ABSTRACT
In order to study the effect of wet electrostatic precipitators(WESP) on emission characteristics of condensable particulate matter (CPM) from ultra-low emission coal-fired power plants that are under different capacity conditions, a set of CPM sampling devices was built based on US EPA Method 202, and an ultra-low emission coal-fired power plant was detected. This study evaluated the emission level of the CPM from the flue gas of coal-fired power plants, the effects of different unit capacity conditions on the CPM emission concentrations, and the removal efficiency of WESP for different components of the CPM. The results suggested that the emission concentrations of the CPM from ultra-low emission power plants were 27.27 mg·m-3 and 28.71 mg·m-3under the conditions of 75% and 100% capacity, respectively. The removal efficiencies of WESP for the CPM were 35.59% and 27.59%, respectively. SO42- was the main component of water-soluble ions of the CPM. The proportion of SO42- in inorganic components of the CPM reached more than 65% under different capacity conditions. In addition, the removal efficiency of WESP for Cl-, K+, Ca2+, Mg2+, Na+, and other inorganic ions reached 30%-50%, but the mass concentrations of SO42- and NO3- increased.
Subject(s)
Air Pollutants , Particulate Matter , Air Pollutants/analysis , Coal/analysis , Ions , Particulate Matter/analysis , Power PlantsABSTRACT
It is recognized that prenatal care plays an important role in reducing adverse birth. Chinese pregnant women with medical condition were required to seek additional health care based on the recommended at least 5 times health care visits. This study was to estimate the association between prenatal care utilization (PCU) and preterm birth (PTB), and to investigate if medical conditions during pregnancy modified the association. This population-based case control study sampled women with PTB as cases; one control for each case was randomly selected from women with term births. The Electronic Perinatal Health Care Information System (EPHCIS) and a questionnaire were used for data collection. The PCU was measured by a renewed Prenatal Care Utilization (APNCU) index. Logistic regression models were used to estimate odds ratios (OR) and the 95% confidence interval (95% CI). Totally, 2393 women with PTBs and 4263 women with term births were collected. In this study, 695 (10.5%) women experienced inadequate prenatal care, and 5131 (77.1%) received adequate plus prenatal care. Inadequate PCU was associated with PTB (adjusted OR: 1.41, 95% CI: 1.32-1.84); the similar positive association was found between adequate plus PCU and PTB. Among women with medical conditions, these associations still existed; but among women without medical conditions, the association between inadequate PCU and PTB disappeared. Our data suggests that women receiving inappropriate PCU are at an increased risk of having PTB, but it does depend on whether the woman has a medical condition during pregnancy.
Subject(s)
Asian People , Premature Birth/epidemiology , Prenatal Care/statistics & numerical data , Adult , Case-Control Studies , Confounding Factors, Epidemiologic , Female , Humans , Risk FactorsABSTRACT
It is recognized that prenatal care plays an important role in reducing adverse birth.Chinese pregnant women with medical condition were required to seek additional health care based on the recommended at least 5 times health care visits.This study was to estimate the association between prenatal care utilization (PCU) and preterm birth (PTB),and to investigate if medical conditions during pregnancy modified the association.This population-based case control study sampled women with PTB as cases;one control for each case was randomly selected from women with term births.The Electronic Perinatal Health Care Information System (EPHCIS) and a questionnaire were used for data collection.The PCU was measured by a renewed Prenatal Care Utilization (APNCU) index.Logistic regression models were used to estimate odds ratios (OR) and the 95％ confidence interval (95％ CI).Totally,2393 women with PTBs and 4263 women with term births were collected.In this study,695 (10.5％) women experienced inadequate prenatal care,and 5131 (77.1％) received adequate plus prenatal care.Inadequate PCU was associated with PTB (adjusted OR:1.41,95％ CI:1.32-1.84);the similar positive association was found between adequate plus PCU and PTB.Among women with medical conditions,these associations still existed;but among women without medical conditions,the association between inadequate PCU and PTB disappeared.Our data suggests that women receiving inappropriate PCU are at an increased risk of having PTB,but it does depend on whether the woman has a medical condition during pregnancy.
ABSTRACT
Five new metal-organic frameworks based on 2,4,6-tris(4-pyridyl)-1,3,5-triazine (tpt) ligand have been hydrothermally synthesized. Reaction of tpt and AgNO 3 in an acidic solution at 180 degrees C yields {[Ag(Htpt)(NO3)]NO(3).4H2O}n (1).Ag(I) is trigonally coordinated by two pyridyl nitrogen and one nitrato oxygen to form a 1D zigzag chain. Reaction of tpt with CuSO4 affords {[Cu2(tpt)2(SO4)2(H2O)2].4H2O}n (2). Copper(II) is bonded to two pyridyl nitrogen, two sulfato oxygen, and two water oxygen atoms to form an elongated octahedral geometry. Each H2O ligand bridges two copper(II), whereas sulfate bridges copper(II) via micro-1,3 and micro-1,1 fashions. The copper(II)-sulfate-H2O2D layers are linked by bidentate tpt to form a 3D polymeric structure. Reaction of Cu(SO4)2, tpt, and 1,2,4,5-benzenetetracarboxylic acid (H4btec) in the presence of piperidine gives [Cu(tpt)(H2btec)1/2]n (3). Copper(I) is located in a trigonal-pyramidal coordination environment and coordinated by three pyridyl nitrogen of tpt in a plane, whereas a carboxylate oxygen is coordinated to the copper(I) axially. The tpt-Cu forms a layer, and the layers are linked through H 2btec2- to form a 2D double-layered coordination polymer. Replacing CuSO4 with ZnI2 in the synthesis gives {[Zn(tpt)(btec)1/2].H2O}n (4). Zinc(II) is in a distorted tetrahedral geometry and linked through bidentate tpt and exotetradentate btec4- to form a 2D coordination grid. Reaction of tpt with CuCN leads to the assembly of a 3D metal-organic framework [Cu3(CN)3(tpt)]n (5). Copper(I) is trigonally coordinated by one pyridyl nitrogen and two cyanides to form an intriguing honeycomb architecture. Luminescence study shows that 1, 3, 4, and 5 have blue fluorescence, which can be assigned to be ligand-centered emissions. Thermal analysis shows that all of these complexes are quite stable, and especially for 4, the framework is stable up to 430 degrees C.
ABSTRACT
In the title complex, [Mn(C(8)H(4)NO(6))(2)(H(2)O)(4)] x 2H(2)O, cyclic water tetramers forming one-dimensional metal-water chains have been observed. The water clusters are trapped by the co-operative association of coordination interactions and hydrogen bonds. The Mn(II) ion resides on a center of symmetry and is in an octahedral coordination environment comprising two O atoms from two 5-carboxy-2-nitrobenzoate ligands and four O atoms from water molecules.
