[Design and experiment of online monitoring system for long-term culture of embryo].

In the study of embryo development process, the morphological features at different stages are essential to evaluate developmental competence of the embryo, which can be used to optimize and improve the system for embryo culture. In this paper, an online monitoring system was designed for long-term culture of embryos, based on a monitoring strategy of low-magnification search and high-magnification observation. Three optical modules of 4× phase contrast, 10× and 20× Hoffman modulation phase contrast were configured in this system to meet the requirements of different fields of view, especially when the size of the embryo increases during the culture.

The device performance of Cu(In, Ga)Se2 solar cells influenced by the type-inverted layer.

The type-inversion to n-type at the surface of p-type Culn(1-x)Ga(x)Se2 absorber layer is taken as an important factor for the high efficiency of Culn(1-x)Ga(x)Se2 (CIGS) with low Ga content, however, the further increase of Ga content makes the n-type doping difficult and the type-inverted layer vanish, which may have a negative effect on the device performance. Previous first-principles calculation had shown that the donor density becomes lower and level deeper when Ga content increases, while it's not clear how significantly the changes in the type-inverted layer influence the device performance. Through device simulation, we show that the efficiency decreases obviously as the donor density becomes lower and the level deeper in the inversion layer, thus they are important factors responsible for the limitation of the efficiency of CIGS solar cell, i.