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1.
给出了相距为d的两个单电子圆盘量子点构成的人造分子的能级结构,讨论了能级随d,ω0(谐振子圆频率)及B(外磁场强度)变化的情况。 相似文献
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采用高温固相法合成了Na3Gd1-xTbxSi2O7(x=0.01,0.02,0.04,0.06,0.08,0.1)系列荧光粉。研究了荧光粉的真空紫外-可见发光光谱和荧光寿命,讨论了Tb3+在扭曲八面体结构(标示为Gd(1)3+)和正三棱柱构型(标示为Gd(2)3+)两种格位中的最低5d轨道能级。同时研究了Gd3+→Tb3+之间无辐射能量传递速率K和无辐射能量传递效率η。研究结果表明:Tb3+在Gd(1)3+格位中的最低允许跃迁和禁戒跃迁的5d轨道能级分别位于235 nm和280 nm,在Gd(2)3+格位中的最低允许跃迁和禁戒跃迁的5d轨道能级分别位于224nm和256 nm。随着Tb3+浓度的增加,能量传递效率及速率显著增大,说明在Na3Gd1-xTbxSi2O7中存在有效的Gd3+-Tb3+能量传递。 相似文献
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测量了在真空紫外光激发下,SrAl12O19∶Pr3 在不同温度(308~483 K)时的发射光谱,同时观测到了电偶极禁戒的4f2→4f2和电偶极允许的4f5d→4f2跃迁。随温度升高,4f5d→4f2与1S0发射的相对强度逐渐增强。运用Pr3 4f2组态最高的能级—1S0能级和4f5d组态最低能级间的热平衡模型成功解释了SrAl12O19∶Pr3 发射光谱随温度变化的现象。 相似文献
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类Li钙离子精细结构能级和软X射线光谱的理论计算 总被引:1,自引:1,他引:0
用多组态HFR方法计算了类Li等电子序列钙(Ca,Z=20)离子1s~2nl(n=2~6,l=0~5)组态的所有能级和电偶极跃迁的软X射线光谱,其中4f→3d,5f→3d及5d→3p、4d→3p由于其下能级跃迁速率较大,容易形成粒子数反转因而可作为激光跃迁,5f→3d、6f→3d跃迁已处于“水窗”波段,而4f→3d的激光跃迁(5.77nm)已为我们最近的实验所证实.并将我们的计算结果与其它理论计算和实验数据进行了比较. 相似文献
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CO谱带的微扰给谱线的标识和分析带来挑战.这里针对CO A1Ⅱ(v=1)对d3△(v=5)态的徵扰,首先采用有效哈密顿矩阵的方法重新分析了d3△-a3Ⅱ(5,0)带高精度的涉及d3△2和d3△3的振转光谱数据,发现A1Ⅱ的微扰可忽略不计.进一步理论计算了由A1Ⅱ的微扰产生的d3△的△1,△2和△3的转动能级移动扣d3△-a3Ⅱ(5,0)光谱强度的变化.发现△1的能级移动最大,最大可达4 cm-1,这个能级移动随J值的增大而减小;对△2和△3的影响在J小时可忽略不计.光谱强度的改变有类似的变化趋势,涉及到△1的d3△1-a3Ⅱ光谱强度减小量最大可达20%,随J的增大,此减小量变小;对涉及△2和△3的光谱强度此微扰可忽略不计,从而给出了上面实验数据分析中不考虑微扰的原因. 相似文献
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六钛酸钾(K_2Ti_6O_(13))是宽带隙半导体光催化材料,只能响应波长较短的紫外光.为了使K_2Ti_6O_(13)对可见光响应,本文采用第一性原理方法,研究过渡金属Mn和Cu掺杂改性后K_2Ti_6O_(13)的电子结构和光学性质.计算结果表明:Mn,Cu掺杂后K_2Ti_6O_(13)禁带中出现了杂质能级,这些杂质能级由O 2p和Ti 3d与Mn 3d或Cu 3d态杂化而成.对于Mn掺杂的K_2Ti_6O_(13),其带隙值变小,位于能带中间的杂质能级可作为电子跃迁的桥梁,从而实现了对可见光的吸收.对于Cu掺杂的K_2Ti_6O_(13),其带隙值虽略有增大,但是若考虑将与价带相连的杂质能级,带隙值将大大减小,且此杂质能级可抑制光生载流子的复合,使得掺杂后K_2Ti_6O_(13)吸收带边红移至可见光区并在可见光范围内吸收强度明显增强.总的而言,Mn,Cu的掺杂实现了钛酸钾对可见光的吸收,同时Cu掺杂的效果要优于Mn掺杂的效果.研究结果对K_2Ti_6O_(13)在光催化领域上的应用具有重要的意义. 相似文献
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用紫外光电子能谱(UPS)研究了非晶Nb100-xNix(x=65,59.8,56.4)合金的电子结构,得到Nb-Ni合金的费密能级位于态密度曲线极小附近。从电子结构说明了Nb-Ni合金中存在双居里点现象的原因。对非晶Nb-Ni合金的电子结构分析指出:能量接近的两个d带杂化结果致使在费密面附近形成新的杂化带,杂化程度与两元素的价差有关。电荷转移引起带峰移动。费密能级态密度中应包含两部分的贡献:有利于磁性的3d电子态和有利于超导的4d电子态。费密能级处这两部分的分
关键词: 相似文献
9.
按着4f~6(~7F_J)和5dΓ_1耦合模型,提出了计算KX(X=Cl,Br,I)晶体中Eu~(2+)离子4f~65d能级的方法,导出了能级的参数表达式,并进行了数值计算,计算结果和实验符合较好. 相似文献
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We present here a systematic investigation of the atomic displacements in bcc transition metal (TM) dilute alloys. We have
calculated the atomic displacements in bcc (V, Cr, Fe, Nb, Mo, Ta and W) transition metals (TMs) due to 3d, 4d and 5d TMs
at the substitutional site using the Kanzaki lattice static method. Wills and Harrison interatomic potential is used to calculate
the atomic force constants, the dynamical matrix and the impurity-induced forces. We have thoroughly investigated the atomic
