Production of modified liquid glass and quartz materials from kaolinite clay of Alekseev deposit of Kazakhstan was studied. The sodium liquid glass processed by kaolinite clay, with chemical composition (g/dm3): SiO2-...Production of modified liquid glass and quartz materials from kaolinite clay of Alekseev deposit of Kazakhstan was studied. The sodium liquid glass processed by kaolinite clay, with chemical composition (g/dm3): SiO2-350;Na2O-155;Al2O3-2.1;Fe2O3- 0.3, silicate module-2.33 and density-1.49 g/cm3 has been used. The sodium liquid glass complies with the Russian Interstate standard 13078-81 for sodium liquid glass.10 samples of modified liquid glass were synthesized by introducing modifiers in an amount of 4% by weight of the solution into the liquid glass. Hard quartz material produced by using synthesized modified liquid glass was obtained. It has been established that the obtained modified liquid glass from kaolinite clay can improve the strength of the quartz material for 1.6 - 3.12 times higher than the initial liquid glass. Using liquid glass modifier to the inorganic sodium nitrate (NaNO3) increases the strength 3.12 times.展开更多
This paper reports that anomalous local order in liquid and glassy A1FeCe alloy has been detected by x-ray diffraction measurements. The addition of the element Ce has a great effect on this local structural order. Th...This paper reports that anomalous local order in liquid and glassy A1FeCe alloy has been detected by x-ray diffraction measurements. The addition of the element Ce has a great effect on this local structural order. The element Ce favours interpenetration of the icosahedra by sharing a common face and edges. It argues that frustration between this short-range order and the long-range crystalline order controls the glass-forming ability of these liquids. The obtained results suggest that a system having a stronger tendency to show local icosahedral order should be a better glass-former. This scenario also naturally explains the close relationship between the local icosahedral order in a liquid, glass-forming ability, and the nucleation barrier. Such topological local order has also been analysed directly using the reverse Monte Carlo method. It also estimated the fraction of local ordered and disordered structural units in a glassy AlFeCe alloy.展开更多
A measurement scheme for detecting theαrelaxation time(τ)of glass-forming liquid is proposed,which is based on the measured ionic conductivity of the liquid doped with probing ions by low-and middle-frequency dielec...A measurement scheme for detecting theαrelaxation time(τ)of glass-forming liquid is proposed,which is based on the measured ionic conductivity of the liquid doped with probing ions by low-and middle-frequency dielectric spectroscopy and according to the Nernst-Einstein,Stokes-Einstein,and Maxwell equations.The obtainedτvalues of glycerol and propylene carbonate by the scheme are consistent with those obtained by traditional dielectric spectroscopy,which confirms its reliability and accuracy.Moreover,theτof 1,2-propanediol in a larger temperature range is compared with existing data.展开更多
Uniform crystalline TiO2 thin films were coated on silica glass fibers by liquid phase deposition from aqueous solution of ammonium hexafluorotitanate at low temperature. TiO2 thin films and nanopowders were prepared ...Uniform crystalline TiO2 thin films were coated on silica glass fibers by liquid phase deposition from aqueous solution of ammonium hexafluorotitanate at low temperature. TiO2 thin films and nanopowders were prepared by adding H3BO3 into （NH4）2TiF6 solution supersaturated with anatase nano-crystalline TiO2 at 40 ℃. The effects of the deposition conditions on the surface morphology, section morphology, thickness of the deposited TiO2 thin films were investigated. The results indicate that the growth rate and particle size of the thin films were controlled by both the deposition conditions and the amount of anatase nano-crystalline TiO2.展开更多
In this work, network former SiO_2 and network intermediate Al_2O_3 were introduced into typical low-melting binary compositions CaO·B_2O_3, CaO·2B_2O_3, and BaO·B_2O_3 via an aqueous solid-state suspen...In this work, network former SiO_2 and network intermediate Al_2O_3 were introduced into typical low-melting binary compositions CaO·B_2O_3, CaO·2B_2O_3, and BaO·B_2O_3 via an aqueous solid-state suspension milling route. Accordingly, multiple-phase aluminosilicate glass-ceramics were directly obtained via liquid-phase sintering at temperatures below 950°C. On the basis of liquid-phase sintering theory, mineral-phase evolutions and glass-phase formations were systematically investigated in a wide MO–SiO_2–Al_2O_3–B_2O_3(M = Ca, Ba) composition range. The results indicate that major mineral phases of the aluminosilicate glass-ceramics are Al_(20)B_4O_(36), CaAl_2Si_2O_8, and BaAl_2Si_2O_8 and that the glass-ceramic materials are characterized by dense microstructures and excellent dielectric properties.展开更多
