[Conversion Characterizations of Sulfate Ion and Nitrate Ion in Particulate Matter from Coal-fired Power Plants].

The particulate matter emitted from coal-fired power plants includes condensable particulate matter(CPM) and filterable particulate matter(FPM). By analyzing the concentration of SO42-and NO3- components of CPM and FPM in the inlet/outlet of wet flue gas desulfurization(WFGD) and the outlet of wet electrostatic precipitator(WESP) from 7 ultra-low emission coal-fired power plants, the variation laws and transformation characteristics were investigated. The results showed that the concentration of SO42- and NO3- of CPM decreased after WFGD, with reduction rates of 43.12%-86.84% and 17.99%-91.58%, respectively, which were different from the conversion trend of FPM. The concentrations of SO42- and NO3- of CPM increased after WESP, with reduction rates of 21.05%-424.65% and 13.51%-298.37%, respectively, which were also different from that of FPM. In the WFGD system, CPM could be transformed into FPM due via condensation and aggregation under the decreasing temperature and increasing of humidity of the flue gas. In the WESP system, SO2 and NO2 in the flue gas combine with water vapor in a redox reaction, which promotes the generation of SO42- and NO3- in CPM through synergistic action.

[Conversion Characteristics of Combustible Particles from Coal-fired Flue Gas in WFGD and WESP].

Monitoring of condensable particulate matter (CPM) emitted from stationary pollution sources has often been neglected. To reduce the emission of CPM, it is necessary to study its transformation rules in flue-gas cleaning devices. The results show that the wet flue gas desulfurization (WFGD) and wet electrostatic precipitator (WESP) have a good synergistic effect on the removal of CPM. The concentration of CPM in flue gas is higher than that of filterable particulate matter, but the concentration of total particulate matter (sum of the condensable particulate matter and filterable particulate matter) reaches ultra-low emission requirements. The organic mass concentration of CPM in the WFGD inlet and outlet is larger than that of inorganic components, which is equalized during the treatment of WESP. Based on measurements of the components and concentrations of water-soluble ions in the inorganic part of the CPM, PM0.3 can be joined during the CPM trapping process and an acid mist is generated during the condensable particulate matter formation. The acid mist is strengthened through the treatment of WFGD and WESP. The experiment results also show that SO42- is the main component of water-soluble ions in the inorganic part of CPM.

[Poisoning effect of Ca depositing over Mn-Ce/TiO2 catalyst for low-temperature selective catalytic reduction of NO by NH3].

Calcium carbonate (CaCO3), calcium sulfate (CaSO4), and calcium chloride (CaCl2) were chosen as the precursors to prepare the Ca salts deposited Mn-Ce/TiO2 catalysts through an impregnation method. The influence of Ca on the performance of the Mn-Ce/TiO2 catalyst for low-temperature selective catalytic reduction of NO by NH3 was investigated. Experimental results showed that Ca salts had negative effects on the activity of Mn-Ce/TiO2 and the precursors of Ca salts also affected the catalytic activity. The precursor CaCl2 had a greater impact on the catalytic activity, while CaCO3 had minimal effect. The samples were characterized by Brunner-Emmet-Teller measurements (BET), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and NH3temperature programmed desorption (NH3 -TPD). The characterization results indicated that the significant changes in physical and chemical properties of Mn-Ce/TiO2 were observed after Ca was deposited on the catalysts. The significant decreases in surface areas and NH,3adsorption amounts were observed after Ca was deposited on the catalysts, which could be considered as the main reasons for the deactivation of Ca deposited Mn-Ce/TiO,2

TPX2 expression and its significance in squamous cell carcinoma of lung / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the expression of targeting protein for Xklp2 (TPX2) and its significance in squamous cell carcinoma (SCC) of the lung.</p><p><b>METHOD</b>Two SCC cell lines and 4 immortalized bronchial epithelial cell lines (as a precancerous model) were examined by Western blot for TPX2 expression. Reverse transcription-polymerase chain reaction analysis for TPX2 was also performed using tumor tissues from 21 patients with SCC of the lung. The expression of TPX2 was studied by immunohistochemistry (using tissue microarray) on paraffin-embedded sections of pulmonary SCC and corresponding precancerous lesions from a group of 319 patients.</p><p><b>RESULTS</b>TPX2 was variably expressed in all the cell lines studied. Compared with matched controls using normal lung tissue, high level of TPX2 mRNA was detected in 16 of the 21 SCC tumor tissue samples analyzed. Immunohistochemical study showed that TPX2 was mainly present in tumor tissues but not in normal controls. The expression of TPX2 correlated with tumor grade, stage and nodal status. As for precancerous lesions, the level of TPX2 was also increased, in accordance with the degree of dysplasia.</p><p><b>CONCLUSIONS</b>Expression of TPX2 may play a role in carcinogenesis of bronchial epithelium and tumor progression of pulmonary SCC. It may also represent a potential biomarker for surveillance of SCC of lung.</p>