Conventional ignition methods are proving to be ineffective for low-sensitivity energetic materials,highlighting the need to investigate alternative ignition systems,such as laser-based techniques.Over the past decade...Conventional ignition methods are proving to be ineffective for low-sensitivity energetic materials,highlighting the need to investigate alternative ignition systems,such as laser-based techniques.Over the past decade,lasers have emerged as a promising solution,providing focused energy beams for controllable,efficient,and reliable ignition in the field of energetic materials.This study presents a comparative analysis of two state-of-the-art ignition approaches:direct laser ignition and laser-driven flyer ignition.Experiments were performed using a Neodymium-doped Yttrium Aluminum Garnet(Nd:YAG)laser at different energy beam levels to systematically evaluate ignition onset.In the direct laser ignition test setup,the laser beam was applied directly to the energetic tested material,while laserdriven flyer ignition utilized 40 and 100μm aluminum foils,propelled at velocities ranging from 300 to 1250 m/s.Comparative analysis with the Lawrence and Trott model substantiated the velocity data and provided insight into the ignition mechanisms.Experimental results indicate that the ignition time for the laser-driven flyer method was significantly shorter,with the pyrotechnic composition achieving complete combustion faster compared to direct laser ignition.Moreover,precise ignition thresholds were determined for both methods,providing critical parameters for optimizing ignition systems in energetic materials.This work elucidates the advantages and limitations of each technique while advancing next-generation ignition technology,enhancing the reliability and safety of propulsion systems.展开更多
In order to investigate the damage tolerance of a metastable Ti-5Al-3V-3Mo-2Cr-2Zr-1Nb-1Fe(Ti5321)alloy with bimodal microstructure using void growth quantification and micromechanical modeling,in situ tensile testing...In order to investigate the damage tolerance of a metastable Ti-5Al-3V-3Mo-2Cr-2Zr-1Nb-1Fe(Ti5321)alloy with bimodal microstructure using void growth quantification and micromechanical modeling,in situ tensile testing was performed during X-ray microtomography experiments.Compared with investigations of surface voids by traditional two-dimensional(2D)methods involving post-mortem characterization,three-dimensional(3D)information on void evolution inside optically opaque samples obtained through X-ray microtomography is essential.The Rice and Tracey model and Huang model were applied to predict void growth and show good agreement with experimental data using calibration of the damage parameterα.The void growth kinetics of Ti5321 with bimodal microstructure was analyzed by comparing theαvalue with that of Ti64 for different microstructure morphologies.The damage mechanism of ductile fracture of Ti5321 with bimodal microstructure is discussed.It was found that the size of the voids apparently increases with the triaxiality of stress.Post-mortem scanning electron microscopy(SEM)was also used to demonstrate this damage mechanism of ductile fracture of Ti5321.展开更多
This study reviews light-responsive polymers in various applications,including drug delivery,information storage,sensor,self-healing material,antibacterial or anti-fouling,and environmental applications.Light-responsi...This study reviews light-responsive polymers in various applications,including drug delivery,information storage,sensor,self-healing material,antibacterial or anti-fouling,and environmental applications.Light-responsive polymers are a new material type being developed for various medical,electronics,engineering,and environmental applications.The working principle of light-responsive materials is based on metalligand interactions or non-covalent interactions between polymer functional groups,metal ions,and other filler functional groups.Light irradiation causes physical and mechanical changes in drug delivery and antibacterial systems,which results in the materials releasing more drugs or antibacterial substances.When materials in information storage devices and sensors are exposed to light,they can change color or glow.This has been applied for data storage to reveal QR codes under UV light.Additionally,this review discusses the thermodynamic aspects and computer modeling of light-responsive materials to emphasize the importance and development of these materials.Finally,light-responsive polymer development for various applications is presented.展开更多
