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The formability of magnesium alloys at ambient temperature can be enhanced by alloying additions such as Ca and RE elements, which is ascribed to the weakened basal texture. To produce magnesium alloy sheets with excellent comprehensive performance, the evolution of texture characterization during fabrication process and subsequent effect of texture on mechanical properties are vital controlling factors. In this investigation, three experimental Mg-3Al series alloys were hot rolled and annealed to sheets with 1 mm thickness. The microstructure evolution during rolling and annealing process was investigated. Furthermore, the influence of texture on tensile properties along different tensile directions was also studied. The results show that weakened basal texture and refined grains were achieved with the co-addition of Ca and RE element. However, strengthening of mechanical properties wasn't obtained. During hot rolling process, microstructure was refined, second phase particles broken, and basal texture was increased. While basal texture was weakened during annealing process. Recrystallization behavior influenced by formation of second phase was dominated to attenuate basal texture. Tensile deformation behavior was controlled by basal slip and followed Schmid factor criterion. Moreover, the weakened basal texture and activation of non-basal slips during hot rolling process can contribute to diminish the anisotropy of tensile properties.

Owing to the cocktail effect in high-entropy alloys, a good combination of strength and toughness of a welded joint could be theoretically achieved, by modifying the elemental composition of the filler metals with a high-entropy design. However, few studies have concentrated on this issue so far. In the present study, multi-component mixed powders of (CrMnFe)x(CoNi)y, with five types of the content ratios of the body-centered cube (BCC) and face-centered cube (FCC) forming elements, were used as filler metals to achieve dissimilar welding between 304 stainless steel and Q235 carbon steel by laser deposition welding. By comparative analysis of the microstructures and mechanical properties of the dissimilar joints, the effects of an elemental composition factor of μ (μ = x/y) on the hardness, tensile and bending properties of the dissimilar joints were explored. It was found that the elemental composition of mixed powders had an impact on the mechanical properties of dissimilar joints. Too high or too low content of BCC/FCC forming elements in filler metals cannot promote the appropriate mechanical properties. As an increase in the content of BCC forming elements, the hardness in weld zones was significantly increased, especially for the mixed powders with a high value of μ (≥7/3). The powders of (CrMnFe)5(CoNi)5 resulted in the best comprehensive mechanical properties of the dissimilar joint.

This paper analyzed the effect of long period stacking ordered phases (LPSO) and aged-precipitations on corrosion behavior of Mg–6Gd–2Y–1Zn–0.3Zr magnesium alloys. As-forged alloys were subjected to aging at 225 °C for a period of 4 and 12 h such as to acquire the required microstructure. For these as-forged Mg alloys, some structures of LPSO phases were broken and replaced by fine dynamic recrystallized grains. After undergoing the aging treatment for a 4 h period, these alloys demonstrated a higher number of recrystallized grains and lesser LPSO phases. However, the 12 aging of the alloys produced the least number of LPSO phases, but produced a considerable amount of aged-precipitations on the recrystallized grains. During the period of 120 h immersion in 0.1 mol NaCl solution, the corrosion behavior of the alloys was mainly determined by the decreased volume fraction of LPSO phases and the increased volume fraction of aged-precipitations. Alloys after aging for a 12 h period, displayed the most critical corrosion rate owing to the severe micro-galvanic corrosion between high voltage aged-precipitations or LPSO phases and Mg-matrix, whereas, the alloys after aging for a 4 h period, displayed the best corrosion resistance due to the lesser volume fraction of LPSO phases. As-forged alloys with the most amount of volume fraction of LPSO phases displayed a moderate corrosion resistance.

Abstract Glaucoma is well-known clinical eye conditions that damage the optic nerve due to abnormal pressure conditions in eye. Hesperidin is well-known glycoside widely present in the citrus fruits, and its aglycone form is known as hesperetin. Hesperidin is major flavone found in orange fruits. Hypotensive effect of hesperidin in acute and chronic glaucoma rats, glutamate level in vitreous humour and glutathione (GSH) level in aqueous humour were determined following 25, 50 and 100 mg/kg of hesperidin treatment. Acetazolamide (5 mg/kg) was used as positive control. Hesperidin treatment significantly reduced the increased intraocular pressure (IOP) level in dextrose induced ocular hypertension than saline treated rats. The effect of hesperidin was comparable to the positive control acetazolamide. Similarly, hesperidin treatment significantly reduced the IOP level in prednisolone acetate induced ocular hypertension than saline treated rats. In the aqueous humour, hesperidin treatment increased the glutathione level 125%, 184.4% and 231.2% at 25, 50 and 100 mg/kg of hesperidin respectively. In the vitreous humour, hesperidin treatment reduced the glutamate level 9.9%, 13.2% and 25.3% at 25, 50 and 100 mg/kg of hesperidin respectively. Histopathological analysis of normal saline treated rats showed morphological alteration in ciliary bodies. However, rats treated with hesperidin showed the reduced level of morphological alteration in ciliary bodies. Taking all these data together, it is suggested that the hesperidin supplementation was effective against glaucoma in experimental rats.

