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芦竹碱法合成DL-色氨酸 总被引:3,自引:0,他引:3
以芦竹碱和海因为原料,经缩合、水解合成DL-色氨酸,收率达41.6%。缩合反应的最佳工艺条件为:反应时间5 h、碘甲烷与芦竹碱的摩尔比为1.2∶1、乙醇钠与芦竹碱的摩尔比为0.8∶1、原料芦竹碱与海因的摩尔比为0.9∶1;水解反应的最佳工艺条件为:NaOH浓度为1.5 mol/L、水解时间10 h、吲哚甲基海因的浓度为0.2 mol/L、温度为100℃。 相似文献
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杯芳烃衍生物和丙烯酰胺作为复合功能单体的分子印迹聚合物对海因类化合物的选择性识别研究 总被引:2,自引:0,他引:2
以杯[4]芳烃衍生物+丙烯酰胺作为复合功能单体,将其运用到分子印迹技术中,对海因类化合物R-苄基海因进行选择性识别.研究结果表明,由单一的杯[4]芳烃衍生物或丙烯酰胺作为功能单体的分子印迹聚合物对R-苄基海因的选择性均不高,而由杯[4]芳烃衍生物+丙烯酰胺作为复合功能单体的分子印迹聚合物对模板分子具有较高的特异选择性. 相似文献
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液相色谱-质谱法同时测定甜瓜样品中的噻菌灵、甲基托布津、扑海因 总被引:9,自引:0,他引:9
采用液相色谱-质谱法同时测定甜瓜样品中的噻菌灵、甲基托布津和扑海因含量。离子化技术采用大气压电喷雾( )方式,定量测定使用选择离子监测模式。检测离子m/x:202.25、343.28、331.07。检出限:噻菌灵为0.1pg,甲基托布津为10.2pg,扑海因为2.42ng;回收率为81.0%~110%;相对标准偏差为1.5%~16.8%。方法灵敏度高,选择性好,准确度高,用于甜瓜样品中噻菌灵、甲基托布津、扑海因的测定,获得了满意的结果。 相似文献
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Ayman M. Atta Manar E. Abdel-Rauf Nermine E. Maysour Amani K. Gafer 《Journal of Dispersion Science and Technology》2013,34(5):583-595
Water-soluble surfactants based on rosin acids were synthesized from condensed rosin acid-formaldehyde. This was completed by esterification of series of rosin acid formaldehyde resins with poly(ethylene glycol) having different molecular weights to produce series of rosin esters. The structure of the produced resins was determined by infrared and 1HNMR analysis. The molecular weight of the produced surfactants was determined by gel permeation chromatography (GPC) technique. The surface properties of the prepared surfactants were determined by measuring the surface tension at different temperatures. The surface tension, critical micelle concentration (CMC), and surface activities were determined at different temperatures. Surface parameters such as surface excess concentration (Γmax), the area per molecule at interface (Amin), and the effectiveness of surface tension reduction (πCMC) were determined from the adsorption isotherms of the prepared surfactants. Some thermodynamic data for the adsorption process were calculated and are discussed. The dispersion efficiency of the prepared surfactants as petroleum oil spill dispersants was determined and correlated with the surface activity, concentrations of the prepared surfactants and type of petroleum crude oil. 相似文献
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试样用等体积硝酸和盐酸混合酸溶解,用高氯酸将Cr(Ⅲ)氧化为Cr(Ⅵ),用定量Fe(Ⅱ)将Cr(Ⅵ)定量还原为Cr(Ⅲ),用铬酸"剩余光度法"测定铬,丁二酮肟光度法测定镍,硫氰酸盐光度法测定钼,变色酸(1,8-二羟基萘-3,6-二磺酸)光度法测定钛,高锰酸光度法测定锰。测定结果与标准值基本一致,铬、镍、钼、钛、锰测定结果的相对标准偏差分别为0.2%、0.3%、1.5%、2.0%、2.0%。 相似文献
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In this work, Cs+ ion sorption on some clays and zeolite were investigated. 137Cs was used as a tracer. Activities were measured with a NaI crystal gamma counter. The particle size distribution was determined
by a laser sizer. Surface area of the particles were determined by BET (Brunauer, Emmett and Teller method). Structure analysis
was made by using X-ray diffraction. The chemical compositions of the solid samples were determined using a ICAP-OE spectrometer.
