Ammonia induces astrocyte swelling, which is strongly associated with overexpression of aquaporin-4. However, the mechanisms by which ammonia induces astrocyte swelling, and subsequently upregulating aquaporin-4 expre...Ammonia induces astrocyte swelling, which is strongly associated with overexpression of aquaporin-4. However, the mechanisms by which ammonia induces astrocyte swelling, and subsequently upregulating aquaporin-4 expression, remain unknown. In the present study, astrocytes were cultured in vitro and exposed to ammonium chloride (NH4CI), followed by propofol protein kinase C agonist, or antagonist, respectively. Astrocyte morphology was observed by light microscopy, and aquaporin-4 expression was detected by western blot analysis. Results showed that propofol or protein kinase C agonist significantly attenuated the degree of NH4CI-induced astrocyte swelling and inhibited increased aquaporin-4 expression. Propofol treatment inhibited aquaporin-4 overexpression in cultured astrocyte induced by NH4CI; protein kinase C pathway activation is potentially involved.展开更多
The dissolution kinetics of calcined ulexite in ammonium chloride solutions at high solid-to-liquid ratios were investigated. In the experiments, calcination temperature, solution concentration, reaction temperature, ...The dissolution kinetics of calcined ulexite in ammonium chloride solutions at high solid-to-liquid ratios were investigated. In the experiments, calcination temperature, solution concentration, reaction temperature, and pre-hydration were chosen as parameters. It was observed that the dissolution rate increased with increasing calcination temperature, solution concentration, and reaction temperature, whereas it was not affected by pre-hydration. Employing graphical and statistic methods, the dissolution rate, based on homogeneous reaction model, can be given as: (1-X(B2O3))-1-1= k(c(NH4Cl))1.982t. The activation energy for the dissolution of the ulexite sample calcined at 160 ℃ was found to be 84.04 kJ·mol-1.展开更多
Starch is easy to breed bacteria,which affects its performance and application in medical dressings.In this research,antibacterial starch was prepared by physical blending method with glycidyl trimethyl ammonium chlor...Starch is easy to breed bacteria,which affects its performance and application in medical dressings.In this research,antibacterial starch was prepared by physical blending method with glycidyl trimethyl ammonium chloride(GTA)and potassium sorbate as antibacterial agents.The antibacterial activities of GTA,potassium sorbate,GTA-starch and potassium sorbate-starch were investigated with the purpose of understanding the growth of bacteria in starch system.Results showed that GTA had good antibacterial activity,and the bacteriostasis rate of 0.05 g/mL GTA against Staphylococcus aureus(S.aureus)was 96.55%.The antibacterial properties of starch increased with an increase of mass fraction of potassium sorbate and then decreased with the continuously increasing of mass fraction of GTA.GTA-starch with30%GTA showed the best antibacterial activities,the bacteriostasis rate of Escherichia coli(E.coli)and S.aureus were 26.48%and20.26%,respectively;50%potassium sorbate in potassium sorbatestarch showed the best antibacterial activities,the bacteriostasis rate of E.coli and S.aureus were 67.68%and 74.75%,respectively.展开更多
Based on the composition characteristics of carbide slag and the application of polyvinyl chloride,a method of preparing calcium carbonate with microstructure and nanostructure by using carbide slag as a raw material ...Based on the composition characteristics of carbide slag and the application of polyvinyl chloride,a method of preparing calcium carbonate with microstructure and nanostructure by using carbide slag as a raw material and ammonium chloride as a leaching agent was proposed.The factors for the preparation of calcium carbonate and the effects of different conditions on the crystal phase,grain size,and morphology of calcium carbonate were systematically studied.The results showed that the nanosized calcium carbonate was prepared at 60 mL/min,25°C,no additional ammonia,and 60 min.The product of spherical vaterite was in accordance with the relevant standards for the industrial precipitation of calcium carbonate.Moreover,the reuse of carbonation filtrate was realized.The crystal phase,grain size,and morphology of the carbonation product could be controlled by adjusting the reaction conditions.The manuscript provided a new idea for resource utilization of carbide slag and preparing nanocalcium carbonate.展开更多
Difluoromethyltri(n-butyl)ammonium chloride 1 was found to be an effective difluorocarbene reagent for O-, S-, N-, C-difluoromethylation under basic conditions. It is particularly remarkable that, when only 1.2 equi...Difluoromethyltri(n-butyl)ammonium chloride 1 was found to be an effective difluorocarbene reagent for O-, S-, N-, C-difluoromethylation under basic conditions. It is particularly remarkable that, when only 1.2 equivalent of reagent 1 was used, the difluoromethylated products were obtained in moderate to excellent yields.展开更多
