Porous materials have promise as sound insulation, heat barrier, vibration attenuation, and catalysts. Most industrial solid wastes, such as tailings, coal gangue, and fly ash are rich in silicon. Additionally, a high...Porous materials have promise as sound insulation, heat barrier, vibration attenuation, and catalysts. Most industrial solid wastes, such as tailings, coal gangue, and fly ash are rich in silicon. Additionally, a high silicon content waste is a potential raw material for the syn- thesis of silicon-based, multi-porous materials such as zeolites, mesoporous silica, glass-ceramics, and geopolymer foams. Representative sil- icon-rich industrial solid wastes (SRISWs) are the focus of this mini review of the processing and application of porous silicon materials with respect to the physical and chemical properties of the SRISW. The transformation methods of preparing porous materials from SRISWs are summarized, and their research status in micro-, meso-, and macro-scale porous materials are described. Possible problems in the application of SRISWs and in the preparation of functional porous materials are analyzed, and their development prospects are discussed. This review should provide a typical reference for the recycling and use of industrial solid wastes to develop sustainable “green materials.”展开更多
The separation of Al from the silicon-rich diasporic bauxite is of great significance in alumina production.Herein,we proposed a low-temperature ammonium sulfate roasting-water leaching process to extract aluminum fro...The separation of Al from the silicon-rich diasporic bauxite is of great significance in alumina production.Herein,we proposed a low-temperature ammonium sulfate roasting-water leaching process to extract aluminum from silicon-rich diasporic bauxite.Parameters including roasting temperature,dosage of ammonium sulfate,roasting time,and particle size of ore were investigated.Under the condition of roasting temperature of 400℃,roasting time of 5 h,ammonium sulfate dosage of 2.5 times of the theoretical value and ore particle size of 80−96μm,more than 98%leaching rate of aluminum was obtained.The phase transformation and mechanism during the roasting process were revealed by using X-ray diffraction,thermogravimetric analysis,differential thermal analysis,and scanning electron microscope methods.The diaspore and kaolinite phases in the silicon-rich diasporic bauxite could react with ammonium sulfate to form corresponding sulfates(NH_(4))_(3)Al(SO_(4))_(3) Al(SO_(4))_(2) and Al_(2)(SO_(4))_(3).The proposed technology could provide an effective method for the direct and separation of aluminum from silicon-rich diasporic bauxite.展开更多
The silicon-rich silica films were prepared by a dual-ion-beam co-sputtering method from a composite Target in an argon atmosphere. The structure of the films studied by the aid of TEM and XRD is amorphous. The photol...The silicon-rich silica films were prepared by a dual-ion-beam co-sputtering method from a composite Target in an argon atmosphere. The structure of the films studied by the aid of TEM and XRD is amorphous. The photoluminescence (PL) spectra were found to have a 4- luminescent band peak at 320 nm, 410 nm, 560 nm, and 630 nm, respectively, at room temperature. The intensity and the wavelength position of PL are dependent on annealing temperature (Ta), and the luminescent mechanism is analyzed.展开更多
CMOS platforms with a high nonlinear figure of merit are highly sought after for high photonic quantum efficiencies, enabling functionalities not possible from purely linear effects and ease of integration with CMOS e...CMOS platforms with a high nonlinear figure of merit are highly sought after for high photonic quantum efficiencies, enabling functionalities not possible from purely linear effects and ease of integration with CMOS electronics. Silicon-based platforms have been prolific amongst the suite of advanced nonlinear optical signal processes demonstrated to date. These include crystalline silicon, amorphous silicon, Hydex glass, and stoichio- metric silicon nitride. Residing between stoichiometric silicon nitride and amorphous silicon in composition, silicon-rich nitride films of various formulations have emerged recently as promising nonlinear platforms for high nonlinear figure of merit nonlinear optics. Silicon-rich nitride films are compositionally engineered to create bandgaps that are sufficiently large to eliminate two-photon absorption at telecommunications wavelengths while enabling much larger nonlinear waveguide parameters （5x-500x） than those in stoichiometric silicon uitride. This paper reviews recent developments in the field of nonlinear optics using silicon-rich nitride platforms, as well as the outlook and future opportunities in this burgeoning field.展开更多
Dispersion engineering in optical waveguides allows applications relying on the precise control of phase matching conditions to be implemented. Although extremely effective over relatively narrow band spectral regions...Dispersion engineering in optical waveguides allows applications relying on the precise control of phase matching conditions to be implemented. Although extremely effective over relatively narrow band spectral regions,dispersion control becomes increasingly challenging as the bandwidth of the process of interest increases.Phase matching can also be achieved by exploiting the propagation characteristics of waves exciting different spatial modes of the same waveguide. Phase matching control in this case relies on achieving very similar propagation characteristics across two, and even more, waveguide modes over the wavelengths of interest, which may be rather far from one another. We demonstrate here that broadband(>40 nm) four-wave mixing can be achieved between pump waves and a signal located in different bands of the communications spectrum(separated by50 nm) by exploiting interband nonlinearities. Our demonstration is carried out in the silicon-rich silicon nitride material platform, which allows flexible device engineering, allowing for strong effective nonlinearity at telecommunications wavelengths without deleterious nonlinear-loss effects.展开更多
基金National Natural Science Foundation of China(No.51774331)Funds for Nationsl&Local Joint Engineering Research Center of Mineral Salt Deep Utilization(No.SF202103).
