scholarly journals Effects of Accumulated Energy on Nanoparticle Formation in Pulsed-Laser Dewetting of AgCu Thin Films

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
H. K. Lin ◽  
C. W. Huang ◽  
Y. H. Lin ◽  
W. S. Chuang ◽  
J. C. Huang

AbstractAg50Cu50 films were deposited on glass substrates by a sputtering system. Effects of accumulated energy on nanoparticle formation in pulse-laser dewetting of AgCu films were investigated. The results showed that the properties of the dewetted films were found to be dependent on the magnitude of the energy accumulated in the film. For a low energy accumulation, the two distinct nanoparticles had rice-shaped/Ag60Cu40 and hemispherical/Ag80Cu20. Moreover, the absorption spectra contained two peaks at 700 nm and 500 nm, respectively. By contrast, for a high energy accumulation, the nanoparticles had a consistent composition of Ag60Cu40, a mean diameter of 100 nm and a peak absorption wavelength of 550 nm. Overall, the results suggest that a higher Ag content of the induced nanoparticles causes a blue shift of the absorption spectrum, while a smaller particle size induces a red shift.

2019 ◽  
Vol 61 (8) ◽  
pp. 1526
Author(s):  
Ю.А. Кузнецов ◽  
М.Н. Лапушкин ◽  
Е.В. Рутьков ◽  
Н.Р. Галль

Electron stimulated desorption (ESD) of neutral atomic Cs from graphene on Ir has been studied for two cases: when Cs intercalation does present and when it does not take place. Two peaks have been found at desorbed atom energy distribution: high-energy (HE) at the energy of 0.36 eV and low-energy (LE) one at the energy of 0.13 eV. HE peak has been observed for both cases, we attribute it with excitation of 2s carbon core level. LE peak was observed only when intercalation does not take place; we attribute it with excitation of 4f and 5p core levels of Ir. A model is put forward to describe atomic Cs ESD; we proposed that graphene on Ir acts as dielectric in the processes discussed above.


Author(s):  
Юрий Александрович Кузнецов ◽  
Михаил Николаевич Лапушкин

Получена тонкая пленка интерметаллида LiAu при комнатной температуре при напылении атомов Li на слой адсорбированного золота на поверхности вольфрама. Исследованы процессы электронно-стимулированной десорбции (ЭСД) атомов Li с поверхности LiAu. Показано, что ЭСД атомов Li может наблюлаться только в том случае, когда напылено не менее одного монослоя атомов Li и с Au . Зависимость выхода ЭСД атомов Li от количества напыленного Li и Au имеет максимум при напылении двух монослоев атомов Li на Au. Полученные результаты свидетельствуют о формировании LiAu различной стехиометрии: от LiAu с дефицитом атомов лития до LiAu при напылении двух монослоев атомов Li. В энергетическом распределении по кинетическим энергиям десорбирующихся атомов Li обнаружено два пика: высокоэнергетический и низкоэнергетический. Первый из них связан с десорбцией атомов Li из LiAu, а второй в десорбцией атомов Li из верхнего монослоя атомов Li. A thin film of the intermetallic compound LiAu was obtained at room temperature by deposition Li atoms onto a layer of adsorbed gold on the tungsten surface. The processes of electron-stimulated desorption of Li atoms from the surface are investigated. It is shown that electron-stimulated desorption of Li atoms can be observed only in the case when at least one monolayer of Li and Au atoms is deposited. The dependence of the electron-stimulated desorption yield of Li atoms on the amount of deposited has a maximum when two monolayers of atoms Li are deposited on Au . The results obtained indicate the LiAu formation of various stoichiometry: from with a deficit of lithium atoms to the deposition of two monolayers of atoms. In the kinetic energy distribution of desorbed Li atoms, two peaks were found: high-energy and low-energy. The first of them is associated with the desorption of Li atoms from LiAu, and the second with the desorption of Li atoms from the upper monolayer of Li atoms.


2001 ◽  
Vol 28 (1) ◽  
pp. 37-40 ◽  
Author(s):  
Gabriele Carannante ◽  
A. Laviano ◽  
D. Ruberti ◽  
Lucia Simone ◽  
G. Sirna ◽  
...  

