NaY and ion exchanged NaNH4Y zeolite with NH4NO3 were used as the support to prepare CuY cata‐lysts by a high temperature anhydrous interaction between the support and copper (II) acety‐lacetonate Cu(acac)2. The...NaY and ion exchanged NaNH4Y zeolite with NH4NO3 were used as the support to prepare CuY cata‐lysts by a high temperature anhydrous interaction between the support and copper (II) acety‐lacetonate Cu(acac)2. The catalysts were used for the oxidative carbonylation of methanol to dime‐thyl carbonate (DMC) at atmospheric pressure. The textural and acidic properties of NaNH4Y zeolite and the CuY catalysts were investigated by X‐ray diffraction, scanning electron microscopy, N2 ad‐sorption‐desorption, temperature programmed reduction of H2, X‐ray photoelectron spectroscopy and temperature programmed desorption of NH3. With increasing NH4NO3 concentration, the NH4+exchange degree increased while the crystallinity of the zeolite remained intact. Crystalline CuO was formed when the NH4+exchange degree of NaNH4Y was low, and the corresponding CuY catalyst showed low catalytic activity. With increasing of the NH4+exchange degree of NaNH4Y, the content of surface bound Cu+active centers increased and the catalytic activity of the corresponding CuY catalyst also increased. The surface bound Cu+content reached its maximum when the NH4+ex‐change degree of NaNH4Y reached towards saturation. The CuY exhibited optimal catalytic activity with 267.3 mg/(g·h) space time yield of DMC, 6.9%conversion of methanol, 68.5%selectivity of DMC.展开更多
In order to more efficiently utilize gypsum to improve meadow alkali soil slightly salinized by soda and sulfate chloride, a total of 27 treatments were de- signed from the perspectives of field capacity, alkalinity, ...In order to more efficiently utilize gypsum to improve meadow alkali soil slightly salinized by soda and sulfate chloride, a total of 27 treatments were de- signed from the perspectives of field capacity, alkalinity, alkaline salt content, optimal irrigation, gypsum conversion, gypsum and soil treatment and improvement depth. The ions on the obtained filtrate were analyzed in terms of salts. The improving ef- ficiency of gypsum for meadow alkali soil was analyzed through comparing the con- tents of soluble salts in pre-improvement and post-improvement soil by reasoning and calculation. The results showed that, (1) the dissolved amount and conversion amount of gypsum were increased, and the soil alkalinity was decreased corre- spondingly with the increased irrigation amount. However, after reaching a certain extent, the linear relationships became unobvious gradually. Therefore, the irrigation amount should be arranged reasonably for different treatment. (2) Compared with those at low temperature, the dissolved amount of gypsum at high temperature was increased by 1.47-1.50 times, the release amount of exchangeable sodium was in- creased by 2.98-4.70 times, and the release amount of exchangeable magnesium was increased by 2.07-2.90 times. In overall, the improving efficiency of gypsum in summer was better. However, gypsum had two shortcomings in summer. First, a large amount of gypsum leaked away. Second, a large amount of exchangeable magnesium, along with exchangeable sodium, was substituted by gypsum. (3) Compared with the other two treatments, treatment B (mixing gypsum and top 20- cm soil) showed the best improving efficiency, and it was characterized by stepwise dealkalization from top to down. In addition, mixing gypsum and topsoil is more practical in the production.展开更多
In consideration of the spectral character of MODIS (Moderate Resolution Imaging Spectroradiometer) dataand the reflective spectrum of vegetation and soil, NDVI (Normalized Difference Vegetation Index) and NDWI (Nor-m...In consideration of the spectral character of MODIS (Moderate Resolution Imaging Spectroradiometer) dataand the reflective spectrum of vegetation and soil, NDVI (Normalized Difference Vegetation Index) and NDWI (Nor-malized Difference Water Index) are deduced using one visible band (0.66μm) and two near-infrared bands (0.86μm,1.24 μm). Vegetation canopy temperature is derived using two thermal infrared bands (8.6 μm and 11μm). Then thevegetation/soil synthesis water index (VSWI) is acquired through analyzing the coupling character of three indexeswhich can reflect the water condition of vegetation. Finally, the synthesis index is verified by equivalent water contentof a single leaf. The matching results show that the synthesis index is directly proportional to the modeled data,which means that the vegetation water content can be reflected using the synthesis index effectively.展开更多
