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The high-speed ice-ball impact damage research of epoxy resin/carbon fiber 3D four-way braided composites was carried out. Using the air gun impact test system, ice balls with three different impact velocities were used to conduct impact tests. After the test, industrial CT scans were performed on the main damage positions of the test pieces, and the internal damage forms were observed. The composite macro constitutive model based on surface unit-cell and interior unit-cell and a strain rate related material model of the ice were used to establish the finite element model. The simulation model was compared with the test. The results show that the damage of the matrix in the surface unit-cell area is more serious than that in the interior unit-cell area, the damage area of the front surface is generally larger than that of the back surface, the oblique impact angle has an influence on the damage area and damage location. As the impact angle decreases, the damage area of the composite material also decreases. Increasing the thickness of plate can improve the ability to absorb energy and reduce the damage area of the material.

The artificial accelerated cyclic hygrothermal aging test was conducted on T700/TDE86 carbon fiber reinforced resin matrix composites, and the effects of different cyclic hygrothermal aging days on interlaminar fracture toughness of composites with open type (mode Ⅰ) and slip type (mode Ⅱ) were investigated. The results show that the model Ⅰ interlaminar fracture toughness of composite after cyclic hygrothermal aging exists an obvious R curve, the initial extend energy release rate (GIC,init) and the propagational extend energy release rate (GIC,prop) of composite are improved remarkably with the increase of cyclic hygrothermal aging days. The model Ⅱ interlaminar fracture toughness of composite appears a trapezoidal descent with the increase of cyclic hygrothermal aging days, and the decline is the largest at the early stage of cyclic hygrothermal aging and the largest descent is 21.68%.

This study investigates the use of calcium-based slurry for simultaneous removal NO and SO2 from oxy-fuel combustion flue gas, and recovery of the sulfur and nitrogen species in resulting solutions. The experiments were performed in a bubbling reactor in a transient mode under the pressure of 20 bar. The various influencing factors including the CaO amount, carrier gas (N2/CO2), and absorption time on the simultaneous NO and SO2 removal process, and the solution products were studied comprehensively. The results show that the NO2 removal efficiency can be improved by the presence of CO2, and the gas phase HNO2 produces in this process. The addition of CaO has positive effects not only on the NO2 removal efficiency but also on the formation of stable HNO3. With the presence of CO2, CaCO3 is formed in a solution initially. With the decrease of pH, CaCO3 is gradually converted to CaSO4, and in particular CaCO3 can be fully avoided through decreasing the pH of an absorption solution to 1.14. At the same time, the formation of unstable S(IV) and NO2- can be prevented when the solution pH is lower than 1.37. The nitrogen and sulfur compounds in the absorption solution (at pH 1.14) were further separated by the addition of different amounts of CaO. In particular, 95% of SO42- finally can be recovered in the form of CaSO4.2H2O with nitrogen in solution existing as NO3- by controlling the Ca/S ratio at 4.70. The effectiveness of calcium-based slurry on the removal and recovery of SO2 and NO is confirmed.

A comprehensive computational micromechanics has been presented to predict the transverse mechanical properties and failure envelop of bi-axial stress in a 22-33 plane at high temperatures. First, a paraboloidal elasto-plastic damage model considering the temperature effect of epoxy has been employed. Then, in order to rapidly create the random fiber distribution of the representative volume element (RVE), a simple and effective algorithm of fiber placement and an auto modeling and calculating python script have been developed, where the thickness size effect of RVEs has been discussed. Finally, the transverse tension/compression and out-of-plane shear properties and the corresponding failure envelop of RVEs are analyzed systematically by means of finite element simulations. The results show that the in-plane shear strength exists strongly thickness size effect, and high temperature can significantly weaken the transverse strength, especially for transverse compression, and the temperature effect of modulus can be depicted by a specific Gaussian function. In addition, Hashin and Tsai-wu criteria may be more appropriate to predict the bi-axial failure envelop of σ 2 2 − τ 23 at high temperature, and Tsai-Wu criterion is better and more suitable than Hashin and Catalanotti criteria for considering bi-axial compression. [ABSTRACT FROM AUTHOR]

A direct implicit discretization approach is presented for an arbitrary non-conformal interface by using a virtual cell on unstructured meshes. In this study, the virtual cell is supposed to be located at the neighbour of a target cell adjacent to the non-conformal interface. Any computational value on a virtual cell is formulated as a linear combination of values on contribution cells, which are determined by the nearest neighbouring cells or surface intersecting cells. The linear formulation simplifies the process of implementing implicit discretization for the governing equations. The approach is simple and efficient for information transfer through the interface because it avoids mesh stitching or iterations based on explicit discretization for treating topologically inconsistent meshes. Several numerical tests verify that the proposed method is capable and efficient for dealing with the arbitrary non-conformal interface. [ABSTRACT FROM AUTHOR]

