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Effects of boric acid on microstructure and corrosion resistance of boric/sulfuric acid anodic film on 7050 aluminum alloy 被引量:13
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作者 杜楠 王帅星 +1 位作者 赵晴 邵志松 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第7期1655-1660,共6页
The microstructure and corrosion resistance of different boric/sulfuric acid anodic(BSAA) films on 7050 aluminum alloy were studied by atomic force microscopy(AFM),electrochemical impedance spectroscopy(EIS) and... The microstructure and corrosion resistance of different boric/sulfuric acid anodic(BSAA) films on 7050 aluminum alloy were studied by atomic force microscopy(AFM),electrochemical impedance spectroscopy(EIS) and scanning Kelvin probe(SKP).The results show that boric acid does not change the structure of barrier layer of anodic film,but will significantly affect the structure of porous layer,consequently affect the corrosion resistance of anodic film.As the content of boric acid in electrolyte increases from 0 to 8 g/L,the resistance of porous layer(Rp) of BSAA film increases,the capacitance of porous layer(CPEp) decreases,the surface potential moves positively,the pore size lessens,and the corrosion resistance improves.However,the Rp,CPEp and surface potential will change towards opposite direction when the content of boric acid is over 8 g/L. 展开更多
关键词 aluminum alloy anodic film corrosion resistance boric acid
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Influence of adipic acid on anodic film formation and corrosion resistance of 2024 aluminum alloy 被引量:4
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作者 李英东 张优 +1 位作者 李松梅 赵丕植 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第2期492-500,共9页
The influence of adipic acid on the formation and corrosion resistance of anodic oxide film fabricated on 2024 aluminum alloy was investigated. The morphology was investigated by scanning electron microscopy (SEM) a... The influence of adipic acid on the formation and corrosion resistance of anodic oxide film fabricated on 2024 aluminum alloy was investigated. The morphology was investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. The corrosion resistance was evaluated by electrochemical impedance spectroscopy (EIS). The results showed that the adipic acid was absorbed at the electrolyte/anodic layer interface during anodizing. The corrosion rate of anodic film decreased and the film thickness increased. The film was uniform and compact especially at the film/substrate interface. After sealing procedure, anodic film formed with the addition of adipic acid exhibited improved dielectric property and corrosion resistance in aggressive environment. 展开更多
关键词 aluminum alloy anodic oxidation adipic acid ADSORPTION CORROSION
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Callus Induction of Alfalfa and Evaluation of Callus Tolerance to Acid and Aluminum 被引量:2
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作者 吴丽芳 魏晓梅 +1 位作者 张鸭关 陆伟东 《Agricultural Science & Technology》 CAS 2014年第7期1079-1081,1130,共4页
Medicago is an important grass in the legume family,which is suitable to be grown in neutral or alkalescent soils,and hence,can be widely spread in south of China with low pH value.It is one of major objectives to cul... Medicago is an important grass in the legume family,which is suitable to be grown in neutral or alkalescent soils,and hence,can be widely spread in south of China with low pH value.It is one of major objectives to cultivate acid-aluminum tolerant species.In the research,6 high-quality species with high-yielding potential were taken as materials to make evaluation on acid-aluminum tolerance by cell-culture technique,and the results showed that tolerance capacity from high to low was GT13R>Muge 701=Muge 702>Acrora>AC-3>Sheshou No.2=Medicago sativa. 展开更多
关键词 Medicago sativa L. CALLUS Tolerance to acid and aluminum EVALUATION
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Extraction and characterization of alumina nanopowders from aluminum dross by acid dissolution process 被引量:25
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作者 Saifur Rahman Sarker Zahangir Alam +2 位作者 Rakibul Qadir M A Gafur Mohammad Moniruzzaman 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2015年第4期429-436,共8页
