Cr<Superscript>3+</Superscript> activated Zn<Subscript>3</Subscript>Al<Subscript>2</Subscript>Ge<Subscript>3</Subscript>O<Subscript>12</Subscript>: a novel near-infrared long persistent phosphor

The near-infrared (NIR) long persistent phosphors have gained considerable attention owing to the potential applications in in vivo imaging. A novel NIR long-persistent phosphors Zn₃Al₂Ge₃O₁₂:Cr³⁺ was successfully synthesized by a high temperature solid-state reaction. The luminescent properties and the afterglow behaviors of the Zn₃Al₂Ge₃O₁₂:Cr³⁺ were investigated in detail. On the basis of thermoluminescence analyses, the mechanism of the persistent afterglow of the phosphors was also discussed briefly. The afterglow duration of this phosphor can last more than 12 h with the 650–750 nm emission range after stoppage of 254 nm ultraviolet light irradiation. Specifically, the persistent luminescence intensity and duration were regulated by changing Cr³⁺ doping concentration. All the results indicate that the Cr³⁺ activated Zn₃Al₂Ge₃O₁₂ has promising potential of practical applications.     

Mushrooms as Efficient Solar Steam‐Generation Devices

Solar steam generation is emerging as a promising technology, for its potential in harvesting solar energy for various applications such as desalination and sterilization. Recent studies have reported a variety of artificial structures that are designed and fabricated to improve energy conversion efficiencies by enhancing solar absorption, heat localization, water supply, and vapor transportation. Mushrooms, as a kind of living organism, are surprisingly found to be efficient solar steam‐generation devices for the first time. Natural and carbonized mushrooms can achieve ≈62% and ≈78% conversion efficiencies under 1 sun illumination, respectively. It is found that this capability of high solar steam generation is attributed to the unique natural structure of mushroom, umbrella‐shaped black pileus, porous context, and fibrous stipe with a small cross section. These features not only provide efficient light absorption, water supply, and vapor escape, but also suppress three components of heat losses at the same time. These findings not only reveal the hidden talent of mushrooms as low‐cost materials for solar steam generation, but also provide inspiration for the future development of high‐performance solar thermal conversion devices.     

Bioinspired Copper Single-Atom Catalysts for Tumor Parallel Catalytic Therapy

The oxidation of intracellular biomolecules by reactive oxygen species (ROS) forms the basis for ROS-based tumor therapy. However, the current therapeutic modalities cannot catalyze H₂O₂ and O₂ concurrently for ROS generation, thereby leading to unsatisfactory therapeutic efficacy. Herein, it is reported a bioinspired hollow N-doped carbon sphere doped with a single-atom copper species (Cu-HNCS) that can directly catalyze the decomposition of both oxygen and hydrogen peroxide to ROS, namely superoxide ion (O₂•⁻) and the hydroxyl radical (•OH), respectively, in an acidic tumor microenvironment for the oxidation of intracellular biomolecules without external energy input, thus resulting in an enhanced tumor growth inhibitory effect. Notably, the Fenton reaction turnover frequency of Cu species in Cu-HNCS is ≈5000 times higher than that of Fe in commercial Fe₃O₄ nanoparticles. Experimental results and density functional theory calculations reveal that the high catalytic activity of Cu-HNCS originates from the single-atom copper, and the calculation predicts a next-generation Fenton catalyst. This work provides an effective paradigm of tumor parallel catalytic therapy for considerably enhanced therapeutic efficacy.     

Cooperative Catalysis toward Oxygen Reduction Reaction under Dual Coordination Environments on Intrinsic AMnO3-Type Perovskites via Regulating Stacking Configurations of Coordination Units

It remains challenging for pure-phase catalysts to achieve high performance during the electrochemical oxygen reduction reaction to overcome the sluggish kinetics without the assistance of extrinsic conditions. Herein, a series of pristine perovskites, i.e., AMnO₃ (A = Ca, Sr, and Ba), are proposed with various octahedron stacking configurations to demonstrate the cooperative catalysis over SrMnO₃ jointly explored by experiments and first-principles calculations. Comparing with the unitary stacking of coordination units in CaMnO₃ or BaMnO₃, the intrinsic SrMnO₃ with a mixture of corner-sharing and face-sharing octahedron stacking configurations demonstrates superior activity (E_half-wave = 0.81 V), and charge–discharge stability over 400 h without the voltage gap (≈0.8 V) increasing in zinc–air batteries. The theoretical study reveals that, on the SrMnO₃(110) surface, the active sites switch from coordinatively unsaturated atop Mn (*OO, *OOH) to Mn–Mn bridge (*O, *OH). Therefore, the intrinsic dual coordination environments of Mn–O_corner and Mn–O_face enable cooperative modulation of the interaction strength of the oxygen intermediates with the surface, inducing the decrease of the *OH desorption energy (rate-limiting step) unrestricted by scaling relationships with the overpotential of ≈0.28 V. This finding provides insights into catalyst design through screening intrinsic structures with multiple coordination unit stacking configurations.     

