Synthesis of diversifolide and structure revision

The synthesis of diversifolide and its structural revision are reported. We synthesized the assigned structure of diversifolide via two methods, but the NMR spectra of the synthetic material did not match those of the natural material. Through careful investigation, we found that the spectra were identical with those of 11-epi-sundiversifolide.     

Pickup lens inspection on the 5th order aberration using shearing interference by grating with curve fitting algorithm

An optical system based on shearing interference using diffraction grating was applied, to carry out the aberration inspection process of the pickup lens of a digital versatile disc (DVD) at high speed. An algorithm was devised that processes points allocated on certain lines on a fringe and fits relations between the distance from basis point to the measurement points, and phase data of the fringe at these points to an equation of higher degree as curve fitting. Aberration was numerically estimated as the size of a certain coefficient. Simulation showed that this algorithm could detect all 5th order aberrations independently. An inspection system developed based on this optical system and algorithm detected aberration as accurately as a conventional interferometer that has been used as the standard, attaining an inspection time of 1/10-1/20. In comparison with the spot method, this system has 5th order aberration detecting ability and 1/3 the inspection time.     

Responsive microstructures on organic–inorganic hybrid films

Micro-periodic structures exhibiting shape memory have been fabricated on organic–inorganic hybrid films. The microscale structures are obtained by forming wrinkles via buckling of the stiff surface layer. The surface-modified layers are obtained by surface photopolymerization or by oxidation of the hybrid films. The microscale structures are spontaneously formed by the shrinkage of the underlayer via gelation. The surface microstructures on titania- or silica-based films with hydrophilic swellable polymers exhibit a humidity response, i.e., a shape memory effect. This is observed when the surface microstructure disappears and is subsequently recovered with cyclic variation of the surrounding humidity. Micro-rolls are also fabricated by the selective swelling of surface-modified layers.     

Zr-based bulk metallic glass as a cylinder material for high pressure apparatuses

Zirconium-based bulk metallic glass (Zr-based BMG) has outstanding properties as a cylinder material for piston-cylinder high pressure apparatuses and is especially useful for neutron scattering. The piston-cylinder consisting of a Zr-based BMG cylinder with outer/inner diameters of 8.8/2.5?mm sustains pressures up to 1.81?GPa and ruptured at 2.0?GPa, with pressure values determined by the superconducting temperature of lead. The neutron attenuation of Zr-based BMG is similar to that of TiZr null-scattering alloy and more transparent than that of CuBe alloy. No contamination of sharp Bragg reflections is observed in the neutron diffraction pattern for Zr-based BMG. The magnetic susceptibility of Zr-based BMG is similar to that of CuBe alloy; this leads to a potential application for measurements of magnetic properties under pressure.     

Mössbauer characterization of calcium–ferrite oxides prepared by calcining Fe2O3 and CaO

Calcium ferrite oxides were prepared by calcining a mixture powder of iron- and calcium oxide. The ⁵⁷Fe-Mössbauer spectra of the calcium ferrites oxides were measured, revealing that the products should be Ca₂Fe₂O₅ and CaFe₂O₄, the ratio of which was dependent of the Fe/Ca atomic ratio of the mixture powder.     

Asymmetric synthesis of β-trifluoromethylated β-amino aldehyde as well as carboxylic acid derivatives using enantiopure α-trifluoromethylated homoallylamine

Asymmetric synthesis of β-trifluoromethylated β-amino aldehyde and acid derivatives via the oxidation of enantiopure α-trifluoromethylated homoallylamine as a new trifluoromethylated chiral building block is described.     

Self-sorting self-complementary assemblies of π-conjugated acyclic anion receptors

Pyrrole-based π-conjugated anion-responsive molecules bearing an anionic moiety form self-complementary dimers, which exhibit self-sorting behaviours depending on the substituted positions of anionic sites.     

Study of Conformers of 6,6'-Dimethyl-2,2'-bipyridine in the Ground and Excited States

UV absorption, luminescence, and luminescence-excitation spectra of the trans and metal-free cis conformers of 6,6'-dimethyl-2,2'-bipyridine (6,6'-Me₂bpy) and its Zn²⁺ complex have been observed in 2-propanol and 2-propanol-water mixtures at 77 K. The stable conformation of 6,6'-Me₂bpy in the ground state depends on the composition of the mixture at 77 K and the conformation remains unchanged upon photoexcitation. The lowest excited sing let energy is sensitive to the coordination to Zn²⁺, while the fluorescence lifetime is sensitive to both the conformation change of 6,6'-Me₂bpy and to the coordination to Zn²⁺.     

Addendum to: Search for anomalous top–gluon couplings at LHC revisited

In our latest paper “Search for anomalous top–gluon couplings at LHC revisited” in Eur. Phys. J. C 65 (2010), 127–135 (arXiv:0910.3049 [hep-ph]), we studied possible effects of nonstandard top–gluon couplings through the chromoelectric and chromomagnetic moments of the top quark using the total cross section of \(p\bar{p}/pp\to t\bar{t}X\) at Tevatron/LHC. There we pointed out that LHC data could give a stronger constraint on them, which would be hard to obtain from Tevatron data alone. We show here that the first CMS measurement of this cross section actually makes it possible.     

Asymmetric ortho-lithiation of 1,n-dioxa[n]paracyclophane derivatives for the generation of planar chirality

The asymmetric induction of planar chirality in 1,n-dioxa[n]paracyclophane derivatives via asymmetric ortho-lithiation is described. Enantioselective ortho-lithiation of unflippable 1,n-dioxa[n]paracyclophanes (n≤11) using sec-BuLi-(?)-sparteine at ?78 °C and subsequent treatment with electrophiles gave the corresponding planar-chiral monosubstituted paracyclophanes with excellent ee. Further lithiation of these compounds and treatment with electrophiles gave planar-chiral paracyclophanes with two different substituents. Dilithiation of unflippable 1,n-dioxa[n]paracyclophanes gave the corresponding C₂-symmetrical disubstituted products with almost perfect ee. In the case of flippable 1,n-dioxa[n]paracyclophanes (n≥12), a stepwise reaction was required for the highly enantioselective formation of disubstituted products.