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Dynamic simulation insights into friction weakening effect on rapid long-runout landslides:A case study of the Yigong landslide in the Tibetan Plateau,China

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China Geology 2024年第2期7卷 222-236页

作者： Zi-zheng Guo Xin-yong Zhou Da Huang Shi-jie Zhai Bi-xia Tian Guang-ming Li School of Civil and transportation Engineering Hebei University of TechnologyTianjin 300401China School of Geological Engineering and Geomatics Chang’an UniversityXi’an 710054China Tianjin Municipal Engineering Design&Research institute(TMEDI) Tianjin 300392China

This study proposed a novel friction law dependent on velocity,displacement and normal stress for kinematic analysis of runout process of rapid *** well-known Yigong landslide occurring in the Tibetan Plateau of China was employed as the case,and the derived dynamic friction formula was included into the numerical simulation based on Particle Flow *** showed that the friction decreased quickly from 0.64(the peak)to 0.1(the stead value)during the 5s-period after the sliding initiation,which explained the behavior of rapid movement of the *** monitored balls set at different sections of the mass showed similar variation characteritics regarding the velocity,namely evident increase at the initial phase of the movement,followed by a fluctuation phase and then a stopping *** peak velocity was more than 100 m/s and most particles had low velocities at 300s after the landslide *** spreading distance of the landslide was calculated at the two-dimension(profile)and three-dimension scale,*** with the simulation result without considering friction weakening effect,our results indicated a max distance of about 10 km from the initial unstable position,which fit better with the actual situation.

关键词： Rapid long-runout landslide PFC Friction weakening Three-dimension Numerical simulation Tibetan Plateau Hydrogeology Engineering Geological hazards survey engineering

Attribution analysis of groundwater level fluctuation in the Xinxiang section of the Lower Yellow River's suspended river after the construction of the Xiaolangdi Reservoir

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Journal of Geographical Sciences 2024年第7期34卷 1348-1370页

作者： LI He PING Jianhua LENG Wei MEI Xuemei ZHANG Min LIU Jiaqi School of Water Conservancy and transportation Zhengzhou UniversityZhengzhou450001China College of Ecology and Environment Zhengzhou UniversityZhengzhou450001China Geothermal and Ecological Geology Research Center Zhengzhou UniversityZhengzhou450001China institute of Geology and Geophysics CASBeijing100101China

The clear identification and quantification of the factors affecting groundwater systems is crucial for protecting groundwater resources and ensuring safety in agricultural *** Lower Yellow River(LYR)is a suspended river that replenishes groundwater continuously due to clear differences in the water head,especially in the Xinxiang *** its construction,the Xiaolangdi Reservoir has reversed the LYR’s *** accurately determine the factors influencing the groundwater level(GWL),the study area was divided into five subzones based on hydrogeology.A dynamic factor model(DFM),variational mode decomposition(VMD),and a multiple linear regression model were used to identify and quantify the factors influencing the *** impact of the suspended river on the groundwater before and after the construction of the Xiaolangdi Reservoir was *** results show that:(1)The rate of decrease in the GWL was 8.53×10^(–4)m/month,and the rate of decrease in the Yellow River water level(RWL)was 4.63×10^(–4)m/month.(2)Mountain front recharge(MFR)(scale=3 months)and precipitation(scale=9 months)were the dominant factors in subzones I and II,accounting for more than 40%of the fluctuation in the *** III was dominated by exploitation(scale=7 months)and precipitation(scale=12months),accounting for 28.43%,and 23.44%of changes in the GWL,*** subzone IV,agricultural irrigation(scale=12 months)was the major factor,accounting for32.47%of GWL changes,while in subzone V,the RWL(scale=12 months)accounted for52.52%of these changes.(3)The Xiaolangdi Reservoir has increased the lateral seepage of the suspended river and altered the inter-annual *** results of this study can provide a valuable reference for controlling groundwater overexploitation and ensuring water supply security.

关键词： groundwater level influencing factor dynamic factor analysis Xiaolangdi Reservoir Lower Yellow River lateral seepage of the Yellow River

Patterned microsphere-lens projection lithography using an electrohydrodynamic-jetprinting-assisted assembly

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Photonics Research 2024年第7期12卷 1502-1512页

作者： YA ZHONG HAIBO YU PEILIN ZHOU HONGJI GUO TIANMING ZHAO HAO LUO YANGDONG WEN XIAODUO WANG LIANQING LIU State Key Laboratory of Robotics Shenyang Institute of AutomationChinese Academy of SciencesShenyang 110016China institutes for Robotics and Intelligent Manufacturing Chinese Academy of SciencesShenyang 110016China University of Chinese Academy of Sciences Beijing 100049China College of Mechanical and Electrical Engineering Henan Agricultural UniversityZhengzhou 450002China institute of Urban Rail transportation Southwest Jiaotong UniversityChengdu 610000China

