[Characterization of Metal Elements in Atmospheric Fine Particulate Matter and Their Sources in Winter in the Southern Sichuan Urban Agglomeration].

To investigate the concentration characteristics and sources of metal elements in PM2.5 during winter heavy pollution in the southern Sichuan urban agglomeration (Zigong, Luzhou, Neijiang, and Yibin), the metal elements in PM2.5 were measured using membrane sampling methods from December 30, 2018 to January 14, 2019, and the enrichment factor method (EF) and positive matrix factorization(PMF) were applied to investigate the sources of metal elements. The metal element observation data of Zigong in the same period of 2015 were also used to investigate the changes in metal element pollution and enrichment in Zigong in the middle and end of the implementation of China's Air Pollution Prevention and Control Action Plan. The main findings were as follows:① The concentrations and percentages of metal elements in particulate matter in different cities did not differ significantly. The elements with higher concentrations in the four cities showed similarities, with Al, Sb, and Fe at the top. From the comparison of different observation periods in Zigong, the concentrations of all elements except Tl changed. ② The results of the enrichment factor calculation showed that the enrichment of the elements Cr (Zigong and Yibin), Ni, Cu, As, Se, Ag, Cd, Sb, Tl, and Pb in the urban agglomeration was high. The comparison of the enrichment levels of elements in Zigong for different observation periods showed that the enrichment levels of all elements, except Cu, tended to decrease in the winter observation period of 2018. ③ The results of PMF source analysis showed that the metal elements in each city mainly originated from dust sources, coal-fired sources, industrial sources, and traffic sources, whereas there was a mixed contribution among the sources. The contribution of the main sources differed among cities, in which Zigong was dominated by traffic dust sources and mixed sources, Luzhou was dominated by industrial sources, Neijiang had a similar contribution from different sources, and Yibin was dominated by traffic sources.

The transcription factor MhZAT10 enhances antioxidant capacity by directly activating the antioxidant genes MhMSD1, MhAPX3a, and MhCAT1 in apple rootstock SH6 (Malus honanensis × M. domestica).

Stress tolerance in apple (Malus domestica) can be improved by grafting to a stress-tolerant rootstock, such as 'SH6' (Malus honanensis × M. domestica 'Ralls Genet'). However, the mechanisms of stress tolerance in this rootstock are unclear. In Arabidopsis (Arabidopsis thaliana), the transcription factor ZINC FINGER OF ARABIDOPSIS THALIANA 10 (ZAT10) is a key component of plant tolerance to multiple abiotic stresses and positively regulates antioxidant enzymes. However, how reactive oxygen species (ROS) are eliminated upon activation of ZAT10 in response to abiotic stress remains elusive. Here, we report that MhZAT10 in the rootstock SH6 directly activates the transcription of three genes encoding the antioxidant enzymes MANGANESE SUPEROXIDE DISMUTASE 1 (MhMSD1), ASCORBATE PEROXIDASE 3A (MhAPX3a), and CATALASE 1 (MhCAT1) by binding to their promoters. Heterologous expression in Arabidopsis protoplasts showed that MhMSD1, MhAPX3a, and MhCAT1 localize in multiple subcellular compartments. Overexpressing MhMSD1, MhAPX3a, or MhCAT1 in SH6 fruit calli resulted in higher superoxide dismutase, ascorbate peroxidase, and catalase enzyme activities in their respective overexpressing calli than in those overexpressing MhZAT10. Notably, the calli overexpressing MhZAT10 exhibited better growth and lower ROS levels under simulated osmotic stress. Apple SH6 plants overexpressing MhZAT10 in their roots via Agrobacterium rhizogenes-mediated transformation also showed enhanced tolerance to osmotic stress, with higher leaf photosynthetic capacity, relative water content in roots, and antioxidant enzyme activity, as well as less ROS accumulation. Overall, our study demonstrates that the transcription factor MhZAT10 synergistically regulates the transcription of multiple antioxidant-related genes and elevates ROS detoxification.

Transcription factors MhDREB2A/MhZAT10 play a role in drought and cold stress response crosstalk in apple.

