内质网应激对碳离子辐照宫颈癌HeLa 细胞的影响

利用不同剂量的碳离子辐照二硫苏糖醇(2.5 mmol/L) 预处理的HeLa 细胞,探讨了内质网应激反应对碳离子辐照宫颈癌HeLa 细胞的影响。实验发现:与单独辐照组相比,二硫苏糖醇联合碳离子辐照后细胞的存活率下降,而凋亡率增加;二硫苏糖醇联合碳离子辐照加重了碳离子辐照引起的细胞周期阻滞;且联合辐照组的自噬被明显激活。结果表明,持续的内质网应激可改变宫颈癌HeLa 细胞对碳离子辐照反应,且二硫苏糖醇可能通过影响HeLa 细胞的自噬性细胞死亡通路发挥作用。To investigate the effect of endoplasmic reticulum stress on HeLa cells to 12C6+ ion irradiation,HeLa cells were pretreated with 2.5 mmol/L dithiothreitol and irradiated by 12C6+ ions with different doses.The results showed that, compared with IR alone, dithiothreitol combined with carbon ion irradiation caused HeLa cell survival decreased, and the apoptosis increased. Moreover, dithiothreitol and carbon ion radiation combination treatment led to a significant increase of G2/M phase, and autophagy was activated obviously in combination treatment group. The results imply that continuous endoplasmic reticulum stress can change the response of HeLa cells to 12C6+ irradiation, and dithiothreitol may affect HeLa cells through the autophagy cell death pathway.     

辐照诱导人正常肝细胞系HL-7702 细胞远后的微卫星不稳定性

采用高传能线密度(LET) 的12C6+离子束和低LET 的X 射线辐照人正常肝细胞系HL-7702 细胞,利用微卫星不稳定性(MSI) 检测来分析直接受照射细胞和通过转移培养基方式旁细胞传代八代子细胞以MSI 表征的远后效应。实验结果表明,12C6+离子束诱导的远后效应较X射线的低;旁细胞的远后效应较直接受照射细胞的高;辐射引起的MSI 与杂合性丢失(LOH) 的发生率具有位点特异性。结果提示,重离子放射治疗较X 射线放射治疗对正常组织引发的辐射风险要小,可通过对MSI 高发位点的筛选来评估放疗后患者长期生存状况和二次癌症发生风险。Human normal liver cell line HL-7702 cells were irradiated with high linear energy transfer (LET) 12C6+ ions and low-LET X-rays, respectively. Delayed effect in terms of microsatellite instability (MSI) in progenies of the directly irradiated cells and bystander cells, obtained in the way of medium transfer at the 8th passage postirradiation,were examined. The delayed effect induced by the high-LET 12C6+ ions was different from that induced by the low-LET X-rays, and a higher incidence of MSI was observed in the progenies of the cells after exposure to the X-rays than to the 12C6+ ions. We also found that the delayed effect in the progenies of the bystander cells was much more severe than thoseof directly irradiated cells. Furthermore, the events of MSI and loss of heterozygosity (LOH) induced by the ionizing radiations were not randomly distributed throughout the genome and specific loci existed indeed. These results imply that the radiation risk to normal tissues is lower in heavy ion therapy than in conventional X-ray radiotherapy, and the analysis of microsatellite loci with MSI high frequency occurrence can be applied to access long-term survival condition and second cancer risk for the patients after radiotherapy.     

