摘要：
Using recycled asphalt pavement (RAP) materials in the pavement industry is a hot issue now, which can reduce carbon emissions significantly. The agglomeration and variability of the RAP materials treated by a conventional crushing and screening process present a challenge for the gradation design and variability control of the reclaimed asphalt mixture, resulting in a lower RAP content and thus a limited environmental and economic benefit. To address it, a refined crushing and screening process was employed for the RAP material to separate the asphalt mortar and the coarse aggregates in this study. To evaluate its applicability on the RAP material, the basic composition, agglomeration degree, variability, and gradation refinement of the RAP material were discussed. The aggregate dispersion uniformity and road performance of the reclaimed asphalt mixtures made with the obtained RAP materials were further investigated; the correlation between the RAP properties and the road performance of the reclaimed asphalt mixture was explored. The results show that the agglomeration degree and variability of the coarse RAP material are reduced significantly by the refined crushing and screening process. The use of the RAP material treated by the refined crushing and screening process can largely improve the uniformity of aggregate dispersion and conventional road performance compared with the use of the RAP material treated by conventional methods. Pearson correlation analysis demonstrates that the RAP agglomerates increase the variability of 4.75 mm sieve passage rates and the asphalt-aggregate ratio, resulting in an uneven distribution of aggregates in the structural composition, thus reducing the moisture sensitivity and fatigue performance. By utilizing the refined crushing and screening process, the variability of the RAP materials can be considerably reduced, thereby enhancing the RAP content and the key performance of reclaimed asphalt mixture. The popularization of the refined crushing and screening process is an effective approach to promote the high-quality use of the RAP materials.
摘要：
Abstract: Developing modern supply chain has become a national strategy, and the ideological and political education of the supply chain management course is just in time. The ideological and political elements system of the supply chain management course is included in teaching objectives, integrated into teaching links, embedded in teaching system, and deeply embedded in teaching content. The ideological and political resources of the supply chain management course are excavated from the perspectives of professional knowledge, industry development, industry change, history, international and social reality. The ideological and political education methods of the supply chain man-agement course are explored from the perspectives of education and teaching concepts, ideological and political education methods, and ideological and political education laws.#@#@#摘要: 发展现代供应链上升为国家战略，供应链管理课程思政建设恰逢其时。供应链管理课程思政元素体系从教学目标中纳入、教学环节中融入、教学体系中嵌入、教学内容中深入。供应链管理课程思政资源从专业知识、行业发展、产业变革、历史、国际、社会现实视角深入挖掘。供应链管理课程思政教育方式从教育教学理念、思政教育方法、思政教育规律进行探索。
摘要：
Schematic diagram of the CEA aging mechanism. Abstract In environmental conditions, the ultraviolet (UV) light from sunshine will trigger epoxy asphalt (EA) paving materials aging and performance reduction. This work studied the influence of UV aging on the structure and mechanical performance of cold‐mixed epoxy asphalt (CEA) to evaluate its aging mechanism. The chemical structure of CEA was tested by Fourier transform infrared spectra, X‐ray photoelectron spectroscopy, and micromorphology was observed through fluorescence microscopy. The mechanical properties of CEA were studied by tensile tests and dynamic mechanical analysis. The results indicated that the toughness of CEA went down due to UV aging, and the elongation at break and glass transition temperature decreased by 35.5% and 6.0°C, respectively. Based on structural analysis, the UV aging mechanism of CEA was summarized as follows: (1) the curing network of epoxy resin was partially broken, and the asphalt particle aggregated; (2) the asphalt and epoxy resin in UV aging‐CEA were oxidized and formed carbonyl group and sulfonic group. Highlights Both asphalt and ER components in CEA underwent oxidation reactions and formed more CO, SO, and CO groups. UV‐CEA showed a decrease in toughness due to destruction of the cured ER cross‐linked network and shortening of the asphalt molecular chain E' and Tg of UV‐CEA was decreased, resulting from a decrease in ER crosslink density and an increase in molecular chain segment mobility of ER and asphalt.
摘要：
Complex road sections without lane markings cannot constrain vehicles to follow the lane disciplines. As a result, vehicles often exhibit more disorderly rapid lateral movements (RLMs) in these areas, making it difficult to accurately predict vehicle trajectories. This study takes toll plaza diverging area as an example to propose a framework incorporated the Hidden Markov Model (HMM) and Temporal Fusion Transformer (TFT) for vehicle trajectory prediction in non-lane based complex road sections. The results demonstrate that the vehicles exhibit more RLMs when there are more toll lanes matching their toll collection types. Validated on two toll plaza diverging areas with different structures, the proposed framework achieves higher prediction accuracy than other state-of-the-art predictive methods, particularly in long prediction horizons. In addition, the interpretability of TFT suggests that incorporating RLM intention prediction and environmental factors specific to non-lane based areas into trajectory prediction is of great importance.