Drought and cold stresses seriously affect tree growth and fruit yield during apple (Malus domestica) production, with combined stress causing injury such as shoot shriveling. However, the molecular mechanism underlying crosstalk between responses to drought and cold stress remains to be clarified. In this study, we characterized the zinc finger transcription factor ZINC FINGER OF ARABIDOPSIS THALIANA 10 (ZAT10) through comparative analysis of shoot-shriveling tolerance between tolerant and sensitive apple rootstocks. MhZAT10 responded to both drought and cold stresses. Heterologous expression of MhZAT10 in the sensitive rootstock 'G935' from domesticated apple (Malus domestica) promoted shoot-shriveling tolerance, while silencing of MhZAT10 expression in the tolerant rootstock 'SH6' of Malus honanensis reduced stress tolerance. We determined that the apple transcription factor DEHYDRATION RESPONSE ELEMENT-BINDING PROTEIN 2A (DREB2A) is a direct regulator activating the expression of MhZAT10 in response to drought stress. Apple plants overexpressing both MhDREB2A and MhZAT10 genes exhibited enhanced tolerance to drought and cold stress, while plants overexpressing MhDREB2A but with silenced expression of MhZAT10 showed reduced tolerance, suggesting a critical role of MhDREB2A-MhZAT10 in the crosstalk between drought and cold stress responses. We further identified drought-tolerant MhWRKY31 and cold-tolerant MhMYB88 and MhMYB124 as downstream regulatory target genes of MhZAT10. Our findings reveal a MhDREB2A-MhZAT10 module involved in crosstalk between drought and cold stress responses, which may have applications in apple rootstock breeding programs aimed at developing shoot-shriveling tolerance.

[Characteristics of Carbonaceous Species in PM2.5 in Chengdu Under the Background of Emission Reduction].

The Air Pollution Prevention and Control Action Plan and Three-year Plan on Defending the Blue Sky promulgated by the State Council of the People's Republic of China have played an important role in the overall improvement of air quality in China. However, few studies have evaluated the implementation effects of these two policies in Sichuan Basin and the new characteristics of PM2.5 chemical components after the implementation of these policies. The key periods for evaluating the implementation effects of these two pollution reduction policies are 2017 and 2020, respectively. In order to study the atmospheric PM2.5 and carbonaceous species in Chengdu during these two periods, this study sampled the PM2.5 in Chengdu from October 2016 to July 2017 and December 2020, respectively, and the organic carbon (OC) and elemental carbon (EC) were analyzed. The results showed that the annual ρ(PM2.5) from 2016-2017 in Chengdu was (114.0±76.4) µg·m-3. The maximum value of the ρ(PM2.5) appeared in winter[(193.3±98.5) µg·m-3], and the minimum value appeared in spring[(73.8±32.3) µg·m-3]. By contrast, the ρ(PM2.5) in winter decreased significantly in 2020, with a value of (96.0±39.3) µg·m-3. The annual ρ(OC) and ρ(EC) from 2016-2017 were (21.1±16.4) µg·m-3 and (1.9±1.3) µg·m-3, which accounted for 18.5% and 1.7% of the PM2.5 mass, respectively. The seasonal variation characteristic of ρ(OC) was:winter[(40.6±21.5) µg·m-3]>autumn[(17.0±7.0) µg·m-3]>summer[(14.4±3.9) µg·m-3]>spring[(12.6±6.0) µg·m-3], whereas the ρ(EC) in the four seasons were close, ranging from 1.3 to 2.4 µg·m-3. The annual ρ(SOC) was (9.4±9.1) µg·m-3, which accounted for 44.5% of the OC mass. Compared with that in winter 2016, the ρ(OC) decreased by 52.7% in winter 2020, whereas the ρ(EC) increased by 26.1%. With the aggravation of pollution, the change trends of carbon species and their contributions were different. Compared with that in winter 2016, the variation in the contribution of OC with the aggravation of pollution in winter 2020 was more stable, whereas the proportion of SOC increased more obviously. There were obvious differences in the direction of air masses and the potential source area of pollutants in each season. Although there was no significant change in the direction of air masses in winter 2020 compared with those in winter 2016, the pollutant concentrations corresponding to each cluster decreased significantly, and the potential source area of pollutants expanded significantly to the eastern area.

Nano-Sized Antioxidative Trimetallic Complex Based on Maillard Reaction Improves the Mineral Nutrients of Apple (Malus domestica Borkh.).

