Multi-level programmable photonic integrated circuits(PICs)and optical metasurfaces have gained widespread attention in many fields,such as neuromorphic photonics,opticalcommunications,and quantum information.In this ...Multi-level programmable photonic integrated circuits(PICs)and optical metasurfaces have gained widespread attention in many fields,such as neuromorphic photonics,opticalcommunications,and quantum information.In this paper,we propose pixelated programmable Si_(3)N_(4)PICs with record-high 20-level intermediate states at 785 nm wavelength.Such flexibility in phase or amplitude modulation is achieved by a programmable Sb_(2)S_(3)matrix,the footprint of whose elements can be as small as 1.2μm,limited only by the optical diffraction limit of anin-house developed pulsed laser writing system.We believe our work lays the foundation for laser-writing ultra-high-level(20 levels and even more)programmable photonic systems and metasurfaces based on phase change materials,which could catalyze diverse applications such as programmable neuromorphic photonics,biosensing,optical computing,photonic quantum computing,and reconfigurable metasurfaces.展开更多
Defective structures,such as DNA mismatches,occur in DNA with a high frequency in some biological processes.They are difficult to identify and have recently become the focus of singlemolecule investigations.Three sing...Defective structures,such as DNA mismatches,occur in DNA with a high frequency in some biological processes.They are difficult to identify and have recently become the focus of singlemolecule investigations.Three single-molecule experiments were successively conducted to detect the effects of DNA mismatch on the stability of DNA hairpins.However,there was no consensus regarding the results of the intermediate state caused by DNA mismatch.Based on the extended ox-DNA model,DNA mismatch was introduced to the stem of DNA hairpins with different stem lengths(12-20 bps)and 4T in hairpin loops.The intermediate state and its dependence on the position of the DNA mismatch in the stem from the hairpin loop were systematically studied.The results indicated that DNA mismatch definitely reduced the critical forces of DNA hairpins.At the same time,a common rule about the dependence of the intermediate state on the position of DNA mismatch was generalized in a phase diagram constructed in a phase space of a scaled position of DNA mismatch.Three segments on its diagonal line corresponded to the ranges of the scaled position of DNA mismatch[0,0.55),[0.55,0.85),and[0.85,1],respectively.In the[0.55,0.85)range,the extension probability distribution of DNA hairpins had unfolded,intermediate,and folded states.In contrast,in the other ranges[0,0.55)and[0.85,1],the extension probability distributions had unfolded and folded states.The scaled positions of DNA mismatch for the DNA hairpins used in the three single-molecule experiments(0.65,0.4736,and 0.5)fell in the ranges[0.55,0.85)and[0,0.55).Obviously,the common rule generalized in the phase diagram not only clarifies the nonconsensus between the three single-molecule experiments but also highlights the design of single-molecule experiments in the future.展开更多
We extend the third perturbation theory to study the polarization control behavior of the intermediate state absorption in Nd^（3＋）ions. The results show that coherent interference can occur between the single-photo...We extend the third perturbation theory to study the polarization control behavior of the intermediate state absorption in Nd^（3＋）ions. The results show that coherent interference can occur between the single-photon and three-photon excitation pathways, and depends on the central frequency of the femtosecond laser field. Moreover,single-photon and three-photon absorptions have different polarization control efficiencies, and the relative weight of three-photon absorption in the whole excitation processes can increase with increasing the laser intensity.Therefore, the enhancement or suppression of the intermediate state absorption can be realized and manipulated by properly designing the intensity and central frequency of the polarization modulated femtosecond laser field.This research can not only enrich theoretical research methods for the up-conversion luminescence manipulation of rare-earth ions, but also can provide a clear physical picture for understanding and controlling multi-photon absorption in a multiple energy level system.展开更多
Multi-waypoint planning is essential for manipulators to execute complex tasks efficiently.It requires the manipulator to swiftly traverse designated waypoints while adhering to all the kinematic constraints.However,p...Multi-waypoint planning is essential for manipulators to execute complex tasks efficiently.It requires the manipulator to swiftly traverse designated waypoints while adhering to all the kinematic constraints.However,previous research has not fully exploited the kinematic capabilities of manipulators and has overlooked collision considerations.To address these problems,this paper presents two novel methods called recursive intermediate state optimization(RISO)and overall intermediate state optimization(OISO).RISO decomposes the multi-waypoint planning problem into a sequence of one-waypoint planning tasks,employing a recursive approach to generate feasible solutions efficiently.OISO utilizes an improved whale optimization algorithm(WOA),incorporating multiple iterative processes to perform secondary optimization in high-dimensional space based on the initial value,yielding better solutions.The proposed methods have been validated on a six-degree-of-freedom manipulator platform and compared with several traditional algorithms,as well as the state-of-the-art algorithm,Ruckig.The results show that RISO outperforms Ruckig in scenarios where computation time is critical,while OISO is better suited for scenarios where trajectory quality is prioritized over time.Furthermore,the proposed methods can also handle collisions,ensuring the generation of collision-free trajectories.展开更多
