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

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

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

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Many potential applications have been proposed for carbon nanotubes, including conductive and high-strength composites; energy storage and energy conversion devices; sensors; field emission displays and radiation sources; hydrogen storage media; and nanometer-sized semiconductor devices, probes, and interconnects. Some of these applications are now realized in products. Others are demonstrated in early to advanced devices, and one, hydrogen storage, is clouded by controversy. Nanotube cost, polydispersity in nanotube type, and limitations in processing and assembly methods are important barriers for some applications of single-walled nanotubes.

http://science.sciencemag.org/content/sci/297/5582/787.full.pdf

Carbon Nanotubes--the Route Toward Applications

A massive number of CNTs can be in situ grown directly from reaction gases on substrate or ex situ aligned from as-grown random CNTs under various fields to preserve the strong anisotropic nature of individual CNTs. In this chapter, we introduce various techniques to fabricate CNTs along a certain direction. The morphology of aligned CNTs is illustrated and the fabrication mechanism of each technique is discussed.

Technologies to Achieve Carbon Nanotube Alignment

Carbon nanotubes (CNT) have exceptional mechanical strength at small diameters needed for measuring high aspect ratio features. Manually attached carbon nanotube atomic force microscopy probes have demonstrated exceptional longevity. Unfortunately, due to the manual attachment process, and the usually arbitrary diameter and length of the used CNT, such probes are not suitable for high aspect ratio critical dimension metrology (CDM). For reproducible and accurate CDM measurements precisely defined CNT probes are necessary. We are reporting about the progress made growing carbon nanotubes (CNT) directly on top of standard Si probes. The goal is to produce well-defined long lasting probes for CDM measurements in the <100 nm pitch range. Our efforts currently focus on manufacturing precisely aligned CNT having defined locations, diameters and lengths. This is accomplished by using plasma assisted chemical vapor deposition in combination with focused ion beam (FIB) patterned catalyst films. Our results demonstrate that it is possible to manufacture 1:10 aspect ratio CNT probes at <100 nm diameters.

Making carbon nanotube probes for high aspect ratio scanning probe metrology

The effect of titanium (Ti) substitution for hafnium (Hf) on thermoelectric properties of (Hf, Zr)based n-type half-Heuslers: Hf0.75xTixZr0.25NiSn0.99Sb0.01, has been studied. The samples are made by arc melting followed by ball milling and hot pressing via the nanostructuring approach. A peak thermoelectric figure-of-merit (ZT )o f1.0 is achieved at 500 1C in samples with a composition of Hf0.5Zr0.25Ti0.25NiSn0.99Sb0.01 due to a slight increase in carrier concentration and also a lower thermal conductivity caused by Ti. The ZT values below 500 1C of hot pressed Hf0.5Zr0.25Ti0.25NiSn0.99Sb0.01 samples are significantly higher than those of the same way prepared Hf0.75Zr0.25NiSn0.99Sb0.01 samples at each temperature, which are very much desired for midrange temperature applications such as waste heat recovery in automobiles.

Enhancement of thermoelectric figure-of-merit at low temperatures by titanium substitution for hafnium in n-type half-Heuslers

Aligned CNT assemblies have many applications besides what were discussed in the previous chapters. In this chapter, we introduce some potential applications of aligned CNTs, which is possible from theoretical point of view but might take a long time to realize because of the immature of the needed techniques.

Potential Applications of Carbon Nanotube Arrays

Porous gallium nitride microtubes were self-fabricated from gallium nitride submicron irregular structures. The microtubes were of square cross-section. Electron diffractions indicated that the microtubes were composed of zincblende gallium nitride. Electron energy-loss spectrum and photoluminescence spectrum of the microtubes were collected and compared with that of single crystals.

/pdf/nanoporous-gallium-nitride-square-microtubes-588ia7du8j.pdf

Zhifeng Ren

Papers

Technologies to Achieve Carbon Nanotube Alignment

Making carbon nanotube probes for high aspect ratio scanning probe metrology

Enhancement of thermoelectric figure-of-merit at low temperatures by titanium substitution for hafnium in n-type half-Heuslers

Potential Applications of Carbon Nanotube Arrays

Nanoporous gallium nitride square microtubes