摘要：
To investigate the effects of compaction (K), rock content (RC), and wet-dry cycle (WD) on the road performance of carbonaceous mudstone soil-rock mixtures (CMSRM), orthogonal tests were designed to measure the unconfined compressive strength (UCS) and California bearing ratio (CBR). The correlation degree of K, RC, and WD with the UCS and CBR of CMSRM was investigated using orthogonal theory and grey correlation theory. Based on multivariate nonlinear regression analysis, mathematical models of the road performance of CMSRM were built. The results show that the UCS and CBR of CMSRM were positively correlated with K and negatively correlated with the WD. With increasing RC, UCS increased at first and then decreased, while CBR increased continuously. The failure modes of CMSRM change from tensile failure to shear failure as the K increases under uniaxial compression. The RC and WD affect the structural integrity of the failed samples. Combining the results of range analysis, variance analysis, and grey relational analysis, the most significant influence on the UCS is K, and the most significant influence on the CBR is RC. It is recommended to select 94%–96% for K and 40%–60% for RC in engineering.
关键词：
Damage constitutive model;Heating and water-cooling cycles;Residual strength;Silty mudstone;Temperature
摘要：
Understanding the deformation and damage behaviors of soft rocks under temperatures and water–rock interactions is crucial for designing rock engineering structures and for assessing geotechnical disasters. Hence, the physical–mechanical characteristics and damage mechanisms of silty mudstone under heating and water-cooling cycles were determined by a series of laboratory tests. The results indicate that heating and water-cooling treatments prompt crack development within silty mudstone, observable through volume augmentation along with reductions in mass, density, and P-wave velocity. The interconnections between the decrease of mechanical properties such as elastic modulus, cohesion, and internal friction angle of silty mudstone and the factors including temperatures and cycle number are explicitly established. The deterioration of the physical–mechanical properties of silty mudstone primarily arises from the thermal expansion, dehydration, and hydrolysis of mineral constituents. Furthermore, a new damage constitutive model for silty mudstone considering temperature and the number of heating and water-cooling cycles is established based on lognormal distribution and the Mohr–Coulomb criterion. Additionally, the model parameters S0 and F0 characterize the homogeneity and average strength, enabling a quantitative assessment of the damage degree of rocks.
关键词：
shared electric vehicle system;autonomous driving;opportunity cost;spatio-temporal-state network;Lagrangian relaxation
摘要：
Shared autonomous electric vehicle systems (SAEVS) combine autonomous driving technology with shared electric vehicle services to provide advantages over traditional shared vehicle systems, including autonomous vehicle relocation and rapid response to user needs. In this study, we seek to enhance the operational efficiency and profitability of SAEVS by considering trip selection and the potential opportunity cost associated with unmet user demands. An integer linear programming (ILP) model is developed using a spatio-temporal state network to optimize the system design planning (e.g., charging facility, vehicle fleet sizing and distribution) and operational decisions (e.g., vehicle operational relocation and trip selection strategy). To handle the computational complexities of this model, we propose a Lagrangian relaxation (LR) algorithm. The performance of the LR algorithm is evaluated through a case study. The results, along with a parameter sensitivity analysis, reveal several key findings: (i) Allocating vehicles to stations with concentrated early peak demand, distributing charging facilities to stations with high total demand throughout the day and implementing vehicle relocation after the early demand peak can mitigate uneven vehicle distribution; (ii) Implementing trip selection enhances SAEVS profitability; (iii) Increasing opportunity cost meets user demands but at the expense of reduced profit; (iv) It is recommended that SAEVS be equipped with charging facilities of suitable charging power based on operational conditions.
摘要：
In this paper, experimental investigations are carried out to assess the weld strength of S700 steel during and after fire. Standard and nonstandard tensile coupons were tested during fire and postfire stages at temperatures ranging from 500 degrees C to 800 degrees C. In this experiment, all the standard specimens failed at the base material without any distinct yield plateau in the stress-strain relationship. The postfire specimens display yield strength reduction from-70% at 500 degrees C to-55% at 800 degrees C; while the ultimate strength reduced by-20%-30%. The slower cooling process (cooling in air) show lower ultimate strength regain than the quicker cooling process (cooling in water). The heat treatment does not affect the elastic modulus. As compared to the postfire residual ultimate strength of the parent material is not affected by heat treatment, the strength of air-cooled weld specimens display considerable (-30% less) strength reduction. The S700 weld connection display
摘要：
In order to improve the water damage resistance of styrene butadiene styrene (SBS) modified asphalt, anti-stripping agents (BWH551 and LY) and nanomaterial (Nano-SiO2) were utilized as modifiers to enhance the properties of SBS modified asphalt. Firstly, various modifiers were incorporated into SBS modified asphalt to prepare three kinds of compound modified asphalt. Then, the regular physical and rheological properties were tested. Meanwhile, the adhesion of the specimen was systematically evaluated with four indexes, as well as the image analysis method. Finally, the micro-test of compound modified asphalt was carried out with various approaches. The test results showed that 0.2% of BWH551, 0.3% of LY, and 2% of Nano-SiO2 were the optimal content. Compared with SBS modified asphalt, the surface free energy of three kinds of compound modified asphalts was more significantly promoted, revealing that the modifiers can boost the adsorption capacity of the asphalt. The modification interaction was revealed by Fourier transform infrared spectroscopy (FTIR). No chemical reaction occurred among anti-stripping agents, nanomaterial, and SBS modified asphalt, but physical blending. The fluorescence microscope (FM) test indicates that LY has excellent compatibility and stability with SBS modified asphalt. The scanning electron microscope (SEM) test results showed that evenly dispersed Nano-SiO2 particles enhanced the interaction between SBS particles. The atomic force microscope (AFM) test results illustrated that the bee-like structure of Nano-SiO2/SBS compound modified asphalt was significantly larger than SBS modified asphalt. The number of bee-like structures of BWH551/SBS and LY/SBS compound modified asphalts was similar to the SBS modified asphalt. Therefore, BWH551, LY, and Nano-SiO2 had favorable modification effects to obtain high-performance asphalt.
