利用微量热法研究Cd~(2+)和Cu~(2+)对嗜热四膜虫(Tetrahymena thermophila)的毒性效应

利用微量热法研究Cd2 + 和Cu2 + 对嗜热四膜虫BF5(TetrahymenathermophilaBF5)生长代谢毒性效应 ,结果表明 :①低浓度的Cd2 + (0～ 0 .4mgL-1)和Cu2 + (0～ 10mgL-1)对四膜虫的生长有促进作用 ,而高浓度的Cd2 + (0 .8～ 3.2mgL-1)和Cu2 + (2 0～ 2 0 0mgL-1)则产生抑制作用 ;②Cd2 + 和Cu2 + 的半抑制浓度IC50 分别为 2 .0 4mg/L和15 5 .5mg/L ;③联合毒性为协同作用

Molecular Characterization and Functional Commonality of Nucleophosmin/Nucleoplasmin in Two Cyprinid Fish

Nucleophosmin/nucleoplasmin has been studied mostly in mammals and amphibians. To clarify the characteristics and function of nucleophosmin/nucleoplasmin in teleost fish, we cloned a full-length cDNA sequence from two cyprinid fish, Carassius auratus gibelio and Carassius auratus. Molecular characterization and multiple sequence alignments suggested that they are the homologs of nucleophosmin. RT-PCR and Western blot detected a specific expression in gonads, and immunofluorescence localization revealed their distribution in oogenic and spermatogenic cells. Furthermore, a sperm decondensation function was demonstrated by immunodepletion and in vitro sperm decondensation experiments. The data suggest that the cloned nucleophosmin should share expressional and functional characterization with nucleoplasmin and therefore provide novel evidence for a functional commonality of nucleophosmin and nucleoplasmin in fish.

CFD analysis of thermodynamic cycles in a pulse tube refrigerator

The objectives of this paper are to study the thermodynamic cycles in an inertance tube pulse tube refrigerator (ITPTR) by means of CFD method The simulation results show that gas parcels working in different parts of ITPTR undergo different thermodynamic cycles The net effects of those thermodynamic cycles are pumping heat from the low temperature part to the high temperature part of the system The simulation results also show that under different frequencies of piston movement the gas parcels working in the same part of the system will undergo the same type of thermodynamic cycles The simulated thermal cycles are compared with those thermodynamic analysis results from a reference Comparisons show that both CFD simulations and theoretical analysis predict the same type of thermal cycles at the same location However only CFD simulation can give the quantitative results while the thermodynamic analysis is still remaining in quality (C) 2010 Elsevier Ltd All rights reserved

相对论平均场理论对Pb同位素位移的研究

运用变形的相对论平均场理论研究了Pb同位素链的基态性质．对关联的处理采用了BCS方法,不成对核子的处理运用了“阻塞”法．计算的结果很好地符合了实验上Pb的平均结合能,中子分离能,同位素位移．接着从原子核的微观结构出发,比较详细地研究了Pb链同位素位移出现反常扭折这一重要性质的物理机制．