The Irradiation Effects of Metal Gold Surface by Intense Pulsed Ion Beam

2013 ◽  
Vol 690-693 ◽  
pp. 2085-2088
Author(s):  
Di Wu ◽  
Yong Jian Du
Keyword(s):  
Ion Beam ◽  
Gold Surface ◽  
Distribution Models ◽  
Temporal And Spatial Distribution ◽  
Gold Target ◽  
Beam Density ◽  
Modification Method ◽  
Deposited Energy ◽  
Temporal And Spatial ◽  
Thermal Conduction Equation

We report a modification method for Gold target by intense pulsed ion beam (IPIB) irradiation. Based on the temporal and spatial distribution models of the ion beam density detected by Faraday cup in the chamber and the ions accelerating voltage, the energy deposition of the beam ions in Au is calculated by Monte Carlo method. Taking this time-dependent nonlinear deposited energy as the source term of two-dimensional thermal conduction equation, we obtain the temporal and spatial ablation process of metal Au during a pulse time. The top-layer Gold material in thickness of about 0.25μm is ablated by vaporization and the layer in thickness of 1.40μm is melted after one shot at the ion beam density of 300 A/cm2.

Research on Thermo Effects of Silver Modified by High-Intensity Pulsed Ion Beam

2013 ◽  
Vol 423-426 ◽  
pp. 294-297
Author(s):  
Di Wu
Keyword(s):  
High Intensity ◽  
Ion Beam ◽  
Distribution Models ◽  
Temporal And Spatial Distribution ◽  
Beam Density ◽  
Modification Method ◽  
Deposited Energy ◽  
Silver Target ◽  
Temporal And Spatial ◽  
Thermal Conduction Equation

We report a modification method for Silver target by high-intensity pulsed ion beam (HIPIB) irradiation. Based on the temporal and spatial distribution models of the ion beam density detected by Faraday cup in the chamber and the ions accelerating voltage, the energy deposition of the beam ions in Ag is calculated by Monte Carlo method. Taking this time-dependent nonlinear deposited energy as the source term of two-dimensional thermal conduction equation, we obtain the temporal and spatial ablation process of metal Ag during a pulse time. The top-layer silver material in thickness of about 0.33μm is ablated by vaporization and the layer in thickness of 1.6μm is melted after one shot at the ion beam density of 300 A/cm2.

scholarly journals Dog colour patterns explained by modular promoters of ancient canid origin

2021 ◽  
Author(s):  
Danika L. Bannasch ◽  
Christopher B. Kaelin ◽  
Anna Letko ◽  
Robert Loechel ◽  
Petra Hug ◽  
...  
Keyword(s):  
Colour Pattern ◽  
Hair Cycle ◽  
Temporal And Spatial Distribution ◽  
Multiple Alleles ◽  
Haplotype Combination ◽  
Regulatory Modules ◽  
Regulatory Module ◽  
Temporal And Spatial ◽  
Selection For ◽  
Colour Patterns

AbstractDistinctive colour patterns in dogs are an integral component of canine diversity. Colour pattern differences are thought to have arisen from mutation and artificial selection during and after domestication from wolves but important gaps remain in understanding how these patterns evolved and are genetically controlled. In other mammals, variation at the ASIP gene controls both the temporal and spatial distribution of yellow and black pigments. Here, we identify independent regulatory modules for ventral and hair cycle ASIP expression, and we characterize their action and evolutionary origin. Structural variants define multiple alleles for each regulatory module and are combined in different ways to explain five distinctive dog colour patterns. Phylogenetic analysis reveals that the haplotype combination for one of these patterns is shared with Arctic white wolves and that its hair cycle-specific module probably originated from an extinct canid that diverged from grey wolves more than 2 million years ago. Natural selection for a lighter coat during the Pleistocene provided the genetic framework for widespread colour variation in dogs and wolves.

scholarly journals Analysis of the Temporal and Spatial Characteristics of Material Cultural Heritage Driven by Big Data—Take Museum Relics as an Example

Information ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 153
Author(s):  
Penglong Li ◽  
Zuoqin Shi ◽  
Yi Ding ◽  
Ling Zhao ◽  
Zezhong Ma ◽  
...  
Keyword(s):  
Cultural Heritage ◽  
Life Cycles ◽  
Cultural Communication ◽  
Temporal And Spatial Distribution ◽  
State Administration ◽  
Cultural Relic ◽  
Temporal And Spatial ◽  
Temporal And Spatial Characteristics ◽  
And Migration ◽  
Cultural Relics

Museum cultural relics represent a special material cultural heritage, and modern interpretations of them are needed in current society. Based on the catalogue data of cultural relics published by the State Administration of Cultural Heritage, this paper analyzes the continuity and intermittentness of cultural relics in time series by using the method of continuity judgment of cultural relics, analyzes the aggregation and migration of cultural relics in space by using the method of spatial analysis, and then uses cosine similarity to explain the similarity distribution in space and time. The results show that the overall distribution of cultural relics exhibits the characteristics of class aggregation, dynasty aggregation and regional aggregation. From the perspective of a time scale, cultural relics have different “life cycles”, displaying continuity, intermittentness, and similarity. From the perspective of a spatial scale, the cultural relic distribution forms a small “cultural communication circle”, showing aggregation, migration, and similarity. The temporal and spatial distribution of cultural relics exhibited more similar characteristics among dynasties that were closer together than those that were far away.

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