Topological materials and metamaterials opened new paradigms to create and manipulate phases of matter with unconventional properties.Topological D-class phases(TDPs)are archetypes of the ten-fold classification of to...Topological materials and metamaterials opened new paradigms to create and manipulate phases of matter with unconventional properties.Topological D-class phases(TDPs)are archetypes of the ten-fold classification of topological phases with particle-hole symmetry.In two dimensions,TDPs support propagating topological edge modes that simulate the elusive Majorana elementary particles.Furthermore,a piercing ofπ-flux Dirac-solenoids in TDPs stabilizes localized Majorana excitations that can be braided for the purpose of topological quantum computation.Such two-dimensional(2D)TDPs have been a focus in the research frontier,but their experimental realizations are still under debate.Here,with a novel design scheme,we realize 2D TDPs in an acoustic crystal by synthesizing both the particle-hole and fermion-like time reversal symmetries for a wide range of frequencies.The design scheme leverages an enriched unit cell structure with real-valued couplings that emulate the targeted Hamiltonian of TDPs with complex hoppings:A technique that could unlock the realization of all topological classes with passive metamaterials.In our experiments,we realize a pair of TDPs with opposite Chern numbers in two independent sectors that are connected by an intrinsic fermion-like timereversal symmetry built in the system.We measure the acoustic Majorana-like helical edge modes and visualize their robust topological transport,thus revealing the unprecedented D and DIII class topologies with direct evidence.Our study opens up a new pathway for the experimental realization of two fundamental classes of topological phases and may offer new insights in fundamental physics,materials science,and phononic information processing.展开更多
The demand for injectable dermal filler has unde rgone significant growth with the rapid development of the beauty industry.Poly(lactic acid)(PLA) as a benefit of excellent biocompatibility and long-term promotion of ...The demand for injectable dermal filler has unde rgone significant growth with the rapid development of the beauty industry.Poly(lactic acid)(PLA) as a benefit of excellent biocompatibility and long-term promotion of collagen regeneration has been favored as a commonly used filler.However,the effects of chirality and particle size of PLA on the efficacy of dermal filler have not been studied.In this study,we prepared three kinds of microspheres(MSs) consisting of poly(D-lactic acid)(PDLA MS),poly(L-lactic acid)(PLLA MS),or meso-PLA(PDLLA MS)at 5,10 and 20 μmto reveal the different biological functions as dermal filler.Following intradermal injection into guinea pig,it was found that PLLA MS induced the slightest inflammation,and the level of pro-inflammatory cytokine IL-1β induced by PLLA MS is only 0.3 or 0.7-fold of that induced by PDLA or PDLLA MS,respectively.More importantly,PLLA MS significantly stimulated the regeneration of collagen,which was 1.4 or 1.1 times higher than those stimulated by PDLA MS or PDLLA MS,respectively.The size of PLA MSs did not affect the levels of inflammation and collagen regeneration.The results confirmed the superiority of PLLA as a dermal filler.展开更多
The proportion of organic matter and mineral composition are important factors determining the formation and type of non-extractable residues(NERs) of pesticides in soil. In this study, we investigated the enantiosele...The proportion of organic matter and mineral composition are important factors determining the formation and type of non-extractable residues(NERs) of pesticides in soil. In this study, we investigated the enantioselectivity in degradation and NER formation of the chiral fungicide metalaxyl in soil particle size fractions(silt and clay). Microbial and extracellular enzyme activities during these processes were monitored in incubation of silt and clay samples isolated from sterilized and non-sterilized soil samples collected from a long-term agricultural field experimental site in Ultuna, Sweden. The temporal influence on the fate of the fungicide was noted by short-term(10-d) and long-term(92-d) incubations. Besides the acquisition of quantitative data with gas chromatography-mass spectrometry(GC/MS), stereoselective analyses were performed with chiral GC/MS. Quantitative results pointed to a higher metabolism rate of the pesticide through microbial activity than through extracellular enzyme activity. This was also confirmed by the enantioselective depletion of R-metalaxyl and the subsequent formation of R-metalaxyl acid in microbially active samples from non-sterilized soil. The silt fraction containing a high amount of organic matter exhibited a significant hydrolyzable proportion of metalaxyl NERs that was releasable under alkaline conditions. On the contrary, the clay fraction showed an enhanced affinity for covalently bound residues. Based on our results, we recommend differentiating between reversibly and irreversibly bound proportions of pesticides in persistence and environmental risk assessment because the reversible fraction contained potentially bioavailable amounts of residues that may be released under natural conditions.展开更多