Models for when and how the continental crust was formed are constrained by estimates in the rates o crustal growth. The record of events preserved in the continental crust is heterogeneous in time with distinctive pe...Models for when and how the continental crust was formed are constrained by estimates in the rates o crustal growth. The record of events preserved in the continental crust is heterogeneous in time with distinctive peaks and troughs of ages for igneous crystallisation, metamorphism, continental margin and mineralisation. For the most part these are global signatures, and the peaks of ages tend to b associated with periods of increased reworking of pre-existing crust, reflected in the Hf isotope ratios o zircons and their elevated oxygen isotope ratios. Increased crustal reworking is attributed to periods o crustal thickening associated with compressional tectonics and the development of supercontinents Magma types similar to those from recent within-plate and subduction related settings appear to hav been generated in different areas at broadly similar times before ~3.0 Ga. It can be difficult to put th results of such detailed case studies into a more global context, but one approach is to consider when plate tectonics became the dominant mechanism involved in the generation of juvenile continental crust The development of crustal growth models for the continental crust are discussed, and a number o models based on different data sets indicate that 65%-70% of the present volume of the continental crus was generated by 3 Ga. Such estimates may represent minimum values, but since ~3 Ga there has been reduction in the rates of growth of the continental crust. This reduction is linked to an increase in th rates at which continental crust is recycled back into the mantle, and not to a reduction in the rates a which continental crust was generated. Plate tectonics results in both the generation of new crust and it destruction along destructive plate margins. Thus, the reduction in the rate of continental crustal growth at ~3 Ga is taken to reflect the period in which plate tectonics became the dominant mechanism b which new continental crust was generated.展开更多
Among cervids,maternal investment,estimated as the amount of resources and care allocated to the offspring,was expected to be related to species body size. Therefore,maternal investment in a herd of captive Chinese wa...Among cervids,maternal investment,estimated as the amount of resources and care allocated to the offspring,was expected to be related to species body size. Therefore,maternal investment in a herd of captive Chinese water deer Hydropotes inermis,a relatively small species of cervid,was investigated over 3 years. Except during the lactation period,reproductive females spent about 2-fold more time resting than feeding. During lactation,the amount of time spent feeding increased highly (25.3 min/h during lactation vs 17.3 min/h during the gestation period). Females spent less than 30% of time in communal behaviours with offspring. They did not reject alien fawns during this care period. Frequency and duration of suckling events decreased exponentially from the second week onwards. More than 10% of suckling bouts were non-filial. Prenatal investment leads to a mean litter mass (about 12% of maternal mass) higher than in most cervid species. Postnatal investment in fawns represents a daily mass gain of ca. 85 g/d during the first 2 weeks,without any sexual difference. Female production,timing and synchrony of births and survival of fawns characterized reproductive success. Seventy percent of mature females gave birth,with a mean of 1.9 offspring per female. The sex ratio was even. Births were synchronous,80% of births occurring in 25 days. In this herd,0.74 fawn per female was successfully weaned and 0.56 fawn per female survived through their first year. Based on these results we conclude that reproductive strategy of Chinese water deer was efficient and characterized by mother-offspring relationships typical of hiders and high levels of pre-and postnatal investments. This strategy seems typical of small species of cervids without marked sexual dimorphism.展开更多
This paper reports on a study of active vibration control of functionally graded beams with upper and lower surface-bonded piezoelectric layers. The model is based on higher-order shear deformation theory and implemen...This paper reports on a study of active vibration control of functionally graded beams with upper and lower surface-bonded piezoelectric layers. The model is based on higher-order shear deformation theory and implemented using the finite element method （FEM）. The proprieties of the functionally graded beam （FGB） are graded along the thickness direction. The piezoelectric actuator provides a damping effect on the FGB by means of a velocity feedback control algorithm. A Matlab program has been developed for the FGB model and compared with ANSYS APDL. Using Newmark＇s method numerical solutions are obtained for the dynamic equations of FGB with piezoelectric layers. Numerical results show the effects of the constituent volume fraction and the influence the feedback control gain on the frequency and dynamic response of FGBs.展开更多
