Nitrogen and phosphorus co-doped graphene quantum dot-modified Bi5O7 I(NPG/Bi5O7 I)nanorods were fabricated via a simple solvothermal method.The morphology,structure,and optical properties of the as-prepared samples w...Nitrogen and phosphorus co-doped graphene quantum dot-modified Bi5O7 I(NPG/Bi5O7 I)nanorods were fabricated via a simple solvothermal method.The morphology,structure,and optical properties of the as-prepared samples were investigated by X-ray diffraction,scanning electron microscopy,high-resolution transmission electron microscopy,X-ray photoelectron spectroscopy(XPS),and diffused reflectance spectroscopy.The photocatalytic performance was estimated by degrading the broad-spectrum antibiotics tetracycline and enrofloxacin under visible light irradiation.The photodegradation activity of Bi5O7 I improved after its surface was modified with NPGs,which was attributed to an increase in the photogenerated charge transport rate and a decrease in the electron-hole pair recombination efficiency.From the electron spin resonance spectra,XPS valence band data,and free radical trapping experiment results,the main active substances involved in the photocatalytic degradation process were determined to be photogenerated holes and superoxide radicals.A possible photocatalytic degradation mechanism for NPG/Bi5O7 I nanorods was proposed.展开更多
The ab initio generalized gradient approximation (GGA)+U study of multiferroic (La Bi )<sub>2</sub>FeCrO<sub>6</sub> in pnma structure and ferri-magnetic order, including Hubbard corrections ( ...The ab initio generalized gradient approximation (GGA)+U study of multiferroic (La Bi )<sub>2</sub>FeCrO<sub>6</sub> in pnma structure and ferri-magnetic order, including Hubbard corrections ( eV) for transition metal/rare earth d-electrons with 20 atoms cell, shows optimum local magnetic moments of (Cr , Fe equal to (−2.56, 4.14) μB and an ideal spin-down band gap of 1.54 eV. Tuned-band gap La-substituted double oxide perovskites BFCO should exhibit enhanced visible-light absorption and carrier mobility, thus could be convenient light absorbers and then efficient alternatives to wide-gap chalcopyrite absorber-based solar cells failing to achieve highest power conversion efficiencies, and even compete with their metal-organic halide perovskites counterparts.展开更多
We demonstrate a white light fiber source based on Bismuth and Erbium co-doped fiber and a single 830nm laser diode pump. The light spectral intensity from 1100 to 1570nm is over -45dBm, which provide ~40dB dynamic ra...We demonstrate a white light fiber source based on Bismuth and Erbium co-doped fiber and a single 830nm laser diode pump. The light spectral intensity from 1100 to 1570nm is over -45dBm, which provide ~40dB dynamic range for an OSA based spectral measurement.展开更多
为响应BIS注册用户的需求,印度标准局（Bureau of Indian Standards,BIS）于2015年12月3日公告新推出BIS CRS认证标准标志相关信息,以便统一标识要求,简化注册程序。BIS新标志制作注意事项：（1）BIS CRS标准标志图案制作必须依据比例图...为响应BIS注册用户的需求,印度标准局（Bureau of Indian Standards,BIS）于2015年12月3日公告新推出BIS CRS认证标准标志相关信息,以便统一标识要求,简化注册程序。BIS新标志制作注意事项：（1）BIS CRS标准标志图案制作必须依据比例图,可按比例放大缩小。（2）BIS CRS标准标志图案可以是单色或是多色;详细规格及尺寸信息可参考http：//www.bis.org.in/qazwsx/cmd/circular-mark_registration.展开更多
At first, Cr-Si (28 wt% Cr, 72 wt% Si) and Ni-Cr (80 wt% Ni, 20 wt% Cr) thin-film materials were deposited by using sputtering method at the same parameters, and their physical and electrical properties were investiga...At first, Cr-Si (28 wt% Cr, 72 wt% Si) and Ni-Cr (80 wt% Ni, 20 wt% Cr) thin-film materials were deposited by using sputtering method at the same parameters, and their physical and electrical properties were investigated. The resistances of Cr-Si and Ni-Cr thin-film resistors decreased with the increase of deposition time (thickness) and their resistivity had no apparent variations as the deposition time increased. The temperature coefficient of resistance (TCR) of single-layer Cr-Si thin-film resistors was negative and the TCR value of single-layer Ni-Cr thin-film resistors was positive. For that, we used Cr-Si thin films as upper (or lower) layer and Ni-Cr thin films as lower (upper) layer to investigate a bi-layer thin-film structure. The deposition time of Ni-Cr thin films was fixed at 10 min and the deposition time of Cr-Si thin films was changed from 10 min to 60 min. We had found that as Cr-Si thin films were used as upper or lower layers they had similar deposition rates. We had also found that the thickness and stack method of Cr-Si thin films had large effects on the resistance and TCR values of the bi-layer thin-film resistors.展开更多
