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This article presents a miniaturized C-band triplexer fabricated with high-temperature superconducting (HTS) microstrip lines and to be applied to quantum computers. The triplexer consists of three bandpass filters and branch lines. In the design of the bandpass filters, folded step impedance resonators (SIRs) are firstly used to achieve good stopband performances by harmonic suppression. Secondly, cross-coupling structures are also utilized to further improve the passband edge steepness of the bandpass filters. Finally, the parasitic transmission zeros originating from the assembling box sizes are employed to achieve a deeper out-of-band rejection. Three bandpass filters are designed and connected to the common input port of the triplexer. After that, the triplexer is coarsely optimized by advanced design system (ADS) for time-saving and is finely optimized by Sonnet for better accuracy. The optimized layout of the triplexer is fabricated on a 2-inch diameter and 0.5 mm thickness MgO wafer; here, the MgO wafer is double-sided coated with HTS YBa2Cu3O7 (YBCO) thin films. The measured passband bandwidths (return loss greater than 12 dB) of the triplexer are 6.420-6.680 GHz, 6.780-7.030 GHz, and 7.110-7.380 GHz, respectively, which satisfy the required design specifications. [ABSTRACT FROM AUTHOR]

Binder jet 3D printing combined with post-deposition sintering is a non-beam additive manufacturing (AM) method for the creation of complex 3-dimensional structures. Binder saturation and particle morphology are two important factors affecting the quality of printed parts. Here, we investigated the effects of binder saturation on dimension accuracy, porosity, microstructure, and microhardness of nickel-based alloy 625 samples made of differently atomized powders. Argon gas atomized (GA) and water atomized (WA) nickel-based alloy 625 powders were used to binder jet samples for a detailed comparative study. The optimal binder saturation for WA system is 60 to 70%, whereas for GA system the optimal is about 80%. Generally, GA samples achieved better overall quality than WA samples in terms of packing density, dimensional accuracy, sintered density, and microhardness. This difference is attributed mainly to the particle morphology including sphericity and roundness. The critical threshold for visible binder bleeding phenomenon in WA and GA systems is determined to be 120% and 140% binder saturation, respectively. Mechanisms for binder bleeding phenomenon at different saturation levels for WA and GA systems are discussed in detail. A pore evolution model is proposed to better understand the printing and sintering processes. [ABSTRACT FROM AUTHOR]

The real-time tracking of moving objects has extensive applications in various domains. Existing tracking methods typically utilize video image processing, but their performance is limited due to the high information throughput and computational requirements associated with processing continuous images. Additionally, imaging in certain spectral bands can be costly. This paper proposes a non-imaging real-time three-dimensional tracking technique for distant moving targets using single-pixel LiDAR. This novel approach involves compressing scene information from three-dimensional to one-dimensional space using spatial encoding modulation and then obtaining this information through single-pixel detection. A LiDAR system is constructed based on this method, where the peak position of the detected full-path one-dimensional echo signal is used to obtain the target distance, while the peak intensity is used to obtain the azimuth and pitch information of the moving target. The entire process requires minimal data collection and a low computational load, making it feasible for the real-time three-dimensional tracking of single or multiple moving targets. Outdoor experiments confirmed the efficacy of the proposed technology, achieving a distance accuracy of 0.45 m and an azimuth and pitch angle accuracy of approximately 0.03° in localizing and tracking a flying target at a distance of 3 km. [ABSTRACT FROM AUTHOR]

The effects of post-build heat-treatments on the microstructure, phase formation, recrystallization behavior, and mechanical properties of laser powder bed additively manufactured Inconel 718 superalloy were investigated. Several heat-treatment schedules were used, including simulated hot isostatic pressing (HIP), and variations of the standard double aging treatment with various soaking times and quench procedures. Their effects on the precipitation, grain morphology, grain size, texture sharpness and mechanical properties were all documented. For the as-built coupons, columnar grains with inter-dendritic micro-segregation were formed along the build direction (xz-plane) with equiaxed grains forming on perpendicular sections to the build direction (xy-plane). After prolonged soaking times during the simulated HIP process, the microstructure transitioned from heterogeneous columnar grains to homogenous recrystallized grains with MC-type carbide precipitates. This leads to changes of microhardness (281 HV 2.0 to 171 HV 2.0), Young's modulus (209 GPa–229 GPa) and texture intensity. However, aging treatments increased both hardness and Young's modulus possibly because of formation of γ″ and γ′ precipitates in the Ni-matrix and the small effective grain size. Phase analysis using XRD confirmed the evolution of the precipitate formation. The combination of additive manufacturing and post-build heat-treatments can result in optimized microstructures and mechanical properties for specific applications depending on part requirements and operating conditions. [ABSTRACT FROM AUTHOR]