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Identifying drivers of urban landuse changes in the Wenchuan earthquake- affected area by using night-time light data

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Journal of Mountain Science 2024年第4期21卷 1140-1159页

作者： HUANG Tao DING Mingtao geng Dongxian GAO Zemin ZHENG Hao School of Civil Engineering and Architecture Southwest University of Science and TechnologyMianyang 621010China Faculty of Geosciences and Environmental Engineering Southwest Jiaotong UniversityChengdu 611756China Analysis and Test Center of Sichuan Province Chengdu 610023China

To learn the process of urban land evolution before and after an earthquake is vital to formulate the urban reconstruction control policies and recovery measures in the earthquake-stricken ***,spatiotemporal evolution and its driving factors of urban land in earthquake-prone areas remains limited due to the scarcity of ground observation *** research,leveraging night-time light remote sensing imagery and land cover data,conducted a comprehensive analysis of the long-term evolution characteristics of urban land in earthquake-prone *** introduced methodologies for assessing the socio-economic impact and the primary natural environmental factors driving urban land evolution in these *** validate the proposed methods,the 2008 Wenchuan earthquake-affected area in China was selected as a representative study *** results indicated that the average Digital Number(DN)values in socio-economically impacted areas showed a trend of rising,falling,and then rising again after the *** values in three types of damaged areas including Type Ⅱ,Type Ⅲ,and Type Ⅳ exceeded pre-earthquake *** analysis of determinative factors influencing urban land evolution revealed that slope and elevation were key elements in controlling urban land expansion before the earthquake,whereas factors such as slope,elevation,lithology,and faults had a stronger influence on urban land expansion after the *** can be seen that,in view of the differences in the natural conditions of regions for post-disaster reconstruction,the local government need to actively adjust and adapt to urban spatial planning,so as to leverage the scale effect of large-scale inputs of funds,facilities,human resources and other factors after the disaster,thus enhancing resilience and recovery efficiency in response to disaster impacts.

关键词： Wenchuan earthquake Night-time lights Urban land Post-earthquake reconstruction

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Extraction method of typical IEQ spatial distributions based on low-rank sparse representation and multi-step clustering

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Building Simulation 2024年第6期17卷 983-1006页

作者： Yuren Yang Yang geng Hao Tang Mufeng Yuan Juan Yu Borong Lin School of Architecture Tsinghua UniversityBeijingChina Key Laboratory of Eco Planning&Green Building Ministry of EducationTsinghua UniversityBeijingChina

Indoor environment quality(IEQ)is one of the most concerned building performances during the operation *** non-uniform spatial distribution of various IEQ parameters in large-scale public buildings has been demonstrated to be an essential factor affecting occupant comfort and building energy ***,IEQ sensors have been widely employed in buildings to monitor thermal,visual,acoustic and air ***,there is a lack of effective methods for exploring the typical spatial distribution of indoor environmental quality parameters,which is crucial for assessing and controlling non-uniform indoor *** this study,a novel clustering method for extracting IEQ spatial distribution patterns is ***,representation vectors reflecting IEQ distributions in the concerned space are generated based on the low-rank sparse ***,a multi-step clustering method,which addressed the problems of the“curse of dimensionality”,is designed to obtain typical IEQ distribution patterns of the entire indoor *** proposed method was applied to the analysis of indoor thermal environment in Beijing Daxing international airport *** a result,four typical temperature spatial distribution patterns of the terminal were extracted from a four-month monitoring,which had been validated for their good *** typical patterns revealed typical environmental issues in the terminal,such as long-term localized overheating and temperature increases due to a sudden influx of *** extracted typical IEQ spatial distribution patterns could assist building operators in effectively assessing the uneven distribution of IEQ space under current environmental conditions,facilitating targeted environmental improvements,optimization of thermal comfort levels,and application of energy-saving measures.

