在独立α集团模型下对敲出反应16O(p,pα)12C和16 O(α,2α)12C的研究

在独立α集团模型下，利用扭曲波冲量近似(DWIA)，计算了实验室系下入射能量为101.5MeV 的敲出反应¹⁶O(p，pα)¹²C和实验室系下入射能量分别为90Me V和140MeV 的敲出反应¹⁶O(α,2α)¹²C.得到的反应截面和谱因子与实 验数据基本符 合，比用壳模型的结果有了一定的改进，表明独立α集团模型能较好地描述α集团敲出反应 的机理. 关键词： α集团模型 敲出反应 反应截面 谱因子     

On the use of yttrium and sodium anodes in photoelectron spectroscopy

Low-cost anodes of the active metals yttrium and sodium were constructed and used under modest vacuum conditions. The yttrium Mζ line (132.3 eV) was used to determine np/ns cross-section ratios in the valence shells of three rare gases. The NaKα_{1 2} line and its satellites were characterized with a neon converter. It yielded a linewidth of 0.58(1) eV on the neon 1s line, from which an upper limit of 0.42 eV was set for the NaKα_{1 2} X-ray linewidth. On several “test cases” the NaKα _{1 2} X-ray fell between other characteristic X-rays (e.g., MgKα _{1 2}) and monochromatized sources in its ability to resolve fine structure. The methane C 1s peak was asymmetric and the correct vibrational spacing was obtained by fitting with three components of the correct intensity ratios. Similarly, relative chemical shifts of the unsubstituted carbons in m-difluorobenzene were determined almost completely by fitting the asymmetric peak. In the PF₅ (F 1s) and O₂ (O 1s) cases some new information was obtained.     

明永乐青花瓷片的显微拉曼光谱分析

利用显微拉曼光谱对明永乐青花瓷釉及釉中的结晶物进行了分析,釉的拉曼谱中Si-O弯曲振动与伸缩振动峰的面积比(Ip=A500/A1000)与陶瓷的烧成温度相关连。同时在釉中还发现有Fe3O4、α-Fe2O3、Co3O4、MnO、Mn2O3、硅酸钙、磷酸钙等结晶物。研究结果表明,显微拉曼光谱是一种简便、可靠的无损检测手段,对古陶瓷的鉴定与分析有重要的应用意义。     

Ionization energies of the N2, CO,CO2, N2O,C2H2 and SiH4 molecules calculated by universal model potential

Acta physica Academiae Scientiarum Hungaricae - A modified XαSW method with universal potential (MXαSWU) was used to calculate ionization energies of the N2, CO, CO2, N2O, C2H2 and SiH4...     

Synthesis of ZnAl2O4/α-Al2O3 complex substrates and growth of GaN films

With the solid phase reaction between pulsed-laser-deposited (PLD) ZnOfilm and α-Al2O3 substrate, ZnAl2O4/α-Al2O3 complex substrates were synthesized. X-ray diffraction (XRD) spectra show that as the reaction proceeds, ZnAl2O4 changes from the initial (111)-oriented single crystal to poly-crystal, and then to inadequate (111) orientation. Corresponding scanning electron microscope (SEM)images indicate that the surface morphology of ZnAl2O4 transforms from uniform islands to stick structures, and then to bulgy-line structures. In addition, XRDspectra present that ZnAl2O4 prepared at low temperature is unstable at the environment of higher temperature. On the as-obtained ZnAl2O4/α-Al2O3 substrates, GaN films were grown without any nitride buffer using light-radiation heating low-pressure MOCVD (LRH-LP-MOCVD). XRD spectra indicate that GaN film on this kind of complex substrate changes from c-axis single crystal to poly-crystal as ZnAl2O4 layer is thickened. For the single crystal GaN, its full width at half maximum (FWHM) of X-ray rocking curve is 0.4°. Results indicate that islands on thin ZnAl2O4 layer can promote nucleation at initial stage of GaN growth, which leadsto the (0001)-oriented GaN film.     

O（αsV2） correction to J/ψ plus ηc production in e＋e-annihilation at √s=10.6 GeV

Based on the nonrelativistic QCD factorization approach, O（αsv2） corrections to J/ψ plus ηc production in e＋e- annihilation at √s= 10.6 GeV are calculated in this work. The numerical results show that the correction at αsv2 order is only about a few percent of the total theoretical result. This indicates that the perturbative expansions become convergent and that a higher order correction will be smaller. The uncertainties from the long-distance matrix elements, renormalization scale and the measurement in the experiment are also discussed. Our result is in agreement with the previous result by Jia.     

