Entrance channel dependence of the correlation function of IMFs in Ar-36+Sn-112,Sn-124 at 35MeV/u

The reduced velocity correlation functions of the Intermediate Mass Fragments (IMFs) were measured in the reactions of Ar-36+ Sn-112,Sn-124 at 35MeV/u. The anti-correlation at small reduced velocities is more pronounced in Ar-36+ Sn-124 system than that in Ar-36+ Sn-112 system. The difference of the correlation functions between the two reactions is mainly contributed by the particle pairs with high momenta. A three-body Coulomb repulsive trajectory code (MENEKA) is employed to calculate the emission time scale of IMFs for-the both systems. The time scale is 150fm/c in the Ar-36+ Sn-112 system and 120fm/c in the Ar-36+ Sn-124 system, respectively. A calculation based on an Isospin dependence Quantum Molecular Dynamics code (IQMD) reveals that the emission time spectrum of IMFs is shifted slightly leftwards in Ar-36+ Sn-124 compared with that in the Ar-16+ Sn-112 system, indicating a shorter emission time scale. Correspondingly, the central density of the hot nuclei decreases faster in Ar-36+ Sn-124 than in Ar-36+ Sn-112

Electron emission induced by the interaction of highly charged ions Pb-207(q+) (24 <= q <= 36) with solid surface of Si(110)

The electron emission induced by highly charged ions Pb-207(q+) (24 <= q <= 36) interacting with Si(110) surface is reported. The result shows that the electron emission yield Y has a strong dependence on the projectile charge state q, incidence angle psi and impact energy E. In fitting the experimental data we found a nearly 1/tan psi dependence of Y. Theoretical analysis shows that these processes are closely related to the process of potential electron emission based on the classical over-the-barrier model.

Experimental study of the U-238(S-36,3-5n)(269-271)Hs reaction leading to the observation of (270)Hs

The deformed doubly magic nucleus (270)Hs has so far only been observed as the four-neutron (4n) evaporation residue of the reaction Mg-26+Cm-248, where a maximum cross section of 3 pb was measured. Theoretical studies on the formation of (270)Hs in the 4n evaporation channel of fusion reactions with different entrance channel asymmetry in the framework of a two-parameter Smoluchowski equation predict that the reactions Ca-48+Ra-226 and S-36+U-238 result in higher cross sections due to lower reaction Q values, in contrast to simple arguments based on the reaction asymmetry, which predict opposite trends. Calculations using HIVAP predict cross sections for the reaction S-36+U-238 that are similar to those of the Mg-26+Cm-248 reaction. Here, we report on the first measurement of evaporation residues formed in the complete nuclear fusion reaction S-36+U-238 and the observation of (270)Hs, which is produced in the 4n evaporation channel, with a measured cross section of 0.8(-0.7)(+2.6) pb at 51-MeV excitation energy. The one-event cross-section limits (68% confidence level) for the 3n, 4n, and 5n evaporation channels at 39-MeV excitation energy are 2.9 pb, while the cross-section limits of the 3n and 5n channel at 51 MeV are 1.5 pb. This is significantly lower than the 5n cross section of the Mg-26+Cm-248 reaction at similar excitation energy.

PROJECTILE FRAGMENTATION OF Ar-36,Ar-40 INDUCED REACTIONS

Fragment yields for Z >= 5 from projectile fragmentation using primary beams of Ar-36,Ar-40 at 50 MeV/nucleon on Ni-64 target have been measured in RIBLL fragment separator. We compare the fragment cross sections with the predictions of the empirical EPAX parametrization of fragmentation cross-sections and Statistical Abration-Ablation model (SAA) by considering the RIBLL separator transmission rate. Isotope yield ratios between these two reactions were calculated and isoscaling parameters alpha and beta are extracted, their dependences on fragment atomic number Z and neutron number N were presented.

