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Inter-well internal resonance analysis of rectangular asymmetric cross-ply bistable composite laminated cantilever shell under transverse foundation excitation

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Applied Mathematics and Mechanics(English Edition) 2024年第8期45卷 1353-1370页

作者： Lele REN Wei zhang Yufei zhang State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China Department of Mechanics Guangxi UniversityNanning 530004China Beijing Key Laboratory of Nonlinear Vibrations and Strength of Mechanical Structures College of Mechanical EngineeringBeijing University of TechnologyBeijing 100124China

The chaotic dynamic snap-through and complex nonlinear vibrations are investigated in a rectangular asymmetric cross-ply bistable composite laminated cantilever shell,in cases of 1:2 inter-well internal resonance and primary *** transverse foundation excitation is applied to the fixed end of the structure,and the other end is in a free *** first-order approximate multiple scales method is employed to perform the perturbation analysis on the dimensionless two-degree-of-freedom ordinary differential motion control *** four-dimensional averaged equations are derived in both polar and rectangular coordinate *** from the obtained frequency-amplitude and force-amplitude response curves,a detailed analysis is conducted to examine the impacts of excitation amplitude,damping coefficient,and tuning parameter on the nonlinear internal resonance characteristics of the *** nonlinear softening characteristic is exhibited in the upper stable-state,while the lower stable-state demonstrates the softening and linearity *** simulation is carried out using the fourth-order Runge-Kutta method,and a series of nonlinear response curves are *** the excitation amplitude further elucidates the global bifurcation and chaotic dynamic snap-through characteristics of the bistable cantilever shell.

关键词： bistable composite laminated cantilever shell inter-well internal resonance primary resonance chaotic dynamic snap-through complex nonlinear vibration

Oxygen reduction electrocatalysis:From conventional to single-atomic platinum-based catalysts for proton exchange membrane fuel cells

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Frontiers in Energy 2024年第2期18卷 206-222页

作者： Cheng YUAN Shiming zhang Jiujun zhang Institute for Sustainable Energy/College of Sciences Shanghai UniversityShanghai 200444China

Platinum(Pt)-based materials are still the most efficient and practical catalysts to drive the sluggish kinetics of cathodic oxygen reduction reaction(ORR)in proton exchange membrane fuel cells(PEMFCs).However,their catalysis and stability performance still need to be further improved in terms of corrosion of both carbon support and Pt catalyst particles as well as Pt loading *** on the developed synthetic strategies of alloying/nanostructuring Pt particles and modifying/innovating supports in developing conventional Pt-based catalysts,Pt single-atom catalysts(Pt SACs)as the recently burgeoning hot materials with a potential to achieve the maximum utilization of Pt are comprehensively reviewed in this *** design thoughts and synthesis of various isolated,alloyed,and nanoparticlecontained Pt SACs are *** single-atomic Pt coordinating with non-metals and alloying with metals as well as the metal-support interactions of Pt single-atoms with carbon/non-carbon supports are emphasized in terms of the ORR activity and stability of the *** advance further research and development of Pt SACs for viable implementation in PEMFCs,various technical challenges and several potential research directions are outlined.

关键词： oxygen reduction electrocatalysis Pt singleatom catalysts conventional Pt-based catalysts design thoughts and synthesis metal-support interactions

Deep Guided Attention Network for Joint Denoising and Demosaicing in Real Image

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Chinese Journal of Electronics 2024年第1期33卷 303-312页

作者： Tao zhang Ying FU Jun zhang School of Computer Science and Technology Beijing Institute of Technology Advanced Reasearch Institute of Multidisciplinary Science Beijing Institute of Technology

Denoising(DN) and demosaicing(DM) are the first crucial stages in the image signal processing pipeline. Recently, researches pay more attention to solve DN and DM in a joint manner, which is an extremely undetermined inverse problem. Existing deep learning methods learn the desired prior on synthetic dataset, which limits the generalization of learned network to the real world data. Moreover, existing methods mainly focus on the raw data property of high green information sampling rate for DM, but occasionally exploit the high intensity and signalto-noise(SNR) of green channel. In this work, a deep guided attention network(DGAN) is presented for real image joint DN and DM(JDD), which considers both high SNR and high sampling rate of green information for DN and DM, respectively. To ease the training and fully exploit the data property of green channel, we first train DN and DM sub-networks sequentially and then learn them jointly, which can alleviate the error accumulation. Besides, in order to support the real image JDD, we collect paired raw clean RGB and noisy mosaic images to conduct a realistic dataset. The experimental results on real JDD dataset show the presented approach performs better than the state-of-the-art methods, in terms of both quantitative metrics and qualitative visualization.

