2D Ruddlesden-Popper(RP)polar perovskite,displaying the intrinsic optical anisotropy and structural polarity,has a fantastic application perspective in self-powered polarized light detection.However,the weak van der W...2D Ruddlesden-Popper(RP)polar perovskite,displaying the intrinsic optical anisotropy and structural polarity,has a fantastic application perspective in self-powered polarized light detection.However,the weak van der Waals interaction between the organic spacing bilayers is insufficient to preserve the stability of RP-type materials.Hence,it is of great significance to explore new stable 2D RP-phase candidates.In this work,we have successfully constructed a highly-stable polar 2D perovskite,(t-ACH)_(2)PbI_(4)(1,where t-ACH^(+)is HOOC_(8)H_(12)NH_(3)^(+)),by adopting a hydrophobic carboxylate trans-isomer of tranexamic acid as the spacing component.Strikingly,strong O-H…O hydrogen bonds between t-ACH^(+)organic bilayers compose the dimer,thus decreasing van der Waals gap and enhancing structural stability.Besides,such orientational hydrogen bonds contribute to the formation of structural polarity and generate an obvious bulk photovoltaic effect in 1,which facilitates its self-powered photodetection.As predicted,the combination of inherent anisotropy and polarity leads to self-powered polarized-light detection with a high ratio of around∼5.3,superior to those of inorganic 2D counterparts.This work paves a potential way to design highly-stable 2D perovskites for high-performance optoelectronic devices.展开更多
Qualification of polarization can be realized either on a macroscopic scale as an average property by P-E hysteresis measurements or on a nano/micro scale by piezoelectric force microscopy,transmission electron micros...Qualification of polarization can be realized either on a macroscopic scale as an average property by P-E hysteresis measurements or on a nano/micro scale by piezoelectric force microscopy,transmission electron microscopy,scanning electron microscopy,and so on.However,visualization and qualification of polarization distribution in the micron to millimeter scale is still a challenge.Polarizing light microscopy(PLM)is often used in the study of ferroelectric domain structures mainly for domain patterns.A phe-nomenon called“chromatic polarization”has been observed in transparent ferroelectric crystals by using a crossed-PLM system viewed with white light,which contains rich information about local polariza-tion distribution.In this study,an automatic full-angle light intensity detection(AFALID)algorithm com-bined with colorimetry is developed to analyze the distribution of nonuniform local spontaneous polar-ization distribution in transparent ferroelectric single crystals.Temperature-dependent spontaneous po-larizations from the color analysis for PMN-0.36PT single crystals with single tetragonal domain state are in good coincidence with those extracted from temperature-dependent hysteresis loops and pyroelectric current measurements.We further apply this method to quantify the nonuniform domain distributions with nano-indentations.This non-contact and non-destructive characterization can provide fast and au-tomatic detection of polarization distributions in ferroelectric materials.展开更多
OBJECTIVE:To evaluate the effects of external application of warm meridian medicated wine and polarized light therapy combined with acupuncture on pain management following vertebroplasty. METHODS:A total of 120 patie...OBJECTIVE:To evaluate the effects of external application of warm meridian medicated wine and polarized light therapy combined with acupuncture on pain management following vertebroplasty. METHODS:A total of 120 patients with osteoporotic vertebral compression fractures treated by vertebroplasty at our hospital were divided into four groups. The control group received non-steroidal anti-inflammatory drugs, the Treatment Group Ⅰ received acupuncture alone, Treatment Group Ⅱ was treated with medicated wine for warming meridians alongside polarized light physiotherapy, and Treatment Group Ⅲ received a combination of medicated wine for warming meridians, polarized light therapy, and acupuncture. The clinical efficacy, pain thresholds at various time points, temperature pain threshold, electric pain threshold, quality of life, sleep quality index, lumbar dysfunction index, visual analog scale(VAS) scores, and incidence of adverse reactions were compared and analyzed across the four groups. RESULTS:The total clinical effective rate in Treatment Group Ⅲ was significantly higher than that in the control group, Treatment Group Ⅰ, and Treatment Group Ⅱ(P < 0.05). At 24 and 72 h post-treatment, the VAS scores, temperature pain thresholds, and electric pain thresholds in Treatment Group Ⅲ were significantly lower than those in the control group, Treatment Group Ⅰ, and Treatment Group Ⅱ(P < 0.05). Additionally, quality-of-life scores in Treatment Group Ⅲ were markedly higher compared to the control group, Treatment Group Ⅰ, and Treatment Group Ⅱ, while the Pittsburgh Sleep Quality Index scores, Oswestry Disability Index scores, and incidence of adverse reactions in Treatment Group Ⅲ were significantly lower than in the other groups(P < 0.05). CONCLUSION:The external application of warm meridian medicated wine and polarized light therapy combined with acupuncture significantly reduces postoperative pain following vertebroplasty, enhances lumbar function, and improves both sleep quality and overall quality of life for patients. This approach is recommended for clinical application.展开更多
Nighttime navigation faces challenges from limited data and interference,especially when satellite signals are unavailable.Leveraging lunar polarized light,polarization navigation offers a promising solution for night...Nighttime navigation faces challenges from limited data and interference,especially when satellite signals are unavailable.Leveraging lunar polarized light,polarization navigation offers a promising solution for nighttime autonomous navigation.Current algorithms,however,are limited by the requirement for known horizontal attitudes,restricting applications.This study introduces an autonomous 3-D attitude determination method to overcome this limitation.Our approach utilizes the Angle of Polarization(AOP)at night to extract neutral points from the AOP pattern.This allows for the calculation of polarization meridian plane information for attitude determination.Subsequently,we present an optimized Polarization TRIAD(Pol-TRIAD)algorithm to acquire the 3-D attitude.The proposed method outperforms the existing approaches in outdoor experiments by achieving lower Root Mean Square Error(RMSE).For one baseline attitude,it improves pitch by 31.7%,roll by 21.7%,and yaw by 2.6%,while for the attitude with a larger tilt angle,the improvements are 64.4%,30.4%,and 9.1%,respectively.展开更多
