Correlation between Wear Resistance and Lifetime of Electrical Contacts

Electrical contacts are usually plated in order to prevent corrosion. Platings of detachable electrical contacts experience wear because of the motion between contacts. Once the protecting platings have been worn out, electrical contacts will fail rapidly due to corrosion or fretting corrosion. Therefore the wear resistance of the platings is a very important parameter for the long lifetime of electrical contacts. Many measures which improve the wear resistance can diminish the conductivity of the platings. Due to the fact that platings of electrical contacts must have both a high wear resistance and a high electrical conductivity, the manufacturing of high performance platings of electrical contacts poses a great challenge. Our study shows firstly the correlation between the wear resistance of platings and lifetime of electrical contacts and then the measures, which improve the wear resistance without impairing the electrical performance of the contacts

Combining hydrogen peroxide addition with sunlight regulation to control algal blooms

The concentration, light conditions during treatment, and the number of hydrogen peroxide (H2O2) additions as well as the H2O2 treatment combined with subsequent shading to control algal blooms were studied in the field (Lake Dianchi, China). The cyanobacterial stress and injury due to H2O2 were dose dependent, and the control effectiveness and degradation of H2O2 were better and faster under full light than under shading. However, H2O2 was only able to control a bloom for a short time, so it may have promoted the recovery of algae and allowed the biomass to rebound due to the growth of eukaryotic algae. A second addition of H2O2 at the same dose had no obvious effect on algal control in the short term, suggesting that a higher concentration or a delayed addition should be considered, but these alternative strategies are not recommended so that the integrity of the aquatic ecosystem is maintained and algal growth is not promoted. Moreover, shading (85%) after H2O2 addition significantly reduced the algal biomass during the enclosure test, no restoration was observed for nearly a month, and the proportion of eukaryotic algae declined. It can be inferred that algal blooms can be controlled by applying a high degree of shading after treatment with H2O2.</p

EFFECTS OF MINIMALIST FOOTWEAR ON THE LOWER LIMB LINEAR ACCELERATION AND ANGULAR VELOCITY DURING RUNNING

The purpose of this study was to explore if the tri-axial linear acceleration and angular velocity of knee and ankle joints differ between barefoot and minimal footwear running through investigating the extreme value difference. Eight participants were recruited for this experiment, acceleration parameters were measured utilizing IMU sensors. For the angular velocity, the minimum value in the frontal plane (p = 0.028) showed a decrease in the ankle joint. The minimal value in the sagittal plane and maximal value in the transverse plane (p = 0.001, p = 0) increased significantly. For the knee joint, the extreme values in the frontal plane increased (p = 0, p = 0), the maximal value increased and minimal value decreased with p = 0 and p = 0 in the sagittal plane. A significant decrease in the maximal value (p = 0) was exhibited in the transverse plane. The increased angular velocity may contribute to a result, with an insufficient arch support condition (minimalist shoes running) causing the foot’s intrinsic and extrinsic muscles and lower limb joints injury. These injuries should be a consideration for the novice minimalist runners

On-chip generation and collectively coherent control of the superposition of the whole family of Dicke states

Integrated quantum photonics has recently emerged as a powerful platform for generating, manipulating, and detecting entangled photons. Multipartite entangled states lie at the heart of the quantum physics and are the key enabling resources for scalable quantum information processing. Dicke state is an important class of genuinely entangled state, which has been systematically studied in the light-matter interactions, quantum state engineering and quantum metrology. Here, by using a silicon photonic chip, we report the generation and collectively coherent control of the entire family of four-photon Dicke states, i.e. with arbitrary excitations. We generate four entangled photons from two microresonators and coherently control them in a linear-optic quantum circuit, in which the nonlinear and linear processing are achieved in a chip-scale device. The generated photons are in telecom band, which lays the groundwork for large-scale photonic quantum technologies for multiparty networking and metrology.Comment: 19 pages, 4 figures in the main text and 13 figures in the Supplemental Materia