Epiphytes with crassulacean acid metabolism(CAM)photosynthesis are widespread among vascular plants,and repeated evolution of CAM photosynthesis is a key innovation for micro-ecosystem adaptation.However,we lack a com...Epiphytes with crassulacean acid metabolism(CAM)photosynthesis are widespread among vascular plants,and repeated evolution of CAM photosynthesis is a key innovation for micro-ecosystem adaptation.However,we lack a complete understanding of the molecular regulation of CAM photosynthesis in epiphytes.Here,we report a high-quality chromosome-level genome assembly of a CAM epiphyte,Cymbidium mannii(Orchidaceae).The 2.88-Gb orchid genome with a contig N50 of 22.7 Mb and 27192 annotated genes was organized into 20 pseudochromosomes,82.8%of which consisted of repetitive elements.Recent expansions of long terminal repeat retrotransposon families have made a major contribution to the evolution of genome size in Cymbidium orchids.We reveal a holistic scenario of molecular regulation of metabolic physiology using high-resolution transcriptomics,proteomics,and metabolomics data collected across a CAM diel cycle.Patterns of rhythmically oscillating metabolites,especially CAM-related products,reveal circadian rhythmicity in metabolite accumulation in epiphytes.Genomewide analysis of transcript and protein level regulation revealed phase shifts during the multifaceted regulation of circadian metabolism.Notably,we observed diurnal expression of several core CAM genes(especially bCA and PPC)that may be involved in temporal fixation of carbon sources.Our study provides a valuable resource for investigating post-transcription and translation scenarios in C.mannii,an Orchidaceae model for understanding the evolution of innovative traits in epiphytes.展开更多
Reconfigurable intelligent surface(RIS)for wireless networks have drawn lots of attention in both academic and industry communities.RIS can dynamically control the phases of the reflection elements to send the signal ...Reconfigurable intelligent surface(RIS)for wireless networks have drawn lots of attention in both academic and industry communities.RIS can dynamically control the phases of the reflection elements to send the signal in the desired direction,thus it provides supplementary links for wireless networks.Most of prior works on RIS-aided wireless communication systems consider continuous phase shifts,but phase shifts of RIS are discrete in practical hardware.Thus we focus on the actual discrete phase shifts on RIS in this paper.Using the advanced deep reinforcement learning(DRL),we jointly optimize the transmit beamforming matrix from the discrete Fourier transform(DFT)codebook at the base station(BS)and the discrete phase shifts at the RIS to maximize the received signal-to-interference plus noise ratio(SINR).Unlike the traditional schemes usually using alternate optimization methods to solve the transmit beamforming and phase shifts,the DRL algorithm proposed in the paper can jointly design the transmit beamforming and phase shifts as the output of the DRL neural network.Numerical results indicate that the DRL proposed can dispose the complicated optimization problem with low computational complexity.展开更多
This paper considers a secure multigroup multicast multiple-input single-output(MISO)communication system aided by an intelligent reflecting surface(IRS).Specifically,we aim to minimize the transmit power at Alice via...This paper considers a secure multigroup multicast multiple-input single-output(MISO)communication system aided by an intelligent reflecting surface(IRS).Specifically,we aim to minimize the transmit power at Alice via jointly optimizing the transmit beamformer,artificial noise(AN)vector and phase shifts at the IRS subject to the secrecy rate constraints as well as the unit modulus constraints of IRS phase shifts.To tackle the optimization problem,we first transform it into a semidefinite relaxation(SDR)problem,and then alternately update the transmit beamformer and AN matrix as well as the phase shifts at the IRS.In order to reduce the high computational complexity,we further propose a low-complexity algorithm based on second-order cone programming(SOCP).We decouple the optimization problem into two sub-problems and optimize the transmit beamformer,AN vector and the phase shifts alternately by solving two corresponding SOCP subproblem.Simulation results show that the proposed SDR and SOCP schemes require half or less transmit power than the scheme without IRS,which demonstrates the advantages of introducing IRS and the effectiveness of the proposed methods.展开更多
In this paper, we study the scattering properties of s-wave Schrdinger equation for the multi-parameter potential,which can be reduced into four special cases for different values of potential parameters, i.e., Hulthn...In this paper, we study the scattering properties of s-wave Schrdinger equation for the multi-parameter potential,which can be reduced into four special cases for different values of potential parameters, i.e., Hulthn, Manning–Rosen,and Eckart potentials. We also obtain and investigate the scattering amplitudes of these special cases. Some numerical results are also obtained and reported.展开更多
