ESR研究非晶Ag+导体的晶化

用电子自旋共振(ESR)方法对非晶Ag⁺离子导体0.85AgI~0.15Ag₄P₂O₇的热处理晶化过程进行研究,在样品中掺入微量(约1×10^-3 g/g)的Mn²⁺或V⁴⁺离子作为自旋探针离子,它们的ESR谱强度随升温线性减弱,当样品完全晶化时ESR谱消失。这样测定的样品完全晶化的温度分别为98℃(掺Mn的)和108℃(掺V的).本文还对Mn²⁺和V⁴⁺的ESR谱进行了分析。     

On problem of ultrasensitive determination of man-made plutonium in living species

To improve the sensitivity of the method of Pu determination in specimens we applied two additional steps of chemical separation of Pu from U. After the usual chemical separation of Pu we used second step with ion-exchange column, where the ions of U⁴⁺ were absorbed by sorbent and Pu³⁺ ions remains in solution. For converting Plutonium to Pu³⁺ state the electrochemical procedure has been used. After the electrochemical separation procedure the solution was deposited onto quartz glass. Then the quartz glass plates were inserted into the gas mixture flow (SOCL₂+air) at the temperature 650°C. Such a procedure extracts ≥90% U from Pu layer. Now we provide the chemical separation of Pu from U by a factor ≥10⁷. It means that now we are able to perform the routine Pu analysis at the level of sensitivity 10⁻¹⁴–10⁻¹⁵ g/g.

By using combined n-γ activation technique we can determine the Pu content in the small fragments of tissues of living species with the weight as small as 0,05-0,1 gram. The new technique could be used in routine analysis of Pu in population of heavily Pu damaged regions (Chernobyl, Ural Region, Semipalatinsk).     

Man-made plutonium in environment — possible serious hazard for living species

It is pointed out that, contrary to the situation with natural Rn, the growing concentration of man-made Pu in environment — natural water soil plants and food — can provide the serious danger for all kind of animals and especially for mankind. Really, as it was established recently, element Pu is accumulated in human body during all the life and the dangerous concentration estimated to be 10⁻¹² – 10⁻¹³ grapm Pu per gram of human tissues. Unfortunately up to now there are no simple nonexpensive methods of Pu determination at the level of sensitivity 10⁻¹⁴ – 10¹⁵ g/g which can provide the determination of Pu even in 0.2 g of human tissue. We warn that now the average concentration of Pu in human body is not less than 10⁻¹⁴ g/g and much higher for some “hot” regions in Europe and Asia. We propose to discuss the problem of organizing world net exploration of Pu in environment — similarly to Rn exploration program — and personnel Pu monitoring for inhibitions of Pu damaged regions. Our approach to the problem is based on chemical separation of Pu, on determination of Plutonium by high fission cross section with thermal neutrons ²³⁹Pu(n,f) reaction and by control of possible admixture of ²³⁵U isotope by ²³⁸U(γ, f) reaction in Pu preparations. The problem of increasing of sensitivity of Pu analysis up to 10⁻¹⁴ – 10⁻¹⁵ g/g is discussed in detail.     

Biocompatible Water Soluble Polyacrylic Acid Coated CdSe/Cu Quantum Dot Conjugates for Biomolecule Detection

Biocompatible polyacrylic acid functionalized CdSe/Cu quantum dot conjugates were synthesized to be used for biomolecules detection. The study results demonstrate the conjugation of the 2.5-3 nm QD with gram negative bacteria with a low detection limit of 28 cfu/ml. The photoluminescence (PL) intensity was correlated to bacterial count, cellular proteins and exopolysaccharides in the tested samples. Confocal Scanning Laser Microscopy (CSLM) images showed significant QD uptake within the cells, both cytoplasm and DNA were the predominant targeted biomolecules, higher fluorescent uptake was shown in gram negative bacteria than that observed for gram positive bacteria. Moreover, PL showed that there was a distinction between live and dead cells as well as gram negative and gram positive cells. Cell viability was not affected even after 6 days (100% viability) rendering it a non-toxic QD. The method is simple and is performed in a single step within approximately 10 min as compared to multi-step protocols for classical microbial count or fluorescent dye staining. All the above results indicate that the CdSe/Cu-PAA QDs are suitable for biomolecule detection, bio-labeling and bioimaging applications.     

