Two-dimensional(2D)nitride MXenes are predicted to exhibit exceptional metallic properties and high polarity;however,their synthesis remains challenging.Research has relied on traditional molten salt etching,highlight...Two-dimensional(2D)nitride MXenes are predicted to exhibit exceptional metallic properties and high polarity;however,their synthesis remains challenging.Research has relied on traditional molten salt etching,highlighting the need for a scalable,high-purity approach.Here,we present the first solution-based synthesis of Ti_(4)N_(3)T_(x)MXene via a novel saturated salt solution(S^(3))etching technique employing alkali metal salts.By optimizing the sintering process for high-purity Ti_(4)AlN_(3)MAX and refining the S^(3)etching route,we significantly reduced the etch pit density to 1.2×10^(6)cm^(-2)and lowered the etch pit formation rate to 4%,yielding high-quality,phasepure Ti_(4)N_(3)T_(x)MXene.Our study highlights the critical role of alkali metal ions in selective A-layer removal and demonstrates the impressive electrical conductivity and electromagnetic interference shielding performance of 2D nitride MXene,setting a new benchmark for this underexplored material.These findings pave the way for advancing 2D nitride MXenes and their diverse applications.展开更多
Abstract A method of Baotou mixed rare earth concen- trate leaching was investigated. According to the principle of complex leaching, the quadratic orthogonal regression experiment was used to investigate effect of si...Abstract A method of Baotou mixed rare earth concen- trate leaching was investigated. According to the principle of complex leaching, the quadratic orthogonal regression experiment was used to investigate effect of six factors. An optimal condition of low energy and environment friendly was determined as follows： HCl acidity is 4 mol.L-1, AlCl3 concentration is 2 mol.L-l, reaction temperature is 85 ℃, reaction time is 90 rain, liquid to solid ratio is 35 ml.g-1, and stirring speed is 100 r.min-1. According to this condition, the leaching ratio of mixed rare earth con- centrate is 76.5 %. The analyses of X-ray diffraction shows that bastnasite disappears, and the main peaks of filter residue is monazite and cheralite after leaching of HCl- AlCl3 solution. The result indicates that REFCO3 of the mixed rare earth concentrate can be dissolved, but REPO4 remains in the leaching residue. This method provides a way to separate and extract rare earth.展开更多
This paper demonstrated our discovery of the movement effect of BiFeO_3 nanoparticles in solution by strong electrical polarization. First, BiFeO_3 nanoparticles were prepared by ball milling and characterized by SEM....This paper demonstrated our discovery of the movement effect of BiFeO_3 nanoparticles in solution by strong electrical polarization. First, BiFeO_3 nanoparticles were prepared by ball milling and characterized by SEM. Then, the preparation of BiFeO_3 solution was finished. BiFeO_3 nanoparticles are found to move in solution due to electrical field. The movement velocity of BiFeO_3 nanoparticles, which is about 10 μm·s^-1 , is influenced and controlled by the applied electrical field. The concentration of BiFeO_3 solution and the nanoparticle sizes also have effects on its movement properties. The movement of BiFeO_3 nanoparticles in solution is induced by strong polarization, and BiFeO_3 nanoparticles have net negative electric charges because of the electrostatic force between BiFeO_3 nanoparticles and the negative ions in water resolver.展开更多
