We study the exceptional-point(EP) structure and the associated quantum dynamics in a system consisting of a non-Hermitian qubit and a Hermitian qubit. We find that the system possesses two sets of EPs, which divide t...We study the exceptional-point(EP) structure and the associated quantum dynamics in a system consisting of a non-Hermitian qubit and a Hermitian qubit. We find that the system possesses two sets of EPs, which divide the systemparameter space into PT-symmetry unbroken, partially broken and fully broken regimes, each with distinct quantumdynamics characteristics. Particularly, in the partially broken regime, while the PT-symmetry is generally broken in the whole four-dimensional Hilbert space, it is preserved in a two-dimensional subspace such that the quantum dynamics in the subspace are similar to those in the PT-symmetry unbroken regime. In addition, we reveal that the competition between the inter-qubit coupling and the intra-qubit driving gives rise to a complex pattern in the EP variation with system parameters.展开更多
This work focuses on the evolution behaviors of ring dark solitons(RDSs) and the following vortices after the collapses of RDSs in spin-1 Bose–Einstein condensates. We find that the weighted average of the initial de...This work focuses on the evolution behaviors of ring dark solitons(RDSs) and the following vortices after the collapses of RDSs in spin-1 Bose–Einstein condensates. We find that the weighted average of the initial depths of three components determines the number and motion trajectories of vortex dipoles. For the weighted average of the initial depths below the critical depth, two vortex dipoles form and start moving along the horizontal axis.For the weighted average depth above the critical depth, two or four vortex dipoles form, and all start moving along the vertical axis. For the RDS with weighted average depth at exactly the critical point, four vortex dipoles form, half of the vortex dipoles initiate movement vertically, and the other half initiate movement horizontally.Our conclusion is applicable to the two-component system studied in earlier research, indicating its universality.展开更多
Limited by the dynamic range of the detector,saturation artifacts usually occur in optical coherence tomography(OCT)imaging for high scattering media.The available methods are difficult to remove saturation artifacts ...Limited by the dynamic range of the detector,saturation artifacts usually occur in optical coherence tomography(OCT)imaging for high scattering media.The available methods are difficult to remove saturation artifacts and restore texture completely in OCT images.We proposed a deep learning-based inpainting method of saturation artifacts in this paper.The generation mechanism of saturation artifacts was analyzed,and experimental and simulated datasets were built based on the mechanism.Enhanced super-resolution generative adversarial networks were trained by the clear–saturated phantom image pairs.The perfect reconstructed results of experimental zebrafish and thyroid OCT images proved its feasibility,strong generalization,and robustness.展开更多
Majorana quantum computation offers a potential approach to securely manipulating and storing quantum data in a topological manner that may effectively resist the decoherence induced by local noise. However, actual Ma...Majorana quantum computation offers a potential approach to securely manipulating and storing quantum data in a topological manner that may effectively resist the decoherence induced by local noise. However, actual Majorana qubit setups are susceptible to noise. In this study, from a quantum dynamics perspective, we develop a noise model for Majorana qubits that accounts for quasi-particle poisoning and Majorana overlapping with fluctuation. Furthermore, we focus on Majorana parity readout methodologies, specifically those leveraging an ancillary quantum dot, and carry out an indepth exploration of continuous measurement techniques founded on the quantum jump model of a quantum point contact.Utilizing these methodologies, we proceed to analyze the influence of noise on the afore-mentioned noise model, employing numerical computation to evaluate the power spectrum and frequency curve. In the culmination of our study, we put forward a strategy to benchmark the presence and detailed properties of noise in Majorana qubits.展开更多
To study controlled evolution of nonautonomous matter-wave breathers and rogue waves in spinor Bose–Einstein condensates with spatiotemporal modulation,we focus on a system of three coupled Gross–Pitaevskii equation...To study controlled evolution of nonautonomous matter-wave breathers and rogue waves in spinor Bose–Einstein condensates with spatiotemporal modulation,we focus on a system of three coupled Gross–Pitaevskii equations with spacetime-dependent external potentials and temporally modulated gain-loss distributions.With different external potentials and gain-loss distributions,various solutions for controlled nonautonomous matterwave breathers and rogue waves are derived by the Darboux transformation method,such as breathers and rogue waves on arched and constant backgrounds which have the periodic and parabolic trajectories.Effects of the gain-loss distribution and linear potential on the breathers and rogue waves are studied.Nonautonomous two-breathers on the arched and constant backgrounds are also derived.展开更多
