Interface-hydrothermal synthesis of Sn3S4/graphene sheet composites and their application in electrochemical capacitors

An efficient interface-hydrothermal approach is developed to synthesize Sn₃S₄/graphene sheet composites (SSGSCs), where the graphene sheets (GSs) are separated by fine Sn₃S₄ nanoparticles (NPs) well-dispersed onto their surfaces. The SSGSCs are investigated as electroactive materials for electrochemical capacitors (ECs) application. Due to the positive synergistic effect of GSs and Sn₃S₄ NPs, the unique SSGSCs electrode owns the ability to deliver large specific capacitance and good electrochemical stability at high rates. Moreover, the method we proposed here provides a universal and simple approach to synthesize other metal sulfides/GSs composites for ECs and even for Li-ion battery applications.     

Effect of damaged concrete cover on the behavior of corroded concrete beams repaired with CFRP sheets

Fiber reinforced polymer matrix composites are being increasingly considered for use in civil infrastructure. These materials have found the maximum current use as materials for rapid and cost-effective rehabilitation (retrofit, repair and strengthening) of deteriorating and under-strength structural concrete components. This paper presents the experimental results of damaged/repaired reinforced concrete (RC) beams. The experimental program consisted of RC rectangular beam specimens exposed to accelerated corrosion. The corrosion rate was varied from 5% to 15% which represents loss in cross-sectional area of the steel reinforcement in the tension side. Half of the damaged beams were repaired by bonding Carbon Fiber Reinforced Polymer (CFRP) sheets to the tension side to restore the strength loss due to corrosion. The other half of the beams was first cleaned by removing spalled concrete cover and rusted bars were thoroughly cleaned. A new layer of concrete was cast to replace the removed spalled concrete cover. Then the CFRP sheets were attached to the new concrete layer. Corroded beams showed lower stiffness and strength than control (uncorroded) beams. Strength of damaged beams due to corrosion was restored to the undamaged state when repaired with CFRP sheets for all repaired beams, but the stiffness was almost unchanged. However, the repaired beams with replaced concrete cover layer resisted higher loads on average of 13% compared to damaged beams repaired without replacing the concrete cover layer.     

Aligned carbon nanotube sheets for the electrodes of organic solar cells

Aligned carbon nanotube sheets are developed as a new family of electrodes to fabricate dye-sensitized solar cells. The energy conversion efficiency of the resulting cell is higher than the randomly dispersed carbon nanotube film and comparable with the platinum. Novel and flexible solar cells can be easily made from such carbon nanotube sheets with high potentials.     

Vibrational characteristics of bilayer graphene sheets

Bilayer graphene sheets (BLGSs) are currently receiving increasing attention. In this paper, the vibration characteristics of BLGSs are investigated using analytical and atomistic finite element approaches. Various possible scenarios, namely different geometrical configuration (armchair and zigzag), boundary conditions, and aspect ratio are considered in the present study. The dynamic characteristics of BLGS studied have shown dependence on aspect ratio and the boundary conditions. The unique vibrational properties and large stiffness of BLGS identified in the present work make them suitable candidates for manufacturing nanosensors; electromechanical resonators also will aid the nanomaterials research community to design nanodevices.     

某高层住宅楼大跨度楼板加固处理

通过加固工程实例介绍了大跨度楼板板面有墙荷载,楼板承载力不足时,采用板面浇筑混凝土叠合层,板底粘贴碳纤维布的加固方法。对该大跨度楼板进行加固处理后,后期使用荷载作用下的挠度进行了计算,找出加固时需要进行顶升处理的楼板,针对现场情况提出了一种简单、易行的顶升处理方法。     

Design of short CFRP-reinforced steel tubular columns

This paper presents the design and experimental evaluation of externally bonded carbon fibre-reinforced polymer (CFRP) sheets for strengthening circular steel tubular short columns. In addition to its ease of handling due to its light weight, the high-strength CFRP sheet can provide a degree of restraint to delay buckling of the thin steel wall. Ten short cold-formed steel circular hollow section (CHS) columns, with externally bonded orthogonal (hoop and longitudinal) CFRP sheets, were tested under axial compression. The experimental results indicate that enhancement of the axial section capacity is possible by fibre-reinforcing the steel tube. The design variables investigated to evaluate the strengthening efficiency include the steel yield strength, the modulus of elasticity of the hoop fibre, and the amount and configuration of the fibre reinforcement. Design curves predicting the section capacity of composite steel-CFRP tubular short columns are calculated based on current design guidelines for steel columns. The results highlight the ease of the use of such curves in the FRP strengthening or retrofitting design of tubular columns for section capacity enhancement.     

预应力CFRP加固钢筋混凝土梁补强效果的数值模拟分析

通过升温法模拟碳纤维布内预应力值,利用单元生死模拟钢筋混凝土梁在卸载加固和不卸载加固时预应力CFRP的补强加固效果,对11根预应力CFRP加固钢筋混凝土梁进行了数值模拟,并与试验结果比较,得到了基本一致的结论,说明采用ANSYS可以较好地对预应力CFRP加固梁的补强效果进行数值模拟分析,可有效地补充有限的预应力CFRP加固梁的试验数据和实验分析,为实际工程加固设计提供更多的理论依据.     

热镀锌IF钢基板的实验研究

研究了不同微合金化元素加入量条件下,无间隙原子(IF)钢的再结晶温度和组织,获得了对实际生产十分有益的微合金元素含量与间隙原子碳、氮间的定量关系式,并着重分析了化学成分、工艺参数对IF钢成型性能的影响,提出了合理的生产工艺参数.     

锌层对深冲镀锌板r值的影响

通过对镀锌板和裸钢板r值的实测,并通过扫描电镜观察和理论分析,提出锌层在单向拉伸过程中出现的横向裂纹是造成r值下降的主要原因.     

铜元素和退火温度对TRIP冷轧钢板组织和力学性能的影响

将含铜和不含铜的两种TRIP钢板(0．2％C、1．5％Si、1．5％Mn)冷轧至1mm厚,然后分别在750℃、760℃、770℃、780℃下退火5min,最后在450℃等温3min,获得了不同含量和不同稳定性的残留奥氏体。金相和力学性能试验结果表明,铜元素能提高残留奥氏体量和钢板的力学性能;退火温度影响残留奥氏体量和力学性能,当退火温度选择在Ac1 10％时可获得最佳的力学性能。