摘要：In this paper, we summarize some recent activities in the field of metamaterial research at the national university of singapore (NUS). Integral equations are applied for electromagnetic modelling of supernatural materials. Some special charac- teristics of the metamaterials are shown. Moreover, quasi-static Lorentz theory and numerical method (i.e., the method of moments for solving the electric field integral equation) and the transmission line theory are both presented to obtain the effective consti- tutive relations of metamaterials, respectively. Finally, feasibility of fabricating metamaterials based on analysis of equivalent transmission line model in the microwave spectrum and even higher is also shown and correspondingly some broad-bandwidth and low-loss metamaterial structures are designed and synthesized.

摘要：Lattice structures have drawn much attention in engineering applications due to their lightweight and multi-functional *** this work,a mathematical design approach for functionally graded(FG)and helicoidal lattice structures with triply periodic minimal surfaces is *** types of lattice structures including uniform,helicoidal,FG,and combined FG and helicoidal are fabricated by the additive manufacturing *** deformation behaviors,mechanical properties,energy absorption,and acoustic properties of lattice samples are thoroughly *** load-bearing capability of helicoidal lattice samples is gradually improved in the plateau stage,leading to the plateau stress and total energy absorption improved by over 26.9%and 21.2%compared to the uniform sample,*** phenomenon was attributed to the helicoidal design reduces the gap in unit cells and enhances fracture *** acoustic properties,the design of helicoidal reduces the resonance frequency and improves the peak of absorption coefficient,while the FG design mainly influences the peak of absorption *** broad range of frequency from 1000 to 6300 Hz,the maximum value of absorption coefficient is improved by18.6%-30%,and the number of points higher than 0.6 increased by 55.2%-61.7%by combining the FG and helicoidal *** study provides a novel strategy to simultaneously improve energy absorption and sound absorption properties by controlling the internal architecture of lattice structures.

摘要：While thiolate-protected Au nanoclusters （NCs） have drawn considerable interest in various fields, their poor stability in aqueous solution remains a major hurdle for practical applications. Here, we report a unique strategy based on ligand-shell engineering to improve the stability of thiolated Au NCs in solution. By employing two thiol-terminated ligands having oppositely charged functional groups on the surface of the NCs, we demonstrate that the electrostatic attraction between the oppositely charged functional groups of neighboring ligands could amplify the coordination among surface ligands, leading to the formation of pseudo-cage-like structures on the NC surface that could offer higher protection to the Au core in aqueous solution. The strategy developed in this study could be extended to toward practical applications. other metal NCs, further paving the way

摘要：Perovskite solar cells are one of the most promising alternatives to conventional photovoltaic devices, and extensive studies are focused on device optimization to further improve their performance. A compact layer of TiO2 is generally used in perovskite solar cells to block holes from reaching the fluorine-doped tin oxide electrode. In this contribution, we engineered a TiO2 compact layer using Nb doping, which resulted in solar cells with a power conversion efficiency （PCE） of 10.26%, which was higher than that of devices with the same configuration but containing a pristine TiO2 compact layer （PCE = 9.22%）. The device performance enhancement was attributed to the decreased selective contact resistance and increased charge recombination resistance resulting from Nb doping, which was revealed by the impedance spectroscopy measurements. The developed strategy highlights the importance of interface optimization for perovskite solar cells.

摘要：Introduction The climax of the industrial revolution was marked by the rapid growth of industry,and advancement in technologies have further fueled this industrial expansion,leading to a surge in economic *** technologies have also increased the degree of destructive human inter-ference with the biosphere.

摘要：We present a kirigami-inspired design scheme for a robotic hand by 3D printable folds and *** unique contribution is the printable flexible hand,which provides flexibility and maneuverability that is unavailable in rigid robotic *** integration of sensors in the robotic system enables force adjustment for robotic systems applicable in the *** experimental results have shown that this design can perform everyday tasks through grasping and pinching different *** fingers can bend from 40 to 100 ***,the direct printable kirigami cuts and folds from soft elastic printable materials have significant potential for prosthetic *** printable kirigami design framework opens the possibility for future developments and modifications in numerous robotic applications.

