Effect of some cement components on ion contents in different brain areas of adult male albino mice

The aim of this study is to investigate the chronic effect of some cement components on the content of ions in different brain areas in adult male albino mice. It is clear that chronic intraperitoneal administration of 0.0013 mg/g aluminum ion caused a significant increase in aluminum, calcium and sodium ions and significant decrease in iron ions, the chronic intraperitoneal administration of 0.00065 mg/g iron caused a significant increase in iron, calcium, and sodium ions but No significant change in potassium and aluminum ions. Chronic intraperitoneal administration of 0.0013 mg/g silicon caused no significant change in calcium, potassium, sodium, aluminum and iron. Chronic intraperitoneal administration of 0.0013 mg/g aluminum, 0.0013 mg/g silicon and 0.00065 mg/g iron, respectively, --using separating time interval 30 min between each--caused a higher elevation in calcium, sodium, aluminum and iron concentrations than the elevation in other groups and no significant change in potassium ions. This may be due to the elevation in glutamate which leads to increase in the intracellular of calcium concentration and the inhibition of membrane-bound Na(+), K(+), Ca(2+) ATPase activity which lead to cellular alterations and may be death. So long-term exposure to cement components as environmental pollutants may lead to neurodegenerative diseases.     

化铣液稀释比及温度变化对Al3+去除率的影响

为了减少化铣液的报废,通过采用纯水对化铣液进行稀释及其温度变化,得出了化铣液中Al3+和NaOH成分的变化状态。结果表明:(1)稀释比为1.0~3.0,温度为25℃时,结晶时间小于8 d,Al3+基本无消除,8~14 d时Al3+去除率上升到60%;(2)同样的稀释倍数,温度55℃时,结晶时间为2 d时,Al3+去除率为10%,4~6 d时,Al3+去除率上升到25%(稀释比为1.0)~40%(稀释比为2.0),多于6 d去除率基本维持不变;(3)在Al3+去除过程中,NaOH的浓度基本保持不变。     

Mechanochemical synthesis of a hydroxycarbonate form of layered magnesium aluminum hydroxides

Mechanical activation of a mixture of magnesium hydroxide, aluminum hydroxide, and sodium bicarbonate in an AGO-2 planetary mill, followed by water washing leads to the formation of a layered magnesium aluminum hydroxide. The double hydroxide obtained at a magnesium hydroxide to aluminum hydroxide ratio of 3:1 is essentially phase-pure and contains both carbonate and bicarbonate ions in its interlayer spaces. The synthesized double hydroxide was characterized by x-ray diffraction, IR spectroscopy, thermogravimetry, differential thermal analysis, and chemical analysis.     

Influence of the heat treatment procedure and irradiation on the structure of the anionic motif and crystallization of uranium-containing phosphate glasses

The solubility of UO₃ in sodium almino(ferro)phosphate (SAFP) glasses prepared by quenching of melts reaches almost 50 wt %. The structure of the anionic motif of the network of such glasses is formed by polyanions and consists of alumino(ferro)phosphate and uranium–oxygen constituents. Irradiation with electrons of up to 8 MeV energy to an absorbed dose of 10⁶ Gy does not lead to appreciable changes in the glass structure, except insignificant increase in the fraction of octahedrally coordinated aluminum. After annealing, samples of sodium aluminophosphate glasses with low content of uranium oxides (up to 10 wt %) partially crystallize with the formation of phosphotridymite, whereas high-uranium glasses (up to ~50 wt % UO₃) remain X-ray amorphous. Samples of SAFP glasses at low concentrations of uranium oxides remain amorphous and at high concentrations undergo phase segregation with the formation of a SAFP glass phase enriched in uranium oxides and crystalline phase of sodium aluminum iron orthophosphate Na₃(Al,Fe)₂(PO₄)₃ containing impurity amounts of uranium ions. The incorporation of uranium ions is most probably due to the occurrence of redox processes between uranyl and iron ions.     