Positive-parity doublet bands were reported in 120I.Based on these,we discuss the corresponding experimental characteristics,including rotational alignment,and re-examine the corresponding configuration assignment.The...Positive-parity doublet bands were reported in 120I.Based on these,we discuss the corresponding experimental characteristics,including rotational alignment,and re-examine the corresponding configuration assignment.The self-consistent tilted axis cranking relativistic mean-field calculations indicate that the doublet bands are built on the configurationπh11/2νh11/2^-1.By adopting the two quasiparticles coupled with a triaxial rotor model,the excitation energies,energy staggering parameter S(I),B(M1)/B(E2),effective angles,and K plots are discussed and compared with available data.The obtained results support the interpretation of chiral doublet bands for the positive-parity doublet bands in 120I,and hence identify this nucleus as the border of the A≈130 island of chiral candidates.展开更多
Current trends in chiral analysis of pharmaceutical drugs are focused on faster separations and higher separation efficiencies, Core-shell or superficially porous particles （SPP） based chiral stationary phases （CSP...Current trends in chiral analysis of pharmaceutical drugs are focused on faster separations and higher separation efficiencies, Core-shell or superficially porous particles （SPP） based chiral stationary phases （CSPs） provide reduced analysis times while maintaining high column efficiencies and sensitivity. In this study, mobile phase conditions suitable for chiral analyses with electrospray ionization LC-MS were systematically investigated using vancomycin as a representative CSP. The performance of a 2.7 μm SPP based vancomycin CSP （SPP-V） 10 cm ×0.21 cm column was compared to that of a corresponding 5 μm fully porous particles based analogue column. The results demonstrated that the SPP-V column provides higher efficiencies, 2-5 time greater sensitivity and shorter analysis time for a set of 22 basic pharma- ceutical drugs. The SPP-V was successfully applied for the analysis of the degradation products of racemic citalopram whose enantiomers could be selectively identified by MS.展开更多
The chiral geometry of multiple chiral doublet bands with identical configuration is discussed for different triaxial deformation parameters γ in the particle rotor model with πh11/2×γh11/2^-1.The energy spect...The chiral geometry of multiple chiral doublet bands with identical configuration is discussed for different triaxial deformation parameters γ in the particle rotor model with πh11/2×γh11/2^-1.The energy spectra,electromagnetic transition probabilities B（M1） and B（E2）,angular momenta,and K-distributions are studied.It is demonstrated that the chirality still remains not only in the yrast and yrare bands,but also in the two higher excited bands whenγ deviates from 30°.The chiral geometry relies significantly on γ,and the chiral geometry of the two higher excited partner bands is not as good as that of the yrast and yrare doublet bands.展开更多
The candidate chiral doublet bands in 98 Tc with configuration πg9/2νh11/2 are studied the- oretically for the first time via the triaxial particle rotor model. The main properties of the doublet bands including the...The candidate chiral doublet bands in 98 Tc with configuration πg9/2νh11/2 are studied the- oretically for the first time via the triaxial particle rotor model. The main properties of the doublet bands including the energy spectra and electromagnetic transitions are calculated for different triaxiality parameter γ, and the data in 98Tc can be well described by the calculations with γ = 38°. Based on the analysis of angular momentum components, it is found that the chiral rotational geometry in 98Tc deviates from the ideal chiral picture.展开更多
Multiple chiral doublet bands （MχD） in the 80, 130 and 190 mass regions are studied by the model of γ=90°triaxial rotor coupled with identical symmetric proton-neutron configurations. By selecting a suitable ...Multiple chiral doublet bands （MχD） in the 80, 130 and 190 mass regions are studied by the model of γ=90°triaxial rotor coupled with identical symmetric proton-neutron configurations. By selecting a suitable basis, the calculated wave functions are explicitly exhibited to be symmetric under the operator A, which is defined as rotation by 90° about the 3-axis with the exchange of valance proton and neutron. We found that both M1 and E2 transitions are allowed between levels with different values of A, while they are forbidden between levels with same values of A. Such a selection rule holds true for MχD in different mass regions.展开更多
