[en] The paper discusses the various effects of load cycle shape and load cycle duration on the fatigue damage and thus on the endurance fatigue life of a material. The author illustrates his point by explaining experiments with two high-temperature alloys 800H and 617, which cannot be age-hardened or only slightly. (orig.)

[en] Mitreola liui sp. nov., a new species from Chongqing, China, is described and illustrated. This species is close to M. petiolatoides in morphological characters. Both of them have terete stem, lateral veins 4-6 pairs, stamens 5, inserted at corolla tube base but are distinguished by perennial, leaves blade long elliptic to oblanceolate, apex acute, the flower with narrow-triangular bracts. The key to the species of Mitreola in China is provided. (author)

[en] Organic pollutants in water have become a serious environmental problem and WO₃ is a photocatalytic material for this issue. In this work, there will be the first time that we try to use physical methods to prepare WO₃ films and modify them by chemical methods. The characterization results show that Ag/AgCl/WO₃ films have bigger surface areas and high absorption efficiency in the visible region. Due to the interface of heterojunction structure of Ag/AgCl and WO₃, the transfer and separation efficiency of photogenerated charges are enhanced. WO₃ films decorated with Ag/AgCl can greatly enhance photocatalytic efficiency under visible light. At the same time, the film catalysts were easy to recycle, and the tests show that the photocatalytic efficiency of the film is not significantly reduced after it has been reused for 3 times. In addition, the main active radicals in the photodegradation process are superoxide radicals (·O₂ ⁻) and holes (h⁺). Based on the test results, we proposed the possible photocatalytic mechanism. (paper)

[en] The effects of processing parameters on flow curves and microstructure evolution in the isothermal compression of Ti-17 alloy are investigated. The experiments are conducted in a deformation temperature range of 800–920 °C, strain rate range of 0.01–10.0 s⁻¹ and height reduction range of 30–70%. The flow stress increases with a decrease in deformation temperature or an increase in strain rate. Based on the optical microstructure observations, both of deformation temperature and strain rate have a great effect on the volume fraction of α grains. The effect of strain rate on primary α grains morphology and softening mechanism is of first-order importance compared with the effects of deformation temperature and strain. Transmission electron microscope (TEM) analysis is carried out at a deformation temperature of 840 °C, strain rate of 0.1 s⁻¹ and 10.0 s⁻¹ to reveal the two mechanisms for the morphology evolution of primary α grains. When the strain rate is relatively low, the primary α grains are globularized after the penetration of β phase along α/α subboundaries. While the strain rate is relatively high, the primary α grains are elongated, and the dislocation density in grain interior is relatively high

[en] Compared with a single piezoelectric poly(vinylidene fluoride) (PVDF) sheet, a bimorph can enhance driving performance. The main aim of this work is to study a soft piezoelectric bimorph as an actuator used in a soft sail. PVDF samples were prepared using a high-temperature solvent evaporation method and were then drawn and poled. The crystalline phase, mechanical properties, piezoelectric property and energy-harvesting performance were analyzed. A PVDF piezoelectric bimorph was designed. The capacity of deformation of the parallel bimorph with a pulsed electric field was studied. The deformation of the sample increased almost linearly, and the deformation performance was obvious with the increase in voltage. To evaluate its driving performance in the engineering model, a sail made of Kapton was produced, and the PVDF bimorph was used as an actuator to drive the sail. The deformation was observed by a Video-Simultaneous Triangulation and Resection System. Furthermore, the finite element method was used to further understand the actuation effect of the Kapton sail matrix and PVDF bimorph actuator according to three different laying methods. (paper)

[en] We present a grazing incidence fast atom diffraction (GIFAD) study of monolayer graphene on 6H-SiC(0001). This system shows a Moiré-like 13 × 13 superlattice above the reconstructed carbon buffer layer. The averaging property of GIFAD results in electronic and geometric corrugations that are well decoupled; the graphene honeycomb corrugation is only observed with the incident beam parallel to the zigzag direction while the geometric corrugation arising from the superlattice is revealed along the armchair direction. Full-quantum calculations of the diffraction patterns show the very high GIFAD sensitivity to the amplitude of the surface corrugation. The best agreement between the calculated and measured diffraction intensities yields a corrugation height of 0.27 ± 0.03 Å