Based on the analyses of the lining technologies of the hot press formed carbon brick iu U.S.A., of the ce-ramic cup in France and of the creative self-baking car-bon brick in China,the technology of semi-graphitized...Based on the analyses of the lining technologies of the hot press formed carbon brick iu U.S.A., of the ce-ramic cup in France and of the creative self-baking car-bon brick in China,the technology of semi-graphitized car-bon block-ceramic brickwork has been studied and developed ,and has successfully ben used in No.7 blast furnace (2580m^3) at Anshan Irom and Steel Company and in No.3 blast furnace (1200m^3) at Taiyuan Iron and Steel Company,This paper puts fourward a feasible scheme for realization of long service lives of the bootms and the hearths of large-sized blast furaces in China.展开更多
The electrical characteristics of graphene Schottky contacts formed on undoped GaN semiconductors were investigated. Excellent rectifying behavior with a rectification ratio of -10^7 at ±2 V and a low reverse lea...The electrical characteristics of graphene Schottky contacts formed on undoped GaN semiconductors were investigated. Excellent rectifying behavior with a rectification ratio of -10^7 at ±2 V and a low reverse leakage current of 1.0 × 10^-8 A/cm^2 at -5 V were observed. The Schottky barrier heights, as determined by the thermionic emission model Richardson plots, and barrier inhomogeneity model, were 0.90, 0.72, and 1.24 ± 0.13 eV, respectively. Despite the predicted low barrier height of -0.4 eV at the graphene-GaN interface, the formation of excellent rectifying characteristics with much larger barrier heights is attributed to the presence of a large number of surface states （1.2 x 1013 states/cm2/eV） and the internal spontaneous polarization field of GaN, resulted in a significant upward surface band bending or a bare surface barrier height as high as of 2.9 eV. Using the S parameter of 0.48 （measured from the work function dependence of Schottky barrier height） and the mean barrier height of 1.24 eV, the work function of graphene in the Au/graphene/GaN stack could be approximately estimated to be as low as 3.5 eV. The obtained results indicate that graphene is a promising candidate for use as a Schottky rectifier in GaN semiconductors with n-type conductivity.展开更多
Semiconductor nanomaterials with photocatalytic activity have potential for many applications. An effective way of promoting photocatalytic activity is depositing noble metal nanoparticles （NPs） on a semiconductor, ...Semiconductor nanomaterials with photocatalytic activity have potential for many applications. An effective way of promoting photocatalytic activity is depositing noble metal nanoparticles （NPs） on a semiconductor, since the noble metal NPs act as excellent electron acceptors which inhibit the quick recombination of the photoexcited electron-hole pairs and thereby enhance the generation of reactive oxygen species （ROS）. Herein, a highly effective platform, graphitic carbon nitride （g-C3N4） nanosheets with embedded Ag nanopartides （Ag/g-C3N4）, was synthesized by a facile route. Under visible light irradiation, the ROS production of Ag/g-C3N4 nanohybrids was greatly improved compared with pristine g-C3N4 nanosheets, and moreover, the nanohybrids showed enhanced antibacterial efficacy and ability to disperse bacterial biofilms. We demonstrate for the first time that the Ag/g-C3N4 nanohybrids are efficient bactericidal agents under visible light irradiation, and can also provide a new way for biofilm elimination. The enhanced antibacterial properties and biofilm-disrupting ability of Ag/g-C3N4 nanohybrids may offer many biomedical applications.展开更多
文摘Based on the analyses of the lining technologies of the hot press formed carbon brick iu U.S.A., of the ce-ramic cup in France and of the creative self-baking car-bon brick in China,the technology of semi-graphitized car-bon block-ceramic brickwork has been studied and developed ,and has successfully ben used in No.7 blast furnace (2580m^3) at Anshan Irom and Steel Company and in No.3 blast furnace (1200m^3) at Taiyuan Iron and Steel Company,This paper puts fourward a feasible scheme for realization of long service lives of the bootms and the hearths of large-sized blast furaces in China.
文摘The electrical characteristics of graphene Schottky contacts formed on undoped GaN semiconductors were investigated. Excellent rectifying behavior with a rectification ratio of -10^7 at ±2 V and a low reverse leakage current of 1.0 × 10^-8 A/cm^2 at -5 V were observed. The Schottky barrier heights, as determined by the thermionic emission model Richardson plots, and barrier inhomogeneity model, were 0.90, 0.72, and 1.24 ± 0.13 eV, respectively. Despite the predicted low barrier height of -0.4 eV at the graphene-GaN interface, the formation of excellent rectifying characteristics with much larger barrier heights is attributed to the presence of a large number of surface states （1.2 x 1013 states/cm2/eV） and the internal spontaneous polarization field of GaN, resulted in a significant upward surface band bending or a bare surface barrier height as high as of 2.9 eV. Using the S parameter of 0.48 （measured from the work function dependence of Schottky barrier height） and the mean barrier height of 1.24 eV, the work function of graphene in the Au/graphene/GaN stack could be approximately estimated to be as low as 3.5 eV. The obtained results indicate that graphene is a promising candidate for use as a Schottky rectifier in GaN semiconductors with n-type conductivity.
基金This work was supported by the National Basic Research Program of China （Nos. 2011CB936004 and 2012CB720602） and the National Natural Science Foundation of China （Nos. 21210002, 21431007, 91413111, 21402183）.
文摘Semiconductor nanomaterials with photocatalytic activity have potential for many applications. An effective way of promoting photocatalytic activity is depositing noble metal nanoparticles （NPs） on a semiconductor, since the noble metal NPs act as excellent electron acceptors which inhibit the quick recombination of the photoexcited electron-hole pairs and thereby enhance the generation of reactive oxygen species （ROS）. Herein, a highly effective platform, graphitic carbon nitride （g-C3N4） nanosheets with embedded Ag nanopartides （Ag/g-C3N4）, was synthesized by a facile route. Under visible light irradiation, the ROS production of Ag/g-C3N4 nanohybrids was greatly improved compared with pristine g-C3N4 nanosheets, and moreover, the nanohybrids showed enhanced antibacterial efficacy and ability to disperse bacterial biofilms. We demonstrate for the first time that the Ag/g-C3N4 nanohybrids are efficient bactericidal agents under visible light irradiation, and can also provide a new way for biofilm elimination. The enhanced antibacterial properties and biofilm-disrupting ability of Ag/g-C3N4 nanohybrids may offer many biomedical applications.
