Dependence of tracking error characteristics of in-line-type differential push-pull methods on arrangement error of segmented gratings

We present the validity of in-line-type differential push-pull methods using segmented gratings with respect to arrangement errors by numerical calculation for the first time. In these differential push-pull methods, the segmented gratings for generating subspots are divided into more than two regions, each with a specific width and a specific phase value, and are ideally arranged on the optical axis. We calculate tracking error signals in these methods with respect to the arrangement errors against the optical axis under parameter conditions of the widths of the segmented regions of the gratings. The obtained results show that the grating with a simpler configuration with two regions reveals good compatibility between DVD-recordable (DVD-R) and DVD-random access memory (DVD-RAM) compared with those with three or four regions, when the arrangement error is less than 10% of the radius of the incident laser beam.     

Relativistic correlating basis sets for 57La and 89Ac

Developed and reported are compact yet efficient correlating basis sets for the ₅₇La and ₈₉Ac atoms, missing in the literature. Good performance of these correlating sets is exemplified in molecular applications to diatomic oxides and fluorides. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010     

A comparative study on chemical conversion of cellulose between the batch-type and flow-type systems in supercritical water

Microcrystalline cellulose (avicel) was treated in supercritical waterusing batch-type and flow-type systems. The flow-type system made it possibletoshorten the heating, treating and cooling times, compared with the batch-typesystem. As a result, the flow-type system was able to liquefy avicel withoutproducing any supercritical water-insoluble residue. Although hydrolyzedproducts such as glucose and fructose, and pyrolyzed products such aslevoglucosan, 5-hydroxymethyl furfural, erythrose, methylglyoxal,glycolaldehydeand dihydroxyacetone were found in common from the water-soluble portiontreatedby both systems, the flow-type system gave a water-soluble portion with morehydrolyzed and less pyrolyzed products, together with water-solubleoligosaccharides consisting of cellobiose to cellododecaose and theirdecomposedproducts at their reducing end of glucose, such as[–glucopyranosyl]_1–11 –levoglucosan,[–glucopyranosyl]_1–11 –erythrose and[–glucopyranosyl]_1–11 –glycolaldehyde. Inaddition, the precipitates of polysaccharides were recovered after 12h setting of the water-soluble portion. These results indicatedthat the flow-type system can hydrolyze cellulose with minimizing pyrolyzedproducts. On the other hand, the batch-type system resulted in a higher yieldof the pyrolyzed products due to the longer treatment, but a higher yield ofglucose due possibly to the higher pressure and concomitantly higher ionicproduct of water. Based on these lines of evidence, the process to increase theyield of the sugar is discussed under supercritical water treatment.     

Metallic conductivity and ferromagnetic interaction of iron(III) d spins in the needle crystals of (ethylenedithiotetrathiafulvalenoquinone-1,3-dithiolemethide)(2).FeBr(4) salt

The 2:1 charge-transfer (CT) salts (1(2).FeBr(4) and 1(2).GaBr(4)) of ethylenedithiotetrathiafulvalenoquinone-1,3-dithiolemethide (1) with FeBr(4)(-) and GaBr(4)(-) counteranions were obtained as needle crystals, whose structures are almost the same as each other. The 1 molecules form a one dimensionally stacked column with alternation of their molecular axis direction, while the counteranions are aligned in parallel with the 1-stacked columns with the direction of their distorted-tetrahedral geometry maintained. The room-temperature electrical conductivities measured on the single crystals of 1(2).FeBr(4) and 1(2).GaBr(4) were 4.6 and 2.1 S cm(-1), respectively. From the temperature dependences of their electrical conductivities in both cases the electrical conducting properties were metallic between ca. 170 and 300 K, but below ca. 170 K converted to be semiconducting and continued till 5 K, although the activation energies are very small (4-10 meV). For 1(2).FeBr(4) very weak and antiferromagnetic interaction occurred between the d spins of FeBr(4)(-) ions in the temperature range of ca. 1-300 K. However, below ca. 15 K the ferromagnetic interaction was reversely preferential possibly by participation of the pi spin of 1.     

An assembled complex of palladium and non-cross-linked amphiphilic polymer: a highly active and recyclable catalyst for the Suzuki-Miyaura reaction

An insoluble and assembled catalyst of palladium and a non-cross-linked amphiphilic polymer were developed. In the presence of 50-500 ppm mol equiv of catalyst, the Suzuki-Miyaura reaction proceeded efficiently under organic solvent-free conditions. The catalyst was reused 10 times without any decrease in activity and was recycled without any special treatment.[structure: see text]     

Novel synthesis of L-ribose from D-mannono-1,4-lactone

[reaction: see text] D-Mannono-1,4-lactone was efficiently converted into L-ribose in eight steps. A key step of this synthesis is the cyclization of a gamma-hydroxyalkoxamate under Mitsunobu conditions. It is noteworthy that the O-alkylation product was obtained in 94% yield and that none of the N-alkylation product was detected in this cyclization.     

Molecular vibrations and force fields of alkyl sulfides: Part XV. C-S stretching vibrations of aliphatic alkyl sulfides

The C-S stretching vibrations of 28 aliphatic sulfides including one thiol are summarized, and all of the C-S stretching bands are classified into several groups. An extraordinarily low frequency associated with the ethyl group is discussed briefly.     

Resistivity minimum of high-concentrated gold-chromium alloys at low temperature

An electrical resistivity minimum has been found at low temperature in high-concentrated $\text{Au}$Cr alloys with an antiferromagnetic long-range order. The anomalous part obtained under a simple assumption is approximately proportional to ? log T, and increases with Cr concentration up to the solubility limit.