Applications of differential scanning calorimetry in developing cryopreservation strategies for Parkia speciosa, a tropical tree producing recalcitrant seeds

Shoot-tips of Parkia speciosa, a recalcitrant seed producing tropical leguminous tree withstood cryopreservation using encapsulation-vitrification in combination with trehalose preculture. Differential scanning calorimetry (DSC) revealed that trehalose moderated the thermal characteristics of the shoot-tips. A 30 min PVS2 treatment had the lowest glass transition temperature (Tg) (-50.2 +/- 1.1 degree C) when applied in combination with 5% (w/v) trehalose. The Tg increased to -40.2 +/- 1.0 degree C as the sugar concentration was decreased to 2.5 percent (w/v). Tg heat capacity for shoot-tips treated with 2.5 percent and 5 percent (w/v) trehalose and exposed to PVS2 for 30 min increased from 0.17 +/ 0.05 to 0.23 +/- 0.01 J per gram, respectively. Enthalpies of the melt-endotherm varied in proportion to trehalose concentration, for the 30 min PVS2 treatment, whereas the melt enthalpy for control shoots was greater than 150 J per gram and decreased to ca. 60 J per gram with 2.5 percent (w/v) trehalose. For 5 percent and 10 percent (w/v) trehalose treatments, enthalpy declined to ca. 24 and 12 J per gram respectively and freezing points were depressed to -75 degree C and -85 degree C with 2.5 percent and 5 percent trehalose (w/v), respectively. DSC elucidated the critical points at which vitrification occurred in germplasm exposed to trehalose and PVS2. A 60 min PVS2 treatment supporting ca. 70 percent survival was found optimal for stable glass formation during cooling and on rewarming.     

Effects of Pr substitution on the hydrogenating process and magnetocaloric properties of La_(1-x)Pr_xFe_(11.4)Si_(1.6)H_y hydrides

In this paper, we study the effects of Pr substitution on the hydrogenating process and magnetocaloric properties of La_(1-x)Pr_xFe_(11.4)Si_(1.6)H_y hydrides. The powder x-ray diffraction patterns of the La_(1-x)Pr_xFe_(11.4)Si_(1.6) and its hydrides show that each of the alloys is crystallized into the single phase of cubic Na Zn_(13)-type structure. There are hydrogen-absorbing plateaus under 0.4938 MPa and 0.4882 MPa in the absorbing curves for the La_(0.8)Pr_(0.2)Fe_(11.4)Si_(1.6) and La_(0.6)Pr_(0.4)Fe_(11.4)Si_(1.6) compounds. The releasing processes lag behind the absorbing process, which is obviously different from the coincidence between absorbing and releasing curves of the La Fe_(11.4)Si_(1.6) compound. The remnant hydrogen content for La_(0.6)Pr_(0.4)Fe_(11.4)Si_(1.6) is significantly more than that for La_(0.8)Pr_(0.2)Fe_(11.4)Si_(1.6) after hydrogen desorption, indicating that more substitutions of Pr for La are beneficial to retaining more hydrogen atoms in the alloys. The values of maximum magnetic entropy change are 14.91 J/kg·K and 17.995 J/kg·K for La_(0.8)Pr_(0.2)Fe_(11.4)Si_(1.6)H_(0.13) and La_(0.6)Pr_(0.4)Fe_(11.4)Si_(1.6)H_(0.87),respectively.     

