Numerical Simulation of Continuous Tension Leveling Process of Thin Strip Steel and Its Application

 Cold rolled thin strip steel of high flatness quality undergoes multistage deformation during tension leveling. Thus, the parameters of set up and manipulating are more difficult. With the aid of FE code MSCMARC, the tension leveling process of thin strip steel was numerically simulated. Concentrating on the influence of the roll intermeshes in 2# anti cambering on the distribution and magnitude of residual stresses in leveled strip steel, several experiments were done with the tension leveler based on the results from the simulation. It was found from the simulation that the magnitude of longitudinal residual stresses in the cross section of the leveled strip steel regularly presents obvious interdependence with the roll intermeshes in 2# anti cambering. In addition, there is a steady zone as the longitudinal residual stresses of the surface layers in leveled strip steel vary with the roll intermeshes of 2# anti cambering, which is of importance in the manipulation of tension levelers. It was also found that the distribution of strains and stresses across the width of strip steel is uneven during leveling or after removing the tension loaded upon the strip, from which it was found that 3D simulation could not be replaced by 2D analysis because 2D analysis in this case cannot represent the physical behavior of strip steel deformation during tension leveling.     

一种可消除承印物影响的电流体动力喷墨打印技术

电流体动力喷墨打印技术(EHDP)已广泛应用于直接印刷.然而,现有的EHDP方法,其印刷特性受承印物的影响,且打印线宽由喷嘴的尺寸决定.本文提出的一种EHDP新方法能够消除承印物的影响,并且能够通过控制喷嘴阵列中每个喷嘴的开关来实现对打印线宽的控制.本文检验了EHDP系统的印刷特性,同时证明了喷嘴阵列开关控制的可行性.这种新型EHDP技术可以不受承印物的影响得到稳定的弯月形液面;即使使用同样的喷嘴也能得到不同的线宽.     

Improvement of Electrical Conductivity in Conjugated Polymers through Cascade Doping with Small-Molecular Dopants

Doping capability is primitively governed by the energy level offset between the highest occupied molecular orbital (HOMO) of conjugated polymers (CPs) and the lowest unoccupied molecular orbital (LUMO) of dopants. A poor doping efficiency is obtained when doping directly using NOBF₄ forming a large energy offset with the CP, while the devised doping strategy is found to significantly improve the doping efficiency (electrical conductivity) by sequentially treating the NOBF₄ to the pre-doped CP with 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquino-dimethane (F4TCNQ), establishing a relatively small energy level offset. It is verified that the cascade doping strategy requires receptive sites for each dopant to further improve the doping efficiency, and provides fast reaction kinetics energetically. An outstanding electrical conductivity (>610 S cm⁻¹) is achieved through the optimization of the devised doping strategy, and spectroscopy analysis, including Hall effect measurement, supports more efficient charge carrier generation via the devised cascade doping.     

A SLIP-based Robot Leg for Decoupled Spring-like Behavior: Design and Evaluation

International Journal of Control, Automation and Systems - We present a spring loaded inverted pendulum (SLIP) based robot leg to enable decoupled swing motion and spring-like behavior. The two...     

薄壁复合箱型梁的弯曲-扭转屈曲分析

对一轴心受压薄壁复合构件的屈曲进行研究。提出一个广义的分析模型,可用于分析轴心受压薄壁复合箱型梁的弯曲、扭转以及弯扭屈曲作用。此模型基于经典层压理论,考虑了任意层压堆积规律,结构的弯曲和扭转模式的耦合问题,如非对称以及对称和各种边界条件。采用一个基于位移的一维有限元模型来预测薄壁复合钢筋的临界荷载和随后的屈曲模式。从总势能的平稳值原则中推导出屈曲控制方程。轴心受压薄壁复合件的数值计算结果可用于估测纤维角、各向异性和边界条件对临界屈曲荷载和复合件模态的影响。     

