Der Zerfall des Se71

The present paper starts form the original Ginzburg-Landau-equations of superconductivity and the linear theory of elasticity for internal stresses as well as the experimental fact that the specific volume and the elastic constants vary throughout the superconducting phase. With the aid of phenomenological expressions for the free energy and the spontaneous deformation (superconductive magnetostriction) of a deformable type II superconductor, a general method is given for the determination of the interaction between the field of the order parameter, the magnetic field, and the field of the elastic deformations. For an isolated straight vortex-line and for a straight vortex-line in the neighbourhood of a dislocation of arbitrary character, formulas for the internal stresses are derived using first order perturbation theory (corresponding to first powers in the changes of specific volume and elastic constants).     

Energy levels of 71Ge from 71Ga(p,nγ)71Ge

Energy levels of ⁷¹Ge were populated by the ⁷¹Ga(p, n) reaction at proton energies between 1.72 and 2.96 MeV and their decay studied by both γ-γ and γ-n coincidences. Spins were determined within the framework of the statistical theory from angular distributions of de-excitation γ-rays and from excitation strengths of levels derived from γ-ray intensities and branching. A level and decay scheme for ⁷¹Ge up to an excitation of 1.3 MeV is presented.     

Cross Section of Neutrino Absorption by the Gallium-71 Nucleus

Physics of Atomic Nuclei - The cross sections of neutrino absorption by the gallium-71 nucleus are obtained for neutrinos from artificial 37Ar, 51Cr, and 65Zn sources. The calculations rely on the...     

Doublet structure of the first excited state of 71As

The possible multiplet structure of the first-excited state of ⁷¹As has been investigated by the high resolution ⁷⁰Ge(³He, dγ) reaction and the γ-rays emitted in the decay of ⁷¹Se. Both studies reveal a doublet at 143.2 keV and 147.3 keV excitation energies. The existence of this doublet in ⁷¹As brings the low-lying level structure in better resemblance to the heavier odd-A arsenic isotopes.     

Beta-decay of 71Co and 73Co

A decay spectroscopy study of the neutron-rich cobalt isotopes has been performed using fragmentation of a ⁸⁶Kr³⁶⁺ beam and the new LISE2000 spectrometer at GANIL. For ⁷¹Co and ⁷³Co, the -delayed radiation has been observed for the first time, and the half-lives were found to be 79(5) ms and 41(4) ms, respectively. Features of the decay are discussed qualitatively in terms of nuclear models.     

Effect of chemical structure on the radioactive decay rate of71Ge

The influence of the chemical structure on the electron capture radioactive decay rate of⁷¹Ge was observed.⁷¹Ge nuclei in bivalent sulphide GeS decay faster than in quadrivalent sulphide GeS₂. The relative change / of the decay constant is+(11.4±1.7) · 10^–4.A possibility to use the experimental values of / to determine the chemical changes in the electron density at germanium nuclei in germanium chemical compounds is discussed. Quantitative determination of the changes in the electron density is complicated because of insufficient reliability of the published values of exchange and overlap corrections to the electron capture probabilities.     

High spin states in ~(71)Ga

Excited states in the odd-A nucleus ~(71)Ga have been studied via the ~(70)Zn(~7 Li,α2 n)~(71)Ga fusion-evaporation reaction with incident beam energies of 30 and 35 MeV.The level scheme is established up to spin I~π=(29/2~+)and an excitation energy ～6.6 MeV.A previously known sequence built on the 9/2~+ state is extended as a novel rotational band originating from the v(g_(9/2)~2) alignment.Furthermore,a negative-parity sequence is also reported.The observed energy levels of ~(71)Ga have been interpreted in the framework of the nuclear shell model(SM).     

On the structure of71As and 73As

The structure of the nuclei ⁷¹As and ⁷³As has been investigated by studying the decay of ⁷¹Se, ^73gSe and ^73mSe, the ⁷²Ge(p, 2nγ)⁷¹As reaction, the ⁷³Ge(p, nγ)⁷³As reaction and the ⁷²Ge(³He, d) ⁷³As reaction. Level schemes of ⁷¹As and ⁷³As are constructed on basis of the energies and intensities of the gamma transitions and their coincidence relations. Spins and parities are deduced from log ft values, l-values and the decay properties of the excited states. The measured half-life of the lowest excited state in ⁷¹As is $\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{= 59 ± 10}\text{ns}$. The experimental level-schemes are compared with the predictions of the cluster-vibrational coupling model.     

Beta decay of 94Pd and of the 71 s isomer of 94Rh

The β decay of ⁹⁴Pd and of the 71s isomer of ⁹⁴Rh was investigated by using total γ-ray absorption techniques. Several levels in ⁹⁴Rh are established, including a new low-lying isomer characterized by a half-life of 0.48(3)μs and a de-exciting transition of 55keV. E2 multipolarity is determined for this transition by measuring the intensities of its γ-rays and the characteristic X-rays from its electron conversion. On the basis of the measured reduced β-decay transition rates to known ⁹⁴Ru levels and shell model considerations, the spin-parity of the 71s and the 0.48μs isomers of ⁹⁴Rh is assigned to be (4⁺) and (2⁺), respectively. The β-decay strength distributions measured for ⁹⁴Pd and the 71s isomer of ⁹⁴Rh yield Q _EC values of 6700(320) and 9750(320)keV for these decays and give evidence for the population of those states below and above the magic N = 50 gap that belong to both components of the 0g spin-orbit doublet.     

A planar subharmonically-pumped 71 GHz receiver with integral feed antenna

A planar, subharmonically-pumped, hybrid millimeter-wave receiver with integral antenna is described. Coplanar waveguide filters are used to isolate the ports and provide image enhancement. The integral planar antenna has 12 dB gain and is suited for use as a feed. The main lobe is normal to the substrate surface. The receiver is designed for an instantaneous bandwidth of 10 GHz. Experiments at 71 GHz indicate single-sideband mixer conversion loss of 6.5 dB. We believe that this represents the highest level of integration yet demonstrated in this frequency range.     

Influence of morphology of PCDTBT:PC71BM on the performance of solar cells

Because of the restriction of low energy difference between the highest occupied molecular orbital of P3HT and the lowest unoccupied molecular orbital of PCBM, the obtained power conversion efficiency of P3HT:PCBM solar cells is merely half the ideal value. In this paper, we have fabricated bulk heterojunction solar cells based on PCDTBT and PC71BM (structure: ITO/PEDOT:PSS/PCDTBT:PC71BM/LiF (0.8 nm)/Al (80 nm)). In order to optimize the performance of the cells, the weight ratio of PCDTBT to PC71BM, the thickness of the active layer and thermal annealing are investigated. When the weight ratio of PCDTBT to PC71BM is 1:2 and the thickness of the active layer is 73 nm, a short circuit current density of 10.36 mA/cm², an open-circuit voltage of 0.91 V, a fill factor of 55.06 % and a power conversion efficiency of 5.19 % can be achieved. Moreover, we probe the influence of annealing temperature on the performance of organic solar cells, and find that the thermal treatment methodology (apart from the removal of trapped casting solvent) is of limited benefit.     

GaP中1.71eV发光带的研究

本文研究了GaP中普遍出现的1.71eV光致发光(PL)宽带。这是一个与多个杂质能级有关的发光带,由吸收谱和光致发光激发谱(PLE)检测到在价带上方0.37—0.089eV范围内与该发光带有关的深能级。时间分辨谱测量表明。随着衰减过程的延续,谱峰移向低能方向,说明该带起源于D—A对复合。讨论了该发光带与背景Cu杂质有关的可能性及其发光机制和激发途径。