Calculations of the dynamic dipole polarizabilities for the Li~+ ion

The B-spline configuration-interaction method is applied to the investigations of dynamic dipole polarizabilities for the four lowest triplet states(2~3S,3~3S,2~3P,and 3~3P) of the Li~+ ion.The accurate energies for the triplet states of n~3S,n~3P,and n~3D,the dipole oscillator strengths for 2~3S(3~3S)→n~3P,2~3P(3~3P)→n~3S,and 2~3P(3~3P)→n~3D transitions,with the main quantum number n up to 10 are tabulated for references.The dynamic dipole polarizabilities for the four triplet states under a wide range of photon energy are also listed,which provide input data for analyzing the Stark shift of the Li~+ ion.Furthermore,the tune-out wavelengths in the range from 100 nm to 1.2 μm for the four triplet states,and the magic wavelengths in the range from 100 nm to 600 nm for the 2~3S→3~3S,2~3S→2~3P,and 2~3S→3~3P transitions are determined accurately for the experimental design of the Li~+ ion.     

有机阳离子对卤素钙钛矿太阳能电池性能的影响

采用第一性原理计算了CH_3NH_3PbI_3中有机部分CH_3NH_3~+和CH_3NH_3的静电特性.结果表明:CH_3NH_3~+具有强的亲电特性,CH_3NH_3的CH_3~-端具有弱亲电性,而NH_3~-端具有弱亲核性.发现在CH_3NH_3PbI_3中CH_3NH_3~+之间强静电排斥作用在相变中起着重要的作用,且在室温条件下CH_3NH_3~+在无机笼中具备活性和无序的特性,使得TiO_2/CH_3NH_3PbI_3异质结中n型TiO_2的电子通过界面扩散到CH_3NH_3PbI_3材料,并与CH_3NH_3~+结合形成CH_3NH_3,CH_3NH_3的静电特性导致在内建电场作用下更容易取向,取向的CH_3NH_3周围形成的静电场会变得更弱和更加均匀.这对无机框架上载流子的产生和传输更加有利,这样的异质结比传统的pn结具有更大优势.这是CH_3NH_3PbI_3太阳能电池高的光电转换效率的重要原因.     

氟利昂F1110分子在飞秒激光脉冲作用下的多光子解离动力学

含氟利昂在内的含氯化合物在太阳光辐射下解离生成破坏臭氧的游离态氯原子, 是破坏大气臭氧层的主要元凶. 本文利用飞行时间质谱技术及离子速度成像技术研究了氟利昂F1110(四氯乙烯)分子在800 nm飞秒脉冲光作用下的多光子解离动力学. 利用飞行时间质谱探测技术, 得到了四氯乙烯在800 nm飞秒激光脉冲作用下发生多光子解离产生的碎片质谱, 发现了两个主要碎片离子C₂Cl₃⁺和 C₂Cl₂⁺. 对应的解离机理分别为单个C-Cl键断裂直接生产氯自由基C₂Cl₄⁺→C₂Cl₃⁺ +Cl 和两个C—Cl 键断裂C₂Cl₄⁺→C₂Cl₂⁺+2Cl: 利用离子速度成像技术对这两种机理产生的碎片离子进行成像, 得到了C₂Cl₃⁺ 和C₂Cl₂⁺ 离子的速度影像. 分析发现这两个碎片离子的动能分布均可由两个高斯分布曲线拟合, 说明这两种解离机理分别还对应了两种解离通道. 通过影像分析得到了解离的平动能分布和角向分布各向异性参数等详尽的动力学信息. 通过高精度密度泛函理论计算对解离动力学进行了进一步的分析和讨论.     