A series of numerical simulations of conventional and true triaxial tests for soft rock materials using the three-dimensional finite difference code FLAC3D were presented. A hexahedral element and a strain hardening/s...A series of numerical simulations of conventional and true triaxial tests for soft rock materials using the three-dimensional finite difference code FLAC3D were presented. A hexahedral element and a strain hardening/softening constitutive model based on the unified strength theory(UST) were used to simulate both the consolidated-undrained(CU) triaxial and the consolidated-drained(CD) true triaxial tests. Based on the results of the true triaxial tests simulation, the effect of the intermediate principal stress on the strength of soft rock was investigated. Finally, an example of an axial compression test for a hard rock pillar with a soft rock interlayer was analyzed using the two-dimensional finite difference code FLAC. The CD true triaxial test simulations for diatomaceous soft rock suggest the peak and residual strengths increase by 30% when the effect of the intermediate principal stress is taken into account. The axial compression for a rock pillar indicated the peak and residual strengths increase six-fold when the soft rock interlayer approached the vertical and the effect of the intermediate principal stress is taken into account.展开更多
The rovibrational state-selectivity in photoassociation （PA） is investigated for the ground electronic state of OH radical. The calculated results show that population can be transferred from continuum state to the ...The rovibrational state-selectivity in photoassociation （PA） is investigated for the ground electronic state of OH radical. The calculated results show that population can be transferred from continuum state to the target states through three-, four-, and nine-photon transitions by choosing suitable pulse parameters and initial collision energy. To control population transfer to a lower rovibrational state, a shorter pulse frequency has to be chosen and the photon number transferred to target state should be increased. In PA process, some associated OH radicals can be dissociated via intermediate and background states, which decreases the nal population of the target state.展开更多
Nanobubble is a rising research field,which attracts more and more attentions due to its potential applications in medical science,catalysis,electrochemistry and etc.To better implement these applications,it is urgent...Nanobubble is a rising research field,which attracts more and more attentions due to its potential applications in medical science,catalysis,electrochemistry and etc.To better implement these applications,it is urgent to understand one of the most important mechanisms of nanobubbles,the evolution.However,few attentions have been paid in this aspect because of the methodology difficulties.Here we successfully used dark-field microscopy to study the evolution process of single nanobubbles generated from formic acid dehydrogenation on single Pd-Ag nanoplates.We found some of the nanobubbles in this system can exhibit three distinct states representing different sizes,which can transform among each other.These transitions are not direct but through some intermediate states.Further kinetic analysis reveals complicated mechanisms behind the evolution of single nanobubbles.The results acquired from this study can be applicable to nanobubble systems in general and provide insights into the understanding of mechanisms affecting the stability of nanobubbles and their applications.展开更多
We present a general discussion on the eigenstate problem of a bipartite complicated-coupled-oscillator system. By use of a generalized intermediate entangled state representation, the eigenvalue and eigenfunction of ...We present a general discussion on the eigenstate problem of a bipartite complicated-coupled-oscillator system. By use of a generalized intermediate entangled state representation, the eigenvalue and eigenfunction of Hamiltonian are analytically obtained. As its application, we obtain the energy spectrum for two special situations of Hamiltonian.展开更多
基金funded by the National Nature Science Foundation of China(Grant Nos.52175509 and 52130504)National Key Research and Development Program of China(2017YFF0204705)2021 Postdoctoral Innovation Research Plan of Hubei Province(0106100226)。
文摘Multi-level programmable photonic integrated circuits(PICs)and optical metasurfaces have gained widespread attention in many fields,such as neuromorphic photonics,opticalcommunications,and quantum information.In this paper,we propose pixelated programmable Si_(3)N_(4)PICs with record-high 20-level intermediate states at 785 nm wavelength.Such flexibility in phase or amplitude modulation is achieved by a programmable Sb_(2)S_(3)matrix,the footprint of whose elements can be as small as 1.2μm,limited only by the optical diffraction limit of anin-house developed pulsed laser writing system.We believe our work lays the foundation for laser-writing ultra-high-level(20 levels and even more)programmable photonic systems and metasurfaces based on phase change materials,which could catalyze diverse applications such as programmable neuromorphic photonics,biosensing,optical computing,photonic quantum computing,and reconfigurable metasurfaces.