Zebrafish is an important animal model,which is used to study development,pathology,and genetic research.The zebrafish skin model is widely used in cutaneous research,and angiogenesis is critical for cutaneous wound h...Zebrafish is an important animal model,which is used to study development,pathology,and genetic research.The zebrafish skin model is widely used in cutaneous research,and angiogenesis is critical for cutaneous wound healing.However,limited by the penetration depth,the available optical methods are difficult to describe the internal skin structure and the connection of blood vessels between the skin and subcutaneous tissue.By a homemade high-resolution polarization-sensitive optical coherence tomography(PS-OCT)system,we imaged the polarization contrast of zebrafish skin and the zebrafish skin vasculature with optical coherence tomography angiography(OCTA).Based on these OCT images,the spatial distribution of the zebrafish skin vasculature was described.Furthermore,we monitored the healing process of zebrafish cutaneous wounds.We think the high-resolution PS-OCT system will be a promising tool in studying cutaneous models of zebrafish.展开更多
Rational design of photocatalyst to maximize the use of sunlight is one of the issues to be solved in photocatalysis technology.In this study,the CuFe_(2)O_(4)@C/Cd_(0.9)Zn_(0.1)S(CFO@C/CZS)S-scheme photocatalyst with...Rational design of photocatalyst to maximize the use of sunlight is one of the issues to be solved in photocatalysis technology.In this study,the CuFe_(2)O_(4)@C/Cd_(0.9)Zn_(0.1)S(CFO@C/CZS)S-scheme photocatalyst with photothermal effect was synthesized by ultrasonic self-assembly combined with calcination.The dark CFO@C absorbed visible light and partly converted into heat to promote the hydrogen evolution reaction.The presence of heterojunctions inhibited the photogenerated electron-hole recombination.The graphite-carbon layer provided a stable channel for electron transfer,and the presence of magnetic CFO made recycle easier.Under the action of photothermal assistance and heterojunction,the hydrogen evolution rate of the optimal CFO@C/CZS was 80.79 mmol g^(-1) h^(-1),which was 2.55 times and 260.61 times of that of pure CZS and CFO@C,respectively.Notably,the composite samples also exhibit excellent stability and a wide range of environmental adaptability.Through experimental tests and first-principles simulation calculation methods,the plausible mechanism of photoactivity enhancement was proposed.This work provided a feasible strategy of photothermal assistance for the development of heterojunction photocatalysts with distinctive hydrogen evolution.展开更多
The Cs_(2)NaInCl_(6) double perovskite is one of the most promising lead-free perovskites due to its exceptional stability and straightforward synthesis.However,it faces challenges related to inefficient photoluminesc...The Cs_(2)NaInCl_(6) double perovskite is one of the most promising lead-free perovskites due to its exceptional stability and straightforward synthesis.However,it faces challenges related to inefficient photoluminescence.Doping and high pressure are employed to tailor the optical properties of Cs_(2)NaInCl_(6).Herein,Sb^(3+)doped Cs_(2)NaInCl_(6)(Sb^(3+):Cs_(2)NaInCl_(6)) was synthesized and it exhibits blue emission with a photoluminescence quantum yield of up to 37.3%.Further,by employing pressure tuning,a blue stable emission under a very wide range from 2.7 GPa to 9.8 GPa is realized in Sb^(3+):Cs_(2)NaInCl_(6).Subsequently,the emission intensity of Sb^(3+):Cs_(2)NaInCl_(6) experiences a significant increase(3.3 times)at 19.0 GPa.It is revealed that the pressure-induced distinct emissions can be attributed to the carrier self-trapping and detrapping between Cs_(2)NaInCl_(6) and Sb^(3+).Notably,the lattice compression in the cubic phase inevitably modifies the band gap of Sb^(3+):Cs_(2)NaInCl_(6).Our findings provide valuable insights into effects of the high pressure in further boosting unique emission characteristics but also offer promising opportunities for development of doped double perovskites with enhanced optical functionalities.展开更多
Two-dimensional(2D)topological materials have recently garnered significant interest due to their profound physical properties and promising applications for future quantum nanoelectronics.Achieving various topologica...Two-dimensional(2D)topological materials have recently garnered significant interest due to their profound physical properties and promising applications for future quantum nanoelectronics.Achieving various topological states within one type of materials is,however,seldom reported.Based on first-principles calculations and tightbinding models,we investigate topological electronic states in a novel family of 2D halogenated tetragonal stanene(T-SnX,X=F,Cl,Br,I).All the four monolayers are found to be unusual topological nodal-line semimetals(NLSs),protected by a glide mirror symmetry.When spin-orbit coupling(SOC)is turned on,T-SnF and TSnCl are still ascertained as topological NLSs due to the remaining band inversion,primarily composed of Sn pxy orbitals,while T-Sn Br and T-SnI become quantum spin Hall insulators.The phase transition is ascribed to moving up in energy of Sn s orbitals and increasing of SOC strengths.The topology origin in the materials is uniformly rationalized through elementary band representations.The robust and diverse topological states found in the 2D T-SnX monolayers position them as an excellent material platform for development of innovative topological electronics.展开更多
