Q. F. Wang
,
J. H. Liu
,
Z. Y. Li
,
P. H. Li
,
G. F. Zhou and X. Chen( 1) Huazhong University of Sci. & Tech.
,
Wuhan 430074
,
China 2) Technology Center of WISCO
,
Wuhan 430080
,
China)
金属学报(英文版)
The microstructure and properties of stmulated heat affected zone (HAZ) of laser welded ULCB600 steel were investigate by applying the simulation technique with gleeble - 2000 dynamic thermal - me - chanical simulator.The influence of the preheat condition on the microstructure and properties of simu- lated HAZ of laser welded plate was also studied in order to evaluate the feasibility of reducing arisk that the ductility and toedness of HAZ may be poor by using preheat treatment.The results indicate that the grain size of laser - welded HAZ simulated is very small no matter if there is preheat, the toughness of simulated HAZ is therefore improved comparing to the base metal,and there is no obvious brittle - ductile transition in the range from - 80℃ to 20℃. The TEM analyses of sub -microstruc- ture also discover that microstructure constituent of both simulated HAZ is dominative lath martensite. However, the shaf of martensite is relatively coarse,and the dislocation density is relatively high for simulated HAZ with 200℃ preheat because of slower cooling rate. Combination of these tow factors is responsible for farer bardness and better toughness of simulated HAZ with preheat condition.
关键词:
physical simulation laser beam welding
,
null
,
null
卢洋藩
,
叶志镇
,
曾昱嘉
,
陈兰兰
,
朱丽萍
,
赵炳辉
无机材料学报
doi:10.3724/SP.J.1077.2006.01511
采用Li-N-H共掺技术在玻璃衬底上生长p型ZnO薄膜. XRD结果表明共掺ZnO薄膜具有高度cll轴取向, Hall测试表明薄膜的电阻率为25.2Ω·cm, Hall迁移率为0.5cm2/(V·s), 空穴浓度为4.92×1017/cm3. 此外, p-ZnO薄膜在可见光区域具有90%的高透射率.
关键词:
p-ZnO
,
magnetron sputtering
,
codoping
卢洋藩
,
叶志镇
,
曾昱嘉
,
陈兰兰
,
朱丽萍
,
赵炳辉
无机材料学报
doi:10.3321/j.issn:1000-324X.2006.06.039
采用Li-N-H共掺技术在玻璃衬底上生长p型ZnO薄膜.XRD结果表明共掺ZnO薄膜具有高度c轴取向,Hall测试表明薄膜的电阻率为25.2Ω·cm,Hall迁移率为0.5cm2/(V·s),空穴浓度为4.92×1017/cm3.此外,p-ZnO薄膜在可见光区域具有90%的高透射率.
关键词:
p-ZnO
,
磁控溅射
,
共掺
赵中伟
,
刘旭恒
中国有色金属学报
运用同系线性规律对Li-Fe-P-H2O系中缺少的LiFePO4和Li3PO4的△GΘ进行估算.结合已有的热力学数据,运用ψ-pH图的绘制原理,得到25℃时Li-Fe-P-H2O系在不同浓度下的ψ-pH图.结果表明,在水溶液中,LiFePO4具有较大的热力学稳定区域,这对湿法制备LiFePO4很有利.根据所绘制的热力学平衡图,详细讨论了各种LiFePO4软化学制备方法的可行性途径,并就液相法制备LiFePO4可能的技术途径和条件进行分析,为在水溶液中用软化学法制备LiFePO4提供理论依据.
关键词:
Li-Fe-P-H2O系
,
磷酸铁锂
,
热力学
李志宏
,
柳卫平
,
白希祥
,
郭冰
,
连钢
,
颜胜权
,
王宝祥
,
陆昀
,
曾晟
,
苏俊
原子核物理评论
doi:10.3969/j.issn.1007-4627.2005.01.006
利用8Li次级束测量了质心系能量7.8 MeV 2H(8Li, 9Li)1H反应的角分布, 导出了8Li(d, p)9Li反应的天体物理S因子及9Li→8Li+n虚衰变的渐近归一化系数.
