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根据原子分子反应静力学和群论,确定TiH2,TiD2和TjT2的基电子状态为^3A2.应用基函数6-311G^**和密度泛函理论B3P86方法,全电子计算了氢同位素分子及其钛化物的能量E、定容热容Cv和熵S应用电子振动近似理论,即用单个分子TiH2,TiD2和TjT2中的电子和振动能量和熵近似代表他们处于固态时的能量和熵,计算所得到的金属钛的氢化热力学函数△Hc^0,△S^0,△G^0以及平衡压力与温度的关系,与文献符合很好,这表明电子振动近似理论的可应用性,选用金属钛作为中子靶是很正确的。 相似文献
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分别采用直接测量法、同位素交换法和溶解法测量铀床中的氚残留量, 并分析了这三种测量方法在本实验条件下的误差. 直接测量法测量铀床的氚残留量的结果如下: 铀床的氚残留量为2.68%, 即每克铀含(0.0308±0.0003) mmol 氚气; 当压力读数在1500~133332 Pa之间时, 基于理想气体状态方程的测量方法(简称PVT法)的标准差小于0.95%. 同位素交换法测量铀床氚的结果如下: 加热充分解吸过的铀床经多次同位素交换后, 其交换效率仅为2.84%, 即不到3%(摩尔分数)的氚被氘气载带出来, 其同位素交换法测量的标准差为7.35%. 溶解法能够彻底地测量铀床中残留的氚, 其溶解法测量的标准差为6.49%. 相似文献
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根据原子分子反应静力学和群论,确定TiH2,TiD2和TiT2的基电子状态为3A2.应用基函数6-311G**和密度泛函理论B3P86方法,全电子计算了氢同位素分子及其钛化物的能量E、定容热容Cv和熵S.应用电子振动近似理论,即用单个分子TiH2,TiD2和TiT2中的电子和振动能量和熵近似代表他们处于固态时的能量和熵. 计算所得到的金属钛的氢化热力学函数ΔH0,ΔS0,ΔG0以及平衡压力与温度的关系,与文献符合很好,这表明电子振动近似理论的可应用性,选用金属钛作为中子靶是很正确的. 相似文献
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锆-氘反应热力学特性研究 总被引:3,自引:1,他引:2
The p-c-T curves and the relation between equilibrium pressure and temperature of deuterium absorption and desorption from zirconium were measured in the temperature range of 400~675 ℃. Equilibrium pressure of the absorption and desorption at different temperatures were given and then the thermodynamic parameters and the deuterium absorption capacity were determined according to Vant Hoff equation. There are different changes of enthalpy and entropy when zirconium changes to different phases. The change of enthalpy in the phase of α plus δ is -98.9 kJ·mol-1 in the temperature range of 400~475 ℃. The changes of enthalpy in the first and second plateau are -75.1 kJ·mol-1 and -161.7 kJ·mol-1, respectively in the temperature range of 525~675 ℃. The corresponding changes of entropy are -66.5 J·K-1·mol-1, -32.4 J·K-1·mol-1 and -146.5 J·K-1·mol-1, respectively. There are obvious lagging effects when zirconium desorbs deuterium. 相似文献
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采用二项式方案构建了FenOm+(n+m=4)团簇的大量可能初始结构.运用广义梯度近似(GGA)密度泛函理论中的PW91交换关联泛函对这些初始结构进行优化和频率分析,得到12个稳定的异构体.在此基础上计算和分析了它们的结合能、对称性、键长、磁矩,最高占据轨道与最低未占据轨道的能隙.发现Fe—O键在FenOm+(n+m=4)团簇的稳定中具有重要作用,团簇的总磁矩主要取决于铁原子的磁矩和各个原子磁矩排布情况. 相似文献
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On the basis of density-functional theory (PW91) and an all-electron numerical basis set, 60 optimized structures of Fe3O3+ clusters were obtained through optimization calculation and frequency analysis of 216 initial structures. 28 different isomers were ultimately confirmed after analyzing and re-calculating. The binding energies, the energy gaps between the highest occupied molecular orbital and lowest unoccupied molecular orbital, and the total magnetic moments of all stable isomers are reported. Some discussion of the relationship between electronic properties and structures is also presented. 相似文献
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