The hydrophilic ZSM-5 zeolite membranes are applied to separate the inorganic acid solutions and inorganic acid/inorganic salt mixtures by pervaporation,and the membrane presents good stability,dehydration,and desalin...The hydrophilic ZSM-5 zeolite membranes are applied to separate the inorganic acid solutions and inorganic acid/inorganic salt mixtures by pervaporation,and the membrane presents good stability,dehydration,and desalination performance.Influences of inorganic acid type(H_(2)SO_(4),H_(3)PO_(4),HNO_(3),and HCl),H_(2)SO_(4)concentration(1-6 mol·L^(-1)),test temperature(60-90℃)and inorganic acid/inorganic salt type(2 mol·L^(-1)H_(2)SO_(4)and sulfate,2 mol·L^(-1)H3PO4 and phosphate)on the pervaporation performance are investigated in this work.Either for concentrating 3%(mass)H_(2)SO_(4)solution or consecutive dehydrating 20%(mass)H_(2)SO_(4)solution,the hydrophilic ZSM-5 zeolite membrane has a good dehydration performance and stability.Even though the H_(2)SO_(4)concentration and test temperature are increased to 6 M and 90℃,only H_(2)O molecules could pass through the membrane and pH value of the permeation is kept neutral.Besides,the membrane has good dehydration and desalination performance for H_(2)SO_(4)/sulfates and H_(3)PO_(4)/phosphate mixtures,and the rejection of natrium salt,molysite,and magnesium is almost 100%.展开更多
Polypyrrole(PPy)is wildly used as electrode material in supercapacitors due to its high conductivity,low cost,ease of handling,and ease of fabrication.However,limited capacitance and poor cycling stability hinder its ...Polypyrrole(PPy)is wildly used as electrode material in supercapacitors due to its high conductivity,low cost,ease of handling,and ease of fabrication.However,limited capacitance and poor cycling stability hinder its practical application.After developing carboxylated cellulose nanocrystals(CNC-COO^(-))as immobile dopants for PPy to improve its cycling stability,we investigated the effect of different commonly used salts(KCl,NaCl,KBr,and NaClO_(4))as dopants during electrode fabrication by electropolymerization.The film’s capacitance increased from 160.6 to 183.4 F g^(-1)after adding a combination of KCl and NaClO_(4) into the electrodeposition electrolyte.More importantly,the porous and interconnected PPy/CNC-COO^(-)-Cl-(Cl O_(4)^(-))_0.5 electrode film exhibited an excellent capacitance of 125.0 F g^(-1)(0.78 F cm^(-2))at a high current density of 2.0 Ag^(-1)(20 m A cm^(-2),allowing charging in less than 1 min),increasing almost 204%over PPy/CNC-COO-films.A symmetric PPy/CNC-COO^(-)-Cl-(ClO_(4)^(-))_0.5 supercapacitor retained its full capacitance after 5000 cycles,and displayed a high energy density of 5.2 Wh kg^(-1)at a power density of 25.4 W kg^(-1)(34.5μWh cm^(-2) at 1752.3μW cm^(-2)).These results reveal that the porous structure formed by doping with CNC-COO-and inorganic salts opens up more active reaction areas to store charges in PPy-based films as the stiff and ribbon-like CNC-COO-as permanent dopants improve the strength and stability of PPy-based films.Our demonstration provides a simple and practical way to deposit PPy based supercapacitors with high capacitance,fast charging,and excellent cycling stability.展开更多
In this study,to better understand the reaction mechanism between inorganic salts and nitrocellulose,CaCO_(3) and Li_(2)CO_(3) were evaluated with respect to their effects on the thermal degradation of NC in nitrogen ...In this study,to better understand the reaction mechanism between inorganic salts and nitrocellulose,CaCO_(3) and Li_(2)CO_(3) were evaluated with respect to their effects on the thermal degradation of NC in nitrogen atmosphere using TG/DSC at three different heating rates(2,5,10 K/min).The numerical relationship between activation energy(E)and conversion rate was obtained by FWO and KAS method,and it was discovered that CaCO_(3) could improve the thermal stability of NC.Activation energy values were calculated by Kissinger method,and it was found that NC that contain Li2CO3had the highest activation energy while NC containing CaCO3had the lowest E value.By combining the thermal analysis data with Malek method,the most probable mechanism model of thermal degradation is obtained as Sesták-Berggren model,which expression is f(α)=α^(m)(1-α)^(n).As a result of this study,there are certain guiding principles that can be applied to the pyrolysis reaction model and to the actual production process of nitrocellulose.展开更多
