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<jats:p>The decomposition reaction of phosphate rock under the action of microwave plasma was investigated. Phosphate rock and its decomposition products were characterized by x-ray diffraction (XRD), energy disperse spectroscopy (EDS), and chemical analysis. The measurements of electron temperature (<jats:italic>T</jats:italic> <jats:sub>e</jats:sub>) and electron density (<jats:italic>N</jats:italic> <jats:sub>e</jats:sub>) of plasma plume under atmospheric pressure were carried out using optical emission spectroscopy(OES). The electron temperature (<jats:italic>T</jats:italic> <jats:sub>e</jats:sub>) was determined based on the calculation of the relative intensity of the O II (301.91 nm) and O II (347.49 nm) spectral lines. Correspondingly, electron densities were obtained using the Saha ionization equation which was based on the C I (247.86 nm) line and the C II (296.62 nm) line under the assumption of local thermodynamic equilibrium (LTE). The relationship between the relative intensity of the active components and the gas output was studied by the spectrometer. Finally the reaction mechanism of the decomposition of the phosphate rock under the action of the atmospheric pressure microwave plasma was proposed. The results showed that with the increase of CO flow and microwave power, the electron temperature and electron density in the plasma show a decreasing and increasing trend. The CO is dissociated into gaseous carbon ions under the action of microwave plasma, and the presence of gaseous carbon ions promotes the decomposition of the phosphate rock.</jats:p>

<jats:p>Pulse inductively coupled plasma has been widely used in the microelectronics industry, but the existence of overshoot phenomenon may affect the uniformity of plasma and generate high-energy ions, which could damage the chip. The overshoot phenomenon at various spatial locations in pulsed inductively coupled Ar and Ar/CF<jats:sub>4</jats:sub> discharges is studied in this work. The electron density, effective electron temperature, relative light intensity, and electron energy probability function (EEPF) are measured by using a time-resolved Langmuir probe and an optical probe, as a function of axial and radial locations. At the initial stage of pulse, both electron density and relative light intensity exhibit overshoot phenomenon, <jats:italic>i.e.</jats:italic>, they first increase to a peak value and then decrease to a convergent value. The overshoot phenomenon gradually decays, when the probe moves away from the coils. Meanwhile, a delay appears in the variation of the electron densities, and the effective electron temperature decreases, which may be related to the reduced strength of electric field at a distance, and the consequent fewer high-energy electrons, inducing limited ionization and excitation rate. The overshoot phenomenon gradually disappears and the electron density decreases, when the probe moves away from reactor centre. In Ar/CF<jats:sub>4</jats:sub> discharge, the overshoot phenomenon of electron density is weaker than that in the Ar discharge, and the plasma reaches a steady density within a much shorter time, which is probably due to the more ionization channels and lower ionization thresholds in the Ar/CF<jats:sub>4</jats:sub> plasma.</jats:p>

<jats:p>The attenuation characteristics of obliquely incident electromagnetic (EM) wave in L-Ka frequency band in weakly ionized dusty plasma are analyzed based on the modified Bhatnagar–Gross–Krook (BGK) collision model. According to the kinetic equation and the charging theory, the total complex dielectric constant of the weakly ionized dusty plasma is derived by considering that the minimum velocity of the electron accessible to the dust particle surface is non-zero and the second potential part of the collision cross-section contributes to the charging. The attenuation characteristics within the modified model are compared with those within the traditional model. The influence of the dusty plasma parameters and the incident angle of EM waves on the attenuation in weakly ionized dusty plasma is further analyzed. Finally, the influence of different reentry heights on the attenuation characteristics of the obliquely incident EM wave is discussed. The results show that the effect of the minimum electron velocity and the second term of the collision cross-section on the attenuation characteristics of EM waves cannot be ignored. When the dust density and dust radius are changed, the trends of the attenuation of obliquely incident EM waves are consistent, but the influence of dust density is weaker than that of dust radius due to the constraint of orbit-limited motion (OLM) theory. The plasma thickness, electron density, and incident angle are proportional to the attenuation amplitude of EM waves. The effect of different reentry heights on the attenuation obliquely incident EM waves is related to the electron density and plasma thickness.</jats:p>

