We employ a Hall-effect magnetic sensor array to accurately track the trajectory of a single magnetic sphere,referred to as the“intruder,”within a three-dimensional vibro-fluidized granular bed to unravel the underl...We employ a Hall-effect magnetic sensor array to accurately track the trajectory of a single magnetic sphere,referred to as the“intruder,”within a three-dimensional vibro-fluidized granular bed to unravel the underlying physical mechanism governing the motion of the intruder.Within the acceleration range of 3.5 g≥Γ≥1.5 g,we find that,regardless of the intruder's initial position,it consistently reaches the same equilibrium depth when the vibration acceleration(Γ)and frequency(ω)are fixed.ForΓ≤2.5 g,the equilibrium position lies on the surface of the granular bed,while forΓ>2.5 g,it shifts below the surface.Additionally,intruders with different densities exhibit varying equilibrium depths,with higher density resulting in a deeper equilibrium position.To understand the mechanism behind the intruder's upward or downward motion,we measure its rising or sinking velocities under different vibration parameters.Our findings demonstrate that the rising velocity of the intruder,under varying vibration accelerations(Γ)and frequencies(ω),can be collapsed using the ratioΓ/ω,while the sinking velocity remains unaffected by the vibration strength.This confirms that the upward motion of the larger sphere,associated with the Brazil nut effect,primarily arises from the void-filling mechanism of the bed particles.Furthermore,our experiments reveal that the presence of convection within the bed particles has minimal impact on the motion of the intruder.展开更多
AIM: To detect the pathogenetic mutations responsible for nonsyndromic autosomal recessive retinitis pigmentosa(RP) in 2 nonconsanguineous Chinese families. METHODS: The clinical data, including detailed medical histo...AIM: To detect the pathogenetic mutations responsible for nonsyndromic autosomal recessive retinitis pigmentosa(RP) in 2 nonconsanguineous Chinese families. METHODS: The clinical data, including detailed medical history, best corrected visual acuity(BCVA), slit-lamp biomicroscope examination, fundus photography, optical coherence tomography, static perimetry, and full field electroretinogram, were collected from the members of 2 nonconsanguineous Chinese families preliminarily diagnosed with RP. Genomic DNA was extracted from the probands and other available family members;wholeexome sequencing was conducted with the DNA samples provided by the probands, and all mutations detected by whole-exome sequencing were verified using Sanger sequencing in the probands and the other available family members. The verified novel mutations were further sequenced in 192 ethnicity matched healthy controls.RESULTS: The patients from the 2 families exhibited the typical symptoms of RP, including night blindness and progressive constriction of the visual field, and the fundus examinations showed attenuated retinal arterioles, peripheral bone spicule pigment deposits, and waxy optic discs. Whole-exome sequencing revealed a novel nonsense mutation in FAM161 A(c.943 A>T, p.Lys315*) and compound heterozygous mutations in RP1 L1(c.56 C>A, p.Pro19 His;c.5470 C>T, p.Gln1824*). The nonsense c.5470 C>T, p.Gln1824* mutation was novel. All mutations were verified by Sanger sequencing. The mutation p.Lys315* in FAM161A co-segregated with the phenotype, and all the nonsense mutations were absent from the ethnicity matched healthy controls and all available databases.CONCLUSION: We identify 2 novel mutations in genes responsible for autosomal recessive RP, and the mutation in FAM161A is reported for the first time in a Chinese population. Our result not only enriches the knowledge of the mutation frequency and spectrum in the genes responsible for nonsyndromic RP but also provides a new target for future gene therapy.展开更多
