Photocatalytic activity of α‐PbO2‐type TiO2

The α‐PbO₂‐type TiO₂ is synthesized under high‐pressure and high‐temperature environment and it shows higher photocatalytic activity as compared to rutile and anatase under UV irradiation. The reduction in α‐PbO₂‐type TiO₂ induces visible‐light photocatalytic activity. These results indicate that α‐PbO₂‐type TiO₂ is an important candidate material for use in a photocatalytic matrix.

     

Melting kinetics of it-polypropylene crystals over wide heating rates

Melting kinetics of it-polypropylene crystals has been examined over wide heating rates of 0.6 K min^?1?10⁴ K s^?1 using a standard DSC and a fast-scan DSC. With fast-scan DSC, we have an access to the melting of crystals obtained at low temperatures, which are susceptible to re-organization at the heating rates applicable with standard DSC. It is clearly discernible that the appearance and disappearance of multiple melting peaks are strongly influenced by the applied heating rates and dependent on the crystallization temperatures. By examining the heating rate dependence of superheating of melting, we have determined the melting points of as-grown crystals formed under wide crystallization temperatures.     

Synthesis and Characterization of Thiophenetriptyeene-8-sulfenic Acid

Abstract:

Reaction of the trilithium salt, prepared by treatment of 1,1,1-tris(2-bromo-5-methyl-3-thienyl)ethane, with O,O′-diethyl thiocarbonate gave thiophenetriptycene-8-thiol in 42% yield. The thiol was not oxidized with m-chloroperoxybenzoic acid (MCPBA). However, treatment of the thiol with NaH in THF followed by oxidation with MCPBA gave thiophenetriptycene-8-sulfenic acid in 70% yield. The structure of the sulfenic acid was determined by spectroscopic means and X-ray single-crystal analysis.     

Our Future,Our Heritage. The Chemical Family Tree of Tetsuo Nozoe

Note from the Editor: When I was editing Tetsuo Nozoe's autobiography Seventy Years in Organic Chemistry in the late 1980s, I realized that the history of Japanese organic chemistry was not too well known in countries other than Japan. I urged Professor Nozoe to include the historical context of his life in his writings, and I was absolutely delighted that he did so. I also suggested that he publish a “Riko Majima Family Tree in Chemistry.” Majima was not only Nozoe's professor but, as detailed in Nozoe's autobiography and elsewhere in the literature, the father figure of Japanese organic chemistry. Nozoe was reluctant because to single‐out some chemical academics but not others in such a public manner could—would—prove embarrassing. But faithful to his profession, the obligations to history prevailed and Nozoe's autobiography contains the Majima Family Tree. We now skip ahead 25 years where we are immersed in the publication of the Nozoe Autograph Books (see: http://www.tcr.wiley‐vch.de/nozoe and this introductory essay: J. I. Seeman, Chem. Rec. 2012 , 12, 517–531). I find myself once again an editor studying in the life and legacies of Riko Majima and Tetsuo Nozoe. The “repeating experiences” of history have been felt once again! ² I asked Professors Ichiro Murata, Shô Itô, and Toyonobu Asao (who are Professor Nozoe's students and biographers) to follow Professor Nozoe's lead and provide his Family Tree in Chemistry. What follows is a reproduction of the Majima Family Tree as provided by Professor Nozoe along with the next generation Family Tree, that being the students of Tetsuo Nozoe's students who themselves became illustrious professors. —Jeffrey I. Seeman Guest Editor University of Richmond Richmond, Virginia 23173, USA E‐mail: jseeman@richmond.edu     

Palladium-catalyzed intramolecular cyanoboration of allenes leading to the regioselective synthesis of β-cyanoallylboranes

Inter- and intramolecular addition of the boron-cyanide bond of cyanoboranes across a carbon-carbon double bond of allenes proceeded in the presence of palladium catalysts, affording allylboranes that bear a cyano group at the β-position regioselectively.     

Low-Driving-Voltage Optical Modulation Utilizing FWM for High-Speed Transmission Systems

We propose an optical transmitter with reduced modulator driving voltage. This reduction is achieved through an on-off ratio improvement technique based on FWM. We confirmed the feasibility of the method in a 43-Gbit/s experiment.     

Determination of low-level 54Mn in soils by ultra low-background gamma-ray spectrometry after radiochemical separation

An analytical method was developed for the measurement of low-level ⁵⁴Mn in soil sample by ultra low-background g-ray spectrometry after radiochemical separation. The method consists of decomposition of sample by a mixture of HNO₃ and HF, dissolution by HNO₃, precipitation as hydroxide, solvent extraction with diisopropyl ether and anion exchange. Finally, for purification of Mn it was precipitated as MnO₂ by adding KClO₃. ⁵⁴Mn in the precipitate was measured by ultra low-background well-type Ge detector at Ogoya Underground Laboratory. Measurements of ⁵⁴Mn using 30-200 g of soil samples from the JCO grounds were successfully performed by the present method. The minimum detectable activity of ⁵⁴Mn was about 0.01 dpm (0.2 mBq) for a 7-day counting period.     

Two-dimensional Si photonic crystals on oxide using SOI substrate

Two-dimensional photonic crystals (2D-PhCs) on oxide can be easily incorporated into photonic integrated circuits. Although an asymmetrical structure (air/PhC/oxide) is advantageous in terms of ease of fabrication, it has been pointed out that such a structure may have no photonic band gap (PBG). To clarify the characteristics of the asymmetrical structure, we calculated the band structure using the three-dimensional (3D) FDTD method and measured the transmission characteristics of a fabricated 2D Si-PhC on oxide. The calculations show that we can use a quasi-PBG even in an asymmetrical structure when the PhC thickness satisfies the single-mode condition. The measured transmission characteristics correspond to the calculated band structure and reveal the existence of a quasi-PBG. These results show that the asymmetrical 2D Si-PhC-on-oxide structure can be applied to various optical devices.