<jats:p>Using the calypso algorithm with first-principles calculations, we have predicted two orthorhombic <jats:italic>Cmmm</jats:italic> and <jats:italic>Pmmm</jats:italic> structures for YB<jats:sub>3</jats:sub>. The new structures are energetically much better than the previously proposed WB<jats:sub>3</jats:sub>-type, ReB<jats:sub>3</jats:sub>-type, FeB<jats:sub>3</jats:sub>-type, and TcP<jats:sub>3</jats:sub>-type structures. We find that the <jats:italic>Cmmm</jats:italic> phase transforms to the <jats:italic>Pmmm</jats:italic> phase at about 31 GPa. Subsequent calculations show that the <jats:italic>Cmmm</jats:italic> phase is mechanical and dynamical stable at ambient conditions. The analysis of the chemical bonding properties indicates that there are strong B–B bonds that make considerable contributions to its stability.</jats:p>

<jats:p>First-principles calculations are performed to investigate the effect of strain on the electrochemical performance of Janus MoSSe monolayer. The calculation focuses on the specific capacity, intercalation potential, electronic structure, and migration behavior of Li-ion under various strains by using the climbing-image nudged elastic band method. The result shows that the specific capacity is nearly unchanged under strain. But interestingly, the tensile strain can cause the intercalation potential and Li-ion migration energy barrier increase in MoSSe monolayer, whereas the compressive strain can lead to the intercalation potential and energy barrier decreasing. Thus, the rate performance of the MoSSe anode is improved. By analyzing the potential energy surface of MoSSe surface and equilibrium adsorption distance of Li-ion, we explain the physical origin of the change in the intercalation potential and migration energy barrier. The increase of MoSSe potential energy surface and the decrease of adsorption distance caused by tensile strain are the main reason that hinders Li-ion migration.</jats:p>

<jats:p>When developing high performance lithium-ion batteries, high capacity is one of the key indicators. In the last decade, the progress of two-dimensional (2D) materials has provided new opportunities for boosting the storage capacity. Here, based on first-principles calculation method, we predict that MnN monolayer, a recently proposed 2D nodal-loop half-metal containing the metallic element Mn, can be used as a super high-capacity lithium-ion batteries anode. Its theoretical capacity is above 1554 mA⋅h/g, more than four times that of graphite. Meanwhile, it also satisfies other requirements for a good anode material. Specifically, we demonstrate that MnN is mechanically, dynamically, and thermodynamically stable. The configurations before and after lithium adsorption exhibit good electrical conductivity. The study of Li diffusion on its surface reveals a very low diffusion barrier (∼ 0.12 eV), indicating excellent rate performance. The calculated average open-circuit voltage of the corresponding half-cell at full charge is also very low (∼ 0.22 V), which facilitates higher operating voltage. In addition, the lattice changes of the material during lithium intercalation are very small (∼ 1.2%–∼ 4.8%), which implies good cycling performance. These results suggest that 2D MnN can be a very promising anode material for lithium-ion batteries.</jats:p>