The results of the study of raw mix preparation and foam glass-ceramics production using diatomite as a raw material were presented in the following article. A mixture of diatomite and 40% NaOH solution was subjected ...The results of the study of raw mix preparation and foam glass-ceramics production using diatomite as a raw material were presented in the following article. A mixture of diatomite and 40% NaOH solution was subjected to heating at a constant temperature of 775 ℃. Samples of foam glass-ceramic from diatomite with an average density of 290-580 kg/m^3, compressive strength of 1.7-7.8 MPa and thermal conductivity of 0.08-0.14 W/（m·K） were obtained. The investigations have shown that the hydrothermal pretreatment of mixture at the temperature of 90 ℃ may lead to the acceleration of the leaching of amorphous SiO_2 from diatomite. It was discovered that the resulting soluble alkali silicates promote the process of foaming during heating and reduce the average density of the obtained samples. The optimal duration of the leaching process was estimated to be 30 minutes, which corresponds to the yield of SiO_2 equal to 42.5% by the weight of dry diatomite.展开更多
Influence of structural variations of N-vinylimidazolium tetrahalogenidoferrate(III) magnetic ionic liquids(MILs) on thermal properties was investigated. Using Gaussian09/B3 PW91/6-311 G(2d, p) density functional meth...Influence of structural variations of N-vinylimidazolium tetrahalogenidoferrate(III) magnetic ionic liquids(MILs) on thermal properties was investigated. Using Gaussian09/B3 PW91/6-311 G(2d, p) density functional methods, the microstructure of the MILs were analyzed. With differential scanning calorimeter(DSC) and thermogravimetric analysis(TGA), the thermal properties of the MILs were performed. The results showed that the interaction energies of ion pairs decreased, the crystallization temperature increased first and then decreased, and the surfusion first decreased and then increased with the elongation of the alkyl chain length on cation;with the increase of Br atom, the interaction energies of ion pairs increased;the interaction energies of ion pairs increased in the MILs with the same cation or anion, the nature of polarity of MILs increased and the melting point rose;as the cation or anion in MILs had a smaller size, it could have the solidsolid transition temperature. The results indicated that the decomposition temperature with the same type of MILs increased with the interaction energies of ion pairs. The interaction energy of ion pairs can be used to illuminate the correlation between the thermal properties and the structure of MILs. ILs possesses the properties of macromolecular.展开更多
Pd81Si19 amorphous alloys were prepared by combination methods of melt spinning and B2O3 flux treatment. A compari- son between the ribbons prepared from the fluxed ingots and the non-fluxed ones has been carried out....Pd81Si19 amorphous alloys were prepared by combination methods of melt spinning and B2O3 flux treatment. A compari- son between the ribbons prepared from the fluxed ingots and the non-fluxed ones has been carried out. The result reveals that after fluxing treatment the glass transition temperature of the as-prepared glassy ribbons is reduced while the initial crystallization tem- perature is enhanced. It results in that the supercooled liquid region (defined as the difference between the initial crystallization tem- perature and the glass transition temperature) of the glassy alloy treated with fluxing technology has been increased from 31 to 42 K. This shows that fluxing technique can enhance the glass forming ability (GFA) of the binary alloy and improve the thermal stability of supercooled liquid of the glassy alloy.展开更多
Quantum spin liquids（QSLs） represent a novel state of matter in which quantum fluctuations prevent the conventional magnetic order from being established, and the spins remain disordered even at zero temperature. Th...Quantum spin liquids（QSLs） represent a novel state of matter in which quantum fluctuations prevent the conventional magnetic order from being established, and the spins remain disordered even at zero temperature. There have been many theoretical developments proposing various QSL states. On the other hand, experimental movement was relatively slow largely due to limitations on the candidate materials and difficulties in the measurements. In recent years, the experimental progress has been accelerated. In this topical review, we give a brief summary of experiments on the QSL candidates under magnetic fields. We arrange our discussions by two categories： i） Geometrically-frustrated systems, including triangularlattice compounds YbMgGaO4 and YbZnGaO4, κ-（BEDT-TTF）2 Cu2（CN）3, and EtMe3 Sb[Pd（dmit）2]2, and the kagom′e system ZnCu3（OH）6 Cl2; ii） the Kitaev material α-RuCl3. Among these, we will pay special attention to α-RuCl3, which has been intensively studied by ours and other groups recently. We will present evidence that both supports and rejects the QSL ground state for these materials, based on which we give several perspectives to stimulate further research activities.展开更多
