Persistent Josephson tunneling between Bi2_2Sr2_2CaCu2_2O8+x_{8+x} flakes twisted by 45∘^\circ across the superconducting dome

There is a heated debate on the Josephson effect in twisted Bi$_2$Sr$_2$CaCu$_2$O$_{8+x}$ flakes. Recent experimental results suggest the presence of either anomalously isotropic pairing or exotic $d$+i$d$-wave pairing, in addition to the commonly believed $d$-wave one. Here, we address this controversy by fabricating ultraclean junctions with uncompromised crystalline quality and stoichiometry at the junction interfaces. In the optimally doped regime, we obtain prominent Josephson coupling (2-4 mV) in multiple junctions with the twist angle of 45$^\circ$, in sharp contrast to a recent report that shows two orders of magnitude suppression around 45$^\circ$ from the value at 0$^\circ$. We further extend this study to the previously unexplored overdoped regime and observe pronounced Josephson tunneling at 45$^\circ$ together with Josephson diode effect up to 50 K. Our work helps establish the persistent presence of an isotropic pairing component across the entire superconducting phase diagram.Comment: 6 pages, 5 figure

Assessment of black soldier fly (Hermetia illucens) larvae meal as a potential substitute for soybean meal on growth performance and flesh quality of grass carp Ctenopharyngodon idellus

A 90-day feeding trial was conducted to assess the effects of black soldier fly larvae meal (BSFLM) as a replacement for soybean meal (SM) on growth performance and flesh quality of grass carp. A total of 420 grass carp (299.93 ± 0.85 g) were randomly divided into 7 groups (triplicate) and fed 7 diets with SM substitution of 0% (SM, control), 15% (BSFLM15), 30% (BSFLM30), 45% (BSFLM45), 60% (BSFLM60), 75% (BSFLM75) and 100% (BSFLM100) by BSFLM. The growth performance of grass carp in the BSFLM75 and BSFLM100 groups were significantly lower compared to other groups (P < 0.05). The mid-gut villus height was the lowest in the BSFLM100 group (P < 0.05). Muscle nutritional value was improved due to increased DHA (docosahexaenoic acid), EPA (eicosapentaenoic acid), total HUFA (highly unsaturated fatty acids) and glycine levels, and reached the optimum in the BSFLM100 group (P < 0.05). According to the results of principal component analysis and weight analysis of muscle texture and body color, all the BSFLM diets except BSFLM15 could improve muscle texture and body color and reached the optimum level in the BSFLM100 group. Muscle drip loss and hypoxanthine content were the lowest and muscle antioxidant capacity was the highest in the BSFLM75 group, and water- and salt-soluble protein contents reached the optimum level in the BSFLM60 group (P < 0.05). Dietary BSFLM significantly reduced muscle fiber area and diameter, and increased muscle fiber density and the proportion of small fiber (diameter <20 μm) (P < 0.05). Additionally, sarcomere lengths in the BSFLM75 and BSFLM100 groups were significantly higher than that in the SM group (P < 0.05). The mRNA relative expression levels of MyoD, Myf5, MyHC and FGF6b were remarkably up-regulated at an appropriate dietary BSFLM level (P < 0.05). In conclusion, BSFLM could replace up to 60% SM without an adverse effect on growth performance and improve the flesh quality of grass carp. The optimum levels of dietary BSFLM were 71.0 and 69.1 g/kg diet based on the final body weight and feed conversion ratio. The flesh quality was optimal when dietary SM was completely replaced with BSFLM (227 g/kg diet)

Comparative study on the load carrying capacities of DLC, GLC and CrN coatings under sliding-friction condition in different environments

