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<jats:p>We investigate theoretically Rabi-like splitting and Fano resonance in absorption spectra of quantum dots (QDs) based on a hybrid QD-semiconducting nanowire/superconductor (SNW/SC) device mediated by Majorana fermions (MFs). Under the condition of pump on-resonance and off-resonance, the absorption spectrum experiences the conversion from Fano resonance to Rabi-like splitting in different parametric regimes. In addition, the Fano resonances are accompanied by the rapid normal phase dispersion, which will indicate the coherent optical propagation. The results indicate that the group velocity index is tunable with controlling the interaction between the QD and MFs, which can reach the conversion between the fast- and slow-light. Fano resonance will be another method to detect MFs and our research may indicate prospective applications in quantum information processing based on the hybrid QD-SNW/SC devices.</jats:p>

<jats:p>The thermoelectric (TE) materials and corresponding TE devices can achieve direct heat-to-electricity conversion, thus have wide applications in heat energy harvesting (power generator), wearable electronics and local cooling. In recent years, aerogel-based TE materials have received considerable attention and have made remarkable progress because of their unique structural, electrical and thermal properties. In this review, the recent progress in both organic, inorganic, and composite/hybrid TE aerogels is systematically summarized, including the main constituents, preparation method, TE performance, as well as factors affecting the TE performance and the corresponding mechanism. Moreover, two typical aerogel-based TE devices/generators are compared and analyzed in terms of assembly modes and output performance. Finally, the present challenges and some tentative suggestions for future research prospects are provided in conclusion.</jats:p>

<jats:p>SnO<jats:sub>2</jats:sub>/Co<jats:sub>3</jats:sub>O<jats:sub>4</jats:sub> nanofibers (NFs) are synthesized by using a homopolar electrospinning system with double jets of positive polarity electric fields. The morphology and structure of SnO<jats:sub>2</jats:sub>/Co<jats:sub>3</jats:sub>O<jats:sub>4</jats:sub> hetero-nanofibers are characterized by using field emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM), x-ray diffraction (XRD), and x-ray photoelectron spectrometer (XPS). The analyses of SnO<jats:sub>2</jats:sub>/Co<jats:sub>3</jats:sub>O<jats:sub>4</jats:sub> NFs by EDS and HRTEM show that the cobalt and tin exist on one nanofiber, which is related to the homopolar electrospinning and the crystallization during sintering. As a typical n-type semiconductor, SnO<jats:sub>2</jats:sub> has the disadvantages of high optimal operating temperature and poor reproducibility. Comparing with SnO<jats:sub>2</jats:sub>, the optimal operating temperature of SnO<jats:sub>2</jats:sub>/Co<jats:sub>3</jats:sub>O<jats:sub>4</jats:sub> NFs is reduced from 350°C to 250°C, which may be related to the catalysis of Co<jats:sub>3</jats:sub>O<jats:sub>4</jats:sub>. The response of SnO<jats:sub>2</jats:sub>/Co<jats:sub>3</jats:sub>O<jats:sub>4</jats:sub> to 100-ppm ethanol at 250°C is 50.9, 9 times higher than that of pure SnO<jats:sub>2</jats:sub>, which may be attributed to the p–n heterojunction between the n-type SnO<jats:sub>2</jats:sub> crystalline grain and the p-type Co<jats:sub>3</jats:sub>O<jats:sub>4</jats:sub> crystalline grain. The nanoscale p–n heterojunction promotes the electron migration and forms an interface barrier. The synergy effects between SnO<jats:sub>2</jats:sub> and Co<jats:sub>3</jats:sub>O<jats:sub>4</jats:sub>, the crystalline grain p–n heterojunction, the existence of nanofibers and the large specific surface area all jointly contribute to the improved gas sensing performance.</jats:p>

