检索结果-南通市图书馆

Machine Learning Analysis of Impact of Western US Fires on Central US Hailstorms

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2024年第7期41卷 1450-1462页

作者： Xinming LIN Jiwen FAN Yuwei ZHANG ZJason HOU Pacific Northwest national laboratory RichlandWA 99354USA Argonne national laboratory LemontIL 60439USA

Fires,including wildfires,harm air quality and essential public services like transportation,communication,and *** fires can also influence atmospheric conditions,including temperature and aerosols,potentially affecting severe convective ***,we investigate the remote impacts of fires in the western United States(WUS)on the occurrence of large hail(size:≥2.54 cm)in the central US(CUS)over the 20-year period of 2001–20 using the machine learning(ML),Random Forest(RF),and Extreme Gradient Boosting(XGB)*** developed RF and XGB models demonstrate high accuracy(>90%)and F1 scores of up to 0.78 in predicting large hail occurrences when WUS fires and CUS hailstorms coincide,particularly in four states(Wyoming,South Dakota,Nebraska,and Kansas).The key contributing variables identified from both ML models include the meteorological variables in the fire region(temperature and moisture),the westerly wind over the plume transport path,and the fire features(i.e.,the maximum fire power and burned area).The results confirm a linkage between WUS fires and severe weather in the CUS,corroborating the findings of our previous modeling study conducted on case simulations with a detailed physics model.

关键词： wildfire severe convective storm hailstorm machine learning

Nano-enhanced solid-state hydrogen storage:Balancing discovery and pragmatism for future energy solutions

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第10期17卷 8729-8753页

作者： Chaochao Dun Xinyi Wang Linfeng Chen Sichi Li Hanna M.Breunig Jeffrey J.Urban The Molecular Foundry Lawrence Berkeley National Laboratory BerkeleyBerkeleyCA 94720USA Energy Analysis and Environmental Impacts Division Lawrence Berkeley National LaboratoryBerkeleyCA 94720USA Lawrence Livermore national laboratory LivermoreCA 94550USA

Nanomaterials have revolutionized the battery industry by enhancing energy storage capacities and charging speeds,and their application in hydrogen(H_(2))storage likewise holds strong potential,though with distinct challenges and mechanisms.H_(2) is a crucial future zero-carbon energy vector given its high gravimetric energy density,which far exceeds that of liquid ***,its low volumetric energy density in gaseous form currently requires storage under high pressure or at low *** review critically examines the current and prospective landscapes of solid-state H_(2) storage technologies,with a focus on pragmatic integration of advanced materials such as metal-organic frameworks(MOFs),magnesium-based hybrids,and novel sorbents into future energy *** materials,enhanced by nanotechnology,could significantly improve the efficiency and capacity of H_(2) storage systems by optimizing H_(2) adsorption at the nanoscale and improving the kinetics of H_(2) uptake and *** discuss various H_(2) storage mechanisms—physisorption,chemisorption,and the Kubas interaction—analyzing their impact on the energy efficiency and scalability of storage *** review also addresses the potential of“smart MOFs”,single-atom catalyst-doped metal hydrides,MXenes and entropy-driven alloys to enhance the performance and broaden the application range of H_(2) storage systems,stressing the need for innovative materials and system integration to satisfy future energy ***-throughput screening,combined with machine learning algorithms,is noted as a promising approach to identify patterns and predict the behavior of novel materials under various conditions,significantly reducing the time and cost associated with experimental *** closing,we discuss the increasing involvement of various companies in solid-state H_(2) storage,particularly in prototype vehicles,from a techno-economic *** forward-looking perspective underscores t

关键词： nanomaterials nanotechnology solid-state H_(2)storage techno-economic analysis model-driven material development processes

Functional genomics of Brassica napus:Progresses,challenges,and perspectives

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2024年第3期66卷 484-509页

作者： Zengdong Tan Xu Han Cheng Dai Shaoping Lu Hanzi He Xuan Yao Peng Chen Chao Yang Lun Zhao Qing-Yong Yang Jun Zou Jing Wen Dengfeng Hong Chao Liu Xianhong Ge Chuchuan Fan Bing Yi Chunyu Zhang Chaozhi Ma Kede Liu Jinxiong Shen Jinxing Tu Guangsheng Yang Tingdong Fu Liang Guo Hu Zhao national Key laboratory of Crop Genetic Improvement Hubei Hongshan LaboratoryHuazhong Agricultural UniversityWuhan 430070China Yazhouwan national laboratory Sanya 572025China

