Outdoor light at night and depressive symptoms in male veterans: a multicenter cross-sectional study in China.

Previous studies have indicated depression was associated with environmental exposures, but evidence is limited for the association between outdoor light at night (LAN) and depression. This study aims to examine the association between long-term outdoor LAN exposure and depressive symptoms using data from the Chinese Veteran Clinical Research platform. A total of 6445 male veterans were selected from 277 veteran communities in 18 cities of China during 2009‒2011. Depressive symptoms were evaluated using the Chinese version of the Center for Epidemiological Studies Depression scale. Outdoor LAN was estimated using the Global Radiance Calibrated Nighttime Lights data. The odds ratio and 95% confidence intervals of depressive symptoms at the high level of outdoor LAN exposure against the low level during the 1 years before the investigation was 1.49 (1.15, 1.92) with p-value for trend < 0.01, and those associated with per interquartile range increase in LAN exposure was 1.22 (1.06, 1.40).

Effect of Thermal Annealing Treatment and Defect Analysis on AgGaGeS4 Single Crystals.

AgGaGeS4 is a new promising nonlinear-optical crystal for frequency-shifting a 1.064 µm laser into mid-IR. This quaternary compound single crystal has been successfully grown by a modified vertical Bridgman method. Although it has high transparency in the 0.5-11.5 µm spectral range, the nonideal transparency at 2.9, 4, and 10 µm restricts further optical experiments and applications. Therefore, in this work, AgGaGeS4 wafers were annealed in vacuum and with a AgGaGeS4 polycrystalline powder at different temperatures. After annealing, under certain conditions, the optical quality of AgGaGeS4 wafers shows evident improvement, and it is found that volatile GeS2 easily results in stoichiometric deviation, even decomposition, so that the choice of temperature plays a pivotal role in the annealing treatment. Conclusively, the results confirm that thermal annealing could effectively improve the optical quality of the as-grown AgGaGeS4 crystal and annealings with a AgGaGeS4 polycrystalline powder at 550 °C and in vacuum at 500 °C are optimum processes. After such treatment, the transmittance of the wafer is about 70% and the absorptions at 2.9, 4, and 10 µm have almost been eliminated. Besides, the binding energy tends to get smaller with increasing temperature and the Raman phonon frequency has scarcely changed, indicating that the thermal annealing processes only renovate the crystal structure by atomic diffusion or dislocation climbing but without changes in the main structure. At last, through Hall measurement and positron annihilation lifetime spectroscopy, we find that the carrier concentration has little change after annealing, while the cation vacancy sharply declines, and the trapping state of the positron is mainly attributed by the substitution of Ge4+ by Ga3+.

Polycrystal Synthesis, Crystal Growth, Structure, and Optical Properties of AgGaGe nS2( n+1) ( n = 2, 3, 4, and 5) Single Crystals for Mid-IR Laser Applications.

AgGaGe nS2( n+1) crystal is a series of quaternary nonlinear optical materials for mid-IR laser applications of converting a 1.064 µm pump signal (Nd:YAG laser) to 4-11 µm laser output, but only AgGaGeS4 has attracted the most attention, remaining the other promising AgGaGe nS2( n+1) crystal whose physicochemical properties can be modulated by n value. In this work, AgGaGe nS2( n+1) ( n = 2, 3, 4, and 5) polycrystals are synthesized by vapor transport and mechanical oscillation method with different cooling processes. High-resolution X-ray diffraction analysis and refinement have revealed that all the four compounds are crystallized in the noncentrosymmetric orthorhombic space group Fdd2, resulting in the excellent nonlinear optical property, and the distortion of tetrahedron with the variation of n value causes the discrepancy of physicochemical property. Besides, using the modified Bridgman method, AgGaGe nS2( n+1) single crystals with 15 mm diameter and 20-40 mm length have been grown. We have discussed the structure and composition of AgGaGe nS2( n+1) by XPS spectra and analyzed the three kinds of vibration modes of tetrahedral clusters by the Raman spectra. The Hall measurement indicates that the AgGaGe nS2( n+1) single crystals are p-type semiconductor, and the carrier concentration decreases with the increasing n value. All the transmittances of as-grown AgGaGe nS2( n+1) samples exceeds 60% in the transparent range, especially the transmittance of AgGaGe2S6, is up to 70% at 1064 nm, and the band gap of as-grown crystal increases from 2.85 eV for AgGaGe2S6 to 2.92 eV for AgGaGe5S12. After a thermal annealing treatment, the absorptions at 2.9, 4, and 10 µm have been eliminated, and the band gap changed into the range of 2.89-2.96 eV.

Enhanced formic acid electro-oxidation on PdIr nanoparticles prepared by ethylene glycol-assisted NaBH4 reduction process.

The carbon supported PdIr nanoparticles were synthesized by an ethylene glycol-assisted NaBH4 reduction method, and the mass ratio of Pd to Ir was optimized. Then, their performances for formic acid electro-oxidation (FAEO) were investigated. The XRD and TEM characterizations show that the prepared PdIr/C catalysts have small mean size and good dispersion of PdIr nanoparticles. The electrochemical measurements demonstrate that the PdIr/C catalysts have greatly enhanced performance for FAEO compared with the Pd/C catalyst. The PdIr/C catalysts show higher current density and more than 50 mV negative shift of onset and peak potential than that of the Pd/C catalyst. With the optimal mass ratio of Pd to Ir, the PdIr/C-5 catalyst presents the highest catalytic activity for FAEO.

Spatial distributions of the energy and energy flux density of partially coherent electromagnetic beams in atmospheric turbulence.

The formulas of the energy and energy flux density of partially coherent electromagnetic beams in atmospheric turbulence are derived by using Maxwell's equations. Expressions expressed by elements of electric cross spectral density matrixes of the magnetic and the mutual cross spectral density matrix are obtained for the partially coherent electromagnetic beams. Taken the partially coherent Cosh-Gaussian (ChG) electromagnetic beam as a typical example, the spatial distributions of the energy and energy flux density in atmospheric turbulence are numerically calculated. It is found that the turbulence shows a broadening effect on the spatial distributions of the energy and energy flux density. Some interesting results are obtained and explained with regard to their physical nature.