The effects of an external DC(direct current)electric field on recrystallization texture evolution in the cold-rolled aluminum sheets with 99.99%purity were investigated by means of X-ray diffraction techniques.The co...The effects of an external DC(direct current)electric field on recrystallization texture evolution in the cold-rolled aluminum sheets with 99.99%purity were investigated by means of X-ray diffraction techniques.The cold-rolled high-purity aluminum sheets were annealed for 60 min at 200,300 and 400℃,respectively with and without an external DC electric field of 800 V/mm.The results show that with DC electric field,the recrystallization cube texture is strengthened at the stage of grain growth. Possible reason for the strengthening of the recrystallization cube texture with the applied electric field may be attributed to both selected nucleation and selected growth of cube oriented crystal nuclei.展开更多
This paper reviews the common mechanical features of the metallic cellular material under impact loading as well as the characterization methods of such behaviours. The main focus is on the innovations of various test...This paper reviews the common mechanical features of the metallic cellular material under impact loading as well as the characterization methods of such behaviours. The main focus is on the innovations of various testing methods at impact loading rates.Following aspects were discussed in details.（1） The use of soft nylon Hopkinson/Kolsky bar for an enhanced measuring accuracy in order to assess if there is a strength enhancement or not for this class of cellular materials under moderate impact loading;（2） The use of digital image correlations to determine the strain fields during the tests to confirm the existence of a pseudo-shock wave propagation inside the cellular material under high speed impact： （3） The use of new combined shear compression device to determine the loading envelop of cellular materials under impact multiaxial loadings.展开更多
Gold nanoparticles dispersed Y2O3 films were prepared through a sol-gel method by using yttrium acetate and Au nanoparticles colloid as precursors. The films were characterized by X-ray diffraction （XRD）, transmissi...Gold nanoparticles dispersed Y2O3 films were prepared through a sol-gel method by using yttrium acetate and Au nanoparticles colloid as precursors. The films were characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM） and UV-VIS absorption spectra. XRD patterns and TEM images of Y2O3 ＋ Au films give the same resuits on structure and particle size as that of pure Y2O3 films. The surface plasma resonance （SPR） of Au nanoparticles in Y2O3 ＋ Au film was observed around 550 nm in the absorption spectrum and its position shifts to red with increasing annealing temperature is caused by the increase of dielectric constant of Y2O3 matrix and the size of Au nanoparticles. The second and third order nonlinear optical effects of Y2O3 ＋ Au films were also observed. The photoluminescent properties of Y2O3 ： Eu ＋ Au films were investigated and results indicate that there exist an energy transfer from Eu^3 ＋ to Au nanoparticles and this energy transfer decreases the emission of Eu^3 ＋ in Y2O3 ： Eu ＋ Au film.展开更多
The commercially pure copper with dimension of 80 mm×20 mm×4 mm was used for equal channel angular pressing (ECAP), of which their outward appearance coordinate is corresponded with that of rolling deformati...The commercially pure copper with dimension of 80 mm×20 mm×4 mm was used for equal channel angular pressing (ECAP), of which their outward appearance coordinate is corresponded with that of rolling deformation modes. Cold-deformed texture was investigated. The results show that the texture character in pure copper processed by ECAP is related with intersection angle (Φ) of the die channel. When Φ is 90° and the sample is extruded for one pass, its texture consists of α and β orientation lines including mainly C, B, S and Goss components, moreover a little rotated cube is found. When Φ is 135°, as extrusion pass increases, the weak texture forms on the scope of deviation from rotated cube (ψ=0°, θ=0°,φ=450°±150°) and develops to the ψ=45° fiber mainly including rotated cube. When Φ is 120°, the texture is ψ=45° fiber mainly including rotated cube that is maintained constant as extrusion pass increases.展开更多
