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Influence of Transportation Accessibility on Urban-rural Income Disparity and Its Spatial Heterogeneity

Chinese Geographical Science 2024年第3期34卷 453-467页

作者： HUANG Xiaoyan KANG Chenchen YIN Chun TANG Junqing Northwest Land and Resources Research Center Global Regional and Urban Research InstituteShaanxi Normal UniversityXi’an 710119China School of Resource and Environmental Sciences Wuhan UniversityWuhan 430079China International Institute of Spatial Lifecourse Health(ISLE) Wuhan UniversityWuhan 430079China School of Urban Planning and design Shenzhen Graduate SchoolPeking UniversityShenzhen 518055China Key Laboratory of Earth Surface System and Human-Earth Relations of Ministry of Natural Resources of china Shenzhen Graduate SchoolPeking UniversityShenzhen 518055China

Transportation accessibility has been treated as an important means of reducing the urban-rural income ***,only a few studies have examined the effects of different types of transportation accessibility on urban-rural income disparity and their spatial *** on data from 285 prefecture-level(and above)Chinese cities in 2000,2005,2010,2015,and 2020,this study uses spatial econometric models to examine how highway accessibility and railway accessibility influence the urban-rural income disparity and to identify their spatial *** result reveals that highway accessibility and railway accessibility have‘coreperiphery’ring-like circle *** urban-rural income disparity exhibits strong spatial clustering *** highway accessibility and railway accessibility are negatively associated with urban-rural income disparity,and the former having a greater effect ***,there is a substitution effect between highway accessibility and railway accessibility in the whole ***,these associations differ in geographic *** the central region,highway accessibility is more important in reducing the urban-rural income disparity,but its effect is weakened with the increase of railway *** the western region,railway accessibility has a larger effect on narrowing the urban-rural income disparity,and this effect is strengthened by the increase of highway *** conclude that improving transportation accessibility is conducive to reducing the urban-rural income disparity but its effect is spatial *** and railways should be developed in a coordinated manner to promote an integrated transport network system.

关键词： transport accessibility income gap regional divergence spatial heterogeneity urban and rural areas china

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Numerical investigation on the spewing mechanism of earth pressure balance shield in a high-pressure water-rich sand stratum

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Deep Underground Science and Engineering 2023年第1期2卷 74-87页

作者： Zhiyong Yang Weiqiang Qi Yanjie Ding Yusheng Jiang Xinkang Yang Xing Yang Xiaokang Shao School of Mechanics and Civil Engineering China University of Mining and Technology‐BeijingBeijingChina china railway first survey and design Institute Group Co. LtdXi'anChina

The spewing of a screw conveyor easily occurs from the earth pressure balance(called EPB)shield in a water-rich sand *** may lead to the collapse of the tunnel face and even serious subsidence of the ground *** understand the spewing mechanism of the shield screw conveyor and explore the critical hydraulic condition of soil spewing in a shield–soil chamber,a simplified theoretical model for the spewing of the screw conveyor was developed based on the equation of groundwater flow in the screw conveyor under turbulent ***,coupling Darcy's law with Brinkman's equation,this model was implemented within the COMSOL Multiphysics *** underground water flow in the shield screw conveyor was simulated so as to obtain its velocity and flow *** simulations show that the water pressure distribution is concentrated in the lower part of the soil chamber after the groundwater enters the soil *** the groundwater enters the screw conveyor,its pressure gradually decreases along the direction of the screw *** the water flow reaches the stratum–shield interface,the flow velocity changes markedly:first increases and concentrates at the entrance of the lower soil chamber,plummets and stabilizes gradually,and increases again at the *** soil chamber and screw conveyor are significantly *** is also found that the soil permeability coefficient can be reduced to k<2.6×10^(−4)cm/s through appropriate soil improvement,which can effectively prevent the occurrence of spewing disasters.