In water, ammonium chloride was found to promote palladium-catalyzed Ullmann coupling reactions of aryl bromides. In the presence of Pd/C, zinc, NH4Cl, and water, coupling of various aryl bromides was carried out smoo...In water, ammonium chloride was found to promote palladium-catalyzed Ullmann coupling reactions of aryl bromides. In the presence of Pd/C, zinc, NH4Cl, and water, coupling of various aryl bromides was carried out smoothly to afford the corresponding homocoupling products in moderate yields.展开更多
This investigation deals with the free radical polymerization both of (2-methacryloyloxyethyl) trimethyl ammonium chloride (QACEMA) and of diallyldimethyl ammonium chloride (DADMAC) in inverse emulsion. The influences...This investigation deals with the free radical polymerization both of (2-methacryloyloxyethyl) trimethyl ammonium chloride (QACEMA) and of diallyldimethyl ammonium chloride (DADMAC) in inverse emulsion. The influences of some factors, such as the concentration of monomers, initiator and emulsifier are discussed. The polymerization rate equations of above two monomers can be written as follows: R(p) = k[M](1.21)[I](0.82)[E](0.57) (for QACEMA) R(p) = k'[M](1.34)[I](0.90)[E](0.62) (for DADMAC)展开更多
X-ray diffractometry was utilized to study the mineralogical characteristics of the inhalable particles (PM10) sampled during two dust storms in Beijing city on March 18th and May 21st, 2008. We confirm, for the fir...X-ray diffractometry was utilized to study the mineralogical characteristics of the inhalable particles (PM10) sampled during two dust storms in Beijing city on March 18th and May 21st, 2008. We confirm, for the first time, that there stably exists ammonium chloride in the atmosphere when temperature is low. The total sulfates particles were affected by relative humidity. Both species and concentration of sulfates decreased first and then grew back by the end of each dust storm. Koninckite, a phosphate mineral never reported as particulate aerosol before, was identified. Meanwhile, our result shows that a chemical modification on dust minerals occurs during long range transportation. PM10 samples collected during the period of dust storms were dominated by crustal minerals such as quartz, illite/smectite, illite, chlorite, feldspar and calcite, and were notably higher in concentration than that in normal periods of time. The amounts of total sulfates, calcite and feldspar altered in each dust storm. It is derived from 24-hour isentropic backward trajectories that two dust events in spring 2008 originated in different sources.展开更多
The effects of Br- and I- concentrations on the cell voltage, anodic polarization, current efficiency (CE), and energy consumption (EC) of zinc electrodeposition from ammoniacal ammonium chloride solutions were in...The effects of Br- and I- concentrations on the cell voltage, anodic polarization, current efficiency (CE), and energy consumption (EC) of zinc electrodeposition from ammoniacal ammonium chloride solutions were investigated. The surface morphology of zinc deposits was also examined. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to characterize the morphology of zinc deposits and the phase of anodic sediments produced during electrolysis. The results clearly showed that the CE slightly increased from approximately 95.12% in the absence of F and Br- to 97.08% in the presence of 10 g·L-1 Br; in contrast, the CE significantly decreased to less than 83% in the presence of 10 g·L-1 I- . The addition of Br and I- positively affected the EC, which decreased from 2514 kW·h·t-1 to approximately 2300 kW·h·t-1. The results of anodic polarization measurements showed that the voltage drops were 130 and 510 mV when the concentrations of Br- and I- were 10 g·L-1 at a eUlTent density of 400 A·m2, respectively. SEM images showed that the addition of Br- and I- caused different crystal growth mechanisms, which resulted in the production of compact and smooth zinc deposits. The anodic reactions of I were also studied.展开更多
This study examined the potential antilithic effects of a traditional Chinese medicine Urtica dentata Hand (UDH) in experimental rats and screened the optimal extract of UDH as a possible therapeutic agent for kidne...This study examined the potential antilithic effects of a traditional Chinese medicine Urtica dentata Hand (UDH) in experimental rats and screened the optimal extract of UDH as a possible therapeutic agent for kidney stones. The rat model of urinary calcium oxalate stones was induced by intragastric (i.g.) administration of 2 mL of 1.25% ethylene glycol (EG) and 1% ammonium chloride (AC) for 28 days and was confirmed by Color Doppler ultrasound imaging. The rats in different experimental groups were then intragastrically given petroleum ether extract (PEE), N-butanol extract (NBE), aqueous extract (AqE) of UDH, Jieshitong (positive control drug), and saline, respectively. Treatment with NBE significantly reduced the elevated levels of urinary calcium, uric acid, phosphate, as well as increased urinary output. Accordingly, the increased calcium, oxalate levels and the number of calcium oxalate crystals deposits were remarkably reverted in the renal tissue of NBE-treated rats. In addition, NBE also prevented the impairment of renal function to decrease the contents of blood urea nitrogen (BUN) and creatinine. Taken together, these data suggest that NBE of UDH has a beneficial effect on calcium oxalate urinary stones in rats by flushing the stones out and protecting renal function.展开更多
