Y.J. Luo
,
S.P. Li
,
J.F. Zheng
金属学报(英文版)
In sheet metal forming, drawbeads are often used to control uneven material flow which may cause defects such as wrinkles, fracture, surface distortion and springback.Appropriate setting and adjusting the drawbead force is one of the most important parameters in sheet metal forming process control. This paper derives the model of loop drawbead restraining force (DBRF) using plastic forming theory, and gives the minimum blankholding force. Experiments are carried out to verify the proposed DBRF model. The good agreement between the calculated values and experiments data justifies the proposed loop drawbead restraining force model.
关键词:
drawbead
,
null
,
null
,
null
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
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
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
马保国
,
许婵娟
,
钟开红
,
蹇守卫
,
李相国
材料科学与工程学报
doi:10.3969/j.issn.1673-2812.2005.04.006
本文系统地研究了F、S、P元素对水泥熟料矿物形成过程和组成的影响及其叠加矿化效应,并通过化学分析和XRD分析探讨了其作用机理.研究结果表明:F、S、P元素在水泥烧成中均可降低液相出现和C3S形成温度,改善易烧性,但F、S叠加矿化效果最好,而且可以改善熟料的矿物组成及性能,避免了单掺F造成的熟料活性降低等问题.
关键词:
矿化效应
,
氟石膏
,
磷石膏
,
易烧性
余庚华
,
仲嘉琪
,
王谨
,
詹明生
量子电子学报
doi:10.3969/j.issn.1007-5461.2012.03.001
Ba原子是光频标的候选者之一,对其进行有效的激光冷却与囚禁需要相关能级的寿命和跃迁几率的信息.Ba原子激发态6s6p3P1能级在激光冷却实验中很重要,通过Hanle效应实验测量了这一能级的寿命和自发辐射率,从理论和实验上研究了探测激光有限线宽和光强对Ba原子基态6s21S0与激发态6s6p3P1之间跃迁(波长791nm)Hanle效应荧光信号的影响.在考虑了激光线宽和光强因素后所得到的激发态6s6p3P1的能级寿命和自发辐射率与其他方法给出的结果符合很好.
关键词:
光谱学
,
能级寿命
,
Hanle效应
,
线宽
,
Ba原子
,
原子频标
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
