X-ray diffraction and selective chemical dissolution methods were used to investigate the composition of Mn oxide minerals in Fe-Mn nodules of several main types of soils in China. The changes of relative intensity of...X-ray diffraction and selective chemical dissolution methods were used to investigate the composition of Mn oxide minerals in Fe-Mn nodules of several main types of soils in China. The changes of relative intensity of X-ray diffraction patterns were studied both before and after chemically selective dissolution. It was found that lithiophorite was a common Mn oxide in all examined Fe-Mn nodules. Todorokite, however, was a predominant Mn oxide in Fe-Mn nodules in caf-aquic Vertisols of Linyi, Shandong Province. The Fe-Mn nodules of arp-udic Luvisols in Wuhan and Zaoyang, Hubei Province, contained birnessite and vernadite. Hollandite was found in Fe-Mn nodules of alt-udic Ferrisols of Yizhang, Hunan Province; arp-udic Luvisols of Zaoyang, Hubei Province; and cal-aquic Vertisols of Linyi, Shandong Province. The Fe-Mn nodules in alt-udic Ferrisols of Guiyang, Hunan Province, had a few coronadites. Mineralogy of Mn oxide minerals in soil Fe-Mn nodules was related to soil environment, soil types and quantities of relevant cations.展开更多
Twinned substructure in lath martensite was induced in the interstitial free(IF)steel via a high pressure thermal cycle(heating up to 1100℃and holding for 30 min,cooling at 10℃/s to room temperature under a pressure...Twinned substructure in lath martensite was induced in the interstitial free(IF)steel via a high pressure thermal cycle(heating up to 1100℃and holding for 30 min,cooling at 10℃/s to room temperature under a pressure of 4 GPa).Experimental observations and theoretical simulation confrm that the twinned substructure has the origin related to the twinned variants rather than the bcc{112}<111>twins,while extra difraction spots were caused by crystal overlapping rather than any extra phase.The diferences in crystallography and electron difraction behavior between twinned variants and{112}<111>twins were discussed in detail.展开更多
Laser elktacytometry is a technique widely used for measuring the deformability of red blood cells(erythrocytes)in blood samples in vitro.In ektacytometer,a flow of highly diluted suspension of erythrocytes in variabl...Laser elktacytometry is a technique widely used for measuring the deformability of red blood cells(erythrocytes)in blood samples in vitro.In ektacytometer,a flow of highly diluted suspension of erythrocytes in variable shear stress conditions is iluninated with a laser beam to obtain a diffraction pattern.The diffraction pattern provides information about the shapes(shear induced elongations)of the cells under investigation.This paper is dedicated to developing the technique of laser ektacytometry s0 that it would enable one to measure the distrilbution of the erythrocytes in deformability.We discuss the problem of calibration of laser elktacytometer and test a novel data processing algorithm allowing to determine the parameters of the distribution of ery-throcytes deformability.Experimentally,we examined 12 specimens of blood of rats under the action of 4 shear stresses.Analysis of the data shows that in conditions of a limited range of digitizing the diffraction patterns,the measurement errors for the mean deformability,deform-ability scatter and the skewness of erythrocytes distribution in deformability by our method are respectively 15%,20%and 20%.展开更多
Light manipulation and control are essential in various contemporary technologies,and as these technologies evolve,the demand for miniaturized optical components increases.Planar-lens technologies,such as metasurfaces...Light manipulation and control are essential in various contemporary technologies,and as these technologies evolve,the demand for miniaturized optical components increases.Planar-lens technologies,such as metasurfaces and difractive optical elements,have gained attention in recent years for their potential to dramatically reduce the thickness of traditional refractive optical systems.However,their fabrication,particularly for visible wavelengths,involves complex and costly processes,such as high-resolution lithography and dry-etching,which has limited their availability.In this study,we present a simplifed method forfabricating visible Fresnel zone plate(FZP)planar lenses,a type of diffractive optical element,using an i-line stepper and a special photoresist(color resist)that only necessitates coating,exposure,and development,eliminating the need for etching or other post-processing steps.We fabricated visible FZp lens patterns using conventional photolithography equipment on 8-inch silica glass wafers,and demonstrated focusing of 550 nm light to a diameter of 1.1μm with a focusing efficiency of 7.2%.Numerical simulations showed excellent agreement with experimental results,confirming the high precision and designability of our method.Our lenses were also able to image objects with features down to 1.1μm,showcasing their potential for practical applications in imaging.Our method is a cost-effective,simple,and scalable solution for mass production of planar lenses and other optical components operating in the visible region.It enables the development of advanced,miniaturized optical systems to meet modern technology demand,making it a valuable contribution to optical component manufacturing.展开更多
