Showing papers by "Haibo Chen published in 2022"
TL;DR: In this article , monetary impact values of exhaust and non-exhaust emissions emitted from internal combustion engine vehicles (ICEVs) and their equivalent EVs from an economic-environmental perspective, expressed as monetary impact value, were calculated according to the emission factors and damage costs of these pollutants.
25 citations
TL;DR: In this article , normalized solutions for the following Choquard equations with lower critical exponent and a local perturbation were studied and several nonexistence and existence results were proved. But they were not considered for the case of double critical exponents.
Abstract: We study normalized solutions for the following Choquard equations with lower critical exponent and a local perturbation $ -\Delta u+\lambda u=\gamma (I_{\alpha }\ast |u|^{\frac{\alpha }{N}+1})|u|^{\frac{\alpha }{N}-1}u+\mu |u|^{q-2}u \quad \text{in}\quad \mathbb{R}^{N}, \int_{\mathbb{R}^{N}}$ $|u|^{2}dx=c^{2},$ where $\gamma ,\,\mu,\,c$ are given positive numbers and $2
22 citations
TL;DR: In this paper , the changes in the surface functional groups, carbon chemical state, and graphitization degree during thermal treatment in an inert gas environment at intermediate temperatures of 600°C, 800°C and 1000°C were investigated.
Abstract: The thermal deactivation of diesel soot particles exerts a significant influence on the control strategy for the regeneration of diesel particulate filters (DPFs). This work focused on the changes in the surface functional groups, carbon chemical state, and graphitization degree during thermal treatment in an inert gas environment at intermediate temperatures of 600°C, 800°C, and 1000°C and explore the chemical species that were desorbed from the diesel soot surface during thermal treatment using a thermogravimetric analyser coupled with a gas-chromatograph mass spectrometer (TGA-GC/MS). The surface functional groups and carbon chemical state were characterized using Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The graphitization degree was evaluated by means of Raman spectroscopy (RS). The concentrations of aliphatic C-H, C-OH, C=O, and O-C=O groups are reduced for diesel soot and carbon black when increasing the thermal treatment temperature, while the sp2/sp3 hybridized ratio and graphitization degree enhance. These results provide comprehensive evidence of the decreased reactivity of soot samples. Among oxygenated functional groups, the percentage reduction during thermal treatment is the largest for the O-C=O groups owing to its worst thermodynamic stability. TGA-GC/MS results show that the aliphatic and aromatic chains and oxygenated species would be desorbed from the soot surface during 1000°C thermal treatment of diesel soot.
9 citations
TL;DR: Wang et al. as discussed by the authors examined the impact of the national urban agglomeration construction (NUAC) on PM2.5 pollution reduction and found that NUAC has a positive effect on PM 2.5 control.
Abstract: Urban agglomerations, as a new model of urbanization and a means of regional integration, provide modern ideas for achieving haze pollution control. Treating the implementation of Urban Agglomeration Development Plan as a quasi-natural experiment, the multi period DID method is applied to examine the impact of the national urban agglomeration construction (NUAC) on PM2.5 pollution reduction. Furthermore, the heterogeneity analysis, transmission mechanism and spatial spillover effects are explored in depth. Our analysis yields the following conclusions. First, NUAC has a positive effect on PM2.5 pollution control. More Specifically, the annual average PM2.5 concentration will decrease by 7.9% in urban agglomeration cities. And a series of robustness tests confirms the credibility of this conclusion. Second, regarding the heterogeneity of urban characteristics, the pollution mitigation effect of NUAC is more pronounced in central and western cities, small-scale cities, non-resource-based cities and cities with stricter environmental regulation. Third, analysis of transmission mechanism suggests that NUAC suppresses haze pollution mainly by accelerating industrial agglomeration, promoting technological innovation and reducing resource misallocation. Finally, taking the spatial correlation of air pollutants into account, the environmental improvement effect of NUAC still exists. Furthermore, results of spatial spillover effects show that the pilot policy is detrimental to PM2.5 pollution reduction in other urban agglomeration cities, which means that there is no linkage effect in regional pollution control and environmental management. These results provide reference to not only the Chinese government for effective strategies to cope with PM2.5 pollution but also the studies on regional environmental governance in the international context.
8 citations
TL;DR: In this paper , a machine learning method (i.e., Extreme Gradient Boosting (XGBoost)) was used to probe the effect of driving behaviour on tyre wear by monitoring real-time driving behaviour.
7 citations
TL;DR: In this paper, three Euro-6 compliant direct injection gasoline passenger cars and a diesel passenger car are tested in a real-world driving trial in which nineteen drivers are involved, and novel key performance indicators with reference to the regimes of specific NOx and PN contributions to total emissions are defined.