Computerized Simulation of Structure of NaAIO_2 Melt

The structure of NaAlO_2 melt has been studied by computerized simulation using Monte Carlomethod.The radial distribution functions and Local structure of this melt are calculated.It has beenfound that NaAlO_2 melt contains ionic clusters formed by corner-sharing AlO_4 tetrahedra,sodiumions and xNa~+.yO~(2-) ionic clusters.     

补加合金成分对铝合金熔体直接氧化生长的影响

为了控制DIMOX工艺中复合材料的生长速度和体积,采用压差法补加合金,使剩余铝合金熔体的成分得到调整并与正在氧化生长的Al₂O₃/Al复合材料层保持连续接触。试验研究了补加合金成分对Al-3Mg-10Si合金氧化生长的影响作用。结果表明:补加纯Al或低Mg、Si含量的铝合金,能够降低合金熔体的含镁量,缩短材料生长前沿合金熔体成分到达Al₂O₃-(Al,Mg)两相区的时间,促进传质过程,加速材料生长,有利于获取较大体积的复合材料。     

Investigation of the entrainment of silicon atoms by “vacancies” formed in an aluminum melt when its surface is exposed to an ion-electron flux

It is established that when a liquid-aluminum-silicon (Al-Si) structure is bombarded with ions and electrons having energies up to 6 keV, the process of Si dissolution in the aluminum is slowed. Mechanisms are put forward for the formation of an excess concentration of atomic-size voids (“vacancies”), the formation of a vacancy flux normal to the Si surface, and entrainment of impurity atoms by this flux. It is shown experimentally that zones completely free from Si atoms, where the silicon exhibits maximum solubility, in the aluminum may be formed in the bulk of the aluminum melt. The size of these zones can easily be controlled by the parameters of the ion-electron flux. Pis’ma Zh. Tekh. Fiz. 25, 58–65 (August 12, 1999)     

Pressure-driven mold filling model of aluminum alloy melt/semi-solid slurry based on rheological behavior

The pressure-driven mold filling ability of aluminum alloy melt/semi-solid slurry is of great significance in pressure casting processes, and the rheological behavior of the alloy has a crucial effect on the mold filling ability according to fluid dynamics. In this work, a pressure-driven mold filling model is first proposed based on the rheological behavior of the alloys. A356 alloy is employed as an example to clarify the rheological behavior of aluminum alloys, which obeys the power law model and is affected by temperature. The rheological behavior of the alloy in semi-solid state is modelled with the coupling of shear rate and temperature. The stop of mold filling attributes to the pressure loss which is caused by the viscosity during the flow of the melt/semi-solid slurry. Pressure loss caused by viscous flow and heat transfer between the alloy and the mold are calculated and coupled during the mold filling of the melt/semi-solid slurry. A pressure-driven mold filling model of aluminum alloy melt/semi-solid slurry is established based on steady-state rheological behavior. The model successfully predicts the filling length of melt/semi-solid slurry in pressure casting processes. Compared with the experimental results,the model can provide a quantitative approach to characterize the pressure-driven mold filling ability of aluminum alloy melt. The model is capable of describing the stop filling behavior of other aluminum alloys in pressure casting processes with corresponding rheological parameters and heat transfer coefficient.     

Computerized Simulation on the Structure of Cryolite-Alumina Melts

Monte Carlo calculations were performedon liquid ionic solution of saturated aluminain cryolite melt containing a total of 205 ions.The local structure and radial distributionfunctions of the melt were computerized by MonteCarlo method at 1283 K. It has been found thatthere exist the complex ionic clusters suchas AlOF_3~(2-), AlOF_4~(3-), AlF_4~-, AlF_5~(2-), AlOF_2~- etc.,as well as oxygen-bridge and flourine-bridgeionic clusters. In the melt studied, Al~(3+) ionstend to have preferential even coordinationnumber of 4F~- ions.     

