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Variational quantum algorithms for scanning the complex spectrum of non-Hermitian systems

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Frontiers of physics 2024年第4期19卷 275-285页

作者： Xu-Dan Xie Zheng-Yuan Xue Dan-Bo Zhang Key Laboratory of Atomic and Subatomic Structure and Quantum control(ministry of education) Guangdong Basic Research Center of Excellence for Structure and Fundamental Interactions of Matterand School of PhysicsSouth China Normal UniversityGuangzhou 510006China Guangdong Provincial Key Laboratory of Quantum engineering and Quantum Materials Guangdong–Hong Kong Joint Laboratory of Quantum Matterand Frontier Research Institute for PhysicsSouth China Normal UniversityGuangzhou 510006China

Solving non-Hermitian quantum many-body systems on a quantum computer by minimizing the variational energy is challenging as the energy can be ***,we propose a variational quantum algorithm for solving the non-Hermitian Hamiltonian by minimizing a type of energy variance,where zero variance can naturally determine the eigenvalues and the associated left and right ***,the energy is set as a parameter in the cost function and can be tuned to scan the whole spectrum efficiently by using a two-step optimization *** numerical simulations,we demonstrate the algorithm for preparing the left and right eigenstates,verifying the biorthogonal relations,as well as evaluating the *** also investigate the impact of quantum noise on our algorithm and show that its performance can be largely improved using error mitigation ***,our work suggests an avenue for solving non-Hermitian quantum many-body systems with variational quantum algorithms on near-term noisy quantum computers.

关键词： quantum algorithm non-Hermitian physics quantum manybody systems

Manufacturing process of water-soluble salt-based ceramic cores based on vat photopolymerization

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Journal of Advanced Ceramics 2024年第5期13卷 652-665页

作者： Yuzhen Zhang Wenyan Duan Yue Gu Xingyao Sun Shan Li Bingshan Liu Gong Wang Key Laboratory of Space Manufacturing Technology(SMT) Technology and Engineering Center for Space UtilizationChinese Academy of SciencesBeijing 100094China University of Chinese Academy of Sciences Beijing 100049China ministry of education Key Laboratory for Cross-Scale Micro and Nano Manufacturing Changchun University of Science and TechnologyChangchun 130022China

Water-soluble salt-based ceramic cores can be recycled and have excellent high-temperature chemical *** this work,vat photopolymerization was successfully applied to water-soluble salt-based ceramic cores for the first *** powder raw materials of the printing suspension were sodium chloride and ***-precision green bodies were manufactured by optimizing suspensions and *** addition,the postprocessing method was optimized according to the microstructure and mechanical *** sintered part had a high bending strength and smooth ***,the dissolution rate and moisture resistance were compared under different dissolution and storage *** to traditional manufacturing methods,vat photopolymerization enables the production of complex structures without molds and reduces production *** technology is suitable for the rapid iteration of complex structural parts and can be applied to precision parts in aerospace,military,and other technical fields with high cost-effectiveness and sustainability.

关键词： vat photopolymerization water-soluble salt-based ceramic cores defect formation control accuracy moisture rate

Hybrid model for BOF oxygen blowing time prediction based on oxygen balance mechanism and deep neural network

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International Journal of Minerals,Metallurgy and Materials 2024年第1期31卷 106-117页

作者： Xin Shao Qing Liu Zicheng Xin Jiangshan Zhang Tao Zhou Shaoshuai Li State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China engineering Research center of MES Technology for Iron&Steel Production Ministry of EducationBeijing 100083China Laiwu Iron and Steel Group Yinshan Section Steel Co. Ltd.Jinan 271104China

The amount of oxygen blown into the converter is one of the key parameters for the control of the converter blowing process,which directly affects the tap-to-tap time of converter. In this study, a hybrid model based on oxygen balance mechanism (OBM) and deep neural network (DNN) was established for predicting oxygen blowing time in converter. A three-step method was utilized in the hybrid model. First, the oxygen consumption volume was predicted by the OBM model and DNN model, respectively. Second, a more accurate oxygen consumption volume was obtained by integrating the OBM model and DNN model. Finally, the converter oxygen blowing time was calculated according to the oxygen consumption volume and the oxygen supply intensity of each heat. The proposed hybrid model was verified using the actual data collected from an integrated steel plant in China, and compared with multiple linear regression model, OBM model, and neural network model including extreme learning machine, back propagation neural network, and DNN. The test results indicate that the hybrid model with a network structure of 3 hidden layer layers, 32-16-8 neurons per hidden layer, and 0.1 learning rate has the best prediction accuracy and stronger generalization ability compared with other models. The predicted hit ratio of oxygen consumption volume within the error±300 m^(3)is 96.67%;determination coefficient (R^(2)) and root mean square error (RMSE) are0.6984 and 150.03 m^(3), respectively. The oxygen blow time prediction hit ratio within the error±0.6 min is 89.50%;R2and RMSE are0.9486 and 0.3592 min, respectively. As a result, the proposed model can effectively predict the oxygen consumption volume and oxygen blowing time in the converter.