In the feld of information processing,all-optical routers are signifcant for achieving high-speed,high-capacity signal processing and transmission.In this study,we developed three types of structurally simple and fexi...In the feld of information processing,all-optical routers are signifcant for achieving high-speed,high-capacity signal processing and transmission.In this study,we developed three types of structurally simple and fexible routers using the deep difractive neural network(D2 NN),capable of routing incident light based on wavelength and polarization.First,we implemented a polarization router for routing two orthogonally polarized light beams.The second type is the wavelength router that can route light with wavelengths of 1550,1300,and 1100 nm,demonstrating outstanding performance with insertion loss as low as 0.013 dB and an extinction ratio of up to 18.96 dB,while also maintaining excellent polarization preservation.The fnal router is the polarization-wavelength composite router,capable of routing six types of input light formed by pairwise combinations of three wavelengths(1550,1300,and 1100 nm)and two orthogonal linearly polarized lights,thereby enhancing the information processing capability of the device.These devices feature compact structures,maintaining high contrast while exhibiting low loss and passive characteristics,making them suitable for integration into future optical components.This study introduces new avenues and methodologies to enhance performance and broaden the applications of future optical information processing systems.展开更多
This work focuses on the structural,electrical and magnetic properties of Bi_(0.8)Tb_(0.1)Ba_(0.1)Fe_(0.9)Ti_(0.1)O_(3)ceramics,fabricated by solid state reaction procedure.XRD forms of the samples at RT exhibited per...This work focuses on the structural,electrical and magnetic properties of Bi_(0.8)Tb_(0.1)Ba_(0.1)Fe_(0.9)Ti_(0.1)O_(3)ceramics,fabricated by solid state reaction procedure.XRD forms of the samples at RT exhibited perovskite phase through the hexagonal structure at room temperature.Dielectric studies of the materials with frequency at different temperatures(25-400℃)exhibit two dielectric anomalies,first at 175℃(ferroelectric-ferroelectric transition)and second at around 320℃(ferroelectric-paraelectric transition).The Curie temperature moved towards the low side temperature with the increase in frequency.The less value of activation energy got for these samples could be attributed to the influence of electronic contribution to the conductivity.A significant change in the magnetic studies was observed for Bi_(0.8)Tb_(0.1)Ba_(0.1)Fe_(0.9)Ti_(0.1)O_(3) ceramic.The impedance analysis confirms the non-Debye type nature of the ceramic and relaxation frequency moved to a higher temperature.The Nyquist plot and conductivity studies showed the NTCR behavior of samples.The highest magnetization field was found at temperature-268.15℃.展开更多
Ternary solid solutions of BiFeO_(3),GdFeO_(3)and BaTiO_(3)have been prepared by solid-state reaction method.Dielectric properties of these ceramics have been characterized in the tem-perature range between room tempe...Ternary solid solutions of BiFeO_(3),GdFeO_(3)and BaTiO_(3)have been prepared by solid-state reaction method.Dielectric properties of these ceramics have been characterized in the tem-perature range between room temperature and 673 K and magnetic properties between 5 K and 300K.For the understanding of the multiferroic property,the relation between the crystal structures,magnetic transition and ferroelectric transitions with increasing temperature have been analyzed.All ceramic samples show single perovskite phase.When Ba content exceeds 0.2 wt%,the sintering ability is weakened and the phase structure of Bi_(1-x-y)Gd_(x)Ba_(y)Fe_(1-y)Ti_(y)O_(3)(with x=0.2 and y=0.1,0.2,0.3,0.4,0.5)solid solution changes from rhombohedral to tetragonal phase.The maximum ferroelectric transition temperature(T_(c))of this system was in the range 154-165℃with the dielectric constant peak of 6000 for y=0.5 at 100 kHz.Well-saturated piezoresponse hysteresis loops were observed for all compositions indicating room temperature ferroelectricity.With increasing Ba content(up to 0.3 wt%)the remanent magnetization M,increased and the coercive magnetic field decreased.展开更多
Neodymium-doped barium phosphate(NdBP)was prepared as single crystal by room temperature solution technique known as gel encapsulation technique.Single crystal X-ray diffraction shows that the crystal belongs to ortho...Neodymium-doped barium phosphate(NdBP)was prepared as single crystal by room temperature solution technique known as gel encapsulation technique.Single crystal X-ray diffraction shows that the crystal belongs to orthorthombic system.The flower type morphology was observed by scanning electron microscope(SEM)and the stoichiometric composition of the prepared crystal was observed by energy dispersive X-ray analysis(EDAX).The presence of functional group and other groups was studied by Fourier transform infrared spectroscopy(FTIR).The electrical properties of these materials like dielectric constant(ε′),dieletric loss(tan σ)and ac conductivity[ln(σac)]was studied at different temperatures ranging from 40℃ to 420℃ in the frequency range of 5 kHz to 1 MHz.The activation energy values decreases with increase in frequency suggesting that the conduction mechanism is because of hopping of charge carriers.展开更多
