Synthesis of gold nanoclusters-loaded lysozyme nanoparticles for ratiometric fluorescent detection of cyanide in tap water, cyanogenic glycoside-containing plants, and soils.

The modification of protein-stabilized gold nanoclusters with fluorophores has been intensively applied for the ratiometric detection of biomolecules, metal ions, and anions. This study developed a straightforward strategy to prepare lysozyme nanoparticle-encapsulated gold nanoclusters (LysNP-AuNCs) as a dual-emission probe for the ratiometric sensing of cyanide through fluorescence resonance energy transfer (FRET) without the conjugation of additional fluorophores. The reduction of gold ion precursors with lysozyme generated lysozyme-stabilized AuNCs under an alkaline pH, which were demonstrated to self-assemble into nanoaggregates during the formation of AuNCs. The aggregated lysozyme molecules on the AuNCs were treated with glutaraldehyde, triggering the conversion of the aggregated lysozymes into blue-emitting lysozyme nanoparticles. As a result, the AuNCs were well distributed inside a single lysozyme nanoparticle, as demonstrated by transmission electron microscopy. The presence of cyanide triggered the etching of the AuNCs in the LysNP-AuNCs, leading to the suppression of FRET from lysozyme nanoparticle to AuNCs. The LysNP-AuNC probe was implemented for FRET detection of cyanide with a linear range of 3-100 µM. Additionally, the selectivity of the LysNP-AuNC probe for cyanide toward other anions was remarkably high. The practicality of the proposed probe was evaluated by quantifying cyanide in tap water and soils and monitoring the liberation of hydrogen cyanide from cyanogenic glycoside-containing foods.

Dynamic prediction of uneven-aged natural forest for yield of Pinus taiwanensis using joint modelling.

In order to determine the stand age in the uneven-aged natural forest, a dynamic prediction model of stand volume and biomass was established in this study. In the model, the site quality grade was used as the dumb variable and the interval was used as the independent variable. In addition, the parameters of the model were estimated using immune evolutionary algorithm. The model was verified with the field data and the result revealed that the model had high accuracy. On this basis, the dynamic prediction model for forest stock was applied to evaluate the asset evaluation of uneven-aged natural forest and estimate carbon storage/sink potential of forest biomass. The selective logging period of the forest in the four plots was determined at the selective logging intensity of 40%. However, at the selective logging intensity of 40%, the forest ecological environment was suffered from the adverse effect to a certain extent from the perspective of scientific management, diversity of species, etc. Based on the comprehensive consideration of all the factors, it is recommended to set the selective cutting intensity in the range of 30 to 35%. The results can provide technical support for the application of selective logging income method in asset evaluation. Therefore, the results of this study have theoretical significance and practical application value in dynamic prediction of forest resources, asset evaluation and management, decision-making, etc.

Comparison of polycyclic aromatic hydrocarbon emissions on gasoline- and diesel-dominated routes.

Three diesel-dominated routes (DDRs) and three gasoline-dominated routes (GDRs) were chosen as the study sites. The total number of vehicles on GDRs (47,200) was much higher than that on DDRs (14,500). The concentration of polycyclic aromatic hydrocarbons (PAHs), elemental carbon, organic carbon, and metals from GDR roadsides was higher than that for DDRs. The diagnostic ratios (ANTHR/PHE + ANTHR, FLT/FLT + PYR, BaA/BaA + CHR, and IND/IND + BghiP + ANTHN) all indicated that the major PAH source on DDR and GDR was emissions from vehicle engine combustion. The marked diesel ratios of low molecular weight PAH2.5/T-PAH2.5, methyl-PAH2.5/T-PAH2.5, methyl-PHE/PHE, and Mo/PM2.5 on DDRs were higher than those on GDRs. Significant correlations were found between the number of vehicles and the concentration of T-PAH2.5, Car-PAHs2.5, and BaPeq2.5 on DDRs and GDRs. The increase in the levels of T-PAH2.5, Car-PAHs2.5, and BaPeq2.5 per 100 vehicles on DDRs was about 3.3, 3.5, and 4.2 times higher than that on GDRs, respectively. The higher percentage of high-exhaust volume from the larger amount of diesel vehicles on DDRs than that on GDRs was the main factor leading to these results. The diagnostic ratios BaA2.5/CHR2.5 and (BbF + BkF)2.5/BghiP2.5 showed significant differences between the fine PAH sources emitted on DDRs and GDRs, whereas the diagnostic ratios Me-PAH2.5/T-PAH2.5 and (BbF + BkF)2.5/BghiP2.5 showed good correlations with the percentages of diesel exhaust volume in the total exhaust volume (E(diesel)/E(total)) on DDRs.