Water-using operations in the process industry have demands for water usually both on water quality and temperature, and the existing mathematical models of heat exchange networks cannot guarantee the energy performan...Water-using operations in the process industry have demands for water usually both on water quality and temperature, and the existing mathematical models of heat exchange networks cannot guarantee the energy performance of a water network optimal. In this paper, the effects of non-isothermal merging on energy performance of water allocation networks are analyzed, which include utility consumption, total heat exchange load, and number of heat exchange matches. Three principles are proposed to express the effects of non-isothermal merging on energy performance of water allocation networks. A rule of non-isothermal merging without increasing utility consumption is deduced. And an approach to improve energy performance of water allocation network is presented. A case study is given to demonstrate the method.展开更多
The oxidative desulfurization of a real refinery feedstock (i.e.,non-hydrotreated kerosene with total sulfur mass content of 0.16%) with a mixture of hydrogen peroxide and acetic acid was studied.The influences of var...The oxidative desulfurization of a real refinery feedstock (i.e.,non-hydrotreated kerosene with total sulfur mass content of 0.16%) with a mixture of hydrogen peroxide and acetic acid was studied.The influences of various operating parameters including reaction temperature (T),acid to sulfur molar ratio (nacid/nS),and oxidant to sulfur molar ratio (nO/nS) on the sulfur removal of kerosene were investigated.The results revealed that an increase in the reaction temperature (T) and nacid/nS enhances the sulfur removal.Moreover,there is an optimum nO/nS related to the reaction temperature and the best sulfur removal could be obtained at nO/nS=8 and 23 for the reaction temperatures of 25 and 60°C,respectively.The maximum observed sulfur removal in the present oxidative desulfurization system was 83.3%.展开更多
Ultrasonic speeds of 4-aminobutyric acid in 0.0041,0.0125 and 0.0207 mol·kg^-1 aqueous salbutamol sulphate(SBS) solutions are measured at 308.15,313.15 and 318.15 K.Isentropic compressibility kS,change in isent...Ultrasonic speeds of 4-aminobutyric acid in 0.0041,0.0125 and 0.0207 mol·kg^-1 aqueous salbutamol sulphate(SBS) solutions are measured at 308.15,313.15 and 318.15 K.Isentropic compressibility kS,change in isentropic compressibility△k S,relative change in isentropic compressibility( △kS /kS^0) ,apparent molal compressibility kφ,limiting apparent molal compressibility kφ^0 ,transfer limiting apparent molal compressibility k φ^0,hydration number nH,pair and triplet interaction parameters kAS,kASS are estimated.The above parameters are used to interpret the solute-solute and solute-solvent interactions of 4-aminobutyric acid in the aqueous salbutamol sulphate solutions.展开更多
Novelthree-dimensionalstring and ball-like titanium dioxide/reduced graphene oxide, TiO_2/rGO(STG) composites were prepared using a one-step hydrolysis process followed by a low-temperature hydrothermaltreatment. The ...Novelthree-dimensionalstring and ball-like titanium dioxide/reduced graphene oxide, TiO_2/rGO(STG) composites were prepared using a one-step hydrolysis process followed by a low-temperature hydrothermaltreatment. The STG composites exhibited excellent photo-catalytic degradation performance for methylene blue owing to a good synergistic effect between TiO_2 and rGO. The STG composites with 1.0 wt% of rGO loading exhibited the highest removalrate of 86.0% for methylene blue and its reaction rate constant(5.27 × 10^(-3) min^(-1)) was much higher than those of pure string and ball-like TiO_2(ST). In addition, the STG composites also showed an outstanding capability for the photo-catalysis degradation of other cationic dyes. In addition, a possible photo-catalytic degradation mechanism for the STG composite was postulated, in which~?O_2^- and~·OH were the main oxidizing groups. This work of fers new insights into a better design and preparation of novelcomposite materials for the removalof organic dyes.展开更多
It is promising to simultaneously develop multiple products through the combined utilization of seawater by solar chimney technology. A small scale experimental system was set up. The collector temperature, the seawat...It is promising to simultaneously develop multiple products through the combined utilization of seawater by solar chimney technology. A small scale experimental system was set up. The collector temperature, the seawater temperature, and the temperature and humidity of the airflow under the collector were measured. Thermal network analysis of the system was carried out. The results show that the airflow is nearly saturated at the entrance of the chimney, and the mean dry-bulb and wet-bulb temperatures of the airflow have increased by 8.4 ℃ and 9.6 ℃, respectively. The radiation heat transfer between the collector and the sky is the biggest heat loss in the system, which is up to 29.1% on average of the solar energy. However, the water evaporation heat is about 23.6% on average of the solar energy. To reduce the heat loss and enhance the water evaporation, it is necessary to reduce the emissivity and thermal conductivity of the collector and increase the evaporation areas.展开更多
