For plane singly-connected domains with insulating boundary and four point-sized contacts, C<sub>0</sub> …C<sub>3</sub>, van der Pauw derived a famous equation relating the two trans-...For plane singly-connected domains with insulating boundary and four point-sized contacts, C<sub>0</sub> …C<sub>3</sub>, van der Pauw derived a famous equation relating the two trans-resistances R<sub>01,23</sub>, R<sub>12,30</sub> with the sheet resistance without any other parameters. If the domain has one hole van der Pauw’s equation becomes an inequality with upper and lower bounds, the envelopes. This was conjectured by Szymański et al. in 2013, and only recently it was proven by Miyoshi et al. with elaborate mathematical tools. The present article gives new proofs closer to physical intuition and partly with simpler mathematics. It relies heavily on conformal transformation and it expresses for the first time the trans-resistances and the lower envelope in terms of Jacobi functions, elliptic integrals, and the modular lambda elliptic function. New simple formulae for the asymptotic limit of a very large hole are also given.展开更多
Reducing the blasting vibration is important for blasting excavation in subway tunnel construction.Taking the 3rd bid section of Line 3 of Qingdao subway project as an example,the distance between tunnel vault and gro...Reducing the blasting vibration is important for blasting excavation in subway tunnel construction.Taking the 3rd bid section of Line 3 of Qingdao subway project as an example,the distance between tunnel vault and ground is 5 ~ 8 m.In order to insure the safety of the upper buildings,technologies of parallel cut with large diameter empty hole,one-time initiation and delay by parts,and multiple shallow holes were adopted in the project.The results showed that the maximum value of vertical vibration was limited in the criterion allowance,and the upper buildings were not damaged.Besides,problems were solved that the number of nonel detonator was difficult to meet the requirements of excavating a large cross-section tunnel by blasting,multiple cross-section could’t be initiated simultaneously,and construction efficiency was low,which ensure the construction safety and schedule.展开更多
在酸性电解液中,采用逐步升压法制备了高度有序的大面积阳极氧化铝(anodic aluminum oxide,AAO)模板.与传统方法制得的AAO模板相比,其有效氧化面积提高了20多倍.扫描电子显微镜(scanning electron micro-scope,SEM)对模板微观结构的表...在酸性电解液中,采用逐步升压法制备了高度有序的大面积阳极氧化铝(anodic aluminum oxide,AAO)模板.与传统方法制得的AAO模板相比,其有效氧化面积提高了20多倍.扫描电子显微镜(scanning electron micro-scope,SEM)对模板微观结构的表征结果表明,二者几乎具有相同的有序度和孔密度,且孔洞分布均匀.但相比之下,采用逐步升压法制备的模板孔径要小得多,电压为42V时制得的模板的平均孔径(32.4nm)约为传统方法制得的模板平均孔径(63.2nm)的1/2.展开更多
文摘For plane singly-connected domains with insulating boundary and four point-sized contacts, C<sub>0</sub> …C<sub>3</sub>, van der Pauw derived a famous equation relating the two trans-resistances R<sub>01,23</sub>, R<sub>12,30</sub> with the sheet resistance without any other parameters. If the domain has one hole van der Pauw’s equation becomes an inequality with upper and lower bounds, the envelopes. This was conjectured by Szymański et al. in 2013, and only recently it was proven by Miyoshi et al. with elaborate mathematical tools. The present article gives new proofs closer to physical intuition and partly with simpler mathematics. It relies heavily on conformal transformation and it expresses for the first time the trans-resistances and the lower envelope in terms of Jacobi functions, elliptic integrals, and the modular lambda elliptic function. New simple formulae for the asymptotic limit of a very large hole are also given.
文摘Reducing the blasting vibration is important for blasting excavation in subway tunnel construction.Taking the 3rd bid section of Line 3 of Qingdao subway project as an example,the distance between tunnel vault and ground is 5 ~ 8 m.In order to insure the safety of the upper buildings,technologies of parallel cut with large diameter empty hole,one-time initiation and delay by parts,and multiple shallow holes were adopted in the project.The results showed that the maximum value of vertical vibration was limited in the criterion allowance,and the upper buildings were not damaged.Besides,problems were solved that the number of nonel detonator was difficult to meet the requirements of excavating a large cross-section tunnel by blasting,multiple cross-section could’t be initiated simultaneously,and construction efficiency was low,which ensure the construction safety and schedule.
文摘在酸性电解液中,采用逐步升压法制备了高度有序的大面积阳极氧化铝(anodic aluminum oxide,AAO)模板.与传统方法制得的AAO模板相比,其有效氧化面积提高了20多倍.扫描电子显微镜(scanning electron micro-scope,SEM)对模板微观结构的表征结果表明,二者几乎具有相同的有序度和孔密度,且孔洞分布均匀.但相比之下,采用逐步升压法制备的模板孔径要小得多,电压为42V时制得的模板的平均孔径(32.4nm)约为传统方法制得的模板平均孔径(63.2nm)的1/2.