A hypercrosslinked adsorption resin (ZH-05) modified by N-acetylaniline in the post crosslinking process was prepared. The adsorption properties of ZH-05 toward 2,4-dichlorophenol in comparison with granular activat...A hypercrosslinked adsorption resin (ZH-05) modified by N-acetylaniline in the post crosslinking process was prepared. The adsorption properties of ZH-05 toward 2,4-dichlorophenol in comparison with granular activated carbon (GAC) and Amberlite XAD-4 were observed. The present study mainly focuses on the static equilibrium adsorption behaviors, desorption profiles and the proof of chemisorption. The results show that the Langmuir equation can give a perfect fitting to experimental data, and high temperature was favorable for adsorption of 2,4-dichlorophenol on ZH-05. A related equation was used to correlate the amount of chemisorption and the suppositionai chemisorption equilibrium concentration of adsorbate in aqueous solution. The adsorption capacities from different ranges of temperature and the static desorption experiment both reveal the same conclusion, i.e., the adsorption of 2,4-dichlorophenol from water on ZH-05 is a coexistent process of physical adsorption and chemical transition as on GAC.展开更多
The early diagenetic characteristics of pyrite formation processes in a Miocene freshwater sequence of mixed sediments (coal fragments in clays, sandstones or shales) alternating with continuous brown coal layers wa...The early diagenetic characteristics of pyrite formation processes in a Miocene freshwater sequence of mixed sediments (coal fragments in clays, sandstones or shales) alternating with continuous brown coal layers was investigated. Based on abundant minerals, the following main sedimentary environments were distinguished: the illite-montmorillonitic (I-M), calcitic (Ct) and coal-forming environment (CL). For these hydrogeochemically differing environments the effects of limiting factors on the pyrite formation process (availability of sulphate and Fe, amount of organic matter and participation of organic sulphur) were assessed by correlation analysis. Significant differences in the effects of these limiting factors in the particular environments were observed. These differences were explained taking in account the different oxidative activity, Fe-complex and surface complex forming properties of humic substances in dependence of pH of environment and the abundance of sorptionally active clay minerals. In environments having a relatively low pH and containing clay minerals (I-M- and CL-environments) the oxidative activity of humic substances (Hs) on pyrite precursors was greatly prevented however pyrite formation depended on reactive Fe availability as the consequence of complex formation. On the contrary, in environments with a relatively high pH, as it was the calcitic, the oxidative activity of Hs was greatly enhanced, thus oxidizing the sulfur precursors of pyrite. The oxidation degree of organic matter was probably also a consequence of the differing activity of the humic electron-acceptors.展开更多
Since September 2011,A 2/O-MBR wastewater treatment plant in Xi'an Siyuan University has been successfully running without replacing any of membrane modules.A total of 6.661 million m^3 of campus wastewater has be...Since September 2011,A 2/O-MBR wastewater treatment plant in Xi'an Siyuan University has been successfully running without replacing any of membrane modules.A total of 6.661 million m^3 of campus wastewater has been treated,and 4.405 million m^3 of water reaching the national urban miscellaneous water standard has been reclaimed and reused.A total of 25 km pipeline,5 pits,scenery fountains,lakes,and 12 pump stations have been constructed for flushing toilets,irrigating green grass lawn and afforest,and cleaning hardened pavement.The design and construction of 5 pits,scenery fountains,and lakes are important to meet the national urban miscellaneous water standard under occasional phosphorus and/or nitrogen exceed concentration.The unit water cost is 4.19 yuan/m^3,including membrane modules depreciation and amortization.After the A 2/O-MBR system passes the membrane modules depreciation and amortization period,the unit water cost is 2.82 yuan/m^3.The water productivity of the membrane stack rises first at the beginning of operation,reaches the maximum value,and then decreases.The average annual transmembrane pressure difference increases by 1.12 kPa.The average VMD of industrial permeability decreases annually by 0.45 m^3.展开更多
