350MHz强流质子RFQ加速器工艺腔的研制与测量

为研究强流质子RFQ加速腔的设计与加工工艺,研制了一台全尺寸无氧铜工艺腔.本文介绍了其物理设计与机械设计、机械加工与钎焊工艺研究及其高频性能的测量和调节.经调节,RFQ工艺腔可以达到较为理想的电场分布,其4个象限电场分布的一致性和平整度均能满足要求,二极场分量也足够小     

分段共振耦合BFQ的调谐与测量

对一长度为3m的分段共振耦合RFQ冷模进行了多次调谐和测量，得到了RF电场平整度好于4％的场分布；解决了分段共振耦合RFQ调谐时捐合单元处RF电场分布出现的台阶问题；确定了分段共振耦合RFQ的调谐步骤。     

THE POWER SPECTRUM OF THE MASS IN A SANDPILE MODEL WITH STOCHASTIC SLIDE

The power spectrum of the mass in a theoretical sandpile model with stochastic slide is examined. The simulations show that the power spectrum has the form of l/f^α, and the exponent α may vary with the average time interval between the successive events af the sands flowing off the sandpile. The conditions of generating 1/f noise are also discussed.     

高效液相色谱法同时测定食品中脂溶性维生素A,D3,E,K3

１引言维生素是维持细胞正常生理功能的营养成分之一。许多维生素是酶的辅基或酶的组成成分，因此，测定食品中维生素的含量是食品营养分析的主要内容之一。脂溶性维生素的分析方法一般采用生物法、分光光度法及薄层色谱法等，但这些方法都只能单独测定食品中的维生素，进入８０年代后，随着高效液相色谱（ＨＰＬＣ）技术在食品分析中的应用，国外许多研究工作者在利用高效液相色谱技术分析脂溶性维生素的研究上作了许多工作，发展了更具选择性的方法如电化学法、质谱法等，并且对同时测定脂溶性维生素的方法作了一些探索。本文旨在综合国内…     

Status of CSNS H- ion source

A new H^- ion source has been installed successfully and will be used to serve the China Spallation Neutron Source (CSNS). In this paper, we report various components of the ion source, including the discharge chamber, temperature, cooling system, extraction electrodes, analyzing magnet, remote control system and so on. Compared to the previous experimental ion source, some improvements have been made to make the ion source more compact and convenient. In the present arrangement, the Penning field is generated by a pair of pole tip extensions on the 90° analyzing magnet instead of by a separate circuit. For the remote control system, F3RP61-2L is applied to the accelerator online control system for the first time. In the running of the ion source, a stable pulse H^- beam with a current of 50 mA at an energy of 50 keV is produced. The extraction frequency and pulse width is 25 Hz and 500 μs, respectively. Furthermore, an emittance scanner has been installed and measurements are in progress.     

Thermal analysis of the CSNS H~- ion source

There are two cooling systems to maintain the thermal stability of the CSNS H- ion source during its operation:Air-cooling in the source body of the discharging chamber and water-cooling in the flange on which the discharging chamber is installed.The optimal cooling parameters to ensure the operation of the H- ion source are determined through a thermal analysis.In addition,a transient analysis is also performed to know exactly the transient temperature variation during the whole 40 ms period of the pulsed ...     

复合材料力学的Hamilton体系和辛几何方法(Ⅲ)——弯曲问题和板的振动*

把本文第一部分建立的方法用于求解各向异性板的弯曲问题和振动问题.     

低能、强流质子圆形加速器共振现象的模型研究

详细讨论了低能强流质子圆形加速器中质子穿越整数及半整数共振点的现象.通过对注入能量为1MeV,加速电压分别为1kV和2kV时的模拟计算,确定了束流安全穿越整数及半整数共振点对二极铁和四极铁加工误差的要求.     

混凝土构件长期干缩应力的计算

本文用有限元法从砼的水分扩散方程中求出湿度和自由干缩应变场,分别由砼的线性和非线性蠕变理论及拉应变软化模型,推导出计算砼构件的干缩应力的递推公式,并编制了电算程序。计算表明,非线性理论的结果与线性理论的结果相差不大,而拉应变软化模型的结果与前两者有较大差异。