In this work,the head-on collisions of the non-stationary dissipative soliton in ultracold neutral plasmas(UNPs)are investigated.The extended Poincare-Lighthill-Kuo(PLK)approach is adopted for reducing the fluid equat...In this work,the head-on collisions of the non-stationary dissipative soliton in ultracold neutral plasmas(UNPs)are investigated.The extended Poincare-Lighthill-Kuo(PLK)approach is adopted for reducing the fluid equations of the UNPs to two-counterpropagating damped Korteweg-de Vries(dKdV)equations.The dKdV equation is not an integrable Hamiltonian system,i.e.,does not have an exact solution.Thus,one of the main goal of this paper is to find a new general approximate analytical solution to the dKdV equation for investigating the mechanism of the propagation and interaction of the non-stationary dissipative solitons.The residual error is estimated for checking the accuracy of the new obtained solution.The approximate analytical soliton solutions are adopted for deriving the temporal phase shifts after the collision.The impact of physical parameters on the nonstationary dissipative soliton profile and the temporal phase shifts is discussed.The obtained results will contribute to understand the mechanism of propagation and interaction of many nonlinear phenomena in different nonlinear mediums such as ocean,sea,optical fiber,plasma physics,etc.展开更多
Although often used in molecular dynamics,in this work the Manning-Rosen potential is parameterized to compute the scattering phase shifts for the nucleon-nucleon and the alphanucleon systems by exploiting the standar...Although often used in molecular dynamics,in this work the Manning-Rosen potential is parameterized to compute the scattering phase shifts for the nucleon-nucleon and the alphanucleon systems by exploiting the standard phase function method.We obtain excellent agreement in phase shifts with the more sophisticated calculations up to partial waves l=2.展开更多
In contrast to Gaussian or Woods-Saxon potential a two-term four parameter nuclear Hulthdn type inter- action is considered to describe the a-a, t-a He and t=3 H systems. By exploiting the phase function method, scatt...In contrast to Gaussian or Woods-Saxon potential a two-term four parameter nuclear Hulthdn type inter- action is considered to describe the a-a, t-a He and t=3 H systems. By exploiting the phase function method, scattering phase shifts are computed up to ELb -- 100 MeV for the a-a system and ELab = 15 MeV for a-3He and a-3H systems. The S-wave phase shift 5o for the system tends to 2n and 53/2_ for thea-3He system tends to n, in the limit of zero energy. Reasonable agreements in phase shifts with the standard data are obtained with this simple potential model except for the 5/2- states of a-3He and a-3H systems, With an additional energy-dependent correction factor to our potential, a good agreement with experimental data is obtained for 5/2- states. We have also compared our results with the convenient Born approximations.展开更多
The low-energy region kaon-pion S- and P-wave phase shifts with isospin I = 1/2 and I = 3/2 are dynamically studied in the chiral SU(3) quark model by solving a resonating group method equation. The model parameters a...The low-energy region kaon-pion S- and P-wave phase shifts with isospin I = 1/2 and I = 3/2 are dynamically studied in the chiral SU(3) quark model by solving a resonating group method equation. The model parameters are taken to be the values fitted by the energies of the baryon ground states and the kaon-nucleon elastic scattering phase shifts of different partial waves. As a preliminary study the s-channel q(-q) annihilation interactions are not included since they only act in the very short range and are subsequently assumed to be unimportant in the low-energy domain. The numerical results are in qualitative agreement with the experimental data.展开更多
In this paper, exact solutions of scattering states of the Klein-Gordon equation with Coulomb potential plus a new ring-shaped potential are studied under the condition that the scalar potential is equal to the vector...In this paper, exact solutions of scattering states of the Klein-Gordon equation with Coulomb potential plus a new ring-shaped potential are studied under the condition that the scalar potential is equal to the vector potential. The normalized wave functions of scattering states on the “k/27π scale” and the calculation formula of phase shifts are presented. Analytical properties of the scattering amplitude are discussed.展开更多
基金funded by the Strategic Priority Research Program of the Chinese Academy of Sciences(grant no.XDB31000000)to D.-Z.L.and J.-B.Y.CAS Pioneer Hundred Talents Program to A.Z.+1 种基金the Project for Innovation Team of Yunnan Province(grant no.202105AE160012)to S.-B.Z.the Science and Technology Basic Resources Investigation Program of China(grant no.2021FY100200)to J.-B.Y.
