锌介导的炔酰胺串联氧化/卤化反应合成α-卤代酰胺

α-卤代酰胺是一类十分重要的羰基化合物,广泛存在于众多天然产物和生物活性分子之中.本工作实现了通过卤化锌同时作为催化剂和卤素源的炔酰胺串联氧化/卤化反应,从而避免使用其他的外加卤化试剂.该反应可以中等到良好的产率得到一系列合成上非常有用的α-卤代酰胺化合物

基于HIRFL-CSR中剥离器的支束线物理设计

介绍了通过剥离器后不同电荷态的束流在弯曲磁铁中的传输情况,由此引出一种切割束流的方法,在此基础上设计了一条支束线,以实现两个实验终端同时供束,增加供束时间.在束运线设计过程中,根据HIRFL CSR的实际条件,对束流的中心轨迹和束流包络做了详细的计算,给出了束流输运线的几何布局和各个元件的基本物理参数

Synthesis of Porous Carbon Nanosheets and Its Application in Sodium-Ion Battery

本文以氯化钠为硬模板、硝酸镍为金属源、葡萄糖为碳源，在氮气气氛中于750 oC通过一步热解法合成嵌镍碳纳米片，然后经酸处理得到多孔碳纳米片. 通过扫描电镜（SEM）、透射电镜（TEM）、拉曼光谱（Raman）和比表面积测定（BET）表征多孔碳纳米片的形貌和结构. 结果显示：多孔碳纳米片孔分布均匀，孔径大小均一；经过酸处理后，碳材料的石墨化程度降低；具有较大的比表面积（约340 m2•g-1）. 电化学测试表明，电极在100 mA•g-1电流密度下，经过200周循环放电后比容量可维持在309.4 mAh•g-1，甚至在1000 mA•g-1 的大电流下其放电比容量仍然可达到173 mAh•g-1，表现出良好的循环稳定性和倍率性能，其在钠离子电池负极材料方面具有潜在的应用前景.Owning to sodium’s high abundance, relatively low cost, similar chemical properties to Li and very suitable redox potential of E0(Na+/Na) = -2.71 V versus SHE which is only 0.3 V above that of lithium, rechargeable sodium ion battery hold much promise as potential alternatives to current lithium ion batteries for energy storage applications. Carbon material is regarded as the most promising anode candidate for sodium ion battery. Particularly, carbon nanosheet with porous structure and high conductivity is expected to have improved sodium ion storage properties. In this paper, we present a two-step pyrolysis-based method for facile synthesis of porous carbon nanosheets with high capacity as anode in sodium-ion battery. In this method, sodium chloride was selected as a hard template, nickel nitrate as the metal source and glucose as the carbon source with pyrolysis temperature of 750 °C in nitrogen atmosphere. The first obtained is Ni-incorporated carbon nanosheets which were refluxed with dilute hydrochloric acid to produce uniform porous carbon nanosheets. TEM images shows that the pores in the as-prepared porous nanosheets spread evenly with narrow-distributed diameter; Raman spectra indicate that the graphitic degree of the product decreases after acid treatment; BET results demonstrate that the specific surface area can reach 340 m2•g-1; Electrochemical characterization says that the as-prepared porous nanosheets have excellent Na+ storage rate capability of 173 mAh•g-1 at 1000 mAh•g-1 and exhibit outstanding cycle stability at 100 mA•g-1 with 309.4 mAh•g-1 capacity even after 200-cycle running. The super sodium ion storage performance of the produced carbon nanosheets could be attributed to the specific structure, where the interconnected micro- and meso-pores inside minimized the diffusion lengths and the 2D carbon nanosheet structure enhanced electronic conductivity. These results show that the porous carbon nanosheet is a promising anode material for sodium ion batteries.国家自然科学基金项目（No. 21376122、No. 21576139和No. 21503111）资助作者联系地址：南京师范大学 化学与材料科学学院，江苏省新型动力电池重点实验室，江苏 南京 210023Author's Address: Jiangsu Key Laboratory of New Power Batteries, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, China通讯作者E-mail：[email protected]

激发态~(17)Ne双质子2p发射的实验

<正>在中国科学院近代物理研究所放射性束流装置RIBLL上完成了17Ne+197Au的实验,采用硅条探测器与CsI(Tl)+PIN探测器阵列进行运动学完全测量,研究了17Ne双质子发射的机制。实验选

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies