Charged functional groups modified porous spherical hollow carbon material as CDI electrode for salty water desalination.

As a new electrochemical technology, capacitive deionization (CDI) has been increasingly applied in environmental water treatment and seawater desalination. In this study, functional groups modified porous hollow carbon (HC) were synthesized as CDI electrode material for removing Na and Cl in salty water. Results showed that the average diameter of HC was approximately 180 nm, and the infrared spectrum showed that its surface was successfully modified with sulfonic and amino groups, respectively.

Omnidirectional thermal-electric signatures of functional illusion device with anisotropic geometry.

The omnidirectional thermal-electric signatures induced by the anisotropic functional illusion device and the corresponding camouflage device are reported. We first theoretically derive the anisotropic effective parameters of confocal elliptical bilayer core-shell structure for constructing the functional illusion device. Then, the thermal-electric signatures of the functional illusion device with camouflage device are presented numerically.

Design of an omnidirectional camouflage device with anisotropic confocal elliptic geometry in thermal-electric field.

The designed confocal elliptical core-shell structure can realize the omnidirectional camouflage effect without disturbing temperature and electric potential profiles as the directions of heat flux and electric current change. Based on the anisotropy of the confocal ellipse, the anisotropic effective parameters of the confocal elliptical core-shell structure are derived under different heat flux and electric current launching. Then, the matrix material should be anisotropic as the effective parameters to satisfy the omnidirectional camouflage effect, which is demonstrated numerically.

Synergy Effect and Symmetry-Induced Enhancement Effect of Surface Multi-Defects on Nanohardness by Quasi-Continuum Method.

The quasicontinuum method has been applied to probe the thin film with surface multi-defects, which is commonly seen in nanoimprint technique and bulk micromachining. Three unilaterally distributed multi-defect models and six bilaterally distributed multi-defect models of Pt thin film have been carried out in nanoindentation. The results show that the nanohardness gradually decreases as the number of unilaterally distributed multi-defects increases, along with the increasingly low decline rate of the nanohardness.

Assessment of predicted aircraft engine non-volatile particulate matter emissions at Hangzhou Xiaoshan International Airport using an integrated method.

Assessing the aircraft engine nonvolatile particulate matter (nvPM) emissions during landing and take-off (LTO) cycles is significant for airport air quality management. However, presently few prior studies have examined aircraft engine nvPM emissions on a daily basis for optimizing flight operations at airports. Therefore, based on the latest first-order approximation method of engine nvPM emissions, we introduce the engine emission data and aircraft flight data to establish an integrated method for estimating daily aircraft engine nvPM emissions at airports.

Shape Effect of Surface Defects on Nanohardness by Quasicontinuum Method.

Nanoindentation on a platinum thin film with surface defects in a rectangular shape and triangular shape was simulated using the quasicontinuum method to study the shape effect of surface defects on nanohardness. The results show that the nanohardness of thin film with triangular defects is basically larger than those with rectangular defects, which is closely related to the height of the surface defects at the boundary near to the indenter. Moreover, the triangular defect might have an enhancement effect on nanohardness by a certain size of the defects and the boundary orientation of the defect, where such an enhancement effect increases as the defect grows.

Atomistic Study of Interactions between Intrinsic Kink Defects and Dislocations in Twin Boundaries of Nanotwinned Copper during Nanoindentation.

In order to study the effects of kink-like defects in twin boundaries on deformation mechanisms and interaction between dislocations and defects in twin boundaries under localized load, nanotwinned Cu with two defective twin (TDT) boundaries is compared with the nanotwinned Cu with two perfect twin (TPT) boundaries, and nanotwinned Cu with single defective twin (SDT) boundary and single perfect twin boundary by simulating spherical nanoindentations using molecular mechanics. The indenter force-depth and hardness-contact strain responses were analyzed. Results show that the existence of intrinsic defects in twin boundary could reduce the critical load and critical hardness of nanotwinned material.

Multiscale Analysis of Size Effect of Surface Pit Defect in Nanoindentation.

The nanoindentation on a pit surface has been simulated using the quasicontinuum method in order to investigate the size effect of surface pit defect on the yield load of thin film. Various widths and heights of surface pit defect have been taken into account. The size coefficient has been defined as an index to express the influence of the width or height of surface pit defect.

Temperature-Dependent Transformation Thermotics: From Switchable Thermal Cloaks to Macroscopic Thermal Diodes.

The macroscopic control of ubiquitous heat flow remains poorly explored due to the lack of a fundamental theoretical method. Here, by establishing temperature-dependent transformation thermotics for treating materials whose conductivity depends on temperature, we show analytical and simulation evidence for switchable thermal cloaking and a macroscopic thermal diode based on the cloaking. The latter allows heat flow in one direction but prohibits the flow in the opposite direction, which is also confirmed by our experiments.

Multiscale simulation of indentation, retraction and fracture processes of nanocontact.

The process of nanocontact including indentation and retraction between a large Ni tip and a Cu substrate is investigated using quasicontinuum (QC) method. The multiscale model reveals that significant plastic deformation occurs during the process of nanocontact between Ni tip and Cu substrate. Plastic deformation is observed in an area as large as 20 nm wide and 10 nm thick beneath Ni tip during the indentation and retraction.

Effects of Crystalline Anisotropy and Indenter Size on Nanoindentation by Multiscale Simulation.

Nanoindentation processes in single crystal Ag thin film under different crystallographic orientations and various indenter widths are simulated by the quasicontinuum method. The nanoindentation deformation processes under influences of crystalline anisotropy and indenter size are investigated about hardness, load distribution, critical load for first dislocation emission and strain energy under the indenter. The simulation results are compared with previous experimental results and Rice-Thomson (R-T) dislocation model solution.