Structured illumination microscopy (SIM), with the advantages of full-field imaging and low photo-damage, is one of the most well-established fluorescence super-resolution microscopy techniques that raised great interest in biological sciences. However, conventional SIM techniques generally require at least nine images for image reconstruction, and the quality of super-resolution significantly depends on high-accuracy illumination parameter estimation, which is usually computationally intense and time-consuming. To address these issues, we propose a robust seven-frame SIM reconstruction algorithm with accelerated correlation-enabled parameter estimation. First, a modulation-assigned spatial filter is employed to remove unreliable backgrounds associated with low signal-to-noise ratios. Then, we propose a coarse-to-fine accelerated correlation algorithm to eliminate the redundant iterations of the traditional correlation-based scheme. The frame reduction is achieved by a specially designed phase-shifting strategy combined with pixel-wise fluorescence pre-calibration. We experimentally demonstrate that, compared with conventional iterative correlation-based methods, the proposed algorithm improves the computational efficiency by a factor of 4.5 while maintaining high accuracy illumination parameter estimation. Meanwhile, our method achieves high-quality super-resolution reconstruction even with a reduction in two raw images, which improves the efficiency of image acquisition and ensures the robustness toward complex experimental environments. [ABSTRACT FROM AUTHOR]

Clear cell renal cell carcinoma (ccRCC) is the most common subtype of kidney cancer, and it is the major cause of kidney cancer death. Understanding tumor immune microenvironments (TMEs) is critical in cancer immunotherapies. Here, we studied the immune characterization at single-cell resolution by integrating public data of ccRCC across different tissue types, and comparing the transcriptome features and tumor TME differences in tumors, normal adjacent tissue, and peripheral blood. A total of 16 different types of cell components of ccRCC were identified. We revealed that there is an overall increase in T-cell and myeloid populations in tumor-infiltrated immune cells compared to normal renal tissue, and the B-cell population in the tumor showed a sharp decrease, which indicates that the cells in tumor tissue undergo strong immune stress. In addition, the cell–cell communication analysis revealed specific or conserved signals in different tissue types, which may aid to uncover the distinct immune response. By combining and analyzing publicly available ccRCC bulk RNA-seq datasets, 10 genes were identified as marker genes in specific cell types, which were significantly associated with poor prognosis. Of note, UBE2C, which may be a good indicator of tumor proliferation, is positively associated with reductions in overall survival and highly associated with tumor grade. Our integrated analysis provides single-cell transcriptomic profiling of ccRCC and their TME, and it unmasked new correlations between gene expression, survival outcomes, and immune cell-type components, enabling us to dissect the dynamic variables in the tumor development process. This resource provides deeper insight into the transcriptome features and immune response of ccRCC and will be helpful in kidney cancer immunotherapy. [ABSTRACT FROM AUTHOR]

The longitudinal compressive behavior of the three-dimensional four-step braided composites after cyclic hygrothermal aging was investigated using a split Hopkinson pressure bar (SHPB) apparatus under high strain rates (1100~1250 s−1, 1400~1600 s−1, 1700~1850 s−1, respectively). The SEM micrographs were examined to the damage evolution of the composites after cyclic hygrothermal aging. A high-speed camera was employed to capture the progressive damage process for the composites. The results indicate that the saturated moisture absorption of the composites was not reached during the whole 210 cyclic hygrothermal aging days. The composites mainly underwent epoxy hydrolysis and interfaces debonding during continuous cyclic hygrothermal aging time. The peak stress of the composites still behaved as a strain rate effect after different cyclic hygrothermal aging days, but the dynamic stiffness modulus clearly had no specific regularity. In addition, the peak stress and the dynamic stiffness modulus of the composites after 210 cyclic hygrothermal aging days almost decreased by half when subjected to longitudinal compression. [ABSTRACT FROM AUTHOR]

