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

Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

The surface science of titanium dioxide

The richness of optical and electronic properties of graphene attracts enormous interest. Graphene has high mobility and optical transparency, in addition to flexibility, robustness and environmental stability. So far, the main focus has been on fundamental physics and electronic devices. However, we believe its true potential lies in photonics and optoelectronics, where the combination of its unique optical and electronic properties can be fully exploited, even in the absence of a bandgap, and the linear dispersion of the Dirac electrons enables ultrawideband tunability. The rise of graphene in photonics and optoelectronics is shown by several recent results, ranging from solar cells and light-emitting devices to touch screens, photodetectors and ultrafast lasers. Here we review the state-of-the-art in this emerging field.

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Graphene photonics and optoelectronics

The conformational flexibility of isotactic polypropylene, isotactic poly-1-butene and isotactic poly(3-methyl-1-butene) has been studied by theoretical methods, especially in relation to their polymorphism. The energy calculations show the predominant contribution of intramolecular effects and allow a valid interpretation of polymorphous behaviour. Furthermore, the conformational mobility of the side chains of the macromolecules plays a very important role in establishing the lowest-energy structure.

Conformational flexibility of isotactic poly‐1‐olefins

Ab initio STO-3G calculations have been employed to study electronic properties associated with the lowest-lying virtual molecular orbitals of all the fluorinated benzenes. The results show that the lowest unoccupied molecular orbital, which would assist the first electron transfer in the electrode reduction of the title compounds, is invariably of π type along the series, no σ*—π* crossover being predicted. The perfluoro effect on the virtual molecular orbitals manifests itself by affecting the lowest σ* orbital significantly more than the π* orbitals. Orbital energies can be correlated with experimental vertical attachment energies. Following the nature and nodal characteristics of the lowest unoccupied molecular orbital, only a small fraction of the extra charge in the fluorobenzene anions resides on the CF bond. Possible implications between the present results and the polarographic reduction of halobenzenes are briefly mentioned.

The nature of the lowest virtual molecular orbitals in fluorobenzenes

Angle-scanned photoelectron diffraction measurements have been performed prior to and after CO exposure onto a Ni monolayer deposited on Pt(111). Ni is known to grow epitaxially on Pt(111), but there is evidence for an adsorbate-induced restructuring such that the initial atomically flat Ni layer gives place to at least two-layer-high Ni islands. As far as the driving force for the restructuring is concerned, some hypotheses can be put forward considering the Ni–Ni nearest neighbor distances in the Ni monolayer and in the restructured layer, along with some thermodynamical arguments.

EVIDENCE BY ANGLE-SCANNED PHOTOELECTRON DIFFRACTION FOR A CO-INDUCED RESTRUCTURING OF A Ni/Pt(111) MONOLAYER

He(I) and He(II) excited photoelectron spectra of the methyltin chlorides Sn(CH3)3Cl and Sn(CH3)2Cl2 are reported. On the basis of the variation of relative-intensity patterns on passing from He(I) to He(II) excitation, a reassignment of the spectra is suggested.

He(I) and He(II) photoelectron spectra of methyltin chlorides

In this work, three TiO2 thin films with thicknesses of 22.7, 48.5 and 102.9 nm were grown on Si (100) substrates by the technique of electron beam evaporation. The films were deposited at a substrate temperature of 150°C with a deposition rate of 0.3 - 0.5 A/sec. The films thicknesses were characterized by spectroscopic ellipsometry and profilometry. The surface roughness was measured by AFM obtaining RMS of less than 0.7nm. Investigations performed by XPS method have shown that stoichiometric TiO2 was obtained on all the samples with no suboxide presences. Reflectance measurements of the samples were performed in EUV and SX spectral regions from 25.5 to 454.2eV using synchrotron radiation. Analyzing the refractive index N=n+ik of TiO2 thin films, optical constants (n,k) in this energy range were both determined by fitting the Fresnel equations with least-square fitting methods.

Gaetano Granozzi

Papers

Conformational flexibility of isotactic poly‐1‐olefins

The nature of the lowest virtual molecular orbitals in fluorobenzenes

EVIDENCE BY ANGLE-SCANNED PHOTOELECTRON DIFFRACTION FOR A CO-INDUCED RESTRUCTURING OF A Ni/Pt(111) MONOLAYER

He(I) and He(II) photoelectron spectra of methyltin chlorides

Characterization of TiO2 thin films in the EUV and soft x-ray region