Ketone bodies have emerged as central mediators of metabolic health,and multiple beneficial effects of a ketogenic diet,impacting metabolism,neuronal pathologies and,to a certain extent,tumorigenesis,have been reporte...Ketone bodies have emerged as central mediators of metabolic health,and multiple beneficial effects of a ketogenic diet,impacting metabolism,neuronal pathologies and,to a certain extent,tumorigenesis,have been reported both in animal models and clinical research.Ketone bodies,endogenously produced by the liver,act pleiotropically as metabolic intermediates,signaling molecules,and epigenetic modifiers.The endothelium and the vascular system are central regulators of the organism’s metabolic state and become dysfunctional in cardiovascular disease,atherosclerosis,and diabetic micro-and macrovascular complications.As physiological circulating ketone bodies can attain millimolar concentrations,the endothelium is the first-line cell lineage exposed to them.While in diabetic ketoacidosis high ketone body concentrations are detrimental to the vasculature,recent research revealed that ketone bodies in the low millimolar range may exert beneficial effects on endothelial cell(EC)functioning by modulating the EC inflammatory status,senescence,and metabolism.Here,we review the long-held evidence of detrimental cardiovascular effects of ketoacidosis as well as the more recent evidence for a positive impact of ketone bodies—at lower concentrations—on the ECs metabolism and vascular physiology and the subjacent cellular and molecular mechanisms.We also explore arising controversies in the field and discuss the importance of ketone body concentrations in relation to their effects.At low concentration,endogenously produced ketone bodies upon uptake of a ketogenic diet or supplemented ketone bodies(or their precursors)may prove beneficial to ameliorate endothelial function and,consequently,pathologies in which endothelial damage occurs.展开更多
This study used a flame atomic absorption spectrometer (FAAS) and atomic fluorescence spec-trophotometer (AFS) to detect the concentrations of chromium (Cr), cadmium (Cd), lead (Pb), hy-drargyrum (Hg) and arsenic (As)...This study used a flame atomic absorption spectrometer (FAAS) and atomic fluorescence spec-trophotometer (AFS) to detect the concentrations of chromium (Cr), cadmium (Cd), lead (Pb), hy-drargyrum (Hg) and arsenic (As) in soils and three genotypes of vegetables in greenhouse, as well as analyzed the physical and chemical properties of soils, including soil pH, soil organic matter (OM), basic nutrients, electrical conductivity (EC) and cation exchange capacity (CEC) in Guan- zhong areas, Shaanxi province, China. The results showed that comparing to subsoil, the sampled topsoil is enriched in Cr, Cd, Pb, As and Hg. Cd (0.83 - 3.17 mg·kg-1) and Hg (0.40 - 1.44 mg·kg-1) are exceeding the limited value stated in “the 2006 Greenhouse Vegetable Producing Environmental Quality Evaluation Standards” of 0.40 mg·kg-1 and 0.35 mg·kg-1 respectively. However, Nanzhuang greenhouse soil is within the limits. The heavy metal pollution index (HPI) of soil in Sanyuan (8.10) is the highest and in Dongzhang (4.23) is the lowest. The contents of Pb (0.201 - 0.376 mg·kg-1) were exceeding the limited value (0.20 mg·kg-1) in vegetables species, and Cd (0.0363 - 0.0572 mg·kg-1) in some place were also exceeding the limited value (0.05 mg·kg-1). Greenhouse soils were becoming acidified year after year;the ratios of N, P and K in soil were seriously imbalanced. According to the impacting factors, OM, pH, available P, EC and CEC have obviously effected the accumulation of Cr and Hg. However, there was not enough evidence for the effects of available nitrogen and available potassium.展开更多
The three systems of pure Zn, Zn-0.10% Mg(mass fraction), and Zn-0.15% Mg(mass fraction) were cast under controlled atmosphere and their microstructures were characterized by SEM/EDS analysis. The electrochemical corr...The three systems of pure Zn, Zn-0.10% Mg(mass fraction), and Zn-0.15% Mg(mass fraction) were cast under controlled atmosphere and their microstructures were characterized by SEM/EDS analysis. The electrochemical corrosion behavior of these three samples was examined in the very aggressive solution of 50% H2SO4(mass fraction) using electrochemical impedance spectroscopy(EIS) and potentiodynamic polarization measurements. The results show that magnesium improves in some extent the corrosion resistance of pure Zn in 50% H2SO4(mass fraction) confirmed by EIS test. Results of polarization measurment also demonstrate that small amount of Mg significantly improves the passivation of Zn in the test solution. Results of surface morphology of the samples and EDS analysis reveal that Mg reduced the corrosion attacks to pure Zn.展开更多
