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Tensile tests on high purity Fe-P alloys with 0, 0.05 and 0.1 mass%P were carried out at temperatures between 300 K and 1073 K to clarify the intrinsic effect of phosphorus on the mechanical properties of iron at elevated temperatures. Microstructures of as-quenched, interrupted and ruptured specimens were observed. Experimental results show that the addition of phosphorus causes a remarkable increase in proof stress of high purity iron at 300 K, but the increase in proof stress by phosphorus decreases with increasing test temperature. The strengthening effect of phosphorus reduces to zero at 1073 K. High purity iron and Fe-P alloys rupture at almost 100% reduction in area at the whole test temperatures. However, Fe-P alloys show much larger elongation at test temperatures above 773 K than high purity iron. The increased elongation of high purity iron by addition of phosphorus was shown to be related to the effect of phosphorus on dynamic recovery and recrystallization of iron as its intrinsic effect.

4-Propylcyclohexanone 10a (69 g/L) is reduced by the catalysis of Galactomyces geotrichum JCM 6359 using i-PrOH (4.0 equiv) as an auxiliary substrate for recycling externally supplemented NAD⁺ (0.001 equiv) in 40 mM potassium phosphate buffer (pH 7.5) for 20 h to provide a mixture of cis-4-propylcyclohexanol 3a [cis/trans (99:0.5); 74%] and unconsumed 10a (22%). Practically pure 3a can be isolated in 69% yield after removing the entailed ketone 10a via bisulfite adduct formation. In the meantime, the crude reduction product [3a/10a (74:22)], without further purification, can be elaborated into trans-2-(4-propylcyclohexyl)-1,3-propanediol 1a, a compound deemed versatile in liquid-crystals development, in 30% overall yield from 10a in four steps.

The effect of cold-working and ageing (CA) treatment on the ductility of an Al-Zn-Mg alloy was investigated at temperatures from 4.2 to 293 K. The ductility was improved by the CA treatment at 4.2, 77, 196 and 293 K. It was found that both the fracture strain and the reduction of area vary linearly with the area fraction of transgranular fracture. The improvement of ductility was thought to be due to the shape of the grain boundary, the formation of a subboundary and the scattering precipitate size in grains by which both the ledge- and the dimple-formation type intergranular fractures are difficult to occur. The increase of intergranular fracture with decreasing temperature is attributed to the increase of the difference between flow stresses in PFZ and in the matrix, the brittleness of grain boundary precipitates themselves, and the incoherent interface between grain boundary precipitates and the matrix. An intergranular fracture mechanism in the CA specimen is proposed.

Third elements including vanadium, tantalum, chromium, molybdenum, tungsten, iron, nickel, aluminium and germanium, were added to L12-type Co3Ti polycrystals with a composition of 23 at % Ti. Tensile tests from 77 to 1273 K were carried out to investigate the mechanical properties of these alloys. Anomalous increases of the yield stress with increasing temperature were observed from 473 to 973 K (or 1100 K depending on the strain rates) for all tested alloys. It was also observed that the yield stress increased with decreasing temperature below 473 K and decreased with increasing temperature above 973 K (or 1100 K). The yield stresses above the peak temperature were very sensitive to the strain rate and grain size. Microstructural observation showed that gram-boundary sliding had a considerable contribution to the fall in yield stress at high temperatures. The elongation showed a maximum around 673 K and a minimum around 1073 K for all alloys. Microstructural and fractographic observation showed that most alloys tested suffered from hydrogen-related embrittlement at ambient temperatures and grain-boundary cavitation-related embrittlement around 1073 K. Addition of aluminium and iron was found to produce a significant improvement in hydrogen-related embrittlement at room temperature.

The physical contrast ratios (CRs) of an electrooptic switching element using a pyrimidine type ferroelectric liquid crystal (LC) was investigated. The electrooptic response of the element to the AC square wave voltages was shown to be strongly dependent both on the amplitudes and frequencies of the applied voltages. The CR showed a peak at V = 20 volts and at 500 Hz. This behavior was shown to be fairly well correlated to the voltage and frequency dependence of the apparent cone angle which was observed with a polarizing microscope.The element made of this material showed a bistability depending on the surface treatments and the LC layer thickness. Almost all samples, which did not always have the bistability capability, showed that an AC electric field stabilized bistability even though all the tested LC materials have a small but positive dielectric anisotropy of about 0.2.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Consumption of diamondback moth, Plutella xylostella (L.), larvae by 24 species of adult carabids and 2 species of carabid larvae was investigated using small containers in a laboratory. Thirteen species of adult carabids were evaluated for their suppressive effect on diamondback moth larvae using small enclosed arenas simulating field conditions. Consumption by adult carabids varied from zero 4th instars per individual per day of each sex of Amara simplicidens Morawitz to 23/d for a female Chlaenius posticalis Motschulsky. Larvae of Chlaenius micans (F.) and C. posticalis consumed ≈191 and 92 early 4th instars of diamondback moths per individual, respectively, through the entire larval period. These larvae were often observed in cabbage heads. In the enclosure experiment, C. micans, C. posticalis, and Dolichus halensis (Schaller) caused >95% mortality for diamondback moth larvae during 4-d trials. Pterostichus planicollis (Motschulsky) caused 71–77% mortality; the other 9 species in 6 genera, however, contributed <20% to mortality. The high prey suppression by C. micans, C. posticalis, and D. halensis can be attributed to the beetles habit of climbing plants as well as high consumption rate. These results indicate that C. micans and C. posticalis (particularly the larvae of these species) can be important predators of diamondback moth larvae; they have high consumption rates and the habit of climbing plants in both immature and adult stages.