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101.
L. N. Yang S. J. Qiu F. Xu L. X. Sun Z. B. Zhao J. G. Liang C. G. Song 《Journal of Thermal Analysis and Calorimetry》2007,89(3):875-879
The effects of Amoxicillin Sodium and Cefuroxime Sodium on the growth of E. coli DH5α were investigated by microcalorimetry. The metabolic power-time curves of E. coli DH5α growth were determined by using a TAM air isothermal microcalorimeter at 37°C. By evaluation of the obtained parameters,
such as growth rate constants (k), inhibitory ratio (I), the maximum heat power (P
m) and the time of the maximum heat power (t
m), one found that the inhibitory activity of Amoxicillin Sodium vs. E. coli DH5α is enhanced with the increasing of the Amoxicillin Sodium concentration, and the Cefuroxime Sodium has a stimulatory effect on the E. coli DH5α growth when the concentration is about 1 μg mL−1. The IC50 for the Amoxicillin Sodium and the Cefuroxime Sodium are 1.6 and 2.0 μg mL−1, respectively, it implicates that the E. coli DH5α is more sensitive to Amoxicillin Sodium than Cefuroxime Sodium. 相似文献
102.
Semiconductor alpha-MoTe2 nanorods have been synthesized by annealing Te-seeded particles of an amorphous MoTe2 intermediate. This intermediate is prepared by a solution reaction between Mo(CO)6 and elemental Te in diphenylmethane. The as-synthesized products were characterized by structural, compositional, and morphological techniques of X-ray diffraction, selected area electron diffraction, selected area energy dispersive spectroscopy, energy dispersive X-ray analysis, X-ray photoelectron spectroscopy, transmission electron microscopy, and high-resolution transmission electron microscopy. The results of the annealing process are MoTe2 nanorods with diameters of 50-200 nm and lengths ranging from 0.1 to 3.0 microm. Here, the rodlike structure of MoTe2 is reported for the first time, and added to the list as one kind of new morphology of MoTe2 nanomaterials. A mechanism for the formation of the nanorods is proposed. The sandwich-layered structure of Te-Mo-Te and the similarity in the structure between hexagonal alpha-MoTe2 and hexagonal Te are responsible for the formation of nanorods of MoTe2. 相似文献
103.
104.
Two novel sesquiterpene dimers, compounds 1 and 2 , were isolated from the rhizome of Ligularia virgaurea, together with the six known sesquiterpenoids 3 – 8 . Their structures were established by physico‐chemical and spectroscopic methods, especially by means of 1D‐ and 2D‐NMR as well as HR‐MS analyses. A mechanism based on a classical Diels–Alder cyclization is proposed for the formation of the dimer 1 from the precursors 8 and the quinone form of 6 (Scheme). 相似文献
105.
四(2,4—二叔戊基苯氧基)酞菁铜(Ⅱ)的合成及其LB膜 总被引:5,自引:3,他引:5
合成了标题酞菁铜衍生物,并通过元素分析,高压液相色谱,紫外光谱,红外光谱,核磁共振谱,电镜,顺磁共振谱及质谱加以确认。该化合物在稀氯仿溶液和LB膜中各以单,双分子缔合的形式存在。Z型沉积形成的单层LB膜对氨气有很高的灵敏度和选择性。 相似文献
106.
测定了亲水性甲基丙烯酸羟烷基酯如HEMA、MHPMA分别与AN或AAM,在60℃不同溶剂中自由基聚合反应的竞聚率。AN(M_1)-HEMA(M_2)共单体,在DMSO或DMF溶剂以AIBN或KPS-IPA引发剂条件下共聚,用Kelen-Tüds法计算的竞聚率变化不大,r_1=0.22-0.25、r_2=0.97-1.05,说明在此均相溶液共聚中,所用的溶剂及引发剂对竞聚率的影响较小,这两种单体能很好共聚。但AAM-MHPMA或AAM-HEMA共单体时,r_1与r_2值相差很大,如前者r_1=0.0433、r_2=3.98,后者r_1=0.0535、r_2=1.89,说明不易共聚,共聚物中主要是MHPMA或HEMA组分。 相似文献
107.
