971 resultados para M1 (Tank)


Relevância:

10.00% 10.00%

Publicador:

Resumo:

The candidate chiral doublet bands recently observed in Cs-126 have been extended to higher spins, several new linking transitions between the two partner members of the chiral doublet bands are observed, and gamma-intensities related to the chiral doublet bands are presented by analyzing the gamma-gamma coincidence data collected earlier at the NORDBALL through the Cd-116(N-14, 4n)Cs-126 reaction at a beam energy of 65 MeV. The intraband B(M1)/B(E2) and interband B(M1)(in)/B(M1)(out) ratios and the energy staggering parameter, S(I), have been deduced for these doublet bands. The results are found to be consistent with the chiral interpretation for the two structures. Furthermore, the observation of chiral doublet bands in Cs-126 together with those in Cs-124, Cs-128, Cs-130, and Cs-132 also indicates that the chiral conditions do not change rapidly with decreasing neutron number in these odd-odd Cesium isotopes.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The heavy ion linac in Lanzhou is designed as a future injector for the Cooling Storage Ring (CSR). In order to keep the total machine within 40 meters, the IH (Interdigital H-type) structure is adopted for its higher acceleration gradient compared with the traditional DTL structure. The designed minimum charge over mass ratio is 1/6, the output energy is 16MeV/u and the beam current is 1A.mu A. The RFQ and the first DTL tank will work at 100MHz, and the other DTL tanks will work at the double frequency. The design criteria, main parameters and the detailed beam dynamic design are introduced in this paper.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

通过重离子熔合蒸发反应142Nd(32S,1p3nγ)170Re布居了缺中子双奇核170Re的高自旋激发态,识别出了该核的一条转动带并建议了其组态为πh1/2 νi13/2。基于对同中子素能级系统性、旋称反转系统性、带内B(M1)/B(E2)、准粒子Routhians、动力学转动惯量和Total Routhian Surface(TRS)等带结构特征的详细分析和讨论,进一步确认了对A=170核区目前最缺中子双奇核高自旋转动带组态、宇称和自旋值的指定。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

利用兰州重离子加速器提供的12C6+和36Ar18+离子束对玉米自交系郑58、鲁9801、金象4C-1、CSR24001、308和478进行辐照诱变育种试验,探讨了重离子辐照对玉米的诱变效应。结果显示,重离子辐照后种子出苗率和成苗率根据材料不同表现不一,浸泡后种子对辐照敏感性增加。辐照后M1代叶型变异较大;M2代植株经济性状发生变异较多,产生了许多有益的突变性状;M3代部分突变性状能够稳定遗传。由此可见,重离子束辐照育种有利于品种改良和种质创新,是玉米遗传改良的一种有效手段。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A linear accelerator as a new injector for the SSC (Separated Sector Cyclotron) of the HIRFL (Heavy ton Research Facility Lanzhou) is being designed. The DTL (Drift-Tube-Linac) has been designed to accelerate U-238(34+) from 0.140 MeV/u to 0.97 MeV/u. To the first accelerating tank which accelerates U-238(34+) to 0.54 MeV/u, the approach of Alternating-Phase-Focusing (APF) is applied. The phase array is obtained by coupling optimization software Dakota and beam optics code LINREV. With the hybrid of Multi-objective Genetic Algorithm (MOGA) and a pattern search method, an optimum array of asynchronous phases is determined. The final growth, both transversely and longitudinally, can meet the design requirements. In this paper, the deign optimization of the APF DTL is presented.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

通过重离子核反应116Cd(27Al,4n)与在束γ谱的实验技术,对A=130~140核区的奇A核139Pm的高自旋态进行了研究.根据γ-γ符合关系、γ射线的相对强度和各向异性度的测量结果,扩展并更新了139Pm的能级纲图.实验观测到基于πh11/2和πg7/2-[πh11/2]2(或者πd5/2-[πh11/2]2)组态的转动带,利用已有的理论计算结果对这些转动带进行了解释.同时还观测到三个具有很强M1跃迁、旋称劈裂很小的-I=1的带.通过简单分析和系统学比较,指认了它们的组态,发现它们具备磁转动带的特性,很可能是磁转动带.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

利用30,90,180Gy3种剂量的12C6+重离子束辐照大葱种子,研究其在细胞水平和农艺性状的诱变效应并进行RAPD分析。通过与M1代的研究结果比较后表明:经过不同剂量12C6+重离子照射后能有效地诱导大葱细胞形成微核和染色体畸变,这种诱变效应,在M2代仍然有所表现。M1代大葱结果期的株高、白长、花序直径和种子产量随辐照剂量增加产生明显差别,其中30Gy辐照组增幅最大。大葱总水溶性蛋白质和维生素C的含量在30Gy组中积累最多,在90Gy组有明显下降。与M1代一致,M2代中大葱染色体微核率及RAPD分析所得的DNA多态性比率仍然与辐照剂量呈正相关,但比率整体下降;说明高能量重离子辐照造成的DNA变异在M2代被修复和淘汰。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The high-spin states of Pm-140 have been investigated through the reaction Te-126(F-19, 5n) at a beam energy of 90 MeV. A previous level scheme based on the 8(-) isomer has been updated with spin up to 23 (h) over bar. A total of 22 new levels and 41 new transitions were identified. Six collective bands were observed. Five of them were expanded or re-constructed, and one of them was newly identified. The systematic signature splitting and inversion of the yrast pi h(11/2)circle times vh(11/2) band in Pr and Pm odd-odd isotopes has been discussed. Based on the systematic comparison, two Delta I = 2 bands were proposed as double-decoupled bands; other two bands with strong Delta I = 1 M1 transitions inside the bands were suggested as oblate bands with gamma similar to -60 degrees; another band with large signature splitting has been proposed with oblate-triaxial deformation with gamma similar to -90 degrees. The characteristics for these bands have been discussed.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