The glass-transition behavior of Pd40Cu30Ni10P20 bulk metallic glass was investigated by differential scanning calorimetry （DSC） and X-ray powder diffraction （XRD）. The effect of pressure on the crystallization be...The glass-transition behavior of Pd40Cu30Ni10P20 bulk metallic glass was investigated by differential scanning calorimetry （DSC） and X-ray powder diffraction （XRD）. The effect of pressure on the crystallization behavior of Pd40Cu30Ni10P20 bulk glass was studied by in situ high-pressure and high-temperature X-ray powder diffraction using synchrotron radiation. Phase analyses show at least six crystalline phases in the crystallized sample, namely, monoclinic, tetragonal CuaPd-like, rhombohedral, fcc-Ni2Pd2P, fcc-（Ni, Pd） solid solution, and body-centered tetragonal （bct） NiaP-like phases. The onset crystallization temperature increases with pressure having a slope of 1 1 K/GPa in the range of 0 to 4 GPa. The results are attributed to the competing process between the thermodynamic potential barrier and the diffusion activation energy under pressure.展开更多
Metallic glasses(MG)represent an interesting group of materials as they possess outstanding physical,chemical and mechanical properties compared to their crystalline counterparts.This paper reviews the synergistic inf...Metallic glasses(MG)represent an interesting group of materials as they possess outstanding physical,chemical and mechanical properties compared to their crystalline counterparts.This paper reviews the synergistic influence of Ni and Nb elements on thermal stability of supercooled liquid and corrosion resistance of as-cast Cu-Zr(Hf)-Ti-Ni-Nb bulk metallic glasses(BMGs).Additionally,in-situ second phase reinforced Cu-based BMG composites with high corrosion resistance and excellent mechanical properties are investigated.On the other hand,this paper reports the development of ultra-high corrosion resistant Ni-based metallic glasses at high temperatures for their potential applications.Corrosion resistance and XPS analysis of the Nifree Ti-based BMG are also introduced.展开更多
文摘Production of modified liquid glass and quartz materials from kaolinite clay of Alekseev deposit of Kazakhstan was studied. The sodium liquid glass processed by kaolinite clay, with chemical composition (g/dm3): SiO2-350;Na2O-155;Al2O3-2.1;Fe2O3- 0.3, silicate module-2.33 and density-1.49 g/cm3 has been used. The sodium liquid glass complies with the Russian Interstate standard 13078-81 for sodium liquid glass.10 samples of modified liquid glass were synthesized by introducing modifiers in an amount of 4% by weight of the solution into the liquid glass. Hard quartz material produced by using synthesized modified liquid glass was obtained. It has been established that the obtained modified liquid glass from kaolinite clay can improve the strength of the quartz material for 1.6 - 3.12 times higher than the initial liquid glass. Using liquid glass modifier to the inorganic sodium nitrate (NaNO3) increases the strength 3.12 times.
基金Project supported partially by the National Natural Science Foundation of China (Grant Nos 50831003 and 50871062)New Century Excellent Talent Program of Ministry of Education of China (Grant No NCET-05-0599)+3 种基金the National Basic Research Program of China (Grant No 2007CB613901)the National Science Foundation for Distinguished Young Scholars of China (Grant No 50625101)the Scientific Research Foundation for Returned Overseas Chinese Scholars, Ministry of Education of China (Grant No JIAO WAI SI LIU2007-1108)the National Science Foundation for Distinguished Young Scholars of Shandong Province, China (Grant No JQ200817)
文摘This paper reports that anomalous local order in liquid and glassy A1FeCe alloy has been detected by x-ray diffraction measurements. The addition of the element Ce has a great effect on this local structural order. The element Ce favours interpenetration of the icosahedra by sharing a common face and edges. It argues that frustration between this short-range order and the long-range crystalline order controls the glass-forming ability of these liquids. The obtained results suggest that a system having a stronger tendency to show local icosahedral order should be a better glass-former. This scenario also naturally explains the close relationship between the local icosahedral order in a liquid, glass-forming ability, and the nucleation barrier. Such topological local order has also been analysed directly using the reverse Monte Carlo method. It also estimated the fraction of local ordered and disordered structural units in a glassy AlFeCe alloy.
