正电子素

It was found that the spectra contained two intense components and a weak one; the long lived component corresponds to the positronium.

配合时域介电谱方法用正电子湮没技术对硫酸三甘肽的铁电相变过程进行了测量，发现正电子寿命谱有两个较强的成份和一个很弱的成份，后者相应于正电子偶素，各分量在相变点附近很窄的温区出现奇异性质，对其起因作了解

The reaction kinetics of positronium o-Ps on MoNi/Al2O3 hydrotreating catalyst was studied by using the positron annihilation spectroscopy for chemical analysis.

采用化学分析正电子湮没谱技术研究正电子素在MoNi/Al2O3加氢催化剂上的反应动力学。

Even bellow the energy threshold for positronium formation, the laser can supply the extra energy to form a Ps atom.

对于激光辅助正电子对原子的重排反应，电子偶素的形成伴随着多光子过程发生，即使入射能量低于Ps形成阈值，辐射场可提供额外的能量形成电子偶素。

AMOC results reveal that S parameter of three lifetime components in oxygen are all bigger than that in nitrogen atmosphere. These are probably caused by the oxygen making the spin-conversion of positronium atoms.

结合正电子寿命-动量关联谱测量结果，本工作分析了不同气氛下多孔硅样品中电子偶素湮没寿命及动量变化关系，讨论了多孔硅中电子偶素的湮没机制以及气氛对孔径计算理论模型的影响。

The longest lifetime component in PALS results is ascribed to the annihilation of positronium in cavities of PS sample. It is found that 80% of the positrons implanted in PS film have formed positronium atoms. PALS results show that the lifetime of ortho-Positronium has small value when the sample was in oxygen gas medium compared with those in other medium.

正电子湮没寿命谱测试结果表明，样品中存在长达40ns的电子偶素湮没成分，并且进入多孔硅膜层的正电子约有80%形成电子偶素，具有非常高的电子偶素产额；在氧气气氛下，由于气体导致o-Ps发生自旋转化猝灭是使多孔硅样品中电子偶素寿命缩短的主要原因。

The relative small o-Ps lifetime (1.48—1.63ns) can beexplained by the rigidity and high packing density of molecule chain, due to theintrachain and interchain hydrogen bond interaction respectively, whereas in 〓-containing chitosan, the grafted 〓 that play a significant chemical inhibition andquenching role on positronium formation and annihilation is first observed.

CS的相对小的尺寸和较低的自由体积浓度归因于氢键作用而致分子链较为致密的堆砌，在〓-CS中首次发现了〓基团对正电子素湮没的抑制和猝灭作用，此时〓和〓不再直接对应于自由体积尺寸和浓度。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