碳离子辐照对神经胶质瘤干细胞杀伤的研究

虽然重离子束治癌已经被证明有着射程精确、入口坪区剂量小、相对生物学效应高等显著优点,但重离子辐照对肿瘤干细胞所产生的辐射生物学效应特性依旧不明确。本研究使用人源神经胶质瘤干细胞来研究在面对肿瘤干细胞时,重离子相对于传统X射线是否有明显的生物学优势。实验结果证明,在神经胶质瘤干细胞中,2 Gy碳离子造成的DNA损伤的修复率比X射线造成的损伤修复率要低;MTT实验则证明经过碳离子辐照的肿瘤干细胞活力要比X射线辐照的肿瘤干细胞低得多。综上所述,面对神经胶质瘤干细胞,碳离子能更有效地靶向肿瘤干细胞从而相对于传统X射线有明显的生物学优势。这些发现对于更好地理解重离子束治癌相关的生物学效应有重要的作用。Though heavy-ion therapy has demonstrated significant benefits such as well-defined range, small entrance dose and high relative biological effectiveness, the characteristics of radio-biological effects on cancer stem cells induced by heavy-ion treatment is not completely clear. In this paper, we used human glioma cancer stem cells to investigate whether heavy ions offered a biological advantage, by effectively targeting cancer stem cells, in comparison to conventional X-rays. Our results showed that the repair rate of DNA damage generated by 2 Gy of carbon ions was lower than that generated by X-rays in glioma stem cells. MTT assay showed that the viability of cancer stem cells irradiated by carbon ions was significant lower than that irradiated by X-rays. Taken together, carbon ions showed a biological advantage over X-rays by effectively targeting glioma cancer stem cells. These findings have significant importance in understanding the biological effects related to heavy-ion therapy.     

碳离子辐照对人肺癌细胞A549细胞周期进程的影响

选取对数生长期人肺癌细胞A549接受0—6.0 Gy 碳离子照射， 用克隆形成法检测细胞的存活率； 并于照射后12和24 h收集细胞， 用流式细胞术检测细胞周期各时相的细胞百分比， 观察不同剂量碳离子辐照对A549细胞周期进程的影响。 结果显示: 0—6.0 Gy 碳离子照射后细胞存活率显著下降； 照射后12 h细胞发生G0/G1期阻滞， 而照射后24 h， 1.0 Gy 照射组细胞在G0/G1期阻滞， 2.0—6.0 Gy 照射组细胞在G2/M期阻滞。 上述结果表明， 在A549细胞接受碳离子照射后的12 和24 h内， 1.0 Gy 照射可持续激活细胞G1期检查点， 而2.0—6.0 Gy 碳离子照射后其细胞周期进程是随时间变化的。 To investigate the effects of cell cycle progression of A549 cell induced by 12C6+ ion irradiation at different doses, the survival fractions of the A549 cells were determined by colony forming assay; cell cycles were analyzed by FACS at 12 h or 24 h after irradiation. The results showed that the percentage of survival in the A549 cells decreased with irradiation doses. Compared with control group， the percentage of the cells in G0/G1 phase significantly increased at 12 h after irradiation with different doses of 12C6+ ions. However， at 24 h after irradiation the percentage of the cells in G0/G1 phase significantly increased with 1.0 Gy 12C6+ ions， while the cells showed increasing percentage in G2/M phase with 2.0, 4.0 or 6.0 Gy 12C6+ ions. The results suggested that G1 cell cycle checkpoint was activated in 12—24 h after irradiation with 1.0 Gy 12C6+ ions， but after irradiation with 2.0—6.0 Gy 12C6+ ions， the cell cycle progression of the A549 cells changed with time.     

