Mössbauer, X-ray diffraction and magnetization studies of Fe–Mn–Al–Nb alloys prepared by high energy ball milling

Fe₆₀Mn₁₀Al₂₀Nb₁₀, (Fe₆₀Mn₁₀Al₃₀)₉₅Nb₅ and (Fe₆₀Mn₁₀Al₃₀)₉₀Nb₁₀ ball milled powdered alloys were investigated using X-ray diffraction, Mössbauer spectrometry, thermomagnetic (TGM) and magnetization measurements. We studied the influence of Nb content and of different milling times on the structural and magnetic properties. Two main features can be concluded: (1) the FeAlMn induces a BCC phase whatever the Nb content is, and (2) as both increasing Nb content and milling time give rise to an highly disordered state in conjunction with a decrease of the ferromagnetic behavior.     

铁(Ⅲ)-邻菲罗啉溶液体系的光化学还原 Ⅱ.气相色谱法研究光化反应机理

关于Fe(Ⅲ)-邻菲罗啉(phen)溶液的光化学还原现象的记载可追溯到十九世纪末。     

Fe(110)面上CO化学吸附状态的吸附历史依赖关系

Fe(110)面上直接在室温时吸附的CO同先在170 K吸附然后升温到室温的CO吸附有所不同. 前者有解离而后者无解离; 另外, 前者的饱和吸附量比后者低. 这可以用前者发生了解离来解释. 根据以上结果, 提出了以下的设想, Fe(110)面上的CO解离除了需要足够的热能而外, 还需要在表面的吸附位上有邻近的其它未被覆盖Fe原子的存在, 即需要一定的表面结构.     

LaNi4Fe催化合成氨反应性能的研究

用冶金法、还原扩散法、共沉淀法制得了LaNiFe,并对其催化合成氨反应性能进行了研究。实验结果表明:还原扩散法,共沉淀法制得的LaNi_4Fe催化活性均比冶金法好。X—射线分析指出LaNi_4Fe在合成氨反应过程中变为Ni_4Fe和LaN。     

铁／锌催化剂的物相结构及其还原行为的穆斯堡尔谱研究

以Mossbauer谱为手段,研究了用于F-T合成的Fe/Zn催化剂的物相结构,并考察了组成及制备方法的影响,同时还对其还原、碳化行为进行了探讨.发现锌对铁的还原有抑制作用,它能够稳定二价铁不被进一步还原.研究还表明,我们所研制的Fe/Zn催化剂是一种高分散度的铁锌化合物,室温下具有超顺磁特性.     

New catalytic effect of thiourea on the oxidative cyanation of N-aryltetrahydroisoquinolines

Thiourea itself has been introduced as a mild and efficient organocatalyst for the oxidative α -cyanation of N-aryltetrahydroisoquinolines (THIQs) with trimethylsilyl cyanide (TMSCN), giving the corresponding products in good to excellent yields. Experimental investigations demonstrated that thiourea acts as a radical initiator by abstracting hydroxyl radical (OH) from tert-butyl hydroperoxide (TBHP) directly instead of non-covalent hydrogen bondings (H-bondings) activation. The use of thiourea as a radical initiator offers a new avenue for innovative chemical transformations in organocatalyzed radical chemistry.     

活泼配盐[(μ-RE)(μ-E′)Fe_2(CO)_6][Et_3NH][E,E′=S,Se]的亲电反应研究——蝶状Fe_2SSe及Fe_2Se_2簇合物的合成及表征

本文由［（μｔＢｕＳ）（μＣＯ）Ｆｅ２（ＣＯ）６］［Ｅｔ３ＮＨ］和硒粉形成的［（μｔＢｕＳ）（μＳｅ）Ｆｅ２（ＣＯ）６］［Ｅｔ３ＮＨ］，分别与溴化苄，二碘甲烷及邻一、间一、对一双（溴甲基）苯反应，合成了蝶状Ｆｅ２ＳＳｅ单簇物（μｔＢｕＳ）（μＰｈＣＨ２Ｓｅ）Ｆｅ２（ＣＯ）６（３ａ）和双簇物［（μｔＢｕＳ）Ｆｅ２（ＣＯ）６］２（μＳｅＺＳｅμ）［Ｚ＝ＣＨ２，ｏ．ｍ．ｐ双（亚甲基）苯］（４ａｄ）。类似地，由［（μＰｈＳｅ）（μＣＯ）Ｆｅ２（ＣＯ）６］［Ｅｔ３ＮＨ］和硫粉或硒粉所形成的［（μＰｈＳｅ）（μＳ）Ｆｅ２（ＣＯ）６］［Ｅｔ３ＮＨ］或［（μＰｈＳｅ）（μＳｅ）Ｆｅ２（ＣＯ）６］［Ｅｔ３ＮＨ］分别与对一双（溴甲基）苯反应合成了蝶状Ｆｅ２ＳＳｅ和Ｆｅ２Ｓｅ２双簇物［（μＰｈＳｅ）Ｆｅ２（ＣＯ）６］２［μＳ（ｐＣＨ２Ｃ６Ｈ４ＣＨ２）Ｓμ］（５ａ）及［（μＰｈＳｅ）Ｆｅ２（ＣＯ）６］２［μＳｅ（ＰＣＨ２Ｃ６Ｈ４ＣＨ２）Ｓｅμ］（５ｂ）。所有产物均经元素分析、ＩＲ和１ＨＮＭＲ表征。     

Synthesis of new α,α,β,β-tetrafluoroesters

Substituted phenyl iodides or diiodides reacted with ethyl iodotetrafluoroproponylate ICF₂CF₂CO₂Et, 1 in the presence of copper powder to give the coupled products 2 or 3 in good yields. Addition of 1 to ethylene and allyl acetate proceeded smoothly under thermal and radical conditions to give the corresponding adducts, which underwent elimination reaction to give β-vinyl and β-allyl α,α,β,β-tetrafluoroesters, CH₂CHCF₂CF₂CO₂Et, 4 and CH₂CHCH₂CF₂CF₂CO₂Et, 5, respectively. 1 also readily reacted with 1,5-hexadiene and 1-hexene with copper or palladium complex, followed by reduction to remove iodine to produce ω-alkenyl-α,α,β,β-tetrafluoroester CH₂CH(CH₂)₄CF₂CF₂CO₂Et 6 and α,α,β,β-tetrafluoroester C₄H₉CH₂CHICF₂CF₂CO₂Et.     

反复上呼吸道感染患儿发样微量元素锌,铜,铁检测结果分析

采用示波极谱法对１８３名反复上呼吸道感染患儿及１１８名健康体检儿同时进行发样锌，铁，铜测定，结果表明，反复上呼吸道感染儿发锌，铁均低于健康体检儿，有高度显著性差异，铜只在婴儿组反复感儿高于健康体检儿，其它各年龄组反复上感儿低于健康栓检儿或无显著性差异，说明以２儿童进行常规发样微量元素普查，发现低锌，低铁者及时给予补充，可减少感染性疾病的发生率。铜与免疫功能的关系尚待研究。