400 GeV/c PP碰撞的阶乘关联子数据 *

用400GeV/c质子-质子(PP)碰撞产生的带电粒子赝快度分布的实验数据,计算了阶乘关联子和累积关联子.结果表明阶乘关联子随着关联距离的减小而增加,与赝快度的分辨率无关.两粒子关联长度近似与平均多重数无关.对阶乘关联子与阶乘矩之间存在的相加规则进行了实验检验.     

取代基对咔咯锰(V)-氧配合物Mn―O的成键影响

用密度泛函理论(DFT)方法对一系列A₃型咔咯锰(V)氧配合物进行了理论计算. 结果表明: 咔咯锰(V)-氧配合物中Mn―O键是由1 个σ键和2 个π键构成的叁键结构; 当咔咯中位取代基由推电子过渡到拉电子性质时, 咔咯骨架紧缩, Mn―O键缩短, 其拉曼光谱的伸缩振动峰往高波数移动; 取代基与氧原子的静电作用模式由正-负吸引转化为负-负排斥, 导致Mn―O键解离能ΔE减少, 即拉电子基团有利于增强咔咯锰(V)-氧配合物氧原子的活泼性.     

高能电子束流引发的横向极化气体氢靶共振退极化研究

对于HERMES横向极化气体氢靶, 高能电子束流所激发的高频磁场会引发共振退极化. 本文就该极化度下降的产生机制进行研究, 并给出σ₂₄共振点发生位置的测量结果, 并且将极化靶磁场的强度稳定在远离共振点处, 挽回了数据获取时极化度近3%的共振损失.     

Hall-A上小角度GDH实验中量能器的刻度修正

在JLab的A大厅上的小角度GDH实验中, 采用了Fumili拟合方法对位于高分辨谱仪上的量能器进行刻度. 因为实验过程中硬件条件的变化以及大量的运动学数据的存在, 对该实验数据分批进行了刻度. 刻度结果表明, 此刻度修正是合适的. 在散射电子动量为1GeV的时候, 量能器对该粒子的分辨率为0.06GeV.     

Hall-A上小角度GDH实验中气体契仑柯夫探测器的刻度修正

在JLab的A大厅上的小角度GDH实验中, 因为实验过程中硬件条件的变化, 对位于高分辨谱仪上的CO₂阈契仑柯夫探测器进行了多次刻度修正, 并得到7套修正系数. 单光电峰在阈契仑柯夫探测器的10个PMT中的信号响应均被调整到两百. 通过对在该探测器中的信号响应的判断, 本底π粒子可以被有效的去除.     

A “Pre-Division Metal Clusters” Strategy to Mediate Efficient Dual-Active Sites ORR Catalyst for Ultralong Rechargeable Zn-Air Battery

To conquer the bottleneck of sluggish kinetics in cathodic oxygen reduction reaction (ORR) of metal-air batteries, catalysts with dual-active centers have stood out. Here, a “pre-division metal clusters” strategy is firstly conceived to fabricate a N,S-dual doped honeycomb-like carbon matrix inlaid with CoN₄ sites and wrapped Co₂P nanoclusters as dual-active centers (Co₂P/CoN₄@NSC-500). A crystalline {Co^II ₂ } coordination cluster divided by periphery second organic layers is well-designed to realize delocalized dispersion before calcination. The optimal Co₂P/CoN₄@NSC-500 executes excellent 4e⁻ ORR activity surpassing the benchmark Pt/C. Theoretical calculation results reveal that the CoN₄ sites and Co₂P nanoclusters can synergistically quicken the formation of *OOH on Co sites. The rechargeable Zn-air battery (ZAB) assembled by Co₂P/CoN₄@NSC-500 delivers ultralong cycling stability over 1742 hours (3484 cycles) under 5 mA cm⁻² and can light up a 2.4 V LED bulb for ≈264 hours, evidencing the promising practical application potentials in portable devices.     

Two-particle Pseudorapidity Correlations in pp Collisions at 400GeV/c

The pseudorapidity distributions of charged produced in pp collisions at 400GeV/c have been measured using LEBC films.Two-particle pseudorapidity correlations at fixed multiplicity have been studied.The experimental data was fitted by cluster model.It is found that the average cluster multiplicities as well as the cluster decay widths both vary slightly with charged multiplicity.