Background: Rapid economic development in China has resulted in an increase in severe air pollution in city groups such as the Beijing-Tianjin-Hebei Metropolitan Region. PM2.5(fine particles with an aerodynamic equiva...Background: Rapid economic development in China has resulted in an increase in severe air pollution in city groups such as the Beijing-Tianjin-Hebei Metropolitan Region. PM2.5(fine particles with an aerodynamic equivalent diameter of 2.5 μm or less) is one of the most important pollutants. The deposition process is an important way of removing particles from the air. To evaluate the effect of an urban forest on atmospheric particle removal, a concentration gradient method was used to measure the deposition velocities of water-soluble inorganics in PM2.5 in two national forest parks in Beijing, China. The following eight water-soluble inorganic ions in PM2.5 were investigated: sodium, ammonium, potassium, magnesium, calcium, chloride, nitrate, and sulfate.Methods: Samples were taken from two sites in Beijing from the 7 th to the 15 th May, 2013. The concentrations of water-soluble inorganic ions were analyzed with ion chromatography. We used the concentration gradient technique to estimate the deposition flux and velocity. To determine the relationships between leaf traits and particle accumulation, typical leaf samples from each selected species were studied using scanning electron microscopy.Results: The total deposition flux and total deposition velocity during the daytime were higher than those at night.Sulfate showed the biggest deposition flux and velocity at both study sites, whereas the other ions showed different trends at each site. Result from higher proportion of coniferous to broadleaved trees, the total deposition flux of the eight ions measured in Jiufeng National Forest Park was greater than that in Olympic Forest Park.Conclusions: The deposition velocity was affected by meteorological conditions such as wind speed, temperature,and humidity. The deposition velocity was also influenced by tree species. The surface of plants is an important factor influencing particle deposition. The results of this study may help in assessing the effects of forestry systems on particle removal and provide evidence for urban air pollution control and afforestation of urban areas.展开更多
[Objective] The aim was to study on effects of inorganic sodium salt in soil on concentration of zinc ion in different patterns. [Method] Tessier sequential extraction was used to study on effects of inorganic sodium ...[Objective] The aim was to study on effects of inorganic sodium salt in soil on concentration of zinc ion in different patterns. [Method] Tessier sequential extraction was used to study on effects of inorganic sodium salts （in different species and different concentrations） on concentration of zinc ion in different patterns. [Result] Different inorganic sodium salts had different effects on zinc form. Content of ex- changeable Zn would reduce if Na2CO3 or Na2SO4 was added and the content would increase if NaCI was added. Content of carbonate zinc, which was significantly influ- enced by Na2SO4, would increase if NaCI or Na2SO4 was added, and would decrease if Na2CO3 was added. For Zn bound to Fe-Mn oxides and organic matters, and residual Zn, the contents would decrease if NaCI or Na2SO4 was added and the decrease showed much more significantly if high concentration sodium salts were added. In addition, content of Zn bound to Fe-Mn oxides decreased if Na2CO3 was added. If low concentration Na2CO3 was added, Zn bound to organic matters and residual would increase in content but would lower if high concentration one was added. [Conclusion] The research provided references for measurement of heavy metal ion content in soil in different places.展开更多
The advantages and disadvantages of organic antioxidant and inorganic salt on suppressing coal oxidation were analyzed on the basis of the theory that coal oxidation mechanisms can be attributed to the free radical ch...The advantages and disadvantages of organic antioxidant and inorganic salt on suppressing coal oxidation were analyzed on the basis of the theory that coal oxidation mechanisms can be attributed to the free radical chain-type reaction mechanism. The inhibition curves on suppressing coal oxidation of the different type and different concentration of organic antioxidant and inorganic salt were given through experimental study and data processing. Then some conclusions can be gained from the experimental study combining with theoretical analysis. First the inhibition mechanism of the organic antioxidant and inorganic salt is different. The former is that the chemical action is the dominant position. It can be called as the chain termination theory because the free radical is captured during coal oxidation. And the later is that the physical effect is the dominant position. It can be called as the decreasing-temperature theory because the liquid membrane which was formed by the inorganic salt can make coal body be the state of wetness and prevent oxygen from coal surface. Second the inhibition effect of the organic antioxidant is higher than the inorganic salt in the later period. But it is lower in the early period.展开更多
Static experiments and dynamic displacement experiments were conducted to quantitatively determine the amount of precipitate generated by the CO_(2)-formation water reaction at different temperatures,pressures,and sca...Static experiments and dynamic displacement experiments were conducted to quantitatively determine the amount of precipitate generated by the CO_(2)-formation water reaction at different temperatures,pressures,and scaling ion concentrations during CO_(2) flooding in the Chang 8 block of Changqing Oilfield,the influence of precipitate on the physical properties of reservoirs was investigated,and the corresponding mathematical characterization model was established.The mathematical characterization equation was used to correct the numerical simulation model of E300 module in Eclipse software.The distribution pattern of inorganic salt precipitates during continuous CO_(2) flooding in Chang 8 block was simulated,and the influence of inorganic salt precipitates on oil recovery was predicted.The inorganic salt precipitate generated during CO_(2)-formation water reaction was mainly CaCO_(3),and the pressure difference and scaling ion concentration were proportional to the amount of precipitate generated,while the temperature was inversely proportional to the amount of precipitate.The rate of core porosity change before and after CO_(2) flooding was positively correlated with temperature and flooding pressure difference.The core porosity increase in the CO_(2)-formation water-core reaction experiment was always lower than that of CO_(2)-distilled water-core reaction experiment because of precipitation.The area around the production wells had the most precipitates generated with the injection of CO_(2).The oil field became poor in development because of the widely distributed precipitate and the recovery decreased to 33.45% from 37.64% after 20-year-CO_(2) flooding when considering of precipitation.展开更多
Removal of water contained in extra-viscous crude oil is quite difficult because of the high viscosity and high resins content of heavy oil.The microwave technology was introduced for the separation of water from high...Removal of water contained in extra-viscous crude oil is quite difficult because of the high viscosity and high resins content of heavy oil.The microwave technology was introduced for the separation of water from high-viscosity crude oil in the presence of sodium acetate.The decrease in zeta-potential of interface and the viscosity of crude oil are responsible for the accelerated separation of water under microwave irradiation.The influences of the concentration of sodium acetate in sample,irradiation pressure,irradiation time and irradiation power on the separation efficiency were investigated.The optimum technological condition for the refining process was determined.Upon treating the sample 1 (with a water concentration of 50%),the water removal rate was 98.44%,when the optimum conditions were identified to be a sodium acetate concentration of 2%,an irradiation pressure of 0.1 MPa,an irradiation time of 2 min,and an irradiation power of 225 W,with the recovery of sodium acetate reaching 97.88%.Upon treating the sample 2 (the concentration of water was 20%),the water removal rate was 93.85%,when the optimum conditions were determined to be a sodium acetate concentration of 3%,an irradiation pressure of 0.1 MPa,an irradiation time of 4 min,and an irradiation power of 375 W,with the recovery of sodium acetate reaching 93.54%.By using this method,the dehydration efficiency was increased rapidly.展开更多
The article is focused on the influence of inorganic salts on the adsorption of cationically modified starch to fibers. Results show that low concentrations of inorganic salts usually affect the process of adsorption ...The article is focused on the influence of inorganic salts on the adsorption of cationically modified starch to fibers. Results show that low concentrations of inorganic salts usually affect the process of adsorption in a positive way. Adsorption efficiency at higher concentrations, however, depends on the type of inorganic salts as well as the sequence of adding inorganic salts and starch to paper suspension.展开更多
The influence of salts on concrete durability,pore structure of cement pastes with inorganic salts,including CaCl2,NaCl,Na2SO4,NaNO2,Ca(NO3)2 and Ca(NO2)2,was studied through mercury intrusion porosimetry (MIP),and hy...The influence of salts on concrete durability,pore structure of cement pastes with inorganic salts,including CaCl2,NaCl,Na2SO4,NaNO2,Ca(NO3)2 and Ca(NO2)2,was studied through mercury intrusion porosimetry (MIP),and hydration degree of each paste was also tested.The results show that porosity of the paste with inorganic salt cured for 3 d or 28 d was related with its hydration degree.For the pore size distribution,the pores smaller than 50 nm in paste with salts cured for 3 d increased;the amount of pores larger than 100 nm increased because of the addition of Ca (NO3)2 at 3 d,but these coarse pores turned into fine pores and reduced significantly at 28 d;coarse pores lager than 1000 nm in cement pastes containing NaCl and Na2SO4 increased.展开更多
Fifteen inorganic salts were evaluated as possible sterilants against the Red Palm Weevil （RPW） Rhvachophorus ferrugineus, by applying the pupal dipping method in a screening program. Results showed that all tested ...Fifteen inorganic salts were evaluated as possible sterilants against the Red Palm Weevil （RPW） Rhvachophorus ferrugineus, by applying the pupal dipping method in a screening program. Results showed that all tested salts adversely affected the adtflt emergence and reduced the egg laying capacity and egg hatchability. Among the tested salts Ca（OH）2. LiC1, CuCl2, ZnSO4, KBr and KI gave various 97%-100% percent sterility at the tested non toxic concentration under different pupal dipping periods. Percentage of sterility increased with the increase of the concentration and the dipping period. All other salts induced degrees oi sterility ranging from 63% to 96%.展开更多
Hydrophobically associating water-soluble polymers (HPAP) have been synthesized from acrylamide(AM), acrylate (AA), 2-acrylamido-2-methyl propane sulfonic acid (AMPS) and hydrophobic monomer (AP) in aqueous solution...Hydrophobically associating water-soluble polymers (HPAP) have been synthesized from acrylamide(AM), acrylate (AA), 2-acrylamido-2-methyl propane sulfonic acid (AMPS) and hydrophobic monomer (AP) in aqueous solution by radical polymerization. New polymer drilling fluids are made up of HPAP, which is used as viscosifiers and encapsulation agents. Properties of this system are reported in this paper. Results indicate that this system has a high value of yield point to plastic viscosity (YP/PV≥0.7), high viscosity at a low-shear rate (LSRV≥30000mPa·s), excellent shear thinning behavior, good solid-carrying behavior, resistance to shear, good thermal stability (as high as 140℃) and salt resistance. The system has excellent behavior in high-density solution of NaCl and in calcium and magnesium rich saline solutions. Hence, HPAP also can be used in saltwater polymer drilling fluids.展开更多
Atmospheric particle pollution is one of the major factors leading to degradation of ancient wall paintings,particularly heritage sites in arid and semi-arid regions.However,current systematic research on the changes,...Atmospheric particle pollution is one of the major factors leading to degradation of ancient wall paintings,particularly heritage sites in arid and semi-arid regions.However,current systematic research on the changes,sources,and influential factors of atmospheric particulate matter and its water-soluble ion concentrations is not sufficient.Thus,the major water-soluble ion concentrations,sources,and influential factors of atmospheric particles PM_(2.5) and PM_(10)(particulate matter with an aerodynamic equivalent diameter≤2.5 and 10.0μm,respectively,in ambient air)were collected from Cave 16 and its ambient exterior environment in the Dunhuang Mogao Grottoes,China,between April 2015 and March 2016.Results showed that the concentrations of PM_(2.5) and PM_(10) inside and outside the cave were the highest in March 2016 and the lowest in December 2015.The higher particle concentration from March to May was related to the frequent occurrence of sand and dust events,and the lower particle concentration from June to September was associated with good diffusion conditions,increased precipitation,and an established cave shelterbelt.The concentration of particulate matter inside the cave was affected by the concentration of particles in the air outside the cave.Ca2+,NH+4,Na+,Cl-,and SO2-4were the main components of the total ions of PM_(2.5) and PM_(10) both inside and outside the cave.The total ions inside the cave were frequently affected by the disturbance of tourists'activities during the peak tourist season from May to August.Under the influence of dust,the total concentrations of Cl-,SO2-4,Na+,NH+4,and Ca2+in particles of different sizes inside and outside the cave increased,and the concentrations of Cl-,SO2-4,Na+,and Ca2+decreased during precipitation period.Backward air mass trajectory analysis suggested that the pollutants were mainly from Xinjiang,China.The pollutant sources of air particulates are straw burning,secondary pollution sources,soil dust,dry spring rivers,and tourist activities.展开更多
基金supported by the National Natural Science Foundation of China(21868012 and 22368025)Jiangxi Provincial Department of Science and Technology(20171BCB24005 and 20202BAB203011).
