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Understanding Urban Vitality from the Economic and Human Activities Perspective:A Case Study of Chongqing,China

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Chinese Geographical Science 2024年第1期34卷 52-66页

作者： YANG Fiona Fan LIN Geng LEI Yubing WANG Ying YI Zheng School of Geography and Planning Sun Yat-sen UniversityGuangzhou510006China Southern Marine Science and engineering Guangdong Laboratory(Zhuhai) Zhuhai519100China Chongqing Planning and design institute Chongqing401147China

The literature on urban vitality tends to focus on the built *** paper argues that some important processes in shaping vitality may be overlooked without examining the intensity and diversity of economic and human *** newly developed spatial big data and adopting the methods of multi-indicator measurement and spatial analysis methods,we analyzed the pattern of urban vitality in Chongqing,a provincial city in western China and,on this basis,evaluated the creation and maintenance of urban vitality from the economic and human activities *** findings indicate that the impacts of economic and human activities are positive and *** the three intensity and diversity indicators,economic intensity and population density show an effect on urban vitality stronger than that of economic ***,economic diversity has the strongest superposition or interactive effect,and is thus an important foundation *** positive effect of population density on urban vitality is largely a result of Chongqing’s jobs-housing *** case of Chongqing highlights the importance of topographic features,historical inheritance,large-scale migration,and cultural activities in shaping the distinctive vitality pattern of a *** study contends that the creation and maintenance of urban vitality can not be fully explained without incorporating the impacts of economic and human *** contributes to a comprehensive measurement of urban vitality and enriches its connotations.

关键词： urban vitality economic diversity economic intensity population density Chongqing,China

Particles attrition of binary mixtures in the coal-fueled chemical looping system based on fluidized bed

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Particuology 2024年第3期86卷 281-290页

作者： Heyu Li Zhe Sun Yan Cao guangzhou institute of Energy Conversion Chinese Academy of SciencesGuangzhou 510640China University of Chinese Academy of Sciences Bejing 100049China CAS Key Laboratory of Renewable Energy Guangzhou 510640China Guangdong Provincial Key Laboratory of New and Renewable Energy research and Development Guangzhou 510640China College of Chemistry and Chemical engineering Anhui UniversityHefei230601China

In this work,a reactive air jet attrition device with auto-recording and collection of elutriated fines was *** established insights into the physiochemical interaction and further correlated attrition behaviors between char and oxygen carriers under various operation *** attrition rate increased by over 110% upon the introduced CO_(2),which brought in the significant effect of thermo-chemical stress,similarly in effects of the increased char addition ratio and the decreased sizes of char or hematite in different *** the char-hematite co-attrition process,the elutriated carbon loss of char with poor mechanical strength was found to be over 10%,while the reactive iron loss of hematite was found to be 6.3%,and was enriched in elutriated *** reaction-derived thermochemical stress and the collision-derived mechanical stress jointly controls the particle attrition during the cyclic transformation of oxygen carrier particles in coal-fueled chemical looping fluidization,especially sig-nificant in its reduction stage.

关键词： Attrition Binary species Chemical looping Oxygen carrier CO_(2)capture

Can urban forests provide acoustic refuges for birds?Investigating the influence of vegetation structure and anthropogenic noise on bird sound diversity

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Journal of Forestry research 2024年第2期35卷 163-175页

作者： Zezhou Hao Chengyun Zhang Le Li Bing Sun Shuixing Luo Juyang Liao Qingfei Wang Ruichen Wu Xinhui Xu Christopher A.Lepczyk Nancai Pei research institute of Tropical Forestry Chinese Academy of ForestryGuangzhou 510520People’s Republic of China School of Electronics and Communication engineering Guangzhou UniversityGuangzhou 510006People’s Republic of China Hunan Botanical Barden Changsha 410116People’s Republic of China Guangdong Eco-engineering Polytechnic Guangzhou 510520People’s Republic of China College of Forestry Wildlife and EnvironmentAuburn UniversityAuburnAL 36849USA