基金Project(No.49771049)supported by the National Natural Science Foundation of China
文摘X-ray diffraction and selective chemical dissolution methods were used to investigate the composition of Mn oxide minerals in Fe-Mn nodules of several main types of soils in China. The changes of relative intensity of X-ray diffraction patterns were studied both before and after chemically selective dissolution. It was found that lithiophorite was a common Mn oxide in all examined Fe-Mn nodules. Todorokite, however, was a predominant Mn oxide in Fe-Mn nodules in caf-aquic Vertisols of Linyi, Shandong Province. The Fe-Mn nodules of arp-udic Luvisols in Wuhan and Zaoyang, Hubei Province, contained birnessite and vernadite. Hollandite was found in Fe-Mn nodules of alt-udic Ferrisols of Yizhang, Hunan Province; arp-udic Luvisols of Zaoyang, Hubei Province; and cal-aquic Vertisols of Linyi, Shandong Province. The Fe-Mn nodules in alt-udic Ferrisols of Guiyang, Hunan Province, had a few coronadites. Mineralogy of Mn oxide minerals in soil Fe-Mn nodules was related to soil environment, soil types and quantities of relevant cations.
基金supported by the Natural Science Foundation-Steel and Iron Foundation of Hebei Province(No.E2021203051)the Hundred Outstanding Creative Talents Projects in Universities of Hebei Province,Chinathe Project Program of Heavy Machinery Collaborative Innovation Center,China.
文摘Twinned substructure in lath martensite was induced in the interstitial free(IF)steel via a high pressure thermal cycle(heating up to 1100℃and holding for 30 min,cooling at 10℃/s to room temperature under a pressure of 4 GPa).Experimental observations and theoretical simulation confrm that the twinned substructure has the origin related to the twinned variants rather than the bcc{112}<111>twins,while extra difraction spots were caused by crystal overlapping rather than any extra phase.The diferences in crystallography and electron difraction behavior between twinned variants and{112}<111>twins were discussed in detail.
基金supported by RFBR grants No.13-02-01372 and No.12-02-01329.
文摘Laser elktacytometry is a technique widely used for measuring the deformability of red blood cells(erythrocytes)in blood samples in vitro.In ektacytometer,a flow of highly diluted suspension of erythrocytes in variable shear stress conditions is iluninated with a laser beam to obtain a diffraction pattern.The diffraction pattern provides information about the shapes(shear induced elongations)of the cells under investigation.This paper is dedicated to developing the technique of laser ektacytometry s0 that it would enable one to measure the distrilbution of the erythrocytes in deformability.We discuss the problem of calibration of laser elktacytometer and test a novel data processing algorithm allowing to determine the parameters of the distribution of ery-throcytes deformability.Experimentally,we examined 12 specimens of blood of rats under the action of 4 shear stresses.Analysis of the data shows that in conditions of a limited range of digitizing the diffraction patterns,the measurement errors for the mean deformability,deform-ability scatter and the skewness of erythrocytes distribution in deformability by our method are respectively 15%,20%and 20%.
文摘Light manipulation and control are essential in various contemporary technologies,and as these technologies evolve,the demand for miniaturized optical components increases.Planar-lens technologies,such as metasurfaces and difractive optical elements,have gained attention in recent years for their potential to dramatically reduce the thickness of traditional refractive optical systems.However,their fabrication,particularly for visible wavelengths,involves complex and costly processes,such as high-resolution lithography and dry-etching,which has limited their availability.In this study,we present a simplifed method forfabricating visible Fresnel zone plate(FZP)planar lenses,a type of diffractive optical element,using an i-line stepper and a special photoresist(color resist)that only necessitates coating,exposure,and development,eliminating the need for etching or other post-processing steps.We fabricated visible FZp lens patterns using conventional photolithography equipment on 8-inch silica glass wafers,and demonstrated focusing of 550 nm light to a diameter of 1.1μm with a focusing efficiency of 7.2%.Numerical simulations showed excellent agreement with experimental results,confirming the high precision and designability of our method.Our lenses were also able to image objects with features down to 1.1μm,showcasing their potential for practical applications in imaging.Our method is a cost-effective,simple,and scalable solution for mass production of planar lenses and other optical components operating in the visible region.It enables the development of advanced,miniaturized optical systems to meet modern technology demand,making it a valuable contribution to optical component manufacturing.
