Bi2O3-ZnO-B2O3 system glass is a kind of lead-free low melting sealing glasses. The structure of Bi2O3-ZnO-B2O3 system low-melting sealing glass was investigated by DSC, FT-IR, XRD and SEM. The results show that with ...Bi2O3-ZnO-B2O3 system glass is a kind of lead-free low melting sealing glasses. The structure of Bi2O3-ZnO-B2O3 system low-melting sealing glass was investigated by DSC, FT-IR, XRD and SEM. The results show that with the increase of B2O3 content, the transition temperature Tg and softening temperature Tf of Bi2O3-ZnO-B2O3 system low-melting sealing glasses increase, which leads to the liquid phase precipitation temperature increasing and promotes the structure stability in the glass. With increasing the heat treatment temperature, a large number of liquid phases appear in samples and the sinter efficiency of the samples increases. The FT-IR spectra of the glasses show the presence of some bands that are assigned to vibrations of Bi--O bond from [BO3] pyramidal and [BiO6] octahedral units and B--O from [BO3] and [BO4] units. With the decrease of B203 content, the crystallization tendency of the glass increases. In glass samples Bl and B〉 crystallization starts at 460 ℃ and 540 ℃, respectively. Both of them precipitate Bi24B2O39 phases.展开更多
Tensile impact experiments of EC8.0-24×7 glass fiber bundles atdifferent low tempera- tures T(14 deg. C, -40 deg. C and -100 deg. C)and strain rates ε were carried out, and complete stres-straincurves were obtai...Tensile impact experiments of EC8.0-24×7 glass fiber bundles atdifferent low tempera- tures T(14 deg. C, -40 deg. C and -100 deg. C)and strain rates ε were carried out, and complete stres-straincurves were obtained. Within the range of the experiment temperaturesand strain rates, it is found that the initial modulus E, theultimate strength σ_max and the unstable strain ε_b of the glassfiber bundles all increase with ε at an identical T. At an identicalε, with the decrease of T, E and σ_max increase; but ε_b increaseswhen 14 deg. C >T>-40 deg. C and decreases when -40 deg. C>T>-100deg. C.展开更多
A kind of neat asphalt and three kinds of diatomite asphalt are tested using differential scanning calorimetry（DSC）. The anti-cracking mechanism of diatomite asphalt is analyzed by DSC and the thermal stress restrai...A kind of neat asphalt and three kinds of diatomite asphalt are tested using differential scanning calorimetry（DSC）. The anti-cracking mechanism of diatomite asphalt is analyzed by DSC and the thermal stress restrained specimen test（TSRST） of the asphalt mixtures. The results show that the low temperature performance of diatomite asphalt is better than that of neat asphalt. The glass transition temperature can reflect the low temperature performance of the diatomite asphalt better and has a good relationship with breaking temperatures. Besides, the TSRST, the bending test, the compressing test and the contraction coefficient test are used to study the low temperature performance of the diatomite asphalt mixture. The results prove that the low temperature performance of the diatomite asphalt mixture is better than that of the neat asphalt mixture. The critical bending strain energy density and the compressing strain energy density of the diatomite asphalt mixture are greater than those of the neat asphalt mixture. After adding diatomite to the asphalt mixture, the contraction coefficient is reduced. Based on the above results, the anti-cracking mechanism of the diatomite asphalt mixture is analyzed from the angle of contraction performance and breaking energy.展开更多
Owing to adjustable thermal expansion performance, BaO–CaO–Al_2O_3–B_2O_3–SiO_2(BCABS) glass has a promising commercialization prospect for intermediate temperature-solid oxide fuel cells(IT-SOFCs) sealing. Herein...Owing to adjustable thermal expansion performance, BaO–CaO–Al_2O_3–B_2O_3–SiO_2(BCABS) glass has a promising commercialization prospect for intermediate temperature-solid oxide fuel cells(IT-SOFCs) sealing. Herein, Al_2O_3 with two different contents was added into the same glass formulation, referred to as A and B glass, respectively. In terms of the non-isothermal crystallization kinetic behavior, the effect of Al_2O_3 as the unique intermediate was innovatively studied on the long-term performance of BCABS sealing glass. After the heat treatment at 1023 K for 100 h, the change of the network structure and the expansion coefficient of the glass were characterized. The results showed that the addition of Al_2O_3 as a network forming body could enhance the structure of glass, and increase the activation energy for glass transition, which could effectively inhibit the crystallization ability of sealing glass. Therefore, the B glass with the higher Al_2O_3 content showed the better long-term sealing ability, which was greatly beneficial for IT-SOFCs sealing.展开更多