<jats:p>A multi-phase field model is established to simulate the growth competition and evolution behavior between seaweed and columnar dendrites during directional solidification. According to the effects of surface tension and interfacial energy, we quantitatively analyze the influences of factors such as inclination angles, pulling velocity, and anisotropic strength on twin growth. The results demonstrate that the pulling velocity and anisotropic strength have an important influence on the morphology and evolution of the seaweed and dendritic growth. The low pulling velocity and anisotropic strength are both key parameters for maintaining the stable morphology of seaweed during competitive growth in a bicrystal, showing that the lateral branching behavior is the root of the dendrites that can ultimately dominate the growth. And it is clarified that the lateral branching behavior and lateral blocking are the root causes of the final dominant growth of dendrites. With the increase of anisotropy strength, the seaweed is eliminated fastest in case 1, the seaweed is transformed into degenerate dendritic morphology, and eliminates the seaweed by promoting the generation and lateral growth of the lateral branches of the dendrites. The increase of pulling velocity is to increase the undercooling of favorable oriented grain and accelerate the growth rate of dendrites, thus producing more new primary dendrites for lateral expansion and accelerating the elimination rate of unfavorable oriented grain.</jats:p>

<jats:p>The reduced graphene oxide/silver selenide nanowire (rGO/Ag<jats:sub>2</jats:sub>Se NW) composite powders were fabricated via a wet chemical approach, and then flexible rGO/Ag<jats:sub>2</jats:sub>Se NW composite film was prepared by a facile vacuum filtration method combined with cold-pressing treatment. A highest power factor of 228.88 μW·m<jats:sup>−1</jats:sup>·K<jats:sup>−2</jats:sup> was obtained at 331 K for the cold-pressed rGO/Ag<jats:sub>2</jats:sub>Se NW composite film with 0.01 wt% rGO. The rGO/Ag<jats:sub>2</jats:sub>Se NW composite film revealed superior flexibility as the power factor retained 94.62% after bending for 500 times with a bending radius of 4 mm, which might be due to the interwoven network structures of Ag<jats:sub>2</jats:sub>Se NWs and pliability of rGO as well as nylon membrane. These results demonstrated that the GO/Ag<jats:sub>2</jats:sub>Se NW composite film has a potential for preparation of flexible thermoelectric devices.</jats:p>

<jats:p>Several pH-dependent processes and reactions take place in the human body; hence, the pH of body fluids is the best indicator of disturbed health conditions. However, accurate and real-time diagnosis of the pH of body fluids is complicated because of limited commercially available pH sensors. Hence, we aimed to prepare a flexible, transparent, disposable, user-friendly, and economic strip-based solid-state pH sensor using palladium nanoparticles (PdNPs)/N-doped carbon (NC) composite material. The PdNPs/NC composite material was synthesized using wool keratin (WK) as a precursor. The <jats:italic>in-situ</jats:italic> prepared PdNPs played a key role in the controlled switching of protein structure to the N-doped carbon skeleton with <jats:italic>π</jats:italic>–<jats:italic>π</jats:italic> arrangement at the mesoscale level, which mimics the A–B type polymeric structure, and hence, is highly susceptible to H<jats:sup>+</jats:sup> ions. The optimized carbonization condition in the presence of PdNPs showed that the material obtained using a modified Ag/AgCl reference electrode had the highest pH sensitivity with excellent stability and durability. The optimized pH sensor showed high specificity and selectivity with a sensitivity of 55 mV/pH unit and a relative standard deviation of 0.79%. This study is the first to synthesize PdNPs using WK as a stabilizing and reducing agent. The applicability of the sensor was investigated for biological samples, namely, saliva and gastric juices. The proposed protocol and material have implications in solid-state chemistry, where biological material will be the best choice for the synthesis of materials with anticipated performance.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Strong field ionization-photofragmentation (SFI-PF) with ultrafast pump–probe scheme is a powerful approach to study the dynamics of molecular cationic electronic states. Here we carry out a SFI-PF study on the cationic electronic states of vinyl bromide, C<jats:sub>2</jats:sub>H<jats:sub>3</jats:sub>Br. The yields of the parent C<jats:sub>2</jats:sub>H<jats:sub>3</jats:sub>Br<jats:sup>+</jats:sup> and the formation of the fragment (Br<jats:sup>+</jats:sup>, C<jats:sub>2</jats:sub>H<jats:sub>2</jats:sub> <jats:sup>+</jats:sup> and C<jats:sub>2</jats:sub>H<jats:sub>3</jats:sub> <jats:sup>+</jats:sup>) ions have been measured at different pump–probe delay time. Analysis provides experimental evidence of <jats:inline-formula> <jats:tex-math><?CDATA ${{\rm{A}}}^{2}{A}^{\prime}$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msup> <mml:mrow> <mml:mi mathvariant="normal">A</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:msup> <mml:msup> <mml:mrow> <mml:mi>A</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>′</mml:mo> </mml:mrow> </mml:msup> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_31_2_028202_ieqn1.gif" xlink:type="simple" /> </jats:inline-formula>–X<jats:sup>2</jats:sup>A<jats:sup>″</jats:sup> internal conversion of vinyl bromide cations which occurs in a time of about 220 fs, and the time of C<jats:sub>2</jats:sub>H<jats:sub>3</jats:sub> <jats:sup>+</jats:sup> formation induced by the dissociation of the <jats:inline-formula> <jats:tex-math><?CDATA ${{\rm{A}}}^{2}{A}^{\prime}$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msup> <mml:mrow> <mml:mi mathvariant="normal">A</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:msup> <mml:msup> <mml:mrow> <mml:mi>A</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>′</mml:mo> </mml:mrow> </mml:msup> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_31_2_028202_ieqn2.gif" xlink:type="simple" /> </jats:inline-formula> state around 300 fs. The study would add our knowledge of the behavior of electronic excited states of complex molecular cations.</jats:p>

