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Journal of Ocean University of China 2024年第3期23卷 583-593页

作者： GONG Yijie XIE Botao FU Dianfu WANG Zhifeng pang Liang College of Engineering Ocean University of ChinaQingdao 266100China CNOOC Research Institute Ltd. Beijing 100028China

The generation and propagation mechanism of strong nonlinear waves in the South China Sea is an essential research area. In this study, the third-generation wave model WAVEWATCH Ⅲ is employed to simulate wave fields under extreme sea states. The model, integrating the ST6 source term, is validated against observed data, demonstrating its credibility. The spatial distribution of the occurrence probability of strong nonlinear waves during typhoons is shown, and the waves in the straits and the northeastern part of the South China Sea show strong nonlinear characteristics. The high-order spectral model HOS-ocean is employed to simulate the random wave surface series beneath five different platform areas. The waves during the typhoon exhibit strong nonlinear characteristics, and freak waves exist. The space-varying probability model is established to describe the short-term probability distribution of nonlinear wave series. The exceedance probability distributions of the wave surface beneath different platform areas are compared and analyzed. The results show that with an increase in the platform area, the probability of a strong nonlinear wave beneath the platform increases.

关键词： strong nonlinear wave typhoon wave series probability distribution model exceedance probability

An improved construction algorithm of polar codes based on the frozen bits

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Optoelectronics Letters 2024年第3期20卷 157-162页

作者： YUAN Jianguo ZHANG Fengguo YU Linfeng pang Yu School of Optoelectronic Engineering Chongqing University of Posts and TelecommunicationsChongqing 400065China

In order to improve the problems that the minimum hamming weight(MHW) of the polar codes of the traditional Gaussian approximation(GA) construction is small and its performance is not good enough, an improved channel construction algorithm of polar codes based on frozen bits is proposed by combining the construction of the Reed-Muller(RM) code to effectively increase the MHW and analyzing the correcting and checking functions of the frozen bits in the successive cancellation list(SCL) decoding.

关键词： polar algorithm successive

Spatial and Temporal Differences of Climate Suitability of Ice and Snow Sports in Major Ski Tourism Destinations in China

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Chinese Geographical Science 2024年第5期34卷 967-982页

作者： XIE Xia pang Zhengjin ZHU Haiqiang GAO Jun ZHOU Qiaoya Key Laboratory of the Sustainable Development of Xinjiang’s Historical and Cultural Tourism Xinjiang UniversityUrumqi 830046China College of Tourism Xinjiang UniversityUrumqi 830046China School of Tourism Management Sun Yat-sen UniversityZhuhai 519000China

Ice and snow tourism in China has grown significantly since the country successfully hosted the Beijing Winter *** conditions profoundly impact the development of ice and snow tourism;however,most studies have focused on constructing different climate suitability indicators for ice and snow tourism to evaluate individual regions,lacking horizontal comparative studies across multiple *** study aims to enrich the connotation of climate suitability for ice and snow sports,establish an evaluation model based on snowfall amount,temperature,and wind speed,and use daily meteorological data from 1991 to 2021 to horizontally compare the climate suitability for ice and snow sports in major ski tourism destinations in *** study boasts four major findings:1)the average ice and snow sports climate index of each region decreases over time,and the overall suitability of the climate for ice and snow sports is reducing;2)northern Xinjiang exhibits the most evident regional differentiation from‘very suitable’to‘generally suitable’;3)the spatial zoning of climate suitability for ice and snow sports exhibits heterogeneity,as northern Xinjiang is divided into two‘suitable and above’zones with rotating empirical orthogonal function(REOF).Correspondingly,the four provinces of Hebei,Heilongjiang,Jilin,and Liaoning are divided into three‘generally suitable and above’zones;4)snowfall amount is the main factor affecting the climate suitability of ice and snow sports in the major ski tourist destinations in China.

