Fabrication of titania nanocoatings on ZnS-type phosphors using the titanium diethanolamine as the precursor in an aqueous solution

The titania nanocoatings on ZnS: Ag, Cl phosphors were successfully obtained by the sol–gel process in an aqueous solution using the titanium diethanolamine complex as the precursor. The titanium diethanolamine complex was prepared with diethanolamine (DEA) and titanium butoxide at the temperature of 120 °C. The nanocoatings synthesized by this technique were uniform and continuous with a thickness of about 10–15 nm, and the photoluminescent (PL) spectra showed that no other luminescent center was introduced. The titania coatings with an appropriate thickness were expected to prevent the degradation of ZnS phosphors in field emission displays (FEDs).     

Metastable Hexagonal Phase SnO2 Nanoribbons with Active Edge Sites for Efficient Hydrogen Peroxide Electrosynthesis in Neutral Media

Electrochemical two-electron oxygen reduction reaction (2 e⁻ ORR) to produce hydrogen peroxide (H₂O₂) is a promising alternative to the energetically intensive anthraquinone process. However, there remain challenges in designing 2 e⁻ ORR catalysts that meet the application criteria. Here, we successfully adopt a microwave-assisted mechanochemical-thermal approach to synthesize hexagonal phase SnO₂ (h-SnO₂) nanoribbons with largely exposed edge structures. In 0.1 M Na₂SO₄ electrolyte, the h-SnO₂ catalysts achieve the excellent H₂O₂ selectivity of 99.99 %. Moreover, when employed as the catalyst in flow cell devices, they exhibit a high yield of 3885.26 mmol g⁻¹ h⁻¹. The enhanced catalytic performance is attributed to the special crystal structure and morphology, resulting in abundantly exposed edge active sites to convert O₂ to H₂O₂, which is confirmed by density functional theory calculations.     

Tetralithio Metalla‐aromatics with Two Independent Perpendicular Dilithio Aromatic Rings Spiro‐fused by One Manganese Atom

Herein, we present the realization of a class of unprecedented aromatic structures 2 : metalla‐aromatics with two independent and perpendicular aromatic rings spiro‐fused by a transition‐metal spiro atom, of which their corresponding organic analogues are impossible. Tetralithio spiro manganacycles 2 are readily synthesized from 1,4‐dilithio‐1,3‐butadienes 1 and MnCl₂ in the presence of lithium. The aromaticity of 2 is supported by experimental measurements (X‐ray structural analysis, NMR) and theoretical analyses (NICS, ACID, MOs). The spiro atom Mn in 2 uses its 3d_xz and 3d_xy orbitals to form the two perpendicular manganacycles, which are two independent 6π aromatic systems. Theoretical analyses reveal that the Li cations play an indispensable role in governing their geometric and electronic structures and hence their aromaticity. Therefore, this work contributes not only to enrich the concept of aromaticity, but also to deepen the understanding of the fundamental chemical bonding.     

Electrochemical non-enzymatic glucose sensors based on nano-composite of Co3O4 and multiwalled carbon nanotube

Nanocomposite of Co₃O₄ and MCNT was synthesised using one step solvothermal method, and an electrochemical non-enzymatic glucose sensor (Co₃O₄-MCNT/GCE) was successfully constructed. This sensor was used successfully for the quantitative analysis of trace glucose in serum sample.     