The luminescent properties of ZnSe, ZnSe：Cr（0.05 at.% Cr）, ZnSe：Yb（0.03 at.% Yb） and ZnSe：Cr：Yb（0.05 at.% Cr, 0.05 at.% Yb） crystals, doped during the growth process by the chemical vapor transport method, w...The luminescent properties of ZnSe, ZnSe：Cr（0.05 at.% Cr）, ZnSe：Yb（0.03 at.% Yb） and ZnSe：Cr：Yb（0.05 at.% Cr, 0.05 at.% Yb） crystals, doped during the growth process by the chemical vapor transport method, were studied within the temperature interval of 6–300 K. At the 6 K temperature in the visible spectral range 2 bands were observed： a band in the excitonic spectral region and a band of self-activated luminescence. It was shown that co-doping of zinc selenide crystals with the chromium and ytterbium led to the combination of the impurities influence on the photoluminescent properties. At the liquid helium temperature in the middle infrared range of the spectra of the ytterbium and chromium co-doped crystal a band with the maximum localized at 1.7μm was observed, which was overlapped with a complex band in the middle-IR spectral range, characteristic for the chromium doped ZnSe crystals. On the basis of obtained data an interaction mechanism of the chromium and ytterbium co-doping impurities was proposed. Guided by the existent model of the ytterbium ion incorporation in the selenide sublattice of the ZnSe crystals, an assumption about stabilization of single charged chromium ions in the zinc sublattice crystal nodes, by means of formation of the local charge compensating clusters, was made. It was assumed that the resonant energy transfer from one chromium ion to another,which led to the concentration quenching of the IR emission in the ZnSe：Cr PL spectra, would lead to the broadening of the IR emission in the spectra of ytterbium and chromium co-doped zinc selenide crystals.g展开更多
In this Letter,the optical amplification characteristics of the home-made Bi/P co-doped silica fiber were systematically explored in the range of 1270–1360 nm.The maximum gain of 24.6 dB was obtained in the single-pa...In this Letter,the optical amplification characteristics of the home-made Bi/P co-doped silica fiber were systematically explored in the range of 1270–1360 nm.The maximum gain of 24.6 dB was obtained in the single-pass amplification device,and then improved to 38.3 dB in the double-pass amplification device for-30 dBm signal power.In addition,we simultaneously investigated the laser performance of the fiber with the linear cavity.A slope efficiency of 16.4%at~1313 nm was obtained with a maximum output power of about 133 mW under the input pump power of 869 mW at 1240 nm.As far as we know,it is the first laser reported based on the bismuth-doped fiber in China.展开更多
Highly competent and economical photocatalysts are one of the most charming targets in environmental restoration and clean production.Herein,a novel sulfur-vacancy-rich Bi/Bi_(2)S_(3)/SnS_(2)Z-scheme heterostruc-ture ...Highly competent and economical photocatalysts are one of the most charming targets in environmental restoration and clean production.Herein,a novel sulfur-vacancy-rich Bi/Bi_(2)S_(3)/SnS_(2)Z-scheme heterostruc-ture was constructed in situ and applied for the photoreduction Cr(VI)and nitrogen fixation.The fab-ricated Bi/Bi_(2)S_(3)/SnS_(2)-2 exhibits the optimum photoreduction Cr(VI)performance with the efficiency of 94.5%within 15 min visible light irradiation.The remarkably enhanced catalytic efficiency derived from the synergistic effect of the construction of intimate contacted interface,abundant sulfur vacancy and surface plasmon resonance(SPR)effect of metal Bi.Meanwhile,the excellent photocatalytic nitrogen fix-ation property(96.4μmol g^(-1)h^(-1))was achieved by Bi/Bi_(2)S_(3)/SnS_(2)-2 under full solar illumination because sulfur vacancy could provide sufficient catalytic sites to accelerate the adsorption and nitrogen activation.The Z-scheme heterostructure was proposed to expound the photocatalytic mechanism.This work offers a new perspective on hierarchical heterostructure with plentiful vacancies for environmental remediation and energy development.展开更多