AIM：To investigate the relationship between high myopia [with or without complete congenital stationary night blindness（CSNB1）] and TRPM1 and NYX.METHODS： Two unrelated families with early-onset high myopia（eo HM...AIM：To investigate the relationship between high myopia [with or without complete congenital stationary night blindness（CSNB1）] and TRPM1 and NYX.METHODS： Two unrelated families with early-onset high myopia（eo HM） and 96 normal controls were recruited.Sanger sequencing or clone sequencing were used for mutation screening.Further analyses of the available family members and the 96 normal controls were subsequently conducted to obtain additional evidence of the pathogenicity of these variants.The initial diagnosis of the probands was eo HM.We performed a further comprehensive examination of the available family members after mutations were detected in TRPM1 or NYX. RESULTS： Two novel compound heterozygous mutations in TRPM1 were detected in the recruited families.The proband in family A with eo HM carried a c.2594 C 〉T missense mutation in exon 19 and a c.669 ＋3_669 ＋6del AAGT splicing mutation,which was co-segregated with CSNB1 in this family.A patient in family B with a compound heterozygous missense mutation（c.3262 G〉A and c.3250 T〉C） was detected.No mutations were found in NYX.These two identified compound heterozygous mutations were not found in the 96 normal controls.After further examination of the family members,the patients in family A could be diagnosed as eo HM with CSNB1.However due to the limited clinic data,the patient in family B cloud not clearly diagnosed as CSNB1.CONCLUSION： This study has expanded the mutation spectrum of TRPM1 for CSNB1 and additional studiesare needed to elucidate the association between isolated high myopia and TRPM1 and NYX.展开更多
By using the beat frequency technique,the dual-wavelength digital holography(DWDH)can greatly increase the measurement range of the system.However,the beat frequency technique has a limitation in measurement range.The...By using the beat frequency technique,the dual-wavelength digital holography(DWDH)can greatly increase the measurement range of the system.However,the beat frequency technique has a limitation in measurement range.The measurement range is not larger than a synthetic wavelength.Here,to break through this limitation,we propose a novel DWDH method based on the constrained underdetermined equations,which consists of three parts:(i)prove that the constrained underdetermined equation has a unique integer solution,(ii)design an algorithm to search for the unique integer solution,(iii)introduce a third wavelength into the DWDH system,and design a corresponding algorithm to enhance the anti-noise performance of DWDH.As far as we know,it is the first time that we have discovered that the problem of DWDH can belong in a problem of contained underdetermined equations,and it is also the first time that we have given the mathematical proof for breaking through the limitation of the measurement range.A series of results is shown to test the theory and the corresponding algorithms.More importantly,since the principle of proposed DWDH is based on basic mathematical principles,it can be further extended to various fields,such as dual-wavelength microwave imaging and dual-wavelength coherent diffraction imaging.展开更多
Niobium telluride(NbTe_(2)),a kind of few-layer two-dimensional(2D)transition metal dichalcogenides(TMDs)material,has been theoretically predicted with nonlinear absorption properties and excellent optical response.He...Niobium telluride(NbTe_(2)),a kind of few-layer two-dimensional(2D)transition metal dichalcogenides(TMDs)material,has been theoretically predicted with nonlinear absorption properties and excellent optical response.Herein,we experimentally demonstrated an Er-doped fiber(EDF)laser based NbTe_(2)as saturable absorber(SA).Few-layer NbTe_(2)nanosheets were successfully prepared by adopting the commonly used liquid-phase exfoliation(LPE)method.The nonlinear optical response of highly stable few-layer NbTe_(2)was investigated through an open-aperture Z-scan laser measurement,the nonlinear absorption coefficient was 2.45×10^(-11)m/W.Both Q-switched and mode-locked operation centered at 1559 nm were recorded based on NbTe_(2)SA.The pulse duration was varied from 4.88 ms to 1.75 ms,and the adjustable range of repetition frequency is changed from 44.01 kHz to 64.12 kHz in passively Q-switched operation.Furthermore,a constant repetition rate of 5.33 MHz and pulse width of 2.67 ps were observed in mode-locked operation.Our experimental results fully reveal the nonlinear optical prop-erties of NbTe_(2)used in pulsed fiber lasers and broaden its ultrafast applications in the optics field.展开更多
