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

J. Appl. Cryst.の発刊に際して

The applications of copper (Cu) and Cu-based nanoparticles, which are based on the earth-abundant and inexpensive copper metal, have generated a great deal of interest in recent years, especially in the field of catalysis. The possible modification of the chemical and physical properties of these nanoparticles using different synthetic strategies and conditions and/or via postsynthetic chemical treatments has been largely responsible for the rapid growth of interest in these nanomaterials and their applications in catalysis. In addition, the design and development of novel support and/or multimetallic systems (e.g., alloys, etc.) has also made significant contributions to the field. In this comprehensive review, we report different synthetic approaches to Cu and Cu-based nanoparticles (metallic copper, copper oxides, and hybrid copper nanostructures) and copper nanoparticles immobilized into or supported on various support materials (SiO2, magnetic support materials, etc.), along with their applications i...

http://pubs.acs.org/doi/pdfplus/10.1021/acs.chemrev.5b00482

Cu and Cu-Based Nanoparticles: Synthesis and Applications in Catalysis.

: The unpolarized absorption and circular dichroism spectra of the fundamental vibrational transitions of the chiral molecule, 4-methyl-2-oxetanone, are calculated ab initio. Harmonic force fields are obtained using Density Functional Theory (DFT), MP2, and SCF methodologies and a 5S4P2D/3S2P (TZ2P) basis set. DFT calculations use the Local Spin Density Approximation (LSDA), BLYP, and Becke3LYP (B3LYP) density functionals. Mid-IR spectra predicted using LSDA, BLYP, and B3LYP force fields are of significantly different quality, the B3LYP force field yielding spectra in clearly superior, and overall excellent, agreement with experiment. The MP2 force field yields spectra in slightly worse agreement with experiment than the B3LYP force field. The SCF force field yields spectra in poor agreement with experiment.The basis set dependence of B3LYP force fields is also explored: the 6-31G* and TZ2P basis sets give very similar results while the 3-21G basis set yields spectra in substantially worse agreements with experiment. jg

Ab initio calculation of vibrational absorption and circular dichroism spectra using density functional force fields

Spectroscopic Studies on the Hexafluorides of Rhenium, Osmium, Iridium, and Platinum Isolated in Low-temperature Matrices

XAS at the nickel K-edge and UV-visible studies of rhombohedral nickel trifluoride indicate that the compound has a mixed valence composition Ni[NiF6] and is isostructural with Pd[PdF6]. XAS data are reported for NiF2, [NiF6]2–, [NiF6]3–, Pd[PdF6], CoF3 and RhF3 in support of the Ni[NiF6] study. New data from refinements of X-ray powder diffraction of CoF3 and IrF3 are reported in the context of the distortion from hexagonal close packing of rhombohedral trifluorides.



Die Struktur von gemischt-valentem „R–NiF3”



Rontgen-Absorptionsspektren (XAS) an der Nickelkante und UV-Vis-Untersuchungen an rhomboedrischem Nickeltrifluorid zeigen, das diese Verbindung, Ni[NiF6], eine gemischt-valente Zusammensetzung hat und isostrukturell mit Pd[PdF6] ist. XAS-Daten von NiF2, [NiF6]2–, [NiF6]3–, Pd[PdF6], CoF3 und RhF3 werden zur Bestatigung der Untersuchung an Ni[NiF6] mitgeteilt. Neue Daten der Verfeinerung von Rontgen-Pulverdiffraktogrammen von CoF3 und IrF3 werden im Zusammenhang mit der Verzerrung der hexagonal-dichtesten Packung der rhomboedrischen Trifluoride mitgeteilt.

The mixed valence structure of "R-NiF3"

Nickel K-edge extended X-ray absorption fine structure data are reported for the tris(diamine) complexes [Ni(L–L)3]X2[L–L = H2NCH2CH2NH2(en), H2NCHMeCH2NH2(pn), H2NCH2CH2NHMe, H2NCH2CMe2NH2, and H2N[graphic omitted]HNH2; X = Cl, Br, sometimes F or BF4]. In all cases the data show two clearly defined shells of six nitrogen and six carbon atoms respectively, and for the cyclohexanediamine complexes a third shell of six carbons is well defined. However for the pn, H2NCH2CH2NHMe, and H2NCH2CMe2NH2 complexes the Ni ⋯ C(Me) distances are not clearly defined, and the data could not distinguish between Ni ⋯ N(Me) and Ni ⋯ NCbackbone distances. The initial chlorine oxidation products of the nickel(II) complexes suspended in dry CCl4, have been shown to be [Ni(diamine)3]Cl3, which decompose to known [Ni(diamine)2X2]X or mixed-valence materials in solution.

Nickel K-edge extended X-ray absorption fine structure studies of tris(diamine) complexes of nickel(II) and their halogen oxidation products

Inside Cover: Electrodeposition of Protocrystalline Germanium from Supercritical Difluoromethane (ChemElectroChem 5/2016)

The structure of the title compound, [Zr(C5H5)2(C9H11Te)2], consists of a zirconium(IV) centre bonded to two η5-coord­inated cyclo­penta­dienyl groups and two mesityltellurolate ligands; the discrete mol­ecule has crystallographic twofold rotation symmetry. The structural parameters compared with those in [(η5-Me5Cp)2Zr(TePh)2] [Howard, Trnka & Parkin (1995). Inorg. Chem. 34, 5900–5909] show that the greater steric demands of the bulky mesityl substituents are accommodated by widening Te—Zr—Te (∼8°) and by more acute Zr—Te—C (∼5°) angles, although the Zr—Te distances are essentially the same. The crystal studied exhibited some inversion twinning.

William Levason

Papers

Spectroscopic Studies on the Hexafluorides of Rhenium, Osmium, Iridium, and Platinum Isolated in Low-temperature Matrices

The mixed valence structure of "R-NiF3"

Nickel K-edge extended X-ray absorption fine structure studies of tris(diamine) complexes of nickel(II) and their halogen oxidation products

Inside Cover: Electrodeposition of Protocrystalline Germanium from Supercritical Difluoromethane (ChemElectroChem 5/2016)

Bis(η5-cyclopentadienyl)bis(2,4,6-trimethylphenyltellurolato)zirconium(IV)

William Levason

Papers

Spectroscopic Studies on the Hexafluorides of Rhenium, Osmium, Iridium, and Platinum Isolated in Low-temperature Matrices

The mixed valence structure of "R-NiF3"

Nickel K-edge extended X-ray absorption fine structure studies of tris(diamine) complexes of nickel(II) and their halogen oxidation products

Inside Cover: Electrodeposition of Protocrystalline Germanium from Supercritical Difluoromethane (ChemElectroChem 5/2016)

Bis(η5-cyclo­penta­dien­yl)bis­(2,4,6-tri­methyl­phenyl­tellurolato)zirconium(IV)

Bis(η5-cyclopentadienyl)bis(2,4,6-trimethylphenyltellurolato)zirconium(IV)