Microlens arrays have been widely used in the fields of micro-optics and micro-and nanofabrication. Traditional preparation methods utilize commercial photoresists and thermosetting materials, thereby restricting the optical properties of microlenses. In recent years, significant advancements have been achieved in near-field super-resolution imaging by utilizing microspheres and forming arrays of microsphere lenses via self-assembly. However, self-assembly approaches lack flexibility in terms of pattern selection. This study proposes a method that utilizes electrohydrodynamic jet (E-jet) printing to code ultraviolet (UV)-curable adhesives and assist in the assembly of patterned microsphere-lens arrays. Simulation results demonstrate that the UV-curable adhesive has little impact on the optical properties of the microsphere lens. Moreover, the microsphere lens exhibits a superior imaging resolution compared with traditional microlenses. A projection-lithography system is developed to achieve an accurate alignment between the focal plane of the microsphere lenses and the plane of the photoresist, facilitating the fabrication of patterned nanostructures. The lithographic nanostructures have a minimum feature size of 850 nm. This method enables the fabrication of arrays of microsphere lenses with arbitrary patterns and presents an inexpensive and simple strategy for fabricating micro-and nanostructure arrays with submicrometer features.

关键词： projection utilize utilizing

A Comparative Study of Machine Learning Models for Traffic Accident Severity Prediction on Rural Highways

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Journal of Traffic and transportation Engineering(English Edition) 2024年

作者： Fengxiang Guo Jingyang Li Feng Zhu Bijiang Tian Wenchen Yang School of transportation Science and Engineering， Harbin institute of Technology Yunnan Key Laboratory of Digital Communications National Engineering Research Center for Efficient Maintenance， Safety and Durability of Roads and Bridges，Broadvision Engineering Consultants Co.， Ltd Kunming Faculty of transportation Engineering， Kunming University of Science and Technology School of Civil and Environmental Engineering， Nanyang Technological University

The use of machine learning models for analyzing Traffic Accident Severity (TAS) is increasingly common in safety assessment and traffic accident prevention. However， many existing studies have not fully considered the importance of feature engineering， model hyperparameter optimization， and training set proportions， all of which significantly affect the performance of these models. This study addresses the research gap by developing a TAS model using the Light Gradient Boosting Machine (LightGBM) and integrating two feature engineering methods (Random Forest (RF) and Principal Component Analysis (PCA)). Additionally， we compared the LightGBM with three other machine learning models: Support Vector Machine (SVM)， Binary Logistic Regression (BL)， and Deep Neural Network (DNN). This comparison evaluates the effectiveness of different machine learning approaches in classifying TAS， taking into account variations in feature engineering techniques and training set proportions. The case study examines rural highway accidents in Yunnan Province， China， focusing on three categories of factors influencing TAS: accident characteristics， traffic flow， and highway conditions. Moreover， the SHAP (SHapley Additive exPlanations) values were employed to identify the primary factors contributing to the accident severity. The results show that with the training set size of 80%， all four models achieve the highest predictive accuracy for severe accidents. Notably， the PCA+lightGBM combination model outperforms others in overall accident prediction accuracy and has the highest recall rate and F1 score for severe accidents. Comparing the four models under different feature inputs， the impact of feature selection on model performance is less significant than reducing the data heterogeneity. LightGBM and DNN are more susceptible to data heterogeneity， and improving data homogeneity markedly boosts the model’s performance. Through SHAP analysis， it is evident that the modes of transportati

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Responses of runoff to changes in climate and human activities in the Liuhe River Basin, China

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Journal of Arid Land 2024年第8期16卷 1023-1043页

作者： LI Mingqian WANG He DU Wei GU Hongbiao ZHOU Fanchao CHI Baoming School of Ecology and Environment Institute of Disaster PreventionLangfang 065201China Hebei Key Laboratory of Resource and Environmental Disaster Mechanism and Risk Monitoring Sanhe 065201China Suzhou Qianxing Environmental Engineering Co. Ltd.Suzhou 215000China College of transportation Engineering Nanjing Tech UniversityNanjing 210000China Tianjin North China Geological Exploration General institute Tianjin 300000China