The metallic complex is widely used in agricultural applications. Due to the oxidation of the metal and environmental unfriendliness of ligand, maintaining an efficient mineral supply for plants without causing environmental damage is difficult. Herein, an antioxidative trimetallic complex with high stability was synthesized by interacting Ca2+, Fe2+, and Zn2+ with the biocompatible ligands from the Maillard reaction. The composite structure elucidation was carried out by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR). Thermal stability was measured by thermogravimetric (TG). Antioxidative activities were evaluated by ferric reducing antioxidant power and radical scavenging activity assays. The three metals were successfully fabricated on the Maillard reaction products (MRPs) with contents of Ca (9.01%), Fe (8.25%), and Zn (9.67%). Microscopy images revealed that the three metals were uniformly distributed on the MRPs with partial aggregation of <30 nm. FTIR and XPS results revealed that the metals were interacted with MRPs by metal-O and metal-N bonds. TG and antioxidative activity assays showed that the trimetallic complex meets the requirements of thermodynamics and oxidation resistance of horticultural applications. Additionally, the results of the exogenous spraying experiment showed that the trimetallic complex significantly increased the mineral contents of the "Fuji" apple. By treatment with the complex, the concentrations of Ca, Fe, and Zn were increased by 85.4, 532.5, and 931.1% in the leaf; 16.0, 225.2, and 468.6% in the peel; and 117.6, 217.9, and 19.5% in the flesh, respectively. The MRP-based complexes offered a higher growth rate of the mineral content in apples than ones based on sugars or amino acids. The results of the spraying experiment carried out in 2 years show that the method has high reproducibility. This study thus promotes the development of green metallic complexes and expands the scope of agrochemical strategy.

[Characteristics of Water-soluble Ions in an Autumn Haze Process in the Southern Sichuan Urban Agglomeration After the Implementation of China's Air Pollution Prevention and Control Action Plan].

To investigate the PM2.5 pollution in the southern Sichuan urban agglomeration after the implementation of China's Air Pollution Prevention and Control Action Plan (APPCAP), PM2.5 samples were simultaneously collected in four cities (Neijiang, Zigong, Yibin, and Luzhou) from November 7 to 19, 2018. The pollution characteristics of PM2.5 and main water-soluble ions were analyzed in combination with the synoptic situation, and the influence of regional transport on atmospheric pollution was also discussed in this study. The results showed that the mean ρ(PM2.5) in this region was (67.2±38.3) µg·m-3, being highest in Luzhou and lowest in Neijiang. The proportion of SNA (SO42-, NO3-, and NH4+) in PM2.5 was 33.3%, among which NO3- was dominant. From the intermediate stage (2015) to the end(2018) of the implementation of APPCAP, ρ(PM2.5) values were increased by 13.8%, 47.2%, and 69.1% in Neijiang, Yibin, and Luzhou, respectively, though unchanged in Zigong. Due to the significant reduction in ρ(SO2) but slight decrease or increase in ρ(NO2), as well as the lack of controlling NH3 emissions, from 2015 to 2018, ρ(NO3-) had increased by 36.7%-116.0%, whereas ρ(SO42-) decreased by 19.8%-40.2%, and ρ(NH4+) changed slightly in four cities. On haze days, the nitrogen oxidation rate (NOR) increased by 60.0%-118.2%, whereas the sulfur oxidation rate (SOR) increased slightly or decreased, leading to a significant increase in ρ(NO3-) (2.7-3.0 times that on clean days) and NO3-/SO42- mass ratios (1.7-1.9 on haze days). These values indicated that the secondary formation of nitrate was the dominant chemical mechanism in this haze process. On haze days, the PM2.5 pollution in this region was mainly affected by the regional transport within Sichuan Basin, particularly by the northeasterly air masses passing through Chongqing.

[Characteristics of Water-soluble Inorganic Ions in PM2.5 in Beijing During 2017-2018].

