The morphology and structure of crystals in Qing Dynasty purple‐gold glaze excavated from the Forbidden City

Ancient Chinese purple‐gold glaze (zijinyou) is popular for its beautiful figuration, unique allure and fine craftsmanship. To understand the crystalline nature in the purple‐gold glaze, the morphology and structure of crystals precipitated in the glaze layer of purple‐gold glaze porcelain fired during the Qing Dynasty were characterized by a variety of methods combining X‐ray and electron‐based techniques. A large quantity of single‐phase twinning ε‐Fe₂O₃ crystals with lengths of 1‐3 μm, widths of less than 1 μm, and thickness of approximately 150 nm are found dispersed across the glaze surface to a depth of approximately tens of micrometers. These crystals show stratification across the cross‐section of the purple glaze consisting of 4 sublayers according to the crystal size. The formation of ε‐Fe₂O₃ crystals primarily contributed to the reddish‐brown tones of the purple‐gold glaze. The presence of anorthite, a strong reducing atmosphere during the firing process and the vitreous nature of the glaze influenced the growth of ε‐Fe₂O₃ crystals. These results suggest the controllability of single‐phase ε‐Fe₂O₃ crystals by identifying and understanding the underlying chemical processes in ancient Chinese crystalline glaze porcelain, and the findings will provide insights for modern material scientists in preparing ε‐Fe₂O₃ crystals with large sizes and high purities.     

Nanoscale Parallel Circuitry Based on Interpenetrating Conductive Assembly for Flexible and High‐Power Zinc Ion Battery

High‐rate capability has become an important feature for energy storage devices, but it is often accompanied with a significant reduction in energy density. Therefore, developing an energy storage technology that combines high‐rate capability with high energy density is a great challenge for next‐generation electronic devices. Here, parallel circuitry is constructed at the nanoscale to lower the resistance for ion and electron transport that largely determines the rate performance. The parallel circuitry is constructed through intertwining continuous carbon nanotubes with an interpenetrating conductive assembly based on hierarchically layered MXene (Ti₃C₂T_x ) functionalized by KMnO₄ (MnO_x @Ti₃C₂T_x ). The assembly shows ultrafast rate capability, e.g., maintaining 50% capacity when the current density increases from 0.1 to 10 A g^?1. Investigations of the kinetics and charge storage mechanisms confirm the efficiency of the designed parallel circuitry in improving rate capability by providing rapid pathways for ions and electrons, as well as dividing the current flow evenly into individual MnO_x @Ti₃C₂T_x flakes in the assembly. The flexible MnO_x @Ti₃C₂T_x based electrode endows zinc ion batteries with outstanding mechanical robustness and good power delivering performance. The paradigm presented here paves a new way for designing electrodes with high‐rate capability toward next‐generation energy storage technologies.     

废PET塑料纤维对再生混凝土基本性能的影响

为了提高再生混凝土(RAC)的力学性能,将废聚对苯二甲酸乙二酯(PET)塑料瓶剪成纤维条制成纤维再生混凝土(FRRAC)。通过纤维再生混凝土与再生混凝土的坍落度试验和强度试验,研究废PET塑料纤维长度、掺量对再生混凝土基本性能的影响,并进行强度影响因素的显著性分析和混凝土微观结构分析。结果表明：与不掺纤维的再生混凝土相比,纤维再生混凝土的流动性降低,且随废PET塑料纤维掺量、长度的增大而下降;掺PET纤维后,再生混凝土的抗压强度总体上有所提高,劈裂抗拉强度明显大幅提高。对于抗压强度,废PET塑料纤维的掺量影响显著;对于劈裂抗拉强度,纤维掺量、长度及二者交互作用均影响显著。掺PET纤维虽然会引入薄弱的界面过渡区,但适量时可使再生混凝土结构致密。     

基于线模行波突变的配电网全架空线路单相接地的多端检测定位新方法

针对配电网单相接地故障,提出了两种有效的故障定位方法。离线状态下,先后在线路的首端和末端向三相注入相同的高压脉冲,并分别在首末端采集线模电压信号的双端注入法。在线路首端向三相注入相同的高压脉冲,并在首端、末端和必要的二级分支末端检测线模电压信号的单端注入多端检测法。两种方法都利用了线模电压首个非零突变点对应时刻与故障点到测量点之间距离的关系进行综合定位。通过理论推导,PSCAD仿真和Matlab分析,证明了单端注入法比双端注入法效率更高,同时单端注入多端检测法能准确定位故障。     

铂合金含量测试—强度比值法的扩展应用研究

采用电感耦合等离子体发射光谱仪(ICP-AES)测定铂含量的强度比值法(GB/T 21198.2-2007)是比较常用的方法,经过对该法的测试条件、标准溶液、强度积分面积优化后,对钯含量为80%、40%和20%的铂钯二元配方样品进行检测,探讨优化后的方法对钯含量较高的样品检测准确性。结果表明,优化后的方法,对于钯含量较高的铂钯合金,检测结果的稳定性和准确性较好,适用于高钯含量的铂钯配方首饰样品。     

Temperature modulation of concentration quenching in lanthanide-doped nanoparticles for enhanced upconversion luminescence

Nano Research - The doping concentration of lanthanide ions is important for manipulating the luminescence properties of upconversion nanoparticles (UCNPs). However, the serious concentration...     

