In this study,X-ray diffraction,N_(2)adsorption(N_(2)A),and mercury intrusion(MI)experiments were used to investigate the influence of acid treatment on pore structure and fractal characterization of tight sandstones....In this study,X-ray diffraction,N_(2)adsorption(N_(2)A),and mercury intrusion(MI)experiments were used to investigate the influence of acid treatment on pore structure and fractal characterization of tight sandstones.The results showed that acid treatment generated a certain number of ink-bottle pores in fine sandstone,aggravated the ink-bottle effect in the sandy mudstone,and transformed some smaller pores into larger ones.After the acid treatment,both the pore volume in the range of 2–11 nm and 0.271–8μm for the fine sandstone and the entire pore size range for the sandy mudstone significantly increased.The dissolution of sandstone cement causes the fine sandstone particles to fall off and fill the pores;the porosity increased at first but then decreased with acid treatment time.The fractal dimension obtained using the Frenkel-Halsey-Hill model was positively correlated with acid treatment time.However,the total fractal dimensions obtained by MI tests showed different changes with acid treatment time in fine sandstone and sandy mudstone.These results provide good guiding significance for reservoir acidification stimulation.展开更多
In this work,cathode materials of spent lithium-ion ternary batteries are recovered and used as metal precursor to prepare multi-metal oxides MnO_(x)(SY)and GdMnO_(3)(SY)via combustion method and sol-gel method,respec...In this work,cathode materials of spent lithium-ion ternary batteries are recovered and used as metal precursor to prepare multi-metal oxides MnO_(x)(SY)and GdMnO_(3)(SY)via combustion method and sol-gel method,respectively.Furthermore,a series of MnO_(x)(SY)-n and GdMnO_(3)(SY)-n(n=0.05,0.10,1.00,4.00,n represents the dilute HNO_(3) concentration)catalysts are fabricated by acid treatment of MnO_(x)(SY)and GdMnO_(3)(SY)samples and catalytic activities of oxygenated VOCs oxidation over all the prepared catalysts are investigated.Catalytic evaluation results show that acid-treated MnO_(x)(SY)-0.10 and GdMnO_(3)(SY)-0.05 samples perform the optimum VOCs removal efficiency respectively,which may be attributed to their obvious enhancement of physicochemical properties.In detail,Mn O_(x)(SY)-0.10 and GdMnO_(3)(SY)-0.05 samples exhibit the larger specific surface area,bigger amount of surface high-valence metal ions(Mn^(4+),Co^(3+),Ni^(3+)),more abundant adsorbed oxygen species and better low-temperature reducibility,which can play a crucial role in the significant improvement of VOCs oxidation.In situ DRIFTS results imply that the possible main intermediates are-OCO,-COO and-C-O species produced during VOCs oxidation.Possible by-products are further determined via TD/GC-MS analysis.展开更多
Hollow polymer latex particles were prepared by seeded emulsion polymerization. A seed latex consisting of styrene (St), butyl acrylate(BA) copolymer was first prepared, and seeded terpolymerization of St BA MA(methac...Hollow polymer latex particles were prepared by seeded emulsion polymerization. A seed latex consisting of styrene (St), butyl acrylate(BA) copolymer was first prepared, and seeded terpolymerization of St BA MA(methacrylic acid) were then carried out in the absence of surfactant. Final latex was treated by a two step treatment under alkaline and acidic conditions, thus, the particles with hollow structure were obtained. We discussed the effects of pH value, temperature and time in alkali and acid treatment processes on hollow structure within the polymer latex particles and amount of carboxylic group on particle surface. The results show that the hollow polymer latex particles with the largest hollow size can be obtained under a certain condition (pH12.5, 90°C, 3 h in alkali treatment stage and pH2.5, 85°C, 3 h in acid treatment stage).展开更多
Heat and acid treatments were reported to be a promising substitute for SO_2 fumigation in color protection of postharvest lychee (Litchi chinensis Sonn.) fruits, but the mechanism was not clear. In the present study,...Heat and acid treatments were reported to be a promising substitute for SO_2 fumigation in color protection of postharvest lychee (Litchi chinensis Sonn.) fruits, but the mechanism was not clear. In the present study, hot water (70°C) dipping followed by immersion in 2% HCl (heat-acid) substantially protected the red color of the fruit during storage at 25°C and inhibited anthocyanin degradation while hot water dipping alone (heat) led to rapidly browning and about 90% loss in anthocyanin content. The pH values in the pericarp of the heat-acid treated fruit dropped to 3.2, while the values maintained around 5.0 in the heat-treated and control fruit. No significantly different pH values were detected among the arils of heat-acid, heat treated and control fruit. Heat-acid treatment dramatically reduced the activities of anthocyanin degradation enzyme (ADE), peroxidase (POD) and polyphenol oxidase in the pericarp. A marked reduction in LcPOD gene expression was also detected in heat-acid treated fruit, in contrast, induction was found in heat treated fruit. The pericarp of heat-acid treated fruit exhibited significantly lower respiration rate but faster water loss than that of the untreated or heat treated fruit. Taken together, heat treatment triggered quick browning and anthocyanin loss in lychee fruit, while heat-acid treatment protected the fruit color by a great reduction in the activities/gene expression of anthocyanin degradation enzymes and acidification of lychee perica.展开更多