Backgrounds In advanced pancreatic ductal adenocarcinoma (PDAC), immune therapy, including immune checkpoint inhibitors, has limited efficacy, encouraging the study of combination therapy.Methods Tumor necrosis factor receptor 2 (TNFR2) was analyzed via immunohistochemistry, immunofluorescence, western blotting, and ELISAs. The in vitro mechanism that TNFR2 regulates programmed cell death 1 ligand 1 (PD-L1) was investigated using immunofluorescence, immunohistochemistry, flow cytometry, western blotting, and chromatin immunoprecipitation (ChIP). In vivo efficacy and mechanistic studies, using C57BL/6 mice and nude mice with KPC cell-derived subcutaneous and orthotopic tumors, employed antibodies against TNFR2 and PD-L1. Survival curves were constructed for the orthotopic model and a genetically engineered PDAC model (LSL-KrasG12D/+; LSL-Trp53R172H/+; Pdx1-Cre). Mass cytometry, immunohistochemistry, and flow cytometry analyzed local and systemic alterations in the immunophenotype.Results TNFR2 showed high expression and is a prognostic factor in CD8+ T cell-enriched pancreatic cancer. TNFR2 promotes tumorigenesis and progression of pancreatic cancer via dual effect: suppressing cancer immunogenicity and partially accelerating tumor growth. TNFR2 positivity correlated with PD-L1, and in vitro and in vivo, it could regulate the expression of PDL1 at the transcription level via the p65 NF-κB pathway. Combining anti-TNFR2 and PD-L1 antibodies eradicated tumors, prolonged overall survival in pancreatic cancer, and induced strong antitumor immune memory and secondary prevention by reducing the infiltration of Tregs and tumor-associated macrophages and inducing CD8+ T cell activation in the PDAC microenvironment. Finally, the antitumor immune response derived from combination therapy is mainly dependent on CD8+ T cells, partially dependent on CD4+ T cells, and independent of natural killer cells.Conclusions Anti-TNFR2 and anti-PD-L1 combination therapy eradicated tumors by inhibiting their growth, relieving tumor immunosuppression, and generating robust memory recall.

Optical non-reciprocal transmission plays an important role in many applications such as optical isolation, switching, and integrated photonic circuits. However, the non-reciprocity of natural magneto-optical (MO) materials is too weak to be widely used in the actual applications. Magnetized metamaterials enable the exploration of a new regime about the MO effect, including the enhanced non-reciprocal transmission and one-way surface waves. In this work, the Fano-type interference effect is studied in the heterostructure composed of a magnetized epsilon-near-zero material and a truncated photonic crystal. The inherent weak MO activity is significantly enhanced in the heterostructure because of the field intensity enhancement mechanism and Fano interference. The results provide a way to design novel optical non-reciprocal devices with excellent performance using metamaterials.

2198 aluminum–lithium alloy was friction stir-welded with a KUKA Robot integrated with a compact friction stir-welding head with a rotation speed of 800 rpm at different welding speeds. The real-time tool force in the three directions of Fx, Fy and Fz was measured with a load sensor. Mechanical properties and microstructure evolution were investigated systematically. The results showed that Fz force increased from 3.2 kN to 8.5 kN as welding speed increased from 50 mm/min to 500 mm/min. Ultimate tensile strength of 383 MPa, 88% of base metal, was obtained when the welding speed was 100 mm/min. The nugget zone consisted of refined grains with an average size of 4 μm. TEM investigation demonstrates that T1 precipitation predominated in the base metal and disappeared in the nugget zone, as a small amount of δ’ was retained. The W-shape hardness profile in all weldments and higher welding speed lead to a higher hardness value.

The hot deformation behavior of TiAl alloy is analyzed by combining the true stress–strain curve and microstructure analysis. The results show that the flow stress of TiAl alloy presents the characteristics of work hardening-dynamic softening, it increases with the increase of strain rate and decreases with the increase of temperature. Based on the true stress–strain curves, the flow stress of TiAl alloy under different deformation conditions is predicted by hyperbolic sinusoidal formula. In addition, the effects of deformation temperature and strain rate on the microstructure evolution of TiAl alloy are revealed. In the process of hot compression deformation, dynamic recrystallization and γ → α , β → α phase transformation occurs. During tensile deformation, TiAl alloy exhibits super-plasticity, which is mainly due to grain rotation and coordinated deformation of β phase.

