SULFUR IX TO XIII SPECTRAL MEASURMENTS BETWEEN 170 AND 500Å

This paper reports laboratory measurements of the spectrum of highly ionized sulfur. The spectrum of S Ⅸ–S ⅩⅢ has been observed in the wavelength range 170–500 Å. A total of 54 lines have been measured. Forty-two of them have been classified as 2s22pk–2s2pk+1and 2s2pk–2pk+1 transitions. Twelve other lines have been ascribed to 2s–2p,4p–5s,5p–6s,5d–6p, and 6p–8d transitions. These spectral lines have been identified, among which 22 are new and accurately measured. The analysis of the spectra was based on a comparison with other experimental results and calculated values.

双奇核~(170)Re高自旋态实验研究

在 16 6MeV的束流能量下 ,利用重离子熔合蒸发反应14 2 Nd(3 2 S ,1p3nγ) 170 Re布居了170 Re的高自旋激发态 .用 12套带BGO反康普顿抑制的高纯锗探测器阵列进行了在束X -γ和γ -γ符合测量 .基于对实验测量结果及周围邻近核已知信息的综合分析 ,首次建立了双奇核170 Re的转动带能级纲图 .根据实验提取出的准粒子顺排、旋称劈裂等结构特征和Re双奇核同位素带结构系统学知识的比较分析 ,指出该带的准粒子组态是πh11 2 υi13 2 .

双奇核~(170)Re高自旋转动带分析(英文)；Analysis of High-spin Rotational Band in Odd-odd ~(170)Re

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。

High-spin states of odd-odd nuclei in the A similar to 170 mass region

Efforts have been made in our group to study the band structure of odd-odd nuclei in the A similar to 170 mass region. We aimed at providing new data of high-spin states and searching for the low-spin signature inversion in the 2-qp bands built on the pi h(9/2) circle times nu i(13/2) and pi i(13/2)circle times nu i(13/2) configurations. In this talk, main results of our work will be summarized, and some systematic features of signature inversion discussed. The spin and parity assignments for the pi i(13/2) circle times nu i(13/2) band in (184)An could be regarded as firm providing a good example for systematic and theoretical investigations.

激光离子源用于A>170重丰中子新核素的研究

本文概述了 A > 170 质量区重丰中子同位素研究的主要工作和意义；介绍了 A > 170 重丰中子同位素合成、分离和鉴别方法；详细论述了激光离子源的原理、设计及其同传统离子源相比所具有的优越性；在文章结尾，设计了一个物理实验，实验目的在于：1）寻找 ~(181)Yb新核素；2）揭示天体物理学中~(180m)Ta 的产生问题。我们对反应截面进行了分析，并对产额进行了估计，证明了此实验设计的合理性，进而说明了带激光离子源的同位素分离器适用于产生截面很低的新核素和衰变研究。本文重点讨论了激光离子源的各方面问题：介绍了激光多步共振电离原理和激光离子源原理；具体分析了热毛细管式激光离子源元素选择性的产生及其影响的因素；讨论了在设计、加工过程中的具体问题；描述了所使用的激光技术；通过在线实验验证了热毛细管式激光离子源的元素选择性和分离效率。

A>170新丰中子同位素合成、分离和鉴别方法与研究

本文概述了关于远离β稳定线研究的进展；分析了A>170新丰中子同位素研究的主要工作和意义。介绍了A>170新丰中子同位素合成、分离和鉴别方法，阐述了在A>170区新核素合成研究中，传统的合成、分离和鉴别手段要比新兴的次级束装置方法更具有优越性，产额中前者有103—104倍的优势，能获得剩余激发能较低的产物，及能进行较长寿命（大于1秒）核研究；激光离子源在线同位素分离器的使用，使之具有很好的元素选择性和质量分辨本领，从而可以使用低本底、高效率的探测方法。 本文侧重介绍了激光离子源在线同位素分离器的研究和使用中的一系列实验和结果：1）激光离子源的研制，得到了501-10000的元素选择性；2）进行了核反应产物从靶中快速释放的研究；3）完成了激光离子源在线同位素分离器的离线实验；4）低本底、高效率的ΔE—ΔEβ探测器的制作及其性能的初步研究；5）实现了激光离子源在线同位素分离器的首次在线实验，获得了良好的元素选择性和一定的分离效率。 最后，对进一步的在线实验和激光的应用做了介绍。

