinyl alcohol (PVA), methylcellulose (MC) and their potyblend in an amount of 10 wt % with respect to cemen...
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The texture of interfacial zone between cement paste and quartz in the cement-based composites containing polyvinyl alcohol (PVA), methylcellulose (MC) and their potyblend in an amount of 10 wt % with respect to cement, as well as the texture of dehydrated bodies of PVA, MC, and the potyblend solutions, were investigated with SEM. The network texture of the dehydrated polyblend is confirmed by comparing the texture of dehydrated bodies of PVA and MC. The network texture has restrained the movement of polyblend molecules in the cement mortar but is helpful to forming a coherent interface between cement paste and quartz. The key factor of forming the coherent interface is not the neutralization reaction between H + from hydrolysis of quarts: and OH- from hydration of cement, but the electrostatic attraction and the chemical reaction between polar groups on the polyblend molecule and cations and onions from hydrolysis of quartz and hydration of cement, respectively. The model of the coherent interface formation is that excessive [HSiO3]- and [SiO3]2- onions are bonded with the hydrated cations such as Ca2+ and Al3+ , which is confirmed by the gel containing Ca and Si on the quartz surface.
By using such flier-plate material,quasi-isentropic compression can be *** on it,hypervelocity launching is further *** a result,an extremely high dynamic pressure can be obtained in laboratory,offering a practical me...
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By using such flier-plate material,quasi-isentropic compression can be *** on it,hypervelocity launching is further *** a result,an extremely high dynamic pressure can be obtained in laboratory,offering a practical method for the comprehensive determination of materials behavior,response,equation-of-state and properties in dynamic loading process.
b Department of Chemistry, Wuhan University, Wuhan, Hubei 430072, China The action of β ( N selenomorpholine) ethyl phenyl ketone hydrochloride and 4 ( N selenomorpholine) 2 butanone hydro chl...
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b Department of Chemistry, Wuhan University, Wuhan, Hubei 430072, China The action of β ( N selenomorpholine) ethyl phenyl ketone hydrochloride and 4 ( N selenomorpholine) 2 butanone hydro chloride on Escherichia coli and Staphylococcus aureus was studied by microcalorimetry. Differences in their capacities to affect the metabolism of this bacterium were observed. The kinetics shows that the selenomorpholine compounds had action on the metabolism process of Escherichia coli and Staphylococcus aureus. The rate constant ( k ) of the studied bacterium in the presence of the drugs are concentration dependant. The growth rate constants decrease with an increase in the mass of the selenomorpholine compounds, but their relationship is different. As deduced from the rate constant ( k ) of the studied bacterium (in log phase) and the half inhibitory concentration (IC 50 ), the experimental results reveal that the studied selenomorpholine compounds all have good antibiotic activity and better antibacterial activity on Staphylococcus aureus than on Escherichia coli.
In contrast to the commonly used arc melting method, samples in the present paper were prepared by the solid-state reaction from element powders at 1173K under a flowing argon atmosphere for 4-7 days. The constituent ...
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In contrast to the commonly used arc melting method, samples in the present paper were prepared by the solid-state reaction from element powders at 1173K under a flowing argon atmosphere for 4-7 days. The constituent phases and the element compositions were determined and showing that samples were of single phase and stoichiometric. ZrNiSn powder was then consolidated by using the spark plasma sintering technique. The effect of sintering temperature and holding time on the density was discussed. It is found that, dense ZrNiSn compounds with fine grain size and homogeneous microstructure were achieved under the condition of 1123K-40MPa-25min.
Millimeter wave processing of materials is a method which has wide application prospect for improving material characteristics. In this paper, the investigated results of millimeter wave processing of materials in IEC...
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ISBN:
(纸本)0780374231
Millimeter wave processing of materials is a method which has wide application prospect for improving material characteristics. In this paper, the investigated results of millimeter wave processing of materials in IECAS, such as millimeter wave sintering of Al/sub 2/O/sub 3/, ZnO, Nd/sub 2/Ti/sub 3/O/sub 9/, and chemical syntheses of spinels LiMn/sub 2/O/sub 4/ and LiCo/sub 0.1/Mn/sub 1.99/O/sub 3.92/S/sub 0.08/, as cathode materials of Li-ion batteries, with millimeter wave heating are presented.
The solid solutions of Al2(1.x)MgxTi 1+xO5 (x=0,0.01,0.05,0.1) were fabricated by the solid phase reaction method, and they were sintered under normal pressure. The thermal performance of Al2(1-x)MgxTi1+xO 5 was mainl...
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The solid solutions of Al2(1.x)MgxTi 1+xO5 (x=0,0.01,0.05,0.1) were fabricated by the solid phase reaction method, and they were sintered under normal pressure. The thermal performance of Al2(1-x)MgxTi1+xO 5 was mainly investigated. The results show that, the additive MgTi2O5 can not only restrain the decomposition of Al 2TiO5, but also greatly improve the densification of the solid solutions. With increasing mole percent of x, the thermal stability of Al2(1-x)MgxTi1+xO5 increases and the expansion coefficient decreases.
A kind of W/W-Mo/Mo system layered flier-plate material (LFP) was fabricated in this study by the methods of powder metallurgy and bonding together. Such LFP had high parallelism,planeness and densification and its de...
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A kind of W/W-Mo/Mo system layered flier-plate material (LFP) was fabricated in this study by the methods of powder metallurgy and bonding together. Such LFP had high parallelism,planeness and densification and its density varied from 17.25x103 kg/m3 to 10.22x103 kg/m3 through a total thickness of 3.0 mm. The W-Mo interlayer of this LFP was obtained by hot-press sintering and its densification at 1573 K was studied. Then by using additives 4Ni-3Cu (in wt pct), the LFP was fabricated under 1573 K-30 MPa-60 min. The mechanism of the interfacial bonding of the W/W-Mo/Mo system LFP was also mainly investigated.
Al/Al2O3 composites of different ratios were hot-press sintered at 575～640℃ under a pressure of 30 MPa for 2 h in a vacuum furnace. It was found that the relative density of the Al/Al2O3composites could be increased...
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Al/Al2O3 composites of different ratios were hot-press sintered at 575～640℃ under a pressure of 30 MPa for 2 h in a vacuum furnace. It was found that the relative density of the Al/Al2O3composites could be increased evidently with the rise of sinter temperature. No reaction occurred between Al and Al2O3 at the sinter temperatures. Under 640℃-30 MPa-2 h experimental condition, Al/Al2O3 system FGM was successfully fabricated, and its density range changed quasi-continuously from 2.887x103 kg/m3 to 3.1909x103 kg/m3 within the middle 1.0 mmthickness range.
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