关键词： basic oxygen furnace oxygen consumption oxygen blowing time oxygen balance mechanism deep neural network hybrid model

Floating plants reduced methane fluxes from wetlands by creating a habitat conducive to methane oxidation

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Journal of Environmental Sciences 2024年第1期135卷 149-160页

作者： Fuwei Wang Songhe Zhang Xiuren Hu Xin Lv Min Liu Yu Ma Benjamin Manirakiza Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes Ministry of EducationHohai UniversityNanjing 210098China College of Environment Hohai UniversityNanjing 210098China China Machinery International engineering Desigh and Research Institute co. Ltd.East China Regional CenterNanjing 210008China

Wetlands are one of the important natural sources of atmospheric methane (CH_4),as an important part of wetlands,floating plants can be expected to affect methane ***,the effects of floating plants on methane release are *** this study,methane fluxes,physiochemical properties of the overlying water,methane oxidation potential and rhizospheric bacterial community were investigated in simulated wetlands with floating plants Eichhornia crassipes,Hydrocharis dubia,and Trapa *** found that ***,***,and *** plants could inhibit 84.31%-97.31%,4.98%-88.91%and 43.62%-92.51%of methane fluxes at interface of water-atmosphere compared to control,*** fluxes were negatively related to nutrients concentration in water column but positively related to the aerenchyma proportions of roots,stems,and *** the same biomass,root of *** (36.44%) had the highest methane oxidation potential,followed by *** (12.99%) and *** (11.23%).Forty-five bacterial phyla in total were identified on roots of three plants and 7 bacterial genera (2.10%-3.33%) were known *** I methanotrophs accounted for 95.07%of total *** pmoA gene abundances ranged from 1.90×10^(16)to 2.30×10^(18)copies/g fresh weight of root *** of pmoA gene was significantly positively correlated with environmental *** (5.40%) and methanotrophy (3.75%) function were closely related to methane *** study highlights that floating plant restoration can purify water and promote carbon neutrality partially by reducing methane fluxes through methane oxidation in wetlands.

关键词： Floating plants Methane fluxes Aerenchyma Methanotrophs

Health benefits from the rapid reduction in ambient exposure to air pollutants after China's clean air actions:progress in efficacy and geographic equality

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National Science Review 2024年第2期11卷 103-113页

作者： Tao Xue Ruohan Wang Meng Wang Yanying Wang Dan Tong Xia Meng Conghong Huang Siqi Ai Fangzhou Li Jingyuan Cao Mingkun Tong Xueqiu Ni Hengyi Liu Jianyu Deng Hong Lu Wei Wan Jicheng Gong Shiqiu Zhang Tong Zhu Institute of Reproductive and Child Health National Health Commission Key Laboratory of Reproductive Health/Department of Epidemiology and Biostatistics Ministry of Education Key Laboratory of Epidemiology of Major Diseases(PKU) School of Public Health Peking University Health Science Centre State Environmental Protection Key Laboratory of Atmospheric Exposure and Health Risk Management and Center for Environment and Health Peking University Advanced Institute of Information Technology Peking University Department of Epidemiology and Environmental Health School of Public Health and Health ProfessionsUniversity at Buffalo State Key Joint Laboratory of Environment Simulation and Pollution control College of Environmental Sciences and EngineeringPeking University Department of Earth System Science Tsinghua University School of Public Health Key Laboratory of Public Health Safety of the Ministry of Education and Key Laboratory of Health Technology Assessment of the Ministry of HealthFudan University College of Land Management Nanjing Agricultural University National&Local Joint engineering Research Center for Rural Land Resources Use and Consolidation Clean Air Asia