As a crucial component of terrestrial ecosystems,urban forests play a pivotal role in protecting urban biodiversity by providing suitable habitats for acoustic *** studies note that vegetation structure is a key factor influencing bird sounds in urban forests;hence,adjusting the frequency composition may be a strategy for birds to avoid anthropogenic noise to mask their ***,it is unknown whether the response mechanisms of bird vocalizations to vegetation structure remain consistent despite being impacted by anthropogenic *** was hypothesized that anthropogenic noise in urban forests occupies the low-frequency space of bird songs,leading to a possible reshaping of the acoustic niches of forests,and the vegetation structure of urban forests is the critical factor that shapes the acoustic space for bird *** acoustic monitoring in various urban forests was used to monitor natural and anthropogenic noises,and sounds were classified into three acoustic scenes(bird sounds,human sounds,and bird-human sounds)to determine interconnections between bird sounds,anthropogenic noise,and vegetation *** noise altered the acoustic niche of urban forests by intruding into the low-frequency space used by birds,and vegetation structures related to volume(trunk volume and branch volume)and density(number of branches and leaf area index)significantly impact the diversity of bird *** findings indicate that the response to low and high frequency signals to vegetation structure is *** clarifying this relationship,our results contribute to understanding of how vegetation structure influences bird sounds in urban forests impacted by anthropogenic noise.

关键词： Anthropogenic noise Bird sounds Urban forests Vegetation structure

Vibration response and safety control for blasting vibration of the existing tunnel with defects

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Underground Space 2024年第2期15卷 76-89页

作者： Junying Xia Bo Wang Xinxin Guo Zhuoxiong Xie Key Laboratory of Transportation Tunnel engineering Ministry of EducationSouthwest Jiaotong UniversityChengdu 610031China College of Environment and Civil engineering Chengdu University of TechnologyChengdu 610059China Guangdong Communication Planning&design institute Group Co. LtdGuangzhou 510507China

Current studies on blasting construction of small clear-distance tunnels have not considered the impact of existing tunnel lining defects when establishing safety *** paper offers a series of study results based on the blasting project of a new tunnel adjacent to the existing defect Xinling tunnel to thoroughly examine the dynamic response,safety control standards,and measures of the existing defect ***,structural models were developed to investigate the influence of the presence or absence of specific defects(like lining cracks and cavities behind the lining)on the dynamic response of the current tunnel lining to identify the most unfavorable defect ***,establish safety control standards for intact linings and those with the most unfavorable ***,two types of control measures,single safe charge and reasonable delay time,were studied based on the established safety control *** particular,the most adverse position of cracks was the wall facing the explosion,the rise in depth was more unfavorable for vibration response,and the impact of the longitudinal crack was restricted to the vicinity of the *** the vault was the most adverse cavity position,the rise in cavity area was more damaging,and the influence range varied with longitudinal cavity ***,the impact of cracks was mainly evident in the amplification effect of stress at the crack *** contrast,cavities had varied degrees of amplification effects on the vibration velocity and stress response and a relatively extensive influence *** control research was conducted,when the tunnel was intact,with a right wall crack,a vault cavity,and both vault cavity and crack for this project,the peak particle velocity(PPV)of the safety control standard for vibration velocity was 13,10,13,and 8 cm/s,respectively,and the respective single safe charge could be adjusted at 64,53,37,and 25 ***,the presence of different defects had a relati

关键词： Existing tunnel Defect Blasting construction Vibration response Control standards and measures

Controllable self-transport of bouncing droplets on ultraslippery surfaces with wedge-shaped grooves

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Droplet 2024年第2期3卷 138-145页

作者： Chuchen Yue Qingwen Dai Xiaolong Yang Carsten Gachot Wei Huang Xiaolei Wang College of Mechanical and Electrical engineering Nanjing University of Aeronautics&AstronauticsNanjingChina institute of engineering design and Product Development Tribology Research GroupTU WienViennaAustria

Preventing the accretion of droplets on surfaces is vital and slippery liquid-infused porous surfaces(SLIPS)have promising application prospects,such as surface self-cleaning and droplet *** this work,controllable self-transport of bouncing droplets on ultraslippery surfaces with wedge-shaped grooves is *** impact behaviors of droplets on SLIPS under various impact velocities and diameters are explored,which can be classified as hover,total bounce,partial bounce,Worthington jet,and *** with wedge-shaped grooves were designed to transport accreted *** energy and transport model is established to explain the impact and self-transport mechanism,where the Laplace pressure and moving resistance between droplets play a key ***,SLIPS with branched wedge-shaped grooves were designed for droplet self-transport and demonstrated *** work provides a general reference for spontaneous motion control of sessile droplets,droplets with initial impacting velocity,or even liquid films.

