网孔电流法及其应用

以网孔电流替代支路电流为求解对象的网孔电流法在求解复杂电路上具有明显优势, 基于此介绍了网 孔电流法的基本原理和在物理竞赛中的应用, 并给出示例     

乘积∏_(k=1)~n(ak~2+bk+c)的平方性

本文证明了乘积∏_(k=1)~n(ak~2+6k+c)(f(x)=ax~2+bx+c∈Z[x]是二次不可约多项式)在n充分大时不是平方数.     

HIRFL-CSR complex

The construction and commissioning of HIRFL-CSR were finished in 2007. From 2000 to 2005 the subsystem and key devices of CSR were successfully fabricated, such as magnet, power supply, UHV system, e-cooler, electric-static deflector with the septum of 0.1 mm, and the fast-pulse kicker with the rise time of 150 ns. After that the CSR commissioning activities were performed in 2006 and 2007, including the accumulation of those heavy ions of C, Ar, Kr and Xe by the combination of stripping injection （STI） or multiple multi-turn injection （MMI） and e-cooling with a hollow e-beam, wide energy-range synchrotron ramping by changing the RF harmonic-number at mid-energy, the beam stacking in the experimental ring CSRe, the RIBs mass-measurement with the isochronous-mode in CSRe by using the time-of-flight method, and the ion beam slow-extraction from CSRm.     

CR超导二极磁铁线圈受力分析

介绍了FAIR项目CR超导二极铁的线圈结构。 采用有限元分析方法， 对线圈的电磁力作用进行二维计算分析， 得到了线圈的二维位移变形和应力分布规律， 同时也分析计算了线圈、 线圈盒的三维受力以及位移形变， 为线圈盒和支撑结构的优化设计提供了参考依据。 Coil structure of CR superferric dipole for FAIR is presented in this paper. Finite Element Method(FEM) is used to calculate 2d magnetic force, displacement and stress distribution. 3d magnetic force and displacement of coil and coilcase are also analyzed, which shows that the design is fit for the desire result. Some results will be taken as a reference for further design.     

丢番图方程(m2+1)x+(cm2-1)y=(am)z

设m,a,c均是大于1的正整数.当am≡1(mod 4)或am≡3(mod 8),3■m或2■a,2|m,3■m时,得到了丢番图方程(m²+1)^x+(cm²-1)^y=(am)^z,1+c=a²,m≥2只有正整数解(x,y,z)=(1,1,2).特别地,当a≡1,3,5 (mod 8),a≠3或a≡7 (mod 8),a≡2(mod 3)时,方程2^x+(a²-2)^y=(a)^z只有正整数解(x,y,z)=(1,1,2).     

Simulation and experimental study of the solid pulse forming lines for dielectric wall accelerator

Two types of pulse forming lines for dielectric wall accelerator (DWA) were investigated preliminarily. By simulation with CST Microwave Studio, the results indicate the pulse forming process, which can help to understand the voltage wave transmission process and optimize the line parameters. Furthermore, the principle of the pulse forming process was proved by experiments and some excellent pulse waveforms were obtained. During the experiments, the Blumlein line and zero integral pulse (ZIP) forming line, constructed with aluminum foil, poly plate and air gap self-closing switch, were tested. The full width at half maximum (FWHM) of the waveform is 16 nanoseconds (BL) and 17 nanoseconds (ZIP line),and the formed pulse voltage amplitude is 5 kV (BL) and +2.2 kV/ - 1.6 kV (ZIP line). The experiments result coincides well with the simulation.     

CSR60°二极C型铁磁场特性的研究

兰州重离子加速器冷却储存环主环注入线二极C型磁铁首次采用了磁极头中埋置垫补线圈调整磁场均匀度的设计.在其磁场测量中,使用了点测和积分测量的方法对其各方面特性参数进行了测量,并对积分场的测量结果以及内置垫补线圈对均匀场的垫补效果进行了详细的非线性分析.     

冷却储存环主环注入线四极磁铁测量

 介绍了兰州重离子加速器冷却储存环工程主环注入线四极磁铁谐波测磁系统和谐波磁场测量结果。分析了磁铁误差产生的原因以及磁铁加工存在的问题和注意事项。     

四极透镜的三阶像差分析

用Lie代数方法推导了四极透镜的三阶像差.像差源于四极透镜场在轴向的有限分布.在一阶焦距不变的条件下,增加透镜的长度或增加透镜的孔径可以减小三阶像差     

在茶叶农药残留测定中用四氧化三铁纳米粒子去除样品中的色素

对Fe3O4纳米粒子去除茶叶中的色素进行了研究。优化了净化吸附条件,在此基础上研制了纳米粒子与石墨化碳(Graphitic carbon,GCB)、无水MgSO4混合装填的固相萃取柱。实验表明:此柱对茶叶乙腈提取液的净化效果明显优于商品化基质分散萃取剂(PSA)+石墨化碳+无水MgSO4)。因Fe3O4纳米粒子的成本远低于PSA,新研制的混合固相萃取柱亦能有效节约实验成本。本研究的样品通过混合装填的固相萃取小柱净化后,用气相色谱-质谱联用(GC-MS)分析并进行了分析方法学的考察,16种农药回收率为80%～114%,检出限低于0.021 mg/kg,精密度(n=6)为1.4%～11.5%。证实Fe3O4纳米粒子混合型固相萃取柱净化后的分析结果在回收率、检出限及精密度等方面不仅能与商品化PSA混合基质净化法相媲美,而且在色素去除和成本控制方面明显优于商品化基质分散萃取法。