According to the data of main environmental factors and the depth of localized corrosion of carbon steel and low alloy steels in China seas, combined with the result of grey interrelation analysis, double-factor metho...According to the data of main environmental factors and the depth of localized corrosion of carbon steel and low alloy steels in China seas, combined with the result of grey interrelation analysis, double-factor method was proposed to evaluate and classify seawater corrosiveness. According to the temperature of seawater and the biologically adhesive area on steels, the corrosiveness of seawater from low to high level is classified into five levels (C l-C5), which was identified by the data of corrosion depth of carbon steel immersed in water for one year.展开更多
Legionellae are found in freshwater environments or wet soil, but the major reservoirs are man-made aquatic environments, particularly warm water systems. Our aim was to study the occurrence of Legionella contaminatio...Legionellae are found in freshwater environments or wet soil, but the major reservoirs are man-made aquatic environments, particularly warm water systems. Our aim was to study the occurrence of Legionella contamination in hot potable water supply systems in apartment and public buildings. Correlations between Legionella spp. positive cases and water source, sampling point and temperature of hot water at the point of consumption were studied. A total of 149 hot water samples were collected in 16 cities and districts of Latvia. Only Legionella pneumophila was isolated. L. pneumophila was found in 63 out of 149 (42%) hot water samples. From all Legionella spp. positive samples, 17% represented L. pneumophila serogroup 1 and 78% L. pneumophila serogroups 2-14 (15). In 5% of Legionella spp. positive samples, both serogroups 1 and 2-14(15) were isolated. Statistically significant differences were observed in the distribution of L. pneumophila serogroup 1 in samples from various water sources. L. pneumophila was found in 45% of samples from private apartments and in 27% of samples from public buildings. Data analysis confirmed that the temperature of hot water significantly affects the frequency of L. pneumophila positive cases (p 〈 0.05). Data showed that 85% of consumers received hot water at a temperature below 50°C.展开更多
This paper presents an extensive study of the heat pump cycle and associated working fluids to generate electricity from low temperature industrial waste heat. An Aspen Plus simulation has been developed to evaluate t...This paper presents an extensive study of the heat pump cycle and associated working fluids to generate electricity from low temperature industrial waste heat. An Aspen Plus simulation has been developed to evaluate the effect of various working fluids on the net heat pump efficiency over a wide range of turbine inlet temperatures between 50℃ and 250℃. One hundred eight (108) refi'igerants were investigated from the environmental classifications of Hydrochlorofluorocarbons (HCFC), Hydrofluorocarbons (HFC), Chlorofluorocarbons (CFC) and Hydrocarbons (HC) with boiling points between -88.65 ℃ and 110.65℃. Net efficiency, which ranged from 0.1% to 25.8% in this work tends to increases with the temperature of the waste heat. Results of the present study demonstrate that working fluid R41 (with source temperature of 44 ℃) provides the maximum efficiency among those evaluated. Refrigerants R13B1 and R32 provide the best efficiency for waste heat source temperatures ranges 60 - 67 ℃ and 68 - 78℃ respectively. Ammonia shows the highest efficiency from 79℃ to 132 ℃. Refrigerants R31, R21, 17,30 and benzene perform well in the temperature ranges 133-151 ℃, 152-178 ℃, 179-236℃ and 237-250 ℃respectively. The optimal heat pump systems are applied to the hybrid copper sulfate-copper oxide thermochemical cycle for hydrogen production from water. 100.8 MW of electrical energy is produced, which increased the efficiency from 24.1% to 25.9%.展开更多
In this paper, the novel control structures of differential pressure thermally coupled reactive distillation process for methyl acetate hydrolysis were proposed. The RadFrac module of Aspen Plus was adopted in the ste...In this paper, the novel control structures of differential pressure thermally coupled reactive distillation process for methyl acetate hydrolysis were proposed. The RadFrac module of Aspen Plus was adopted in the steady-state simulation. Sensitive analysis was applied to find the stable intial value and provide a basis for the improved control structure design. The Aspen Dynamics software was adopted to study the process dynamic behaviors, and two novel control structures provided with feed ratio controllers and sensitive tray temperature controllers were proposed. The reflux ratio controllers were applied in the improved novel control structures. Both control structures abandoned the composition controllers that were replaced by simpler controllers with which the product purity could meet the specification requiring under a ± 20% disturbance to the total feed flowrate / MeAc composition.展开更多