Yun‐Yu Liu Guang‐Shan Zhu Guo‐Zhen Fan Shi‐Lun Qiu 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(4):m159-m160
In the title compound, poly[μ5‐pyrazine‐2,3‐dicarboxylato‐cadmium(II)], [Cd(C6H2N2O4)]n or [Cd(pdc)]n, where pdc is the pyrazine‐2,3‐dicarboxylate anion, the CdII atom is six‐coordinated by five carboxylate O atoms and one N atom from five different pdc ligands in a distorted octahedral CdO5N coordination geometry. Two CdII atoms are bridged by carboxylate groups of the pdc ligands to create a dimeric unit. The dimeric units are further connected by the pdc ligands to generate an interesting two‐dimensional structure. 相似文献
108.
Xi-yan Liu Dong Qiu Mei-li Guo Zhen-zhong Yang 《高分子科学》2005,(5):561-566
Sub-micron sized phenolic epoxy resin waterborne particles were prepared by phase inversion emulsification. Micro-phase separation occurred during the curing process at high temperature. The as-prepared samples possessed one glass transition temperature (Tg) and two exothermal processes during DSC heating scannings. After being thermally treated above the exothermal peak temperature, they possessed two glass transition temperatures with the disappearance of exothermal peaks, whilst a core/shell structure was formed. This was likely related with the outward diffusion of reactive oligomers to the outer layer of particles. 相似文献
109.
Ohsuna T Slater B Gao F Yu J Sakamoto Y Zhu G Terasaki O Vaughan DE Qiu S Catlow CR 《Chemistry (Weinheim an der Bergstrasse, Germany)》2004,10(20):5031-5040
High-resolution electron microscopy (HREM) has been used to image the surface structure of nano- and micrometer-sized synthetic crystals of zeolite-Linde-L (LTL). Columnar holes and rotational, nano-sized, wheel-like defects were observed within the crystals, where the hole has a minimum size equal to that of the rotational defect. Predictions of surface structure from atomistic computer simulation concur with the observations from HREM and provide insight into the crystal growth mechanism of perfect and defective LTL. Analysis of the energetics of the formation of rotational defect structures reveals that the driving force for defect creation is thermodynamic and furthermore, the rotational defects could be created in high concentrations. Formation of a columnar hole is found to be slightly energetically unfavourable and therefore we speculate that the incidence of both rotational and nano-sized vacancy defects is strongly dependent on kinetic factors and reaction conditions. The morphology of nano- and microcrystalline LTL is contradistinct and we use insights from simulation to propose an explanation of the disparity in crystal shape. 相似文献
110.
A simple and sensitive HPLC method for quantitative determination of guanidine in high salt and protein matrices was developed. The HPLC system consisted of an Agilent 1100 pump with an online degasser, a UV detector, an autosampler, and Dionex CS 14 cation-exchange guard (4 mm x 50 mm) and analytical (4 mm x 250 mm) columns. The mobile phase was 3.75 mM methanesulfonic acid (MSA) with a flow rate of 1 mL/min. The other analysis parameters were: 50 microL injection volume, 195 nm UV detection, and 21 min runtime. The limit of quantitation (LOQ) for guanidine HCl was determined to be 0.25 mg/L and the standard curve ranged from 0.25 mg/L to 10 mg/L. Sample preparation was required for the samples containing high protein concentrations. Proteins were removed by centrifuging a sample in a 30 K NanoSep centrifugal filter at 15,300 x g for 20 min. The method could determine guanidine accurately in sample matrices containing up to 200 mM sodium ion or up to 50 mM potassium ion. The method can be used for clearance testing of guanidine in biopharmaceutical products. 相似文献