摘要：As a bone scaffold,meeting all basic requirements besides dealing with other bone-related issues-bone cancer and accelerated regeneration-is not expected from traditional scaffolds,but a newer class of scaffolds called *** a clinical point of view,being a multifunctional scaffold means reducing in healing time,direct costs-medicine,surgery,and hospitalization-and indirect costs-loss of mobility,losing job,and *** main aim of the present review is following the multifunctional bone scaffolds trend to deal with both bone regeneration and cancer *** consideration is given to different fabrication techniques which have been applied to yield these materials spanning from traditional to modern ***,the hierarchical structure of bone plus bone cancers and available medicines to them are introduced to familiarize the potential reader of review with the pluri-disciplinary essence of the ***,a brief discussion relating to the future trend of these materials is provided.

摘要：Four types of seismic design details were tested using 11 transfer column specimens and one comparison specimen of RC under low cyclic reversed loading. Test results show that diagonal cracks control the failure pattern and damage occurs mainly in the RC section with weak shear capacity in the transfer columns. There is a large difference in the bearing capacity and ductility of the transfer columns according to the test results, which indicates that the strengthening effect of diverse structural measures is quite different. The section ratio of I-section-encased steel and the axial compression ratio also have a great influence on the bearing capacity and ductility. Although the bearing capacity of transfer columns with additional longitudinal bars and additional X bars is relatively large, they have poor deformation capacity. Setting more stirrups along the columns is the best structural measure to enhance the seismic performance. The studs on the I-sectionencased steel by welding can help to complete the stress transfer between the steel and concrete, and avoid performance degradation of the two materials due to bonding failure.

摘要：This paper presents the design guide based on analytical,numerical and experimental investigation of Steel-concrete-steel(SCS)sandwich structural members comprising a lightweight concrete core with density ranged from 1300 to 1445 kg/m3 subjected to static,impact and blast *** performance of lightweight sandwich members is also compared with similar members with normal weight concrete core and ultra high strength concrete core(fc=180 MPa).Novel J-hook shear connectors were invented to prevent the separation of face plates from the concrete core under extreme loads and their uses are not restricted by the concrete core *** and punching are the primary modes of failure under static point *** test results show that the SCS sandwich panels with the J-hook connectors are capable of resisting impact load with less damage in comparison than equivalent stiffened steel plate *** tests with 100 kg TNT were performed on SCS sandwich specimens to investigate the key parameters that affect the blast resistance of SCS sandwich *** yield line method is proposed to predict the plastic capacity and post peak large deflection of the sandwich ***,an energy balanced model is developed to analyze the global behavior of SCS sandwich panels subjected to dynamic load.

摘要：Orthopedic bone plates are most commonly used for bone fracture fixation for more than 100 *** bone plate design had evolved over time overcoming many challenges such as insufficient strength and excessive plate–bone contact affecting the blood ***,it is only made of two materials,either stainless steel(AISI 316L)or titanium(Ti–6Al–4V).There are two main limitations of metallic bone implants,namely stress shielding and the problem of malocclusion caused by the displacement of the fracture site during *** overcome the two problems,a new bone plate design with the incorporation of auxetic structures is proposed in this *** study aims to use auxetic structure section in the bone plate that would decrease the stiffness of the region,thereby mitigating the stress-shielding effect and at the same time act as a deformable section to enable intra-operative bending for effective alignment while having enough bending strength and *** different auxetic structures namely re-entrant honeycomb and missing rib structures were *** auxetic structure incorporated bone plates were designed,finite element analysis was done,fabricated using direct metal laser sintering technique,and *** results indicate that the re-entrant honeycomb structure incorporated bone plates serve as an effective bone design compared to the conventional bone plate design,in terms of stress shielding and intra-operative bending while offering similar mechanical and bending strength.