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In this study, ZnO/ZnO nanocrystal-modified reduced graphene oxide (rGO) foam composites having various morphologies and mass ratios were synthesized using the hydrothermal and freeze-drying processes. The free Zn2+ present in the composites controlled their morphology by regulating the pH value, and the Zn2+ ions adsorbed onto the rGO sheets to form ZnO nanocrystals. The rGO sheets were dispersed by growing ZnO and ZnO nanocrystals on them, effectively preventing their agglomeration. The effects of the ZnO morphology and ZnO:rGO mass ratio on the complex permittivity and microwave absorption properties of the composites were systematically studied. The results revealed that the composite with small hexagonal cylindrical ZnO and the ZnO:rGO mass ratio of 8:1 (pH = 8.5) showed considerable microwave absorption, and the bandwidths of the reflection loss (≤−10 dB) were 8.7–11.1 and 11.5–12.4 GHz when the thickness was 3.4 mm. The microwave absorption mechanism of the composites was investigated systematically. The results indicated the potential of the composites as an absorber material with high performance, broad bandwidth, and light weight.

China’s enhanced international influence creates a good environment for spreading its traditional culture overseas. In recent years, Chinese subtitle translation is no longer restricted to translating foreign works into Chinese, with costume drama subtitle translation gaining more and more attention. However, relevant research in China is inadequate, and differences between Chinese and English aggravate this difficulty, which may be solved by studying and analyzing the subtitle translation of The Longest Day in Chang'an under the guidance of Nida's functional equivalence theory from the perspectives of lexical equivalence, syntactic equivalence, and stylistic equivalence, so as to provide the guidance to translators to render a proper translation both in the conveying of information as well as ensuring readers' response.

CoCrNiCux (x = 0.16, 0.33, 0.75, and 1) without macro-segregation medium-entropy alloys (MEAs) was prepared using laser directed energy deposition (LDED). The microstructure and mechanical properties of CoCrNiCux alloys with increasing Cu content were investigated. The results indicate that a single matrix phase changes into a dual-phase structure and the tensile fracture behaviors convert from brittle to plastic pattern with increasing Cu content in CoCrNiCux alloys. In addition, the tensile strength of CoCrNiCux alloys increased from 148 to 820 MPa, and the ductility increased from 1 to 11% with increasing Cu content. The nano-precipitated particles had a mean size of approximately 20 nm in the Cu-rich phase area, and a large number of neatly arranged misfit dislocations were observed at the interface between the two phases due to Cu-rich phase precipitation in the CoCrNiCu alloy. These misfit dislocations hinder the movement of dislocations during tensile deformation, as observed through transmission electron microscopy. This allows the CoCrNiCu alloy to reach the largest tensile strength and plasticity, and a new strengthening mechanism was achieved for the CoCrNiCu alloy. Moreover, twins were observed in the matrix phase after tensile fracture. Simultaneously, the dual-phase structure with different elastic moduli coordinated with each other during the deformation process, significantly improving the plasticity and strength of the CoCrNiCu alloy.

In respect of laser metal deposition (LMD) 3-D additive manufacturing technology, the method of non-parallel slicing is applied for the deposition of the overhanging and unequal-height parts and is capable of improving the deposition accuracy, stability and efficiency. Nevertheless, the produced uneven top surface derived from variable height deposition process has a possibility to result in instability and even failure of the deposition. In this study, the novel control strategies for the precise control of the unequal-height part were proposed. An inside-beam powder feeding nozzle was applied for the deposition with large overhanging angle. Based on a developed deposition height control system, multiple PI controllers were designed for varying desired deposition heights in an unequal-height layer. The actual heights of the uneven top surface in different positions were memorized by the deposition of a layer, and the process parameters for the next layer could be planned in advance to smooth this unevenness. Under the proposed control strategies, a geometrical stable and convergent process was made achievable when depositing a “fan-shaped” part and a “bent-pipe-shaped” part as the typical overhanging and unequal-height structures. The microstructures were observed to be uniform and compact, and the grain sizes and microhardness in different height positions were found to vary slightly.

Polyarylsulfone (PASF) has excellent features of heat resistant and mechanical performance, however it is difficult to be welded by laser directly because of the perfect light transmittance. Zinc particles with carbon black (ZPCB) as laser absorbers were used to weld PASF plates. The effects of processing parameters, laser power (P) and welding speed (v), on the interface structure and welding strength were investigated. Morphological analysis was performed in order to evaluate the composition of the fracture surface and the longitudinal section of the welded samples. The element distribution and chemical composition on the fracture surface were analyzed with X-ray photoelectron spectroscopy (XPS). A physical model was established to illustrate the change of bonding interface structure before and after the welding.

The microstructure and corrosion resistance of FeCrCuTiV high entropy alloy prepared by vacuum arc melting and laser melting deposition were studied. The microstructure and phase composition of FeCrCuTiV high entropy alloy were characterized by SEM, XRD, EBSD, etc. It is found that both of them are composed of the FCC Cu-rich phase, BCC Fe-rich phase and, BCC V-rich phase. Comparing with FeCrCuTiV high entropy alloy prepared by vacuum arc melting, the grain size of FeCrCuTiV high entropy alloy prepared by the laser melting deposition reduces from 29.48 µm to 1.85 µm. Meanwhile, the Cu-rich phase volume fraction decreases from 44.7 % to 31.5 %. Two reasons contribute to this phenomenon: On the one hand, the higher cooling rate of high entropy alloy makes the grain growth limited and the grain size reduced. On the other hand, the higher cooling rate reduces the volume fraction of intergranular segregation Cu-rich phase formed under non-uniform solidification due to the lack of long-range migration of Cu element, which makes the solidification state of FeCrCuTiV high entropy alloy prepared by laser melting deposition deviate from the ideal thermodynamic equilibrium. In addition, the corrosion resistance test of FeCrCuTiV high entropy alloy prepared by two processes indicates: FeCrCuTiV high entropy alloy prepared by laser melting deposition shows better corrosion resistance under the electrochemical corrosion of salt solution. This result is caused by the reduction of the Cu-rich phase, which weakens its corrosion effect as the anode of galvanic cell. Laser melting deposition technology provides new ideas and methods for controlling the phase structure of complex solid solution high entropy alloys to improve their physical properties.

Laser additive manufacturing is used to repair the damaged area of the rail, which is prone to martensite microstructure in the cladding layers, and it seriously affects the mechanical properties and threatens the safety of rail service. Therefore, in order to avoid the formation of martensite microstructure in the cladding layers, U75V steel rail cladding layer process experiment with different layers was carried out and the pearlite microstructure was successfully prepared by considering self-tempering characteristics. Moreover, combined with the finite element method to research the phase transformation behavior of U75V steel rail affected by thermal history, the mechanism of pearlite transformation in the process of laser directed energy deposition (LDED) repairing steel rail was studied. The results indicate that the cooling rate of the solid phase transformation stage is approximately 100–101 °C/s. Two indispensable conditions for pearlite formation in U75V steel repaired by LDED were revealed: the laser thermal accumulation must enable the cladding layers to maintain the valley temperature above the martensite start temperature and the cooling rate of the cladding layers in the solid phase transformation must be lower than the critical cooling rate of pearlite transformation. Based on this theory, pearlite microstructure can be obtained efficiently by means of preheating pretreatment and Co element doped alloying and optimizing the process parameters. Preheating pretreatment is beneficial to increase basic temperature, and Co-doped alloying can change continuous cooling transformation curve of U75V steel rail.

Recently, research of carbon nanotubes (CNTs) doping reinforced aluminum matrix nanocomposites has drawn significant attention. In this study, we conducted annular beam directed energy deposition (DED) experiments using CNTs/AlSi10Mg composites, prepared using a new procedure to improve the laser absorptivity of AlSi10Mg. The effect of the dispersant on CNTs adsorption and that of CNTs adsorption on temperature field, microstructure evolution, formability, and properties were clarified experimentally. The results show that CNTs exhibit good dispersion and adsorption in pure N-methyl pyrrolidone (NMP). Further, grains in the DED track were refined as the CNTs content increased, micro-hardness and laser absorptivity also improved. High-quality thin walls of 0.5- wt%-CNTs/AlSi10Mg were successfully formed, demonstrating that the new DED method for the preparation of CNTs/AlSi10Mg metal matrix nanocomposites is viable, expanding the potential application scenarios of composite material structures.

