scholarly journals Aircraft Emission Inventory and Characteristics of the Airport Cluster in the Guangdong–Hong Kong–Macao Greater Bay Area, China

Atmosphere ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 323
Author(s):  
Jie Li ◽  
Haotian Yang ◽  
Xingang Liu ◽  
Nu Yu ◽  
Yong Tian ◽  
...  
Keyword(s):  
Hong Kong ◽  
Emission Inventory ◽  
Order Approximation ◽  
Pollutant Emissions ◽  
Standard Atmosphere ◽  
Bay Area ◽  
Hc Emissions ◽  
First Order Approximation ◽  
The Impact ◽  
Aircraft Emission

In this study, a compound method using modified Boeing Fuel Flow Method 2 (BFFM2) and an updated First Order Approximation V3.0 (FOA3.0) method deploying the ICAO Time-in-Mode (TIM) was used to produce a more reliable aircraft emission inventory for the Guangdong–Hong Kong–Macao Greater Bay Area (GBA). The results show that compared with the International Standard Atmosphere (ISA) conditions, the total emission of nitrogen oxides(NOx) decreased by 17.7%, while carbon monoxide(CO) and hydrocarbons(HC) emissions increased by 11.2%. We confirmed that taxiing is the phase in which an aircraft emits the most pollutants. These pollutant emissions will decrease by 0.3% to 3.9% if the taxiing time is reduced by 1 minute. Furthermore, the impact of reducing taxi-out time on emissions is more significant than that of reducing the taxi-in time. Taking the total aircraft emission factors as the main performance indicators, Hong Kong International Airport (VHHH) contributes the most to the total emissions of the GBA, while the Zhuhai airport(ZGSD) contributes the least. The contribution of an individual airport to the total emissions of the GBA is mainly determined by the proportion of Boeing B77L, B77W, and B744.

Impact parameter treatments of certain hydrogen-proton and hydrogen-hydrogen excitation collisions

1958 ◽  
Vol 245 (1242) ◽  
pp. 299-311 ◽  
Keyword(s):  
Impact Parameter ◽  
Stationary State ◽  
Born Approximation ◽  
Order Approximation ◽  
Hydrogen Atoms ◽  
First Order ◽  
Normal Hydrogen ◽  
First Order Approximation ◽  
The Impact

Consideration is given to the impact parameter form of the Born approximation and of the pRA approximation (i.e. the first-order approximation to which the perturbed stationary state, or PSS, approximation tends). Calculations are carried out on the excitation of normal hydrogen atoms to the 2 s or 2 p states in encounters with protons and other normal hydrogen atoms. The results obtained provide some information on the range of validity of the Born approximation. The impact-parameter treatment corresponding to a simplified version of the second Born approximation is given and discussed. Attention is drawn to the fact that for certain transitions the pRA approximation fails seriously when the encounter is very close.

scholarly journals Study on the Spatial Pattern of Innovation Output and Influencing Factors in Guangdong-Hong Kong-Macao Greater Bay Area

2019 ◽  
Author(s):  
Dongliang Yang ◽  
Chunfeng Li
Keyword(s):  
Hong Kong ◽  
Spatial Pattern ◽  
Industrial Structure ◽  
Study Region ◽  
Bay Area ◽  
Innovation Activities ◽  
Level Of Economic Development ◽  
Innovation Output ◽  
Countermeasures And Suggestions ◽  
The Impact

The advantageous location, port clusters, strong economic strength, developed financial system, rational and orderly urban division of labor and modern industrial system of Guangdong-Hong Kong-Macao greater bay area provide sustainable driving force for innovation activities in this region. This paper selected the Gini-coefficient, first degree index and concentration index to measure the spatial pattern characteristics of innovation output in Guangdong-Hong Kong-Macao greater bay area. The results show that the innovation output presented a spatial pattern of center-periphery in the study region with Shenzhen and Guangzhou as the dual centers and engines of innovation and Dongguan and Foshan as the main innovative areas. Further empirical analysis of the impact of various factors on innovation output in the study region found that R&D expenditure, the number of R&D personnel, the level of economic development and industrial structure all have significant promoting effects on innovation output. Accordingly, this paper put forward countermeasures and suggestions to promote the innovative development of Guangdong-Hong Kong-Macao greater bay area and build a world-class scientific and technological innovation bay area.

scholarly journals The Impact of Entrepreneurial Environment on Entrepreneurial Will of The Youth in Guangdong-Hong Kong-Macao Greater Bay Area ——Mediating Effects of Entrepreneurial Attitude, Subjective Norm and Perceived Behavior Control

2021 ◽  
Vol 3 (2) ◽  
pp. 27-46
Author(s):  
Yuxuan HUANG ◽  
Xinyu ZHANG ◽  
Yaxuan FENG
Keyword(s):  
Hong Kong ◽  
Subjective Norm ◽  
Mediating Effect ◽  
Mediating Effects ◽  
Behavior Control ◽  
Bay Area ◽  
Entrepreneurial Attitude ◽  
Perceived Behavior Control ◽  
The Impact ◽  
Perceived Behavior