基金Project supported by the National Natural Science Foundation of China(Grant No.11664042)
文摘A measurement scheme for detecting theαrelaxation time(τ)of glass-forming liquid is proposed,which is based on the measured ionic conductivity of the liquid doped with probing ions by low-and middle-frequency dielectric spectroscopy and according to the Nernst-Einstein,Stokes-Einstein,and Maxwell equations.The obtainedτvalues of glycerol and propylene carbonate by the scheme are consistent with those obtained by traditional dielectric spectroscopy,which confirms its reliability and accuracy.Moreover,theτof 1,2-propanediol in a larger temperature range is compared with existing data.
文摘Uniform crystalline TiO2 thin films were coated on silica glass fibers by liquid phase deposition from aqueous solution of ammonium hexafluorotitanate at low temperature. TiO2 thin films and nanopowders were prepared by adding H3BO3 into （NH4）2TiF6 solution supersaturated with anatase nano-crystalline TiO2 at 40 ℃. The effects of the deposition conditions on the surface morphology, section morphology, thickness of the deposited TiO2 thin films were investigated. The results indicate that the growth rate and particle size of the thin films were controlled by both the deposition conditions and the amount of anatase nano-crystalline TiO2.
基金financially supported by the Fundamental Research Funds for the Central Universities of China(No.A0920502051513-5)
文摘In this work, network former SiO_2 and network intermediate Al_2O_3 were introduced into typical low-melting binary compositions CaO·B_2O_3, CaO·2B_2O_3, and BaO·B_2O_3 via an aqueous solid-state suspension milling route. Accordingly, multiple-phase aluminosilicate glass-ceramics were directly obtained via liquid-phase sintering at temperatures below 950°C. On the basis of liquid-phase sintering theory, mineral-phase evolutions and glass-phase formations were systematically investigated in a wide MO–SiO_2–Al_2O_3–B_2O_3(M = Ca, Ba) composition range. The results indicate that major mineral phases of the aluminosilicate glass-ceramics are Al_(20)B_4O_(36), CaAl_2Si_2O_8, and BaAl_2Si_2O_8 and that the glass-ceramic materials are characterized by dense microstructures and excellent dielectric properties.
文摘The results of the study of raw mix preparation and foam glass-ceramics production using diatomite as a raw material were presented in the following article. A mixture of diatomite and 40% NaOH solution was subjected to heating at a constant temperature of 775 ℃. Samples of foam glass-ceramic from diatomite with an average density of 290-580 kg/m^3, compressive strength of 1.7-7.8 MPa and thermal conductivity of 0.08-0.14 W/（m·K） were obtained. The investigations have shown that the hydrothermal pretreatment of mixture at the temperature of 90 ℃ may lead to the acceleration of the leaching of amorphous SiO_2 from diatomite. It was discovered that the resulting soluble alkali silicates promote the process of foaming during heating and reduce the average density of the obtained samples. The optimal duration of the leaching process was estimated to be 30 minutes, which corresponds to the yield of SiO_2 equal to 42.5% by the weight of dry diatomite.
基金Funded by the Special Funds of the National Natural Science Foundation of China(No.81903579)the Natural Science Basis Research Plan in Shaanxi Province of China(No.2018JM7079)the Cultivating Special Funds of the National Natural Science Foundation of China from Xi’an Medical University(No.2017GJFY12).
文摘Influence of structural variations of N-vinylimidazolium tetrahalogenidoferrate(III) magnetic ionic liquids(MILs) on thermal properties was investigated. Using Gaussian09/B3 PW91/6-311 G(2d, p) density functional methods, the microstructure of the MILs were analyzed. With differential scanning calorimeter(DSC) and thermogravimetric analysis(TGA), the thermal properties of the MILs were performed. The results showed that the interaction energies of ion pairs decreased, the crystallization temperature increased first and then decreased, and the surfusion first decreased and then increased with the elongation of the alkyl chain length on cation;with the increase of Br atom, the interaction energies of ion pairs increased;the interaction energies of ion pairs increased in the MILs with the same cation or anion, the nature of polarity of MILs increased and the melting point rose;as the cation or anion in MILs had a smaller size, it could have the solidsolid transition temperature. The results indicated that the decomposition temperature with the same type of MILs increased with the interaction energies of ion pairs. The interaction energy of ion pairs can be used to illuminate the correlation between the thermal properties and the structure of MILs. ILs possesses the properties of macromolecular.
