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1.
The Mg-based hydrogen storage alloys Mg2Ni, Mg2Ni0.7Fe0.3 and Mgl.7Alo.3Ni were successfully synthesized by a two-step process （sintering and ball milling）. The crystal structure and microstructure were examined by X-ray diffraction, Scanning Electron Microscope and Malvern particle size analyzer. New phase appears in the tripe alloys doped with A1 and Fe, and the particle size ranges from 3μm to 5 μm. The electrochemical performance studies indicate that the partial substitution of AI for Mg, and Fe for Ni significantly improve the cycle life, reversibility of hydrogen absorption and desorption. The diffusion process is the control step in the electrode reaction of hydrogen storage alloys. 相似文献
2.
1 Ｉｎｔｒｏｄｕｃｔｉｏｎ ＩｒｏｎａｌｕｍｉｎｉｄｅｓｂａｓｅｄｏｎＦｅ3 Ａｌｈａｖｅｍａｎｙａｄｖａｎｔａｇｅｓｆｏｒｓｔｒｕｃｔｕｒａｌｕｓｅｓａｔｅｌｅｖａｔｅｄｔｅｍｐｅｒａｔｕｒｅｂｅｃａｕｓｅｏｆｔｈｅｉｒｅｘｃｅｌｌｅｎｔｃｏｒｒｏｓｉｏｎｒｅｓｉｓｔａｎｃｅａｎｄｒｅｌａｔｉｖｅｌｙｌｏｗｍａｔｅｒｉａｌｃｏｓｔ.Ｈｏｗｅｖｅｒ,ｔｈｅｓｅａｌｌｏｙｓｈａｖｅｎｏｔｙｅｔｆｏｕｎｄｗｉｄｅｓｐｒｅａｄｕｓｅｂｅｃａｕｓｅｔｈｅｙｅｘｈｉｂｉｔｐｏｏｒｄｕｃｔｉｌｉｔｙａｎｄｂｒ… 相似文献
3.
Ultra-high vacuum gaseous hydrogen permeation experiments on Fe3Al-based alloy were performed in the temperature range of 330∼450°C with an upstream hydrogen pressure between 3. 38×104 Pa and 7.28×104 Pa. The results show that the hydrogen diffusivity and permeability in Fe3Al-based alloy obey Arrhenius relationship in the experimental temperature range and the hydrogen permeation process is controlled
by the lattice diffusion of hydrogen at relative high temperature. The activation energy of hydrogen diffusion in the Fe3Al-based alloy was found to be 75 kJ/mol.
Supported by the National Natural Science Foundation of China (59895157) 相似文献
4.
The process of gaseous hydrogen charging into a Ti3Al-based alloy in the temperature range of 500–650°C is investigated. The results showe that the relationship between the
average hydrogen concentration at constant temperature and charging time reveals a parabolic rate law. Applying the theory
of lattice diffusion to analyze the hydrogen diffusion in the alloy, we find that the apparent activation energy of hydrogen
diffusion is 90.40 kJ/mol, and the equilibrium hydrogen content in the alloy depends on the temperature of the gaseous hydrogen
charging process.
Project supported by the Natural Science Foundation of Shanghai (93QE14002) 相似文献
5.
采用水热合成法合成了标题化合物C7H7NO2·C10H8N2,并测定了其晶体结构.该晶体属于三斜晶系,P-1空间群,晶体学参数为:a=8.3253(18),b=9.980(2),c=10.099(2);α=116.340(2)°,β=90.435(3)°,γ=90.354(3)°,V=751.9(3)3,Z=2,Dc=1.296 mg/m3,最终偏差因子R1=0.0531,wR2=0.1366(I>2σ(I)).该化合物通过分子间氢键形成一维链状结构. 相似文献
6.
合成了一种新颖的配合物[Zn（H2O）6]（NO2-C9H4O6）2-4H2O,并用x-射线单晶衍射仪测定了其结构．晶体数据表明,该配合物属三斜晶系,P-1空间群,晶胞参数为：a=6．850（19）A,b=6．92（2）A,c=19．25（6）A,α=92．74（5）°,β=92．10（5）°,γ=118．13（3）°,V=802（4）A3,Z=1,Dcalc=1．562g·cm-3,／I,=0．869mm-1,F（000）=388,R1=0．0787,wR2=0．2106．在配合物结构单元中,zn原子与六个水分子配位,形成略有畸变的八面体阳离子基团,阳离子基团和5-硝基-1,2,3-苯三甲酸负一价阴离子通过氢键相互作用连接在一起形成二维三明治状超分子化合物． 相似文献
7.