Brassica napus,commonly known as rapeseed or canola,is a major oil crop contributing over 13%to the stable supply of edible vegetable oil *** and understanding the gene functions in the *** genome is crucial for genomic breeding.A group of genes controlling agronomic traits have been successfully cloned through functional genomics studies in *** this review,we present an overview of the progress made in the functional genomics of ***,including the availability of germplasm resources,omics databases and cloned functional *** on the current progress,we also highlight the main challenges and perspectives in this *** advances in the functional genomics of *** contribute to a better understanding of the genetic basis underlying the complex agronomic traits in *** and will expedite the breeding of high quality,high resistance and high yield in *** varieties.

关键词： accelerate breeding Brassica napus functional genomics high resistance high yield

Learnware:small models do big

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第1期67卷 39-50页

作者： Zhi-Hua ZHOU Zhi-Hao TAN national Key laboratory for Novel Software Technology Nanjing University

There are complaints about current machine learning techniques such as the requirement of a huge amount of training data and proficient training skills,the difficulty of continual learning,the risk of catastrophic forgetting,and the leaking of data privacy/*** research efforts have been focusing on one of those concerned issues separately,paying less attention to the fact that most issues are entangled in *** prevailing big model paradigm,which has achieved impressive results in natural language processing and computer vision applications,has not yet addressed those issues,whereas becoming a serious source of carbon *** article offers an overview of the learnware paradigm,which attempts to enable users not to need to build machine learning models from scratch,with the hope of reusing small models to do things even beyond their original purposes,where the key ingredient is the specification which enables a trained model to be adequately identified to reuse according to the requirement of future users who know nothing about the model in advance.

关键词： artificial intelligence machine learning learnware

Balancing the Quantum Speed Limit and Instantaneous Energy Cost in Adiabatic Quantum Evolution

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2024年第4期41卷 7-12页

作者：徐建文张宇佳郑文蔡浩阳周浩宇李先科廖绪东张钰李邵雄兰栋谭新生于扬 national laboratory of Solid State Microstructures School of PhysicsNanjing UniversityNanjing 210093China Shishan laboratory Suzhou Campus of Nanjing UniversitySuzhou 215163China Hefei national laboratory Hefei 230088China

Adiabatic time-optimal quantum controls are extensively used in quantum technologies to break the constraints imposed by short coherence ***,practically it is crucial to consider the trade-off between the quantum evolution speed and instantaneous energy cost of process because of the constraints in the available control ***,we experimentally show that using a transmon qubit that,even in the presence of vanishing energy gaps,it is possible to reach a highly time-optimal adiabatic quantum driving at low energy cost in the whole evolution *** validates the recently derived general solution of the quantum Zermelo navigation problem,paving the way for energy-efficient quantum control which is usually overlooked in conventional speed-up schemes,including the well-known counter-diabatic *** designing the control Hamiltonian based on the quantum speed limit bound quantified by the changing rate of phase in the interaction picture,we reveal the relationship between the quantum speed limit and instantaneous energy ***,we demonstrate fast and high-fidelity quantum adiabatic processes by employing energy-efficient driving strengths,indicating a promising strategy for expanding the applications of time-optimal quantum controls in superconducting quantum circuits.

关键词： process quantum adiabatic

The quantum Ising model for perfect matching and solving it with variational quantum eigensolver

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第9期67卷 306-320页

作者： Qilin ZHENG Pingyu ZHU Chao WU Miaomiao YU Weihong LUO Ping XU Institute for Quantum Information and State Key laboratory of High Performance Computing College of Computer Science and Technology National University of Defense Technology Hefei national laboratory

Obtaining all perfect matchings of a graph is a tough problem in graph theory, and its complexity belongs to the #P-Complete class. The problem is closely related to combinatorics, marriage matching problems, dense subgraphs, the Gaussian boson sampling, chemical molecular structures, and dimer *** this paper, we propose a quadratic unconstrained binary optimization formula of the perfect matching problem and translate it into the quantum Ising model. We can obtain all perfect matchings by mapping them to the ground state of the quantum Ising Hamiltonian and solving it with the variational quantum eigensolver. Adjusting the model's parameters can also achieve the maximum or minimum weighted perfect matching. The experimental results on a superconducting quantum computer of the Origin Quantum Computing Technology Company show that our model can encode 2~n dimensional optimization space with only O（n） qubits consumption and achieve a high success probability of the ground state corresponding to all perfect matchings. In addition, the further simulation results show that the model can support a scale of more than 14 qubits, effectively resist the adverse effects of noise, and obtain a high success probability at a shallow variational depth. This method can be extended to other combinatorial optimization problems.

