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1.
ZHOU Zheng 《保鲜与加工》2002,(6):139-142
The processes, microstructures, properties and mechanisms of DIMOX in synthesizing Al/Al 2O 3 by Al-Mg-Si alloy are reviewed and their problems are considered mainly as following:non_homogeneous oxidation growth of Al/Al 2O 3 at the surface of melts and the porosity of Al/Al 2O 3 limites structural application of Al/Al 2O 3 composite. The mechanisms and models of microchannel,magnesium action,silicon action,and induction are outlined. Several problems which need to be noticed are pointed out,which are diffusion and transfer of oxygen in aluminium melts;the role of MgO and MgAl 2O 4 at outer layer;the reaction feature of solid_gas in the oxidation microstructures of Al_Mg_Si alloy;SiO 2 induction mechanism of silicon and its correlation with the mechanism of magnesium action in Al_Mg_Si alloy. 相似文献
2.
采用浸渍法制备CaO/MgO固体碱催化剂,并应用于菜籽油与甲醇的酯交换反应制备生物柴油。考察了镁钙比对CaO/MgO催化活性的影响。试验表明,用质量分数22.6%的乙酸钙浸渍MgO,镁钙摩尔比为3～4时最接近等体积浸渍,镁钙摩尔比为1~2时为过量浸渍。镁钙摩尔比越低,催化剂活性越高,但镁钙摩尔比低于3时,催化剂活性组分分布不均匀,且活性增加不明显。所以最佳镁钙摩尔比为3～4。 相似文献
3.
ZnO is formed in the course of directed nitriding with Al-Zn alloy, and that the effect of zinc and magnesium on the directed nitriding process is big different. The long fibers which diameter are far less than one micrometer, short bar-like and tetrapod-like zinc oxide is obtained. The three important stages of initial growth kinetic of ZnO approving ZnO have growth mechanism of VS, they are stage of accelerating, linear and parabola, are discovered. Experimental results show that the volatilization of zinc play a very important role in the growth of ZnO,the growth of ZnO is controlled by the diffusion of zinc in the Al-Zn alloy , and the morphologies of ZnO is depend on the saturation level of the vapour. 相似文献
4.
First smelting MnSi alloy by using high-bearing manganese slag of BF by electric smelting process in a 25 kVA arc furnace in lab has been introduced. In order to increase the content of manganese and silicon in MnSi alloy , a little amount of MgO is added into the slag and the lower alkalinity has been adapted. Then smelting AlMnSi alloy using MnSi alloy containing high silicon that obtained by experiments and waste Al with an induction furnace has been studied. The controlling of temperature is the key in smelting process. The high quality AlMnSi alloy has been obtained successfully,Which can be extensively used for the compound oxygen removal agent for making steel and the metal alloy additive. 相似文献
5.
The cathodic electrodeposition coatings(E-coatings) with silane modifying ceramics are prepared on magnesium alloy for improving the abrasion resistance of organic E-coating. Hardness, adhesion, corrosion resistance, circle-drawing method and abrasion resistance are evaluated by pencil hardness, UMT abrasion test system, and Machu test. The results show that the abrasion resistance and hardness of E-coatings are enhanced by adding Al2O3 ceramic powders. Meanwhile, corrosion resistance and adhesion of E-coatings remain unchanged. 相似文献
6.
地衣芽孢杆菌产β-甘露聚糖酶分批发酵动力学模型的建立 总被引：2，自引：2，他引：0
为研究其菌体生长、产物合成以及底物消耗情况,本文以分离自亚麻温水沤麻液的β-甘露聚糖酶高产菌株地衣芽孢杆菌(Bacillus licheniformis)HDYM-04为供试菌株。以初始魔芋粉加入量2 %、接种量6.7 %、初始pH值 8.0、培养温度37 ℃、搅拌速率300 r/min、通气量3 L/min、发酵周期30 h为基础发酵条件进行5L发酵罐发酵。并基于Logistic方程和Luedeking-Piret等方程建立了该菌株的菌体生长、产物生成、底物消耗三个分批发酵动力学模型,其相关系数分别为0.99021、0.98908、0.98812,均达到0.988以上,这些模型能真实描述菌体发酵过程中菌体生长、酶的合成以及底物消耗的情况。该试验为菌株HDYM-04的工业化应用奠定了理论基础并提供了实践指导,为小试数据的放大提供了重要参考。 相似文献
7.
