Optimization simulation and crushing experiment of anti-impact energy absorption component of hydraulic support column

Hydraulic support, being the primary supporting equipment in coal mining operations, is frequently subjected to rock burst pressure. Hence, the anti-impact energy absorption components play a pivotal role in safeguarding the hydraulic support system. Based on the research foundation established by our anti-impact components research group, a detailed investigation on the parameters of energy-absorbing components was conducted for achieving an enhanced initial peak force and absorption energy, as well as reducing the dispersion of reaction forces. Subsequently, the ABAQUS finite element software was employed for modeling and simulating the crushing impact behavior of these energy-absorbing components. The energy absorption performance and buckling deformation characteristics of the energy absorption component were determined, and the optimal size was experimentally validated for its energy absorption performance. By comparing the predicted average support force data of the energy-absorbing member with the finite element simulation results, it was observed that the error is below 15%. Furthermore, for the optimal size member, the prediction error of the average support force model is −3.40%, thus confirming a higher level of accuracy in predicting data for the energy-absorbing members. A test platform was constructed to evaluate the crushing behavior of energy-absorbing components. The experiment involved conducting axial loading crushing tests on the custom-designed components under quasi-static conditions, with five different loading speeds selected. The experimental results demonstrate that the fluctuation of support reaction remains consistent across axial crushing experiments conducted at different loading speeds. The maximum peak value of initial support reaction is 2 253.52 kN, with a standard deviation of 206.23 kN. The minimum peak value of the initial support reaction is recorded as 2 096.26 kN, with a standard deviation of 189.83 kN. The average value for the initial support reaction peak is determined to be 2 149.32 kN, accompanied by an average standard deviation of 196.77 kN. The relative errors of the initial support reaction peak and standard deviation, compared to the finite element simulation data, are 5.6% and 11.07%, respectively. The energy absorption performance of the optimally sized energy-absorbing component was analyzed using three methods: a prediction model, finite element simulation, and crushing experiments. The average support reaction force obtained from the prediction model method is 1 879.7 kN, while that from the finite element simulation method is 1 945.9 kN, and that from the crushing experiment method is 1 919.8 kN. The prediction model exhibits an error rate of 3.41%, while the crushing experiment demonstrates a deviation of −1.3%. The reliability and feasibility of the analysis method for the energy-absorbing components are substantiated through the data verification results from these three approaches

The Asian arowana (<i>Scleropages formosus</i>) genome provides new insights into the evolution of an early lineage of teleosts

The Asian arowana (Scleropages formosus), one of the world’s most expensive cultivated ornamental fishes, is an endangered species. It represents an ancient lineage of teleosts: the Osteoglossomorpha. Here, we provide a high-quality chromosome-level reference genome of a female golden-variety arowana using a combination of deep shotgun sequencing and high-resolution linkage mapping. In addition, we have also generated two draft genome assemblies for the red and green varieties. Phylogenomic analysis supports a sister group relationship between Osteoglossomorpha (bonytongues) and Elopomorpha (eels and relatives), with the two clades together forming a sister group of Clupeocephala which includes all the remaining teleosts. The arowana genome retains the full complement of eight Hox clusters unlike the African butterfly fish (Pantodon buchholzi), another bonytongue fish, which possess only five Hox clusters. Differential gene expression among three varieties provides insights into the genetic basis of colour variation. A potential heterogametic sex chromosome is identified in the female arowana karyotype, suggesting that the sex is determined by a ZW/ZZ sex chromosomal system. The high-quality reference genome of the golden arowana and the draft assemblies of the red and green varieties are valuable resources for understanding the biology, adaptation and behaviour of Asian arowanas

The Asian Arowana (Scleropages formosus) Genome Provides New Insights into the Evolution of an Early Lineage of Teleosts

The Asian arowana (Scleropages formosus), one of the world’s most expensive cultivated ornamental fishes, is an endangered species. It represents an ancient lineage of teleosts: the Osteoglossomorpha. Here, we provide a high-quality chromosome-level reference genome of a female golden-variety arowana using a combination of deep shotgun sequencing and high-resolution linkage mapping. In addition, we have also generated two draft genome assemblies for the red and green varieties. Phylogenomic analysis supports a sister group relationship between Osteoglossomorpha (bonytongues) and Elopomorpha (eels and relatives), with the two clades together forming a sister group of Clupeocephala which includes all the remaining teleosts. The arowana genome retains the full complement of eight Hox clusters unlike the African butterfly fish (Pantodon buchholzi), another bonytongue fish, which possess only five Hox clusters. Differential gene expression among three varieties provides insights into the genetic basis of colour variation. A potential heterogametic sex chromosome is identified in the female arowana karyotype, suggesting that the sex is determined by a ZW/ZZ sex chromosomal system. The high-quality reference genome of the golden arowana and the draft assemblies of the red and green varieties are valuable resources for understanding the biology, adaptation and behaviour of Asian arowanas