和厚朴酚对非小细胞肺癌细胞的辐射增敏效应

研究了和厚朴酚（HNK）对非小细胞肺癌（NSCLC）细胞系A549和H1299对低线性能量转移（LET） X射线和高LET碳离子的辐射增敏效应。首先用CCK-8检测了HNK对A549和H1299细胞的生长抑制情况,发现20 μmol/L的HNK处理对细胞的生长抑制作用较弱。用该浓度HNK预处理细胞2 h后给予不同剂量X射线或碳离子的照射,克隆存活法检测细胞的辐射敏感性,Annexin-PI双染法检测细胞凋亡,γH2AX焦点法检测DNA的双链断裂（DSB）损伤。实验结果显示:与X射线相比,NSCLC细胞对碳离子更敏感,HNK预处理仅对碳离子照射有辐射增敏作用;与碳离子单独照射相比,HNK预处理联合碳离子照射诱导了更明显的细胞凋亡;在照射后24 h,HNK预处理联合碳离子照射引起的细胞γH2AX焦点阳性率维持在较高水平,而X射线照射没有这些效应。实验结果表明,HNK预处理抑制了NSCLC细胞DNA的DSB修复,诱导了细胞凋亡的发生,从而提高了细胞对碳离子的辐射敏感性。The radiosensitizing effect of Honokiol (HNK) on non-small cell lung carcinoma (NSCLC) cell lines A549 and H1299 to low-linear energy transfer (LET) X-rays and high-LET carbon ions was investigated in this study. First, the inhibitory effects of HNK on the growth of A549 and H1299 cells were detected by CCK-8 assay, and 20 μmol/L HNK treatment was found to induce a growth inhibitory effect slightly in these two cell lines. Cells were pre-treated with HNK and then irradiated with X-rays and carbon ions of different doses. Cellular radiosensitivity, apoptosis and DNA damage were analyzed by clonogenic survival, Annexin-PI staining and γH2AX foci, respectively. The results showed the cells were more sensitive to carbon ion irradiation compared to X-rays and the radiosensitization of HNK was only observed after carbon ion irradiation. Furthermore, the co-treatment led to higher apoptosis rate 48 h after irradiation and increased the positive rate of γH2AX foci 24 h after irradiation in A549 and H1299 cells compared with those in the groups treated with carbon ion irradiation alone. These phenomena were not observed after X-ray irradiation. Our data suggest that the pre-treatment with HNK inhibited DNA DSB repair, induced apoptosis and then enhanced the cellular radiosensitivity to carbon ions in NSCLC cells.     

Ne离子束辐照引起Gd2Ti2O7烧绿石体积肿胀效应研究

在液氮低温下用400 keV的Ne2+离子束对Gd₂Ti₂O₇多晶烧绿石进行了辐照实验研究, 离子束辐照量范围为5×1014—1×1016ions/cm2。利用掠X射线衍射技术对样品辐照层的结构变化进行了分析表征, X射线的掠射角分别为γ=0.25°, 0.5°, 1°和3°。结果表明: 在该实验条件的离子束辐照下, Gd₂Ti₂O₇辐照层会发生明显的体积肿胀效应, 体积肿胀程度随入射离子束辐照量的增大而增大; 在同一辐照量下, 辐照层的体积肿胀程度也随X射线入射角的增大而增大。当辐照量达到1×1016ions/cm2时, 辐照层发生非晶化相变。Polycrystalline pyrochlore Gd₂Ti₂O₇ compounds were irradiated with 400 keV Ne2+ ions at cryogenic temperature (~77 K). The irradiation fluences was ranging from 5×1014 to 1×1016 ions/cm2, corresponding to a peak ballistic damage dose of ~0.16 to 3.3 displacements per atom . Irradiation\|induced structural evolution was examined using grazing incidence X\|ray diffraction (GIXRD) at angles from 0.25° to 3° degrees. It was found that the lattice parameter increases as a function of (1) X\|ray incident angle and (2) ion irradiation fluence, suggesting that the irradiated layer is volumetrically swelled compared with the underlying un\|irradiated substrate. At ion fluence of 1×1016 ions/cm2, the irradiation layer was found to be amorphous.     

替拉扎明-金纳米粒子复合物对人肝癌HepG2细胞的辐射增敏效应研究

将替拉扎明(TPZ) 与聚乙二醇包被的金纳米粒子(PEG-GNP) 偶联,形成新型替拉扎明-金纳米粒子复合物(TPZ-PEG-GNP)。利用酶标仪获得TPZ-PEG-GNP 在200  800 nm范围内的紫外-可见光吸收光谱;采用电感耦合等离子体质谱(ICP-MS) 检测TPZ-PEG-GNP 在人肝癌HepG2 细胞中的摄取量;MTT法检测TPZ-PEG-GNP 对HepG2 细胞增殖活力的影响;香豆素-3-羧酸(3-CCA) 羟自由基探针检测X 射线和碳离子辐照下TPZ-PEG-GNP 在水中的羟自由基辐射增强效应;克隆形成法检测X 射线及碳离子辐照下TPZ-PEG-GNP 对HepG2 细胞的辐射增敏效应。实验结果表明:TPZ偶联到PEG-GNP 上形成的TPZPEG-GNP 对HepG2 细胞基本无毒;在有氧条件下,TPZ-PEG-GNP 在水中显著增加X射线和碳离子辐照下的羟自由基产额,对HepG2 细胞具有明显的辐射增敏效应;在X 射线及碳离子辐照下10% 存活水平时,TPZ-PEG-GNP 对HepG2 细胞的辐射增敏比分别为1.23 和1.47。