We report on the fabrication of circular cladding waveguides with cross-section diameters of 60−120μm in Pr:YAG crystal by applying femtosecond laser inscription.The fabricated waveguides present 2D guidance on the c...We report on the fabrication of circular cladding waveguides with cross-section diameters of 60−120μm in Pr:YAG crystal by applying femtosecond laser inscription.The fabricated waveguides present 2D guidance on the cross-section and fairly low propagation losses.Multiple high-order guiding modes are observed in waveguides with different diameters.Corresponding simulation results reveal the origin of a specific kind of guiding modes.Confocal micro-Raman(μ-Raman)experiments demonstrate the modification effects in femtosecond laser affected areas and ascertain the refractive index induced guiding mechanism.In addition,luminescence emission properties of Pr3+ions at waveguide volume are well preserved during the femtosecond laser inscription process,which may result in a potential high-power visible waveguide laser.展开更多
We solve the fermionic master equation for a thermal bath to obtain its explicit Kraus operator solutions via the fermionic state approach. The normalization condition of the Kraus operators is proved. The matrix repr...We solve the fermionic master equation for a thermal bath to obtain its explicit Kraus operator solutions via the fermionic state approach. The normalization condition of the Kraus operators is proved. The matrix representation for these solutions is obtained, which is incongruous with the result in the book completed by Nielsen and Chuang [Quan- tum Computation and Quantum Information, Cambridge University Press, 2000]. As especial cases, we also present the Kraus operator solutions to master equations for describing the amplitude-decay model and the diffusion process at finite temperature.展开更多
Hydrogel is frequently used as a solid electrolyte for all solid-state supercapacitors(SCs)because of its liquid-like ion-transport property and high conformability.However,due to the higher water content,the hydrogel...Hydrogel is frequently used as a solid electrolyte for all solid-state supercapacitors(SCs)because of its liquid-like ion-transport property and high conformability.However,due to the higher water content,the hydrogel electrolyte undergoes inevitable freezing and/or dehydration with climate change.Herein,polypyrrole/carbon all-solid-state SCs(PCSCs)were developed based on a hierarchical polypyrrole/carbon nanotube electrode and a highly stretchable double-network polymer hydrogel electrolyte with LiCl/ethylene glycol as a mixed solvent.The PCSCs showed excellent electrochemical performance and cycle stability with a wide operating temperature.The specific capacitances could reach 202.2 and 112.3 mF cm^(−2) at current densities of 0.5 and 3.0 mA cm^(−2),respectively.Meanwhile,the PCSCs showed outstanding mechanical properties in maintaining a high areal capacitance under deformations of bending and tension.The excellent water retention of the device also ensured the stable electrochemical performance of PCSCs in a wide temperature range(30–80℃),which could potentially represent a reliable application in various harsh environments.展开更多
Surgical excision is an effective treatment for oral squamous cell carcinoma(OSCC),but exact intraoperative differentiation OSCC from the normal tissue is the first premise.As a noninvasive imaging technique,optical c...Surgical excision is an effective treatment for oral squamous cell carcinoma(OSCC),but exact intraoperative differentiation OSCC from the normal tissue is the first premise.As a noninvasive imaging technique,optical coherence tomography(OCT)has the nearly same resolution as the histopathological examination,whose images contain rich information to assist surgeons to make clinical decisions.We extracted kinds of texture features from OCT images obtained by a home-made swept-source OCT system in this paper,and studied the identification of OSCC based on different combinations of texture features and machine learning classifiers.It was demonstrated that different combinations had different accuracies,among which the combination of texture features,gray level co-occurrence matrix(GLCM),Laws'texture measnres(LM),and center symmetric auto-correlation(CSAC),and SVM as the classifier,had the optimal comprehensive identification effect,whose accuracy was 94.1%.It was proven that it is feasible to distinguish OSCC based on texture features in OCT images,and it has great potential in helping surgeons make rapid and accurate decisions in oral clinical practice.展开更多
This paper presents the anisotropic optical feedback of a single frequency intra-cavity He-Ne laser. A novel phenomenon was discovered that the laser output an elliptical polarized frequency instead of the initial lin...This paper presents the anisotropic optical feedback of a single frequency intra-cavity He-Ne laser. A novel phenomenon was discovered that the laser output an elliptical polarized frequency instead of the initial linear polarized one. Two intensities with a phase difference were detected, both of which were modulated in the form of cosine wave and a fringe shift corresponds to a λ/2 movement of the feedback mirror. The phase difference can be continuously modulated by the wave plate in the external cavity. Frequency stabilization was used to stabilize the laser frequency so as to enlarge the measuring range and improve the measurement precision. This anisotropic optical feedback system offers a potential displacement measurement technology with the function of subdivision of λ/2 and in-time direction judgment. The three-mirror Fabry Perot cavity model is used to present the experimental results. Given the lack of need of lasing adjustment, this full intra-cavity laser can significantly improve the simplicity and stability of the optical feedback system.展开更多