文摘The hydrophilic ZSM-5 zeolite membranes are applied to separate the inorganic acid solutions and inorganic acid/inorganic salt mixtures by pervaporation,and the membrane presents good stability,dehydration,and desalination performance.Influences of inorganic acid type(H_(2)SO_(4),H_(3)PO_(4),HNO_(3),and HCl),H_(2)SO_(4)concentration(1-6 mol·L^(-1)),test temperature(60-90℃)and inorganic acid/inorganic salt type(2 mol·L^(-1)H_(2)SO_(4)and sulfate,2 mol·L^(-1)H3PO4 and phosphate)on the pervaporation performance are investigated in this work.Either for concentrating 3%(mass)H_(2)SO_(4)solution or consecutive dehydrating 20%(mass)H_(2)SO_(4)solution,the hydrophilic ZSM-5 zeolite membrane has a good dehydration performance and stability.Even though the H_(2)SO_(4)concentration and test temperature are increased to 6 M and 90℃,only H_(2)O molecules could pass through the membrane and pH value of the permeation is kept neutral.Besides,the membrane has good dehydration and desalination performance for H_(2)SO_(4)/sulfates and H_(3)PO_(4)/phosphate mixtures,and the rejection of natrium salt,molysite,and magnesium is almost 100%.
基金supported by the Research Foundation Flanders(grant 3E181170)supported by the China Scholarship Council(CSC,201806220066)。
文摘Polypyrrole(PPy)is wildly used as electrode material in supercapacitors due to its high conductivity,low cost,ease of handling,and ease of fabrication.However,limited capacitance and poor cycling stability hinder its practical application.After developing carboxylated cellulose nanocrystals(CNC-COO^(-))as immobile dopants for PPy to improve its cycling stability,we investigated the effect of different commonly used salts(KCl,NaCl,KBr,and NaClO_(4))as dopants during electrode fabrication by electropolymerization.The film’s capacitance increased from 160.6 to 183.4 F g^(-1)after adding a combination of KCl and NaClO_(4) into the electrodeposition electrolyte.More importantly,the porous and interconnected PPy/CNC-COO^(-)-Cl-(Cl O_(4)^(-))_0.5 electrode film exhibited an excellent capacitance of 125.0 F g^(-1)(0.78 F cm^(-2))at a high current density of 2.0 Ag^(-1)(20 m A cm^(-2),allowing charging in less than 1 min),increasing almost 204%over PPy/CNC-COO-films.A symmetric PPy/CNC-COO^(-)-Cl-(ClO_(4)^(-))_0.5 supercapacitor retained its full capacitance after 5000 cycles,and displayed a high energy density of 5.2 Wh kg^(-1)at a power density of 25.4 W kg^(-1)(34.5μWh cm^(-2) at 1752.3μW cm^(-2)).These results reveal that the porous structure formed by doping with CNC-COO-and inorganic salts opens up more active reaction areas to store charges in PPy-based films as the stiff and ribbon-like CNC-COO-as permanent dopants improve the strength and stability of PPy-based films.Our demonstration provides a simple and practical way to deposit PPy based supercapacitors with high capacitance,fast charging,and excellent cycling stability.