The phenomenon of planar cell polarity is critically required for a myriad of morphogenetic processes in metazoan and is accurately controlled by several conserved modules.Six“core”proteins,including Friz zled,Flami...The phenomenon of planar cell polarity is critically required for a myriad of morphogenetic processes in metazoan and is accurately controlled by several conserved modules.Six“core”proteins,including Friz zled,Flamingo(Celsr),Van Gogh(Vangl),Dishevelled,Prickle,and Diego(Ankrd6),are major components of the Wnt/planar cell polarity pathway.The Fat/Dchs protocadherins and the Scrib polarity complex also function to instruct cellular polarization.In vertebrates,all these pathways are essential for tissue and organ morphogenesis,such as neural tube closure,left-right symmetry breaking,heart and gut morphogenesis,lung and kidney branching,stereociliary bundle orientation,and proximal-distal limb elongation.Mutations in planar polarity genes are closely linked to various congenital diseases.Striking advances have been made in deciphering their contribution to the establishment of spatially oriented pattern in developing or gans and the maintenance of tissue homeostasis.The challenge remains to clarify the complex interplay of different polarity pathways in organogenesis and the link of cell polarity to cell fate specification.Inter disciplinary approaches are also important to understand the roles of mechanical forces in coupling cellular polarization and differentiation.This review outlines current advances on planar polarity regulators in asymmetric organ formation,with the aim to identify questions that deserve further investigation.展开更多
The Late Paleozoic–Early Mesozoic Mongol-Okhotsk Ocean extended between the Siberian and Amur–North China continents.The timing and modalities of the oceanic closure are widely discussed.It is largely accepted that ...The Late Paleozoic–Early Mesozoic Mongol-Okhotsk Ocean extended between the Siberian and Amur–North China continents.The timing and modalities of the oceanic closure are widely discussed.It is largely accepted that the ocean closed in a scissor-like manner from southwest to northeast(in modern coordinates),though the timing of this process remains uncertain.Recent studies have shown that both western(West Transbaikalia)and eastern(Dzhagda)parts of the ocean closed almost simultaneously at the Early–Middle Jurassic boundary.However,little information on the key central part of the oceanic suture zone is available.We performed U-Pb(LA-ICP-MS)dating of detrital zircon from wellcharacterized stratigraphic sections of the central part of the Mongol-Okhotsk suture zone.These include the initial marine and final continental sequences of the East Transbaikalia Basin,deposited on the northern Argun-Idemeg terrane basement.We provide new stratigraphic ages for the marine and continental deposits.This revised chronostratigraphy allows assigning an age of~165–155 Ma,to the collisionrelated flexure of the northern Argun-Idemeg terrane and the development of a peripheral foreland basin.This collisional process took place 5 to10 million years later than in the western and eastern parts of the ocean.We demonstrate that the northern Argun-Idemeg terrane was the last block to collide with the Siberian continent,challenging the widely supported scissor-like model of closure of the MongolOkhotsk Ocean.Different segments of the ocean closed independently,depending on the initial shape of the paleo continental margins.展开更多
Gaseous naphthalene has been removed by air plasma generated by pulsed corona discharges at 100°C(LSPM)and dielectric barrier discharges(DBD)up to 250℃(LPGP)in different reactors geometries.Naphthalene has been ...Gaseous naphthalene has been removed by air plasma generated by pulsed corona discharges at 100°C(LSPM)and dielectric barrier discharges(DBD)up to 250℃(LPGP)in different reactors geometries.Naphthalene has been chosen as one of unbumed hydrocarbon present in exhaust gas engine during the cold start of vehicles.The comparison between the different discharge geometries has been possible using the specific input energy(SIE)as relevant parameter for pollutant removal process control considering the differences in the electrical characteristics and the differences of gas flow.The best naphthalene degradation is obtained in the wire-to cylinder(WTC)corona discharge and the stem-to-cylinder DBD with an energy costβrespectively of 10 and 20 J L^-1.The main by-products issues of the naphthalene oxidation are CO2 and CO reaching 45%in Multi-Pin-to-Plan corona discharge.We detected polyaromatic hydrocarbons in the gas phase(few ppm)and in the solid phase deposited in the reactors.The introduction of water in the discharges promotes the naphthalene degradation by OH-atom,which has better oxidising power than O-atom in dry air.展开更多
