There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Surface composites by friction stir processing: A review

Corrosion behavior of an equiatomic CoCrFeMnNi high-entropy alloy compared with 304 stainless steel in sulfuric acid solution

Friction stir welding/processing of metals and alloys: A comprehensive review on microstructural evolution

Limiting oxidation of high entropy alloy via high strain-rate deformation: Insights from electrochemical impedance spectroscopy

Tribological behavior of NiTi alloy processed under different cooling conditions

This chapter presents a comprehensive study on the influence of friction stir processing/welding (FSW/FSP) on corrosion behaviour. It briefly discusses the different aspects of corrosion including corrosion types, measurement techniques and data analysis. The corrosion behaviour of a wide range of friction stir processed materials, including light weight metals such as magnesium and aluminum alloys, as well as high strength metals such as steel, has been discussed in detail. The influence of FSP parameters on the microstructural evolution, comprising grain-size and precipitate refinement along with its correlation with the corrosion properties, has been described for different materials.

Corrosion behaviour in friction stir processed and welded materials

Abstract In the present work, we investigated the effectiveness of microwave processing and thermal spraying for developing tungsten carbide (WC)-based erosion-resistant claddings. The microwave cladding showed a columnar structure with a well-bonded interface compared to discrete splat morphology and discontinuous interface of the thermal spray coating. The cladding showed a lower hardness (800 HV) compared to thermal spray coating (1,300 HV) and a two times higher fracture toughness due to the absence of splat boundaries and pores. The microwave cladding also showed 14 times and 10 times higher cavitation erosion resistance than thermal spray coating and SS316L substrate steel, respectively. The improved cavitation erosion resistance of the microwave cladding is explained on the basis of the optimized combination of hardness and fracture toughness. The surface of eroded cladding showed plastically deformed micropits compared to the thermal spray coatings, which showed large craters. Results show that microwave claddings can help improve the durability of engineering systems.

Development of Cavitation Erosion–Resistant Microwave Processed WC-based Cladding

Structural changes in a bulk metallic glass subjected to high-strain plastic deformation was investigated. A zirconium-based bulk metallic glass was friction stir processed at different tool rotational speeds. The alloy retained its fully amorphous structure at lower speed. At higher tool rotational speed there was partial nano-crystallization with nearly three times increase in surface hardness. Changes in the glass transition temperature, relaxation and crystallization enthalpies were analyzed to explain the physics of high-strain deformation in amorphous metals.

Harpreet Singh Grewal

Papers

Limiting oxidation of high entropy alloy via high strain-rate deformation: Insights from electrochemical impedance spectroscopy

Tribological behavior of NiTi alloy processed under different cooling conditions

Corrosion behaviour in friction stir processed and welded materials

Development of Cavitation Erosion–Resistant Microwave Processed WC-based Cladding

Structural changes in amorphous metals from high-strain plastic deformation