The present study was carried out on the effect of acid leaching on the modification and structure alteration of montmorillonite. A nanostructured, activated material was prepared by selective leaching of pure smectit...The present study was carried out on the effect of acid leaching on the modification and structure alteration of montmorillonite. A nanostructured, activated material was prepared by selective leaching of pure smectite clay with different concentrations of sulfuric acid (1 - 10 N/L) at 85°C for 120 min using a solid/liquid ratio of 1:20 and a reflux system. The Fourier transform infrared (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-Ray diffraction (XRD) techniques were used for the characterization and study of the acid-treated montmorillonite clay. Chemical structure of specimens was distinguished by FTIR. The results showed that the formation of Si-OH bonds and leaching of Al3+ ions increased progressively with severity of the acid treatment. As the FTIR studies indicated, acid treatment led to the removal of the octahedral Al3+ cations and an increase in the Si-OH bonds. The morphological alteration of the untreated and treated montmorillonite was investigated by using TEM and SEM. X-ray fluorescence (XRF) analysis revealed a considerable decrease in the relative content of Al by increasing the acid strength. Moreover, the XRD results showed that the treatment using highly concentrated acid resulted in the formation of an amorphous silica phase.展开更多
Using HCl to activate the diapause eggs is a traditional technique of artificial hatching applied in silkworm egg production. Its mechanism has not yet been clarified. This experiment explored the effect of HCl on the...Using HCl to activate the diapause eggs is a traditional technique of artificial hatching applied in silkworm egg production. Its mechanism has not yet been clarified. This experiment explored the effect of HCl on the termination of diapause of silkworm eggs cold-stored for 45 days from the point of proteomes. Two-dimensional electrophoresis techniques and ESI- MS-MS were used to compare and analyze the variation expression of difficult-dissolved-proteins of diapause eggs cold- stored for 45 days before and after acid treatment. Through analysis on the two-dimensional electrophoretogram, there were 296 dots before acid treatment and 302 after the treatment, respectively. Amongst them 265 dots were matchable. The matchability reached 88.6%. There were 31 specific protein dots before acid treatment and 37 after acid treatment, respectively. ESI-MS-MS analysis was conducted for two specific protein-rich dots which disappeared after acid treatment. The results indicated that the sequence of No. 1 protein dot had 55 amino acids’ peptide matched with those of chorion protein (Bombyx mori). While the sequence of No. 2 protein dot had only 15 amino acids’ peptide matched with those of heat shock protein hsp 19.9 (Bombyx mori), and it was presumed to be an unknown protein. The difficult-dissolved- proteins of diapause eggs have variation expression after acid treatment. Some proteins before and after acid treatment are changed in MW.展开更多
In this study, a comparison of a variety of existing acid treatment methods for zeolite based on their abilities to modify physical properties of the particles is performed. Evaluation of the effects that four differe...In this study, a comparison of a variety of existing acid treatment methods for zeolite based on their abilities to modify physical properties of the particles is performed. Evaluation of the effects that four different acids have on numerous properties of the zeolites including surface area, pore size, pore volume, thermal stability, IR spectra, crystallinity, and morphology is conducted and compared with the reference untreated zeolite. Furthermore, all five zeolite particles are evaluated for their adsorption properties in column mode experiments. The importance of the examined features is discussed. The results obtained in this work are compared to similar studies to examine which conditions greatly influence the zeolite modifications.展开更多
Three approaches of treating carbon nanotubes (CNTs) including acid treatment, air oxidization and heat treatment at high temperature were studied to enhance the crystalline degree of carbon nanotubes. High temperatur...Three approaches of treating carbon nanotubes (CNTs) including acid treatment, air oxidization and heat treatment at high temperature were studied to enhance the crystalline degree of carbon nanotubes. High temperature heat-treatment elevates the crystalline degree of carbon nanotubes. Acid treatment removes parts of amorphous carbonaceous matter through its oxidization effect.Air oxidization disperses carbon nanotubes and amorphous carbonaceous matter. The treatment of combining acid treatment with heat-treatment further elevates the crystalline degree of carbon nanotubes comparing with acid treatment or heat-treatment. The combination of the three treatments creates the thorough effects of enhancing the crystalline degree of carbon nanotubes.展开更多