A significant amount of aluminum dross is available as a waste in foundry industries in Bangladesh. In this study, alumina was ex- tracted from aluminum dross collected from two foundry industries situated in Dhamrai ... A significant amount of aluminum dross is available as a waste in foundry industries in Bangladesh. In this study, alumina was ex- tracted from aluminum dross collected from two foundry industries situated in Dhamrai and Manikgang, near the capital city, Dhaka. Alu- minum dross samples were found to approximately contain 75wt% A1203 and 12wt% SIO2. An acid dissolution process was used to recover the alumina value from the dross. The effects of various parameters, e.g., temperature, acid concentration, and leaching time, on the extrac- tion of alumina were studied to optimize the dissolution process. First, AI(OH)3 was produced in the form of a gel. Calcination of the AI(OH)3 gel at 1000℃, 1200℃, and 1400℃ for 2 h produced O-AlcOa, (t~+O)-A1203, and u-alumina powder, respectively. Thermal charac- terization of the AI(OH)3 gel was performed by thermogravimetric/differential thermal analysis (TG/DTA) and differential scanning calo- rimetry (DSC). The phases and crystallite size of the alumina were determined by X-ray diffraction analysis. The dimensions of the alumina were found to be on the nano level. The chemical compositions of the aluminum dross and alumina were determined by X-ray fluorescence (XRF) spectroscopy. The microstructure and morphology of the alumina were studied with scanning electron microscopy. The purity of the alumina extracted in this study was found to be 99.0%. Thus, it is expected that the obtained alumina powders can be potentially utilized as biomaterials. 展开更多
关键词 aluminum dross ALUMINA NANOPARTICLES acid dissolution CALCINATION X-ray fluorescence analysis
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ATR-FTIR and XPS study on the structure of complexes formed upon the adsorption of simple organic acids on aluminum hydroxide 被引量:8
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作者 GUAN Xiao-hong CHEN Guang-hao SHANG Chii 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2007年第4期438-443,共6页
Information on the binding of organic ligands to metal (hydr)oxide surfaces is useful for understanding the adsorption behaviour of natural organic matter on metal (hydr)oxide. In this study, benzoate and salicyla... Information on the binding of organic ligands to metal (hydr)oxide surfaces is useful for understanding the adsorption behaviour of natural organic matter on metal (hydr)oxide. In this study, benzoate and salicylate were employed as the model organic ligands and aluminum hydroxide as the metal hydroxide. The attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectra revealed that the ligands benzoate and salicylate do coordinate directly with the surface of hydrous aluminum hydroxide, thereby forming innersphere surface complexes. It is concluded that when the initial pH is acidic or neutral, monodentate and bridging complexes are to be formed between benzoate and aluminum hydroxide while bridging complexes predominate when the initial pH is alkalic. Monodentate and bridging complexes can be formed at pH 5 while precipitate and bridging complexes are formed at pH 7 when salicylate anions are adsorbed on aluminum hydroxide. The X-ray photoelectron (XP) spectra demonstrated the variation of C 1 s binding energy in the salicyate and phenolic groups before and after adsorption. It implied that the benzoate ligands are adsorbed through the complexation between carboxylate moieties and the aluminum hydroxide surface, while both carboxylate group and phenolic group are involved in the complexation reaction when salicylate is adsorbed onto aluminum hydroxide. The information offered by the XPS confirmed the findings obtained with ATR-FTIR. 展开更多
关键词 ADSORPTION aluminum hydroxide benzoic acid COMPLEXATION natural organic matter salicylic acid
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Effects of fulvic acid and humic acid on aluminum speciation in drinking water 被引量:6
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作者 Wendong Wang Hongwei Yang +2 位作者 Xiaochang Wang Jing Jiang Wanpeng Zhu 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2010年第2期211-217,共7页