Highly c-axis-oriented GaN films were deposited on Ti coated glass substrates using low temperature electron cyclotron resonance plasma enhanced metal organic chemical vapor deposition system(ECR-PEMOCVD)with trimethy...Highly c-axis-oriented GaN films were deposited on Ti coated glass substrates using low temperature electron cyclotron resonance plasma enhanced metal organic chemical vapor deposition system(ECR-PEMOCVD)with trimethyl gallium(TMGa)as gallium source.The influence of TMGa flux on the properties of GaN films were systematically investigated by reflection high energy electron diffraction(RHEED),X-ray diffraction analysis(XRD),atomic force microscopy(AFM)and Raman scattering.The GaN film with small surface roughness and high c-axis preferred orientation was successfully achieved at the optimized TMGa flux of 1.0 sccm.The ohmic contact characteristic between GaN and Ti layer was clearly demonstrated by the near-linear current-voltage(I-V)curve.The GaN/Ti/glass structure has great potential to dramatically improve the scalability and reduce the cost of solid-state lighting light emitting diodes.展开更多
Effects of Zn/P ratio on the structures and properties of glasses with the general composition of （80-x）ZnO-20Fe2O3-xP2O5 （x=40, 45, 50, 55, 60） （molar fraction, %） were investigated. Glass structure was measure...Effects of Zn/P ratio on the structures and properties of glasses with the general composition of （80-x）ZnO-20Fe2O3-xP2O5 （x=40, 45, 50, 55, 60） （molar fraction, %） were investigated. Glass structure was measured by infrared absorption spectrum. Glass density （/9） was measured by the Archimedes method. Coefficients of thermal expansion （a） and characterization temperature were obtained by a dilatometer. Water durability of each glass was estimated from the dissolution rate （DR）in water at 90 ℃ for 24 h. With increasing Zn/P ratio, water durability of zinc-iron phosphate glasses increases dramatically without large increase in the characterization temperature. （80-x）ZnO-20Fe2O3-xP2O5 glasses with 0.3≤Zn/P≤0.5 are suit for low-to-mid temperature sealing application for substrates with a〈8.0× 10^-6℃^-1.展开更多
Different heating treatments with the variation of heating rates,holding temperatures and holding time were used to simulate the LTPS procedure.The experimental results show that the reheating shrinkage rates of glass...Different heating treatments with the variation of heating rates,holding temperatures and holding time were used to simulate the LTPS procedure.The experimental results show that the reheating shrinkage rates of glass substrates are rarely changed with increasing the heating rate,but strongly enhanced by raising the holding temperature and time,which shows that the reheating shrinkage of glass is closely related to heat treatment and structural relaxation.The production process of glass is critical to the reheating shrinkage of glass.展开更多
基金Project(50272043) supported by the National Natural Science Foundation of China
文摘Bi2O3-ZnO-B2O3 system glass is a kind of lead-free low melting sealing glasses. The structure of Bi2O3-ZnO-B2O3 system low-melting sealing glass was investigated by DSC, FT-IR, XRD and SEM. The results show that with the increase of B2O3 content, the transition temperature Tg and softening temperature Tf of Bi2O3-ZnO-B2O3 system low-melting sealing glasses increase, which leads to the liquid phase precipitation temperature increasing and promotes the structure stability in the glass. With increasing the heat treatment temperature, a large number of liquid phases appear in samples and the sinter efficiency of the samples increases. The FT-IR spectra of the glasses show the presence of some bands that are assigned to vibrations of Bi--O bond from [BO3] pyramidal and [BiO6] octahedral units and B--O from [BO3] and [BO4] units. With the decrease of B203 content, the crystallization tendency of the glass increases. In glass samples Bl and B〉 crystallization starts at 460 ℃ and 540 ℃, respectively. Both of them precipitate Bi24B2O39 phases.
基金the National Natural Science Foundation of China(No.19772058)
文摘Tensile impact experiments of EC8.0-24×7 glass fiber bundles atdifferent low tempera- tures T(14 deg. C, -40 deg. C and -100 deg. C)and strain rates ε were carried out, and complete stres-straincurves were obtained. Within the range of the experiment temperaturesand strain rates, it is found that the initial modulus E, theultimate strength σ_max and the unstable strain ε_b of the glassfiber bundles all increase with ε at an identical T. At an identicalε, with the decrease of T, E and σ_max increase; but ε_b increaseswhen 14 deg. C >T>-40 deg. C and decreases when -40 deg. C>T>-100deg. C.