Kinetic and thermodynamic parameters were determined. Due to very high uptake results; clay and zeolite can be proposed as
a good sorbents in waste management considerations. 相似文献
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《高分子科学杂志,A辑:纯化学与应用化学》2013,50(10):1211-1225
Copolymers of 4-cinnmoylphenyl methacrylate (CPMA) with glycidyl methacrylate were synthesized in methyl ethyl ketone solution using benzoyl peroxide as initiator at 70 ± 1°C. They were characterized by UV, IR, 1H-NMR, and 13C-NMR spectra. Their compositions were determined by 1H-NMR technique. The monomer reactivity ratios were determined by the Fineman-Ross and Kelen-Tüdös methods. The molecular weights ([Mbar]w and [Mbar]n) of the polymers were determined by GPC technique. Thermogravimetric analysis of the copolymers were carried out in air. The Tg of the polymers were determined by differential scanning calorimetry. The photocrosslinking properties of the homo and copolymers were also discussed. 相似文献
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通过在谱仪真空中对碱土金属氧化物作原位加热, 使其表面碳酸盐分解, 然后记录其晶格氧的O_(1s)电子结合能. 结果表明测得的MgO, CaO, SrO和BaO 的O_(1s)结合能明显地低于大部分文献报导的数值. 本文测得的碱土金属氧化物的O_(1s)电子结合能与氧原子上的Sanderson电荷分数有合理的相关性. 本文测得的BaO_2的O_(1s)结合能是530.9 eV, 它比文献报导的数值要低. 相似文献
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根据文献查得的Q,e值,计算了醋酸乙烯-二乙烯基二元共聚的竞聚率,预测其共聚的可能性。以甲苯为汽油为致孔剂,采用悬浮聚合方法合成该二元大孔共聚物。红外光谱分析跟踪共聚反应过程中乙酰氧基和苯环相对比例的变化,并测定共聚反应过程中比表面积,孔率和平均孔径的变化。 相似文献
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《高分子科学杂志,A辑:纯化学与应用化学》2013,50(10):1521-1535
The oxidation of polypropylene (PP) homopolymer in air was performed using dodecanol-1 as an accelerator. The experiments were conducted under atmospheric pressure at 180-220°C. Spectroscopic data indicated the formation of polar groups such as ketones, esters, alcohols, anhydrides etc. as determined by FTIR and ESCA. The scanning electron microscopy (SEM) showed the variations of morphology of the oxidation products. The fusion temperatures were determined by differential scanning calorimetry (DSC). The variations of solubility of PPO as compared with the original PP were investigated in solvents such as MEK, THF, and toluene. Surface tension and molecular weights were determined by tensiometry and gel premeation chromatography (GPC). The melt flow index (MFI) of different samples were determined. 相似文献
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电感耦合等离子体原子发射光谱同时测定不锈钢食用器皿铬、镍、镉溶出量 总被引:1,自引:0,他引:1
庞晋山 《分析测试技术与仪器》2003,9(4):247-250
用4%醋酸溶液浸泡取自不锈钢食用器皿钢片样品,在室温条件下浸泡24h,将浸泡液按6:1浓缩.通过优化试验确定实验条件,用电感耦合等离子体发射光谱仪准确测定浸泡液中Cr、Ni、Cd的浓度。实验过程操作简单,多种元素同时测定节约试验时间,精密度试验和回收率试验说明该方法检测结果准确可靠。 相似文献
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Gaseous species of the thermal methyltrichlorosilane decomposition were determined qualitatively and quantitatively by in situ infrared spectroscopy and gas chromatography. Surface species like SiCl
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were detected by reflexion in situ infrared spectroscopy. A CVD mechanism of this decomposition is introduced. The comparison between the layer composition
determined by EPMA and determined by gas phase analysis is given. 相似文献
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用IR和负离子FAB-MS测定不同pH值下EDTA,DTPA,及其碱金属盐类,能直接给出它们的结构及其分子量,对于其碱金属盐类的混合物,不经分离,可以直接测定,能同时得到混合物中各组分的相对分子质量。 相似文献