This article focused on the influences of fulvic acid and humic acid on aluminum speciation in drinking water. Factors including the concentration of residual chlorine and pH value had been concerned. Aluminum species... This article focused on the influences of fulvic acid and humic acid on aluminum speciation in drinking water. Factors including the concentration of residual chlorine and pH value had been concerned. Aluminum species investigated in the experiments included inorganic mononuclear, organic mononuclear, mononuclear, polymer, soluble, and suspended forms. It was found that the effects of fulvic acid and humic acid on aluminum speciation depended mainly on their molecular weight. Fulvic acid with molecular weight less than 5000 Dalton had little influence on aluminum speciation; while fulvic acid with molecular weight larger than 5000 Dalton and humic acid would increase the concentration of soluble aluminum significantly even at concentration below 0.5 mg/L (calculated as TOC). Aluminum species, in the present of fulvic acid with molecular weight larger than 5000 Dalton and humic acid, were more stable than that in the present of fluvic acid with molecular mass less than 5000 Dalton, and varied little with reaction time. Within pH range 6.5-7.5, soluble aluminum increased notably in water with organic matter. As the concentration of residual chlorine increased, the effects of fulvic acid and humic acid became weak. The reactions between humic acid, fulvic acid with large molecular weight, and aluminum were considered to be a multi-dentate coordination process. With the consideration of aluminum bioavailability, reducing the concentration of fulvic acid and humic acid and keeping the pH value among 6.5-7.5 were recommended during drinking water treatment. 展开更多
关键词 aluminum species drinking water fluorometric method fulvic acid humic acid
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A review: The beneficial effects and possible mechanisms of aluminum on plant growth in acidic soil 被引量:5
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作者 Noor Muhammad Gerald Zvobgo ZHANG Guo-ping 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2019年第7期1518-1528,共11页
Aluminum(Al) is the third most abundant element in the earth’s crust and a major factor inhibiting plant growth and reducing crop yield in acidic soil.Although there is substantial research on the phytotoxic effects ... Aluminum(Al) is the third most abundant element in the earth’s crust and a major factor inhibiting plant growth and reducing crop yield in acidic soil.Although there is substantial research on the phytotoxic effects and the underlying mechanisms of Al by applying Al alone hydroponically,soil is a complex medium containing numerous mineral elements that can interact with Al and other elements and their bioavailability in plants.In this review,we describe the roles of Al in promoting plant growth,enhancing phosphorus availability and efficient use in plants,and alleviating H+,iron,and manganese toxicity in acidic conditions.Furthermore,we discuss the possible mechanisms of enhanced abiotic stress tolerance induced by Al.We also elucidate the role of Al in attracting plant growth promoting rhizo-bacteria(PGPR) and their interactions with plants by increasing organic exudates. 展开更多
关键词 aluminum interaction IRON MANGANESE ORGANIC acidS phosphorous TOLERANCE
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Effects of acetic acid on microstructure and electrochemical properties of nano cerium oxide films coated on AA7020-T6 aluminum alloy 被引量:7
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作者 H. Hasannejad T. Shahrabi M. Aliofkhazraei 《Rare Metals》 SCIE EI CAS CSCD 2009年第1期98-101,共4页
Nano cerium oxide films were applied on AA7020-T6 aluminum alloy and the effects of acetic acid concentration on the microstructure and electrochemical properties of the coated samples were investigated by using scann... Nano cerium oxide films were applied on AA7020-T6 aluminum alloy and the effects of acetic acid concentration on the microstructure and electrochemical properties of the coated samples were investigated by using scanning electron microscopy (SEM), X-ray diffraction (XRD), and potentiodynamic polarization methods. It has been found that by increasing the acetic acid/CeCl3·7H2O molar ratio, high uniform and crack-free films with well-developed grains were obtained and grain sizes of the films decreased. Elimination of cracks and decreasing grain size of the nano cerium oxide films caused corrosion resistance to increase. 展开更多
关键词 nano cerium oxide films acetic acid aluminum alloy electrochemical property MICROSTRUCTURE
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Dissolution of Aluminum in Variably Charged Soils as Affected by Low-Molecular-Weight Organic Acids 被引量:23
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作者 LI Jiu-Yu XU Ren-Kou JI Guo-Liang 《Pedosphere》 SCIE CAS CSCD 2005年第4期484-490,共7页