The high mortality rates of colon and rectal tumors have put forward an urgent need for rapid, sensitive, and accurate diagnosis. The polarization imaging technology, with the advantages of noninvasiveness, noncontact...The high mortality rates of colon and rectal tumors have put forward an urgent need for rapid, sensitive, and accurate diagnosis. The polarization imaging technology, with the advantages of noninvasiveness, noncontact, quantification, rapidity, and high sensitivity, is expected to be used for auxiliary diagnosis of colorectal cancer. Herein, the differences in colorectal tissues of four pathological types were studied using this powerful technology. Polarized light imaging combined with the Mueller matrix decomposition (MMPD) method was applied to extract structural features that may be related to colorectal tumors. It demonstrated that parameters δ and θ could reflect the structural differences of colorectal tumors. Preliminary simulated experiment results revealed that the parameter δ was related to the fiber density, and the parameter θ was related to the fiber angle. Then Tamura image texture analysis was used to quantitatively describe tissues of different pathological types, and the results showed that the coarseness, contrast, directionality, and roughness of the four groups were statistically different. Texture analysis based on the quantitative data of the four dimensions could be applied for the identification of benign and malignant colorectal tumors.展开更多
The COVID-19 pandemic,caused by the SARS-CoV-2 virus,has triggered a global health crisis,necessitating accurate predictive models to forecast disease severity and aid in clinical decision-making.This study introduces...The COVID-19 pandemic,caused by the SARS-CoV-2 virus,has triggered a global health crisis,necessitating accurate predictive models to forecast disease severity and aid in clinical decision-making.This study introduces an innovative machine learning approach,the bDWPLO-FKNN model,designed to predict the severity of COVID-19 pneumonia in patients.The model incorporates the Differential Weibull Polar Lights Optimizer(DWPLO),an enhancement of the Polar Lights Optimizer(PLO)with the differential evolution operator and the Weibull flight operator,to perform effective feature selection.The DWPLO’s performance was rigorously tested against IEEE CEC 2017 benchmark functions,demonstrating its robust optimization capabilities.The binary version of DWPLO(bDWPLO)was then integrated with the Fuzzy K-Nearest Neighbors(FKNN)algorithm to form the predictive model.Using a dataset from the People’s Hospital Affiliated with Ningbo University,the model was trained to identify patients at risk of developing severe pneumonia due to COVID-19.The bDWPLO-FKNN model exhibited exceptional predictive accuracy,with an accuracy of 84.036% and a specificity of 88.564%.The analysis revealed key predictors,including albumin,albumin to globulin ratio,lactate dehydrogenase,urea nitrogen,gamma-glutamyl transferase,and inorganic phosphorus,which were significantly associated with disease severity.The integration of DWPLO with FKNN not only enhances feature selection but also bolsters the model’s predictive power,providing a valuable tool for clinicians to assess patient risk and allocate healthcare resources effectively during the COVID-19 pandemic.展开更多
Due to its broken out-of-plane symmetry,z-cut periodically poled lithium niobate(PPLN)has exhibited ultrahigh second-order optical nonlinearity.Precise quantification of the domain structure of z-cut PPLN plays a crit...Due to its broken out-of-plane symmetry,z-cut periodically poled lithium niobate(PPLN)has exhibited ultrahigh second-order optical nonlinearity.Precise quantification of the domain structure of z-cut PPLN plays a critical role during poling fabrication.To enhance the imaging detection efficiency of the domain structure in z-cut PPLN,we have developed a second-harmonic generation microscope system specifically designed to produce a longitudinal electric field in foci for the imaging domain inversion.We demonstrated that imaging using a longitudinal electric field can achieve a contrast ratio enhancement by a factor of 1.77,showing high imaging efficiency and making the proposed method suitable for in situ monitoring of the z-cut PPLN poling process.展开更多
Floquet engineering provides a powerful and flexible method for modifying the band structures of quantum materials.While circularly polarized light has been shown to convert curved nodal lines in three-dimensional sem...Floquet engineering provides a powerful and flexible method for modifying the band structures of quantum materials.While circularly polarized light has been shown to convert curved nodal lines in three-dimensional semimetals into Weyl points,such a transformation is forbidden for an isolated straight nodal line.In this work,we uncover a dramatic shift in this paradigm when multiple straight nodal lines intersect.We observe that circularly polarized light not only gaps them into Weyl points but also induces unprecedented surface-state Fermi arcs that extend across the entire surface Brillouin zone and form a linked topological structure.These findings advance our fundamental understanding of light-driven transitions in topological semimetals and unveil a unique Weyl semimetal phase defined by linked Fermi arcs.We discuss potential exotic phenomena arising from this phase,applications of our predictions to spin-split antiferromagnets,and the extension of this Weyl semimetal phase to classical systems.展开更多
Background:The medicinal material known as Os Draconis(Longgu)originates from fossilized remains of ancient mammals and is widely used in treating emotional and mental conditions.However,fossil resources are nonrenewa...Background:The medicinal material known as Os Draconis(Longgu)originates from fossilized remains of ancient mammals and is widely used in treating emotional and mental conditions.However,fossil resources are nonrenewable,and clinical demand is increasingly difficult to meet,leading to a proliferation of counterfeit products.During prolonged geological burial,static pressure from the surrounding strata severely compromises the microstructural integrity of osteons in Os Draconis,but Os Draconis still largely retains the structural features of mammalian bone.Methods:Using verified authentic Os Draconis samples over 10,000 years old as a baseline,this study summarizes the ultrastructural characteristics of genuine Os Draconis.Employing electron probe microanalysis and optical polarized light microscopy,we examined 28 batches of authentic Os Draconis and 31 batches of counterfeits to identify their ultrastructural differences.Key points for ultrastructural identification of Os Draconis were compiled,and a new identification approach was proposed based on these differences.Results:Authentic Os Draconis exhibited distinct ultrastructural markers:irregularly shaped osteons with traversing fissures,deformed/displaced Haversian canals,and secondary mineral infill(predominantly calcium carbonate).Counterfeits showed regular osteon arrangements,absent traversal fissures,and homogeneous hydroxyapatite composition.Lab-simulated samples lacked structural degradation features.EPMA confirmed calcium carbonate infill in fossilized Haversian canals,while elemental profiles differentiated lacunae types(void vs.mineral-packed).Conclusion:The study established ultrastructural criteria for authentic Os Draconis identification:osteon deformation,geological fissures penetrating bone units,and heterogenous mineral deposition.These features,unattainable in counterfeits or modern processed bones,provide a cost-effective,accurate identification method.This approach bridges gaps in TCM material standardization and supports quality control for clinical applications.展开更多