On the corrections of the wave function in weakly bound quarkonium

A non-relativistic quark-antiquark system with perturbative gluonic interactions (quarkonium) is considered, which allows a systematic expansion in the strong coupling constant α_s. In a non-abelian gauge theory, non-trivial corrections of the wave function already occur to O(α_s). We emphasize the existence of a renormalization, which is “natural” for such a system leaving only little freedom in the choice of the renormalization point Λ. The general corrections to O(α_s) including coulombic binding are presented. An explicit application to the lowest-order gluonic corrections of the leptonic decay of quarkonium is made. In this process the new term is sometimes much larger than the gluonic correction at the photon vertex and it varies greatly between different coulombic (S-wave) bound states.     

5α-雄甾烷-3,17二-酮在一元溶剂中的红外光谱

在20种不同纯有机溶剂中,研究了5α-雄甾烷-3,17-二酮C3位和C17位羰基的红外光谱。将其羰基伸缩振动频率分别与经验溶剂参数如溶剂接受数AN、Brownstein的溶剂参数S和Schleyer线性自由能方程参数G值进行了相关分析。结果表明,C3位C=O在一元溶剂体系中出现2种谱带,而C17位C=O则出现3种谱带。羰基伸缩振动频率位移与AN值、G值具有较好的线性相关性,而在非醇溶剂中与S值线性相关较差。采用简单化合物丙酮分别对溶剂硝基苯、乙腈、二氯甲烷和氯仿的S值进行修正,并将复杂甾酮化合物5α-雄甾烷-3,17-二酮的羰基红外频率与S修正值进行线性分析,相关性良好。     

CalciumK X-ray spectra produced by oxygen,alpha-particle,and proton bombardment

Kα andKβ X-rays of calcium were produced by bombarding a thick calcium wafer with oxygen, helium and hydrogen ions. These reactions produce a substantial amount of inner shell ionization. TheK X-ray spectra contain X-ray lines from calcium which emanate from initial states with a varying degree ofK orL shell vacancies. The initial configurations were assigned on the basis of Hartree-Fock-Slater calculated energies. Related intensity ratio of1s→2p (Kα) transitions and of1s→3p (Kβ) transitions of H plus Ca, He plus Ca and O plus Ca were obtained. In addition to observing many new transitions due to multipleK and/or multipleL shell vacancies, energy shifts relative to the H plus Ca spectrum were observed in the O plus Ca spectrum due toM shell vacancies.     

Dominance of α decay from the isoscalar giant quadrupole resonance in 16O

The charged particle (c) decay of the isoscalar giant quadrupole resonance in a ¹⁶O has been studied in a ¹⁶O(α,α'c) coincidence experiment at E_α=155 MeV. The J=2 character of this resonance was established by angular correaltion measurements. Its dominant decay proceeds through the α₁ channel which contains about 40% of the E2 energy weighted sum rule. This explains difficulties of capture reactions to locate the GQR.     

16O(α,γ)20Ne反应的实验研究

讨论了目前16O(α ,γ) 2 0 Ne反应的实验研究工作 ,并对2 0 Na β+—→2 0 N →16O +α的β+ 缓发衰变α能谱的相对强度值同文献进行了比较 ,讨论了低能激发能级、共振强度及其对共振截面的贡献、S因子的理论研究.The experimental investigations of 16 O(α,γ) 20 Ne reaction is reviewed. The energy spectrum of β + delay α decay were measured through the 20 Naβ +-→ 20 Ne *→ 16 O+α process, and the relative densities of α decays are compared with the reference s results. The low excitation energy levels, resonance strength and its contribution to the resonance crosses section are also discussed. Finally, we have calculated the reaction rate of the direct capture reaction.......     

First-principles FP-LAPW calculations and X-ray spectroscopy studies of the electronic structure of Zr3V3O and Zr3V3O0.6 oxides

Electronic properties of Zr₃V₃O oxide, a very promising hydrogen-storage material, were studied both from theoretical and experimental points of view employing the full potential linearized augmented plane wave (FP-LAPW) method as well as X-ray photoelectron spectroscopy (XPS) and X-ray emission spectroscopy (XES). Total and partial densities of states of the constituting atoms of Zr₃V₃O have been derived from the FP-LAPW calculations. These data indicate that, the O 2p-like states are the dominant contributors in the bottom of the valence band, whilst the top of the valence band and the bottom of the conduction band of Zr₃V₃O are dominated by contributions of the V2 3d-like states, with slightly smaller contributions of the V1 3d-like states as well. Significant contributions of the Zr 4d-like states throughout the whole valence-band region and near the bottom of the conduction band are also characteristic of the electronic structure of Zr₃V₃O. The XPS valence-band spectra and the XES Zr Lβ_2,15, V L_α and O K_α bands have been derived and compared on a common energy scale for Zr₃V₃O and Zr₃V₃O_0.6 oxides. This comparison of the experimental spectra was found to be in excellent agreement with the results of the FP-LAPW calculations. In addition, the XPS Zr 3d, V 2p and O 1s core-level binding energies have been measured for Zr₃V₃O and Zr₃V₃O_0.6 oxides.     

