We report a systematic study on layered metal SrCu_(4-x)P_(2) single crystals via transport, magnetization, thermodynamic measurements and structural characterization. We find that the crystals show large linear magne...We report a systematic study on layered metal SrCu_(4-x)P_(2) single crystals via transport, magnetization, thermodynamic measurements and structural characterization. We find that the crystals show large linear magnetoresistance without any sign of saturation with a magnetic field up to 30T. We also observe a phase transition with significant anomalies in resistivity and heat capacity at T_(p)~140 K. Thermal expansion measurement reveals a subtle lattice parameter variation near Tp, i.e.,?L_(c)/L_(c)~0.062%. The structural characterization confines that there is no structure transition below and above T_(p). All these results suggest that the nonmagnetic transition of SrCu_(4-x)P_(2) could be associated with structural distortion.展开更多
Non-penetration laser welding of lap joints in austenitic stainless steel sheets is commonly preferred in fields where the surface quality is of utmost importance.However,the application of non-penetration welded aust...Non-penetration laser welding of lap joints in austenitic stainless steel sheets is commonly preferred in fields where the surface quality is of utmost importance.However,the application of non-penetration welded austenitic stainless steel parts is limited owing to the micro bulging distortion that occurs on the back surface of the partial penetration side.In this paper,non-penetration lap laser welding experiments,were conducted on galvanized and SUS304 austenitic stainless steel plates using a fiber laser,to investigate the mechanism of bulging distortion.A comparative experiment of DC01 galvanized steel-Q235 carbon steel lap laser welding was carried out,and the deflection and distortion profile of partially penetrated side of the sheets were measured using a noncontact laser interferometer.In addition,the cold-rolled SUS304 was subjected to heat holding at different temperatures and water quenching after bending to characterize its microstructure under tensile and compressive stress.The results show that,during the heating stage of the thermal cycle of laser lap welding,the partial penetration side of the SUS304 steel sheet generates compressive stress,which extrudes the material in the heat-affected zone to the outside of the back of the SUS304 steel sheet,thereby forming a bulge.The findings of these experiments can be of great value for controlling the distortion of the partial penetrated side of austenitic stainless steel sheet during laser non-penetration lap welding.展开更多
Maps, essential tools for portraying the Earth’s surface, inherently introduce distortions to geographical features. While various quantification methods exist for assessing these distortions, they often fall short w...Maps, essential tools for portraying the Earth’s surface, inherently introduce distortions to geographical features. While various quantification methods exist for assessing these distortions, they often fall short when evaluating actual geographic features. In our study, we took a novel approach by analyzing map projection distortion from a geometric perspective. We computed the fractal dimensions of different stretches of coastline before and after projection using the divide-and-conquer algorithm and image processing. Our findings revealed that map projections, even when preserving basic shapes, inevitably stretch and compress coastlines in diverse directions. This analysis method provides a more realistic and practical way to measure map-induced distortions, with significant implications for cartography, geographic information systems (GIS), and geomorphology. By bridging the gap between theoretical analysis and real-world features, this method greatly enhances accuracy and practicality when evaluating map projections.展开更多
In this paper,we define the class S_(g)^(BX)of g-parametric starlike mappings of real order γ on the unit ball BX in a complex Banach space X,where g is analytic and satisfies certain conditions.By establishing the d...In this paper,we define the class S_(g)^(BX)of g-parametric starlike mappings of real order γ on the unit ball BX in a complex Banach space X,where g is analytic and satisfies certain conditions.By establishing the distortion theorem of the Fr´echet-derivative type of S_(g)^(BX)with a weak restrictive condition,we further obtain the distortion results of the Jacobi-determinant type and the Fr´echet-derivative type for the corresponding classes(compared with S_(g)^(BX))defined on the unit polydisc(resp.unit ball with the arbitrary norm)in the space of n-dimensional complex variables,n≥2.Our results extend the classic distortion theorem of holomorphic functions from the case in one-dimensional complex space to the case in the higher dimensional complex space.The main theorems also generalize and improve some recent works.展开更多