After compositing three representative ENSO indices,El Nio events have been divided into an eastern pattern(EP) and a central pattern(CP).By using EOF,correlation and composite analysis,the relationship and possible m...After compositing three representative ENSO indices,El Nio events have been divided into an eastern pattern(EP) and a central pattern(CP).By using EOF,correlation and composite analysis,the relationship and possible mechanisms between Indian Ocean Dipole(IOD) and two types of El Nio were investigated.IOD events,originating from Indo-Pacific scale air-sea interaction,are composed of two modes,which are associated with EP and CP El Ni o respectively.The IOD mode related to EP El Nio events(named as IOD1) is strongest at the depth of 50 to 150 m along the equatorial Indian Ocean.Besides,it shows a quasi-symmetric distribution,stronger in the south of the Equator.The IOD mode associated with CP El Nio(named as IOD2) has strongest signal in tropical southern Indian Ocean surface.In terms of mechanisms,before EP El Nio peaks,anomalous Walker circulation produces strong anomalous easterlies in equatorial Indian Ocean,resulting in upwelling in the east,decreasing sea temperature there;a couple of anomalous anticyclones(stronger in the south) form off the Equator where warm water accumulates,and thus the IOD1 occurs.When CP El Nio develops,anomalous Walker circulation is weaker and shifts its center to the west,therefore anomalous easterlies in equatorial Indian Ocean is less strong.Besides,the anticyclone south of Sumatra strengthens,and the southerlies east of it bring cold water from higher latitudes and northerlies west of it bring warm water from lower latitudes to the 15° to 25°S zone.Meanwhile,there exists strong divergence in the east and convergence in the west part of tropical southern Indian Ocean,making sea temperature fall and rise separately.Therefore,IOD2 lies farther south.展开更多
Waterborne acrylic emulsions modified with organic siloxanes and aziridine crosslinker were synthesized and applied as coating of controlled release fertilizer. The free films were characterized and the nutrient relea...Waterborne acrylic emulsions modified with organic siloxanes and aziridine crosslinker were synthesized and applied as coating of controlled release fertilizer. The free films were characterized and the nutrient release profiles of the coated fertilizers were determined. The results show that methyl silicone oil and methylsilanolate sodium could not improve water resistance performance and glass transition temperature Tgof coatings, while the firmness is enhanced. Aziridine crosslinker improves the water resistance performance, firmness and Tg. Incorporation of methyl silicone oil and aziridine crosslinker gives an excellent aqueous acrylic emulsion for coated controlled release fertilizer, with the 30-day cumulative nutrient release reduced to 16% and an estimated nutrient release duration over 190 days. Therefore, this waterborne coating is promising to meet the requirements for controlled release of nutrient and environmental protection.展开更多
The solubilities of 2-naphthalenesulfonic acid monohydrate and sodium 2-naphthalenesulfonate in sulfuric acid solutions were measured at temperatures ranging from 278,15 to 338.15 K by using a dynamic method. The conc...The solubilities of 2-naphthalenesulfonic acid monohydrate and sodium 2-naphthalenesulfonate in sulfuric acid solutions were measured at temperatures ranging from 278,15 to 338.15 K by using a dynamic method. The concentration of sulfuric acid solution ranged from 0 to 80wt%. The solubilities of 2-naphthalenesulfonic acid monohydrate and sodium 2-naphthalenesulfonate increased with temperature, and both of them were the lowest at 70wt% of sulfuric acid solution ( w3 0 = 0.70) while the highest in pure water. The solubility data were correlated by the modified Apelblat equation. Based on the solubility difference between 2-naphthalenesulfonic acid monohydrate and sodium 2-naphthalenesulfonate, a new technique in which sodium sulfate was used to replace sodium sulfite in the neutralization reaction was developed. The suitable mole ratio of H20 to Na2SO4 in the neutralization reaction was 80 : 1, and that of 2-naphthalenesulfonic acid monohydrate to Na2SO4 was 3.2 : 1. The material balance under the suitable mole ratios was given and discussed.展开更多
