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Numerical study of submerged bending vegetation under unidirectional flow

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Water Science and Engineering 2024年第1期17卷 92-100页

作者： pei-pei Zhang Yi-qing Gong Ken Vui Chua Jie Dai Jing-qiao Mao College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing 210098China Institute of Water Science and Technology Hohai UniversityNanjing 210098China School of Engineering Cardiff UniversityCardiff CF243AAUK

Submerged vegetation commonly grows and plays a vital role in aquatic ecosystems,but it is also regarded as a barrier to the passing flow.Numerical simulations of flow through and over submerged vegetation were carried out to investigate the effect of vegetation density on flow field.Numerical simulations were computationally set up to replicate flume experiments,in which vegetation was mimicked with flexible plastic strips.The fluid-structure interaction between flow and flexible vegetation was solved by coupling the two modules of the COMSOL packages.Two cases with different vegetation densities were simulated,and the results were successfully validated against the experimental data.The contours of the simulated time-averaged streamwise velocity and Reynolds stress were extracted to highlight the differences in mean and turbulent flow statistics.The turbulence intensity was found to be more sensitive to vegetation density than the time-averaged velocity.The developing length increased with the spacing between plants.The snapshots of the bending vegetation under instantaneous velocity and vorticity revealed that flexible vegetation responded to the effects of eddies in the shear layer by swaying periodically.The first two rows of vegetation suffered stronger approaching flow and were prone to more streamlined postures.In addition,the origin of tip vortices was investigated via the distribution of vorticity.The results reveal the variation of flow properties with bending submerged vegetation and provide useful reference for optimizationofrestorationprojects.

关键词： Computational fluid dynamics Fluid-structure interaction Turbulence Flexible and submerged vegetation

Emerging mechanisms of ferroptosis and its implications in lung cancer

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中华医学杂志(英文版) 2024年第7期137卷 818-829页

作者： Li Qian Song Qibin pei Huadong Chen Yali USA State Key Laboratory of Medical Proteomics National Center for Protein Sciences (Beijing) Beijing Institute of Lifeomics Beijing 102206 Cancer Center Renmin Hospital of Wuhan University Wuhan Hubei 430060 China Department of Oncology Georgetown Lombardi Comprehensive Cancer Center Georgetown University Medical Center Washington D.C. 20057

Lung cancer is one of the most common malignancies and has the highest number of deaths among all cancers. Despite continuous advances in medical strategies, the overall survival of lung cancer patients is still low, probably due to disease progression or drug resistance. Ferroptosis is an iron-dependent form of regulated cell death triggered by the lethal accumulation of lipid peroxides, and its dysregulation is implicated in cancer development. Preclinical evidence has shown that targeting the ferroptosis pathway could be a potential strategy for improving lung cancer treatment outcomes. In this review, we summarize the underlying mechanisms and regulatory networks of ferroptosis in lung cancer and highlight ferroptosis-targeting preclinical attempts to provide new insights for lung cancer treatment.

关键词： Lung cancer Ferroptosis Ferroptosis regulators Ferroptosis inducers Cancer treatment

Iron-Catalyzed Reductive C(aryl)—Si Cross-Coupling of Diaryl Ethers with Chlorosilanes

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Chinese Journal of Chemistry 2024年第6期42卷 578-584页

作者： pei Liu Baowei Wu Xuefeng Cong Jie Kong School of Chemistry and Chemical Engineering Northwestern Polytechnical UniversityXi'anShaanxi710072 China Institute of Molecular Plus Department of Chemistry and Haihe Laboratory of Sustainable Chemical TransformationsTianjin University92 Weijin RoadTianjin300072 China

The reductive cross-coupling between C(aryl)—O and Si—Cl bonds is of much importance as a valuable strategy for the construction of C(aryl)—Si bonds but has remained a great challenge.Herein,we report a reductive cross-coupling of diaryl ethers and chlorosilanes via strong electrophilic C(aryl)—O and Si—Cl bonds cleavage by iron catalysis,which constitutes an efficient protocol for the synthesis of a range of functionalized arylsilanes.The combination of low cost FeCl2 as the precatalyst and iPrMgCl as the reductant shows high activity in the successive cleavage of unactivated C(aryl)—O bonds of diaryl ethers and strong electrophilic Si—Cl bonds of chlorosilanes,allowing their cross-coupling in a reductive fashion.The low-valent iron species generated in situ by reduction of FeCl2 with iPrMgCl was proposed,which prefers to initially cleavage the C(aryl)—O bond of diaryl ethers with the chelation help of an o-amide auxiliary.

