Corrugated steel web is folded along the longitudinal direction and has the mechanical properties such as axial compression stiffness corrugation effect, shear modulus corrugation effect, similar to that of an accordi...Corrugated steel web is folded along the longitudinal direction and has the mechanical properties such as axial compression stiffness corrugation effect, shear modulus corrugation effect, similar to that of an accordion. In order to study the lateral-torsional buckling of box beams with corrugated steel webs (BBCSW) under the action of bending moment load, the neutral equilibrium equation of BBCSW under the action of bending moment load is derived through the stationary value theory of total potential energy and further, along with taking Kollbrunner-Hajdin correction method and the mechanical properties of the corrugated web into consideration. The analytical calculation formula of lateral-torsional buckling critical bending moment of BBCSW is then obtained. The lateral-torsional buckling critical bending moment of 96 BBCSW test specimens with different geometry dimensions are then calculated using both the analytical calculation method and ANSYS finite element method. The results show that the analytical calculation results agree well with the numerical calculation results using ANSYS, thus proving the accuracy of the analytical calculation method and model simplification hypothesis proposed in this paper. Also, compared with the box beams with flat steel webs (BBFSW) with the same geometry dimensions as BBCSW, within the common range of web space-depth ratio and web span-depth ratio, BBCSW’s lateral-torsional buckling critical bending moment is larger than that of BBFSW. Moreover, the advantages of BBCSW’s stability are even more significant with the increase of web space-depth ratio and web depth-thickness ratio.展开更多
AIM：To present a novel scleral flap suturing technique for filtering glaucoma surgery in order to control high postoperative intraocular pressure（IOP）.METHODS：Description of ‘the accordion suture＇ technique for ...AIM：To present a novel scleral flap suturing technique for filtering glaucoma surgery in order to control high postoperative intraocular pressure（IOP）.METHODS：Description of ‘the accordion suture＇ technique for mitomycin C augmented trabeculectomy.In cases of postoperative high IOP,pulling the loop of the suture helps to lift up the scleral flap by an even pressure on both edges.By means of this technique,the scleral flap opens up in an ‘‘accordion＇＇ manner,thus preventing flap obstruction and providing adequate aqueous flow.RESULTS：Our study group consisted of 8 eyes of 8 patients with neovascular glaucoma.Mean age of the subjects was 67.42±8.21 y and female/male ratio was 4/4.Mean preoperative IOP was 37±7.48 mm Hg.Mitomycin C augmented trabeculectomy was carried out on the subjects without any complications.The scleral flap closure is performed with three separate sutures;initially,our accordion suture through the center of the flap,and two releasable sutures on both corners.All the patients received removal of two side releasable sutures concomitant with pulling the accordion suture,without any complications.The average traction time was 3.5±0 wk postoperatively.The mean postoperative IOP was 11.37±2.72 mm Hg.No suture related complications were observed.CONCLUSION：This technique can be the suture of choice for filtering glaucoma surgery in experienced hands by its easy learning curve for precisely indicated patients.展开更多
Implementing high-performance silicon(Si)anode in actual processing and application is highly desirable for next-generation,high-energy Li-ion batteries.However,high content of inactive matrix(including conductive age...Implementing high-performance silicon(Si)anode in actual processing and application is highly desirable for next-generation,high-energy Li-ion batteries.However,high content of inactive matrix(including conductive agent and binder)is often indispensable in order to ensure local conductivity and suppress pulverization tendency of Si particles,which thus cause great capacity loss based on the mass of whole electrode.Here,we designed an accordion-structured,high-performance electrode with high Si content up to 95%.Si nanoparticles were well anchored into the interlayer spacings of accordion-like graphene arrays,and free-standing electrode was prepared via a simple filtration process without any binder.Conductive accordion framework ensures strong confinement effect of Si nanoparticles and also provides direct,non-tortuous channels for fast electrochemical reaction kinetics.As a consequence,the accordion Si electrodes exhibit ultrahigh,electrode-based capacities up to 3149 mAh g^(-1)(under Si content of 91%),as well as long-term stability.Also,the accordion electrode can bear extreme condition of over-lithiation and maintains stable in full-cell test.This design provides a significant stride in high Si content toward realistic,high-performance electrodes.展开更多
We find by ab initio simulations that significant overall tensile strain can be induced by pure bending in a wide range of two-dimensional crystals perpendicular to the bending moment, just like an accordion being ben...We find by ab initio simulations that significant overall tensile strain can be induced by pure bending in a wide range of two-dimensional crystals perpendicular to the bending moment, just like an accordion being bent to open. This bending-induced tensile strain increases in a power law with bent curvature and can be over 20% in monolayered black phosphorus and transition metal dichalcogenides at a moderate curvature of but more than an order weaker in graphene and hexagon boron nitride. This accordion effect is found to be a quantum mechanical effect raised by the asymmetric response of chemical bonds and electron density to the bending curvature.展开更多