关键词： perfect matching Ising model quantum Hamiltonian variational quantum eigensolver quadratic unconstrained binary optimization

Simulating a Chern Insulator with C = ±2 on Synthetic Floquet Lattice

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2024年第9期41卷 4-11页

作者：雷凌霄王伟臣黄光耀胡顺曹希张鑫方邓明堂陈平形 Institute for Quantum Science and Technology College of ScienceNational University of Defense Technology Institute for Quantum Information & State Key laboratory of High Performance Computing College of Computer Science and Technology National University of Defense Technology Greatwall Quantum laboratory Hefei national laboratory

The synthetic Floquet lattice, generated by multiple strong drives with mutually incommensurate frequencies,provides a powerful platform for quantum simulation of topological phenomena. In this study, we propose a 4-band tight-binding model of the Chern insulator with a Chern number C = ±2 by coupling two layers of the half Bernevig-Hughes-Zhang lattice and subsequently mapping it onto the Floquet lattice to simulate its topological properties.

关键词： Quantum computers

New Opportunities for Neutrons in Environmental and Biological Sciences

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2024年第7期18卷 179-186页

作者： Alexander Johs Shuo Qian Leighton Coates Brian H.Davison James G.Elkins Xin Gu Jennifer Morrell-Falvey Hugh O'Neill Jeffrey M.Warren Eric M.Pierce Kenneth Herwig Oak Ridge national laboratory Oak RidgeTN37831USA

The use of neutron methods in environmental and biological sciences is rapidly emerging and accelerating with the development of new instruments at neutron user *** article,based on a workshop held at Oak Ridge national laboratory(ORNL),offers insights into the application of neutron techniques in environmental and biological *** highlight recent advances and identify key challenges and potential future research *** include soil and rhizosphere processes,root water dynamics,plant-microbe interactions,structure and dynamics of biological systems,applications in synthetic biology and enzyme engineering,next-generation bioproducts,biomaterials and bioenergy,nanoscale structure,and fluid dynamics of porous materials in *** provide an outlook on emerging opportunities with an emphasis on new capabilities that will be enabled at the Spallation Neutron Source Second Target Station currently under design at *** mission of scientific neutron user facilities worldwide is to enable science using state-of-the-art neutron *** aim to encourage researchers in the environmental and biological research community to explore the unique capability afforded by neutrons at these facilities.

关键词： Neutrons Environment Biology Neutron imaging Neutron scattering Second Target Station(STS)

Adaptive learning-based optimal tracking control system design and analysis of a disturbed nonlinear hypersonic vehicle model

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第6期67卷 1893-1906页

作者： AN Kai WANG ZhenGuo HUANG Wei Hypersonic Technology laboratory National University of Defense TechnologyChangsha410073China

We propose an adaptive learning-based optimal control scheme for height-velocity control models considering model uncertainties and external disturbances of hypersonic winged-cone *** longitudinal nonlinear model is first established and transformed into the control-oriented error equations,and the control scheme is organized by a steady-compensation *** overcome and eliminate the impact of model uncertainties and external disturbances,an adaptive radial basis function neural network(RBFNN)is designed by a q-gradient *** the height-velocity error system with estimated uncertainties into account,the adaptive learning-based optimal tracking control(ALOTC)scheme is proposed by combining the critic-only adaptive dynamic programming(ADP)framework and parameter optimization of system settling ***,a novel weight update law is proposed to satisfy the online iteration requirements,and the algorithm convergence and closedloop stability are discussed by the Lyapunov ***,four simulation cases are provided to prove the effectiveness,accuracy,and robustness of the proposed scheme for the hypersonic longitudinal control system.

关键词： optimal tracking control adaptive dynamic programming RBFNN hypersonic vehicle