基金supported by the National Natural Science Foundation of China(Grant Nos.11734001,11704017,91950204,92150302,12274478,and 61775244)the National Key Research and Development Program of China(Nos.2018YFB2200403,2021YFB2800604,and 2021YFB2800302)the Natural Science Foundation of Beijing Municipality(No.Z180015).
文摘In the feld of information processing,all-optical routers are signifcant for achieving high-speed,high-capacity signal processing and transmission.In this study,we developed three types of structurally simple and fexible routers using the deep difractive neural network(D2 NN),capable of routing incident light based on wavelength and polarization.First,we implemented a polarization router for routing two orthogonally polarized light beams.The second type is the wavelength router that can route light with wavelengths of 1550,1300,and 1100 nm,demonstrating outstanding performance with insertion loss as low as 0.013 dB and an extinction ratio of up to 18.96 dB,while also maintaining excellent polarization preservation.The fnal router is the polarization-wavelength composite router,capable of routing six types of input light formed by pairwise combinations of three wavelengths(1550,1300,and 1100 nm)and two orthogonal linearly polarized lights,thereby enhancing the information processing capability of the device.These devices feature compact structures,maintaining high contrast while exhibiting low loss and passive characteristics,making them suitable for integration into future optical components.This study introduces new avenues and methodologies to enhance performance and broaden the applications of future optical information processing systems.
基金the Defence Research and Development Organisation(DRDO)Govt.of India,for financial support under the research project ERIP/ER/1303129/M/01/1564.
文摘This work focuses on the structural,electrical and magnetic properties of Bi_(0.8)Tb_(0.1)Ba_(0.1)Fe_(0.9)Ti_(0.1)O_(3)ceramics,fabricated by solid state reaction procedure.XRD forms of the samples at RT exhibited perovskite phase through the hexagonal structure at room temperature.Dielectric studies of the materials with frequency at different temperatures(25-400℃)exhibit two dielectric anomalies,first at 175℃(ferroelectric-ferroelectric transition)and second at around 320℃(ferroelectric-paraelectric transition).The Curie temperature moved towards the low side temperature with the increase in frequency.The less value of activation energy got for these samples could be attributed to the influence of electronic contribution to the conductivity.A significant change in the magnetic studies was observed for Bi_(0.8)Tb_(0.1)Ba_(0.1)Fe_(0.9)Ti_(0.1)O_(3) ceramic.The impedance analysis confirms the non-Debye type nature of the ceramic and relaxation frequency moved to a higher temperature.The Nyquist plot and conductivity studies showed the NTCR behavior of samples.The highest magnetization field was found at temperature-268.15℃.
基金Radheshyam Rai is grateful to the Foundation for Science and Technology of Portugal(FCT)fornan-cial support(Grant No.SFRH/BPD/38001/2007).
文摘Ternary solid solutions of BiFeO_(3),GdFeO_(3)and BaTiO_(3)have been prepared by solid-state reaction method.Dielectric properties of these ceramics have been characterized in the tem-perature range between room temperature and 673 K and magnetic properties between 5 K and 300K.For the understanding of the multiferroic property,the relation between the crystal structures,magnetic transition and ferroelectric transitions with increasing temperature have been analyzed.All ceramic samples show single perovskite phase.When Ba content exceeds 0.2 wt%,the sintering ability is weakened and the phase structure of Bi_(1-x-y)Gd_(x)Ba_(y)Fe_(1-y)Ti_(y)O_(3)(with x=0.2 and y=0.1,0.2,0.3,0.4,0.5)solid solution changes from rhombohedral to tetragonal phase.The maximum ferroelectric transition temperature(T_(c))of this system was in the range 154-165℃with the dielectric constant peak of 6000 for y=0.5 at 100 kHz.Well-saturated piezoresponse hysteresis loops were observed for all compositions indicating room temperature ferroelectricity.With increasing Ba content(up to 0.3 wt%)the remanent magnetization M,increased and the coercive magnetic field decreased.
文摘Neodymium-doped barium phosphate(NdBP)was prepared as single crystal by room temperature solution technique known as gel encapsulation technique.Single crystal X-ray diffraction shows that the crystal belongs to orthorthombic system.The flower type morphology was observed by scanning electron microscope(SEM)and the stoichiometric composition of the prepared crystal was observed by energy dispersive X-ray analysis(EDAX).The presence of functional group and other groups was studied by Fourier transform infrared spectroscopy(FTIR).The electrical properties of these materials like dielectric constant(ε′),dieletric loss(tan σ)and ac conductivity[ln(σac)]was studied at different temperatures ranging from 40℃ to 420℃ in the frequency range of 5 kHz to 1 MHz.The activation energy values decreases with increase in frequency suggesting that the conduction mechanism is because of hopping of charge carriers.