文摘Nitrogen and phosphorus co-doped graphene quantum dot-modified Bi5O7 I(NPG/Bi5O7 I)nanorods were fabricated via a simple solvothermal method.The morphology,structure,and optical properties of the as-prepared samples were investigated by X-ray diffraction,scanning electron microscopy,high-resolution transmission electron microscopy,X-ray photoelectron spectroscopy(XPS),and diffused reflectance spectroscopy.The photocatalytic performance was estimated by degrading the broad-spectrum antibiotics tetracycline and enrofloxacin under visible light irradiation.The photodegradation activity of Bi5O7 I improved after its surface was modified with NPGs,which was attributed to an increase in the photogenerated charge transport rate and a decrease in the electron-hole pair recombination efficiency.From the electron spin resonance spectra,XPS valence band data,and free radical trapping experiment results,the main active substances involved in the photocatalytic degradation process were determined to be photogenerated holes and superoxide radicals.A possible photocatalytic degradation mechanism for NPG/Bi5O7 I nanorods was proposed.
文摘The ab initio generalized gradient approximation (GGA)+U study of multiferroic (La Bi )<sub>2</sub>FeCrO<sub>6</sub> in pnma structure and ferri-magnetic order, including Hubbard corrections ( eV) for transition metal/rare earth d-electrons with 20 atoms cell, shows optimum local magnetic moments of (Cr , Fe equal to (−2.56, 4.14) μB and an ideal spin-down band gap of 1.54 eV. Tuned-band gap La-substituted double oxide perovskites BFCO should exhibit enhanced visible-light absorption and carrier mobility, thus could be convenient light absorbers and then efficient alternatives to wide-gap chalcopyrite absorber-based solar cells failing to achieve highest power conversion efficiencies, and even compete with their metal-organic halide perovskites counterparts.
文摘We demonstrate a white light fiber source based on Bismuth and Erbium co-doped fiber and a single 830nm laser diode pump. The light spectral intensity from 1100 to 1570nm is over -45dBm, which provide ~40dB dynamic range for an OSA based spectral measurement.
文摘为响应BIS注册用户的需求,印度标准局（Bureau of Indian Standards,BIS）于2015年12月3日公告新推出BIS CRS认证标准标志相关信息,以便统一标识要求,简化注册程序。BIS新标志制作注意事项：（1）BIS CRS标准标志图案制作必须依据比例图,可按比例放大缩小。（2）BIS CRS标准标志图案可以是单色或是多色;详细规格及尺寸信息可参考http：//www.bis.org.in/qazwsx/cmd/circular-mark_registration.
文摘At first, Cr-Si (28 wt% Cr, 72 wt% Si) and Ni-Cr (80 wt% Ni, 20 wt% Cr) thin-film materials were deposited by using sputtering method at the same parameters, and their physical and electrical properties were investigated. The resistances of Cr-Si and Ni-Cr thin-film resistors decreased with the increase of deposition time (thickness) and their resistivity had no apparent variations as the deposition time increased. The temperature coefficient of resistance (TCR) of single-layer Cr-Si thin-film resistors was negative and the TCR value of single-layer Ni-Cr thin-film resistors was positive. For that, we used Cr-Si thin films as upper (or lower) layer and Ni-Cr thin films as lower (upper) layer to investigate a bi-layer thin-film structure. The deposition time of Ni-Cr thin films was fixed at 10 min and the deposition time of Cr-Si thin films was changed from 10 min to 60 min. We had found that as Cr-Si thin films were used as upper or lower layers they had similar deposition rates. We had also found that the thickness and stack method of Cr-Si thin films had large effects on the resistance and TCR values of the bi-layer thin-film resistors.