The flow behavior of a novel Cr-Si alloyed hot stamping steel (Cr-Si steel) at elevated temperature was investigated via isothermal compression tests on a Gleeble-3500 thermomechanical simulator with a temperature range of 600 ∼ 900 °C and a strain rate range of 0.1 ∼ 10 s ^−1 . Subsequently, the Arrhenius-type constitutive model, comprising strain compensation, was established in accordance with the friction and adiabatic heating corrected stress-strain curves. Furthermore, the predictability and prediction accuracy of the constitutive model were verified. The results reveal that at a constant strain rate, the flow stress of the Cr-Si steel initially increases as the strain increases before tending to stabilize, owning to the combined effects of work hardening and dynamic recovery. The peak flow stresses decrease as the temperatures increase and the strain rates decrease. The constitutive model can accurately predict the elevated temperature constitutive relationship of the Cr-Si steel during the hot stamping process.

Objective Anastomotic leakage (AL) is the most serious postoperative complication following anterior resection for rectal cancer. We aimed to investigate the efficacy of active drainage for the management of AL. Methods This was a retrospective study using information from a database of patients who underwent colorectal resection without a defunctioning ileostomy at our center between September 2013 and January 2021. We identified 122 cases with definitive AL who did not require revision emergent laparotomy. Among these patients, we evaluated those who received active drainage to replace the original passive drainage. Results There were 62 cases in the active drainage group and 60 cases in the passive drainage group. The active drainage group had a shorter mean AL spontaneous resolution time (26.9 ± 3.3 vs. 32.2 ± 4.8 days) and lower average hospitalization costs (82,680.6 vs. 92,299.3 renminbi (RMB)) compared with the passive drainage group, respectively. Moreover, seven patients in the passive drainage group subsequently underwent diverting stoma to resolve the Al, while all ALs resolved spontaneously after replacing the passive drainage with active drainage. Conclusions Our study suggests that active drainage may accelerate the spontaneous resolution of AL.

Planar waveguides limit the transmission of electromagnetic waves in a specific direction and have a wide range of applications in filters, sensors, and energy‐transfer devices. However, given the increasing demand for planar‐integrated photonics, new waveguides are required with excellent characteristics such as more functionality, greater efficiency, and smaller size. Herein, the experimental results for a planar microwave‐regime waveguide fabricated from circuit‐based magnetic hyperbolic metamaterial (HMM) are reported. HMM is a special type of anisotropic metamaterial, whose isofrequency contour (IFC) takes the form of an open hyperboloid. Because of the open‐dispersion IFCs, HMMs support propagating high‐k modes with large effective refractive indices, which allow planar hyperbolic waveguides to be miniaturized. Especially, as opposed to the traditional dielectric slab waveguide, the group velocity and phase velocity in hyperbolic waveguides are oriented in opposite directions—a characteristic that is exploited to realize the backward propagation of electromagnetic waves. Based on this property, a backward coupler based on the hyperbolic waveguide is designed and experimented with. Herein, the significant potential of circuit‐based platforms for the experimental study of the propagation and coupling of guided modes is not only revealed but also the use of HMMs for numerous integrated functional devices is promoted.

Objective: This study aimed to develop an RNA-binding protein (RBP)-based signature for risk stratification and guiding clinical therapy in gastric cancer.Methods: Based on survival-related RBPs, an RBP-based signature was established by LASSO regression analysis in TCGA dataset. Kaplan–Meier curves were drawn between high- and low-risk groups. The predictive efficacy of this signature was assessed via ROCs at 1-, 3-, and 5-year survival. Its generalizability was verified in an external dataset. Following adjustment with other clinicopathological characteristics, the independency of survival prediction was evaluated via multivariate Cox regression and subgroup analyses. GSEA was utilized in identifying activated pathways in two groups. Stromal score, immune score, tumor purity, and infiltration levels of 22 immune cells were determined in each sample via the ESTIMATE and CIBERSORT algorithms. The sensitivity to chemotherapy drugs was assessed through the GDSC database.Results: Data showed that patients with high risk exhibited unfavorable clinical outcomes than those with low risk. This signature possessed good performance in predicting 1-, 3-, and 5-year survival and can be independently predictive of patients' survival. Calcium, ECM receptor interaction, and focal adhesion were highly enriched in high-risk samples. High-risk samples presented increased stromal and immune scores and reduced tumor purity. Moreover, this signature presented close relationships with immune infiltrations. Low-risk specimens were more sensitive to sorafenib, gefitinib, vinorelbine, and gemcitabine than high-risk specimens.Conclusion: This RBP-based signature may be a promising tool for predicting clinical outcomes and guiding clinical therapy in gastric cancer.