The dynamics of two-dimensional rigid circles filled with chiral active particles are investigated by employing the overdamped Langevin dynamics simulations. Unidirectional rotation of rigid circles is observed, and t...The dynamics of two-dimensional rigid circles filled with chiral active particles are investigated by employing the overdamped Langevin dynamics simulations. Unidirectional rotation of rigid circles is observed, and the rotational angular velocity（ω） relies mainly on the length（l）, the number（nB）, and tilt angle（γ） of boards, and the angular velocity（ω）and area fraction（ρ） of chiral active particles. There are optimum values for these parameters at which the average angular velocity of circle reaches its maximum. The center-of-mass mean square displacement for circles drops by about two orders of magnitude for large angular velocity ω of chiral active particles with oscillations in the short-time regime. Our work demonstrates that nanofabricated objects with suitable designs immersed in a bath of chiral active particles can extract and rectify energy in a unidirectional motion.展开更多
Using the model with one particle and one hole coupled with a triaxial rotor, the πg9/2/1/2νh11/2 doublet bands in the A～100 mass region are studied, and compared with the πg9/2/1/2νh11/2 doublet bands. It is fou...Using the model with one particle and one hole coupled with a triaxial rotor, the πg9/2/1/2νh11/2 doublet bands in the A～100 mass region are studied, and compared with the πg9/2/1/2νh11/2 doublet bands. It is found that the calculated results for the configuration of πg9/2/1/2νh11/2 are very similar the results for a pure h11/2 proton particle and a neutron quasiparticle with λn = ε5. After including the pair correlation, the model describes the candidate chiral doublet bands in 106Rh successfully, which supports the interpretation of chirality geometry.展开更多
Different definitions for chiral doublet bands based on excitation energies, B(E2) and B(M1) respectively are discussed in the triaxial particle rotor model. For the ideal chiral geometry, the selection rules of the e...Different definitions for chiral doublet bands based on excitation energies, B(E2) and B(M1) respectively are discussed in the triaxial particle rotor model. For the ideal chiral geometry, the selection rules of the electromagnetic transitions in different band definitions are illustrated. It is also shown that the energy-level crossings between chiral doublet bands may occur.展开更多
基金the support from the National Key R&D Program of China(2022YFA1404400)the National Natural Science Foundation of China(12125504 and 12074281)+5 种基金the support from the National Natural Science Foundation of China(12047541)the Gusu Leading Innovation Scientists Program of Suzhou City,and the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutionsthe Research Fund of Guangdong-Hong Kong-Macao Joint Laboratory for Intelligent Micro-Nano Optoelectronic Technology(2020B1212030010)support from the US National Science Foundation(CMMI2131759)support from the US National Science Foundation(DMR-1823800 and CMMI-2131760)the U.S.Army Research Office through contract W911NF-23-1-0127。
文摘Topological materials and metamaterials opened new paradigms to create and manipulate phases of matter with unconventional properties.Topological D-class phases(TDPs)are archetypes of the ten-fold classification of topological phases with particle-hole symmetry.In two dimensions,TDPs support propagating topological edge modes that simulate the elusive Majorana elementary particles.Furthermore,a piercing ofπ-flux Dirac-solenoids in TDPs stabilizes localized Majorana excitations that can be braided for the purpose of topological quantum computation.Such two-dimensional(2D)TDPs have been a focus in the research frontier,but their experimental realizations are still under debate.Here,with a novel design scheme,we realize 2D TDPs in an acoustic crystal by synthesizing both the particle-hole and fermion-like time reversal symmetries for a wide range of frequencies.The design scheme leverages an enriched unit cell structure with real-valued couplings that emulate the targeted Hamiltonian of TDPs with complex hoppings:A technique that could unlock the realization of all topological classes with passive metamaterials.In our experiments,we realize a pair of TDPs with opposite Chern numbers in two independent sectors that are connected by an intrinsic fermion-like timereversal symmetry built in the system.We measure the acoustic Majorana-like helical edge modes and visualize their robust topological transport,thus revealing the unprecedented D and DIII class topologies with direct evidence.Our study opens up a new pathway for the experimental realization of two fundamental classes of topological phases and may offer new insights in fundamental physics,materials science,and phononic information processing.