Asymptotic stability of linear and interval linear fractional-order neutral delay differential systems described by the Caputo-Fabrizio (CF) fractional derivatives is investigated. Using Laplace transform, a novel cha...Asymptotic stability of linear and interval linear fractional-order neutral delay differential systems described by the Caputo-Fabrizio (CF) fractional derivatives is investigated. Using Laplace transform, a novel characteristic equation is derived. Stability criteria are established based on an algebraic approach and norm-based criteria are also presented. It is shown that asymptotic stability is ensured for linear fractional-order neutral delay differential systems provided that the underlying stability criterion holds for any delay parameter. In addition, sufficient conditions are derived to ensure the asymptotic stability of interval linear fractional order neutral delay differential systems. Examples are provided to illustrate the effectiveness and applicability of the theoretical results.展开更多
文摘Conventional ignition methods are proving to be ineffective for low-sensitivity energetic materials,highlighting the need to investigate alternative ignition systems,such as laser-based techniques.Over the past decade,lasers have emerged as a promising solution,providing focused energy beams for controllable,efficient,and reliable ignition in the field of energetic materials.This study presents a comparative analysis of two state-of-the-art ignition approaches:direct laser ignition and laser-driven flyer ignition.Experiments were performed using a Neodymium-doped Yttrium Aluminum Garnet(Nd:YAG)laser at different energy beam levels to systematically evaluate ignition onset.In the direct laser ignition test setup,the laser beam was applied directly to the energetic tested material,while laserdriven flyer ignition utilized 40 and 100μm aluminum foils,propelled at velocities ranging from 300 to 1250 m/s.Comparative analysis with the Lawrence and Trott model substantiated the velocity data and provided insight into the ignition mechanisms.Experimental results indicate that the ignition time for the laser-driven flyer method was significantly shorter,with the pyrotechnic composition achieving complete combustion faster compared to direct laser ignition.Moreover,precise ignition thresholds were determined for both methods,providing critical parameters for optimizing ignition systems in energetic materials.This work elucidates the advantages and limitations of each technique while advancing next-generation ignition technology,enhancing the reliability and safety of propulsion systems.
基金supported by the China Postdoctoral Science Foundation(No.2022M720399).
文摘In order to investigate the damage tolerance of a metastable Ti-5Al-3V-3Mo-2Cr-2Zr-1Nb-1Fe(Ti5321)alloy with bimodal microstructure using void growth quantification and micromechanical modeling,in situ tensile testing was performed during X-ray microtomography experiments.Compared with investigations of surface voids by traditional two-dimensional(2D)methods involving post-mortem characterization,three-dimensional(3D)information on void evolution inside optically opaque samples obtained through X-ray microtomography is essential.The Rice and Tracey model and Huang model were applied to predict void growth and show good agreement with experimental data using calibration of the damage parameterα.The void growth kinetics of Ti5321 with bimodal microstructure was analyzed by comparing theαvalue with that of Ti64 for different microstructure morphologies.The damage mechanism of ductile fracture of Ti5321 with bimodal microstructure is discussed.It was found that the size of the voids apparently increases with the triaxiality of stress.Post-mortem scanning electron microscopy(SEM)was also used to demonstrate this damage mechanism of ductile fracture of Ti5321.
基金the Franco-Thai Cooperation Programme in Higher Education and Research(Franco-Thai Mobility Programme/PHC SIAM)Year 2024-2025。
文摘This study reviews light-responsive polymers in various applications,including drug delivery,information storage,sensor,self-healing material,antibacterial or anti-fouling,and environmental applications.Light-responsive polymers are a new material type being developed for various medical,electronics,engineering,and environmental applications.The working principle of light-responsive materials is based on metalligand interactions or non-covalent interactions between polymer functional groups,metal ions,and other filler functional groups.Light irradiation causes physical and mechanical changes in drug delivery and antibacterial systems,which results in the materials releasing more drugs or antibacterial substances.When materials in information storage devices and sensors are exposed to light,they can change color or glow.This has been applied for data storage to reveal QR codes under UV light.Additionally,this review discusses the thermodynamic aspects and computer modeling of light-responsive materials to emphasize the importance and development of these materials.Finally,light-responsive polymer development for various applications is presented.