The ionic cross-linking treatment with 3-chloro-2-hydroxypropyl trimethyl ammonium chloride( CHTAC) and 1,2,3,4-butanetetracarboxylic acid( BTCA) was treated on untreated and plasma treated Tencel fabrics,and then TiO...The ionic cross-linking treatment with 3-chloro-2-hydroxypropyl trimethyl ammonium chloride( CHTAC) and 1,2,3,4-butanetetracarboxylic acid( BTCA) was treated on untreated and plasma treated Tencel fabrics,and then TiO_2/SiO_2 sol was applied to the treated samples. Self-cleaning characteristic was investigated using the color measurement spectrophotometer with 7 h UV irradiation. Moreover, the surface morphology, structure change of samples were observed by scanning electron microscopy( SEM) and Fourier transform infrared spectroscopy( FTIR),respectively. The results revealed that with the increase of CHTAC concentration, breaking strength of Tencel fabric increased,whiteness index decreased,and wrinkle recovery angle first dropped and then rose. It was also found that increasing concentration of BTCA,breaking strength of Tencel fabric decreased,whiteness index and wrinkle recovery angle increased. FTIR studies revealed that CHTAC and BTCA had grafted on Tencel fabric. Nevertheless,the molar ratio of 50∶1 of TiO_2/SiO_2 sol endowed Tencel fabric with better self-cleaning properties,compared with sample treated with pure TiO_2. Furthermore,compared with sample treated with TiO_2/SiO_2 sol alone, the combination of plasma and cross-linking treatment( plasma + CHTAC + BTCA + TiO_2/SiO_2) decreased the value of K/S,and increased the value of ΔE,ensured more efficient photodegradation of methylene blue, and thus got a better performance of self-cleaning.展开更多
The leaching kinetics of magnesium slag in ammonium chloride solutions was investigated.The effects of initial ammonium chloride concentration,liquid-solid ratio and reaction temperature on the leaching rate of calciu...The leaching kinetics of magnesium slag in ammonium chloride solutions was investigated.The effects of initial ammonium chloride concentration,liquid-solid ratio and reaction temperature on the leaching rate of calcium were determined.The results showed that the leaching rate increased with the increase in initial ammonium chloride concentration,reaction temperature and liquid-solid ratio.It was determined that the leaching rate fit the Avrami equation,and the leaching process was controlled by diffusion.The activation energy was 13.22 kJ/mol.展开更多
In order to intensify the leaching process of rare earth(RE) and reduce the impurities in the leachate, ammonium chloride(NH4Cl) and ammonium nitrate(NH4NO3) were mixed as a compound leaching agent to treat the ...In order to intensify the leaching process of rare earth(RE) and reduce the impurities in the leachate, ammonium chloride(NH4Cl) and ammonium nitrate(NH4NO3) were mixed as a compound leaching agent to treat the weathered crust elution-deposited RE ore. Effects of molar ratio of NH~+_4Cl and NH_4NO_3, ammonium(NH_4) concentration, leaching agent pH and flow rate on the leaching process of RE were studied and evaluated by the chromatographic plate theory. Leaching process of the main impurity aluminium(Al) was also discussed in detail. Results showed that a higher initial ammonium concentration in a certain range could enhance the mass transfer process of RE and Al by providing a driving force to overcome the resistance of diffusion. pH almost had no effects on the mass transfer efficiency of RE and Al in the range of 4 to 8. The relationship between the flow rate and height equivalent to a theoretical plate(HETP) could fit well with the Van Deemter equation, and the flow rate at the lowest HETP was determined. The optimum conditions of column leaching for RE and Al were 1:1(molar ratio) of NH_4Cl and NH_4NO_3, 0.2 mol/L of ammonium concentration, pH 4–8 of leaching agent and 0.5 mL /min of flow rate. Under this condition, the mass transfer efficiency of RE was improved, but no change was observed for Al compared with the most widely used ammonium sulfate. Moreover, the significant difference value(around 20 mL) of retention volume at the peak concentration between RE and Al provided a possibility for their separation. It suggested the potential application of the novel compound leaching agent(NH_4Cl/NH_4NO_3). It was found that the relative concentration of RE in the leachate could be easily obtained by monitoring the pH of leachate.展开更多
This study focused on the extraction of valuable metals from the cathode-active materials in spent lithiumion batteries using a high-concentration chloride solution.The effects of the concentrations of ammonium chlori...This study focused on the extraction of valuable metals from the cathode-active materials in spent lithiumion batteries using a high-concentration chloride solution.The effects of the concentrations of ammonium chloride(NH4 Cl),hydrochloric acid(HCl),and reductants such as hydrogen peroxide(H_(2)O_(2))and urea(CO(NH_(2))_(2))on metal extraction and chlorine production were studied experimentally.The leaching mechanism was analyzed,and a leaching model was established.It was found that the addition of solid NH4 Cl to an HCl solution significantly improved the metal extraction capability of the latter and reduced the formation of chlorine gas by 96.0%compared to that only using HCl.The activation energies for leaching Li,Ni,Co,and Mn were determined to be 30.4,38.5,30.6,and 38.2 kJ·mol^(-1),respectively.This study demonstrates an environmentally friendly method for recycling metal resources from cathode-active materials and furthers understanding of how NH4 Cl inhibits chlorine production when leaching with mixed solutions of HCl and NH4 Cl.展开更多