The Basofil fiber is a new type of high-temperature fiber. Its Limiting Oxygen Index (LOI) value reaches 32. It does not melt, drop down or smolder when it contacts fire. The fiber is condensed from melamine and forma...The Basofil fiber is a new type of high-temperature fiber. Its Limiting Oxygen Index (LOI) value reaches 32. It does not melt, drop down or smolder when it contacts fire. The fiber is condensed from melamine and formaldehyde into a cross-linked with methylene-ether and methylene bridge bond. This thesis discusses the change of fiber structure and performance after the acid treatment.展开更多
A new molecularly imprinted polymer (MIP) was synthesized by precipitation polymerization using diclofenac (DFC) as a template. Binding characteristics of the MIP particles were evaluated by equilibrium binding experi...A new molecularly imprinted polymer (MIP) was synthesized by precipitation polymerization using diclofenac (DFC) as a template. Binding characteristics of the MIP particles were evaluated by equilibrium binding experiments. DFC-MIP aqueous suspension and non-imprinted polymer (NIP) suspension were exposed to monochromatic UV light (253.7 nm) from low-pressure mercury lamps. UV-visible spectrophotometry (especially absorbance at 276 nm) showed that the DFC inside MIP particles degraded completely. After DFC-MIP suspension exposure to UV light the particles were completely regenerated after washing with water at least six times. The regenerated MIP particles rebounded considerable amount of DFC (approximately 88% removal of 44 ppm DFC). The stability of DFC was examined in the presence of various concentrations of hydrochloric acid (0.025 to 125 mM). Experimental results showed that degradation of DFC was efficient, depending on the acid concentration as well as the treatment time. However, there was no re-binding of DFC by the MIP particles after HCl treatment (and DDW washing) when exposed to DFC for 24 hours.展开更多
The purpose of this paper is to explore the effects of acid treatment on root morphology and architecture in seedlings of Malus hupehensis var. pingyiensis. The rootstock seedlings were cultured in 1/2 Hoagland nutrie...The purpose of this paper is to explore the effects of acid treatment on root morphology and architecture in seedlings of Malus hupehensis var. pingyiensis. The rootstock seedlings were cultured in 1/2 Hoagland nutrient solutions of different pH (pH 4, pH 4.5, pH 5 and pH 6), respectively. The parameters of root architecture were measured in the day 4, 8 and 12 with the professional WinRHIZO 2007. Compared with the control (pH 6), the treatments significantly decreased the fractal dimension, length, diameter, surface area and volume of roots in day 8 and 12, and they kept decreasing followed the increase of the acidity and treatment time. The growth of lateral roots was more susceptible to acid treatment than taproots. In addition, the acid treatment mainly inhibited the growth of rootlets, significantly decreased the proportion of rootlets that changed the composition of roots, and then simplified the space structure of roots.展开更多
In karst areas,the drainage pipes of aging tunnels are prone to be clogged by precipitated carbonates,resulting in lining cracking and tunnel leaking.As a result,not only the driving safety will be deteriorated,but al...In karst areas,the drainage pipes of aging tunnels are prone to be clogged by precipitated carbonates,resulting in lining cracking and tunnel leaking.As a result,not only the driving safety will be deteriorated,but also the water pressure on the lining might also be elevated significantly.For the structural stability and service lifespan of old tunnels,it is of great importance to remove these precipitated carbonates in time.Traditional treatment methods are often destructive to some extent or not efficient enough.This study aims to experimentally develop an eco-friendly acid-based chemical cleaning method to remove carbonate precipitations efficiently.The proposed chemical cleaning agent is an aqueous solution with strong acidity,consisting of sulfamic acid,water,and additives.The factors affecting the cleaning efficiency include the acid solubility,temperature and flow rate of the cleaning agent,as well as additives.Elevating the solution temperature to 50C or a flow rate of no less than 0.2 m/s can improve cleaning efficiency.Although the salt effect cannot work,1 wt%of polymaleic acid as a surfactant could further promote the cleaning rate.The cleaning efficiency will increase with the flow rate in a power function.The relatively low flow rate that improves the cleaning rate considerably can avoid highpressure-induced mechanical damage to tunnel drainpipes.The waste could be easily treated to acceptable levels using commercial sewage treatment products and can also be recycled in agriculture.With the chemical cleaning,the water pressure at the arch springing of the lining will reduce with the increased radius of transverse drainpipes in a power function.The proposed acid-based cleaning method,which is highly efficient,non-or low-destructive to aging tunnels,sufficiently safe for humans,and friendly enough to the environment,will offer a promising alternative to remove the precipitated carbonates in tunnel drainpipes efficiently.展开更多