一种新的脑动静脉畸形血液动力学模型

建立了一个新的非定常脑AVM血液动力学模型。模型克服了以往的定常AVM模型无法反映血流实际脉动，以及模型结构和血管性质描述上的缺陷，并依据临床实测数据提出了一种更为符合生理和病理实际的描述AVM供血动脉扩张现象的方法。模型模拟了AVM造成的脑血管压力、流量波形和脑血管输入阻抗的变化，并对脑AVM病人脑血管系统的输入阻抗进行了分析。为研究具有复杂结构的脑AVM血液动力学的特征，提供了一个有效的工具。

饱和砂土中桶形基础承载力的实验研究

桶形基础是近年开发的一种新型的可广泛应用于海洋工程结构的基础形式。由于多种优越性而受到各国石油部门的重视,并引起许多研究人员的关注。通过在饱和砂中的单桶和四桶基础模型实验,研究了桶形基础的静承载特性。分别进行了垂直方向和水平方向的加载实验,其中,四桶基础水平方向加载又分为沿四桶中心构成的正方形的平行边方向和对角线方向施加,得到了载荷位移曲线,对单桶和四桶基础承载力特性,以及加载方向和速率的影响进行了分析和比较。 更多还原

Energy Principle And Nonlinear Electric-Mechanical Behavior Of Ferroelectric Ceramics

Many experimental observations have shown that a single domain in a ferroelectric material switches by progressive movement of domain walls, driven by a combination of electric field and stress. The mechanism of the domain switch involves the following steps: initially, the domain has a uniform spontaneous polarization; new domains with the reverse polarization direction nucleate, mainly at the surface, and grow though the crystal thickness; the new domain expands sideways as a new domain continues to form; finally, the domain switch coalesces to complete the polarization reversal. According to this mechanism, the volume fraction of the domain switching is introduced in the constitutive law of the ferroelectric material and used to study the nonlinear constitutive behavior of a ferroelectric body in this paper. The principle of stationary total potential energy is put forward in which the basic unknown quantities are the displacement u(i), electric displacement D-i and volume fraction rho(I) of the domain switching for the variant I. The mechanical field equation and a new domain switching criterion are obtained from the principle of stationary total potential energy. The domain switching criterion proposed in this paper is an expansion and development of the energy criterion established by Hwang et al. [ 1]. Based on the domain switching criterion, a set of linear algebraic equations for determining the volume fraction rho(I) of domain switching is obtained, in which the coefficients of the linear algebraic equations only contain the unknown strain and electric fields. If the volume fraction rho(I) of domain switching for each domain is prescribed, the unknown displacement and electric potential can be obtained based on the conventional finite element procedure. It is assumed that a domain switches if the reduction in potential energy exceeds a critical energy barrier. According to the experimental results, the energy barrier will strengthen when the volume fraction of the domain switching increases. The external mechanical and electric loads are increased step by step. The volume fraction rho(I) of domain switching for each element obtained from the last loading step is used as input to the constitutive equations. Then the strain and electric fields are calculated based on the conventional finite element procedure. The finite element analysis is carried out on the specimens subjected to uniaxial coupling stress and electric field. Numerical results and available experimental data are compared and discussed. The present theoretic prediction agrees reasonably with the experimental results.

Proper orthogonal decomposition of oscillatory Marangoni flow in half-zone liquid bridges of low-Pr fluids

Proper orthogonal decomposition (POD) using method of snapshots was performed on three different types of oscillatory Marangoni flows in half-zone liquid bridges of low-Pr fluid (Pr = 0.01). For each oscillation type, a series of characteristic modes (eigenfunctions) have been extracted from the velocity and temperature disturbances, and the POD provided spatial structures of the eigenfunctions, their oscillation frequencies, amplitudes, and phase shifts between them. The present analyses revealed the common features of the characteristic modes for different oscillation modes: four major velocity eigenfunctions captured more than 99% of the velocity fluctuation energy form two pairs, one of which is the most energetic. Different from the velocity disturbance, one of the major temperature eigenfunctions makes the dominant contribution to the temperature fluctuation energy. On the other hand, within the most energetic velocity eigenfuction pair, the two eigenfunctions have similar spatial structures and were tightly coupled to oscillate with the same frequency, and it was determined that the spatial structures and phase shifts of the eigenfunctions produced the different oscillatory disturbances. The interaction of other major modes only enriches the secondary spatio-temporal structures of the oscillatory disturbances. Moreover, the present analyses imply that the oscillatory disturbance, which is hydrodynamic in nature, primarily originates from the interior of the liquid bridge. (C) 2007 Elsevier B.V. All rights reserved.

材料分叉的数值分析

通过与解析解法相对比,说明了分析材料分叉时采用数值法的特点.文中揭示了在单向和弱双向加载条件下材料分叉(平面剪切带和表面皱曲)的一些特征.单向拉伸的实验表明,所计算的临界值是合理的.