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Random Forest-Based Fatigue Reliability-Based Design Optimization for Aeroengine Structures

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Computer Modeling in Engineering & Sciences 2024年第7期140卷 665-684页

作者： xue-qin Li Lu-Kai Song School of Energy and Power Engineering Beihang UniversityBeijing100191China Department of Mechanical Engineering The Hong Kong Polytechnic UniversityKowloonHong Kong999077China Research Institute of Aero-Engine Beihang UniversityBeijing100191China

Fatigue reliability-based design optimization of aeroengine structures involves multiple repeated calculations of reliability degree and large-scale calls of implicit high-nonlinearity limit state function,leading to the traditional direct Monte Claro and surrogate methods prone to unacceptable computing efficiency and accuracy.In this case,by fusing the random subspace strategy and weight allocation technology into bagging ensemble theory,a random forest(RF)model is presented to enhance the computing efficiency of reliability degree;moreover,by embedding the RF model into multilevel optimization model,an efficient RF-assisted fatigue reliability-based design optimization framework is developed.Regarding the low-cycle fatigue reliability-based design optimization of aeroengine turbine disc as a case,the effectiveness of the presented framework is validated.The reliabilitybased design optimization results exhibit that the proposed framework holds high computing accuracy and computing efficiency.The current efforts shed a light on the theory/method development of reliability-based design optimization of complex engineering structures.

关键词： Random forest reliability-based design optimization ensemble learning machine learning

Experimental and numerical investigation of the impacts of rotor tip-rake on excitation forces of pump-jet propulsors

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Journal of Hydrodynamics 2024年第1期36卷 142-157页

作者： xue-qin Ji Xiao-song Zhang Chen-jun Yang Xiao-qian Dong State Key Laboratory of Ocean Engineering Marine Numerical Experiment CentreSchool of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China CSSC Shanghai Marine Energy Saving Technology Co. Ltd.Shanghai200011China China Ship Scientific Research Center Shanghai Branch Shanghai200011China

The tip-clearance flow in a pump-jet propulsor exerts great impacts on the fluctuating pressures and resultant unsteady forces,which are important sources of structural vibrations and radiated noise underwater.The blade geometry close to the tip is an important factor determining the vortex strength in the tip-clearance flow.In the open-water condition,the effects of raking the rotor tips on the duct-surface fluctuating pressures and the resultant unsteady forces acting on different components of the propulsor are investigated via physical model experiments and the numerical solution of Reynolds-averaged Navier-Stokes(RANS)equations coupled with the SST k-ωturbulence model.The measured and simulated results of hydrodynamic pressures are consistent to each other,and the simulated flows help better understand why the fluctuating pressures change with the tip geometry.The strong fluctuations of duct-surface pressures are caused by intensive tip separation vortices.The duct-surface pressure fluctuations are effectively reduced by using the rake distribution near the tip towards blade back side and,for the combination of the five-bladed rotor and the seven-bladed stator,the resultant unsteady horizontal(and vertical)forces acting on the duct and stator are also reduced;while increasing rake leads to negative effect on pressure fluctuations and unsteady horizontal(and vertical)forces acting on all the components of the propulsor.

关键词： Pump-jet tip-clearance tip-rake fluctuating pressures excitation forces

The stance and factors of international organizations towards countries from a Chinese perspective

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Data Intelligence 2024年第1期6卷 158-182页

作者： qin Zhang Haili xue Yaotian Wang Yao Wang Ziqin Zhang qinghua qin Haoguang Liang National Science Library Chinese Academy of Sciences100190China China Center for Modernization Research 100190China Beijing International Studies University 100024China Beijing Key Laboratory of National Belt and Road Data Analysis and Decision Support 100024China University College London WC1E 6BTUK

The degree and scope of constraints imposed by International Organizations(IOs)on States are increasing,and identifying the factors affecting the IOs’stances on States is helpful to enhance the state's discourse power and influence in the international community.First,by coding the records of Regular Press Conferences of the Speaking Office of the Chinese Ministry of Foreign Affairs during the period of 20182022,we obtained a dataset of IOs’stances on China-related events.Second,we constructed political relation,economic relation,and humanistic relation indicators to complement the influence factors,adopted the Bayesian logit model,and applied the Monte Carlo Markov chain algorithm and Gibbs sampling to analyze the probability of IOs’positive stances towards China.The result shows that IOs’category,length of establishment,functional position,and relationship with China are all related to their tendency of making a statement about China.In terms of the heterogeneity of event types,forum-type IOs are significantly inclined to give positive assessment compared to service-type IOs on events focusing on China's own development.Further analysis reveals that the model for analyzing and predicting the attitudes of IOs is more effective when the international situation is in a stable period.