基金supported by grants from the LeverhulmeTrust RPG-2015-422 and EM-2017-047\4 to Chris HawkesworthNERC NE/K008862/1 to Bruno Dhuimefrom AustralianResearch Council FL160100168 to Peter A. Cawood
文摘Models for when and how the continental crust was formed are constrained by estimates in the rates o crustal growth. The record of events preserved in the continental crust is heterogeneous in time with distinctive peaks and troughs of ages for igneous crystallisation, metamorphism, continental margin and mineralisation. For the most part these are global signatures, and the peaks of ages tend to b associated with periods of increased reworking of pre-existing crust, reflected in the Hf isotope ratios o zircons and their elevated oxygen isotope ratios. Increased crustal reworking is attributed to periods o crustal thickening associated with compressional tectonics and the development of supercontinents Magma types similar to those from recent within-plate and subduction related settings appear to hav been generated in different areas at broadly similar times before ~3.0 Ga. It can be difficult to put th results of such detailed case studies into a more global context, but one approach is to consider when plate tectonics became the dominant mechanism involved in the generation of juvenile continental crust The development of crustal growth models for the continental crust are discussed, and a number o models based on different data sets indicate that 65%-70% of the present volume of the continental crus was generated by 3 Ga. Such estimates may represent minimum values, but since ~3 Ga there has been reduction in the rates of growth of the continental crust. This reduction is linked to an increase in th rates at which continental crust is recycled back into the mantle, and not to a reduction in the rates a which continental crust was generated. Plate tectonics results in both the generation of new crust and it destruction along destructive plate margins. Thus, the reduction in the rate of continental crustal growth at ~3 Ga is taken to reflect the period in which plate tectonics became the dominant mechanism b which new continental crust was generated.
文摘Among cervids,maternal investment,estimated as the amount of resources and care allocated to the offspring,was expected to be related to species body size. Therefore,maternal investment in a herd of captive Chinese water deer Hydropotes inermis,a relatively small species of cervid,was investigated over 3 years. Except during the lactation period,reproductive females spent about 2-fold more time resting than feeding. During lactation,the amount of time spent feeding increased highly (25.3 min/h during lactation vs 17.3 min/h during the gestation period). Females spent less than 30% of time in communal behaviours with offspring. They did not reject alien fawns during this care period. Frequency and duration of suckling events decreased exponentially from the second week onwards. More than 10% of suckling bouts were non-filial. Prenatal investment leads to a mean litter mass (about 12% of maternal mass) higher than in most cervid species. Postnatal investment in fawns represents a daily mass gain of ca. 85 g/d during the first 2 weeks,without any sexual difference. Female production,timing and synchrony of births and survival of fawns characterized reproductive success. Seventy percent of mature females gave birth,with a mean of 1.9 offspring per female. The sex ratio was even. Births were synchronous,80% of births occurring in 25 days. In this herd,0.74 fawn per female was successfully weaned and 0.56 fawn per female survived through their first year. Based on these results we conclude that reproductive strategy of Chinese water deer was efficient and characterized by mother-offspring relationships typical of hiders and high levels of pre-and postnatal investments. This strategy seems typical of small species of cervids without marked sexual dimorphism.
文摘This paper reports on a study of active vibration control of functionally graded beams with upper and lower surface-bonded piezoelectric layers. The model is based on higher-order shear deformation theory and implemented using the finite element method （FEM）. The proprieties of the functionally graded beam （FGB） are graded along the thickness direction. The piezoelectric actuator provides a damping effect on the FGB by means of a velocity feedback control algorithm. A Matlab program has been developed for the FGB model and compared with ANSYS APDL. Using Newmark＇s method numerical solutions are obtained for the dynamic equations of FGB with piezoelectric layers. Numerical results show the effects of the constituent volume fraction and the influence the feedback control gain on the frequency and dynamic response of FGBs.