Removals of fly ash and NO in a fluidized-bed reactor with CuO/activated carbon catalysts.

This study investigates the effects of fly ash compositions (SiO(2) and Al(2)O(3)), particle sizes (4-10 µm and 40 µm), and concentrations on the simultaneous removals of fly ash and NO using a fluidized-bed catalyst reactor. Experimental results show that the removal efficiencies of fly ash and NO at particle concentrations of 968-11,181 mg m(-3) are 71-97% and 42-57%, respectively. SiO(2) particles have more influences than Al(2)O(3) particles on the performances of fluidized-bed CuO/AC catalyst. As the concentration of fine particle increases, the pores and active sites on catalyst surface are obstructed and therefore the activities of catalysts are depressed.

Collection of SiO2, Al2O3 and Fe2O3 particles using a gas-solid fluidized bed filter.

The filtration of SiO(2), Al(2)O(3) and Fe(2)O(3) particles with average sizes of 4 and 40 microm using a fluidized bed filter at 40 and 300 degrees C was studied. The collection mechanisms, interparticle forces and bounce-off effect between filtered particles and collectors were analyzed to determine their effect on particle filtration. Experimental results showed that the collection efficiency of 4 microm SiO(2) and Al(2)O(3) particles exceeded that of 40 microm particles. Contrarily, the 40 microm Fe(2)O(3) particles were collected more efficiently than the 4 microm particles, because of the differences between the microstructures of SiO(2), Al(2)O(3,) and Fe(2)O(3) particles. The interaction between the particles affected the removal of mixed SiO(2), Al(2)O(3) and Fe(2)O(3). The particle size distribution (PSD) of the particles in the exit was governed by the operating temperature, the original size of the filtered particles, the interparticle force and the hardness of the particles and the collectors. The smallest particles were not those most easily elutriated from the fluidized bed filter because they agglomerated with each other or with large particles. The van der Waal's force dominated the forces between 4 and 40 microm particles. The main collection mechanism for 4 and 40 microm particles was direct interception. The effect of impaction increased with particle size above 40 microm. The strong impaction and bounce-off effect reduced the collection efficiency of 40 microm SiO(2) and Al(2)O(3) particles. However, the strong interparticle force between Fe(2)O(3) particles and collectors contributed to the high collection efficiency of the Fe(2)O(3) particles.

Characterizing PAH emission concentrations in ambient air during a large-scale joss paper open-burning event.

Large-scale open burning of joss paper is an important ritual practice for deity worshipping during Buddhist and Taoist festivals. Since Buddhism and Taoism are two of the most popular religions in Chinese societies and some Asian countries, the impact of joss paper burning on the air quality needs further investigation. This study explores the concentrations of polycyclic aromatic hydrocarbons (PAHs) in ambient air during one of the most important festivals, in which large-scale burning of joss paper occurs in temples and in people's houses. The PAH concentrations were measured simultaneously at a temple site and a background site during both the festival and non-festive (ordinary) periods. Each ambient sample was extracted by the Soxhlet analytical method (for both particle-bound and gas-phase) and analyzed with gas chromatography. Experimental results indicate that the total PAH concentration during the festival period is approximately 4.2 times higher than that during the ordinary period (5384 ng m(-3) vs. 1275 ng m(-3)). This study also employed statistical methods including diagnostic ratios and principal component analysis (PCA) to identify the possible PAH emission sources. Joss paper burning and vehicular emissions are identified as the principal sources of airborne PAHs during the large-scale open-burning event. The results of this work provide useful information for public awareness concerning PAH emission from the open burning of joss paper.