ICP-AES法测定石膏中的多元素含量

分别采用酸溶和碱熔两种样品前处理方法处理样品,ICP-AES测定石膏中多元素。酸溶法适用于样品中CaO,SO₃,Al₂O₃,Fe₂O₃,MgO,K₂O,Na₂O,TiO₂,P₂O₅,MnO,SrO,BaO的同时测定。碱熔法适用于样品中CaO,SO₃,SiO₂,Al₂O₃,Fe₂O₃,MgO,TiO₂,P₂O₅,MnO,SrO,BaO,B₂O₃的同时测定。根据各个元素的性质、含量高低和基体因素配制了不同的系列标准溶液,确定了各个元素的最佳分析谱线和相应分析谱线下方法的检出限和定量限。结果表明,除酸溶法测定TiO₂的回收率略低外(81%～87%),两种前处理方法测定石膏样品中各元素的整体回收率为93%～110%,RSD(n=6)为0.70%～3.42%。但CaO和SO₃测定的准确度还比不上化学分析方法。采用本方法测定石膏中的CaO和SO₃仅适用于对测定结果准确度要求相对较低的情况。本方法操作简单,分析速度快,测定结果可靠,可以同时测定石膏中的多元素,综合酸溶和碱熔两种处理方法,可以实现石膏样品的全元素分析。     

Theoretical study of spin-forbidden cooling transitions of indium hydride using ab initio methods

The feasibility of spin-forbidden cooling of the In H molecule is investigated based on ab initio quantum chemistry calculations. The potential energy curves for the X~1Σ_(0~+)~+, a~3Π_~(0~-), a~3Π_(0~+), a~3Π_1, a~3Π_2, A~1Π_1, 1~3Σ_(0~-)~+, and 1~3Σ_1~+states of In H are obtained based on multi-reference configuration interaction plus the Davidson corrections method. The calculated spectroscopic constants are in good agreement with the available experimental data. In addition, the influences of the active space and spin–orbit coupling effects on the potential energy curves and spectroscopic constants are also studied. For Re of a~3Π_(0~-), a~3Π_(0~+), a~3Π_1, and a~3Π_2 states, the error from large active space is small. The potential energy curve of the A~1Π_1state is not smooth for small active space. The spin–orbit coupling effects have great influences on the potential well depth and equilibrium internuclear distance of the A~1Π state. The Franck–Condon factors and radiative lifetimes are obtained on the basis of the transition dipole moments of the a~3Π_(0~+) → X~1Σ_(0~+)~+, a~3Π_1 → X~1Σ_(0~+)~+, and A~1Π_1 → X~1Σ_(0~+)~+ transitions. Our calculation indicates that the a~3Π_1( ν'= 0) → X~1Σ_(0~+)~+(ν = 0) transition provides a highly diagonally distributed Franck–Condon factor and a short radiative lifetime for the a3Π1 state, which can ensure rapid and efficient laser cooling of In H.The proposed laser drives a~3Π_1 → X~1Σ_(0~+)~+ transitions by using three wavelengths.     

Numerical analysis of motional mode coupling of sympathetically cooled two-ion crystals

A two-ion pair in a linear Paul trap is extensively used in the research of the simplest quantum-logic system; however,there are few quantitative and comprehensive studies on the motional mode coupling of two-ion systems yet. This study proposes a method to investigate the motional mode coupling of sympathetically cooled two-ion crystals by quantifying three-dimensional(3 D) secular spectra of trapped ions using molecular dynamics simulations. The 3 D resonance peaks of the ~(40)Ca~+ – ~(27)Al~+ pair obtained by using this method were in good agreement with the 3 D in-and out-of-phase modes predicted by the mode coupling theory for two ions in equilibrium and the frequency matching errors were lower than 2%.The obtained and predicted amplitudes of these modes were also qualitatively similar. It was observed that the strength of the sympathetic interaction of the ~(40)Ca~+ – ~(27)Al~+ pair was primarily determined by its axial in-phase coupling. In addition,the frequencies and amplitudes of the ion pair's resonance modes(in all dimensions) were sensitive to the relative masses of the ion pair, and a decrease in the mass mismatch enhanced the sympathetic cooling rates. The sympathetic interactions of the ~(40)Ca~+ – ~(27)Al~+ pair were slightly weaker than those of the ~(24)Mg~+– ~(27)Al~+ pair, but significantly stronger than those of ~9Be~+ – ~(27)Al~+ . However, the Doppler cooling limit temperature of ~(40)Ca~+ is comparable to that of ~9Be~+ but lower than approximately half of that of ~(24)Mg~+. Furthermore, laser cooling systems for ~(40)Ca~+ are more reliable than those for ~(24)Mg~+and ~9Be~+ . Therefore, ~(40)Ca~+ is probably the best laser-cooled ion for sympathetic cooling and quantum-logic operations of ~(27)Al~+ and has particularly more notable comprehensive advantages in the development of high reliability, compact, and transportable ~(27)Al~+ optical clocks. This methodology may be extended to multi-ion systems, and it will greatly aid efforts to control the dynamic behaviors of sympathetic cooling as well as the development of low-heating-rate quantum logic clocks.     