关键词： Training Visualization Inverse problems Green products Noise reduction Pipelines Signal processing

Host plant traits play a crucial role in shaping the composition of epiphytic microbiota in the arid desert,Northwest China

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Journal of Arid Land 2024年第5期16卷 699-724页

作者： zhang Jun zhang Yuanming zhang Qi State Key Laboratory of Desert and Oasis Ecology Key Laboratory of Ecological Safety and Sustainable Development in Arid LandsXinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China Xinjiang Key Laboratory of Biodiversity Conservation and Application in Arid Lands Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China Xinjiang Field Scientific Observation Research Station of Tianshan Wild Fruit Forest Ecosystem Yili Botanical GardenXinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China College of Life Sciences Shihezi UniversityShihezi 832003China

Phyllosphere microorganisms are a crucial component of environmental microorganisms,highly influenced by host characteristics,and play a significant role in plant health and ***,the impact of host characteristics on shaping phyllosphere microbial communities of plants with different life forms remains *** high-throughput sequencing technology,this study analyzed the diversity and community composition of phyllosphere epiphytic microorganisms(e.g.,bacteria and fungi)of various plant life forms in the hinterland of the Gurbantunggut Desert,Northwest *** annotation of prokaryotic taxa(FAPROTAX)and fungi function guild(FUNGuild)were employed to assess the ecological functions of microorganisms and to investigate the role of stochastic and deterministic processes in shaping phyllosphere microbial *** showed a diverse array of phyllosphere epiphytic microorganisms in the desert plants,with Proteobacteria,Cyanobacteria,and Actinobacteriota dominating bacterial community,while Ascomycota and Basidiomycota were prevalent in fungal *** across different plant life forms highlighted distinct microbial communities,indicating strong filtering effects by plant *** prediction identified intracellular parasites(accounting for 27.44%of bacterial community abundance),chemoheterotrophy(10.12%),and phototrophy(17.41%)as the main functions of epiphytic bacteria on leaves of different life form *** prediction indicated that phyllosphere epiphytic fungi primarily served as Saprotrophs(81.77%),Pathotrophs(17.41%),and Symbiotrophs(0.82%).Co-occurrence network analysis demonstrated a predominance of positive correlations among different microbial ***-Crick dissimilarity index analysis revealed that deterministic processes predominantly influenced phyllosphere bacterial and fungal community *** partitioning analysis and random forest modeling suggested that pla

关键词： phyllosphere epiphytic bacteria phyllosphere epiphytic fungi community structure community diversity functional diversity plant life form plant functional traits

Value Iteration-Based Cooperative Adaptive Optimal Control for Multi-Player Differential Games With Incomplete Information

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IEEE/CAA Journal of Automatica Sinica 2024年第3期11卷 690-697页

作者： Yun zhang Lulu zhang Yunze Cai the Department of Automation Shanghai Jiao Tong UniversityShanghai 200240 the Key Laboratory of System Control and Information Processing Ministry of Education of ChinaShanghai 200240China

This paper presents a novel cooperative value iteration(VI)-based adaptive dynamic programming method for multi-player differential game models with a convergence *** players are divided into two groups in the learning process and adapt their policies *** method removes the dependence of admissible initial policies,which is one of the main drawbacks of the PI-based ***,this algorithm enables the players to adapt their control policies without full knowledge of others’ system parameters or control *** efficacy of our method is illustrated by three examples.

关键词： Adaptive dynamic programming incomplete information multi-player differential game value iteration

Proximal Femur Bionic Nail (PFBN): A Panacea for Unstable Intertrochanteric Femur Fracture

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Engineering 2024年第6期37卷 152-158页

作者： Kaixuan zhang Wei Chen Yingze zhang School of Medicine Nankai UniversityTianjin 300071China Department of Orthopedic Surgery of Hebei Province The Third Hospital of Hebei Medical UniversityShijiazhuang 050051China Key Laboratory of Biomechanics of Hebei Province Orthopaedic Research Institute of Hebei ProvinceShijiazhuang 050051China National Health Commission(NHC)Key Laboratory of Intelligent Orthopeadic Equipment The Third Hospital of Hebei Medical UniversityShijiazhuang 050051China Chinese Academy of Engineering Beijing 100088China

With the aging population,intertrochanteric femur fracture in the elderly has become one of the most serious public health issues and a hot topic of research in trauma *** to the limitations of internal fixation techniques and the insufficient mechanical design of nails,the occurrence of complications delays patient recovery after surgical *** of a proximal femur bionic nail(PFBN)based on zhang’s N triangle theory provides triangular supporting fixation,which dramatically decreases the occurrence of complications and has been widely used for clinical treatment of unstable intertrochanteric femur fracture *** this work,we developed an equivalent biomechanical model to analyze improvement in bone remodeling of unstable intertrochanteric femur fracture through PFBN *** results show that compared with proximal femoral nail antirotation(PFNA)and InterTan,PFBN can dramatically decrease the maximum strain in the proximal *** on Frost’s mechanostat theory,the local mechanical environment in the proximal femur can be regulated into the medium overload region by using a PFBN,which may render the proximal femur in a state of physiological overload,favoring post-operative recovery of intertrochanteric femur fracture in the *** work shows that PFBN may constitute a panacea for unstable intertrochanteric femur fracture and provides insights into improving methods of internal fixation.