Characteristic study of dry deposition, concentration, compositions for particulates mass and ionic species during summer and autumn season at a traffic sampling site.

Aerosol samples for dry deposition and total suspend particulates (TSP) were collected from August to November of 2003 in central Taiwan. Ion chromatography was used to analyze the related water-soluble ionic species (Cl(-), NO(3)(-), SO(4)(2-), Na(+), NH(4)(+), K(+), Mg(2+) and Ca(2+)). The results obtained in this study indicated that the ambient air particulate mass concentrations in the daytime period (averaged 975.4 microg m(-3)) were higher than the nighttime period (averaged 542.1 microg m(-3)). And the daytime dry deposition fluxes (averaged 58.12 microg m(-2) sec(-1)) were about 2.2 times as that of nighttime dry deposition fluxes (averaged 26.54 microg m(-2) sec(-1)) of the downward dry deposition. The average values downward and upward of dry deposition fluxes for the weekend period were almost higher than the weekday period for either daytime or nighttime period. Furthermore, the average daytime dry deposition fluxes (averaged 26.37 microg m(-2) sec(-1)) were also about 2.3 times as that of nighttime dry deposition fluxes (averaged 11.52 microg m(-2) sec(-1)). Moreover, the results also indicate that SO(4) (2-) and Ca(2+) have higher average composition for total suspended particulates in the daytime period while Ca(2+), SO(4) (2-), and Na(+) have the higher average composition for total suspends particulates in the nighttime period.

Ambient air particulate concentrations and metallic elements principal component analysis at Taichung Harbor (TH) and WuChi Traffic (WT) near Taiwan Strait during 2004-2005.

The purpose of this study is to characterize metallic elements associated with atmospheric particulate matter of total suspended particulate (TSP), fine particle (particle matter with aerodynamical diameter <2.5 microm, PM(2.5)), coarse particle (particle matter with aerodynamical diameter 2.5-10 microm, PM (2.5-10)) at the Taichung Harbor (TH) and WuChi Traffic (WT) sampling site of central Taiwan during March 2004 to February 2005. The result indicated the average total suspended particulate concentration in 1 year was 157.31 and 112.58 microg m(-3) at TH and WT sampling site, respectively. Fine particle (PM(2.5)) size was the dominant species at TH and WT sampling site. In TH sampling site, higher correlation coefficient was observed on total suspended particulates of metallic elements Fe and Zn. And in WT sampling site, higher correlation coefficients displayed on total suspended particulates of metallic elements Fe and Zn, Fe and Mn. Ambient airborne particle principal component analysis of metallic metals was used to identify the possible pollutant sources in this study. At the TH sampling site, 50.81% of the total variance of the data was observed in factor 1. Higher loading of Fe (0.86), Zn (0.79), Pb (0.76), and Mn (0.68) were contributed by traffic emission and the soil source. At the WT sampling site, factor 1 explained 53.74% of the total variance of the data and had high loading for Zn (0.86) and Cu (0.85), which were identified as industrial/traffic emission sources.

Atmospheric pollutants study of particles and metallic elements during high wind speed (wind speed >6 m/s) near Taiwan Strait around central Taiwan.

The purpose of this study was to characterize metallic elements associated with atmospheric particulate matter in total suspended particulate (TSP), fine particles (particle matter with an aerodynamic diameter of <2.5 microm, PM2.5) and coarse particles (particle matter with an aerodynamic diameter of 2.5-10 microm, PM2.5-10), at high wind speed (wind speed >6 m/s) at Taichung Harbor (TH) and Wuci traffic (WT) in central Taiwan from March to December 2004. The correlation coefficient (R2) between TSP, coarse, fine particulate concentrations versus wind speed at the TH and WT sampling site during high wind speed (>6 m/s) are shown in this study. In addition, the correlation coefficients between TSP, coarse and fine particles of metallic species versus high wind speed were also observed. The results indicated that the correlation coefficient order was TSP> coarse>fine for particles at both sampling sites during high wind speed (>6 m/s) near central Taiwan. In addition, the concentrations of Fe, Zn, Mn, Cu, Pb, Cr, Mg for TSP, coarse and fine particulates were also analysed in this study.