Single-molecule devices not only promise to provide an alternative strategy to break through the miniaturization and functionalization bottlenecks faced by traditional semiconductor devices,but also provide a reliable...Single-molecule devices not only promise to provide an alternative strategy to break through the miniaturization and functionalization bottlenecks faced by traditional semiconductor devices,but also provide a reliable platform for exploration of the intrinsic properties of matters at the single-molecule level.Because the regulation of the electrical properties of single-molecule devices will be a key factor in enabling further advances in the development of molecular electronics,it is necessary to clarify the interactions between the charge transport occurring in the device and the external fields,particularly the optical field.This review mainly introduces the optoelectronic effects that are involved in single-molecule devices,including photoisomerization switching,photoconductance,plasmon-induced excitation,photovoltaic effect,and electroluminescence.We also summarize the optoelectronic mechanisms of single-molecule devices,with particular emphasis on the photoisomerization,photoexcitation,and photo-assisted tunneling processes.Finally,we focus the discussion on the opportunities and challenges arising in the single-molecule optoelectronics field and propose further possible breakthroughs.展开更多
By extending the usual Weyl transformation to the s-parameterized Weyl transformation with s being a real parameter,we obtain the s-parameterized quantization scheme which includes P–Q quantization, Q–P quantization...By extending the usual Weyl transformation to the s-parameterized Weyl transformation with s being a real parameter,we obtain the s-parameterized quantization scheme which includes P–Q quantization, Q–P quantization, and Weyl ordering as its three special cases. Some operator identities can be derived directly by virtue of the s-parameterized quantization scheme.展开更多
To probe the behavior of hydrogen bonds in solid energetic materials, we conduct ReaxFF and SCC-DFTB molecular dynamics simulations of crystalline TATB, RDX, and DATB. By comparing the intra- and inter-molecular hydro...To probe the behavior of hydrogen bonds in solid energetic materials, we conduct ReaxFF and SCC-DFTB molecular dynamics simulations of crystalline TATB, RDX, and DATB. By comparing the intra- and inter-molecular hydrogen bond- ing rates, we find that the crystal structures are stabilized by inter-molecular hydrogen bond networks. Under high-pressure, the inter- and intra-molecular hydrogen bonds in solid TATB and DATB are nearly equivalent. The hydrogen bonds in solid TATB and DATB are much shorter than in solid RDX, which suggests strong hydrogen bond interactions existing in these energetic materials. Stretching of the C-H bond is observed in solid RDX, which may lead to further decomposition and even detonation.展开更多
We study how can an angular momentum coherent state |τ> keeps its form-invariant during time evolution governed by the Hamiltonian H = f(t)J++ f^*(t)J-+ g(t)Jz. We discuss this topic in the context of boson realiz...We study how can an angular momentum coherent state |τ> keeps its form-invariant during time evolution governed by the Hamiltonian H = f(t)J++ f^*(t)J-+ g(t)Jz. We discuss this topic in the context of boson realization of |τ>. By employing the entangled state representation |ζ> and deriving a new binomial theorem involving two-subscript Hermite polynomials, we derive the wave function <ζ|τ>, which turns out to be a single-subscript Hermite polynomial. Based on this result the maintenance of angular momentum coherent state during time evolution is examined, and the value of τ(t) is totally determined by the parameters involved in the Hamiltonian.展开更多
基金partly funded by the Natural Science Foundation of Shandong Province of China (Grant Nos. ZR2021MA091 and ZR2018MA044)Introduction and Cultivation Plan of Youth Innovation Talents for Universities of Shandong Province (Research and Innovation Team on Materials Modification and Optoelectronic Devices at extreme conditions)。
文摘We study the exceptional-point(EP) structure and the associated quantum dynamics in a system consisting of a non-Hermitian qubit and a Hermitian qubit. We find that the system possesses two sets of EPs, which divide the systemparameter space into PT-symmetry unbroken, partially broken and fully broken regimes, each with distinct quantumdynamics characteristics. Particularly, in the partially broken regime, while the PT-symmetry is generally broken in the whole four-dimensional Hilbert space, it is preserved in a two-dimensional subspace such that the quantum dynamics in the subspace are similar to those in the PT-symmetry unbroken regime. In addition, we reveal that the competition between the inter-qubit coupling and the intra-qubit driving gives rise to a complex pattern in the EP variation with system parameters.