The interaction of Si anions with AI sites during the hydration process was observed by NMR, IR and SEM to understand the reaction mechanism of the hydrates formation mixed with oil shale calcined at different tempera...The interaction of Si anions with AI sites during the hydration process was observed by NMR, IR and SEM to understand the reaction mechanism of the hydrates formation mixed with oil shale calcined at different temperatures. As the reaction progressed,the coordination of AI (IV, V, and VI) changed almost completely to IV, when mixed with oilshale calcined at 700^(。)C. However, when mixed with oil shale calcined at 400^(。)C, some6-coordination of AI still remained in the hydrates. Under the function of alkaline solutions,which were produced with the hydration of clinker, a certain amount of Si and AI atomsdissolved or hydrolyzed from aluminosilicate, formed geomonomers in solutions, and thenpolycondensed to form networks.展开更多
Background:Multi-purpose use of forests in a sustainable way forces a recognition of how introduction of alien woody species in forests with different land use histories affect native plants other than trees.Lingonber...Background:Multi-purpose use of forests in a sustainable way forces a recognition of how introduction of alien woody species in forests with different land use histories affect native plants other than trees.Lingonberry Vaccinium vitis-idaea is an important understory component of temperate and boreal forests and provider of valuable non-wood forest products.Here we studied effects of land use changes and introduction of Northern red oak Quercus rubra on lingonberry in mesic Scots pine forests(in central Poland).We measured lingonberry cover,height of shoots,biomass of stems and leaves,and fruit productivity.Shoots were collected within 200 research plots located in recent and ancient Scots pine forests,with and without Q.rubra.Results:We found that V.vitis-idaea reached lower cover,aboveground biomass and fruit production in recent than ancient forests and in forests with than without Q.rubra.The fruit production in recent pine forest was only 2%of that reported in ancient pine forest,and V.vitis-idaea did not reproduce generatively in forests with Q.rubra.Biomass and carbon sequestration of V.vitis-idaea in forests with alien(invasive)trees decreased by 75%compared to ancient pine forest.Effects were also clear at the individual shoot level–in less suitable conditions we found taller heights and higher biomass allocation into stems than foliage.Biomass allocation in fruiting and non-fruiting shoots in pine forests was also different–less of the dry biomass of fruiting shoots was allocated to leaves than to stems.Conclusions:In the age of high interest in ecosystem services and discussions about usage of alien tree species as alternatives in forest management,our results clearly indicate disruption of ecosystem services provided by V.vitisidaea in the presence of Q.rubra.Lingonberry benefited from the continuity of forest land use,however,regardless of land-use legacy,alien tree introduction led to decline in abundance of species crucial for ecosystem functioning.Therefore,to maintain valuable native species and for conservation of ecosystem services delivery,we suggest limiting the introduction of Q.rubra in areas with abundant V.vitis-idaea,especially in forests with continuous forest land-use history.展开更多
Compared with the traditional wet-type de-dusting technology ,the dry-type de-dusting technology is considered to be environmentally friendly and energy-saving. However, the pipes carrying the de-dusted blast fiLrnace...Compared with the traditional wet-type de-dusting technology ,the dry-type de-dusting technology is considered to be environmentally friendly and energy-saving. However, the pipes carrying the de-dusted blast fiLrnace gas (BFG) tends to be corrosive more quickly and seriously. In order to investigate the reasons for the quick corrosion, the gas pipes and auxiliary bellows installed in Baosteel' s newly built BFG dry-type de-dusting system are studied. The corrosive properties of the condensed water, such as the pH value, are measured and analyzed. Meanwhile, various factors that may influence the corrosion rate of the pipes are studied by experiment. On the basis of the investigation and research, the