Search

Based on 2D and 3D seismic data, the latest drilling data and field outcrop data of the northern slope of the Central Sichuan paleo‐uplift, the structural analysis method is used to analyze unconformity development characteristics and fault characteristics during the key structural transformation period, discussing the influence of the structural characteristics on the hydrocarbon accumulation of deep carbonate rocks. The results show that: (1) The two key unconformities of the Tongwan and Caledonian periods were primarily developed in deep carbonate rocks. Firstly, Tongwan's unconformities are characterized by regional disconformities between the second and third members of the Dengying Formation, the top formation of the Sinian and the lower Cambrian, strips of which zigzag through the north and south sides of the study area. Secondly, the Caledonian unconformity is characterized by a regional unconformable contact between the lower Permian and the ower Paleozoic strata. From NE to SW, the age of the strata, which were subject to erosion, changes from new to old, the denudation distribution showing as a nose‐shaped structure which inclines towards the ENE. (2) Boundary fault and transtensional strike‐slip faults developed in the Sinian to Paleozoic strata. In profile, there are three types of structural styles: steep and erect, flower structures, 'Y' and reversed 'Y' type faults. In plane view, the Sinian developed extensional boundary faults extending in an almost NS direction, strike‐slip faults developing and extending linearly in approximately EW, WNW and NE strikes in the Cambrian, with characteristically more in the south and less in the north. (3) The faults in the northern slope show obvious zonal deformations in transverse view as well as significant stages and stratified activity in a longitudinal direction. Among them, the activity of faults in the Sinian was the strongest, followed by the activity in the Cambrian period, the activity intensity of faults in the Permian period being the weakest. This fault activity can be divided into four periods: Sinian, Cambrian‐Permian, the early Indosinian period and the late Indosinian‐Himalayan period, the transtensional strike‐slip faults being the products of oblique extensions of pre‐existing weak zones in the Xingkai and Emei taphrogenesis, with a particular inheritance in the main faults. (4) Combined with hydrocarbon accumulation factors, it is considered that the epigenetic karstification of the Tongwan and Caledonian unconformities in the northern slope controlled the formation and distribution of carbonate karst reservoirs over a large area, also acting as a good pathway for oil and gas migration. The extensional faults developed at the margin of the NS trending rift, controlling the sag‐platform sedimentary pattern in the Dengying Formation of the Sinian. Strike‐slip faults in NE, WNW and ENE directions may control the micro‐geomorphological pattern inside the platform and intensify the differential distribution of grain beach facies. The multi‐stage hereditary activity of strike‐slip faults not only improved the porosity and permeability of the reservoirs, but also acted as the main channel of oil and gas migration, providing favorable conditions for the development of the current multi‐layer gas‐bearing scenario in the northern slope of the Central Sichuan Basin. [ABSTRACT FROM AUTHOR]

As the installed energy storage stations increase year by year, the safety of energy storage batteries has attracted the attention of industry and academia. In this work, an intelligent fault diagnosis scheme for series-connected battery packs based on wavelet characteristics of battery voltage correlations is designed. First, the cross-cell voltages of multiple cells are preprocessed using an improved recursive Pearson correlation coefficient to capture the abnormal electrical signals. Secondly, the wavelet packet decomposition is applied to the coefficient series to obtain fault-related features from wavelet sub-bands, and the most representative characteristic principal components are extracted. Finally, the artificial neural network (ANN) and multi-classification relevance vector machine (mRVM) are employed to classify and evaluate fault mode and fault degree, respectively. Physical injection of external and internal short circuits, thermal damage, and loose connection failure is carried out to collect real fault data for model training and method validation. Experimental results show that the proposed method can effectively detect and locate different faults using the extracted fault features; mRVM is better than ANN in thermal fault diagnosis, while the overall diagnosis performance of ANN is better than mRVM. The success rates of fault isolation are 82% and 81%, and the success rates of fault grading are 98% and 90%, by ANN and mRVM, respectively. [ABSTRACT FROM AUTHOR]