基金supported by the National Natural Science Foundation of China (Grant Nos.12261131495,11975172,and 12381240286)。
文摘This work focuses on the evolution behaviors of ring dark solitons(RDSs) and the following vortices after the collapses of RDSs in spin-1 Bose–Einstein condensates. We find that the weighted average of the initial depths of three components determines the number and motion trajectories of vortex dipoles. For the weighted average of the initial depths below the critical depth, two vortex dipoles form and start moving along the horizontal axis.For the weighted average depth above the critical depth, two or four vortex dipoles form, and all start moving along the vertical axis. For the RDS with weighted average depth at exactly the critical point, four vortex dipoles form, half of the vortex dipoles initiate movement vertically, and the other half initiate movement horizontally.Our conclusion is applicable to the two-component system studied in earlier research, indicating its universality.
基金supported by the National Natural Science Foundation of China(62375144 and 61875092)Tianjin Foundation of Natural Science(21JCYBJC00260)Beijing-Tianjin-Hebei Basic Research Cooperation Special Program(19JCZDJC65300).
文摘Limited by the dynamic range of the detector,saturation artifacts usually occur in optical coherence tomography(OCT)imaging for high scattering media.The available methods are difficult to remove saturation artifacts and restore texture completely in OCT images.We proposed a deep learning-based inpainting method of saturation artifacts in this paper.The generation mechanism of saturation artifacts was analyzed,and experimental and simulated datasets were built based on the mechanism.Enhanced super-resolution generative adversarial networks were trained by the clear–saturated phantom image pairs.The perfect reconstructed results of experimental zebrafish and thyroid OCT images proved its feasibility,strong generalization,and robustness.
基金supported by the Innovation Program for Quantum Science and Technology (Grant No.2021ZD0302400)the National Natural Science Foundation of China (Grants No.11974198)the Natural Science Foundation of Shandong Province of China (Grant No.ZR2021MA091)。
文摘Majorana quantum computation offers a potential approach to securely manipulating and storing quantum data in a topological manner that may effectively resist the decoherence induced by local noise. However, actual Majorana qubit setups are susceptible to noise. In this study, from a quantum dynamics perspective, we develop a noise model for Majorana qubits that accounts for quasi-particle poisoning and Majorana overlapping with fluctuation. Furthermore, we focus on Majorana parity readout methodologies, specifically those leveraging an ancillary quantum dot, and carry out an indepth exploration of continuous measurement techniques founded on the quantum jump model of a quantum point contact.Utilizing these methodologies, we proceed to analyze the influence of noise on the afore-mentioned noise model, employing numerical computation to evaluate the power spectrum and frequency curve. In the culmination of our study, we put forward a strategy to benchmark the presence and detailed properties of noise in Majorana qubits.
基金supported by the National Natural Science Foundation of China (Grant Nos.11975172 and 12261131495)。
文摘To study controlled evolution of nonautonomous matter-wave breathers and rogue waves in spinor Bose–Einstein condensates with spatiotemporal modulation,we focus on a system of three coupled Gross–Pitaevskii equations with spacetime-dependent external potentials and temporally modulated gain-loss distributions.With different external potentials and gain-loss distributions,various solutions for controlled nonautonomous matterwave breathers and rogue waves are derived by the Darboux transformation method,such as breathers and rogue waves on arched and constant backgrounds which have the periodic and parabolic trajectories.Effects of the gain-loss distribution and linear potential on the breathers and rogue waves are studied.Nonautonomous two-breathers on the arched and constant backgrounds are also derived.
基金This work was supported by National Natural Science Foundation of China(NSFC)(61875092)Science and Technology Support Program of Tianjin(17YFZCSY00740)the Beijing-Tianjin-Hebei Basic Research Cooperation Special Program(19JCZDJC65300).
文摘Zebrafish is an important animal model,which is used to study development,pathology,and genetic research.The zebrafish skin model is widely used in cutaneous research,and angiogenesis is critical for cutaneous wound healing.However,limited by the penetration depth,the available optical methods are difficult to describe the internal skin structure and the connection of blood vessels between the skin and subcutaneous tissue.By a homemade high-resolution polarization-sensitive optical coherence tomography(PS-OCT)system,we imaged the polarization contrast of zebrafish skin and the zebrafish skin vasculature with optical coherence tomography angiography(OCTA).Based on these OCT images,the spatial distribution of the zebrafish skin vasculature was described.Furthermore,we monitored the healing process of zebrafish cutaneous wounds.We think the high-resolution PS-OCT system will be a promising tool in studying cutaneous models of zebrafish.
