[en] High-spin states in "1"8"9Pt are populated through the heavy-ion fusion-evaporation reaction"1"7"6Yb ("1"8O, 5n)"1"8"9Pt at 87MeV beam energy. An array consisting of 13 HPGe detectors is used in conjunction with the plunger device in CIAE. The lifetimes of two levels in the yrast band are determined by using the recoil distance Doppler shift method. The transition quadrupole moments Q_t are extracted. The results show that the (17"+)/2 state has a much larger Q_t value than that of the ground state, whereas the value deceases quickly with spin increasing. This may contribute to the shape driving effect of the quasi-neutron from the i_1_3_/_2 orbital.

[en] Ultrafast anisotropic decay is a prominent parameter revealing ultrafast energy and electron transfer; however, it is difficult to be determined reliably owing to the requirement of a simultaneous availability of the parallel and perpendicular polarized decay kinetics. Nowadays, any measurement of anisotropic decay is a kind of approach to the exact simultaneity. Here we report a novel method for a synchronous ultrafast anisotropy decay measurement, which can well determine the anisotropy, even at a very early time, as the rising phase of the excitation laser pulse. The anisotropic decay of the B850 in bacterial light harvesting antenna complex LH2 of Rhodobacter sphaeroides in solution at room temperature with coherent excitation is detected by this method, which shows a polarization response time of 30 fs, and the energy transfer from the initial excitation to the bacteriochlorophylls in B850 ring takes about 70 fs. The anisotropic decay that is probed at the red side of the absorption spectrum, such as 880 nm, has an initial value of 0.4, corresponding to simulated emission, while the blue side with an anisotropy of 0.1 contributes to the ground-state bleaching. Our results show that the coherent excitation covering the whole ring might not be realized owing to the symmetry breaking of LH2: from C_9 symmetry in membrane to C_2 symmetry in solution. (atomic and molecular physics)

[en] We synthesize hollow-structured Ag@Au nanoparticles with single porous shell and Ag@Au/Ag@Au double shells by using the galvanic replacement reaction and investigate their linear and nonlinear optical properties. Our results show that the surface plasmon resonance wavelength of the hollow porous nanoparticles could be easily tuned in a wide range in the visible and near infrared region by controlling the volume of HAuCl_4. The nonlinear optical refraction of the double-shelled Ag@Au/Ag@Au nanoparticles is prominently enhanced by the plasmon resonance. Our findings may find applications in biosensors and nonlinear optical nanodevices. (fundamental areas of phenomenology(including applications))

[en] The simple fluid model, an extended fluid model, and the fluid model with nonlocal ionization are applied for the calculations of static breakdown voltages, Paschen curves and current-voltage characteristics. The best agreement with the experimental data for the Paschen curve modeling is achieved by using the model with variable secondary electron yield. The modeling of current-voltage characteristics is performed for different inter-electrode distances and the results are compared with the experimental data. The fluid model with nonlocal ionization shows an excellent agreement for all inter-electrode distances, while the extended fluid model with variable electron transport coefficients agrees well with measurements at short inter-electrode distances when ionization by fast electrons can be neglected. (physics of gases, plasmas, and electric discharges)

[en] An algorithm is developed to calculate the entanglement of formation for bipartite quantum states to determine numerically the sufficient condition of separability. The algorithm is applied to two 3×3 positive partial transpose states mixed with white noise. For these two noisy states, our numerical sufficient conditions of separability are not far from the best necessary conditions of separability

[en] High-pressure structural phase transitions in PbTe are investigated by means of the first principles total energy calculations within the generalized gradient approximation (GGA) and local density approximation (LDA) by using the density functional theory. First principle calculation shows that PbTe is stable with the NaCl-type (B1) structure under ambient conditions and transforms to the CsCl-type (B2) structure under high pressure via an intermediate phase. Two candidate structures of the intermediate phase, namely Pnma and Cmcm, are chosen for total energy calculations and discussed. It indicates that the intermediate phase adopts the Pnma structure rather than the Cmcrn structure, and lattice parameters of the Pnma phase calculated by using GGA and LDA are in consistent with experimental results

[en] We apply the localized surface plasmon resonance (LSPR) of gold nanoparticles (GNPs) covalently coupled with cytochrome c (cyt c) to create a nanobiosensor for detecting hydrogen sulfide (H_2S) in the range of 15–100 ppb. Monolayer formation of GNPs on glass surface functionalized with 3-aminopropyltrimethoxysilane (APTMS) is performed for fabricating a chip-based format of the optical transducer. By chemical introduction of short-chain thiol derivatives on cyt c protein shell via its lysine residues, a very fast self-assembled monolayer (SAM) of cyt c is formed on the GNPs. Significant shifts in the LSPR peak (Δλ_L_S_P_R) are observed by reacting H_2S with cyt c. Results show a linear relationship between Δλ_L_S_P_R and H_2S concentration. Furthermore, shifts in the LSPR peak are reversible and the peak positions return to their pre-exposure values once the H_2S is removed. The experimental results strongly indicate that the protein based LSPR chip can be successfully used as a simple, fast, sensitive and quantitative sensor for H_2S detection

[en] We report on a high energy, high repetition rate Ho:YAG master oscillator and power amplifier (MOPA), resonantly dual-end-pumped by Tm:YLF lasers at room temperature. At the pulse repetition frequency of 1 kHz, we demonstrate a maximum energy of 30 mJ per pulse with a 28.2 ns pulse width in a Ho:YAG oscillator system resonantly double-end-pumped by Tm:YLF lasers. A maximum energy of 52 mJ per pulse with a 30.5 ns pulse width is achieved in the Ho:YAG amplifier, corresponding to a peak power of approximately 1.7 MW. The output wavelength is at 2090.6 nm and 2096.9 nm, and a beam quality factor of M"2 ∼ 2.1 is achieved. (fundamental areas of phenomenology(including applications))

[en] A phosphorescent organic light emitting diode by using tetrafluorotetracyanoquinodimethane (F_4TCNQ) as the indium-tin-oxide modification layer and 4,4'-bis(carbazol-9-yl)biphenyl (CBP) as the hole transporting layer is reported. CBP doped with a green phosphorescent dopant, tris(2-(p-tolyl)pyridine) iridium(III) (Ir(mppy)_3) is used as the emission layer in this device, and the maximum current efficiency of 31.3 cd/A is achieved. Furthermore, low efficiency roll-off of 10.4% is observed with device luminance increasing from 100 cd/m"2 (29.7 cd/A) to 10000 cd/m"2 (26.5 cd/A). It is demonstrated that a charge-generation area is formed at F_4TCNQ/CBP interface, which will benefit hole injection into the hole transporting layer. Moreover, use of the CBP hole transporting layer will benefit the low efficiency roll-off by broadening triplet exciton formation, as well as by avoiding accumulation of unbalanced carrier at the hole transporting layer/emission layer interface. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

[en] We report a longitudinal Zeeman slower based on ring-shaped permanent magnetic dipoles used for the strontium optical lattice clock. The Zeeman slower is composed of 40 permanent magnets with the same outer diameter but different inner diameters. The maximum variation of the axial field from its target values is less than 2%. In most parts of the Zeeman slower, the intensity variations of the field in radial spatial distribution are less than 0.1 mT. With this Zeeman slower, the strontium atoms are slowed down to 95 m/s, and approximately 2% of the total atoms are slowed down to less than 50 m/s. (paper)