Observation of tunable topological polaritons in a cavity waveguide

Topological polaritons characterized by light-matter interactions have become a pivotal platform in exploring new topological phases of matter. Recent theoretical advances unveiled a novel mechanism for tuning topological phases of polaritons by modifying the surrounding photonic environment (light-matter interactions) without altering the lattice structure. Here, by embedding a dimerized chain of microwave helical resonators (electric dipole emitters) in a metallic cavity waveguide, we report the pioneering observation of tunable topological phases of polaritons by varying the cavity width which governs the surrounding photonic environment and the strength of light-matter interactions. Moreover, we experimentally identified a new type of topological phase transition which includes three non-coincident critical points in the parameter space: the closure of the polaritonic bandgap, the transition of the Zak phase, and the hybridization of the topological edge states with the bulk states. These results reveal some remarkable and uncharted properties of topological matter when strongly coupled to light and provide an innovative design principle for tunable topological photonic devices.Comment: 6 pages, 4 figure

Design of multi-link transmission for bottom-drive fast press

In this paper, a multi-link transmission mechanism is designed for the bottom-drive fast press, which adopts the combination of gears and connecting rods, with a more compact structure and a wider range of velocity. In order to facilitate the analysis, it is simplified into a double crank mechanism for kinematics calculation and analysis. At the same time, MATLAB/SimMechanics module is used to conduct modeling and simulation analysis. In addition, the multi-link transmission mechanism is further optimized through variable control, which provides a reference for the design of the bottom-drive fast press.</p

Uneven Distribution of Ecosystem Services along the Yarlung Zangbo River Basin in Tibet Reveals the Quest for Multi-Target Policies of Rural Development in Less-Favored Areas

This study was conducted in the Qinghai-Tibet Plateau which is a typical less-favored ecologically fragile area. First, we constructed a GIS-based spatial gridding structure over the study area, the Yarlung Zangbo river basin in China’s Tibet, and used a value-assessment model to measure supply, support, regulation, and culture ecosystem services in each study grid. We then analyzed the spatiotemporal patterns of different ecosystem services in the region from 2000 to 2020. In addition, we conducted a spatial visualized analysis of the trade-off and synergies of multiple ecosystem services in each study grid. We found that: (1) On the temporal scale, from 2000 to 2020, the values of the four ecosystem services for supply, support, regulation, and culture along the basin demonstrated an upward trend. (2) On the spatial scale, the values of ecosystem services showed an uneven distribution, with a decline trend from east to west along the basin. (3) From the perspective of land use types, due to the large areas of water, grassland, and forest along the river basin, the ecosystem service values of the three types of land use ranked among the top levels. (4) The trade-offs and synergies between different ecosystem services and their spatial distribution along the river basin showed an uneven distribution pattern. The ecosystem services zoning revealed that the policies in guiding rural sustainability in the less-favored areas should adjust the measures to local conditions, it’s necessary to establish multiple targets across the entire region

Effect of heat treatment process on mechanical properties and microstructure of FeAlCoCrNiTi0.5 alloy

In order to study the effects of different sintering processes on the properties of the alloy, including the microstructure, hardness, friction and wear properties of the alloy, the optimum sintering method and process parameters were selected. A series of FeAlCoCrNiTi0.5 high-entropy alloy blocks were prepared by mechanical alloying using inert alloy sintering technology. XRD pattern showed that when the sintering temperature was 1000°C and the holding time was 3h, the phase structure would be a simple body-centered cubic BCC2 phase and a face-centered cubic FCC phase. SEM observation showed that the microstructure is denser, and the grain refinement of the high entropy alloy is remarkably better. The evaluation of hardness, friction and wear properties showed that the high-entropy alloy had the best overall performance

Effects of the CNTs content and plating solution pH after purified on the performance of Ni-P/CNTs composite coating

After CNTs were purified, Ni-P/CNTs composite coating were prepared at different CNTs contents and plating solution pH values by univariate experimental method. Besides, the surface appearance, hardness, corrosion resistance and wear-resisting property of the coating were tested and analyzed by X-ray Diffractometer (XRD), scanning electronic microscope (SEM), microhardness tester, electrochemical workstation, tribometer and other means. The results suggest that fibers on the surface of purified CNTs are clear and well-dispersed. During dummy-plating, purified CNTs were more likely to deposit on Ni-P coating. a proper amount of CNTs could reasonably improve the structure of Ni-P/CNTs composite coating; different pH values would lead to different specific gravities of alloying elements and CNTs deposition, and a reasonable pH value would help the coating reach the optimal hardness, wearability and corrosion resistance. In general, Ni-P/CNTs composite coating has the best comprehensive performance when the CNTs content is 40mg/L and pH value is 6

