Transportation mobility during COVID-19:a systematic review and bibliometric analysis

The COVID-19 pandemic has significantly affected global transportation mobility,presenting unprecedented challenges to transportation management.Public transit and ride-hailing services saw a drastic reduction in ridership,leading to an increased inclination towards private vehicles.The pandemic also altered travel patterns and individual mobility due to various COVID-19 protocols.This study conducted a comprehensive review of 96 academic papers spanning from January 1,2020,to December 31,2022,focusing on transportation and mobility using the Scopus database.Three major themes were identified:‘Impact on Ride-Hailing Services',‘Impact on Mode Preference',and‘Impact on Trip Purpose',with subdivisions based on keywords and key findings extracted using VOSviewer.The pandemic significantly impacted ride-hailing services,altering demand,usage,and safety measures.Mode preference shifted towards private vehicles due to safety concerns.The present study underscores the long-term implications of the pandemic,emphasizing recovery strategies for ride-hailing services and mode preferences post-pandemic.It highlights the need for sustainable transportation policies,advocating for enhanced public transportation systems,promoting active travel modes,and addressing socioeconomic disparities in mobility patterns.The findings emphasize the need for resilient transportation strategies in the face of future disruptions.

Flex Ethernet Technology and Application in 5G Mobile Transport Network

With the advent of 5G era,the rise of cloud services,virtual reality/virtual reality(AR/VR),vehicle networking and other technologies has put forward new requirements for the bandwidth and delay of the bearer network.Traditional Ethernet technology cannot meet the new requirements very well.Flex Ethernet(FlexE)technology has emerged as the times require.This paper introduces the background,standardization process,functional principle,application mode and technical advantages of FlexE technology,and finally analyses its application prospects and shortcomings in 5G mobile transport network.

PARAMETERIZATION OF MOBILIZATION AND TRANSPORT OF SAND-DUST DURING BLACK STORM AND MESOSCALE NUMERICAL EXPERIMENTS

The typical black storms or sand-dust storms in the northwestern China are generated and developed through an interaction between the specific large scale circulation pattern and mesoseale systems.The passing by/over a huge sand-abundant desert of a strong cold front with intensive frontal zone at mid and lower levels is a necessary condition for the formation and development of a black storm or a severe sand-dust storm.In order to investigate the mechanism of the sand-dust mobilization,transport and sedimentation during the black or sand-dust storms,a parameterization scheme of sand-dust source-sink terms and an equation of transport for the sand-dust were proposed and incorporated into the MM4 mesoscale model.The modified MM4 model was applied to the“May 1993”black storm case and succeeded in reproducing the evolution of the weather systems associated with the black-storm,the sand-dust concentration at surface layer and its vertical distribution,and the sand-dust sedimentation and transport.Our results show that the numerical simulating method by using a mesoscale model,with inclusion of an equation of the sand-dust transport and a parameterization scheme of the sand-dust source-sink terms,is a promising approach to study the mechanism for sand-dust mobilization,transport and sedimentation during a sand-dust storm event.

Opportunities and challenges of smart mobile applications in transportation

Smart mobile applications are software applications that are designed to run on smart phones, tablets, and other mobile electronic devices. In this era of rapid technological advances, these applications have become one of the primary tools we use daily both in our personal and professional lives. The applications play key roles in facilitating many applications that are pivotal in our today＇s society including communication, education, business, entertainment, medical, finance, travel, utilities, social, and transportation. This paper reviewed the opportunities and challenges of the applications related to transportation. The opportunities revealed include route planning, ridesharing/carpooling, traffic safety, parking information, transportation data collection, fuel emissions and consumption, and travel information. The potential users of these applications in the field of transportation include （I） transportation agencies for travel data collection, travel information, ridesharing/carpooling, and traffic safety, （2） engineering students for field data collection such as travel speed, travel time, and vehicle count, and （3） general traveling public for route planning, ridesharing/carpooling, parking, traffic safety, and travel information. Significant usage of smart mobile applications can be potentially very beneficial, particularly in automobile travel mode to reduce travel time, cost, and vehicle emissions. In the end this would make travel safer and living environments greener and healthier. However, road users＇ interactions with these applications could manually, visually, and cognitively divert their attention from the primary task of driving or walking. Distracted road users expose themselves and others to unsafe behavior than undistracted. Road safety education and awareness programs are vital to discourage the use of applications that stimulate unsafe driving/walking behaviors. Educating the traveling public about the dangers of unsafe driving/walking behavior could have significant safety benefits to all road users. Future research needs to compare accuracies of the applications and provide guidelines for selecting them for certain transportation related applications.

Aggregation of graphene oxide and its environmental implications in the aquatic environment

Graphene oxide(GO) with unique characteristics grasps striking potentials in both academic and industrial applications. After being released into natural waters, the dispersity and stability of GO might be altered by the chemical conditions in the receiving water bodies. In this review, we summarized that the aggregation of GO in aquatic environments is mostly dependent on properties of nanoparticles(size,structure, and functional groups) and complex water chemistry(p H, temperature, light, ionic strength,and dissolved organic matter). The knowledge about the aggregation/stability of GO is still insufficient due to the variations in GO properties and complex system of natural waters. Although studies about environmental transformation of graphene-related materials can be accessed but a systematic study taking into consideration the various factors of GO and aquatic systems responsible for aggregation of GO is still lacking. Therefore, we summarized that GO homoaggregation or heteroaggregation with other solid particles can affect the distribution in different depths of rivers and toxicity toward plankton or benthic organisms. More studies are needed to investigate the stability of GO in the long term, the effect of other nanomaterial on GO aggregation, the alteration of water constituents at different regions/time and its effect on GO aggregation, to understand the transportation and impact of GO in the environment.

Current Reversals of an Underdamped Brownian Particle in an Asymmetric Deformable Potential

Transport of an underdamped Brownian particle in a one-dimensional asymmetric deformable potential is investigated in the presence of both an ac force and a static force,respectively.From numerical simulations,we obtain the current average velocity.The current reversals and the absolute negative mobility are presented.The increasing of the deformation of the potential can cause the absolute negative mobility to be suppressed and even disappear.When the static force is small,the increase of the potential deformation suppresses the absolute negative mobility.When the force is large,the absolute negative mobility disappears.In particular,when the potential deformation is equal to0.015,the two current reversals present with the increasing of the force.Remarkably,when the potential deformation is small,there are three current reversals with the increasing of the friction coefficient and the average velocity presents a oscillation behavior.