4-1 Dielectronic Recombination of 36Ar15+ and 112Sn34+ at the CSRm

The total recombination rate coefficients of lithium-like 36Ar15+ ions have been measured by employing the electron-ion merged-beams technique at the heavy ion storage ring CSRm at IMP[1]. Fig. 1 (a) shows the DR spectrum for electron energy from 0 to 35 eV in the center-of-mass (c.m.) frame involving all the DR resonances associated with 2s1=2!2p1=2 and 2s1=2!2p3=2 excitations.

4-8 Dielectronic Recombination of 112Sn35+ Ions at the CSRm

The total recombination rate coefficient of Phosphorus-like 112Sn35+ have been measured at the main cooler storage ring (CSRm) employing the electron-ion merged-beams technique. The Phosphorus-like 112Sn35+ ions were injected into the CSRm at an energy of 3.7 MeV/u with a typical current of 50 eA, and the momentum spread of the ion beam is 210?4 after several seconds of cooling.

6-3 Closed Orbit Correction in Electron Cooler Section at CSRe

The injecting section and the cooler section are apart from each other at CSRm, while the electron cooler systemis installed at the injecting section of CSRe[1]. So for the CSRe we not only need to satisfy the beam injectingcondition but also need to satisfy the beam cooling condition. At present, we use the ramping bump and the kickerto inject beam, and after injection the bump disappear quickly and the beam goes to the cooling orbit and begincooling. This method has a disadvantage that the beam cooling condition cannot be satised until the bump isdown. In the past year, we try to nd a new method to correct the orbit of cooler section. Instead of using rampingbump we use the xed bump to satisfy the injecting and the cooling condition at the same time.

4-5 Dielectronic Recombination of Li-like Argon Ions at the CSRm

The main cooler storage ring (CSRm) equipped with an electron-cooler creates an ideal platform for dielectronicrecombination (DR) experiments. In order to fully understand our DR experimental setup and especially the electronenergy detuning system, we have performed a DR calibration experiment using the Li-like argon ions at theCSRm. The Ar15+ has a simple electronic structure so the DR spectrum can be calculated with an ultra-highprecision and compared with the existing experimental data. The experiment was carried out at the relative energyfrom 0 to 32 eV that includes all DR resonances associated with 2s1=2 ! 2p1=2 and most of the 2s1=2 ! 2p3=2excitations.

6-4 Longitudinal Electron Cooling Experiments at HIRFL-CSRe

The electron cooler was installed in one of the straight sections of CSRe which is used to provide high-qualitybeams for experiments. Longitudinally the dynamics of the cooling process have been studied for a series of electronbeam parameters and the friction force was measured with the aid of an RF-buncher for C6+ (122 MeV/u) and O8+(122 MeV/u) ions. The cooling time at different electron beam state have been measured, too.

First Beam Commissioning of SSC-Linac as an Injector of SSC

The construction of the SSC-Linac has made significant progress in 2019.The first beam commissioning of SSC-Linac as an injector of the Separated Sector Cyclotron(SSC)was performed succssfully with ^(40)Ar^(7+) beam and the particle energy of 5.98 MeV/u was obtained at the exit of SSC on December 17,2019.

黄土高原植被的时空变化及其驱动力分析研究

为研究气候变化及人类活动对植被的影响,本研究通过趋势分析探究黄土高原地区植被的时空变化,结合Hurst指数法以研究黄土高原植被的可持续性,采用相关分析和多元回归分析、残差分析等方法,探讨气候变化和人类活动对区域植被变化的影响。结果表明:1)黄土高原的植被在空间上由东南向西北呈现递减趋势,1982—2015年NDVI变化总体上呈弱上升趋势,2000年是NDVI时间序列的转折点,NDVI上升速度加快;2)Hurst指数表明研究区NDVI的未来变化趋势呈现持续性和反持续性的区域分别占13.70%和86.30%;3)相关分析和偏相关分析表明平均温度和降水对黄土高原NDVI均有显著影响,并且平均温度和降水对NDVI的综合影响更加明显;4)根据残差分析发现人类活动对植被的变化也有影响,改善和破坏作用并存。因此,1982—2015年黄土高原植被变化是气候变化和人类活动共同作用的结果,其中主要影响因素为人类活动,黄土高原地区气候因子对植被恢复的贡献率4.56%,非气象因子(人类活动)对植被恢复的贡献率为32.74%。