关键词： Intertrochanteric femur fracture Internal fixation Proximal femur bionic nail(PFBN) Biomechanics Bone remodeling

Experimentally Ruling Out Joint Reality Based on Locality with Device-Independent Steering

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Chinese Physics Letters 2024年第1期41卷 1-5页

作者： Shuaining zhang Xiang zhang Zhiyue Zheng Wei zhang Beijing Academy of Quantum Information Sciences Beijing 100193China Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials and Micro-nano Devices Renmin University of ChinaBeijing 100872China Key Laboratory of Quantum State Construction and Manipulation(Ministry of Education) Renmin University of ChinaBeijing 100872China

As an essential concept to understand the world,whether the real values(or physical realities)of observables are suitable to physical systems beyond the classic has been debated for many *** standard nogo results based on Bell inequalities have ruled out the joint reality of incompatible quantum observables,the possibility of giving simple yet strong arguments to rule out joint reality in any physical system(not necessarily quantum)with weaker assumptions and less observables has been explored and proposed ***,we perform a device-independent experiment on a two-qubit superconducting system to show that the joint reality of two observables is incompatible with locality under the weaker assumption of the reality of observables in a single space-time region(or single qubit).Our results clearly show the violation of certain inequalities derived from both linear and nonlinear *** addition,we study the robustness of the linear and nonlinear criterion against the effect of systematic *** demonstration opens up the possibility of delineating classical and non-classical boundaries with simpler nontrivial quantum system.

关键词： observable quantum system

Improving lipid production by Rhodotorula glutinis for renewable fuel production based on machine learning

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Frontiers of Chemical Science and Engineering 2024年第5期18卷 23-35页

作者： Lihe zhang Changwei zhang Xi Zhao Changliu He Xu zhang National Energy R&D Center for Biorefinery Beijing University of Chemical TechnologyBeijing 100029China Collage of Life Science and Technology Beijing University of Chemical TechnologyBeijing 100029China Beijing Key Laboratory of Bioprocess Beijing University of Chemical TechnologyBeijing 10029China

Microbial lipid fermentation encompasses intricate complex cell growth processes and heavily relies on expert experience for optimal *** modeling of the fermentation process assists researchers in making intelligent decisions,employing logical reasoning and strategic planning to optimize lipid *** this study,the effects of medium components and concen-trations on lipid fermentation were investigated,*** then,leveraging the collated data,a variety of machine learning algorithms were used to model and optimize the lipid fermentation *** models,based on artificial neural networks and support vector machines,achieved R?values all higher than 0.93,ensuring accurate predictions of the fermentation *** linear regression was used to evaluate the respective target parameter,which were affected by the medium components of lipid ***,single and multi-objective optimiza-tion were conducted for lipid fermentation using the genetic *** results demonstrated the maximum biomass of 50.3 g·L^(-1) and maximum lipid concentration of 14.1 g:L^(-1) with the error between the experimental and predicted values less than 5%.The results of the multi-objective optimization reveal the synergistic and competitive relationship between biomass,lipid concentration,and conversion rate,which lay a basis for in-depth optimization and amplification.

关键词： microbial lipid machine learning artificial neural network support vector machine genetic algorithm

Nanophononic metamaterials induced proximity effect in heat flux regulation

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Frontiers of physics 2024年第2期19卷 149-156页

作者： Jian zhang Haochun zhang Gang zhang School of Energy Science and Engineering Harbin Institute of TechnologyHarbin 150001China Institute of High Performance Computing Agency for ScienceTechnology and Research(A*STAR)Singapore 138632Singapore

Recent studies have shown that the construction of nanophononic metamaterials can reduce thermal conductivity without affecting electrical properties,making them promising in many fields of application,such as energy conversion and thermal ***,although extensive studies have been carried out on thermal conductivity reduction in nanophononic metamaterials,the local heat flux characteristic is still *** this work,we construct a heat flux regulator which includes a silicon nanofilm with silicon *** regulator has remarkable heat flux regulation ability,and various impacts on the regulation ability are ***,even in the region without nanopillars,the local heat current is still lower than that in pristine silicon nanofilms,reduced by the neighboring nanopillars through the thermal proximity *** combine the analysis of the phonon participation ratio with the intensity of localized phonon modes to provide a clear *** findings not only provide insights into the mechanisms of heat flux regulation by nanophononic metamaterials,but also will open up new research directions to control local heat flux for a broad range of applications,including heat management,thermoelectric energy conversion,thermal cloak,and thermal concentrator.

关键词： nanophononic metamaterials proximity effect