In combination with Huimin high-phosphorus iron smelted by smelting reduction and HIsmelt ironmaking technologywhich have the advantages of high efficient dephosphorizationCaO-SiO2-Al2O3-MgO-FeO-P2O5 slags with basicity R (mass ratio of CaO to SiO2)ranging from 0.8 to 1.4Al2O3 ranging from 6.4% to 15.4%P2O5 ranging from 0 to 3% and the content of MgO and FeO fixed as 4% and 6% respectivelyare studied.The slags are synthesized by reagent grade.The mineral composition and microstructure of the slags are studied with scanning electron microscope and the effects of changes in the composition of smelting reduction slags on its viscosity are studied by RTW-10 melt comprehensive physical properties measuring apparatus.Results show that the mineral structure of slags are mainly composed of melilite(gehlenite and akermanite)which is characterized by square and thick skeleton form.The viscosity decreases with the increasing of the slag basicity at fixed P2O5 or Al2O3 mass fractionincreases with the increasing of Al2O3 mass fraction at fixed slag basicity or P2O5 mass fractionand increases with the increasing of P2O5 mass fraction at fixed slag basicity or Al2O3 mass fraction. 相似文献
8.
福建烟区土壤镁素营养与镁肥合理施用 总被引：9，自引：1，他引：8
caigen@.com 《中国农学通报》2006,22(5):261-261
(1光泽县烟草公司,福建,光泽,354100;2福建省烟草公司,福建,福州 ,350003;
3福建农林大学资源与环境学院,福建,福州,350002) 相似文献
9.
摘 要：探讨蔵灵菇马克斯克鲁维酵母M3菌株胆盐水解酶的特性及其发酵动力学原理。采用单因素多水平试验,在pH4~8、温度31~43℃、底物浓度4~8 mmol/L及不同化学试剂(SDS、EDTA、尿素、Cu2+ 、Mg2+、Ca2+、Fe3+、Al3+、Mn2+)的条件下,胆盐水解酶与底物反应30min,检测酶活力。胆盐水解酶最适反应条件：pH为6.0、底物浓度为7 mmol/L、温度为37℃,Mn2+、Fe3+、Ca2+金属离子对酶活性有较大提高作用,其他化学试剂对酶活性影响不大。胆盐水解酶的酶促反应动力学常数Km为2.60 mmol/L。M3菌株在18~21 h进入稳定期,18h对数生长期时酶活性达到最高,表明其胆盐水解酶发酵动力学类型为生长偶联合成型。 相似文献
10.
A method of preparing the spinel LiV_(x)Mn_(2-x)O_(4) with liquid phaseis introduced at a low temperature. With cyclic voltammogram and discharge-charge tests at content current, we find that the doped vanadium leads to the spinel structure more stable, the reversible behaviors of LiV_(x)Mn_(2-x)O_(4)is improved, and the capacity fade on cycling is reduced.The cycle life of the battery based on LiV_(x)Mn_(2-x)O_(4)is also found improved. 相似文献
11.
To realize the transforms of stress and strain and obtain the multi-scale constitutive equation across micro/meso/macro scales.strain-stress curves for magnesium alloy(AM60) and magnesium matrix are carried out with the machine MTS.By means of mixture law,mechanical property of particle is obtained.Based on the character of magnesium alloy structure,the finite element model of unit-cell included complex micro-structures is carried out.Via finite element numerical simulation of magnesium alloy unit-cell,the methodology overcome the limitation of present analytical method.Finally the multi-scale constitutive equation has been used for the analysis of the tensile stress vs. strain curve for magnesium alloy.Results show satisfactory agreement between the stress vs strain curve by the present methodology and the experimental data for AM60. 相似文献
12.
A new mold slag with low content SiO2 and high content Al2O3 is designed in order to avoid or alleviate the reaction between Al and SiO2 during the continuous casting of high-Al steel, the acidity of this slag is adjusted by adding B2O3, and the effect of B2O3 content on the fusion property, viscosity property and heat transfer characteristics through the mold slag film of the mold slag is analyzed. The results show that the fusion temperature, viscosity, viscous flow activation energy decrease and heat flux through the slag film increases with the increase of B2O3 content in the range of 4%~10%; temperature time transformation (TTT) diagrams move to longer incubation time with the increase of B2O3, while the crystallization speed of mold fluxes decreases; under this experiment condition, the precipitation of CaF2 crystals can be restrained by the increase of B2O3 content in the mold slag. 相似文献
13.
研究旨在分析土壤中可培养细菌菌株的氮代谢特征,并进一步探讨微生物在土壤氮素转化中的可能作用机制。以2株分离自苹果园土壤的细菌菌株SY5-4和SY11-10为试材,采用传统培养方法结合分子检测技术,分别测定菌株生长特性及其氮素转化能力。研究结果表明,异养条件下,菌株SY5-4和SY11-10的世代时间分别为243.5 min和202.7 min。菌株生长过程中,培养液中铵态氮浓度始终维持在较高水平,铵态氮、亚硝态氮和硝态氮浓度均表现出先升后降的趋势。硝化（amoA和hao）和反硝化（nosZ、norB、nirK和nap）基因检测结果表明,菌株SY11-10具有多种氮素转化潜能。综上,供试菌株培养过程中,培养液中氮素发生变化,并在菌体中检测到不同氮转化基因,表明菌株参与多种氮代谢途径。 相似文献
14.
