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. ...

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A comprehensive review of zno materials and devices

Additive manufacturing of metallic components – Process, structure and properties

Zinc oxide is a unique material that exhibits semiconducting and piezoelectric dual properties. Using a solid–vapour phase thermal sublimation technique, nanocombs, nanorings, nanohelixes/nanosprings, nanobelts, nanowires and nanocages of ZnO have been synthesized under specific growth conditions. These unique nanostructures unambiguously demonstrate that ZnO probably has the richest family of nanostructures among all materials, both in structures and in properties. The nanostructures could have novel applications in optoelectronics, sensors, transducers and biomedical sciences. This article reviews the various nanostructures of ZnO grown by the solid–vapour phase technique and their corresponding growth mechanisms. The application of ZnO nanobelts as nanosensors, nanocantilevers, field effect transistors and nanoresonators is demonstrated.

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Zinc oxide nanostructures: growth, properties and applications

We demonstrate in this paper that laser ablation allows efficient analysis of organic and biological materials Such analysis is based on laser-induced breakdown spectroscopy (LIBS) which consists in the detection of the optical emission from the plasma induced by a high intensity laser pulse focused on the sample surface The optimization of the ablation regime in terms of laser parameters (pulse duration, wavelength, fluence) is important to generate a plasma suitable for the analysis We first present the results of a study of laser ablation of organic samples with different laser parameters using time-resolved shadowgraph We correlate the early stage expansion of the plasma to its optical emission properties, which allows us to choose suitable laser parameters for an efficient analysis of organic or biological samples by LIBS As an illustration of the analytical ability of LIBS for biological materials, we show that the emission from CN molecules can be used to distinguish between biological and inorganic samples Native CN molecular fragment directly ablated from a biological sample are identified using time-resolved LIBS Those due to recombination with nitrogen contained in atmospheric air can be distinguished with their specific time evolution behavior

Laser ablation of organic materials for discrimination of bacteria in an inorganic background

Ion bombardment on the surface of a substrate during deposition of a thin film [ion‐assisted (IA) deposition] is used to control thin‐film crystalline orientation and phase. Ion‐assisted deposition is demonstrated with the relatively new pulsed‐laser deposition (PLD) technique, a method of thin‐film growth that has shown promise for the synthesis of high‐temperature superconductor and other complex oxide films. A versatile vacuum chamber with independent control of ion‐gun parameters was developed for ion‐assisted pulsed‐laser deposition (IAPLD). Control of crystalline orientation and alignment of yttria‐stabilized zirconia and CeO2 layers for use in YBa2Cu3O7−δ superconductor devices is demonstrated using this IAPLD technology.

Ion‐assisted pulsed‐laser deposition

The method of photothermal beam deflection was demonstrated for measuring the absorption spectrum of an aqueous Nd3+ solution at temperatures between 25°C and 90°C. Changes in the magnitude of the observed deflection can be correlated with the temperature dependence of both the absorptivity of the Nd3+ ions and the physical properties of the solvent, most notably the thermo-optic coefficient dn/dT.

Collinear photothermal deflection spectroscopy of liquid samples at varying temperature

For laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) imaging experiments – as well as other techniques used for elemental or molecular mapping – the accordance of the measured distribution with the actual distribution is of utmost importance to guarantee reliability of the obtained images. In most experiments reported in the past, the experimental conditions have been chosen so that washout effects and signal carry-over are minimized by scanning the sample surface very slowly. Therefore, measurement times become very long and decently resolved images will require acquisition times of several hours up to more than one day. To increase the application range of LA-ICP-MS for imaging it is important to decrease the measurement times, which is best accomplished by increasing the scanning rates. However, depending on the instrumentation, this can lead to blurring and compromised image quality. In this work, we present a metric to compare the measured elemental distribution with their actual distribution based on a sample with visually distinguishable features. This approach allows quantitative determination of the image quality and enables comparison of multiple measurement conditions. This information can be used for method optimization, to get a reasonable tradeoff between image quality and measurement time.

Richard E. Russo

Papers

Laser ablation of organic materials for discrimination of bacteria in an inorganic background

Ion‐assisted pulsed‐laser deposition

Collinear photothermal deflection spectroscopy of liquid samples at varying temperature

A metric for evaluation of the image quality of chemical maps derived from LA-ICP-MS experiments

Dual-beam optical fiber thermal lens spectroscopy