关键词:
8Li(d,p)9Li反应
,
角分布
,
天体物理S因子
,
渐近归一化系数
Journal of Materials Research
The effect of Li(3)N additive on the Li-Mg-N-H system was examined with respect to the reversible dehydrogenation performance. Screening Study with varying Li(3)N additions (5, 10, 20, and 30 mol%) demonstrates that all are effective for improving the hydrogen desorption capacity. Optimally, incorporation of 10 mol% Li(3)N improves the practical capacity from 3.9 wt% to approximately 4.7 wt% hydrogen at 200 degrees C, which drives the dehydrogenation reaction toward completion. Moreover, the capacity enhancement persists well over 10 de-/rehydrogenation cycles. Systematic x-ray diffraction examinations indicate that Li(3)N additive transforms into LiNH(2) and LiH phases and remains during hydrogen cycling. Combined structure/property investigations suggest that the LiNH(2) "seeding" should be responsible for the capacity enhancement, which reduces the kinetic barrier associated with the nucleation of intermediate LiNH(2). In addition, the concurrent incorporation of LiH is effective for mitigating the ammonia release.
关键词:
complex hydrides;improvement;mixtures;imides;amide;h-2
A.H. Salama
材料科学技术（英文）
Li-doped p-type ZnO ceramics were prepared by conventional methods according to the chemical formula Zn1-x LixO2 where x=0.5, 1.0, 1.5 and 2.0 mole fraction, respectively. The crystal structures of the prepared samples were studied by X-ray diffraction analysis. The dielectric properties (including dielectric constant ε'
and dielectric loss ε") and dc-electrical conductivity [σ(Ω-1·cm-1)] were investigated. The dielectric constant ε' was sharply decreased at the low frequency range and independent on frequency at high frequency range. Otherwise, the dielectric loss "00 varied with frequency and showed absorption peak located from 200 Hz to
4 kHz and moved to higher frequency as the concentration of Li+ doped increased. It was found that dc-electrical conductivity log¾ varied from -9 to-5 and the energy gap width were calculated by using Arrhenius equation. The p-type conductivity of Li-doped ZnO may be attributed to the formation of a LiZn-Lii donor complex, which is limited by reducing the amount of Lii.
关键词:
P-type ZnO ceramics
杨昊
,
范广涵
,
李军
材料科学与工程学报
采用基于密度泛函理论的第一性原理赝势法计算了本征ZnO、N掺杂、Li掺杂以及Li、N共掺杂ZnO的能带结构、电子态密度和差分电荷分布.计算结果表明:N掺杂的受主能级局域性较强,导致N溶解度较低,Li替位原子受主能级较浅,但是会受到Li间隙原子的补偿.Li、N共同掺入时,N_o-Li_(Zn)复合受主结构并不是ZnO的主要P型来源,N_o受主可以与间隙原子Li_i形成N_o-Li_i结构,该结构可促进N的掺入,并抑制Li_i施主的补偿效应,因而对实现ZnO的P型非常有利.
关键词:
ZnO
,
第一性原理
,
密度泛函理论
,
双受主共掺杂
曹笃盟
,
李志友
,
周科朝
稀有金属材料与工程
采用固相反应法制备了Li1+xV3-yMyO8(M=Mo,P;0≤y≤0.4),研究了不同Mo和P含量对Li1+xV3O8相的影响,并首次对其进行了高温阴极放电性能的研究.结果表明:Mo和P掺杂量分别为y≤0.2和y＜0.2时可获得纯Li1+xV3O8相;Mo掺杂使Li1+xV3O8峰值电压提高0.3 V,比容量提高25%,嵌入的Li+量最高可达x=3.8;P掺杂(y≤0.20)对Li1+xV3O8的峰值电压和比容量影响较小.化学嵌锂实验也证实掺杂后的材料具有更快的Li+嵌入速度.
关键词:
Li1+xV3O8
,
热电池
,
掺杂
,
比容量
陈玉红
,
吕晓霞
,
杜瑞
,
董肖
,
张材荣
,
康龙
,
罗永春
稀有金属材料与工程
采用第一性原理方法研究了H2分子在Li2NH (110)晶面的表面吸附.通过研究Li2NH (110)/H2体系的吸附位置、吸附能和电子结构,发现H2分子吸附在Li长桥位时会发生解离,并在Li2NH (110)面形成NH2基,其吸附能为1.178 eV,属于强化学吸附,吸附最稳定.此时,NH2基中的H原子与Li2NH表面的相互作用主要源于H1s轨道与Li2NH表层N原子的2s,2p轨道重叠杂化的贡献,且N-H键为共价键；另一个H原子与Li2NH表面的相互作用主要是与Li之间的离子键作用；H2分子的解离能垒为1.31 eV,表明在一定热激活条件下H2分子在Li2NH(110)表面发生解离吸附.N顶位吸附时,优化结束后形成NH3,但该吸附方式不稳定,可见Li2NH (110)面与H2反应不易直接生成NH3.
关键词:
第一性原理
,
Li2NH(110)
,
H2
,
吸附能
,
解离