关键词： ice and snow tourism climate suitability rotating empirical orthogonal function(REOF) spatial division China

High-entropy materials:Excellent energy-storage and conversion materials in the field of electrochemistry

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Particuology 2024年第9期92卷 42-60页

作者： Jincan Li Huiyu Duan Qi Long Bianjiang Zhang Changyun Chen Huan pang Key Laboratory of Advanced Functional Materials of Nanjing School of Environmental ScienceNanjing Xiaozhuang UniversityNanjing211171China School of Chemical Engineering Institute for Innovative Materials and EnergyYangzhou UniversityYangzhou225009China

High-entropy materials(HEMs),a new type of materials,have attracted significant attention in the field of electrocatalytic reactions,batteries and energy-storage materials over the past few years owing to their unique structure,controllable elementary composition,and adjustable *** excellent characteristics result from four major factors:high entropy,sluggish-diffusion,severe lattice distortion,and cocktail effect,and are used widely in energy-energy *** review aims to summarize the recent progress of HEMs in electrochemical *** begin with the concept,structure,and four core effects of HEMs that provide the basic information on ***,we discuss the major properties of HEMs and analyze the relationship between their structures and ***,we highlight the outstanding performance of HEMs in hydrogen storage,electrode materials of batteries,catalysis,and supercapacitors,and briefly explain the mechanisms of these materials that are crucial in energy storage and *** review will assist in understanding the excellent energy-storage properties,intricacies of the phase structures,elemental interactions,and reaction mechanisms associated with ***,challenges and future development prospects are *** work will provide insight into the factors that are crucial for designing HEMs with energy storage properties.

关键词： High-entropy materials Hydrogen storage Electrode materials of batteries Catalyst Supercapacitor

Enhanced electric-field induced strain in Eu^(3+) doped 0.67BiFeO_(3)-0.33BaTiO_(3) lead-free piezoelectric ceramics

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Journal of Rare Earths 2024年第9期42卷 1747-1754,I0004页

作者： Wei Li Tongxiang Liang Xiang He Vyunov Oleg Dongfang pang Shan Wu College of Rare Earths Jiangxi University of Science and TechnologyGanzhou341000China Key Laboratory of High Performance Ceramics and Ultrastructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghai201800China

Lead-free ferroelectric ceramics,0.67Bi_(1-x)Eu_(x)FeO_(3)-0.33BaTiO_(3)(BF-BT-xEu,x=0-0.02),were prepared via a solid-state reaction,The effect of Eu^(3+) doping on the microstructure,dielectric properties,ferroelectric properties,and electric-field-induced strain was *** X-ray diffraction(XRD) results indicate the presence of a mixed phase of tetragonal and rhombohedral at the morphotropic phase boundary(MPB).Doping with an appropriate amount of Eu^(3+) reduces the Fe^(3+) content and decreases the leakage current in the binary system.A converse piezoelectric coefficient(d_(33)*) of 392 pm/V is obtained at BF-BT-0.003Eu under an electric field of 60 kV/cm at room temperature,which has a Curie temperature(T_(C)) of 414℃,The unipolar strain and d_(33)* of BF-BT-0.003Eu ceramics increase to 0.438%and 730 pm/V at 125℃ The field-induced strain response of the BF-BT-0.003Eu ceramics is greater than that of 0.67BF-0.33BT,mainly due to its optimal grain size,reduction of leakage current,and coexistence of ferroelectric-relaxation phases,BF-BT-0.003Eu ceramic is a lead-free candidate for high-temperature actuator applications.

关键词： Ferroelectric Field-induced strain Ceramics Lead-free Rare earths

The mechanisms of thermal solidification agent promoting steam diversion in heavy oil reservoirs

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Petroleum Science 2024年第3期21卷 1902-1914页

作者： Zhan-Xi pang Qian-Hui Wang Qiang Meng Bo Wang Dong Liu State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing102249China Liaohe Oilfield Institute CNPC ChinaPanjin124000LiaoningChina Henan Oilfield Institute Sinopec ChinaNanyang473400HenanChina Tianjin Branch of China National Offshore Oil Company(CNOOC)Ltd. Tianjin300452China

At high cycles of steam huff&puff,oil distribution in reservoirs becomes stronger heterogeneity due to steam *** solidification agent can be used to solve this *** solution is a lowviscosity liquid at normal temperature,but it can be solidified above 80℃.The plugging degree is up to 99%at 250℃.The sweep efficiency reaches 59.2%,which is 7.3%higher than pure steam *** addition,simultaneous injection of viscosity reducer and/or nitrogen foams can further enhance oil *** mechanism of this technology depends on its strong plugging ability,which changes the flowing pattern of steam to effectively mobilize remaining *** reducer and nitrogen foams further expand the sweep range and extends the effective ***,thermal solidification agent can plug steam channeling paths and adjust steam flowing direction to significantly enhance oil recovery at high cycles of steam huff&puff.

