
Shaojun Zhang- Ph.D.
- Professor (Associate) at Tsinghua University
Shaojun Zhang
- Ph.D.
- Professor (Associate) at Tsinghua University
Associate Professor
About
173
Publications
69,659
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6,947
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Introduction
Shaojun Zhang serves as associate professor at the School of Environment of Tsinghua University. His research areas focus on the advanced measurement and modeling techniques for emissions, energy consumption, climate impacts and atmospheric effects of transportation sectors (on-road vehicles, aviation). Before joining in Tsinghua, Shaojun worked with Ford Motor Company in Michigan, and later at Cornell University supported by the Atkinson Fellowship on Sustainability.
Current institution
Additional affiliations
June 2022 - present
July 2019 - present
February 2017 - January 2019
Education
August 2009 - July 2014
August 2005 - July 2009
Publications
Publications (173)
https://www.nature.com/articles/s41893-019-0398-8
China has emerged as a leading electric vehicle (EV) market, accounting for approximately half of the global EV sales volume. We employed an atmospheric chemistry model to evaluate the air quality impacts from multiple scenarios by considering various EV penetration levels in China and assessed the...
Significance
We capitalize on large variations of urban air quality during the COVID-19 pandemic and real-time observations of traffic, meteorology, and air pollution in Los Angeles to develop a machine-learning air pollution prediction model. Such a model can adequately account for the nonlinear relationships between emissions, atmospheric chemist...
China has made great progress in the electrification of passenger cars, and the sales of battery electric vehicles (BEVs) have exceeded 10%. We applied a life-cycle assessment (LCA) method to estimate the carbon dioxide (CO 2) emissions of the past (2015), present (2020), and future (2030) BEVs, incorporating China's carbon peaking and neutrality p...
China’s civil aviation market has rapidly expanded, becoming the world’s second-largest. However, the air quality and health impacts caused by its aircraft emissions have been inadequately assessed. Here, we leverage an updated emission inventory of air pollutants with improved temporal and spatial resolution based on hundreds of thousands of fligh...
The electrification of trucks is a major challenge in achieving zero-emission transportation. Here we gathered year-long records from 61,598 electric trucks in China. Current electric trucks were found to be significantly underutilized compared with their diesel counterparts. Twenty-three per cent of electric delivery trucks and 30% of semi-trailer...
Shuwen Guo Xuan Zheng Xiao He- [...]
Ye Wu
The role of intermediate-volatility and semi-volatile organic compounds (I/SVOCs) in heavy-duty diesel vehicle (HDDV) exhaust remains a significant research gap in previous studies, with limited focus on cumulative mileage and ambient temperature effects. This study analyzed gaseous and particulate I/SVOCs from four in-use HDDVs using thermal desor...
In this study, through a novel network-based data-driven method, we reveal a likely unintended, nighttime-specific impact of construction activities on elevated coarse particulate matter (PMc) concentrations in a metropolitan area. We analyzed the spatial and temporal patterns of coarse particulate matter (PMc) levels in the urban part of a 165-nod...
Shuwen Guo Xuan Zheng Xiao He- [...]
Ye Wu
The role of intermediate- and semi-volatile organic compounds (I/SVOCs) in heavy-duty diesel vehicle (HDDV) exhaust remains a significant research gap across previous studies, with limited focus on cumulative mileage and ambient temperature effects. This study analyzed gaseous and particulate I/SVOCs from four in-use HDDVs using thermal desorption...
The response to climate change and air pollution control demonstrates strong synergy across scientific mechanisms, targets, strategies, and governance systems. This report, based on a monitoring indicator system for coordinated governance of air pollution and climate change, employs an interdisciplinary approach combining natural and social science...
The adoption of zero-emission vehicles (ZEVs) offers multiple benefits for the climate, air quality, and public health by reducing tailpipe emissions. However, the environmental justice implications of the nonexhaust emissions from future ZEV fleets for near-roadway communities remain unclear. Here, we model the on-road fine particulate matter (PM2...
Traffic-related air pollutants (TRAPs) emitted from vehicle tailpipes disperse into nearby microenvironments, posing potential exposure risks. Thus, accurately identifying the emission hotspots of TRAPs is essential for assessing potential exposure risks. We investigated the relationship between turbulent kinetic energy (TKE) and pollutant dispersi...
Xiao He Xuan Zheng Shuwen Guo- [...]
Ye Wu
The advancement of analytical techniques, such as comprehensive two-dimensional gas chromatography coupled with mass spectrometry (GC×GC–MS), enables the efficient separation of complex organics. Developing innovative methods for data processing and analysis is crucial to unlock the full potential of GC×GC–MS in understanding intricate chemical mix...
Implementing temporary traffic control measures is a common strategy to prevent air pollution and alleviate traffic congestion during mega-events. Accurate assessment of event-time vehicular emissions is useful for local authorities to develop effective policies. However, many previous assessments were based on policy-based scenarios, which often f...