关键词： indoor environment quality(IEQ) thermal environment spatial distribution temperature field low-rank sparse representation(LRSR) clustering

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A continuous-wave Nd:YVO_(4)-KGW intracavity Raman laser with over 34% diode-to-Stokes optical efficiency

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High Power Laser Science and Engineering 2024年第2期12卷 62-68页

作者： Quan Sheng Jingni geng Tianchang Liu Shijie Fu Wei Shi Jianquan Yao Institute of Laser and Optoelectronics School of Precision Instrument and Optoelectronics EngineeringTianjin UniversityTianjinChina Key Laboratory of Optoelectronic Information Technology(Ministry of Education) Tianjin UniversityTianjinChina

We demonstrate a continuous-wave(CW)Nd:YVO_(4)-potassium gadolinium tungstate(KGW)intracavity Raman laser with a diode-to-Stokes optical efficiency of 34.2%.By optimizing the cavity arrangement and reducing the cavity losses,8.47 W Stokes output at 1177 nm was obtained under an incident 878.6 nm diode pump power of 24.8 *** influence of cavity losses on the power and efficiency of the CW Raman laser,as well as the potential for further optimization,was investigated based on the numerical *** observation of thermally-induced output rollover was well explained by the calculation of the thermal lensing and cavity stability,indicating that the end-face curvature played an important role when the end-face of the crystal was highly reflective coated to make the cavity.A 10.9 W Stokes output under 40.9 W incident pump was also demonstrated with a cavity arrangement less sensitive to the end-face curvature,which is the highest output power of CW intracavity Raman lasers reported.

关键词： continuous wave intracavity Raman laser KGW crystal thermal lens

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Complex granular flows of sticky-wet material on flip-flow screens:Calibration of discrete element simulations

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Particuology 2024年第1期84卷 290-308页

作者： Ningning Xu Sen Tang Dongdong Lin Runhui geng Xinwen Wang Xihui Liang School of Chemical and Environmental Engineering China University of Mining and Technology(Beijing)Beijing100083China Department of Mechanical Engineering University of ManitobaWinnipegManitobaR3T 5V6Canada

Discrete element method(DEM)is an effective approach for studying the screening process of flip-flow ***,there have been few studies focusing on the thick layer of sticky-wet particles on flip-flow *** achieve accurate simulations of the thick layer of sticky-wet particles on a flip-flow screen,firstly,the movement law of particle flow was studied,and a multi-regime combination cali-bration method based on characteristics of particle flow regimes was *** on the Plackett-Burman experiment,the curse of dimensionality caused by multi-state and multi-contact parameters was ***,the lifting cylinder,rotating drum,and trampoline tests were carried out to obtain macroscopic reference values under various granular flow *** calibration results were then determined using the response surface method and climbing ***,the calibration results were tested at both macroscopic and mesoscopic scales and compared with a commonly used calibration *** results demonstrate that the calibration method,which considers the multi-state characteristics,improves simulation accuracy by 2%-10%and reduces the simulation error to less than 10%,thus meeting the requirements for engineering optimization of flip-flow screens.

关键词： DEM Complex granular flow Parameter calibration Flip-flow screen Sticky-wet particles Thick layer

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Residual levels and health risk assessment of trace metals in Chinese resident diet

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Journal of Environmental Sciences 2024年第2期136卷 451-459页

作者： Yubing Dai Shuai Sun Rong Cao Haijun Zhang Jiping Chen Ningbo geng CAS Key Laboratory of Separation Science for Analytical Chemistry Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China Shenyang Pharmaceutical University Shenyang 110016China University of Chinese Academy of Sciences Beijing 100049China

Large-scale metal contamination across the food web is an intractable problem due to increasing pollutant emissions,atmospheric transport,and dry and wet deposition of *** present study focus on several trace metals that are rarely studied but have special toxicity,including tin(Sn),antimony(Sb),gold(Au),hafnium(Hf),palladium(Pd),platinum(Pt),ruthenium(Ru),tellurium(Te)and iridium(Ir).We investigated trace metals residues and distribution characteristics,and further evaluated the potential health risks from major daily food intakes in 33 cities in ***,Sb,Ir,Hf,and Au were frequently detected in food samples with the concentrations ranged from ND(not detected)to 24.78μg/kg ww(wet weight).Eggs exhibited the highest residual level of all detected metals(13.70±14.70μg/kg ww in sum),while the lowest concentrations were observed in vegetables(0.53±0.17μg/kg ww in sum).Sn accounting for more than 50%of the total trace metals concentration in both terrestrial and aquatic animal origin *** terrestrial plant origin foods,Sn and Ir were the most abundant *** and Au were the most abundant elements in egg *** addition,Sb and Ir showed a clear trophic dilution effect in terrestrial environments,while in aquatic ecosystems,Sn,Hf,and Au exhibited obvious trophic amplification *** calculated average estimated daily intake(EDI)via food consumption in five regions of China was 0.09μg/(kg·day),implying the health risk of aforementioned elements was acceptable.

