Ti(C,N) based cermets are composite materials composed of a hard phase and a binder phase structure. Cubic-structured Co particles are the best choice for the binder phase of Ti(C,N) based cermets ...due to their excellent toughness performance. However, the application of β-Co particles in cermets has not been reported in the literature so far. In this pioneer study, ultrafine Ti(C,N) based cermet samples were prepared by separately using Co particles of different structures as the binder phase, and the effect of the Co particle structures on the mechanical properties and microstructure of the cermets were studied: First, the Empirical Electron Theory was used to calculate the difference in the interface density (∆ρ) for different crystals, and the interface combined strength between the hard phase of different structures containing Co particles were evaluated. Second, we systematically investigated the evolution of the microstructures of the two cermets during the sintering process, and evaluated the characteristics of the microstructure (which determines the properties of the cermets). Finally, the mechanical properties of the samples were tested, and the performances of the Co structures were evaluated. The results show that β-Co particles can optimize the cermet microstructure, which leads to excellent mechanical performance.
A fully dense nanocrystalline (nc) Ni film on the brass substrate was fabricated by a simple electrodeposition from a choline chloride-based ionic liquid (choline chloride–ethylene glycol) at working ...voltage (between the two electrodes) of 1.0
V and room temperature. It is found that the nc Ni with an average grain size of about 6
nm has a face-centered cubic crystal structure. At the film/substrate interface, the epitaxial growth of some nc Ni grains on brass grains can be evidenced by the high resolution transmission electron microscope. The 6
nm grain sized Ni exhibits a high strain rate sensitivity (
m
=
0.051) and enhanced hardness values in the range of 7.6–9.7
GPa. The deformation mechanism of the nc Ni under indentation is also discussed with the theoretical model fitting. The potentiodynamic polarization curve shows that the nc Ni film exhibits a much negative corrosion potential, which provides a sacrificial anode protection for the brass substrate.
► Electrodeposition of 6 nm grain sized Ni film from a non-aqueous electrolyte. ► Epitaxial growth of Ni nanocrystallites on the brass substrate. ► Nanocrystalline Ni with high hardness (7.6–9.7
GPa) and obvious passivation. ► No elongated grains on cross-section of electrodeposited nanocrystalline Ni film.
We propose and design a novel dual-wavelength-band grating coupler on 220-nm-thick silicon-on-insulator and experimentally investigate its capability to couple two wavelength bands simultaneously ...under surface-normal fiber placement. Such dual-wavelength-band operation take advantage of a dual-etch grating design not only with increased directionality but also with unique diffraction angle dispersion characteristics for the two targeted wavelength bands. The role of high numerical aperture fiber is theoretically investigated, leading to reduced angular sensitivity in general and subsequently increased coupling efficiency for our proposed dual-wavelength-band operation scheme. Our device is further fabricated using 248-nm deep-UV lithography on an 8-inch wafer for verification. The peak coupling efficiency is measured to be -5.0 dB at 1275 nm and -5.9 dB at 1519 nm for O-band and S/C-band respectively.
•Fracture prediction based on a two-parameter J-Ad* approach was investigated for cracked plate.•The prediction methodologies for crack initiation locations and fracture loads were proposed.•The ...two-parameter approach with considering constraint can provide accurate prediction.•For the best prediction accuracy, the two parameters should be calculated at the crack initiation location.
In this work, the fracture prediction method based on two-parameter J-Ad* (J-integral and a new load-independent unified constraint parameter Ad*) with considering both in-plane and out-of-plane constraints has been investigated for semi-elliptical surface cracks in plates under bending. The crack initiation locations and fracture initiation loads for different crack sizes have been comparatively predicted and analyzed by using the two-parameter J-Ad* and the conventional single-parameter J-integral. The predicted results based on the two-parameter J-Ad* approach have been verified by finite element simulation based on the GTN (Gurson–Tvergaard–Needleman) micromechanics model. The results indicate that the two-parameter approach can provide more accurate predictions. The conventional single parameter approach can produce conservative (for shorter and shallower cracks) or non-conservative (for longer and deeper cracks) results. It is recommended that in the application of the two-parameter approach, for obtaining the best prediction accuracy, the two parameters should be calculated at the crack initiation location.
Aim
Junctophilins (JPs), a protein family of the junctional membrane complex, maintain the close conjunction between cell surface and intracellular membranes in striate muscle cells mediating the ...crosstalk between extracellular Ca2+ entry and intracellular Ca2+ release. The small‐conductance Ca2+‐activated K+ channels are activated by the intracellular calcium and play an essential role in the cardiac action potential profile. Molecular mechanisms of regulation of the SK channels are still uncertain. Here, we sought to determine whether there is a functional interaction of junctophilin type 2 (JP2) with the SK channels and whether JP2 gene silencing might modulate the function of SK channels in cardiac myocytes.
