四角帽

The calculated results show: the ground state structures of PtNi5, Pt2Ni4 and Pt3Ni3 clusters are quadrangular bi-pyramid, and Pt4Ni2 and Pt5Ni clusters are triangular bi-pyramid with hat and triangular pyramid with quadrilateral, respectively. From the point of view of thermodynamics, PtnNim clusters are stable because of the negative enthalpy of formation; the positive NICS of PtNi5 clusters show anti-aromaticity, The negative NICS of Pt2Ni4 and Pt5Ni clusters show aromaticity. The number of the IR absorption peak of Pt3Ni3 is the most. The IR and raman absorption peak of PtNi5 , IR of Pt2Ni4, Raman of Pt3Ni3 and Pt4Ni2 have only one. The absorption peak of Pt5Ni appears in the bigger frequencies only, and is zero almost in the small frequencies.

研究结果表明：PtNi5、、Pt2Ni4、Pt3Ni3团簇的基态结构都为四角双锥结构，Pt4Ni2 和Pt5Ni团簇的基态结构分别是戴帽三角双锥和三角锥戴四边形结构；PtnNim团簇的生成焓都为负值，表明团簇在热力学上是稳定的；由NICS值可得，PtNi5团簇具有反芳香性，Pt2Ni4和Pt5Ni团簇具有芳香性；从光谱分析来看，Pt3Ni3团簇的IR较强吸收峰的个数最多，PtNi5团簇的IR和Raman、Pt2Ni4团簇的IR、Pt3Ni3和Pt4Ni2团簇的Raman只有一个强吸收峰值，Pt5Ni团簇的峰值只出现在频率较大的位置，频率小的位置几乎为零。

Magic number CoGe10(superscript -), CoSn10(superscript -) and CoPb10(superscript -) may have bi-capped tetragonal antiprism structure and CoPb12(superscript -) is icosahedral structure.

幻数离子CoGe10、CoSn10和CoPb10可能具有双帽四角反棱柱结构，而CoPb12可能具有二十面体构型，钴原子均为笼状结构的中心。

Rays showed that the adult male?who was buried with items of social prestige such as panpipes, a four-pointed hat, and a snuffing tray?had damage near the nose, perhaps from sniffing.

线表明那些被与他们的社会威望，诸如牧羊笛，四角帽，和一个鼻吸盘等埋葬成年男子的鼻子已经受损，可以是由于用鼻吸的原因。

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。