To explore the characteristics of water-soluble inorganic ions (WSIIs) in PM2.5 during the process of continuous improvement of air quality in Beijing in recent years, a continuous collection of PM2.5 sample campaign was conducted in Beijing from 2017 to 2018. The PM2.5 mass concentration and WSIIs were then determined. The results showed that the average concentration of PM2.5 in Beijing was (77.1±52.1) µg ·m-3, with the highest and lowest values during spring [(102.9±69.1) µg ·m-3]and summer [(54.7±19.9) µg ·m-3], respectively. The average concentration of WSIIs was (31.7±30.1) µg ·m-3, accounting for 41.1% of the PM2.5 mass, and the seasonal contributions were: autumn (45.9%) > summer (41.9%) > spring (39.9%) ≥ winter (39.2%). SNA was an important component of the WSIIs that accounted for 86.0%, 89.5%, 74.6%, and 73.0% of the total WSIIs during spring, summer, autumn, and winter, respectively. With an increase in temperature, the concentration of NO3- increased initially and then decreased, while the concentration of SO42- increased. When the relative humidity was less than 90%, the concentrations of both NO3- and SO42- increased with an increase in relative humidity. With the aggravation of pollution, the overall contribution of WSIIs in PM2.5 increased significantly, and the evolution characteristics of different ions were different. Among them, the concentration and contribution of NO3- continued to increase, while the contributions of SO42- and the ions from dust (Mg2+, Ca2+, and Na+) decreased. During the observation period, the primary sources of WSIIs were secondary conversion, combustion source, and dust. The control of coal combustion and motor vehicles is critical to reduce the emission of WSIIs. The backward trajectory analysis showed that the air masses from the south and west of Beijing corresponded to the high PM2.5 concentration and proportion of WSIIs, and the contribution of secondary ions was significant. However, the concentrations and proportions of the air masses from the northwest and north were relatively low, but the contribution of Ca2+ was high.

[Characteristics of Carbonaceous Species in PM2.5 in Southern Beijing].

To investigate the characteristics of carbonaceous species in PM2.5 in Beijing after the implementation of the Action Plan for the Prevention and Control of Air Pollution, PM2.5 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 PM2.5, OC, and EC in Beijing varied in wide ranges of 4.2-366.3, 0.9-74.5, and 0.0-5.5 µg ·m-3, respectively, and the average mass concentration were (77.1±52.1), (11.2±7.8), and (1.2±0.8) µg ·m-3. Overall, the carbonaceous species (OC and EC) accounted for 16.1% of the PM2.5 mass. The seasonal characteristics of the OC mass concentrations were: winter [(13.8±8.7) µg ·m-3] > spring [(12.7±9.6) µg ·m-3] > autumn [(11.8±6.2) µg ·m-3] > summer [(6.5±2.1) µg ·m-3]. The concentration of the EC during the four seasons was low, ranging from 0.8 to 1.5 µg ·m-3. The annual average mass concentration and contribution of secondary organic carbon (SOC) were (5.4±5.8) µg ·m-3 and 48.2%, respectively, highlighting the significant contribution of the secondary process. With the aggravation of pollution, although the contribution proportion of OC and EC decreased, their mass concentrations during "heavily polluted" days were 6.3 and 3.2 times that of "excellent" days, respectively. Compare to non-heating period, the mass concentrations of PM2.5, OC, and SOC increased by 14.4%, 47.9%, and 72.1% in heating period, respectively, which emphasized the importance of carbonaceous species during heating periods. Potential source contribution function (PSCF) analysis showed that the southwest areas of Beijing (such as Shanxi and Henan province) were the main potential source areas of PM2.5 and OC. The high value area of the PSCF of EC was less and the main potential source area was in the south of Beijing (such as Shandong and Henan province).

[Pollution Characteristics of Water-soluble Inorganic Ions in Chengdu in Summer and Winter].