6 citations
TL;DR: Wang et al. as mentioned in this paper examined whether innovative city construction can contribute to meet carbon mitigation targets, and the results showed that innovative city pilots significantly reduce carbon emissions compared to nonpilot areas.
Abstract: As a sustainable urban design, innovative city pilots offer a way for developing countries to achieve carbon reduction goals. To date, a total of 78 innovative cities have been established in China. In this context, this study examines whether innovative city construction can contribute to meet carbon mitigation targets. On the basis of expounding the mechanism of innovative city pilots on carbon emissions, the multiperiod difference in differences method is applied to investigate the average treatment effect and the mediating effect model is used to validate the transmission mechanism. The results show that innovative city pilots significantly reduce carbon emissions. Compared to nonpilot areas, the pilot areas reduce carbon emissions by 15%. Specifically, technological innovation is the primary channels for innovative city pilots to influence carbon emissions but industrial structure effect does not work. Furthermore, the superimposed effect analysis indicates that the carbon reduction effect of the city as both innovative city pilot and other pilot (low-carbon pilot, broadband China pilot, intellectual property pilot) is greater than that of a single pilot. Results of heterogeneity analysis indicate that carbon mitigation efforts are more effective in central and western cities, nonmega cities, resource-based cities and cities with high human capital and financial development. In addition, the pilot policy has a positive spatial spillover effects on carbon reduction in cities with geographical proximity and economic ties. These results can contribute to precisely assess the environment benefits of promoting innovative city pilot projects and provide a decision making reference for fighting climate change in the era of knowledge economy.
6 citations
TL;DR: In this paper , a multi-level, discrete-time decomposition of the problem is presented in which speed profiles are optimized within each link, given boundary conditions of entry/exit times and speeds, within which the joint choice of path and speed profile is made.
4 citations
TL;DR: In this paper , the authors developed an environmental life cycle assessment model to evaluate e-bikes powered by lithium-ion battery, compared with a petrol car and a battery electric vehicle (BEV) for commuting.
Abstract: Electric bikes (e-bikes) represent an increasing share of urban mobility due to their small sizes and clean fuels. This study developed an environmental life cycle assessment model to evaluate e-bikes powered by lithium-ion battery, compared with a petrol car and a battery electric vehicle (BEV) for commuting. System boundary included vehicle lifecycle and fuel lifecycle. The model also included emissions from tyre and brake wear, and noise impacts in a case study in the UK. Results showed that BEVs and e-bikes reduce CO2, and this reduction can increase with change in electricity mix and battery recycling. Advantages of e-bikes are not proportional to the weight of the vehicle. Non-exhaust emissions are significant to respiratory effects and human toxicity, so are noise reductions due to the use of electric vehicles. The model and data should help to conduct similar studies elsewhere in the world and to develop policies for electric vehicles.
4 citations
TL;DR: In this article , the authors quantified the change in traffic flow on the M25 motorway in the UK due to the COVID-19 outbreak and explored the impact of the change on non-exhaust PM2.5 and PM10 emissions for different categories of vehicle.
4 citations
TL;DR: In this article , real driving performance and exhaust emissions of a diesel car were tested over sixteen drivers under real-world conditions, and the results indicated that DPF regeneration events occurred in three of thirty-two test trips and the maximum exhaust temperature was 250 °C during the regeneration process.
TL;DR: In this paper , the authors used finite element analysis (FEA) and experimental approaches to predict brake wear PM10 emissions during the WLTP-B cycle and found that the top five most important factors governing brake wear were dissipation energy, initial braking speed, final rotor temperature, braking power, and deceleration rate.
TL;DR: In this article , it was shown that the Choquard equation (0.1) has infinitely many non-radial positive solutions when a and b satisfy some suitable conditions.
TL;DR: In this article , a finite element analysis (FEA) approach was used to predict PM10 emissions from brake wear per braking event in three test driving cycles (WLTP, LACT, and WLTP-Brake).
TL;DR: In this paper , the effect of the lockdown on TPN and NPN in the UK was quantified and the effect varies between rural, urban background and traffic sites, and also the effect on particle numbers was compared with particle mass concentrations, mainly PM10 and PM2.5.
TL;DR: In this paper , the impact of smart traffic interventions on air quality was assessed in Thatcham, West Berkshire, UK, where the intervention linked NO2 levels with the cycle time of the traffic lights.
Abstract: In this paper, the impact of smart traffic interventions on air quality was assessed in Thatcham, West Berkshire, UK. The intervention linked NO2 levels with the cycle time of the traffic lights. When NO2 levels exceeded a certain threshold, the strategy was triggered, which reduced the traffic congestion by turning the traffic lights green. Eight Earthsense Zephyrs air quality sensors and nine inductive-loop traffic detectors were installed in Thatcham to simultaneously monitor the air quality and traffic flows, respectively. Compared to the pre-intervention period, the observed NO2 concentrations decreased in June, July and August and increased in September 2021, however, this does not reveal the true effect of smart traffic intervention. Using the observed data on the days with- and without-exceedances, we developed two machine learning models to predict the Business-as-usual (BAU) air quality level, i.e., a generalised additive model for average concentration and a quantile regression model for peak concentration. Our results demonstrated that average predicted concentrations (BAU) were lower than the observed concentrations (with intervention) by 12.45 %. However, we found that peak concentrations decreased by 20.54 %.
