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

The semiconductor ZnO has gained substantial interest in the research community in part because of its large exciton binding energy (60meV) which could lead to lasing action based on exciton recombination even above room temperature. Even though research focusing on ZnO goes back many decades, the renewed interest is fueled by availability of high-quality substrates and reports of p-type conduction and ferromagnetic behavior when doped with transitions metals, both of which remain controversial. It is this renewed interest in ZnO which forms the basis of this review. As mentioned already, ZnO is not new to the semiconductor field, with studies of its lattice parameter dating back to 1935 by Bunn [Proc. Phys. Soc. London 47, 836 (1935)], studies of its vibrational properties with Raman scattering in 1966 by Damen et al. [Phys. Rev. 142, 570 (1966)], detailed optical studies in 1954 by Mollwo [Z. Angew. Phys. 6, 257 (1954)], and its growth by chemical-vapor transport in 1970 by Galli and Coker [Appl. Phys. ...

/pdf/a-comprehensive-review-of-zno-materials-and-devices-21a3zjadem.pdf

A comprehensive review of zno materials and devices

Spread Spectrum It’s not just for breakfast anymore! Don't blame me, the title is the work of this month's guest columnist, Steve Bible, N7HPR (n7hpr@tapr.org). While cruising the net recently, I noticed a sudden bump in the number of times Spread Spectrum (SS) techniques were mentioned in the amateur digital areas. While QEX has discussed SS in the past, we haven't touched on it in this forum. Steve was a frequent cogent contributor, so I asked him to give us some background. Steve enlisted in the Navy in 1977 and became a Data Systems Technician, a repairman of shipboard computer systems. In 1985 he was accepted into the Navy’s Enlisted Commissioning Program and attended the University of Utah where he studied computer science. Upon graduation in 1988 he was commissioned an Ensign and entered Nuclear Power School. His subsequent assignment was onboard the USS Georgia, a trident submarine stationed in Bangor, Washington. Today Steve is a Lieutenant and he is completing a master’s degree in computer science at the Naval Postgraduate School in Monterey, California. His areas of interest are digital communications, amateur satellites, VHF/UHF contesting, and QRP. His research area closely follows his interest in amateur radio. His thesis topic is Multihop Packet Radio Routing Protocol Using Dynamic Power Control. Steve is also the AMSAT Area Coordinator for the Monterey Bay area. Here's Steve, I'll have some additional comments at the end.

http://ieeexplore.ieee.org/iel5/5/31355/01457623.pdf

Digital communications

Fundamentals of Plasmonics.- Electromagnetics of Metals.- Surface Plasmon Polaritons at Metal / Insulator Interfaces.- Excitation of Surface Plasmon Polaritons at Planar Interfaces.- Imaging Surface Plasmon Polariton Propagation.- Localized Surface Plasmons.- Electromagnetic Surface Modes at Low Frequencies.- Applications.- Plasmon Waveguides.- Transmission of Radiation Through Apertures and Films.- Enhancement of Emissive Processes and Nonlinearities.- Spectroscopy and Sensing.- Metamaterials and Imaging with Surface Plasmon Polaritons.- Concluding Remarks.

/pdf/plasmonics-fundamentals-and-applications-4syb9877sr.pdf

Plasmonics: Fundamentals and Applications

We report on the first observation of third‐order intersubband nonlinearities in a quantum well structure. We have measured the dc Kerr effect in a symmetric quantum well and found that the Kerr coefficients due to intersubband transitions are six orders of magnitude larger than that of bulk GaAs. To our best knowledge this is the largest value ever measured for the third‐order susceptibility. By including dc screening effects and evaluating the internal electric field in the well, a good agreement between the calculated coefficients and the experimental ones was found.

Observation of third‐order intersubband dc Kerr effect at the midinfrared wavelengths in GaAs quantum wells

We present an all optically tunable wavelength-selective reflector for planar lightwave technology based on coupled microring resonators. By employing the Vernier effect, we demonstrate narrow-band reflection and strong side-lobe suppression in an optical polymer device fabricated by soft lithography. Wide and simple tuning of the reflection peak using an external control beam is demonstrated.

/pdf/all-optically-tunable-wavelength-selective-reflector-1ctyv69gqs.pdf

All optically tunable wavelength-selective reflector consisting of coupled polymeric microring resonators

A theory of longitudinal mode lasing spectrum of semiconductor lasers is developed which takes into account the nonuniform carrier and photon distributions and local gain spectrum shifts inside lasers with low end mirror reflectivities. The theory gives results consistent with observed longitudinal mode behavior in lasers with reduced facet reflectivity.

/pdf/a-theory-of-longitudinal-modes-in-semiconductor-lasers-2uf9jt82ij.pdf

A theory of longitudinal modes in semiconductor lasers

We introduce a fiber ring optical resonator based on adiabatic fused-fiber grating couplers. The coupling of a through fiber to the resonator is controlled by the strength of the fiber Bragg gratings. By using two of these couplers and incorporating erbium-doped (ED) fiber in the ring, we control the internal loss of the ring by pumping the ED fiber. The transmission spectra of the through port and the drop port of a four-port configuration, a ring coupled to two waveguides, are measured. We show that the loss/coupling ratio of the ring-fiber system can be changed and thus that the transmission properties of the fiber can be controlled.

/pdf/ring-fiber-resonators-based-on-fused-fiber-grating-add-drop-1bvw17qkp5.pdf

Ring fiber resonators based on fused-fiber grating add–drop filters: application to resonator coupling

Optical bistable oscillation beams with a self-pumped phase-conjugate mirror are reported. The results of an experimental demonstration are given, and an explanation based on the threshold of oscillation is presented.

/pdf/bistable-oscillations-with-a-self-pumped-phase-conjugate-2s68auxv5a.pdf

Amnon Yariv

Papers

Observation of third‐order intersubband dc Kerr effect at the midinfrared wavelengths in GaAs quantum wells

All optically tunable wavelength-selective reflector consisting of coupled polymeric microring resonators

A theory of longitudinal modes in semiconductor lasers

Ring fiber resonators based on fused-fiber grating add–drop filters: application to resonator coupling

Bistable oscillations with a self-pumped phase-conjugate mirror