Analysis of the interaction between the ? meson and nucleus

In this study, we systematically investigate the ? meson and nucleus interaction by analyzing and fitting the cross sections of \begin{document}$ \gamma N $\end{document}\begin{document}$ \rightarrow \phi $\end{document}N reactions near the threshold, where N represents the nucleus. Using the vector meson dominant model, the distribution of the ?-N scattering length is presented as a function of energy, and the results show that there is a slight increase in scattering length with increasing energy. Based on this, the average scattering length of a ?-proton is obtained as\begin{document}$ 0.10\pm0.01 $\end{document} fm by combining experimental data and theoretical models. Moreover, the average scattering length of the ?-deuteron interaction is derived to be \begin{document}$ 0.014\pm0.002 $\end{document} fm for the first time. Furthermore, the effect of the momentum transfer \begin{document}$|t_{{\rm min}}|$\end{document} on the ?-N scattering length at the threshold is discussed. The obtained results not only provide important theoretical information for a more comprehensive and accurate study of the ?-N scattering length, but also a basis for future experimental measurements of ? meson production.     

RIBLL束流诊断

描述了兰州放射性离子次级束流线(RIBLL)上研制并安装使用的放射性束流(RIB)诊断装置的种类、结构、性能及在AIBLL上的位置和功能.重点叙述了以光纤为基础的几种诊断元件,它们探测效率高、响应时间快、制作容易、性能稳定.给出了RIB¹⁷N等高图,说明诊断装置辅助MBLL得到RIB的水平.     

Pithecellobium Clypearia Benth Fiber/Recycled Acrylonitrile-Butadiene-Styrene (ABS) Composites Prepared in a Vane Extruder: Analysis of Mechanical Properties and Morphology

The effect of compatibilizer types and concentrations on the mechanical properties and morphology of Pithecellobium Clypearia Benth Fiber (PCBF)/recycled ABS composites prepared by a vane extruder were characterized. In addition, the percentage of compatibilizer was fixed at 8%, and the effect of lubricant concentrations on the mechanical properties and torque behaviors of the composites was also studied. Maleic anhydride grafted ABS (ABS-g-MAH) and maleic anhydride grafted PS (PS-g-MAH) were used as compatibilizers; the lubricant used was Struktol TPW 604 (blend of aliphatic carboxylic acid salts and mono diamides). The composite with 8% ABS-g-MAH showed superior mechanical properties compared to the composite without compatibilizer and the 8% PS-g-MAH compatibilized composites. Compared with PS-g-MAH, ABS-g-MAH was more effective for the composites to improve the interfacial interaction and mechanical properties. The comprehensive mechanical properties of PCBF/recycled ABS composite filled with 4% lubricant were better than the composites without lubricant and the composites with any other content of TPW 604. Moreover, the torque of the composites in an internal mixer decreased with an increasing lubricant content.     

RIBLL中的TOF测量

描述了一种为兰州放射性核束流线(AIBLL)研制的时间拾取装置.次级束引起闪烁薄膜发光,椭球面镜聚焦,光电倍增管读出,CAMACTDC记录次级束的飞行时间.其时间分辨可以达到140ps,计数率可以达到10⁸pps.     

用位置灵敏光电倍增管读出的CsI(Tl)探测器

报道了用双维位置灵敏光电倍增管读出的CsI(T1)探测器,其CsI(T1)晶体厚度为10mm,灵敏面积为60mm×60mm.探测器的空间位置分辨为0.81mm(FWHM).用蒙特卡罗的方法对该探测器作了进一步模拟研究,其结果与实际测试的结果很好地一致.     

外伸梁差分离散系统的模态反问题

研究外伸梁模态的反问题,即由两组位移模态或应变模态及相应的频率构造外伸梁差分离散模型物理参数的方法,讨论反问题解存在的充要条件.提出算法并用算例验证.结果表明,由应变模态构造外伸梁的物理参数比用位移模态构造梁的物理参数精度要高.     

Theoretical Study of the Energies of the Oscillating System with a Well- Distributed Mass of the Spring

The energy of a spring with a well-distributed mass m_s is theoretically studied in this paper. The solution of the wave equation is derived in detail, and then the kinetic energy and potential energy of the spring are studied with the wave equation, as well as the kinetic energy of the oscillating mass M. The kinetic energy and potential energy of the spring, and total energy are numerically simulated for different ratios m_s/M with considering the spring’s mass, which makes the property of energy of the oscillating system understood easily.     

一种基因芯片光学扫描图像倾斜校正方法研究

针对在基因芯片光学扫描时产生的图像倾斜问题,提出了一种基于像素灰度的芯片图像倾斜校正方法。结合基因芯片图像的结构特点,基于行、列方向像素灰度定义芯片图像的校正指标。在角度检测范围内,利用折半搜索方法,基于校正指标来检测芯片图像的校正角度和芯片图像的校正位置。实验结果表明,该方法能有效地检测多类基因芯片图像的倾斜角度,具有较强的鲁棒性和实用性。     

Radioactive ion beam line in Lanzhou

Radioactive ion beam line in Lanzhou (RIBLL) has been constructed for the production of short-lived radioactive nuclei and studies of exotic nuclei far from the β-stability line. It has been put into operation recently at the National Laboratory of Heavy Ion Accelerator Lanzhou. RIBLL consists of two doubly achromatic parts with a solid acceptance ΔΩ⩾6.5 msr, momentum acceptance Δp/p=±5% and maximum magnetic rigidityBp _max=4.2 Tm. The second part of RIBLL serving as a spectrometer gives an element resolutionZ/ΔZ>150 and mass resolutionA/ΔA>300. The polarized secondary beams can be obtained by using a swinger dipole magnet to change the incident direction of primary projectile from 0° to 5°. The shortest lift time for secondary beams on RIBLL is less than 1 μs. First experiments were performed with neutron rich nuclei for understanding the properties of halo nuclei and exotic nuclear reactions. Project supported by the Chinese Academy of Sciences, the State Science and Technology Commission of China, the National Natural Science Foundation of China (Grant No. 19675055).