arXiv subjects

Xiaowei Xu

Publications and source records attributed to Xiaowei Xu.

93 records · Page 6Linked to original sources

arXiv2015

Study of digital pulse shape discrimination method for n-γ separation of EJ-301 liquid scintillation detector

A digital pulse shape discrimination system based on a programmable module NI-5772 has been established and tested with EJ-301 liquid scintillation detector. The module was operated by means of running programs developed in LabVIEW with the sampling frequency up to 1.6GS/s. Standard gamma sources 22Na, 137Cs and 60Co were used to calibrate the EJ-301 liquid scintillation detector, and the gamma response function has been obtained. Digital algorithms for charge comparison method and zero-crossing method have been developed. The experimental results showed that both digital signal processing (DSP) algorithms could discriminate neutrons from gamma-rays. Moreover, the zero-crossing method shows better n-γ discrimination at 80 keVee and lower, whereas the charge comparison method gives better results at higher thresholds. In addition, the figure-of-merit (FOM) of two different dimension detectors were extracted at 9 energy thresholds, and it was found that the smaller one presented a better n-γ separation property for fission neutrons.

physics.ins-det↗

arXiv2012

Left Derivations and Strong Commutativity Preserving Maps on Semiprime $Γ$-Rings

In this paper, firstly as a short note, we prove that a left derivation of a semiprime $Γ$-ring $M$ must map $M$ into its center, which improves a result by Paul and Halder and some results by Asci and Ceran. Also we prove that a semiprime $Γ$-ring with a strong commutativity preserving derivation on itself must be commutative and that a strong commutativity preserving endomorphism on a semiprime $Γ$-ring $M$ must have the form $σ(x)=x+ζ(x)$ where $ζ$ is a map from $M$ into its center, which extends some results by Bell and Daif to semiprime $Γ$-rings.

math.RA↗

arXiv2012

Skew $N$-Derivations on Semiprime Rings

For a ring $R$ with an automorphism $σ$, an $n$-additive mapping $Δ:R\times R\times... \times R \rightarrow R$ is called a skew $n$-derivation with respect to $σ$ if it is always a $σ$-derivation of $R$ for each argument. Namely, it is always a $σ$-derivation of $R$ for the argument being left once $n-1$ arguments are fixed by $n-1$ elements in $R$. In this short note, starting from Brešar Theorems, we prove that a skew $n$-derivation ($n\geq 3$) on a semiprime ring $R$ must map into the center of $R$.

math.RA↗