Resonance analysis of 151,153Eu from neutron capture cross section measurements in the energy range from 1 to 20 eV

The neutron capture cross sections of Europium-151 and Europium-153 have been measured by the time-of-flight method in the energy range from 0.005 to 100 eV using the Kyoto University Research Reactor Institute-Linear Accelerator (KURRI-LINAC). An assembly of Bismuth Germanate (BGO) scintillators was used to detect the prompt capture of γ rays. The absolute values of the neutron capture cross sections of ¹⁵¹Eu and ¹⁵³Eu were deduced by normalizing the thermal capture cross sections in JENDL-4.0 and ENDF/B-VII.1, respectively. Then, we have obtained the resonance parameters of 20 resonances in ¹⁵¹Eu and 17 resonances in ¹⁵³Eu using the code SAMMY.

For the 3.36-eV resonance of ¹⁵¹Eu, the evaluated resonance peak area in JENDL-4.0 is about 95% smaller than the present result. For the 7.00-, 7.22-, and 7.42-eV resonance; we confirmed that there are significant differences between the measured peaks and evaluated peaks in JENDL-4.0, ENDF/B-VII.1, and JEFF-3.2. For the ¹⁵³Eu, the evaluated resonance peak areas in JENDL-4.0, ENDF/B-VII.1, and JEFF-3.2 are about 15% larger than the measured resonance peak areas at the 2.46-, 3.29-, and 3.94-eV resonances.     

Unraveling Doping Capability of Conjugated Polymers for Strategic Manipulation of Electric Dipole Layer toward Efficient Charge Collection in Perovskite Solar Cells

Developing electrical organic conductors is challenging because of the difficulties involved in generating free charge carriers through chemical doping. To devise a novel doping platform, the doping capabilities of four designed conjugated polymers (CPs) are quantitatively characterized using an AC Hall‐effect device. The resulting carrier density is related to the degree of electronic coupling between the CP repeating unit and 2,3,5,6‐tetrafluoro‐7,7,8,8‐tetracyanoquinodimethane (F4‐TCNQ), and doped PIDF‐BT provides an outstanding electrical conductivity, exceeding 210 S cm^?1, mainly due to the doping‐assisted facile carrier generation and relatively fast carrier mobility. In addition, it is noted that a slight increment in the electron‐withdrawing ability of the repeating unit in each CP diminishes electronic coupling with F4‐TCNQ, and severely deteriorates the doping efficiency including the alteration of operating doping mechanism for the CPs. Furthermore, when PIDF‐BT with high doping capability is applied to the hole transporting layer, with F4‐TCNQ as the interfacial doping layer at the interface with perovskite, the power conversion efficiency of the perovskite solar cell improves significantly, from 17.4% to over 20%, owing to the ameliorated charge‐collection efficiency. X‐ray photoelectron spectroscopy and Kelvin probe analyses verify that the improved solar cell performance originates from the increase in the built‐in potential because of the generation of electric dipole layer.     

薄壁组合箱梁的自由振动

研究薄壁叠加组合梁的自由振动。建立了适用于薄壁组合箱梁截面动力性能的一般分析模型。该模型基于古典叠加理论，考虑任意层压板叠合次序情况下弯曲和扭转的耦合，也就是非对称和对称以及各种边界条件。对薄壁组合梁，建立基于位移的一维有限元模型以预测自振频率和相应的振型，并由Hamilton原理派生出运动方程；考虑薄壁组合梁纤维角度、模数比、振动频率的边界条件以及组合形式的影响，得出计算结果。     

Perceptual analysis of gray and color scale measurements

Recently, the gamma subcommittee of the International Committee for Display Metrology has adopted various gamma measurement methods in Information Display Measurements Standard. This article describes further tests including perceptual verification of the suggested measurement methods. In order to verify the suggested measurement method, visual assessment has been carried out. The results of visual assessment can be applied to provide gamma distortion threshold values of the suggested metrology in Information Display Measurements Standard.