关键词： Bayesian Logit Model IOs' stances Attitude analysis Monte Carlo Markov chain International relation indicator

Efficacy of electroacupuncture on myocardial protection and postoperative rehabilitation in patients undergoing cardiac surgery with cardiopulmonary bypass:a systematic review and Meta-analysis

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Journal of Traditional Chinese Medicine 2024年第1期44卷 1-15页

作者： qin Xiaoyu WANG Chunai xue Jianjun ZHANG Jie LU Xiaoting DING Shengshuang GE Long WANG Minzhen the First Clinical Medical College Gansu University of Chinese MedicineLanzhou 730030China Department of Anesthesiology Gansu Provincial Hospital of Traditional Chinese MedicineLanzhou 730050China Evidence-based Medicine Center Lanzhou UniversityLanzhou 730030China Institute of Epidemiology and Statistics School of Public HealthLanzhou UniversityLanzhou 730030China

OBJECTIVE:To evaluate the efficacy of electroacupuncture(EA)intervention on myocardial protection and postoperative rehabilitation in patients undergoing cardiac surgery with cardiopulmonary bypass(CPB).METHODS:Eight databases,including Pub Med,Embase,the Cochrane Library,Web of Science,Chinese Bio Medical Literature Database,China National Knowledge Infrastructure Database,Wanfang Data,China Science and Technology Journal Database,and two clinical trial registries,were searched.All randomized controlled trials(RCTs)related to EA intervention in cardiac surgery with CPB were collected.Based on the inclusion and exclusion criteria,two researchers independently screened articles and extracted data.After the quality evaluation,RevMan 5.3 software was used for analysis.RESULTS:Fourteen RCTs involving 836 patients were included.Compared with the control treatment,EA significantly increased the incidence of cardiac automatic rebeat after aortic unclamping[relative risk(RR)=1.15,95%confidence interval(CI)(1.01,1.31),P<0.05;moderate].Twenty-four hours after aortic unclamping,EA significantly increased the superoxide dismutase[standardized mean difference(SMD)=0.96,95%CI(0.32,1.61),P<0.05;low],and interleukin(IL)-2[SMD=1.33,95%CI(0.19,2.47),P<0.05;very low]expression levels and decreased the malondialdehyde[SMD=-1.62,95%CI(-2.15,-1.09),P<0.05;moderate],tumour necrosis factor-α[SMD=-1.28,95%CI(-2.37,-0.19),P<0.05;moderate],and cardiac troponin I[SMD=-1.09,95%CI(-1.85,-0.32),P<0.05;low]expression levels as well as the inotrope scores[SMD=-0.77,95%CI(-1.22,-0.31),P<0.05;high].There was no difference in IL-6 and IL-10 expression levels.The amount of intraoperative sedative[SMD=-0.31,95%CI(-0.54,-0.09),P<0.05;moderate]and opioid analgesic[SMD=-0.96,95%CI(-1.53,-0.38),P<0.05;low]medication was significantly lower in the EA group than in the control group.Moreover,the postoperative tracheal intubation time[SMD=-0.92,95%CI(-1.40,-0.45),P<0.05;low]and intensive care unit stay[SMD=-1.71,95%CI(-3.06,-0.36),P<0.05;low]were significan

关键词： electroacupuncture cardiopulmonary bypass thoracic surgery myocardial ischaemia-reperfusion injury myocardial protection postoperative rehabilitation Meta-analysis randomized controlled trial

Digital CEOs in Digital Enterprises:Automating,Augmenting,and Parallel in Metaverse/CPSS/TAOs

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IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 820-823页

作者： Juanjuan Li Rui qin Sangtian Guan Xiao xue Peng Zhu Fei-Yue Wang with State Key Laboratory of Multimodal Artificial Intelligence Systems Institute of AutomationChinese Academy of SciencesBeijing 100190China the College of Intelligence and Computing Tianjin UniversityTianjin 300072China School of Economics and Management Nanjing University of Science and TechnologyNanjing 210094China the State Key Laboratory for Management and Control of Complex Systems Chinese Academy of SciencesBeijing 100190 Faculty of Innovation Engineering Macao University of Science and TechnologyMacao 999078China

BIG models or foundation models are rapidly emerging as a key force in advancing intelligent societies[1]–[3]Their significance stems not only from their exceptional ability to process complex data and simulate advan... 详细信息

关键词： exceptional Auto advancing

Bioprinting of inorganic-biomaterial/neural-stem-cell constructs for multiple tissue regeneration and functional recovery

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National Science Review 2024年第4期11卷 228-244页

作者： Hongjian Zhang Chen qin Zhe Shi Jianmin xue Jianxin Hao Jinzhou Huang Lin Du Hongxu Lu Chengtie Wu State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of Ceramics Chinese Academy of Sciences Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences

Tissue regeneration is a complicated process that relies on the coordinated effort of the nervous, vascular and immune systems. While the nervous system plays a crucial role in tissue regeneration, current tissue engineering approaches mainly focus on restoring the function of injury-related cells, neglecting the guidance provided by nerves. This has led to unsatisfactory therapeutic outcomes. Herein, we propose a new generation of engineered neural constructs from the perspective of neural induction, which offers a versatile platform for promoting multiple tissue regeneration. Specifically, neural constructs consist of inorganic biomaterials and neural stem cells(NSCs), where the inorganic biomaterials endows NSCs with enhanced biological activities including proliferation and neural differentiation. Through animal experiments, we show the effectiveness of neural constructs in repairing central nervous system injuries with function recovery. More importantly, neural constructs also stimulate osteogenesis, angiogenesis and neuromuscular junction formation, thus promoting the regeneration of bone and skeletal muscle, exhibiting its versatile therapeutic performance. These findings suggest that the inorganic-biomaterial/NSC-based neural platform represents a promising avenue for inducing the regeneration and function recovery of varying tissues and organs.