基金the National Natural Science Foundation of China(NSFC,Grants No.52176114 and 52111530091)Jiangsu Funding Program for Excellent Postdoctoral Talent。
文摘In this study,to better understand the reaction mechanism between inorganic salts and nitrocellulose,CaCO_(3) and Li_(2)CO_(3) were evaluated with respect to their effects on the thermal degradation of NC in nitrogen atmosphere using TG/DSC at three different heating rates(2,5,10 K/min).The numerical relationship between activation energy(E)and conversion rate was obtained by FWO and KAS method,and it was discovered that CaCO_(3) could improve the thermal stability of NC.Activation energy values were calculated by Kissinger method,and it was found that NC that contain Li2CO3had the highest activation energy while NC containing CaCO3had the lowest E value.By combining the thermal analysis data with Malek method,the most probable mechanism model of thermal degradation is obtained as Sesták-Berggren model,which expression is f(α)=α^(m)(1-α)^(n).As a result of this study,there are certain guiding principles that can be applied to the pyrolysis reaction model and to the actual production process of nitrocellulose.
基金supported by the grants from the Beijing Collaborative Innovation Center for eco-environmental improvement with forestry and fruit trees(PXM2017_014207_000024)the Special Found for Beijing Common Construction Project for Beijing Laboratory of Urban and Rural Ecological Environment,Beijing Municipal Education Commission
文摘Background: Rapid economic development in China has resulted in an increase in severe air pollution in city groups such as the Beijing-Tianjin-Hebei Metropolitan Region. PM2.5(fine particles with an aerodynamic equivalent diameter of 2.5 μm or less) is one of the most important pollutants. The deposition process is an important way of removing particles from the air. To evaluate the effect of an urban forest on atmospheric particle removal, a concentration gradient method was used to measure the deposition velocities of water-soluble inorganics in PM2.5 in two national forest parks in Beijing, China. The following eight water-soluble inorganic ions in PM2.5 were investigated: sodium, ammonium, potassium, magnesium, calcium, chloride, nitrate, and sulfate.Methods: Samples were taken from two sites in Beijing from the 7 th to the 15 th May, 2013. The concentrations of water-soluble inorganic ions were analyzed with ion chromatography. We used the concentration gradient technique to estimate the deposition flux and velocity. To determine the relationships between leaf traits and particle accumulation, typical leaf samples from each selected species were studied using scanning electron microscopy.Results: The total deposition flux and total deposition velocity during the daytime were higher than those at night.Sulfate showed the biggest deposition flux and velocity at both study sites, whereas the other ions showed different trends at each site. Result from higher proportion of coniferous to broadleaved trees, the total deposition flux of the eight ions measured in Jiufeng National Forest Park was greater than that in Olympic Forest Park.Conclusions: The deposition velocity was affected by meteorological conditions such as wind speed, temperature,and humidity. The deposition velocity was also influenced by tree species. The surface of plants is an important factor influencing particle deposition. The results of this study may help in assessing the effects of forestry systems on particle removal and provide evidence for urban air pollution control and afforestation of urban areas.
基金Supported by National Natural Science Foundation of China (40973078)Tianjin Normal University Project (5RL083)~~
文摘[Objective] The aim was to study on effects of inorganic sodium salt in soil on concentration of zinc ion in different patterns. [Method] Tessier sequential extraction was used to study on effects of inorganic sodium salts （in different species and different concentrations） on concentration of zinc ion in different patterns. [Result] Different inorganic sodium salts had different effects on zinc form. Content of ex- changeable Zn would reduce if Na2CO3 or Na2SO4 was added and the content would increase if NaCI was added. Content of carbonate zinc, which was significantly influ- enced by Na2SO4, would increase if NaCI or Na2SO4 was added, and would decrease if Na2CO3 was added. For Zn bound to Fe-Mn oxides and organic matters, and residual Zn, the contents would decrease if NaCI or Na2SO4 was added and the decrease showed much more significantly if high concentration sodium salts were added. In addition, content of Zn bound to Fe-Mn oxides decreased if Na2CO3 was added. If low concentration Na2CO3 was added, Zn bound to organic matters and residual would increase in content but would lower if high concentration one was added. [Conclusion] The research provided references for measurement of heavy metal ion content in soil in different places.