Tirapazamine (TPZ) was conjugated with polyethylene-glycol-coated gold nanoparticles (PEGGNP) to form new tirapazamine-gold nanoparticle compounds (TPZ-PEG-GNP). UV-vis absorption spectrum of TPZ-PEG-GNP at wavelengths from 200 to 800 nm was measured with a microplate reader. The kinetics
of TPZ-PEG-GNP uptake by human hepatoma  HepG2 cells was determined using inductively coupled plasma mass spectrometry (ICP-MS). To evaluate the cellular toxicity of TPZ-PEG-GNP, the effect of TPZ-PEG-GNP on HepG2 cell viability was examined by means of the MTT method. Moreover, the radiation enhancement effect of hydroxide radical production in ultra-pure water with TPZ-PEG-GNP exposed to X-rays and carbon ions was investigated using coumarin-3-carboxylic acid (3-CCA) as the free radical probe. More importantly, the radiosensitizing effect of TPZ-PEG-GNP on HepG2 cells irradiated with X-rays and carbon ions was assessed with the clonogenic survival assay. Our experimental results indicate that TPZ-PEG-GNP had nearly no toxicity to HepG2 cells. The yield of hydroxide radicals in ultra-pure water in the presence of TPZ-PEG-GNP after exposure to X-rays and carbon ions increased obviously and an obvious radiosensitizing effect of TPZ-PEG-GNP on HepG2 cells was observed under aerobic conditions. The radiation enhancement ratio of TPZ-PEG-GNP on HepG2 cells exposed to X-rays and carbon ions was 1.23 and 1.47 at 10% survival level.     

12C6+离子束辐照番茄种子当代效应

利用辐射能量为80 MeV/u 的12C6+重离子束辐照番茄种子, 辐照剂量分别为30, 60, 90, 120和160 Gy研究其对番茄M1代的生物学效应。结果表明, 随着辐照剂量的增大, 番茄的发芽率和成苗率降低, 且成苗率明显低于发芽率, 发现辐照损伤主要抑制了根的生长; MDA和脯氨酸含量变化的总体趋势为随着辐照剂量的增大先升后降再升高, 说明高剂量C离子辐照对生物膜造成更严重的损伤; APX活性随着辐照剂量的增大呈先升后降再升高的趋势, 表明APX在清除活性氧中起主要作用; POD和SOD活性的总体趋势是随着辐照剂量的增大而降低, 且明显低于对照组。综合分析表明, 12C6+重离子束辐照番茄种子, 对M1代具有明显的损伤效应, 高剂量辐照对番茄种子造成的损伤更大, 使酶的活性降低, 抑制植株生长。 To investigate the M1 biological effects of heavy ions irradiation on Lycopersicon esculentum Mill., its seeds were irradiated by 12C6+heavy ions (80 MeV/u) with the dosages of 30, 60, 90, 120 and 160 Gy respectively . The results showed that with doses increased gradually, germination rate and seedling rate of Lycopersicon esculentum Mill. were decreased, and the latter was lower than the former, mainly due to the inhibition of root growth. The irradiation increased the content of MDA and proline evidently, showing irradiation could damage biomembrane, and also decreased the activities of POD and SOD with distinct inhibition pattern. However, the low dose and high dose irradiation promoted APX activity, illustrating APX was induced to protect irradiation injury. In brief, exposure to 12C6+ heavy ions had obvious injury effects on the seeds of Lycopersicon esculentum Mill.. Heavy ions irradiation damaged biomembrane, inhibited activities of enzymes, and finally inhibited the growth of the first generation of these seeds.     