Out-of-plane weak ferromagnetic(OWFM)spin arrangements with topological properties can realize a series of interesting physical properties.However,this spin structure tends to exist at low temperatures.The OWFM struct...Out-of-plane weak ferromagnetic(OWFM)spin arrangements with topological properties can realize a series of interesting physical properties.However,this spin structure tends to exist at low temperatures.The OWFM structure can also be induced at room temperature by hydrostatic pressure,whereas this isotropic approach tends to form helical AFM structures.We report the OWFM spin arrangement in single crystal Mn_(3)Sn by an anisotropic strategy of high-stressconstrained compression deformation at room temperature.Both experimental and theoretical simulation results show that the alignment of the OWFM spin structure is due to the distortion of the atomic scale caused by the strain energy during deformation.The OWFM spin arrangement can significantly change the magnetic property of Mn_(3)Sn.As a result,the remanent magnetization M_(r)for the deformed sample(0.056μ_(B)/f.u.)is about eleven times that for the pre-deformed sample(0.005μ_(B)/f.u.),and the coercivity(H_(c))increases from 0 k Oe(pre-deformed sample)to 6.02 k Oe(deformed sample).Our findings provide a way to generate the OWFM spin structure at room temperature and may give fresh ideas for creating antiferromagnetic materials with excellent physical properties.展开更多
Electromagnetic pulse(EMP)is a kind of transient electromagnetic phenomenon with short rise time of the leading edge and wide spectrum,which usually disrupts communications and damages electronic equipment and system....Electromagnetic pulse(EMP)is a kind of transient electromagnetic phenomenon with short rise time of the leading edge and wide spectrum,which usually disrupts communications and damages electronic equipment and system.It is challenging for an EMP sensor to measure a wideband electromagnetic pulse without distortion for the whole spectrum.Therefore,analyzing the distortion of EMP measurement is crucial to evaluating the sensor distortion characteristics and correcting the measurement results.Waveform fidelity is usually employed to evaluate the distortion of an antenna.However,this metric depends on specific signal waveforms,thus is unsuitable for evaluating and analyzing the distortion of EMP sensors.In this paper,an associated-hermite-function based distortion analysis method including system transfer matrices and distortion rates is proposed,which is general and independent from individual waveforms.The system transfer matrix and distortion rate can be straightforwardly calculated by the signal orthogonal transformation coefficients using associated-hermite functions.Distortion of a sensor vs.frequency is then visualized via the system transfer matrix,which is convenient in quantitative analysis of the distortion.Measurement of a current probe,a coaxial pulse voltage probe and a B-field sensor were performed,based on which the feasibility and effectiveness of the proposed distortion analysis method is successfully verified.展开更多
Background:Studies on animals have demonstrated that maternal iron deficiency anaemia(IDA)could result in decreased cochlear sensory hair cells and reduced amplitudes of distortion-product otoacoustic emissions(DPOAEs...Background:Studies on animals have demonstrated that maternal iron deficiency anaemia(IDA)could result in decreased cochlear sensory hair cells and reduced amplitudes of distortion-product otoacoustic emissions(DPOAEs)of young guinea pigs.Thus,it is essential to study the functioning of cochlear hair cells using DPOAEs in human newborn babies with maternal IDA.The current study explores maternal IDA’s effect on DPOAEs in newborn babies.Method:A total of 110 newborn babies with gestational age≥34 weeks were considered and a‘betweensubjects’design was used.The participants were divided into 3 groups-“Normal”(61 babies without maternal IDA),“Mild”(28 babies with mild maternal IDA)and“Moderate”(21 babies with moderate maternal IDA).The cord blood was collected and the DPOAEs were recorded for each baby for a range of frequencies(1 k 8 kHz)and a range of intensities(7040 dB SPL in 10 dB steps).Results:The analysis of both DP-gram and DP input-output(I/O)function showed that there was no significant difference(p>0.05)across the normal,mild,and moderate groups in the overall presence of DPOAEs as well as the amplitude across frequencies or intensities(7040 dB SPL).Also,the overall correlation of RBC indices with DPOAE amplitude across frequencies as well as the slope of the I/O function showed no relationship.Conclusion:The current study concludes that there is no effect of late-term maternal IDA on the DPOAEs of newborn babies.展开更多