关键词： Cross-coupling Diaryl ethers Chlorosilanes C—O bond cleavage Iron catalyst 3d transition metals Selectivity Regioselectivity

Design of efficient thermoelectric generators

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Science China Materials 2024年第1期67卷 377-378页

作者： Min Liu Yanzhong pei Interdisciplinary Materials Research Center School of Materials Science and EngineeringTongji UniversityShanghai 201804China

Thermoelectricity,which enables direct conversion between heat and electricity,undergoes impressive developments in recent decades,and is particularly promising for recovering low-grade heat of<600 K[1,2].Currently,only Bi2Te3-based thermoelectric devices are commercialized[3].However,the scarcity of tellurium(Te)(Fig.1a)is the main concern.This leads to numerous recent efforts on the development of efficient nonBi2Te3 thermoelectrics as potential alternatives,and successful examples(Fig.1b)include Mg3Sb2-alloys[2,3]and MgAgSb[1,2].

关键词： enable efficient electricity

A passive sampler for synchronously measuring inorganic and organic pollutants in sediment porewater:Configuration and field application

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Journal of Environmental Sciences 2024年第2期136卷 201-212页

作者： pei Lei Mingying Chen Nan Rong Wenzhong Tang Hong Zhang School of Environment Nanjing Normal UniversityNanjing 210023China State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China South China Institute of Environmental Sciences Ministry of Ecology and EnvironmentGuangzhou 510530China State Environmental Protection Key Laboratory of Water Environmental Simulation and Pollution Control Guangzhou 510530China University of Chinese Academy of Sciences Beijing 100049China

In situ measurement of multiple pollutants coexisting in sediment porewater is an essential step in comprehensively assessing the bioavailability and risk of pollutants,but to date,this needs to be better developed.In this study,a passive sampler,consisting of an“I-shaped”supporting frame and inorganic/organic sampling units,incorporating equilibrium dialysis theory and kinetic/equilibrium sorption principle,was developed for the synchronous measurement of inorganic(e.g.,phosphorus and metal(loid)s)and organic pollutants(e.g.,parent and substituted PAHs).The equilibrium time and sampling rates were explored in laboratory tests to support in situ application.Profiles of pollutants in porewater within a vertical resolution of centimeters,i.e.,1 cm and 2 cm for inorganic and organic pollutants,respectively,were obtained by field deployment of the sampler for further estimation of diffusive fluxes across the sediment-water interface.The results suggested that the role of sediments for a specific pollutant may change(e.g.,from“sink”to“source”)during the sampling time.This study demonstrated the feasibility of synchronous measurement of inorganic and organic pollutants in sediment porewater by the passive sampler.In addition,it provided new insight for further investigation into the combined pollution effects of various pollutants in sediments.

关键词： Passive sampling Bioavailability Polycyclic aromatic hydrocarbons Combined pollution Diffusive flux

Study on 6-DOF active vibration-isolation system of the ultra-precision turning lathe based on GA-BP-PID control for dynamic loads

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Advances in Manufacturing 2024年第1期12卷 33-60页

作者： Bo Wang Zhong Jiang pei-Da Hu Department of Precision Instrument Tsinghua UniversityBeijing100084People’s Republic of China Institute of Machinery Manufacturing Technology China Academy of Engineering PhysicsMianyang621900SichuanPeople’s Republic of China

The vibration disturbance from an external environment affects the machining accuracy of ultra-precision machining equipment.Most active vibration-isolation systems(AVIS)have been developed based on static loads.When a vibration-isolation load changes dynamically during ultra-precision turning lathe machining,the system parameters change,and the efficiency of the active vibration-isolation system based on the traditional control strategy deteriorates.To solve this problem,this paper proposes a vibration-isolation control strategy based on a genetic algorithm-back propagation neural network-PID control(GA-BP-PID),which can automatically adjust the control parameters according to the machining conditions.Vibration-isolation simulations and experiments based on passive vibration isolation,a PID algorithm,and the GA-BP-PID algorithm under dynamic load machining conditions were conducted.The experimental results demonstrated that the active vibration-isolation control strategy designed in this study could effectively attenuate vibration disturbances in the external environment under dynamic load conditions.This design is reasonable and feasible.