All-inorganic cesium lead halide perovskites （CsPbX3, X=CF, Br-, I-） could provide comparableoptoelectronic properties as a promising class of materials for photovoltaic cell （PV）, photodetector andlight-emitting ...All-inorganic cesium lead halide perovskites （CsPbX3, X=CF, Br-, I-） could provide comparableoptoelectronic properties as a promising class of materials for photovoltaic cell （PV）, photodetector andlight-emitting diode （LED） with enhanced thermal and moisture stabilities compared to organic-inorganic lead halide species. However, fabrication of CsPbI3 perovskite via facile solution process hasbeen difficult due to instability of CsPbl3 in the perovskite cubic phase in ambient air. Herein, we reportthe synthesis of CsPbl3 perovskite microcrystals by low-temperature, catalyst-free, solution-phasemethod. By applying the time-resolve spectroscopic technique, we determine the carrier diffusioncoefficient of 0.6-1.2 cm2/s, the intrinsic carrier lifetimes of 200-1300 ns and diffusion length of4-10 μm in different individual CsPbl3 perovskite microcrystals. Our results suggest the CsPbl3 perovskitemicrocrystals synthesized by solution process exhibit high quality feature and are suitable forapplications in optoelectronic devices.展开更多
In this paper,effect of two strategies on afterglow behavior of Lu_(2)O_(3):Eu single crystal scintillato r,Pr^(3+)codoping and solid solution with Sc_(2)O_(3),were studied systematically.Two groups of Lu_(2)O_(3):5 a...In this paper,effect of two strategies on afterglow behavior of Lu_(2)O_(3):Eu single crystal scintillato r,Pr^(3+)codoping and solid solution with Sc_(2)O_(3),were studied systematically.Two groups of Lu_(2)O_(3):5 at%Eu,x at%Pr(x=0,0.2,0.5,1,2 and 5)and(Lu1-yScy)_(2)O_(3):5 at%Eu(y=0,20 at%,50 at%and 70 at%)single crystals were grown by floating zone(FZ)method in air atmosphere.The structures of as-grown crystals were determined by X-ray diffraction(XRD).The scintillation,photoluminescence properties and carrier trap states were investigated through afterglow,X-ray excitation luminescence(XEL),transmittance,photoluminescence excitation(PLE)and photoluminescence(PL),PL decay and thermal stimulated luminescence(TSL)curves.It is found that with the increase of Pr^(3+)concentration,the afterglow level of the system decreases at the expense of scintillation luminescence efficiency.Meanwhile,although Sc_(2)O_(3):Eu presents much lower afterglow intensity than Lu_(2)O_(3):Eu,the addition of Sc_(2)O_(3)will just increase the afterglow level of the(Lu1-yScy)_(2)O_(3):5 at%Eu single crystal system.Possible mechanisms for above phenomena are discussed based on experimental results.展开更多
The corrosion behavior of Cu-Cr alloy in 3.5%NaCl+NH3 solution had been studied, and the influences of the concentration of NH3 on corrosion resistance discussed by means of Metallograph, XRD, SEM and electrochemical ...The corrosion behavior of Cu-Cr alloy in 3.5%NaCl+NH3 solution had been studied, and the influences of the concentration of NH3 on corrosion resistance discussed by means of Metallograph, XRD, SEM and electrochemical method. The results show that the Cu is easier to corrosion than Cr, and the corrosion rate increases with the increasing of the concentration of NH3, and deformation worsen the corrosion resistance of the alloy in such corrosive environment.展开更多
As new generation mobile networks, 3G networks focus on data services and integrate voice, data and multimedia services. However, traditional Optical Transport Networks (OTNs) cannot meet the requirements of 3G networ...As new generation mobile networks, 3G networks focus on data services and integrate voice, data and multimedia services. However, traditional Optical Transport Networks (OTNs) cannot meet the requirements of 3G networks anymore, because of their complicated configuration, low bandwidth efficiency, high cost, and bad network and service scalability. The emerging of Multi-Service Transport Platform (MSTP), Wavelength Division Multiplexing (WDM), and Automatically Switched Optical Network (ASON) technologies for optical fiber communications makes up for these weaknesses. The leading solution to 3G access transport networks is the MSTP technology based on Synchronous Digital Hierarchy (SDH), while that to 3G core transport network is ASON+WDM.展开更多