The water-soluble inorganic ions (WSIIs) in PM2.5 and gaseous precursors of Chengdu were continuously observed by a gas and aerosol collector combined with ion chromatography (GAC-IC) in the summer and winter of 2017, and both their pollution characteristics and a typical pollution process in winter were analyzed. It was found that the concentration of PM2.5 in winter (100.2 µg·m-3) was significantly higher than that in summer (34.0 µg·m-3). WSIIs were important components of PM2.5 and their total contributions to PM2.5 were 52.9% and 53.3% in summer and winter, respectively. Secondary ions (SNA) accounted for 73.2% and 87.6% of WSIIs in summer and winter, respectively. SO42- and NO3- dominated the SNA in summer and winter, and the contributions to SNA were 37.7% and 59.7%, respectively. The NO3-/SO42- ratio (2.7) in winter was significantly higher than that in summer (0.8), reflecting the important contribution of mobile sources (especially motor vehicles) to PM2.5 in this season. The diurnal variation of SNA in the two seasons was obviously different due to the differences in sources and meteorological conditions. In winter, with the aggravation of pollution, the concentrations of WSIIs and gaseous precursors increased significantly, and NO3- was the key component in causing heavy pollution. Backward trajectory analysis revealed that the air masses in the two seasons in Chengdu differed significantly from each other. The WSIIs in summer and winter were dominated by SO42- and NO3-, respectively. The short-distance and low-altitude transmission from the east and south of Chengdu contributed significantly to PM2.5 pollution in Chengdu.

[Multivariate analysis of relationship between soil nutrient factors and fruit quality characte-ristic of 'Fuji' apple in two dominant production regions of China]. / 两大优势产区'富士'è‹¹æžœå›­åœŸå£¤å »åˆ†ä¸Žæžœå®žå“è´¨å ³ç³»çš„å¤šå˜é‡åˆ†æž.

The objective of this experiment is to probe into the influence of soil nutrient contents on fruit quality features of 'Fuji' apple, screen major soil nutrient factors affecting fruit quality features, clarify the suitable soil nutrient content for good fruit quality indicators, and to provide theoretical basis in reasonable orchard soil fertilizer application for improving fruit qua-lity in the Circum-Bohai and Loess Plateau apple production regions in China. The soil nutrient contents and 'Fuji' fruit qualities were respectively analyzed at 66 commercial 'Fuji' apple orchards standard rootstock in the Circum-Bohai and Loess Plateau apple production regions of 22 counties in China from 2010 to 2011. The partial least squares regression (PLS) was used to screen major soil nutrient elements affecting fruit quality, and to establish regression equation of relationship between fruit quality and major soil nutrition factors. Linear programming was used to obtain optimum proposals of soil nutrient elements for good apple quality. The results showed that alkaline hydrolytic N, available P, Ca, Fe, and Zn of soil were significantly higher while pH and available K were significantly lower in Circum-Bohai region than in Loess Plateau apple production region. Soluble solid content in Loess Plateau was higher than in Circum-Bohai; moreover, ratio of soluble solids content and titratable acidity was lower. The soil available B in the Circum-Bohai and Loess Plateau apple production regions had positive effect on fruit mass, and total N had negative effect on fruit firmness. The soluble solid contents in the Circum-Bohai were mainly negatively affected by total N and positively by available B, while positively affected by available Ca and negatively by alkaline hydrolytic N in the Loess Plateau region. The desired soil nutrients for good fruit qualities were high avai-lable B, pH and suitable available K in the Circum-Bohai, and low total N, high alkaline hydrolytic N, available K, Fe and suitable available Zn and B in the Loess Plateau region. It was the key technical measures in soil nutrient management for good fruit quality to increase available B and pH, adjust available K in the Circum-Bohai, and to enhance alkaline hydrolytic N, available K, Fe, and to decrease pH, and adjust available Zn and B in the Loess Plateau region.

[Composition characteristics of atmospheric volatile organic compounds in the urban area of Beibei District, Chongqing].