Due to both the hidden nature and the irreversibility of Alzheimers disease (AD), it has become the killer of the elderly and is thus the focus of much attention in the medical field. Radiologists compare the predicted brain age with the ground truth in order to provide a preliminary analysis of AD, which helps doctors diagnose AD as early in its development as possible. In this paper, a transfer learning-based method of predicting brain age using MR images and dataset of a public brain was proposed. In order to get the best transfer results, we froze different layers and only fine-tuned the remaining layers. We used three planes of brain MR images together to predict age for the first time and experiment results showed that the proposed method performs better than the state-of-the-art method under mean absolute error metric by 0.6 years. In addition, to explore the relationship between brain MR images of different planes and predicted age accuracy, we used three different planes of brain MR images to predict age respectively for the first time and found that sagittal plane MR images outperformed two other planes in age estimation. Finally, our research identified, the effective regions that contribute to brain age estimation for cognitively normal individuals and for AD patients with deep learning. For AD patients, the effective region is mainly concentrated in the frontal lobe of the brain, verifying the relevant medical conclusions about AD.

Abstract Bladder cancer (BC) is a complex disease and could be classified into nonmuscle‐invasive BC (NMIBC) or muscle‐invasive BC (MIBC) subtypes according to the distinct genetic background and clinical prognosis. Until now, the golden standard and confirmed diagnosis of BC is cystoscopy and the major problems of BC are the high rate of recurrence and high costs in the clinic. Recent molecular and genetic studies have provided perspectives on the novel biomarkers and potential therapeutic targets of BC. In this article, we provided an overview of the traditional diagnostic approaches of BC, and introduced some new imaging, endoscopic, and immunological diagnostic technology in the accurate diagnosis of BC. Meanwhile, the minimally invasive precision treatment technique, immunotherapy, chemotherapy, gene therapy, and targeted therapy of BC were also included. Here, we will overview the diagnosis and therapy methods of BC used in clinical practice, focusing on their specificity, efficiency, and safety. On the basis of the discussion of the benefits of precision medicine in BC, we will also discuss the challenges and limitations facing the non‐invasive methods of diagnosis and precision therapy of BC. The molecularly targeted and immunotherapeutic approaches, and gene therapy methods to BC treatment improved the prognosis and overall survival of BC patients.

This paper addresses the asynchronous stabilization problem of two typical stochastic switching systems, i.e., dual switching systems and semi-Markov jump systems. By dual switching, it means that the systems contain both deterministic and stochastic switching dynamics. New stability criteria are firstly proposed for these two switched systems, which can well handle the asynchronous phenomenon. The conditional expectation of Lyapunov functions is allowed to increase during some unmatched interval to reduce the conservatism. Next, we present numerically testable asynchronous controller design methods for the dual switching systems. The proposed method is suitable for the situation where the asynchronous modes come from both inaccurate mode detection and time varying delay. Meanwhile, the transition probabilities are both uncertain and partly accessible. Finally, novel asynchronous controller design methods are proposed for the semi-Markov jump systems. The sojourn time of the semi-Markov jump systems can have both lower and upper bounds, which could be more practical than previous scenarios. Examples are utilized to demonstrate the effectiveness of the proposed methods.

Background: Alternative splicing (AS) is an important regulatory mechanism that greatly contributes to eukaryotic transcriptome diversity. A substantial amount of evidence has demonstrated that AS complexity is relevant to eukaryotic evolution, development, adaptation, and complexity. In this study, six teosinte and ten maize transcriptomes were sequenced to analyze AS changes and signatures of selection in maize domestication and improvement. Results: In maize and teosinte, 13,593 highly conserved genes, including 12,030 multiexonic genes, were detected. By identifying AS isoforms from mutliexonic genes, we found that AS types were not significantly different between maize and teosinte. In addition, the two main AS types (intron retention and alternative acceptor) contributed to more than 60% of the AS events in the two species, but the average unique AS events per each alternatively spliced gene in maize (4.12) was higher than that in teosinte (2.26). Moreover, 94 genes generating 98 retained introns with transposable element (TE) sequences were detected in maize, which is far more than 9 retained introns with TEs detected in teosinte. This indicates that TE insertion might be an important mechanism for intron retention in maize. Additionally, the AS levels of 3864 genes were significantly different between maize and teosinte. Of these, 151 AS level-altered genes that are involved in transcriptional regulation and in stress responses are located in regions that have been targets of selection during maize improvement. These genes were inferred to be putatively improved genes. Conclusions: We suggest that both maize and teosinte share similar AS mechanisms, but more genes have increased AS complexity during domestication from teosinte to maize. Importantly, a subset of AS level-increased genes that encode transcription factors and stress-responsive proteins may have been selected during maize improvement. [ABSTRACT FROM AUTHOR]