Low-molecular-weight (LMW) organic acids exist widely in soils and play an important role in soil processes such as mineral weathering, nutrient mobilization and A1 detoxification. In this research, a batch experime... Low-molecular-weight (LMW) organic acids exist widely in soils and play an important role in soil processes such as mineral weathering, nutrient mobilization and A1 detoxification. In this research, a batch experiment was conducted to examine the effects of LMW organic acids on dissolution of aluminum in two variably charged soils, an Ultisol and an Oxisol. The results showed that the LMW organic acids enhanced the dissolution of A1 in the two investigated soils in the following order: citric 〉 oxalic 〉 malonic 〉 malic 〉 tartaric 〉 salicylic 〉 lactic 〉 maleic. This was generally in agreement with the magnitude of the stability constants for the Al-organic complexes. The effects of LMW organic acids on Al dissolution were greater in the Ultisol than in the Oxisol as compared to their controls. Also, the accelerating effects of citric and oxalic acids on dissolution of A1 increased with an increase in pH, while the effects of lactic and salicylic acids decreased. Additionally, when the organic acid concentration was less than 0.2 mmol L-I, the dissolution of A1 changed Iittle with increase in acid concentration. However, when the organic acid concentration was greater than 0.2 mmol L^-1,the dissolution of A1 increased with increase in acid concentration. In addition to the acid first dissociation constant and stability constant of Al-organic complexes, the promoting effects of LMW organic acids on dissolution of A1 were also related to their sorption-desorption equilibrium in the soils. 展开更多
关键词 aluminum dissolution low-molecular-weight organic acid variably charged soil
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Chemical Species of Aluminum Ions in Acid Soils *1 被引量:8
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作者 XURENKOU JIGUOLIANG 《Pedosphere》 SCIE CAS CSCD 1998年第2期127-133,共7页
Soil samples collected from several acid soils in Guangdong, Fujian, Zhejiang and Anhui provinces of the southern China were employed to characterize the chemical species of aluminum ions in the soils. The proportio... Soil samples collected from several acid soils in Guangdong, Fujian, Zhejiang and Anhui provinces of the southern China were employed to characterize the chemical species of aluminum ions in the soils. The proportion of monomeric inorganic Al to total Al in soil solution was in the range of 19% to 70%, that of monomeric organic Al (Al OM) to total Al ranged from 7.7% to 69%, and that of the acid soluble Al to total Al was generally smaller and was lower than 20% in most of the acid soils studied. The Al OM concentration in soil solution was positively correlated with the content of dissolved organic carbon (DOC) and also affected by the concentration of Al 3+ . The complexes of aluminum with fluoride (Al F) were the predominant forms of inorganic Al, and the proportion of Al F complexes to total inorganic Al increased with pH. Under strongly acid condition, Al 3+ was also a major form of inorganic Al, and the proportion of Al 3+ to total inorganic Al decreased with increasing pH. The proportions of Al OH and Al SO 4 complexes to total inorganic Al were small and were not larger than 10% in the most acid soils. The concentration of inorganic Al in solution depended largely on pH and the concentration of total F in soil solution. The concentrations of Al OM, Al 3+ ,Al F and Al OH complexes in topsoil were higher than those in subsoil and decreased with the increase in soil depth. The chemical species of aluminum ions were influenced by pH. The concentrations of Al OM, Al 3+ , Al F complexes and Al OH complexes decreased with the increase in pH. 展开更多
关键词 acid soil aluminum ion chemical species
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Liver injury after aluminum potassium sulfate and tannic acid treatment of hemorrhoids 被引量:6
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作者 Kenichi Yoshikawa Reimi Kawashima +13 位作者 Yuki Hirose Keiko Shibata Takafumi Akasu Noriko Hagiwara Takeharu Yokota Nami Imai Akira Iwaku Go Kobayashi Hirohiko Kobayashi Akiyoshi Kinoshita Nao Fushiya Hiroyuki Kijima Kazuhiko Koike Masayuki Saruta 《World Journal of Gastroenterology》 SCIE CAS 2017年第27期5034-5040,共7页