基金Projects(51408449,51778630)supported by the National Natural Science Foundation of ChinaProject(2018zzts189)supported by the Fundamental Research Funds for the Central Universities,China
文摘Corrugated steel web is folded along the longitudinal direction and has the mechanical properties such as axial compression stiffness corrugation effect, shear modulus corrugation effect, similar to that of an accordion. In order to study the lateral-torsional buckling of box beams with corrugated steel webs (BBCSW) under the action of bending moment load, the neutral equilibrium equation of BBCSW under the action of bending moment load is derived through the stationary value theory of total potential energy and further, along with taking Kollbrunner-Hajdin correction method and the mechanical properties of the corrugated web into consideration. The analytical calculation formula of lateral-torsional buckling critical bending moment of BBCSW is then obtained. The lateral-torsional buckling critical bending moment of 96 BBCSW test specimens with different geometry dimensions are then calculated using both the analytical calculation method and ANSYS finite element method. The results show that the analytical calculation results agree well with the numerical calculation results using ANSYS, thus proving the accuracy of the analytical calculation method and model simplification hypothesis proposed in this paper. Also, compared with the box beams with flat steel webs (BBFSW) with the same geometry dimensions as BBCSW, within the common range of web space-depth ratio and web span-depth ratio, BBCSW’s lateral-torsional buckling critical bending moment is larger than that of BBFSW. Moreover, the advantages of BBCSW’s stability are even more significant with the increase of web space-depth ratio and web depth-thickness ratio.
文摘AIM：To present a novel scleral flap suturing technique for filtering glaucoma surgery in order to control high postoperative intraocular pressure（IOP）.METHODS：Description of ‘the accordion suture＇ technique for mitomycin C augmented trabeculectomy.In cases of postoperative high IOP,pulling the loop of the suture helps to lift up the scleral flap by an even pressure on both edges.By means of this technique,the scleral flap opens up in an ‘‘accordion＇＇ manner,thus preventing flap obstruction and providing adequate aqueous flow.RESULTS：Our study group consisted of 8 eyes of 8 patients with neovascular glaucoma.Mean age of the subjects was 67.42±8.21 y and female/male ratio was 4/4.Mean preoperative IOP was 37±7.48 mm Hg.Mitomycin C augmented trabeculectomy was carried out on the subjects without any complications.The scleral flap closure is performed with three separate sutures;initially,our accordion suture through the center of the flap,and two releasable sutures on both corners.All the patients received removal of two side releasable sutures concomitant with pulling the accordion suture,without any complications.The average traction time was 3.5±0 wk postoperatively.The mean postoperative IOP was 11.37±2.72 mm Hg.No suture related complications were observed.CONCLUSION：This technique can be the suture of choice for filtering glaucoma surgery in experienced hands by its easy learning curve for precisely indicated patients.
基金supported by Shaanxi Yanchang Petroleum Co.,Ltd.(18529)Yiwu Research Institute of Fudan University(21557)+1 种基金the National Science Foundation of China(22075048)the Shanghai International Collaboration Research Project(19520713900).
文摘Implementing high-performance silicon(Si)anode in actual processing and application is highly desirable for next-generation,high-energy Li-ion batteries.However,high content of inactive matrix(including conductive agent and binder)is often indispensable in order to ensure local conductivity and suppress pulverization tendency of Si particles,which thus cause great capacity loss based on the mass of whole electrode.Here,we designed an accordion-structured,high-performance electrode with high Si content up to 95%.Si nanoparticles were well anchored into the interlayer spacings of accordion-like graphene arrays,and free-standing electrode was prepared via a simple filtration process without any binder.Conductive accordion framework ensures strong confinement effect of Si nanoparticles and also provides direct,non-tortuous channels for fast electrochemical reaction kinetics.As a consequence,the accordion Si electrodes exhibit ultrahigh,electrode-based capacities up to 3149 mAh g^(-1)(under Si content of 91%),as well as long-term stability.Also,the accordion electrode can bear extreme condition of over-lithiation and maintains stable in full-cell test.This design provides a significant stride in high Si content toward realistic,high-performance electrodes.
基金supported by the 973 program (Grants 2012CB937500, 2013CB932604)the National Natural Science Foundation of China (Grants 51535005, 51472117, 11021262, 11172303, 11132011)the Fundamental Research Funds for the Central Universities (Grant NP2013309)
文摘We find by ab initio simulations that significant overall tensile strain can be induced by pure bending in a wide range of two-dimensional crystals perpendicular to the bending moment, just like an accordion being bent to open. This bending-induced tensile strain increases in a power law with bent curvature and can be over 20% in monolayered black phosphorus and transition metal dichalcogenides at a moderate curvature of but more than an order weaker in graphene and hexagon boron nitride. This accordion effect is found to be a quantum mechanical effect raised by the asymmetric response of chemical bonds and electron density to the bending curvature.
