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

The interaction of an electron beam with the optical field of a periodically perturbed dielectric thin‐film waveguide is considered. When the electron velocity is nearly equal to that of one of the spatial harmonics of the field, a coherent exchange of energy can take place. This interaction, which can lead in principle to a voltage‐tunable optical oscillation, is examined in the light of presently available thin‐film techniques. An estimate of the oscillation threshold is made.

/pdf/traveling-wave-oscillations-in-the-optical-region-a-4pjopzapm3.pdf

Traveling wave oscillations in the optical region: a theoretical examination

Single‐growth liquid‐phase embedded epitaxy in the GaInAsP/InP system is described, and a new heterostructure laser is grown using this technique. These lasers exhibit excellent current and optical confinement. Threshold currents as low as 45 mA are achieved for a laser with 4‐mm‐wide active region.

/pdf/embedded-epitaxial-growth-of-low-threshold-gainasp-inp-4p61l4zkrr.pdf

Embedded epitaxial growth of low‐threshold GaInAsP/InP injection lasers

The generation of ultra-wideband (UWB), high-frequency waveforms based on nonlinear propagation of pulses in optical fibers is reported. Self-phase modulation and subsequent optical filtering are used to implement all-optical edge detectors, which generate two temporally-narrowed replicas of each input pulse. The shapes of the narrowed pulses are subtracted from that of the original one in a balanced differential detector, providing a UWB waveform. The use of multiple replicas and nonlinear propagation allows for the generation of higher-order pulse shapes, beyond those of a Gaussian monocycle or doublet. The output pulse shape is reconfigurable through adjusting the input power and detuning the optical filters. The central radio-frequency of the generated waveforms is as high as 34 GHz, with a fractional bandwidth of 70%.

/pdf/reconfigurable-generation-of-high-order-ultra-wideband-475qas39np.pdf

Reconfigurable Generation of High-Order Ultra-Wideband Waveforms Using Edge Detection

An orthorhombic spectrum of U3+ in CaF2 was measured. The orthorhombic X, Y axes are found to lie in the (110) plane and the Z axis perpendicular to these axes. The X axes are at ±(19±1)° with the [110] direction. There are, in general, twelve inequivalent magnetic sites. The g factors corresponding to one set of axes are gx=1.38±0.01, gy=2.85±0.02, and gz=2.94±0.01. Various models explaining this spectrum are discussed. The most likely model is that of an interstitial F- in the second-nearest neighbor position.

Orthorhombic Electron Spin Resonance Spectrum of U3+ in CaF2

We apply coupled-wave theory to describe the lateral modes of semiconductor lasers with a periodic gain and refractive-index variation across their widths. The model is relevant to devices whose complex index of refraction is determined by current injection from closely spaced parallel electrodes. Good agreement is observed between the analytical modes and those computed numerically for comparison.

/pdf/coupled-wave-theory-of-multiple-stripe-semiconductor-44ie2tstyl.pdf

Amnon Yariv

Papers

Traveling wave oscillations in the optical region: a theoretical examination

Embedded epitaxial growth of low‐threshold GaInAsP/InP injection lasers

Reconfigurable Generation of High-Order Ultra-Wideband Waveforms Using Edge Detection

Orthorhombic Electron Spin Resonance Spectrum of U3+ in CaF2

Coupled-wave theory of multiple-stripe semiconductor injection lasers.