基金The National Natural Science Foundation of China(No.50778057)
文摘A kind of neat asphalt and three kinds of diatomite asphalt are tested using differential scanning calorimetry（DSC）. The anti-cracking mechanism of diatomite asphalt is analyzed by DSC and the thermal stress restrained specimen test（TSRST） of the asphalt mixtures. The results show that the low temperature performance of diatomite asphalt is better than that of neat asphalt. The glass transition temperature can reflect the low temperature performance of the diatomite asphalt better and has a good relationship with breaking temperatures. Besides, the TSRST, the bending test, the compressing test and the contraction coefficient test are used to study the low temperature performance of the diatomite asphalt mixture. The results prove that the low temperature performance of the diatomite asphalt mixture is better than that of the neat asphalt mixture. The critical bending strain energy density and the compressing strain energy density of the diatomite asphalt mixture are greater than those of the neat asphalt mixture. After adding diatomite to the asphalt mixture, the contraction coefficient is reduced. Based on the above results, the anti-cracking mechanism of the diatomite asphalt mixture is analyzed from the angle of contraction performance and breaking energy.
基金financially supported by the research project of National Natural Science Foundation of China (Grant Nos.51662015 and 51462011)
文摘Owing to adjustable thermal expansion performance, BaO–CaO–Al_2O_3–B_2O_3–SiO_2(BCABS) glass has a promising commercialization prospect for intermediate temperature-solid oxide fuel cells(IT-SOFCs) sealing. Herein, Al_2O_3 with two different contents was added into the same glass formulation, referred to as A and B glass, respectively. In terms of the non-isothermal crystallization kinetic behavior, the effect of Al_2O_3 as the unique intermediate was innovatively studied on the long-term performance of BCABS sealing glass. After the heat treatment at 1023 K for 100 h, the change of the network structure and the expansion coefficient of the glass were characterized. The results showed that the addition of Al_2O_3 as a network forming body could enhance the structure of glass, and increase the activation energy for glass transition, which could effectively inhibit the crystallization ability of sealing glass. Therefore, the B glass with the higher Al_2O_3 content showed the better long-term sealing ability, which was greatly beneficial for IT-SOFCs sealing.
基金supported by the Opening Project of Key Laboratory of Inorganic Coating Materials,Chinese Academy of Sciences(KLICM2012-01)the Fundamental Research Funds for the Central Universities(DUT13LK02,DUT13JN08)
文摘Highly c-axis-oriented GaN films were deposited on Ti coated glass substrates using low temperature electron cyclotron resonance plasma enhanced metal organic chemical vapor deposition system(ECR-PEMOCVD)with trimethyl gallium(TMGa)as gallium source.The influence of TMGa flux on the properties of GaN films were systematically investigated by reflection high energy electron diffraction(RHEED),X-ray diffraction analysis(XRD),atomic force microscopy(AFM)and Raman scattering.The GaN film with small surface roughness and high c-axis preferred orientation was successfully achieved at the optimized TMGa flux of 1.0 sccm.The ohmic contact characteristic between GaN and Ti layer was clearly demonstrated by the near-linear current-voltage(I-V)curve.The GaN/Ti/glass structure has great potential to dramatically improve the scalability and reduce the cost of solid-state lighting light emitting diodes.
基金Project(7602110340) supported by the Postdoctoral Science Foundation of Central South University, ChinaProject(721500277)supported by the Fundamental Research Funds for the Central Universities of China
文摘Effects of Zn/P ratio on the structures and properties of glasses with the general composition of （80-x）ZnO-20Fe2O3-xP2O5 （x=40, 45, 50, 55, 60） （molar fraction, %） were investigated. Glass structure was measured by infrared absorption spectrum. Glass density （/9） was measured by the Archimedes method. Coefficients of thermal expansion （a） and characterization temperature were obtained by a dilatometer. Water durability of each glass was estimated from the dissolution rate （DR）in water at 90 ℃ for 24 h. With increasing Zn/P ratio, water durability of zinc-iron phosphate glasses increases dramatically without large increase in the characterization temperature. （80-x）ZnO-20Fe2O3-xP2O5 glasses with 0.3≤Zn/P≤0.5 are suit for low-to-mid temperature sealing application for substrates with a〈8.0× 10^-6℃^-1.
基金Funded by the National Key R&D Program of China(2017YFB0310201-04)。
文摘Different heating treatments with the variation of heating rates,holding temperatures and holding time were used to simulate the LTPS procedure.The experimental results show that the reheating shrinkage rates of glass substrates are rarely changed with increasing the heating rate,but strongly enhanced by raising the holding temperature and time,which shows that the reheating shrinkage of glass is closely related to heat treatment and structural relaxation.The production process of glass is critical to the reheating shrinkage of glass.
