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<jats:p>We demonstrate digital and analog devices with an Ag/<jats:italic>M</jats:italic>PS<jats:sub>3</jats:sub>/Au structure based on layered <jats:italic>M</jats:italic>PS<jats:sub>3</jats:sub> (<jats:italic>M</jats:italic> = Mn, Co, Ni) 2D materials. All devices show the bipolar behavior of resistive switching. In addition, Ag/MnPS<jats:sub>3</jats:sub>/Au and Ag/NiPS<jats:sub>3</jats:sub>/Au devices show synaptic characteristics of potentiation and depression. The digital and analog characteristics of resistance states enable Ag/<jats:italic>M</jats:italic>PS<jats:sub>3</jats:sub>/Au devices to work as both binary memory and artificial synapse devices. The Ag/<jats:italic>M</jats:italic>PS<jats:sub>3</jats:sub>/Au memory devices are promising for applications of flexible eye-like and brain-like systems on a chip when they are integrated with photodetectors and FETs composed of full <jats:italic>M</jats:italic>PS<jats:sub>3</jats:sub> materials.</jats:p>

<jats:p>Bulk anisotropic Sm<jats:sub>2</jats:sub>Co<jats:sub>7</jats:sub> nanocrystalline magnets were successfully prepared by hot deformation process using spark plasma sintering technology. The coercivity of the isotropic Sm<jats:sub>2</jats:sub>Co<jats:sub>7</jats:sub> nanocrystalline magnet is 34.76 kOe, further, the ultra-high coercivity of 50.68 kOe is obtained in the anisotropic hot deformed Sm<jats:sub>2</jats:sub>Co<jats:sub>7</jats:sub> magnet when the height reduction is 70%, which is much higher than those of the ordinarily produced hot deformed Sm<jats:sub>2</jats:sub>Co<jats:sub>7</jats:sub> magnet. X-ray diffraction (XRD) analysis shows that all the samples are Sm<jats:sub>2</jats:sub>Co<jats:sub>7</jats:sub> single phase. The investigation by electron backscatter diffraction indicates that increasing the amount of deformation is beneficial to the improvement of the (00l) texture of Sm<jats:sub>2</jats:sub>Co<jats:sub>7</jats:sub> magnets. The Sm<jats:sub>2</jats:sub>Co<jats:sub>7</jats:sub> nanocrystalline magnet generates a strong <jats:italic>c</jats:italic>-axis crystallographic texture during large deformation process.</jats:p>

<jats:p>The optical properties of AlGaN-based quantum well (QW) structure with two coupled thin well layers are investigated by the six-by-six <jats:italic> <jats:bold>K</jats:bold> </jats:italic>–<jats:italic> <jats:bold>P</jats:bold> </jats:italic> method. Compared with the conventional structure, the new structure, especially the one with lower Al-content in the barrier layer, can enhance the TE-/TM-polarized total spontaneous emission rate due to the strong quantum confinement and wide recombination region. For the conventional QW structure, the reduction of well thickness can lead the degree of polarization (DOP) to decrease and the internal quantum efficiency (IQE) to increase. By using the coupled thin well layers, the DOP for the structure with high Al-content in the barrier layer can be improved, while the DOP will further decrease with low Al-content in the barrier layer. It can be attributed to the band adjustment induced by the combination of barrier height and well layer coupling. The IQE can also be further enhanced to 14.8%–20.5% for various Al-content of barrier layer at <jats:italic>J</jats:italic> = 100 A/cm<jats:sup>2</jats:sup>. In addition, the efficiency droop effect can be expected to be suppressed compared with the conventional structure.</jats:p>

