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

Following Sharpless' visionary characterization of several idealized reactions as click reactions, the materials science and synthetic chemistry communities have pursued numerous routes toward the identification and implementation of these click reactions. Herein, we review the radical-mediated thiol-ene reaction as one such click reaction. This reaction has all the desirable features of a click reaction, being highly efficient, simple to execute with no side products and proceeding rapidly to high yield. Further, the thiol-ene reaction is most frequently photoinitiated, particularly for photopolymerizations resulting in highly uniform polymer networks, promoting unique capabilities related to spatial and temporal control of the click reaction. The reaction mechanism and its implementation in various synthetic methodologies, biofunctionalization, surface and polymer modification, and polymerization are all reviewed.

Thiol–Ene Click Chemistry

What makes organizations so similar? We contend that the engine of rationalization and bureaucratization has moved from the competitive marketplace to the state and the professions. Once a set of organizations emerges as a field, a paradox arises: rational actors make their organizations increasingly similar as they try to change them. We describe three isomorphic processes-coercive, mimetic, and normative—leading to this outcome. We then specify hypotheses about the impact of resource centralization and dependency, goal ambiguity and technical uncertainty, and professionalization and structuration on isomorphic change. Finally, we suggest implications for theories of organizations and social change.

The iron cage revisited: Institutional isomorphism and collective rationality in organizational fields (Chinese Translation)

A cylindrical lens is demonstrated using two planar substrates and a homogeneous liquid crystal (LC) layer. The top substrate has slit electrodes on its outer surface and the bottom has a transparent electrode on its inner surface. An applied voltage across the cell induces a cylindrical-like gradient refractive index within the LC layer which causes light to focus. The focal length is tunable by the applied voltage. Such a cylindrical lens can be easily fabricated with wide aperture size.

/pdf/tunable-focus-cylindrical-liquid-crystal-lenses-4phehukenr.pdf

Tunable-Focus Cylindrical Liquid Crystal Lenses

— Refractive indices of two photocurable polymers, NOA65 and NOA81 (Norland Optical Adhesive), and two series of Merck liquid crystals, E-series (E44, E48, and E7) and BL-series (BL038, BL003 and BL006), and two UCF high-birefringence liquid-crystal mixtures were measured using an Abbe refractometer in the visible spectral region and 15–55°C temperature range. Some liquid crystals have excellent index matching with NOA65 in the red, while some fit better in the blue spectral region. To validate this index-matching property found in the material level, we prepared some polymer-dispersed liquid-crystal devices. Good correlations between material and device performances are obtained.

Refractive-index matching between liquid crystals and photopolymers

A polymer-dispersed liquid crystal confined in a 90° twisted cell (T-PDLC) is demonstrated. In comparison to a conventional PDLC, the T-PDLC is also polarization independent while exhibiting a higher contrast ratio. Potential applications of the T-PDLC are in polarizer-free reflective display and light switch. A black and white segmented-alphabet reflective display using a dye-doped T-PDLC is demonstrated.

/pdf/high-contrast-polymer-dispersed-liquid-crystal-in-a-90-6mefptndxr.pdf

High contrast polymer-dispersed liquid crystal in a 90° twisted cell

An electrically tunable focusing LC lens with a low voltage and simple planar electrodes is demonstrated. The inhomogeneous electric field of the LC lens without any hole-patterned-electrode is generated by using an embedded polymeric layer with a gradient distribution of dielectric constants (or relative permittivity). LC directors in the LC layer experience spatially inhomogeneous voltages even though a single voltage is applied to the planar electrodes. Such a LC lens has a low voltage (~2.6 Vrms) and simple design of electrodes. The gradient distribution of dielectric constants of polymeric layer is discussed and the performance of the LC lens is investigated. The applications of such a LC lens are cell phones, webcam, and pico projectors.

https://ir.nctu.edu.tw:443/bitstream/11536/15678/1/000300499500014.pdf

An electrically tunable-focusing liquid crystal lens with a low voltage and simple electrodes

An augmented reality (AR) system involving the electrically tunable location of a projected image is implemented using a liquid-crystal (LC) lens. The projected image is either real or virtual. By effectively doubling the LC lens power following light reflection, the position of a projected virtual image can be made to vary from 42 to 360 cm, while the tunable range for a projected real image is from 27 to 52 cm on the opposite side. The optical principle of the AR system is introduced and could be further developed for other tunable focusing lenses, even those with a lower lens power. The benefits of this study could be extended to head-mounted display systems for vision correction or vision compensation. We believe that tunable focusing LC optical elements are promising developments in the thriving field of AR applications.

https://ir.nctu.edu.tw:443/bitstream/11536/129574/1/1f8cfbbd5a831f6b32ff02234343ba59.pdf

Yi-Hsin Lin

Papers

Tunable-Focus Cylindrical Liquid Crystal Lenses

Refractive-index matching between liquid crystals and photopolymers

High contrast polymer-dispersed liquid crystal in a 90° twisted cell

An electrically tunable-focusing liquid crystal lens with a low voltage and simple electrodes

Electrically adjustable location of a projected image in augmented reality via a liquid-crystal lens.