气体喷嘴反冲传输技术及在核科学中的应用

气体喷嘴反冲传输技术是继“跑兔”装置之后发展和完善起来的适合于短寿命核素研究的一种快速而有效的在线脱束方法。 它能够将短寿命核反应产物传输至远离高辐射区的低本底场所进行收集和测量。 该技术已在加速器和反应堆上得到了广泛的应用, 是一种研究核反应、 核谱学和合成与鉴别新元素、 新核素的一种不可缺少的基本实验技术和工具。 描述了气嘴系统的结构、 基本原理、 设计要求以及它的主要特性, 特别是对系统的气体动力学机制以及各种参数对系统特性的影响等进行了讨论。 最后, 综述了它在核物理、 核化学以及质谱学等领域的应用情况, 并且给出了几个应用的典型例子。 The gas jet recoil transport technique is developed and improved as a new rapid and effective on line and off beam method following “rabbit” apparatus in the study of short lives nuclei. It can transport the short half life nuclear reaction products far from high radioactive area for collection and measurement at low background area. This technique has been widely used in the researches with accelerator and reactor. It is indispensable basic experimental technology and tool applied to nuclear reaction, spectroscopy, as well as synthesis and identification of new elements and nuclei. The basic principle, structure, design requirement and main characteristics of gas jet system are described in this paper, especially the mechanism of gas dynamics and the effect of several parameters on the system properties are discussed. Finally, the applications of this technique in several fields such as nuclear physics, nuclear chemistry and mass spectroscopy etc. are comprehensively represented. Several typical applications are also illustrated.     

超声衰减和速度谱测量亚微米乳液的粒径

研究了超声衰减谱法和相速度测量高浓度多分散脂肪两相乳浊液的粒径分布问题.在理论分析基础上,实验测量了多个浓度(2%～20%)脂肪乳试样在2～13 MHz频带下超声衰减和相速度谱,结合反演算法由实验数据计算出乳浊液颗粒的粒径分布,并讨论了相速度法的意义和特点.将原始浓度(20%)下测得粒径分布与消光法在稀释条件下相同试样测量结果作对比,二者比较吻合,表明超声谱法可在无稀释的高浓度条件下作乳浊液粒径分布的表征.     

On-line arbitrarily vertex decomposable suns

We give a complete characterization of on-line arbitrarily vertex decomposable graphs in the family of unicycle graphs called suns. A sun is a graph with maximum degree three, such that deleting vertices of degree one results in a cycle. This result has already been used in another paper to prove some Ore-type conditions for on-line arbitrarily decomposable graphs.     

两台可拒绝同型机半在线排序问题

本文讨论一个两台可拒绝同型机半在线排序问题.当工件到达时,可以被拒绝,但要付出一定的罚值,也可以被接收加工,消耗一定的加工时间.其目标是要使所有加工工件生成的makespan和被拒绝工件的总罚值之和最小.加工不允许中断.进一步,机器带有两个并行处理子系统,可以提供两种排序方案,最后选取较好的一种.这是第一个在可拒绝同型机排序模型中使用半在线信息,我们设计出一个近似算法,其竞争比为3/2,另外又给出一个√3+1/2≈1.366的下界.     

在线净化液相色谱-串联质谱法快速测定牛奶中的6种孕激素

建立了在线净化液相色谱-串联质谱同时测定牛奶中炔诺酮、17α-羟基孕酮、甲羟孕酮、乙酸甲地孕酮、孕酮和醋酸美伦孕酮6种孕激素的方法。本方法采用乙腈为提取溶剂提取目标化合物。提取液经在线净化柱Cyclone-P净化,经Phenyl-Hexyl色谱柱分离,流动相采用0.5%（v/v）甲酸水溶液-乙腈,在电喷雾正离子模式下以多反应监测（MRM）方式测定,内标法定量。方法在0.1~50 μg/L范围内呈线性关系,线性相关系数均大于0.999。6种分析物的测定低限为0.5 μg/kg,在牛奶中3个水平的添加回收率在90.8%~107.5%之间,相对标准偏差在6.3%~11.8%之间。该方法快速简便,灵敏度高,选择性好,可用于牛奶样品中孕激素的快速定性定量分析。     