<jats:p>The adsorption of CO<jats:sub>2</jats:sub> on MgAl layered double hydroxides (MgAl-LDHs) based adsorbents has been an effective way to capture CO<jats:sub>2</jats:sub>, however the adsorption capacity was hampered due to the pore structure and the dispersibility of adsorption active sites. To address the problem, we investigate the effect of intercalated anion and alkaline etching time on the structure, morphology and CO<jats:sub>2</jats:sub> uptake performances of MgAl-LDHs. MgAl-LDHs are synthesized by the one-pot hydrothermal method, followed by alkaline etching of NaOH, and characterized by x-ray diffraction, N<jats:sub>2</jats:sub> adsorption, scanning electron microscopy and Fourier transform infrared spectroscopy. The CO<jats:sub>2</jats:sub> adsorption tests of the samples are performed on a thermogravimetric analyzer, and the adsorption data are fitted by the first-order, pseudo-second-order and Elovich models, respectively. The results demonstrate that among the three intercalated samples, MgAl(Cl) using chloride salts as precursors possesses the highest adsorption capacity of CO<jats:sub>2</jats:sub>, owing to high crystallinity and porous structure, while MgAl(Ac) employing acetate salts as precursors displays the lowest CO<jats:sub>2</jats:sub> uptake because of poor crystallinity, disorderly stacked structure and unsatisfactory pore structure. With regard to alkaline etching, the surface of the treated MgAl(Cl) is partly corroded, thus the specific surface area and pore volume increase, which is conducive to the exposure of adsorption active sites. Correspondingly, the adsorption performance of the alkaline-etched adsorbents is significantly improved, and MgAl(Cl)-6 has the highest CO<jats:sub>2</jats:sub> uptake. With the alkaline etching time further increasing, the CO<jats:sub>2</jats:sub> adsorption capacity of MgAl(Cl)-9 sharply decreases, mainly due to the collapse of pore structure and the fragmentized sheet-structure. Hence, the CO<jats:sub>2</jats:sub> adsorption performance is greatly influenced by alkaline etching time, and appropriate alkaline etching time can facilitate the contact between CO<jats:sub>2</jats:sub> molecules and the adsorbent.</jats:p>

<jats:p>Epitaxial growth on transition metal surfaces is an effective way to prepare large-area and high-quality graphene. However, the strong interaction between graphene and metal substrates suppresses the intrinsic excellent properties of graphene and the conductive metal substrates also hinder its applications in electronics. Here we demonstrate the decoupling of graphene from metal substrates by germanium oxide intercalation. Germanium is firstly intercalated into the interface between graphene and Ir(111) substrate. Then oxygen is subsequently intercalated, leading to the formation of a GeO<jats:sub> <jats:italic>x</jats:italic> </jats:sub> layer, which is confirmed by x-ray photoelectron spectroscopy. Low-energy electron diffraction and scanning tunneling microscopy studies show intact carbon lattice of graphene after the GeO<jats:sub> <jats:italic>x</jats:italic> </jats:sub> intercalation. Raman characterizations reveal that the intercalated layer effectively decouples graphene from the Ir substrate. The transport measurements demonstrate that the GeO<jats:sub> <jats:italic>x</jats:italic> </jats:sub> layer can act as a tunneling barrier in the fabricated large-area high-quality vertical graphene/GeO<jats:sub> <jats:italic>x</jats:italic> </jats:sub>/Ir heterostructure.</jats:p>

<jats:p>We investigate the microphase transition of asymmetric diblock copolymer induced by nanorods of different properties using cell dynamics simulation and Brown dynamics. The results show the phase diagram and representative nanostructures of the diblock copolymer nanocomposite. Various structures such as sea-island structure (SI), sea-island and lamellar structure (SI-L), and lamellar structure (L) are observed in the phase diagram. The system undergoes phase transition from SI-L to SI or from L to SI with increasing length of A-like sites for all numbers of nanorods except 10 and 300, and from SI to L with increasing number of nanorods for all lengths of A-like sites. Notably, the polymer system transforms from a tilted layered structure to a parallel lamellar, perpendicular lamellar, and subsequently sea-island structure with increasing length of A-like sites for a rod number of 240. To gain more detailed insight into these structural formation mechanisms, we analyze the evolution kinetics of the system with various lengths of A-like sites of the rods. The pattern evolution and domain growth of the ordered parallel/perpendicular lamellar structure are also investigated. Furthermore, the effects of the wetting strength, rod-rod interaction, polymerization degree, and length of nanorods on the self-assembled structure of asymmetric diblock copolymer/nanorods are studied. Our simulations provide theoretical guidance on the construction of complex-assembled structures and the design of novel functional materials.</jats:p>

<jats:p>Frequency combs are useful in a wide range of applications, such as optical metrology and high-precision spectroscopy. We experimentally study a controllable frequency comb generated in a tunable superconducting coplanar-waveguide resonator in the microwave regime. A two-tone drive is applied on one of the resonance modes of the resonator and comb generation is observed around the resonance frequency of the resonator. Both central frequency and teeth density of the comb are precisely controllable, and the teeth spacing can be adjusted from Hz to MHz. Moreover, we show that a few hundreds of sidebands can be generated using a sufficiently strong drive power and the weakest drive power needed to generate the comb can be reduced to approach the quantum limit. These experimental results can be qualitatively explained via theoretical analysis.</jats:p>