The youth from Guangdong-Hong Kong-Macao Greater Bay Area, as the main body of science and technology innovation, is the core driving force for Guangdong-Hong Kong-Macao Greater Bay Area to become an international innovation and entrepreneurship base. Based on the TPB, this paper analyzes the mediating effects of entrepreneurial attitude, subjective norm and perceived behavior control, and establishes a structural equation model, to explore the mechanism and path of the impact of the entrepreneurial environment on the entrepreneurial will of the youth in the bay area. This paper finds that these three dimensions of the TPB play multiple mediating roles in the path of the impact of the entrepreneurial environment on the entrepreneurial will, and it has a completely mediating effect, that is, the entrepreneurial environment influences the entrepreneurial will by influencing personal attitude, perceptual behavior control and subjective norm. Therefore, in the future, the Guangdong-Hong Kong-Macao Greater Bay Area government should enhance the entrepreneurship willingness of the young people in the three places through preferential policies for starting businesses, open channels for innovation and business start-up information, and deepening the openness and innovation of the institutional mechanism of Guangdong, Hong Kong and Macao.

scholarly journals Ecological Security Evaluation and Spatial-temporal Evolution Characteristics of Natural Resources Based on Wind-Driven Optimization Algorithm------A case study of Guangdong-Hong Kong-Macao Greater Bay Area

2021 ◽  
Author(s):  
Xiaoling Ke ◽  
wei shi ◽  
Chang Yang ◽  
Haixiang Guo ◽  
Amal Mougharbel
Keyword(s):  
Hong Kong ◽  
Natural Resources ◽  
Optimization Algorithm ◽  
Evaluation System ◽  
Sustainable Urban Development ◽  
Security Evaluation ◽  
Security Level ◽  
Ecological Security ◽  
Bay Area ◽  
The Impact

As a complex system, the urban natural resources system comprises water, land, forest, and air resources. Natural resources are the essential elements of economic and social development and the source of sustainable urban development. However, there are few articles which regard different natural resources as a comprehensive system to evaluate. This study aimed to reveal the patterns of natural resources and highlight the impact of natural resource subsystem. Firstly, this study establishes the ecological security evaluation system of natural resources based on the “Driving Force-Pressure-State-Response” model. Secondly, we use the Wind-Driven Optimization algorithm to optimize the Projection Pursuit model to calculate the value of ecological security level and the comprehensive value of ecological security in Guangdong-Hong Kong-Macao Greater Bay Area (2013-2018). The temporal characteristics and spatial layout of natural resources ecological security, the impact of mechanism of water, land, forest, and air resources subsystems on natural resources ecological security were assessed. The results shows that the ecological security level of natural resources in nine cities of Guangdong-Hong Kong-Macao Greater Bay Area is on the rise as a whole from 2013 to 2018. However, the ecological security level in the central region of the Greater Bay Area is low, which is directly related to the severe environmental pollution of its water and air resources. The results are basically consistent with the actual situation, which can provide a reference for the ecological security evaluation of natural resources in other urban agglomerations.

scholarly journals Spectral Analyses of Wolf-Rayet Stars: The Impact of Clumping

1999 ◽  
Vol 169 ◽  
pp. 239-242 ◽  
Author(s):  
Wolf-Rainer Hamann ◽  
Lars Koesterke
Keyword(s):  
Mass Loss ◽  
Electron Scattering ◽  
Loss Rate ◽  
Order Approximation ◽  
Mass Loss Rate ◽  
Spectral Analyses ◽  
First Order ◽  
Homogeneous Models ◽  
First Order Approximation ◽  
The Impact

AbstractInhomogeneities are accounted for in our non-LTE stellar wind models in a first-order approximation. When applied for spectral analyses, clumpy models yield lower mass-loss rates than homogeneous models, while other parameters are not affected. For representative WR stars, we determine the density contrast from the electron-scattering line wings and obtain mass-loss rate reductions by a factor of two, typically.

scholarly journals Atmospheric Pollution Impact Assessment of Brick and Tile Industry: A Case Study of Xinmi City in Zhengzhou, China

2021 ◽  
Vol 13 (4) ◽  
pp. 2414
Author(s):  
Liuzhen Xie ◽  
Qixiang Xu ◽  
Ruidong He
Keyword(s):  
Air Quality ◽  
Emission Inventory ◽  
Census Data ◽  
Emission Control ◽  
Temporal Distribution ◽  
Point Sources ◽  
Control Measures ◽  
Pollutant Emissions ◽  
Brick And Tile ◽  
The Impact