Quaternary ammonium compounds(QACs)are a class of antimicrobial disinfectants whose use in cleaning products increased during the COVID-19 pandemic.Chemically,their low vapor pressure indicates a proclivity to persist...Quaternary ammonium compounds(QACs)are a class of antimicrobial disinfectants whose use in cleaning products increased during the COVID-19 pandemic.Chemically,their low vapor pressure indicates a proclivity to persist on surfaces,and their presence suggests a level of protection against microorganisms.The widespread application of QACs in response to the SARS CoV-2 virus created a need to evaluate their longevity on surfaces,for both efficacy and possible health risks.There are however,no standardized analytical methods for QAC surface sampling and analysis,and no published studies quantifying their concentrations on mass transportation vehicles-a high occupancy,close-contact microenvironment documented to facilitate the spread the SARS CoV-2 virus.Here,we describe a robust liquid chromatography mass spectrometry(LC-MS)method for the analysis of QACs and simultaneous development of a direct surface sampling and extraction protocol.We demonstrate the applicability of the method through the analysis of surface samples collected from in-service public transportation buses.The rapid,sensitive LC-MS method included 8 target QACs quantified on a Q-Exactive HF Hybrid Quadrupole-Orbitrap mass spectrometer using an electrospray ionization source and Dionex UltiMate 3000 UHPLC system for analyte separation.QAC standard mixtures at concentrations between 0.1 ng mL^(-1)and 2000 ng mL^(-1)were analyzed,and chromatographic separation of all analytes was achieved in less than 10 min.All correlation coefficients were reported at r>0.986,and LODs ranged from 0.007 to 2.103 ng mL^(-1)for all compounds,confirming the method's sensitivity.A previously reported surface sampling and extraction protocol was modified to further simplify the procedure and expand the number of target compounds.The new sampling protocol was optimized from 10 commercially available wipes and 4 solvent types by quantifying recovery from the surface.Band-Aid brand small gauze pads saturated with isopropanol had the highest recovery efficiencies,ranging from 61.5 to 102.9%across all analytes.To test the real-world applicability,wipe samples were collected from 4 in-circulation New Jersey Transit buses on 5 separate days over the course of a month to assess the occurrence and longevity of QACs on sanitized mass transportation vehicles.Concentrations of QACs were detected on every wipe sample taken,and at all sampled time points,confirming their persistence on hard surfaces.QACs have the potential to form polymers,and detection of the polymer might serve as a secondary indication of their effectiveness on surfaces.None of the polymers detected however,were unique to QACs from this study.The polymers detected were already present in the wipe and used as an internal standard to demonstrate the efficacy of extraction and analysis of polymeric QACs.展开更多
The equilibrium data on the ternary system of NH_(4)Cl-CaCl_(2)-H_(2)O at 50℃were investigated using the wet-residue method.The experimental results show that there are three pure phase crystal areas of NH_(4)Cl,2NH_...The equilibrium data on the ternary system of NH_(4)Cl-CaCl_(2)-H_(2)O at 50℃were investigated using the wet-residue method.The experimental results show that there are three pure phase crystal areas of NH_(4)Cl,2NH_(4)Cl·CaCl_(2)·3H_(2)O and CaCl·2H_(2)O,two mixture phase crystal areas of NH_(4)Cl and 2NH_(4)Cl·CaCl·3H_(2)O,and 2NH_(4)Cl·CaCl_(2)·3H_(2)O and CaCl·2H_(2)O in the system.A new hydration double salt(2NH_(4)Cl·CaCl·3H_(2)O)was found in the ternary equilibrium system for the first time.展开更多
In pH 3.8 acetic acid-sodium acetate (HAC-NaAC) buffer solution, laccase exhibited a strong catalytic effect on the H2O2 oxidation of I- to form I2, and I2 combined with excess I- to form I3- that reacted with catio...In pH 3.8 acetic acid-sodium acetate (HAC-NaAC) buffer solution, laccase exhibited a strong catalytic effect on the H2O2 oxidation of I- to form I2, and I2 combined with excess I- to form I3- that reacted with cationic surfactants of tetradecyl dimethylbenzyl ammonium chloride (TDMAC) to produce the (TDMAC-I3)n association complex particles, which exhibited a strong resonance scattering (RS) peak at 468 nm. Under the chosen conditions, as the concentration of laccase activity increased, the RS intensity at 468 nm (1468 nm) increased linearly. The increased RS intensity A1468 nm was linear to laccase activity in the range of 0.08-0.96 U/mL, with a regression equation of △1468 nm =88.8 U-1.9, and a detection limit of 0.02 U/mL laccase. This proposed method was applied to detect laccase activity in waste water, with satisfactory results.展开更多
