[Research on Spectrum Matching Method for PbSe Quantum Dots Luminescence Spectrum and Gas Absorption Spectrum].

As typical nano metarials in near infrared waveband, PbSe Quantum Dots have a very large exciton Bohr radius of 46 nm and a small band gap of 0.28 eV at room temperature. PbSe QDs have very unique properties, such as the quantum confined optical property, and which possess high photoluminescence (PL) quantum yield (QY) with size dependent tunable wavelength emissions. By analyzing the luminescence spectrum of PbSe Quantum Dots, a method through adjusting the particle size of PbSe Quantum Dots (QDs) to match gas absorption spectrum was presented in this paper. 4.6 and 6.1 nm PbSe QDs were synthesized and deposited on the GaN chip to fabricate the NIR QDs light sources. The PbSe QDs-UV glue composites thickness was determined to be 48.0 and 671.5 µm for 6.1 and 4.6 nm PbSe QDs. The NIR QDs were used to detect the C2H2 and NH3 gas. The experiments show that the PL spectrum of 4.6 nm NIR QDs can cover the entire absorption spectrum of C2H2 gas (from 1 500 to 1 550 nm) and the PL spectrum of 6.1 nm NIR QDs can cover the entire absorption spectrum of NH3 gas (from 1 900 to 2 060 nm). By changing the quantum size of QDs, the PL peak of the NIR QDS light source can be adjusted to cover the absorption peak of different gases. The matching method presented in this paper is efficient and feasible, which has great application potential in gas detection.

Conditions and possible mechanisms of VCD-induced ovarian failure.

Perimenopause is an important period in women's lives, in which they experience a series of physiological changes. Current animal models of perimenopause fail to adequately replicate this particular stage in female life, while current in vitro models are too simplistic and cannot account for systemic effects. Neither the naturally-ageing animal model, nor the ovariectomised animal model, mimic the natural transitional process that is the menopause. In vivo and in vitro studies have confirmed that the occupational chemical, 4-vinylcyclohexene diepoxide (VCD), can cause selective destruction of the ovarian primordial and primary follicles of rats and mice by accelerating the apoptotic process, which successfully mimics the perimenopausal state in women. However, it is the in vivo VCD-induced rodent perimenopausal models that are currently the most widely used in research, rather than any of the available in vitro models. Studies on the mechanisms involved have found that VCD induces ovotoxicity via interference with the c-kit/kit ligand and apoptotic signalling pathways, among others. Overall, the VCD-induced perimenopausal animal models have provided some insight into female perimenopause, but they are far from ideal models of the human situation.