基金Project supported by the National Key Research and Development Program of China (Grant Nos.2023YFA1607403,2021YFA1600201,and 2022YFA1602603)the Natural Science Foundation of China (Grant Nos.U19A2093,U2032214,and U2032163)+5 种基金the Collaborative Innovation Program of Hefei Science Center,CAS (Grant No.2019HSC-CIP 001)the Youth Innovation Promotion Association of CAS (Grant No.2021117)the Natural Science Foundation of Anhui Province (No.1908085QA15)the HFIPS Director’s Fund (Grant No.YZJJQY202304)the CASHIPS Director’s Fund (Grant No.YZJJ2022QN36)supported by the High Magnetic Field Laboratory of Anhui Province。
文摘We report a systematic study on layered metal SrCu_(4-x)P_(2) single crystals via transport, magnetization, thermodynamic measurements and structural characterization. We find that the crystals show large linear magnetoresistance without any sign of saturation with a magnetic field up to 30T. We also observe a phase transition with significant anomalies in resistivity and heat capacity at T_(p)~140 K. Thermal expansion measurement reveals a subtle lattice parameter variation near Tp, i.e.,?L_(c)/L_(c)~0.062%. The structural characterization confines that there is no structure transition below and above T_(p). All these results suggest that the nonmagnetic transition of SrCu_(4-x)P_(2) could be associated with structural distortion.
文摘Non-penetration laser welding of lap joints in austenitic stainless steel sheets is commonly preferred in fields where the surface quality is of utmost importance.However,the application of non-penetration welded austenitic stainless steel parts is limited owing to the micro bulging distortion that occurs on the back surface of the partial penetration side.In this paper,non-penetration lap laser welding experiments,were conducted on galvanized and SUS304 austenitic stainless steel plates using a fiber laser,to investigate the mechanism of bulging distortion.A comparative experiment of DC01 galvanized steel-Q235 carbon steel lap laser welding was carried out,and the deflection and distortion profile of partially penetrated side of the sheets were measured using a noncontact laser interferometer.In addition,the cold-rolled SUS304 was subjected to heat holding at different temperatures and water quenching after bending to characterize its microstructure under tensile and compressive stress.The results show that,during the heating stage of the thermal cycle of laser lap welding,the partial penetration side of the SUS304 steel sheet generates compressive stress,which extrudes the material in the heat-affected zone to the outside of the back of the SUS304 steel sheet,thereby forming a bulge.The findings of these experiments can be of great value for controlling the distortion of the partial penetrated side of austenitic stainless steel sheet during laser non-penetration lap welding.
文摘Maps, essential tools for portraying the Earth’s surface, inherently introduce distortions to geographical features. While various quantification methods exist for assessing these distortions, they often fall short when evaluating actual geographic features. In our study, we took a novel approach by analyzing map projection distortion from a geometric perspective. We computed the fractal dimensions of different stretches of coastline before and after projection using the divide-and-conquer algorithm and image processing. Our findings revealed that map projections, even when preserving basic shapes, inevitably stretch and compress coastlines in diverse directions. This analysis method provides a more realistic and practical way to measure map-induced distortions, with significant implications for cartography, geographic information systems (GIS), and geomorphology. By bridging the gap between theoretical analysis and real-world features, this method greatly enhances accuracy and practicality when evaluating map projections.
基金the National Natural Science Foundation of China(12071354)XIONG was the National Natural Science Foundation of China(12061035)+2 种基金the Jiangxi Provincial Natural Science Foundation(20212BAB201012)the Research Foundation of Jiangxi Provincial Department of Education(GJJ201104)the Research Foundation of Jiangxi Science and Technology Normal University(2021QNBJRC003)。
文摘In this paper,we define the class S_(g)^(BX)of g-parametric starlike mappings of real order γ on the unit ball BX in a complex Banach space X,where g is analytic and satisfies certain conditions.By establishing the distortion theorem of the Fr´echet-derivative type of S_(g)^(BX)with a weak restrictive condition,we further obtain the distortion results of the Jacobi-determinant type and the Fr´echet-derivative type for the corresponding classes(compared with S_(g)^(BX))defined on the unit polydisc(resp.unit ball with the arbitrary norm)in the space of n-dimensional complex variables,n≥2.Our results extend the classic distortion theorem of holomorphic functions from the case in one-dimensional complex space to the case in the higher dimensional complex space.The main theorems also generalize and improve some recent works.