The service performance of U75V rail steel depends entirely on its laser-deposited microstructure, as coarse martensite has a damaging effect on wheel-rail contact behaviors. In this study, the formation mechanism of the microstructure in the rail steel was investigated based on simulated temperature fields in both solid and annular laser heat source models. U75V rail steel with pearlite was first fabricated via laser additive manufacturing with the annular laser beam and had a microstructure superior to that of the commercial U75V rail steel produced using the traditional slow-cooling heat treatment. This overcomes the long-perceived limitation that high-carbon steel can only form martensite through laser additive manufacturing. Active design of the grain size and the microstructure of U75V rail steel were proposed by controlling the cooling rate in two stages of solid phase transformation. The primary stage extended from the melting temperature to Ar1 and the secondary stage extended from Ar1 to the valley temperature. Granular pearlite in the annular laser beam-deposited sample shows considerably finer grains than the tempered martensite of the solid laser beam-deposited counterpart; therefore, the impact toughness of the sample can be increased by approximately 150%. The high cooling rate in the primary stage aids grain refinement in the annular laser beam-deposited sample, while the high valley temperature of the thermal cycle combined with the low cooling rate in the secondary stage leads to the formation of pearlite, instead of twin martensite.

In this paper, the skin-core combined with the triple contour method is proposed to solve the density and roughness problems of selective laser melting. Based on the skin-core strategy, the surface roughness is optimized by laser parameter adjustment, and the high-quality side-surface formation is achieved by the triple contour method. The results showed that the relative density increases first and then decreases with increasing in-skin energy density, and surface roughness decreases with increasing up-skin energy density. The effects of the skin-core parameters have been analyzed. In addition, a triple contour scanning strategy was also conducted, and the variation of surface roughness caused by the different number of contours has been analyzed, along with the fabrication of the Ti6Al4V denture bracket. Results showed that the inclined surface roughness could be improved by the triple contour method to an average roughness (Ra) of 3.5 μm. An average surface roughness of less than 4.3 μm and a relative density of 99.8% have been achieved at the same time using the skin-core and triple contour strategy. The curved surface and overhanging structure quality of the denture bracket was also improved. This work provided a novel approach for the additive manufacturing of a medical titanium alloy.

A new laser metal desposition process based on an inside-laser coaxial powder feeding system was successfully applied to manufacture reduced activation steel, which is featured with fine microstructure and excellent mechanical properties. In addition, infrared thermal imaging experiments and Abaqus numerical simulation were conducted to characterize the complex thermal history during the laser metal deposition process. The microstructure and mechanical properties of reduced activation steel were systematically investigated in the as-fabricated and heat-treated samples. The results indicat that the peak temperature increased and the cooling rate decreased in the melt pool when the additional layers were deposited as a result of a cumulative effect of heat in the fabricated thin wall samples. The reduced cooling rate directly contributed to the decreased heterogeneous nucleation rate and the coarsening of austenite grains in the top domain. The differences in terms of microstructure and hardness of the as-fabricated samples along the building direction were also in a good agreement with the evolution of temperature field. The thermal cycling experimental and cyclic heat treatment results confirmed that in-situ thermal cycles were unable to trigger recrystallization because the stored strain energy was insufficient to induce nucleation of new austenite grains during laser directed energy deposition.