基金This work was financially supported by the National Natural Science Foundation of China (No.50431030, 50671050)the Basic Science Research Foundation of Tsinghua University (No.091201107)the National Center for Nanoscience and Technology of China.
文摘Pd81Si19 amorphous alloys were prepared by combination methods of melt spinning and B2O3 flux treatment. A compari- son between the ribbons prepared from the fluxed ingots and the non-fluxed ones has been carried out. The result reveals that after fluxing treatment the glass transition temperature of the as-prepared glassy ribbons is reduced while the initial crystallization tem- perature is enhanced. It results in that the supercooled liquid region (defined as the difference between the initial crystallization tem- perature and the glass transition temperature) of the glassy alloy treated with fluxing technology has been increased from 31 to 42 K. This shows that fluxing technique can enhance the glass forming ability (GFA) of the binary alloy and improve the thermal stability of supercooled liquid of the glassy alloy.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11674157 and 11822405)the Fundamental Research Funds for the Central Universities(Grant No.020414380105)
文摘Quantum spin liquids（QSLs） represent a novel state of matter in which quantum fluctuations prevent the conventional magnetic order from being established, and the spins remain disordered even at zero temperature. There have been many theoretical developments proposing various QSL states. On the other hand, experimental movement was relatively slow largely due to limitations on the candidate materials and difficulties in the measurements. In recent years, the experimental progress has been accelerated. In this topical review, we give a brief summary of experiments on the QSL candidates under magnetic fields. We arrange our discussions by two categories： i） Geometrically-frustrated systems, including triangularlattice compounds YbMgGaO4 and YbZnGaO4, κ-（BEDT-TTF）2 Cu2（CN）3, and EtMe3 Sb[Pd（dmit）2]2, and the kagom′e system ZnCu3（OH）6 Cl2; ii） the Kitaev material α-RuCl3. Among these, we will pay special attention to α-RuCl3, which has been intensively studied by ours and other groups recently. We will present evidence that both supports and rejects the QSL ground state for these materials, based on which we give several perspectives to stimulate further research activities.
基金the National Natural Science Foundation of Beijing (No.2042014).
文摘The glass-transition behavior of Pd40Cu30Ni10P20 bulk metallic glass was investigated by differential scanning calorimetry （DSC） and X-ray powder diffraction （XRD）. The effect of pressure on the crystallization behavior of Pd40Cu30Ni10P20 bulk glass was studied by in situ high-pressure and high-temperature X-ray powder diffraction using synchrotron radiation. Phase analyses show at least six crystalline phases in the crystallized sample, namely, monoclinic, tetragonal CuaPd-like, rhombohedral, fcc-Ni2Pd2P, fcc-（Ni, Pd） solid solution, and body-centered tetragonal （bct） NiaP-like phases. The onset crystallization temperature increases with pressure having a slope of 1 1 K/GPa in the range of 0 to 4 GPa. The results are attributed to the competing process between the thermodynamic potential barrier and the diffusion activation energy under pressure.
基金supported by the"100 Talents Project"of Hebei province,China(E2012100009)the Natural Science Foundation of Hebei province,China(E2012202017)the"Development of Self Structural Organizational Origination Type Supercooled Metal Project"by Japan Science and Technology Agency(JST)
文摘Metallic glasses(MG)represent an interesting group of materials as they possess outstanding physical,chemical and mechanical properties compared to their crystalline counterparts.This paper reviews the synergistic influence of Ni and Nb elements on thermal stability of supercooled liquid and corrosion resistance of as-cast Cu-Zr(Hf)-Ti-Ni-Nb bulk metallic glasses(BMGs).Additionally,in-situ second phase reinforced Cu-based BMG composites with high corrosion resistance and excellent mechanical properties are investigated.On the other hand,this paper reports the development of ultra-high corrosion resistant Ni-based metallic glasses at high temperatures for their potential applications.Corrosion resistance and XPS analysis of the Nifree Ti-based BMG are also introduced.