Clean air actions （CAAs） in China have been linked to considerable benefits in public ***,whether the beneficial effects of CAAs are equally distributed geographically is *** high-resolution maps of the distributions of major air pollutants (fine particulate matter[PM2.5]and ozone[O3]) and population,we aimed to track spatiotemporal changes in health impacts from,and geographic inequality embedded in,the reduced exposures to PM2.5and O3from 2013 to *** used a method established by the Global Burden of Diseases *** analyzing the changes in loss of life expectancy（LLE） attributable to PM2.5and O3,we calculated the gain of life expectancy （GLE） to quantify the health benefits of the air-quality ***,we assessed the geographic inequality embedded in the GLE using the Gini index （GI）.Based on risk assessments of PM2.5and O3,during the first stage of CAAs（2013 to 2017）,the mean GLE was 1.87 *** of the sum of the GLE was disproportionally distributed in about one quarter of the population exposed （GI 0.44）.During the second stage of CAAs（2017 to 2020）,the mean GLE increased to 3.94 months and geographic inequality decreased （GI 0.18）.According to our assessments,CAAs were enhanced,from the first to second stages,in terms of not only preventing premature mortality but also ameliorating health *** enhancements were related to increased sensitivity to the health effects of air pollution and synergic control of PM2.5and *** findings will contribute to optimizing future CAAs.

关键词： clean air action public health inequality fine particulate matter ozone

Numerical analysis of wind effects on aerodynamic characteristics of a ducted fan

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Chinese Journal of Aeronautics 2024年第5期37卷 263-280页

作者： Yiwei LUO Tianfu AI Yuhang HE Bin XU Yuping QIAN Yangjun ZHANG State Key Laboratory of Intelligent Green Vehicle and Mobility School of Vehicle and MobilityTsinghua UniversityBeijing 100084China Key Laboratory of Conveyance and Equipment ministry of education East China Jiaotong UniversityNanchang 330013China Vehicle Research center School of Mechanical EngineeringBeijing Institute of TechnologyBeijing 100081China Beijing Institute of Technology Chongqing Innovation center Chongqing 401120China

Ducted fans have been extensively used in Unmanned Aerial Vehicles(UAVs)for a variety of missions because of high efficiency,high safety and low ***,as a kind of typical meteorological condition,brings significant aerodynamic interference to the ducted fan,which seriously threatens flight stability and *** this work,the numerical simulation with the Unsteady Reynolds Averaged Navier-Stokes(URANS)method and the sliding mesh technique is performed to evaluate the steady wind *** results show that the wind will lead to serious unsteady effects in the flow field,and the thrust fluctuates at the blade passing frequency of 200 *** the wind speed increases,the rotor thrust increases,the duct thrust decreases,and the total thrust changes *** instability may occur when the wind speed exceeds 8 m/*** the angle of low-speed wind increases,the rotor thrust changes little,the duct thrust increases,and the total thrust *** addition,we figure out that cases with the same crosswind ratio are similar in results,and increasing the rotating speed or fan radius is beneficial to performance improvement in *** findings are essential to the ducted fan design and UAV flight control design for stable and safe operations in wind conditions.

关键词： Unmanned Aerial Vehicle(UAV) Ducted fan Wind effect Thrust fluctuations Computational Fluid Dynamics(CFD)

Cogitation on developing a dynamic model of soil wind erosion

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Science China Earth Sciences 2015年第3期58卷 462-473页

作者： ZOU XueYong ZHANG ChunLai CHENG Hong KANG LiQiang WU YongQiu State Key Laboratory of Earth Surface Processes and Resource Ecology MOE Engineering Center of Desertification and Blown-sand ControlBeijing Normal University

Studies on soil wind erosion began with single factors affecting soil wind erosion; with increasing quantities of data being accumulated,the wind erosion equation(WEQ),the revised wind erosion equation(RWEQ),the wind erosion prediction system(WEPS),and other soil wind erosion models have been successively established,and great advances have been *** we briefly review the soil wind erosion research course and analyze the advantages and disadvantages of the current soil wind erosion *** the perspective of the dynamics of wind erosion,we classified the factors affecting soil wind erosion into three categories,namely,wind erosivity factors(WEF),soil antierodibility factors(SAF),and roughness interference factors(RIF).We proposed the concept of a standard plot of soil wind erosion to solve the problem of uncertainty of the soil wind erosion modulus on a spatial scale,and provided methods to set similarity conditions in wind tunnel simulation experiments and to convert the spatial scale of the wind erosion modulus from the standard plot to a large scale *** also proposed a conceptual model on the basis of the dynamics of soil wind erosion with the theoretical basis that wind produces a shear force on the soil *** shear force is partitioned by barely erodible soil surfaces and roughness elements on the ground,and the amount of soil loss by wind should be calculated by comparing the shear force of the wind on barely erodible soil surfaces with the anti-erosion force of the surface *** advantage of this conceptual model is that the calculated soil wind erosion modulus is not subject to changes of spatial ***,we recommended continual improvement of the existing models while also establishing new models.

