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塑料光导纤维的材料和功能
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作者 中村一己 高桥聪 《高科技纤维与应用》 CAS 1997年第Z4期33-35,共3页
4.1 何谓光导纤维 光导纤维是由透明材料组成的园柱形芯及位于其周围的折射率比它略低的鞘材构成的。入射到光导纤维的光中,只有由芯和鞘材间的折射率差所决定的具有临界角以内的传导角的成分(或断开以下的次数传输模),才进闭于芯部内... 4.1 何谓光导纤维 光导纤维是由透明材料组成的园柱形芯及位于其周围的折射率比它略低的鞘材构成的。入射到光导纤维的光中,只有由芯和鞘材间的折射率差所决定的具有临界角以内的传导角的成分(或断开以下的次数传输模),才进闭于芯部内进行传导。4.1.1 展开更多
关键词 塑料光导纤维 折射率 低损耗 多模光导纤维 交联聚合物 鞘材 中央技术研究所 单模光导纤维 吸收损失 传导角
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Differential Interference Angle of Collision-induced Rotational Energy Transfer in Na_2(A^1∑_u^+,v=8-b^3∏_(0u),v=14)-Na System
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作者 李健 李永庆 +1 位作者 王伟丽 马凤才 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 北大核心 2006年第6期469-472,共4页
Here wc report calculation of the differential interference angles (including b≤p gild b≥p ) for singlet-triplet mixed states of Na2(A^1∑u^+,ν=8-b^3∏0u,ν=14) system in collision with Na, in order to study t... Here wc report calculation of the differential interference angles (including b≤p gild b≥p ) for singlet-triplet mixed states of Na2(A^1∑u^+,ν=8-b^3∏0u,ν=14) system in collision with Na, in order to study the collision- induced quantum interference on rotational energy transfer in an atom-diatom system. The calculation is based on the first-order Born approximation of time-dependent perturbation theory, and the anisotropic Lennard-Jones intcraction potentials are also employed, The relationships between differential interference angle and impact parameter, including collision diameter and velocity, are obtained, 展开更多
关键词 Rotational energy transfer Collision induced quantum interference Interference angle
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Deformation effect of lateral roof roadway in close coal seams after repeated mining 被引量:2
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作者 Xie Jianlin Xu Jialin +2 位作者 Wang Feng Guo Jiekai Liu Donglin 《International Journal of Mining Science and Technology》 SCIE EI 2014年第5期597-601,共5页
This paper analyzed the deformation mechanism in lateral roof roadway of the Ding Wu-3 roadway which was disturbed by repeated mining of close coal seams Wu-8 and Wu-10 in Pingdingshan No. 1 Mine. To determine the str... This paper analyzed the deformation mechanism in lateral roof roadway of the Ding Wu-3 roadway which was disturbed by repeated mining of close coal seams Wu-8 and Wu-10 in Pingdingshan No. 1 Mine. To determine the strata disturbance scope, the strata displacement angle was used to calculate the protection pillar width. A numerical model was built considering the field geological conditions. In simulation, the mining stress borderline was defined as the contour where the induced stress is 1.5 times of the original stress. Simulation results show the mining stress borderline of the lateral roadway extended 91.7 m outward after repeated mining. Then the original stress increased, deforming the road- way of interest. This deformation agreed with the in situ observations. Moreover, the strata displacement angle changed due to repeated mining. Therefore, reselection of the displacement angle was required to design the protective pillar width. Since a constant strata displacement angle was used in traditional design, the orooosed method was beneficial in field cases. 展开更多
关键词 Repeated mining Mining stress borderline Strata displacement angle Lateral roof roadway Protective pillar
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Densely quaternized anion exchange membranes synthesized from Ullmann coupling extension of ionic segments for vanadium redox flow batteries 被引量:8
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作者 Yu Chen Qilang Lin +2 位作者 Yuying Zheng Yan Yu Dongyang Chen 《Science China Materials》 SCIE EI CSCD 2019年第2期211-224,共14页
Membranes with high ion conductivity and selectivity are important for vanadium redox flow batteries.Herein, densely quaternized anion exchange membranes based on quaternary ammonium functionalized octa-benzylmethyl-c... Membranes with high ion conductivity and selectivity are important for vanadium redox flow batteries.Herein, densely quaternized anion exchange membranes based on quaternary ammonium functionalized octa-benzylmethyl-containing poly(fluorenyl ether ketone)s(QA-OMPFEKs) were prepared from the(i) condensation polymerization of a newly developed octa-benzylmethyl-containing bisphenol monomer via Ullmann coupling,(ii) bromination at the benzylmethyl sites using N-bromosuccinimide, and(iii)quaternization of the bromomethyl groups using trimethylamine. The QA-OMPFEK-20 with an ion exchange capacity(IEC) of 1.66 mmolg^-1 exhibited a higher SO42-conductivity(9.62mScm^-1) than that of the QA-TMPFEK-40(4.82mScm^-1) at room temperature, which had a slightly higher IEC of 1.73 mmolg-1but much lower QA density.The enhanced SO42-conductivity of QA-OMPFEK-20 was attributed to the ion-segregated structure arising from the densely anchored QA groups, which was validated by SAXS observation. Furthermore, the QA-OMPFEK-20 showed much lower VO2+permeability(1.24×10^-14m^2s^-1) than QA-TMPFEK-40(5.40×10^-13m^2s^-1) and Nafion N212(5.36×10^-12m^2s^-1), leading to improved Coulombic and energy efficiencies in Vanadium redox flow batteries(VRFBs). Therefore, the Ullmann coupling extension is a valuable approach for the development of high performance anion exchange membranes for VRFBs. 展开更多
关键词 anion exchange membranes quaternary ammonium poly(fluorenyl ether ketone)s Ullmann coupling extension phase separation
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