利用N-对甲苯磺酰甘氨酸与钐(Ⅲ)盐反应合成了一种新型链状配合物[Sm2(tsglyO)6(H2O)4]·3H2O(tsglyO=N-对甲苯磺酰甘氨酸),通过X-射线单晶衍射测定了晶体结构.配合物中,两个Sm(Ⅲ)原子[Sm1、Sm2]分别与N-对甲苯磺酰甘氨酸的羧基氧原子及水分子配位,形成双核单元结构.N-对甲苯磺酰甘氨酸采用双单齿和双齿鳌合桥联配位模式将双核单元连接在一起形成一维聚合链.链间通过氢键作用力组装为3D超分子体系. 相似文献
8.
制备了不同晶型的二氧化锰,并研究了不同晶型的二氧化锰对催化过氧化氢分解反应速率的影响.结果表明,β-MnO2(K2CO3)的催化活性最好.温度和用量对β-MnO2(K2CO3)催化分解过氧化氢反应有着明显的影响,随着温度和用量的增加,过氧化氢催化分解的反应速率也不断增加.催化剂的重复使用效果并不理想. 相似文献
9.
本文合成了一个新的自由基与铜的配合物[Cu(NIT-1'-MeBzIm)2Cl2].4H2O,并测定了其晶体结构.该晶体属于单斜晶系,C2/c空间群,晶胞参数:a=17.353(5),b=21.083(6),c=11.978(3),α=90°,β=111.964(3)°,γ=90°,V=4064.0(19)3,Z=4,Dc=1.277 mg/m3,最终偏差因子R1=0.0786,wR2=0.2213[I>2σ(I)],F(000)=1636.该配合物通过分子间氢键作用形成一维链状结构. 相似文献
10.
吴茂江 《雁北师范学院学报》2011,27(3)
从水的密度、水分子结构、冰的结构、水分子间的氢键及水分子的缔合等入题,分析了对水的反常膨胀;从微冰结构、晶体结构、极性分子及分子缔合几种解释方法,认为用水分子间形成氢键缔合水分子理论解释水的反常膨胀最为科学,与实验事实及晶体理论相吻合。 相似文献
11.
利用硝酸铜[Cu（NO3）2·6H2O]和均苯三甲酸在氨水溶液中反应,通过氨对铜（Ⅱ）离子的配合来调控配位反应速率,合成配合物{[Cu3（blc）2（NH3）（H2O）]·2H2O}n,并经元素分析和X射线单晶衍射法证实。配合物属单斜晶系,空间群为C2／c,晶体学参数：a=13．9213（5）,b=17．1210（6）,c=12．5271（5）A,V=2710．9（2）A3,Z=4。在标题化合物的结构中,Cu,离子为四配位而Cu2离子是五配位的,Cu1和Cu2被均苯三甲酸根离子桥联,由于均苯三甲酸根离子的结构中有C3对称轴而形成了二维六员环状平面结构,平面间通过N—H…0,O-H…0等氢键和π-π作用形成层状堆积。 相似文献
12.
植物体内活性氧代谢及功能研究进展 总被引：1，自引：0，他引：1
徐新娟 《河南科技学院学报》2007,35(2):10-12
最近生物化学和遗传学研究证明活性氧不仅仅是需氧生物细胞的代谢副产物,而且还是细胞内重要的信号分子,其中过氧化氢在介导植物体对生物和非生物胁迫响应中起一种信号分子作用。作为信号分子的活性氧有其特定的合成途径、专一性的代谢响应机制、专一性的作用靶标和信号调节完成之后的代谢消除途径。过氧化氢介导的信号调节作用包括ABA控制的气孔关闭、生长激素控制的根的向地性生长中、氧剥夺抗性的产生等。过氧化氢的合成和作用与一氧化氮有关系。过氧化氢调节的下游信号事件包括细胞内钙流动、蛋白质磷酸化和基因表达。钙和小G蛋白信号通路对于细胞内部过氧化氢的稳定状态维持具有重要作用。 相似文献
13.
本文合成了一个新的化合物C39H44N8O10:(NIT-1′-MeBzIm)2.(H3bta)(NIT-1′-MeBzIm=2-{2′-[(l′-甲基)苯并咪唑]}-4,4,5,5-四甲基咪唑啉-3-氧化-1-氧基自由基,H3bta=1,2,4-苯三酸),并测定了其晶体结构.该晶体属三斜晶系,P1空间群,晶胞参数:a=7.372(12),b=8.705(15),c=15.65(3),α=100.81(3)°,β=97.47(3)°,γ=101.55(2)°,V=952(3)3,Z=1,Dc=1.369 mg/m3,最终偏差因子R1=0.1047,WR2=0.2650(I>2σ(I)),F(000)=414.该化合物通过分子间氢键和π-π堆积作用形成二维网状结构. 相似文献
14.
