On the Integrability of the One-Dimensional Open XYZ Spin Chain

The Lax pair for the one-dimensional open XYZ spin chain is constructed, this shows that the system is completely integrable.     

Invariant-mass distribution of top-quark pairs and top-quark mass determination

In this study, we investigate the invariant-mass distribution of top-quark pairs near the 2m_t threshold, which strongly influences the determination of the top-quark mass m_t. Higher-order non-relativistic corrections lead to large contributions, which are not included in the state-of-the-art theoretical predictions. A factorization formula is derived to resum such corrections to all orders in the strong-coupling, and necessary ingredients are calculated to perform the resummation at next-to-leading power. We combine the resummation with fixed-order results and present phenomenologically relevant numerical results. The resummation effect significantly increases the differential cross-section in the threshold region and makes the theoretical prediction more compatible with experimental data. We estimate that using our prediction in the determination of \begin{document}$m_t $\end{document} will lead to a value closer to the direct measurement result.     

Fragment Angular Distributions of the 600 MeV 40)Ar+197 Au Reaction

The angular distributions of the fragments in the range of 4π solid angle for the 600 MeV ⁴⁰Ar+¹⁹⁷Au reaction have been measured using the beam-off γ-ray spectroscopy technique. The features of the fragment angular distributions and the reaction mechanisms of the production of fragments have been discussed.     

组态相互作用和相对论修正对类He离子双电子谱的影响

研究了组态相互作用和相对论修正对低Z(原子序数)及中等Z类He离子双电子谱的影响,使用准相对论及非相对论的Hartree-Fock自洽场方法计算了描写双电子伴线的原子参数。计算结果表明,(1)组态相互作用对类He离子双电子诺有显著影响;(2)对中等Z的类He离子,仅以能量微扰的形式计入相对论修正是不足够的,为了获得更加精确的计算结果,不仅要考虑相对论修正对单、双激发态能量的影响,而且要考虑该效应对径向波函数的影响。     

Repair of Pd/α-Al2O3 composite membrane with defects

A palladium composite membrane with a large number of defects was repaired using the electroless plating combined with the technique of osmosis. The loose structure of palladium film prepared by the conventional electroless plating was densified. Defects were repaired. Hydrogen selectivity was thus significantly increased without significantly increasing palladium film thickness and reducing hydrogen permeability. Project supported by the Chinese Academy of Sciences (Grant No. KJ951-A1-508) and the National Natural Science Foundation of China (Grant No. 29392003).     

Dynamic torsional buckling of multi-walled carbon nanotubes embedded in an elastic medium

In this paper the dynamic torsional buckling of multi-walled carbon nanotubes （MWNTs） embedded in an elastic medium is studied by using a continuum mechanics model. By introducing initial imperfections for MWNTs and applying the preferred mode analytical method, a buckling condition is derived for the buckling load and associated buckling mode. In particular, explicit expressions are obtained for embedded double-walled carbon nanotubes （DWNTs）. Numerical results show that, for both the DWNTs and embedded DWNTs, the buckling form shifts from the lower buckling mode to the higher buckling mode with increasing the buckling load, but the buckling mode is invari- able for a certain domain of the buckling load. It is also indicated that, the surrounding elastic medium generally has effect on the lower buckling mode of DWNTs only when compared with the corresponding one for individual DWNTs.     

INFLUENCE OF SOL-GEL METHOD ON CATALYTIC PERFORMANCE OF PARTIAL OXIDATION OF METHANE TO SYNCES OAR NiO/|?-Al2O3 CATALYSTS

NiO/r-A12O3 catalysts were prepared by impregnation and sol-gel method. Comparative study of the POM catalytic performance for 80 h life-test over them was performed to investigate the effects of the preparation methods. The carbon deposition, surface composition, total nickel content, specific surface area, pore volume and crystal phase of catalysts were investigated with TG, XPS, AAS, TPR, BET, and XRD. The results indicated that the thermal stability of support during the redox reaction at high temperature could not be improved only by sol-gel method.     

结合脉冲梯度场的选择激发技术在溶剂峰抑制中的应用

对结合脉冲梯度场的选择激发技术在溶剂峰抑制中的四种可行序列进行比较,实验表明非对称的双梯度自旋回波序列在谱图的相位特性和溶剂峰抑制效果两方面均是最佳的方案,并将其推广应用到溶剂峰抑制的gCOSY实验中,获得较理想的溶剂峰抑制效果     

Commutants of certain analytic operator algebras

We prove that algebraic commutants of maximal subdiagonal algebras and of analytic operator algebras determined by flows in a -finite von Neumann algebra are self-adjoint.

     

在30MeV/u 40Ar+159Tb、natAg反应中比较热核两种温度值

用双同位素产额比方法和能谱斜率方法,在110°对30MeV/u ⁴⁰Ar+¹⁵⁹Tb和^natAg反应得到的热核的温度进行了研究.对于不同的双同位素产额比,同位素温度值相同,为4.6MeV.能谱斜率温度随粒子或复杂碎片的不同而异.从α粒子能谱和质量数小于4的粒子能谱得到的斜率温度均是正常的,但是更重的碎片的斜率温度则高于极限温度Tlim,这可能是更重的碎片发射于复合核形成后的早期阶段,或者是库仑不稳定的发射.同时还分析了斜率温度高于极限温度T_lim的较重碎片能谱随探测角的变化.