不同剂量重离子辐照玉米自交系的生物学效应比较

用12C6+和 36Ar18+离子束分别辐照玉米自交系干种子和浸泡种子, 研究了M1—M3代重离子束辐照的生物学效应。 结果表明: 种子发芽势和发芽率随辐照剂量的增加而下降, 不同生理状态的种子对重离子辐照的敏感性也不同。 一般12C6+ 离子辐照干种子的适宜剂量为20—25 Gy; M1代叶型发生明显的变化, M2代植株在株高、穗位、单株穗数、雄穗花药颜色、粒质、穗行数、粒重和抗性等方面均发生了变化, 并产生了许多有益的变异,包括株高和穗位降低、同位多穗、穗行数和粒重增加、粒质由粉质变为硬粒以及抗锈病和红叶病的植株等, 有益突变的频率达7.0％—17.9％;在M3代出现能够稳定遗传的,并且光合效率增加的有益突变株。由此可见,重离子束辐照是玉米种质改良的一种高效手段。 In order to study biological effects of heavy ion irradiation on maize inbred lines, the agronomic traits and photosynthetic rates were investigated from M1 to M3 of maize seeds irradiated with 12C6+ and 36Ar18+ ions．The results showed that the germination rate and planting percent of maize seeds irradiated were decrease as dosage increasing of heavy ion irradiation. Different physiological status of seeds had disparate sensibility to heavy-ion irradiation and the suitable dosage of 12C6+ ion irradiation was 20—25 Gy for dry maize seeds. The leaf type of the plant happened visible changes in M1 generation. The plant height, spike position, spike number per plant, anther color of staminate,grain texture,spike row,grain weight and resistance had changes in M2 generation. Among them occurred some beneficial mutations that include degrading of plant height and spike position height, multi spike at same position in the plant, increasing of pike row and grain change of grain texture from powder seed to hard seed,resistance to rust disease and red leaf disease and so on. The frequency of beneficial mutation was 7.0％—17.9％. Those beneficial mutations could be stably inherited and mutant plants with high photosynthetic efficiency emerged in M3 generation. The study above showed that heavy ion irradiation is a high performance means for improvement germplasm of maize.     

二烯丙基二硫对12C6+离子束辐照损伤小鼠的保护作用研究

研究大蒜素重要活性成分二烯丙基二硫( Diallyl disulfide, 简称DADS) 对12C6+离子束辐照损伤小鼠的保护作用。利用4 Gy 剂量12C6+离子束对不同浓度DADS 预处理的雄性昆明小鼠进行单次全身照射。随后检测骨髓细胞微核率和肝组织中丙二醛(MDA) 含量、蛋白质总羰基含量、总抗氧化能力( TAOC)及谷丙转氨酶(ALT ) 活性。结果显示,与单纯照射组相比,低浓度DADS 预处理组骨髓细胞微核率和肝组织ALT 活性均显著降低(p<0.001),而肝组织T-AOC明显增强( p < 0.05 );中浓度DADS 预处理组肝组织中MDA 含量和蛋白质总羰基含量均显著减少( p < 0.05 )。结果提示,DADS通过抑制氧化应激,有效地保护了脂质、蛋白质和遗传物质免受12C6+离子束辐照引起的损伤。The radioprotective effect of Diallyl disulfide (DADS) on 12C6+ ion irradiation was studied. Pretreated with DADS of different concentration, male Kung-Ming mice were exposed to whole body irradiation with dosage of 4 Gy 12C6+ ion. The animals were sacrificed after irradiation. Then the bone marrow cells micronucleus rate, malondialdehyde (MDA) levels, content of protein carbonylation, total antioxidant capacity ( T-AOC) and alanine aminotransferase ( ALT ) activity were measured. As compared with those in irradiated group, the ratio of micronucleus cells in marrow and the hepatic ALT activity in the pretreatment group with low dose DADS decreased significantly ( p < 0.001 ). Similarly,the content of protein carbonylation and the levels of MDA droped dramatically in the group with middle dose DADS treatment ( p < 0.05 ). On the contrary, the hepatic T-AOC increased markedly in the group of pretreatment with low dose DADS ( p < 0.05 ). The results showed that DADS protect lipoid, protein and genetic material from 12C6+ ion irradiation by right of resisting oxidative stress.     