The problem of nonlinear forced oscillations for elliptical sandwich plates is dealt with. Based on the governing equations expressed in terms of five displacement components, the nonlinear dynamic equation of an elli...The problem of nonlinear forced oscillations for elliptical sandwich plates is dealt with. Based on the governing equations expressed in terms of five displacement components, the nonlinear dynamic equation of an elliptical sandwich plate under a harmonic force is derived. A superpositive-iterative harmonic balance (SIHB) method is presented for the steady-state analysis of strongly nonlinear oscillators. In a periodic oscillation, the periodic solutions can be expressed in the form of basic harmonics and bifurcate harmonics. Thus, an oscillation system which is described as a second order ordinary differential equation, can be expressed as fundamental differential equation with fundamental harmonics and incremental differential equation with derived harmonics. The 1/3 subharmonic solution of an elliptical sandwich plate is investigated by using the methods of SIHB. The SIHB method is compared with the numerical integration method. Finally, asymptotical stability of the 1/3 subharmonic oscillations is inspected.展开更多
In this work, ZnO, Ce<sup>3+</sup> doped ZnO (ZnO/Ce<sup>3+</sup>) and Cu<sup>2+</sup> + Ce<sup>3+</sup> co-doped ZnO (ZnO/Cu<sup>2+</sup> + Ce<sup>3+&...In this work, ZnO, Ce<sup>3+</sup> doped ZnO (ZnO/Ce<sup>3+</sup>) and Cu<sup>2+</sup> + Ce<sup>3+</sup> co-doped ZnO (ZnO/Cu<sup>2+</sup> + Ce<sup>3+</sup> ) solid solutions powders were synthesized by a solution combustion method maintaining the Ce<sup>3+</sup> ion concentration constant in 3%Wt while the Cu<sup>2+</sup> ion concentration was varied in 1, 2, 3, 10 and 20%Wt. After its synthesis, all the samples were annealed at 900?C by 24 h. The ZnO, ZnO/Ce<sup>3+</sup> and ZnO/Cu<sup>2+</sup> + Ce<sup>3+</sup> powders were structurally characterized using X-ray diffraction (XRD) technique, and the XRD patterns showed that for pure ZnO, Cu<sup>2+</sup> undoped ZnO/Ce<sup>3</sup><sup>+</sup> and ZnO/Ce<sup>3+</sup> doped with the Cu<sup>2+</sup> ion, the three samples exhibited the hexagonal wurtzite ZnO crystalline structure. However, the morphology and particle size of both samples were observed by means of a scanning electron microscopy (SEM);from SEM image, it is observed that the crystallites of both samples are agglomerated forming bigger amorphous particles with an approximate average size of 1 μm. In addition, the photoluminescence of the ZnO, Ce<sup>3+</sup> doped ZnO and Cu<sup>2+</sup> + Ce<sup>3+</sup> doped ZnO samples was measurement under an illumination of 209 nm wavelength (UV region): for the ZnO/Ce<sup>3+</sup> sample, your emission spectrum is in the visible region from blue color until red color;the UV band of the ZnO is suppressed. The multicolor emission visible is attributed to the Ce<sup>3+</sup> ion photoluminescence, while for the ZnO/Cu<sup>2+</sup> + Ce<sup>3+</sup>, its emission PL spectrum is quenching by the Cu<sup>2+</sup> ion, present in the ZnO crystalline.展开更多
l- ions behavior in Ag(SO_3)3-2 solution was studied. The mechanism of Ag particles formation in the solution was discussed, and factors affecting its formation were investigated.
This article introduces Fixed-Mobile Convergence (FMC) based on IP Multimedia Subsystem (IMS), which can provide multimedia services flexibly and merge the fixed and mobile networks smoothly. The article focuses on ZT...This article introduces Fixed-Mobile Convergence (FMC) based on IP Multimedia Subsystem (IMS), which can provide multimedia services flexibly and merge the fixed and mobile networks smoothly. The article focuses on ZTE' s Fixed - line 3G Solution. The Solution proposes an FMC evolution from traditional networks to NGN based on the IMS architecture. It supports a smooth convergence of the 3G network and Softswitch - based NGN. By using an application server, it is able to offer multimedia services without restrictions on access modes.展开更多
When upgrading your network,you should consider ZTE F3G solutions.You get a total solution for Triple-play that increases your revenue dramatically,and you could cut your break-even time by 50%.