Circular RNAs (circRNAs) have been shown to function in the reproductive systems including testis. However, their expression, as well as function in testicular development of sheep remain undefined. Herein, we performed RNA sequencing to reveal circRNA temporal expression patterns in testes of Tibetan sheep from different stages of maturation (3M, 3-month-old; 1Y, 1-year-old; 3Y, 3-year-old). A total of 3,982, 414, and 4,060 differentially expressed (DE) circRNAs were uncovered from 3M vs 1Y, 1Y vs 3Y, and 3M vs 3Y, respectively. Functional enrichment assessment indicated that the source genes of DE circRNAs were primarily engaged in spermatogenesis and testicular immune privilege including blood–testis barrier (BTB). We subsequently constructed the core circRNA–miRNA–mRNA interaction network for genes related to testicular function, such as spermatogenesis, germ cell development, BTB, and cell cycle/meiosis. Furthermore, we validated the target associations between either circ_024949, circ_026259 or IGF1, and oar-miR-29b in this network, and revealed their similar expression signatures in developmental testes that they were extensively expressed in germ cells, Leydig cells, and Sertoli cells, thus suggesting their broad functions in the functional maintenance of Leydig cells and Sertoli cells, as well as the development and maturation of male germ cells. Meanwhile, circ_026259 was shown to promote IGF1 expression through inhibition of oar-miR-29b in sheep Sertoli cells. This work gives the first global view for the expression and regulation of circRNAs in sheep testis, which will be helpful for providing new insights into the molecular mechanism of ovine testis function.

Large bowel perforation is an acute abdominal emergency requiring rapid diagnosis for proper treatment. The high mortality rate associated with large bowel perforation underlines the importance of an accurate and timely diagnosis. Computed tomography is useful for diagnosis of ingested foreign bodies, and endoscopic repair using clips can be an effective treatment of colon perforations. We herein describe a 78-year-old man with sigmoid colon perforation caused by accidental swallowing of a jujube pit. The jujube pit had become stuck in the wall of the sigmoid colon and was successfully removed by colonoscopy, avoiding an aggressive surgery. As a result of developments in endoscopic techniques, endoscopic closure has become a feasible option for the management of intestinal perforation.

Abnormal RAS/RAF signaling plays a critical role in glioma. Although it is known that the V600E mutation of v-raf murine viral oncogene homolog B1 (BRAFV600E) and BRAF amplification (BRAFAMP) both result in constitutive activation of the RAS/RAF pathway, whether BRAFV600E and BRAFAMP have different effects on the survival of glioma patients needs to be clarified. Using cBioPortal, we retrieved studies of both mutations and copy number variations of the BRAF gene in CNS/brain tumors and investigated data from 69 nonredundant glioma patients. The BRAF mutation group had significantly more male patients (64.00% vs. 36.84%; P = 0.046) and a higher occurrence of glioblastoma multiforme (66.00% vs. 31.58%; P = 0.013) compared to those in the other group. The BRAFAMP group had significantly more patients with the mutant isocitrate dehydrogenase 1 and 2 (IDH1/2) (73.68% vs. 18.00%; P = 0.000), tumor protein p53 (TP53) (73.68% vs. 30.00%; P = 0.002), and alpha thalassemia/mental retardation syndrome X linked (ATRX) (63.16% vs. 18.00%; P = 0.001) than the mutation group. The BRAFAMP and IDH1/2WT cohort had lower overall survival compared with the BRAFAMP and IDH1/2MT groups (P = 0.001) and the BRAF mutation cohort (P = 0.019), including the BRAFV600E (P = 0.033) and BRAFnon-V600E (P = 0.029) groups, using Kaplan–Meier survival curves and the log rank (Mantel–Cox) test. The BRAFAMP and IDH1/2WT genotype was found to be an independent predictive factor for glioma with BRAF mutation and BRAFAMP using Cox proportional hazard regression analysis (HR = 0.138, P = 0.018). Our findings indicate that BRAFAMP frequently occurs with IDH1/2, TP53, and ATRX mutations. Adult patients with glioma with BRAFAMP and IDH1/2WT had worse prognoses compared with those with BRAF mutation and BRAFAMP and IDH1/2MT. This suggests that the assessment of the status of BRAFAMP and IDH1/2 in adult glioma/glioblastoma patients has prognostic value as these patients have relatively short survival times and may benefit from personalized targeted therapy using BRAF and/or MEK inhibitors.