AIM:To investigate whether mutations in TGFBI gene or CHST6 gene correlated with stromal corneal dystrophies(CD) in 8 Chinese probands.· METHODS:Eight unrelated patients with stromal corneal dystrophies were recr...AIM:To investigate whether mutations in TGFBI gene or CHST6 gene correlated with stromal corneal dystrophies(CD) in 8 Chinese probands.· METHODS:Eight unrelated patients with stromal corneal dystrophies were recruited in this study;all affected members were assessed by completely ophthalmologic examinations.Genomic DNA was extracted from peripheral leukocytes,17 exons of TGFBI gene and the exon of CHST6 gene were amplified by polymerase chain reaction(PCR),sequenced directly and compared with the reference database.· RESULTS:Three heterozygous mutations in TGFBI gene were identified in six patients:c.370C>T(p.Arg124Cys) was found in exon 4 of TGFBI gene in three members,c.371G>A(p.Arg124His) was found in one patient;c.1663C>T(p.Arg555Trp) was found in exon 12 in other two members.In addition,four polymorphisms with the nucleotide changes rs1442,rs1054124,rs4669,and rs35151677 were found in TGFBI gene.Mutations were not identified in the rest of 2 affected individuals in TGFBI gene or CHST6 gene.· CONCLUSION:Within these patients,R124C,R124H and R555W mutations were co-segregated with the disease phenotypes and were specific mutations for lattice corneal dystrophy type I(LCD I),Avellino corneal dystrophy(ACD,GCDⅡ),granular corneal dystrophy type I(GCD I),respectively.Our study highlights the prevalence of codon 124 and codon 555 mutations in the TGFBI gene among the Chinese stromal corneal dystrophies patients.·展开更多
Industry chain financing,also known as supply chain financing,is a kind of financial innovation in production and transaction emerging from the 1990 s. Recent years,industry chain financing has gradually permeated in ...Industry chain financing,also known as supply chain financing,is a kind of financial innovation in production and transaction emerging from the 1990 s. Recent years,industry chain financing has gradually permeated in agriculture. As one of the major agricultural countries in the world,China should still make great endeavor in satisfying domestic requirement of agricultural products and improving international competitiveness. Based on the empirical and feasible analysis of agricultural industry chain financing,this article emphasizes on the new mode of industry chain financing and puts forward some related policy suggestions to discuss how to quicken agricultural development with financial support as well as promote international competitiveness of China's agriculture.展开更多
Active metasurfaces have recently attracted more attention since they can make the light manipulation be versatile and real-time. Metasurfaces-based holography possesses the advantages of high spatial resolution and e...Active metasurfaces have recently attracted more attention since they can make the light manipulation be versatile and real-time. Metasurfaces-based holography possesses the advantages of high spatial resolution and enormous information capacity for applications in optical displays and encryption. In this work, a tunable polarization multiplexing holographic metasurface controlled by an external magnetic field is proposed. The elaborately designed nanoantennas are arranged on the magneto-optical intermediate layer, which is placed on the metallic reflecting layer. Since the non-diagonal elements of the dielectric tensor of the magneto-optical material become non-zero values once the external magnetic field is applied,the differential absorption for the left and right circularly polarized light can be generated. Meanwhile, the amplitude and phase can be flexibly modulated by changing the sizes of the nanoantennas. Based on this, the dynamic multichannel holographic display of metasurface in the linear and circular polarization channels is realized via magnetic control, and it can provide enhanced security for optical information storage. This work paves the way for the realization of magnetically controllable phase modulation, which is promising in dynamic wavefront control and optical information encryption.展开更多