文摘Epiphytes with crassulacean acid metabolism(CAM)photosynthesis are widespread among vascular plants,and repeated evolution of CAM photosynthesis is a key innovation for micro-ecosystem adaptation.However,we lack a complete understanding of the molecular regulation of CAM photosynthesis in epiphytes.Here,we report a high-quality chromosome-level genome assembly of a CAM epiphyte,Cymbidium mannii(Orchidaceae).The 2.88-Gb orchid genome with a contig N50 of 22.7 Mb and 27192 annotated genes was organized into 20 pseudochromosomes,82.8%of which consisted of repetitive elements.Recent expansions of long terminal repeat retrotransposon families have made a major contribution to the evolution of genome size in Cymbidium orchids.We reveal a holistic scenario of molecular regulation of metabolic physiology using high-resolution transcriptomics,proteomics,and metabolomics data collected across a CAM diel cycle.Patterns of rhythmically oscillating metabolites,especially CAM-related products,reveal circadian rhythmicity in metabolite accumulation in epiphytes.Genomewide analysis of transcript and protein level regulation revealed phase shifts during the multifaceted regulation of circadian metabolism.Notably,we observed diurnal expression of several core CAM genes(especially bCA and PPC)that may be involved in temporal fixation of carbon sources.Our study provides a valuable resource for investigating post-transcription and translation scenarios in C.mannii,an Orchidaceae model for understanding the evolution of innovative traits in epiphytes.
文摘Reconfigurable intelligent surface(RIS)for wireless networks have drawn lots of attention in both academic and industry communities.RIS can dynamically control the phases of the reflection elements to send the signal in the desired direction,thus it provides supplementary links for wireless networks.Most of prior works on RIS-aided wireless communication systems consider continuous phase shifts,but phase shifts of RIS are discrete in practical hardware.Thus we focus on the actual discrete phase shifts on RIS in this paper.Using the advanced deep reinforcement learning(DRL),we jointly optimize the transmit beamforming matrix from the discrete Fourier transform(DFT)codebook at the base station(BS)and the discrete phase shifts at the RIS to maximize the received signal-to-interference plus noise ratio(SINR).Unlike the traditional schemes usually using alternate optimization methods to solve the transmit beamforming and phase shifts,the DRL algorithm proposed in the paper can jointly design the transmit beamforming and phase shifts as the output of the DRL neural network.Numerical results indicate that the DRL proposed can dispose the complicated optimization problem with low computational complexity.
基金supported in part by the National Natural Science Foundation of China under Grants 62071234,61901121 and 61771244in part by the Natural Science Research Project of Education Department of Anhui Province of China under Grant KJ2019A1002.