关键词： EPB shield multiphysical coupling permeability coefficient screw conveyor spewing

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Optimization of modelling strategies for regional landslide susceptibility assessment based on machine learning methods -A viewpoint from the modelling dataset design and partition

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Journal of Earth Science 2024年

作者： Yuhang Zhu Kunlong Yin Shuhao Liu Zhenyi Liu Taorui Zeng Institute of Geological survey， china University of Geosciences Wuhan Faculty of Engineering， china University of Geosciences Institute of Future Civil Engineering Science and Technology， Chongqing Jiaotong University Institute of Frontier Interdisciplinary Technology， Chongqing Jiaotong University

The inappropriatemodelling strategies can lead to unsatisfactory prediction results for landslide susceptibility assessment (LSA). The objectivesof this study are to reveal the impact of dataset design value (ratio of negative to positive samples) and partition (ratio of training to testing dataset) on the accuracy of LSA based on different machine learning models. The Yunyang County of the Three Gorges Reservoir area (china) was taken as the study area and 15 conditioning factors were determined. Ten modelling datasets design values (0.125， 0.25， 0.5， 1， 2， 5， 8， 10， 12 and 15) were determined for the ratio of non-landslide and landslide samples， and each modelling dataset was divided into five partitions ((50:50) %， (60:40) %， (70:30) %， (80:20) % and (90:10) %) for the ratio of training and testing datasets. Each scenario was then applied on four machine learning models (Classification and Regression tree (CART)， Bayes Network (BN)， Logistic Regression (LR) and Multilayer Perceptron (MLP)). The optimal parameters of the modelling dataset were obtained by comparing 200 sets of the AUC under different combined scenarios. The results showed that different sampling strategies significantly affect the accuracy of LSA. With increasing of the design values， the AUC of the CART and MLP models first increased and then decreased， peaking at 1 (AUC=0.85 and 0.83)， while the AUC of the BN and LR models remained stable， vary from 0.755 to 0.796. Comparatively， different partitions had less impact on the AUC of various models， AUC vary by around 0.04. The highest prediction accuracy was obtained when the design value was 1 and the partition was (80:20) %. The outcome can provide a guideline for researchers to choose an optimal modelling strategy for LSA in the future.

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Optimization and design of Cloud-Edge-End Collaboration Computing for Autonomous Robot Control Using 5G and Beyond

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Journal of Beijing Institute of Technology 2022年第5期31卷 454-463页

作者： Hao Wang china railway Siyuan survey and design Group Co. Ltd.Wuhan 430063China

Robots have important applications in industrial production, transportation, environmental monitoring and other fields, and multi-robot collaboration is a research hotspot in recent years. Multi-robot autonomous collaborative tasks are limited by communication, and there are problems such as poor resource allocation balance, slow response of the system to dynamic changes in the environment, and limited collaborative operation capabilities. The combination of 5G and beyond communication and edge computing can effectively reduce the transmission delay of task offloading and improve task processing efficiency. first, this paper designs a robot autonomous collaborative computing architecture based on 5G and beyond and mobile edge computing(MEC).Then, the robot cooperative computing optimization problem is studied according to the task characteristics of the robot swarm. Then, a reinforcement learning task offloading scheme based on Qlearning is further proposed, so that the overall energy consumption and delay of the robot cluster can be minimized. Finally, simulation experiments demonstrate that the method has significant performance advantages.

关键词： robot collaboration mobile edge computing(MEC) 5G and beyond network task offloading resource allocation

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Numerical calculation on solar temperature field of a cable-stayed bridge with U-shaped section on high-speed railway

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Journal of Central South University 2014年第8期21卷 3345-3352页

作者：刘文硕戴公连饶少臣 School of Civil Engineering Central South University china railway Siyuan survey and design Group Co.Ltd.

Based on transient temperature field theory of heat conduction, the solar temperature field calculation model of U-shape sectioned high-speed railway cable-stayed bridge under actions of concrete beams and ballast was established. Using parametric programming language, finite element calculation modules considering climate conditions, bridge site, structure dimension and material thermophysical properties were compiled. Six standard day cycles with the strongest yearly radiation among the bridge sites were selected for sectional solar temperature field calculation and temperature distributions under different temperature-sensitive parameters were compared. The results show that under the influence of sunshine, U-shape section of the beam shows obvious nonlinear distribution characteristics and the maximum cross-section temperature difference is more than 21℃; the ballast significantly reduces sunshine temperature difference of the beam and temperature peak of the bottom margin lags with the increase of ballast thickness; the maximum cross-section vertical temperature gradient appears in summer while large transverse temperature difference appears in winter.