The in-depth investigation of the high black carbon (BC) emission scenarios of heavy-duty diesel vehicles (HDDVs) is a crucial step toward developing effective control strategies. Chassis dynamometer tests were conducted for three in-use HDDVs, namely, vehicle #1, #2, and #3, focusing on the instantaneous BC characterizations during multiple drivin...
Xiao He Xuan Zheng Shuwen Guo- [...]
Ye Wu
The advancement of analytical techniques, such as comprehensive two-dimensional gas chromatography coupled with mass spectrometry (GC×GC-MS), enables the efficient separation of complex organic matrix. Developing innovative methods for data processing and analysis is crucial to unlock the full potential of GC×GC-MS in understanding intricate chemic...
Nitrogen oxides (NOx) emissions from heavy-duty diesel vehicles (HDDVs) have adverse effects on human health and the environment. On-board monitoring (OBM), which can continuously collect the vehicle performance and NOx emissions throughout the operation lifespan, is recognized as the core technology for future vehicle in-use compliance, but its la...
Some in-use China IV and China V heavy-duty diesel vehicles (HDDVs) with selective catalytic reduction (SCR) systems probably fail to mitigate nitrogen oxide (NOX) emissions as expected. Meanwhile, these SCR-equipped HDDVs might emit excessive ammonia (NH3). To better understand the NOX and NH3 emissions from typical HDDVs in China, seventeen in-us...
Vehicle electrification has been recognized for its potential to reduce emissions of air pollutants and
greenhouse gases in China. Several studies have estimated how national-level policies of electric vehicle
(EV) adoption might bring very large environmental and public health benefits from improved air quality to
China. However, large-scale adopt...
China, the world leader in automobile production and sales, confronts the challenge of transportation emissions, which account for roughly 10% of its total carbon emissions. This study, utilizing real-world vehicle data from three major Chinese cities, assesses the impact of Battery Electric Vehicles (BEVs) on air quality. Our analysis reveals that...
Yu Lei Zhicong Yin Xi Lu- [...]
Kebin He
China is now confronting the intertwined challenges of air pollution and climate change. Given the high synergies between air pollution abatement and climate change mitigation, the Chinese government is actively promoting synergetic control of these two issues. The Synergetic Roadmap project was launched in 2021 to track and analyze the progress of...
Real-world heavy-duty diesel trucks (HDTs) were found to emit far more excess nitrogen oxides (NOx) and black carbon (BC) pollutants than regulation limits. It is essential to systematically evaluate on-road NOx and BC emission levels for mitigating HDTs emissions. This study launched 2109 plume chasing campaigns for NOx and BC emissions of HDTs ac...
In response to climate change, China is making great efforts to increase the green area for carbon sequestration. Road verges, as marginal land with favorable conditions for plant growth and ease of transportation, can be used for biomass production, but the biomass production and carbon sequestration potential have not been assessed. Here, we mapp...
Vehicle emissions in China have been decoupled from the rapid motorization owing to the comprehensive control strategies. China’s increasingly ambitious goals for better air quality are calling for deep emission mitigation, posing a need to develop an up-to-date emission inventory that can reflect the fast-developing policies on vehicle emission co...
A widening gap between official and real-world fuel consumption of passenger cars has been reported worldwide. However, previous policy evaluation has not adequately incorporated real-world performance. To comprehensively evaluate China’s orporate Average Fuel Consumption (CAFC) policy, we update the fuel
consumption gap with millions of consumer-r...
China is facing the challenge of synergistic reduction of air pollutants and CO2 emissions. However, the studies on its historical progress and future priorities are insufficient. This study compiled China's emission inventory of air pollutants and CO2 from 2005 to 2021 (ABaCAS-EI v2.0 dataset) based on a unified emission-source framework by consid...
The synergetic benefit of air quality improvements together with greenhouse gas (GHG) mitigations from fleet electrification can be maximized if the power used for electric vehicles (EVs) is from renewables. The worth-noting mismatch between renewable power generation and EV fleet charging demand requires appropriate coordination strategy. Here, we...
It is well recognized that carbon dioxide and air pollutants share similar emission sources so that synergetic policies on climate change mitigation and air pollution control can lead to remarkable co-benefits on greenhouse gas reduction, air quality improvement, and improved health. In the context of carbon peak, carbon neutrality, and clean air p...
On-road ammonia (NH3) emissions play a significant role in fine particulate matter (PM2.5) formation in urban areas, posing severe risks for human health. Limited studies have depicted the spatial and temporal variations of on-road NH3 emissions, in particular lacking detailed quantification of their contributions within densely populated areas. In...