We are reporting a rare case of acute liver injury that developed after an internal hemorrhoid treatment with the aluminum potassium sulfate and tannic acid(ALTA) regimen. A 41-year-old man developed a fever and liver... We are reporting a rare case of acute liver injury that developed after an internal hemorrhoid treatment with the aluminum potassium sulfate and tannic acid(ALTA) regimen. A 41-year-old man developed a fever and liver injury after undergoing internal hemorrhoid treatment with a submucosal injection of ALTA with lidocaine. The acute liver injury was classified clinically as hepatocellular and pathologically as cholestastic. We could not classify the mechanism of injury. High eosinophil and immunoglobulin E levels characterized the injury,and a drug lymphocyte stimulation test was negative on postoperative day 25. Fluid replacement for two weeks after hospitalization improved the liver injury. ALTA therapy involves injecting chemicals into the submucosa,from the rectum to the anus,and this is the first description of a case that developed a severe liver disorder after this treatment; hence,an analysis of future cases as they accumulate is desirable. 展开更多
关键词 aluminum potassium sulfate and tannic acid injection aluminum potassium sulfate and tannic acid therapy Rectal submucosal injection Drug-induced lymphocyte stimulation test Drug-induced liver injury
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Aluminum potassium sulfate and tannic acid sclerotherapy for Goligher Grades Ⅱ and Ⅲ hemorrhoids: Results from a multicenter study 被引量:11
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作者 Hidenori Miyamoto Takenori Hada +2 位作者 Gentaro Ishiyama Yoshito Ono Hideo Watanabe 《World Journal of Hepatology》 CAS 2016年第20期844-849,共6页
AIM: To show that aluminum potassium sulfate and tannic acid(ALTA) sclerotherapy has a high success rate for Grade Ⅱ and Ⅲ hemorrhoids.METHODS: This study was based on the clinical data of 604 patients with hemorrho... AIM: To show that aluminum potassium sulfate and tannic acid(ALTA) sclerotherapy has a high success rate for Grade Ⅱ and Ⅲ hemorrhoids.METHODS: This study was based on the clinical data of 604 patients with hemorrhoids who underwent ALTA sclerotherapy between January 2009 and February 2015. The objective of this study was to assess the efficacy of this treatment for Grades Ⅱ and Ⅲ hemorrhoids. Preoperative and postoperative symptoms, complications and success rate were all assessed retrospectively. Follow-up consisted of a simple questionnaire, physical examination and an anoscopy. Patients were followed-up at one day, one week, two weeks, one month, one year, two years, three years, four years and five years after the ALTA sclerotherapy.RESULTS: One hundred and sixty-nine patients were diagnosed with Grade Ⅱ hemorrhoids and 435 patients were diagnosed with Grade Ⅲ hemorrhoids. The one year, three year and five year cumulative success rates of ALTA sclerotherapy for Grades Ⅱ and Ⅲ hemo-rrhoids were 95.9% and 93.1%; 89.3% and 83.7%; and 89.3% and 78.2%, respectively. No significant differences were observed in the cumulative success rates after ALTA sclerotherapy between Grades Ⅱ and Ⅲ hemorrhoids(P = 0.09). There were forty-seven post-operative complications(low grade fever; anal pain; urinary retention; rectal ulcer; and others). No serious or life-threatening complications occurred and all cases improved through conservative treatment. At univariate analysis there were no predictive factors of failure.CONCLUSION: ALTA sclerotherapy has had a high success rate for Grade Ⅱ and Ⅲ hemorrhoids during five years of post-operative treatment. However, additional studies are needed to evaluate the efficacy of this ALTA sclerotherapy in the management of hemorrhoidal disease. 展开更多
关键词 SCLEROTHERAPY aluminum potassium sulfate and tannic acid Goligher grade Minimally invasive treatment HEMORRHOID
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Effects of Subchronic Aluminum Exposure on Amino Acids Neurotransmitters in Chicken Brain 被引量:2
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作者 Han Yan-fei Xia Shi-liang +2 位作者 Bai Chong-sheng Zhang Ji-hong Li Yan-fei 《Journal of Northeast Agricultural University(English Edition)》 CAS 2012年第4期58-61,共4页