The addition of a hardener is necessary for the curing of urea-formaldehyde (UF) adhesives in the production of MDF and particleboard. The most commonly used hardener, ammonium chloride, however, is suspected to cause...The addition of a hardener is necessary for the curing of urea-formaldehyde (UF) adhesives in the production of MDF and particleboard. The most commonly used hardener, ammonium chloride, however, is suspected to cause the formation of poisonous dioxin when waste boards are combusted and hence considered as a potential source of pollution. To assess the feasibility of substituting ammonium sulphate for ammonium chloride, working properties and bonding strength were measured for UF adhesives with the two ...展开更多
基金Supported by a Grant from Zhejiang Provincial Health Department, No. 2007A057
文摘Ammonia induces astrocyte swelling, which is strongly associated with overexpression of aquaporin-4. However, the mechanisms by which ammonia induces astrocyte swelling, and subsequently upregulating aquaporin-4 expression, remain unknown. In the present study, astrocytes were cultured in vitro and exposed to ammonium chloride (NH4CI), followed by propofol protein kinase C agonist, or antagonist, respectively. Astrocyte morphology was observed by light microscopy, and aquaporin-4 expression was detected by western blot analysis. Results showed that propofol or protein kinase C agonist significantly attenuated the degree of NH4CI-induced astrocyte swelling and inhibited increased aquaporin-4 expression. Propofol treatment inhibited aquaporin-4 overexpression in cultured astrocyte induced by NH4CI; protein kinase C pathway activation is potentially involved.
文摘The dissolution kinetics of calcined ulexite in ammonium chloride solutions at high solid-to-liquid ratios were investigated. In the experiments, calcination temperature, solution concentration, reaction temperature, and pre-hydration were chosen as parameters. It was observed that the dissolution rate increased with increasing calcination temperature, solution concentration, and reaction temperature, whereas it was not affected by pre-hydration. Employing graphical and statistic methods, the dissolution rate, based on homogeneous reaction model, can be given as: (1-X(B2O3))-1-1= k(c(NH4Cl))1.982t. The activation energy for the dissolution of the ulexite sample calcined at 160 ℃ was found to be 84.04 kJ·mol-1.
文摘Starch is easy to breed bacteria,which affects its performance and application in medical dressings.In this research,antibacterial starch was prepared by physical blending method with glycidyl trimethyl ammonium chloride(GTA)and potassium sorbate as antibacterial agents.The antibacterial activities of GTA,potassium sorbate,GTA-starch and potassium sorbate-starch were investigated with the purpose of understanding the growth of bacteria in starch system.Results showed that GTA had good antibacterial activity,and the bacteriostasis rate of 0.05 g/mL GTA against Staphylococcus aureus(S.aureus)was 96.55%.The antibacterial properties of starch increased with an increase of mass fraction of potassium sorbate and then decreased with the continuously increasing of mass fraction of GTA.GTA-starch with30%GTA showed the best antibacterial activities,the bacteriostasis rate of Escherichia coli(E.coli)and S.aureus were 26.48%and20.26%,respectively;50%potassium sorbate in potassium sorbatestarch showed the best antibacterial activities,the bacteriostasis rate of E.coli and S.aureus were 67.68%and 74.75%,respectively.
基金Sichuan Science and Technology Program(grant Nos.2023NSFSC0348,2023JDRC0070)Sichuan City Solid Waste Energy and Building Materials Conversion Technology Engineering Research Center,Chengdu University(grant Nos.GF2022ZD002,GF2022ZC002).
文摘Based on the composition characteristics of carbide slag and the application of polyvinyl chloride,a method of preparing calcium carbonate with microstructure and nanostructure by using carbide slag as a raw material and ammonium chloride as a leaching agent was proposed.The factors for the preparation of calcium carbonate and the effects of different conditions on the crystal phase,grain size,and morphology of calcium carbonate were systematically studied.The results showed that the nanosized calcium carbonate was prepared at 60 mL/min,25°C,no additional ammonia,and 60 min.The product of spherical vaterite was in accordance with the relevant standards for the industrial precipitation of calcium carbonate.Moreover,the reuse of carbonation filtrate was realized.The crystal phase,grain size,and morphology of the carbonation product could be controlled by adjusting the reaction conditions.The manuscript provided a new idea for resource utilization of carbide slag and preparing nanocalcium carbonate.
基金Projrct supportted by the National Natural Science Foundation of China (Nos. 20772144, 20825209, 20832008) and the Chinese Academy of Sciences (Hundreds-Talent Program and Knowledge Innovation Program).
文摘Difluoromethyltri(n-butyl)ammonium chloride 1 was found to be an effective difluorocarbene reagent for O-, S-, N-, C-difluoromethylation under basic conditions. It is particularly remarkable that, when only 1.2 equivalent of reagent 1 was used, the difluoromethylated products were obtained in moderate to excellent yields.
