平方公尺

At the experimental intensity of 20W/cm^2 and in the dose range studied (0.00, 0.24, 0.48, 0.72, 0.96 and 1.20kJ/m^2), both the population number and growthrate was the highest in the control and decreased with the increment of UV-B radiation. In addition, the population number and growth rate of rotifer Brachionus urceus showed a similar tendency of decrease with the dose increase of UV-B radiation. Both of them could be used as an ideal biomarker for the enhancement of UV-B radiation.

实验表明，在本实验辐射强度(20W/平方公分)和剂量范围内（0.24、0.48、0.72、0.96和1.20kJ/平方人公尺）壶状臂尾轮虫的种群数量和种群增殖率均以对照组最高，各UV-B辐射处理组则随UV-B辐射剂量的增大而呈一致性减小，说明该种群的种群数量和种群增殖率随UV-B辐射的增强显示一致性的影响，两者都可以作为大气UV-B辐射强弱的生物指标。

The result showed that the strong storm followed by mesoscale squall line was primary cause of strong sandstorm producing, steps and ladders short wave trough of 500 hPa was great criterion triggering system for the mesoscale squall line producing, the essential dynamic condition was provided by distortion field and the mesoscale low pressure of 700 hPa for the strong sandstorm forming and maintaining in mid-west of Hexi Corridor, the deep vertical circulation development condition was basic power that urged squall line to occur and sand dust to curl up, which was provided for the deep convection development by superimposition of lifting movement before ground cold front and ascendant current of secondary circulation in upper air jet entrance region, temperature and the barometric gradient around the cold front was enlarged by enhancement of ground thermal low and temperature diurnalvariation of afternoon, by which essential thermal energy unstable condition was provided for the gale and strong sandstorm eruption, the strong sandstorm appeared in downstream of -200 m^2s^(-2) center of vertical helicity, the vertical helicity had good instruction significance for development of squall line and landing region of sandstorm, the mesoscale squall line occurred in unstable stratification, basic condition of potential energy transforming as kinetic energy was provided by strong unstable stratification for the strong sandstorm forming and developing.

结果表明：中尺度飑线所伴随的强风暴是产生强沙尘暴的主要原因；500 hPa阶梯短波槽是中尺度飑线产生的大尺度触发系统，河西走廊中西部700 hp变形场、中尺度低压为强沙尘暴形成和维持提供了必要的动力条件；地面冷锋前上升运动与高空急流入口区次级环流的上升气流的叠加，为深对流发展提供了深厚的垂直环流发展条件，是促使飑线发生和沙尘卷起的基本动力；地面热低压的加强和午后气温的日变化加大了冷锋前后的温度和气压梯度，为大风、强沙尘暴爆发提供了必要的热力不稳定条件；强沙尘暴出现在垂直螺旋度为－200平方公尺/s^2中心的下游，垂直螺旋度对飑线的发展和沙尘暴的落区具有较好的指示意义；中尺度飑线发生在不稳定层结内，较强的不稳定层结为强沙尘暴形成、发展提供了位能转化为动能的基本条件。

According to the museum, it is the biggest of its kind in Germany and one of the five biggest in the world with more than 30 million objects in its zoological, palaeontological, geological and mineralogical collections and with its exhibition halls with an area of about 6500 square meters.

馆方说，这是德国首见最大的展览，也是全世界五大展览之一，共将展出逾3，000万件动物学、古生物学、地质学及矿物学收藏品，展览馆总面积约6，500平方公尺。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。