基金financially supported by the National Natural Science Foundation of China(Nos.51703012 and 51603204)the Science and Technology Development Program of Jilin Province(No.20190701004GH)。
文摘The demand for injectable dermal filler has unde rgone significant growth with the rapid development of the beauty industry.Poly(lactic acid)(PLA) as a benefit of excellent biocompatibility and long-term promotion of collagen regeneration has been favored as a commonly used filler.However,the effects of chirality and particle size of PLA on the efficacy of dermal filler have not been studied.In this study,we prepared three kinds of microspheres(MSs) consisting of poly(D-lactic acid)(PDLA MS),poly(L-lactic acid)(PLLA MS),or meso-PLA(PDLLA MS)at 5,10 and 20 μmto reveal the different biological functions as dermal filler.Following intradermal injection into guinea pig,it was found that PLLA MS induced the slightest inflammation,and the level of pro-inflammatory cytokine IL-1β induced by PLLA MS is only 0.3 or 0.7-fold of that induced by PDLA or PDLLA MS,respectively.More importantly,PLLA MS significantly stimulated the regeneration of collagen,which was 1.4 or 1.1 times higher than those stimulated by PDLA MS or PDLLA MS,respectively.The size of PLA MSs did not affect the levels of inflammation and collagen regeneration.The results confirmed the superiority of PLLA as a dermal filler.
基金Financial support by the German Research Foundation (DFG) (SCHW750/9) in the frame of the Priority Program SPP 1315。
文摘The proportion of organic matter and mineral composition are important factors determining the formation and type of non-extractable residues(NERs) of pesticides in soil. In this study, we investigated the enantioselectivity in degradation and NER formation of the chiral fungicide metalaxyl in soil particle size fractions(silt and clay). Microbial and extracellular enzyme activities during these processes were monitored in incubation of silt and clay samples isolated from sterilized and non-sterilized soil samples collected from a long-term agricultural field experimental site in Ultuna, Sweden. The temporal influence on the fate of the fungicide was noted by short-term(10-d) and long-term(92-d) incubations. Besides the acquisition of quantitative data with gas chromatography-mass spectrometry(GC/MS), stereoselective analyses were performed with chiral GC/MS. Quantitative results pointed to a higher metabolism rate of the pesticide through microbial activity than through extracellular enzyme activity. This was also confirmed by the enantioselective depletion of R-metalaxyl and the subsequent formation of R-metalaxyl acid in microbially active samples from non-sterilized soil. The silt fraction containing a high amount of organic matter exhibited a significant hydrolyzable proportion of metalaxyl NERs that was releasable under alkaline conditions. On the contrary, the clay fraction showed an enhanced affinity for covalently bound residues. Based on our results, we recommend differentiating between reversibly and irreversibly bound proportions of pesticides in persistence and environmental risk assessment because the reversible fraction contained potentially bioavailable amounts of residues that may be released under natural conditions.
基金Supported by the National Natural Science Foundation of China(11675063,11205068,11475072,11847310)。
文摘Positive-parity doublet bands were reported in 120I.Based on these,we discuss the corresponding experimental characteristics,including rotational alignment,and re-examine the corresponding configuration assignment.The self-consistent tilted axis cranking relativistic mean-field calculations indicate that the doublet bands are built on the configurationπh11/2νh11/2^-1.By adopting the two quasiparticles coupled with a triaxial rotor model,the excitation energies,energy staggering parameter S(I),B(M1)/B(E2),effective angles,and K plots are discussed and compared with available data.The obtained results support the interpretation of chiral doublet bands for the positive-parity doublet bands in 120I,and hence identify this nucleus as the border of the A≈130 island of chiral candidates.
基金supported by the Robert A.Welch Foundation(Y0026)the French National Center for Scientific Research(ISA-CNRS-UMR5280)
文摘Current trends in chiral analysis of pharmaceutical drugs are focused on faster separations and higher separation efficiencies, Core-shell or superficially porous particles （SPP） based chiral stationary phases （CSPs） provide reduced analysis times while maintaining high column efficiencies and sensitivity. In this study, mobile phase conditions suitable for chiral analyses with electrospray ionization LC-MS were systematically investigated using vancomycin as a representative CSP. The performance of a 2.7 μm SPP based vancomycin CSP （SPP-V） 10 cm ×0.21 cm column was compared to that of a corresponding 5 μm fully porous particles based analogue column. The results demonstrated that the SPP-V column provides higher efficiencies, 2-5 time greater sensitivity and shorter analysis time for a set of 22 basic pharma- ceutical drugs. The SPP-V was successfully applied for the analysis of the degradation products of racemic citalopram whose enantiomers could be selectively identified by MS.