An increasing divergence regarding fuel consumption (and/or CO2 emissions) between real-world and type-approval values for light-duty gasoline vehicles (LDGVs) has posed severe challenges to mitigating greenhouse gases (GHGs) and achieving carbon emissions peak and neutrality. To address this divergence issue, laboratory test cycles with more real-...
Ammonia (NH3) plays a vital role in the formation of fine particulate matter (PM2.5). Prior studies have primarily focused on the control of agricultural NH3 emissions, the dominant source of anthropogenic NH3 emissions. The air quality impact from vehicular NH3 emissions, which could be particularly important in urban areas, has not been adequatel...
China is facing the challenge of synergistic reducing air pollutants and CO2 emissions in the coming decades. The coupled emission inventory of air pollutants and CO2 is a prerequisite to designing the synergetic emission reduction strategy. This study compiled China’s emission inventory of air pollutants and CO2 during 2005–2021 (ABaCAS-EI v2.0 da...
On-road ammonia (NH3) emissions play a significant role in fine particulate matter (PM2.5) formation in urban areas, posing severer risks for human health. Limited studies have depicted the spatial and temporal variations of on-road NH3 emissions, in particular lacking detailed quantification of their contributions within densely-populated areas. I...
The rapidly growing vehicle population has become a crucial contributor to severe air-pollution and public health issues. In urban areas, vehicles have become one of the important sources of air pollutants such as nitrogen oxides and fine particulate matter (PM2.5). In particular, the on-road concentrations of traffic-related air pollutants (TRAPs)...
The distribution pattern of near-road air pollutants is important for addressing air pollution issues. In this study, size-segregated particle number concentration (PNC) and black carbon (BC) concentration were measured at different locations perpendicular to a major roadway in Shanghai, aiming to improve the understanding of distribution patterns...
Dong Ma Xiaomeng Wu Xin Sun- [...]
Ye Wu
Vehicle mileage is one of the key parameters for accurately evaluating vehicle emissions and energy consumption. With the support of the national annual vehicle emission inspection networked platform in China, this study used big data methods to analyze the activity level characteristics of the light-duty passenger vehicle fleet with the highest ow...
Tailpipe emissions from three heavy-duty diesel vehicles (HDDVs), complying with varying emission standards and installed with diverse aftertreatment technologies, are collected at a certified chassis dynamometer laboratory. The HDDV-emitted intermediate-volatility and semi-volatile organic compound (I/SVOC) emission and the gas–particle partitioni...
During the COVID-19 lockdown, the dramatic reduction of anthropogenic emissions provided a unique opportunity to investigate the effects of reduced anthropogenic activity and primary emissions on atmospheric chemical processes and the consequent formation of secondary pollutants. Here, we utilize comprehensive observations to examine the response o...
Efforts have been directed to pollution control of fine particles (PM2.5) since exposure to PM2.5 could result in adverse health effects. However, PM2.5 exposure disparities persisted even with largely declined concentrations. Here, we applied taxi-based measurements to characterize hyper-localized PM2.5 exposures (30-m resolution) in Xi'an in 2019...
Tailpipe emissions from three heavy-duty diesel vehicles (HDDVs), complying with varying emission standards and installed with diverse aftertreatment technologies, are collected at a certified chassis dynamometer laboratory. The HDDV-emitted intermediate-volatility and semi-volatile organic compound (I/SVOC) emission and the gas-particle partitioni...
Progressively stringent regulations regarding vehicle emissions and fuel economy have spurred technology diversification in light-duty passenger vehicles (LDPVs). To assess the real-world emissions and fuel economy performances of hybrid electric vehicles (HEVs) compared to conventional internal combustion engine (ICE) vehicles, on-road measurement...
Assessing the disparities of urban-rural air quality response to changes in emissions is essential for the development of effective air pollution mitigation strategies in megacities. However, meteorology and nonlinear atmospheric chemistry complicate the determination of emission-air quality responses. Here, we established a machine� learning (ML)-...
In recent years, with rapid increases in the number of vehicles in China, the contribution of vehicle exhaust emissions to air pollution has become increasingly prominent. To achieve the precise control of emissions, on-road remote sensing (RS) technology has been developed and applied for law enforcement and supervision. However, data quality is s...
Vehicle interior air quality is usually determined by the levels of in-cabin air pollutants, such as particulate matter (PM), gaseous air pollution (volatile organic compounds [VOCs], oxides of nitrogen [NOx], and carbon monoxide [CO]), and carbon dioxide [CO2], which reflect the freshness of indoor air. Nowadays, cabin air filters play a key role...
Xiao He Xuan Zheng Yan You- [...]
Ye Wu
Intermediate-volatility and semi-volatile organic compounds (I/SVOCs) are key precursors of secondary organic aerosol (SOA). However, the comprehensive characterization of I/SVOCs has long been an analytical challenge. Here, we develop a novel method of speciating and quantifying I/SVOCs using two-dimensional gas chromatography time-of-flight mass...