In order to study the composition and distribution of VOCs (Volatile Organic Compounds) in the atmosphere in the urban area of Beibei district, Chongqing, atmospheric samples were collected from March 2012 to February 2013 with special stainless steel cylinders, and analyzed with a three-stage preconcentration method coupled with GC-MS. 78 species of VOCs were detected in this study, of which there were 25 species of alkanes, 15 species of olefins, 28 species of aromatic hydrocarbons and 10 species of halogenated hydrocarbons. The results showed that the top seven species of VOCs according to the order of annual average concentration in the atmosphere of Beibei were: Dichloromethane (3. 08 x 10(-9) ) , Benzene (2. 09 x 10-9) , Isopentane (1. 85 x 10 -9) , Toluene (1. 51 x 10(-9)) , Propane (1. 51 x 10(-9)), m/p-xylene (1.43 x 10(-9)) and Styrene (1. 39 x 10-9). The concentration of TVOCs (Total Volatile Organic Compounds) in the atmosphere of Beibei was 33. 89 x 10 -9 during the measuring period, and the seasonal variation was obvious with the order of spring (42. 57 x 10 -9) > autumn (33.89 x 10-9) > winter (31.91 x 10 -9) > summer (27.04 x 10(-9)). In the composition of TVOCs, alkanes and aromatic hydrocarbons provided the largest contribution to TVOCs (31.5% and 30.7% ) , followed by halogenated hydrocarbon, accounting for 27.4% , and the last one was olefins, with only 10.4%. By means of ozone formation potential, the analysis results showed that olefins and aromatic hydrocarbon compounds were the two important materials which made the biggest contribution to the formation of ozone in the atmosphere of Beibei. We further analyzed the sources of VOCs in atmosphere of Beibei by the method of Principal Component Analysis (PCA). Vehicle exhaust was the biggest source and its contribution to VOCs was 50. 41%. The calculated results with T/B value also confirmed that traffic was the biggest source contributing to the VOCs in atmosphere of Beibei.

[Observation of atmospheric pollutants in the urban area of Beibei District, Chongqing].

To study the characteristics of atmospheric pollutants in the urban area of Beibei district of Chongqing, the concentrations of the atmospheric pollutants were measured by automatic on-line continuous monitoring equipments from Jan. 2012 to Feb. 2013. The results showed that the concentrations of the pollutants often exceeded the corresponding values of the new National Ambient Air Quality Standards (GB 3095-2012) except SO2. Of these pollutants, PM2.5 was the most serious in this area. The concentrations of the atmospheric pollutants had significant seasonal variation. The concentrations of O3 and O(x) were both the highest in summer and the lowest in winter. The average concentrations of O3 were (36.1 +/- 19.2), (48.8 +/- 32.6), (29.8 +/- 28.6) and (18.2 +/- 15.8) microg x m(-3), and the average O(x) concentrations were (77.6 +/- 20.6), (91.3 +/- 37.6), (77.5 +/- 30.6) and (69.4 +/- 18.2) microg x m(-3) in spring, summer, autumn and winter in 2012, respectively. The concentrations of NO(x) appeared higher in winter and lower in summer, the average concentrations of NO, NO2 and NO(x) were (11.8 +/- 9.4), (42.3 +/- 13.1) and (54.1 +/- 20.8) microg x m(-3) in spring, (8.2 +/- 4.9), (40.5 +/- 9.9) and (48.7 +/- 12.6) microg x m(-3) in summer, (20.7 +/-17.1), (47.2 +/- 14.1) and (67.9 +/- 25.5) microg x m(-3) in autumn, and (30.4 +/- 25.1), (51.2 +/- 15.9), (81.6 +/- 37.9) microg x m(-3) in winter. The concentrations of SO2 appeared higher in spring and winter, and lower in summer and autumn. The concentrations of SO2 were (50.5 +/- 23.3), (26.3 +/- 16.7), (38.8 +/- 18.4) and (53.7 +/- 23.4) microg x m(-3) in spring, summer, autumn and winter, respectively. The concentrations of PM2.5 appeared higher in winter and changed smoothly in other seasons, with the average concentration of (61.4 +/- 28.5), (68.1 +/- 32.5), (61.9 +/- 27.1) and (89.6 +/- 44.2) microg x m(-3) in spring, summer, autumn and winter, respectively. The curves of diurnal variations of O3, O(x), NO, NO(x) and SO2 all showed single peak. However, the time of the peak values varied for different pollutants, 16:00 for O3 and O(x), and 8:00-11:00 for NO, NO(x) and SO2. The diurnal variations of NO2 and PM2.5 were similar to the two peaks that appeared in the morning and at night, respectively. Moreover, the diurnal ranges of O3 and O(x) concentrations were much wider in summer, while the wider ranges were observed in winter for NO, NO2, NO(x), SO2 and PM2.5. There was no difference in the diurnal pattern of NO between weekends and weekdays, the concentrations of N2O in weekdays were much higher than those on weekends, but with O3 the situation was the opposite. Correlation analysis indicated that the O3 concentration was positively correlated with temperature and wind speed, while negatively correlated with relative humidity. However, the situation of NO(x) was the opposite. PM2.5 concentration was negatively correlated with temperature and wind speed, while positively correlated with relative humidity. SO2 concentration had different correlations with the meteorological parameters in different seasons. In addition, wind direction was an important factor affecting the concentrations of the atmospheric pollutants.