For decades,chiral nanomaterials have been extensively studied because of their extraordinary properties.Chiral nanostructures have attracted a lot of interest because of their potential applications including biosens...For decades,chiral nanomaterials have been extensively studied because of their extraordinary properties.Chiral nanostructures have attracted a lot of interest because of their potential applications including biosensing,asymmetric catalysis,optical devices,and negative index materials.Circularly polarized light(CPL)is the most attractive source for chirality owing to its high availability,and now it has been used as a chiral source for the preparation of chiral matter.In this review,the recent progress in the field of CPL-enabled chiral nanomaterials is summarized.Firstly,the recent advancements in the fabrication of chiral materials using circularly polarized light are described,focusing on the unique strategies.Secondly,an overview of the potential applications of chiral nanomaterials driven by CPL is provided,with a particular emphasis on biosensing,catalysis,and phototherapy.Finally,a perspective on the challenges in the field of CPL-enabled chiral nanomaterials is given.展开更多
Circularly polarized light(CPL)has been given great attention because of its extensive application.While several devices for CPL detection have been studied,their performance is affected by the magnitude of photocurre...Circularly polarized light(CPL)has been given great attention because of its extensive application.While several devices for CPL detection have been studied,their performance is affected by the magnitude of photocurrent.In this paper,a self-powered photodetector based on hot electrons in chiral metamaterials is proposed and optimized.CPL can be distinguished by the direction of photocurrent without external bias owing to the interdigital electrodes with asymmetric chiral metamaterials.Distinguished by the direction of photocurrent,the device can easily detect the rotation direction of the CPL electric field,even if it only has a very weak responsivity.The responsivity of the proposed detector is near 1.9 mA/W at the wavelength of 1322 nm,which is enough to distinguish CPL.The detector we proposed has the potential for application in optical communication.展开更多
Based on the vector diffraction theory, a super-resolution longitudinally polarized optical needle with ultra-long depth of focus(DOF) is generated by tightly focusing a radially polarized beam that is modulated by a ...Based on the vector diffraction theory, a super-resolution longitudinally polarized optical needle with ultra-long depth of focus(DOF) is generated by tightly focusing a radially polarized beam that is modulated by a self-designed ternary hybrid(phase/amplitude) filter(THF). Both the phase and the amplitude patterns of THF are judiciously optimized by the versatile particle swarm optimization(PSO) searching algorithm. For the focusing configuration with a combination of a high numerical aperture(NA) and the optimized sine-shaped THFs, an optical needle with the full width at half maximum(FWHM) of 0.414λ and the DOF of 7.58λ is accessed, which corresponds to an aspect ratio of 18.3. The demonstrated longitudinally polarized super-resolution light needle with high aspect ratio opens up broad applications in high-density optical data storage, nano-photolithography, super-resolution imaging and high-efficiency particle trapping.展开更多
Sensory drive, the concept that sensory systems primarily evolve under the influence of environmen tal features and that animal signals are evolutionarily shaped and tuned by these previously existing sensory systems,...Sensory drive, the concept that sensory systems primarily evolve under the influence of environmen tal features and that animal signals are evolutionarily shaped and tuned by these previously existing sensory systems, has been thoroughly studied regarding visual signals across many animals. Much of this work has focused on spectral aspects of vision and signals. Here, I review work on polarized light signals of animals and relate these to what is known of polarization visual systems, polarized light aspects of visual scenes, and polarizationrelated behavior （e.g., orientation, habitatfinding, contrast enhancement）. Other than the broad patterns of scattered polarized light in the sky, most po larization in both terrestrial and aquatic environments results from either reflection or scattering in the horizontal plane. With overhead illumination, horizontal features such as the surfaces of many leaves or of air： water interfaces reflect horizontal polarization, and water scatters horizontally polar ized light under most conditions. Several animal species have been demonstrated to use horizontally polarized light fields or features in critical aspects of their biology. Significantly, most biological sig nals are also horizontally polarized. Here, I present relevant polarizationrelated behavior and discuss the hypothesis that sensory drive has evolutionarily influenced the structure of polarization signals. The paper also considers the evolutionary origin of circular polarization vision and circularly polar ized signals. It appears that this class of signals did not evolve under the influence of sensory drive. The study of signals based on polarized light is becoming a mature field of research.展开更多
In recent years, the bionic polarized light compass has been widely studied for the unmanned aerial vehicle navigation. However, it is found from the obtained investigation results that a polarized light compass with ...In recent years, the bionic polarized light compass has been widely studied for the unmanned aerial vehicle navigation. However, it is found from the obtained investigation results that a polarized light compass with a sensitive and high dynamic range polarimeter still provides inferior output precision of the heading angle due to the presence of the noise generating from the compass.The noise is existed not only in the angle of the polarization image acquired by polarimeters but also in the output heading data, which leads to a sharp reduction in the accuracy of a polarized light compass. Herein, we present noise analysis and a novel multiscale transform denoising method of a polarized light compass used for the unmanned aerial vehicle navigation. Specifically, a multiscale principle component analysis utilizing one-dimensional image entropy as classification criterion is directly implemented to suppress the noise in the acquired polarization image. Subsequently, a multiscale time–frequency peak filtering method using the sample entropy as classification criterion is applied for the output heading data so as to further increase the heading measurement accuracy from the denoised image above. These two approaches are combined to significantly reduce the heading error affected by different types of noises. Our experimental results indicate the proposed multiscale transform denoising method exhibits high performance in suppressing the noise of a polarized light compass used for the unmanned aerial vehicle navigation compared to existing prior arts.展开更多