文摘This paper considers a secure multigroup multicast multiple-input single-output(MISO)communication system aided by an intelligent reflecting surface(IRS).Specifically,we aim to minimize the transmit power at Alice via jointly optimizing the transmit beamformer,artificial noise(AN)vector and phase shifts at the IRS subject to the secrecy rate constraints as well as the unit modulus constraints of IRS phase shifts.To tackle the optimization problem,we first transform it into a semidefinite relaxation(SDR)problem,and then alternately update the transmit beamformer and AN matrix as well as the phase shifts at the IRS.In order to reduce the high computational complexity,we further propose a low-complexity algorithm based on second-order cone programming(SOCP).We decouple the optimization problem into two sub-problems and optimize the transmit beamformer,AN vector and the phase shifts alternately by solving two corresponding SOCP subproblem.Simulation results show that the proposed SDR and SOCP schemes require half or less transmit power than the scheme without IRS,which demonstrates the advantages of introducing IRS and the effectiveness of the proposed methods.
文摘In this paper, we study the scattering properties of s-wave Schrdinger equation for the multi-parameter potential,which can be reduced into four special cases for different values of potential parameters, i.e., Hulthn, Manning–Rosen,and Eckart potentials. We also obtain and investigate the scattering amplitudes of these special cases. Some numerical results are also obtained and reported.
基金funded by the Deanship of Scientific Research at Princess Nourah bint Abdulrahman University through the Fasttrack Research Funding Program.
文摘In this work,the head-on collisions of the non-stationary dissipative soliton in ultracold neutral plasmas(UNPs)are investigated.The extended Poincare-Lighthill-Kuo(PLK)approach is adopted for reducing the fluid equations of the UNPs to two-counterpropagating damped Korteweg-de Vries(dKdV)equations.The dKdV equation is not an integrable Hamiltonian system,i.e.,does not have an exact solution.Thus,one of the main goal of this paper is to find a new general approximate analytical solution to the dKdV equation for investigating the mechanism of the propagation and interaction of the non-stationary dissipative solitons.The residual error is estimated for checking the accuracy of the new obtained solution.The approximate analytical soliton solutions are adopted for deriving the temporal phase shifts after the collision.The impact of physical parameters on the nonstationary dissipative soliton profile and the temporal phase shifts is discussed.The obtained results will contribute to understand the mechanism of propagation and interaction of many nonlinear phenomena in different nonlinear mediums such as ocean,sea,optical fiber,plasma physics,etc.
文摘Although often used in molecular dynamics,in this work the Manning-Rosen potential is parameterized to compute the scattering phase shifts for the nucleon-nucleon and the alphanucleon systems by exploiting the standard phase function method.We obtain excellent agreement in phase shifts with the more sophisticated calculations up to partial waves l=2.
文摘In contrast to Gaussian or Woods-Saxon potential a two-term four parameter nuclear Hulthdn type inter- action is considered to describe the a-a, t-a He and t=3 H systems. By exploiting the phase function method, scattering phase shifts are computed up to ELb -- 100 MeV for the a-a system and ELab = 15 MeV for a-3He and a-3H systems. The S-wave phase shift 5o for the system tends to 2n and 53/2_ for thea-3He system tends to n, in the limit of zero energy. Reasonable agreements in phase shifts with the standard data are obtained with this simple potential model except for the 5/2- states of a-3He and a-3H systems, With an additional energy-dependent correction factor to our potential, a good agreement with experimental data is obtained for 5/2- states. We have also compared our results with the convenient Born approximations.
文摘The low-energy region kaon-pion S- and P-wave phase shifts with isospin I = 1/2 and I = 3/2 are dynamically studied in the chiral SU(3) quark model by solving a resonating group method equation. The model parameters are taken to be the values fitted by the energies of the baryon ground states and the kaon-nucleon elastic scattering phase shifts of different partial waves. As a preliminary study the s-channel q(-q) annihilation interactions are not included since they only act in the very short range and are subsequently assumed to be unimportant in the low-energy domain. The numerical results are in qualitative agreement with the experimental data.
基金The project supported by the Protessor and Doctor Foundation of Yancheng Teachers College
文摘In this paper, exact solutions of scattering states of the Klein-Gordon equation with Coulomb potential plus a new ring-shaped potential are studied under the condition that the scalar potential is equal to the vector potential. The normalized wave functions of scattering states on the “k/27π scale” and the calculation formula of phase shifts are presented. Analytical properties of the scattering amplitude are discussed.