关键词： Trace metals Accumulation characteristics Dietary exposure Estimated daily intake(EDI)

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Interconnected microstructure and flexural behavior of Ti_(2)C-Ti composites with superior Young’s modulus

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International Journal of Minerals,Metallurgy and Materials 2024年第9期31卷 2088-2101页

作者： Fengbo Sun Rui Zhang Fanchao Meng Shuai Wang Lujun Huang Lin geng School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China Waikato Centre for Advanced Materials and Manufacturing School of EngineeringUniversity of WaikatoHamilton 3240New Zealand State Key Laboratory of Precision Welding&Joining of Materials and Structures Harbin Institute of TechnologyHarbin 150001China

To enhance the Young’s modulus(E)and strength of titanium alloys,we designed titanium matrix composites with intercon-nected microstructure based on the Hashin-Shtrikman *** to the results,the in-situ reaction yielded an interconnected microstructure composed of Ti_(2)C particles when the Ti_(2)C content reached 50vol%.With widths of 10 and 230 nm,the intraparticle Ti lamellae in the prepared composite exhibited a bimodal size distribution due to precipitation and the unreacted Ti phase within the grown Ti_(2)C *** composites with interconnected microstructure attained superior properties,including E of 174.3 GPa and ultimate flexural strength of 1014 *** with that of pure Ti,the E of the composite was increased by 55% due to the high Ti_(2)C content and interconnected *** outstanding strength resulted from the strong interfacial bonding,load-bearing capacity of interconnected Ti_(2)C particles,and bimodal intraparticle Ti lamellae,which minimized the average crack driving *** flexural tests revealed preferential crack initiation along the{001}cleavage plane and grain boundary of Ti_(2)C in the region with the highest tensile *** addition,the propagation can be efficiently inhibited by interparticle Ti grains,which prevented the brittle fracture of the composites.

关键词： titanium matrix composites titanium carbide interface Young’s modulus flexural behavior

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Probing signals of atmospheric gravity waves excited by the July 29,2021 M_(W)8.2 Alaska earthquake

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Geodesy and Geodynamics 2024年第3期15卷 219-229页

作者： geng Zhang Jianqiao Xu Xiaodong Chen Heping Sun Lizhuo Gong State Key Laboratory of Geodesy and Earth's Dynamics Innovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhan430077China University of Chinese Academy of Sciences Beijing100049China

It is commonly believed that the atmosphere is decoupled from the solid ***,it is difficult for the seismic wave energy inside the Earth to propagate into the atmosphere,and atmospheric pressure wave signals excited by earthquakes are unlikely to exist in atmospheric *** increasing number of studies have shown that earthquakes,volcanoes,and tsunamis can perturb the Earth's atmosphere due to various coupling ***,the observations mainly focus on acoustic waves with periods of less than 10 min and inertial gravity waves with periods of greater than 1 *** are almost no clear observations of gravity waves that coincide with observations of low-frequency signals of the Earth's free oscillation frequency band within 1 *** paper investigates atmospheric gravity wave signals within1 h of surface-atmosphere observations using the periodogram method based on seismometer and microbarometer observations from the global seismic network before and after the July 29,2021 M_(w)8.2 Alaska earthquake in the United *** numerical results show that the atmospheric gravity wave signals with frequencies similar to those of the Earth's free oscillations _(0)S_(2) and _(0)T_(2) can be detected in the microbaro meter *** results con firm the existence of atmospheric gravity waves,indicating that the atmosphere and the solid Earth are not decoupled within this frequency band and that seismic wave energy excited by earthquakes can propagate from the interior of the Earth to the atmosphere and enhance the atmospheric gravity wave signals within 1 h.

关键词： Atmospheric gravity modes Atmospheric gravity waves Alaska earthquake Normal modes Coupling of solid earth and atmosphere

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A novel deep learning framework with variational auto-encoder for indoor air quality prediction

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Frontiers of Environmental Science & Engineering 2024年第1期18卷 97-109页

作者： Qiyue Wu Yun geng Xinyuan Wang Dongsheng Wang ChangKyoo Yoo Hongbin Liu Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources Nanjing Forestry UniversityNanjing 210037China College of Automation&College of Artificial Intelligence Nanjing University of Posts and TelecommunicationsNanjing 210023China Guangxi Key Laboratory of Clean Pulp&Papermaking and Pollution Control College of Light Industry and Food EngineeringGuangxi UniversityNanning 530004China Laboratory for Comprehensive Utilization of Paper Waste of Shandong Province Shandong Huatai Paper Co.Ltd.Dongying 257335China Department of Environmental Science and Engineering College of EngineeringKyung Hee UniversityYongin 446701Republic of Korea