Characteristic study of ionic species in nano, ultrafine, fine and coarse particle size mode at a traffic sampling site.

A micro-orifice uniform deposit impactor (MOUDI) and a nano-MOUDI were used to measure the atmospheric coarse (PM2.5-10), fine (PM2.5), ultrafine (PM0.056-1) and nano (<0.056 microm) particle concentrations at a traffic sampling site in central Taiwan during the winter period from November 2004 to January 2005. Meanwhile, concentrations of major ionic species (Cl-, NO3-, SO(2-)4, NH4+, Na+, K+, Ca2+ and Mg2+) were also extracted from various particle size modes (nano, ultrafine, fine and coarse) and analysed by ion chromatography (DIONEX-100). The mass size distribution of ambient suspended particles exhibited two modes. The size ranges of the particles at these two particle size modes were between 1.0 and 1.8 microm and 3.2 and 5.6 microm, respectively. The average mass media aerodynamic diameter (MMAD) of suspended particles was 0.99 microm in this study. In addition, statistical methods, such as correlation coefficient and principal component analysis, were also used to identify the possible pollutant source for various particles size modes (nano, ultrafine, fine and coarse) during the winter months at a traffic sampling site in central Taiwan.

Dry deposition, ionic species measured and source interpretation during seasonal cycle at offshore areas near Taiwan Strait.

The characterization for water-soluble species of total suspended particulate (TSP), dry deposition flux, and dry deposition velocity (V(d)) were studied at Taichung Harbor (TH) and Wuchi traffic sampling sites at offshore sampling site near Taiwan Strait of central Taiwan during March 2004-January 2005. The average concentrations of TSP and dry deposition flux at the TH sampling site were higher than at the WT sampling site during the sampling period. The samples collected were analyzed by a ion chromatography (DIONEX-100) for the ionic species (Cl(-), SO(4)(2-), NO(3)(-), NH(4)(+), Na(+), Ca(2+), and Mg(2+)) analysis. The dominant ionic species for TSP are SO(4)(2-), NO(3)(-), and NH(4)(+) of the total mass of the inorganic ions at both sampling sites. In addition, the results indicated that the NH(4)(+), NO(3)(-) and SO(4)(2-) showed higher concentrations in winter and lower in summer for both TH and Wuchi sampling sites. Statistical methods such as correlation coefficient and principal component analysis were also used to identify the possible pollutant source.

Characterization of atmospheric particulate and metallic elements at Taichung Harbor near Taiwan Strait during 2004-2005.

Air aerosol samples for TSP (total suspended particulate), coarse particulate (particle matter with aerodynamical diameter 2.5-10 microm, PM(2.5-10)), fine particulate (particle matter with aerodynamical diameter <2.5 microm, PM(2.5)) and metallic elements were collected during March 2004 to January 2005 at TH (Taichung Harbor) in central Taiwan. The seasonal variation average concentration of TSP (total suspended particulate), coarse particulate (particle matter with aerodynamical diameter 2.5-10 microm, PM(2.5-10)) and fine particulate (particle matter with aerodynamical diameter <2.5 microm, PM(2.5)) were in the range 132-171.1 microg m(-3) and 43-49.5 microg m(-3), respectively. Seasonal variation of metallic elements Cu, Mn, Zn and Fe in the TSP (total suspended particulate) shows that higher concentration was observed during spring. Seasonal variation of metallic elements Pb, Cr and Mg in the TSP (total suspended particulate) shows that higher concentration was observed during winter. The average metallic element TSP (total suspended particulate) concentration order was Fe>Zn>Mg>Cu>Cr>Mn>Pb in spring. In addition, at the TH sampling site, the average concentration variation of TSP (total suspended particulate) displayed the following order: spring>winter>autumn>summer. However, the average concentration variation of coarse particulate (particle matter with aerodynamical diameter 2.5-10 microm, PM(2.5-10)) displayed the following order: spring>winter>summer>autumn. Finally, the average concentration variations of fine particulate (particle matter with aerodynamical diameter <2.5 microm, PM(2.5)) were in the following order: winter>spring>summer>autumn at the TH sample site.