Water temperature observation in wells,as a precursor observation project in China,aims to capture stress-strain information during the preparation of earthquakes. The study of the water temperature tidal effect has i...Water temperature observation in wells,as a precursor observation project in China,aims to capture stress-strain information during the preparation of earthquakes. The study of the water temperature tidal effect has important significance,for water temperature tidal effect is both a reflection of stress-strain in crust and an interference factor of precursor observations. With a view of thermal conditions in artesian wells,the paper holds that there are two mechanisms for interpreting tidally induced water temperature changes in artesian wells. Namely,thermal conduction mechanisms and thermal convection mechanism. The paper then derives the quantitative relationship between water temperature and tidal volumetric strain changes in an ideal artesian well. Finally,the water temperature tidal effect in the Benxi artesian well is analyzed. The results show that the water temperature tidal effect in Benxi well is the result of joint action of thermal conduction mechanism and thermal convection mechanism,in which thermal conduction mechanism plays a leading role.展开更多
基金supported by the National Natural Science Foundation of China (21276169)~~
文摘NaY and ion exchanged NaNH4Y zeolite with NH4NO3 were used as the support to prepare CuY cata‐lysts by a high temperature anhydrous interaction between the support and copper (II) acety‐lacetonate Cu(acac)2. The catalysts were used for the oxidative carbonylation of methanol to dime‐thyl carbonate (DMC) at atmospheric pressure. The textural and acidic properties of NaNH4Y zeolite and the CuY catalysts were investigated by X‐ray diffraction, scanning electron microscopy, N2 ad‐sorption‐desorption, temperature programmed reduction of H2, X‐ray photoelectron spectroscopy and temperature programmed desorption of NH3. With increasing NH4NO3 concentration, the NH4+exchange degree increased while the crystallinity of the zeolite remained intact. Crystalline CuO was formed when the NH4+exchange degree of NaNH4Y was low, and the corresponding CuY catalyst showed low catalytic activity. With increasing of the NH4+exchange degree of NaNH4Y, the content of surface bound Cu+active centers increased and the catalytic activity of the corresponding CuY catalyst also increased. The surface bound Cu+content reached its maximum when the NH4+ex‐change degree of NaNH4Y reached towards saturation. The CuY exhibited optimal catalytic activity with 267.3 mg/(g·h) space time yield of DMC, 6.9%conversion of methanol, 68.5%selectivity of DMC.
基金Supported by National Natural Science Foundation of China(41401559)Project of Hubei Provincial Science and Technology Department(2014CFB558)Project of Hubei Provincial Department of Education(D20141001)~~
文摘In order to more efficiently utilize gypsum to improve meadow alkali soil slightly salinized by soda and sulfate chloride, a total of 27 treatments were de- signed from the perspectives of field capacity, alkalinity, alkaline salt content, optimal irrigation, gypsum conversion, gypsum and soil treatment and improvement depth. The ions on the obtained filtrate were analyzed in terms of salts. The improving ef- ficiency of gypsum for meadow alkali soil was analyzed through comparing the con- tents of soluble salts in pre-improvement and post-improvement soil by reasoning and calculation. The results showed that, (1) the dissolved amount and conversion amount of gypsum were increased, and the soil alkalinity was decreased corre- spondingly with the increased irrigation amount. However, after reaching a certain extent, the linear relationships became unobvious gradually. Therefore, the irrigation amount should be arranged reasonably for different treatment. (2) Compared with those at low temperature, the dissolved amount of gypsum at high temperature was increased by 1.47-1.50 times, the release amount of exchangeable sodium was in- creased by 2.98-4.70 times, and the release amount of exchangeable magnesium was increased by 2.07-2.90 times. In overall, the improving efficiency of gypsum in summer was better. However, gypsum had two shortcomings in summer. First, a large amount of gypsum leaked away. Second, a large amount of exchangeable magnesium, along with exchangeable sodium, was substituted by gypsum. (3) Compared with the other two treatments, treatment B (mixing gypsum and top 20- cm soil) showed the best improving efficiency, and it was characterized by stepwise dealkalization from top to down. In addition, mixing gypsum and topsoil is more practical in the production.
基金Project G2000077907 supported by National Key Basic Research Plan Foundation of China
文摘In consideration of the spectral character of MODIS (Moderate Resolution Imaging Spectroradiometer) dataand the reflective spectrum of vegetation and soil, NDVI (Normalized Difference Vegetation Index) and NDWI (Nor-malized Difference Water Index) are deduced using one visible band (0.66μm) and two near-infrared bands (0.86μm,1.24 μm). Vegetation canopy temperature is derived using two thermal infrared bands (8.6 μm and 11μm). Then thevegetation/soil synthesis water index (VSWI) is acquired through analyzing the coupling character of three indexeswhich can reflect the water condition of vegetation. Finally, the synthesis index is verified by equivalent water contentof a single leaf. The matching results show that the synthesis index is directly proportional to the modeled data,which means that the vegetation water content can be reflected using the synthesis index effectively.
