用于放射性束流实验的低气压二维位置灵敏多丝正比室

为在放射性束流线上进行核反应研究而研制了灵敏面积为50mm×50mm的二维位置灵敏的低气压多丝正比室。低气压多丝正比室为穿透式,在真空中使用,工作气压为800Pa,透射性好,不干扰束流。放射性束流在束测试结果表明:它的x、y方向的位置双径迹分辨为1mm;对30～40MeV的低Z放射性束的探测效率大于80%,适用于中能次级束实验中入射束的定位和反应中产生的带电粒子出射角度的测量。

洞穴次生碳酸盐中“死碳”对~(14)C法测年的影响

IEECAS SKLLQG

Circumstantial Evidence for a Soft Nuclear Symmetry Energy at Suprasaturation Densities

Within an isospin- and momentum-dependent hadronic transport model, it is shown that the recent FOPI data on the pi(-)/pi(+) ratio in central heavy-ion collisions at SIS/GSI energies [Willy Reisdorf , Nucl. Phys. A 781, 459 (2007)] provide circumstantial evidence suggesting a rather soft nuclear symmetry energy E-sym(rho) at rho >= 2 rho(0) compared to the Akmal-Pandharipande-Ravenhall prediction. Some astrophysical implications and the need for further experimental confirmations are discussed.

用于粒子探测器的CMOS FET采样保持电路的设计与仿真(英文)；Design and Simulation of Track/Hold Circuit with CMOS FET for Particle Detector

介绍了一个峰保持电路。该电路适用于silicon strip,Si(Li),CdZn Te and CsI等探测器,实现采样-保持功能。已成功进行了基于CMOSFET的采样-保持电路的设计和仿真,通过使用Proteus的PSPICE仿真器和BSIMV3.3模型参数完成了电路性能的仿真。同时,实现了采样时间可在60ns到4.44s范围内进行选择,该电路具有较好的线性。

Dipole bands in nucleus Pm-139

High-spin states in nucleus Pm-139 have been studied using the reaction Cd-116(Al-27, 4n)Pm-139. Two dipole cascades have been found. Spin and parity assignments were based on the Directional Correlation of Oriented Nuclei (DCO) ratios and systematic behavior in neighboring odd-proton nuclei. The level structures of Pm-139 are compared with those of the N = 78 isotone Eu-141 in which two dipole bands have been confirmed as magnetic rotational bands. The close similarity between them suggests that the dipole bands in Pm-139 may be magnetic rotational bands.

医用回旋加速器电源控制器软件设计

医用回旋加速器控制系统是在HIRFL—CSR控制系统上总结完善出来的，医用回旋加速器控制系统是一个基于网络的分布式控制系统，它由许多分控制系统组成。磁铁电源控制系统是回旋加速器控制系统中一个重要部分，它是一个集波形发生、数据采集、状态监测与一体的系统。输出波形的参数由实验需要而计算得到。因为加速器所有的运行激励都由电源所控制，电源控制着磁场的状态，磁场的状态决定着加速器的状态，所以控制系统的直接控制对象就是磁场电源。在整个控制系统中最重要的就是控制波形的同步和波形的精度，这是同步加速器控制系统的关键所在。波形的同步由同步时序系统控制，这是回旋加速器成功运行的先决条件。数据的采集、电源状态的监测由数据采集模块CPLD+ARM负责完成，CPLD与ARM控制器结合，形成数据的上行通道。采集到的数据均存放在中央控制室的数据库中，以供参考、后期分析及应用。论文论述了对医用回旋加速器电源控制器软件的设计实现。对磁铁电源控制系统，主要从系统的结构、I/O部件的硬件设计和软件设计这几个方面进行论述；对软件系统，主要描述各类硬件驱动设计、对数据预处理和与数据库通信的设计实现。本文的工作在医用回旋加速器控制系统中具有很重要的意义，为重离子束治疗肿瘤做了基础准备。从测试及验收结果来看，我们对控制系统的优化不仅在硬件结构上，还是在软件设计实现上都达到了设计要求

Swelling behaviour of alginate-chitosan microcapsules prepared by external gelation or internal gelation technology

Swelling behaviour is one of the important properties for microcapsules made by hydrogels, which always affects the diffusion and release of drugs when the microcapsules are applied in drug delivery systems. In this paper, alginate-chitosan microcapsules were prepared by different technologies called external or internal gelation process respectively. With the volume swelling degree (S-w) as an index, the effect of properties of chitosan on the swelling behaviour of both microcapsules was investigated. It was demonstrated that the microcapsules with low molecular weight and high concentration of chitosan gave rise to low S-w. Considering the need of maintaining drug activity and drug loading, neutral pH and short gelation time were favorable. It was also noticed that S-w of internal gelation microcapsules was lower than that of external gelation microcapsules, which was interpreted by the structure analysis of internal or external gelation Ca-alginate beads with the aid of confocal laser scanning microscope. (C) 2004 Elsevier Ltd. All rights reserved.

东北地区植被多样性的研究Ⅰ.寒温带针叶林区域垂直植被多样性分析

用Renyi及Hill多样性指数簇相结合的方法 ,对中国寒温带针叶林区域垂直植被的区系多样性、生活型多样性及叶级多样性进行了分析 ,将亚高山矮曲林带 (Ⅰ )、寒温性针叶疏林带 (Ⅱ )、山地上部寒温性针叶林亚带 (Ⅲ1 )、山地中部寒温性针叶林亚带 (Ⅲ2 )和山地下部寒温性针叶林亚带 (Ⅲ3) ,划分为生物多样性的特殊性植被带 (Ⅰ )、过渡性植被带 (Ⅱ )及生物多样性的交汇性植被亚带 (Ⅲ1 )、稀疏性植被亚带 (Ⅲ2 )和富集性植被亚带 (Ⅲ1 ) .对Ⅰ、Ⅱ带及Ⅲ1 亚带的植被宜采取保护性经营对策 ,对Ⅲ2 、Ⅲ3亚带 ,采取恢复和提高其生物多样性 ,促进植被进展演替的经营对策 .

对改善环境的经济动力的探讨

对改善环境的经济动力的探讨李法云，范志平中科院沈阳应用生态研究所由于人口的增加、工业生产的发展，资源消耗在加快，我们正面临着环境污染蔓延和生态环境恶化这一环境问题的挑战。我国目前的环境状况不容乐观，森林面积仍在减少，水土流失面积也在增大，河流污染现状...

根际微域研究中土样采集方法的研究进展

综述了 60年代以来植物根际微域研究中土壤样品的采集方法 ,认为根际土样采集的发展趋势是从田间的粗略采集到室内模拟实验的精细划分 ,再把模拟装置运用到田间 ,最终达到指导生产的目的 .同时 ,随着根际概念的拓宽 (生态界面Eco boundarylayer) ,根际土样的采集朝着保持原位和更精细的方向发展 .

the estimation of thyroxine in human plasma by an electrophoretic technique

A new method for the determination of thyroxine in blood is described. It relies upon the quantitative dependence of the distribution of thyroxine between albumin and thyroxine-binding protein when exogenous 131I-labelled thyroxine is added to serum in vitro. Preliminary results suggest an accuracy in the estimate of the hormone of about 5–10%. Results in a group of patients whose plasma P.B.I, levels were also determined are given and shown to be similar.