合成了一种新颖的配合物[Zn(H2O)(bpp)(Bript)2]n(其中,bpp=1,3-二(4-吡啶)丙烷,H2Bript=5-溴间苯二甲酸),并用X-射线单晶衍射仪测定了其结构.晶体数据表明,该配合物属单斜晶系,空间群P21/c,晶胞参数为:a=7.862(3),b=27.530(10),c=9.664(4),β=96.694(6)°,V=2077.6(13)3,Z=4,Dcalc=1.677 g·cm-3,μ=3.141 mm-1,F(000)=1056,R1=0.1119,wR2=0.2760.在配合物中,Zn原子被5-溴间苯二甲酸离子连接为一维链,这些一维链通过氢键和π…π相互作用连接在一起形成二维超分子化合物. 相似文献
15.
氢键广泛存在于气体、液体和晶体等各种状态之中，影响着物质的性质和结构。本文仅就氢键对含氮有机化合物的性质、化学反应和结构的影响作进一步的分析论证。 相似文献
16.
JIANG Xiao-chun LI Ze-lin YIN Jian-jun 《黄冈师范学院学报》2007,27(6):26-29
A new electrochemical oscillatory system of bromate in alkaline solution is reported.In Pt-Bromate-Alkaline solution system,two different types of electrochemical oscillations(Type Ⅰ and Type Ⅱ) can be observed.Type Ⅰ appears before hydrogen evolution and Type Ⅱ involves periodic hydrogen evolution.Type Ⅰ relates to the adsorption/desorption of the hydrogen on platinum electrode,and Type Ⅱ with periodic oscillation stems from the coupling of electrochemical reactions(the reduction of bromate and evolution hydrogen reaction) with mass transfer(diffusion and convection).More over,under the right conditions,the two types appear in different oscillatory modes,for example,simple periodical mode and mixed one,etc..Crossed cycle in the cyclic voltammograms,which is the basic characteristics for electrochemical oscillatory systems,has also been observed as expected. 相似文献
17.
制备了一个结构新颖的镍的二价配合物,并过元素分析,红外光谱和X-射线衍射对其进行表征.结果表明该配合物属三斜晶系,空间群为P-3c1,晶胞晶胞参数为:a=11.9404(8),b=11.9404(8),c=17.087(2),V=2109.8(3)3,Z=4,Dc=1.389 Mg/m3,F(000)=924,化学式C7H26N7N i O1S1,化学式量为317.7.中心镍离子与3个乙二胺的六个氮原子配位成一个变形八面体结构.同时,晶体中含有没有配位的逆硫氰根离子和水分子.配合物结构单元的分子之间是通过氢键相连接,从而形成了比较稳定的一维链状结构. 相似文献
18.
合成了一个新的配合物,经元素分析及X-射线衍射对其结构进行了表征.化合物晶体属单斜晶系,P2(1)/c空间群,晶胞参数:a=6.4824(13),b=6.1325(12),c=19.980(4),α=90°,β=91.925(2)°,γ=90°,V=793.8(3)A3,M=245.05,Z=4,Dc=2.050Mg.m-3,F(000)=492,吸收系数μ=1.671mm-1,最终偏离因子R1=0.0263,wR2=0.0692.化合物的分子结构存在一维链状的结构,由于复杂氢键的存在,它的堆积结构呈二维网状排列,而且在[010]方向看到了纳米空洞. 相似文献
19.
1IntroductionNickel-based alloys containing 20 -30 wt % Mo isknown to be essential for corrosion resistance in re-ducing media[1],especially for resistance to HCl at alltemperatures and concentrations[2]. However , uponexposure to elevated temperatures in the range of600 -800 ℃,these alloys suffer an al most completeloss of roomtemperature ductility as a result of long-range ordering (LRO) to Ni4Mo .It is considered thatthe loss of ductility mainly results from the environ-mental embrittle… 相似文献
20.
The fracture behavior of disordered and ordered Ni4Mo alloy was investigated by tensile tests in hydrogen gas or during hydrogen charging. The results show that the ductility of the disordered alloy decreased slightly with the hydrogen pressure increasing, while that of the ordered alloy decreased rapidly with the hydrogen pressure increasing. However, the ductility of both disordered and ordered alloys reduced similarly seriously with the charging current density increasing. Therefore, the mechanism of order-induced embrittlement of Ni4 Mo alloy in hydrogen gas is supposed to be that atomic order accelerates the kinetics of the catalytic reaction for the dissociation of molecular H2 into atomic H. 相似文献