基金Project supported by the National Natural Science Foundation of China (No. 20202002) Hunan Province Department of Education (No. 02C211) and Hunan Normal University (2001).
文摘In water, ammonium chloride was found to promote palladium-catalyzed Ullmann coupling reactions of aryl bromides. In the presence of Pd/C, zinc, NH4Cl, and water, coupling of various aryl bromides was carried out smoothly to afford the corresponding homocoupling products in moderate yields.
基金This project is supported by Tianjin Science Foundation for Youths.
文摘This investigation deals with the free radical polymerization both of (2-methacryloyloxyethyl) trimethyl ammonium chloride (QACEMA) and of diallyldimethyl ammonium chloride (DADMAC) in inverse emulsion. The influences of some factors, such as the concentration of monomers, initiator and emulsifier are discussed. The polymerization rate equations of above two monomers can be written as follows: R(p) = k[M](1.21)[I](0.82)[E](0.57) (for QACEMA) R(p) = k'[M](1.34)[I](0.90)[E](0.62) (for DADMAC)
基金supported by the National Natural Science Foundation of China(No.40972033, 40872034,40572032)the 15th and 16th Laboratory Funds of Peking University
文摘X-ray diffractometry was utilized to study the mineralogical characteristics of the inhalable particles (PM10) sampled during two dust storms in Beijing city on March 18th and May 21st, 2008. We confirm, for the first time, that there stably exists ammonium chloride in the atmosphere when temperature is low. The total sulfates particles were affected by relative humidity. Both species and concentration of sulfates decreased first and then grew back by the end of each dust storm. Koninckite, a phosphate mineral never reported as particulate aerosol before, was identified. Meanwhile, our result shows that a chemical modification on dust minerals occurs during long range transportation. PM10 samples collected during the period of dust storms were dominated by crustal minerals such as quartz, illite/smectite, illite, chlorite, feldspar and calcite, and were notably higher in concentration than that in normal periods of time. The amounts of total sulfates, calcite and feldspar altered in each dust storm. It is derived from 24-hour isentropic backward trajectories that two dust events in spring 2008 originated in different sources.
基金supported by the National Basic Research Program of China (No. 2014CB643404)the National Natural Science Foundation of China (Nos. 51274094 and 51374254)
文摘The effects of Br- and I- concentrations on the cell voltage, anodic polarization, current efficiency (CE), and energy consumption (EC) of zinc electrodeposition from ammoniacal ammonium chloride solutions were investigated. The surface morphology of zinc deposits was also examined. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to characterize the morphology of zinc deposits and the phase of anodic sediments produced during electrolysis. The results clearly showed that the CE slightly increased from approximately 95.12% in the absence of F and Br- to 97.08% in the presence of 10 g·L-1 Br; in contrast, the CE significantly decreased to less than 83% in the presence of 10 g·L-1 I- . The addition of Br and I- positively affected the EC, which decreased from 2514 kW·h·t-1 to approximately 2300 kW·h·t-1. The results of anodic polarization measurements showed that the voltage drops were 130 and 510 mV when the concentrations of Br- and I- were 10 g·L-1 at a eUlTent density of 400 A·m2, respectively. SEM images showed that the addition of Br- and I- caused different crystal growth mechanisms, which resulted in the production of compact and smooth zinc deposits. The anodic reactions of I were also studied.
基金supported by a grant from the National Natural Sciences Foundation of China (No. 81073124)
文摘This study examined the potential antilithic effects of a traditional Chinese medicine Urtica dentata Hand (UDH) in experimental rats and screened the optimal extract of UDH as a possible therapeutic agent for kidney stones. The rat model of urinary calcium oxalate stones was induced by intragastric (i.g.) administration of 2 mL of 1.25% ethylene glycol (EG) and 1% ammonium chloride (AC) for 28 days and was confirmed by Color Doppler ultrasound imaging. The rats in different experimental groups were then intragastrically given petroleum ether extract (PEE), N-butanol extract (NBE), aqueous extract (AqE) of UDH, Jieshitong (positive control drug), and saline, respectively. Treatment with NBE significantly reduced the elevated levels of urinary calcium, uric acid, phosphate, as well as increased urinary output. Accordingly, the increased calcium, oxalate levels and the number of calcium oxalate crystals deposits were remarkably reverted in the renal tissue of NBE-treated rats. In addition, NBE also prevented the impairment of renal function to decrease the contents of blood urea nitrogen (BUN) and creatinine. Taken together, these data suggest that NBE of UDH has a beneficial effect on calcium oxalate urinary stones in rats by flushing the stones out and protecting renal function.