The two-way shape memory effect in a Ti-18.5Zr-10Nb-3.5Ta high-temperature shape memory alloy was investigated.X-ray diffraction measurem ent shows that the alloy is composed of orthorhombicα"-martensite.ωphase...The two-way shape memory effect in a Ti-18.5Zr-10Nb-3.5Ta high-temperature shape memory alloy was investigated.X-ray diffraction measurem ent shows that the alloy is composed of orthorhombicα"-martensite.ωphase is not found in Ti-18.5Zr-10Nb-3.5Ta alloy due to the suppressing effect of Ta element.Theα"-martensite laths are found in the transmission electron microscope observation;after the bending deformation,there appear a lot of dislocations.The alloy exhibits a shape memory strain of 3.8%aud a high reverse martensite transformation start temperature of 464 K.The maximum two-way shape memory strain of 1.2%is obtained in the alloy with the prebending training strain of 10%.The mechanism can be ascribed to the effect of internal stress field caused by dislocations.展开更多
有机-无机杂化卤化物钙钛矿太阳能电池(perovskite solar cells, PSCs)由于其成本低廉、制备工艺简单、光电转换率高等优点引起了越来越多的关注,在下一代半导体光伏技术中显示出巨大的发展潜力。然而PSCs器件在商业化生产应用之前,必...有机-无机杂化卤化物钙钛矿太阳能电池(perovskite solar cells, PSCs)由于其成本低廉、制备工艺简单、光电转换率高等优点引起了越来越多的关注,在下一代半导体光伏技术中显示出巨大的发展潜力。然而PSCs器件在商业化生产应用之前,必须解决某些关键问题,例如器件在湿度、光照和过热条件下缺乏稳定性,性能会急剧衰退。层状二维(two-dimensional, 2D)钙钛矿由于其优异的环境稳定性而受到研究人员的广泛关注。通过引入不同种类的疏水性大体积有机铵阳离子可以在钙钛矿体内形成稳定的2D结构。然而,由于绝缘有机间隔阳离子的存在,使其电荷输运能力受阻并影响光电转换性能。本文根据不同种类2D钙钛矿光伏器件的发展进程,总结了影响2D钙钛矿结构和性能的关键问题,如晶体垂直取向设计、量子阱调控和有机层间隔阳离子替换工程等。最后对2D PSCs的未来发展进行展望。展开更多
Novel ternary Cr2O3-SiC-TiO2 composites were synthesized by implanting Cr3＋ into SiC-TiO2 via sol-gel and impregnation approaches. The results from X-ray diffraction, scanning electron microscopy and trans- mission e...Novel ternary Cr2O3-SiC-TiO2 composites were synthesized by implanting Cr3＋ into SiC-TiO2 via sol-gel and impregnation approaches. The results from X-ray diffraction, scanning electron microscopy and trans- mission electron microscopy show that the Cr3. species were doped onto the surface of the SiC-TiO2 carrier. The diffuse reflectance ultraviolet-visible absorption spectra revealed that the absorption edges of the ternary Cr2O3-SiC-TiO2 composites were gradually shifted red with increasing chromium content. The luminescence intensities of the composites decreased with increasing doped Cr3＋ content due to the reduction in the number of recombination sites of electron-hole pairs. The ternary Cr2O3-SiC-TiO2 com- posites showed high hydrogen-producing activities, which probably results from the formation of donor levels of the Cr3＋ species in the forbidden band of the SiC semiconductor.展开更多
基金Project supported by the Space Application System of China Manned Space Programthe National Natural Science Foundation of China(Grant Nos.12072200 and 12002213)。
文摘We employ a Hall-effect magnetic sensor array to accurately track the trajectory of a single magnetic sphere,referred to as the“intruder,”within a three-dimensional vibro-fluidized granular bed to unravel the underlying physical mechanism governing the motion of the intruder.Within the acceleration range of 3.5 g≥Γ≥1.5 g,we find that,regardless of the intruder's initial position,it consistently reaches the same equilibrium depth when the vibration acceleration(Γ)and frequency(ω)are fixed.ForΓ≤2.5 g,the equilibrium position lies on the surface of the granular bed,while forΓ>2.5 g,it shifts below the surface.Additionally,intruders with different densities exhibit varying equilibrium depths,with higher density resulting in a deeper equilibrium position.To understand the mechanism behind the intruder's upward or downward motion,we measure its rising or sinking velocities under different vibration parameters.Our findings demonstrate that the rising velocity of the intruder,under varying vibration accelerations(Γ)and frequencies(ω),can be collapsed using the ratioΓ/ω,while the sinking velocity remains unaffected by the vibration strength.This confirms that the upward motion of the larger sphere,associated with the Brazil nut effect,primarily arises from the void-filling mechanism of the bed particles.Furthermore,our experiments reveal that the presence of convection within the bed particles has minimal impact on the motion of the intruder.