When upgrading your network, you should consider ZTE F3G solutions.You get a total solution for Triple-play that increases your revenue dramatically, and you could cut your break-even time by 50%.
基金supported by the Nano&Material Technology Development Program through the National Research Foundation of Korea(NRF)funded by Ministry of Science and ICT(Grant No.RS-2024-00408180)by Institute for Basic Science(No.IBS-R019-G1).
文摘Two-dimensional(2D)nitride MXenes are predicted to exhibit exceptional metallic properties and high polarity;however,their synthesis remains challenging.Research has relied on traditional molten salt etching,highlighting the need for a scalable,high-purity approach.Here,we present the first solution-based synthesis of Ti_(4)N_(3)T_(x)MXene via a novel saturated salt solution(S^(3))etching technique employing alkali metal salts.By optimizing the sintering process for high-purity Ti_(4)AlN_(3)MAX and refining the S^(3)etching route,we significantly reduced the etch pit density to 1.2×10^(6)cm^(-2)and lowered the etch pit formation rate to 4%,yielding high-quality,phasepure Ti_(4)N_(3)T_(x)MXene.Our study highlights the critical role of alkali metal ions in selective A-layer removal and demonstrates the impressive electrical conductivity and electromagnetic interference shielding performance of 2D nitride MXene,setting a new benchmark for this underexplored material.These findings pave the way for advancing 2D nitride MXenes and their diverse applications.
基金financially supported by the National Nature Science Foundation of China (No. 51174115)National Outstanding Youth Science Foundation of China (No. 51025416)Program for Changjiang Scholars and Innovative Research Team in University (No. IRT1065)
文摘Abstract A method of Baotou mixed rare earth concen- trate leaching was investigated. According to the principle of complex leaching, the quadratic orthogonal regression experiment was used to investigate effect of six factors. An optimal condition of low energy and environment friendly was determined as follows： HCl acidity is 4 mol.L-1, AlCl3 concentration is 2 mol.L-l, reaction temperature is 85 ℃, reaction time is 90 rain, liquid to solid ratio is 35 ml.g-1, and stirring speed is 100 r.min-1. According to this condition, the leaching ratio of mixed rare earth con- centrate is 76.5 %. The analyses of X-ray diffraction shows that bastnasite disappears, and the main peaks of filter residue is monazite and cheralite after leaching of HCl- AlCl3 solution. The result indicates that REFCO3 of the mixed rare earth concentrate can be dissolved, but REPO4 remains in the leaching residue. This method provides a way to separate and extract rare earth.
基金supported by the National Natural Science Foundation of China(No.50807042)the Research Fund for the Doctoral Program of Higher Education of China(No.200806981043)+1 种基金the Fundamental Research Fund for the Central Universities(No.xjj2012088)the fund of StateKey Laboratory of Electrical Insulation and Power Equipment(Xi'an Jiaotong University No.EIPE12305)
文摘This paper demonstrated our discovery of the movement effect of BiFeO_3 nanoparticles in solution by strong electrical polarization. First, BiFeO_3 nanoparticles were prepared by ball milling and characterized by SEM. Then, the preparation of BiFeO_3 solution was finished. BiFeO_3 nanoparticles are found to move in solution due to electrical field. The movement velocity of BiFeO_3 nanoparticles, which is about 10 μm·s^-1 , is influenced and controlled by the applied electrical field. The concentration of BiFeO_3 solution and the nanoparticle sizes also have effects on its movement properties. The movement of BiFeO_3 nanoparticles in solution is induced by strong polarization, and BiFeO_3 nanoparticles have net negative electric charges because of the electrostatic force between BiFeO_3 nanoparticles and the negative ions in water resolver.