A novel polarization splitter based on photonic crystal fibers(PCFs) with three cores of high birefringence is proposed.The 45o linearly polarized light is launched into a core.After a coupling length(about 1500 μm),...A novel polarization splitter based on photonic crystal fibers(PCFs) with three cores of high birefringence is proposed.The 45o linearly polarized light is launched into a core.After a coupling length(about 1500 μm),the xand y-polarized light beams are separated into different cores.When the light is launched into another core,the xand y-polarized light from different cores can be obtained and the degree of separation can be also adjusted.The polarization splitter is highly flexible and adjustable.The length of the polarization splitter is about 1500 μm which is just the coupling length.So it has appreciate significance of manufacturing mini-type photonic apparatus in integrated optics.展开更多
We theoretically study the spin transport through a two-terminal quantum dot device under the influence of a symmetric spin bias and circularly polarized light. It is found that the combination of the circularly polar...We theoretically study the spin transport through a two-terminal quantum dot device under the influence of a symmetric spin bias and circularly polarized light. It is found that the combination of the circularly polarized light and the applied spin bias can result in a net charge current. The resultant charge current is large enough to be measured when properly choosing the system parameters. The resultant charge current can be used to deduce the spin bias due to the fact that there exists a simple linear relation between them. When the external circuit is open, a charge bias instead of a charge current can be induced, which is also measurable by present technologies. These findings indicate a new approach to detect the spin bias by using circularly polarized light.展开更多
In this paper,two ways of micro structural characterization,optical microscopy(OM) and polarized light microscopy(PLM),were both employed to describe the micro structure of semisolid slurry prepared by swirling enthal...In this paper,two ways of micro structural characterization,optical microscopy(OM) and polarized light microscopy(PLM),were both employed to describe the micro structure of semisolid slurry prepared by swirling enthalpy equilibration device(SEED).The results show that PLM is more reliable and accurate than OM to describe the special morphology feature of semisolid slurry made by SEED process.Meanwhile,the effects of pouring temperature and mass of molten liquid on the primary α-Al particle size and morphology were also investigated using PLM.The quantitative metallographic results measured from PLM demonstrate that the grain size and morphology and their distribution are significantly affected by both pouring temperature and the mass of molten liquid.The grain size poured with 2.7 kg liquid decreases from 659 to186 μm,and grain morphology transforms from dendrite to globular structure with pouring temperature reducing from690 to 630℃.The decreasing pouring temperature also promotes the distribution of spherical structure on the cross section.Meanwhile,the mass of molten liquid decreasing from 2.7 to 2.3 kg can decrease the grain size by maximum of 44% at high pouring temperature.展开更多
Circularly polarized light(CPL)is an inherently chiral entity and is regarded as one of the possible deterministic signals that led to the evolution of homochirality in earth.Thus,CPL as an external physical field has...Circularly polarized light(CPL)is an inherently chiral entity and is regarded as one of the possible deterministic signals that led to the evolution of homochirality in earth.Thus,CPL as an external physical field has been widely used in a technique known as absolute asymmetric synthesis,because a product enriched in one enantiomer is formed from racemic precursor molecules without the intervention of a chiral catalyst.In this review,we retrospect the historical research of CPL-induced absolute asymmetric synthesis,including chiral organic molecules,helical polymers,supramolecular assemblies,noble metal nanostructures.However,based on these results,we concluded that the chiral photon-matter interaction is very faint due to the arrangement of molecular bonds giving rise to chiral features,is over a smaller distance than the helical pitch of CPL,leading extremely small enantiomeric excess for product.Therefore,we highlight the recently emerged technology called superchiral field,in which the superchiral far-field and near-field could enhance the dissymmetry of optical field and near-field,respectively.In sum,we hope this review could bring some enlightenment to researchers and further improve the enantioselectivity of CPL-induced absolute asymmetric synthesis.展开更多
We investigate the electron retroreflection and the Klein tunneling across a graphene-based n-p-n junction irradiated by linearly polarized off-resonant light with the polarization along the x direction.The linearly p...We investigate the electron retroreflection and the Klein tunneling across a graphene-based n-p-n junction irradiated by linearly polarized off-resonant light with the polarization along the x direction.The linearly polarized off-resonant light modifies the band structure of graphene,which leads to the anisotropy of band structure.By adjusting the linearly polarized light and the direction of n-p-n junction simultaneously,the electron retroreflection appears and the anomalous Klein tunneling,the perfect transmission at a nonzero incident angle regardless of the width and height of potential barrier,happens,which arises from the fact that the light-induced anisotropic band structure changes the relation of wavevector and velocity of electron.Our finding provides an alternative and flexible method to modulate electron retroreflection and Klein tunneling.展开更多
In the fields of tissue engineering and controlled drug release, electro-spun fibers are often required to have structural characteristics such as high porosity and large specific surface area. The traditional scannin...In the fields of tissue engineering and controlled drug release, electro-spun fibers are often required to have structural characteristics such as high porosity and large specific surface area. The traditional scanning electron microscope can observe the microscopic appearance of the sample clearly, but it damage to the polymer electro-spun fiber, and the detection takes a long time. In view of this, we have tested a polarization method to quickly distinguish different morphological features of the samples, such as smooth surface, microporous, and beaded microspheres using the depolarization parameter MMDD-△,which is obtained by the Mueller matrix polar decomposition. The preliminary results show that this method is simple, fast, and potentially capable of non-destructive evaluation of the microstructure properties of the object surface.展开更多
基金supported by the National Natural Science Foundation of China(NSFC,Nos.22125110,U23A2094,22205233,22193042,21921001,22305248 and U21A2069)the Natural Science Foundation of Fujian Province(No.2023J02028)+3 种基金the Key Research Program of Frontier Sciences of Chinese Academy of Sciences(No.ZDBS-LY-SLH024)Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(No.2021ZR126)the National Key Research and Development Program of China(No.2019YFA0210402)the China Postdoctoral Science Foundation(Nos.2022TQ0337 and 2023M733497).