基金Supported by the National Natural Science Foundation of China(No.81360154)
文摘AIM: To detect the pathogenetic mutations responsible for nonsyndromic autosomal recessive retinitis pigmentosa(RP) in 2 nonconsanguineous Chinese families. METHODS: The clinical data, including detailed medical history, best corrected visual acuity(BCVA), slit-lamp biomicroscope examination, fundus photography, optical coherence tomography, static perimetry, and full field electroretinogram, were collected from the members of 2 nonconsanguineous Chinese families preliminarily diagnosed with RP. Genomic DNA was extracted from the probands and other available family members;wholeexome sequencing was conducted with the DNA samples provided by the probands, and all mutations detected by whole-exome sequencing were verified using Sanger sequencing in the probands and the other available family members. The verified novel mutations were further sequenced in 192 ethnicity matched healthy controls.RESULTS: The patients from the 2 families exhibited the typical symptoms of RP, including night blindness and progressive constriction of the visual field, and the fundus examinations showed attenuated retinal arterioles, peripheral bone spicule pigment deposits, and waxy optic discs. Whole-exome sequencing revealed a novel nonsense mutation in FAM161 A(c.943 A>T, p.Lys315*) and compound heterozygous mutations in RP1 L1(c.56 C>A, p.Pro19 His;c.5470 C>T, p.Gln1824*). The nonsense c.5470 C>T, p.Gln1824* mutation was novel. All mutations were verified by Sanger sequencing. The mutation p.Lys315* in FAM161A co-segregated with the phenotype, and all the nonsense mutations were absent from the ethnicity matched healthy controls and all available databases.CONCLUSION: We identify 2 novel mutations in genes responsible for autosomal recessive RP, and the mutation in FAM161A is reported for the first time in a Chinese population. Our result not only enriches the knowledge of the mutation frequency and spectrum in the genes responsible for nonsyndromic RP but also provides a new target for future gene therapy.
基金Supported by the National Nature Science Foundation of China(No.81362138)
文摘AIM：To investigate the relationship between high myopia [with or without complete congenital stationary night blindness（CSNB1）] and TRPM1 and NYX.METHODS： Two unrelated families with early-onset high myopia（eo HM） and 96 normal controls were recruited.Sanger sequencing or clone sequencing were used for mutation screening.Further analyses of the available family members and the 96 normal controls were subsequently conducted to obtain additional evidence of the pathogenicity of these variants.The initial diagnosis of the probands was eo HM.We performed a further comprehensive examination of the available family members after mutations were detected in TRPM1 or NYX. RESULTS： Two novel compound heterozygous mutations in TRPM1 were detected in the recruited families.The proband in family A with eo HM carried a c.2594 C 〉T missense mutation in exon 19 and a c.669 ＋3_669 ＋6del AAGT splicing mutation,which was co-segregated with CSNB1 in this family.A patient in family B with a compound heterozygous missense mutation（c.3262 G〉A and c.3250 T〉C） was detected.No mutations were found in NYX.These two identified compound heterozygous mutations were not found in the 96 normal controls.After further examination of the family members,the patients in family A could be diagnosed as eo HM with CSNB1.However due to the limited clinic data,the patient in family B cloud not clearly diagnosed as CSNB1.CONCLUSION： This study has expanded the mutation spectrum of TRPM1 for CSNB1 and additional studiesare needed to elucidate the association between isolated high myopia and TRPM1 and NYX.
基金Project supported by the Foundation of Science and Technology Department of Shaanxi Province,China(Grant No.2018JQ6009)the Foundation of Education Department of Shaanxi Province,China(Grant No.17JK1165)+4 种基金the Beijing Natural Science Foundation,China(Grant No.Z190004)the National Natural Science Foundation of China(Grant No.61575197)the Innovation Capability Improvement Plan,Hebei Province,China(Grant No.20540302D)the Fundamental Research Funds for the Central Universities,China,the Youth Innovation Promotion Association,Chinese Academy of Sciences(Grant No.2017489)the Natural Science Foundation of Hebei Province,China(Grant No.F2018402285).
