Microcalorimetric Evaluation of the Effect of Kanamycin： An Analysis Based on the Median-Effect Principle

A study of the effect of drug, kanamycin, on the growth metabolism of recombinant Escherichia coli B 1 was carded out by microcalorimeter monitoring of the metabolic activity of treated cells. Power-time curves of growing recombinant Escherichia coli cell suspensions, treated with different kanamycin doses, were recorded. The extent of the effect was evaluated by changes in the slopes of the microcalorimetric curves and the kinetics of the drug action was interpreted from the time at which these changes reached their maximum values and maintained their maximum values. Experimental dose-effect relationships conform to the median-effect principle of the mass-action law： fa/（1-fa）=（D/D50）^m. A plot of y=lg[（fa）^1-1]^-1 versus x=lg D gives the slope m, D50 and R∞. The experimental results revealed that high concentration of kanamycin had an inhibitory effect on the growth of recombinant Escherichia coli B 1 in the lg phase, and had a promoting effect in the stationary period. Moreover, it was demonstrated that microcalorimetry was a reliable method for the detection of modulatory effects in biology.     

ECR离子源束流发射度的实验研究

利用最新自行研制的电扫描发射度探测系统, 在ECR离子源上进行了一系列关于ECR离子源引出束流发射度的研究. 这套电扫描发射度探测系统安装在中国科学院近代物理研究所(兰州)的LECR3试验平台的束运线上. 试验中, 通过测量相关参数, 研究了磁场、微波、掺气效应及负偏压效应等对引出束流发射度的影响. 利用实验所得的结果与关于ECR等离子体和离子源束流发射度的半经验理论, 分析推导了离子源各可调参数与ECR等离子体的直接关系, 这为分析探索ECR离子源的工作机制提供了一定的参考依据.     

SECRAL在18GHz频率下产生强流高电荷态离子束的初步结果

A Superconducting ECR ion source with Advanced design in Lanzhou (SECRAL) was successfully built to produce intense beams of highly charged ions for Heavy Ion Research Facility in Lanzhou (HIRFL).The ion source has been optimized to be operated at 28GHz for its maximum performance.The superconducting magnet confinement configuration of the ion source consists of three axial solenoid coils and six sextupole coils with a cold iron structure as field booster and clamping.For 28GHz operation,the magnet assembly can produce peak mirror fields on axis 3.6T at injection,2.2T at extraction and a radial sextupole field of 2.0T at plasma chamber wall.A unique feature of SECRAL is that the three axial solenoid coils are located inside of the sextupole bore in order to reduce the interaction forces between the sextupole coils and the solenoid coils. During the ongoing commissioning phase at 18GHz with a stainless steel chamber,tests with various gases and some metals have been conducted with microwave power less than 3.2kW and it turned out the performance is very promising.Some record ion beam intensities have been produced,for instance,810eμA of O~(7 ),505eμA of Xe~(20 ),306eμA of Xe~(27 ),21eμA of Xe~(34 ),2.4eμA of Xe~(38 ) and so on.To reach better results for highly charged ion beams,further modifications such as an aluminium chamber with better cooling,higher microwave power and a movable extraction system will be done,and also emittance measurements are being prepared.     

兰州全永磁ECR离子源——LAPECR1

The Lanzhou All Permanent magnet ECR ion source NO.1(LAPECR1)is the first all permanent magnet multiple ECRIS made in IMP.This ECRIS is running at 14.5GHz and can provide intense low charge state ion beams(varying from several to hundreds of eμA)or medium charge state ion beams(varying from several to tens of eμA).The size of source body is (?)102mm×296mm,the compactness and economical features enable the source suitable to be put on a HV platform or equipped by a small laboratory.This article gives the main parameters of the ion source.     

离子液体的黏度与其扩散系数和电导率的新型关系方程

离子液体的传递性质对其在化学化工等领域的研究和应用至关重要,但迄今文献中缺乏可靠的理论预测模型或传递性质间的相互关系式,因此,有必要建立传递性质间的相互关系以便应用.本文建立了离子液体黏度与扩散系数或电导率间的定量关系,并利用文献实验数据进行了系统检验.结果表明,新方程可由离子液体黏度数据准确预测其扩散系数和电导率.与Stokes-Einstein方程相比,新方程不仅可解释离子液体中的许多实验现象,而且实现了定量预测(无需离子的有效流体力学半径数据).     

花状TiO2分级结构的可控合成与其光催化性能

采用水热法可控合成了花状TiO₂分级结构材料,运用扫描电镜、透射电镜、X射线衍射、N₂物理吸附-脱附等手段,对其进行了表征,系统研究了NaOH用量、H₂O₂浓度、HNO₃浓度、反应温度及时间等因素对所得样品形貌的影响,并评价了它们的光催化性能.结果表明,花状TiO₂分级结构为锐钛矿相,颗粒大小均一;随制备条件的变化,构成花状TiO₂分级结构的基元结构分别为纳米线、纳米片,纳米线直径约25nm,纳米片厚度不足10nm;该样品具有较高的比表面积,表现出良好的单次光催化活性与重复使用性能.     

基于席夫碱配体构筑的Ln2Ⅲ配合物的结构、荧光性质及生物活性

以多齿席夫碱配体 H₂L(H₂L=(E)-N′-(3-乙氧基-2-羟基亚苄基)-3-羟基吡啶甲酰肼)为配体,与 Ln(acac)₃·2 H₂O(Ln=Tb、Ho、Er;acac^-=乙酰丙酮根)反应,通过溶剂热法,成功得到了 3例新的双核稀土配合物[Ln₂(acac)₂(L)₂(C₂H₅OH)₂](Ln=Tb (1)、Ho(2)、Er(3))。单晶X射线衍射分析表明：配合物1~3的结构主要由2个Ln^Ⅲ离子、2个乙酰丙酮根(acac^-)、2个L^2-及2个C₂H₅OH组成,中心Ln^Ⅲ离子通过2个μ₂-O原子相互连接,形成一个平行四边形的Ln₂O₂核心。固体荧光实验测试结果表明：配合物1在室温下表现出Tb^Ⅲ离子的荧光特征发射峰。此外,生物活性研究表明,与配体H₂L和稀土离子相比较,配合物1~3具有更强的抗菌活性。采用紫外光谱法、循环伏安法、凝胶电泳法和荧光光谱法研究了配合物 1~3与小牛胸腺 DNA之间的相互作用,结果表明配合物主要以插入作用的方式与小牛胸腺DNA结合。     

环状PIN阵列测量全口径背向散射光空间分布的实验研究

基于由同心环状排布的多个 PIN 探测器组成的环状 PIN 阵列,发展了一种测量激光等离子体全口径背向散射光空间分布的实验方法.采用该方法,在神光Ⅱ装置激光与黑腔靶相互作用实验中,对全口径背向散射光空间分布进行了测量,获得了全口径受激 Brillouin 散射背向散射光空间分布的图像.初步建立了全口径背向散射光空间分布...