High-pressure elastic anisotropy and superconductivity of hafnium:A first-principles calculation

The elastic anisotropy and superconductivity upon hydrostatic compression of α, ω, and β Hf are investigated using first-principle methods. The results of elastic anisotropies show that they increase with increasing pressure for α andω phases, while decrease upon compression for β phase. The calculated superconducting transition temperatures are in excellent agreement with experiments. Electron–phonon coupling constants(λ) are increasing with pressure for α and ωphases, while decreasing for β phase. For β phase, the large values of λ are mainly due to the obvious TA1 soft mode.Under further compression, the TA1 soft vibrational mode will disappear gradually.     

Enhancement of AC-losses of magnetic nanoparticles for heating applications

Aqueous ferrofluids of maghemite nanoparticles coated with carboxydextran were investigated with respect to their specific loss power (SLP) in dependence on frequency and field amplitude of magnetic AC-fields. In order to elucidate the effect of the size distribution on SLP fluid fractions with different mean particle core size were prepared by a magnetic separation procedure from the original ferrofluid. Structural characterisation by means of TEM and XRD as well as reconstruction of core size distributions from magnetisation curves reveals that the narrow size distributions of the fractions cover a range of mean core sizes from about 8 up to 20 nm. Spectra of the complex susceptibility were measured for a frequency range of 20 Hz to 1 MHz. From the imaginary part of the susceptibility the specific loss power is calculated in dependence on frequency. The results are compared with calorimetrical measurements performed in dependence on field amplitude up to 11 kA/m at 410 kHz. A very high specific loss power in the order of 400 W per gram maghemite was found at 410 kHz and 11 kA/m for the fluid fraction having the largest mean core diameter. A deviation from linear response behaviour is found for this sample showing a power law field dependence of the specific loss power SLPH^2.5. In addition to liquid suspensions measurements were performed with particles immobilised in mannitol or gel in order to elucidate the role of Brownian relaxation. The experimentally found dependence of SLP on the mean particle core diameter may be understood in the frame of the Debye dispersion model. Results are discussed with respect to applications of ferrofluids in RF-magnetic hyperthermia.     

氟利昂F113分子在飞秒激光作用下的多光子电离解离动力学

大气臭氧层因吸收太阳紫外光, 是人类必不可少的保护伞. 氟利昂在太阳光辐射下解离生成破坏臭氧的游离态氯原子, 是破坏大气臭氧层的主要元凶之一. 本文利用飞行时间质谱技术和离子速度成像技术研究了氟利昂F113(三氟三氯乙烷)分子在800 nm 飞秒光作用下的多光子电离解离动力学. 利用飞行时间质谱探测技术, 得到了三氟三氯乙烷在该波长飞秒激光作用下发生多光子电离解离产生的碎片质谱. 通过荷质比对碎片质谱进行了详细的标定和分析. 在质谱上未发现母体离子, 所有观察到的离子都是由于激光脉冲作用下产生的碎片. 三个最主要的碎片离子是CFCl₂⁺, CF₂Cl⁺, C₂F₃Cl₂⁺. 通过飞行时间质谱标定, 发现并归属了多个解离通道. 三个主要的解离机理分别为: 1) C-Cl键断裂直接生产氯自由基的通道C₂F₃Cl₃⁺→C₂F₃Cl₂⁺+Cl; 2) C--C键断裂C₂F₃Cl₃⁺→CFCl₂⁺+CF₂Cl; 3) C--C键断裂C₂F₃Cl₃⁺→CF₂Cl⁺+CFCl₂. 利用离子速度成像技术对这三个主要通道产生的碎片离子进行成像, 得到了C₂F₃Cl₂⁺, CFCl₂⁺和CF₂Cl⁺离子的速度影像. 由C--Cl键断裂产生的碎片离子C₂F₃Cl₂^{+}的速度分布由两个高斯分布曲线拟合, 而由C--C键断裂产生的碎片离子CFCl₂⁺和CF₂Cl⁺可以用一个高斯曲线拟合. 通过影像分析得到了解离碎片的平动能分布和角向分布各向异性参数等详尽的动力学信息. 结合高精度密度泛函理论计算对解离动力学进行了进一步的分析和讨论.深入认识氟利昂的解离动力学可为进一步控制破坏臭氧层提供理论参考和实验依据.     

