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

Fourier- and Hartley-related transforms are realized in a family of interferometers. The implementation of these interferometers as image correlators is investigated theoretically and experimentally with both coherent and spatially incoherent illumination. Several correlators that can be used for pattern recognition are studied and demonstrated experimentally as special cases.

/pdf/interferometric-electro-optical-signal-processors-with-1s9xfk9rtm.pdf

Interferometric electro-optical signal processors with partially coherent illumination

As Part III of this series, this paper focuses on an above-threshold modal analysis which includes gain saturation effects in the surface-emitting chirped circular grating lasers. We derive an exact energy relation which states that, in steady state, the net power generated in the gain medium is equal to the sum of peripheral leakage power and vertical emission power. This relation is particularly useful in checking the accuracy of numerical mode solving. Numerical simulations demonstrate the dependence of required pump level on the vertical emission power and compare the laser threshold and energy conversion efficiency under uniform, Gaussian, and annular pump profiles. A larger overlap between the pump profile and modal intensity distribution leads to a lower threshold and a higher energy conversion efficiency. Finally the dependence of required pump level on device sizes offers us new design guidelines of these lasers for single-mode, high-efficiency, high-power applications.

Surface-Emitting Circular DFB, Disk-, and Ring-Bragg Resonator Lasers with Chirped Gratings. III: Gain Saturation Effects and Above-Threshold Analysis

We have designed and fabricated an optical microcavity formed from a defect in a two-dimensionally patterned, half wavelength thick, InGaAs/InGaAsP multi-quantum well membrane.

Photonic bandgap membrane microresonator

A new research area in coherent optics has emerged and has been receiving increasing attention from many scientists as its important applications are recognized. Phase conjugate optics is the name which seems to have attached itself to this new field. The main feature of phase conjugate optics is the generation of an electromagnetic wave with a phase distribution which is, at each point in space, the reversal of that of an arbitrary incoming monochromatic wave. The wavefront, after being generated, proceeds to propagate in the opposite direction, retracing in reverse the path of the incoming wave. Thus, the phase reversal or conjugation process results in what is frequently called a time-reversed replica of the incident wave. If we consider, as an example, an incoming spherical wavefront which, diverging from a point, has a radius of curvature R, its conjugate-replica will be an outgoing spherical wavefront converging toward the same point and with a radius of curvature -R. Phase conjugation techniques have been used in the past for imaging through phase distorting media; well known examples can be found in holography [1] and adaptive optical systems [2]. The new and attractive feature, which differentiates phase conjugate optics from the previous techniques, is the use of nonlinear optical mixing to generate in real time without the need for intermediate electronics, and with amplification if desired, a time-reversed replica of an incident wave.

Phase-Conjugate Optics,

The state filling effect in semiconductor quantum well lasers significantly affects the modulation dynamics The state filling effect strongly depends on the optical confining layer structure As a direct consequence of the reduction of the state filling effect in a properly designed graded index separate confinement heterostructure, a record 3dB bandwidth in excess of 9 GHz has been obtained in uniformly pumped single quantum well GaAs/AlGaAs lasers by a careful tailoring of the device parameters

/pdf/modulation-bandwidth-enhancement-in-single-quantum-well-gaas-1d217pirsf.pdf

Amnon Yariv

Papers

Interferometric electro-optical signal processors with partially coherent illumination

Surface-Emitting Circular DFB, Disk-, and Ring-Bragg Resonator Lasers with Chirped Gratings. III: Gain Saturation Effects and Above-Threshold Analysis

Photonic bandgap membrane microresonator

Phase-Conjugate Optics,

Modulation Bandwidth Enhancement in Single Quantum Well GaAs/AlGaAs Lasers