基金supported by Erasmus Mundus(BMUMID2011238)Moldavian Academy of Science(11.817.05.11F)Jenny and AnttiWihuri Foundation
文摘The luminescent properties of ZnSe, ZnSe：Cr（0.05 at.% Cr）, ZnSe：Yb（0.03 at.% Yb） and ZnSe：Cr：Yb（0.05 at.% Cr, 0.05 at.% Yb） crystals, doped during the growth process by the chemical vapor transport method, were studied within the temperature interval of 6–300 K. At the 6 K temperature in the visible spectral range 2 bands were observed： a band in the excitonic spectral region and a band of self-activated luminescence. It was shown that co-doping of zinc selenide crystals with the chromium and ytterbium led to the combination of the impurities influence on the photoluminescent properties. At the liquid helium temperature in the middle infrared range of the spectra of the ytterbium and chromium co-doped crystal a band with the maximum localized at 1.7μm was observed, which was overlapped with a complex band in the middle-IR spectral range, characteristic for the chromium doped ZnSe crystals. On the basis of obtained data an interaction mechanism of the chromium and ytterbium co-doping impurities was proposed. Guided by the existent model of the ytterbium ion incorporation in the selenide sublattice of the ZnSe crystals, an assumption about stabilization of single charged chromium ions in the zinc sublattice crystal nodes, by means of formation of the local charge compensating clusters, was made. It was assumed that the resonant energy transfer from one chromium ion to another,which led to the concentration quenching of the IR emission in the ZnSe：Cr PL spectra, would lead to the broadening of the IR emission in the spectra of ytterbium and chromium co-doped zinc selenide crystals.g
基金supported by the National Key R&D Program of China(No.2020YFB1805902)。
文摘In this Letter,the optical amplification characteristics of the home-made Bi/P co-doped silica fiber were systematically explored in the range of 1270–1360 nm.The maximum gain of 24.6 dB was obtained in the single-pass amplification device,and then improved to 38.3 dB in the double-pass amplification device for-30 dBm signal power.In addition,we simultaneously investigated the laser performance of the fiber with the linear cavity.A slope efficiency of 16.4%at~1313 nm was obtained with a maximum output power of about 133 mW under the input pump power of 869 mW at 1240 nm.As far as we know,it is the first laser reported based on the bismuth-doped fiber in China.
基金supported by the National Natural Science Foun-dation of China(Nos.22178038 and 21878031)Innovation Supporting Plan for High-level Talents of Dalian(No.2021RQ116).
文摘Highly competent and economical photocatalysts are one of the most charming targets in environmental restoration and clean production.Herein,a novel sulfur-vacancy-rich Bi/Bi_(2)S_(3)/SnS_(2)Z-scheme heterostruc-ture was constructed in situ and applied for the photoreduction Cr(VI)and nitrogen fixation.The fab-ricated Bi/Bi_(2)S_(3)/SnS_(2)-2 exhibits the optimum photoreduction Cr(VI)performance with the efficiency of 94.5%within 15 min visible light irradiation.The remarkably enhanced catalytic efficiency derived from the synergistic effect of the construction of intimate contacted interface,abundant sulfur vacancy and surface plasmon resonance(SPR)effect of metal Bi.Meanwhile,the excellent photocatalytic nitrogen fix-ation property(96.4μmol g^(-1)h^(-1))was achieved by Bi/Bi_(2)S_(3)/SnS_(2)-2 under full solar illumination because sulfur vacancy could provide sufficient catalytic sites to accelerate the adsorption and nitrogen activation.The Z-scheme heterostructure was proposed to expound the photocatalytic mechanism.This work offers a new perspective on hierarchical heterostructure with plentiful vacancies for environmental remediation and energy development.
