摘要 :
Al contamination becomes a growing problem in human society. Accumulation of Al in blood could destroy the structure and disorder function of erythrocyte, and finally cause blood diseases. In the present study, AlCl3 and Al(malt)(...
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Al contamination becomes a growing problem in human society. Accumulation of Al in blood could destroy the structure and disorder function of erythrocyte, and finally cause blood diseases. In the present study, AlCl3 and Al(malt)(3) are respectively used in the erythrocyte system, in order to investigate the comparative toxic effect on erythrocyte fragility, the influence on cellular biochemical components and lipid peroxidation level. We find that the osmotic fragility, the number of Heinz bodies, the content of MDA and advanced oxidation protein product of the AlCl3 treated erythrocytes were higher than the Al(malt)(3) treated erythrocytes at the same concentrations of Al(III). The morphological and membrane protein changes of the AlCl3 treated group show superior to the Al (malt)(3) treated group. In summary, we conclude that the comparative effect on the erythrocyte between organic aluminum and inorganic aluminum is significantly different, and the prime comparative difference between the toxic effects of both the compounds is oxidative stress. Further research should focus on in vivo experiments to confirm the differential toxicity and to elucidate the molecular mechanisms underlying Al-induced erythrocyte toxicity in order to prevent hematological disorders.
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Reaction of malonic acid with Et _3Al results in the formation of the hexanuclear aluminum compound Et _(12)Al _6[CH(COO) _2] _2(THF) _2 (1) containing malonate trianion ligands. Molecular studies showed that the centrosymmetric m...
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Reaction of malonic acid with Et _3Al results in the formation of the hexanuclear aluminum compound Et _(12)Al _6[CH(COO) _2] _2(THF) _2 (1) containing malonate trianion ligands. Molecular studies showed that the centrosymmetric molecule of 1 consists of a tricyclic structure formed by a central four-membered Al _2O _2 ring and two six-membered AlO _2C _3 rings. All the aluminum atoms are four-coordinate. The compound showed low activity as an initiator of ε-caprolactone polymerization.
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Aluminum metal foil is the optimal choice as an anode material for aluminum-ion batteries for its key advantages such as high theoretical capacity, safety, and low cost. However, the metallic nature of aluminum foil is very likely...
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Aluminum metal foil is the optimal choice as an anode material for aluminum-ion batteries for its key advantages such as high theoretical capacity, safety, and low cost. However, the metallic nature of aluminum foil is very likely to induce severe dendrite growth with further electrode disintegration and cell failure, which is inconsistent with previous reports. Here, we discover that it is aluminum oxide film that efficiently restricts the growth of crystalline Al dendrite and thus improves the cycling stability of Al anode. The key role of surficial aluminum oxide film in protecting Al metal anode lies in decreasing the nucleation sites, controlling the metallic dendrite growth, and preventing the electrode disintegration. The defect sites in aluminum oxide film provide channels for electrolyte infiltration and further stripping/depositing. Attributed to such a protective aluminum oxide film, the Al-graphene full cells can attain up to 45 000 stable cycles.
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While the involvement of environmental aluminum toxicity in the advent of senile dementias is still debated, acute aluminum toxicity of iatrogenic origin is well documented. So far, the only treatment available against it has been...
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While the involvement of environmental aluminum toxicity in the advent of senile dementias is still debated, acute aluminum toxicity of iatrogenic origin is well documented. So far, the only treatment available against it has been desferrioxamine (DFO), which induces major side effects. New drugs are thus highly desirable, and possible DFO substitutes have already been considered through various techniques. An important test for such new drugs is to assess their Al-mobilizing capacity in vivo. This can be done by computer-aided speciation provided formation constants for the corresponding Al(III) complexes are known beforehand. The present work reports and investigation of Al(III) complex equilibria with five sequestering ligands including DFO, and predicts the respective capacities of these to mobilize aluminum in vivo under normal and inflammatory conditions.
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Despite their typically high Si content of up to 30 ma.-%, spray-formed Al alloys exhibit excellent nitridability in plasma processes. This results from the exclusive primary solidified and homogeneously dispersed small Si precipi...