文摘The advantages and disadvantages of organic antioxidant and inorganic salt on suppressing coal oxidation were analyzed on the basis of the theory that coal oxidation mechanisms can be attributed to the free radical chain-type reaction mechanism. The inhibition curves on suppressing coal oxidation of the different type and different concentration of organic antioxidant and inorganic salt were given through experimental study and data processing. Then some conclusions can be gained from the experimental study combining with theoretical analysis. First the inhibition mechanism of the organic antioxidant and inorganic salt is different. The former is that the chemical action is the dominant position. It can be called as the chain termination theory because the free radical is captured during coal oxidation. And the later is that the physical effect is the dominant position. It can be called as the decreasing-temperature theory because the liquid membrane which was formed by the inorganic salt can make coal body be the state of wetness and prevent oxygen from coal surface. Second the inhibition effect of the organic antioxidant is higher than the inorganic salt in the later period. But it is lower in the early period.
文摘Static experiments and dynamic displacement experiments were conducted to quantitatively determine the amount of precipitate generated by the CO_(2)-formation water reaction at different temperatures,pressures,and scaling ion concentrations during CO_(2) flooding in the Chang 8 block of Changqing Oilfield,the influence of precipitate on the physical properties of reservoirs was investigated,and the corresponding mathematical characterization model was established.The mathematical characterization equation was used to correct the numerical simulation model of E300 module in Eclipse software.The distribution pattern of inorganic salt precipitates during continuous CO_(2) flooding in Chang 8 block was simulated,and the influence of inorganic salt precipitates on oil recovery was predicted.The inorganic salt precipitate generated during CO_(2)-formation water reaction was mainly CaCO_(3),and the pressure difference and scaling ion concentration were proportional to the amount of precipitate generated,while the temperature was inversely proportional to the amount of precipitate.The rate of core porosity change before and after CO_(2) flooding was positively correlated with temperature and flooding pressure difference.The core porosity increase in the CO_(2)-formation water-core reaction experiment was always lower than that of CO_(2)-distilled water-core reaction experiment because of precipitation.The area around the production wells had the most precipitates generated with the injection of CO_(2).The oil field became poor in development because of the widely distributed precipitate and the recovery decreased to 33.45% from 37.64% after 20-year-CO_(2) flooding when considering of precipitation.
基金the financial support of Liaoning Province Education Department Project(2004D06)
文摘Removal of water contained in extra-viscous crude oil is quite difficult because of the high viscosity and high resins content of heavy oil.The microwave technology was introduced for the separation of water from high-viscosity crude oil in the presence of sodium acetate.The decrease in zeta-potential of interface and the viscosity of crude oil are responsible for the accelerated separation of water under microwave irradiation.The influences of the concentration of sodium acetate in sample,irradiation pressure,irradiation time and irradiation power on the separation efficiency were investigated.The optimum technological condition for the refining process was determined.Upon treating the sample 1 (with a water concentration of 50%),the water removal rate was 98.44%,when the optimum conditions were identified to be a sodium acetate concentration of 2%,an irradiation pressure of 0.1 MPa,an irradiation time of 2 min,and an irradiation power of 225 W,with the recovery of sodium acetate reaching 97.88%.Upon treating the sample 2 (the concentration of water was 20%),the water removal rate was 93.85%,when the optimum conditions were determined to be a sodium acetate concentration of 3%,an irradiation pressure of 0.1 MPa,an irradiation time of 4 min,and an irradiation power of 375 W,with the recovery of sodium acetate reaching 93.54%.By using this method,the dehydration efficiency was increased rapidly.
文摘The article is focused on the influence of inorganic salts on the adsorption of cationically modified starch to fibers. Results show that low concentrations of inorganic salts usually affect the process of adsorption in a positive way. Adsorption efficiency at higher concentrations, however, depends on the type of inorganic salts as well as the sequence of adding inorganic salts and starch to paper suspension.
