Zhang Yan-Ping

Oscillator Strength for n = 2 Transitions in Highly Ionized Sulfur

Oscillator strength f-values for L-shell transitions in highly ionized sulfur are studied by the beam-foil technique at the HI-13 tandem accelerator in China Institute of Atomic Energy. The lifetimes of the upper levels 2s2p P-1(1)o, 2p(2) S-1(0), 2p(2) P-3(1), 2p(2) P-3(2), 2p(2) P-3(0) of Be-like sulfur are measured to be 129 +/- 4, 81 +/- 5, 165 +/- 7, 159 +/- 8, 176 +/- 11 ps. By using the measured lifetimes, the f-values are calculated to be 0.074, 0.082, 0.060, 0.066, 0.229, 0.056, 0.083, 0.089, 0.028 for the transitions 2s(2)2p(2) P-3(1)-2s2p(3) P-3(1)o, 2s(22)p P-2(3/2)o-2s2p(2) P-2(1/2), 2s2p(2) P-4(3/2)-2p(3) S-4(3/2)o, 2s(2)2p P-2(1/2)o-2s2p(2) D-2(3/2), 2s(2) S-1(0)-2s2p P-1(1)o, 2s2p(1) P-1(o)-2p(2) S-1(0), 2s2p(3) P-0(o)-2p(2) P-3(1), 2s2p P-3(2)o-2p(2) P-3(2) and 2s2p P-3(1)o-2p(2) P-3(0). Most of the experimental results are in agreement with theoretical studies, but differ slightly from the previous experimental data.

Time-Dependent Density-Functional Calculations for Optical Spectra of Na2 and Na4 Clusters

With the frame of the time-dependent local density approximation, an efficient description of the optical response of clusters has been used to study the photo-absorption cross section of Na-2 and Na-4 clusters. It is shown that our calculated results are in good agreement with the experiment. In addition, our calculated spectrum for the Na-4 cluster is in better agreement with experiment than the GW absorption spectrum.

High-order harmonic generation and multi-photon ionization of Na2 in laser fields

In this paper high-order harmonic generation (HHG) spectra and the ionization probabilities of various charge states of small cluster Na2 in the multiphoton regimes are calculated by using time-dependent local density approximation (TDLDA) for one-colour (1064 nm) and two-colour (1064 nm and 532 nm) ultrashort (25 fs) laser pulses. HHG spectra of Na2 have not the large extent of plateaus due to pronounced collective effects of electron dynamics. In addition, the two-colour laser field can result in the breaking of the symmetry and generation of the even order harmonic such as the second order harmonic. The results of ionization probabilities show that a two-colour laser field can increase the ionization probability of higher charge state.

Spectra of highly ionized nickel

The spectrum of highly ionized nickel in the region 12-40nm was studied by means of the beam-foil method. Nickel ions of 45 and 70MeV were provided by the HI-13 tandem accelerator at China Institute of Atomic Energy. Numerous lines attributed to Ni XIII to XX transitions have been identified, and eighteen lines of them were newly measured.

Microbial electrosynthesis: CO 2 fixation driven by electricity

Carbon dioxide (CO2) is a widespread carbon resource on the earth. The biological conversion of CO2 into organic compounds is an important route for production of biofuels and bio-based chemicals. Owing to the insufficient energy supply and inefficient catalytic activities, the efficiency for biological CO2 fixation remains to be low. The electricity-driven reduction of CO2 using whole microorganisms, which termed as microbial electrosynthesis, provides a novel strategy for biological conversion of CO2. This review summarizes recent advances on microbial electrosynthesis, which covers the microorganisms used for electrosynthesis, extracellular electron transfer, and selection of electrode materials. Furthermore, future challenges and prospects of microbial electrosynthesis were discussed.

Spectra of Highly Ionized Sulfur below 200 Å

Spectra of carbon-, boron-, beryllium-, lithium-, helium-, and hydrogen-like sulfur ions were obtained and studied for the wavelengths below 200 A and the energy of 80 MeV by using beam-foil method. Thirty-five lines have been identified, in which 15 lines are newly accurately measured. The spectra were analysed based on the theoretical results and other experimental data.