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The safety and reliability of high-speed trains depend on the brake disc. In order to improve the lifetime of brake disc and reduce the waste of resources, a coating with higher microhardness and well wear resistance is urgently needed. The effect of chromium content on the microstructure, microhardness and wear resistance of NiCr coating has been studied. Nano-crystalline Ni and NiCr coatings with superior mechanical properties were successfully prepared on the 30CrNiMo steel substrate by pulse current electrodeposition method. The inclusion of formic acid and sodium citrate was found to significantly expedite the co-deposition of Ni and Cr. The NiCr coatings with various Cr contents were prepared at current densities ranging from 200 to 300 mA/cm2. These coatings significantly enhance microhardness and wear resistance of the substrate. The microhardness of the NiCr coating increased to 603 HV, outperforming pure Ni coating by 119 HV. Additionally, the wear rate of the NiCr coating decreased by 50% at a load of 10 N in comparison to the Ni coating. The high microhardness is attributed to grain refinement and solution strengthening. This study successfully addresses the challenges associated with electrodepositing Ni-based coatings on 30CrNiMo steel substrate and lays a theoretical foundation for the utilization of Ni-based coatings to enhance the tribological properties of materials used in high-speed train brake disc.

ABSTRACTThis study aims to explore the molecular mechanism of N6-methyladenosine (m6A) modification-related long noncoding RNA (lncRNA)–microRNA (miRNA)–messenger RNA (mRNA) network in regulating autophagy and affecting the occurrence and development of acute pancreatitis (AP). RNA-seq datasets related to AP were obtained from Gene Expression Omnibus (GEO) database and merged after batch effect removal. lncRNAs significantly related to m6A in AP, namely candidate lncRNA, were screened by correlation analysis and differential expression analysis. In addition, candidate autophagy genes were screened through the multiple databases. Furthermore, the key pathways for autophagy to play a role in AP were determined by functional enrichment analysis. Finally, we predicted the miRNAs binding to genes and lncRNAs through TargetScan, miRDB and DIANA TOOLS databases and constructed two types of lncRNA-miRNA-mRNA regulatory networks mediated by upregulated and downregulated lncRNAs in AP. Nine lncRNAs related to m6A were differentially expressed in AP, and 21 candidate autophagy genes were obtained. Phosphoinositide 3-kinase (PI3K)-Akt signaling pathway and Forkhead box O (FoxO) signaling pathway might be the key pathways for autophagy to play a role in AP. Finally, we constructed a lncRNA-miRNA-mRNA regulatory network. An upregulated lncRNA competitively binds to 13 miRNAs to regulate 6 autophagy genes, and a lncRNA-miRNA-mRNA regulatory network in which 2 downregulated lncRNAs competitively bind to 7 miRNAs to regulate 2 autophagy genes. m6A modification-related lncRNA Pvt1, lncRNA Meg3 and lncRNA AW112010 may mediate the lncRNA-miRNA-mRNA network, thereby regulating autophagy to affect the development of AP.

The effect of Lanthanum content on the microstructure and mechanical properties of Al–5Mg–2Si-0.6Mn alloy in squeeze casting was studied. The microstructure of the alloy was characterized by scanning electron microscope (SEM) and X-ray diffractometer (XRD). The mechanical properties of the alloy were tested by tensile testing machine. The results show that the rare earth Lanthanum has a significant effect on the secondary dendrite spacing and the volume fraction of α-Al + Mg2Si eutectic phase, both of which increase at first and then decrease with the increase of Lanthanum. When the content of Lanthanum is 0.05 wt.%, the maximum volume fraction of eutectic phase is 45.09%. When the content of Lanthanum is 0.05 wt.%, the minimum secondary dendrite spacing is 25.85 μm. When the addition of Lanthanum is more than 0.2 wt.%, the bulk LaAlSi phase is formed in the alloy, which is not coherent with the matrix, which reduces the mechanical properties of the alloy. When the addition of Lanthanum is 0.1 wt.%, the microstructure and mechanical properties of the alloy are the best. The ultimate tensile strength, yield strength and elongation of the alloy reached the maximum, which were 274 MPa, 197.2 MPa and 5.7%, respectively.

Background: Quantitative susceptibility mapping (QSM) technique had been used to measure the magnetic susceptibility of brain tissue in clinical practice. However, QSM presented echo-time (TE) dependence, and an appropriate number of echo-times (nTEs) for QSM became more important to obtain the reliable susceptibility value. Objective: The aim of the study was to explore the optimal nTEs for quantitative susceptibility mapping (QSM) measurements of basal ganglia nuclei in the healthy brain. Methods: 3D multi-echo enhanced gradient recalled echo T2 star weighted angiography (ESWAN) sequence was acquired on a 3.0T MR scanner for QSM analysis. Regions of interests (ROIs) were drawn along the margin of the head of the caudate nucleus (HCN), putamen (Pu) and globus pallidus (GP). The mean susceptibility value and standard deviation of the ROIs were derived from the pixels within each region. Results: CV analysis demonstrated that TE6, TE8 and TE14 ESWAN sequences presented consistent lower CV value (< 1) for QSM measure of HCN, Pu and GP. ANOVA identified that susceptibility value showed no significant difference between TE6 and TE8 in HCN, Pu and GP (P > 0.05). ICC analysis demonstrated that the susceptibility value of TE6-TE8 had the highest ICC value as compared with TE6-TE14 and TE8-TE14 in HCN, Pu and GP. Combined with the timeefficiency of MRI scanning, TE6 sequence could not only provide the reliable QSM measurement but also short imaging time. Conclusion: The current study identified that the optimal nTEs of ESWAN were 6 TEs (2.9ms ~ 80.9ms) for QSM measurement of basal ganglia nuclei in the healthy brain.

