Nitrogen dilution effect for small angle GDH experiment in JLab Hall-A

In the GDH sum rule measurement in JLab Hall-A,to obtain the cross section of electron scattering on polarized 3He and its asymmetry in different helicity states,the dilution effect from unpolarized nitrogen mixed in the polarized 3He target were calculated at different kinematic settings.     

JLab Hall-A上小角度GDH实验中的粒子鉴别及其效率

在JLab的A大厅上的小角度GDH实验中, 因为散射截面及截面不对称度的测量需要干净的电子样本和足够的事例统计, 径迹在簇射量能器和气体阈契仑柯夫探测器理的信息被用来完成粒子鉴别的任务. 通过优化粒子在两种探测器里的信息筛选条件, 可以得到较高的电子接收效率和π的去除能力. 因为探测器的分辨能力与粒子的动量等运动学参量有关, 所以对于不同的数据的粒子鉴别条件分别进行了优化, 并得到了对应的电子接收效率和π的去除能力.     

糖的基质辅助激光解吸/电离质谱(MALDI-MS)研究

通过糖类化合物3种常用基质MALDI-MS分析效果的比较以及寡糖和多糖正、负离子MALDI-MS谱的对比,找到了适合糖分析的基质2,5-DHB,探讨了糖类化合物激光解吸/电离条件下形成离子的过程,指出了Na⁺、K⁺离子在寡糖分子量测定中的重要作用,借助柱层析分离手段,成功地测出了分子量大于10000的葡聚糖的分子量。     

NaI (T1) calorimeter calibration and simulation for Coulomb sum rule experiment in Hall-A at Jefferson Lab

A precision measurment of inclusive electron scattering cross sections is carried out at Jefferson Lab in the quasi-elastic region for <'4>He, <'12>C, <'56>Fe and <'208>pb targets. The longitudinal (R<,L>) and transverse (R<,T>) response functions of the nucleon need to be extracted precisely in the momentum transfer range 0.55 GeV/c≤ |q|≤1.0 GeV/c. To achieve the above goal, a NaI (T1) calorimeter is used to distinguish good electrons from background, including pions and low energy electrons rescattered from the walls of the spectrometer magnets. Due to a large set of kinematics and changes in HV settings, a number of calibrations are performed for the NaI (T1) detector. Corrections for a few blocks of NaI (T1) with bad or no signal are applied. The resolution of the NaI (T1) detector after calibration reached δE/√E≈3% at E=1 GeV. The performance of the NaI (T1) detector is compared with a simulation. The good calibration and background analysis for the NaI(T1) detector are very important for the reduction of the systematic error of cross sections and the separation of R<,L> and R<,T>.     

三维多枝雪花状银粉的制备及催化性能

室温下,以聚乙烯醇为保护剂,采用抗坏血酸还原硝酸银,于水相中一步合成出三维多枝雪花状银粉。结合X射线粉末衍射(XRD)、扫描电子显微镜(SEM)等结构表征手段,对三维多枝雪花状银粉的微观结构进行详细分析,在此基础上提出其可能的形成机理。此外,三维多枝雪花状银粉在4-硝基苯酚催化加氢反应中还表现出优异的催化活性。     

Fokker-Planck Type Equations Associated with Subordinated Processes Controlled by Tempered α-stable Processes

In this paper we introduce two models of stochastic processes driven by Brownian motion and fractional Brownian motion subordinated with tempered α-stable waiting times. By using a new integro-differential operator we obtain the generalized Fokker-Planck type equations associated with these subordinated stochastic processes.     

MULTIPLICITY DISTRIBUTIONS OF CHARGED PARTICLES PRODUCED IN pp COLLISIONS AT 400GeV/c

Charged particle multiplicity distributions in pp collisions at 400GeV/c have been studied by using the LEBC films which were offered by CERN NA27 Collaboration.
The corrections to the raw data are described.The results are compared with data at other energies.It is shown that the charged particle multiplicity distribution for the nonsingle diffractive process has KNO scaling behavior,whereas for the inelastic process shows a deviation from KNO scaling up to ISR energy.     

三维多枝雪花状银粉的制备及催化性能

室温下,以聚乙烯醇为保护剂,采用抗坏血酸还原硝酸银,于水相中一步合成出三维多枝雪花状银粉。结合X射线粉末衍射（XRD）、扫描电子显微镜（SEM）等结构表征手段,对三维多枝雪花状银粉的微观结构进行详细分析,在此基础上提出其可能的形成机理。此外,三维多枝雪花状银粉在4-硝基苯酚催化加氢反应中还表现出优异的催化活性。     

Time-changed geometric fractional Brownian motion and option pricing with transaction costs

This paper deals with the problem of discrete time option pricing by a fractional subdiffusive Black–Scholes model. The price of the underlying stock follows a time-changed geometric fractional Brownian motion. By a mean self-financing delta-hedging argument, the pricing formula for the European call option in discrete time setting is obtained.