基金Supported by the National Natural Science Foundation of China (20436040).
文摘Water-using operations in the process industry have demands for water usually both on water quality and temperature, and the existing mathematical models of heat exchange networks cannot guarantee the energy performance of a water network optimal. In this paper, the effects of non-isothermal merging on energy performance of water allocation networks are analyzed, which include utility consumption, total heat exchange load, and number of heat exchange matches. Three principles are proposed to express the effects of non-isothermal merging on energy performance of water allocation networks. A rule of non-isothermal merging without increasing utility consumption is deduced. And an approach to improve energy performance of water allocation network is presented. A case study is given to demonstrate the method.
基金Supported by the R&D center of Esfahan refinery (Esfahan,Iran)the technical supports of central laboratory of Esfahan Refinery for total sulfur analysis
文摘The oxidative desulfurization of a real refinery feedstock (i.e.,non-hydrotreated kerosene with total sulfur mass content of 0.16%) with a mixture of hydrogen peroxide and acetic acid was studied.The influences of various operating parameters including reaction temperature (T),acid to sulfur molar ratio (nacid/nS),and oxidant to sulfur molar ratio (nO/nS) on the sulfur removal of kerosene were investigated.The results revealed that an increase in the reaction temperature (T) and nacid/nS enhances the sulfur removal.Moreover,there is an optimum nO/nS related to the reaction temperature and the best sulfur removal could be obtained at nO/nS=8 and 23 for the reaction temperatures of 25 and 60°C,respectively.The maximum observed sulfur removal in the present oxidative desulfurization system was 83.3%.
文摘Ultrasonic speeds of 4-aminobutyric acid in 0.0041,0.0125 and 0.0207 mol·kg^-1 aqueous salbutamol sulphate(SBS) solutions are measured at 308.15,313.15 and 318.15 K.Isentropic compressibility kS,change in isentropic compressibility△k S,relative change in isentropic compressibility( △kS /kS^0) ,apparent molal compressibility kφ,limiting apparent molal compressibility kφ^0 ,transfer limiting apparent molal compressibility k φ^0,hydration number nH,pair and triplet interaction parameters kAS,kASS are estimated.The above parameters are used to interpret the solute-solute and solute-solvent interactions of 4-aminobutyric acid in the aqueous salbutamol sulphate solutions.
基金supported by the National High Technology Research and Development Program of China ("863" Program, No. 2012AA063504)the National Natural Science Foundation of China (Nos. 21276193, 215111300020, 201405008, and U1407116)the Natural Science Foundation of Tianjin, China (No. 13JCZDJC35600)
文摘Novelthree-dimensionalstring and ball-like titanium dioxide/reduced graphene oxide, TiO_2/rGO(STG) composites were prepared using a one-step hydrolysis process followed by a low-temperature hydrothermaltreatment. The STG composites exhibited excellent photo-catalytic degradation performance for methylene blue owing to a good synergistic effect between TiO_2 and rGO. The STG composites with 1.0 wt% of rGO loading exhibited the highest removalrate of 86.0% for methylene blue and its reaction rate constant(5.27 × 10^(-3) min^(-1)) was much higher than those of pure string and ball-like TiO_2(ST). In addition, the STG composites also showed an outstanding capability for the photo-catalysis degradation of other cationic dyes. In addition, a possible photo-catalytic degradation mechanism for the STG composite was postulated, in which~?O_2^- and~·OH were the main oxidizing groups. This work of fers new insights into a better design and preparation of novelcomposite materials for the removalof organic dyes.
基金Supported by Tianjin Technological Development Program Project of China (No05YFGZSF02800 and No06YFSZSF04600)the Key Research Program of the National Eleventh Five-Year Plan of China (No 2006BAA04B03-03)
文摘It is promising to simultaneously develop multiple products through the combined utilization of seawater by solar chimney technology. A small scale experimental system was set up. The collector temperature, the seawater temperature, and the temperature and humidity of the airflow under the collector were measured. Thermal network analysis of the system was carried out. The results show that the airflow is nearly saturated at the entrance of the chimney, and the mean dry-bulb and wet-bulb temperatures of the airflow have increased by 8.4 ℃ and 9.6 ℃, respectively. The radiation heat transfer between the collector and the sky is the biggest heat loss in the system, which is up to 29.1% on average of the solar energy. However, the water evaporation heat is about 23.6% on average of the solar energy. To reduce the heat loss and enhance the water evaporation, it is necessary to reduce the emissivity and thermal conductivity of the collector and increase the evaporation areas.
