[Vertical Distribution Characteristics of Boundary Layer Volatile Organic Compounds in Autumn in the Mixed Industrial and Rural Areas over the Northern Suburb of Nanjing].

Based on the sounding data of VOCs in the lower troposphere (0-1000 m) in the northern suburb of Nanjing in the autumn of 2020, the vertical profile distribution, diurnal variation, and photochemical reactivity of VOCs in this area were analyzed. The results showed that the volume fraction of VOCs decreased with the increase in height (72.1×10±28.

Research on the Influence Mechanism of Consumers' Perceived Risk on the Advertising Avoidance Behavior of Online Targeted Advertising.

In China, online sales continue to grow against the generally adverse effects of the COVID-19 pandemic on economic development. Although advertisers favor online targeted advertising for its precision, consumers may find it intrusive and avoid it. This study constructed a conceptual model based on Stimulus-Organism-Response (SOR) theory, Approach-Avoidance Theory, and Brand Avoidance Theory to investigate the influence mechanism of consumers' perceived risk on the avoidance behavior of online targeted advertising via an online survey.

[Concentration and Reactivity of Carbonyl Compounds in the Atmosphere of North China].

To reveal the characteristics of photochemical pollution in North China, adsorbing columns with 2, 4-dinitrophenylhydrazine(DNPH) were used to sample carbonyl compounds in Shijiazhuang and Xinglong between May 2018 and April 2019. The samples were analyzed by high-performance liquid chromatography to understand the composition, volume fraction, source, ·OH loss rate, and ozone formation potential of the carbonyl compounds. A total of 13 carbonyl compounds containing carbonyl groups were determined, of which acetone, formaldehyde, and acetaldehyde were highest at(6.

[Characteristics of Carbonaceous Species in PM in Southern Beijing].

To investigate the characteristics of carbonaceous species in PM in Beijing after the implementation of the Action Plan for the Prevention and Control of Air Pollution, PM was continuously sampled in the heavily polluted southern urban area of Beijing from December 2017 to December 2018. The characteristics of organic carbon (OC) and element carbon (EC) were then determined. The results showed that the annual concentrations of PM, OC, and EC in Beijing varied in wide ranges of 4.

[Characteristics of Water-soluble Inorganic Ions in PM in Beijing During 2017-2018].

To explore the characteristics of water-soluble inorganic ions (WSIIs) in PM during the process of continuous improvement of air quality in Beijing in recent years, a continuous collection of PM sample campaign was conducted in Beijing from 2017 to 2018. The PM mass concentration and WSIIs were then determined. The results showed that the average concentration of PM in Beijing was (77.

[Variation Characteristics and Sources Analysis of Atmospheric Volatile Organic Compounds in Changbai Mountain Station].

Volatile organic compounds (VOCs) play very important roles in the formation of ozone and secondary organic aerosols. The concentrations, compositions, and seasonal variation of VOCs were measured in 2012 at Changbai Mountain Forest Ecosystem Research Station, a remote station in Northeast China. Weekly samples were collected in the Changbai Mountain area and analyzed via gas chromatography-mass spectrometry.

[Characteristics of Winter Atmospheric Mixing Layer Height in Beijing-Tianjin-Hebei Region and Their Relationship with the Atmospheric Pollution].

Atmospheric mixing layer height (MLH) is one of the main factors affecting the atmospheric diffusion and plays an important role in air quality assessment and distribution of the pollutants. Based on the ceilometers data, this paper has made synchronous observation on MLH in Beijing-Tianjin-Hebei region (Beijing, Tianjin, Shijiazhuang and Qinhuangdao) in heavy polluted February 2014 and analyzed the respective overall change and its regional features. Results show that in February 2014,the average of mixing layer height in Qinhuangdao is the highest, up to 865 +/- 268 m, and in Shijiazhuang is the lowest (568 +/- 207 m), Beijing's and Tianjin's are in between, 818 +/- 319 m and 834 +/- 334 m respectively; Combined with the meteorological data, we find that radiation and wind speed are main factors of the mixing layer height; The relationship between the particle concentration and mixing layer height in four sites suggests that mixing layer is less than 800 m, concentration of fine particulate matter in four sites will exceed the national standard (GB 3095-2012, 75 microg x m(-3)).

[Application of passive sampler to monitor and study atmospheric trace gases in Beijing-Tianjin-Hebei area].

Applying of passive sampler which is a cheap and simple method, the concentrations of SO2, NO2, O3 and NH3 were monitored in ten stations as network in Beijing-Tianjin-Hebei area from Dec. 2007 to investigate the concentration level and change of contaminants as well as the compound pollution in this region. Passive sampler method was fully evaluated to check the applicability in the area and the concentration and spatial distribution of pollutants were studied in this paper.

[Effects of synoptic type on surface ozone pollution in Beijing].

Ozone (O), influenced by meteorological factors, is a primary gaseous photochemical pollutant during summer to fall in Beijing' s urban ambient. Continuous monitoring during July to September in 2008 was carried out at four sites in Beijing. Analyzed with synoptic type, the results show that the ratios of pre-low cylonic (mainly Mongolia cyclone) and pre-high anticylonic to total weather conditions are about 42% and 20%, illustrating the high-and low-ozone episodes, respectively.