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Spring snow-albedo feedback from satellite observation,reanalysis and model simulations over the Northern Hemisphere

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Science China Earth Sciences 2022年第8期65卷 1463-1476页

作者： Hui Guo Yuting YANG State Key Laboratory of Hydroscience and Engineering Department of Hydraulic EngineeringTsinghua UniversityBeijing100084China

The snow-albedo feedback(SAF)is one of the key processes that lead to rapid temperature increases at high latitude and altitude regions.Here,we examine the strength of SAF in the Northern Hemisphere(NH,30°-90°N)from satellite-based observation,climate reanalysis(i.e.,ERA5)and climate model projections(i.e.,CMIP5 and CMIP6).Using satellite-derived estimates as an observational reference,our results show that the strength of SAF is considerably overestimated by both climate reanalysis and climate models throughout the NH.This positive bias is mainly caused by a much higher month-to-month changing rate of surface albedo simulated by climate reanalysis and climate models,compared with satellite-based observation.In addition,we find that the strength of SAF is primarily controlled by changes in snow cover fraction(SNC)while the snow metamorphosis effect only plays a secondary role at the hemispheric scale and the regional scales.Finally,we demonstrate that there exists an emergent relationship between historical SAF and future SAF in climate model projections,which is then used to constrain modeled SAF in both CMIP5 and CMIP6 under various climate change scenarios.After constraining,the magnitude of modeled SAF is reduced to be more consistent with satellite-based estimates and the uncertainties of the modeled SAF are reduced by 10-50%for 13 sub-regions of the NH.Our results highlight the need for improving the representation of surface albedo and snow cover fraction in climate reanalysis and models and the advantage of combining observation and model predictions such that to achieve a more realistic quantification of SAF and a better understanding of the impacts of SAF on the climate system.

关键词： Snow-albedo feedback Satellite observation Climate reanalysis Climate model Emergent constraint

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Analytical modeling on the vibration response of a beam-stiffened Mindlin thick plate with free boundary conditions

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International Journal of Mechanical System Dynamics 2023年第2期3卷 119-126页

作者： Hui Guo Kai Zhang School of Mechanical and Automotive Engineering Qingdao University of TechnologyQingdaoChina Department of Mechanical and Electrical Engineering Ocean University of ChinaQingdaoChina

This paper presents a new analytical solution for the vibration response of a beamstiffened Mindlin plate having a completely free boundary condition by utilizing a finite cosine integral transform.In the solution,the unknown coupling force and moments at the beam/plate interface and the unknown modal constants from the integral transform are determined by the continuity and compatibility conditions at the interface as well as the boundary conditions.It provides an easily implemented tool for exploring complex edge value problems for a class of higher-order partial differential equations represented by fully free‐stiffened Mindlin thick plates.The validity of the model is evaluated by comparing the calculated free and forced vibration responses of the beam‐stiffened plate with those calculated using a beamstiffened thin plate and those from finite element analysis.

关键词： vibration beam-stiffened mindlin thick plate free boundary condition finite integral transform

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POSITIVITY-PRESERVING LOCAL DISCONTINUOUS GALERKIN METHOD FOR PATTERN FORMATION DYNAMICAL MODEL IN POLYMERIZING ACTIN FLOCKS

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Journal of Computational Mathematics 2023年第4期41卷 623-642页

作者： XiuHui Guo Lulu Tian Yang Yang Hui Guo College of Science China University of PetroleumQingdao 266580China Department of Mathematical Sciences Michigan Technological UniversityHoughtonMI 49931 The College of Science China University of PetroleumQingdao 266580China

In this paper,we apply local discontinuous Galerkin(LDG)methods for pattern formation dynamical model in polymerizing actin focks.There are two main dificulties in designing effective numerical solvers.First of all,the density function is non-negative,and zero is an unstable equilibrium solution.Therefore,negative density values may yield blow-up solutions.To obtain positive numerical approximations,we apply the positivitypreserving(PP)techniques.Secondly,the model may contain stif source.The most commonly used time integration for the PP technique is the strong-stability-preserving Runge-Kutta method.However,for problems with stiff source,such time discretizations may require strictly limited time step sizes,leading to large computational cost.Moreover,the stiff source any trigger spurious filament polarization,leading to wrong numerical approximations on coarse meshes.In this paper,we combine the PP LDG methods with the semi-implicit Runge-Kutta methods.Numerical experiments demonstrate that the proposed method can yield accurate numerical approximations with relatively large time steps.