Endothelial cell apoptosis is an important pathophysiology in many cardiovascular diseases. The gasotransmitter nitric oxide (NO) is known to regulate cell survival and apoptosis. However, the mechanism underlying the effect of NO remains unclear. In this research, by targeting cytosolic copper/zinc superoxide dismutase (SOD1) monomerization, we aimed to explore how NO inhibited endothelial cell apoptosis. We showed that treatment with the NO synthase (NOS) inhibitor nomega‐nitro‐l‐arginine methyl ester hydrochloride (L‐NAME) significantly decreased the endogenous NO content of endothelial cells, facilitated the formation of SOD1 monomers, inhibited dismutase activity, and promoted reactive oxygen species (ROS) accumulation in human umbilical vein endothelial cells (HUVECs); by contrast, supplementation with the NO donor sodium nitroprusside (SNP) upregulated NO content, prevented the formation of SOD1 monomers, enhanced dismutase activity, and reduced ROS accumulation in L‐NAME‐treated HUVECs. Mechanistically, tris(2‐carboxyethyl) phosphine hydrochloride (TCEP), a specific reducer of cysteine thiol, increased SOD1 monomer formation, thus preventing the NO‐induced increase in dismutase activity and the decrease in ROS. Furthermore, SNP inhibited HUVEC apoptosis caused by the decrease in endogenous NO, whereas TCEP abolished this protective effect of SNP. In summary, our data reveal that NO protects endothelial cells against apoptosis by inhibiting cysteine‐dependent SOD1 monomerization to enhance SOD1 activity and inhibit oxidative stress. [ABSTRACT FROM AUTHOR]

Recently, endogenous sulfur dioxide (SO 2) has been found to exert an important function in the cardiovascular system. However, the regulatory mechanism for SO 2 generation has not been entirely clarified. Hence, we aimed to explore the possible auto-regulation of endogenous SO 2 generation and its mechanisms in vascular endothelial cells. We showed that SO 2 did not affect the protein expression of aspartate aminotransferase 1 (AAT1), a major SO 2 synthesis enzyme, but significantly inhibited AAT activity in primary human umbilical vein endothelial cells (HUVECs) and porcine purified AAT1 protein. An AAT1 enzymatic kinetic study showed that SO 2 reduced the Vmax (1.89 ± 0.10 vs 2.55 ± 0.12, μmol/mg/min, P < 0.05) and increased the Km (35.97 ± 9.54 vs 19.33 ± 1.76 μmol/L, P < 0.05) values. Furthermore, SO 2 induced S-sulfenylation of AAT1 in primary HUVECs and purified AAT1 protein. LC-MS/MS analysis indicated that SO 2 sulfenylated AAT1 at Cys192. Mechanistically, thiol reductant DTT treatment or C192S mutation prevented SO 2 -induced AAT1 sulfenylation and the subsequent inhibition of AAT activity in purified AAT1 protein and primary HUVECs. Our findings reveal, for the first time, a mechanism of auto-regulation of SO 2 generation through sulfenylation of AAT1 at Cys192 to suppress AAT activity in vascular endothelial cells. These findings will greatly deepen the understanding of regulatory mechanisms in the cardiovascular homeostasis. Image 1 • SO 2 controls its producing key enzyme AAT1 activity to achieve a negative auto-regulation of sulfur dioxide generation. • SO 2 sulfenylates AAT1 to inhibit its activity in vascular endothelial cells. • Cys192 site on AAT1 serves as a sulfenylating target of SO 2. [ABSTRACT FROM AUTHOR]

We report a 3- $\mu \text{m}$ -waveband passively Q-switched $\text{Ho}^{\mathbf {3+}}$ -doped ZBLAN fiber laser based on nonlinear polarization rotation (NPR) in the ring cavity for the first time, to the best of our knowledge. The laser can operate in stable single- and dual-wavelength regimes. The stable single-wavelength pulse train is obtained with a ∼104 pm spectral linewidth at 2960.7 nm for 1.064-W launched pump power. By further increasing the launched pump power, the dual-wavelength pulsed laser can be observed, which is caused by the combination of intra-cavity birefringence and polarizer. The resulting dual-wavelength pulse has a narrow spectral linewidth of ∼87 pm and ∼131 pm at the central wavelength of 2966.8 nm and 2971.7 nm, respectively, under the maximum launched pump power of 3.86 W. The corresponding maximum output power and shortest pulse duration are 86.6 mW and $1.6~\mu \text{s}$ , respectively. [ABSTRACT FROM AUTHOR]