文摘By using the beat frequency technique,the dual-wavelength digital holography(DWDH)can greatly increase the measurement range of the system.However,the beat frequency technique has a limitation in measurement range.The measurement range is not larger than a synthetic wavelength.Here,to break through this limitation,we propose a novel DWDH method based on the constrained underdetermined equations,which consists of three parts:(i)prove that the constrained underdetermined equation has a unique integer solution,(ii)design an algorithm to search for the unique integer solution,(iii)introduce a third wavelength into the DWDH system,and design a corresponding algorithm to enhance the anti-noise performance of DWDH.As far as we know,it is the first time that we have discovered that the problem of DWDH can belong in a problem of contained underdetermined equations,and it is also the first time that we have given the mathematical proof for breaking through the limitation of the measurement range.A series of results is shown to test the theory and the corresponding algorithms.More importantly,since the principle of proposed DWDH is based on basic mathematical principles,it can be further extended to various fields,such as dual-wavelength microwave imaging and dual-wavelength coherent diffraction imaging.
基金National Natural Science Foundation of China(Grant nos.61971271,11904213,62271294)the Jinan City-School Integration Development Strategy Project(JNSX2021023)+3 种基金the Major Program of Shandong Province Natural Science Foundation(ZR2022ZD16)the Shandong Province Major Technological Innovation Project(2022CXGC010502,2022CXGC020507,2022CXGC020505)the Key Project of Department of Education of Guangdong Province(Grant no.2018KCXTD026)the Deanship of Scientific Research(DSR)at King Abdulaziz University,Jeddah(Grant no:KEP-MSc-70-130-42),supported by“Opening Foundation of Shandong Provincial Key Laboratory of Laser Technology and Application”.
文摘Niobium telluride(NbTe_(2)),a kind of few-layer two-dimensional(2D)transition metal dichalcogenides(TMDs)material,has been theoretically predicted with nonlinear absorption properties and excellent optical response.Herein,we experimentally demonstrated an Er-doped fiber(EDF)laser based NbTe_(2)as saturable absorber(SA).Few-layer NbTe_(2)nanosheets were successfully prepared by adopting the commonly used liquid-phase exfoliation(LPE)method.The nonlinear optical response of highly stable few-layer NbTe_(2)was investigated through an open-aperture Z-scan laser measurement,the nonlinear absorption coefficient was 2.45×10^(-11)m/W.Both Q-switched and mode-locked operation centered at 1559 nm were recorded based on NbTe_(2)SA.The pulse duration was varied from 4.88 ms to 1.75 ms,and the adjustable range of repetition frequency is changed from 44.01 kHz to 64.12 kHz in passively Q-switched operation.Furthermore,a constant repetition rate of 5.33 MHz and pulse width of 2.67 ps were observed in mode-locked operation.Our experimental results fully reveal the nonlinear optical prop-erties of NbTe_(2)used in pulsed fiber lasers and broaden its ultrafast applications in the optics field.
文摘AIM:To investigate whether mutations in TGFBI gene or CHST6 gene correlated with stromal corneal dystrophies(CD) in 8 Chinese probands.· METHODS:Eight unrelated patients with stromal corneal dystrophies were recruited in this study;all affected members were assessed by completely ophthalmologic examinations.Genomic DNA was extracted from peripheral leukocytes,17 exons of TGFBI gene and the exon of CHST6 gene were amplified by polymerase chain reaction(PCR),sequenced directly and compared with the reference database.· RESULTS:Three heterozygous mutations in TGFBI gene were identified in six patients:c.370C>T(p.Arg124Cys) was found in exon 4 of TGFBI gene in three members,c.371G>A(p.Arg124His) was found in one patient;c.1663C>T(p.Arg555Trp) was found in exon 12 in other two members.In addition,four polymorphisms with the nucleotide changes rs1442,rs1054124,rs4669,and rs35151677 were found in TGFBI gene.Mutations were not identified in the rest of 2 affected individuals in TGFBI gene or CHST6 gene.· CONCLUSION:Within these patients,R124C,R124H and R555W mutations were co-segregated with the disease phenotypes and were specific mutations for lattice corneal dystrophy type I(LCD I),Avellino corneal dystrophy(ACD,GCDⅡ),granular corneal dystrophy type I(GCD I),respectively.Our study highlights the prevalence of codon 124 and codon 555 mutations in the TGFBI gene among the Chinese stromal corneal dystrophies patients.·
文摘Industry chain financing,also known as supply chain financing,is a kind of financial innovation in production and transaction emerging from the 1990 s. Recent years,industry chain financing has gradually permeated in agriculture. As one of the major agricultural countries in the world,China should still make great endeavor in satisfying domestic requirement of agricultural products and improving international competitiveness. Based on the empirical and feasible analysis of agricultural industry chain financing,this article emphasizes on the new mode of industry chain financing and puts forward some related policy suggestions to discuss how to quicken agricultural development with financial support as well as promote international competitiveness of China's agriculture.