基金supported by the Shandong Provincial Natural Science Foundation(ZR2022ME179,ZR2021QE086)the Shandong Provincial Key Research and Development Program(Public Welfare Science and Technology Research)(2019GGX103010)+2 种基金the Science and Technology Planning Project of Higher School in Shandong Province(J18KA243)the Liaocheng Key Research and Development Program(Policy guidance category)(2022YDSF90)the Liaocheng University High-level Talents&PhD Research Startup Foundation(318051619)。
文摘Rational design of photocatalyst to maximize the use of sunlight is one of the issues to be solved in photocatalysis technology.In this study,the CuFe_(2)O_(4)@C/Cd_(0.9)Zn_(0.1)S(CFO@C/CZS)S-scheme photocatalyst with photothermal effect was synthesized by ultrasonic self-assembly combined with calcination.The dark CFO@C absorbed visible light and partly converted into heat to promote the hydrogen evolution reaction.The presence of heterojunctions inhibited the photogenerated electron-hole recombination.The graphite-carbon layer provided a stable channel for electron transfer,and the presence of magnetic CFO made recycle easier.Under the action of photothermal assistance and heterojunction,the hydrogen evolution rate of the optimal CFO@C/CZS was 80.79 mmol g^(-1) h^(-1),which was 2.55 times and 260.61 times of that of pure CZS and CFO@C,respectively.Notably,the composite samples also exhibit excellent stability and a wide range of environmental adaptability.Through experimental tests and first-principles simulation calculation methods,the plausible mechanism of photoactivity enhancement was proposed.This work provided a feasible strategy of photothermal assistance for the development of heterojunction photocatalysts with distinctive hydrogen evolution.
基金supported by the National Key Research and Development Program of China(Grant Nos.2021YFA1400200 and2021YFA0718701)the National Natural Science Foundation of China(Grant Nos.U2032127,11904322,12104411,12174347)+4 种基金the Natural Science Foundation of Henan province of China(Grant No.202300410356)the China Postdoctoral Science Foundation(Grant Nos.2019M652560 and 2020M682326)the CAS Interdisciplinary Innovation Team(Grant No.JCTD-2019-01)the Postdoctoral Research Grant in Henan Province(Grant No.1902013)the Science Foundation for Highlevel Talents of Wuyi University(Grant No.2021AL019)。
文摘The Cs_(2)NaInCl_(6) double perovskite is one of the most promising lead-free perovskites due to its exceptional stability and straightforward synthesis.However,it faces challenges related to inefficient photoluminescence.Doping and high pressure are employed to tailor the optical properties of Cs_(2)NaInCl_(6).Herein,Sb^(3+)doped Cs_(2)NaInCl_(6)(Sb^(3+):Cs_(2)NaInCl_(6)) was synthesized and it exhibits blue emission with a photoluminescence quantum yield of up to 37.3%.Further,by employing pressure tuning,a blue stable emission under a very wide range from 2.7 GPa to 9.8 GPa is realized in Sb^(3+):Cs_(2)NaInCl_(6).Subsequently,the emission intensity of Sb^(3+):Cs_(2)NaInCl_(6) experiences a significant increase(3.3 times)at 19.0 GPa.It is revealed that the pressure-induced distinct emissions can be attributed to the carrier self-trapping and detrapping between Cs_(2)NaInCl_(6) and Sb^(3+).Notably,the lattice compression in the cubic phase inevitably modifies the band gap of Sb^(3+):Cs_(2)NaInCl_(6).Our findings provide valuable insights into effects of the high pressure in further boosting unique emission characteristics but also offer promising opportunities for development of doped double perovskites with enhanced optical functionalities.
基金supported by the National Natural Science Foundation of China(Grant Nos.12174059,11874117,11904101,and 11604134)the Natural Science Foundation of Shanghai(Grant No.21ZR140820)。
文摘Two-dimensional(2D)topological materials have recently garnered significant interest due to their profound physical properties and promising applications for future quantum nanoelectronics.Achieving various topological states within one type of materials is,however,seldom reported.Based on first-principles calculations and tightbinding models,we investigate topological electronic states in a novel family of 2D halogenated tetragonal stanene(T-SnX,X=F,Cl,Br,I).All the four monolayers are found to be unusual topological nodal-line semimetals(NLSs),protected by a glide mirror symmetry.When spin-orbit coupling(SOC)is turned on,T-SnF and TSnCl are still ascertained as topological NLSs due to the remaining band inversion,primarily composed of Sn pxy orbitals,while T-Sn Br and T-SnI become quantum spin Hall insulators.The phase transition is ascribed to moving up in energy of Sn s orbitals and increasing of SOC strengths.The topology origin in the materials is uniformly rationalized through elementary band representations.The robust and diverse topological states found in the 2D T-SnX monolayers position them as an excellent material platform for development of innovative topological electronics.