[Effects of tillage-cropping systems on methane and nitrous oxide emissions from agro-ecosystems in a purple paddy soil].

Using the static opaque chamber method, a field experiment, located in the Key Field Station for Monitoring of Eco-Environment of Purple Soil of the Ministry of Agriculture of China in the farm of Southwest University (30 degrees 26'N, 106 degrees 26'E) in Chongqing, was conducted in situ for one year to study the effect of different tillage systems on CH4 and N2O emission from ago-ecosystems in a purple paddy soil. In this paper, four tillage treatments including conventional tillage with rice only system (CT), conventional tillage with rotation of rice and rape system (CTR), no-till and plain culture with rotation of rice and rape system (NTP) and no-till and ridge culture with rotation of rice and rape system (NTR) were selected as research objectives. The results showed that the annual CH4 and N2O emissions were mainly occurred in the rice growing period, and were about 77.6% and 55.0% of the total annual of them emitted from this period. The total annual CH4 under CT was higher than that of other treatments. The annual average flux of CH4[CH4, mg x (m2 x h)(-1)] order was CT (2.96 +/- 0.04) >NTR (1.83 +/- 0.21) >NTP (1.42 +/- 0.01) >CTR (0.96 +/- 0.09); the annual average flux of N2O[N2O, microg x (m2 x h)(-1)] order was CTR (123.6 +/- 47.1) > NTR (115.2 +/- 22.1) > NTP (100.5 +/- 25.8) > CT (81.3 +/- 13.5), and the total annual N2O under CTR was higher than that of CT. The global warming potentials (GWPs) of CH4 and N2O emissions under different tillage-cropping systems were assessed in an integrated way. The results showed that the integrated GWPs of CH4 and N2O emission were in the following sequence: CT > NTR > NTP > CTR, and CTR was the best treatment for decrease the integrated GWPs in this area.

[Study on atmospheric VOCs in Gongga Mountain base station].

Volatile organic compounds (VOCs) play important roles in the atmosphere as precursors of secondary air pollutants. The regional background concentrations and variation characteristics of VOCs in the atmosphere of southwestern China were studied. Meanwhile, a receptor model based on principal component analysis (PCA) was used to identify the major sources of VOCs. Weekly samples were collected in 2007 in the Gongga Mountain base station and analyzed with a three-stage preconcentration method coupled with GC-MS. The annual mean concentration of TVOCs and NMHCs were 9.40 x 10(-9) +/- 4.55 x 10(-9) and 7.73 x 10(-9) +/- 4.43 x 10(-9), respectively. Aromatic hydrocarbons provided the largest contribution to TVOCs (37.3%), follow by alkanes (30.0%) and halogenated hydrocarbons (19.8%), the smallest contribution was from alkenes (12.9%). Three major sources were resolved by the receptor model, traffic sources, biogenic sources and combustion sources. The seasonal variation of TVOCs in this area was obviously, and the order was autumn > winter > spring > summer. TVOCs concentration in autumn was very significantly higher than that in summer (P < 0.01). The seasonal variation of the four types of VOCs showed different characteristics due to the differences in photochemical properties. Isoprene emissions were from biogenic sources. Regression analysis revealed a good exponential relationship between the isoprene concentration and temperature. High temperatures increased the isoprene concentrations. However, the isoprene concentration remained constant when the ambient air temperature was below 20 degrees C. The TVOCs in Gongga Mountain were at a medium level comparing with the results of other regions, and there was a clear background station emission characteristic.

[Analysis on the part of local medicinal herbs in Guangyangzaji (Guang Yang Miscellaneous Notes)].

Guangyangzaji (Guang Yang Miscellaneous Notes) are historical notes written by a scholar of the Qing dynasty: Liu Xian-ting. This book recorded much medical content of the people. Doing simple research and analysis on the name, physical nature and effectiveness of the Lobular Pyrolae, Kai Wood (Chinese pistache), Huanglian snakes (a snake habitat with Coptis grass) and other native herbs can contribute to understanding the evolution of the medicinal herbs.