In this paper,we describe the synthesis of the AC-PtNi/G catalysts with graphene as the carrier,via the alcohol reduction and the sulfuric acid treatment.The prepared catalysts were microscopically characterized by X-...In this paper,we describe the synthesis of the AC-PtNi/G catalysts with graphene as the carrier,via the alcohol reduction and the sulfuric acid treatment.The prepared catalysts were microscopically characterized by X-ray diffractometry(XRD),X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM),electron spectroscopy(EDAX),and transmission electron micros-copy(TEM).We tested the electrochemical performance of the prepared catalysts using an electrochemical workstation and in situ infrared spectroscopy(FTIR).The results showed that the acid-treated AC-PtNi/G catalysts had a more uniform dispersion and with the increased of treatment time,the particle size of the catalyst became smaller.And the electrocatalytic performance of the AC-PtNi/G-48h catalyst treated with sulfuric acid for 48 h was significantly better than that of the untreated PtNi/G catalyst.Its electrochemically active surface area was 76.63 m^(2)/g,and the peak current density value for catalytic oxidation of ethanol was 1218.83 A/g,which was 10 times that of ordinary commercial Pt/C catalyst.The steady-state current density value of 1100 s was 358.77 A/g,and it has excellent anti-CO toxicity performance.It was determined that a sulfuric acid treatment controlled catalyst particle size and increased the electrocatalytic activity of the catalytic oxidation of ethanol.展开更多
A new method of extracting chlorogenic acid from flos lonicerae, and treating the materials with enzyme before being extracted by ethanol is developed, and the optimum conditions are also investigated in detail. Three...A new method of extracting chlorogenic acid from flos lonicerae, and treating the materials with enzyme before being extracted by ethanol is developed, and the optimum conditions are also investigated in detail. Three important factors, enzyme dosage, treatment time and treatment temperature are adapted to optimize the extraction process. The experimental results show that the extract yield of flos lonicerae and chlorogenic acid can be obviously increased by the cellulase treatment, 61.5 mg chlorogenic acid is obtained from 1.00 g flos lonicerae at most. The optimal temperature of enzymatic treatment is 40 50 ℃. Compared with the use of single cellulase, the combined treatment of cellulase and pectinase increase the extract yield obviously but fail to improve that of chlorogenic acid.展开更多
Novel catalysts of phosphotungstic heteropolyacids(PW_(12))supported on neutral alumina were prepared by assistance of ultrasound and plasma treatment.The prepared catalysts were characterized by FT-IR pyridine adsorp...Novel catalysts of phosphotungstic heteropolyacids(PW_(12))supported on neutral alumina were prepared by assistance of ultrasound and plasma treatment.The prepared catalysts were characterized by FT-IR pyridine adsorption(Py-IR),temperature programmed desorption of Pyridine(Py-TPD),BET and X-ray diffraction(XRD),and their catalytic performances were evaluated by the cationic polymerization of tetrahydrofuran.The results indicate that plasma treatment remarkably increases the surface acidity of the prepared catalyst while ultrasonic treatment induces PW_(12)to uniformly disperse on the support surface and expose more active sites for the acid catalytic reaction.A higher catalytic activity(69.7%)is obtained on the novel catalyst,which significantly outstripped that on the conventional sample(57.5%).展开更多
It is difficult to treat 2-amino-thiazoline-4-carboxylic acid (ATC) waste liquid effectively at present for its characteristics of high chemical oxygen demand (COD), high salinity and low biodegradability. In or...It is difficult to treat 2-amino-thiazoline-4-carboxylic acid (ATC) waste liquid effectively at present for its characteristics of high chemical oxygen demand (COD), high salinity and low biodegradability. In order to solve this problem, this paper presents several kinds of physical-chemical treatment unit techniques, including acid separation, catalytic oxidation and coagulation. First of all, acid separation was adopted to precipitate relevant organics at isoelectric point. When the temperature and pH value of acid separation were controlled at about 5 ℃ and 2.2 respectively, the COD removal rate could reach 27.600. Secondly, oxidation was used to break chemical constitution of refractory organics. The optimal reaction parameters of catalytic oxidation should be 20 ℃, pH adjusted to 5.0 and [Fe2+] 300 mg/L. Then with 500 H2O2 added and after one-hour reaction, the COD removal rate could achieve about 5200. Finally, coagulation was adopted to remove a portion of refractory organics, and 1500 polymeric molysite flocculant was the best for the coagulation, and the COD removal rate could reach about 1500. Therefore, the proposed feasible process of physical-chemical pretreatment for ATC waste liquid could have about 7000 COD removed in total.展开更多
