Plasma properties of laser-ablated St target in air

Ｐｌａｓｍａｐｒｏｐｅｒｔｉｅｓｏｆｌａｓｅｒ－ａｂｌａｔｅｄＳｔｔａｒｇｅｔｉｎａｉｒＷａｎｇＸｉａｎｇ－Ｔａｉ（王象泰）；ＭａｎＢａｏ－Ｙｕａｎ（满宝元）；ＷａｎｇＧｏｎｇ－Ｔａｎｇ（王公堂）；ＦａｎＸｉ－Ｊｕｎ（樊锡君）；ＷａｎｇＪｕｎ（王军）...     

Advances in the management of bronchial asthma

The ultrastructure of rat precorneal tear film was visualized by the quick freezing-freeze substitution (QF-FS) method and the conventional fixative method under the scanning electron microscope (SEM). In the QF-FS method, the eyeballs of rats were quickly frozen with an isopentane-propane mixture cooled by liquid nitrogen applied directly to the eyes. After enucleating the eyes and fracturing the frozen corneas, the corneas were prepared for SEM observation. In contrast to the conventional fixative method, by which the microvilli of the surface epithelial cells could be visualized clearly, a very thin membrane-like structure was observed to cover the corneal surface in the eyes prepared by the QF-Fs method. Between the membrane-like structure and corneal surface, a homogeneous and fine network-like structure was observed. The results suggest that the structure of the tear film might be different from the one we have believed to consist of three layers until now. The QF-FS method is considered to be useful for the morphological study of the precorneal tear film.     

水布垭水电站右岸防淘墙设计方案施工优化

水布垭水电站右岸防淘墙工程规模大、工程地质条件复杂、施工工期紧、危险性大,由于施工中参建各方的共同努力,对施工设计方案进行了优化,先后克服了地质条件差、塌方、大流量渗水等难题,从而确保了防淘墙全线提前完工,为电站尾水系统施工赢得了时间,也为水布垭水电站按期发电奠定了坚实的基础。     

Development of a physics analysis procedure for the prismatic very high temperature gas-cooled reactors

A new physics analysis procedure has been developed for a prismatic very high temperature gas-cooled reactor based on a conventional two-step procedure for the PWR physics analysis. The HELIOS and MASTER codes were employed to generate the coarse group cross sections through a transport lattice calculation, and to perform the 3-dimensional core physics analysis by a nodal diffusion calculation, respectively. Physics analysis of the prismatic VHTRs involves particular modeling issues such as a double heterogeneity of the coated fuel particles, a neutron streaming in the coolant channels, a strong core-reflector interaction, and large spectrum shifts due to changes of the surrounding environment and state parameters. Double heterogeneity effect was considered by using a recently developed reactivity-equivalent physical transformation method. Neutron streaming effect was quantified through 3-dimensional Monte Carlo transport calculations by using the MCNP code. Strong core-reflector interaction could be handled by applying an equivalence theory to the generation of the reflector cross sections. The effects of a spectrum shift could be covered by optimizing the coarse energy group structure. A two-step analysis procedure was established for the prismatic VHTR physics analysis by combining all the methodologies described above. The applicability of our code system was tested against core benchmark problems. The results of these benchmark tests show that our code system is very accurate and practical for a prismatic VHTR physics analysis.