Concentrations of ambient air particulates (TSP, PM2.5 and PM2.5-10) and ionic species at offshore areas near Taiwan Strait.

The concentrations of total suspended particulate (TSP), fine particles PM(2.5) (with aerodynamic diameter <2.5 microm), coarse particles PM(2.5-10) (with aerodynamic diameter 2.5-10 microm,), and water-soluble inorganic ions were studied at two offshore sampling sites, Taichung Harbor (TH) and Wuci Traffic (WT), near Taiwan Strait in central Taiwan during March 2004 to January 2005. Statistical analyses were also carried out to estimate the possible sources of particulate pollution. Experimental results showed that the average mass concentrations of TSP, PM(2.5) and PM(2.5-10) at TH and WT sampling sites were 154.54 +/- 31.45 and 113.59 +/- 31.94 microg m(-3), 54.03 +/- 16.92 and 42.76 +/- 12.52 microg m(-3), and 30.31+/- 9.79 and 24.16 +/- 7.27 microg m(-3), respectively. The dominant inorganic ions at two sampling sites were SO(4)(2-), NO(3)(-), and NH(4)(+) for TSP and PM(2.5), but that were Ca(2+), Cl(-), and Na(+) for PM(2.5-10). The concentrations of most particulates and inorganic ions were higher in winter at both two sampling sites, and were higher at TH than WT sampling site in each season. From statistical analysis, air-slake of crust surface, sea-salt aerosols, agriculture activities, coal combustion, and mobile vehicles were the possible emission sources of particulate pollution at TH and WT sampling sites.

Review of atmospheric water-soluble ionic species in Asia during 1998-2001.

Anthropogenic acid precursor emissions in Asia are increasing at a significant rate and this is expected to continue for the next several years. This paper comprises of studies that included sulfate, nitrate and ammonium around Asian countries (China, Korea, Japan and Taiwan) in recent years. The paper also provides the water-soluble ionic fine and coarse particulate concentrations in these Asian countries in recent years. Fine and coarse particulates in Taiwan (Kaohsiung and Talchung) and China (Nanjing and Shanghai) were found to have higher sulfate (average 18.68 and 15.75 microg/m3) and nitrate (average 12.77 and 7.71 microg/m3) concentrations than any other Asian country. The average sulfate concentrations for Japan and Korea were 7.31 and 5.84 microg/m3, respectively. The average nitrate concentrations for Japan and Korea were 6.73 and 4.65 microg/m3, respectively during the years 1998-2001. The different sample collection devices, analysis methods and pollutant concentrations are discussed in this study. The purpose of this study is to arrange the atmospheric water-soluble ionic species (SO4(2-) and NO3) investigations in the Asian region. The data obtained here can also help to understand the sources, concentrations, phase distribution and health impact of atmospheric water-soluble ionic species (SO4(2-) and NO3-) in other Asian regions.

Ambient air particulate dry deposition, concentrations and ionic species study at Taichung Harbor near Taiwan Strait.