Methods
Association of JP2 with SK2 channel in mouse heart tissue as well as HEK293 cells was studied using in vivo and in vitro approaches. siRNA knockdown of JP2 gene was assessed by real‐time PCR. The expression of proteins was analysed by Western blotting. Ca2+‐activated K+ current (IK,Ca) in infected adult mouse cardiac myocytes was recorded using whole‐cell voltage‐clamp technique. The intracellular Ca2+ transient was measured using an IonOptix photometry system.
Results
We showed for the first time that JP2 associates with the SK2 channel in native cardiac tissue. JP2, via the membrane occupation and recognition nexus (MORN motifs) in its N‐terminus, directly interacted with SK2 channels. A colocalization of the SK2 channel with its interaction protein of JP2 was found in the cardiac myocytes. Moreover, we demonstrated that JP2 is necessary for the proper cell surface expression of the SK2 channel in HEK293. Functional experiments indicated that knockdown of JP2 caused a significant decrease in the density of IK,Ca and reduced the amplitude of the Ca2+ transient in infected cardiomyocytes.
Conclusion
The present data provide evidence that the functional interaction between JP2 and SK2 channels is present in the native mouse heart tissue. Junctophilin 2, as junctional membrane complex (JMC) protein, is an important regulator of the cardiac SK channels.
This study investigated the effects of tea saponins (TSP) on milk performance, milk fatty acids, and blood immune function in dairy cows. A total of 20 early-lactation Holstein cows (days in milk = ...66.4 ± 16.8 d; parity = 1.75 ± 0.91; and milk yield = 36.3 ± 7.32 kg/d; mean ± standard deviation) were randomly divided into 4 homogeneous treatment groups, with TSP added at 0, 20, 30, and 40 g/d per head, respectively. All cows had 2 wk of adaptation and 6 wk of treatments. Feed, milk, and blood were sampled and analyzed weekly. At the end of the experimental period (wk 6), the dry matter intake and yields of energy-corrected milk, milk, and milk protein, fat, and lactose in the cows fed TSP showed a quadratic response, with the lowest values in cows fed TSP at 40 g/d. The milk fat content of cows fed TSP increased linearly. Significant interactions for treatment by week were found in milk C16:1 cis-9 and C18:1 cis-9, with the highest values at wk 2, 3, and 4 in the cows fed TSP at 40 g/d. The levels declined quickly after 4 wk of feeding to values similar to those for other TSP treatments and the control at wk 5 and 6. Plasma malondialdehyde concentration decreased as the supplement level of TSP increased. The concentration of superoxide dismutase increased as the supplement level of TSP increased. The plasma concentration of tumor necrosis factor-α increased as the supplement level of TSP increased. In summary, this study showed that an intermediate dose of TSP (20 and 30 g/d) had no significant effect on feed intake, but the supplementation of 40 g/d TSP decreased feed intake, resulting in a lower milk yield. The energy-corrected milk of cows fed 40 g/d TSP declined at first but increased after 3 wk of feeding, indicating the potential adaptation to high doses of TSP supplements in dairy cows. The supplementation of TSP could reduce oxidative stress in cows and improve the immunity of dairy cows during 6 wk of feeding.
Grating coupling is a widely adopted strategy for coupling light into optical waveguides. While this versatile approach benefits both fabrication and alignment, grating couplers are particularly ...sensitive to both wavelength and polarization. These drawbacks hinder its application in integrated wavelength-division-multiplexing passive optical network (WDM-PON) transceivers, where widely separated wavelength bands are utilized for upstream and downstream signals. In this letter, we propose a three-port grating coupler that enables polarization-independent receiving for the downstream signal from fiber and single-polarized coupling of the upstream signal from chip. Dual-wavelength-band operation is obtained by adding an output port to couple upstream wavelength on existing polarization-splitting grating coupler for downstream wavelength. Peak coupling efficiencies of -2.93 dB and -3.50 dB are achieved for 1266 nm and 1481 nm respectively. This grating coupler design can be adopted in transceivers for fiber-to-the-home (FTTH) networks.
In this work, we proposed and experimentally demonstrated a compact and low polarization-dependent silicon waveguide crossing based on subwavelength grating multimode interference couplers. The ...subwavelength grating structure decreases the effective refractive index difference and shrinks the device footprint. Our designed device is fabricated on the 220-nm SOI platform and performs well. The measured crossing is characterized with low insertion loss (< 1 dB), low polarization-dependence loss (< 0.6 dB), and low crosstalk (< -35 dB) for both TE and TM polarizations with a compact footprint of 12.5 μm × 12.5 μm.
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