文摘The ionic cross-linking treatment with 3-chloro-2-hydroxypropyl trimethyl ammonium chloride( CHTAC) and 1,2,3,4-butanetetracarboxylic acid( BTCA) was treated on untreated and plasma treated Tencel fabrics,and then TiO_2/SiO_2 sol was applied to the treated samples. Self-cleaning characteristic was investigated using the color measurement spectrophotometer with 7 h UV irradiation. Moreover, the surface morphology, structure change of samples were observed by scanning electron microscopy( SEM) and Fourier transform infrared spectroscopy( FTIR),respectively. The results revealed that with the increase of CHTAC concentration, breaking strength of Tencel fabric increased,whiteness index decreased,and wrinkle recovery angle first dropped and then rose. It was also found that increasing concentration of BTCA,breaking strength of Tencel fabric decreased,whiteness index and wrinkle recovery angle increased. FTIR studies revealed that CHTAC and BTCA had grafted on Tencel fabric. Nevertheless,the molar ratio of 50∶1 of TiO_2/SiO_2 sol endowed Tencel fabric with better self-cleaning properties,compared with sample treated with pure TiO_2. Furthermore,compared with sample treated with TiO_2/SiO_2 sol alone, the combination of plasma and cross-linking treatment( plasma + CHTAC + BTCA + TiO_2/SiO_2) decreased the value of K/S,and increased the value of ΔE,ensured more efficient photodegradation of methylene blue, and thus got a better performance of self-cleaning.
基金Funded by the Iron and Steel Joint Fund of National Natural Science Foundation of China (No.U1760120)the National Key R&D Program of China (Nos.2017yfc0210403-04, 2017YFC0210404)。
文摘The leaching kinetics of magnesium slag in ammonium chloride solutions was investigated.The effects of initial ammonium chloride concentration,liquid-solid ratio and reaction temperature on the leaching rate of calcium were determined.The results showed that the leaching rate increased with the increase in initial ammonium chloride concentration,reaction temperature and liquid-solid ratio.It was determined that the leaching rate fit the Avrami equation,and the leaching process was controlled by diffusion.The activation energy was 13.22 kJ/mol.
基金Project supported by the National Natural Science Foundation of China(51274152 and 41472071)the Program for Excellent Young Scientific and Technological Innovation Team of Hubei Provincial Department of Education,China(T201506)
文摘In order to intensify the leaching process of rare earth(RE) and reduce the impurities in the leachate, ammonium chloride(NH4Cl) and ammonium nitrate(NH4NO3) were mixed as a compound leaching agent to treat the weathered crust elution-deposited RE ore. Effects of molar ratio of NH~+_4Cl and NH_4NO_3, ammonium(NH_4) concentration, leaching agent pH and flow rate on the leaching process of RE were studied and evaluated by the chromatographic plate theory. Leaching process of the main impurity aluminium(Al) was also discussed in detail. Results showed that a higher initial ammonium concentration in a certain range could enhance the mass transfer process of RE and Al by providing a driving force to overcome the resistance of diffusion. pH almost had no effects on the mass transfer efficiency of RE and Al in the range of 4 to 8. The relationship between the flow rate and height equivalent to a theoretical plate(HETP) could fit well with the Van Deemter equation, and the flow rate at the lowest HETP was determined. The optimum conditions of column leaching for RE and Al were 1:1(molar ratio) of NH_4Cl and NH_4NO_3, 0.2 mol/L of ammonium concentration, pH 4–8 of leaching agent and 0.5 mL /min of flow rate. Under this condition, the mass transfer efficiency of RE was improved, but no change was observed for Al compared with the most widely used ammonium sulfate. Moreover, the significant difference value(around 20 mL) of retention volume at the peak concentration between RE and Al provided a possibility for their separation. It suggested the potential application of the novel compound leaching agent(NH_4Cl/NH_4NO_3). It was found that the relative concentration of RE in the leachate could be easily obtained by monitoring the pH of leachate.
基金the National Key Research and Development Program(No.2018YFB0605702)the National Natural Science Foundation of China(Nos.51774260,21606241 and 51804289)+1 种基金the Key Research Program of Frontier Sciences of Chinese Academy of Sciences(No.QYZDJ-SSW-JSC021)CAS Interdisciplinary Innovation Team。
文摘This study focused on the extraction of valuable metals from the cathode-active materials in spent lithiumion batteries using a high-concentration chloride solution.The effects of the concentrations of ammonium chloride(NH4 Cl),hydrochloric acid(HCl),and reductants such as hydrogen peroxide(H_(2)O_(2))and urea(CO(NH_(2))_(2))on metal extraction and chlorine production were studied experimentally.The leaching mechanism was analyzed,and a leaching model was established.It was found that the addition of solid NH4 Cl to an HCl solution significantly improved the metal extraction capability of the latter and reduced the formation of chlorine gas by 96.0%compared to that only using HCl.The activation energies for leaching Li,Ni,Co,and Mn were determined to be 30.4,38.5,30.6,and 38.2 kJ·mol^(-1),respectively.This study demonstrates an environmentally friendly method for recycling metal resources from cathode-active materials and furthers understanding of how NH4 Cl inhibits chlorine production when leaching with mixed solutions of HCl and NH4 Cl.