利用电解铝液直接生产铝及合金铸锭

利用电解铝液直接配料生产铝及铝合金铸锭是当前国内外盛行的一种生产技术。本文介绍了它的生产意义、熔炼和保温技术、铝熔体的处理技术,铸造工艺技术及其生产流程图。希望引起铸造工作者的注意,并进一步研究开发。     

电工圆铝杆的铝熔体炉内精炼工艺现状与展望

近年来随着电力行业的飞速发展,普通圆铝杆已经无法满足电力行业的实际需要,亟需生产具备高强度、高导电率等优异性能的电工圆铝杆,以助力电力行业的发展。铝熔体的炉内精炼是生产高品质电工圆铝杆的基础及技术关键,但受限于熔体中夹杂的去除、杂质元素（Fe、Si、Mn、Ti、V、Cr等）、除气装备、测夹杂和测氢能力等影响因素,无法很好地满足生产高品质产品的需要。当前,许多学者致力于研究高效环保的新型精炼剂和更为先进的精炼装备与技术,目的是改善传统炉内精炼技术存在的精炼效果不好、对环境产生负面影响、精炼自动化程度低等问题。而未来铝熔体炉内精炼技术的发展也应该呈现为更加安全、环保、高效的趋势。重点介绍了铝熔体的炉内熔剂和气体精炼原理、炉内精炼技术现状、铝熔体中夹杂和氢的检测方法及其他杂质元素的去除现状,同时还对传统炉内精炼技术的不足及改进方向提出建议和展望,旨在为炉内铝熔体的高品质精炼和后续高质量电工圆铝杆的生产提供参考。     

电解质和酸碱性对天然鲜胶乳电动特性的影响

采用高速冷冻离心处理天然鲜胶乳制备离心胶乳,通过改变胶乳中酸碱度和电解质,结合激光多普勒技术、扫描电子显微镜以及电感耦合等离子体质谱仪等仪器对处理前后的胶乳进行电动特性、形貌及金属离子含量分析。结果表明pH值的降低能使胶乳电泳迁移率的正负发生反转。增加电解质浓度,天然鲜胶乳负的电泳迁移率随之降低,相同浓度条件下阴离子电解质对天然胶乳电泳迁移率与电导率的影响顺序为NaClNaBrNaNO3SDS(十二烷基硫酸钠)。金属阳离子压缩天然胶乳双电层效率由大到小依次为Al 3+Fe3+Fe2+Cu2+Mn2+Co2+Ca2+Na+。高价金属阳离子如铜离子、铁离子与铝离子能使胶乳带电性质反转,酸碱度及形貌分析表明这些电解质会改变胶乳pH值环境,使胶乳发生团聚甚至破乳现象。     

Effects of viscosity on cellular structure of foamed aluminum in foaming process

The effects of melt viscosity on the foaming process and the structures of foamed aluminum have been examined. Methods for measuring the melt viscosity, pore structure, and foaming process are introduced. To increase the stability of the foaming melt and get the sample with a uniform pore distribution, a proper viscosity is needed. Further, the structure of foamed aluminum can be controlled by adjusting the Ca addition and other process parameters.     

Effect of Process Parameters on Porosity in Aluminum Lost Foam Process

1.IntroductionLost foam casting process is still a new technology,and is gaining confidence among manufacturers[1].It isexpected to dramatically improve the competitiveness ofthe foundry industry.Many advantages like eliminatingmachining steps,making complex casting without coresand reducing environmental loads can be offered by thisprocess,because molding binder is not added into themold of the lost foam process.Aluminum alloy castings are widely used in the auto-mobile and aerospace industri…     

电脉冲孕育处理对纯铝凝固组织的影响

金属熔体结构对液-固相变动力学及其凝固组织具有重要影响.本文通过对处于熔点以上的纯铝施加电脉冲,系统研究了其凝固组织及其力学性能的变化.结果表明:脉冲电场处理后,试样晶粒明显细化,表现为等轴晶区扩展,柱状晶长大受到抑制,同时力学性能亦有较大提升.另一方面,电脉冲孕育处理后的铝熔体具有较强的遗传性和抗衰退性,DSC测试揭示了采用电脉冲孕育处理的高纯铝试样在液相线以上存在物相改变.     