基金We are grateful for financial supports from National Natural Science Foundation of China(NSFC)(Grants No.61575097 and 11704201)National Natural Science Foundation of Tianjin City(NSFTJ)(17JCQNJC01600 and 19JCZDJC32700)the Fundamental Research Funds for the Central Universities.
文摘We report on the fabrication of circular cladding waveguides with cross-section diameters of 60−120μm in Pr:YAG crystal by applying femtosecond laser inscription.The fabricated waveguides present 2D guidance on the cross-section and fairly low propagation losses.Multiple high-order guiding modes are observed in waveguides with different diameters.Corresponding simulation results reveal the origin of a specific kind of guiding modes.Confocal micro-Raman(μ-Raman)experiments demonstrate the modification effects in femtosecond laser affected areas and ascertain the refractive index induced guiding mechanism.In addition,luminescence emission properties of Pr3+ions at waveguide volume are well preserved during the femtosecond laser inscription process,which may result in a potential high-power visible waveguide laser.
基金supported by the National Natural Science Foundation of China(Grant No.11347026)the Natural Science Foundation of Shandong Province+1 种基金China(Grant Nos.ZR2013AM012 and ZR2012AM004)the Research Fund for the Doctoral Program and Scientific Research Project of Liaocheng University,Shandong Province,China
文摘We solve the fermionic master equation for a thermal bath to obtain its explicit Kraus operator solutions via the fermionic state approach. The normalization condition of the Kraus operators is proved. The matrix representation for these solutions is obtained, which is incongruous with the result in the book completed by Nielsen and Chuang [Quan- tum Computation and Quantum Information, Cambridge University Press, 2000]. As especial cases, we also present the Kraus operator solutions to master equations for describing the amplitude-decay model and the diffusion process at finite temperature.
基金NSF of Jiangsu Province,Grant/Award Number:BK20190688NSF of Jiangsu Higher Education Institutions,Grant/Award Number:21KJB430039+1 种基金NSF of Shandong Province,Grant/Award Number:ZR2020KB018Taishan Scholars”Construction Special Fund of Shandong Province,and the Industrial Alliance Fund of Shandong Provincial Key Laboratory,Grant/Award Number:SDKL016038。
文摘Hydrogel is frequently used as a solid electrolyte for all solid-state supercapacitors(SCs)because of its liquid-like ion-transport property and high conformability.However,due to the higher water content,the hydrogel electrolyte undergoes inevitable freezing and/or dehydration with climate change.Herein,polypyrrole/carbon all-solid-state SCs(PCSCs)were developed based on a hierarchical polypyrrole/carbon nanotube electrode and a highly stretchable double-network polymer hydrogel electrolyte with LiCl/ethylene glycol as a mixed solvent.The PCSCs showed excellent electrochemical performance and cycle stability with a wide operating temperature.The specific capacitances could reach 202.2 and 112.3 mF cm^(−2) at current densities of 0.5 and 3.0 mA cm^(−2),respectively.Meanwhile,the PCSCs showed outstanding mechanical properties in maintaining a high areal capacitance under deformations of bending and tension.The excellent water retention of the device also ensured the stable electrochemical performance of PCSCs in a wide temperature range(30–80℃),which could potentially represent a reliable application in various harsh environments.
基金This study was supported by the National Natural Science Foundation of China(No.61875092)Science and Technology Support Program of Tianjin(17YFZCSY00740)+1 种基金the Beijing-Tianjin-Hebei Basic Research Cooperation Special Program(19JCZDJC65300)the Fundamental Research Funds for the Central Universities,Nankai University(63201178).
文摘Surgical excision is an effective treatment for oral squamous cell carcinoma(OSCC),but exact intraoperative differentiation OSCC from the normal tissue is the first premise.As a noninvasive imaging technique,optical coherence tomography(OCT)has the nearly same resolution as the histopathological examination,whose images contain rich information to assist surgeons to make clinical decisions.We extracted kinds of texture features from OCT images obtained by a home-made swept-source OCT system in this paper,and studied the identification of OSCC based on different combinations of texture features and machine learning classifiers.It was demonstrated that different combinations had different accuracies,among which the combination of texture features,gray level co-occurrence matrix(GLCM),Laws'texture measnres(LM),and center symmetric auto-correlation(CSAC),and SVM as the classifier,had the optimal comprehensive identification effect,whose accuracy was 94.1%.It was proven that it is feasible to distinguish OSCC based on texture features in OCT images,and it has great potential in helping surgeons make rapid and accurate decisions in oral clinical practice.
