A low‐loss Ka‐band coupled‐resonator bandpass filter based on the printed ridge gap waveguide (PRGW) technology is presented for millimetre‐wave communication applications. The PRGW is employed to ...allow electromagnetic‐wave propagation in the air gap in order to avoid dielectric loss and improve transmission performance which is suitable for millimetre‐wave applications. The bandpass filter is implemented with two transmission zeros which are easily obtained by adjusting the stub length of two T‐shape stub‐loaded resonators (SLR). From its simulation frequency response, the filter has an insertion loss of 0.8 dB, a return loss less than −20 dB during the passband and high selectivity in cut‐off frequency. The prototype of the proposed filter is fabricated and tested and a good agreement can be observed between the measured and simulated results.
We present ClothFlow, an appearance-flow-based generative model to synthesize clothed person for posed-guided person image generation and virtual try-on. By estimating a dense flow between source and ...target clothing regions, ClothFlow effectively models the geometric changes and naturally transfers the appearance to synthesize novel images as shown in Figure 1. We achieve this with a three-stage framework: 1) Conditioned on a target pose, we first estimate a person semantic layout to provide richer guidance to the generation process. 2) Built on two feature pyramid networks, a cascaded flow estimation network then accurately estimates the appearance matching between corresponding clothing regions. The resulting dense flow warps the source image to flexibly account for deformations. 3) Finally, a generative network takes the warped clothing regions as inputs and renders the target view. We conduct extensive experiments on the DeepFashion dataset for pose-guided person image generation and on the VITON dataset for the virtual try-on task. Strong qualitative and quantitative results validate the effectiveness of our method.
During the solidification process, the precipitation of inclusions is inevitable due to micro-segregation, especially AlN and MnS in TWIP steel. In order to reasonably control the precipitation of ...inclusion, the cooling rate as an important factor in the casting process was studied through the unidirectional solidification experiments. The combined analyses using ASEM-EDS, EPMA and optical microscope revealed that the number density of precipitated inclusion decreased along the solidification direction with the decrease of the solid fraction. The number density of Al2O3, which existed in the liquid alloy was basically stable. On the contrary, the number density of MnS decreased and that of AlN increased with the increasing of cooling rate. Moreover, in the early stage of the solidification (fs<0.1), the order of Al concentration curve slope was 0.58 K/s >0.38 K/s >0.1 K/s due to the entrapment of precipitated AlN by the solid-liquid interface moving relatively fast. Temperature was the main factor to affect the AlN precipitation and the particles were precipitated at the early stage of the solidification process. AlN inclusions can become the core to form the composite particles and have the positive effect on fining grains.
In this study, a novel coupling structure based on half‐mode substrate‐integrated waveguide (HMSIW) is proposed with a small size and broad bandwidth. The HMSIW coupler is realised by connecting ...their equivalent magnetic walls with metal strips, which avoids exposing the semi‐enclosed magnetic walls outside. Hence, it has greater anti‐interference capability than the existing HMSIW couplers. The directional coupling principle is introduced by analysing the proposed single connecting strip coupler. In order to lower return loss and higher isolation, a 3 dB directional coupler working from 10.8 to 16.8 GHz is designed with two connecting strips. Finally, a six‐port circuit is achieved by utilising this compact 3 dB directional coupler. Furthermore, a broadband HMSIW power divider is optimised to satisfy the performance of this six‐port circuit. The proposed coupler with metal strips helps to increase bandwidth and reduce size, which makes it more applicable to demanding systems with complex requirements such as detecting and transceiver systems. The 3 dB coupler and six‐port circuit are fabricated and measured. The measured results are in accordance with the simulated data.
In order to reasonably control the precipitation of inclusions during solidification in TWIP steels, the precipitation behavior of typical MnS inclusions in high manganese steel was investigated by ...unidirectional solidification experiments. Through the combined analyses using ASEM-EDS, optical microscope, and thermodynamic calculation, it was found that Mn concentration in the liquid metal region were higher than those in the solid metal region. Furthermore, closer to the inclusion the liquid phase was, higher its Mn content was. In Fe-18mass%Mn-1Al-0.3C, MnS inclusions can precipitate at the positions located in the junction of dendrites at the end of the solidification (solid fraction fs=0.96), Mn content reaching 34.88 mass%. Already existing Al2O3 particles could become the core of MnS to form composite inclusions to promote the MnS precipitation during the solidification process. When fs achieved 0.7 leading the Mn segregation in the liquid phase to 25 mass%, MnS starts to precipitate to attach the Al2O3 surface to form composite inclusion.