Author(s):  
Peter Rez

Transportation efficiency can be measured in terms of the energy needed to move a person or a tonne of freight over a given distance. For passengers, journey time is important, so an equally useful measure is the product of the energy used and the time taken for the journey. Transportation requires storage of energy. Rechargeable systems such as batteries have very low energy densities as compared to fossil fuels. The highest energy densities come from nuclear fuels, although, because of shielding requirements, these are not practical for most forms of transportation. Liquid hydrocarbons represent a nice compromise between high energy density and ease of use.


2021 ◽  
Vol 22 (15) ◽  
pp. 7879
Author(s):  
Yingxia Gao ◽  
Yi Zheng ◽  
Léon Sanche

The complex physical and chemical reactions between the large number of low-energy (0–30 eV) electrons (LEEs) released by high energy radiation interacting with genetic material can lead to the formation of various DNA lesions such as crosslinks, single strand breaks, base modifications, and cleavage, as well as double strand breaks and other cluster damages. When crosslinks and cluster damages cannot be repaired by the cell, they can cause genetic loss of information, mutations, apoptosis, and promote genomic instability. Through the efforts of many research groups in the past two decades, the study of the interaction between LEEs and DNA under different experimental conditions has unveiled some of the main mechanisms responsible for these damages. In the present review, we focus on experimental investigations in the condensed phase that range from fundamental DNA constituents to oligonucleotides, synthetic duplex DNA, and bacterial (i.e., plasmid) DNA. These targets were irradiated either with LEEs from a monoenergetic-electron or photoelectron source, as sub-monolayer, monolayer, or multilayer films and within clusters or water solutions. Each type of experiment is briefly described, and the observed DNA damages are reported, along with the proposed mechanisms. Defining the role of LEEs within the sequence of events leading to radiobiological lesions contributes to our understanding of the action of radiation on living organisms, over a wide range of initial radiation energies. Applications of the interaction of LEEs with DNA to radiotherapy are briefly summarized.


2021 ◽  
Author(s):  
Quang Hieu Tran ◽  
Thuy Thanh Ho ◽  
Tu Thanh Nguyen

A comprehensive study from Curcuma longa to powder nano curcuminoids has been carried out. Combining of both low energy method (Phase Inversion Temperature) and high-energy method (Ultrasonication), a series of...


2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Martin Bauer ◽  
Matthias Neubert ◽  
Sophie Renner ◽  
Marvin Schnubel ◽  
Andrea Thamm

Abstract Axions and axion-like particles (ALPs) are well-motivated low-energy relics of high-energy extensions of the Standard Model, which interact with the known particles through higher-dimensional operators suppressed by the mass scale Λ of the new-physics sector. Starting from the most general dimension-5 interactions, we discuss in detail the evolution of the ALP couplings from the new-physics scale to energies at and below the scale of electroweak symmetry breaking. We derive the relevant anomalous dimensions at two-loop order in gauge couplings and one-loop order in Yukawa interactions, carefully considering the treatment of a redundant operator involving an ALP coupling to the Higgs current. We account for one-loop (and partially two-loop) matching contributions at the weak scale, including in particular flavor-changing effects. The relations between different equivalent forms of the effective Lagrangian are discussed in detail. We also construct the effective chiral Lagrangian for an ALP interacting with photons and light pseudoscalar mesons, pointing out important differences with the corresponding Lagrangian for the QCD axion.


2021 ◽  
Vol 11 (10) ◽  
pp. 4349
Author(s):  
Tianzhong Xiong ◽  
Wenhua Ye ◽  
Xiang Xu

As an important part of pretreatment before recycling, sorting has a great impact on the quality, efficiency, cost and difficulty of recycling. In this paper, dual-energy X-ray transmission (DE-XRT) combined with variable gas-ejection is used to improve the quality and efficiency of in-line automatic sorting of waste non-ferrous metals. A method was proposed to judge the sorting ability, identify the types, and calculate the mass and center-of-gravity coordinates according to the shading of low-energy, the line scan direction coordinate and transparency natural logarithm ratio of low energy to high energy (R_value). The material identification was satisfied by the nearest neighbor algorithm of effective points in the material range to the R_value calibration surface. The flow-process of identification was also presented. Based on the thickness of the calibration surface, the material mass and center-of-gravity coordinates were calculated. The feasibility of controlling material falling points by variable gas-ejection was analyzed. The experimental verification of self-made materials showed that identification accuracy by count basis was 85%, mass and center-of-gravity coordinates calculation errors were both below 5%. The method proposed features high accuracy, high efficiency, and low operation cost and is of great application value even to other solid waste sorting, such as plastics, glass and ceramics.


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