基金supported by the National Natural Science Foundation of China (Grant No 60437010)
文摘This paper presents the anisotropic optical feedback of a single frequency intra-cavity He-Ne laser. A novel phenomenon was discovered that the laser output an elliptical polarized frequency instead of the initial linear polarized one. Two intensities with a phase difference were detected, both of which were modulated in the form of cosine wave and a fringe shift corresponds to a λ/2 movement of the feedback mirror. The phase difference can be continuously modulated by the wave plate in the external cavity. Frequency stabilization was used to stabilize the laser frequency so as to enlarge the measuring range and improve the measurement precision. This anisotropic optical feedback system offers a potential displacement measurement technology with the function of subdivision of λ/2 and in-time direction judgment. The three-mirror Fabry Perot cavity model is used to present the experimental results. Given the lack of need of lasing adjustment, this full intra-cavity laser can significantly improve the simplicity and stability of the optical feedback system.
基金We acknowledge primary financial supports from the National Key R&D Program of China(2017YFA0204901,2021YFA1200101 and 2021YFA1200102)the National Natural Science Foundation of China(22150013,21727806,21933001 and 22173050)+1 种基金the Tencent Foundation through the XPLORER PRIZE“Frontiers Science Center for New Organic Matter”at Nankai University(63181206).
文摘Single-molecule devices not only promise to provide an alternative strategy to break through the miniaturization and functionalization bottlenecks faced by traditional semiconductor devices,but also provide a reliable platform for exploration of the intrinsic properties of matters at the single-molecule level.Because the regulation of the electrical properties of single-molecule devices will be a key factor in enabling further advances in the development of molecular electronics,it is necessary to clarify the interactions between the charge transport occurring in the device and the external fields,particularly the optical field.This review mainly introduces the optoelectronic effects that are involved in single-molecule devices,including photoisomerization switching,photoconductance,plasmon-induced excitation,photovoltaic effect,and electroluminescence.We also summarize the optoelectronic mechanisms of single-molecule devices,with particular emphasis on the photoisomerization,photoexcitation,and photo-assisted tunneling processes.Finally,we focus the discussion on the opportunities and challenges arising in the single-molecule optoelectronics field and propose further possible breakthroughs.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11147009,11347026,and 11244005)the Natural Science Foundation of Shandong Province,China(Grant Nos.ZR2013AM012 and ZR2012AM004)the Natural Science Foundation of Liaocheng University,China
文摘By extending the usual Weyl transformation to the s-parameterized Weyl transformation with s being a real parameter,we obtain the s-parameterized quantization scheme which includes P–Q quantization, Q–P quantization, and Weyl ordering as its three special cases. Some operator identities can be derived directly by virtue of the s-parameterized quantization scheme.
基金Project supported by the National Natural Science Foundation of China(Grant No.11176020)the Fund from the China Academy of Engineering Physics,China(Grant No.2011A0302014)
文摘To probe the behavior of hydrogen bonds in solid energetic materials, we conduct ReaxFF and SCC-DFTB molecular dynamics simulations of crystalline TATB, RDX, and DATB. By comparing the intra- and inter-molecular hydrogen bond- ing rates, we find that the crystal structures are stabilized by inter-molecular hydrogen bond networks. Under high-pressure, the inter- and intra-molecular hydrogen bonds in solid TATB and DATB are nearly equivalent. The hydrogen bonds in solid TATB and DATB are much shorter than in solid RDX, which suggests strong hydrogen bond interactions existing in these energetic materials. Stretching of the C-H bond is observed in solid RDX, which may lead to further decomposition and even detonation.
基金Project supported by the National Natural Science Foundation of China(Grant No.11347026)the Natural Science Foundation of Shandong Province,China(Grant Nos.ZR2016AM03 and ZR2017MA011)
文摘We study how can an angular momentum coherent state |τ> keeps its form-invariant during time evolution governed by the Hamiltonian H = f(t)J++ f^*(t)J-+ g(t)Jz. We discuss this topic in the context of boson realization of |τ>. By employing the entangled state representation |ζ> and deriving a new binomial theorem involving two-subscript Hermite polynomials, we derive the wave function <ζ|τ>, which turns out to be a single-subscript Hermite polynomial. Based on this result the maintenance of angular momentum coherent state during time evolution is examined, and the value of τ(t) is totally determined by the parameters involved in the Hamiltonian.