基于同步更新外部归档集的NSGA-II改进算法

NSGA-II在执行拥挤系数计算时不考虑父子代种群各自独立的个体分布情况,使某些在全局空间中分布优秀的个体被淘汰。针对NSGA-II收敛结果的较差分布性,提出了改进算法（UEA-NSGA-II）,在迭代过程中随机填充一定量子代种群的非支配个体到外部归档集内,使用拥挤系数算子用于归档集的剪枝操作。同时,针对二进制编码存在陷入局部最优的问题,采用格雷码和动态变异算子增强算法在解空间上搜索速度与宽度。在ZDT系列问题上执行测试,并与两种典型算法和三种NSGA-II改进算法对比,结果表明UEA-NSGA-II在算法的稳定性与优化效果方面均优于所对比的算法。     

球面近场测试高阶探头补偿算法及其在超宽带探头上的应用

为了提高基于超宽带探头的球面近场天线测试系统精度,相应的探头补偿算法需要考虑超宽带探头的高阶方位模式. 文中采用文献[3]中基于球面波的迭代法方案实现了高效高精度的高阶探头补偿算法,并将其应用到一种工作在2～18 GHz的超宽带双脊喇叭探头中. 同时以偶极子阵列为例,研究了本文算法相较于传统低阶算法的精度优势,测试了该算法在多种条件下的收敛性. 结果显示:在相同条件下,高频端比低频端的高阶补偿效应更加明显;当待测天线完全落在该探头的主瓣6 dB宽度区域内时,算法均可以在几次（小于10）迭代后达到理想的精度. 因此,本文算法可以有效地提高基于超宽带探头的球面近场测试系统的精度,并且具有较高的单机计算效率.     

砂岩级配料开采爆破参数试验优化

两河口石料场是两河口水电站工程建设的主要石料来源,其开采质量的好坏直接决定了该工程的进度与成本,为获得较高的级配料开采质量,进行了2次爆破开采试验,获得了适合本工程石料场开采的爆破参数,并为类似工程提供参考。     

压缩感知重构算法的并行化及GPU加速

针对压缩感知重构算法计算实时性太差的问题,提出压缩采样追踪匹配(compressive sampling matching pursuit,CoSaMP)算法的并行化加速算法。 基于多线程技术实现重构算法的粗粒度并行化,分析CoSaMP算法的计算热点,将其中耗时较多的矩阵操作移植在图形处理器(graphics processing unit, GPU)上,实现算法的细粒度并行化。在测试图像上进行试验,结果表明:并行化加速算法取得50倍的加速效果,有效地降低重构算法的计算时间开销。     

微膨胀高强灌注料蹴脆增韧长试验研究

采用水性环氧树脂、丁苯橡胶、橡胶粉3种增韧材料对微膨胀高强灌注料进行减脆增韧研究,对抗压、抗折强度和荷载-变形进行测试,通过对压折比、弹性模量、折弹比等分析表明,所用增韧材料使其脆性降低、韧性提高.分析了不同掺料下的减脆增韧机理,并对微膨胀高强灌注料在路面补强、路面薄层罩面以及防水堵漏、植筋等工程中的应用进行了展望.     

基于MATLAB仿真的PSS参数配置方法

电力系统稳定器(PSS)是增加阻尼抑制低频振荡的重要措施。电网运行准则(GB/T 31464—2015)明确规定100 MW及以上的火电、核电及燃气机组的励磁系统应具备PSS功能。PSS试验中需要配置超前滞后环节的时间常数,针对配置参数时存在效率低下及不能最优化的问题,提出了基于MATLAB最优化函数进行参数自动配置的方法,通过设置各个频率点的相位期望值和构建相位方差和的目标函数,实现了在各频率点特定相位要求下的PSS参数自动计算。给出了该方法的详细步骤,最后在某1000 MW的火电机组PSS试验中进行了验证。