噻嗪酮·毒死蜱乳油防治稻飞虱试验

为探索噻嗪酮·毒死蜱乳油对水稻稻飞虱的防治效果，我们进行了试验。试验表明：42％噻嗪酮·毒死蜱乳油对稻飞虱有较好的防效，以666．7m^2施药40克，有明显防效，施药有效成分量为190克-250克/hm^2。     

300 MeV质子重离子同步加速器慢引出动力学研究

300 MeV质子重离子同步加速器是SESRI(空间环境模拟研究装置)的重要组成部分，慢引出系统动力学研究是该同步环设计的关键。引出系统采用三阶共振慢引出与RF-Knockout(RF-KO)方案为终端提供2～8 s准连续束，在引出静电偏转板处利用3-bump局部凸轨可适当调节螺距和引出角度，但同时也会减小水平工作点，缩小相空间稳定区面积，影响束流正常引出。模拟结果表明，凸轨内二极磁铁和六极磁铁会引起水平工作点减小，造成引出初始阶段粒子大量溢出。因此，基于自主编写的粒子追踪程序SESP对束流时间结构进行了分析，并通过优化激励调幅曲线改善了束流时间结构的均匀性。     

Simulation of loss of uranium ions due to charge changing processes in the CSRm ring

Significant beam loss caused by the charge exchange processes and ion impact-induced outgassing may restrict the maximum number of accelerated heavy ions during the high intensity operation of an accelerator. In order to control beam loss due to charge exchange processes and confine the generated desorption gas, tracking of the beam loss distribution and installation of absorber blocks with low-desorption rate material at appropriate locations in the main Cooler Storage Ring (CSRm) at the Institute of Modern Physics, Lanzhou, will be performed. The loss simulation of uranium ions with electron-loss is presented in this report and the conclusion is that most charge changed particles are lost in the second dipole of the super-period structure. The calculation of the collimation efficiency of the CSRm ring will be continued in the future.     

试论提高初中物理教学质量的举措

初中物理是一门可以贴近生活,可以培养学生问题意识,培养学生实验能力的学科,在初中物理教学中,物理老师可以从这几个方面引导学生学好初中物理,同时也必然能够提高初中物理的教学质量。     

强流电子枪电子光学性能的研究

 利用SLAC-226程序对一种工业用大功率电子加速器(450kW)的电子枪光学系统性能进行了研究。计算程序以带电粒子的洛伦兹力运动方程的相对论形式为基础，在充分考虑了空间电荷效应和电子自身产生磁场的情况下编写而成。在该程序中，网格的划分采用正方形网格；解泊松方程采用半迭代切比雪夫法；解轨迹方程采用四阶龙格 库塔法。经过对轴上电位的优化计算，得到了轴上电场的分布，电子轨迹以及阳极孔处的径迹斜率等结果，并且对外加电场与空间电荷场对束流的聚焦作用作了比较分析。计算发现，电子初始角和初始能量（对束流的）聚焦性能影响很小，二极管间距 d=58.5mm时对束流聚焦最有利。     

Absolute dielectronic recombination rate coefficients of highly charged ions at the storage ring CSRm and CSRe

Dielectronic recombination(DR) is one of the dominant electron–ion recombination mechanisms for most highly charged ions(HCIs) in cosmic plasmas, and thus, it determines the charge state distribution and ionization balance therein.To reliably interpret spectra from cosmic sources and model the astrophysical plasmas, precise DR rate coefficients are required to build up an accurate understanding of the ionization balance of the sources. The main cooler storage ring(CSRm) and the experimental cool...     

Enhancement of electron–ion recombination rates at low energy range in the heavy ion storage ring CSRm

Recombination of Ar¹⁴⁺, Ar¹⁵⁺, Ca¹⁶⁺, and Ni¹⁹⁺ ions with electrons has been investigated at low energy range based on the merged-beam method at the main cooler storage ring CSRm in the Institute of Modern Physics, Lanzhou,China. For each ion, the absolute recombination rate coefficients have been measured with electron–ion collision energies from 0 meV to 1000 meV which include the radiative recombination(RR) and also dielectronic recombination(DR)processes. In order to interpret the measured results, RR cross sections were obtained from a modified version of the semiclassical Bethe and Salpeter formula for hydrogenic ions. DR cross sections were calculated by a relativistic configuration interaction method using the flexible atomic code(FAC) and AUTOSTRUCTURE code in this energy range. The calculated RR + DR rate coefficients show a good agreement with the measured value at the collision energy above 100 meV.However, large discrepancies have been found at low energy range especially below 10 meV, and the experimental results show a strong enhancement relative to the theoretical RR rate coefficients. For the electron–ion collision energy below 1 meV, it was found that the experimentally observed recombination rates are higher than the theoretically predicted and fitted rates by a factor of 1.5 to 3.9. The strong dependence of RR rate coefficient enhancement on the charge state of the ions has been found with the scaling rule of q^3.0, reproducing the low-energy recombination enhancement effects found in other previous experiments.     

HIAF-BRing束团合并过程中的束流负载效应模拟

强流重离子加速器HIAF-BRing在加速完成后进行束团合并,为研究BRing中的束流负载效应对束团合并的影响,对238U35+束流进行了粒子跟踪模拟。模拟结果显示,在束团合并过程中,束流负载效应引起束团长度和束团中心位置的振荡,导致束流动量分散和束团长度的增长。束团合并过程中尾场电压以及不同束团间尾场的耦合导致的势阱畸变,是引起束团长度和束团中心振荡及束流发射度增长的原因。为了降低束流负载效应的影响,采用多谐波前馈系统进行补偿,达到了补偿束团合并过程中的束流负载效应的目的,从而确保了BRing中引出束流的品质,同时根据模拟结果确定了前馈系统需要覆盖的频率范围和需要补偿的最大尾场电压。     

束流物理学的量子方法初探

 量子束流物理学是近年来发展起来的处理束流传输的全新方法，它是经典束流物理学的有益补充。介绍了量子束流物理学的热波模型和基于狄拉克方程的相对论电子束磁透镜量子理论，并与经典束流物理学方法进行了比较。     

SHER-HIAF ring lattice design

The Super Heavy Experimental Ring (SHER), which is one of the rings of the next accelerator complex High Intensity Heavy Ion Accelerator Facility (HIAF) at IMP, has to be optimized for e-cooling. Its lattice is designed for two modes: the first is the isochronous mode, which is a time-of-flight mass spectrometer for short-lived secondary nuclei, the second is the storage ring mode, which is used for collecting and cooling the secondary rare isotope beams from the transport line. In order to fulfil its purpose, the ion optics can be set to different ion optical modes.