The propagation properties of electromagnetic waves depend on media dispersion in momentum space, which can be characterized using isofrequency contours (IFCs). Normal linear‐crossing metamaterials (NLCMMs), which undergo a new type of topological transition between two kinds of hyperbolic media, are attracting attention because of their potential as a new avenue for controlling light propagation and verifying unusual phenomena involving zero‐index and hyperbolic media. Herein, the rotation of the optical axis is treated as a new degree of freedom and a tilted linear‐crossing metamaterial (TLCMM) is theoretically proposed. Upon rotating the optical axis angle such that it is equal to the cone angle, it is found that this special TLCMM has the shape of a type‐III Dirac cone, in condensed matter physics. Boundary conditions and the causality law are used to reveal that electromagnetic waves in this critical TLCMM can achieve abnormal refraction without reflection and filtering. Moreover, these phenomena are observed experimentally in a planar circuit‐based system. The results regarding the manipulation of electromagnetic waves may enable their use in planar‐integrated photonics, including for directional propagation, cloaking, and switching.

A carbonaceous mudstone tunnel is a type of soft rock tunnel. There is little research on the prevention and control measures for the deformation and failure of carbonaceous mudstone tunnels. In this article, we investigated the construction of the Qiguding carbonaceous mudstone tunnel in Meizhou City, Guangdong Province, China. We monitored and analyzed the deformation and stress characteristics of a section under the original support scheme. The monitoring data showed that this section had large peripheral convergence, vault subsidence, steel arch strain, and concrete strain. The deformations exhibited significant differences in the horizontal and vertical directions, eventually resulting in concrete cracking, steel arch bulging, and distortion in the section. The analysis showed that the primary mechanisms for the failure were the softening characteristics of the carbonaceous mudstone, the plastic rheology, and the shear slip of the rock stratum. Based on a comparative analysis and numerical simulation, we proposed a new support measure called the longitudinal rigid enlarged foundation that consists of a steel arch longitudinal connection system and a locking foot anchor pipe system. Several comparative tests were performed at the tunnel site. The results demonstrated the excellent performance and reliability of the proposed support scheme for the deformation control of the carbonaceous mudstone, providing a reference for similar projects.

In this paper, we present the effect of austenitizing temperature on the work hardening behavior of air-hardening steel LH800 by evaluating the influence of austenitizing temperature on microstructure evolution and mechanical properties, using Hollomon, Differential Crussard–Jaoul (DC-J), and Modified C-J (MC-J) work hardening models. The results reveal that with an increase in austenitizing temperature, there is an increase in the percentage of martensite, along with an increase in the strength and hardness of the LH800 steel; on the other hand, there is a decrease in the plasticity. Austenitized at 825 °C, LH800 steel exhibits its highest strength and good plasticity, with a tensile strength of 897 MPa and an elongation of 13.6%. The comparison between the three strain hardening models revealed that the Hollomon model was the finest fit for the experimental data utilized and could illustrate the work hardening behavior of LH800 steel most suitably. This model manifests a two-stage work hardening mechanism; the first stage is related to the plastic deformation of ferrite phase, while the second stage deals with the co-deformation of ferrite and martensite/bainite phase. As austenitizing temperature increases, the work hardening ability of LH800 steel diminishes at each stage, the transition strain decreases, and the plastic deformation of martensite starts earlier.

Conventional photonic bandgaps (PBGs) for linear polarization waves strongly depend on the incident angle. Usually, PBGs will shift toward short wavelengths (i.e., blue-shifted gaps) as the incident angle increases, which limits their applications. In some practices, the manipulation of PBGs for circular polarization waves is also important. Here, the manipulation of PBGs for circular polarization waves is theoretically investigated. We propose one-dimensional photonic crystals (1DPCs) containing anisotropic chiral metamaterials which exhibit hyperbolic dispersion for left circular polarization (LCP) wave and elliptical dispersion for right circular polarization (RCP) wave. Based on the phase variation compensation effect between anisotropic chiral metamaterials and dielectrics, we can design arbitrary PBGs including zero-shifted and red-shifted PBGs for LCP wave. However, the PBGs remain blue-shifted for RCP wave. Therefore, we can design a high-efficiency wide-angle polarization selector based on the chiral PBGs. Our work extends the manipulation of PBGs for circular polarization waves, which has a broad range of potential applications, including omnidirectional reflection, splitting wave and enhancing photonic spin Hall effect.