causes of corrosion and leakage on the pipes are discovered. It is the process of dry de-dusting that is responsible ,to a large extent, for the quick corrosion of the pipes. The equipment of spray tower is introduced and its effects are then discussed. This tower is designed to eliminate most of chloridion and neutralized the acid by spraying the alkaline water to the dedusted gas flow. The practical operation shows that the tower helps to lessen the corrosiveness of the dry de-dusted gas effectively. The last part of this study analyzes the possible impacts of the dry-type de-dusting process of the newly built blast furnace (BF) on the main BFG piping which has been in the state of being corroded for years by estimating its potential corrosion rate, and some suggestions on maintenance are given as well.展开更多
A systematic study was conducted to comprehend the mechanism of thermal activation of silica-alumina materials by using ^29Si and ^27Al magnetic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy. The ...A systematic study was conducted to comprehend the mechanism of thermal activation of silica-alumina materials by using ^29Si and ^27Al magnetic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy. The reaction performance of silica-alumina-based materials with different molar ratios of Si/Al, which were thermally activated, was also investigated. With the increase in calcining temperature, the coordination of Al in metakaolin becomes four, five, and six firstly, and then transforms completely to four and six. It is indicated by identical coupled plasma optical emission spectroscopy (ICP) and NMR that, the reaction performance of monomeric silicate anions is better than that of polymeric silicate anions which are primarily cross-linked in the alkali solution. Moreover, it also shows that the thermal activation temperature, cooling method, and the molar ratio of Na/Ca have remarkable effects on the reaction performance.展开更多
As a high-end tourism activity advocating back to nature and protecting the nature,ecotourism has won increasing attention in recent years home and abroad.Being endowed with outstanding topographical and natural lands...As a high-end tourism activity advocating back to nature and protecting the nature,ecotourism has won increasing attention in recent years home and abroad.Being endowed with outstanding topographical and natural landscape resources,Sichuan has been a major ecotourism province in China.Particularly,western Sichuan mountains is more scarcely populated area with great topographical fluctuations,thus it is more suitable for developing ecotourism activities than eastern Sichuan.Based on previous researches and statistical analysis,this paper reviewed the overall situation of ecotourism landscape resources in western Sichuan mountains,including its geomorphological landforms,hydrographic landscapes,biological landscapes,meteorological and climatic landscapes.More importantly,in view of the blank area found in the statistical analysis,the paper analyzed the shrub landscapes on the basis of fi eld investigation,to support further research on the development and utilization of local ecotourism resources.展开更多
CONSERVING resources and protecting the environment is a fundamental state policy of China. Measurable targets and monitored results are key yardsticks for work in emission reduction and resource thrift.
基金This work was supported by the Educational Bureau (No.05KJD610250)the Science & Technology Bureau (No. BS2006032) of Jiangsu Province, China.
文摘A hypercrosslinked adsorption resin (ZH-05) modified by N-acetylaniline in the post crosslinking process was prepared. The adsorption properties of ZH-05 toward 2,4-dichlorophenol in comparison with granular activated carbon (GAC) and Amberlite XAD-4 were observed. The present study mainly focuses on the static equilibrium adsorption behaviors, desorption profiles and the proof of chemisorption. The results show that the Langmuir equation can give a perfect fitting to experimental data, and high temperature was favorable for adsorption of 2,4-dichlorophenol on ZH-05. A related equation was used to correlate the amount of chemisorption and the suppositionai chemisorption equilibrium concentration of adsorbate in aqueous solution. The adsorption capacities from different ranges of temperature and the static desorption experiment both reveal the same conclusion, i.e., the adsorption of 2,4-dichlorophenol from water on ZH-05 is a coexistent process of physical adsorption and chemical transition as on GAC.