《白色金合金标准样品》的研制

由于目前国内白色K金样品成分复杂、配方更新较快、缺乏可用于生产控制和检测工作使用的白色金合金标准样品,特别是含钯配方的标准样品。采用特殊的熔炼铸造工艺研制了主要成分为金、银、铜、锌、镍、钯、铟和铁等8种元素,金的质量分数范围为80%~37.5%的白色金合金标准样品。利用能量色散型X射线荧光光谱仪(XRF)、波长色散型XRF、电感藕合等离子体发射光谱仪(ICP-AES)和电位滴定仪等仪器设备对标准样品进行均匀性检验、稳定性测试、化学定值等,结果表明标准样品的均匀性和稳定性良好,定值准确,工作曲线线性良好。因此,该标准样品作为国家标准样品,可应用于白色金合金饰品的分析方法的确认及检测过程中的质量控制。     

Cre／loxP系统介导删除酿酒酵母ALD4基因研究

设计与酿酒酵母编码乙脱醛氢酶ALD4因ORF两侧序列同源的删除组件引物,以质粒pUG6为模板进行PCR构建带有Kanr选择标记的删除组件.通过醋酸锂转化法将删除组件导入酿酒酵母菌,采用G418筛选阳性克隆子,将质粒pSH65转入阳性克隆子.半乳精诱导pSH65表达Cre酶切除Kanr基因,在ALD4基因ORF处留下1个loxP位点,通过2次的转化筛选验证获得ALD4双倍体基因缺陷型突变株Y01-ALD4.     

Study of arsenic in Famille rose porcelain from the Imperial Palace of Qing Dynasty,Beijing, China

Famille rose porcelain from the imperial workshop was one of the symbols of the highest level of manufacturing techniques in ancient China. It was very precious and only owned by the royals at the early stage. The major feature of famille rose is the use of opaque white pigment. Considered to originate in Europe, this technique was a witness of technological exchanges between China and European countries in the 17th–18th centuries. However, limited by its preciousness, most of the previous studies focused on the chemical composition of famille rose relics via nondestructive analysis methods. In this work, selected samples excavated at the Forbidden City of China were analysed by microscopy observation, Laser Ablation Inductive Coupled Plasma-Atomic Emission Spectrometry (LA-ICP-AES), synchrotron radiation X-ray Absorption Near-Edge Spectroscopy (XANES) and micro X-ray Diffraction (μXRD). The results revealed that two painting methods which related to Chinese and European techniques were applied. Chemical composition indicate that opaque white is a kind of arsenic-lead white. Moreover, the synchrotron radiation results show that As⁵⁺ is the major state in opaque white and exists mostly probably as AsO₄^3- -ion.     

Structural Stability Boosted in 3D Carbon-Free Iron Selenide through Engineering Heterointerfaces with Se?P Bonds for Appealing Na+-Storage

Iron selenides have emerged as appealing anodes for Na⁺-storage due to their natural abundance, good redox reversibility, and high theoretical capacity. Nevertheless, exploring a carbon-free iron selenide anode with long-term stability and high-rate capability remains an intractable challenge. Herein, a 3D carbon-free iron selenide electrode is designed by heterointerface with Se P bond engineering strategy to realize outstanding Na⁺-storage performance. Theoretical calculations on the stress deformation confirm the construction of Fe₇Se₈/Fe₃(PO₄)₂ not only enables excellent resistance-to-deformation ability but also exhibits strong mechanically stable against sodiation–desodiation. Such fascinating properties combined with the accelerated Na⁺ diffusion kinetics and enhanced electronic conductivity endowed by the 3D interconnected framework contribute to impressive cycling stability and superb rate performance for Na⁺-storage. Consequently, the designed 3D Fe₇Se₈/Fe₃(PO₄)₂ composite with a high tap density of 0.91 cm³ g⁻¹ displays a stable specific capacity of 277.1 mAh cm⁻³ at 30 A g⁻¹, and outstanding long-term cycle stability of up to 1500 cycles at 5 A g⁻¹ without obvious capacity decay. The proposed engineering strategy and results provide new insight to design carbon-free advanced electrodes for future practical applications.