Three‐Dimensional Cuprous Lead Bromide Framework with Highly Efficient and Stable Blue Photoluminescence Emission

Considering the instability and low photoluminescence quantum yield (PLQY) of blue‐emitting perovskites, it is still challenging and attractive to construct single crystalline hybrid lead halides with highly stable and efficient blue light emission. Herein, by rationally introducing d¹⁰ transition metal into single lead halide as new structural building unit and optical emitting center, we prepared a bimetallic halide of [(NH₄)₂]CuPbBr₅ with new type of three‐dimensional (3D) anionic framework. [(NH₄)₂]CuPbBr₅ exhibits strong band‐edge blue emission (441 nm) with a high PLQY of 32 % upon excitation with UV light. Detailed photophysical studies indicate [(NH₄)₂]CuPbBr₅ also displays broadband red light emissions derived from self‐trapped states. Furthermore, the 3D framework features high structural and optical stabilities at extreme environments during at least three years. To our best knowledge, this work represents the first 3D non‐perovskite bimetallic halide with highly efficient and stable blue light emission.     

Chaotic resonance in Izhikevich neural network motifs under electromagnetic induction

Nonlinear Dynamics - Chaotic resonance (CR) is the response of a nonlinear system to weak signals enhanced by internal or external chaotic activity (such as the signal derived from Lorenz system)....     

Stress State of Non-Thin Nearly Circular Cylindrical Shells Made of Continuously Inhomogeneous Materials

International Applied Mechanics - The stress state of dented circular non-thin cylindrical shells under certain boundary conditions at the ends is analyzed. The shells are made of continuously...     

Bioactive PKS–NRPS Alkaloids from the Plant-Derived Endophytic Fungus Xylaria arbuscula

A novel hybrid PKS–NRPS alkaloid, xylarialoid A (1), containing a 13-membered macrocyclic moiety and [5,5,6] fused tricarbocyclic rings, together with ten known cytochalasins (2–11), was isolated from a plant-derived endophytic fungus, Xylaria arbuscula. The chemical structures of all compounds were elucidated using 1D and 2D NMR, HR ESIMS spectroscopic analyses, and electronic circular dichroism (ECD) calculation. Compounds 1–3 and 10 exhibited significant antitumor activities against A549 and Hep G2 cell lines, with IC₅₀ values of 3.6–19.6 μM. In addition, compound 1 showed potent anti-inflammatory activity against LPS-induced nitric oxide (NO) production in macrophage RAW 264.7 cells (IC₅₀, 6.6 μM).     

Energetics of stress relaxation in glassy polymers at high pressures

Kinetics of relaxation of the shear stress in glassy poly(methyl methacrylate) were studied in isobaric, isothermal and isochoric conditions. In isochoric conditions the relaxation rate depends only on temperature and polymer volume is the main parameter for the rate of stress relaxation. Isobaric and isochoric activation energies and activation volume of the stress relaxation were determined. The results are shown to satisfy the thermodynamic relation of activation parameters of the relaxation process. The size of the area in which the elementary stress relaxation process occurs in glassy poly(methyl methacrylate) was evaluated.     

Nanocomposites Based on Poly(Amide-Imide) Matrix with Na–Mg Triple Chain Hydrosilicate

Crystallography Reports - A new polymer-inorganic nanocomposite composed of fibrous Na–Mg triple chain hydrosilicate with a poly(amide-imide) matrix was developed. Its structure, morphology,...     

高速气体与椭圆柱云相互作用的数值研究

高速颗粒流在天文、自然灾害、工业安全、医疗工业和国防等领域有着重要应用。采用基于分层流模型的直接数值模拟方法,对平面激波与椭圆柱云的相互作用进行数值研究,重点关注椭圆柱横截面的不同长短轴之比和椭圆柱横截面长轴与来流方向所成角度对流场的影响,从气体来流方向上的速度、x轴和y轴方向上的均方根速度、动能、内能和湍动能的分布上进行分析,对能量在计算域的上游区域、椭圆柱云区域和下游区域进行定量分析。同时针对椭圆柱改进了一维体积平均模型,利用该模型拟合了由直接数值模拟得到的反射激波和透射激波位置,获得了最适配的一维体积平均模型中的人工有效阻力系数,并探讨此系数的分布规律。     

High-Quality AlN Layers Grown on Si(111) Substrates by Metalorganic Chemical Vapor Deposition

Crystallography Reports - The effect of trimethylaluminum preflow time on the crystalline quality of AlN films grown by metalorganic chemical vapor deposition on Si(111) substrates has been...     

Fully distributed spherical formation tracking control for nonlinear vehicles with spatiotemporal uncertainties and digraphs

Nonlinear Dynamics - This paper addresses the spherical formation tracking control problem of nonlinear vehicles under digraphs, where the dynamics of vehicle contains spatiotemporal uncertainties...