关键词： wedge shaped droplets

Evaluation and attribution of trends in compound dry-hot events for major river basins in China

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Science China Earth Sciences 2024年第1期67卷 79-91页

作者： Shaotang XIONG Tongtiegang ZHAO Chengchao GUO Yu TIAN Fang YANG Wenlong CHEN Xiaohong CHEN Key Laboratory of Water Security Guarantee in Guangdong-Hong Kong-Marco Greater Bay Area of Ministry of Water Resources&Sun Yatsen University/Southern Marine Science and engineering Guangdong Laboratory(Zhuhai) Guangzhou 510275China China institute of Water Resource and Hydropower research Beijing 100038China Pearl River Hydraulic research institute Guangzhou 510611China

Concurrent compound dry and hot events(CDHEs)amplified more damange on the ecosystems and human society than individual *** climate change,compound dry and hot events become more frequent on a global *** paper proposes a mathematical method to quantitatively attribute changes of CDHEs to changes of precipitation,change in temperature and change in the dependence between precipitation and *** attribution is achieved by formulating the total differential equation of the return period of CDHEs among Meta-gaussian model.A case study of China is devised based on monthly precipitation and temperature data during the period from 1921 to 2020 for 80 major river *** is found that temperature is the main driving factor of increases in CDHEs for 49 major river basins in China,except for the upper and middle reaches of the Yangtze *** West China,precipitation changes drove the increase in CDHEs in 18 river basins(23%),particularly in parts of North Xinjiang,Qinghai and *** the other hand,dependence between precipitation and temperature dominated changes of CDHEs in 13 river basins(16%)of China with other factors,including parts of South China,East China and Northwestern ***,changes in both the mean and spread of precipitation and temperature can also contribute to changes in CDHEs.

关键词： Climate extreme Compound dry and hot extreme Precipitation Temperature Return period

Knowledge and data jointly driven aeroengine gas path performance assessment method

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Chinese Journal of Aeronautics 2024年第5期37卷 533-557页

作者： Zhe WANG Xuyun FU Rui ZHANG Zhengfeng BAI Xiangzhao XIA Wei JIANG Department of Mechanical engineering Harbin Institute of TechnologyWeihai 264209China Weihai Key Laboratory of Intelligent Operation and Maintenance Harbin Institute of TechnologyWeihai 264209China Control System design Laboratory AECC ShenYang Engine Research InstituteShenyang 110015China

Aeroengines,as the sole power source for aircraft,play a vital role in ensuring flight *** gas path,which represents the fundamental pathway for airflow within an aeroengine,directly impacts the aeroengine's performance,fuel efficiency,and ***,timely and accurate evaluation of gas path performance is of paramount *** paper proposes a knowledge and data jointly driven aeroengine gas path performance assessment method,combining Fingerprint and gas path parameter deviation ***,Fingerprint is used to correct gas path parameter deviation values,eliminating parameter shifts caused by non-component performance ***,coarse errors are removed using the Romanovsky criterion for short-term data divided by an equal-length overlapping sliding ***,an Ensemble Empirical Mode Decomposition and Non-Local Means(EEMD-NLM)filtering method is designed to“clean”data noise,completing the preprocessing for gas path parameter deviation ***,based on the characteristics of gas path parameter deviation values,a Dynamic Temporary Blended Network(DTBN)model is built to extract its temporal features,cascaded with Multi-Layer Perceptron(MLP),and combined with Fingerprint to construct a Dynamic Temporary Blended AutoEncoder(DTB-AutoEncoder).Eventually,by training this improved autoencoder,the aeroengine gas path multi-component performance assessment model is formed,which can sufficiently decouple the nonlinear mapping relationship between aeroengine gas path multi-component performance degradation and gas path parameter deviation values,thereby achieving the performance assessment of engine gas path *** practical application cases,the effectiveness of this model in assessing the aeroengine gas path multi-component performance is verified.