A high-N austenitic stainless steel (HNASS) was fabricated using a novel approach, in which duplex stainless steel powders were firstly gas nitrided in the temperature range of 700–900 °C and then consolidated using spark plasma sintering, resulting in an FCC matrix with average grain sizes of 1.6–8.2 μm. The Cr 2 N precipitates transformed from cellular precipitates (lamellar within the grains) to intergranular precipitation (equiaxed along the grain boundaries) as the nitriding temperature rose from 700 °C to 750 °C, and the N content rose from 0.68 wt% to 1.71 wt%. The 700 °C-treated alloy exhibits a yield strength of 783 MPa, a high tensile strength of 1091 MPa, and an elongation of 41% while the 900 °C-treated alloy exhibits an ultra-high compressive strength of 3017 MPa, and hardness of 520 HV. These values dramatically exceed the published values of similar HNASSs. Quantitative calculations showed that these superior mechanical properties could be attributed to increased solid solution and grain boundary strengthening. Furthermore, it can be inferred that while the equiaxed Cr 2 N phase increased the yield strength, it greatly degraded the fracture toughness. • A novel method, nitriding and followed spark plasma sintering, was used to fabricate HNASS. • The morphology of Cr 2 N phase changed from lamellar (within the grains) to equiaxed (along the grain boundaries). • The alloy features superior mechanical properties of yield strength (783 MPa) and ultimate tensile strength (1091 MPa). • Solid solution and grain boundary strengthening are dominant strengthening mechanisms. [ABSTRACT FROM AUTHOR]

The evolution of the microstructure and mechanical properties of a powder metallurgical (PM) high-speed steel (HSS) were investigated using a series of tempering times. A near Baker-Nutting (B-N) orientation relationship (OR) between the MC carbide and martensitic matrix was detected, while no OR between the M6C carbide and matrix was observed. The average grain size of the investigated alloys was approximately 4 to 6 μm, which was slightly larger than the thermodynamic calculated grain size of 2 μm. The results indicated that the Rockwell hardness, compressive strength, and in-situ nano-hardness of martensite decreased as the tempering times increased. After quadruple tempering, the fracture strain, compressive strength, and flexural strength declined. Triple tempering contributed to the superior combination of compressive strength, fracture strain, Rockwell hardness, and flexural strength of 3245 MPa, 30.6 pct, HRC 62.2, and 2094 MPa, respectively. The investigated alloys demonstrated strong susceptibility to cracks. The results of this study could provide useful information for the application of this HSS. [ABSTRACT FROM AUTHOR]

The evolution of microstructure and mechanical properties of commercial powder metallurgical high-speed steel S390 steel after different heat treatments were studied. The results show that the austenitic transformation of the alloy starts at 1110 K (837 °C), whereas the martensite transformation starts at 624 K (351 °C). The density of hot isostatic pressed alloy is around 99.2 vol%, and the average pore size is less than 1 μm. There are two types of metal carbides (MC): vanadium-rich MC-type and tungsten-rich M 6 C-type. After proper heat treatment, the alloys exhibit a high Rockwell-C hardness of 64.4 and compressive strength of 3870 MPa, as well as an ultra-large fracture strain of 22.7% under compression, which results from the changes in the size and distribution of the carbides during heat treatment. In addition, the experimental results concerning the dissolution of vanadium carbide varying with temperature are similar to the results obtained by thermodynamic analysis. Finally, for the experimental iron alloy, deep cryogenic treatment during the triple tempering treatment process has little effect on the compressive strength and room temperature hardness. [ABSTRACT FROM AUTHOR]

In this paper, we report a long cavity passively mode-locked fibre laser. The proposed mode locker is a reflective long cavity non-linear optical loop mirror (NOLM) which consists of a 50:50 coupler and 2-km single-mode fibres. The laser achieves stable mode locking at a fundamental repetition rate of 100 kHz. The rectangular pulses operating in dissipative soliton resonance region is generated in the laser. The relationship between the pulse duration and the pump power is investigated in detail. When the pump power is 200 mW, the laser generates rectangular pulses at 1565.57 nm (central wavelength) with pulse duration of 81.5 ns. The single pulse energy as high as 33.34 nJ is obtained. The results show that the reflective NOLM is an efficient mode locker and useful for the generation of high energy pulse. [ABSTRACT FROM AUTHOR]