Objective To evaluate the beneficial effects of hydroxysafflor yellow A (HSYA) on monocrotaline (MCT)-induced pulmonary arterial hypertension (PAH) in rats, and to investigate the main pathophysiological mechanism of HSYA in preventing development of MCT-induced PAH.Methods Four groups (control, control with HSYA treatment, MCT-exposed, and MCT-exposed with HSYA treatment) were evaluated at day 28 following MCT exposure. Haemodynamic measurements, right ventricular hypertrophy, morphometry, inflammatory cytokines and oxidant expression were assessed.Results HSYA significantly reduced haemodynamic changes, right ventricular hypertrophy and morphometric changes induced by exposure to MCT. HYSA also suppressed MCT-induced inflammation and oxidative stress in rat pulmonary tissue.Conclusions Experimental MCT-induced PAH may be reduced by HSYA treatment, and the mechanism may involve suppression of inflammation and oxidative stress.

In this work, the flow features of coaxial rotors measured in water tunnel are investigated via particle image velocimetry technique. The experiments are conducted using a two-bladed model-scale coaxial rotor and a single rotor with the same geometry. Some noticeable flow features are found. For the coaxial rotor in hover, there is an annular region radially inboard of the lower rotor disk, where there are almost no intrusions from the upper rotor wake. At the same time, upwash occurs at the outboard edge of the lower rotor, while no such phenomenon occurs near the upper rotor blade tip. Sometimes, two upwash phenomena are found both at the blade tip and root in the single-rotor case. For both the single and coaxial rotors in forward flight, there is a sudden velocity change at about 0.7 Ron the retreating side. From comparisons with the prior performance experiments, it can also be found that mutual interferences are playing a positive role in the hovering coaxial rotor configuration. The previously prescribed wake models can well describe the tip vortex trajectories of the single rotor and coaxial rotor in hover and forward flight, especially at high advance ratios. However, in this experiment, some special features are also found slightly different with that of the experiment conducted in air. Some valuable results obtained from this experiment would be helpful to reasonable designs of coaxial helicopters in the future.

The noble metal free perovskite-type BaFeO3−xcatalyst has been synthesized by a sol−gel method containing a small amount of spinel and carbonate. NOxis stored on both perovskite and carbonate, and the formed nitrate on the perovskite can be transferred to the neighboring carbonates to regenerate the storage sites on the perovskite. During the sulfation process, both perovskite and carbonate can be sulfated, and the sulfate species formed on the former one is more easily reduced. The poison of the perovskite catalyst is mainly due to the sulfation of the carbonate. The NOxstorage capacity of the sulfated BaFeO3-950 catalyst, on which a trace amount of carbonate exists, drops only 14% comparing with the fresh catalyst. The iron atoms surrounding the barium atoms closely in the crystal lattice of the perovskite inhibit the sulfation of the barium, inducing a high sulfur tolerance.

Abstract Instrumented-indentation testing (IIT) provided with a continuous stiffness measurement (CSM) technique was employed to measure hardness and elastic modulus profiles of thin organic/inorganic hybrid coatings on glass surfaces. Hybrids were synthesized by the hydrolytic condensation of (3-methacryloxypropyl) trimethoxysilane (MPMS) or vinyltrimethoxysilane (VMS), with 5–30 wt% tetraethoxysilane (TEOS), in the presence of formic acid. Coatings of 600–800 nm on glass substrates were obtained by dip-coating solutions of these hybrids with benzoyl peroxide (BPO) addition, and curing in an oven following a thermal cycle up to 120°C. Both hardness and elastic modulus showed a maximum value close to the surface, followed by a plateau and a significant increase at higher penetrations. Hybrids based on MPMS and 20–30 wt% TEOS exhibited a good combination of intrinsic values of hardness (0.50 GPa) and brittle index (0.06–0.07), that makes them suitable for coatings of plastic substrates.

A light-modified resistance switching (RS) memory device with BaTiO3/ ZnO structure is fabricated by radio frequency magnetron sputtering technology. The device exhibits stable resistive switching behavior in the dark and under illumination, respectively. In the dark, the device’s high/low resistance ratio (RH/ RL)is more than 104at 0.1 V read voltage, and the set/reset voltage (Vset< 0.4 V, Vreset> −0.2 V) is low. The RS of the device can be modulated by white light. When the device is irradiated by white light with intensity of 250 uw/cm2, the high/low resistance ratio is modulated from 104to 102, and the set/reset voltage (Vset< 0.3 V, Vreset> −0.2 V) is still low.

Two new borates, Sr8MB18O36(M = Zn or Cd) with expected formulas representing the Sr:M ratio of 8:1, were synthesized. Their structures were determined by single-crystal X-ray diffraction. They both crystallize in the same space group R−3cand possess isolated [B18O36]18−anionic group. In this work, not only Sr8MB18O36(M = Zn or Cd) crystals were designed but they were also synthesized successfully. In addition, the reasons why the ratio of Sr:M is 8:1 in Sr8MB18O36(M = Zn or Cd) are explained.