pH-Triggered Molecular Switch Toward Texture-Regulated Zn Anode

Zn electrodes in aqueous media exhibit an unstable Zn/electrolyte interface due to severe parasitic reactions and dendrite formation. Here, a dynamic Zn interface modulation based on the molecular switch strategy is reported by hiring γ-butyrolactone (GBL) in ZnCl₂/H₂O electrolyte. During Zn plating, the increased interfacial alkalinity triggers molecular switch from GBL to γ-hydroxybutyrate (GHB). GHB strongly anchors on Zn surface via triple Zn−O bonding, leading to suppressive hydrogen evolution and texture-regulated Zn morphology. Upon Zn stripping, the fluctuant pH turns the molecular switch reaction off through the cyclization of GHB to GBL. This dynamic molecular switch strategy enables high Zn reversibility with Coulombic efficiency of 99.8 % and Zn||iodine batteries with high-cyclability under high Zn depth of discharge (50 %). This study demonstrates the importance of dynamic modulation for Zn electrode and realizes the reversible molecular switch strategy to enhance its reversibility.     

矿物桥与珍珠母结构力学性能

本文通过对珍珠母材料的力学实验研究,定性地分析了矿物桥对珍珠母结构弹性模量以及与材料韧性相关的某些力学行为影响,由此说明在珍珠母材料所表现出来的宏观力学性能中矿物桥所起的重要作用．     

Analysis of the strengthening and toughening of a biomaterial interface

Based on the transmission electron micrographs of nacre, the existence of mineral bridges in the organic matrix interface is confirmed. It is proposed that the microarchitecture of nacre should be considered as a “brick-bridge-mortar” (BBM) arrangement rather than traditional “brick and mortar” (BM) one. Experiments and analyses indicate that the mineral bridges effectively affect the strength and toughness of the interfaces in nacre. Comparison with a laminated composite with BM structure, SiC/BN, shows that the pattern of the crack extension and the toughening mechanism of the two materials are different. This reveals that the mineral bridges play a key role in the toughening mechanisms of nacre, which gives a conceptual guidance in material synthesis.     

时间尺度上三阶Emden-Fowler动力方程的振动准则

研究了时间尺度上的三阶Emden-Fowler动力方程的振动性,通过引入参数函数和广义的Riccati变换技巧,借助时间尺度上的有关理论,得到了该动力方程振动性的几个充分条件,所得结果推广和改进了现有文献的相关结果.     

Preparation of highly fluorescent magnetic nanoparticles for analytes-enrichment and subsequent biodetection

Bifunctional nanoparticles with highly fluorescence and decent magnetic properties have been widely used in biomedical application. In this study, highly fluorescent magnetic nanoparticles (FMNPs) with uniform size of ca. 40 nm are prepared by encapsulation of both magnetic nanoparticles (MNPs) and shell/core quantum dots (QDs) with well-designed shell structure/compositions into silica matrix via a one-pot reverse microemulsion approach. The spectral analysis shows that the FMNPs hold high fluorescent quantum yield (QY). The QYs and saturation magnetization of the FMNPs can be regulated by varying the ratio of the encapsulated QDs to MNPs. Moreover, the surface of the FMNPs can be modified to offer chemical groups for antibody conjugation for following use in target-enrichment and subsequent fluorescent detection. The in vitro immunofluorescence assay and flow cytometric analysis indicate that the bifunctional FMNPs-antibody bioconjugates are capable of target-enrichment, magnetic separation and can also be used as alternative fluorescent probes on flow cytometry for biodetection.     

Confinement-induced colloidal attractions in equilibrium

The Poisson-Boltzmann theory for colloidal electrostatic interactions predicts that charged colloidal spheres dispersed in water should repel each other, even when confined by charged surfaces. Direct measurements on highly charged polystyrene spheres, however, reveal strong, long-ranged confinement-induced attractions that have yet to be explained. We demonstrate that anomalous attractions also characterize the equilibrium pair potential for more weakly charged colloidal silica spheres sedimented into a monolayer above a glass surface. This observation substantially expands the range of conditions for which mean-field theory incorrectly predicts the sign of macroions' interactions, and provides new insights into how confinement induces long-ranged like-charge attractions.     

