排序方式: 共有96条查询结果,搜索用时 31 毫秒
11.
基于Cowan的准相对论程序包,中扩充和发展了一系列组态平均、单组态和多组态不同层次的程序包,计算惯性约束聚变数值模拟及光谱诊断中需要的各种原子参数。本以类氢、类氦和类锂的氩原子离子为例,计算了主量子数n≤6所有组态平均层次相关的电子碰撞激发和电离,光激发和电离,自电离,辐射复合、双电子复合、三体复合过程截面和速率系数等全套原子参数。截面和速率系数被拟合成可以方便使用的解析公式。 相似文献
12.
合成了四个从葡萄糖及半乳糖衍生的手性芳基双膦配体,制备了手性双膦-铑(Ⅰ)配合物催化剂,并将其用于苯乙烯不对称氢甲酰化反应中.结果表明,葡萄糖骨架手性中心与联萘基之间有协同作用,对映体过量值和转化率受配体C-4骨架立体中心的绝对构型影响,而产物的绝对构型则主要由联萘单元控制;配体4-双{[(S)-1,1′-联萘基-2,2′-双基]-磷}-苯基-3,6-脱水-β-D-葡萄糖的吡喃糖苷基和联萘基的匹配组合,给出41%的对映体选择性和74∶26(异构/正构)区域选择性. 相似文献
13.
结合阳极氧化法和脉冲沉积法合成SnO2/TiO2纳米管光催化剂,实现了SnO2纳米颗粒在TiO2纳米管表面的均匀负载.利用场发射扫描电子显微镜(FE-SEM)、能谱仪(EDS)、X射线衍射仪(XRD)以及紫外-可见漫反射光谱(UV-Vis DRS)对样品进行表征,以甲基橙为模拟污染物,评价了纳米管的光催化活性.结果表明,SnO2/TiO2纳米管经750℃煅烧后主晶相为锐钛矿相TiO2,含少量金红石相TiO2和SnO2,三者两两之间形成三元异质结,促进光生电子-空穴对的分离,此时SnO2/TiO2纳米管表现出最佳的光催化活性,紫外光下对甲基橙1 h分解比例由32.4;提升至96.5;. 相似文献
14.
A programme is developed to calculate the polarizations of the radiation emitted after electron impact excitation. The fully relativistic distorted-wave method is used in cross-section calculations. The programme is applied to He- and Li-like ions. The calculated values of line polarization are compared with other theoretical results and experimental values. For He-like U, at lower incident energy, the present polarization agrees with the other theoretical ones within 1%, while at higher energy, the differences increase up to about 10%. For He-like Fe and Ti, the present results of polarization degree for most of the lines agree with the experimental data within the experimental error bars. For the Li-like Ti line q (ls2s2p^2p3/2 to ls^22s), the present value of the polarization agree excellently with another theoretical one, and both the values are consistent with the measured data within the experimental error bar. 相似文献
15.
BBZS掺杂对BaO-Sm2O3-TiO2系微波介质陶瓷性能的影响 总被引:1,自引:1,他引:0
利用固相法制备BaO-Sm2O3-TiO2系微波介质陶瓷.通过复合添加氧化物ZnO、CuO和玻璃料Bi2O3-B2O3-ZnO-SiO2(BBZS),系统的烧结温度降至900℃.研究了玻璃料的添加量对介电性能的影响.按BaSm2Ti4O12+1wt;ZnO+1wt;CuO+xwt;BBZS(0相似文献
16.
17.
CaTiO3掺杂PbNb2O6高居里温度压电陶瓷的研究 总被引:1,自引:0,他引:1
采用传统电子陶瓷的制备方法,系统研究了(1-x)PbNb2O6-xCaTiO3(x=0、0.01、0.02、0.03、0.04)系高居里温度压电陶瓷.XRD分析表明,x=0时,材料只能形成三方非铁电相钨青铜结构,而x在0.01~0.04 mol范围内均能形成钨青铜型固溶体,利用XRD数据计算了晶体的晶格常数随x的变化,发现随着CaTiO3含量增加,晶胞体积减小.陶瓷材料的居里温度测试结果表明该体系具有高的居里温度(Tc>400℃).测试了不同组成陶瓷的压电、介电性能,CaTiO3的掺杂量为x=0.03时陶瓷样品的压电常数达到d33=64pC/N,平面机电耦合系数kp=0.269,材料的介电常数ε33T/ε0=293,介质损耗tanδ=0.021,居里温度Tc=570℃,该组成具有优异的压电性能,适合于高温环境下的使用. 相似文献
18.
19.
用相对论性的DF方法与非相对论性的HF方法分别计算了类锂硅离子能级结构及振子强度、跃迁概率,考查了计算精度,对数值结果进行了理论分析并与其它结果进行了比较。 相似文献
20.
A quasi-relativistic distorted-wave approximation is developed to investigate the direct electron-impact ionization processes, in which the configuration interactions are considered in the initial and final states of target. As an example, the direct detailed-level electron-impact ionization cross sections for the ground and low excited states of Ar^6+ (3s^2, 3p^2, 3s3d) are calculated in the energy range from 1.02 to 15Ith ( Ith the ionization threshold). Comparison with the available data demonstrates that our results are reasonable. The effects of configuration interactions are discussed, and the validity of transformation principles by statistical weights between configuration-averaged and detailed-level electron-impact ionization cross sections is analysed. 相似文献