A transient mathematical model was developed to describe soot formation during the combustion of single coal particles based on the static semi-empirical model presented by Fletcher and coworkers. Sensitivity analyses of the model parameters show that soot emissivity and mass diffusivity of tar play an important role in predicting soot volume fraction ( f v ) and flame temperature ( T f ). The model was applied to simulate the combustion of single bituminous coal particles with initial diameter (2 r 0 ) of 83 µm in a drop tube furnace and air atmosphere. It was found that soot is only formed within the first ∼ 5 ms after the appearance of the volatile flame. Although most of the soot is oxidized during the volatile flame phase, a small portion of soot still remains during the char combustion. Due to the soot presence, the volatile flame duration is extended by 2.6 ms. Compared with the soot-free flame, the sooting flame has remarkable lower T f and its peak T f value is ∼ 410 K lower. As a consequence, char combustion starts at a temperature that is ∼ 125 K lower than that of the soot-free case. Spatially, the peak f v at 16.6 ms appears at 4.5 r 0 and soot oxidation zone spans to ∼ 10 r 0 . The model was validated by comparing the predicted T f and f v under different O 2 mole fractions ( x O2 ) with recent experimental results reported by Khatami and coworkers. The predicted trends are consistent with those of the experimental results. With increasing x O2 , T f increases, but the increase rate becomes more gradual at a large x O2 . While for f v , a non-monotonic variation is observed, where soot first increases and then decreases with a peak value occurring at x O2 ≈ 40%. [ABSTRACT FROM AUTHOR]

Fiber-reinforced polymer (FRP) structures used in aviation are typically exposed to cyclic hygrothermal environments in which they may be subjected to impact loads that threaten flight safety. Although the effects of hygrothermal aging on the mechanical behavior of FRPs have been extensively explored, few authors have discussed the impact-induced behavior of composites after long-term hygrothermal aging, and hardly any study has examined the effect of the strain rate of neat epoxy resin after hygrothermal aging. This study examines the quasi-static and dynamic tensile properties of TDE86 epoxy resin under cyclic hygrothermal aging for the first time. The resin specimens were aged for 0, 1, 7, 14, 28, 56, 70, and 140 days, representing specimens that were unaged, and had been in service for one month, six months, one year, two years, four years, five years, and 10 years respectively. The strain rate at which they were tested ranged from 7.5 × 10−6 s−1 to 1000 s−1. This yielded the hygroscopic law, the process of evolution of crack-induced damage, and the viscoelastic behavior of the specimens, including the hygrothermal effect and the effect of the strain rate of the epoxy resin. This information can be used to predict the hygrothermal behavior of FRPs based on the micromechanics method. [ABSTRACT FROM AUTHOR]

In order to study the seismic behavior of CFRP-reinforced seismic-damaged joints in composite frame consisting of concrete-filled square steel tubular (CFSST) columns and steel beams, four one half scaled models of exterior joints in composite frame consisting of CFSST columns and steel beams were designed and manufactured. The test consisted of pre-damage loading, rehabilitation with CFRP and destruction tests under lateral cyclic loading. The effectiveness of CFRP-strengthened seismic-damaged joints and the reinforcement effect on different levels of seismic damage were studied. Based on the test data, the hysteretic loops, skeleton curves, the CFRP strain, ductility, dissipative ability, ultimate strength and stiffness degradation, etc. were obtained. Results show that CFRP-strengthened seismic-damaged exterior joints in composite frame consisting of CFSST columns and steel beams meets the strong column-weak beam requirement of seismic design, and the failure modes of all joints are bending failure of beam. The reinforcement with CFRP has a significant on increasing the ultimate capacity and the seismic behaviors of the joints. The study indicates the rehabilitated joints can reach or even exceed the level of their original seismic performances before seismic damage in a certain extent of damage level. [ABSTRACT FROM AUTHOR]

• Different impact schemes including single-point and multi-point impact were carried out. • Three routes including visual analysis, C-Scan analysis and X-ray tomography were used to observe the intralaminar and interlaminar damage patterns. • An innovative damage category induced by multiple ice impacts were summarized. • The sequence and morphology of delamination damage between plies are different in single-point and multi-point impact. • A strain-rate dependent continuum damage model with interlayer cohesive element was successfully used to evaluate the damage behavior in CFRP laminates. Unlike most research on ice impact threats with single impact and multiple repeated impact, different impact schemes such as single-point repeated impact and multi-point sequential impact were carried out in this article, considering the actual circumstance of hail impacts on aerospace structures. To study the response of CFRP laminates to multiple ice impacts, ice projectiles with a diameter of 25 mm were projected onto laminates. Three different routes, including visual analysis, C-Scan analysis and X-ray tomography, were then used to observe the intralaminar and interlaminar damage patterns. An innovative damage category induced by different impact schemes was summarized from the whole experimental results through the visual analysis. The extent of delamination damage was characterized by C-Scan and CT. Both the damage mode and the area of delamination are not only related to the magnitude of single impact energy, but also to the density of impact points. For numerical approach, a strain-rate dependent continuum damage model with interlayer cohesive element was used to predict the damage evolution in CFRP laminates. It was first verified and then combined with the test data to reveal different damage mechanisms of single-point repeated impact and multi-point sequential impact. [ABSTRACT FROM AUTHOR]