二茂铁甲酰丙酮缩水杨酰肼的d-过渡、ⅡB族及主族金属配合物研究

将二茂铁甲酰丙酮与水杨酰肼缩合,得含二茂铁基的多齿配体C₅H₅FeC₅H₄C(OH)=CHC(CH₃)=NNHCOC₆H₄OH(简记作FcacacshH₂),该配体分别与d-过渡、ⅡB族及主族金属乙酸盐反应,合成了几个中性固体配合物。经元素分析、红外光谱、紫外—可见光谱、氢核磁共振谱、穆斯堡尔谱、摩尔电导测定对配合物进行表征并研究其性质。     

纳米零价铁富集水溶液中铀的表面化学及应用展望

由于铀矿采冶、核能利用等类活动的影响, 铀引起的水体污染问题日益严重. 纳米零价铁(nanoscale zero-valent iron, nZVI)及其复合材料可高效富集水溶液中低浓度的铀, 在放射性废水的处理与铀的资源回收方面具有巨大的应用潜力. 但是, 不同研究对nZVI分离铀的机理和性能尚未形成一致的解释. 因此, 本综述归纳了nZVI分离铀的研究进展, 概括了溶液及固相反应机理(如吸附作用、还原作用、沉淀作用), 重点分析了水质因素(如pH、U(VI)浓度、阳离子、阴离子、溶解氧)的影响机制. 后续研究可注重分析铀废水中nZVI的结构转化规律及水质因素的协同作用对nZVI固定铀的机理、性能的影响; 并基于放射性废水的水质或水处理工艺的特征, 优化nZVI材料结构且评估其处理放射性废水的长期稳定性和生态毒性; 确定nZVI固定铀的性能与水质组分及水处理工艺运行参数的数学相关性, 建立监测和调控工艺的方法.     

Metabolism of a sulfur-containing heteroarotionoid antitumor agent, SHetA2, using liquid chromatography/tandem mass spectrometry

SHetA2 {[(4-nitrophenyl)amino][2,2,4,4-tetramethylthiochroman-6-yl)amino]methanethione], NSC 726189}, a sulfur-containing heteroarotinoid, selectively inhibits cancer cell growth and induces apoptosis without activation of nuclear retinoic acid receptors (RARs). The objective of this study was to investigate its in vitro metabolism in rat and human liver microsomes and in vivo metabolism in the mouse and rat using liquid chromatography-ultraviolet/multi-stage mass spectrometry (LC-UV/MS(n)) on an ion-trap mass spectrometer coupled with a photo-diode array (PDA) detector. In vitro, in the absence of glutathione (GSH), oxidation of the four aliphatic methyl groups of SHetA2 yielded one mono-, two di-, and one tri-hydroxylated SHetA2 metabolites, which were identified based on their UV and multi-stage mass spectra. In the presence of GSH, in addition to these primary oxidative metabolites, four GSH adducts of SHetA2 and a novel rare form thioether GSH adduct was detected and characterized. In vivo, the monohydroxylated SHetA2 metabolites were also detected in mouse and rat plasma and two GSH adducts were detected in rat liver following intravenous (i.v.) bolus administration of SHetA2 at 40 mg/kg.     

Low-cost and Non-flammable Eutectic Electrolytes for Advanced Zn-I2 Batteries

As a burgeoning electrolyte system, eutectic electrolytes based on ZnCl₂/Zn(CF₃SO₃)₂/Zn(TFSI)₂ have been widely proposed in advanced Zn-I₂ batteries; however, safety and cost concerns significantly limit their applications. Here, we report new-type ZnSO₄-based eutectic electrolytes that are both safe and cost-effective. Their universality is evident in various solvents of polyhydric alcohols, in which multiple −OH groups not only involve in Zn²⁺ solvation but also interact with water, resulting in the high stability of electrolytes. Taking propylene glycol-based hydrated eutectic electrolyte as an example, it features significant advantages in non-flammability and low price that is <1/200 cost of Zn(CF₃SO₃)₂/Zn(TFSI)₂-based eutectic electrolytes. Moreover, its effectiveness in confining the shuttle effects of I₂ cathode and side reactions of Zn anodes is evidenced, resulting in Zn-I₂ cells with high reversibility at 1 C and 91.4 % capacity remaining under 20 C. After scaling up to the pouch cell with a record mass loading of 33.3 mg cm⁻², super-high-capacity retention of 96.7 % is achieved after 500 cycles, which exceeds other aqueous counterparts. This work significantly broadens the eutectic electrolyte family for advanced Zn battery design.