30,35MeV/u 36,40Ar＋112,124Sn反应中热核性质同位旋效应的实验研究

针对①中能反应中同位旋自由度是否达到平衡，②同位旋自由度对几中不同方法测量的核温度是否有影响 这两个基本问题，设计了用30和35MeV/u ~(36,40)Ar轰击~(112,124)Sn反应的实验方案。得到如下结果：对于前角5°处的耗散弹核碎裂产物，丰中子同位素与稳定核的产额比随产物出射动能的增加而减小，而丰质子子同位素与稳定核的产额比随动能的增加而增加，呈现明显的剪刀差分布特性。随耗散时间的增大，产物的平均中质比逐渐由弹核的平均中质比向系统的平均中质比过渡。这个结果说明在该反应中，同位旋自由度没有达到完全平衡。而对于20°处的DIC产物，上述剪刀差分布特性变得更不明显，这是同位旋自由度由非平衡向平衡过渡的表现。后角轻粒子的能谱分析表明，初始热核的同位旋会影响斜率核温度的提取，由于丰中子轻粒子~6He在~(40)Ar + ~(112)Sn系统中的蒸发被抑制，相比~(40)Ar + ~(112)Sn而言，其蒸发比较容易发生在衰变链早期，因此提取的温度偏高，同样，丰质子轻粒子~3He的温度在~(40)Ar + ~(112)Sn中略高。但中后角的同位素产额分析表明，反应系统的同位旋对双同位素比核温度几乎没有影响。核温度作为热核的热力学量，是独立于测量方法的，这种不同的方法得出的差异主要来源于同位旋对衰变机制的影响。作为一个尝试，将中高能反应中的熵的提取推广到这个能区，发现两个系统的熵几乎一致。在量子统计模型框架下，考察核温度与熵的关系发现，~(40)Ar + ~(112)Sn反应的挤出时刻密度略高于~(40)Ar + ~(112)Sn。

36单元塑料闪烁体陈列探测器制作与调试

本文描述了一个能在中解（10－100Mev/u）重离子核反应测量中鉴别轻粒子，测量粒子多重性，并能给出轻粒子能量和位置信息的大立体角（θ: 5°-20°φ: 0°-360°）的36单元塑料闪烁体陈列探测器的制作与调试，初步调试结果表明该探测器对轻粒子（p、α等）有较好的分辨。同时对国际上几种规模较大的先进的多单元大立体角粒子探测系统作了比较全面的介绍

Synthesis and characterization of the nanoporous ultrathin multilayer films based on molybdenum polyoxometalate (Mo-36)(n)

Ultrathin multilayer films of the wheel-shaped molybdenum polyoxometalate cluster (Mo-36)(n) and poly(allylamine hydrochloride) (PAH) have been prepared by the layer-by-layer (LbL) self-assembly method. The ((Mo-36)(n)/PAH)(m) multilayer films have been characterized by Xray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). UV-VIS measurements reveal regular film growth with each (Mo-36)(n) adsorption. The electrochemical behavior of the film at room temperature was investigated.

The chemistry of alpha-oxo ketene cyclic dithioacetal .36. Studies on silica G catalyzed decomposition of adducts of beta,beta-1,3-propylenedithio-alpha,beta-unsaturated arylketones with grignard reagents

beta, beta-1, 3-Piopylenedithio-alpha, beta-unsaturated arylketones 2 via chemoselective 1,2-addition with allyl or benzyl Grignard reagents afforded the corresponding carbinols 3 and 4. Catalysed by silica gel, the carbinols 3 and 4 were converted to the beta,gamma-unsaturated arylketones 5, 6. The mechanism and reaction condition were discussed.

青海门源地区大鵟和雕鸮的食性比较

1999～2002年的6～8月份，在青海门源地区收集了大鵟和雕鸮的吐弃块（pellets）和残留食物（food remains），带回实验室进行分检鉴定、研究分析。大鵟食物中共有736个猪物，其中高原鼢鼠28只、高原鼠兔139只、甘肃鼠兔142只、田鼠科动物422只、雀形目鸟类4只、香鼬1只；各猎物对大鵟食物的生物量贡献率分别为14.26%、40.79%、17.39%、26.99%、0.22%、0.35%。雕鸮食物中共有330个猎物，其中高原鼢鼠17只、高原鼠兔77只、甘肃鼠兔44只、田鼠科动物183只、雀形目鸟类2只、红脚鹬2只、高原兔5只；各猎物对雕鸮食物的生物量贡献率分别为11.83%、30.87%、7.36%、16.00%、0.15%、0.62%、33.17%。雕鸮的食物生态位宽度与大鵟的食物生态位宽度相近，食物生态位高度重叠，但是它们捕食同种猎物的比例显著不同。

Practice links [Issue 36, February 2010]

Practice Links is a free e-publication for practitioners working in Irish social services, voluntary and nongovernmental sectors. Practice Links was created to enable practitioners to keep up-to-date with new publications, electronic resources and conference opportunities. Issue 36 features articles on equine assisted personal development, the National Child Care Information System and a report on Fieldwork Training for Social Workers

Cinética de sobrevivencia de Rhizobium meliloti B - 36 sobre semilla preinoculada con diferentes adhesivos y coberturas

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