文摘According to the data of main environmental factors and the depth of localized corrosion of carbon steel and low alloy steels in China seas, combined with the result of grey interrelation analysis, double-factor method was proposed to evaluate and classify seawater corrosiveness. According to the temperature of seawater and the biologically adhesive area on steels, the corrosiveness of seawater from low to high level is classified into five levels (C l-C5), which was identified by the data of corrosion depth of carbon steel immersed in water for one year.
文摘Legionellae are found in freshwater environments or wet soil, but the major reservoirs are man-made aquatic environments, particularly warm water systems. Our aim was to study the occurrence of Legionella contamination in hot potable water supply systems in apartment and public buildings. Correlations between Legionella spp. positive cases and water source, sampling point and temperature of hot water at the point of consumption were studied. A total of 149 hot water samples were collected in 16 cities and districts of Latvia. Only Legionella pneumophila was isolated. L. pneumophila was found in 63 out of 149 (42%) hot water samples. From all Legionella spp. positive samples, 17% represented L. pneumophila serogroup 1 and 78% L. pneumophila serogroups 2-14 (15). In 5% of Legionella spp. positive samples, both serogroups 1 and 2-14(15) were isolated. Statistically significant differences were observed in the distribution of L. pneumophila serogroup 1 in samples from various water sources. L. pneumophila was found in 45% of samples from private apartments and in 27% of samples from public buildings. Data analysis confirmed that the temperature of hot water significantly affects the frequency of L. pneumophila positive cases (p 〈 0.05). Data showed that 85% of consumers received hot water at a temperature below 50°C.
文摘This paper presents an extensive study of the heat pump cycle and associated working fluids to generate electricity from low temperature industrial waste heat. An Aspen Plus simulation has been developed to evaluate the effect of various working fluids on the net heat pump efficiency over a wide range of turbine inlet temperatures between 50℃ and 250℃. One hundred eight (108) refi'igerants were investigated from the environmental classifications of Hydrochlorofluorocarbons (HCFC), Hydrofluorocarbons (HFC), Chlorofluorocarbons (CFC) and Hydrocarbons (HC) with boiling points between -88.65 ℃ and 110.65℃. Net efficiency, which ranged from 0.1% to 25.8% in this work tends to increases with the temperature of the waste heat. Results of the present study demonstrate that working fluid R41 (with source temperature of 44 ℃) provides the maximum efficiency among those evaluated. Refrigerants R13B1 and R32 provide the best efficiency for waste heat source temperatures ranges 60 - 67 ℃ and 68 - 78℃ respectively. Ammonia shows the highest efficiency from 79℃ to 132 ℃. Refrigerants R31, R21, 17,30 and benzene perform well in the temperature ranges 133-151 ℃, 152-178 ℃, 179-236℃ and 237-250 ℃respectively. The optimal heat pump systems are applied to the hybrid copper sulfate-copper oxide thermochemical cycle for hydrogen production from water. 100.8 MW of electrical energy is produced, which increased the efficiency from 24.1% to 25.9%.
基金supported financially by the Fundamental Research Funds for the Central Universities (Grant No.18CX02120A)the Promotive Research Fund for Excellent Young and Middle-aged Scientists of Shandong Province(Grant No. BS2014NJ010)the National Natural Science Foundation of China (Grant No. 21506255)
文摘In this paper, the novel control structures of differential pressure thermally coupled reactive distillation process for methyl acetate hydrolysis were proposed. The RadFrac module of Aspen Plus was adopted in the steady-state simulation. Sensitive analysis was applied to find the stable intial value and provide a basis for the improved control structure design. The Aspen Dynamics software was adopted to study the process dynamic behaviors, and two novel control structures provided with feed ratio controllers and sensitive tray temperature controllers were proposed. The reflux ratio controllers were applied in the improved novel control structures. Both control structures abandoned the composition controllers that were replaced by simpler controllers with which the product purity could meet the specification requiring under a ± 20% disturbance to the total feed flowrate / MeAc composition.