关键词： Performance assessment Aeroengine Fingerprint Gas path parameter deviation values Jointly drive

Simultaneous removal of Cd(Ⅱ)and As(Ⅴ)by ferrihydrite-biochar composite:Enhanced effects of As(Ⅴ)on Cd(Ⅱ)adsorption

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Journal of Environmental Sciences 2024年第5期139卷 267-280页

作者： Wenjun Zeng Yang Lu Jingyan Zhou Jie Zhang Yuanxiao Duan Changxun Dong Wencheng Wu College of Sciences Nanjing Agricultural UniversityNanjing 210095China South China institute of Environmental Sciences Ministry of Ecology and EnvironmentGuangzhou 510655China Guangdong engineering&Technology research Center for System Control of Livestock and Poultry breeding Pollution Guangzhou 510655China

The coexistence of cadmium(Cd(Ⅱ))and arsenate(As(Ⅴ))pollution has long been an environmental ***,a porous carbonaceous material with tunable functionality,has been used for the remediation of contaminated ***,it is still challenging for the dynamic quantification and mechanistic understanding of the simultaneous sequestration of multi-metals in biochar-engineered environment,especially in the presence of *** this study,ferrihydrite was coprecipitated with biochar to investigate how ferrihydritebiochar composite affects the fate of heavy metals,especially in the coexistence of Cd(Ⅱ)and As(Ⅴ).In the solution system containing both Cd(Ⅱ)and As(Ⅴ),the maximum adsorption capacities of ferrihydrite-biochar composite for Cd(Ⅱ)and As(Ⅴ)reached 82.03μmol/g and 531.53μmol/g,respectively,much higher than those of the pure biochar(26.90μmol/g for Cd(Ⅱ),and 40.24μmol/g for As(Ⅴ))and ferrihydrite(42.26μmol/g for Cd(Ⅱ),and 248.25μmol/g for As(Ⅴ)).Cd(Ⅱ)adsorption increased in the presence of As(Ⅴ),possibly due to the changes in composite surface charge in the presence of As(Ⅴ),and the increased dispersion of ferrihydrite by *** microscopic and mechanistic results showed that Cd(Ⅱ)complexed with both biochar and ferrihydrite,while As(Ⅴ)was mainly complexed by ferrihydrite in the Cd(Ⅱ)and As(Ⅴ)coexistence *** posed vital importance for the co-adsorption of Cd(Ⅱ)and As(Ⅴ).The different distribution patterns revealed by this study help to a deeper understanding of the behaviors of cations and anions in the natural environment.

关键词： Ferrihydrite Biochar Cadmium Arsenate Simultaneous sequestration Binding mechanisms

One-year observation of the mixing states of oxygenated organics-containing single particles in guangzhou,China

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Frontiers of Environmental Science & engineering 2024年第5期18卷 155-169页

作者： Liyuan Mao Suxia Yang Xiaoya Cheng Sulin Liu Duanying Chen Zhen Zhou Mei Li Chenglei Pei Chunlei Cheng institute of Mass Spectrometry and Atmospheric Environment Guangdong Provincial Engineering Research Center for the On-line Source Apportionment System of Air PollutionJinan UniversityGuangzhou510632China Guangdong-Hongkong-Macao Joint Laboratory of Collaborative Innovation for Environmental Quality Guangzhou510632China guangzhou research institute of Environment Protection Co. Ltd.Guangzhou510620China guangzhou Ecological and Environmental Monitoring Center of Guangdong Province Guangzhou510030China State Key Laboratory of Marine Resource Utilization in South China Sea Hainan UniversityHaikou570228China State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy SciencesXi’an710061China

Oxygenated organic molecules(OOMs)play an important role in the formation of secondary organic aerosols(SOAs),but the mixing states of OOMs are still *** study investigates the mixing states of OOM-containing single particles from the measurements taken using a single particle aerosol mass spectrometer in guangzhou,China in ***,the particle counts of OOM particles and the mass concentration of secondary organic carbon(SOC)exhibited similar temporal trends throughout the entire *** OOM particles were consistently enriched in secondary ions,including ^(16)O^(−),^(26)CN^(−),^(46)NO_(2)^(−),^(62)NO_(3)^(−),and ^(97)HSO_(4)^(−).In contrast,the number fractions and diurnal patterns of OOM particles among the total detected particles showed similar distributions in August and October;however,the SOC ratios in fine particulate matter were quite different,suggesting that there were different mixing states of single-particle oxygenated *** addition,further classification results indicated that the OOM particles were more aged in October than August,even though the SOC ratios were higher in ***,the distribution of hydrocarbon fragments exhibited a notable decrease from January to October,emphasizing the more aged state of the organics in *** addition,the sharp increase in elemental carbon(EC)-OOM particles in the afternoon in October suggests the potential role of EC in the aging process of ***,in contrast to the bulk analysis of SOC mass concentration,the mixing states of the OOM particles provide insights into the formation process of SOAs in field studies.

关键词： Oxygenated organics Single particles Mixing state Secondary formation Photochemistry