TL;DR: This paper studies the following nonlinear Klein–Gordon–Maxwell system, with a focus on the second half of the second decade of the 1990s.
Abstract: In this paper we study the following nonlinear Klein–Gordon–Maxwell
system
{
−
Δ
u
+
[
m
0
2
−
(
ω
+
φ
)
2
]
u
=
f
(
u
)
in
R
3
,
Δ
φ
=
(
ω
+
φ
)
u
in
R
3
,
where
0
<
ω
<
m
0
. Based on an abstract critical
point theorem established by Jeanjean, the existence of positive ground
state solutions is proved, when the nonlinear term
f
(
u
)
exhibits linear
near zero and a general critical growth near infinity. Compared with other
recent literature, some different arguments have been introduced and some
results are extended.
TL;DR: In this article , the existence result for super-critical problems involving the fractional p-Laplacian (−Δ)psu+V(x)|u|p−2u=|u|ς− 2u+λ|u |u|q −2u,inRN, where 0
TL;DR: In this article , a class of Kirchhoff-Schrödinger-Poisson systems is considered and the existence and multiplicity of nontrivial solutions are proved.
Abstract: We consider a class of Kirchhoff-Schrödinger-Poisson systems. By using the Mountain Pass Theorem and the Symmetric Mountain Pass Theorem of Rabinowitz, we prove the existence and multiplicity of nontrivial solutions. Our conditions weaken the Ambrosetti Rabinowitz type condition.
TL;DR: In this paper , the authors present a methodology for deriving new driving cycles, developed from empirically deduced power relationships, before demonstrating their application under different assumptions on the terrain and vehicle characteristics.
Abstract: Increasingly, demanding environmental standards reflect the need for improved energy efficiency and reduced externalities in the transportation sector. Reference driving cycles provide standard speed profiles against which future developments and innovations may be tested. In the paper, we develop such profiles for a class of electric L-category vehicles, which are anticipated to play an increasing future role in urban areas. While such driving cycles exist for regular L-category vehicles, these may not be suitable in the case of electric vehicles, due to their power output limitations. We present a methodology for deriving these new driving cycles, developed from empirically deduced power relationships, before demonstrating their application under different assumptions on the terrain and vehicle characteristics. The applications demonstrate the feasibility of the method in developing appropriate driving patterns for alternative real-world contexts. On flat terrain, the adjustments made to cope with the power limitations of L-EV do not introduce significant differences in energy consumption, suggesting that the certification does not require extensive modification. However, when considering road slope, differences of up to 5% in energy use and up to 10% in regenerated energy were observed, showing the importance of the developed method for assessing vehicle performance in real-world driving.
22 Feb 2022
TL;DR: In this paper , the authors studied the eigenvalue problem for Kirchhoff-type equation with Hartree nonlinearity, where the Hartree potential is the Riesz potential.
Abstract: In this paper, we study the following eigenvalue problem for Kirchhoff
type equation with Hartree nonlinearity:
\begin{equation}
-M\left(\int_{\mathbb{R}^{N}}|
abla
u|^{2}dx\right)\Delta
u+\mu V(x)u=\left(
I_{\alpha }\ast
Q\left\vert
u\right\vert^{p}\right)
Q\vert u\vert
^{p-2}u+\lambda f(x)u \quad
\text{in}\quad
\mathbb{R}^{N}, \end{equation}
where $N\geq3, a, \mu>0$
parameters, $M(t)=at+1$, $V\in
C(\mathbb{R}^{N},\mathbb{R}%
^{+}) $, $I_{\alpha }$ is the Riesz potential,
$Q(x)\in
L^{\infty}(\mathbb{R}^{N})$
with changes sign in
$\overline{\Omega}:=\left\{V(x)=0\right\}$,
and $0
TL;DR: In this paper , the authors considered a class of Kirchhoff type equation with Hartree nonlinearity and proved that it admits at least two positive solutions under some suitable assumptions for potential V(x) and spatial dimensions N.
Abstract: In this paper, we consider a class of Kirchhoff type equation with Hartree nonlinearity: −(1+a∫RN|∇u|2dx)Δu+λV(x)u=(Iα∗Q|u|p)Q|u|p−2uin RN, where N≥3,a,λ>0 parameters, V∈C(RN,R+), Iα is the Riesz potential, Q(x)≥0 in RN, and 1+αN