基金the support of the Center for Environmental Exposures and Disease(CEED)NIH-NIEHS Grant nos.P30 ES005022 and T32 ES019854This research was supported in part by Grant no.69A3551847102 from the U.S.Department of Transportation,Office of the Assistant Secretary for Research and Technology(OST-R).
文摘Quaternary ammonium compounds(QACs)are a class of antimicrobial disinfectants whose use in cleaning products increased during the COVID-19 pandemic.Chemically,their low vapor pressure indicates a proclivity to persist on surfaces,and their presence suggests a level of protection against microorganisms.The widespread application of QACs in response to the SARS CoV-2 virus created a need to evaluate their longevity on surfaces,for both efficacy and possible health risks.There are however,no standardized analytical methods for QAC surface sampling and analysis,and no published studies quantifying their concentrations on mass transportation vehicles-a high occupancy,close-contact microenvironment documented to facilitate the spread the SARS CoV-2 virus.Here,we describe a robust liquid chromatography mass spectrometry(LC-MS)method for the analysis of QACs and simultaneous development of a direct surface sampling and extraction protocol.We demonstrate the applicability of the method through the analysis of surface samples collected from in-service public transportation buses.The rapid,sensitive LC-MS method included 8 target QACs quantified on a Q-Exactive HF Hybrid Quadrupole-Orbitrap mass spectrometer using an electrospray ionization source and Dionex UltiMate 3000 UHPLC system for analyte separation.QAC standard mixtures at concentrations between 0.1 ng mL^(-1)and 2000 ng mL^(-1)were analyzed,and chromatographic separation of all analytes was achieved in less than 10 min.All correlation coefficients were reported at r>0.986,and LODs ranged from 0.007 to 2.103 ng mL^(-1)for all compounds,confirming the method's sensitivity.A previously reported surface sampling and extraction protocol was modified to further simplify the procedure and expand the number of target compounds.The new sampling protocol was optimized from 10 commercially available wipes and 4 solvent types by quantifying recovery from the surface.Band-Aid brand small gauze pads saturated with isopropanol had the highest recovery efficiencies,ranging from 61.5 to 102.9%across all analytes.To test the real-world applicability,wipe samples were collected from 4 in-circulation New Jersey Transit buses on 5 separate days over the course of a month to assess the occurrence and longevity of QACs on sanitized mass transportation vehicles.Concentrations of QACs were detected on every wipe sample taken,and at all sampled time points,confirming their persistence on hard surfaces.QACs have the potential to form polymers,and detection of the polymer might serve as a secondary indication of their effectiveness on surfaces.None of the polymers detected however,were unique to QACs from this study.The polymers detected were already present in the wipe and used as an internal standard to demonstrate the efficacy of extraction and analysis of polymeric QACs.
基金supported by the National Key Technology R&D Program in the 11th Five Year Plan of China(2006BAB03A10)the guiding projects of Scientific and Technological Research and Development of Hebei Province of China(07215184).
文摘The equilibrium data on the ternary system of NH_(4)Cl-CaCl_(2)-H_(2)O at 50℃were investigated using the wet-residue method.The experimental results show that there are three pure phase crystal areas of NH_(4)Cl,2NH_(4)Cl·CaCl_(2)·3H_(2)O and CaCl·2H_(2)O,two mixture phase crystal areas of NH_(4)Cl and 2NH_(4)Cl·CaCl·3H_(2)O,and 2NH_(4)Cl·CaCl_(2)·3H_(2)O and CaCl·2H_(2)O in the system.A new hydration double salt(2NH_(4)Cl·CaCl·3H_(2)O)was found in the ternary equilibrium system for the first time.
基金Project supported by the National Natural Science Foundation of China (Nos. 20865002, 20965002), the Research Funds of Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education (No. 10012018).
文摘In pH 3.8 acetic acid-sodium acetate (HAC-NaAC) buffer solution, laccase exhibited a strong catalytic effect on the H2O2 oxidation of I- to form I2, and I2 combined with excess I- to form I3- that reacted with cationic surfactants of tetradecyl dimethylbenzyl ammonium chloride (TDMAC) to produce the (TDMAC-I3)n association complex particles, which exhibited a strong resonance scattering (RS) peak at 468 nm. Under the chosen conditions, as the concentration of laccase activity increased, the RS intensity at 468 nm (1468 nm) increased linearly. The increased RS intensity A1468 nm was linear to laccase activity in the range of 0.08-0.96 U/mL, with a regression equation of △1468 nm =88.8 U-1.9, and a detection limit of 0.02 U/mL laccase. This proposed method was applied to detect laccase activity in waste water, with satisfactory results.
文摘The addition of a hardener is necessary for the curing of urea-formaldehyde (UF) adhesives in the production of MDF and particleboard. The most commonly used hardener, ammonium chloride, however, is suspected to cause the formation of poisonous dioxin when waste boards are combusted and hence considered as a potential source of pollution. To assess the feasibility of substituting ammonium sulphate for ammonium chloride, working properties and bonding strength were measured for UF adhesives with the two ...