Tangent Resistance of Soil on Moldboard and the Mechanism of Resistance Reduction of Bionic Moldboard

The tangent resistance on the interface of the soil-moldboard is an important component of the resistance to moving soil . We developed simplified mechanical models to analyze this resistance. We found that it is composed of two components, the frictional and adhesive resistances. These two components originate from the soil pore, which induced a capillary suction effect, and the soil-moldboard contact area produced tangent adhesive resistance. These two components varied differently with soil moisture. Thus we predicted that resistance reduction against soil exerted on the non-smooth bionic moldboard is mainly due to the elimination of capillary suction and the reduction of physical-chemical adsorption of soil.

Measurements of electron-phonon coupling factor and interfacial thermal resistance of metallic nano-films using a transient thermoreflectance technique

Using a transient thermoreflectance （TTR） technique, several Au films with different thicknesses on glass and SiC substrates are measured for thermal characterization of metMlic nano-films, including the electron phonon coupling factor G, interfazial thermal resistance R, and thermal conductivity Ks of the substrate. The rear heating-front detecting （RF） method is used to ensure the femtosecond temporal resolution. An intense laser beam is focused on the rear surface to heat the film, and another weak laser beam is focused on the very spot of the front surface to detect the change in the electron temperature. By varying the optical path delay between the two beams, a complete electron temperature profile can be scanned. Different from the normally used single-layer model, the double-layer model involving interfaciM thermal resistance is studied here. The electron temperature cooling profile can be affected by the electron energy transfer into the substrate or the electron-phonon interactions in the metallic films. For multiple-target optimization, the genetic algorithm （GA） is used to obtain both G and R. The experimental result gives a deep understanding of the mechanism of ultra-fast heat transfer in metals.

Interfacial Issues of All Solid State Lithium Batteries

All solid state lithium battery is a promising next generation battery system with improved cycle life, en ergy density, especially safety. However, its development is greatly hampered by a large impedance between the solid state electrolyte/electrode interface. How to build an ideal electrolyte/electrode interface to improve the inter facial stability and reduce the interracial resistance is a huge challenge for improving battery performance. This pa per reviews interracial problems and introduces the formation mechanism of different interface layers between elec trodes and electrolytes. In addition, the strategies for improving interracial contact and reducing interracial resist ance are described in detail. Finally, the research directions for engineering interfaces in all solid state lithium bat teries are proposed.

Thermal transport in phosphorene and phosphorene-based materials:A review on numerical studies

The recently discovered two-dimensional(2D)layered material phosphorene has attracted considerable interest as a promising p-type semiconducting material.In this article,we review the recent advances in numerical studies of the ther-mal properties of monolayer phosphorene and phosphorene-based heterostructures.We first briefly review the commonly used first-principles and molecular dynamics(MD)approaches to evaluate the thermal conductivity and interfacial thermal resistance of 2D phosphorene.Principles of different steady-state and transient MD techniques have been elaborated on in detail.Next,we discuss the anisotropic thermal transport of phosphorene in zigzag and armchair chiral directions.Subse-quently,the in-plane and cross-plane thermal transport in phosphorene-based heterostructures such as phosphorene/silicon and phosphorene/graphene is summarized.Finally,the numerical research in the field of thermal transport in 2D phospho-rene is highlighted along with our perspective of potentials and opportunities of 2D phosphorenes in electronic applications such as photodetectors,field-effect transistors,lithium ion batteries,sodium ion batteries,and thermoelectric devices.