To investigate the effects of aluminium (Al) exposure on amino acid neurotransmitters, the chickens with different levels of subchronic Al poisoning were estabolished by continuous peritoneal injection of fixed volu... To investigate the effects of aluminium (Al) exposure on amino acid neurotransmitters, the chickens with different levels of subchronic Al poisoning were estabolished by continuous peritoneal injection of fixed volume and different concentrations of gradient of aluminium trichloride (AlCl3). The levels of amino acid neurotransmitters in chicken brains were determined by high performance liquid chromatography (HPLC) after being exposed of Al for 60 days, and Al levels in serum and brain tissue were determined by atomic absorption spectrophotometry (AAS). The results showed that Glu levels increased with the increase of Al, but there was no significant difference compared with the control. The levels of Al, Asp, Gly, GABA and Tau were significantly higher in Al-treated groups than those in the control. The results indicated that Al intoxication led to excitatory neurotoxicity. 展开更多
关键词 subchronic aluminum exposure CHICKEN BRAIN amino acid neurotransmitters
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Thermal stability and oil absorption of aluminum hydroxide treated by dry modification with phosphoric acid 被引量:3
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作者 周向阳 李昌林 +3 位作者 霍登伟 李劼 伍上元 刘业翔 《Journal of Central South University of Technology》 EI 2007年第6期779-782,共4页
The dry modification of aluminum hydroxide powders with phosphoric acid and the effects of modification of technological conditions on thermal stability, morphology and oil absorption of aluminum hydroxide powders wer... The dry modification of aluminum hydroxide powders with phosphoric acid and the effects of modification of technological conditions on thermal stability, morphology and oil absorption of aluminum hydroxide powders were investigated. The results show that the increase of mass ratio of phosphoric acid to aluminum hydroxide, the decrease of mass concentration of phosphoric acid and prolongation of mixing time are favorable to the improvement of thermal stability of aluminum hydroxide; when the mass ratio of phosphoric acid to aluminum hydroxide is 5:100, the mass concentration of phosphoric acid is 200 g/L and the mixing time is 10 min, the initial temperature of loss of crystal water in aluminum hydroxide rises from about 192.10 to 208.66 ℃, but the dry modification results in the appearance of agglomeration and macro-aggregate in the modified powders, and the oil absorption of modified powders becomes higher than that of original aluminum hydroxide. 展开更多
关键词 aluminum hydroxide phosphoric acid thermal stability oil absorption dry modification
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Effects of applied potential on the stress corrosion cracking behavior of 7003 aluminum alloy in acid and alkaline chloride solutions 被引量:6
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作者 Xiao-yan Zhang Ren-guo Song +2 位作者 Bin Sun Hai Lu Chao Wang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2016年第7期819-826,共8页
Potentiodynamic polarization tests and slow strain rate test(SSRT) in combination with fracture morphology observations were conducted to investigate the stress corrosion cracking(SCC) behavior of 7003 aluminum al... Potentiodynamic polarization tests and slow strain rate test(SSRT) in combination with fracture morphology observations were conducted to investigate the stress corrosion cracking(SCC) behavior of 7003 aluminum alloy(AA7003) in acid and alkaline chloride solutions under various applied potentials(Ea). The results show that AA7003 is to a certain extent susceptible to SCC via anodic dissolution(AD) at open-circuit potential(OCP) and is highly susceptible to hydrogen embrittlement(HE) at high negative Ea in the solutions with p H levels of 4 and 11. The susceptibility increases with negative shift in the potential when Ea is less than-1000 m V vs. SCE. However, the susceptibility distinctly decreases because of the inhibition of AD when Ea is equal to-1000 m V vs. SCE. In addition, the SCC susceptibility of AA7003 in the acid chloride solution is higher than that in the alkaline solution at each potential. Moreover, the effect of hydrogen on SCC increases with increasing hydrogen ion concentration. 展开更多
关键词 aluminum alloys stress corrosion cracking susceptibility hydrogen embrittlement potential acid solutions alkaline solutions
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Sequential Extraction of Aluminum and Iron from Acidic Soils by Chemical Selective Dissolution Methods 被引量:1
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作者 HEJIZHENG A.VIOLANTE 《Pedosphere》 SCIE CAS CSCD 1998年第1期37-44,共8页