基金The National Natural Science Foundation of China under Grant Nos.11864006,11874309,12164007,and 12204118Guizhou Scientific and Technological Program(20185781,ZK(2021)004,ZK(2021)032 and20185781-15)Guizhou Provincial Graduate Scientific Research Foundation(YJSKYJJ(2021)066)
文摘Defective structures,such as DNA mismatches,occur in DNA with a high frequency in some biological processes.They are difficult to identify and have recently become the focus of singlemolecule investigations.Three single-molecule experiments were successively conducted to detect the effects of DNA mismatch on the stability of DNA hairpins.However,there was no consensus regarding the results of the intermediate state caused by DNA mismatch.Based on the extended ox-DNA model,DNA mismatch was introduced to the stem of DNA hairpins with different stem lengths(12-20 bps)and 4T in hairpin loops.The intermediate state and its dependence on the position of the DNA mismatch in the stem from the hairpin loop were systematically studied.The results indicated that DNA mismatch definitely reduced the critical forces of DNA hairpins.At the same time,a common rule about the dependence of the intermediate state on the position of DNA mismatch was generalized in a phase diagram constructed in a phase space of a scaled position of DNA mismatch.Three segments on its diagonal line corresponded to the ranges of the scaled position of DNA mismatch[0,0.55),[0.55,0.85),and[0.85,1],respectively.In the[0.55,0.85)range,the extension probability distribution of DNA hairpins had unfolded,intermediate,and folded states.In contrast,in the other ranges[0,0.55)and[0.85,1],the extension probability distributions had unfolded and folded states.The scaled positions of DNA mismatch for the DNA hairpins used in the three single-molecule experiments(0.65,0.4736,and 0.5)fell in the ranges[0.55,0.85)and[0,0.55).Obviously,the common rule generalized in the phase diagram not only clarifies the nonconsensus between the three single-molecule experiments but also highlights the design of single-molecule experiments in the future.
基金Supported by the National Natural Science Foundation of China under Grant Nos 51132004,11474096,11604199,U1704145 and 11747101the Science and Technology Commission of Shanghai Municipality under Grant No 14JC1401500+1 种基金the Henan Provincial Natural Science Foundation of China under Grant No 182102210117the Higher Education Key Program of He’nan Province of China under Grant Nos 17A140025 and 16A140030
文摘We extend the third perturbation theory to study the polarization control behavior of the intermediate state absorption in Nd^（3＋）ions. The results show that coherent interference can occur between the single-photon and three-photon excitation pathways, and depends on the central frequency of the femtosecond laser field. Moreover,single-photon and three-photon absorptions have different polarization control efficiencies, and the relative weight of three-photon absorption in the whole excitation processes can increase with increasing the laser intensity.Therefore, the enhancement or suppression of the intermediate state absorption can be realized and manipulated by properly designing the intensity and central frequency of the polarization modulated femtosecond laser field.This research can not only enrich theoretical research methods for the up-conversion luminescence manipulation of rare-earth ions, but also can provide a clear physical picture for understanding and controlling multi-photon absorption in a multiple energy level system.