<jats:p>Based on the density functional theory (DFT) calculations, we showed that the interactions between different valence anions (<jats:inline-formula> <jats:tex-math><?CDATA ${{\rm{PO}}}_{4}^{3-}$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msubsup> <mml:mrow> <mml:mi mathvariant="normal">PO</mml:mi> </mml:mrow> <mml:mn>4</mml:mn> <mml:mrow> <mml:mn>3</mml:mn> <mml:mo>−</mml:mo> </mml:mrow> </mml:msubsup> </mml:mrow> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_30_4_046801_ieqn1.gif" xlink:type="simple" /> </jats:inline-formula>, <jats:inline-formula> <jats:tex-math><?CDATA ${{\rm{CH}}}_{3}{{\rm{PO}}}_{4}^{2-}$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi mathvariant="normal">CH</mml:mi> </mml:mrow> <mml:mn>3</mml:mn> </mml:msub> <mml:msubsup> <mml:mrow> <mml:mi mathvariant="normal">PO</mml:mi> </mml:mrow> <mml:mn>4</mml:mn> <mml:mrow> <mml:mn>2</mml:mn> <mml:mo>−</mml:mo> </mml:mrow> </mml:msubsup> </mml:mrow> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_30_4_046801_ieqn2.gif" xlink:type="simple" /> </jats:inline-formula>, <jats:inline-formula> <jats:tex-math><?CDATA ${({{\rm{CH}}}_{3})}_{2}{{\rm{PO}}}_{4}^{-}$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mrow> <mml:mo stretchy="false">(</mml:mo> <mml:msub> <mml:mrow> <mml:mi mathvariant="normal">CH</mml:mi> </mml:mrow> <mml:mn>3</mml:mn> </mml:msub> <mml:mo stretchy="false">)</mml:mo> </mml:mrow> <mml:mn>2</mml:mn> </mml:msub> <mml:msubsup> <mml:mrow> <mml:mi mathvariant="normal">PO</mml:mi> </mml:mrow> <mml:mn>4</mml:mn> <mml:mo>−</mml:mo> </mml:msubsup> </mml:mrow> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_30_4_046801_ieqn3.gif" xlink:type="simple" /> </jats:inline-formula>) and graphene significantly increased as the valence of anion increased from negative monovalence to negative trivalence. The adsorption energy of <jats:inline-formula> <jats:tex-math><?CDATA ${({{\rm{CH}}}_{3})}_{2}{{\rm{PO}}}_{4}^{-}$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mrow> <mml:mo stretchy="false">(</mml:mo> <mml:msub> <mml:mrow> <mml:mi mathvariant="normal">CH</mml:mi> </mml:mrow> <mml:mn>3</mml:mn> </mml:msub> <mml:mo stretchy="false">)</mml:mo> </mml:mrow> <mml:mn>2</mml:mn> </mml:msub> <mml:msubsup> <mml:mrow> <mml:mi mathvariant="normal">PO</mml:mi> </mml:mrow> <mml:mn>4</mml:mn> <mml:mo>−</mml:mo> </mml:msubsup> </mml:mrow> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_30_4_046801_ieqn4.gif" xlink:type="simple" /> </jats:inline-formula> on the electron-rich graphene flake (C<jats:sub>84</jats:sub>H<jats:sub>24</jats:sub>) is −8.3 kcal/mol. The adsorption energy of <jats:inline-formula> <jats:tex-math><?CDATA ${{\rm{CH}}}_{3}{{\rm{PO}}}_{4}^{2-}$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi mathvariant="normal">CH</mml:mi> </mml:mrow> <mml:mn>3</mml:mn> </mml:msub> <mml:msubsup> <mml:mrow> <mml:mi mathvariant="normal">PO</mml:mi> </mml:mrow> <mml:mn>4</mml:mn> <mml:mrow> <mml:mn>2</mml:mn> <mml:mo>−</mml:mo> </mml:mrow> </mml:msubsup> </mml:mrow> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_30_4_046801_ieqn5.gif" xlink:type="simple" /> </jats:inline-formula> on the electron-rich graphene flake (C<jats:sub>84</jats:sub>H<jats:sub>24</jats:sub>) is –48.0 kcal/mol, which is about six times that of <jats:inline-formula> <jats:tex-math><?CDATA ${({{\rm{CH}}}_{3})}_{2}{{\rm{PO}}}_{4}^{-}$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mrow> <mml:mo stretchy="false">(</mml:mo> <mml:msub> <mml:mrow> <mml:mi mathvariant="normal">CH</mml:mi> </mml:mrow> <mml:mn>3</mml:mn> </mml:msub> <mml:mo stretchy="false">)</mml:mo> </mml:mrow> <mml:mn>2</mml:mn> </mml:msub> <mml:msubsup> <mml:mrow> <mml:mi mathvariant="normal">PO</mml:mi> </mml:mrow> <mml:mn>4</mml:mn> <mml:mo>−</mml:mo> </mml:msubsup> </mml:mrow> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_30_4_046801_ieqn6.gif" xlink:type="simple" /> </jats:inline-formula> adsorption on electron-rich graphene flake (C<jats:sub>84</jats:sub>H<jats:sub>24</jats:sub>) and is even much larger than that of <jats:inline-formula> <jats:tex-math><?CDATA ${{\rm{CO}}}_{3}^{2-}$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msubsup> <mml:mrow> <mml:mi mathvariant="normal">CO</mml:mi> </mml:mrow> <mml:mn>3</mml:mn> <mml:mrow> <mml:mn>2</mml:mn> <mml:mo>−</mml:mo> </mml:mrow> </mml:msubsup> </mml:mrow> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_30_4_046801_ieqn7.gif" xlink:type="simple" /> </jats:inline-formula> adsorption on electron-deficient aromatic ring C<jats:sub>6</jats:sub>F<jats:sub>6</jats:sub> (–28.4 kcal/mol). The adsorption energy of <jats:inline-formula> <jats:tex-math><?CDATA ${{\rm{PO}}}_{4}^{3-}$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msubsup> <mml:mrow> <mml:mi mathvariant="normal">PO</mml:mi> </mml:mrow> <mml:mn>4</mml:mn> <mml:mrow> <mml:mn>3</mml:mn> <mml:mo>−</mml:mo> </mml:mrow> </mml:msubsup> </mml:mrow> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_30_4_046801_ieqn8.gif" xlink:type="simple" /> </jats:inline-formula> on the electron-rich graphene flake (C<jats:sub>84</jats:sub>H<jats:sub>24</jats:sub>) is –159.2 kcal/mol, which is about 20 times that of <jats:inline-formula> <jats:tex-math><?CDATA ${({{\rm{CH}}}_{3})}_{2}{{\rm{PO}}}_{4}^{-}$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mrow> <mml:mo stretchy="false">(</mml:mo> <mml:msub> <mml:mrow> <mml:mi mathvariant="normal">CH</mml:mi> </mml:mrow> <mml:mn>3</mml:mn> </mml:msub> <mml:mo stretchy="false">)</mml:mo> </mml:mrow> <mml:mn>2</mml:mn> </mml:msub> <mml:msubsup> <mml:mrow> <mml:mi mathvariant="normal">PO</mml:mi> </mml:mrow> <mml:mn>4</mml:mn> <mml:mo>−</mml:mo> </mml:msubsup> </mml:mrow> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_30_4_046801_ieqn9.gif" xlink:type="simple" /> </jats:inline-formula> adsorption on the graphene flake (C<jats:sub>84</jats:sub>H<jats:sub>24</jats:sub>). The super-strong adsorption energy is mainly attributed to the orbital interactions between multivalent anions and graphene. This work provides new insights for understanding the interaction between multivalent anions and <jats:italic>π</jats:italic>–electron-rich carbon-based nanomaterials and is helpful for the design of graphene-based DNA biosensor.</jats:p>