Folding Model Analysis of Elastic Scattering of 11B from Light,Medium, and Heavy Nuclei

The elastic scattering angular distributions of ¹¹B projectile on light, medium, and heavy target nuclei including ⁷Li, ⁹Be, ¹²C, ¹⁶O, ^24,25,26Mg, ²⁷Al, ²⁸Si, ⁴⁰Ca, ⁵⁸Ni, ⁵⁹Co, ⁶⁰Ni, ¹⁹⁷Au, ²⁰⁸Pb, and ²⁰⁹Bi have been analyzed at various incident energies. The theoretical results have been obtained by using two different nuclear potentials within the framework of the optical model (OM). Firstly, the double folding potential for real part and the Wood-Saxon (WS) potential for imaginary part have been applied. Secondly, the calculations with double folding potential for both real and imaginary part have been performed and compared with the experimental data. It has been seen that the results are in very good agreement with the experimental data. Also, the volume integrals and cross-sections for each reaction have been obtained. Finally, a new and simple formula for the imaginary potential depth has been derived to clarify the nuclear interactions of ¹¹B nucleus at low energy reactions.     

First-principles calculations of nitrogen-doped antimony triselenide: A prospective material for solar cells and infrared optoelectronic devices

This study is focused on calculation of the electronic structure and optical properties of non-metal doped Sb2Se3 using the first-principles method. One and two N atoms are introduced to Sb and Se sites in a Sb₂Se₃ crystal. When one and two N atoms are introduced into the Sb₂Se₃ lattice at Sb sites, the electronic structure shows that the doping significantly modifies the bandgap of Sb₂Se₃ from 1.11 eV to 0.787 and 0.685 eV, respectively. When N atoms are introduced to Se sites, the material shows a metallic behavior. The static dielectric constants ε1(0) for Sb₁₆Se₂₄, Sb₁₅N₁Se₂₄, Sb₁₄N₂Se₂₄, Sb₁₆Se₂₃N₁, and Sb₁₆Se₂₂N₂ are 14.84, 15.54, 15.02, 18.9, and 39.29, respectively. The calculated values of the refractive index n(0) for Sb₁₆Se₂₄, Sb₁₅N₁Se₂₄, Sb₁₄N₂Se₂₄, Sb₁₆Se₂₃N₁, and Sb₁₆Se₂₂N₂ are 3.83, 3.92, 3.86, 4.33, and 6.21, respectively. The optical absorbance and optical conductivity curves of the crystal for N-doping at Sb sites show a significant redshift towards the short-wave infrared spectral region as compared to N-doping at Se sites. The modulation of the static refractive index and static dielectric constant is mainly dependent on the doping level. The optical properties and bandgap narrowing effect suggest that the N-doped Sb₂Se₃is a promising new semiconductor and can be a replacement for GaSb due to its very similar bandgap and low cost.     