Since the 1950s,numerous soil and water conservation measures have been implemented to control severe soil erosion in the Liuhe River Basin(LRB),*** these measures have protected the upstream soil and water ecological environment,they have led to a sharp reduction in the downstream flow and the deterioration of the river ecological ***,it is important to evaluate the impact of soil and water conservation measures on hydrological processes to assess long-term runoff *** the Soil and Water Assessment Tool(SWAT)models and sensitivity analyses based on the Budyko hypothesis,this study quantitatively evaluated the effects of climate change,direct water withdrawal,and soil and water conservation measures on runoff in the LRB during different periods,including different responses to runoff discharge,hydrological regime,and flood *** runoff series were divided into a baseline period(1956-1969)and two altered periods,i.e.,period 1(1970-1999)and period 2(2000-2020).Human activities were the main cause of the decrease in runoff during the altered periods,contributing 86.03%(-29.61 mm),while the contribution of climate change was only 13.70%(-4.70 mm).The impact of climate change manifests as a decrease in flood volume caused by a reduction in precipitation during the flood *** of two flood cases indicated a 66.00%-84.00%reduction in basin runoff capacity due to soil and water conservation measures in the upstream *** and water conservation measures reduced the peak flow and total flood volume in the upstream runoff area by 77.98%and 55.16%,respectively,even with nearly double the *** runoff coefficient in the reservoir area without soil and water conservation measures was 4.0 times that in the conservation *** results contribute to the re-evaluation of soil and water conservation hydrological effects and provide important guidance for water resource planning and water conservation policy formu

关键词： runoff soil and water conservation climate variability flood human activities Liuhe River Basin

Evaluating the thermal environment of urban land surfaces in Yakutsk,a city located in a region of continuous permafrost

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Advances in Climate Change Research 2024年第1期15卷 113-123页

作者： Xiang-Long LI Ze ZHANG Jin-Xin LU Anatoli BROUCHKOV Qing-Kai YAN Qi-Hao YU Sheng-Rong ZHANG Andrey MELNIKOV School of Civil Engineering and transportation Institute of Cold Regions Science and EngineeringPermafrost InstituteNortheast Forestry UniversityHarbin150040China China Railway Qinghai-Tibet Group Company Xining 810000China Department of Geocryology Faculty of GeologyLomonosov Moscow State UniversityMoscow 119234Russian Federation State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco Envi ronment and Re sourcesChinese Academy of SciencesLanzhou 730000China Melnikov Permafrost institute Siberian BranchRussian Academy of ScienceYakutsk 677010Russian Federation

Rapid urbanization has led to changes in the urban land surface thermal ***,there are still much unknown about the urban land surface thermal conditions in permafrost *** is a unique geological environment,changes in the urban land surface thermal environment may trigger geological disasters caused by permafrost *** study utilized remote sensing data and geographic de-tectors to identify the dynamic changes in land surface temperature(LST)and land use/land cover(LU/LC)in Yakutsk,as well as the potential factors contributing to LST *** 1992 and 2020,the built-up area in Yakutsk increased by 36%,and the annual average LST in Yakutsk has risen by 6.67℃,accompanied by an expansion of high-temperature *** ongoing greening efforts,rapid urbanization poses a threat to these green *** in the normalized difference built-up index(NDBI)and land use transfer(LDT)were identified as the primary drivers of urban LST *** integrating geographic detector technology and artificial neural network models,we optimized the selection of input factors in the prediction model and used it to explore the future changes in LST in *** average LST in Yakutsk is expected to reach 23.4℃ and 25.1℃ in 2030 and 2040,respectively,with a further increase in high-temperature *** study provides a reference for ecological,hydrological,and geological assessments of cities in permafrost regions.

关键词： Remote sensing Land surface temperature Land use/Land cover Permafrost Yakutsk

二氧化碳静态爆破的边坡振动场地效应和能量分析

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Journal of Central South University 2024年第1期31卷 210-224页

作者：王小飞胡少斌王恩元 School of Safety Engineering China University of Mining and TechnologyXuzhou 221116China Tunnel and Underground Engineering institute College of Civil and Transportation EngineeringHohai UniversityNanjing 210098China

进行真三轴CO_(2)静态爆破压裂实验和现场测试,获得压力曲线、试样裂隙分布、现场振动曲线和岩体破坏特征,并通过分析压力曲线和裂缝扩展特征来研究致裂原理,同时还利用窗函数傅里叶变换提取振动特征,以评估破岩现场边坡的结构安全。研... 详细信息

进行真三轴CO_(2)静态爆破压裂实验和现场测试,获得压力曲线、试样裂隙分布、现场振动曲线和岩体破坏特征,并通过分析压力曲线和裂缝扩展特征来研究致裂原理,同时还利用窗函数傅里叶变换提取振动特征,以评估破岩现场边坡的结构安全。研究结果表明:(1)CO_(2)静态爆破的峰值振动速度在8 m处衰减至满足建筑物保护要求,比传统的钻爆法更安全;(2)CO_(2)静态爆破引起的振动波形的主频高于钻爆法的,且随着距离的加长,振动能量的分布逐渐分散;(3)钻爆法的振动速度预测公式适用于CO_(2)静态爆破的,且带高程的预测公式更为准确。根据压力曲线、试样裂隙分布和现场岩体损伤,提出CO_(2)静态爆破的HIG破岩模型,为新技术的研究提供了基础框架。在实验中没有采集到温度数据,今后迫切需要对聚能剂的瞬时放热特性和温度对CO_(2)状态的影响进行研究。

