基于有机溶剂原位制备的致密疏水铜金属层在保护锌负极中的应用

通过在 N-甲基吡咯烷酮(NMP)有机溶剂中锌电极与 CuI之间的置换反应,在锌电极上原位构建了一层致密且疏水的铜金属保护层(Cu@Zn)。铜金属保护层能有效地隔离锌电极与电解液的接触,减少锌电极-电解液界面的析氢和腐蚀等副反应。同时,铜金属保护层还具有较好的亲锌性,更小的界面电阻,更低的成核能垒,有利于锌离子均匀沉积,从而有效抑制了锌枝晶的生成。Cu@Zn对称电池实现了超过 1 700 h(1 mA·cm^-2)和 1 330 h(3 mA·cm^-2)的循环寿命。采用商用 MnO₂与之匹配得到的Cu@Zn||MnO₂全电池不仅在1 A·g^-1下具有168.5 mAh·g^-1的可逆比容量,还可稳定循环2 000次以上     

数据采集控制器ADAM—5510和上位机通信的实现

介绍了在VISUAL BASIC环境中研华公司的ADAM-5510数据采集控制器和上位机通信实现的方法。     

基于稳定同位素内标的高效液相色谱串联质谱法测定乳制品中L-岩藻糖的含量

基于稳定同位素内标（SIIS）,构建了一种简单的乳制品前处理方法,将乳制品中的L-岩藻糖（L-Fuc）高效地游离出来,利用高效液相色谱串联质谱法（LC-MS/MS）建立了乳制品中L-岩藻糖含量的定量测定方法. 首次引入SIIS来定量乳制品中的L-岩藻糖,采用电喷雾离子源（ESI）负离子扫描模式和多重反应监测（MRM）模式进行定量分析. 研究过程中对质谱鉴定、色谱条件、样品前处理过程都进行了方法的比较优化,并检测了纯牛奶、酸奶等5种乳制品中L-岩藻糖的含量. L-岩藻糖在0.001~1.000 μg·mL^-1范围内线性关系良好,相关系数为0.999 99,样品加标回收率在71.67%~117.27%之间,相对标准偏差（RSD）在2.00%~9.64%之间,检出限为0.1 ng·mL^-1,定量限为0.5 ng·mL^-1. 该方法样品前处理简单,灵敏度高,检测结果准确,可定量不同乳制品中L-岩藻糖的含量,为其他领域中L-岩藻糖含量的测定提供了可借鉴的方法.     

复杂目标散射近区RCS特性预估的研究

本文运用物理光学法（PO）和等效电磁流法（EMC）分析和计算了平板、多面体及某船体等复杂目标的近区单站RCS。作为例子，文中给出了一些目标的“近区”和“远区”单站RCS的比较。数值结果表明：目标“近区”和“远区”的单站RCS特性存在差异，而且这种差异随着目标形体复杂程度的增加而增加，其近区单站RCS特性亦变得复杂起来。该结果可为军用目标近区RCS的预估、雷达截面的减缩、隐身与反隐身、对抗与反对抗、目标别识、目标散射特性的缩比研究和远近场变换等相关的电磁工程技术实验和理论研究提供一定的理论依据。     

角谷猜想的证明

应用马尔可夫链推导出角谷链的状态转移概率,从而得出角谷链中的奇数和偶数出现的概率,再以概率的大数定律为基础证明日本数学家角谷静夫提出的猜想.     

Eudesmanolides and Guaianolides from Carpesium triste

A new eudesmanolide, 1‐oxo‐11αH‐eudesma‐2,4(14)‐dien‐12,8β‐olide ( 1 ), and four new guaianolides, 9β,10β‐epoxy‐4α‐hydroxy‐1βH,11αH‐guaian‐12,8α‐olide ( 2 ), 9β,10β‐epoxy‐4α‐hydroxy‐1βH,11βH‐guaian‐12,8α‐olide ( 3 ), 4α,9α‐dihydroxy‐1βH,11αH‐guai‐10(14)‐en‐12,8α‐olide ( 4 ), and 4α,9α‐dihydroxy‐1βH,11βH‐guai‐10(14)‐en‐12,8α‐olide ( 5 ), together with one known eudesmanolide and two known germacranolides, were isolated from the whole plants of Carpesium triste. Their structures and relative configurations were elucidated on the basis of spectroscopic methods, including 2D‐NMR techniques.     

General π‐Electron‐Assisted Strategy for Ir,Pt, Ru,Pd, Fe,Ni Single‐Atom Electrocatalysts with Bifunctional Active Sites for Highly Efficient Water Splitting

Both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) are crucial to water splitting, but require alternative active sites. Now, a general π‐electron‐assisted strategy to anchor single‐atom sites (M=Ir, Pt, Ru, Pd, Fe, Ni) on a heterogeneous support is reported. The M atoms can simultaneously anchor on two distinct domains of the hybrid support, four‐fold N/C atoms (M@NC), and centers of Co octahedra (M@Co), which are expected to serve as bifunctional electrocatalysts towards the HER and the OER. The Ir catalyst exhibits the best water‐splitting performance, showing a low applied potential of 1.603 V to achieve 10 mA cm^?2 in 1.0 m KOH solution with cycling over 5 h. DFT calculations indicate that the Ir@Co (Ir) sites can accelerate the OER, while the Ir@NC₃ sites are responsible for the enhanced HER, clarifying the unprecedented performance of this bifunctional catalyst towards full water splitting.     

Palladium Nanoparticles Supported on a Porous Organic Polymer: An Efficient Catalyst for Suzuki‐Miyaura and Sonogashira Coupling Reactions

A new porous organic polymer (POP) with high thermal stability and large surface area has been synthesized and applied in the preparation of Pd/POP catalyst. Pd/POP was characterized by XRD, TGA, SEM and TEM. The catalyst consists of highly dispersed palladium nanoparticles of 0.9–4 nm size on POP with a large surface area of 650 m²/g. It presents high catalytic activity for Suzuki‐Miyaura and Sonogashira reactions. The catalyst was reusable for three to five times without significant loss of activity.     

Photoswitchable Sol–Gel Transitions and Catalysis Mediated by Polymer Networks with Coumarin‐Decorated Cu24L24 Metal–Organic Cages as Junctions

Photoresponsive materials that change in response to light have been studied for a range of applications. These materials are often metastable during irradiation, returning to their pre‐irradiated state after removal of the light source. Herein, we report a polymer gel comprising poly(ethylene glycol) star polymers linked by Cu₂₄L₂₄ metal–organic cages/polyhedra (MOCs) with coumarin ligands. In the presence of UV light, a photosensitizer, and a hydrogen donor, this “polyMOC” material can be reversibly switched between Cu^II, Cu^I, and Cu⁰. The instability of the MOC junctions in the Cu^I and Cu⁰ states leads to network disassembly, forming Cu^I/Cu⁰ solutions, respectively, that are stable until re‐oxidation to Cu^II and supramolecular gelation. This reversible disassembly of the polyMOC network can occur in the presence of a fixed covalent second network generated in situ by copper‐catalyzed azide‐alkyne cycloaddition (CuAAC), providing interpenetrating supramolecular and covalent networks.