Potential energy curves,transition dipole moments,and radiative lifetimes of KBe molecule

An ab initio calculations on the ground and low-lying excited states(X~2Σ+, 2~2Σ+, 3~2Σ+, 1~4Π, 2~4Π, 1~4Σ~+, 2~4Σ~+,and 3~4Σ~+) of KBe molecule have been performed using multireference configuration interaction(MRCI) plus Davidson corrections(MRCI+Q) approach with all electron basis set aug-cc-p CV5Z-DK for Be and def2-AQZVPP-JKFI for K.The 3~2Σ+, 1~4Π, 2~4Π, 1~4Σ~+, 2~4Σ~+, and 3~4Σ~+states are investigated for the first time. Inner shell electron correlations are computed on the potential energy curves(PECs) calculations. The spectroscopic and molecular parameters are also predicted. In addition, The transition properties including transition dipole moment, Franck–Condon factors qv'v', Einstein coefficients Av'v', and the radiative lifetimes τυ for the 2~2Σ~+–X~2Σ~+, 3~2Σ~+–X~2Σ~+, and 2~4Π–1~4Π transitions are predicted at the same time.     

GeS分子基态和低激发态的势能曲线与光谱性质

本文以aug-cc-pv5Z为基组, 采用考虑Davidson修正的多参考组态相互作用方法(MRCI+Q)得到了GeS分子基态(X¹Σ⁺)和5个低激发态(1¹Σ, 1¹Δ, A¹Π, 1⁵Σ⁺, 2⁵Σ⁺)的势能曲线. 计算结果表明: 2⁵Σ⁺态为排斥态, 其余5个态为束缚态; 6个态有着共同的离解通道, 离解极限均为Ge(³P)+S(³P). 利用计算得到的势能曲线得了X¹Σ⁺, 1¹Σ^-, 1¹Δ, A¹Π和1⁵Σ⁺态的垂直跃迁能T_e, 平衡键长R_e, 离解能D_e, 谐振频率ω_e, 非谐性常数ω_ex_e及平衡位置的电偶极矩. X¹Σ⁺态的R_e 为2.034 Å, D_e 为5.728 eV, ω_e为571.73 cm^-1, ω_ex_e为1.6816 cm^-1, 平衡位置的电偶极矩为1.9593 Debye. 激发态1¹Σ, 1¹Δ, A¹Π, 1⁵Σ⁺的T_e 依次为25904.81, 26209.22, 32601.19, 43770.26 cm^-1; R_e依次为2.313, 2.322, 2.188, 2.8790 Å; D_e依次为2.524, 2.487, 1.694, 0.3036 eV, ω_e依次为358.90, 353.08, 376.32, 134.96 cm^-1; ω_ex_e依次为1.2421, 1.2151, 1.6608, 1.9095 cm^-1; 平衡位置的电偶极矩依次为1.3178, 1.4719, 1.5917, -1.9785 Debye. 通过求解核运动的薛定谔方程得到了J=0时X¹Σ⁺, 1¹Σ^-, 1¹Δ, A¹Π和1⁵Σ⁺态前30个振动态的振动能级G_v和分子常数B_v, 得到的结果和已有的实验值及其他理论值符合较好.     

Investigation of relative sputtering yields during ionoluminescence of Si

Atomic line emissions resulting from sputtered atoms and ions are investigated on Si(100) bombarded by 60 keV Ne⁺, 300 keV Xe⁺ and 300 keV SF₅⁺ ions. It has been observed that the presence of oxygen enhances light emission due to radiative de-excitation. Relative sputtering yields of Si for 60 keV Ne⁺, 300 keV Xe⁺ and 300 keV SF₅⁺ are estimated from the photon yields. The estimates of sputtering yields of adsorbed oxygen on Si for the above projectiles are also made from the transients of Si I 251.6 nm line. A non-linearity in the sputtering yield for SF₅⁺ ions was observed in comparison with the yields for Ne⁺ and Xe⁺ ions. The results are discussed with the model of overlapping of individual collision cascades.