Background: Comprehensive spatial phenotyping is an increasingly important pathology research tool for investigating the highly complex biology of tumors and their micro-environment. High multiplex immunohistochemical (IHC) strategies enable spatial profiling of tumor samples and expand the depth of information obtained from a single tissue section. Conventional IHC technologies overcome the limitations of low multiplexing by testing serial sections; however, this method does not provide evidence of true marker colocalization and results in inaccurate phenotyping. More recent multiplex methods involving iterative staining and stripping steps have been developed but suffer from low-throughput workflow and can potentially damage samples. Alternative strategies using localized release of mass- or oligonucleotide-tags are not only low-throughput but are also high-cost and require specialized instruments. In this study, we developed a highly streamlined 15-plex fluorescence IHC assay to identify and subtype lymphocytes, macrophages, dendritic cells, antigen presenting cells, and tumor cells on single FFPE tissue sections in a single work day. Methods: InSituPlex® technology was used to perform high-multiplex immune profiling (15 targets) of different FFPE tumor sections. Slides were stained with a Leica® Bond®RX autostainer using a cocktail of 15 primary antibodies. Whole slide images were obtained using commercially available multi-color fluorescence slide scanners. The resulting images were then segmented and analyzed for different phenotypes and their spatial relationships using the Indica Labs HALOTM software. Tissue sections processed with single-antibody staining were used as references to characterize the performance of the 15-plex assay. Results: We demonstrate a 15-plex immuno-fluorescence assay on whole FFPE tumor tissue sections in a single work day using the InSituPlex technology. Equivalence of assay performance between the 15-plex and individually stained reference samples confirmed assay specificity and sensitivity in the high multiplexed format. High-dimensional data obtained from the 15-plex assay allowed for a detailed sub-classification of various cell types and their spatial relationship on each single section. Conclusions: InSituPlex technology empowers immuno-oncology research through the staining of 15 different immune and tumor markers on single FFPE tumor sections, with a fast, automated workflow and reproducible assay. The resulting high-dimensional images are then used to spatially profile various sub-populations of lymphocytes, macrophages, and tumor cells. This study demonstrates the promises of the InSituPlex technology for translational research and discovery applications where rapid imaging of a large number of biomarkers over the entire tissue is highly desired. Citation Format: Abdul Majeed Mohammed, Zhixin Xia, Gourab Chatterjee, Kevin Hwang, Mael Manesse. High-plex spatial profiling of whole FFPE tissue sections using InSituPlex® technology for discovery applications [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1183.

Background: In addition to inducing apoptosis, tumor necrosis factor-α (TNFα) and FAS-induced death receptor signaling also induce necroptosis, a recently defined type of programed necrosis, through activation of the RIP1/RIP3-kinase pathway. The role of death receptor signaling-induced apoptosis in the development of leukemia has been well documented. However, the role of necroptotic signaling in the pathogenesis of leukemia has not been studied. Methods: RIP1/RIP3 signaling was inactivated in murine and human acute myeloid leukemia (AML) cells by genetic deletion of RIP1/RIP3 or pharmacologic inhibition using the specific inhibitor Necrostatin-1. The effects of RIP1/RIP3 signal inactivation on the behavior and interferon-γ (IFNγ)-induced differentiation of AML cells were evaluated by morphologic analysis, cell surface markers, in vitro colony-forming ability and in vivo transplantation/leukemogenic capacity. The responses of mice transplanted with Rip1-/- or Rip3-/-murine AML to IFNγ treatment were compared to the mice transplanted with wild-type AML. Results: We found that most types of AML cells produce TNFα and already show basal level activation of RIP1/RIP3 signaling but they do not undergo necroptosis. Using both pharmacological inhibition and genetic deletion techniques, we determined that inactivation of the RIP1/RIP3 signal resulted in partial differentiation of both human AML cell lines and MLL-AF9-transduced murine AML cells as demonstrated by studies of morphology, cell surface markers and colony-forming ability. Rip1 or Rip3 deletion significantly repressed the leukemogenic capacity of murine AML cells in vivo. In addition, inactivation of RIP1/RIP3 signaling significantly enhanced the complete differentiation of AML cells induced by IFNγ. The combination of RIP1/RIP3 inactivation and IFN treatment significantly further attenuated the clonogenic capacity of both primary AML cells and AML cell lines. Such combination treatment also further compromised the leukemogenic ability of AML cells in vivo. Mechanistically, we found that the RIP1/RIP3 pathway regulates the expression of SOCS1, a key negative regulator of IFNγ signaling. Inactivation of RIP1/RIP3 signaling in AML cells renders them hypersensitive to IFNγ -induced monocytic lineage maturation. Conclusion: Resistance to apoptosis is one of the key mechanisms involved in the development of drug resistance in leukemic cells. RIP1/RIP3-mediated necroptosis induced by TNFα has been proposed to be an alternative therapeutic strategy to treat leukemia. However, our studies suggested that inhibition of RIP1/RIP3-mediated necroptotic signaling might be useful strategy for AML treatment when combined with IFNγ. Disclosures No relevant conflicts of interest to declare.