大学物理教学中必不可少的一个环节——西德大学物理教学考察之三

为了进一步加强我校物理演示实验的建设和广泛应用,笔者在(原)联邦德国对布伦瑞克工业大学、达姆斯达特工业大学和鲁尔大学的物理教学进行考察时,着重了解了演示实验在西德大学物理教学中的地位和作用。耳闻目睹的事实使笔者感到,虽然近几年来演示实验在我国的大学物理教学中已经愈来愈受人们重视,并且得到很大的发展,但是由于各种原因,就目前情况而论,与世界一些发达国家的水平相比还存在着较大的差距.     

Highly—Efficient Blue—Light Generation by Intracavity nFrequency Doubling with LiB3O5

We have investigated the generation of highly-efficient blue light in critically type-I phase-matched LiB3O5 (LBO) with intracavity frequency doubling of diode-pumped Nd:YAG laser.A maximum output power of 502 mW at 473 nm blue light was obtained and the overall optical-to-optical efficiency is up to 11.2%.To the best of our knowledge,this is the highest conversion efficiency for 473nm output using a diode pumped Nd:YAG laser through LBO.     

抛物型点控制系统最优控制与区域扰动

§1.引言设{(?)}_(?)是 R~n 中—族有界开区域,(?)具有足够光滑的边界 (?)_(?),并且局部地位于(?)的一侧.设 T 为一固定正数,记(?)=(?)×(0,T)。在(?)考虑如下抛物型点控制问题:     

1-苯基-4-取代酞嗪衍生物合成及抗肿瘤活性评价（英文）

为了找到更有效和更经济的抗肿瘤药物,合成了一系列1-苯基-4-取代酞嗪衍生物,并评估了其体外抗增殖活性.所合成的化合物的结构都通过~1 H NMR,~(13) C NMR和HRMS确证.并且通过3-(4,5-二甲基噻唑-2)-2,5-二苯基四氮唑溴盐(MTT)法评估了目标化合物对四种人类癌细胞株的抗肿瘤活性.结果表明:一些化合物具有良好的抗肿瘤活性,特别是N-(4-甲氧基苯基)-2-((4-苯基酞嗪-1-基)硫基)乙酰胺(5f)和N-(3-氯-4-氟苯基)-2-(4-(4-苯基酞嗪-1-基)哌嗪-1-基)乙酰胺(8c)表现出了更好的抗肿瘤活性,对人类食管癌细胞的活性优于5-氟尿嘧啶.IC50值分别为8.13和9.31μmol·L~(-1).     

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.     

Eu(DBM)3纳米微晶的低频喇曼光谱

The fractal property and low frequency Raman scattering of Eu(DBM)3 nanosized microcrystals were investigated. The influence of the fractal structure of Eu(DBM)3 non-crystalline solids on low frequency scattering was studied. It was found that vibrational excitations on the fractal are localized and can be described in terms of fractions. It was shown that reduced Raman scattering intensity is of a power law dependence of the vibrational frequencies for all samples. The fractal and spectral dimension were also determined, we found that our experimental value was in fair agreement with the theoretical one.     

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.     

离子置换色谱法测定亚氯酸钠纯度及其杂质阴离子的含量

以常规的抑制型离子色谱仪为基础,在抑制器之后和紫外检测器之前,依次串联两根自制的离子置换柱,第一根为Li+型阳离子置换柱,第二根为IO3-型阴离子置换柱。IC测定中用Dionex IonPac AS18阴离子交换柱为分离柱,以30mmol·L~(-1)氢氧化钠溶液为流动相。在测定亚氯酸钠的纯度及其杂质阴离子含量时,样品溶液(0.100 0g样品溶于水中,定容至50.0mL,分取部分溶液定量稀释100倍)在经过离子置换柱的过程中,亚氯酸根及其他待测阴离子均被定量地置换成同一的碘酸根离子,并通过紫外检测器,在波长210nm处予以测定。结果表明:亚氯酸根及其他4种杂质离子的浓度在一定范围内与其对应的峰面积呈线性关系,检出限(3S/N)在6.09～19.66μg·L~(-1)之间。按标准加入法进行回收试验,回收率在96.0%～101%之间,测定值的相对标准偏差(n=6)在1.1%～3.0%之间。     

Syntheses and Crystal Structures of 4-Amino-3- （3-hyd roxyp ropyl）- 1H-1,2,4-triazole-5（4H）-thione and 6-（4-Biphenylyl）-3-（3-hydroxypropyl）-7H-1,2,4-triazolo[3,4-b][1,3,4]thiadiazine

1INTRODUCTION It has been reported that3,6-disubstituted-7H-1,2,4-triazolo[3,4-b][1,3,4]thiadiazines have a broad spec-trum of bioactivities,such as antimicrobial[1],antibac-terial,antifungal[2],anti-inflammatory[3],diuretic[4],an-thelmintic and analgesic[5].They can also be used as plant-growth regulating agents[6],photographic coup-lers,dyes for improved preservability and absorption characteristics,and inhibitors of malignant cellularZOU K.H.et al.:Syntheses and Crystal Structures o…