基金the financial support from the National Natural Science Foundation of China(No.21473192)the financial support from the National Natural Science Foundation of China(Nos.21373042 and 21677029)
文摘All-inorganic cesium lead halide perovskites （CsPbX3, X=CF, Br-, I-） could provide comparableoptoelectronic properties as a promising class of materials for photovoltaic cell （PV）, photodetector andlight-emitting diode （LED） with enhanced thermal and moisture stabilities compared to organic-inorganic lead halide species. However, fabrication of CsPbI3 perovskite via facile solution process hasbeen difficult due to instability of CsPbl3 in the perovskite cubic phase in ambient air. Herein, we reportthe synthesis of CsPbl3 perovskite microcrystals by low-temperature, catalyst-free, solution-phasemethod. By applying the time-resolve spectroscopic technique, we determine the carrier diffusioncoefficient of 0.6-1.2 cm2/s, the intrinsic carrier lifetimes of 200-1300 ns and diffusion length of4-10 μm in different individual CsPbl3 perovskite microcrystals. Our results suggest the CsPbl3 perovskitemicrocrystals synthesized by solution process exhibit high quality feature and are suitable forapplications in optoelectronic devices.
基金supported by National Natural Science Foundation of China(12175130,11875187)the Opening Project of State Key Laboratory of Key Laboratory of Transparent Opto-functional Inorganic Materials,Chinese Academy of Sciences(KLTOIM202002)。
文摘In this paper,effect of two strategies on afterglow behavior of Lu_(2)O_(3):Eu single crystal scintillato r,Pr^(3+)codoping and solid solution with Sc_(2)O_(3),were studied systematically.Two groups of Lu_(2)O_(3):5 at%Eu,x at%Pr(x=0,0.2,0.5,1,2 and 5)and(Lu1-yScy)_(2)O_(3):5 at%Eu(y=0,20 at%,50 at%and 70 at%)single crystals were grown by floating zone(FZ)method in air atmosphere.The structures of as-grown crystals were determined by X-ray diffraction(XRD).The scintillation,photoluminescence properties and carrier trap states were investigated through afterglow,X-ray excitation luminescence(XEL),transmittance,photoluminescence excitation(PLE)and photoluminescence(PL),PL decay and thermal stimulated luminescence(TSL)curves.It is found that with the increase of Pr^(3+)concentration,the afterglow level of the system decreases at the expense of scintillation luminescence efficiency.Meanwhile,although Sc_(2)O_(3):Eu presents much lower afterglow intensity than Lu_(2)O_(3):Eu,the addition of Sc_(2)O_(3)will just increase the afterglow level of the(Lu1-yScy)_(2)O_(3):5 at%Eu single crystal system.Possible mechanisms for above phenomena are discussed based on experimental results.
文摘The corrosion behavior of Cu-Cr alloy in 3.5%NaCl+NH3 solution had been studied, and the influences of the concentration of NH3 on corrosion resistance discussed by means of Metallograph, XRD, SEM and electrochemical method. The results show that the Cu is easier to corrosion than Cr, and the corrosion rate increases with the increasing of the concentration of NH3, and deformation worsen the corrosion resistance of the alloy in such corrosive environment.
文摘As new generation mobile networks, 3G networks focus on data services and integrate voice, data and multimedia services. However, traditional Optical Transport Networks (OTNs) cannot meet the requirements of 3G networks anymore, because of their complicated configuration, low bandwidth efficiency, high cost, and bad network and service scalability. The emerging of Multi-Service Transport Platform (MSTP), Wavelength Division Multiplexing (WDM), and Automatically Switched Optical Network (ASON) technologies for optical fiber communications makes up for these weaknesses. The leading solution to 3G access transport networks is the MSTP technology based on Synchronous Digital Hierarchy (SDH), while that to 3G core transport network is ASON+WDM.