关键词： Pattern formation dynamical model Local discontinuous Galerkin method Positive-preserving technique Semi-implicit Runge-Kutta method Stiff source

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Multiple characteristic alterations and available therapeutic strategies of cellular senescence

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2023年第2期24卷 101-114页

作者： YUNZI ZHAO hui LI QINGLONG guo hui hui State Key Laboratory of Natural Medicines Jiangsu Key Laboratory of Carcinogenesis and InterventionChina Pharmaceutical UniversityNanjing 210009China

Given its state of stable proliferative inhibition,cellular senescence is primarily depicted as a critical mechanism by which organisms delay the progression of carcinogenesis.Cells undergoing senescence are often associated with the alteration of a series of specific features and functions,such as metabolic shifts,stemness induction,and microenvironment remodeling.However,recent research has revealed more complexity associated with senescence,including adverse effects on both physiological and pathological processes.How organisms evade these harmful consequences and survive has become an urgent research issue.Several therapeutic strategies targeting senescence,including senolytics,senomorphics,immunotherapy,and function restoration,have achieved initial success in certain scenarios.In this review,we describe in detail the characteristic changes associated with cellular senescence and summarize currently available countermeasures.

关键词： Senescence Metabolism Stemness Microenvironment Senolytic Immune surveillance

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Verification of neutron-induced fission product yields evaluated by a tensor decompsition model in transport-burnup simulations

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Nuclear Science and Techniques 2023年第2期34卷 190-201页

作者： Qu‑Fei Song Long Zhu Hui Guo Jun Su School of Nuclear Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China Sino‑French Institute of Nuclear Engineering and Technology Sun Yat-sen UniversityZhuhai 519082China

Neutron-induced fission is an important research object in basic science.Moreover,its product yield data are an indispensable nuclear data basis in nuclear engineering and technology.The fission yield tensor decomposition(FYTD)model has been developed and used to evaluate the independent fission product yield.In general,fission yield data are verified by the direct comparison of experimental and evaluated data.However,such direct comparison cannot reflect the impact of the evaluated data on application scenarios,such as reactor transport-burnup simulation.Therefore,this study applies the evaluated fission yield data in transport-burnup simulation to verify their accuracy and possibility of application.Herein,the evaluated yield data of235U and239Pu are applied in the transport-burnup simulation of a pressurized water reactor(PWR)and sodium-cooled fast reactor(SFR)for verification.During the reactor operation stage,the errors in pin-cell reactivity caused by the evaluated fission yield do not exceed 500 and 200 pcm for the PWR and SFR,respectively.The errors in decay heat and135Xe and149Sm concentrations during the short-term shutdown of the PWR are all less than 1%;the errors in decay heat and activity of the spent fuel of the PWR and SFR during the temporary storage stage are all less than 2%.For the PWR,the errors in important nuclide concentrations in spent fuel,such as90Sr,137Cs,85Kr,and99Tc,are all less than 6%,and a larger error of 37%is observed on129I.For the SFR,the concentration errors of ten important nuclides in spent fuel are all less than 16%.A comparison of various aspects reveals that the transport-burnup simulation results using the FYTD model evaluation have little difference compared with the reference results using ENDF/B-Ⅷ.0 data.This proves that the evaluation of the FYTD model may have application value in reactor physical analysis.

关键词： Fission product yield Tensor decomposition Transport-burnup simulation Machine learning

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Maximum throughput design of wireless powered communication network with IRS-NOMA based on user clustering

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The Journal of China Universities of Posts and Telecommunications 2023年第3期30卷 55-64页

作者： guo hui Zhao Xuehui School of Physics and Electronic Information Engineering Henan Polytechnic UniversityJiaozuo 454003China School of Electrical Engineering Chongqing UniversityChongqing 400044China

A wireless powered communication network(WPCN)assisted by intelligent reflecting surface(IRS)is proposed in this paper,which can transfer information by non-orthogonal multiple access(NOMA)technology.In the system,in order to ensure that the hybrid access point(H-AP)can correctly decode user information via successive interference cancellation(SIC)technology,the information transmit power of user needs to satisfy a certain threshold,so as to meet the corresponding SIC constraints.Therefore,when the number of users who transfer information simultaneously increases,the system performance will be greatly restricted.To minimize the influence of SIC constraints on system performance,users are firstly clustered,and then each cluster collects energy from H-AP and finally,users transfer information based on NOMA with the assistance of IRS.Specifically,this paper aims to maximize the sum throughput of the system by jointly optimizing the beamforming of IRS and resource allocation of the system.The semi-definite relaxation(SDR)algorithm is employed to alternately optimize the beamforming of IRS in each time slot,and the joint optimization problem about user’s transmit power and time is transformed into two optimal time allocation sub-problems.The numerical results show that the proposed optimization scheme can effectively improve the sum throughput of the system.In addition,the results in the paper further reveals the positive impact of IRS on improving the sum throughput of the system.