DLC, GLC and CrN coatings of different thicknesses were prepared by PVD technology using their respective mature process parameters. Field emission scanning electron microscope (FESEM), laser confocal microscopy, and Raman spectrometer were used to analyze the morphologies and microstructures of the coatings. Nanoindentation measurements and scratch tests were executed to characterize mechanical properties. The-load carrying capacities of these coatings in ambient air, distilled water and oil environments were investigated by a reciprocating tribometer with gradually increasing applied load. Results show that the CrN(2 h) coating has the best load carrying capacity in ambient air and base oil, the GLC coating possesses the best load carrying capacity in distilled water. The DLC coating exhibits lower friction when it survives under low load. The different load carrying capacities of these coatings under sliding-friction condition are closely related to their surface roughness, coating thickness and mechanical, properties. (C) 2017 Elsevier B.V. All rights reserved

Continuously Growing Ultrathick CrN Coating to Achieve High Load-Bearing Capacity and Good Tribological Property

Continuous growth of traditional monolayer CrN coatings up to 24 h is successfully achieved to fabricate ultrathickness of up. to 80 pm on the 316, stainless steel substrate using a multiarc ion plating technique.. The microstructures, mechanical properties, and tribological properties evolution with the CrN coating continuously growing was evaluated in. detail. The-transmission electron Microscopy observations and inverse Fourier-filtered images reveal a relaxation mechanism during the continuous growth of CrN coating, which can lead to a decrease in the residual stress when coating growth time exceeds 5 h. The scratch test and friction test results, both show that the load-bearing capacity of coating is significantly increased as CrN coatings growing thicker. During the scratch test, the ultrathick CrN coating of thickness 80.6 mu m is not failed wider the load of 180 N, and the dominant failure mechanism is the cohesive failure including wedge spallation and cracking. The dry-sliding friction test results show the mean coefficient of friction and the wear rate of ultrathick CrN are respectively decreased by 17.2 and 56.8% at most compared with the thin coating (thickness is 5.4 mu m). The,ultrahigh load-bearing capacity and, excellent tribological property are attributed to the relaxation mechanism and limited contact pressure as the coating grows continuously

Facet-Selective Deposition of FeO_<i>x</i> on α‑MoO₃ Nanobelts for Lithium Storage

One-dimensional heterostructures have attracted significant interests in various applications. However, the selective deposition of shell material on specific sites of the backbone material remains a challenge. Herein, a facile facet-selective deposition strategy has been developed for the construction of heterostructured α-MoO₃@FeO_<i>x</i> nanobelts. Because of the anisotropic feature of α-MoO₃ nanobelts, the FeO_<i>x</i> nanoparticles selectively deposit on the edges of α-MoO₃ nanobelts, that is, the {100} and {001} facets. Such a heterostructure facilitates the electron transfer in lithium storage. As a result, the α-MoO₃@FeO_<i>x</i> nanobelts exhibit high capacities of 913 mA h g^–1 after 100 cycles at 200 mA g^–1 and 540 mA h g^–1 after 100 cycles at 1000 mA g^–1. The facet-selective deposition strategy developed here would be extended to the construction of other novel heterostructures with fascinating physical/chemical properties and wide potential applications

Prominent Josephson tunneling between twisted single copper oxide planes of Bi2Sr2-xLaxCuO6+y

Abstract Josephson tunneling in twisted cuprate junctions provides a litmus test for the pairing symmetry, which is fundamental for understanding the microscopic mechanism of high temperature superconductivity. This issue is rekindled by experimental advances in van der Waals stacking and the proposal of an emergent d+id-wave. So far, all experiments have been carried out on Bi2Sr2CaCu2O8+x (Bi-2212) with double CuO2 planes but show controversial results. Here, we investigate junctions made of Bi2Sr2-xLaxCuO6+y (Bi-2201) with single CuO2 planes. Our on-site cold stacking technique ensures uncompromised crystalline quality and stoichiometry at the interface. Junctions with carefully calibrated twist angles around 45° show strong Josephson tunneling and conventional temperature dependence. Furthermore, we observe standard Fraunhofer diffraction patterns and integer Fiske steps in a junction with a twist angle of 45.0±0.2°. Together, these results pose strong constraints on the d or d+id-wave pairing and suggest an indispensable isotropic pairing component