亮氨酸与异亮氨酸在金/银核-壳复合纳米粒子上的吸附状态

The Raman spectra and Surface enhanced Raman spectra (SERS) of leucine and isoleucine adsorbed on core-shell Au/Ag nanoparticles were obtained and assigned, and the different Raman peaks resulting from different vibrational models of the isomers忆groups were analysed. In Raman spectra, the leucine’s (ω(CH3)) is at 962, 945, 924 cm-1, (δas(CH3)) at 1408, 1454 cm-1; corresponding values for isoleucine are, 922 cm-1 and 1448, 1420, 1394 cm-1, respectwely. The difference in the peak positions of corresponding groups between leucine and isoleucine is more apparent in the SERS at acidic and basic conditions. The relationship between leucine and isoleucine’s concentration and SERS was interpreted preliminarily and the adsorption model on the core-shell Au/Ag nanoparticle surface was speculated.     

石墨炉原子吸收法直接测定高温合金中硅

研究了混合基体改进剂，灰北、原子化温度以及共存元素的干扰，采用镧和钙作混合基体改进剂后，硅的灵敏度提高，抗干扰能力增强，可以用石墨炉原子吸收直接测定高温合多中硅。方法特征量为０．２ｎｇ，检出限为２．３μｇ／ｇ，对于含硅量为４００μｇ／ｇ左右的合金样品，相对标准偏差为５％左右，回收率在９０％－１１０％之间。     

Investigation of eutectic transformation of Zn−Al alloy by DTA

The paper discusses the investigation of crystallization of metals and alloys by differential thermal analysis (DTA). It was assumed that this method allows determination of the mechanism and kinetics of volumetric crystallization underiso conditions (e.g. anisothermal) on the basis of the parameters of the equation expressing an integral form of the DTA curve. From DTA, a course of eutectic transformation was determined for a technical Zn?Al alloy containing 4wt% Al. Investigations were carried out under continuous cooling at various rates and the kinetics parameters were determined with the KEKAM equation:-ln(1-x)=kl _n     

锂离子电池负极合金CoSn和Cu-Sn的制备与表征

CoSn alloy and Cu-Sn samples were synthesized by H₂-reduction following solid-state reaction between Co(Ⅱ)， Cu(Ⅱ)， Sn(Ⅳ) and NaOH at ambient temperature. The samples were characterized by XRD， SEM. The results showed that CoSn alloy (80～200nm) is globe-shaped， ultrafine hexagonal material， and Cu-Sn alloy powder consists of two phases， i.e. Cu₆Sn₅ and Cu₃Sn. Cu-Sn powder has spherical morphology and the particle size is estimated to be 60～70nm. The electrochemical performances of CoSn alloy and Cu-Sn powder were studied using lithium-ions model cell Li/LiPF₆ (EC+DMC)/CoSn (or Cu-Sn). It was demonstrated the reversible discharge capacities for 10 cycles keep above 280mAh·g^-1 for nanophase Cu-Sn， and 60mAh·g^-1 for CoSn alloy. Differ-ential capacity plots showed that the reaction mechanisms of Cu-Sn with lithium were reversible.     

低钴AB5型稀土系贮氢电极合金的研究

为了进一步降低AB5型混合稀土系贮氢合金的成本,采用Cr,Si,Cu替代Co和调节化学计量比的方法制备低钴AB5型贮氢合金。结果表明:3种取代元素在寿命方面的效果依次为Si>Cr>Cu,在放电容量和活化性能方面依次是Cu>Cr>Si。Cr,Cu,Si只有少量的替代才可能发挥其有利影响;通过非化学计量比的调节,低钴混合稀土系贮氢电极合金的放电容量、活化性能及倍率放电能力都能较好地达到实用要求,但是循环寿命有待提高。     

N,N-二甲基甲酰胺中电沉积制备镁镍储氢合金

采用恒电位沉积法, 选用适宜的添加剂和络合剂, 成功地从N,N-二甲基甲酰胺(DMF)中沉积出致密的黑色Mg-Ni储氢合金膜. 并初步探讨了其共沉积机理. XRD显示沉积层中含有非晶态Mg-Ni相和微晶态Mg相. SEM图及相应能谱图分析表明合金颗粒以团聚状态存在, 合金成分不是很均匀. AAS分析表明沉积合金中Mg的原子摩尔分数达27.3%. LAND电池测试系统测得所镀合金膜的放电比容量最高为172.4 mAh/g.     

2A12-T6铝合金表面双-(γ-三乙氧基硅丙基)四硫化物薄膜的特性

采用傅立叶变换红外光谱分析了2A12-T6铝合金表面自组装双-(!-三乙氧基硅丙基)四硫化物硅烷偶联剂(SCA)薄膜结构特征,并采用电化学极化曲线评价了薄膜的耐蚀性能.结果表明,铝材表面自然晾干,SCA薄膜分子之间主要通过氢键连接,腐蚀电流密度减小1个数量级以上.120℃的加热处理促进铝板表面通过SiOSi链接而形成SCA网状薄膜结构,并通过在界面上形成SiOAl界面相结构而与铝板表面牢固连接,腐蚀电流密度降低2个数量级以上.SCA乙醇溶液浸泡处理10min比浸泡2s～1min的铝板表面SCA薄膜内氢键缔合羟基要多.     

混合稀土对共晶Al-2%Fe合金组织形态的影响

研究了富La混合稀土对共晶Al-2?合金组织形态的影响. 当混合稀土加入量较少时, 合金中的α-Al相为明显的胞状枝晶;随着混合稀土加入量的增加, α-Al枝晶优先形核生长得到抑制, 共晶Al3Fe相得到细化;当稀土加入量增至0.6% (质量分数)共晶Al3Fe相尺寸逐渐增大. 并对混合稀土对共晶Al-2?合金组织形态的影响机制进行了探讨.     

粉末化学镀法制备的NiB／TiO2非晶态合金催化剂对环丁烯砜加氢反应的催化性能

 采用诱导沉积法及粉末化学镀法分别制备了纯态NiB及负载型NiB／TiO2非晶态合金催化剂．用XRD，ICP，SEM，TEM和DSC等手段对催化剂的物性及TiO2载体与NiB非晶态合金之间的相互作用进行了表征，考察了非晶态合金的结构、组成、形貌和热稳定性，并将其用于环丁烯砜加氢反应中．结果表明，相对于NiB而言，NiB／TiO2催化剂具有优良的热稳定性和催化活性，这缘于NiB和TiO2载体之间的相互作用及载体的分散作用．     

氢化物发生石墨炉原位富集直接测定高温镍基合金中碲

通过选择碲的氢化物发生条件，克服了高含量镍对碲的干扰，把氢化物富集在涂钯石墨管里，然后再原子化，成功地测定了高温镍基合金中碲。