快重离子辐照对MoS2热导率的影响研究

利用0.97 GeV的209Bi离子辐照二硫化钼（MoS₂）晶体,辐照注量范围为1×1010～1×1012 ions/cm2,结合原子力显微镜（AFM）观测和Raman光谱分析研究了快重离子辐照对MoS₂热导率的影响。实验结果显示,快重离子辐照在MoS₂中产生了潜径迹,较高激光功率下的Raman测试使样品局部温度升高,导致E_1/2g和A_1g峰随注量增加向低波数方向移动,且峰形展宽。引入了通过改变激光功率测量Raman光谱得到MoS₂热导率的计算方法,获得了不同辐照注量下MoS₂的热导率的定量分析结果,随注量增加,热导率不断降低,从未辐照样品的563 W/mK下降到1×1012 ions/cm2辐照时的132 W/mK。Molybdenum disulphide (MoS₂) was irradiated by 0.97 GeV 209Bi ions with the fluence of 1×1010 to 1×1012 ions/cm2. The irradiation effect on the thermal conductivity of MoS₂ was analyzed by atomic force microscope (AFM) and Raman spectroscopy. The experimental results show that hillock-like latent tracks are observed on irradiated MoS₂ by AFM. The measurement of MoS₂ by Raman spectrometer with high laser power results in the increase of local temperature of MoS₂, which cause the downshift of peaks position and broadening of E_1/2g and A_1g peak. Furthermore, according to Raman spectra measured at different laser power, thermal conductivity of MoS₂ before and after irradiation was calculated, which show that the thermal conductivity of MoS₂ decreases with increasing fluence, from 563 to 132 W/mK for pristine and 1×1012 ions/cm2 irradiated MoS₂, respectively.     

退火对Pb辐照Al2O3单晶发光特性的影响

研究了230MeV的²⁰⁸Pb²⁷⁺辐照Al₂O₃样品及随后在600,900,1100K高温条件下退火后的光致发光特性。从辐照样品的测试结果可以清楚地看到在波长为390,450nm处出现了强的发光峰。辐照量为1×10¹³ions/cm²时,样品的发光峰最强。经过600K退火2h后测试结果显示,380nm发光峰剧烈增强,而其他发光峰显示不明显。在900K退火条件下,380nm的发光峰开始减弱,而在360,510nm出现了明显的发光峰,至到1100K退火完毕后380nm的发光峰完全消失,而360,510nm的发光峰相对增强。从被辐照样品的FTIR谱中看到,波数在460~510cm^-1间的吸收是振动模式,经过离子辐照后,吸收带展宽,随着辐照量的增大,Al₂O₃振动吸收峰消失,说明Al₂O₃振动模式被完全破坏。1000~1300cm^-1之间为Al—O—Al桥氧的伸缩振动模式,辐照后吸收带向高波数方向移动,说明其振动模式受到影响。辐照剂量较小的样品,损伤程度相对较低,经退火晶化后,振动模式基本恢复到单晶状态;辐照剂量较高的样品,损伤程度大,退火处理后表面变得较粗糙,振动模式并未出现,说明结构破坏严重。     

快重离子辐照对非晶态SiO2薄膜光致发光谱的影响

用湿氧化法在单晶硅表面生长了非晶态SiO2薄膜,再用高能Pb和Xe离子对薄膜进行辐照,最后用荧光光谱分析了辐照参数(剂量、电子能损值)与发光特性改变的相关性.研究发现,快重离子辐照能显著影响薄膜的发光特性,进一步分析显示,辐照导致了SiO2薄膜内O-Si-O缺陷、缺氧缺陷和非桥式氧空位缺陷的产生,且缺氧缺陷和非桥式氧空...     