通讯机构：
[Hao Yang] N;National Engineering Research Center of Highway Maintenance Technology, Changsha University of Science & Technology, Changsha, People’s Republic of China<&wdkj&>School of Traffic and Transportation Engineering, Changsha University of Science & Technology, Changsha, People’s Republic of China
通讯机构：
[Jianbo Yuan] S;School of Traffic and Transportation Engineering, Changsha University of Science and Technology, Changsha 410114, China<&wdkj&>Author to whom correspondence should be addressed.
摘要：
Based on analytical and simulation methods, this paper discusses the path choice behavior of mixed traffic flow with autonomous vehicles, advanced traveler information systems (ATIS) vehicles and ordinary vehicles, aiming to promote the development of autonomous vehicles. Firstly, a bi-level programming model of mixed traffic flow assignments constrained by link capacity is established to minimize travel time. Subsequently, the algorithm based on the incremental allocation method and method of successive averages is proposed to solve the model. Through a numerical example, the road network capacity under different modes is obtained, the impact of market penetration on travel time is analyzed, and the state and characteristics of single equilibrium flow and mixed equilibrium flow are explored. Analysis results show that the road network can be maximized based on saving travel time when all vehicles are autonomous, especially when the autonomous lane is adopted. The travel time can be shortened by increasing the market penetration of autonomous vehicles and ATIS vehicles, while the former is more effective. However, the popularization of autonomous vehicles cannot be realized in the short term; the market penetration of autonomous vehicles and ATIS vehicles can be set to 0.2 and 0.6, respectively, during the introduction period.
期刊：
IEEE Transactions on Intelligent Transportation Systems,2023年24(2):2122-2134 ISSN：1524-9050
通讯作者：
Su, J.
作者机构：
[Duan, Xuting; Tian, Daxin; Zhou, Jianshan] Beihang Univ, Beijing Adv Innovat Ctr Big Data & Brain Comp, Natl Engn Lab Comprehens Transportat Big Data Appl, Sch Transportat Sci & Engn,Beijing Key Lab Coopera, Beijing 100191, Peoples R China.;[Yan, Huiwen] ZTE Corp, Wireless Prod Res & Dev Inst, Wireless Prod Operat Div, Baseband Res & Dev Dept 2, Shanghai 201203, Peoples R China.;[Su, Jian] Nanjing Univ Informat Sci & Technol, Sch Comp & Software, Nanjing 210044, Peoples R China.;[Hao, Wei] Changsha Univ Sci & Technol, Sch Traff & Transportat Engn, Changsha 410114, Peoples R China.
通讯机构：
[Su, J.] N;Nanjing University of Information Science and Technology, China
关键词：
Anomaly detection;Computer hacking;Support vector machines;Safety;Encryption;Autonomous vehicles;Authentication;Controller area network (CAN);anomaly detection;isolation forest (iForest);data mass
摘要：
The development and applications of mobile communication technologies in intelligent autonomous transportation systems have led to an extraordinary rise in the mount of connected and autonomous vehicles (CAVs). Ensuring the security of in-vehicle communication data is the basis for the safety of cooperative transportation systems. An in-vehicle controller area network (CAN) bus is an important issue in in-vehicle security, and some hackers have mastered remote vehicle control methods through the CAN bus network. This paper proposes an improved isolation forest method with data mass (MS-iForest) for data tampering attack detection, in which we use data mass instead of the number of divisions and give an anomaly score ranking to quantify the degree of anomalies. This method is promising to be used as part of the intrusion detection system, like a security component in the onboard gateway, which can effectively avoid the data tampering attacks. We compare the proposed method with other anomaly detection schemes based on the data collected from an in-vehicle simulated dataset and two standard datasets. The experiment results show that the proposed method performs better than the other anomaly detection schemes in terms of the area under the receiver operating curve (AUC).