In various fields, micro-textures have been successfully applied to the surface of friction pairs to effectively improve flow field and friction performance. This paper aims to investigate how different textures affect the sealing performance of compliant foil gas film seals. In theoretical simulations, a facile method for characterizing the shape of micro-textures is proposed, and the equilibrium relationship between the gas film pressure, gas film thickness, and foil deformation is established. The transient Reynolds equation considering the eccentric convergence problem and abrupt Rayleigh step changes is solved to analyze the static and dynamic characteristics. The results show that (i) compared with the directionality of the texture, the gas volume accommodated by the texture has a greater impact on the sealing performance, and a convergent texture can effectively control the leakage rate; (ii) when the texture depth exceeds 9 μm, the sealing system may be unstable; (iii) the compliant foil seal is well suited to higher-speed service conditions, and the inverted triangular texture shows the best comprehensive sealing performance.

Recently, the gapless Dirac/Weyl nodal semimetals with linear dispersion and topologically protected modes degeneracy have been rapidly growing frontiers of topological physics. Especially, type-I, type-II, and critical type-III nodal semimetals are discovered according to the tilt angles of the Dirac/Weyl cones. Here, by introducing hyperbolic metamaterials into one-dimensional photonic crystals, we design the “hypercrystal” and study the photonic fourfold degenerate Dirac nodal-line semimetals (DNLSs) with two types of perpendicularly polarized waves. Moreover, the flexibly controlled photonic DNLSs using the phase compensation effect of hyperbolic dispersion are studied. Our results not only demonstrate a platform to realize the various photonic DNLSs, where the optical polarization plays the role of electron spin in electronic DNLSs, but also may pave a way to explore the abundant Dirac/Weyl physics in the simple classical wave systems.

Two-dimensional periodic patterns with various periods and shapes were investigated via a novel two-axis Lloyd’s mirror interferometer, which allows the two mirrors to rotate independently. We created a theoretical model to reveal the relationships of all parameters in the system configuration and corresponding periodic arrays including the shapes of each nanostructure pattern by the polarization modulation. The wafer-level non-uniformity of the periodic arrays depends on the size of the expanded laser beams. Finally, we developed software with a friendly user interface to provide easy access to the theoretical model that configures the system and designs nanostructure arrays.

In this study, the effect of the hot-cold rolling process on the evolution of the microstructure, texture and magnetic properties of strip-cast non-oriented electrical steel was investigated by introducing hot rolling with different reductions. The results indicate that hot rolling with an appropriate reduction, such as the 20% used in this study, increases the shear bands and {100} deformed microstructure in the cold roll sheet. As a result, in our study, enhanced η and Cube recrystallization texture and the improved magnetic induction were obtained. However, hot rolling with excessive reduction (36–52%) decreased the shear bands and increased the α-oriented deformation microstructure with low stored energy. It enhanced the α recrystallization texture and weakened the η texture, resulting in a decrease in the magnetic induction. In addition, hot rolling promoted the precipitation of supersaturated solid solution elements in the as-cast strip, thereby affecting the subsequent microstructure evolution and the optimization of its magnetic properties.

Recently, topological chains have attracted extensive attention because of their simple structure, rich physics and important applications. In this work, we theoretically and experimentally uncover that the abundant topological phases of periodic trimer chain composed of one kind of meta-atom, namely split-ring resonators (SRRs), can be flexibly controlled by tunning the rotation angle of SRRs. On the one hand, we study the rotation controlled phase transition between two topological distinguished trimer chains with inversion symmetry. The generation of symmetric edge states can be easily controlled in this phase transition. On the other hand, the topological phases of the trimer chain broken inversion symmetry is demonstrated. Especially, the rotation controlled asymmetric edge states are observed in this process. So, rotation provides a new degree of freedom to manipulate edge states in the trimer chain composed of SRRs. The results in this work not only provide a flexible way to observe controlled edge states, but also provide a good research platform for designing other topological models with complex coupling distributions.

Palladium (Pd) nanoparticle catalysts were electrodeposited onto a graphite electrode by cyclic voltammetry (CV) technique from a 0.5 M HCl solution containing 0.2 M PdCl2, and then a film of polypyrrole (PPy) was immobilized onto the as-prepared Pd-coated graphite electrode, leading to a PPy/Pd-coated electrode. Pd particles were repeatedly electrodeposited on the PPy/Pd-coated electrode to generate a Pd/PPy/Pd sandwich structured composite coated electrode. This developed composite electrode showed a satisfactory electrocatalysis toward the formic acid oxidation (FAO). The catalysis mechanism of the sandwich structured Pd/PPy/Pd composite catalyst toward FAO was also discussed on the basis of the obtained cyclic voltammograms and FT-IR spectra. [ABSTRACT FROM AUTHOR]