Field-induced insulator-metal-insulator transitions in low-energy H_2~+ ion-irradiated epitaxial La_(2/3)Ca_(1/3)MnO_3 thin films

Epitaxial La 2/3 Ca 1/3 MnO 3 thin films grown on LaAlO 3 (001) substrates were irradiated with low-energy 120-keV H 2 + ions over doses ranging from 10 12 ions/cm 2 to 10 17 ions/cm 2 . The irradiation suppresses the intrinsic insulator-metal (I-M) transition temperature and increases the resistance by reducing the crystallographic symmetry of the films. No irradiation-induced columnar defects were observed in any of the samples. The specific film irradiated at a critical dose around 8 × 10 15 ions/cm 2 is in a threshold state of the electric insulator where the I-M transition is absent. In an external field of 4 T or higher, the I-M transition is restored and thus an enormous magnetoresistance is observed, while a negative temperature coefficient resumes as the temperature is reduced further. Magnetic relaxation behavior is confirmed in this and other heavily irradiated samples. The results are interpreted in terms of the displacement of oxygen atoms provoked by ion irradiation and the resulting magnetic glassy state, which can be driven into a phase coexistence of metallic ferromagnetic droplets and the insulating glass matrix in a magnetic field.     

The BCC to FCC/HCP phase transformation of the Co70Fe30 alloy produced by ion irradiation of Co70Fe30/Cu discontinuous multilayers

We report on the BCC to FCC/HCP structural transformation of Co₇₀Fe₃₀ alloy produced by room temperature ion irradiation of Co₇₀Fe₃₀/Cu discontinuous multilayers. The structural changes were analyzed by X-ray diffraction and X-ray absorption spectroscopy. For this study, two different samples were examined, one irradiated with 50 keV He⁺ and another with 600 keV Kr⁺ with doses of 1×10¹⁷ and 3×10¹⁵ ions/cm², respectively. No substantial change is observed after He⁺ irradiation, while after Kr⁺ irradiation an unexpected structural transition from BCC to FCC/HCP closed packed of the Co₇₀Fe₃₀ alloy was found.     

Structural modification in swift heavy ion irradiated muscovite mica

Two-layer monoclinic(2 M) muscovite mica sheets with a thickness of 12 μm are irradiated with Sn ions at room temperature with electronic energy loss( dE/dx)_e of 14.7 keV/nm. The ion fluence is varied between 1×10~(11) and1×10~(13) ions/cm~2. Structural transition in irradiated mica is investigated by x-ray diffraction(XRD). The main diffraction peaks shift to the high angles, and the inter-planar distance decreases due to swift heavy ion(SHI) irradiation. Dehydration takes place in mica during SHI irradiation and mica with one-layer monoclinic(1 M) structure is thought to be generated in 2 M mica after SHI irradiation. In addition, micro stress and damage cross section in irradiated mica are analyzed according to XRD data. High resolution transmission electron microscopy(HRTEM) is used on the irradiated mica to obtain the detailed information about the latent tracks and structural modifications directly. The latent track in mica presents an amorphous zone surrounded by strain contrast shell, which is associated with the residual stress in irradiated mica.     