文摘Porous materials have promise as sound insulation, heat barrier, vibration attenuation, and catalysts. Most industrial solid wastes, such as tailings, coal gangue, and fly ash are rich in silicon. Additionally, a high silicon content waste is a potential raw material for the syn- thesis of silicon-based, multi-porous materials such as zeolites, mesoporous silica, glass-ceramics, and geopolymer foams. Representative sil- icon-rich industrial solid wastes (SRISWs) are the focus of this mini review of the processing and application of porous silicon materials with respect to the physical and chemical properties of the SRISW. The transformation methods of preparing porous materials from SRISWs are summarized, and their research status in micro-, meso-, and macro-scale porous materials are described. Possible problems in the application of SRISWs and in the preparation of functional porous materials are analyzed, and their development prospects are discussed. This review should provide a typical reference for the recycling and use of industrial solid wastes to develop sustainable “green materials.”
基金Projects(N 182304020,N 172304045)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(E 2017501073)supported by the Hebei Province Natural Science Fund,ChinaProject(2019 CDXYCL 0031)supported by the New Materials and New Metallurgical Technology Frontier Scientific and Technological Innovation,China。
文摘The separation of Al from the silicon-rich diasporic bauxite is of great significance in alumina production.Herein,we proposed a low-temperature ammonium sulfate roasting-water leaching process to extract aluminum from silicon-rich diasporic bauxite.Parameters including roasting temperature,dosage of ammonium sulfate,roasting time,and particle size of ore were investigated.Under the condition of roasting temperature of 400℃,roasting time of 5 h,ammonium sulfate dosage of 2.5 times of the theoretical value and ore particle size of 80−96μm,more than 98%leaching rate of aluminum was obtained.The phase transformation and mechanism during the roasting process were revealed by using X-ray diffraction,thermogravimetric analysis,differential thermal analysis,and scanning electron microscope methods.The diaspore and kaolinite phases in the silicon-rich diasporic bauxite could react with ammonium sulfate to form corresponding sulfates(NH_(4))_(3)Al(SO_(4))_(3) Al(SO_(4))_(2) and Al_(2)(SO_(4))_(3).The proposed technology could provide an effective method for the direct and separation of aluminum from silicon-rich diasporic bauxite.
文摘The silicon-rich silica films were prepared by a dual-ion-beam co-sputtering method from a composite Target in an argon atmosphere. The structure of the films studied by the aid of TEM and XRD is amorphous. The photoluminescence (PL) spectra were found to have a 4- luminescent band peak at 320 nm, 410 nm, 560 nm, and 630 nm, respectively, at room temperature. The intensity and the wavelength position of PL are dependent on annealing temperature (Ta), and the luminescent mechanism is analyzed.
基金MOE Academic Research Fund Tier 2 GrantNational Research Foundation Competitive Research Grant+3 种基金National Research Foundation Land and Liveability National Innovation Challenge GrantSUTD-MIT International Design CenterTemasek Laboratories grantNational Research Foundation,Prime Minister’s Office,Singapore,under its Medium Sized Centre Program
文摘CMOS platforms with a high nonlinear figure of merit are highly sought after for high photonic quantum efficiencies, enabling functionalities not possible from purely linear effects and ease of integration with CMOS electronics. Silicon-based platforms have been prolific amongst the suite of advanced nonlinear optical signal processes demonstrated to date. These include crystalline silicon, amorphous silicon, Hydex glass, and stoichio- metric silicon nitride. Residing between stoichiometric silicon nitride and amorphous silicon in composition, silicon-rich nitride films of various formulations have emerged recently as promising nonlinear platforms for high nonlinear figure of merit nonlinear optics. Silicon-rich nitride films are compositionally engineered to create bandgaps that are sufficiently large to eliminate two-photon absorption at telecommunications wavelengths while enabling much larger nonlinear waveguide parameters （5x-500x） than those in stoichiometric silicon uitride. This paper reviews recent developments in the field of nonlinear optics using silicon-rich nitride platforms, as well as the outlook and future opportunities in this burgeoning field.
基金Engineering and Physical Sciences Research Council(EPSRC)(EP/L00044X/1)
文摘Dispersion engineering in optical waveguides allows applications relying on the precise control of phase matching conditions to be implemented. Although extremely effective over relatively narrow band spectral regions,dispersion control becomes increasingly challenging as the bandwidth of the process of interest increases.Phase matching can also be achieved by exploiting the propagation characteristics of waves exciting different spatial modes of the same waveguide. Phase matching control in this case relies on achieving very similar propagation characteristics across two, and even more, waveguide modes over the wavelengths of interest, which may be rather far from one another. We demonstrate here that broadband(>40 nm) four-wave mixing can be achieved between pump waves and a signal located in different bands of the communications spectrum(separated by50 nm) by exploiting interband nonlinearities. Our demonstration is carried out in the silicon-rich silicon nitride material platform, which allows flexible device engineering, allowing for strong effective nonlinearity at telecommunications wavelengths without deleterious nonlinear-loss effects.