Lactobacillus species are non-spore-forming, gram-positive bacteria and lactic acid producing bacteria (LAPB) that naturally inhabit the human and animal gastrointestinal and mouth organs. The aim of this review was t...Lactobacillus species are non-spore-forming, gram-positive bacteria and lactic acid producing bacteria (LAPB) that naturally inhabit the human and animal gastrointestinal and mouth organs. The aim of this review was to evaluate the new progress regarding the use of Lactobacillus species as live delivery vectors, prevention, and treatment of pathogenic and metabolic diseases. Lactobacillus strains of probiotics have been extensively studied and have confirmed that they can absolutely improve performance as live delivery vectors, a treatment option of various diseases such as: Hemorrhagic cecal coccidiosis in young poultry, hypertension, avian flu, obesity, diabetes, Derzsy’s disease or parvovirus infection, human immunodeficiency virus infections, irritable bowel syndrome, gastrointestinal disorders, Fungal infections, vaginal eubiosis, fish and shellfish species diseases. We give you an idea about that Lactobacillus species have been proficient in preventing and treating both disorders in animal models and some are used for clinical trials. We present the most current studies on the use of Lactobacillus strains that had an impact on an effective immune response to a specific antigen because a variety of antigens have been expressed. Therefore Lactobacillus strains can be considered as good candidates because of its potential for diseases treatment and vaccine development as heterologous protein secretion to date.展开更多
基金supported by the National Natural Science Foundation of China(51674049,52074044,and 51874053)the Scientific Research Foundation of Hunan Provincial Education Department,China(22B0854)。
文摘In this study,X-ray diffraction,N_(2)adsorption(N_(2)A),and mercury intrusion(MI)experiments were used to investigate the influence of acid treatment on pore structure and fractal characterization of tight sandstones.The results showed that acid treatment generated a certain number of ink-bottle pores in fine sandstone,aggravated the ink-bottle effect in the sandy mudstone,and transformed some smaller pores into larger ones.After the acid treatment,both the pore volume in the range of 2–11 nm and 0.271–8μm for the fine sandstone and the entire pore size range for the sandy mudstone significantly increased.The dissolution of sandstone cement causes the fine sandstone particles to fall off and fill the pores;the porosity increased at first but then decreased with acid treatment time.The fractal dimension obtained using the Frenkel-Halsey-Hill model was positively correlated with acid treatment time.However,the total fractal dimensions obtained by MI tests showed different changes with acid treatment time in fine sandstone and sandy mudstone.These results provide good guiding significance for reservoir acidification stimulation.
基金supported by the National Natural Science Foundation of China(Grant numbers 21876107,21607103)。
文摘In this work,cathode materials of spent lithium-ion ternary batteries are recovered and used as metal precursor to prepare multi-metal oxides MnO_(x)(SY)and GdMnO_(3)(SY)via combustion method and sol-gel method,respectively.Furthermore,a series of MnO_(x)(SY)-n and GdMnO_(3)(SY)-n(n=0.05,0.10,1.00,4.00,n represents the dilute HNO_(3) concentration)catalysts are fabricated by acid treatment of MnO_(x)(SY)and GdMnO_(3)(SY)samples and catalytic activities of oxygenated VOCs oxidation over all the prepared catalysts are investigated.Catalytic evaluation results show that acid-treated MnO_(x)(SY)-0.10 and GdMnO_(3)(SY)-0.05 samples perform the optimum VOCs removal efficiency respectively,which may be attributed to their obvious enhancement of physicochemical properties.In detail,Mn O_(x)(SY)-0.10 and GdMnO_(3)(SY)-0.05 samples exhibit the larger specific surface area,bigger amount of surface high-valence metal ions(Mn^(4+),Co^(3+),Ni^(3+)),more abundant adsorbed oxygen species and better low-temperature reducibility,which can play a crucial role in the significant improvement of VOCs oxidation.In situ DRIFTS results imply that the possible main intermediates are-OCO,-COO and-C-O species produced during VOCs oxidation.Possible by-products are further determined via TD/GC-MS analysis.
文摘Hollow polymer latex particles were prepared by seeded emulsion polymerization. A seed latex consisting of styrene (St), butyl acrylate(BA) copolymer was first prepared, and seeded terpolymerization of St BA MA(methacrylic acid) were then carried out in the absence of surfactant. Final latex was treated by a two step treatment under alkaline and acidic conditions, thus, the particles with hollow structure were obtained. We discussed the effects of pH value, temperature and time in alkali and acid treatment processes on hollow structure within the polymer latex particles and amount of carboxylic group on particle surface. The results show that the hollow polymer latex particles with the largest hollow size can be obtained under a certain condition (pH12.5, 90°C, 3 h in alkali treatment stage and pH2.5, 85°C, 3 h in acid treatment stage).