关键词： 3D bioprinting neural stem cells inorganic biomaterials neural constructs multiple tissue regeneration

Interfacial charge redistribution to promote the catalytic activity of Vs-CoP-CoS_(2)/C n-n heterojunction for oxygen evolution

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Chinese Chemical Letters 2024年第2期35卷 611-616页

作者： Jiawen Sun Hui xue Jing Sun Niankun Guo Tianshan Song Yi-Ru Hao qin Wang College of Chemistry and Chemical Engineering Inner Mongolia UniversityHohhot 010021China

Modulating surface charge redistribution based on interface and defect engineering has been considered as a resultful means to boost electrocatalytic activity.However,the mechanism of synergistic regulation of heterojunction and vacancy defects remains unclear.Herein,a Vs-CoP-CoS_(2)/C n-n heterojunction with sulfur vacancies is successfully constructed,which manifests superior electrocatalytic activity for oxygen evolution,as demonstrated by a low overpotential of 170 mV to reach 10 mA/cm^(2).The experimental results and density functional theory calculations testify that the outstanding OER performance of Vs-CoP-CoS_(2)/C heterojunction is owed to the synergistic effect of sulfur vacancies and built-in electric field at n-n heterogeneous interface,which accelerates the electron transfer,induces the charge redistribution,and regulates the adsorption energy of active intermediates during the reaction.This study affords a promising means to regulate the electrocatalytic performance by the construction of heterogeneous interfaces and defects,and in-depth explores the synergistic mechanisms of n-n heterojunction and vacancies.

关键词： Charge redistribution n-n Heterojunction Built-in electric field Sulfur vacancy Oxygen evolution reaction

An AIEgen nano-assembly for simultaneous detection of ATP and H_(2)S

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Chinese Chemical Letters 2024年第6期35卷 376-379页

作者： Jia-Mei qin xue Li Wei Lang Fu-Hao Zhang Qian-Yong Cao School of Chemistry and Chemical Engineering Nanchang UniversityNanchang 330031China

A new aggregation-induced emission(AIE)-based fluorescence sensor,TPEPy-SS-C14,for simultaneous recognition of adenosine triphosphate(ATP)and hydrogen sulfide(H_(2)S)has been reported via the aggregation-disaggregation mechanism.The probe self-assembles nano-structure aggregations in aqueous solution.It shows fluorescence turn-on response toward ATP for the complexation-enhanced aggregation,but leads to fluorescence quenching of H_(2)S for cleavage the aggregations.

关键词： AIE-based ATP detection H_(2)S detection Fluorescent sensor Cell imaging

Full waveform inversion based on hybrid gradient

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Petroleum Science 2024年第3期21卷 1660-1670页

作者： Chuang Xie Zhi-Liang qin Jian-Hua Wang Peng Song Heng-Guang Shen Sheng-Qi Yu Ben-Jun Ma xue-qin Liu qingdao Innovation and Development Base Harbin Engineering University qingdao Innovation and Development Center Harbin Engineering University CNOOC Research Institute Co. Ltd. College of Marine Geoscience Ocean University of China Weihai Sunfull Geophysical Exploration Equipment Co. Ltd.

The low-wavenumber components in the gradient of full waveform inversion(FWI) play a vital role in the stability of the inversion. However, when FWI is implemented in some high frequencies and current models are not far away from the real velocity model, an excessive number of low-wavenumber components in the gradient will also reduce the convergence rate and inversion accuracy. To solve this problem, this paper firstly derives a formula of scattering angle weighted gradient in FWI, then proposes a hybrid gradient. The hybrid gradient combines the conventional gradient of FWI with the scattering angle weighted gradient in each inversion frequency band based on an empirical formula derived herein.Using weighted hybrid mode, we can retain some low-wavenumber components in the initial lowfrequency inversion to ensure the stability of the inversion, and use more high-wavenumber components in the high-frequency inversion to improve the convergence rate. The results of synthetic data experiment demonstrate that compared to the conventional FWI, the FWI based on the proposed hybrid gradient can effectively reduce the low-wavenumber components in the gradient under the premise of ensuring inversion stability. It also greatly enhances the convergence rate and inversion accuracy,especially in the deep part of the model. And the field marine seismic data experiment also illustrates that the FWI based on hybrid gradient(HGFWI) has good stability and adaptability.

关键词： Full waveform inversion Hybrid gradient Scattering angle weighted Low-wavenumber component