<jats:p>A novel silicon carbide (SiC) on silicon (Si) heterojunction lateral double-diffused metal–oxide semiconductor field-effect transistor with p-type buried layer (PBL Si/SiC LDMOS) is proposed in this paper for the first time. The heterojunction has breakdown point transfer (BPT) characteristics, and the BPT terminal technology is used to increase the breakdown voltage (<jats:italic>BV</jats:italic>) of Si/SiC LDMOS with the deep drain region. In order to further optimize the surface lateral electric field distribution of Si/SiC LDMOS with the deep drain region, the p-type buried layer is introduced in PBL Si/SiC LDMOS. The vertical electric field is optimized by Si/SiC heterojunction and the surface lateral electric field is optimized by the p-type buried layer, which greatly improves the <jats:italic>BV</jats:italic> of device and alleviates the relationship between <jats:italic>BV</jats:italic> and specific on-resistance (<jats:italic>R</jats:italic> <jats:sub>on,sp</jats:sub>). Through TCAD simulation, when the drift region length is 20 μm, the <jats:italic>BV</jats:italic> is significantly improved from 249 V for the conventional Si LDMOS to 440 V for PBL Si/SiC LDMOS, increased by 77%; And the <jats:italic>BV</jats:italic> is improved from 384 V for Si/SiC LDMOS with the deep drain region to 440 V for the proposed structure, increased by 15%. The figure-of-merit <jats:italic>(FOM</jats:italic>) of the Si/SiC LDMOS with the deep drain region and PBL Si/SiC LDMOS are 4.26 MW/cm<jats:sup>2</jats:sup> and 6.37 MW/cm<jats:sup>2</jats:sup>, respectively. For the PBL Si/SiC LDMOS with the drift length of 20 μm, the maximum <jats:italic>FOM</jats:italic> is 6.86 MW/cm<jats:sup>2</jats:sup>. The PBL Si/SiC LDMOS breaks conventional silicon limit.</jats:p>

<jats:p>Doping concentration and thickness of an epitaxy layer are the most essential parameters for power devices. The conventional algorithm extracts these two parameters by calculating the doping profile from its capacitance-voltage (<jats:italic>C</jats:italic>–<jats:italic>V</jats:italic>) characteristics. Such an algorithm treats the device as a parallel-plane junction and ignores the influence of the terminations. The epitaxy layer doping concentration tends to be overestimated and the thickness underestimated. In order to obtain the epitaxy layer parameters with higher accuracy, a new algorithm applicable for devices with field limited ring (FLR) terminations is proposed in this paper. This new algorithm is also based on the <jats:italic>C</jats:italic>–<jats:italic>V</jats:italic> characteristics and considers the extension manner of the depletion region under the FLR termination. Such an extension manner depends on the design parameters of the FLR termination and is studied in detail by simulation and modeling. The analytical expressions of the device <jats:italic>C</jats:italic>–<jats:italic>V</jats:italic> characteristics and the effective doping profile are derived. More accurate epitaxy layer parameters can be extracted by fitting the effective doping profile expression to the <jats:italic>C</jats:italic>–<jats:italic>V</jats:italic> doping profile calculated from the <jats:italic>C</jats:italic>–<jats:italic>V</jats:italic> characteristics. The relationship between the horizontal extension width and the vertical depth of the depletion region is also acquired. The credibility of the new algorithm is verified by experiments. The applicability of our new algorithm to FLR/field plate combining terminations is also discussed. Our new algorithm acts as a powerful tool for analyses and improvements of power devices.</jats:p>

<jats:p>Individuals’ preventive measures, as an effective way to suppress epidemic transmission and to protect themselves from infection, have attracted much academic concern, especially during the COVID-19 pandemic. In this paper, a reinforcement learning-based model is proposed to explore individuals’ effective preventive measures against epidemics. Through extensive simulations, we find that the cost of preventive measures influences the epidemic transmission process significantly. The infection scale increases as the cost of preventive measures grows, which means that the government needs to provide preventive measures with low cost to suppress the epidemic transmission. In addition, the effective preventive measures vary from individual to individual according to the social contacts. Individuals who contact with others frequently in daily life are highly recommended to take strict preventive measures to protect themselves from infection, while those who have little social contacts do not need to take any measures considering the inevitable cost. Our research contributes to exploring the effective measures for individuals, which can provide the government and individuals useful suggestions in response to epidemics.</jats:p>