文摘The early diagenetic characteristics of pyrite formation processes in a Miocene freshwater sequence of mixed sediments (coal fragments in clays, sandstones or shales) alternating with continuous brown coal layers was investigated. Based on abundant minerals, the following main sedimentary environments were distinguished: the illite-montmorillonitic (I-M), calcitic (Ct) and coal-forming environment (CL). For these hydrogeochemically differing environments the effects of limiting factors on the pyrite formation process (availability of sulphate and Fe, amount of organic matter and participation of organic sulphur) were assessed by correlation analysis. Significant differences in the effects of these limiting factors in the particular environments were observed. These differences were explained taking in account the different oxidative activity, Fe-complex and surface complex forming properties of humic substances in dependence of pH of environment and the abundance of sorptionally active clay minerals. In environments having a relatively low pH and containing clay minerals (I-M- and CL-environments) the oxidative activity of humic substances (Hs) on pyrite precursors was greatly prevented however pyrite formation depended on reactive Fe availability as the consequence of complex formation. On the contrary, in environments with a relatively high pH, as it was the calcitic, the oxidative activity of Hs was greatly enhanced, thus oxidizing the sulfur precursors of pyrite. The oxidation degree of organic matter was probably also a consequence of the differing activity of the humic electron-acceptors.
文摘Since September 2011,A 2/O-MBR wastewater treatment plant in Xi'an Siyuan University has been successfully running without replacing any of membrane modules.A total of 6.661 million m^3 of campus wastewater has been treated,and 4.405 million m^3 of water reaching the national urban miscellaneous water standard has been reclaimed and reused.A total of 25 km pipeline,5 pits,scenery fountains,lakes,and 12 pump stations have been constructed for flushing toilets,irrigating green grass lawn and afforest,and cleaning hardened pavement.The design and construction of 5 pits,scenery fountains,and lakes are important to meet the national urban miscellaneous water standard under occasional phosphorus and/or nitrogen exceed concentration.The unit water cost is 4.19 yuan/m^3,including membrane modules depreciation and amortization.After the A 2/O-MBR system passes the membrane modules depreciation and amortization period,the unit water cost is 2.82 yuan/m^3.The water productivity of the membrane stack rises first at the beginning of operation,reaches the maximum value,and then decreases.The average annual transmembrane pressure difference increases by 1.12 kPa.The average VMD of industrial permeability decreases annually by 0.45 m^3.
基金Supported by Polish National Science Centre,Project Grant NCN Harmonia,No.2019/30/M/NZ3/00682NAWA/Campusfrance Polonium,No.PPN/X/RJ/1876/2019.
文摘Ketone bodies have emerged as central mediators of metabolic health,and multiple beneficial effects of a ketogenic diet,impacting metabolism,neuronal pathologies and,to a certain extent,tumorigenesis,have been reported both in animal models and clinical research.Ketone bodies,endogenously produced by the liver,act pleiotropically as metabolic intermediates,signaling molecules,and epigenetic modifiers.The endothelium and the vascular system are central regulators of the organism’s metabolic state and become dysfunctional in cardiovascular disease,atherosclerosis,and diabetic micro-and macrovascular complications.As physiological circulating ketone bodies can attain millimolar concentrations,the endothelium is the first-line cell lineage exposed to them.While in diabetic ketoacidosis high ketone body concentrations are detrimental to the vasculature,recent research revealed that ketone bodies in the low millimolar range may exert beneficial effects on endothelial cell(EC)functioning by modulating the EC inflammatory status,senescence,and metabolism.Here,we review the long-held evidence of detrimental cardiovascular effects of ketoacidosis as well as the more recent evidence for a positive impact of ketone bodies—at lower concentrations—on the ECs metabolism and vascular physiology and the subjacent cellular and molecular mechanisms.We also explore arising controversies in the field and discuss the importance of ketone body concentrations in relation to their effects.At low concentration,endogenously produced ketone bodies upon uptake of a ketogenic diet or supplemented ketone bodies(or their precursors)may prove beneficial to ameliorate endothelial function and,consequently,pathologies in which endothelial damage occurs.