On the basis of previous work, the hyperfine-induced 3s3p P-3(2) -> 3s(2) S-1(0) E1 transition probabilities of Mg-like ions were further calculated using the GRASP2K package based on the multiconfiguration Dirac-Hartree-Fock method. The contribution to the lifetime of the P-3(2) level from the 3s3p P-3(2) -> 3s(2) S-1(0) hyperfine-induced E1, 3s3p P-3(2) -> 3s3p P-3(1) M1, 3s3p P-3(2) -> 3s(2) S-1(0) M2 and 3s3p P-3(2) -> 3s3p P-3(0,1) E2 transition was discussed in detail. It was found that hyperfine interaction has an obvious effect on the lifetime at the beginning of the Mg-like isoelectronic sequence.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

利用在束γ谱学技术和 173Yb(18O, 4n) 熔合蒸发反应研究了 187Pt 的高自旋态能级结构。在 78 和 85 MeV 束流能量下进行了X-γ-t和γ-γ-t符合测量。实验观测到基于νi13/2,ν7/2−[503],νi213/2νj, ν3/2−[512] 和ν1/2−[521] 组态的转动带,并且利用推转壳模型(CSM) 和总Routhian面(TRS) 模型对这些转动带的带交叉,形状共存等性质进行了解释。总Routhian面(TRS)计算表明νi13/2转动带具有显著的负γ形变;负宇称带具有近似长椭球的形变。通过比较带内B(M1)/B(E2)比率的实验值和由 Dönau 和 Frauendorf 的半经典公式得到的理论值,发现ν7/2−[503] 转动带在低转动频率下的带交叉是由一对 h9/2 质子顺排引起的

Relevância:

10.00% 10.00%

Publicador:

Resumo:

能量为140 MeV的27Al束流轰击145Nd氧化靶,通过145Nd (27Al,4nγ)168Ta熔合蒸发反应对双奇核168Ta的高自旋态进行了实验研究。扩展了基于πh11/2(9/2-[514])νi13/2(5/2+[402])和πd5/2(5/2+[402])νi13/2(5/2+[642])准粒子组态下的转动带能级纲图。根据实验测量结果,对两转动带的准粒子顺排特征作了分析。通过B(M1)/B(E2)的理论与实验值比较以及168Ta相邻双奇核能级间隔系统性,进一步确定了两转动带的准粒子组态和能级的自旋宇称

Relevância:

10.00% 10.00%

Publicador:

Resumo:

利用149Sm(27Al,4n)172Re反应产生并研究了双奇核172Re的高自旋态。实验中分别在130,135,140和150MeV束流能量下进行了激发函数测量,确立了最佳布居172Re核激发态的束流能量为130MeV。在130MeV能量下,进行了γ-γ符合测量。基于激发函数的测量结果和Kx-γ符合关系,指定了源于172Re的γ射线。通过分析γ射线之间的符合关系,建立了由6个转动带构成的172Re核的能级纲图。依据二准粒子Routhian的计算结果,以及B(M1)/B(E2)的实验提取值与理论值的比较,并结合相邻双奇核的带结构特征,给出了各转动带的准粒子组态。在推转壳模型框架下对转动带的顺排,动力学转动惯量进行了一些讨论

Relevância:

10.00% 10.00%

Publicador:

Resumo:

利用在束γ谱学技术和 173Yb(18O, 4n) 熔合蒸发反应研究了 187Pt 的高自旋态能级结构。在 78 和 85 MeV 束流能量下进行了X-γ-t和γ-γ-t符合测量。实验观测到基于νi13/2,ν7/2−[503],νi213/2νj, ν3/2−[512] 和ν1/2−[521] 组态的转动带,并且利用推转壳模型(CSM) 和总Routhian面(TRS) 模型对这些转动带的带交叉,形状共存等性质进行了解释。总Routhian面(TRS)计算表明νi13/2转动带具有显著的负γ形变;负宇称带具有近似长椭球的形变。通过比较带内B(M1)/B(E2)比率的实验值和由 Dönau 和 Frauendorf 的半经典公式得到的理论值,发现ν7/2−[503] 转动带在低转动频率下的带交叉是由一对 h9/2 质子顺排引起的

Relevância:

10.00% 10.00%

Publicador:

Resumo:

马蔺子是鸢尾科植物马蔺的干燥成熟的种子。本科植物的种子中富含对醌类化合物,据报道马蔺子甲素具有对γ射线的辐射增敏作用。本文研究了马蔺子甲素的分鉴定,基衍生物的制备以及对荷 S180 小鼠的重离子增敏作用。在研究马蔺子甲素 Q 以及衍生物 Q1-Q8 对荷 S180 小鼠的辐射增敏作用时,分别在有氧和乏氧条件下进行,小鼠被随机分成 6 组,对照组,γ射线照射组,碳离子照射组,背地里纯用药组,γ射线合并用药组,碳离子合并且药级。乏氧条件是通过夹住小鼠的茶瘤肢造成局部缺氧 20 分钟。马蔺子甲素及衍生物用叶温 -80 及生理一盐水稀释,在辐照前用药。γ射线的照射剂量为18Gy,而碳离子选用剂量为 6Gy, 肿瘤体积每隔 2 天测定一次,我们通过计算肿瘤的抑瘤率(IR),增敏比(SER),氧搁置比(OER)发现,在乏氧情况下 Q、Q7、Q8 全并碳离子的增敏比大于有氧情况下,同时氧搁置比降低,而抑瘤率和体外细胞毒率(HCR)的选择性增加。这一结论表明,某些对醌类化合物有选择性的增加乏氧细胞的敏感性。肿瘤中的乏氧细胞一直被认为是放疗不能完全奏效的主要原因,生物还原性药物在肿瘤的治疗中能杀死实体瘤中对射线不敏感的细胞。SR-4233 是一苯并三嗪二氧化物,它已被证明具有放射增敏作用,并且有选择性的细胞毒作用。通过 Beirut 瓜合成了两个(M1,M2) 喹喔啉类化合物,对荷 S180 小鼠的增敏作用实验分为 6 组,在乏氧情况下,单纯碳离子照射的抑瘤率 58.8%,而合并 M2 为 66.36%,合并 M1 为 70.1%。通过紫外光激发 M1 分子的 ESR 谱发现,此类化合物在光激发下发生 O-N=C-C=N-O 体系的的电子转移引起的双键转移,形成氮氧双自由基。推测碳离子可能产生更多的稳定自由基作用于 S180 瘤组织。同时研究了用重离子对乙酰甲喹、喹酰氨醇及 BF0 的结构改性,其可能性及机理通过对其结构与生物活性的分析得到,因为辐照生成的产物复杂且量非常小,分析结构工作困难,然而发现经辐照后搞菌作用明显提高。从这个实验我们和道重离子与药物分子的作用不仅有能量的沉积而且有质量的沉积,这不同于X,γ射线。由于这种原因重离子引起药物结构改变较X,γ射线更重要,重离子作用机制有自己的特点,有待于深入认识,因此加强重离子药物分子改性的基础研究有重要意义。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

应用不同能量、不同剂量的碳离子和氧离子加照普通小麦,研究其M1代和M2代的生物学(形态)性状、染色体畸变率及微核率、生理生化和DNA分子等方面的变化。并对这些变化的生物学机理进行了探讨,结果如下:1.75MeV/u~(16)O~(8+)离子经过适当降能后注入小麦种子的不同部位和贯穿整个种子,对其M1代幼苗的可溶性蛋白质组分以及电脉中不同区段蛋白质组分相对含量加以分析,结果表明:1)同对照相比,随着辐照剂量的增加,所有辐照材料(包括贯穿和注入)第二区段(分子量较高区段)蛋白质组分的相对含量下降;而第五区段(分子量最小区段)蛋白质组分的相对含量升高。2)种子的贯穿处理,同时也引起第一区段(分子量最高区段)和第三区段蛋白质组分相对含量的下降以及第四区段的升高;其中第三、四区段的变化明显区别于注入效应。3)注入胚和胚乳的区别在于后者第一区段蛋白质组分相对含量的较大下降和第五区段的较大提高。4)小剂量辐照的材料,可溶性蛋白质组分的变化异常,可能与低剂量辐射兴奋效应有关。2.碳离子注入胚乳引起胚的后代发生变异,是典型的重离子诱变产生间接效应的结果。主要表现为:1)M1代的生物学性状、幼苗的抗氧化酶活性、MDA含量、蛋白质含量和染色体畸变率及微核率等发生了较大的变化。2)对其矮杆变异株和紫色茎杆突变体(M2)和RAPD和AFLP分子鉴定等研究,结果显示了矮杆变异体和紫色茎杆突变体的DNA序列发生了改变,而非仅仅产生生理损伤;同一种变异体或突变体,在M2代单株间也存在着明显的差异,表明它们可能还处于分离状态。于是,将M2代以上高代再种,以观察遗传能否稳定。3.重离子辐照普通小麦种子的M1代正常(它们可以完成生长发育的过程)植株同对照材料做正、反交,获得染色体组等来源不同的材料。接着对对照、M2代和正、反交材料DNA进行RAPD和AFLP多态性研究,并将实验结果作统计分析,结果表明:在细胞结构层次上,染色体组作为靶物质,产生的直接效应主要引起随机突变;而非染色体组的细胞组成的间接效应主要引起非随机突变。