关键词：破岩技术二氧化碳静态爆破振动速度致裂机理能量计算

Enhanced potassium storage of carbon nanofibers as binderfree anodes enabled by coupling ultra-small amorphous Sb_(2)O_(3),graphene modification and sulfur doping

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Rare Metals 2024年第1期43卷 51-64页

作者： Zhao Huang Yu-Kang Lou Lin Peng Yuan Peng Meng-Meng Wang Ming Zhang College of Railway transportation Hunan University of TechnologyZhuzhou 412007China College of Semiconductors(College of Integrated Circuits) Changsha Semiconductor Technology and Application Innovation Research InstituteHunan UniversityChangsha 410082China Key Laboratory for Micro-Nano Optoelectronic Devices of Ministry of Education College of Semiconductors(College of Integrated Circuits)Hunan UniversityChangsha 410082China

Considering the intrinsic advantages of natural copiousness and cost-effectiveness of potassium resource,potassium-ion batteries(KIBs) are booming as prospective alternatives to lithium-ion batteries(LIBs) in large-scale energy storage scenarios. Nevertheless, lacking desirable electrodes for reversibly hosting the bulky K+hinders the widespread application of KIBs, and it needs to be urgently solved. Hereon, the porous S-doped Sb_(2)O_(3)-graphene-carbon(SAGC) nanofibers are manufactured through an adjustable and facile approach, which involves electrospinning, in situ etching and sulfuration. The synthesized SAGC is featured by the ultra-small amorphous Sb_(2)O_(3) homogeneously wrapped inside the carbon matrix, as well as the co-incorporation of graphene and sulfur. Tentatively,the SAGC nanofiber sheets are applied as binder-free anodes for KIBs, exhibiting a prominent cycling life(256.72 m Ah·g^(-1) over 150 cycles at 100 m A·g^(-1)) and rate·g^(-1) over 100 cycles at 1 A·g^(-1)). The positive synergy among all the active components accounts for the distinguished performances of the SAGC. By reinforcing the tolerability to the swelling stress, producing the valid electrochemical active sites, and promoting the charge transferring for reversible K+uptake, the SAGC finally renders the excellent cyclability, capacity, and rate capability. Moreover, the extrinsic electrochemical pseudocapacitance characteristics induced by the porous carbon substrate elevate the K-storage capacity of the SAGC as well. It is hoped that the conclusions drawn may offer new insights into a direction for the high-performance binderfree KIB anodes.

关键词： S-doped Sb_(2)O_(3)-graphene-carbon Nanofibers Binder-free Anodes Potassium-ion batteries

Automated,economical,and environmentally-friendly asphalt mix design based on machine learning and multi-objective grey wolf optimization

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Journal of Traffic and transportation Engineering(English Edition) 2024年第3期11卷 381-405页

作者： Jian Liu Fangyu Liu Linbing Wang Department of Civil and Environmental Engineering Virginia Polytechnic Institute and State UniversityBlacksburgVA 24061USA School of Environmental CivilAgricultural and Mechanical EngineeringUniversity of GeorgiaAthensGA 30602USA Illinois Center for transportation Department of Civil and Environmental EngineeringUniversity of Illinois Urbana-ChampaignUrbanaIL 61801USA

The increasing impact of the greenhouse effect on ecosystems is prompting transportation agencies to seek methods for reducing CO_(2)emissions during pavement construction and ***,the laboratory mix design process,which involves selecting aggregate gradation and binder content,is time-consuming and *** accelerate the traditional mix design procedure,this study presented a mix design procedure that can automatically determine gradation and binder content based on machine learning(ML)and a meta-heuristic ***,ML approaches were employed to model the relationship between volumetric properties(mixture bulk specific gravity(Gmb)and air void(VV))and both mixture component properties and mixture proportion,based on a dataset collected from literature with 660 mixture *** with the prediction of ML models and the modified multi-objective grey wolf optimization(MOGWO)algorithm,an automatic asphalt mix design was proposed to pursue three goals,including VV,cost,and CO_(2)*** results indicated that least squares support vector regression(LSSVR)and e Xtreme gradient boosting(XGBoost)achieved the highest prediction accuracies(correlation coefficient:0.92 for VV and 0.96 for Gmb).The MOGWO algorithm successfully found the 26 optimal mix designs for the case of VV *** ***_(2)*** to the traditional laboratory design,the optimal mixture with VV of4%achieves a cost saving of 2.46%and a reduction of 4.03%in carbon *** volumetric properties of the mixtures output by the approach also align closely with values measured in a laboratory.

关键词： Asphalt mix design Machine learning MOGWO CO_(2)emission Volumetric properties