displacements using impurities from 3d, 4d and 5d series in the same host metal and the same impurity in different hosts.
We have observed a systematic pattern in the atomic displacements for Cr-, Fe-, Nb-, Mo-, Ta-and W-based dilute alloys. The
atomic displacements are found to increase with increase in the number of d electrons for all alloys considered except for
V dilute alloys. The 3d impurities are found to be more easily dissolved in the 3d host metals than 4d or 5d TMs whereas 4d
and 5d impurities show more solubility in 4d and 5d TMs. In general, the relaxation energy calculation suggests that impurities
may be easily solvable in 5d TM hosts when compared to 3d or 4d TMs.
相似文献
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重元素高电离的离子特性对研究激光核聚变和X射线激光等都很重要,本文用3d^94s,3d^94d,3d^94p,3d^94f组态相互作用研究了类镍铱离子光谱跃迁。 相似文献
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Dr. H. Brückmann Dr. E. L. Haase Dr. W. Kluge Dr. L. Schänzler 《Zeitschrift für Physik A Hadrons and Nuclei》1970,230(4):383-390
The elastic deuteron-deuteron scattering and the reactionsd(d,p)t andd(d,3He)n have been investigated at an incident deuteron energy of 51.5 MeV. Time-of-flight technique was used for the particle identification. The observed angular distributions for the (d, p) and (d, n) reaction are identical within the accuracy of the experimental data. The experimental results for the reactiond(d, p)t are compared with a theoretical prediction based on the application of a generalized separable potential model to the four nucleon systems. Information on the single deuteron break-up reactiond+d→d+p+n and on the double deuteron break-up reactiond+d→p+p+n+n is contained in the observed continuous proton and deuteron spectra. The double break-up seems to be contribute only with a rather small amount to the whole break-up cross section. 相似文献
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The simplified model for 4f-5d transitions is applied to obtain the line strengths for emission, ground-state absorption and excited states absorption involving 4f-5d transitions of Nd3+ in crystals. The results are host independent for the usual case where 5d crystal-field interaction can be considered as strong, in the sense that the calculated 5d-4f emission relative line strengths will be the same for Nd3+ in any host. Also the calculated 4f-5d absorption line strengths can be grouped by the 5d crystal-field components. For each 5d crystal-field component, the group of absorption line strengths for different 4f25d transition final states forms a pattern independent of the 5d crystal-field component and the host. For practical cases, due to strong but still limited 5d crystal-field splitting, the transitions to different 5d crystal-field components may overlap each other. The theoretical results are used to interpret available experimental data. 相似文献
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Đ Miljanić E. Andrade J. Hudomalj-Gabitzsch G.S. Mutchler G.C. Phillips 《Nuclear Physics A》1977,290(1):27-44