基于差分吸收光谱法的大气痕量气体在线检测技术

差分光学吸收光谱学技术（Differential Optical Absorption Spectroscopy,DOAS）是近年来发展起来的一种实时检测大气中痕量气体浓度的有效方法,它采用线性最小二乘拟合方法,用痕量气体标准差分吸收截面对测量得到的差分吸收光谱进行拟合,得出大气中痕量气体的浓度。通过介绍DOAS方法的测量原理,在线监测系统的构成,气体浓度的反演方法,测量结果及讨论等内容,说明它在空气质量监测方面的优越性。     

Chemical-physical aspects of formation and evolution of phase structure in multi-polymers: Intensity fluctuation, phase structure and its fractal characteristics in blends of isotactic polypropylene with poly(cis-1,4-butadiene) rubber

This paper studies the formation and evolution of phase structure of isotactic polypropylene/poly(cis-1,4-butadiene) (iPP/PcBR) blends during molten and mixing in a visual mixer by on-line analysis of the small angle light back scattering. The density fluctuation of iPP/PcBR blends during molten and mixing is discussed using the integral-intensity Js, of the scattering intensity of the blends. The "invariant" Q, which shows fluctuation of the system, is calculated by data of the small angle light back scattering, and the variation of Q with the blending time, temperature and shear rate during molten and mixing in iPP/PcBR blends is discussed. The structure parameters which characterize dimensions of phase in the blends, as the correlation distance ac, and the average chord lengths of two-phase, as li PP and lP cBR, are calculated by data of scattering intensity. The average diameters dp of dispersed phases are calculated from SEM images. The variation of ac, dp, li PP and lP cBR with the blending time and compositions in the blends during molten and mixing is discussed. The scale law is analyzed to find multi-scale characteristics in this system. The generalized fractal dimension Dp is calculated and the relation of Dp with generalized entropy function is discussed to determine that Dp is state function and the physical significance of Dp is the same as that of the generalized entropy function.     

在线样品前处理大体积进样离子色谱法直接测定海水中亚硝酸盐、硝酸盐和磷酸盐

采用戴安公司谱睿(Pre)在线样品除氯技术,结合OnGuard Ba柱去除硫酸盐,建立了离子色谱直接测定海水中亚硝酸盐、硝酸盐和磷酸盐的方法。该方法以IonPac AG23为富集柱,高容量IonPac AS23为分离柱,淋洗液自动发生装置在线产生KOH溶液进行梯度淋洗,抑制电导检测。实验结果表明: 样品稀释5～10倍时,直接进样不会干扰目标物测定。当流速为1 mL/min、进样量为500 μL时,海水中NO~2-N、NO~3-N、PO3~4-P的方法检出限分别为0.3、0.4、0.2 μg/L,线性范围分别为10～500 μg/L、14～680 μg/L、3.4～170 μg/L,线性相关系数r均大于0.9990。测得人工海水样品中目标物的加标回收率为92%～106%,相对标准偏差(RSD, n=6)为1.2%～7.7%。该方法一次进样可在13 min内完成分析,具有操作简单快捷、无污染等优点,能满足近海海水中NO~2、NO~3、PO3~4的定量分析要求。     

分离扇回旋加速器的等时场在线优化

针对兰州重离子加速器冷却储存环（HIRFL-CSR）的分离扇回旋加速器（SSC）的等时场优化问题,依托HIRFL-CSR的主数据库系统Oracle,设计了系统控制界面,该界面不仅能够读取和给定电源电流值,而且能够实时更新束流相位信息。根据束流相位的实时数据,利用Kb-Kr方法以及Lagrange插值算法建立的等时场,实现了对SSC束流等时场的在线优化。优化后的等时场可以有效控制束流相位的漂移,提高束流品质。     

A Microbial Biosensor using Pseudomonas Putida Cells Immobilised in an Expanded Bed Reactor for the Online Monitoring of Phenolic Compounds

ABSTRACT

A cell based biosensor for phenolic substances has been developed. The set up is based on a flow injection system with an expanded bed column with immobilised Pseudomonas cells. The cells were immobilised on glass particles pretreated with poly (ethylene diamine). The system responds to a range of phenolic substances. Storage and operational stabilities are good. The expanded bed concept makes the system reliable also when treating samples with particulate matter.