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电沉积软磁铁箔性能的研究 总被引:1,自引:0,他引:1
为优化电沉积制备软磁铁箔的工艺条件,研究电解液温度和阴极电流密度对铁箔的磁学、力学和电学性能的影响规律,采用软磁材料测试仪、直流电阻电桥和显微硬度计研究了工艺条件变化时对铁箔的磁参数、电阻率和显微硬度的影响,并对铁箔的金相显微组织进行分析.结果表明:阴极电流密度增大时,铁箔的矫顽力增大,最大磁导率降低,显微硬度值及电阻率均提高;电解液温度提高时,铁箔的矫顽力降低,最大磁导率增大,显微硬度值下降,而电阻率提高;在650℃经过真空退火后的铁箔矫顽力降低,最大磁导率提高,其电阻率和硬度都下降,韧性明显提高.电沉积工艺条件改变时,薄膜的晶粒尺寸影响铁箔性能的变化. 相似文献
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目的 为了评价古籍化学品的综合效果,完善其除纸张性能外的墨迹的评价指标,探究不同有机相脱酸体系对老旧书页墨迹的影响.方法 制备胶印、中性笔墨样和书法用墨样,并对墨样进行人工老化处理.选择氢氧化钡的甲醇溶液(质量浓度为20 g/L)、氢氧化钡的二乙二醇溶液(质量浓度为17 g/L)和碳酸镁的甲醛溶液(质量浓度为10 g/L)分别对老旧书页以及人工老化的墨样进行脱酸处理.通过扫描仪高分辨率扫描墨样进行图像观察,用分光光度计测量墨样色密度,对3种有机相脱酸剂处理后的墨迹效果进行主客观评价.结果 主客观评价结果显示,经氢氧化钡的甲醇溶液处理后的墨样变化轻微;经碳酸镁的甲醛溶液处理后,墨样表面覆有1层碳酸镁颗粒,墨迹颜色明显变浅,墨样色密度显著降低;经氢氧化钡的二乙二醇溶液处理后,墨迹颜色变深,墨样色密度和线宽均有所增加.结论 不同脱酸体系会对老化墨样字迹产生不同程度影响,研究从图文信息质量的角度为古籍脱酸化学品的综合效果与评价提供一定的参考和借鉴. 相似文献
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针状焦基活性炭的制备及其作为EDLCs电极材料的电化学性能 总被引:16,自引:7,他引:9
以针状焦生焦为原料,通过KOH化学活化法,在不同活化条件下制备出一系列高比表面积活性炭,并对这些活性炭进行了孔结构表征.而后以30 % KOH溶液为电解液,测试了由所获活性炭制备的一系列电极的电双层电容性能.结果表明:在碱炭比7:1、活化温度850 ℃时,所制活性炭的BET比表面积为2 728 m^2/g,孔容为2.14 cm^3/g,统计平均孔径为4.4 nm,大中孔孔容占总孔孔容约50 %.该活性炭电极的比电容达305 F/g,有相对较高的能量密度、良好的功率特性以及双电层电容特性. 相似文献
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铅是一种相当软的呈青灰色的金属,有毒性。在装饰及使用上受到较大的限制,但铅对硫酸、硫酸盐、硫化物、稀盐酸以及含少量游离碳酸的硬水的作用却具有极大的稳定性。镀铅可用于某些化工设备的内衬,大型冷冻机的盐水槽内衬,某些标准件、轴瓦、蓄由池零件以及船舶工业和军事工业中的特殊镀层。虽然铅的电位比铁正,属阴极性镀层,只有铅镀层达25微米以上且致密、空隙极少时,才具有极好的防腐蚀效果,但镀铅作为一种功能性电镀仍然是不可缺少的。电镀铅大多数采用酸性电解液,这是因为它们的电流效率比碱性电解液高许多。在酸性电解液中 相似文献
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精铋的真空蒸馏硫化除铅 总被引:1,自引:3,他引:1
从理论上分析了用真空蒸馏分离精铋中各杂质和通过加硫除铅的可行性.在真空炉内进行了精铋加硫除铅的实验研究,考察了加硫量、蒸馏温度、残压和蒸馏时间以及加硫次数等因素对除铅效果的影响,得到了最佳工艺条件:每克铋加硫量控制在0.02 g左右、蒸馏温度约1073 K、残压控制在16 Pa左右,蒸馏时间不超过15 min.在此条件下可将金属铋中的杂质铅含量由30 μg/g降到了0.21 μg/g,达到了“5N”高纯铋的要求.良好的实验结果表明,精铋硫化除铅具有工艺流程简单、改善劳动环境及提高生产率等优点,是一种去除精铋中铅的有效方法. 相似文献
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Kazemipour M Ansari M Tajrobehkar S Majdzadeh M Kermani HR 《Journal of hazardous materials》2008,150(2):322-327
In this work, adsorption of copper (Cu), zinc (Zn), lead (Pb), and cadmium (Cd) that exist in industrial wastewater onto the carbon produced from nutshells of walnut, hazelnut, pistachio, almond, and apricot stone has been investigated. All the agricultural shell or stone used were ground, sieved to a defined size range, and carbonized in an oven. Time and temperature of heating were optimized at 15 min and 800 degrees C, respectively, to reach maximum removal efficiency. Removal efficiency was optimized regarding to the initial pH, flow rate, and dose of adsorbent. The maximum removal occurred at pH 6-10, flow rate of 3 mL/min, and 0.1g of the adsorbent. Capacity of carbon sources for removing cations will be considerably decreased in the following times of passing through them. Results showed that the cations studied significantly can be removed by the carbon sources. Efficiency of carbon to remove the cations from real wastewater produced by copper industries was also studied. Finding showed that not only these cations can be removed considerably by the carbon sources noted above, but also removing efficiency are much more in the real samples. These results were in adoption to those obtained by standard mixture synthetic wastewater. 相似文献
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A new method to control electrolytes pH by circulation system in electrokinetic soil remediation 总被引:14,自引:0,他引:14
To simultaneously avoid a decrease of electro-osmotic flow by hydrogen ions and to increase heavy metal precipitation due to hydroxide ions, simulated electrokinetic remediation was conducted in saturated kaolinite specimens loaded with lead(II) using an electrolyte circulation method to control electrolyte pH. At an electrolyte circulation rate of 1.1 ml/min, it was possible to increase the anolyte pH from 2 to 4 and decrease the catholyte pH from 12 to 8. Using electrolyte circulation, it was observed that the rate of decrease of clay pH due to the change of electrolyte pH was reduced. As a result, the operable period was extended and the removal efficiency for lead(II) was also increased. It was observed that most of the effluent lead(II) from the cathode compartment was electroplated onto the cathode and that residual effluent lead(II) did not precipitate onto, or adsorb to, the clay at the anode compartment during circulation. Therefore, there was no need to treat the electrolyte because there was virtually no effluent from the cathode compartment in the circulation system. It was also found that the electrolyte volume required to sustain the electrolytic reaction was sufficient for the whole electrokinetic remediation process. 相似文献
