Thermodynamic equilibrium between locally excited and charge-transfer states through thermally activated charge transfer in 1-(pyren-2′-yl)-o-carborane

Reversible conversion between excited-states plays an important role in many photophysical phenomena. Using 1-(pyren-2′-yl)-o-carborane as a model, we studied the photoinduced reversible charge-transfer (CT) process and the thermodynamic equilibrium between the locally-excited (LE) state and CT state, by combining steady state, time-resolved, and temperature-dependent fluorescence spectroscopy, fs- and ns-transient absorption, and DFT and LR-TDDFT calculations. Our results show that the energy gaps and energy barriers between the LE, CT, and a non-emissive ‘mixed’ state of 1-(pyren-2′-yl)-o-carborane are very small, and all three excited states are accessible at room temperature. The internal-conversion and reverse internal-conversion between LE and CT states are significantly faster than the radiative decay, and the two states have the same lifetimes and are in thermodynamic equilibrium.

Reversible conversion between excited-states is key to many photophysical phenomena. We studied the equilibrium between LE and CT states by time-resolved and temperature-dependent fluorescence, fs- and ns-transient absorption, and LR-TDDFT calculations.     

Study of the structural relaxation and crystallization in amorphous Fe80P20 alloy by mössbauer effect

The structural relaxation and crystallization of amorphous Fe₈₀P₂₀ alloys have been investigated by Mössbauer spectroscopy. The result indicates that the process of the crystallization of Fe₈₀P₂₀ makes slow progress and it was occur from outside into inside. The amorphous alloys may be classified into six different stages from amorphous to crystalline state during annealing.     

碲材料中钠,钾杂质成份的测定

本文揭示了钠、钾受基体元素碲干扰的现象和分析系统中酸度对钠、钾吸光度的影响,在理论上探讨了碲对钠、钾干扰的原因,利用加入盐酸和铝元素的方法分别排除碲对钾、钠的干扰,提出一个方便,实用的测定方法,回收率和RSD分别为95-102%和7.4%。     

Parton-hadron duality in event generators

The validity of local parton-hadron duality within the framework of HERWIG and JETSET event generators is investigated. We concentrate one ⁺ e ^– annihilations in LEP 2 energy range as these interactions provide theoretically the cleanest condition for the discussion of this concept. We conclude that the concept of local parton-hadron duality is not valid in either of the two generators considered.     

自聚焦透镜的薄透镜等效系统

本文分析了自聚焦透镜的成象特性,提出了用薄透镜系统等效自聚焦透镜的方法,这种方法给用几何作图法和解析法求解物象关系带来了很大方便。     

超软X射线流气式正比计数管

介绍了一种用于测量183～933eV超软X射线的圆柱形、侧窗式、流气式正比计数管,工作气体是0.11MPa的P-10气体或氦气-丙烷混合气体。计数管内径为φ25mm,直径为φ0.3mm的入射窗是由厚度80～90μgcm~2聚乙烯甲醛制成的。该计数管的特点:(1)薄窗,对软X射线透过率高。(2)流气式,工作寿命长。(3)能量分辨率好。(4)计数率高(1×10~(14)个/s)。(5)可测能区宽(0.183～10keV)。(6)可以方便更换窗膜材料、厚度及窗口直径。近几年来该计数管已经为高强度低能X光源提供较好监测。     

汉语句法的分段循环分析策略

定义了汉语的分段语法，并根据自然语言的分段循环结构，提出了汉语的分段循环分析策略．它的基本思想是确定语言的一组基本范畴，其相应的句法规则段及其之间的优先关系，对于每一个句法规则段，分别依次采用改进的Ｋｉｌｂｕｒｙ算法、它的优点在于分析过程中的项目集比较小，而且避免了无用分析树的产生，从而大大提高了分析效率．     

闭式－氢硼酸二茂铁甲酰丙酮缩异菸肼稀土配合物

将二茂铁甲酰丙酮与异菸肼缩合，生成金属有机多齿新配体，该配体（ＦＣＲ）与闭式－十二氢十二硼酸稀土化合物反应，得到分子式为［Ｌｎ（ＦｃＲ）２］２（Ｂ１２Ｈ１２）３·ＸＨ２Ｏ（Ｌｎ＝Ｌａ，Ｎｄ，Ｅｕ，Ｇｄ，Ｄｙ，Ｈｏ，Ｅｒ，ＴｍａｎｄＬｕ）的９个配位化合物，经元素分析、红外光谱、紫外光谱对其组成、结构进行了表征，通过ＴＧ－ＤＴＡ研究了它们的热行为．