Excitation Cross Section for Resonance Transitions of Rhenium Atoms Excited by Slow Electrons

Excitation of rhenium atoms by electron impact is investigated by the method of extended crossing beams. At electron energies of 50 eV, the excitation cross sections of 36 resonance and competing transitions in ReI are measured. Within the energy range from the threshold value to 250 eV, six optical excitation functions are detected. The reliability of data on transition probabilities in ReI has been analyzed.     

Single Production of Charged Top-Pions at High Energy Linear e+e- Colliders

The dominant decay modes of charged top-pions (π±t ) are tb or ~b. We consider the single production ofcharged top-pions in association with a top quark via e+ e- annihilation and calculate the production cross section of theprocesses e+ e- → t-bπ+ (tb-π-) at the leading order. We find that it can reach 1.2 fb with reasonable parameter values.The charged top-pions may be detected via the channel tbπ± in the future high energy e+ e- colliders.     

600MeV ~(18)O+~(nat)Pb(厚靶)系统生成Hg同位素独立产额测量(Ⅱ)结果与分析

报道了600MeV（18）O轰击（nat）Ph（厚靶）生成的质量数在180—209之间的Hg同位素产物独立截面的测量结果．通过与600MeV质子轰击天然铅靶生成Hg同位素产额分布的比较，讨论了几个质量区段Hg同位素的生成机制．测量结果也与相对论重离子碎裂反应双质子移出道的产额分布进行了比较．结果表明，中能重离子与中子较富集靶核组成的反应系统对生成丰中子类靶余核具有较明显的优势．     

垂直上升管内液体横掠流动传热特性研究

本文对单相水和单相油横掠流动时的平均换热特性进行了实验研究,对试验的结果进行了分析和讨论,并对实验数据进行关联,得到了垂直上升管内单相水和单相油横掠流动时的换热准则关系式。结果表明,狭窄空间条件下的液体横掠柱体时的流动换热对液相Re数的依赖,较大空间条件下的流动换热相比明显减小,并对单相水和单相油横掠流动时的换热性能进行了比较。     

X-ray fluorescence in some rare earth and high Z elements excited by 661.6 keV γ-rays

The K-shell X-ray fluorescence cross sections are determined experimentally for 10 elements such as Pb, Hg, Ir, W, Lu, Tm, Dy, Tb, Gd and Nd at excitation energy of 661.6 keV associated with γ-rays of ¹³⁷Cs radioisotope. The technique employed involves the measurement of total intensity of fluorescent K X-rays that follow the photoeffect absorption of a known flux of γ-rays using a well type Nal(Tl) detector. The obtained results are compared with the available theoretical values and other measured values.     

不同倾角的脉管制冷机内自然对流影响的研究

本文通过对脉管内自然对流的数值模拟，讨论了当脉管冷端处在不同方向时，脉管内的自然对流对脉管制冷机性能的影响．数值模拟结果表明，当冷端在下时获得的制冷温度最低；当热端在下并与重力方向成３０°时制冷温度最高．结论与实验测量结果定性一致．所做的理论分析对实现脉管制冷机的良好运行有指导意义。     

MEASUREMENTS OF Fe AND Cu K-Shell IONIZATION CROSS SECTIONS BY SLOW ELECTRON IMPACT

ＭＥＡＳＵＲＥＭＥＮＴＳＯＦＦｅＡＮＤＣｕＫ－ＳｈｅｌＩＯＮＩＺＡＴＩＯＮＣＲＯＳＳＳＥＣＴＩＯＮＳＢＹＳＬＯＷＥＬＥＣＴＲＯＮＩＭＰＡＣＴＬｉＴａｉｈｕａＡｎＺｈｕＬｕｏＺｈｅｎｇｍｉｎｇＣｅｎｔｅｒｆｏｒＲａｄｉａｔｉｏｎＰｈｙｓｉｃｓ，Ｉｎｓ...     

电子被HF和HCl分子散射总截面的计算

利用光学势方法计算了能量在１０ｅＶ—１０００ｅＶ范围内电子被Ｈ、Ｆ和Ｃｌ原子散射的总截面，并与已有的实验结果和理论计算进行了比较；又利用可加性规则（ａｄｄｉｔｉｖｉｔｙｒｕｌｅ）计算得到了电子被ＨＦ和ＨＣｌ分子散射的总截面，计算结果也与已有的实验结果和理论计算进行了比较     

超重元素(新核素)合成研究进展情况分析和展望

本文在介绍和分析国际、国内在超重元素（新核素）合成实验研究与理论研究进展情况的基础上对我国今后如何从理论与实验的结合上开展超重元素（核）合成研究工作提出一些看法和建议，提供讨论。     

Synthesis and properties of thermosetting polymers from a phosphorous‐containing fatty acid derivative

A new phosphorous‐containing fatty acid diepoxide was obtained from 10‐undecenoyl chloride and 10‐(2′,5′‐dihydroxyphenyl)‐9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide and crosslinked with 4,4′‐diaminodiphenylmethane and bis(m‐aminophenyl)methylphosphine oxide. The properties of the thermosetting materials were evaluated by differential scanning calorimetry, dynamic mechanical thermal analysis, thermogravimetric analysis, and limiting oxygen index (LOI). Thermal and thermooxidative degradation was studied by gas chromatography/mass spectrometry, FTIR, ³¹P magic angle spinning NMR spectroscopy, and scanning electron microscopy. LOI values indicate good flame‐retardant properties that are related to the formation of a protective phosphorous‐rich layer that slowed down the degradation and prevented it from being total. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5630–5644, 2006