文摘2D Ruddlesden-Popper(RP)polar perovskite,displaying the intrinsic optical anisotropy and structural polarity,has a fantastic application perspective in self-powered polarized light detection.However,the weak van der Waals interaction between the organic spacing bilayers is insufficient to preserve the stability of RP-type materials.Hence,it is of great significance to explore new stable 2D RP-phase candidates.In this work,we have successfully constructed a highly-stable polar 2D perovskite,(t-ACH)_(2)PbI_(4)(1,where t-ACH^(+)is HOOC_(8)H_(12)NH_(3)^(+)),by adopting a hydrophobic carboxylate trans-isomer of tranexamic acid as the spacing component.Strikingly,strong O-H…O hydrogen bonds between t-ACH^(+)organic bilayers compose the dimer,thus decreasing van der Waals gap and enhancing structural stability.Besides,such orientational hydrogen bonds contribute to the formation of structural polarity and generate an obvious bulk photovoltaic effect in 1,which facilitates its self-powered photodetection.As predicted,the combination of inherent anisotropy and polarity leads to self-powered polarized-light detection with a high ratio of around∼5.3,superior to those of inorganic 2D counterparts.This work paves a potential way to design highly-stable 2D perovskites for high-performance optoelectronic devices.
基金This work is financially supported by the National Key Re-search and Development Program of China(No.2021YFF0501001)the Heilongjiang Provincial Natural Science Foundation of China(No.LH2020A006)the Open Fund of Key Laboratory for In-telligent Nano Materials and Devices of the Ministry of Education NJ2022002(No.INMD-2022M08).
文摘Qualification of polarization can be realized either on a macroscopic scale as an average property by P-E hysteresis measurements or on a nano/micro scale by piezoelectric force microscopy,transmission electron microscopy,scanning electron microscopy,and so on.However,visualization and qualification of polarization distribution in the micron to millimeter scale is still a challenge.Polarizing light microscopy(PLM)is often used in the study of ferroelectric domain structures mainly for domain patterns.A phe-nomenon called“chromatic polarization”has been observed in transparent ferroelectric crystals by using a crossed-PLM system viewed with white light,which contains rich information about local polariza-tion distribution.In this study,an automatic full-angle light intensity detection(AFALID)algorithm com-bined with colorimetry is developed to analyze the distribution of nonuniform local spontaneous polar-ization distribution in transparent ferroelectric single crystals.Temperature-dependent spontaneous po-larizations from the color analysis for PMN-0.36PT single crystals with single tetragonal domain state are in good coincidence with those extracted from temperature-dependent hysteresis loops and pyroelectric current measurements.We further apply this method to quantify the nonuniform domain distributions with nano-indentations.This non-contact and non-destructive characterization can provide fast and au-tomatic detection of polarization distributions in ferroelectric materials.
文摘OBJECTIVE:To evaluate the effects of external application of warm meridian medicated wine and polarized light therapy combined with acupuncture on pain management following vertebroplasty. METHODS:A total of 120 patients with osteoporotic vertebral compression fractures treated by vertebroplasty at our hospital were divided into four groups. The control group received non-steroidal anti-inflammatory drugs, the Treatment Group Ⅰ received acupuncture alone, Treatment Group Ⅱ was treated with medicated wine for warming meridians alongside polarized light physiotherapy, and Treatment Group Ⅲ received a combination of medicated wine for warming meridians, polarized light therapy, and acupuncture. The clinical efficacy, pain thresholds at various time points, temperature pain threshold, electric pain threshold, quality of life, sleep quality index, lumbar dysfunction index, visual analog scale(VAS) scores, and incidence of adverse reactions were compared and analyzed across the four groups. RESULTS:The total clinical effective rate in Treatment Group Ⅲ was significantly higher than that in the control group, Treatment Group Ⅰ, and Treatment Group Ⅱ(P < 0.05). At 24 and 72 h post-treatment, the VAS scores, temperature pain thresholds, and electric pain thresholds in Treatment Group Ⅲ were significantly lower than those in the control group, Treatment Group Ⅰ, and Treatment Group Ⅱ(P < 0.05). Additionally, quality-of-life scores in Treatment Group Ⅲ were markedly higher compared to the control group, Treatment Group Ⅰ, and Treatment Group Ⅱ, while the Pittsburgh Sleep Quality Index scores, Oswestry Disability Index scores, and incidence of adverse reactions in Treatment Group Ⅲ were significantly lower than in the other groups(P < 0.05). CONCLUSION:The external application of warm meridian medicated wine and polarized light therapy combined with acupuncture significantly reduces postoperative pain following vertebroplasty, enhances lumbar function, and improves both sleep quality and overall quality of life for patients. This approach is recommended for clinical application.
基金supported in part by the National Key Research and Development Program of China(Nos.2020YFA0711200,2022YFB4701301)in part by the Defense Industrial Technology Development Program,China(No.JCKY2021601B016)+1 种基金in part by the Fundamental Research Funds for the Central Universities,China(No.YWF-23-JC-07)in part by the National Natural Science Foundation of China(No.62425302)。
文摘Nighttime navigation faces challenges from limited data and interference,especially when satellite signals are unavailable.Leveraging lunar polarized light,polarization navigation offers a promising solution for nighttime autonomous navigation.Current algorithms,however,are limited by the requirement for known horizontal attitudes,restricting applications.This study introduces an autonomous 3-D attitude determination method to overcome this limitation.Our approach utilizes the Angle of Polarization(AOP)at night to extract neutral points from the AOP pattern.This allows for the calculation of polarization meridian plane information for attitude determination.Subsequently,we present an optimized Polarization TRIAD(Pol-TRIAD)algorithm to acquire the 3-D attitude.The proposed method outperforms the existing approaches in outdoor experiments by achieving lower Root Mean Square Error(RMSE).For one baseline attitude,it improves pitch by 31.7%,roll by 21.7%,and yaw by 2.6%,while for the attitude with a larger tilt angle,the improvements are 64.4%,30.4%,and 9.1%,respectively.
