摘要：超碱金属离子和超卤素离子通常由不同的核心结构来构建.结合之前报道的Be_(2)H_(3)L2+(L'=NHg和Ne--Xe)是超碱金属离子,本文通过设计超卤素离子Be_(2)H_(3)L2(L=CH_(3)和F-I)证明超碱金属离子和超卤素离子均可使用Be_(2)H_(3)作为核心部分来构建.超卤素离子Be_(2) H_(3)L_(2)^(-)(L=CH_(3)和F-I)是以Be_(2)H_(3)L′_(2)^(+)(L'=NH_(3)和Ne-Xe)为模板,通过L-等电子体取代L'得到.该取代反应放出大量的热,说明Be_(2)H_(3)L_(2)^(-)比Be_(2)H_(3)L2+更稳定.同时,Be_(2)H_(3)L_(2)^(-)(L=CHg和F-I)也具有稳定的电子结构,其HOMO-LUMO能隙值范围为4.69~5.38eV.值得注意的是,这些阴离子结构的垂直电离能均大于5.00 eV(5.38~6.06 eV),可称为飙卤素离子,并且这些结构中的Be-Be距离为1.776~1.826 A,属于超短金属-金属间距.在设计的五个结构中,其中Be_(2)H_(3)L_(2)^(-)(L=CH_(3)、CI和Br)是动力学稳定的全局极小结构,希望这些结构能在负离子光电子能谱中得到并进行表征.本文同时还设计了具有保护基团的分子[t-Bu-Be_(2)H_(3)-t-Bu]-(t-Bu=叔丁基),可作为凝聚相下合成和分离的目标分子.

摘要：To improve the performance of traditional mechanical shock absorber, a new type of high molecular polymer is formulated and applied to overloaded vehicle shock absorber. According to the operating principle of high-performance viscoelastic material shock absorber, the geometrical structure of shock absorber is designed and machined. Then its theoretical model is derived by using analytical method, and the impact test is carried out on high-performance viscoelastic material shock absorber. The results show that experimental and theoretical damping force curves have good agreement, which validates the credibility of theoretical model. The investigation provides a potential way to enhance damping performance and increase vehicle load.

摘要：The optical fiber based on silicon materials has a smaller thermal expansion coefficient, therefore it can be used for the preparation of sensor devices which are insensitive to temperature but sensitive to refractive index, strain, stress, etc. For example, we can use optical fiber Fabry-Perot （F-P） sensor to achieve high sensitivity stress sensing. In this paper, we design an optical fiber F-P sensor with low cost and high sensitivity based on chemical etching method and analyze the stress sensing properties. Hydrofluoric acid is used to prepare the end face concave hole of the optical fiber first, and then the hollow struc-ture of the fiber F-P sensor is obtained by melting and discharge. This preparation method contributes greatly to enhancing the stress sensing properties and temperature insensitivity of the optical fiber device. The experimental results show that interference spectrum peak change is proportional to the stress change of optical fiber F-P sensor, stress sensitivity can reach 5. 2, and the cost is relatively low. Based on this,it has a certain application value in the stress sensing field.