关键词： high-speed railway cable-stayed bridge U-shaped section solar temperature field thermal analysis

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Research on optimization and design methods for air distribution system based on target values

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Building Simulation 2021年第3期14卷 721-735页

作者： Ran Gao Hengchun Zhang Angui Li Shihao Wen Wuyi Du Baoshun Deng School of Building Services Science and Engineering Xi'an University of Architecture and TechnologyXi'an 710055China School of Thermal Engineering Shandong Jianzhu UniversityJinan 250101ShandongChina china railway first survey&design Institute Group Xi'an 710043China

To achieve sufficient air conditioning of large buildings,reasonable air distribution in indoor spaces is an effective method for creating stratified air ***,optimizing the air distribution in large buildings is extremely *** this paper,we expound on a new method for air distribution design and optimization based on target value evaluation and summarize the relevant design processes based on an orthogonal test and by decoupling the effects of the size of the tuyere,airflow temperature,air-supply angle and velocity on air ***,we present a design *** optimize the distribution of a lateral air supply in winter,the deflection angle,velocity and temperature of the air supply can be determined in *** the large and tall building types addressed in this paper,the optimal air-supply angle is 2°,the optimal air-supply velocity is 8 m/s,and the optimal air-supply temperature is 19℃.

关键词： air distribution target value indicator optimization

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A local rainfall-triggered giant landslide occurred in a region along a high-speed railway on the Qinghai-Tibetan Plateau

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Journal of Mountain Science 2024年第09期 2939-2955页

作者： LI Qingpeng LIU Wenhui HE Renjie YING Chunye LIU Hairui DOU Zengning LIU Yabing YANG Sha SONG Xianteng School of Geological Engineering Qinghai University Key Lab of Cenozoic Resource and Environment in North Margin of the Tibetan Plateau Qinghai University College of Eco-Environmental Engineering Qinghai University Qinghai Transportation Planning and design Institute Co Ltd Xining Center for Integrated Natural Resources survey

An increasing number of geological hazards along high-speed railways on the Qinghai-Tibetan Plateau have occurred and have resulted in a profound influence on old infrastructure, which has attracted increasing attention. The landslide event that occurred on September 15, 2022, in Jiujiawan village, Xining city, Qinghai Province, is a typical case. Based on field investigations and remote sensing interpretations, a comprehensive analysis was conducted on the landslide. Additionally, the potential secondary failure of the current Jiujiawan landslide was assessed using Fast Lagrangian Analysis of Continua in Three Dimensions（FLAC3D）. Based on the application of the small baseline subset-interferometric synthetic aperture radar（SBAS-In SAR） technique to SAR images from February 24, 2017 to September 14, 2022, a significant westward horizontal deformation was found to have been formed prior to the occurrence of the landslide. The maximum annual average deformation rate in the line of sight（LOS） direction reached-45 mm/yr, with a maximum cumulative deformation of-178 mm. This value was consistent with the continual increase in annual precipitation（2.51 mm/yr） prior to the occurrence of the landslide. The accumulated precipitation before the landslide was 279.8 mm, accounting for 54.2% of the total annual precipitation, with a particularly notable surge in monthly precipitation observed during August（250.3 mm）. Additionally, the occurrence of a seismic event with a magnitude of Ms 6.9 in Menyuan County, 80 km away from Xining, could be a potential triggering factor to the landslide, as evidenced by an abrupt subsidence alteration observed prior to and following the earthquake. The maximum subsidence in the line of sight（LOS） direction exceeded 11 mm, exhibiting a highly consistent spatial distribution with the occurrence range of landslides. These results suggest that the Jiujiawan landslide was likely induced by earthquake events in the early stage and heavy rainfall in t

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Particle swarm optimization for train schedule of Y-type train routing in urban rail transit

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Journal of Measurement Science and Instrumentation 2020年第1期11卷 87-93页