文摘This study used a flame atomic absorption spectrometer (FAAS) and atomic fluorescence spec-trophotometer (AFS) to detect the concentrations of chromium (Cr), cadmium (Cd), lead (Pb), hy-drargyrum (Hg) and arsenic (As) in soils and three genotypes of vegetables in greenhouse, as well as analyzed the physical and chemical properties of soils, including soil pH, soil organic matter (OM), basic nutrients, electrical conductivity (EC) and cation exchange capacity (CEC) in Guan- zhong areas, Shaanxi province, China. The results showed that comparing to subsoil, the sampled topsoil is enriched in Cr, Cd, Pb, As and Hg. Cd (0.83 - 3.17 mg·kg-1) and Hg (0.40 - 1.44 mg·kg-1) are exceeding the limited value stated in “the 2006 Greenhouse Vegetable Producing Environmental Quality Evaluation Standards” of 0.40 mg·kg-1 and 0.35 mg·kg-1 respectively. However, Nanzhuang greenhouse soil is within the limits. The heavy metal pollution index (HPI) of soil in Sanyuan (8.10) is the highest and in Dongzhang (4.23) is the lowest. The contents of Pb (0.201 - 0.376 mg·kg-1) were exceeding the limited value (0.20 mg·kg-1) in vegetables species, and Cd (0.0363 - 0.0572 mg·kg-1) in some place were also exceeding the limited value (0.05 mg·kg-1). Greenhouse soils were becoming acidified year after year;the ratios of N, P and K in soil were seriously imbalanced. According to the impacting factors, OM, pH, available P, EC and CEC have obviously effected the accumulation of Cr and Hg. However, there was not enough evidence for the effects of available nitrogen and available potassium.
文摘The three systems of pure Zn, Zn-0.10% Mg(mass fraction), and Zn-0.15% Mg(mass fraction) were cast under controlled atmosphere and their microstructures were characterized by SEM/EDS analysis. The electrochemical corrosion behavior of these three samples was examined in the very aggressive solution of 50% H2SO4(mass fraction) using electrochemical impedance spectroscopy(EIS) and potentiodynamic polarization measurements. The results show that magnesium improves in some extent the corrosion resistance of pure Zn in 50% H2SO4(mass fraction) confirmed by EIS test. Results of polarization measurment also demonstrate that small amount of Mg significantly improves the passivation of Zn in the test solution. Results of surface morphology of the samples and EDS analysis reveal that Mg reduced the corrosion attacks to pure Zn.
基金Supported by the National Science and Technology (2006BAE03A11)the National Natural Science Foundation of China(50674062)
文摘The interaction of Si anions with AI sites during the hydration process was observed by NMR, IR and SEM to understand the reaction mechanism of the hydrates formation mixed with oil shale calcined at different temperatures. As the reaction progressed,the coordination of AI (IV, V, and VI) changed almost completely to IV, when mixed with oilshale calcined at 700^(。)C. However, when mixed with oil shale calcined at 400^(。)C, some6-coordination of AI still remained in the hydrates. Under the function of alkaline solutions,which were produced with the hydration of clinker, a certain amount of Si and AI atomsdissolved or hydrolyzed from aluminosilicate, formed geomonomers in solutions, and thenpolycondensed to form networks.
基金financially supported by the Faculty of Biology and Environmental Protection,University of Lodz and the Institute of Dendrology,Polish Academy of Sciences,Kórnik,Poland。
文摘Background:Multi-purpose use of forests in a sustainable way forces a recognition of how introduction of alien woody species in forests with different land use histories affect native plants other than trees.Lingonberry Vaccinium vitis-idaea is an important understory component of temperate and boreal forests and provider of valuable non-wood forest products.Here we studied effects of land use changes and introduction of Northern red oak Quercus rubra on lingonberry in mesic Scots pine forests(in central Poland).We measured lingonberry cover,height of shoots,biomass of stems and leaves,and fruit productivity.Shoots were collected within 200 research plots located in recent and ancient Scots pine forests,with and without Q.rubra.Results:We found that V.vitis-idaea reached lower cover,aboveground biomass and fruit production in recent than ancient forests and in forests with than without Q.rubra.The fruit production in recent pine forest was only 2%of that reported in ancient pine forest,and V.vitis-idaea did not reproduce generatively in forests with Q.rubra.Biomass and carbon sequestration of V.vitis-idaea in forests with alien(invasive)trees decreased by 75%compared to ancient pine forest.Effects were also clear at the individual shoot level–in less suitable conditions we found taller heights and higher biomass allocation into stems than foliage.Biomass allocation in fruiting and non-fruiting shoots in pine forests was also different–less of the dry biomass of fruiting shoots was allocated to leaves than to stems.Conclusions:In the age of high interest in ecosystem services and discussions about usage of alien tree species as alternatives in forest management,our results clearly indicate disruption of ecosystem services provided by V.vitisidaea in the presence of Q.rubra.Lingonberry benefited from the continuity of forest land use,however,regardless of land-use legacy,alien tree introduction led to decline in abundance of species crucial for ecosystem functioning.Therefore,to maintain valuable native species and for conservation of ecosystem services delivery,we suggest limiting the introduction of Q.rubra in areas with abundant V.vitis-idaea,especially in forests with continuous forest land-use history.