调幅W(Mo)/Cu纳米多层膜He+离子辐照响应行为

用磁控溅射技术制备不同调幅波长 (L) 的W(Mo)/Cu纳米多层膜,所制膜系在60 keV氦离子 (He⁺) 辐照条件下注入不同剂量: 0, 1×10¹⁷ He⁺/cm², 5×10¹⁷ He⁺/cm². 用X射线衍射仪 (XRD) 和高分辨透射电子显微镜(TEM)表征W(Mo)/Cu纳米多层膜辐照前后微观结构. 研究结果表明: 1) He⁺离子轰击引起温升效应是导致沉积态亚稳相β-W 转变成稳态 α-W相的主因, 而与调幅波长无明确关联; 2) 纳米多层结构中W(Mo) 和Cu膜显现出的辐照耐受性与调幅波长相关, 调幅波长越小, 抗He⁺的辐照性能越强; 3) 在5×10¹⁷ He⁺/cm²注入条件下, 观察到He团簇/泡在纳米结构W(Mo) 和Cu膜中的积聚行为存在明显差异: 在W (Mo) 膜中He团簇/泡的分布与晶粒取向相关, He团簇/泡倾向于沿W (211) 晶面分布; 而Cu膜非晶化且He团簇/泡在其体内呈均匀分布. 关键词： W(Mo)/Cu纳米多层膜 +辐照')" href="#">He⁺辐照 He团簇/泡 相转变     

Effect of the adiabatic process on the absorption in heavy-ion scattering

We have succeeded in obtaining the optical model potential for ¹²C---¹²C scattering at low incident energies (10 MeV E_cm 20 MeV), by applying the adiabatic approximation to the coupled channels equation. As for this potential inelastic channels of single and mutual excitations of ¹²C^*(2⁺, 4.43 MeV) make a contribution to the real part and not to the imaginary part.     

Modification of optical, chemical and structural response of CR-39 polymer by 50 MeV lithium ion irradiation

CR-39 polymer samples were irradiated with 50 MeV lithium ion beam; the fluence was varied in the range 10¹¹–10¹³ ionscm⁻². Irradiation effects were studied using UV–visible, FTIR spectroscopic and X-ray diffraction techniques. The observation of the recorded spectra shows that the detector is sensitive to swift ions irradiation and its UV absorption is influenced by the stopping power (dE/dx)_e. The FTIR spectra does not show any considerable changes due to the irradiation indicating that the detector is chemically stable. No appreciable change in the diffraction pattern of CR-39 polymer after irradiation upto the fluence level of 10¹³ ionscm⁻² is observed, showing its structural stability also.     

CVD法单层MoS2在209Bi离子辐照下的损伤效应研究

通过光学显微镜、拉曼光谱确定了CVD（化学气相沉积法）制备的不同厚度MoS₂的层数,采用拉曼分析结合原子力显微镜观测分析了由HIRFL提供的高能209Bi离子辐照CVD制备的单层MoS₂样品随辐照注量的损伤规律。随辐照注量增加,E_2g1和A_1g两种声子振动模式对应的拉曼峰逐渐蓝移,且拉曼特征峰强度减弱,这是由于带正电荷的209Bi辐照产生潜径迹型晶格缺陷吸附空气中氧分子而引入p型掺杂引起的。同时,在辐照注量为5×1010 ions/cm2的单层MoS₂的AFM图像中观察到潜径迹主要以凹坑形式出现,与机械剥离法观测到的凸起径迹明显不同,分析了不同制备工艺对径迹形貌的影响。比较了机械剥离法制备MoS₂样品的拉曼光谱和AFM成像的实验数据和结果,认为不同制备方法会影响单层或少层MoS₂的电子密度。The layer number of MoS₂ with different thickness was determined by the optical microscope and Raman spectra. And the damage effect of the CVD (chemical vapor deposition) prepared single-layer MoS₂ sample irradiated by 209Bi ions was analyzed by the combination of Raman analysis and AFM observations. With the increase of irradiation fluence, the Raman characteristic peaks of E_2g1 and A_1g corresponding to both phonon vibration modes gradually bluely shift, and the intensity of the peaks obviously decreased. This is due to the fact that the 209Bi ion irradiation results in the latent track type lattice defects and they adsorb the oxygen molecules in the air ended with the p-type doping. Meanwhile, from the AFM image of the mono-layer of irradiated MoS₂ under the 5×1010 ions/cm2, it can been seen that latent tracks mainly occur in the form of pits, which different from the hillock tracks observed by mechanical stripping method. The influence of different preparation technology to the track morphology is analyzed. Compared with the Raman and AFM results of MoS₂ prepared by mechanical stripping, it is considered that different preparation methods will affect the electron density in single or few layers of MoS₂.