The spatial distribution of elevated particulate matter (PM) concentrations represents a public health concern due to its association with adverse health effects. In this study, a city-wide spatial variability of PM (PM10 and PM2.5) concentrations in Jinan, China is evaluated using a combination of measurements from 1700 fixed sites and taxi-based...
Wood smoke contains large quantities of carbonaceous aerosols known to increase climate forcing and be detrimental to human health. This paper reports the findings from our ambient sampling of fresh residential wood combustion (RWC) plumes in two heating seasons (2015-2016, 2016-2017) in Upstate New York. An Aethalometer (AE33) and a pDR-1500 were...
On-road vehicle emissions are a major contributor to significant atmospheric pollution in populous metropolitan areas. We developed an hourly link-level emissions inventory of vehicular pollutants using two land-use machine learning methods based on road traffic monitoring datasets in the Beijing–Tianjin–Hebei (BTH) region. The results indicate tha...
During the COVID-19 lockdown, the dramatic reduction of anthropogenic emissions provided a unique opportunity to investigate the effects of reduced anthropogenic activity and primary emissions on atmospheric chemical processes and the consequent formation of secondary pollutants. Here, we utilize comprehensive observations to examine the response o...
Plug-in electric vehicles (EVs) are expected to synergize with low or even zero-carbon electricity towards a deep mitigation of greenhouse gas (GHG) emission and ultimately carbon neutrality. These benefits are only obtainable when EV charging maximizes the consumption of electricity generated from renewable energy sources. However, the current mis...
Diesel vehicles have caused serious environmental problems in China. Hence, the Chinese government has launched serious actions against air pollution and imposed more stringent regulations on diesel vehicle emissions in the latest China VI standard. To fulfill this stringent legislation, two major technical routes, including the Exhaust Gas Recircu...
High-emission vehicles (high emitters) likely have significantly higher nitrogen oxide and particle number (PN) emission factors compared to other vehicles. Effective identification of these vehicles in road traffic requires efficient and cost-effective instruments. In this study, a compact, cost-effective sensor platform was developed and evaluate...
The development of intelligent approaches to quantify and mitigate on-road emissions is essential for urban and transportation sustainability for global megacities. Here, we utilize high-density traffic monitoring data and land use data to train random forest models capable of accurately predicting dynamic, link-level vehicle emissions. A total of...
The plume-chasing method has been showing great advantages in measuring on-road emission factors (EFs) compared with regulatory methods like dynamometer and portable emission measurement systems (PEMS). In this study, a new on-board measurement system incorporating ultrasonic anemometers and solid-state Lidar was developed to investigate the uncert...
The Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) is the first programme to tackle carbon dioxide (CO2) emissions from a single industry at the global level, to realize the carbon-neutral growth of international flights from 2020 onwards. However, the COVID-19 pandemic has caused a drastic decline in the global aviation...
The escalating concerns regarding air pollution problems surrounding port cities have attracted much research attention. The Port of Shenzhen is one of the busiest container ports worldwide, only third to Shanghai and Singapore globally. However, 70% of the freight transportation demand is satisfied via on-road trucks, leading to serious traffic co...
On-road vehicle emissions are a major contributor to significant atmospheric pollution in populous metropolitan areas. We developed an hourly-based, link-level emissions inventory of vehicular pollutants using two land-use machine learning methods based on the datasets of road traffic monitoring in the Beijing-Tianjin-Hebei (BTH) region. The result...
In roadside environments, commuters are exposed to a high level of traffic-related pollution. Despite vegetation is often used to mitigate air pollution in road environments, its air quality impacts are complex and could be both positive or negative depending on specific conditions. This study conducted field measurements to assess the air quality...
Black carbon (BC) is considered the second largest anthropogenic climate forcer, but the radiative effects of BC are highly correlated with its combustion sources. On-road vehicles are an important source of anthropogenic BC. However, there are major uncertainties in the estimates of the BC emissions from on-road light-duty passenger vehicles (LDPV...
Black carbon (BC) is the most potent light-absorbing component of particulate matter and can have a significant warming impact. On-road vehicles are a major source of BC and a significant contributor to global warming. This paper establishes an updated inventory to quantify the mitigation potential of efforts to control BC emissions from on-road tr...
Enhancing automobile fuel efficiency is crucial to decarbonizing the transport sector. Recent studies have revealed a gap between real-world fuel efficiency and results from laboratory tests, where “off-cycle” auxiliary devices, like air conditioning (AC) systems, are not turned on. AC consumes the most energy among all off-cycle devices; however,...
Although secondary particulate matter is reported to be the main contributor of PM2.5 during haze in Chinese megacities, primary particle emissions also affect particle concentrations. In order to improve estimates of the contribution of primary sources to the particle number and mass concentrations, we performed source apportionment analyses using...