提高InGaAsP/InP DH面发光管输出光功率的研究

用改进了的射频溅射仪,对InGaAsP/InPDH面发光管窗口沉积Al2O3抗反射层,以提高光功率的输出。本文采用了两种涂层途径,其一是对单个发光管窗口直接涂层,另一则是对发光管管芯片上窗口涂层,并对二者作了比较。     

Evidence for boson-mode excitations in the16O(α,n) and20Ne(α,n) excitation functions

Excitation functions for¹⁶O(α,n) and²⁰Ne(α,n) have been measured from threshold to 26 and 31 MeV compound excitation energy, respectively. The dominating compound states are interpreted as boson excitation modes of nuclei with α-particle structure.     

The K-matrix parametrization of the 12C(α, γ)16O cross section

The experimental data on the El part of the ¹²C(α, γ)¹⁶O cross section and the l = 1 phase shift of ¹²C(α, α)¹²C are analyzed in terms of a two-channel, two-level approximation of a modified K-matrix. The latter allows a unitary parametrization, avoids computing Coulomb wave functions and does not require introducing channel radii; at low energies, it differs very little from the conventional K-matrix. Simple results are obtained which allow the extrapolation of the ¹²C(α, γ)¹⁶O cross section to lower energies of astrophysical interest (E_α(c.m.) ≈ 300 keV). Our results are compared with those of other parametrizations and suggestions are made to improve the uncertainties resulting from the best data presently available.     

On the relationship between string low-energy effective actions and O(α′3) σ-model β-functions

We examine in detail the connection between low-energy string effective actions and the σ-model β-functions up to O(α^′3) in the torsion-free case. In particular we show that the relationship between, on the one hand, the equations of motion derived from the O(α^′3) string effective action, and, on the other hand, the O(α^′3) σ-model β-functions necessarily involves derivative operators acting on the β-functions.     

The interfacial structure of water/protonated α-Al2O3 (11 ?20) as a function of pH

Sum frequency vibrational spectroscopy (SFVS) was used to study the structure of the protonated α-Al(2)O(3) (11 ?20), and water/α-Al(2)O(3) (11 ?20) interfaces as a function of pH. By combining SFVS spectra with an oxygen-terminated model suggested by x-ray reflectivity, we are able to understand several details of the protonated α-Al(2)O(3) (11 ?20) interface structure. For example, the spectral changes observed for the water/α-Al(2)O(3) (11 ?20) interface with varying pH could be accounted for by the protonation/deprotonation of particular surface hydroxyls. Our spectra also indicate that the point of zero charge for this interface is at pH ~ 6.7.     

First-principles study of the adhesive and mechanical properties of the O-terminated α-Al2O3(0001)/Cu(111) interfaces

Adhesive and mechanical properties of the O-terminated (O-rich) α-Al₂O₃(0001)/Cu(111) interface have been examined by the first-principles pseudopotential method. Strong Cu–O covalent and ionic interactions exist, such as Cu3d–O2p hybridization and substantial electron transfer from Cu to O, which result in larger adhesive energy, greater tensile strength and larger interfacial Young's moduli than the Al-terminated (stoichiometric) interface with electrostatic–image and Cu–Al hybridization interactions. Substantial effects of interfacial Cu–O coordination are also present. Changes in the interface electronic structure for cleavage have been examined. Cu–O interlayer potential curves have been analyzed using the universal binding energy relation and compared with Cu–Al and Cu–Cu curves, which is valuable for the development of effective interatomic potentials in large-scale simulations.     

DWBA analysis of the reaction 12C(α, n)15O

Angular distributions of neutrons from the reaction ¹²C(α, n)¹⁵O(g.s.) have been measured at lab energies from 18.4 to 23.1 MeV and angles ranging from 0° to 130°, using a time-of-flight technique. The experimental curves generally show a forward peaking and a strong dependence on the incident energy. The data were compared with the angular distributions predicted by the distorted-wave theory of direct Nuclear reactions, and no agreement could be obtained when only a stripping mechanism was taken into account.