关键词： Ultra-precision diamond turning lathe Active vibration isolation Six degrees of freedom Dynamic load Genetic algorithm-back propagation neural network-PID(GA-BP-PID)control

Generalized load graphical forecasting method based on modal decomposition

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Global Energy Interconnection 2024年第2期7卷 166-178页

作者： Lizhen Wu peixin Chang Wei Chen Tingting pei College of Electrical and Information Engineering Lanzhou University of TechnologyLanzhou 730050P.R.China School of Electrical Data Engineering University of Technology SydneyNSW2007Australia

In a“low-carbon”context,the power load is affected by the coupling of multiple factors,which gradually evolves from the traditional“pure load”to the generalized load with the dual characteristics of“load+power supply.”Traditional time-series forecasting methods are no longer suitable owing to the complexity and uncertainty associated with generalized loads.From the perspective of image processing,this study proposes a graphical short-term prediction method for generalized loads based on modal decomposition.First,the datasets are normalized and feature-filtered by comparing the results of Xtreme gradient boosting,gradient boosted decision tree,and random forest algorithms.Subsequently,the generalized load data are decomposed into three sets of modalities by modal decomposition,and red,green,and blue(RGB)images are generated using them as the pixel values of the R,G,and B channels.The generated images are diversified,and an optimized DenseNet neural network was used for training and prediction.Finally,the base load,wind power,and photovoltaic power generation data are selected,and the characteristic curves of the generalized load scenarios under different permeabilities of wind power and photovoltaic power generation are obtained using the density-based spatial clustering of applications with noise algorithm.Based on the proposed graphical forecasting method,the feasibility of the generalized load graphical forecasting method is verified by comparing it with the traditional time-series forecasting method.

关键词： Load forecasting Generalized load Image processing DenseNet Modal decomposition

Fantastic voyage: The journey of NLRP3 inflammasome activation

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Genes & Diseases 2024年第2期11卷 819-829页

作者： Xiangyong Que Sihao Zheng Qibin Song Huadong pei Pingfeng Zhang Cancer Center Renmin Hospital of Wuhan UniversityWuhanHubei 430060China Department of Oncology Georgetown Lombardi Comprehensive Cancer CenterGeorgetown University Medical CenterWashingtonDC 20057USA

NLRP3 inflammasome,an intracellular multiprotein complex,can be activated by a range of pathogenic microbes or endogenous hazardous chemicals.Its activation results in the release of cytokines such as IL-1β and IL-18,as well as Gasdermin D which eventually causes pyroptosis.The activation of NLRP3 inflammasome is under strict control and regulation by numerous pathways and mechanisms.Its excessive activation can lead to a persistent inflammatory response,which is linked to the onset and progression of severe illnesses.Recent studies have revealed that the subcellular localization of NLRP3 changes significantly during the activation process.In this review,we review the current understanding of the molecular mechanism of NLRP3 inflammasome activation,focusing on the subcellular localization of NLRP3 and the associated regulatory mechanisms.We aim to provide a comprehensive understanding of the dynamic transportation,activation,and degradation processes of NLRP3.

关键词： Inflammasome activation Innate immunity NLRP3 NLRP3 inflammasome Subcellular localization

Terminal attitude selection method of missile attack aircraft

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Chinese Journal of Aeronautics 2024年第2期37卷 385-400页

作者： Peng HOU Yang pei Yuxue GE Mengjie ZHU School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China Research Department Shanghai Electro-Mechanical Engineering InstituteShanghai 201108China

The appropriate terminal attitude of missile is important to improve the damage effectiveness of fragmentation warhead against aircraft targets.In this paper,three missile terminal attitude selection methods are proposed to solve the problem of terminal attitude selection in different situations according to their respective evaluation indexes.The MVE-based method uses the damage probability of each detonation point around the aircraft at a given attitude of missile to calculate the Mean Volume of Effectiveness(MVE)at the corresponding attitude,and then uses the MVE for different attitudes to select the terminal strike attitude.The detonation position-based method addresses the case where the missile detonation position can be assessed in advance.Given the effects of missile guidance errors and fuze activation position errors,Monte Carlo simulations are used to calculate the damage probability of aircraft with different strike attitudes,from which the terminal strike attitude is selected.The BP-ANN model-based method uses the constructed Back Propagation Artificial Neural Network(BP-ANN)model instead of simulation to calculate the evaluation indexes in the corresponding cases of MVE-based method and Detonation position-based method,which can improve the efficiency of attitude selection.Simulations are conducted for different scenarios to verify the feasibility and effectiveness of the proposed method.

关键词： Aircraft vulnerability Attitude selection BP-ANN Damage probability Damage effectiveness