Preliminary Assessment of Wind and Wave Retrieval from Chinese Gaofen-3 SAR Imagery

The Chinese Gaofen-3 (GF-3) synthetic aperture radar (SAR) launched by the China Academy of Space Technology (CAST) has operated at C-band since September 2016. To date, we have collected 16/42 images in vertical-vertical (VV)/horizontal-horizontal (HH) polarization, covering the National Data Buoy Center (NDBC) buoy measurements of the National Oceanic and Atmospheric Administration (NOAA) around U.S. western coastal waters. Wind speeds from NDBC in situ buoys are up to 15 m/s and buoy-measured significant wave height (SWH) has ranged from 0.5 m to 3 m. In this study, winds were retrieved using the geophysical model function (GMF) together with the polarization ratio (PR) model and waves were retrieved using a new empirical algorithm based on SAR cutoff wavelength in satellite flight direction, herein called CSAR_WAVE. Validation against buoy measurements shows a 1.4/1.9 m/s root mean square error (RMSE) of wind speed and a 24/23% scatter index (SI) of SWH for VV/HH polarization. In addition, wind and wave retrieval results from 166 GF-3 images were compared with the European Centre for Medium-Range Weather Forecasts (ECMWF) re-analysis winds, as well as the SWH from the WaveWatch-III model, respectively. Comparisons show a 2.0 m/s RMSE for wind speed with a 36% SI of SWH for VV-polarization and a 2.2 m/s RMSE for wind speed with a 37% SI of SWH for HH-polarization. Our work gives a preliminary assessment of the wind and wave retrieval results from GF-3 SAR images for the first time and will provide guidance for marine applications of GF-3 SAR

Extraction of Dy(III) and Sm(III) with N,N-dimethyl-N,N-dioctylsuccinamide

This work was focused on the applicability of a new diamide N,N-dimethyl- N,N-dioctylsuccinamide (DMDOSA) employing cyclohexane as the diluent to extract Dy(III) and Sm(III) from nitric acid solutions. The extraction from HNO3 was investigated by distributionmeasurements. The stoichiometry of the predominant adducts of DMDOSA with HNO3 is 1:1 (HNO3 .DMDOSA) under the studied conditions. The effect of the concentrations of nitric acid, lithium nitrate and extractant on the distribution ratio was investigated. An IR spectral study was also made of the extracted species

Analysis of miRNA Expression Profiling of RIP2 Knockdown in Chicken HD11 Cells When Infected with Avian Pathogenic E. coli (APEC)

Colibacillosis is an acute and chronic avian disease caused by avian pathogenic E. coli (APEC). Previous studies have demonstrated that RIP2 plays a significant role in APEC infection. Moreover, increasing evidence indicates that microRNAs (miRNAs) are involved in host&ndash;pathogen interactions and the immune response. However, the role of miRNAs in the host against APEC infection remains unclear. Herein, we attempted to reveal new miRNAs potentially involved in the regulation of the immune and inflammatory response against APEC infection, with a particular focus on those possibly correlated with RIP2 expression, via miRNA-seq, RT-qPCR, Western blotting, dual-luciferase reporter assay, and CCK-8. The results showed that a total of 93 and 148 differentially expressed (DE) miRNAs were identified in the knockdown of RIP2 cells following APEC infection (shRIP2+APEC) vs. knockdown of RIP2 cells (shRIP2) and shRIP2 vs. wild-type cells (WT), respectively. Among those identified DE miRNAs, the biological function of gga-miR-455-5p was investigated. It was found that gga-miR-455-5p regulated by RIP2 was involved in the immune and inflammatory response against APEC infection via targeting of IRF2 to modulate the expression of type I interferons. Additionally, RIP2 could directly regulate the production of the type I interferons. Altogether, these findings highlighted the crucial role of miRNAs, especially gga-miR-455-5p, in host defense against APEC infection

Comparison of Usage and Influencing Factors between Governmental Public Bicycles and Dockless Bicycles in Linfen City, China