Exposure to poor indoor air conditions poses significant risks to human health, increasing morbidity and mortality rates. Soft measurement modeling is suitable for stable and accurate monitoring of air pollutants and improving air quality. Based on partial least squares (PLS), we propose an indoor air quality prediction model that utilizes variational auto-encoder regression (VAER) algorithm. To reduce the negative effects of noise, latent variables in the original data are extracted by PLS in the first step. Then, the extracted variables are used as inputs to VAER, which improve the accuracy and robustness of the model. Through comparative analysis with traditional methods, we demonstrate the superior performance of our PLS-VAER model, which exhibits improved prediction performance and stability. The root mean square error (RMSE) of PLS-VAER is reduced by 14.71%, 26.47%, and 12.50% compared to single VAER, PLS-SVR, and PLS-ANN, respectively. Additionally, the coefficient of determination (R2) of PLS-VAER improves by 13.70%, 30.09%, and 11.25% compared to single VAER, PLS-SVR, and PLS-ANN, respectively. This research offers an innovative and environmentally-friendly approach to monitor and improve indoor air quality.

关键词： Indoor air quality PM_(2.5)concentration Variational auto-encoder Latent variable Soft measurement modeling

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Realization of Quantum Secure Direct Communication with Continuous Variable

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Research 2024年第2期6卷 159-170页

作者： Zhengwen Cao Yuan Lu geng Chai Hao Yu Kexin Liang Lei Wang School of Information Science and Technology Northwest UniversityXi'an710127China

With the progress of theoretical and applied technologies,the communication system based on the classical encryption is seriously threatened by quantum computing and distributed computing.A communication method that directly loads confidential information on the quantum state,quantum secure direct communication(QSDC),came into being for resisting security ***,we report the first continuous-variable QSDC(CV-QSDC)experimental demonstration for verifying the feasibility and effectiveness of the CV-QSDC protocol based on Gaussian mapping and propose a parameter estimation for signal classification under the actual *** our experiment,we provided 4×10^(2) blocks,where each block contains 105 data for direct information *** the transmission distance of 5 km in our experiment,the excess noise is 0.0035 SNU,where SNU represents the unit of shot-noise *** 4.08×10^(5) bit per second experimental results firmly demonstrated the feasibility of CV-QSDC under the fiber *** proposed grading judgment method based on parameter estimation provides a practical and available message processing scheme for CV-QSDC in a practical fiber channel and lays the groundwork for the grading reconciliation.

关键词： quantum estimation verify

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Machine learning enabled film pressure sensor to identify surface contacts:An application in surface transmission of infectious disease

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Building Simulation 2024年第6期17卷 1023-1036页

作者： Baotian Chang Jianchao Zhang Yingying geng Jiarui Li Doudou Miao Nan Zhang Beijing Key Laboratory of Green Built Environment and Energy Efficient Technology Beijing University of TechnologyBeijing100124China

The global prevalence of infectious diseases has emerged as a significant challenge in recent *** transmission is a potential transmission route of most gastrointestinal and respiratory infectious diseases,which is related to surface touch *** observation,the traditional method of surface touching data collection,is characterized by limited accuracy and high labor *** this work,we proposed a methodology based on machine learning technologies aimed at obtaining high-accuracy and low-labor-cost surface touch behavioral data by means of sensor-based contact *** touch sensing device,primarily utilizing a film pressure sensor and Arduino board,is designed to automatically detect and collect surface contact data,encompassing pressure,duration and *** make certain the surface touch behavior and to describe the behavioral data more accurately,six classification algorithms(*** Vector Machine and Random Forest)have been trained and tested on an experimentally available dataset containing more than 500 surface *** classification results reported the accuracy of above 85%for all the six classifiers and indicated that Random Forest performed best in identifying surface touch behaviors,with 91.8%accuracy,91.9%precision and 0.98 *** study conclusively demonstrated the feasibility of identifying surface touch behaviors through film pressure sensor-based data,offering robust support for the calculation of viral load and exposure risk associated with surface transmission.

关键词： surface transmission touch behavior film pressure sensor random forest infectious disease

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