基金Project(50374028)supported by the National Natural Science Foundation of China and Shanghai Bao Steel Group of ChinaProject(PRAMX04-02)supported by Sino-French Cooperation Program
文摘The effects of an external DC(direct current)electric field on recrystallization texture evolution in the cold-rolled aluminum sheets with 99.99%purity were investigated by means of X-ray diffraction techniques.The cold-rolled high-purity aluminum sheets were annealed for 60 min at 200,300 and 400℃,respectively with and without an external DC electric field of 800 V/mm.The results show that with DC electric field,the recrystallization cube texture is strengthened at the stage of grain growth. Possible reason for the strengthening of the recrystallization cube texture with the applied electric field may be attributed to both selected nucleation and selected growth of cube oriented crystal nuclei.
文摘This paper reviews the common mechanical features of the metallic cellular material under impact loading as well as the characterization methods of such behaviours. The main focus is on the innovations of various testing methods at impact loading rates.Following aspects were discussed in details.（1） The use of soft nylon Hopkinson/Kolsky bar for an enhanced measuring accuracy in order to assess if there is a strength enhancement or not for this class of cellular materials under moderate impact loading;（2） The use of digital image correlations to determine the strain fields during the tests to confirm the existence of a pseudo-shock wave propagation inside the cellular material under high speed impact： （3） The use of new combined shear compression device to determine the loading envelop of cellular materials under impact multiaxial loadings.
文摘Gold nanoparticles dispersed Y2O3 films were prepared through a sol-gel method by using yttrium acetate and Au nanoparticles colloid as precursors. The films were characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM） and UV-VIS absorption spectra. XRD patterns and TEM images of Y2O3 ＋ Au films give the same resuits on structure and particle size as that of pure Y2O3 films. The surface plasma resonance （SPR） of Au nanoparticles in Y2O3 ＋ Au film was observed around 550 nm in the absorption spectrum and its position shifts to red with increasing annealing temperature is caused by the increase of dielectric constant of Y2O3 matrix and the size of Au nanoparticles. The second and third order nonlinear optical effects of Y2O3 ＋ Au films were also observed. The photoluminescent properties of Y2O3 ： Eu ＋ Au films were investigated and results indicate that there exist an energy transfer from Eu^3 ＋ to Au nanoparticles and this energy transfer decreases the emission of Eu^3 ＋ in Y2O3 ： Eu ＋ Au film.
基金Project(Lnzr0201) supported by the Foundation of Science and Technology Committee of Liaoning Province of China
文摘The commercially pure copper with dimension of 80 mm×20 mm×4 mm was used for equal channel angular pressing (ECAP), of which their outward appearance coordinate is corresponded with that of rolling deformation modes. Cold-deformed texture was investigated. The results show that the texture character in pure copper processed by ECAP is related with intersection angle (Φ) of the die channel. When Φ is 90° and the sample is extruded for one pass, its texture consists of α and β orientation lines including mainly C, B, S and Goss components, moreover a little rotated cube is found. When Φ is 135°, as extrusion pass increases, the weak texture forms on the scope of deviation from rotated cube (ψ=0°, θ=0°,φ=450°±150°) and develops to the ψ=45° fiber mainly including rotated cube. When Φ is 120°, the texture is ψ=45° fiber mainly including rotated cube that is maintained constant as extrusion pass increases.
