[Detection of Factors Affecting the Spatial Distribution of Ozone in Summer over China Based on Geodetector].

To study the factors affecting the spatial distribution of ozone concentration in different regions of China, based on the summer ozone monitoring data of 2019 and three influencing factors, namely, main meteorological, direct emission, and socio-economic factors, the influence degree of various factors on the spatial differentiation of ozone was quantified by using the Geodetector method and the comparison between regions was conducted. The results showed that the spatial differentiation of ozone concentration in summer 2019 was most affected by the main meteorological factors and the average degree of influence reached 0.277.

[Emission Inventory of Building Material Industry in Henan Province Based on Multi-source Data Integration].

The building materials industry is a typical resource and energy-consuming industry, as well as one of the major sources of air pollution. As the world's largest producer and consumer of building material products, China thus far has insufficient research on the emissions of the building materials industry, and the data sources are short of multiplicity. In this study, the building materials industry in Henan Province was chosen,and the control measures inventory for pollution emergency response (CMIPER) was applied to the development of the emission inventory for the first time.

[Characteristics and Source Apportionment of Vehicular VOCs Emissions in a Tunnel Study].

To explore the emission characteristics of volatile organic compounds (VOCs) from vehicular exhaust sources and evaporative sources with ethanol gasoline (E10) as the main fuel, VOCs sampling campaigns were carried out in the north third ring tunnel of Zhengzhou city for two consecutive weeks in December 2019. In addition, the characteristics of traffic flow and environmental information were also monitored in the tunnel. Firstly, 106 VOCs were quantified using gas chromatography/mass spectrometry (GC/MS), and then source apportionment of VOCs in the tunnel was carried out using a positive matrix factorization (PMF5.

[Emission Characteristics of Chemical Composition of Particulate Matter from Coal-fired Boilers].

Samples of particulate matter from coal-fired boilers of different tons were collected in Lanzhou city, and the water-soluble inorganic ions, carbonaceous species, water-soluble organic compounds (WSOC) and polycyclic aromatic hydrocarbons (PAHs) were analyzed. The results showed that SO, Cl, and Ca were the most important water-soluble ions in the coal-fired boiler samples, accounting for 35.13%, 23.

An Optimized Protocol of Azoxymethane-Dextran Sodium Sulfate Induced Colorectal Tumor Model in Mice.

Since azoxymethane (AOM)-dextran sodium sulfate (DSS) induced tumorigenesis was used to explore inflammation-associated carcinogenesis of sporadic colorectal cancer (CRC), different administration modes of AOM or DSS have been reported. In this article we optimized the protocol of the AOM-DSS modeling using C57BL/6 mice for study on sporadic CRC by intraperitoneal injecting AOM solution at a proper concentration with a 100 μl sterile syringe once, feeding with DSS solution for 7 days in a roll and change DSS solution every day. More than 100 C57BL/6 mice had been treated with the optimized protocol, and all mice were demonstrated suffering from colorectal tumors when sacrificed in 8 to 20 weeks after AOM injection.

Comparison of cortical bone trajectory versus pedicle screw techniques in lumbar fusion surgery: A meta-analysis.

Background: Biomechanical studies have demonstrated that cortical bone trajectory (CBT) screw can provide a 30% increase in uniaxial yield pullout load than pedicle screw (PS). In addition, the insertion torque of CBT screw is 1.71 times higher than that of PS.

[Spatial Distribution Characteristics of NMHCs in Spring in Cangzhou City].

Simultaneous collections of non-methane hydrocarbons (NMHCs) were carried out at 15 sampling sites including urban, suburb and potential pollution areas in Cangzhou City in spring 2015. The results showed that NMHCs were generally higher in urban areas than those in suburb and rural areas; the highest concentration of NMHCs was observed at Cangzhou High-tech zone (urban area); the concentrations of NMHCs were significantly lower at rural sites than in most urban sites except Hejian site; vehicular emissions were the main sources of NMHCs in Cangzhou; Cangzhou chemical fertilizer plant and Cangzhou oil refinery had no significant influence on urban NMHCs during their shutdown period; Dagang Oilfield, with better oil and gas recovery systems, did not have a significant impact on urban NMHCs. In general, alkanes, alkenes and aromatics accounted for 65%, 16% and 19% of NMHCs in Cangzhou City, respectively; xylene (19%), ethylene (14%), toluene(11%), propylene (5%), isopentane (5%) and isopentene (5%) were the most dominant contributors to ozone formation potential; aerosol formation potential was mainly derived from toluene (28%), pinene (28%), xylene(16%), ethylbenzene (9%) and benzene (9%).

[Number Concentration and Size Distribution of Particles Emitted by Light-duty Gasoline Vehicles].

In this study, three GDI (gasoline direct injection) and one PFI (port fuel injection) light-duty gasoline vehicles were characterized for their particle emission (number concentration and size distributions). Two condensation particle counters (CPC) with different activation efficiencies (50% cut off diameter) were used. It was found that the number concentration of particles emitted by GDI gasoline vehicle was approximately one order of magnitude higher than that from PFI gasoline vehicle.

[An investigation of the CH4 and N2O emission factors of light-duty gasoline vehicles].

In China, most of the studies of vehicular greenhouse gas (GHG) emissions have been focused on CO2 emissions. The investigation of non-CO2 GHGs, e.g.

[Analysis of surface composition of three-way catalysts of in-use vehicles].

The kinds and contents of surface elements in three-way catalysts of six light-duty in-use taxi cabs, which were mainly operated in Beijing and whose driving mileages were in the range of 34 x 10(4)-59 x 10(4) km, were determined by X-ray fluorescence spectrometry (XRF), and the effect of driving mileage on element content was investigated. Results showed that nearly 30 kinds of elements were present on the catalyst surface. The main elements of different samples were similar.

[Study on on-board measurements and modeling of vehicular emissions].

It's a basic work to study the characteristics of vehicular emissions and give emission factors for development of vehicular emission inventory and decision-making of the control strategies. On-board emission measurements of on-road vehicles are regarded as important complementary to emission laboratory dynamometer tests. On-board exhaust emission measurements were conducted on seven samples of gasoline cars in a typical road in Macao, using AVL DiGas 4000 light five-gas analyzer.