The brick and tile industry was selected to investigate the impact of pollutants emitted from such industry on air quality. Based on the 2018 Zhengzhou City Census data and combined with field sampling and research visits, an emission inventory of the brick and tile industry in Xinmi City was established using the emission factor method. Based on the established emission inventory, the concentrations of SO2, NOX, and PM2.5 emitted by 31 brick and tile enterprises were then predicted using the CALPUFF model (California puff model, USEPA), which had been evaluated for accuracy, and the simulation results were compared with the observed results to obtain the impact of pollutant emissions from the brick and tile industry on air pollution in the simulated region. Results show that SO2, NOX, and PM2.5 emissions from the brick and tile industry in the study area in 2018 were 564.86 tons, 513.16 tons, and 41.01 tons, respectively. The CALPUFF model can simulate the characteristics of meteorological changes and pollutant concentration trends, and the correlation coefficient of the fit curve between the pollutant observed data and the simulated data was higher than 0.8, which can reproduce the impact of key industrial point sources on air quality well. The simulated concentration values and spatial and temporal distribution characteristics of SO2, NOX, PM2.5 in spring, summer, autumn, and winter were obtained from the model simulations. The contribution of pollutant emissions from the brick and tile industry to the monthly average concentrations of SO2, NOX, and PM2.5 in the simulated region were 6.58%, 5.38%, and 1.42%, respectively, with the Housing Administration monitoring station as the receptor point. The brick and tile industry should increase the emission control measures of SO2 and NOX, and at the same time, the emission control of PM2.5 cannot be slackened.

scholarly journals Development of a vehicle emission inventory with high temporal–spatial resolution based on NRT traffic data and its impact on air pollution in Beijing – Part 2: Impact of vehicle emission on urban air quality

2016 ◽  
Vol 16 (5) ◽  
pp. 3171-3184 ◽  
Author(s):  
Jianjun He ◽  
Lin Wu ◽  
Hongjun Mao ◽  
Hongli Liu ◽  
Boyu Jing ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Spatial Resolution ◽  
Emission Inventory ◽  
Emission Factors ◽  
Pollutant Emissions ◽  
Vehicle Emission ◽  
Traffic Data ◽  
Near Surface ◽  
The Impact

Abstract. A companion paper developed a vehicle emission inventory with high temporal–spatial resolution (HTSVE) with a bottom-up methodology based on local emission factors, complemented with the widely used emission factors of COPERT model and near-real-time (NRT) traffic data on a specific road segment for 2013 in urban Beijing (Jing et al., 2016), which is used to investigate the impact of vehicle pollution on air pollution in this study. Based on the sensitivity analysis method of switching on/off pollutant emissions in the Chinese air quality forecasting model CUACE, a modelling study was carried out to evaluate the contributions of vehicle emission to the air pollution in Beijing's main urban areas in the periods of summer (July) and winter (December) 2013. Generally, the CUACE model had good performance of the concentration simulation of pollutants. The model simulation has been improved by using HTSVE. The vehicle emission contribution (VEC) to ambient pollutant concentrations not only changes with seasons but also changes with time. The mean VEC, affected by regional pollutant transports significantly, is 55.4 and 48.5 % for NO2 and 5.4 and 10.5 % for PM2.5 in July and December 2013 respectively. Regardless of regional transports, relative vehicle emission contribution (RVEC) to NO2 is 59.2 and 57.8 % in July and December 2013, while it is 8.7 and 13.9 % for PM2.5. The RVEC to PM2.5 is lower than the PM2.5 contribution rate for vehicle emission in total emission, which may be due to dry deposition of PM2.5 from vehicle emission in the near-surface layer occuring more easily than from elevated source emission.

scholarly journals Can Collaborative Innovation Constrain Ecological Footprint? Empirical Evidence From Guangdong-Hong Kong-Macao Greater Bay Area, China

2021 ◽  
Author(s):  
Xiaojun You ◽  
Qixiang Li ◽  
Kyle M. Monahan ◽  
Fei Fan ◽  
Haiqian Ke ◽  
...  
Keyword(s):  
Hong Kong ◽  
Ecological Footprint ◽  
Economic Status ◽  
Scientific Productivity ◽  
Threshold Effect ◽  
Four Dimensions ◽  
Carbon Neutrality ◽  
Bay Area ◽  
Collaborative Innovation ◽  
The Impact

Abstract Constraining ecological footprint (EF) has become an important policy priority to reach the carbon neutrality goal and deal with environmental issues, as it represents the socio-economic pressures on the environment. Current studies on the impact of collaborative innovation (CI) on EF is insufficient, although CI contributes to scientific productivity which benefits the technological progress in clean technology. In addition, seen from different perspectives, whether CI is effective in reducing EF has remain controversial. To further clarify this issue, this paper took Guangdong-Hong Kong-Macao Greater Bay Area (GBA) of China as a case, calculated EF between annual periods of 2008-2018 at the municipal level, measured CI from four dimensions and applied threshold regression models to compare the impact of CI on EF across different economic intervals. The findings showed that: the EF of GBA displayed an overall upward trend with prominent spatial heterogeneity during the study period. The impact of CI on EF presented a double-threshold effect when examined with different indicators. Among which, the flow of scientific personnel and capital boosted EF, which intensified with economic development; while collaboration in technology exerted significant inhibitory effects on EF, and the influence of inter-city knowledge collaboration was limited. This might inspire policymakers to adopt sustainable strategies depending on the type of CI and the economic status of the city to constrain the growth of EF, thus minimizing impacts of human activities on the environment.

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