摘要：molecular dynamics(MD) simulations were carried out to study the fracture behaviors of several symmetric tilt grain boundaries in γ-Ti Al bicrystals with misorientation axes. Tensile deformation along direction perpendicular to grain boundary was simulated under various strain rates and temperatures. The results indicate that the relative orientation of the grains and the presence of certain atom units are two critical factors of the interface structure affecting the stress required for dislocation nucleation. Dislocations nucleate and extend at or near the symmetric tilt grain boundaries during the tensile deformation of Σ3(111) 109.5°, Σ9(221) 141.1° and Σ27(552) 148.4° interfaces. For Σ27(115) 31.6° and Σ11(113) 50.5° interfaces, the interfaces fractured directly in a cleavage manner due to no dislocation emitted from the boundary. The tensile fracture mechanisms of the bicrystals are that micro-cracks nucleate at the grain boundary and propagate along the interface. The variance of crack propagation is whether there is accommodation of plastic region at the crack tips.

摘要：Classical molecular dynamics(MD)simulations ae performed to investigate the effects of mechanical strain on the thermal conductivity of single-layer black phosphorus(SLBP)nanoribbons along different directions at room *** results show that the tensile strain afects the thermal conductivity of nanoribbons by changing thephonon density of state(DOS)and mean free path(M FP).The thermal conductivity shows a sharp enhancement with the tensile strain applied along the armchai diection,while it increases slowly with the strain applied along the zigzag *** phenomenon cm be mainly explained by effects of the phonon DOS and *** increasing strain along the armchai direction weakens DOS and strengthens MFP ***,when it comes to the increasing strain along the zigzag deection'DOS enliances significantly while MFP decreases *** findings explore the relationship between the tensile strain and the thermal conductivity reasonably and can provide a reliable method to estimate the MFP of black phosphorus.

摘要：Sintering inhibition of a catalyst at high temperatures is a challenge during heterogeneous catalysis. In this paper, we report that hexagonal boron nitride(h-BN) is an optimal material for anti-sintering γ-Al_(2)O_(3)-supported Pt nanoparticles(NPs) originating from the high thermal conductivity of h-BN. The high thermal conductivity of h-BN ensures maximal heat dissipation from Pt NPs to γ-Al_(2)O_(3),thereby causing both Ostwald ripening and particle coalescence of Pt NPs to be decelerated at elevated *** of Pt NP sintering is also shown in the reducible TiO^(2-)supported Pt NPs with the help of h-BN. The proposed anti-sintering strategy using thermal management is universal, providing new insight into the design of anti-sintering materials and structures for a wide range of applications in heterogeneous catalysis.

摘要：Large Hollow nanoparticulate aggregates（LHNAs） based on albumin nanoparticles is a promising technology for developing dry powder inhaler（DPI） with good aerodynamic properties in order to provide a new drug delivery system（DDS） for the treatment of lung disease. Improved understanding of molecular interactions could lead to prepare the DDS rationally. Therefore, this investigation utilized computations and experiments to reveal the mechanisms of budesonide（BUD） interactions with bovine serum albumin（BSA） at the molecular level. The molecular dynamics（MD） simulation revealed that there were three critical stable binding sites of BUD on BSA（P1, P2, P3） mainly by hydrophobic interaction and hydrogen bond. The energy decomposition of each residue to the whole BUD-BSA complex system in P1-P3 showed that nonpolar residues in or around the binding site played an important role in the binding of BUD to BSA. The molar ratio was close to 3 in preparations in drug-loading efficiency experiment, which was confirmed to the simulation results. The details of the binding sites from computation provided a guideline for the design of the BSA nanoparticles carrying BUD, which was prepared successfully at last. Combination of the MD simulation and experiment as well as the mechanism of the molecular interaction provided a solid theoretical basis for the preparation of BSA-LHNAs for DPI in the future.

摘要：铁电材料的力电耦合特性以及在纳米尺度的快速失效导致其剪切过程很难研究,而材料的脆性也限制了这些材料在铁电器件中的潜在应用.在这项工作中,我们使用分子动力学方法模拟了剪切和畴演变的动态过程,揭示了这些畴结构如何影响材料的力电性能.在原子尺度上,一个明显的极化旋涡状的畴结构出现在剪切带的尖端,两侧分别有180°和90°的畴壁.由应变梯度引起的挠曲电效应导致了这些复杂的畴结构.施加外部电场阻碍畴的翻转,并通过减少积累的能量减少了失配应变区域,加速了剪切过程.结果表明极化旋涡畴阻碍了剪切破坏过程,这启示我们可以通过设计畴结构来增韧铁电材料.