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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. 相似文献
84.
Synthesis, Characterization and Properties of Tri-substitute Potassium Salt of Trinitrophloroglucinol 总被引:1,自引:0,他引:1
The title complex [K3(TNPG)·(H2O)2]n was synthesized by the reaction of the aqueous solutions of trinitrophlomglucinol (TNPG) with KHCO3. The complex was characterized by elemental analysis and FTIR spectroscopy, and its single crystal structure was determined by X-ray diffraction analysis. The structural analysis demonstrates that two different coordination modes of K cations [K(1) and K(2)] are around TNPG^3- anions in complex [Ka(TNPG)·(H2O)2]n, where the coordination numbers are eight. All K atoms coordinate with O atoms of phenolic hydroxyl group and nitro-group simultaneously. The thermolysis of the [Ka(TNPG) · (H2O)2]n has been investigated by using differential scanning calorimetry (DSC) and thermogravimetry-derivative thermogravimetry (TG-DTG) at a heating rate of 10 ℃/min. The thermal decomposition processes of the title complex were comprised of one endothermic dehydration stage and one exothermic decomposition stage in 270-320℃, and the final decomposition residue contained KNC. Impact and friction sensitivity results of the complex revealed its sensitive nature towards mechanical stimuli. The experiments verified that the complex has some characteristics of explosive. 相似文献
85.
在纳米级Fe3O4作为种子, 过量的盐酸羟胺为还原剂的条件下, 将Au3+在分散于水相中的Fe3O4胶态种子表面还原为Au0, 得到核壳结构, 粒径为170 nm左右的Fe3O4/Au磁性复合微粒, 并对磁性复合微粒的制备条件进行了优化. 通过激光粒度散射仪和透射电子显微镜分析了不同条件下磁性复合微粒的粒径分布及形貌, 结果表明: Fe3O4种子的磁响应性、悬浮稳定性以及种子表面Au3+的还原条件等是得到单分散性、粒径均一、磁响应性和悬浮性能好的胶态Fe3O4/Au复合微粒的主要影响因素. 通过紫外-可见分光光度计对Fe3O4/Au复合微粒的扫描分析发现, 磁性复合微粒在可见光区域呈现与胶体金类似的特征吸收峰, d (0.5) =168 nm的Fe3O4/Au磁性复合微粒的最大吸收峰位于波长625 nm处. 相似文献
86.
T-jump/FT-IR spectroscopy was used to study the rapid thermal decomposition activity of [Pb2(TNR)2(CHZ)2(H2O)2]·4H2O and Cd(CHZ)2(TNR)(H2O) under 0.1 MPa Ar atmosphere. The results show that the main gaseous products of [Pb2(TNR)2(CHZ)2(H2O)2]·4H2O are NH3, H2O and HONO, while CO and NO are the major gaseous products of flash pyrolysis of Cd(CHZ)2(TNR)(H2O). Thus Cd(CHZ)2(TNR)(H2O) is not an eco-friendly and chemically compatible primary explosive. Both compounds liberate volatile metal carbonate, oxide and isocyanate compounds. The combustion temperature and products of the two compounds were calculated by Real code. The results of theoretical calculation show that the combustion temperature of [Pb2(TNR)2(CHZ)2(H2O)2].4H2O is higher than that of Cd(CHZ)2(TNR)(H2O), there is no HNCO in the combus- tion products and the amount of NO is less than the experiment result from T-jump/FTIR. 相似文献
87.
用新课程标准指导数学教学 总被引:2,自引:0,他引:2
上海市高中数学二期课改已走过三年历程.学生的主动学习精神不断增强,数学教学健康发展.高中数学二期课改给我们带来了新的理念、新的观点、新的方法.回顾三年来的实践,如何充分发挥二期课改所达到的目标,如何更有效的开展数学教学,谈谈笔者的看法.一、高中数学二期课改的改革与创新1.课程目标的改革与创新仔细研读新的课程方案,我们感受最深的是,从时代要求出发,以学生发展为本是课程改革的一个明显的特征.调整后的课程目标突出强调了数学创新精神、数学实践能力以及团队精神和合作能力的培养,以培养学生的数学文化素养为目标,养成学生运用… 相似文献
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89.
ICP-AES法测定钛合金中的6种元素 总被引:4,自引:1,他引:3
用HCl分解钛合金样品,直接用ICP-AES法测定其中的Cr、Mo、Fe、Si、Al及Zr6种元素,方法简便、快速、测定各元素含量范围为0.28%-6.51%,相对标准偏差为0.72%-5.07%,回收率为97.4%-102%。 相似文献
90.