基金supported by the Major Science and Technology Projects for Self-Innovation of FAW(Grant No.20210301032GX)。
文摘Multi-waypoint planning is essential for manipulators to execute complex tasks efficiently.It requires the manipulator to swiftly traverse designated waypoints while adhering to all the kinematic constraints.However,previous research has not fully exploited the kinematic capabilities of manipulators and has overlooked collision considerations.To address these problems,this paper presents two novel methods called recursive intermediate state optimization(RISO)and overall intermediate state optimization(OISO).RISO decomposes the multi-waypoint planning problem into a sequence of one-waypoint planning tasks,employing a recursive approach to generate feasible solutions efficiently.OISO utilizes an improved whale optimization algorithm(WOA),incorporating multiple iterative processes to perform secondary optimization in high-dimensional space based on the initial value,yielding better solutions.The proposed methods have been validated on a six-degree-of-freedom manipulator platform and compared with several traditional algorithms,as well as the state-of-the-art algorithm,Ruckig.The results show that RISO outperforms Ruckig in scenarios where computation time is critical,while OISO is better suited for scenarios where trajectory quality is prioritized over time.Furthermore,the proposed methods can also handle collisions,ensuring the generation of collision-free trajectories.
基金Projects(41172276,51279155)supported by the National Natural Science Foundation of ChinaProjects(106-00X101,106-5X1205)supported by the Central Financial Funds for the Development of Characteristic Key Disciplines in Local University,China
文摘A series of numerical simulations of conventional and true triaxial tests for soft rock materials using the three-dimensional finite difference code FLAC3D were presented. A hexahedral element and a strain hardening/softening constitutive model based on the unified strength theory(UST) were used to simulate both the consolidated-undrained(CU) triaxial and the consolidated-drained(CD) true triaxial tests. Based on the results of the true triaxial tests simulation, the effect of the intermediate principal stress on the strength of soft rock was investigated. Finally, an example of an axial compression test for a hard rock pillar with a soft rock interlayer was analyzed using the two-dimensional finite difference code FLAC. The CD true triaxial test simulations for diatomaceous soft rock suggest the peak and residual strengths increase by 30% when the effect of the intermediate principal stress is taken into account. The axial compression for a rock pillar indicated the peak and residual strengths increase six-fold when the soft rock interlayer approached the vertical and the effect of the intermediate principal stress is taken into account.
基金This work is supported by the National Natural Science Foundation of China （No.11347012）.
文摘The rovibrational state-selectivity in photoassociation （PA） is investigated for the ground electronic state of OH radical. The calculated results show that population can be transferred from continuum state to the target states through three-, four-, and nine-photon transitions by choosing suitable pulse parameters and initial collision energy. To control population transfer to a lower rovibrational state, a shorter pulse frequency has to be chosen and the photon number transferred to target state should be increased. In PA process, some associated OH radicals can be dissociated via intermediate and background states, which decreases the nal population of the target state.
基金supported by Ministry of Science and Technology of China(Nos.2016YFA0200700,2016YFE0105700)the National Natural Science Foundation of China(Nos.21373264,21573275)+3 种基金the Natural Science Foundation of Jiangsu Province(No.BK20150362)Suzhou Institute of Nano-tech and Nanobionics(No.Y3AAA11004)Thousand Youth Talents Plan(No.Y3BQA11001)the Collaborative Innovation Center of Suzhou Nano Science and Technology。
文摘Nanobubble is a rising research field,which attracts more and more attentions due to its potential applications in medical science,catalysis,electrochemistry and etc.To better implement these applications,it is urgent to understand one of the most important mechanisms of nanobubbles,the evolution.However,few attentions have been paid in this aspect because of the methodology difficulties.Here we successfully used dark-field microscopy to study the evolution process of single nanobubbles generated from formic acid dehydrogenation on single Pd-Ag nanoplates.We found some of the nanobubbles in this system can exhibit three distinct states representing different sizes,which can transform among each other.These transitions are not direct but through some intermediate states.Further kinetic analysis reveals complicated mechanisms behind the evolution of single nanobubbles.The results acquired from this study can be applicable to nanobubble systems in general and provide insights into the understanding of mechanisms affecting the stability of nanobubbles and their applications.
文摘We present a general discussion on the eigenstate problem of a bipartite complicated-coupled-oscillator system. By use of a generalized intermediate entangled state representation, the eigenvalue and eigenfunction of Hamiltonian are analytically obtained. As its application, we obtain the energy spectrum for two special situations of Hamiltonian.