基金National Key Basic Research Program of China(973 Program,2012CB417403)
文摘After compositing three representative ENSO indices,El Nio events have been divided into an eastern pattern(EP) and a central pattern(CP).By using EOF,correlation and composite analysis,the relationship and possible mechanisms between Indian Ocean Dipole(IOD) and two types of El Nio were investigated.IOD events,originating from Indo-Pacific scale air-sea interaction,are composed of two modes,which are associated with EP and CP El Ni o respectively.The IOD mode related to EP El Nio events(named as IOD1) is strongest at the depth of 50 to 150 m along the equatorial Indian Ocean.Besides,it shows a quasi-symmetric distribution,stronger in the south of the Equator.The IOD mode associated with CP El Nio(named as IOD2) has strongest signal in tropical southern Indian Ocean surface.In terms of mechanisms,before EP El Nio peaks,anomalous Walker circulation produces strong anomalous easterlies in equatorial Indian Ocean,resulting in upwelling in the east,decreasing sea temperature there;a couple of anomalous anticyclones(stronger in the south) form off the Equator where warm water accumulates,and thus the IOD1 occurs.When CP El Nio develops,anomalous Walker circulation is weaker and shifts its center to the west,therefore anomalous easterlies in equatorial Indian Ocean is less strong.Besides,the anticyclone south of Sumatra strengthens,and the southerlies east of it bring cold water from higher latitudes and northerlies west of it bring warm water from lower latitudes to the 15° to 25°S zone.Meanwhile,there exists strong divergence in the east and convergence in the west part of tropical southern Indian Ocean,making sea temperature fall and rise separately.Therefore,IOD2 lies farther south.
基金Supported by the National 12th Five-Year Science and Technology Supporting Program(2011BAD11B01)the Research & Development Projects Cooperation Project of Chinese Academy of Sciences(YDJDBNJ-2012-023)
文摘Waterborne acrylic emulsions modified with organic siloxanes and aziridine crosslinker were synthesized and applied as coating of controlled release fertilizer. The free films were characterized and the nutrient release profiles of the coated fertilizers were determined. The results show that methyl silicone oil and methylsilanolate sodium could not improve water resistance performance and glass transition temperature Tgof coatings, while the firmness is enhanced. Aziridine crosslinker improves the water resistance performance, firmness and Tg. Incorporation of methyl silicone oil and aziridine crosslinker gives an excellent aqueous acrylic emulsion for coated controlled release fertilizer, with the 30-day cumulative nutrient release reduced to 16% and an estimated nutrient release duration over 190 days. Therefore, this waterborne coating is promising to meet the requirements for controlled release of nutrient and environmental protection.
文摘The solubilities of 2-naphthalenesulfonic acid monohydrate and sodium 2-naphthalenesulfonate in sulfuric acid solutions were measured at temperatures ranging from 278,15 to 338.15 K by using a dynamic method. The concentration of sulfuric acid solution ranged from 0 to 80wt%. The solubilities of 2-naphthalenesulfonic acid monohydrate and sodium 2-naphthalenesulfonate increased with temperature, and both of them were the lowest at 70wt% of sulfuric acid solution ( w3 0 = 0.70) while the highest in pure water. The solubility data were correlated by the modified Apelblat equation. Based on the solubility difference between 2-naphthalenesulfonic acid monohydrate and sodium 2-naphthalenesulfonate, a new technique in which sodium sulfate was used to replace sodium sulfite in the neutralization reaction was developed. The suitable mole ratio of H20 to Na2SO4 in the neutralization reaction was 80 : 1, and that of 2-naphthalenesulfonic acid monohydrate to Na2SO4 was 3.2 : 1. The material balance under the suitable mole ratios was given and discussed.
基金sponsored by the"Subsurface Fluid Observational Specification Research Program"(2060302-8-19),China
文摘Water temperature observation in wells,as a precursor observation project in China,aims to capture stress-strain information during the preparation of earthquakes. The study of the water temperature tidal effect has important significance,for water temperature tidal effect is both a reflection of stress-strain in crust and an interference factor of precursor observations. With a view of thermal conditions in artesian wells,the paper holds that there are two mechanisms for interpreting tidally induced water temperature changes in artesian wells. Namely,thermal conduction mechanisms and thermal convection mechanism. The paper then derives the quantitative relationship between water temperature and tidal volumetric strain changes in an ideal artesian well. Finally,the water temperature tidal effect in the Benxi artesian well is analyzed. The results show that the water temperature tidal effect in Benxi well is the result of joint action of thermal conduction mechanism and thermal convection mechanism,in which thermal conduction mechanism plays a leading role.