Tumor‐Microenvironment‐Induced Degradation of Ultrathin Gadolinium Oxide Nanoscrolls for Magnetic‐Resonance‐Imaging‐Monitored,Activatable Cancer Chemotherapy

The development of biodegradable inorganic nanoparticles with a tumor microenvironment‐activated therapeutic mode of action is urgently needed for precision cancer medicine. Herein, the synthesis of ultrathin lanthanide nanoscrolls (Gd₂O₃ NSs) is reported, which biodegrade upon encountering the tumor microenvironment. The Gd₂O₃ NSs showed highly controlled magnetic properties, which enabled their high‐resolution magnetic resonance imaging (MRI). Importantly, Gd₂O₃ NSs degrade in a pH‐responsive manner and selectively penetrate tumor tissue, enabling the targeted release of anti‐cancer drugs. Gd₂O₃ NSs can be efficiently loaded with an anti‐cancer drug (DOX, 80 %) and significantly inhibit tumor growth with negligible cellular and tissue toxicity both in vitro and in vivo. This study may provide a novel strategy to design tumor microenvironment‐responsive inorganic nanomaterials for biocompatible bioimaging and biodegradation‐enhanced cancer therapy.     

Boron nitride nanotubes composed of four- and eight-membered rings

The properties of boron nitride nanotubes composed of four- and eight-membered rings (referred to as four-eight-membered rings BNNTs) were calculated using density functional theory (DFT). The calculated results show that the band gap of the four-eight-membered rings BNNTs is greatly reduced, down to a range of 2.530–3.975 eV. The band gap decreases as the number of walls increases, not only enabling the allotropes to show semiconductor properties but also to fully meet the third-generation semiconductor band gap requirements, furthermore, the band gap decreases significantly with the number of walls increases.     

延迟Min(N,D)-策略的M/G/1排队系统的队长分布与数值计算

考虑延迟Min(N, D)-策略的M/G/1排队系统. 运用更新过程理论、全概率分解技术和Laplace变换工具, 从任意初始状态出发, 研究了队长的瞬态和稳态性质, 获得了瞬态队长分布的Laplace变换的递推表达式和稳态队长分布的递推表达式, 同时求出了附加队长分布的显示表达式. 进一步讨论了当N \to \infty, 或D \to \infty, 或N=1且P{Y=0}=1, 或P{Y=0}=1时的特殊情形. 最后通过数值实例, 讨论了稳态队长分布对系统参数的敏感性, 并阐述了稳态队长分布的表达式在系统容量优化设计中的重要价值.     

线性Boussinesq方程的色散量子化现象

为研究线性Boussinesq方程的周期初边值问题解在大波数条件下的渐近行为,通过将方程解表示成Fourier级数形式,利用Matlab软件进行数值模拟.结果表明:方程色散关系的渐近行为对方程解在大波数条件下的渐近行为起决定性作用,线性Boussinesq方程存在色散量子化现象.     

自掺杂基团对聚苯胺自组装膜电化学性能的影响

基于离子相互作用,实现了以聚苯胺(PANI)为聚阳离子,以聚(邻氨基苯甲酸)(PCAN)、聚(邻氨基苯磺酸)(PSAN)为聚阴离子的层-层自组装,形成层厚均匀的全共轭超薄功能膜.由于磺酸基—SO3-的电负性高于—COO-,使得PANI-PSAN自组装膜沉积量小于PANI-PCAN;电化学实验结果显示,由于PCAN和PSAN的导电性均弱于PANI,所以两种自组装膜的电化学性能取决于PANI,但同时受到羧酸、磺酸基团的较大影响,使得PANI-PCAN自组装膜的电化学性能要优于PANI-PSAN.     

外磁场对纳米管上Blume-Capel模型磁热性能的研究

利用有效场理论研究了纳米管上外磁场中Blume-Capel模型格点的磁化强度、磁化率、内能、比热和自由能,得到了系统格点的磁化强度、磁化率、内能、比热和自由能与外磁场和晶场的关系.结果表明:外磁场强度、交换相互作用和晶场强度等诸多因素相互竞争,使系统表现出比没有外磁场作用的Blume-Capel模型更为丰富的磁学特性;外磁场能够增大系统格点的磁化强度,导致系统的二级相变消失;负晶场作用系统时,系统会发生一级相变;晶场强度、外磁场强度不同时,系统的磁化率、内能、比热和自由能也呈现出复杂性.