关键词： Heavy oil reservoir Steam huff&puff Steam channeling Steam diversion Plugging performance Mechanism analysis

Recent progress on Sn_(3)O_(4)nanomaterials for photocatalytic applications

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International Journal of Minerals,Metallurgy and Materials 2024年第2期31卷 231-244页

作者： Xin Yu Congcong Li Jian Zhang Lili Zhao Jinbo pang Longhua Ding Institute for Advanced Interdisciplinary Research(iAIR) School of Chemistry and Chemical EngineeringUniversity of JinanJinan 250022China School of Sino-German Engineering Shanghai Technical Institute of Electronics and InformationShanghai 201411China Division of Systems and Synthetic Biology Department of Life SciencesChalmers University of Technology41296 GöteborgSweden

Tin(IV)oxide(Sn_(3)O_(4))is layered tin and exhibits mixed valence *** has emerged as a highly promising visible-light pho-tocatalyst,attracting considerable *** comprehensive review is aimed at providing a detailed overview of the latest advance-ments in research,applications,advantages,and challenges associated with Sn_(3)O_(4)photocatalytic *** fundamental con-cepts and principles of Sn_(3)O_(4)are ***_(3)O_(4)possesses a unique crystal structure and optoelectronic properties that allow it to ab-sorb visible light efficiently and generate photoexcited charge carriers that drive photocatalytic ***,strategies for the control and improved performance of Sn_(3)O_(4)photocatalytic nanomaterials are *** control,ion doping,and hetero-structure construction are widely employed in the optimization of the photocatalytic performance of Sn_(3)O_(4)*** effective imple-mentation of these strategies improves the photocatalytic activity and stability of Sn_(3)O_(4)***,the review explores the diverse applications of Sn_(3)O_(4)photocatalytic nanomaterials in various fields,such as photocatalytic degradation,photocatalytic hydro-gen production,photocatalytic reduction of carbon dioxide,solar cells,photocatalytic sterilization,and optoelectronic *** discus-sion focuses on the potential of Sn_(3)O_(4)-based nanomaterials in these applications,highlighting their unique attributes and ***,the review provides an outlook on the future development directions in the field and offers guidance for the exploration and de-velopment of novel and efficient Sn_(3)O_(4)-based *** the identification of emerging research areas and potential avenues for improvement,this review aims to stimulate further advancements in Sn_(3)O_(4)-based photocatalysis and facilitate the translation of this promising technology into practical applications.

关键词： photocatalysis Sn_(3)O_(4)nanomaterials building heterostructures antibacterial therapy water splitting

Parametric study on contact sensors for MASW measurement-based interfacial debonding detection for SCCS

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Earthquake Engineering and Engineering Vibration 2024年第2期23卷 331-344页

作者： Chen Hongbing pang Xin Gan Shiyu Li Yuanyuan Gokarna Chalise Nie Xin Research Institute of Urbanization and Urban Safety School of Civil and Resource EngineeringUniversity of Science and Technology BeijingBeijing 100083China Department of Civil Engineering Tsinghua UniversityBeijing 100084China Faculty of Infrastructure Engineering Dalian University of TechnologyDalian 116081China

Steel-concrete composite structures(SCCS)have been widely used as primary load-bearing components in large-scale civil *** the basis of the co-working ability of steel plate and concrete,the bonding status plays an essential role in guaranteeing the structural performance of ***,efficient non-destructive testing(NDT)on interfacial debondings in SCCS has become a prominent research ***-channel analysis of surface waves(MASW)has been validated as an effective NDT technique for interfacial debonding detection for ***,the feasibility of MASW must be validated using experimental *** study establishes a high-frequency data synchronous acquisition system with 32 channels to perform comparative verification experiments in ***,the current sensing approaches for high-frequency vibration and stress waves are ***,three types of contact sensors,namely,piezoelectric lead-zirconate-titanate(PZT)patches,accelerometers,and ultrasonic transducers,are selected for MASW ***,the selection and optimization of the force hammer head are *** experiments are carried out for the optimal selection of ultrasonic transducers,PZT patches,and accelerometers for MASW *** addition,the influence of different pasting methods on the output signal of the sensor array is *** results indicate that optimized PZT patches,acceleration sensors,and ultrasonic transducers can provide efficient data acquisition for MASW-based non-destructive *** research findings in this study lay a solid foundation for analyzing the recognition accuracy of contact MASW measurement using different sensor arrays.