基金supported by the National Key R&D Program of China (Nos. 2021YFB2801803 and 2021YFA1401200)the Natural Science Foundation of Shandong Province(No. ZR2023LZH001)+3 种基金the Beijing Outstanding Young Scientist Program (No. BJJWZYJH01201910007022)the National Natural Science Foundation of China (Nos. U21A20140 and 92050117)the Fok Ying-Tong Education Foundation of China(No. 161009)the Beijing Municipal Science&Technology Commission,Administrative Commission of Zhongguancun Science Park (No. Z211100004821009)。
文摘Active metasurfaces have recently attracted more attention since they can make the light manipulation be versatile and real-time. Metasurfaces-based holography possesses the advantages of high spatial resolution and enormous information capacity for applications in optical displays and encryption. In this work, a tunable polarization multiplexing holographic metasurface controlled by an external magnetic field is proposed. The elaborately designed nanoantennas are arranged on the magneto-optical intermediate layer, which is placed on the metallic reflecting layer. Since the non-diagonal elements of the dielectric tensor of the magneto-optical material become non-zero values once the external magnetic field is applied,the differential absorption for the left and right circularly polarized light can be generated. Meanwhile, the amplitude and phase can be flexibly modulated by changing the sizes of the nanoantennas. Based on this, the dynamic multichannel holographic display of metasurface in the linear and circular polarization channels is realized via magnetic control, and it can provide enhanced security for optical information storage. This work paves the way for the realization of magnetically controllable phase modulation, which is promising in dynamic wavefront control and optical information encryption.
基金financially supported by the National Natural Science Foundation of China(No.51371016)the Fundamental Research Funds for the Central Universities(Nos.YWF-16-BJ-J-49 and YWF-17-BJ-J-23)。
文摘The two-way shape memory effect in a Ti-18.5Zr-10Nb-3.5Ta high-temperature shape memory alloy was investigated.X-ray diffraction measurem ent shows that the alloy is composed of orthorhombicα"-martensite.ωphase is not found in Ti-18.5Zr-10Nb-3.5Ta alloy due to the suppressing effect of Ta element.Theα"-martensite laths are found in the transmission electron microscope observation;after the bending deformation,there appear a lot of dislocations.The alloy exhibits a shape memory strain of 3.8%aud a high reverse martensite transformation start temperature of 464 K.The maximum two-way shape memory strain of 1.2%is obtained in the alloy with the prebending training strain of 10%.The mechanism can be ascribed to the effect of internal stress field caused by dislocations.
基金the financial support by the Industrial Key Project of Science and Technology of Shaanxi Province(No.2010K01-080)the Open Fund of State Key Laboratory of Architecture Science and Technology in West China(XAUAT)Xi'an University of Architecture and Technology(No.10KF05)
文摘Novel ternary Cr2O3-SiC-TiO2 composites were synthesized by implanting Cr3＋ into SiC-TiO2 via sol-gel and impregnation approaches. The results from X-ray diffraction, scanning electron microscopy and trans- mission electron microscopy show that the Cr3. species were doped onto the surface of the SiC-TiO2 carrier. The diffuse reflectance ultraviolet-visible absorption spectra revealed that the absorption edges of the ternary Cr2O3-SiC-TiO2 composites were gradually shifted red with increasing chromium content. The luminescence intensities of the composites decreased with increasing doped Cr3＋ content due to the reduction in the number of recombination sites of electron-hole pairs. The ternary Cr2O3-SiC-TiO2 com- posites showed high hydrogen-producing activities, which probably results from the formation of donor levels of the Cr3＋ species in the forbidden band of the SiC semiconductor.