铝钛晶粒细化合金的离心压力铸造及其细化效果

研究了高钛晶粒细化中间合金的制造法以及它对铝合金的作用效果。试验结果表明，由于浇组时旋转离子压力作用，使铝钛合金细化剂中的Ａｌ３Ｔｉ颗粒明显减小，因而可使细化剂中允许的钛含量提高将近４倍，这样可大大减小细化剂在在被处理合金中的加入量。     

Electrochemical Deposition and Nucleation of Aluminum on Tungsten in Aluminum Chloride-Sodium Chloride Melts

Electrochemical deposition and nucleation of aluminum on tungsten electrode from AlCl3-NaCl melts were studied by cyclic voltammetry, chronopotentiometry and chronoamperometry. Cyclic voltammetry and chronopotentiometry analyses showed that Al （Ⅲ） was reduced at 200℃ in two consecutive steps in an electrolyte of molten AlCl3-NaCl system with a composition 52：48 molar ratio. The current-time characteristics of nucleation aluminum on tungsten showed a strong dependence on overpotentials. Chronoamperometry showed that the deposition process of aluminum on tungsten was controlled by an instantaneous nucleation with a hemispherical diffusion-controlled growth mechanism. The results could lead to a better understanding of the AlCl3-NaCl melt system that has technological importance in electrodeposition of metals as well as in rechargeable batteries.     

铝液析氢界面反应过程动力学研究

建立了铝液中氢的界面反应过程的数学物理模型，对界面反应过程进行了动力学推导和计算。利用铝液直接测氢装置对氢的界面反应动力学过程进行了测试。计算结果与测试结果基本吻合。     

Effect of aluminum on the formation of silver metal quantum dots in sol-gel derived alumino-silicate glass film

The effect of aluminum incorporation on silver metal quantum dots formation in the alumino-silicate glass film processed by sol-gel process was investigated. The sol-gel derived glass was coated onto the silica glass plate by spin coating with the mixture solution of tetraethyl orthosilicate (TEOS), C2H5OH, H2O, AgNO3, Al(NO3)3. 39H2O, and HNO3 with the molar ratios of Ag/Si = 0.12 and Al/Si varying from 0 to 0.12. The formation of the silver metal quantum dots was confirmed by the measurements of the UV/VIS optical spectra, the X-ray diffraction patterns, and the transmission electron microscope images. While the radius of silver metal quantum dots increased with the increase of aluminum concentration, the concentration of the silver metal quantum dots decreased. The formation of the silver metal quantum dots was found strongly suppressed by incorporation of aluminum ions in the glass. The change in the glass structure due to the aluminum incorporation was investigated by the analysis of the Raman spectra. The silver ions in the glass contributed to form stable (Al:Ag)O4 tetrahedra by pairing with aluminum ions and thus clustering of silver metal quantum dots was hindered.     

On the crucial influence of some supporting electrolytes during electrocoagulation in the presence of aluminum electrodes

The influence of some supporting electrolytes on aluminum electrode oxidation and pH variation during electrocoagulation of an unskimmed milk sample and a cutting oil emulsion has been investigated. Among the electrolytes studied, sulfate anions were found to be quite harmful both for electrical consumption and electrocoagulation efficiency. At the opposite, chloride and ammonium ions were particularly benefic respectively for aluminum corrosion and pH regulation, whereas sodium cations were observed to have a neutral role. The results indicate that electrocoagulation can be realized at low anodic potential even in the presence of sulfate ions when the [Cl(-)]/[SO(4)(2-)] ratio is around or greater than 1/10. The detrimental effect of sulfates on electrocoagulation efficiency can be thwarted by the use of the ammonium salt thanks to its related buffer effect.