关键词： steel-concrete composite structures(SCCS) interface debonding detection multi-channel analysis of surface waves(MASW) sensor selection comparative experimental study

Turbo-shaft engine adaptive neural network control based on nonlinear state space equation

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Chinese Journal of Aeronautics 2024年第4期37卷 493-507页

作者： Ziyu GU Qiuhong LI Shuwei pang Wenxiang ZHOU Jichang WU Chenyang ZHANG Jiangsu Province Key Laboratory of Aerospace Power System Nanjing University of Aeronautics and AstronauticsNanjing 210016China AECC Hunan Aviation Powerplant Research Institute Zhuzhou 412002China

Intelligent Adaptive Control(AC) has remarkable advantages in the control system design of aero-engine which has strong nonlinearity and uncertainty. Inspired by the Nonlinear Autoregressive Moving Average(NARMA)-L2 adaptive control, a novel Nonlinear State Space Equation(NSSE) based Adaptive neural network Control(NSSE-AC) method is proposed for the turbo-shaft engine control system design. The proposed NSSE model is derived from a special neural network with an extra layer, and the rotor speed of the gas turbine is taken as the main state variable which makes the NSSE model be able to capture the system dynamic better than the NARMA-L2 model. A hybrid Recursive Least-Square and Levenberg-Marquardt(RLS-LM) algorithm is advanced to perform the online learning of the neural network, which further enhances both the accuracy of the NSSE model and the performance of the adaptive controller. The feedback correction is also utilized in the NSSE-AC system to eliminate the steady-state tracking error. Simulation results show that, compared with the NARMA-L2 model, the NSSE model of the turboshaft engine is more accurate. The maximum modeling error is decreased from 5.92% to 0.97%when the LM algorithm is introduced to optimize the neural network parameters. The NSSE-AC method can not only achieve a better main control loop performance than the traditional controller but also limit all the constraint parameters efficiently with quick and accurate switching responses even if component degradation exists. Thus, the effectiveness of the NSSE-AC method is validated.

关键词： Adaptive control systems Turbo-shaft engine Neural network Nonlinear state space equation NARMA-L2

TBAB hydrate formation and growth in a microdevice under static and dynamic conditions

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Petroleum Science 2024年第2期21卷 1396-1404页

作者： Xingxun Li Ming Liu Qingping Li Weixin pang Guangjin Chen Changyu Sun State Key Laboratory of Heavy Oil Processing China University of Petroleum BeijingBeijing102249China State Key Laboratory of Natural Gas Hydrate CNOOC Research Institute Co.Ltd.Beijing100027China

The natural gas hydrate has become one of the most promising future green energy sources on the *** natural gas hydrates mostly exist in the sediments with porous structure, so a solid understanding of the hydrate formation and growth processes in the porous medium is of significance for the exploitation of natural gas hydrate. The micro-packed bed device is one of the efficient microfluidic devices in the engineering field, but it has been rarely used for the hydrate-based research. In this study, a transparent micro-packed bed device filled with glass beads was developed to mimic the porous condition of sediments, and used to in-situ visualize the hydrate formation and growth habits in the pore spaces under both static and dynamic conditions. For the static experiment, two types of hydrate growth patterns in porous medium were observed and identified in the micro-packed bed device, which were the graincoating growth and pore-filling growth. For the dynamic condition, the hydrate formation, growth,distribution habits and hydrate blockage phenomena in the pore spaces were in-situ visually *** impacts of flowrate and subcooling on the pressure variation of the micro-packed bed and the duration of the hydrate growth under dynamic flow condition in pores were in-situ monitored and analyzed. The higher flowrate could result in the faster hydrate growth and more severe blockage in pores, but the effect of subcooling condition might be less significant at the high flowrate.

关键词： Hydrate formation Hydrate growth Microdevice In-situ measurement