作者： WEI Zi-wen china railway first survey and design Institute Group Co. Ltd.Xi’an 710043China

The train schedule usually includes train stop schedule,routing scheme and formation *** is the basis of subway *** the practical experience of transport organizations and the principle of the best match between transport capacity and passenger flow demand,taking the minimum value of passenger travel costs and corporation operating costs as the goal,considering the constraints of the maximum rail capacity,the minimum departure frequency and the maximum available electric multiple unit,an optimization model for city subway Y-type operation mode is constructed to determine the operation section of mainline as well as branch line and the train frequency of the Y-type operation *** particle swarm optimization(PSO)algorithm based on classification learning is used to solve the model,and the effectiveness of the model and algorithm is verified by a practical *** results show that the length of branch line in Y-type operation affects the cost of waiting time of passengers significantly.

关键词： urban traffic train schedule particle swarm optimization(PSO) classification learning Y-type train routing

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Formation and ecological response of sand patches in the protection system of Shapotou section of the Baotou-Lanzhou railway,china

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Journal of Arid Land 2024年第2期16卷 298-313页

作者： DUN Yaoquan QU Jianjun KANG Wenyan LI Minlan LIU Bin WANG Tao SHAO Mei Key Laboratory of Desert and Desertification Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China College of Urban and Environmental Sciences Northwest UniversityXi'an 710100China Zhongwei Works Section of china railway Lanzhou Bureau Group Company Limited Zhongwei 755000China

The development of bare patches typically signifies a process of ecosystem *** the protection system of Shapotou section of the Baotou-Lanzhou railway,the extensive emergence of bare sand patches poses a threat to both stability and ***,there is limited knowledge regarding the morphology,dynamic changes,and ecological responses associated with these sand ***,we analyzed the formation and development process of sand patches within the protection system and its effects on herbaceous vegetation growth and soil nutrients through field observation,survey,and indoor analysis *** results showed that sand patch development can be divided into three stages,i.e.,formation,expansion,and stabilization,which correspond to the initial,actively developing,and semi-fixed sand patches,*** average dimensions of all sand patch erosional areas were found to be 7.72 m in length,3.91 m in width,and 0.32 m in *** actively developing sand patches were the largest,and the initial sand patches were the *** the stage of formation and expansion,the herbaceous community composition changed,and the plant density decreased by more than 50.95%.Moreover,the coverage and height of herbaceous plants decreased in the erosional area and slightly increased in the depositional lobe;and the fine particles and nutrients of soils in the erosional area and depositional lobe showed a decreasing *** the stabilization phases of sand patches,the area from the inlet to the bottom of sand patches becomes initially covered with *** and 0-2 cm surface soil condition improved in the erosional area,but this improvement was not yet evident in the depositional *** such as disturbance,climate change,and surface resistance to erosion exert notable influences on the formation and dynamics of sand *** results can provide evidence for the future treatment of sand patches and the management of the pro

关键词： railway protection system sand patch morphology vegetation characteristic soil property

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Investigation of Student Nurses’Attitudes towards End-of-Life Care and Their Influencing Factors

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Open Journal of Nursing 2024年第5期14卷 183-191页

作者： Lei Peng Jingxian Wang Jia Wang Qiangqiang Liu Department of Emergency Medicine The First Affiliated Hospital of Sun Yat-sen University Guangzhou China

Background: This cross-sectional investigative study aimed to determine student nurses’ attitudes towards end-of-life care. Methods: This study used a descriptive research design with stratified sampling to survey student nurses enrolled in one of four nursing colleges in china from January 2023 to December 2023. Student nurses’ general demographic and prior related information, attitudes towards death and attitudes towards end-of-life care were determined using a general information questionnaire, the Death Attitude Profile—Revised scale and the Professional End-of-Life Attitude Scale (PEAS), respectively. Results: The total PEAS score was 122.91 ± 16.123. Significant differences were noted in the attitude towards end-of-life care scores according to sources of end-of-life care knowledge (P Conclusions: Student nurses lacked an optimistic attitude towards end-of-life care, which was influenced by differences in the sources of end-of-life care knowledge.

关键词： Nursing Students End-of-Life Care Attitude

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