Based on an existing magnesium alloy database, a query system is optimized by considering the design characteristics, and an integrated query system for this magnesium alloy database is developed to meet the demands of more users. The result shows that the new system improves the query efficiency of the magnesium alloy database, especially for queries concerning phase diagrams and the structure of magnesium alloys. This means that the new system provides users a more powerful and useful magnesium alloy database. 相似文献
15.
With the goal of the sintering of magnetite concentrates without carbon,the effect of quality,inert atmosphere and Fe_3O_4 addition on microwave sintering of magnetite concentrates is studied.It is shown that: With the same basicity(CaO/SiO_2=2.5) and microwave heating condition(1000W,2.45GHz,20min),the centre temperature decreaseds with a increasing sample mass;There is no great difference between with and without inert atmosphere in microwave sintering of magnetite in a same microwave heating condition.When 100g sample(CaO/SiO_2=2.5) is heated by microwave irradiation(1000W,2.45GHz,20min),the more Fe_3O_4 is added,the less liquid phase is produced,which is bad for microwave sintering of magnetite concentrate. 相似文献
16.
Suspended sediments play an important role in the transformation process of pollutants in rivers.The adsorption characteristic of suspended sediments in Three Gorges Reservoir Area to phosphate was studied in this paper.Based on the indoor adsorption balancing experiment and kinetic modeling experiment,the main factors for adsorption process of sediments(particle size of sediment,initial concentration etc.) were discussed.The major results of the experiment were as follows:(1) Three kinds of suspended sediments with different particle sizes were used for the study of adsorption characteristic with different sediment concentration.The amount of phosphate adsorption increased with the increase of the sediment concentration and sediment particle size.(2) With the help of Langmuir isotherm theory,the related parameters in kinetic model were estimated,the experiment results indicated that the adsorption isotherm of phosphate in Three Gorges Reservoir Area fitted with the fifth type of Langmuir adsorption isotherm,the maximum amount of phosphate adsorption would emerge when the phosphate concentration was relatively high,but it would move down when the phosphate concentration increased afterwards.(3) Phosphate adsorption increased with the increase of initial phosphate concentration,the average time for adsorption balance was 2-4 hours. 相似文献
17.
The study shows that there will be a good effect to degrade printed circuit board(PCB) waste stripping liquid using UV/Fenton homogeneous photochemical catalysis system.The removal rate of COD could reach 80% at the conditions with double dose of H_2O_2,1:20 mol ratio of Fe~(2+):H_2O_2 and 80min hydraulic retention time(HRT).In all influential factors the H_2O_2 dosing ratio is the most important by order,then follows the ratio of FeSO_4/H_2O_2,and at last the illumination time. 相似文献
18.
两种不同镁盐在牛粪堆肥高温期的保氮效果研究 总被引：1，自引：0，他引：1
利用恒温培养箱模拟堆肥高温期,添加硫酸镁、磷酸二氢钾和含镁废渣,研究磷酸铵镁(MAP)反应中各成分的保氮效果以及含镁废渣作为堆肥过程中氮素固定剂的可行性。结果表明:添加镁盐固定剂显著降低了堆体中的pH值,减少了氮素损失。同时添加硫酸镁和磷酸二氢钾的保氮效果最佳,添加相同比例的含镁废渣和硫酸镁的保氮效果无显著差别。含镁废渣添加量的保氮效果与其添加量成正相关,添加质量比为2%、4%、8%的含镁废渣的保氮率分别为6.15%、10.13%、19.51%。添加镁盐会提高堆体中的EC值,降低GI值,各处理均可达到腐熟。说明可以利用镁盐作为堆肥保氮固定剂,而含镁废渣因其价格低廉,更具应用前景。 相似文献
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20.
The microstructures and kinetics of reaction between aluminum and amorphous silica are investigated by making use of advantages of silica glass's larger dimension.Al/Al2O3 composite microstructures can be synthesized by longer time reaction and the diffusion transit layer is discovered between aluminum melts and the Al/Al2O3 composite layer.The growth kinetics of diffusion transit layer and Al/ Al2O3 composite layer are also measured and discussed.The effect of silicon element on the diffusion transit layer and the composite layer' kinetics is discussed and parabola growth kinetics of Al/Al2O3 composite layer is determined. 相似文献