基金supported by the National Key Basic Research Program of China (2013CB127105)the National Natural Science Foundation of China (30671466)+1 种基金China Litchi and Logan Research System (CARS-33-14)Guangdong Fruit Research System,China (2009-356)
文摘Heat and acid treatments were reported to be a promising substitute for SO_2 fumigation in color protection of postharvest lychee (Litchi chinensis Sonn.) fruits, but the mechanism was not clear. In the present study, hot water (70°C) dipping followed by immersion in 2% HCl (heat-acid) substantially protected the red color of the fruit during storage at 25°C and inhibited anthocyanin degradation while hot water dipping alone (heat) led to rapidly browning and about 90% loss in anthocyanin content. The pH values in the pericarp of the heat-acid treated fruit dropped to 3.2, while the values maintained around 5.0 in the heat-treated and control fruit. No significantly different pH values were detected among the arils of heat-acid, heat treated and control fruit. Heat-acid treatment dramatically reduced the activities of anthocyanin degradation enzyme (ADE), peroxidase (POD) and polyphenol oxidase in the pericarp. A marked reduction in LcPOD gene expression was also detected in heat-acid treated fruit, in contrast, induction was found in heat treated fruit. The pericarp of heat-acid treated fruit exhibited significantly lower respiration rate but faster water loss than that of the untreated or heat treated fruit. Taken together, heat treatment triggered quick browning and anthocyanin loss in lychee fruit, while heat-acid treatment protected the fruit color by a great reduction in the activities/gene expression of anthocyanin degradation enzymes and acidification of lychee perica.
文摘The present study was carried out on the effect of acid leaching on the modification and structure alteration of montmorillonite. A nanostructured, activated material was prepared by selective leaching of pure smectite clay with different concentrations of sulfuric acid (1 - 10 N/L) at 85°C for 120 min using a solid/liquid ratio of 1:20 and a reflux system. The Fourier transform infrared (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-Ray diffraction (XRD) techniques were used for the characterization and study of the acid-treated montmorillonite clay. Chemical structure of specimens was distinguished by FTIR. The results showed that the formation of Si-OH bonds and leaching of Al3+ ions increased progressively with severity of the acid treatment. As the FTIR studies indicated, acid treatment led to the removal of the octahedral Al3+ cations and an increase in the Si-OH bonds. The morphological alteration of the untreated and treated montmorillonite was investigated by using TEM and SEM. X-ray fluorescence (XRF) analysis revealed a considerable decrease in the relative content of Al by increasing the acid strength. Moreover, the XRD results showed that the treatment using highly concentrated acid resulted in the formation of an amorphous silica phase.
基金Guangdong Provincial Science and Technology Project (2005B40101012,2004B20201013)Guangdong Province supported Agricultural Science and Technology Project (2004-295)
文摘Using HCl to activate the diapause eggs is a traditional technique of artificial hatching applied in silkworm egg production. Its mechanism has not yet been clarified. This experiment explored the effect of HCl on the termination of diapause of silkworm eggs cold-stored for 45 days from the point of proteomes. Two-dimensional electrophoresis techniques and ESI- MS-MS were used to compare and analyze the variation expression of difficult-dissolved-proteins of diapause eggs cold- stored for 45 days before and after acid treatment. Through analysis on the two-dimensional electrophoretogram, there were 296 dots before acid treatment and 302 after the treatment, respectively. Amongst them 265 dots were matchable. The matchability reached 88.6%. There were 31 specific protein dots before acid treatment and 37 after acid treatment, respectively. ESI-MS-MS analysis was conducted for two specific protein-rich dots which disappeared after acid treatment. The results indicated that the sequence of No. 1 protein dot had 55 amino acids’ peptide matched with those of chorion protein (Bombyx mori). While the sequence of No. 2 protein dot had only 15 amino acids’ peptide matched with those of heat shock protein hsp 19.9 (Bombyx mori), and it was presumed to be an unknown protein. The difficult-dissolved- proteins of diapause eggs have variation expression after acid treatment. Some proteins before and after acid treatment are changed in MW.
文摘In this study, a comparison of a variety of existing acid treatment methods for zeolite based on their abilities to modify physical properties of the particles is performed. Evaluation of the effects that four different acids have on numerous properties of the zeolites including surface area, pore size, pore volume, thermal stability, IR spectra, crystallinity, and morphology is conducted and compared with the reference untreated zeolite. Furthermore, all five zeolite particles are evaluated for their adsorption properties in column mode experiments. The importance of the examined features is discussed. The results obtained in this work are compared to similar studies to examine which conditions greatly influence the zeolite modifications.
文摘Three approaches of treating carbon nanotubes (CNTs) including acid treatment, air oxidization and heat treatment at high temperature were studied to enhance the crystalline degree of carbon nanotubes. High temperature heat-treatment elevates the crystalline degree of carbon nanotubes. Acid treatment removes parts of amorphous carbonaceous matter through its oxidization effect.Air oxidization disperses carbon nanotubes and amorphous carbonaceous matter. The treatment of combining acid treatment with heat-treatment further elevates the crystalline degree of carbon nanotubes comparing with acid treatment or heat-treatment. The combination of the three treatments creates the thorough effects of enhancing the crystalline degree of carbon nanotubes.