Electron beam welding of the medium-entropy alloy (MEA) (NiCoCr) 94 Al 3 Ti 3 to 304 stainless steel (SS) has been undertaken. Defect-free joints were obtained with coarse columnar grains: the columnar grains on the 304 SS side of the fusion zone (FZ) were finer (94 μm, length-to-width ratio∼2.7) than the grains on the MEA side (204 μm, 2.9), a difference that probably resulted from a higher cooling rate after welding due to the higher thermal conductivity of the 304 SS compared to the MEA. Mixing of the two materials in the FZ led to lower vol.% (14%) and larger diameter (44 nm) of L1 2 nanoparticles compared to the 23 nm dia. and 37% vol.% in the aged MEA, a result consistent with CALPHAD analysis. The joint showed a good combination of yield strength (323 MPa), ultimate tensile strength (670 MPa), and elongation (24%). Failure occurred by ductile fracture in the FZ. [Display omitted] [ABSTRACT FROM AUTHOR]

We demonstrate a self-seeded multi-wavelength Brillouin–erbium fibre laser with double Brillouin frequency gap. The twice channel gap is induced by the gain difference in different directions. Thirty-six stable output channels with 20?GHz frequency gap are obtained when the 980?nm pump power is 300?mW. The factor that induces the double frequency gap is investigated and proved. [ABSTRACT FROM AUTHOR]

Effects of scanning strategy during powder bed fusion electron beam additive manufacturing (PBF-EB AM) on microstructure, nano-mechanical properties, and creep behavior of Ti6Al4V alloys were compared. Results show that PBF-EB AM Ti6Al4V alloy with linear scanning without rotation strategy was composed of 96.9% α-Ti and 2.7% β-Ti, and has a nanoindentation range of 4.11–6.31 GPa with the strain rate ranging from 0.001 to 1 s−1, and possesses a strain-rate sensitivity exponent of 0.053 ± 0.014. While PBF-EB AM Ti6Al4V alloy with linear and 90° rotate scanning strategy was composed of 98.1% α-Ti and 1.9% β-Ti and has a nanoindentation range of 3.98–5.52 GPa with the strain rate ranging from 0.001 to 1 s−1, and possesses a strain-rate sensitivity exponent of 0.047 ± 0.009. The nanohardness increased with increasing strain rate, and creep displacement increased with the increasing maximum holding loads. The creep behavior was mainly dominated by dislocation motion during deformation induced by the indenter. The PBF-EB AM Ti6Al4V alloy with only the linear scanning strategy has a higher nanohardness and better creep resistance properties than the alloy with linear scanning and 90° rotation strategy. These results could contribute to understanding the creep behavior of Ti6Al4V alloy and are significant for PBF-EB AM of Ti6Al4V and other alloys. [ABSTRACT FROM AUTHOR]

Porous high-N Ni-free austenitic stainless steel was fabricated by a powder metallurgical route. The microstructure and properties of the prepared porous austenitic stainless steel were studied. Results reveal that the duplex stainless steel transforms into austenitic stainless steel after nitridation sintering for 2 h. The prepared high-N stainless steel consists of γ-Fe matrix and FCC structured CrN. Worm-shaped and granular-shaped CrN precipitates were observed in the prepared materials. The orientation relationship between CrN and austenite matrix is [011]CrN//[011]γ and (-1-11)CrN//(1-11)γ. Results show that the as-fabricated porous high-nitrogen austenitic stainless steel features a higher mechanical property than common stainless steel foam. Both compressive strength and Young’s modulus decrease with an increase in porosity. The 3D morphology of the prepared porous materials presents good pore connectivity. The prepared porous high-N Ni-free austenitic stainless steel has superior pore connectivity, a good combination of compressive strength and ductility, and low elastic modulus, which makes this porous high-N Ni-free austenitic stainless steel very attractive for metal foam applications. [ABSTRACT FROM AUTHOR]