基金supported by grants from the National Natural Science Foundation of China(grant number 32070813)the French Muscular Dystrophy Association (AFM-Telethon grant number 23545)+1 种基金the Centre National de la Recherche Scientifiquethe Sorbonne University
文摘The phenomenon of planar cell polarity is critically required for a myriad of morphogenetic processes in metazoan and is accurately controlled by several conserved modules.Six“core”proteins,including Friz zled,Flamingo(Celsr),Van Gogh(Vangl),Dishevelled,Prickle,and Diego(Ankrd6),are major components of the Wnt/planar cell polarity pathway.The Fat/Dchs protocadherins and the Scrib polarity complex also function to instruct cellular polarization.In vertebrates,all these pathways are essential for tissue and organ morphogenesis,such as neural tube closure,left-right symmetry breaking,heart and gut morphogenesis,lung and kidney branching,stereociliary bundle orientation,and proximal-distal limb elongation.Mutations in planar polarity genes are closely linked to various congenital diseases.Striking advances have been made in deciphering their contribution to the establishment of spatially oriented pattern in developing or gans and the maintenance of tissue homeostasis.The challenge remains to clarify the complex interplay of different polarity pathways in organogenesis and the link of cell polarity to cell fate specification.Inter disciplinary approaches are also important to understand the roles of mechanical forces in coupling cellular polarization and differentiation.This review outlines current advances on planar polarity regulators in asymmetric organ formation,with the aim to identify questions that deserve further investigation.
基金conducted in the frame of the grant of the Ministry of Science and High Education of the Russian Federation No.075-15-2019-1883。
文摘The Late Paleozoic–Early Mesozoic Mongol-Okhotsk Ocean extended between the Siberian and Amur–North China continents.The timing and modalities of the oceanic closure are widely discussed.It is largely accepted that the ocean closed in a scissor-like manner from southwest to northeast(in modern coordinates),though the timing of this process remains uncertain.Recent studies have shown that both western(West Transbaikalia)and eastern(Dzhagda)parts of the ocean closed almost simultaneously at the Early–Middle Jurassic boundary.However,little information on the key central part of the oceanic suture zone is available.We performed U-Pb(LA-ICP-MS)dating of detrital zircon from wellcharacterized stratigraphic sections of the central part of the Mongol-Okhotsk suture zone.These include the initial marine and final continental sequences of the East Transbaikalia Basin,deposited on the northern Argun-Idemeg terrane basement.We provide new stratigraphic ages for the marine and continental deposits.This revised chronostratigraphy allows assigning an age of~165–155 Ma,to the collisionrelated flexure of the northern Argun-Idemeg terrane and the development of a peripheral foreland basin.This collisional process took place 5 to10 million years later than in the western and eastern parts of the ocean.We demonstrate that the northern Argun-Idemeg terrane was the last block to collide with the Siberian continent,challenging the widely supported scissor-like model of closure of the MongolOkhotsk Ocean.Different segments of the ocean closed independently,depending on the initial shape of the paleo continental margins.
基金supported in part by a Peugeot SociétéAnonyme contract
文摘Gaseous naphthalene has been removed by air plasma generated by pulsed corona discharges at 100°C(LSPM)and dielectric barrier discharges(DBD)up to 250℃(LPGP)in different reactors geometries.Naphthalene has been chosen as one of unbumed hydrocarbon present in exhaust gas engine during the cold start of vehicles.The comparison between the different discharge geometries has been possible using the specific input energy(SIE)as relevant parameter for pollutant removal process control considering the differences in the electrical characteristics and the differences of gas flow.The best naphthalene degradation is obtained in the wire-to cylinder(WTC)corona discharge and the stem-to-cylinder DBD with an energy costβrespectively of 10 and 20 J L^-1.The main by-products issues of the naphthalene oxidation are CO2 and CO reaching 45%in Multi-Pin-to-Plan corona discharge.We detected polyaromatic hydrocarbons in the gas phase(few ppm)and in the solid phase deposited in the reactors.The introduction of water in the discharges promotes the naphthalene degradation by OH-atom,which has better oxidising power than O-atom in dry air.
文摘Asymptotic stability of linear and interval linear fractional-order neutral delay differential systems described by the Caputo-Fabrizio (CF) fractional derivatives is investigated. Using Laplace transform, a novel characteristic equation is derived. Stability criteria are established based on an algebraic approach and norm-based criteria are also presented. It is shown that asymptotic stability is ensured for linear fractional-order neutral delay differential systems provided that the underlying stability criterion holds for any delay parameter. In addition, sufficient conditions are derived to ensure the asymptotic stability of interval linear fractional order neutral delay differential systems. Examples are provided to illustrate the effectiveness and applicability of the theoretical results.