Aiming at the problem of accurately identifying the mechanical state of circuit breaker in the actual operation environment, a new fault diagnosis method of high voltage circuit breaker based on the combination of time-frequency multi-characteristics of acoustic signal was proposed. Firstly, the background noise database was established to remove the template noise. On this basis, the adaptive wavelet transform (AWT) was used to remove the residual noise. Then the kurtosis, crest factor and skewness indexes were extracted respectively to construct the time-domain characteristics. The acoustic signal was decomposed by variational mode decomposition (VMD) to obtain the IMF component. The power spectrum of the IMF was converted to the polar coordinates of the divided sub-region. The sensitivity of the main peak region was improved by the divergence factor, and the spectral difference entropy characteristics were calculated. The two jointly constructed the time-frequency multi-characteristics. Finally, kernel fuzzy 𝑐 means (KFCM) clustering was used to pre-classify the characteristics, and then support vector machine (SVM) was used to establish training models to realize mechanical state identification. The diagnosis result shows that the accuracy of time-frequency multi-characteristics combined with KFCM-SVM diagnosis method is 98.75 %. It can reflect the status information of circuit breaker from multiple dimensions, and has high practical popularization value. [ABSTRACT FROM AUTHOR]

The observation of abundant topological properties in optical platforms has attracted people's attention due to their great advantages in fundamental topological research and practical applications. Here, we use a double Su-Schrieffer-Heeger (SSH) chain structure composed of split ring resonators (SRRs) to mimic a Kitaev model. By properly tuning the orientation angles of the slits of the SRRs, we can ingeniously design the complex coupling distribution. We experimentally measure the topological phase transition of the double SSH model by adjusting the distance between the two chains and observe the topological bound states in the topological nontrivial phase. Importantly, inserting a trivial structure into the topological chain, we show the coupling of two topological bound states. By increasing the length of the inserted trivial chain, we observe that two topological bound states gradually approach each other and degenerate in the critical state. In addition, we theoretically study the controllable topological bound states and exceptional point physics formed by topological bound states. Our findings not only clearly show the establishing process of the photonic bound states in a double SSH chain, but also may facilitate some applications such as sensors, energy transfer, and switch with topological protection.

Since the quantum concept of parity-time (PT) symmetry has been introduced into the conventional inductor–capacitor resonance, strategies based on exceptional points (EP) based strategies redefine our understanding of sensitivity limitation. This considerable enhancement of sensitivity originated in exploration of the non-Hermitian physics in photonics, acoustics and electronics, which exhibits a substantial application to the miniaturization of implanted electronic sensors in medicine field. By continuously accessing the EP, the spectral response of reader ∆ ω follows a dependency of Δ ω ∼ κ ^2/3 to a weakly coupling rate (| κ | ≈ 0), which may approach the theoretical limit of sensitivity in a second-order EP system. In this paper, we experimentally demonstrate a high-order (higher than second-order) PT symmetric system for weak coupling detection, in which a third-order EP can be employed to fulfill the sensitivity of Δ ω ∼ κ ^1/2 . Particularly, we introduce the incoming wave as an effective gain to balance the loss and obtain a pair of purely real eigenfrequencies. There are absence of imaginary parts despite corresponding real parts shifts dramatically by using a neutral resonator, without a broadening of the reflection spectrum so that maintaining a high resolution on the sensitivity. This work may reveal the physical mechanics of a small perturbation at a high-order EP and promote applications in implanted medicine devices.

The effect of Gd, Ce and Y elements on texture, recrystallization and mechanical properties of Mg–1.5Zn alloys was investigated. The results show that the addition of Gd, Ce and Y elements in Mg–1.5Zn alloy, which rolled at 450 °C and subsequently annealed at 350 °C for 1h, can effectively weaken and modify the basal texture, characterized by the splitting basal pole toward to transverse direction, leading to the yield and tensile strength, the highest along the rolling direction and the lowest along the transverse direction. Besides, the unique basal texture contributes to the significant improvement of elongation at room temperature. Electron back scattering diffraction (EBSD) analysis indicated that the non-basal texture in Mg–1.5Zn–0.2RE alloys can be attributed to obstructive effect of static recrystallization and the non-basal orientation grains nucleation near pre-existing grain boundaries during annealing. Specially, the Mg–1.5Zn–0.2Gd sheet exhibits much excellent plasticity with the elongation of 27% than Mg–1.5Zn–0.2Ce and Mg–1.5Zn–0.2Y alloys, resulting from the less and smaller second phase of MgZnGd.