8-羟基喹啉快速共沉淀分离富集原子吸收光谱法测定啤酒中的Cu和Pb

研究了用8-羟基喹啉-Mg(Ⅱ)共沉淀体系,以Mn(Ⅱ)为内标,快速共沉淀分离富集啤酒中的铜和铅,并用火焰原子吸收光谱(FAAS)测定的方法。共沉淀受pH值、载体镁和内标锰用量的影响。结果显示在pH为9的条件下,能够定量共沉淀试样中的铜和铅。当试液为100 mL时,方法的检出限分别为铜6.28×10-3 μg·mL-1,Pb 2.26×10-2 μg·mL-1回收率为97.6%～103.0%,基本消除了基体干扰,取得了较为满意的结果。该方法无需收集全部沉淀,与传统的共沉淀方法比较,克服了收集沉淀费时的缺点。方法快速、简便、重现性好。     

Dynamic Properties of Two-Dimensional Polydisperse Granular Gases

We propose a two-dimensional model of polydisperse granular mixtures with a power-law size distribution in the presence of stochastic driving. A fractal dimension D is introduced as a measurement of the inhomogeneity of the size distribution of particles. We define the global and partial granular temperatures of the multi-component mixture. By direct simulation Monte Carlo, we investigate how the inhomogeneity of the size distribution influences the dynamic properties of the mixture, focusing on the granular temperature, dissipated energy, velocity distribution, spatial clusterization, and collision time. We get the following results: a single granular temperature does not characterize a multi-component mixture and each species attains its own "granular temperature"; The velocity deviation from Gaussian distribution becomes more and more pronounced and the partial density of the assembly is more inhomogeneous with the increasing value of the fractal dimension D; The global granular temperature decreases and average dissipated energy per particle increases as the value of D augments.     

周期性轴对称凹槽结构隔声特性数值模拟

提出一种在钻铤上切割周期性轴对称凹槽方式构建隔声体,消除钻铤模式波的方法.结果表明,其隔声效果与凹槽深度H、长度L、凹槽数目N、凹槽截面形状以及钻铤壁厚有关.选择矩形截面凹槽、减小钻铤壁厚、增加凹槽深度都可有效提高隔声体的隔声效果,该结构最高可获得约36 dB的声衰减,基本满足随钻声波测井仪器对隔声效果要求.     

64通道一维位置灵敏电流分布探测器及其数据获取系统

针对高流强粒子束与绝缘毛细管相互作用的特点, 设计制作了一套64通道一维位置灵敏电流分布探测器及其配套的数据获取系统, 该探测器可分辨最小直径为1 mm的束斑, 通过数据获取系统可实现可视化自动数据采集。 用2 nA和200—2000 eV电子对探测器进行了定标, 并用10 μA和2000 eV的电子束穿越锥形毛细管后的出射电子, 对探测器及数据获取系统进行测试, 获得了出射粒子的位置分布谱及能量信息。 A 64 channel position sensitive current distribution detector with 1 mm position resolution was developed, while the data acquisition system is based on the LabVIEW software. The test result obtained by using a 2 nA, 200—2000 eV electron beam deflecting by different voltages and the position spectra of 10 μA, 2000 eV electrons transmitted through a glass capillary was measured. The result indicated that the detector can be used to detect the charged particles with strong beam current through the capillary.     

加速器高频D电路Q值的计算与测量

 介绍了回旋加速器高频单D型盒D电路Q值的计算与测量方法。重点对Q值的理论计算进行推导，并对计算原理进行说明。然后对计算结果和测量结果进行比较。得出的计算和测量结果基本吻合。误差产生的主要原因是计算过程中的近似和短路片接触电阻的取值，其中短路片接触电阻是一个重要因素，在设计腔体时应引起足够的重视。     

基于开尔文滴水起电器的废水处理系统

基于开尔文滴水起电原理提出了一种利用高压静电场对废水进行氧化的废水处理系统.为了提高对废水的氧化杀菌效率,研究了影响起电效果的因素,并根据实验数据优化了废水处理系统的结构.经过验证实验表明,提出的高压静电场废水处理系统,能有效将亚甲基蓝溶液氧化,体现了氧化杀菌的能力,且无需输入外界能源,具有环保、无二次污染的优势.     

Block （or Hamiltonian） Lie Symmetry of Dispersionless D-Type Drinfeld-Sokolov Hierarchy

In this paper, the dispersionless D-type Drinfeld-Sokolov hierarchy, i.e. a reduction of the dispersionless two-component BKP hierarchy, is studied. The additional symmetry flows of this hierarchy are presented. These flows form an infinite-dimensional Lie algebra of Block type as well as a Lie algebra of Hamiltonian type.     

r-过程路径核β——衰变半衰期的估算

分析了20 < A < 190范围内丰中子核β衰变的实验数据,根据半衰期随质子数、中子数以及衰变能变化所呈现的壳效应和对效应等特点,提出了一种有效估算丰中子核β衰变寿命的公式。新的计算公式形式简单包含了较少的参数、计算量小。用该公式能较为准确地再现丰中子核的β衰变半衰期。用RIKEN最新测量丰中子核半衰期检验了该公式的外推能力,本工作可以为r-过程研究提供可靠的输入数据。Experimental data of the β--decay half-lives for the nuclei with atomic number between 20 and 190 are investigated. We have systematically studied the shell effects and pairing effects on β--decay half-lives versus the decay energy Q and nucleon numbers (Z, N). An empirical formula has been proposed to calculate the β--decay half-lives of neutron-rich nuclei. The empirical formula is simple and has relatively few parameters. Experimental β--decay half-lives of the neutron-rich nuclei are well reproduced by the new formula. In addition, the extrapolating capacity of this formula has been checked with the very recent experimental data from RIKEN. The predicted half-lives for r-process relevant nuclei with the current formula can be served as the reliable input of r-process model calculations.     

Determination of the ~(12)C(p, γ)~(13)N reaction rates fromthe ~(12)C(~7Li,~6He)~(13)N reaction

The angular distribution of the 12C(7Li,6He)13N reaction at E(7Li) = 44.0 MeV was measured at the HI-13 tandem accelerator of Beijing, China. The asymptotic normalization coefficient (ANC) of 13N → 12C + p was derived to be (1.64 ± 0.11) fm-1/2 through the distorted wave Born approximation (DWBA) analysis. The ANC was then used to deduce the astrophysical S (E) factors and reaction rates for the 12C(p,γ)13N direct capture reaction at energies of astrophysical relevance.     

单负材料一维光子晶体的透射谱特性

利用传输矩阵法研究了单负材料一维光子晶体(AB)m(ADBDB)n(AB)mA的透射谱,发现:透射谱中出现2个共振隧穿模,其位置和间距可由周期数m或n,以及介质层厚度d调节控制。改变m,会出现2个恒定间距的共振隧穿模;改变dA,共振隧穿模间距增大,且当dA≥25mm时,间距增大加剧;改变n,共振隧穿模逐渐趋于简并,当n≥6时,两隧穿模合二为一;改变dD,两共振隧穿模亦逐渐趋于简并,当dD≥20mm时,两隧穿模亦合二为一。这些特性可为利用光子晶体设计可调性高品质单通道、双通道滤波器提供参考。