基金supported by the National Natural Science Foundation of China(Grant Nos.52101233 and52071279)the Hebei Natural Science Foundation(Grant No.E2022203010)+1 种基金the China Postdoctoral Science Foundation(Grant No.2022M712685)the Innovation Capability Improvement Project of Hebei Province(Grant No.22567605H)。
文摘Out-of-plane weak ferromagnetic(OWFM)spin arrangements with topological properties can realize a series of interesting physical properties.However,this spin structure tends to exist at low temperatures.The OWFM structure can also be induced at room temperature by hydrostatic pressure,whereas this isotropic approach tends to form helical AFM structures.We report the OWFM spin arrangement in single crystal Mn_(3)Sn by an anisotropic strategy of high-stressconstrained compression deformation at room temperature.Both experimental and theoretical simulation results show that the alignment of the OWFM spin structure is due to the distortion of the atomic scale caused by the strain energy during deformation.The OWFM spin arrangement can significantly change the magnetic property of Mn_(3)Sn.As a result,the remanent magnetization M_(r)for the deformed sample(0.056μ_(B)/f.u.)is about eleven times that for the pre-deformed sample(0.005μ_(B)/f.u.),and the coercivity(H_(c))increases from 0 k Oe(pre-deformed sample)to 6.02 k Oe(deformed sample).Our findings provide a way to generate the OWFM spin structure at room temperature and may give fresh ideas for creating antiferromagnetic materials with excellent physical properties.
基金Research Project of High-Level Talents of Jiangsu Police Institute(No.2911118010).
文摘Electromagnetic pulse(EMP)is a kind of transient electromagnetic phenomenon with short rise time of the leading edge and wide spectrum,which usually disrupts communications and damages electronic equipment and system.It is challenging for an EMP sensor to measure a wideband electromagnetic pulse without distortion for the whole spectrum.Therefore,analyzing the distortion of EMP measurement is crucial to evaluating the sensor distortion characteristics and correcting the measurement results.Waveform fidelity is usually employed to evaluate the distortion of an antenna.However,this metric depends on specific signal waveforms,thus is unsuitable for evaluating and analyzing the distortion of EMP sensors.In this paper,an associated-hermite-function based distortion analysis method including system transfer matrices and distortion rates is proposed,which is general and independent from individual waveforms.The system transfer matrix and distortion rate can be straightforwardly calculated by the signal orthogonal transformation coefficients using associated-hermite functions.Distortion of a sensor vs.frequency is then visualized via the system transfer matrix,which is convenient in quantitative analysis of the distortion.Measurement of a current probe,a coaxial pulse voltage probe and a B-field sensor were performed,based on which the feasibility and effectiveness of the proposed distortion analysis method is successfully verified.
文摘Background:Studies on animals have demonstrated that maternal iron deficiency anaemia(IDA)could result in decreased cochlear sensory hair cells and reduced amplitudes of distortion-product otoacoustic emissions(DPOAEs)of young guinea pigs.Thus,it is essential to study the functioning of cochlear hair cells using DPOAEs in human newborn babies with maternal IDA.The current study explores maternal IDA’s effect on DPOAEs in newborn babies.Method:A total of 110 newborn babies with gestational age≥34 weeks were considered and a‘betweensubjects’design was used.The participants were divided into 3 groups-“Normal”(61 babies without maternal IDA),“Mild”(28 babies with mild maternal IDA)and“Moderate”(21 babies with moderate maternal IDA).The cord blood was collected and the DPOAEs were recorded for each baby for a range of frequencies(1 k 8 kHz)and a range of intensities(7040 dB SPL in 10 dB steps).Results:The analysis of both DP-gram and DP input-output(I/O)function showed that there was no significant difference(p>0.05)across the normal,mild,and moderate groups in the overall presence of DPOAEs as well as the amplitude across frequencies or intensities(7040 dB SPL).Also,the overall correlation of RBC indices with DPOAE amplitude across frequencies as well as the slope of the I/O function showed no relationship.Conclusion:The current study concludes that there is no effect of late-term maternal IDA on the DPOAEs of newborn babies.