Introduction: Oxidative stress in monocyte-derived macrophages is a significant pathophysiological process in atherosclerosis. L-cystathionine (L-Cth) acts as a scavenger for oxygen free radicals. However, the impact of L-Cth on macrophage oxidative stress during atherogenesis has remained unclear. This study aimed to investigate whether L-Cth affects oxidative stress in THP-1-derived macrophages and its subsequent effects on DNA damage and cell apoptosis. Methods: We established a cellular model of oxLDL-stimulated macrophages. The content of superoxide anion, H 2 O 2 , NO, and H 2 S in the macrophage were in situ detected by the specific fluorescence probe, respectively. The activities of SOD, GSH-Px, and CAT were measured by colorimetrical assay. The protein expressions of SOD1, SOD2, and iNOS were detected using western blotting. The DNA damage and apoptosis in the macrophage was evaluated using an fluorescence kit. Results: The results demonstrated that oxLDL significantly increased the content of superoxide anion and H 2 O 2 , the expression of iNOS protein, and NO production in macrophages. Conversely, oxLDL decreased the activity of antioxidants GSH-Px, SOD, and CAT, and downregulated the protein expressions of SOD1 and SOD2 in macrophages. However, treatment with L-Cth reduced the levels of superoxide anion, H 2 O 2 , and NO, as well as the protein expression of iNOS induced by oxLDL. Moreover, L-Cth treatment significantly enhanced GSH-Px, SOD, and CAT activity, and upregulated the expressions of SOD1 and SOD2 proteins in macrophages treated with oxLDL. Furthermore, both L-Cth supplementation and activation of endogenous L-Cth production suppressed DNA damage and cell apoptosis in oxLDL-injured macrophages, whereas inhibition of endogenous L-Cth exacerbated the deleterious effects of oxLDL. Conclusion: These findings suggest that L-Cth exerts a pronounced inhibitory effect on the oxidative stress, subsequent DNA damage and cell apoptosis in oxLDL-stimulated THP-1 monocytes. This study deepens our understanding of the pathogenesis of macrophage-related cardiovascular pathology., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Peng, Zhu, Kong, Tang, Du, Huang and Jin.)

Objectives: The study was designed to explore the role of endogenous gaseous signaling molecule sulfur dioxide (SO 2 ) in the control of cardiomyocyte apoptosis and its molecular mechanisms. Methods: Neonatal mouse cardiac myocytes (NMCMs) and H9c2 cells were used in the cell experiments. The endogenous SO 2 pathway including SO 2 level and the expression of SO 2 -generating enzyme aspartate aminotransferase 1/2 (AAT1/2) were detected in NMCMs. The apoptosis of cardiomyocytes was examined by a TUNEL assay. The cleavage and the activity of apoptotic proteins caspase9 and caspase3 were measured. The content of ATP, the opening of mitochondrial permeability transition pore (mPTP), and the cytochrome c (cytc) leakage were detected by immunofluorescence. The sulphenylation of cyclophilin-D (CypD) was detected by biotin switch analysis. The four CypD mutant plasmids in which cysteine sites were mutated to serine were constructed to identify the SO 2 -affected site in vitro . Results: ISO down-regulated the endogenous SO 2 /AAT pathway of cardiomyocytes in association with a significant increase in cardiomyocyte apoptosis, demonstrated by the increases in apoptosis, cleaved-caspase3/caspase3 ratio, and caspase3 activity. Furthermore, ISO significantly reduced ATP production in H9c2 cells, but the supplement of SO 2 significantly restored the content of ATP. ISO stimulated mPTP opening, resulting in an increase in the release of cytc, which further increased the ratio of cleaved caspase9/caspase9 and enhanced the protein activity of caspase9. While, the supplementation of SO 2 reversed the above effects. Mechanistically, SO 2 did not affect CypD protein expression, but sulphenylated CypD and inhibited mPTP opening, resulting in an inhibition of cardiomyocyte apoptosis. The C104S mutation in CypD abolished SO 2 -induced sulphenylation of CypD, and thereby blocked the inhibitory effect of SO 2 on the mPTP opening and cardiomyocyte apoptosis. Conclusion: Endogenous SO 2 sulphenylated CypD at Cys104 to inhibit mPTP opening, and thus protected against cardiomyocyte apoptosis., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Lv, Peng, Qiu, Zhang, Ge, Bu, Li, Yu, Du, Yang, Tang, Huang, Du and Jin.)