Automobile traffic has shifted the use of bicycles in many developed regions to being mainly for sport, recreation and commuting. Due to the desire to mitigate the impacts of climate change and alleviate traffic jams, bicycle sharing is booming in China. Governmental public bicycles and dockless bicycles are the main types of bicycle sharing in China, each with different types of management and pricing. Field research has found that many bicycle sharing networks are idle and wasteful, and thus we investigated which type is more popular and suitable for Chinese cities. This research comparatively analyzes the application of governmental public bicycles and dockless bicycles, mainly focusing on the cycling destination, cycling frequency, and cycling factors, taking Linfen City as an example. The results show that: (1) The purpose is different between governmental public bicycles and dockless bicycles. On the one hand, the aim of riding a governmental public bicycle to work represents the largest proportion at about 29%, mainly because of the fixed route of travel, and the fact that the fixed placement of governmental public bicycles makes them more available compared to the random arbitrariness of dockless bicycles. On the other hand, the aim of riding a dockless bicycle for entertainment accounts for the largest proportion, at about 34%, mainly due to the ease of borrowing and returning a bike, and mobile payment. (2) In terms of frequency, the public’s choice of riding a dockless bicycle or a governmental public bicycle has no essential difference, given that there are only two options for citizens in Linfen. (3) The response to the two kinds of bicycle sharing is different; the governmental public bicycle has the advantage of lower cost, but the dockless bicycle has more advantages in the procedure of borrowing and returning the bicycle

Development of Wind Speed Retrieval from Cross-Polarization Chinese Gaofen-3 Synthetic Aperture Radar in Typhoons

The purpose of our work is to determine the feasibility and effectiveness of retrieving sea surface wind speeds from C-band cross-polarization (herein vertical-horizontal, VH) Chinese Gaofen-3 (GF-3) SAR images in typhoons. In this study, we have collected three GF-3 SAR images acquired in Global Observation (GLO) and Wide ScanSAR (WSC) mode during the summer of 2017 from the China Sea, which includes the typhoons Noru, Doksuri and Talim. These images were collocated with wind simulations at 0.12° grids from a numeric model, called the Regional Assimilation and Prediction System-Typhoon model (GRAPES-TYM). Recent research shows that GRAPES-TYM has a good performance for typhoon simulation in the China Sea. Based on the dataset, the dependence of wind speed and of radar incidence angle on normalized radar cross (NRCS) of VH-polarization GF-3 SAR have been investigated, after which an empirical algorithm for wind speed retrieval from VH-polarization GF-3 SAR was tuned. An additional four VH-polarization GF-3 SAR images in three typhoons, Noru, Hato and Talim, were investigated in order to validate the proposed algorithm. SAR-derived winds were compared with measurements from Windsat winds at 0.25° grids with wind speeds up to 40 m/s, showing a 5.5 m/s root mean square error (RMSE) of wind speed and an improved RMSE of 5.1 m/s wind speed was achieved compared with the retrieval results validated against GRAPES-TYM winds. It is concluded that the proposed algorithm is a promising potential technique for strong wind retrieval from cross-polarization GF-3 SAR images without encountering a signal saturation problem

Box–Behnken Design Optimizing Sugarcane Bagasse-Based Nitrogen-Doped Carbon Quantum Dots Preparation and Application in Ferric Ion Detection

Sugarcane bagasse is an abundant biomass waste and a promising carbon source for preparing carbon-based materials such as carbon quantum dots (CQDs). Low quantum yield is a major problem for sugarcane bagasse-based carbon quantum dots. Heteroatom-doped modification is an efficient approach to improve the quantum yield. A facile hydrothermal carbonization method was applied to synthesize the nitrogen-doped carbon quantum dot N-CQDs using urea as the nitrogen source. The synthetic procedure was determined by the single-factor experiments and the response surface methodology (RSM) based on Box–Behnken design (BBD). The optical properties of optimized N-CQD-13 were more excellent than those of undoped CQD. Higher quantum yields (both absolute and relative) were observed in N-CQD-13. Additionally, N-CQD-13 exhibited high stability for long-time storage and excellent pH tolerance in aqueous solutions. N-CQD-13 were applied to detect Fe3+ in aqueous solutions with a low detection limit of 0.44 μM. The fluorescence lifetime decay of the N-CQD-13 solutions untreated and treated with Fe3+ indicated the probable involvement of a dynamic fluorescence-quenching mechanism. Thus, this work explored a reliable method for the high-quality utilization of bagasse