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Effect of different extraction agents on metal and organic contaminant removal from a field soil 总被引:12,自引:0,他引:12
This paper presents an evaluation of different extracting solutions for the removal of phenanthrene, lead and zinc from a contaminated soil obtained from a former manufactured gas plant site. The field soil contained 50%-88% sand, 11%-35% fines, 2.7%-3.7% organic matter and high concentrations of phenanthrene (260 mg/kg), lead (50.6 mg/kg) and zinc (84.4 mg/kg). A series of batch extraction experiments were conducted using the field soil with different extracting solutions at various concentrations to investigate the removal efficiency and to optimize the concentration of each extractant. The results showed that removal efficiencies of different flushing systems were significantly influenced by their affinity and selectivity for the contaminants in the soil matrix. Non-ionic surfactants (Igepal CA720 and Tween 80) were found to be effective in removing phenanthrene, but they were ineffective in removing lead and zinc. Chelating agents (ethylenediamine tetra acetic acid, EDTA and diethylene triamine penta acetic acid, DTPA) and selected acids were effective in removing lead and zinc, but they were ineffective for the phenanthrene removal. Co-solvents and cyclodextrins were not effective for removal of any of the contaminants. A sequential use of the 0.2 M EDTA followed by 5% Tween 80 or 5% Tween 80 followed by 1 M citric acid was found to be effective for the removal of lead, zinc, and phenanthrene. Overall, it can be concluded that sequential use of different extracting solutions is required for the removal of both heavy metals and organics from field contaminated silty sand soils. 相似文献
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TiO2/UV/O3-BAC processes for removing refractory and hazardous pollutants in raw water 总被引:5,自引:0,他引:5
TiO2/UV/O3-BAC (biological activated carbon) process was employed to treat raw water and compared to UV/O3-BAC process in its optimum parameters (3 mg/L ozone dosage with 15 min oxidation time and 15 min empty bed contact time in BAC). The results showed that the presence of TiO2 improved ozone utilization and biodegradability of the effluent. For the dissolved organic carbon (DOC) removal, TiO2/UV/O3-BAC was more efficient than UV/O3-BAC and its synergetic effect is more than that in UV/O(3)-BAC process. It was showed that small molecules with MW<3000 Da predominated in the raw water accounting for more than 56% DOC, they were increased after oxidation, accounting for more than 64% DOC. GC/MS analysis showed that TiO2/UV/O3-BAC process was effective in removing phthalate esters (PAEs) and persistent organic pollutants (POPs). PAEs' removal ratio reached more than 94% and reduced with the increase of the length of the alkyl side chains and the alkyl branch chains. TiO2/UV/O3-BAC process was also very effective in removing POPs. Polybromobiphenyls' removal rate reached more than 89% and decreased with the increase of substitutional bromines except for 2,2',5,5'-tetrabromobiphenyl, which can be completely removed. 相似文献
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Yilmaz AE Boncukcuoğlu R Kocakerim MM Keskinler B 《Journal of hazardous materials》2005,125(1-3):160-165