文摘Compared with the traditional wet-type de-dusting technology ,the dry-type de-dusting technology is considered to be environmentally friendly and energy-saving. However, the pipes carrying the de-dusted blast fiLrnace gas (BFG) tends to be corrosive more quickly and seriously. In order to investigate the reasons for the quick corrosion, the gas pipes and auxiliary bellows installed in Baosteel' s newly built BFG dry-type de-dusting system are studied. The corrosive properties of the condensed water, such as the pH value, are measured and analyzed. Meanwhile, various factors that may influence the corrosion rate of the pipes are studied by experiment. On the basis of the investigation and research, the causes of corrosion and leakage on the pipes are discovered. It is the process of dry de-dusting that is responsible ,to a large extent, for the quick corrosion of the pipes. The equipment of spray tower is introduced and its effects are then discussed. This tower is designed to eliminate most of chloridion and neutralized the acid by spraying the alkaline water to the dedusted gas flow. The practical operation shows that the tower helps to lessen the corrosiveness of the dry de-dusted gas effectively. The last part of this study analyzes the possible impacts of the dry-type de-dusting process of the newly built blast furnace (BF) on the main BFG piping which has been in the state of being corroded for years by estimating its potential corrosion rate, and some suggestions on maintenance are given as well.
基金supported by the National Key Technologies R&D Program of China (No.2006BAC21B03)the National Natural Science Foundation of China (No.50674062)
文摘A systematic study was conducted to comprehend the mechanism of thermal activation of silica-alumina materials by using ^29Si and ^27Al magnetic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy. The reaction performance of silica-alumina-based materials with different molar ratios of Si/Al, which were thermally activated, was also investigated. With the increase in calcining temperature, the coordination of Al in metakaolin becomes four, five, and six firstly, and then transforms completely to four and six. It is indicated by identical coupled plasma optical emission spectroscopy (ICP) and NMR that, the reaction performance of monomeric silicate anions is better than that of polymeric silicate anions which are primarily cross-linked in the alkali solution. Moreover, it also shows that the thermal activation temperature, cooling method, and the molar ratio of Na/Ca have remarkable effects on the reaction performance.
基金Sponsored by Sub-Project of Strategic Priority Research Program of the Chinese Academy of Sciences(XDA01050303)National Science and Technology Foundation Program(2015PY110300)。
文摘As a high-end tourism activity advocating back to nature and protecting the nature,ecotourism has won increasing attention in recent years home and abroad.Being endowed with outstanding topographical and natural landscape resources,Sichuan has been a major ecotourism province in China.Particularly,western Sichuan mountains is more scarcely populated area with great topographical fluctuations,thus it is more suitable for developing ecotourism activities than eastern Sichuan.Based on previous researches and statistical analysis,this paper reviewed the overall situation of ecotourism landscape resources in western Sichuan mountains,including its geomorphological landforms,hydrographic landscapes,biological landscapes,meteorological and climatic landscapes.More importantly,in view of the blank area found in the statistical analysis,the paper analyzed the shrub landscapes on the basis of fi eld investigation,to support further research on the development and utilization of local ecotourism resources.
文摘CONSERVING resources and protecting the environment is a fundamental state policy of China. Measurable targets and monitored results are key yardsticks for work in emission reduction and resource thrift.