关键词： conceptual dynamic model of soil wind erosion conversion of soil loss in spatial scales standard plot factors affecting soil wind erosion

Modelling the preventive treatment under media impact on tuberculosis:A comparison in four regions of China

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Infectious Disease Modelling 2024年第2期9卷 483-500页

作者： Jun Zhang Yasuhiro Takeuchi Yueping Dong Zhihang Peng School of Mathematics and Statistics and Key Laboratory of Nonlinear Analysis&Applications(Ministry of Education)Central China Normal UniversityWuhan430079China College of Science and engineering Aoyama Gakuin UniversityKanagawa252-5258Japan National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases Chinese Center for Disease Control and PreventionBeijing102206China

Preventive treatment for people with latent Tuberculosis infection(LTBI)has aroused our great *** this paper,we propose and analyze a novel mathematical model of TB considering preventive treatment with media *** basic reproduction number R_(0)is defined by the next generation matrix *** the case without media impact,we prove that the disease-free equilibrium is globally asymptotically stable(unstable)if R_(0)1).Furthermore,we obtain that a unique endemic equilibrium exists when R_(0)>1,which is globally asymptotically stable in the case of permanent immunity and no media *** fit the model to the newly reported TB cases data from 2009 to 2019 of four regions in China and estimate the *** we estimatedR_(0)=0.50131 in Henan,R_(0)=1.282>1 in Jiangxi andR_(0)=1.930>1 in Xinjiang imply that TB will continue to persist in these three regions without further prevention and control ***,sensitivity analysis is carried out to illustrate the role of model parameters for TB *** finding reveals that appropriately improving the rate of timely treatment for actively infected people and increasing the rate of individuals with LTBI seeking preventive treatment could achieve the goal of TB *** addition,another interesting finding shows that media impact can only reduce the number of active infections to a limited extent,but cannot change the prevalence of TB.

关键词： Latent tuberculosis infection Preventive treatment Media impact Mathematical model Tuberculosis elimination

Boosting kinetic separation of ethylene and ethane on microporous materials via crystal size control

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Chinese Journal of Chemical engineering 2024年第1期65卷 85-91页

作者： Yixuan Ma Cong Yu Lifeng Yang Rimin You Yawen Bo Qihan Gong Huabin Xing Xili Cui Key Laboratory of Biomass Chemical engineering of ministry of education College of Chemical and Biological EngineeringZhejiang UniversityHangzhou 310012China Fundamental Science&Advanced Technology Lab PetroChina Petrochemical Research InstituteChina National Petroleum CorporationBeijing 102200China ZJU-Hangzhou Global Scientific and Technological Innovation center Zhejiang UniversityHangzhou 311200China Shanxi-Zheda Institute of Advanced Materials and Chemical engineering Hangzhou 310027China

The adsorptive separation of C_(2)H_(4)and C_(2)H_(6),as an alternative to distillation units consuming high energy,is a promising yet challenging *** great similarity in the molecular size of C_(2)H_(4)and C_(2)H_(6)brings challenges to the regulation of adsorbents to realize efficient dynamic ***,we reported the enhancement of the kinetic separation of C_(2)H_(4)/C_(2)H_(6)by controlling the crystal size of ZnAtzPO_(4)(Atz=3-amino-1,2,4-triazole)to amplify the diffusion difference of C_(2)H_(4)and C_(2)H_(6).Through adjusting the synthesis temperature,reactant concentration,and ligands/metal ions molar ratio,ZnAtzPO4 crystals with different sizes were *** single-component kinetic adsorption tests and binary-component dynamic breakthrough experiments confirmed the enhancement of the dynamic separation of C_(2)H_(4)/C_(2)H_(6)with the increase in the crystal size of ZnAtzPO_(4).The separation selectivity of C_(2)H_(4)/C_(2)H_(6)increased from 1.3 to 98.5 with the increase in the crystal size of ZnAtzPO_(4).This work demonstrated the role of morphology and size control of adsorbent crystals in the improvement of the C_(2)H_(4)/C_(2)H_(6)kinetic separation performance.

关键词： Adsorption Adsorbent Ethylene Binary mixture Crystal size control Kinetic separation