文摘The Basofil fiber is a new type of high-temperature fiber. Its Limiting Oxygen Index (LOI) value reaches 32. It does not melt, drop down or smolder when it contacts fire. The fiber is condensed from melamine and formaldehyde into a cross-linked with methylene-ether and methylene bridge bond. This thesis discusses the change of fiber structure and performance after the acid treatment.
文摘A new molecularly imprinted polymer (MIP) was synthesized by precipitation polymerization using diclofenac (DFC) as a template. Binding characteristics of the MIP particles were evaluated by equilibrium binding experiments. DFC-MIP aqueous suspension and non-imprinted polymer (NIP) suspension were exposed to monochromatic UV light (253.7 nm) from low-pressure mercury lamps. UV-visible spectrophotometry (especially absorbance at 276 nm) showed that the DFC inside MIP particles degraded completely. After DFC-MIP suspension exposure to UV light the particles were completely regenerated after washing with water at least six times. The regenerated MIP particles rebounded considerable amount of DFC (approximately 88% removal of 44 ppm DFC). The stability of DFC was examined in the presence of various concentrations of hydrochloric acid (0.025 to 125 mM). Experimental results showed that degradation of DFC was efficient, depending on the acid concentration as well as the treatment time. However, there was no re-binding of DFC by the MIP particles after HCl treatment (and DDW washing) when exposed to DFC for 24 hours.
文摘The purpose of this paper is to explore the effects of acid treatment on root morphology and architecture in seedlings of Malus hupehensis var. pingyiensis. The rootstock seedlings were cultured in 1/2 Hoagland nutrient solutions of different pH (pH 4, pH 4.5, pH 5 and pH 6), respectively. The parameters of root architecture were measured in the day 4, 8 and 12 with the professional WinRHIZO 2007. Compared with the control (pH 6), the treatments significantly decreased the fractal dimension, length, diameter, surface area and volume of roots in day 8 and 12, and they kept decreasing followed the increase of the acidity and treatment time. The growth of lateral roots was more susceptible to acid treatment than taproots. In addition, the acid treatment mainly inhibited the growth of rootlets, significantly decreased the proportion of rootlets that changed the composition of roots, and then simplified the space structure of roots.
基金The financial support from the Fundamental Research Funds for the Central Universities,China(Grant No.YJ2021148)is gratefully acknowledged.The authors are also grateful to Prof.Ming Lü,a member of the Norwegian Academy of Technological Sciences from Norway,for his valuable suggestions.
文摘In karst areas,the drainage pipes of aging tunnels are prone to be clogged by precipitated carbonates,resulting in lining cracking and tunnel leaking.As a result,not only the driving safety will be deteriorated,but also the water pressure on the lining might also be elevated significantly.For the structural stability and service lifespan of old tunnels,it is of great importance to remove these precipitated carbonates in time.Traditional treatment methods are often destructive to some extent or not efficient enough.This study aims to experimentally develop an eco-friendly acid-based chemical cleaning method to remove carbonate precipitations efficiently.The proposed chemical cleaning agent is an aqueous solution with strong acidity,consisting of sulfamic acid,water,and additives.The factors affecting the cleaning efficiency include the acid solubility,temperature and flow rate of the cleaning agent,as well as additives.Elevating the solution temperature to 50C or a flow rate of no less than 0.2 m/s can improve cleaning efficiency.Although the salt effect cannot work,1 wt%of polymaleic acid as a surfactant could further promote the cleaning rate.The cleaning efficiency will increase with the flow rate in a power function.The relatively low flow rate that improves the cleaning rate considerably can avoid highpressure-induced mechanical damage to tunnel drainpipes.The waste could be easily treated to acceptable levels using commercial sewage treatment products and can also be recycled in agriculture.With the chemical cleaning,the water pressure at the arch springing of the lining will reduce with the increased radius of transverse drainpipes in a power function.The proposed acid-based cleaning method,which is highly efficient,non-or low-destructive to aging tunnels,sufficiently safe for humans,and friendly enough to the environment,will offer a promising alternative to remove the precipitated carbonates in tunnel drainpipes efficiently.
基金This work was supported by the National Natural Science Foundation of China(Nos.51864040,51974167)the Natural Science Fund of Inner Mongolia Autonomous Region,China(No.2018LH02006).
文摘In this paper,we describe the synthesis of the AC-PtNi/G catalysts with graphene as the carrier,via the alcohol reduction and the sulfuric acid treatment.The prepared catalysts were microscopically characterized by X-ray diffractometry(XRD),X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM),electron spectroscopy(EDAX),and transmission electron micros-copy(TEM).We tested the electrochemical performance of the prepared catalysts using an electrochemical workstation and in situ infrared spectroscopy(FTIR).The results showed that the acid-treated AC-PtNi/G catalysts had a more uniform dispersion and with the increased of treatment time,the particle size of the catalyst became smaller.And the electrocatalytic performance of the AC-PtNi/G-48h catalyst treated with sulfuric acid for 48 h was significantly better than that of the untreated PtNi/G catalyst.Its electrochemically active surface area was 76.63 m^(2)/g,and the peak current density value for catalytic oxidation of ethanol was 1218.83 A/g,which was 10 times that of ordinary commercial Pt/C catalyst.The steady-state current density value of 1100 s was 358.77 A/g,and it has excellent anti-CO toxicity performance.It was determined that a sulfuric acid treatment controlled catalyst particle size and increased the electrocatalytic activity of the catalytic oxidation of ethanol.
