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利用协方差分析将那些认为很难控制的因素,即患者入院时的BI得分或NIHSS得分作为协变量x,在排除协变量x对观测变量y,即治疗90天后患者的BI、NIHSS得分影响的条件下,分析治疗方法对治疗90天后患者的BI、NIHSS得分的影响,从而更加准确地对治疗方法进行评价.  相似文献   
2.
用r×s列连表的Pearson x~2检验法,讨论通脑活络针刺法、溶栓剂法与常规法在各救治时间窗对脑梗死患者BI评分的影响,并得到结论,通脑活络针刺法在各救治时间窗的"治愈率"及较好的康复程度方面显示了显著疗效.  相似文献   
3.
Systematic theoretical calculations are performed to investigate the dopant effect of Fe on stability, electronic and magnetic properties of the newly synthesized all-boron fullerene B40. The results reveal that as a typical ferromagnetic element, Fe atoms can either be chemically externally adsorbed on, or internally encapsulated in the cage of B40, with the binding energies ranging from 3.07 to 5.31 eV/atom. By introducing the dopant states from the doped Fe atom, the energy gaps of the Fe-doped B40-based metallofullerenes are decreased. Our spin-polarized calculations indicate that Fe-doped metallofullerenes have attractive magnetic properties: with alternative binary magnetic moments between 4.00μB and 2.00μB, depending on the resident sites of the doped Fe atom. The findings of the tunable electronic properties and binary magnetic moments of the Fe-doped B40-based metallofullerenes imply that this type of metallofullerene may be applied in single molecular devices.  相似文献   
4.
Kan Zhang 《中国物理 B》2022,31(12):123102-123102
Polyyne, an sp1-hybridized linear allotrope of carbon, has a tunable quasiparticle energy gap, which depends on the terminated chemical ending groups as well as the chain length. Previously, nitrogen doping was utilized to tailor the properties of different kinds of allotrope of carbon. However, how the nitrogen doping tailors the properties of the polyyne remains unexplored. Here, we applied the GW method to study the quasiparticle energy gaps of the N-doped polyynes with different lengths. When a C atom is substituted by an N atom in a polyyne, the quasiparticle energy gap varies with the substituted position in the polyyne. The modification is particularly pronounced when the second-nearest-neighboring carbon atom of a hydrogen atom is substituted. In addition, the nitrogen doping makes the Fermi level closer to the lowest unoccupied molecular orbital, resulting in an n-type semiconductor. Our results suggest another route to tailor the electronic properties of polyyne in addition to the length of polyyne and the terminated chemical ending groups.  相似文献   
5.
用单因素方差分析的方法,讨论通脑活络针刺法、溶栓剂法与常规治疗三种不同的治疗方法在各救治时间窗对脑梗死患者N IHSS评分影响,并得到结论,通脑活络针刺法在各救治时间窗治疗脑梗死患者疗效显著.  相似文献   
6.
We perform the calculations on geometric and electronic structures of Si-doped heterofullerene C5oSi10 and its derivatives, a C40Si20-C40Si20 dimer and a C40Si20-based nanowire by using density-functional theory, The optimized configuration of the C40Si20-based nanowire exhibits a regular dumbbell-shaped chain nanostructure. The electronic structure calculations indicate that the HOMO-LUMO gaps of the heterofullerene-based materials can be greatly modified by substitutionally doping with Si atoms and show a decreasing trend with increase cluster size. Unlike the band structures of the conventional wide band gap silicon carbide nanomaterials, the C40Si20- based nanowire has a very narrow direct band gap of 0.087eV.  相似文献   
7.
We theoretically show that H atoms can be chemically adsorbed onto the surface of the Si-C heterofullerene- based nanotubes. The adsorbing energy of the H atom on Si-C heterofullerene-based nanotubes is in the range of 4.28-5.66 eV without any barrier for the H atom to approach to the Si-C heterofullerene-based nanotubes. The band-gap of Si-C heterofullerene-based nanotubes can be dramatically modified by introducing dopant states, i.e., there is a transition from semiconductor to conductor of the Si-C heterofullerene-based nanotubes induced by the adsorption of the H atom. These results actually open a way to tune electronic properties of heterofullerene-based nanotubes and thus may propose an efficient pathway for band structure engineering.  相似文献   
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