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’

Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

Systems and methods for providing flexible robotic actuators are disclosed. Some embodiments of the disclosed subject matter include a soft robot capable of providing a radial deflection motions: a soft tentacle actuator capable of providing a variety of motions and providing transportation means for various types of materials; and a hybrid robotic system that retains desirable characteristics of both soft robots and hard robots. Some embodiments of the disclosed subject matter also include methods for operating the disclosed robotic systems.

Systems and methods for providing flexible robotic actuators

Rupture of emerging tough hydrogels has received much attention in recent years. It is a fundamental question what length of initial flaws can significantly affect the rupture of a tough hydrogel. Here we study the rupture of a tough hydrogel, using samples with and without initial cuts, under monotonic and cyclic loads. We prepare six samples under the same conditions, either without initial cut, or with initial cuts of the same length, and load them monotonically to inspect the statistical variation of measured rupture stress, rupture stretch and work of rupture. We cycle the six samples in parallel to the same amplitude of stretch and record the number of cycles to rupture of each sample. The average number of cycles to rupture decreases with the amplitude of stretch; and an endurance stretch exists, below which the samples can sustain indefinite number of cycles without rupture. We find that when the initial cut is long, the endurance stretch decreases with the initial cut length. When the initial cut is short, the endurance stretch is insensitive to the initial cut length. We interpret this finding by a material-specific length, the endurance fractocohesive length. We compare the endurance fractocohesive lengths of the hydrogel and other materials, including elastomers, plastics, metals, and ceramics. It is hoped that similar experiments will be soon conducted for other hydrogels to guide their development.

Flaw-sensitivity of a tough hydrogel under monotonic and cyclic loads

A process has been demonstrated recently to assemble microspheres on a patterned electrode under the influence of an applied voltage. Here we examine the mechanics of this process, and describe both the conditions under which excess microspheres jump off the electrode when the voltage is applied, and the forces that attract the remaining microspheres to the desired positions. A quantitative mechanistic understanding of this process rationalizes experimental observations, provides scaling relations, and suggests modifications of the process.

/pdf/mechanics-of-a-process-to-assemble-microspheres-on-a-27vjsbuxn2.pdf

Mechanics of a process to assemble microspheres on a patterned electrode

https://www.onlinelibrary.wiley.com/doi/pdf/10.1002/adma.201370008

Composite Materials: Robotic Tentacles with Three‐Dimensional Mobility Based on Flexible Elastomers (Adv. Mater. 2/2013)

A thin binary epilayer on a substrate often exhibits intriguing phase separation behavior. The phases may self-organize into a regular pattern, such as an array of periodic stripes or a lattice of islands. The size of the phases may be stable on annealing - that is, the phases may resist coarsening. This paper develops a thermodynamic model to study such pattern emergence. We model the substrate-epilayer composite as a bulk solid coupled with a superficial object. The bulk solid is linear elastic. The superficial object is prescribed with an excess energy, which is a function of the concentration, the surface strain, and the concentration gradient. Atomic diffusion is confined within the epilayer, and the surface remains nominally flat. The concentration dependence dictates the relative stability of the phases. The strain dependence couples the morphology in the epilayer with the deformation in the substrate, mediating a long range action that refines the phases. The concentration gradient dependence gives a continuum description of the phase boundary energy, mediating a short range action that coarsens the phases. The competition of the refining and the coarsening actions sets a length scale and leads to phase patterns. We study a diffusion equation consistent with this energetic description, and report on the results of a linear stability analysis.

Zhigang Suo

Papers

Systems and methods for providing flexible robotic actuators

Flaw-sensitivity of a tough hydrogel under monotonic and cyclic loads

Mechanics of a process to assemble microspheres on a patterned electrode

Composite Materials: Robotic Tentacles with Three‐Dimensional Mobility Based on Flexible Elastomers (Adv. Mater. 2/2013)

Coarsening, refining, and pattern emergence in binary epilayers