The characterization for watersoluble species of dry deposition flux, total suspended particulate (TSP), fine particle (particle matter with aerodynamical diameter 2.5 microm, PM2.5), coarse particle (particle matter with aerodynamical diameter 2.5-10 microm, PM(2.5-10)), and dry deposition velocity were studied at Taichung Harbor sampling sites of central Taiwan during February-August 2004. The average downward dry deposition flux, TSP, PM10 concentrations obtained in Taichung Harbor were about 0.51, 0.3, and 3.4 times more than those values obtained by traffic sampling site in central Taiwan. Average dry deposition velocity for mass, Cl-, NO3-, SO4(2-), Na+, NH4+, Mg2+, and Ca2+ were 9, 3.8, 0.3, 0.25, 0.46, 0.18, 0.51 and 2.28 cm respectively at the harbor sampling site. In general, average particle mass dry deposition velocity was about 1.8 times more than those values obtained at the traffic sampling site. Chemical analysis, also indicated that three major soluble inorganic species concentrations (sulfate+nitrate+ammonium) accounted for 59.8% and 80.6% of the PM2.5 and PM(2.5-10) mass concentrations, respectively at the Taichung Harbor sampling site.

Concentrations of nano and related ambient air pollutants at a traffic sampling site.

A micro-orifice uniform deposit impactor (MOUDI) and a nano-MOUDI were used to measure the atmospheric coarse (PM2.5 -10), fine (PM2.5), ultrafine (PM0.056-1) and nano (<0.056 microm) particle concentrations and size distributions at a traffic sampling site in winter in central Taiwan, from November 2004 to January 2005. Concentrations of metallic elements (Fe, Mg, Cr, Zn, Pb, Cu) and major ion (SO4(2-), NO3(-), NH4(+)) in particles of various sizes (nano, ultrafine, fine and coarse) were measured. Ambient air particulates generally exhibited a bimodal size distribution in the range 0.056-10 microm. The results show that the concentrations followed the order, Fe>Mg>Cr>Zn>Pb> Cu in PM10, fine, ultrafine and nano-sized particles. Moreover, the data showed that the average metallic elements Fe and Zn have similar concentration distributions: the concentration decreased as the particle size fell in the nano size range.

Dry deposition (downward, upward) concentration study of particulates and heavy metals during daytime, nighttime period at the traffic sampling site of Sha-Lu, Taiwan.

Downward, upward dry deposition fluxes and total suspended particulate of particulate heavy metals (Fe, Pb, Zn, Cu, Mg and Mn) were measured in daytime and nighttime period in Sha-Lu, a small city in the central Taiwan during summer period of 2003. The results showed that the total suspended particulate concentrations of particulate mass in the daytime period (averaged 996.2 g/m3) were higher than in nighttime period (averaged 560.7 g/m3). And the downward dry deposition fluxes (averaged 54.07 g/m2s) were about two times as that of upward dry deposition fluxes (averaged 26.48 g/m2s) in the daytime period. Furthermore, the average downward dry deposition fluxes (averaged 26.22 g/m2s) were also about two times as that of upward dry deposition fluxes (averaged 12.11 g/m2s) in the nighttime period. In addition, the average downward dry deposition fluxes are greater than the upward dry deposition fluxes for all the heavy metals in either daytime or nighttime period. The proposed reasons are that the wind speed and concentration difference for daytime and nighttime period lead to these results at the traffic sampling site of central Taiwan. In addition, the deposition velocity for mass, heavy metals (Fe, Pb, Zn, Cu, Mg and Mn) during daytime and nighttime period were also calculated. The average daytime dry deposition velocity for downward particulate mass, upward particulate mass, Fe, Pb, Zn, Cu, Mg and Mn were 5.56, 2.66, 1.71, 0.18, 1.06, 0.24, 0.47 and 0.11 (cm/s), respectively. And the average nighttime dry deposition velocity for downward particulate mass, upward particulate mass, Fe, Pb, Zn, Cu, Mg and Mn were 4.70, 2.11, 1.66, 0.18, 0.86, 0.23, 0.32 and 0.07 (cm/s), respectively at traffic sampling site of central Taiwan.

The concentration, dry deposition, composition study of ambient air particulate and metallic pollutants at a traffic sampling site.