<jats:p>Recently, metal–graphene nanocomposite system has aroused much interest due to its radiation tolerance behavior. However, the related atomic mechanism for the metal–graphene interface is still unknown. Further, stainless steels with Fe as main matrix are widely used in nuclear systems. Therefore, in this study, the atomic behaviors of point defects and helium (He) atoms at the Fe(110)–graphene interface are investigated systematically by first principles calculations. The results indicate that graphene interacts strongly with the Fe(110) substrate. In comparison with those of the original graphene and bulk Fe, the formation energy values of C vacancies and Fe point defects decrease significantly for Fe(110)–graphene. However, as He atoms have a high migration barrier and large binding energy at the interface, they are trapped at the interface once they enter into it. These theoretical results suggest that the Fe(110)–graphene interface acts as a strong sink that traps defects, suggesting the potential usage of steel–graphene with multiply interface structures for tolerating the radiation damage.</jats:p>

<jats:p>The MAPbI<jats:sub>3</jats:sub> (110) surface with low indices of crystal face is a stable and highly compatible photosensitive surface. Since the electronic states on the surface can be detrimental to the photovoltaic efficiency of the device, they should be passivated. Phenylethylamine (PEA<jats:sup>+</jats:sup>), as a molecular ligand, has been widely used in continuous degradation and interfacial charge recombination experiments, and has satisfactory performance in improving surface defects. Therefore, we construct an adsorption model of MAPbI<jats:sub>3</jats:sub> with small molecules, calculating the lattice structure and electronic properties of PEA<jats:sup>+</jats:sup>-adsorbed MAPbI<jats:sub>3</jats:sub> (110) surface. It is found that PEA<jats:sup>+</jats:sup> as a passivator can effectively weaken the electronic states and regulate the band gap of the MAPbI<jats:sub>3</jats:sub> (110) surface. Before and after adding the passivator, the peak value of electronic state densities at MAPbI<jats:sub>3</jats:sub> (110) surface is reduced by about 50%, and the band gap is apparently reduced. Moreover, by comparing the Bader atomic charge and spatial charge distributions before and after PEA<jats:sup>+</jats:sup>’s adsorption on the surface of MAPbI<jats:sub>3</jats:sub>, we observe a substantial change of PEA<jats:sup>+</jats:sup> charges, which suggests the surface states have been passivated by PEA<jats:sup>+</jats:sup>.</jats:p>

<jats:p>The degradation mechanisms of enhancement-mode p-GaN gate AlGaN/GaN high-electron mobility transistor was analyzed extensively, by means of drain voltage stress and gate bias stress. The results indicate that: (i) High constant drain voltage stress has only a negligible impact on the device electrical parameters, with a slightly first increase and then decrease in output current; (ii) A negative shift of threshold voltage and increased output current were observed in the device subjected to forward gate bias stress, which is mainly ascribed to the hole-trapping induced by high electric field across the p-GaN/AlGaN interface; (iii) The analyzed device showed an excellent behavior at reverse gate bias stress, with almost unaltered threshold voltage, output current, and gate leakage current, exhibiting a large gate swing in the negative direction. The results are meaningful and valuable in directing the process optimization towards a high voltage and high reliable enhanced AlGaN/GaN high-electron mobility transistor.</jats:p>