The three-body reactions induced by low energy deuterons on 6Li have been studied. The contributions from the sequential processes through the excited states of the intermediate 4He, 5Li, 6Li and 7Li nuclei dominate the coincidence spectra. The quasi-free d + d → d + d, d + α → d + α, and d + d → p + t reactions have been observed and compared with plane wave impulse approximation (PWIA) calculations. 相似文献
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Gaussian-type basis sets for the 3d Rydberg orbitals and 3d correlation orbitals are developed for the first- and second-row main group elements. The numbers of the Gaussian-type functions (GTFs) used for the 3d orbitals are 1–3 for the former elements and 1–4 for the latter elements. The 3d Rydberg orbitals for the first-row main group elements are close to the hydrogen (H) 3d orbitals, but those of the second-row main group elements are very different from H 3d except for Al. A two d or three d GTF set suffices to model the first-row main group elements, but at least four d GTFs are necessary for the second-row main group elements. The Rydberg GTF orbitals, consisting of three GTFs, are converted into correlating orbitals by introducing a single scaling factor. The correlation energies (CEs) calculated using these correlating orbitals cover 99.4–100% of those calculated using Dunning's three primitive GTFs for the first-row main group elements, and 94.9–99.7% of the CEs of Woon and Dunning's d's for the second-row main group elements. The resulting correlating 3d orbitals were tested by picking out F2 and Cl2, yielding spectroscopic constants close to or more accurate than those calculated by Dunning's 3d orbitals and Woon and Dunning's 3d orbitals. 相似文献
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Stereodynamics of the reactions Ne+H<sub>2</sub><sup>+</sup>/Ne+D<sub>2</sub><sup>+</sup>/Ne+T<sub>2</sub> 下载免费PDF全文
The vector correlations between products and reagents for the reactions Ne+H + 2 , Ne+D + 2 , and Ne+T + 2 are calculated by means of the quasi-classical trajectory method on a new potential energy surface constructed by Lü et al. [J. Chem. Phys. 2010 132, 014303]. The polarization-dependent differential cross-sections (2π/σ)(dσ 00 /dω t ), (2π/σ)(dσ 20 /dω t ), (2π/σ)(dσ 22+ /dω t ), and (2π/σ)(dσ 21 /dω t ), and the distributions of P (θ r ), P (φ r ), and P (θ r ,φ r ) are calculated. The isotopic effect, which is associated with the difference in mass factor among the three reactions, is revealed. 相似文献
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在XeCl激光光泵的Ba蒸气中,首次观察到波长为551.9nm、606.3nm及611.1nm的受激辐射,它们分别对应于Ba原子的三重态跃迁:6s6d~3D_2—6s6p~3P_1、5d6p~3P_2-6s5d~3D_3及5d6p~3P_1—6s5d~3D_2.对于Ba原子的自旋禁戒跃迁6s7p~1P_1—6s6d~3D_2的可能性进行了探讨. 相似文献
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D. Kaiser 《Physics letters. A》1975,51(6):375-376
The radiative lifetimes of the 5s, 7s, 8s, 9s and of the 4d, 6d, 7d, 8d, and 9d levels of sodium have been measured by time resolved observations of the fluorescence radiation after stepwise excitation by two pulsed dye lasers. 相似文献