Effect of heat treatment process on mechanical properties and microstructure of FeAlCoCrNiTi_0.5 alloy

In order to study the effects of different sintering processes on the properties of the alloy, including the microstructure, hardness, friction and wear properties of the alloy, the optimum sintering method and process parameters were selected. A series of FeAlCoCrNiTi0.5 high-entropy alloy blocks were prepared by mechanical alloying using inert alloy sintering technology. XRD pattern showed that when the sintering temperature was 1000°C and the holding time was 3h, the phase structure would be a simple body-centered cubic BCC2 phase and a face-centered cubic FCC phase. SEM observation showed that the microstructure is denser, and the grain refinement of the high entropy alloy is remarkably better. The evaluation of hardness, friction and wear properties showed that the high-entropy alloy had the best overall performance.</p

Prediction of Surface Roughness and Optimization of Cutting Parameters of Stainless Steel Turning Based on RSM

The turning test of stainless steel was carried out by using the central composite surface design of response surface method (RSM) and Taguchi design method of central combination design. The influence of cutting parameters (cutting speed, feed rate, and cutting depth) on the surface roughness was analyzed. The surface roughness prediction model was established based on the second-order RSM. According to the test results, the regression coefficient was estimated by the least square method, and the regression equation was curve fitted. Meanwhile, the significance analysis was conducted to test the fitting degree and response surface design and analysis, in addition to establishing a response surface map and three-dimensional surface map. The life of the machining tool was analyzed based on the optimized parameters. The results show that the influence of feed rate on the surface roughness is very significant. Cutting depth is the second, and the influence of cutting speed is the least. Therefore, the cutting parameters are optimized and tool life is analyzed to realize the efficient and economical cutting of difficult-to-process materials under the premise of ensuring the processing quality

Comprehensive analysis of the immune implication of EPHX4 gene in laryngeal squamous cell carcinoma

Objectives: The role of Epoxide Hydrolase-4 (EPHX4), a member of epoxide hydrolase family, has not been investigated in cancer. The purpose of this article is to explore the application value of EPHX4 in laryngeal cancer and its relationship with immune infiltration. Methods: We observed that EPHX4 expression and its survival assays in laryngeal cancer specimens based on The Cancer Genome Atlas (TCGA) cohorts. We also analyzed the correlation between immune cell infiltration levels and EPHX4 gene copy number in laryngeal cancer. Finally, we conducted in vitro assay to evaluate the functions of EPHX4 in laryngeal cancer cell line. Results: EPHX4 is highly expressed in laryngeal cancer specimens and has a poor prognosis. EPHX4 related immune cell analysis showed that it participated in NK Natural killer cell mediated cytotoxicity. Finally, Cell experiments indicate that EPHX4 could promote laryngeal cancer cell line proliferation, colony formation and invasion. Conclusions: Our research results suggest that EPHX4 may be a potential immunotherapy target for laryngeal cancer. The nominated immune signature is a helpful and promising prognostic indicator in laryngeal cancer. Levels of Evidence: Level 3

Prediction of surface roughness and optimization of cutting parameters of stainless steel turning based on RSM

The turning test of stainless steel was carried out by using the central composite surface design of response surface method (RSM) and Taguchi design method of central combination design. The influence of cutting parameters (cutting speed, feed rate, and cutting depth) on the surface roughness was analyzed. The surface roughness prediction model was established based on the second-order RSM. According to the test results, the regression coefficient was estimated by the least square method, and the regression equation was curve fitted. Meanwhile, the significance analysis was conducted to test the fitting degree and response surface design and analysis, in addition to establishing a response surface map and three-dimensional surface map. The life of the machining tool was analyzed based on the optimized parameters. The results show that the influence of feed rate on the surface roughness is very significant. Cutting depth is the second, and the influence of cutting speed is the least. Therefore, the cutting parameters are optimized and tool life is analyzed to realize the efficient and economical cutting of difficult-to-process materials under the premise of ensuring the processing quality.</p