Aerosol samples were collected by total suspended particulate (TSP) and dry deposition plate (downward, upward) from August to November in 2003 in central Taiwan. The particulate metallic elements (Fe, Pb, Zn, Cu, Mg and Mn) were also measured in this study during the summer and autumn periods of 2003. The results obtained in this study indicated that the ambient air particulate mass concentrations in the daytime period (averaged 975.4 microg/m3) were higher than the night-time period (averaged 542.1 microg/m3). And the downward dry deposition fluxes (averaged 58.12 microg/m2-sec) were about 2.2 times that of upward dry deposition fluxes (averaged 26.37 microg/m2-sec) in the daytime period. Furthermore, the average downward dry deposition fluxes (averaged 26.54 microg/m2-sec) were also about 2.3 times that of upward dry deposition fluxes (averaged 11.52 microg/m2-sec) in the night-time period. Moreover, the average downward dry deposition fluxes are greater than the upward dry deposition fluxes for all the heavy metals in either daytime or night-time period. In addition, the deposition velocity for mass, metallic elements (Fe, Pb, Zn, Cu, Mg and Mn) during daytime and night-time period were also calculated. In addition, the average TSP composition (mg/g) in the daytime period of the metallic elements (Fe, Pb, Zn, Cu, Mg and Mn) is 1.73, 0.26, 1.16, 0.28, 0.43 and 0.12 mg/g, respectively. And the average TSP composition in the night-time period of the metallic elements (Fe, Pb, Zn, Cu, Mg and Mn) is 3.02, 0.33, 1.57, 0.41, 0.58 and 0.13 mg/g, respectively at traffic sampling site of central Taiwan.

Dry deposition (downward, upward) concentration study of particulates and water-soluble ionic species during daytime, night-time period at the traffic sampling site of Sha-Lu, Taiwan.

Ambient suspended particulate (dry deposition, TSP) was collected in the traffic sites Sha-Lu, central Taiwan. In addition, the related water-soluble ionic species (Cl-, NO3(-), SO4(2-), Na+, NH4(+), K+, Mg2+ and Ca2+) were analysed and wind speed, wind direction and temperature were also measured in this study. The downward dry deposition fluxes (averaged 54.07 microg/m2-sec) were about twice that of upward dry deposition fluxes (averaged 26.48 microg/m2-sec) in the daytime period. Furthermore, the average downward dry deposition fluxes (averaged 26.22 microg/m2-sec) were also about twice that of upward dry deposition fluxes (averaged 12.11 microg/m2-sec) in the night-time period. The results showed that the total suspended particulate concentrations of particulate mass in the daytime period (averaged 996.2 microg/m3) were higher than in the night-time period (averaged 560.7 microg/ m3). The results showed that the total suspended particulate concentrations of particulate mass in the daytime period (averaged 996.2 microg/m3) were higher than in night-time period (averaged 560.7 microg/ m3). As for water-soluble ionic species, the average dry deposition order and velocity for downward ionic species were Cl- > Ca2+ > NO3(-) > K+ (2.09 cm/sec > 1.46 cm/sec > 1.46 cm/sec > 1.07 cm/sec) anions during the daytime period. And the average dry deposition order and velocity for downward ionic species were NO3(-) > Cl- > K+ > Ca2+ (2.92 cm/sec > 2.74 cm/sec > 0.96 cm/sec > 0.93 cm/sec) anions during the night-time period. The average dry deposition order and velocity for upward ionic species were Cl- > Ca2+ > K+ > Mg2+ (4.69 cm/sec > 0.62 cm/sec > 0.59 cm/sec > 0.55 cm/sec) anions during the daytime period. And the average dry deposition order and velocity for upward ionic species were Cl- > Ca2+ > Mg2+ > K+ (1.65 cm/sec > 0.43 cm/sec > 0.37 cm/sec > 0.33 cm/sec) anions during the night-time period. The results also indicated that the sodium and chloride concentrations in total suspended particulate were highly positively related, indicating that the sea-salt aerosols were the major contributors for these species at this sampling site of central Taiwan.