共查询到13条相似文献,搜索用时 46 毫秒
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利用基于全相对论组态相互作用理论的FlexibleAtomicCode(FAC)程序包,详细研究了Sn5+离子的双电子复合(DR)过程。通过比较发现初态能级Bolzmann分布对总速率系数有降低作用,俘获电子至n=5轨道的双电子复合速率系数最大,随n的增加,双电子复合速率系数逐渐减小,峰位逐渐向高温方向移动,确定了角动量量子数l的取值可以截止至l=8。 相似文献
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应用相对论组态相互作用方法,计算了类氦氪离子(Kr34+)经过1s2lnl’(n=2,3,…,15)态的双电子复合截面,然后在冲量近似下计算了Kr34+与CH4、NH3、H2O和HF共振转移激发(RTE)截面.在低动量端,CH4、NH3、H2O和HF的康普顿轮廓依次减小.相比Kr34+与CH4的RTE截面,Kr34+与NH3、H2O和HF的RTE截面在第1个峰位处截面值分别减小10.7%、23.3%和33.6%,在第2个峰位处截面值分别减小6.0%、12.3%和18.9%.同时,RTE峰的宽度依次增加,这表明随着C、N、O和F的核电荷数增加,库仑作用导致电子动量空间分布变大. 相似文献
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使用完全活化空间自洽场(CASSCF)和多组态的二级微扰理论(CASPT2)方法,对C6H5CN+离子去CN的光解离反应进行了研究.计算了12B1,12A2,12B2,22B1和12A1电子态的去CN解离势能曲线.通过对渐近产物的能量、构型、电荷和自旋密度布居的分析,得出结论:12A1,12B1,12A2,22B1和12B2的解离产物分别为C6H5+ (X1A1)+CN(X2∑+)(第1解离限),C6H5+(1 3B1)+CN(X2∑+)(第2解离限),C6H5 (11A2)+CN(X2∑+)(第3解离限),C6H5+ (11B1)+CN(X2Σ+)(第4解离限)和C6H5+ (X1A1)+CN(12(Ⅱ))(第5解离限). 相似文献
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Jipeng Li Linhan Du Xian Kong Jianzhong Wu Diannan Lu Lei Jiang Wei Guo 《国家科学评论(英文版)》2023,(12):193-202
A biological potassium channel is> 1000 times more permeable to K+than to Na+ and exhibits a giant permeation rate of ~108 ions/s.It is a great challenge to construct artificial potassium channels with such high sele ctivity and ion conduction rate.Herein,we unveil a long-overlo oked structural feature that underpins the ultra-high K+/Na+ selectivity.By carrying out massive molecular dynamics simulation for ion transport through carbonyl-... 相似文献
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关注政府对高新技术企业实施激励政策时有关补贴对象的异质性问题和不同政策对各项创新产出的不同效果,基于2015—2018年科技部火炬中心对广东省高新技术企业的统计调查数据,运用多层线性模型评估税收优惠和财政补贴两类创新激励政策对不同企业规模、行业类型、高企类别的高新技术企业创新质量提升效果。结果表明:税收优惠和财政补贴政策对高新技术企业创新质量有显著提升作用,但对不同规模、行业、类别高新技术企业的科技成果转化能力、知识产权与技术标准、研发投入强度、财务能力、新产品收入等创新质量产出作用效果存在差异。其中,两类政策对企业科技成果转化能力的作用效果较强,对知识产权与技术标准、资产回报率的作用效果较弱;财政补贴对入库培育企业科技成果转化能力有负向作用;税收优惠对电子信息与服务业企业研发投入强度有负向作用。基于此,建议广东省通过继续实施财政补贴、高新技术企业入库培育等创新激励政策,关注中小微高新技术企业需求、促进大型高新技术企业做大做优,打造高新技术企业创新生态链等措施,推动高新技术企业创新质量提升。 相似文献
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Stanley H. Jury 《Journal of The Franklin Institute》1978,305(2):79-98
Classical work on transport in heterogeneous media is reviewed to show the broad interest in it as well as the specific need for a thorough treatment of a more comprehensive model. Such a model is presented and it consists of a random distribution of one or more dispersed phases in a continuous phase. Both the stab and spherical geometry are also considered. Both the transient and steady state transport solutions are developed for each of three different cases. The equivalent diffusivities are extracted from the steady state solutions. Applications are considered to illustrate the validity of the work. It is emphasized that the flux Ji for phase i can be complex as discussed elsewhere in the literature and all of this without any detraction from the exposition presented. It is also pointed out that this exposition is apparently the first to establish the connection between a realistic model, its transient solutions and its steady state solutions from which the equivalent diffusivities have been extracted. In the case of dead-end pores the results suggest application to experimental data to serve as a precision test for the presence and amount of dead-end pores. The advantages of testing under steady state conditions are discussed in detail. An appropriate diffusion cell design is referenced. The results can be useful in the research and design of barrier materials, catalysts, etc. 相似文献
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Frank Hoppensteadt 《Journal of The Franklin Institute》1974,297(5):325-333
The model presented here describes the spread of an infection in a population by keeping track of the chronological ages of the participants as well as their “class ages” (i.e. the length of time since entering their present state). The reasoning behind this model is similar to that used in the equation of age dependent population growth. 相似文献