Potassium chloride, Na-pyrophosphate, CuCl2, NH4-oxalate, dithionite-citrate-bicarbonate (DCB) and Na-citrate solutions were employed to extract aluminum (Al) and iron (Fe) sequentially and separately from 15 acidic s... Potassium chloride, Na-pyrophosphate, CuCl2, NH4-oxalate, dithionite-citrate-bicarbonate (DCB) and Na-citrate solutions were employed to extract aluminum (Al) and iron (Fe) sequentially and separately from 15 acidic soils located at the Mangshan Mountains, Hunan Province, China. Many evidences showed that separate pyrophosphate extracted mainly KCI-extractable Al, organo-Al complexes and some inorganic Al compounds, whereas separate CuCl2 extracted KCl-extractable Al and some organo-Al complexes. CuCl2 extracted much less amounts of Al than pyrophosphate did from the soils. Separate oxalate did not extract all KCl-Pyrophosphate- CuCl2 -oxalate sequentially extractable Al and Fe. Also, separate DCB did not extract all KCl- pyrophosphate- CuCl2 -oxalate- DCB sequentially extractable Al. The forms of Al extracted by oxalate and DCB from the soils were majorly noncrystalline. The interlayered materials of 1.4-nm intergrade minerals of the soils were attributed mainly to hydroxy Al polymers. 展开更多
关键词 acidic soil aluminum forms chemical selective dissolution
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Salicylic Acid Alleviates Aluminum Toxicity in Tomato Seedlings (Lycopersicum esculentum Mill.) through Activation of Antioxidant Defense System and Proline Biosynthesis 被引量:1
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作者 Varalakshmi Surapu Anjaneyulu Ediga Balaji Meriga 《Advances in Bioscience and Biotechnology》 2014年第9期777-789,共13页
The aim of this work was to evaluate the alleviating efficacy of salicylic acid (100, 250 and 500 μM) against the toxic effects of aluminum (Al) on two tomato cultivars (GOWRI and SIRI) differing in their sensitivity... The aim of this work was to evaluate the alleviating efficacy of salicylic acid (100, 250 and 500 μM) against the toxic effects of aluminum (Al) on two tomato cultivars (GOWRI and SIRI) differing in their sensitivity to Al stress. Al treatment (500 μM) caused 40% - 80% drop in plant growth, relative water content (RWC) and cell viability and a reduction of 1 - 2.5 fold and 0.5 - 2 fold in glutathione and proline content respectively, when compared to their control plants grown in Al free medium. Al treatment also resulted in 2 - 5 fold raise in malondialdehyde (MDA) levels, 2 - 3 fold higher Al uptake and 55% - 80% more electrolyte leakage and caused severe DNA damage. Al stress enhanced (1 - 2 fold) the activities of superoxide dismutase (SOD) and peroxidase (POD), but decreased catalase (CAT) activity over their respective controls. Exogenously-applied Salicylic acid (SA) significantly (p < 0.05) and dose-dependently alleviated Al-induced toxicity in tomato seedlings as marked by much improved plant growth, retention of higher RWC, cell viability, glutathione and proline content. SA also caused 0.6 - 1.5 fold reduction in Al uptake, 50% - 80% less electrolyte leakage, 40% - 80% drop in lipid peroxidation and considerable protection against DNA damage. Also, supplementation of SA could considerably reverse the Al-induced changes in the activities of SOD, POD and CAT. Together, our findings demonstrate that, SA is an efficient growth regulator with diversified roles that contribute to its potential alleviating effect against Al induced toxicity and SIRI is a relatively Al-resistant cultivar compared to GOWRI. 展开更多
关键词 aluminum ANTIOXIDANT ENZYMES PROLINE MALONDIALDEHYDE Salicylic acid
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Aluminum(Ⅲ) triflate-catalyzed selective oxidation of glycerol to formic acid with hydrogen peroxide 被引量:1
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作者 Kang Kong Difan Li +3 位作者 Wenbao Ma Qingqing Zhou Guoping Tang Zhenshan Hou 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2019年第4期534-542,M0003,共10页