文摘The high mortality rates of colon and rectal tumors have put forward an urgent need for rapid, sensitive, and accurate diagnosis. The polarization imaging technology, with the advantages of noninvasiveness, noncontact, quantification, rapidity, and high sensitivity, is expected to be used for auxiliary diagnosis of colorectal cancer. Herein, the differences in colorectal tissues of four pathological types were studied using this powerful technology. Polarized light imaging combined with the Mueller matrix decomposition (MMPD) method was applied to extract structural features that may be related to colorectal tumors. It demonstrated that parameters δ and θ could reflect the structural differences of colorectal tumors. Preliminary simulated experiment results revealed that the parameter δ was related to the fiber density, and the parameter θ was related to the fiber angle. Then Tamura image texture analysis was used to quantitatively describe tissues of different pathological types, and the results showed that the coarseness, contrast, directionality, and roughness of the four groups were statistically different. Texture analysis based on the quantitative data of the four dimensions could be applied for the identification of benign and malignant colorectal tumors.
基金supported by the Key Scientific Research Project of Wenzhou Polytechnic(No.WZY2025010).
文摘The COVID-19 pandemic,caused by the SARS-CoV-2 virus,has triggered a global health crisis,necessitating accurate predictive models to forecast disease severity and aid in clinical decision-making.This study introduces an innovative machine learning approach,the bDWPLO-FKNN model,designed to predict the severity of COVID-19 pneumonia in patients.The model incorporates the Differential Weibull Polar Lights Optimizer(DWPLO),an enhancement of the Polar Lights Optimizer(PLO)with the differential evolution operator and the Weibull flight operator,to perform effective feature selection.The DWPLO’s performance was rigorously tested against IEEE CEC 2017 benchmark functions,demonstrating its robust optimization capabilities.The binary version of DWPLO(bDWPLO)was then integrated with the Fuzzy K-Nearest Neighbors(FKNN)algorithm to form the predictive model.Using a dataset from the People’s Hospital Affiliated with Ningbo University,the model was trained to identify patients at risk of developing severe pneumonia due to COVID-19.The bDWPLO-FKNN model exhibited exceptional predictive accuracy,with an accuracy of 84.036% and a specificity of 88.564%.The analysis revealed key predictors,including albumin,albumin to globulin ratio,lactate dehydrogenase,urea nitrogen,gamma-glutamyl transferase,and inorganic phosphorus,which were significantly associated with disease severity.The integration of DWPLO with FKNN not only enhances feature selection but also bolsters the model’s predictive power,providing a valuable tool for clinicians to assess patient risk and allocate healthcare resources effectively during the COVID-19 pandemic.
基金supported by the National Key Research and Development Program of China(Grant Nos.2022YFC3401100 and 2022YFF0712500)the Guangdong Major Project of Basic and Applied Basic Research(Grant No.2020B0301030009)+2 种基金the National Natural Science Foundation of China(Grant Nos.12204017,12004012,12004013,12041602,91750203,91850111,and 92150301)the China Postdoctoral Science Foundation(Grant No.2020M680220 and 2020M680230)the Clinical Medicine Plus X-Young Scholars Project,Peking University,Fundamental Research Funds for the Central Universities.
文摘Due to its broken out-of-plane symmetry,z-cut periodically poled lithium niobate(PPLN)has exhibited ultrahigh second-order optical nonlinearity.Precise quantification of the domain structure of z-cut PPLN plays a critical role during poling fabrication.To enhance the imaging detection efficiency of the domain structure in z-cut PPLN,we have developed a second-harmonic generation microscope system specifically designed to produce a longitudinal electric field in foci for the imaging domain inversion.We demonstrated that imaging using a longitudinal electric field can achieve a contrast ratio enhancement by a factor of 1.77,showing high imaging efficiency and making the proposed method suitable for in situ monitoring of the z-cut PPLN poling process.
基金supported by the National Natural Science Foundation of China (Grant No.12174455)Guangdong Basic and Applied Basic Research Foundation (Grant No.2023B1515040023)。
文摘Floquet engineering provides a powerful and flexible method for modifying the band structures of quantum materials.While circularly polarized light has been shown to convert curved nodal lines in three-dimensional semimetals into Weyl points,such a transformation is forbidden for an isolated straight nodal line.In this work,we uncover a dramatic shift in this paradigm when multiple straight nodal lines intersect.We observe that circularly polarized light not only gaps them into Weyl points but also induces unprecedented surface-state Fermi arcs that extend across the entire surface Brillouin zone and form a linked topological structure.These findings advance our fundamental understanding of light-driven transitions in topological semimetals and unveil a unique Weyl semimetal phase defined by linked Fermi arcs.We discuss potential exotic phenomena arising from this phase,applications of our predictions to spin-split antiferromagnets,and the extension of this Weyl semimetal phase to classical systems.
基金supported by the Scientific and Technological Innovation Project of the China Academy of Chinese Medical Sciences(CI2021A04013)the National Natural Science Foundation of China(82204610)+1 种基金the Qihang Talent Program(L2022046)the Fundamental Research Funds for the Central Public Welfare Research Institutes(ZZ15-YQ-041 and L2021029).
文摘Background:The medicinal material known as Os Draconis(Longgu)originates from fossilized remains of ancient mammals and is widely used in treating emotional and mental conditions.However,fossil resources are nonrenewable,and clinical demand is increasingly difficult to meet,leading to a proliferation of counterfeit products.During prolonged geological burial,static pressure from the surrounding strata severely compromises the microstructural integrity of osteons in Os Draconis,but Os Draconis still largely retains the structural features of mammalian bone.Methods:Using verified authentic Os Draconis samples over 10,000 years old as a baseline,this study summarizes the ultrastructural characteristics of genuine Os Draconis.Employing electron probe microanalysis and optical polarized light microscopy,we examined 28 batches of authentic Os Draconis and 31 batches of counterfeits to identify their ultrastructural differences.Key points for ultrastructural identification of Os Draconis were compiled,and a new identification approach was proposed based on these differences.Results:Authentic Os Draconis exhibited distinct ultrastructural markers:irregularly shaped osteons with traversing fissures,deformed/displaced Haversian canals,and secondary mineral infill(predominantly calcium carbonate).Counterfeits showed regular osteon arrangements,absent traversal fissures,and homogeneous hydroxyapatite composition.Lab-simulated samples lacked structural degradation features.EPMA confirmed calcium carbonate infill in fossilized Haversian canals,while elemental profiles differentiated lacunae types(void vs.mineral-packed).Conclusion:The study established ultrastructural criteria for authentic Os Draconis identification:osteon deformation,geological fissures penetrating bone units,and heterogenous mineral deposition.These features,unattainable in counterfeits or modern processed bones,provide a cost-effective,accurate identification method.This approach bridges gaps in TCM material standardization and supports quality control for clinical applications.
