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一种新型储氢材料——改性四氧化三铁的储氢性能研究 总被引:2,自引:0,他引:2
以金属Mo, Al, Cr, W可溶盐为添加物, 通过共沉淀法由FeCl3和(NH4)2Fe(SO4)2•6H2O的水溶液制备了单金属添加的Fe3O4改性储氢材料. 采用循环储氢性能评价方法, 研究了材料的储氢性能; 利用X射线粉末衍射、SEM扫描电镜和BET比表面积测试手段, 分析了材料储-放氢前后的微观结构. 结果表明: 添加了Mo金属的Fe3O4材料四次循环的放氢温度最低, 为310~314 ℃(放氢速率为300 μmol•min-1•Fe-g-1), 低于目前同类最好的储氢材料(50 ℃左右); 对材料的微观结构研究表明: 采用本文方法制备的金属添加的Fe3O4储氢材料其粒度大约在50~70 nm. 此外, 材料的催化活性主要与掺杂的金属类型和材料粒度的大小有关. 相似文献
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石墨炉原子吸收光谱法直接测定饮料中痕量锰 总被引:4,自引:0,他引:4
提出了以硝酸为改进剂,石墨炉原子吸收光谱法直接测定饮料中痕量锰的方法,对试验条件进行了优化。方法具有简便、快速、检出限低等优点。检出限为0.65μg.L-1,特征灵敏度为2.2×10-2pg。线性范围为1~15μg.L-1,相关系数为0.998 8,回收率在101%~106%范围内。 相似文献
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The refolding of reduced and non-reducing egg white lysozymes in a urea solution was studied by a "phase diagram" method of fluorescence. The result showed that in the refolding of the reduced egg white lysozyme, an intermediate state of an egg white lysozyme exists at the urea concentrations in a final renaturation solution being about 4.5 mol/L, their refolding follows a three-state model; while in the refolding of the non-reducing egg white lysozyme, two intermediate states exist at the urea concentrations being separately 4.0 and 2.5 mol/L, and their refolding follows a four-state model. Through the comparison between the unfolding and refolding of an egg white lysozyme in the urea solution, it was found that both of the refolding of reduced and non-reducing egg white lysozyme molecules was irreversible to their unfolding in the urea solution. Finally, a suggested refolding was separately presented for the reduced and non-reducing egg white lysozymes in the urea solution. 相似文献
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Modified iron oxide, a new material for hydrogen storage and supply to polymer electrolyte fuel cell (PEFC), was prepared by impregnating Fe or Fe2O3 powder with an aqueous solution containing metal cation additives (Al, Cr, Ni, Co, Zr and Mo). Hydrogen storage properties of the samples were investigated. The results show that both Fe and Fe2O3 powder with additive Mo presented excellent catalytic activity and cyclic stability, and their hydrogen producing temperature could be surprisingly decreased. The temperature of forming hydrogen for the Fe2O3-Mo at the rate of 250 μmol·min^-1·Fe-g^-1 could be dramatically decreased from 527 ℃ before addition of Mo to 283 ℃ after addition of Mo in the fourth cycle. The cause for it was probably related to preventing the sinter of the sample particles. In addition, hydrogen storage capacity of the Fe2O3-Mo can reach w=4.5% (72 kg H2/m^3), close to International Energy Agency (IEA) criterion. These show the value of practical application of the Fe2O3-Mo as the promising hydrogen storage material. 相似文献
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ICP-AES法测定色漆可溶性金属含量 总被引:1,自引:0,他引:1
用ICP-AES法测定了色漆中的“可溶性”金属铬、镉、铅元素,考察了不同酸度对分析结果的影响,优化了测试条件。进行了回收率和精密度试验。并用原子吸收光谱国标方法进行对照,结果一致。 相似文献
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酞酰苯胺酸具有突出的生理活性犤1,2犦,其活性随过渡金属配合物生成而增强犤3,4犦,某些氨基酸是人体蛋白质的结构单元,本文报道了铜?与取代酞酰苯胺酸、苯丙氨酸混配配合物的合成、表征及热分解机理。1实验部分1.1配合物的合成酞酰苯胺酸配体的合成按文献犤5犦进行。酞酰苯胺酸与氢氧化钠按1∶1摩尔比溶于热乙醇,苯丙氨酸与氢氧化钠按1∶1摩尔比溶于蒸馏水,分别得到酞酰苯胺酸和苯丙氨酸的钠盐溶液。合并二配体钠盐溶液并置于50~60℃水浴中搅拌,按金属盐与每种配体酸1∶1摩尔比缓慢滴入CuAc2水溶液,即有大量… 相似文献