With the rapid development of human-machine interactions and artificial intelligence, the demand for wearable electronic devices is increasing uncontrollably all over the world; however, an unsustainable power supply for such sensors continues to restrict their applications. In the present work, piezoelectric barium titanate (BaTiO 3 ) ceramic powder with excellent properties was prepared from milled precursors through a solid-state reaction. To fabricate a flexible device, the as-prepared BaTiO 3 powder was mixed with polydimethylsiloxane (PDMS) polymer. The BaTiO 3 /PDMS ink with excellent rheological properties was extruded smoothly by direct ink writing technology (DIW). BaTiO 3 particles were aligned due to the shear stress effect during the printing process. Subsequently, the as-printed composite was assembled into a sandwich-type device for effective energy harvesting. It was observed that the maximum output voltage and current of this device reached 68 V and 720 nA, respectively, for a BaTiO 3 content of 6 vol %. Therefore, the material extrusion-based three-dimensional (3D) printing technique can be used to prepare flexible piezoelectric composites for efficient energy harvesting.

Structured illumination microscopy (SIM) has become one of the most significant super-resolution techniques in bioscience for observing live-cell dynamics, thanks to fast full-field imaging and low photodamage. However, artifact-free SIM super-resolution reconstruction requires precise knowledge about variable environment-sensitive illumination parameters. Conventional algorithms typically, under the premise of known and reliable constant phase shifts, compensate for residual parameters, which will be easily broken by motion factors such as environment and medium perturbations, and sample offsets. In this Letter, we propose a robust motion-resistant SIM algorithm based on principal component analysis (mrPCA-SIM), which can efficiently compensate for nonuniform pixel shifts and phase errors in each raw illumination image. Experiments demonstrate that mrPCA-SIM achieves more robust imaging quality in complex, unstable conditions compared with conventional methods, promising a more compatible and flexible imaging tool for live cells.

Glioma, the most common intrinsic tumor of the central nervous system, is characterized by its high incidence and poor prognosis. The aim of this study was to identify differentially expressed genes (DEGs) between glioblastoma multiforme (GBM) and low-grade glioma (LGG) to explore prognostic factors of different grades of gliomas. Single-cell transcriptome sequencing data of gliomas were collected from the NCBI Gene Expression Omnibus (GEO), which included a total of 29 097 cell samples from three datasets. For the analysis of human gliomas of different grades, 21 071 cells were obtained by filtering, and 70 genes were screened from differentially expressed genes by gene ontology (GO) analysis, Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis, from which the gene DLL3 was focused by reviewing the literature. The TCGA-based gene expression profiling interactive analysis (GEPIA) database was used to explore the survival curves of genes in LGG and GBM, and the gene expression profiling interactive analysis and tumor immune estimation resource (TIMER) database was used to study the expression of key genes in gliomas of different grades, predicting biomarkers that were closely related to immunotherapy. The cBioPortal database was used to explore the relationship between DLL3 expression and 25 immune checkpoints. Gene set enrichment analysis (GSEA) further identified pathways associated with central genes. Finally, the efficacy of biomarkers in prognosis and prediction was validated in the Chinese glioma genome atlas (CGGA). These results demonstrated that prognostic genes are associated with tumor proliferation and progression. Analysis of biological information and survival suggested that these genes might serve as a promising prognostic biomarker and as new targets for selecting therapeutic strategies.

Retinoblastoma (RB) is the most common intraocular malignant tumor in infants and young children. The key causative factors in the progression of RB remain unclear. Therefore, identifying genes closely associated with RB progression may provide important clues for disease diagnosis and gene therapy. However, tumor tissues have strong cellular heterogeneity. There may be significant differences in cell function and gene expression among cells in different pathological states. In this study, we downloaded single-cell transcriptome sequencing data of RB tumors and adjacent tissues from the GEO public database. Subsequently, we analyzed RB tumor transcriptional profiles with different disease duration at the single-cell level and identified cell groups and gene sets potentially associated with RB progression. The results showed that the tumor tissue and the adjacent tissues had overall consistency in the single-cell transcriptional map, but there were obvious differences in the distribution proportions of G1 phase cells, G2 phase cells, and microglia cells of cone precursors in RB tumor and the adjacent tissues. Furthermore, the role of three cell populations in the progression of RB tumors was emphatically analyzed. We found that in the early stage of RB tumors, cone precursor cells proliferated abnormally in G1 phase. With the progression of RB tumors, the proportion of cone precursor cells in G2 phase increased significantly. Meanwhile, the results of differential analysis of microglial populations during RB progression showed that the key genes mainly involved in immune response include RPL23 , B2M , and HLA superfamily genes. This study provides new perspectives and data resources for the research of RB pathogenesis and progress.