<jats:p>The effects of radiation on 3CG110 PNP bipolar junction transistors (BJTs) are characterized using 50-MeV protons, 40-MeV Si ions, and 1-MeV electrons. In this paper, electrical characteristics and deep level transient spectroscopy (DLTS) are utilized to analyze radiation defects induced by ionization and displacement damage. The experimental results show a degradation of the current gain and an increase in the types of radiation defect with increasing fluences of 50-MeV protons. Moreover, by comparing the types of damage caused by different radiation sources, the characteristics of the radiation defects induced by irradiation show that 50-MeV proton irradiation can produce both ionization and displacement defects in the 3CG110 PNP BJTs, in contrast to 40-MeV Si ions, which mainly generate displacement defects, and 1-MeV electrons, which mainly produce ionization defects. This work provides direct evidence of a synergistic effect between the ionization and displacement defects caused in PNP BJTs by 50-MeV protons.</jats:p>

<jats:p>A novel 4H-SiC merged P–I–N Schottky (MPS) with floating back-to-back diode (FBD), named FBD-MPS, is proposed and investigated by the Sentaurus technology computer-aided design (TCAD) and analytical model. The FBD features a trench oxide and floating P-shield, which is inserted between the P+/N– (PN) junction and Schottky junction to eliminate the shorted anode effect. The FBD is formed by the N-drift/P-shield/N-drift and it separates the PN and Schottky active region independently. The FBD reduces not only the <jats:italic>V</jats:italic> <jats:sub>turn</jats:sub> to suppress the snapback effect but also the <jats:italic>V</jats:italic> <jats:sub>on</jats:sub> at bipolar operation. The results show that the snapback can be completely eliminated, and the maximum electric field (<jats:italic>E</jats:italic> <jats:sub>max</jats:sub>) is shifted from the Schottky junction to the FBD in the breakdown state.</jats:p>

<jats:p>A cold preamplifier based on superconducting quantum interference devices (SQUIDs) is currently the preferred readout technology for the low-noise transition edge sensor (TES). In this work, we have designed and fabricated a series SQUID array (SSA) amplifier for the TES detector readout circuit. In this SSA amplifier, each SQUID cell is composed of a first-order gradiometer formed using two equally large square washers, and an on-chip low pass filter (LPF) as a radio-frequency (RF) choke has been developed to reduce the Josephson oscillation interference between individual SQUID cells. In addition, a highly symmetric layout has been designed carefully to provide a fully consistent embedded electromagnetic environment and achieve coherent flux operation. The measured results show smooth <jats:italic>V</jats:italic>–<jats:italic>Φ</jats:italic> characteristics and a swing voltage that increases linearly with increasing SQUID cell number <jats:italic>N</jats:italic>. A white flux noise level as low as 0.28 μ <jats:italic>Φ</jats:italic> <jats:sub>0</jats:sub>/Hz<jats:sup>1/2</jats:sup> is achieved at 0.1 K, corresponding to a low current noise level of 7 pA/Hz<jats:sup>1/2</jats:sup>. We analyze the measured noise contribution at mK-scale temperatures and find that the dominant noise derives from a combination of the SSA intrinsic noise and the equivalent current noise of the room temperature electronics.</jats:p>