文摘A new method of extracting chlorogenic acid from flos lonicerae, and treating the materials with enzyme before being extracted by ethanol is developed, and the optimum conditions are also investigated in detail. Three important factors, enzyme dosage, treatment time and treatment temperature are adapted to optimize the extraction process. The experimental results show that the extract yield of flos lonicerae and chlorogenic acid can be obviously increased by the cellulase treatment, 61.5 mg chlorogenic acid is obtained from 1.00 g flos lonicerae at most. The optimal temperature of enzymatic treatment is 40 50 ℃. Compared with the use of single cellulase, the combined treatment of cellulase and pectinase increase the extract yield obviously but fail to improve that of chlorogenic acid.
基金the National Natural Science Foundation of China(No.205903603)the Ministry of Sciences and Technology of China(No.2005CB221406)the New Century Excellent Talent Project of Ministry of Education of China(No.CET-05-0783)
文摘Novel catalysts of phosphotungstic heteropolyacids(PW_(12))supported on neutral alumina were prepared by assistance of ultrasound and plasma treatment.The prepared catalysts were characterized by FT-IR pyridine adsorption(Py-IR),temperature programmed desorption of Pyridine(Py-TPD),BET and X-ray diffraction(XRD),and their catalytic performances were evaluated by the cationic polymerization of tetrahydrofuran.The results indicate that plasma treatment remarkably increases the surface acidity of the prepared catalyst while ultrasonic treatment induces PW_(12)to uniformly disperse on the support surface and expose more active sites for the acid catalytic reaction.A higher catalytic activity(69.7%)is obtained on the novel catalyst,which significantly outstripped that on the conventional sample(57.5%).
文摘It is difficult to treat 2-amino-thiazoline-4-carboxylic acid (ATC) waste liquid effectively at present for its characteristics of high chemical oxygen demand (COD), high salinity and low biodegradability. In order to solve this problem, this paper presents several kinds of physical-chemical treatment unit techniques, including acid separation, catalytic oxidation and coagulation. First of all, acid separation was adopted to precipitate relevant organics at isoelectric point. When the temperature and pH value of acid separation were controlled at about 5 ℃ and 2.2 respectively, the COD removal rate could reach 27.600. Secondly, oxidation was used to break chemical constitution of refractory organics. The optimal reaction parameters of catalytic oxidation should be 20 ℃, pH adjusted to 5.0 and [Fe2+] 300 mg/L. Then with 500 H2O2 added and after one-hour reaction, the COD removal rate could achieve about 5200. Finally, coagulation was adopted to remove a portion of refractory organics, and 1500 polymeric molysite flocculant was the best for the coagulation, and the COD removal rate could reach about 1500. Therefore, the proposed feasible process of physical-chemical pretreatment for ATC waste liquid could have about 7000 COD removed in total.
文摘Lactobacillus species are non-spore-forming, gram-positive bacteria and lactic acid producing bacteria (LAPB) that naturally inhabit the human and animal gastrointestinal and mouth organs. The aim of this review was to evaluate the new progress regarding the use of Lactobacillus species as live delivery vectors, prevention, and treatment of pathogenic and metabolic diseases. Lactobacillus strains of probiotics have been extensively studied and have confirmed that they can absolutely improve performance as live delivery vectors, a treatment option of various diseases such as: Hemorrhagic cecal coccidiosis in young poultry, hypertension, avian flu, obesity, diabetes, Derzsy’s disease or parvovirus infection, human immunodeficiency virus infections, irritable bowel syndrome, gastrointestinal disorders, Fungal infections, vaginal eubiosis, fish and shellfish species diseases. We give you an idea about that Lactobacillus species have been proficient in preventing and treating both disorders in animal models and some are used for clinical trials. We present the most current studies on the use of Lactobacillus strains that had an impact on an effective immune response to a specific antigen because a variety of antigens have been expressed. Therefore Lactobacillus strains can be considered as good candidates because of its potential for diseases treatment and vaccine development as heterologous protein secretion to date.
基金This work was financially supported by the National Key Technologies R & D Program of China (Grant No. 2006BAC02A12), the National Natural Science Foundation of China (Grant No. 21003077), the Natural Science Foundation of Tianjin (Grant No. 08JCZDJC21400) and MOE (IRT 13R30).