基金financially the National Natural Science Foundation of China(51902136)the Fundamental Research Funds for the Central Universities(JUSRP12003,JUSRP622026)Natural Science Foundation of Jiangsu Province(BK20211236)。
文摘For decades,chiral nanomaterials have been extensively studied because of their extraordinary properties.Chiral nanostructures have attracted a lot of interest because of their potential applications including biosensing,asymmetric catalysis,optical devices,and negative index materials.Circularly polarized light(CPL)is the most attractive source for chirality owing to its high availability,and now it has been used as a chiral source for the preparation of chiral matter.In this review,the recent progress in the field of CPL-enabled chiral nanomaterials is summarized.Firstly,the recent advancements in the fabrication of chiral materials using circularly polarized light are described,focusing on the unique strategies.Secondly,an overview of the potential applications of chiral nanomaterials driven by CPL is provided,with a particular emphasis on biosensing,catalysis,and phototherapy.Finally,a perspective on the challenges in the field of CPL-enabled chiral nanomaterials is given.
基金This work was supported by the National Natural Science Foundation of China(No.61705065)Hunan Provincial Natural Science Foundation of China(No.2017JJ3034)+1 种基金Technology Program of Changsha(No.kq1804001)National Training Program of Innovation and Entrepreneurship for undergraduates(No.S201910532166).
文摘Circularly polarized light(CPL)has been given great attention because of its extensive application.While several devices for CPL detection have been studied,their performance is affected by the magnitude of photocurrent.In this paper,a self-powered photodetector based on hot electrons in chiral metamaterials is proposed and optimized.CPL can be distinguished by the direction of photocurrent without external bias owing to the interdigital electrodes with asymmetric chiral metamaterials.Distinguished by the direction of photocurrent,the device can easily detect the rotation direction of the CPL electric field,even if it only has a very weak responsivity.The responsivity of the proposed detector is near 1.9 mA/W at the wavelength of 1322 nm,which is enough to distinguish CPL.The detector we proposed has the potential for application in optical communication.
基金supported by the National Natural Science Foundation of China(Nos.61575139,61605136,51602213 and 11604236)the Youth Foundation of the Taiyuan University of Technology(No.2015QN066)
文摘Based on the vector diffraction theory, a super-resolution longitudinally polarized optical needle with ultra-long depth of focus(DOF) is generated by tightly focusing a radially polarized beam that is modulated by a self-designed ternary hybrid(phase/amplitude) filter(THF). Both the phase and the amplitude patterns of THF are judiciously optimized by the versatile particle swarm optimization(PSO) searching algorithm. For the focusing configuration with a combination of a high numerical aperture(NA) and the optimized sine-shaped THFs, an optical needle with the full width at half maximum(FWHM) of 0.414λ and the DOF of 7.58λ is accessed, which corresponds to an aspect ratio of 18.3. The demonstrated longitudinally polarized super-resolution light needle with high aspect ratio opens up broad applications in high-density optical data storage, nano-photolithography, super-resolution imaging and high-efficiency particle trapping.
文摘Sensory drive, the concept that sensory systems primarily evolve under the influence of environmen tal features and that animal signals are evolutionarily shaped and tuned by these previously existing sensory systems, has been thoroughly studied regarding visual signals across many animals. Much of this work has focused on spectral aspects of vision and signals. Here, I review work on polarized light signals of animals and relate these to what is known of polarization visual systems, polarized light aspects of visual scenes, and polarizationrelated behavior （e.g., orientation, habitatfinding, contrast enhancement）. Other than the broad patterns of scattered polarized light in the sky, most po larization in both terrestrial and aquatic environments results from either reflection or scattering in the horizontal plane. With overhead illumination, horizontal features such as the surfaces of many leaves or of air： water interfaces reflect horizontal polarization, and water scatters horizontally polar ized light under most conditions. Several animal species have been demonstrated to use horizontally polarized light fields or features in critical aspects of their biology. Significantly, most biological sig nals are also horizontally polarized. Here, I present relevant polarizationrelated behavior and discuss the hypothesis that sensory drive has evolutionarily influenced the structure of polarization signals. The paper also considers the evolutionary origin of circular polarization vision and circularly polar ized signals. It appears that this class of signals did not evolve under the influence of sensory drive. The study of signals based on polarized light is becoming a mature field of research.
基金co-supported by the National Natural Science Foundation of China(No.61973281)The Innovative Research Group Project of National Natural Science Foundation of China(No.51821003)+4 种基金the Aeronautical Science Foundation of China(No.2018ZCU0002)the Program for the Top Young Academic Leaders of Higher Learning Institutions of ShanxiShanxi Postgraduate Innovation Project,China(No.2020BY102)the Young Academic Leaders Foundation in North University of Chinathe Fund for Shanxi‘‘1331 Project”Key Subjects Construction。
文摘In recent years, the bionic polarized light compass has been widely studied for the unmanned aerial vehicle navigation. However, it is found from the obtained investigation results that a polarized light compass with a sensitive and high dynamic range polarimeter still provides inferior output precision of the heading angle due to the presence of the noise generating from the compass.The noise is existed not only in the angle of the polarization image acquired by polarimeters but also in the output heading data, which leads to a sharp reduction in the accuracy of a polarized light compass. Herein, we present noise analysis and a novel multiscale transform denoising method of a polarized light compass used for the unmanned aerial vehicle navigation. Specifically, a multiscale principle component analysis utilizing one-dimensional image entropy as classification criterion is directly implemented to suppress the noise in the acquired polarization image. Subsequently, a multiscale time–frequency peak filtering method using the sample entropy as classification criterion is applied for the output heading data so as to further increase the heading measurement accuracy from the denoised image above. These two approaches are combined to significantly reduce the heading error affected by different types of noises. Our experimental results indicate the proposed multiscale transform denoising method exhibits high performance in suppressing the noise of a polarized light compass used for the unmanned aerial vehicle navigation compared to existing prior arts.