Boron removal from wastewaters by electrocoagulation using aluminum electrode material was investigated in this paper. Several working parameters, such as pH, current density, boron concentration and type and concentration of supporting electrolyte were studied in an attempt to achieve a higher removal capacity. The experiments were carried out by keeping the pH of solution constant and optimum pH of solution was determined 8.0 for the aluminum electrode. Although energy consumption increased with decreasing boron concentration, which conductivity of these solutions were low, boron removal efficiency was higher at 100 mg/L than that of 1000 mg/L. Current density was an important parameter affecting removal efficiency. Boron removal efficiency and energy consumption increased with increasing current density from 1.2 to 6.0 mA/cm2. The types of different supporting electrolyte were experimented in order to investigate to this parameter effect on boron removal. The highest boron removal efficiency, 97%, was found by CaCl2. Added CaCl2 increased more the conductivity of solution according to other supporting electrolytes, but decreased energy consumption. The results showed to have a high effectiveness of the electrocoagulation method in removing boron from aqueous solutions. 相似文献
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An effective method of reducing the mass of a lead acid battery is to replace the lead with a less dense electrical conductor such as carbon. The application of a thin layer of lead onto the surface of carbon fibres can improve the electrical and mechanical properties of the bond between the fibre and battery active material. Under-potential deposition was used to apply a thin layer of lead onto carbon fibre tows. The efficiency of this process using a number of different electrolytes and voltage ranges was assessed. X-ray photoelectron spectroscopy and secondary ion mass spectroscopy were used to evaluate the deposition process. Lead was successfully deposited onto the surface of the fibres at a potential of approximately 262 mV using the electrolyte consisting of 0.1 M HCIO4 and 0.01 M Pb(OAC)2. 相似文献
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Nguyen CV Delziet L Matthews K Chen B Meyyappan M 《Journal of nanoscience and nanotechnology》2003,3(1-2):121-125
Individual, free-standing, vertically aligned multiwall carbon nanotubes or nanofibers are ideal for sensor and electrode applications. Our plasma-enhanced chemical vapor deposition techniques for producing free-standing and vertically aligned carbon nanofibers use catalyst particles at the tip of the fiber. Here we present a simple purification process for the removal of iron catalyst particles at the tip of vertically aligned carbon nanofibers derived by plasma-enhanced chemical vapor deposition. The first step involves thermal oxidation in air, at temperatures of 200-400 degrees C, resulting in the physical swelling of the iron particles from the formation of iron oxide. Subsequently, the complete removal of the iron oxide particles is achieved with diluted acid (12% HCl). The purification process appears to be very efficient at removing all of the iron catalyst particles. Electron microscopy images and Raman spectroscopy data indicate that the purification process does not damage the graphitic structure of the nanotubes. 相似文献
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In this study, activated carbon, kaolin, bentonite, blast furnace slag and fly ash were used as adsorbent with a particle size between 100 mesh and 200 mesh to remove the lead and zinc ions from water. The concentration of the solutions prepared was in the range of 50–100 mg/L for lead and zinc for single and binary systems which are diluted as required for batch experiments. The effect of contact time, pH and adsorbent dosage on removal of lead and zinc by adsorption was investigated. The equilibrium time was found to be 30 min for activated carbon and 3 h for kaolin, bentonite, blast furnace slag and fly ash. The most effective pH value for lead and zinc removal was 6 for activated carbon. pH value did not effect lead and zinc removal significantly for other adsorbents. Adsorbent doses were varied from 5 g/L to 20 g/L for both lead and zinc solutions. An increase in adsorbent doses increases the percent removal of lead and zinc. A series of isotherm studies was undertaken and the data evaluated for compliance was found to match with the Langmuir and Freundlich isotherm models. To investigate the adsorption mechanism, the kinetic models were tested, and it follows second order kinetics. Kinetic studies reveals that blast furnace slag was not effective for lead and zinc removal. The bentonite and fly ash were effective for lead and zinc removal. 相似文献