Glycerol is a by-product of biodiesel production and is an important readily available platform chemical.Valorization of glycerol into value-added chemicals has gained immense attention.Herein,we carried out the conve... Glycerol is a by-product of biodiesel production and is an important readily available platform chemical.Valorization of glycerol into value-added chemicals has gained immense attention.Herein,we carried out the conversion of glycerol to formic acid and glycolic acid using H2O2 as an oxidant and metal(Ⅲ)triflate-based catalytic systems.Aluminum(Ⅲ)triflate was found to be the most efficient catalyst for the selective oxidation of glycerol to formic acid.A correlation between the catalytic activity of the metal cations and their hydrolysis constants(Kh)and water exchange rate constants was observed.At 70 ℃,a formic acid yield of up to 72% could be attained within 12 h.The catalyst could be recycled at least five times with a high conversion rate,and hence can also be used for the selective oxidation of other biomass platform molecules.Reaction kinetics and 1H NMR studies showed that the oxidation of glycerol(to formic acid)involved glycerol hydrolysis pathways with glyceric acid and glycolic acid as the main intermediate products.Both the [Al(OH)x]^n+ Lewis acid species and CF3SO3H Brosted acid,which were generated by the in-situ hydrolysis of Al(OTf)3,were responsible for glycerol conversion.The easy availability,high efficiency,and good recyclability of Al(OTf)3 render it suitable for the selective oxidation of glycerol to high value-added products. 展开更多
关键词 aluminum(Ⅲ)triflate GLYCEROL Hydrogen peroxide Selective oxidation Formic acid
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Aluminum Contents in Dry Leaves and Infusions of Commercial Black and Green Tea Leaves: Effects of Sucrose and Ascorbic Acid Added to Infusions 被引量:1
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作者 Diego Armando Bárcena-Padilla Marisela Bernal-González +2 位作者 Amalia Panizza-de-León Rolando Salvaor García-Gómez Carmen Durán-Domínguez-de-Bazúa 《Natural Resources》 2011年第3期141-145,共5页
Tea consumption has increased due to its beneficial effects. Results from a lab study on the effect of sucrose (5 g per cup, 150 mL) and/or ascorbic acid (2 mL per cup, 150 mL) on dissolved aluminum compounds during t... Tea consumption has increased due to its beneficial effects. Results from a lab study on the effect of sucrose (5 g per cup, 150 mL) and/or ascorbic acid (2 mL per cup, 150 mL) on dissolved aluminum compounds during the infusion of two commercial types of dry tea leaves (black, green) with boiling water (5, 15 min infusion time) are presented. Factors influencing the presence of dissolved aluminum in the infusions of both tea leaves were infusion time and sugar contents, as well as the interaction between ascorbic acid and sucrose (p < 0.05). Aluminum contents found after 15 min of infusion were 0.7 mg L–1 for black tea infusions added with sugar, and 0.69 mg L–1 for green tea added with both sugar and ascorbic acid. Both concentrations are higher than the level accepted in Mexico for drinking water (there is no act concerning tea infusions), that is 0.2 mg L–1. 展开更多
关键词 aluminum Contents COMMERCIAL BLACK and Green Tea DRY LEAVES INFUSIONS SUCROSE Ascorbic acid
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Preparation of anodic films on 2024 aluminum alloy in boric acid-containing mixed electrolyte 被引量:8
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作者 马淞江 罗鹏 +2 位作者 周海晖 付超鹏 旷亚非 《中国有色金属学会会刊:英文版》 EI CSCD 2008年第4期825-830,共6页
The anodizing oxidation process on 2024 aluminum alloy was researched in the mixed electrolyte with the composition of 30 g/L boric acid, 2 g/L sulfosalicylic acid and 8 g/L phosphate. The results reveal that the pre-... The anodizing oxidation process on 2024 aluminum alloy was researched in the mixed electrolyte with the composition of 30 g/L boric acid, 2 g/L sulfosalicylic acid and 8 g/L phosphate. The results reveal that the pre-treatment and the composition of the mixed electrolyte have influence on the properties of the films and the anodizing oxidation process. Under the condition of controlled potential, the anodizing oxidation current—time response curve displays "saddle" shape. First, the current density reaches a peak value of 8-20 A/dm2 and then decreases rapidly, finally maintains at 1-2 A/dm2. The film prepared in the mixed electrolyte is of porous-type with 20 nm in pore size and 500 μm-2 in porosity. Compared with the conventional anodic film obtained in sulfuric acid, the pore wall of the porous layer prepared in this work is not continuous, which seems to be deposited by small spherical grains. This porous structure of the anodic film may result from the characteristics of the mixed electrolyte and the special anodizing oxidation process. The surface analysis displays that the anodic film is amorphous and composed of O, Al, C, P, S, Si and no copper element is detected. 展开更多
关键词 2024铝合金 硼酸 混合电解液 阳极电镀 阳极薄膜
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