文摘The problem of nonlinear forced oscillations for elliptical sandwich plates is dealt with. Based on the governing equations expressed in terms of five displacement components, the nonlinear dynamic equation of an elliptical sandwich plate under a harmonic force is derived. A superpositive-iterative harmonic balance (SIHB) method is presented for the steady-state analysis of strongly nonlinear oscillators. In a periodic oscillation, the periodic solutions can be expressed in the form of basic harmonics and bifurcate harmonics. Thus, an oscillation system which is described as a second order ordinary differential equation, can be expressed as fundamental differential equation with fundamental harmonics and incremental differential equation with derived harmonics. The 1/3 subharmonic solution of an elliptical sandwich plate is investigated by using the methods of SIHB. The SIHB method is compared with the numerical integration method. Finally, asymptotical stability of the 1/3 subharmonic oscillations is inspected.
文摘In this work, ZnO, Ce<sup>3+</sup> doped ZnO (ZnO/Ce<sup>3+</sup>) and Cu<sup>2+</sup> + Ce<sup>3+</sup> co-doped ZnO (ZnO/Cu<sup>2+</sup> + Ce<sup>3+</sup> ) solid solutions powders were synthesized by a solution combustion method maintaining the Ce<sup>3+</sup> ion concentration constant in 3%Wt while the Cu<sup>2+</sup> ion concentration was varied in 1, 2, 3, 10 and 20%Wt. After its synthesis, all the samples were annealed at 900?C by 24 h. The ZnO, ZnO/Ce<sup>3+</sup> and ZnO/Cu<sup>2+</sup> + Ce<sup>3+</sup> powders were structurally characterized using X-ray diffraction (XRD) technique, and the XRD patterns showed that for pure ZnO, Cu<sup>2+</sup> undoped ZnO/Ce<sup>3</sup><sup>+</sup> and ZnO/Ce<sup>3+</sup> doped with the Cu<sup>2+</sup> ion, the three samples exhibited the hexagonal wurtzite ZnO crystalline structure. However, the morphology and particle size of both samples were observed by means of a scanning electron microscopy (SEM);from SEM image, it is observed that the crystallites of both samples are agglomerated forming bigger amorphous particles with an approximate average size of 1 μm. In addition, the photoluminescence of the ZnO, Ce<sup>3+</sup> doped ZnO and Cu<sup>2+</sup> + Ce<sup>3+</sup> doped ZnO samples was measurement under an illumination of 209 nm wavelength (UV region): for the ZnO/Ce<sup>3+</sup> sample, your emission spectrum is in the visible region from blue color until red color;the UV band of the ZnO is suppressed. The multicolor emission visible is attributed to the Ce<sup>3+</sup> ion photoluminescence, while for the ZnO/Cu<sup>2+</sup> + Ce<sup>3+</sup>, its emission PL spectrum is quenching by the Cu<sup>2+</sup> ion, present in the ZnO crystalline.
文摘l- ions behavior in Ag(SO_3)3-2 solution was studied. The mechanism of Ag particles formation in the solution was discussed, and factors affecting its formation were investigated.
文摘This article introduces Fixed-Mobile Convergence (FMC) based on IP Multimedia Subsystem (IMS), which can provide multimedia services flexibly and merge the fixed and mobile networks smoothly. The article focuses on ZTE' s Fixed - line 3G Solution. The Solution proposes an FMC evolution from traditional networks to NGN based on the IMS architecture. It supports a smooth convergence of the 3G network and Softswitch - based NGN. By using an application server, it is able to offer multimedia services without restrictions on access modes.
文摘When upgrading your network,you should consider ZTE F3G solutions.You get a total solution for Triple-play that increases your revenue dramatically,and you could cut your break-even time by 50%.
文摘When upgrading your network, you should consider ZTE F3G solutions.You get a total solution for Triple-play that increases your revenue dramatically, and you could cut your break-even time by 50%.
文摘When upgrading your network, you should consider ZTE F3G solutions.You get a total solution tor Triple-play that increases your revenue dramatically,