In this study, the effects of the addition of Ce and Ti on the evolution of inclusions in Al deoxidized Fe-17Cr-9Ni austenitic stainless steel were investigated. When the Ce was added before Ti, ...Al2O3 can be effectively modified into Ce-containing oxides by Ce. With the increase of Ce content, the oxides evolutionary process is as follows: Al2O3 → CeAl11O18 → CeAlO3 → Ce2O3. After the addition of Ti, TiN appeared on the surface of oxides except Ce2O3. When Ti was added before Ce, due to the simultaneous effects of Ti on the modification of smaller size Al2O3 and precipitation of TiN, spherical Al2O3–TiOx inclusion that was completely wrapped by TiN formed. On the other hand, the larger size Al2O3 was not significantly modified by Ti, and cannot completely be wrapped by TiN. After Ce was added, the oxides which were not completely wrapped by TiN were modified to Ce-containing oxides. However, Ce could not modify the oxides that were completely wrapped by TiN.
We propose a novel polymorph of a hexagonal B3S monolayer by combing structure swarm intelligence and first-principles calculations. Phonon spectrum analysis and ab initio molecular dynamics ...simulation indicate that the new structure is dynamically and thermally stable. Furthermore, the structure is mechanically stable and has a satisfactory elastic modulus. Our results show that the B3S monolayer is a semiconductor with strong visible-light optical absorption. More importantly, the electronic properties of the structure are tunable via surface functionalization. For example, hydrogenation or fluorination could transform the monolayer from the semiconducting to metallic state. On the other hand, surface oxidation could significantly enhance both carrier mobility and near-infrared optical absorption. Furthermore, we also discovered that the monolayer possesses satisfactory storage capacity for H2.
To develop CO2 utilization technology in converter process, it is necessary to study the chemical reactions of the CO2–O2 mixed gas in the cavity. 13CO2–18O2 dual isotope gas was used to distinguish ...the complex reactions and analyzed the effect of injection height. The results show that as the injection height increased from 10 to 30 mm, the influence of CO2 participating in the reaction is relatively unobvious; regarding O2, the flowrate of uninvolved reaction increases; the flowrate of post combustion increases first and then decreases; the flowrate of O2 directly involved in decarburization is basically stable in the range of 20–30 mm after decreasing. Maintaining the injection height of 20 mm, the O2 flowrates of post combustion in the ranges of 0–5 mm, 5–10 mm, and 10–15 mm are 4.95 mL·min−1, 13.85 mL·min−1 and 6.73 mL·min−1, respectively. It can reduce the waste of mixed gas due to post combustion and improve the quality of furnace gas if the injection height is not in the range of high post combustion ratio.
The partial substitution of O2 with CO2 in steelmaking process is an important technology to reduce CO2 emission and recycle. In order to improve CO2–O2 decarburization utilization, the ...decarburization kinetics of Fe–C melt with CO2–O2 mixed gas have been studied using 13CO2–18O2 dual isotope tracing method and established the decarburization kinetic model. The results show that less than 40% of the oxygen is partially replaced by CO2, which improves the O2 utilization involved in the decarburization reaction and the CO2 utilization is still more than 80%. For the rate limiting steps, regarding O2, it is governed by the mixed control mechanism involving gas-phase mass transfer and interfacial chemical reaction; regarding CO2, with the increase of CO2 partial pressure, the rate limiting step changes from the mixed control to gas-phase mass transfer control only. As bath temperature increase from 1723 to 1873 K, the overall decarburization rate increases; bath temperature mainly affects O2 decarburization rates, whereas, the rates of CO2 are not significantly affected. The apparent activation energy of CO2–O2 mixed gas decarburization is 21.5 kJ·mol−1.
The abuse of amphetamine-type stimulants (ATS) has increased rapidly and so development of an easy, cheap and sensitive ATS sensor is of great importance. A facile label-free impedimetric sensor was ...fabricated using cucurbit7uril (CB7) as a recognition molecule to bind ATS. The presence of CB7 enables the formation of three-dimensional AuNP structures (3D-AuNPs@CB7) which were characterized by Fourier transform infrared reflection spectroscopy, scanning electron microscopy and transmission electron microscopy. Due to the large effective area and high electronic transmission of 3D-AuNPs@CB7, the 3D-AuNPs@CB7-modified electrodes produce 63 times the signal enhancement at the limit of detection compared with using CB7 directly. In addition, the fabricated impedimetric sensor can accurately detect an amphetamine-type derivative in artificial urine and serum samples. Combining the properties of 3D nanostructures with a macrocyclic molecule, 3D-AuNPs@CB7 offers a simple and sensitive platform for the detection of ATS.
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•An electrochemical impedance method was used to detect 3‑phenylpropylamine (3-PPA).•A 3-D AuNP structure was simply fabricated using cucurbit7uril (CB7).•The detection method relies on host–guest interactions.•A 3D-AuNPs@CB7-modified electrode had excellent electrochemical performance.
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