关键词： wireless powered communication network(WPCN) intelligent reflecting surface(IRS) user clustering

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Convergence of adaptive MPC for linear stochastic systems

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Science China(Information Sciences) 2023年第5期66卷 130-146页

作者： hui CHEN Lei guo Institute of Systems Science Academy of Mathematics and Systems Science (AMSS) Chinese Academy of Sciences

The convergence of an adaptive model predictive control(MPC) algorithm for discrete-time linear stochastic systems with unknown parameters is investigated in this paper. The proposed adaptive MPC is designed by solving a finite horizon constrained linear-quadratic optimal control problem of online estimated models, which are built on a recursive weighted least-squares(WLS) algorithm together with a random regularization method. By incorporating an attenuating excitation signal into adaptive MPC, the proposed adaptive MPC is shown to converge asymptotically to the ergodic MPC performance with known parameters by using the Markov chain ergodic theory.

关键词： adaptive control linear-quadratic optimal control model predictive control uncertain stochastic system weighted least-squares

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Maximum throughput design for IRS aided WPCN system based on NOMA

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The Journal of China Universities of Posts and Telecommunications 2022年第1期29卷 93-101页

作者： guo hui Zhao Xuehui School of Physics and Electronic Information Engineering Henan Polytechnic UniversityJiaozuo 454003China

This paper considers a wireless powered communication network(WPC network, WPCN) based on non-orthogonal multiple access(NOMA) technology aided by intelligent reflective surfaces(IRS). WPCN mainly focuses on downlink energy transfer(ET) and uplink information transmission(IT). At the ET phase, a dedicated multi-antenna power station(PS) is equipped to supply power to users with the assistance of IRS, and at the IT phase, the IRS adjusts the phase to assist the user in applying NOMA technology to transmit information to the base station(BS), thus minimizing the impact of dynamic IRS on the system. Based on the above settings, the maximization of sum-throughput of the system under this working mode is studied. Due to the non-convexity of maximization problem of the sum-throughput of this system, block coordinate descent(BCD) technology is applied for alternative optimization of each system block by semidefinite relaxation(SDR) and particle swarm optimization(PSO) respectively. The numerical results show that compared with baseline scheme, the proposed optimization scheme can provide greater sum-throughput of the system.

关键词： wireless powered communication network intelligent reflecting surface non-orthogonal multiple access

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Modeling the relationship between gene expression and mutational signature

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Quantitative Biology 2023年第1期11卷 31-43页

作者： Limin Jiang hui Yu Yan guo Department of Internal Medicine Comprehensive Cancer CenterUniversity of New Mexico AlbuquerqueNM 87109USA

Background:Mutational signatures computed from somatic mutations,allow an in-depth understanding of tumorigenesis and may illuminate early prevention strategies.Many studies have shown the regulation effects between somatic mutation and gene expression dysregulation.Methods:We hypothesized that there are potential associations between mutational signature and gene expression.We capitalized upon RNA-seq data to model 49 established mutational signatures in 33 cancer types.Both accuracy and area under the curve were used as performance measures in five-fold cross-validation.Results:A total of 475 models using unconstrained genes,and 112 models using protein-coding genes were selected for future inference purposes.An independent gene expression dataset on lung cancer smoking status was used for validation which achieved over 80%for both accuracy and area under the curve.Conclusion:These results demonstrate that the associations between gene expression and somatic mutations can translate into the associations between gene expression and mutational signatures.

关键词： mutational signature gene expression support vector machine random forest extreme gradient boost

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Cross-scale modulation for aqueous fabrication of monodisperse Cu2−xE(E=S,Se,Te)nanocrystals and supraparticles

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Nano Research 2023年第1期16卷 1448-1458页

作者： hui Zhu Ge guo Yunsheng Xia Key Laboratory of Functional Molecular Solids Ministry of Education College of Chemistry and Materials ScienceAnhui Normal UniversityWuhu 241000China

Exploring aqueous nano-fabrication with monodisperse and hierarchical characteristics is fundamentally and technically significant.Herein,we discover that inter-particle nano–nano scale interactions profoundly affect the products’morphology ranging from polydisperse→monodisperse to individual→hierarchical manipulation.Accordingly,we present a“nucleationgrowth-dispersion triple modulation”strategy for fabricating monodisperse Cu2−xE(E=S,Se,Te)nanocrystals(NCs)and supraparticles(SPs).Such full-process and cross-scale control is conducted by two rationally selected ligands(cysteine and citrate molecules),which are responsible for atom/molecule–nano and nano–nano interaction modulations,respectively.Cysteine reacts with the cations and forms low reactive(cysteine-Cu+)n coordination polymers,which overcomes the commonly concerned nucleation and particle growth induced polydispersity.Citrate,by virtue of its strong negative charge modulated NC–NC interactions,decides the products morphology from polydisperse products to monodisperse NCs to monodisperse hierarchical SPs.These findings not only present new insights into aqueous nano-synthesis chemistry but provide an eco-friendly system for versatile and high-quality nano-entity fabrication.

关键词： aqueous fabrication monodisperse Cu2−xE nanocrystals Cu2−xE supraparticles photoacoustic imaging

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