基金supported by the National Natural Science Foundation of China (No. 60637010)
文摘A novel polarization splitter based on photonic crystal fibers(PCFs) with three cores of high birefringence is proposed.The 45o linearly polarized light is launched into a core.After a coupling length(about 1500 μm),the xand y-polarized light beams are separated into different cores.When the light is launched into another core,the xand y-polarized light from different cores can be obtained and the degree of separation can be also adjusted.The polarization splitter is highly flexible and adjustable.The length of the polarization splitter is about 1500 μm which is just the coupling length.So it has appreciate significance of manufacturing mini-type photonic apparatus in integrated optics.
基金Supported by the National Natural Science Foundation of China under Grant No 11404142the Youth Teacher Foundation of Huaiyin Institute of Technology under Grant No 2717577
文摘We theoretically study the spin transport through a two-terminal quantum dot device under the influence of a symmetric spin bias and circularly polarized light. It is found that the combination of the circularly polarized light and the applied spin bias can result in a net charge current. The resultant charge current is large enough to be measured when properly choosing the system parameters. The resultant charge current can be used to deduce the spin bias due to the fact that there exists a simple linear relation between them. When the external circuit is open, a charge bias instead of a charge current can be induced, which is also measurable by present technologies. These findings indicate a new approach to detect the spin bias by using circularly polarized light.
基金financially supported by the National Key Research and Development Program of China (No. 2016YFB0301003)the Shenzhen Free Exploring Basic Research Project (No. JCYJ20170307110223452)。
文摘In this paper,two ways of micro structural characterization,optical microscopy(OM) and polarized light microscopy(PLM),were both employed to describe the micro structure of semisolid slurry prepared by swirling enthalpy equilibration device(SEED).The results show that PLM is more reliable and accurate than OM to describe the special morphology feature of semisolid slurry made by SEED process.Meanwhile,the effects of pouring temperature and mass of molten liquid on the primary α-Al particle size and morphology were also investigated using PLM.The quantitative metallographic results measured from PLM demonstrate that the grain size and morphology and their distribution are significantly affected by both pouring temperature and the mass of molten liquid.The grain size poured with 2.7 kg liquid decreases from 659 to186 μm,and grain morphology transforms from dendrite to globular structure with pouring temperature reducing from690 to 630℃.The decreasing pouring temperature also promotes the distribution of spherical structure on the cross section.Meanwhile,the mass of molten liquid decreasing from 2.7 to 2.3 kg can decrease the grain size by maximum of 44% at high pouring temperature.
基金the support of Academic promotion program of Shandong First Medical University(No.2019LJ003)。
文摘Circularly polarized light(CPL)is an inherently chiral entity and is regarded as one of the possible deterministic signals that led to the evolution of homochirality in earth.Thus,CPL as an external physical field has been widely used in a technique known as absolute asymmetric synthesis,because a product enriched in one enantiomer is formed from racemic precursor molecules without the intervention of a chiral catalyst.In this review,we retrospect the historical research of CPL-induced absolute asymmetric synthesis,including chiral organic molecules,helical polymers,supramolecular assemblies,noble metal nanostructures.However,based on these results,we concluded that the chiral photon-matter interaction is very faint due to the arrangement of molecular bonds giving rise to chiral features,is over a smaller distance than the helical pitch of CPL,leading extremely small enantiomeric excess for product.Therefore,we highlight the recently emerged technology called superchiral field,in which the superchiral far-field and near-field could enhance the dissymmetry of optical field and near-field,respectively.In sum,we hope this review could bring some enlightenment to researchers and further improve the enantioselectivity of CPL-induced absolute asymmetric synthesis.
基金supported by the National Natural Science Foundation of China(Grant Nos.11804167,11804291,and 11904175)the Natural Science Foundation of Jiangsu Province,China(Grant Nos.BK20180739,BK20180740,and BK20180890)+2 种基金the Innovation Research Project of Jiangsu Province,China(Grant No.CZ0070619002)NJUPT-SF(Grant Nos.NY218128 and NY218135)NJUPT-STITP(Grant No.XYB2020301)。
文摘We investigate the electron retroreflection and the Klein tunneling across a graphene-based n-p-n junction irradiated by linearly polarized off-resonant light with the polarization along the x direction.The linearly polarized off-resonant light modifies the band structure of graphene,which leads to the anisotropy of band structure.By adjusting the linearly polarized light and the direction of n-p-n junction simultaneously,the electron retroreflection appears and the anomalous Klein tunneling,the perfect transmission at a nonzero incident angle regardless of the width and height of potential barrier,happens,which arises from the fact that the light-induced anisotropic band structure changes the relation of wavevector and velocity of electron.Our finding provides an alternative and flexible method to modulate electron retroreflection and Klein tunneling.
文摘In the fields of tissue engineering and controlled drug release, electro-spun fibers are often required to have structural characteristics such as high porosity and large specific surface area. The traditional scanning electron microscope can observe the microscopic appearance of the sample clearly, but it damage to the polymer electro-spun fiber, and the detection takes a long time. In view of this, we have tested a polarization method to quickly distinguish different morphological features of the samples, such as smooth surface, microporous, and beaded microspheres using the depolarization parameter MMDD-△,which is obtained by the Mueller matrix polar decomposition. The preliminary results show that this method is simple, fast, and potentially capable of non-destructive evaluation of the microstructure properties of the object surface.