文摘The influence of salts on concrete durability,pore structure of cement pastes with inorganic salts,including CaCl2,NaCl,Na2SO4,NaNO2,Ca(NO3)2 and Ca(NO2)2,was studied through mercury intrusion porosimetry (MIP),and hydration degree of each paste was also tested.The results show that porosity of the paste with inorganic salt cured for 3 d or 28 d was related with its hydration degree.For the pore size distribution,the pores smaller than 50 nm in paste with salts cured for 3 d increased;the amount of pores larger than 100 nm increased because of the addition of Ca (NO3)2 at 3 d,but these coarse pores turned into fine pores and reduced significantly at 28 d;coarse pores lager than 1000 nm in cement pastes containing NaCl and Na2SO4 increased.
文摘Fifteen inorganic salts were evaluated as possible sterilants against the Red Palm Weevil （RPW） Rhvachophorus ferrugineus, by applying the pupal dipping method in a screening program. Results showed that all tested salts adversely affected the adtflt emergence and reduced the egg laying capacity and egg hatchability. Among the tested salts Ca（OH）2. LiC1, CuCl2, ZnSO4, KBr and KI gave various 97%-100% percent sterility at the tested non toxic concentration under different pupal dipping periods. Percentage of sterility increased with the increase of the concentration and the dipping period. All other salts induced degrees oi sterility ranging from 63% to 96%.
文摘Hydrophobically associating water-soluble polymers (HPAP) have been synthesized from acrylamide(AM), acrylate (AA), 2-acrylamido-2-methyl propane sulfonic acid (AMPS) and hydrophobic monomer (AP) in aqueous solution by radical polymerization. New polymer drilling fluids are made up of HPAP, which is used as viscosifiers and encapsulation agents. Properties of this system are reported in this paper. Results indicate that this system has a high value of yield point to plastic viscosity (YP/PV≥0.7), high viscosity at a low-shear rate (LSRV≥30000mPa·s), excellent shear thinning behavior, good solid-carrying behavior, resistance to shear, good thermal stability (as high as 140℃) and salt resistance. The system has excellent behavior in high-density solution of NaCl and in calcium and magnesium rich saline solutions. Hence, HPAP also can be used in saltwater polymer drilling fluids.
基金supported by the National Natural Science Foundation of China(51962001,32260292)the National Key Research&Development Projects(2020YFC1522200)the Gansu Provincial Science and Technology Plan Project(20JR5RA051,21YF1FF371).
文摘Atmospheric particle pollution is one of the major factors leading to degradation of ancient wall paintings,particularly heritage sites in arid and semi-arid regions.However,current systematic research on the changes,sources,and influential factors of atmospheric particulate matter and its water-soluble ion concentrations is not sufficient.Thus,the major water-soluble ion concentrations,sources,and influential factors of atmospheric particles PM_(2.5) and PM_(10)(particulate matter with an aerodynamic equivalent diameter≤2.5 and 10.0μm,respectively,in ambient air)were collected from Cave 16 and its ambient exterior environment in the Dunhuang Mogao Grottoes,China,between April 2015 and March 2016.Results showed that the concentrations of PM_(2.5) and PM_(10) inside and outside the cave were the highest in March 2016 and the lowest in December 2015.The higher particle concentration from March to May was related to the frequent occurrence of sand and dust events,and the lower particle concentration from June to September was associated with good diffusion conditions,increased precipitation,and an established cave shelterbelt.The concentration of particulate matter inside the cave was affected by the concentration of particles in the air outside the cave.Ca2+,NH+4,Na+,Cl-,and SO2-4were the main components of the total ions of PM_(2.5) and PM_(10) both inside and outside the cave.The total ions inside the cave were frequently affected by the disturbance of tourists'activities during the peak tourist season from May to August.Under the influence of dust,the total concentrations of Cl-,SO2-4,Na+,NH+4,and Ca2+in particles of different sizes inside and outside the cave increased,and the concentrations of Cl-,SO2-4,Na+,and Ca2+decreased during precipitation period.Backward air mass trajectory analysis suggested that the pollutants were mainly from Xinjiang,China.The pollutant sources of air particulates are straw burning,secondary pollution sources,soil dust,dry spring rivers,and tourist activities.