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Despite their typically high Si content of up to 30 ma.-%, spray-formed Al alloys exhibit excellent nitridability in plasma processes. This results from the exclusive primary solidified and homogeneously dispersed small Si precipitates in the base material that occur due to the specific production process. Previous studies reported on the influence of the general technological parameters during plasma nitriding, such as temperature, time and gas composition, as well as chemical composition, of spray-formed Al alloys on their nitriding behavior. However, in connection with progress in automation of process control, such as, for example, in the case of steels, a significant influence of the adaptive control of the plasma duty cycle has been detected. In cases where the specific nitriding technology of direct current (DC) plasma nitriding is used with in situ sputter cleaning, the plasma duty cycle determines different processes that occur on the sample surface. The scope of this report covers both the influence of the duty plasma cycle and the initial surface characteristics, including the specimen shape. Despite equivalent general nitriding conditions (temperature, time, voltage), over time the plasma duty cycle and the target value of plasma duty lead to different thicknesses and coverage of the nitride layer. For a better understanding of the nitriding mechanism, analyses of interrupted nitriding tests were carried out. The results of plasma nitriding have been characterized by examining metallographic cross sections with optical microscopy, surface coverage by scanning electron microscopy (SEM), as well as measuring aluminum nitride layer thickness with different methods. Mechanical properties were studied using microindentation. Adhesion was tested by scratch tests.
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The sessile drop method has been used to determine the temperature dependence of the wetting of boride and borocarbide phases by molten aluminum and copper. Hot-pressed substrates have been used made of aluminum boride and borocar...
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The sessile drop method has been used to determine the temperature dependence of the wetting of boride and borocarbide phases by molten aluminum and copper. Hot-pressed substrates have been used made of aluminum boride and borocarbides, which are well wetted by aluminum above 1000 deg C. Aluminum borocarbide phases are not wetted by copper under these conditions. The temperature dependence is derived for the synthesis of finely divided aluminum boride and borocarbide powders from simple substances. Details are given of the nucleation and formation of an aluminum phase containing boron. The aluminum borides and borocarbides are formed not as a result of boration of the metal lattice (which occurs in the synthesis of transition-metal borides) but by metallation (alumination) of the boron lattice.
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A chemical method with reaction of aluminum alloy D16 and aqueous sodium hydroxide solution is used to prepare very fine aluminum hydroxide powder. It is established by x-ray phase analysis that the powder obtained consists of thr...
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A chemical method with reaction of aluminum alloy D16 and aqueous sodium hydroxide solution is used to prepare very fine aluminum hydroxide powder. It is established by x-ray phase analysis that the powder obtained consists of three aluminum oxide modifications: gibbsite, boehmite, and bayerite. It is shown by laser diffraction that within an aluminum oxide suspension there is extensive bimodal distribution of particle size distribution (0.4 - 190 mu m). The powder obtained is a precursor for preparing aluminum oxide ceramic.
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This paper is focused on evaluating the influence of iron content on SDAS factor, Al5FeSi phase size, and porosity of secondary aluminum alloy AlSi7Mg0.6 used in the automotive industry. These characteristics were evaluated by qua...
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This paper is focused on evaluating the influence of iron content on SDAS factor, Al5FeSi phase size, and porosity of secondary aluminum alloy AlSi7Mg0.6 used in the automotive industry. These characteristics were evaluated by quantitative analysis on sand-casted experimental alloys with various iron contents (0.128; 0.202; 0.429; 0.75; 1.264 %). Results have shown a decrease of SDAS factor with increasing of iron content. Al5FeSi phase average length and thickness values increased with the rising iron content. These dependencies began to reveal themselves when the iron content reached values around the critical value of the iron content - Fecrit.(0.475 % Fe). The average area of pores (2.05 - 3.8 %) and pore size (39 597 - 70 332 μm2) increased with increasing of iron content (0.128; 0.75; 1.264 %) too.
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In the present investigation, aluminum nitrate nonahydrate Al(NO_3)_3·9H_2O has been prepared using aluminum trihydrate Al(OH)_3 as precursor. The reactivity of aluminum trihydrate toward nitric acid was studied as a function of...
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In the present investigation, aluminum nitrate nonahydrate Al(NO_3)_3·9H_2O has been prepared using aluminum trihydrate Al(OH)_3 as precursor. The reactivity of aluminum trihydrate toward nitric acid was studied as a function of water of crystallization, concentration of nitric acid, pressure, reaction time, surface area and aging. It was found dependent primarily on ignition and subsequently on other factors. During ignition, the crystalline phase transformed from gibbsite to amorphous alumina via boehmite with the ultimate reduction of reactivity to half. It was further found that nitric acid either decomposed into nitrite ions or in excess pacifies the reaction. Moreover, aging of precursor in nitric acid and its exposed surface area had critical effect on the reaction time and profoundly increased the percentage yield of aluminum nitrate nonahydrate.
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