基金Supported by Plan Project of Beijing College Students' Scientific Research and Entrepreneurial Action,Major State 973 Program of China(2013CB834400)National Natural Science Foundation of China(11175002,11335002,11375015,11461141002)+2 种基金National Fund for Fostering Talents of Basic Science(NFFTBS)(J1103206)Research Fund for Doctoral Program of Higher Education(20110001110087)China Postdoctoral Science Foundation(2015M580007)
文摘The chiral geometry of multiple chiral doublet bands with identical configuration is discussed for different triaxial deformation parameters γ in the particle rotor model with πh11/2×γh11/2^-1.The energy spectra,electromagnetic transition probabilities B（M1） and B（E2）,angular momenta,and K-distributions are studied.It is demonstrated that the chirality still remains not only in the yrast and yrare bands,but also in the two higher excited bands whenγ deviates from 30°.The chiral geometry relies significantly on γ,and the chiral geometry of the two higher excited partner bands is not as good as that of the yrast and yrare doublet bands.
基金Supported by National Natural Science Foundation of China (11005069, 11175108)Shandong Natural Science Foundation (ZR2010AQ005)
文摘The candidate chiral doublet bands in 98 Tc with configuration πg9/2νh11/2 are studied the- oretically for the first time via the triaxial particle rotor model. The main properties of the doublet bands including the energy spectra and electromagnetic transitions are calculated for different triaxiality parameter γ, and the data in 98Tc can be well described by the calculations with γ = 38°. Based on the analysis of angular momentum components, it is found that the chiral rotational geometry in 98Tc deviates from the ideal chiral picture.
基金Supported by National Natural Science Foundation of China(11675094,11622540,11545011,11405096,11461141001,U1432119)Shandong Natural Science Foundation(ZR2014AQ012)Young Scholars Program of Shandong University,Weihai(2015WHWLJH01)
文摘Multiple chiral doublet bands （MχD） in the 80, 130 and 190 mass regions are studied by the model of γ=90°triaxial rotor coupled with identical symmetric proton-neutron configurations. By selecting a suitable basis, the calculated wave functions are explicitly exhibited to be symmetric under the operator A, which is defined as rotation by 90° about the 3-axis with the exchange of valance proton and neutron. We found that both M1 and E2 transitions are allowed between levels with different values of A, while they are forbidden between levels with same values of A. Such a selection rule holds true for MχD in different mass regions.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.21674096 and 21873082)
文摘The dynamics of two-dimensional rigid circles filled with chiral active particles are investigated by employing the overdamped Langevin dynamics simulations. Unidirectional rotation of rigid circles is observed, and the rotational angular velocity（ω） relies mainly on the length（l）, the number（nB）, and tilt angle（γ） of boards, and the angular velocity（ω）and area fraction（ρ） of chiral active particles. There are optimum values for these parameters at which the average angular velocity of circle reaches its maximum. The center-of-mass mean square displacement for circles drops by about two orders of magnitude for large angular velocity ω of chiral active particles with oscillations in the short-time regime. Our work demonstrates that nanofabricated objects with suitable designs immersed in a bath of chiral active particles can extract and rectify energy in a unidirectional motion.
基金Supported by National Natural Science Foundation of China (10875074, 10605001, 10435010, 10221003, 10505002)
文摘Using the model with one particle and one hole coupled with a triaxial rotor, the πg9/2/1/2νh11/2 doublet bands in the A～100 mass region are studied, and compared with the πg9/2/1/2νh11/2 doublet bands. It is found that the calculated results for the configuration of πg9/2/1/2νh11/2 are very similar the results for a pure h11/2 proton particle and a neutron quasiparticle with λn = ε5. After including the pair correlation, the model describes the candidate chiral doublet bands in 106Rh successfully, which supports the interpretation of chirality geometry.
基金Supported by National Natural Science Foundation of China (10505002, 10435010, 10605001, 10221003)Postdoctoral Science Foundation of China (20060390371)
文摘Different definitions for chiral doublet bands based on excitation energies, B(E2) and B(M1) respectively are discussed in the triaxial particle rotor model. For the ideal chiral geometry, the selection rules of the electromagnetic transitions in different band definitions are illustrated. It is also shown that the energy-level crossings between chiral doublet bands may occur.
