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1.
介绍电导检测器离子色谱检定方法。采用氯离子标准物质,使用泵流量设定值误差、流量稳定性、基线噪声、基线漂移、最小检测浓度、线性相关性、整机性能定性定量重复性等参数对离子色谱仪进行检定。同时用5 μg/mL氯离子为检测离子,结合JJF 1059.1–2012 《测量不确定度评定与表示》对整机性能不确定度来源进行考察。结果表明:在置信区间为95%时(包含因子k=2),氯离子的质量浓度为(4.94±0.35)μg/mL。经不确定度分析,标准工作曲线拟合引入的不确定度最大,其次是样品的重复随机测试过程。  相似文献   

2.
以分光光度法测定高含量膨润土吸蓝量,应用正交试验设计对分光光度法的实验条件进行优化,确定的最佳实验条件:煮沸时间为5 min,4%焦磷酸钠溶液加入体积为20 mL,0.01 mol/L亚甲基蓝溶液加入体积为30mL,振荡时间为15 min。该法与滴定法对比,测定值相对误差在4%以内,相对标准偏差为1.04%,可满足高纯度膨润土吸蓝量的分析要求。  相似文献   

3.
摘要用原位红外和脉冲实验研究了甲醇在氧化锌表面的吸附行为. FTIR结果表明, 甲醇吸附于氧化锌上易生成甲氧基, 且其生成量随着吸附温度的提高而增加. 进一步的研究结果表明, 甲氧基是由甲醇同氧化锌表面的羟基反应生成的, 将其暴露于水蒸汽中后很快消失. 脉冲实验发现, 氧化锌上脉冲甲醇时产生水, 再脉冲水则产生甲醇. 因此甲醇在氧化锌表面吸附生成甲氧基和水的反应是可逆的.  相似文献   

4.
The overall view of the TPD of ammonia to measure the acidic property of zeolites is described. The desorption peaks were identified and the significance of readsorption of ammonia was pointed out for the first time. This part of the work was done using reference catalysts of the Catalysis Society of Japan. The theoretical equation for the TPD with free readsorption of ammonia was then derived. Two methods for determining the strength of zeolite acidity based on the derived equation were proposed. A curve fitting method was then proposed to determine the zeolite acidity; based on this method, not only the strength of acidity but also its distribution could be determined. This method was applied to mordenite and ZSM-5 zeolites with different contents of Al and Na cations, and a simple conclusion was reached; namely, the strength of the acidity was not influenced by the number of acid sites but by the structure of the zeolite. Finally, water vapor treatment to rub out the l-peak (lower temperature peak) was briefly mentioned. This method was applied to precisely determine the acidity of Y-zeolite. A case study about the beta zeolite as the catalyst for the amination of phenol was exemplified; the catalytic activity was discussed in terms of the measured acidity.  相似文献   

5.
化探金样品前处理过程中消解、富集、解吸等环节控制不严格,往往会导致最后数据处理产生过高的校正系数。为了降低校正系数,用统计学的方法对实验过程进行了详细分析,确定了主要影响因素。将水浴时间延长并保温3 h以上,泡塑大小改为0.2 g,清洗时间不大于15 s,解吸到上机时间间隔小于5 h。方法改进后,检测结果校正系数有了明显改善,从改进前有40%批次的校正系数大于1.2,降到了全部小于1.2,甚至不用校正。方法改进后降低了实验过程的误差,提高了分析测试结果的稳定性。  相似文献   

6.
利用X射线微区分析的方法,对吸附交联法得到的固定化脂肪酶的微观活性进行了分析。结果表明:以合成出的大孔吸附树脂为固定化酶栽体,酶活较高,活性脂肪酶分布较均匀。并得到了固定化脂肪酶的活性定位的最佳条件。  相似文献   

7.
对影响酸性大豆蛋白固体饮料品质的因素进行了研究,并优化了酸性大豆蛋白固体饮料制备的工艺条件,研究发现最佳制备工艺条件为大豆蛋白与大豆多糖添加质量比为1∶0.22、干燥前调节混合液p H值为7.0、先混和大豆多糖和麦芽糊精再与大豆蛋白混合、喷雾干燥并取收集桶中样品,在此条件下制备的新型大豆蛋白固体饮料溶解性较好,且调制成的酸性大豆蛋白液体饮料的沉淀率较低,仅为0.95%。  相似文献   

8.
A rapid, sensitive and selective high performance liquid chromatography (HPLC) method was developed and validated for determination of loganin in rat tissues. Samples were prepared based on a simple protein precipitation. Separation of loganin was achieved on a reversed-phase C(18) column (250 x 4.6 mm, 5 microm) with a mobile phase consisting of acetonitrile and water (16:84, v/v) at a flow rate of 1.0 mL/min. The detection wavelength was set at 236 nm and the temperature of the column was kept at 30 degrees C. The method was applied to study tissue distribution of loganin in rats after a single administration of loganin at a dose of 20 mg/kg. The highest level was observed in kidney, then in stomach, lung and small intestine. The lowest level was found in brain. The peak levels were attained at 90 min in most tissues. It was indicated that kidney was the major distribution tissue of loganin in rats, and that loganin had difficulty in crossing the blood-brain barrier. It was also found there was no long-term accumulation of loganin in rat tissues.  相似文献   

9.
本文合成了10,12-双炔廿三酸,并用其在Si、SiO_2、CaF_2等基片上沉积了LB膜,结果表明,10,12-双炔廿三酸的镉盐成膜更稳定。这种LB膜在紫外光辐照下很快聚合,聚合前后的紫外-可见吸收光谱发生规律性的变化,并保持层状结构,等同周期稍变。通过红外吸收的二向色性分析,确定了该分子的取向。  相似文献   

10.
1998年8月-1999年3月采用思密达治疗口腔溃疡32例,并与红霉素(含强的松,维生素B2)治疗口腔溃疡30例比较,结果表明,治疗4天后,思密达组显效率75.00%,总有效率100.0%,而红霉素组显效率6.67%,总有效率40.0%,提示思密达治疗口腔溃疡有较好的临床效果。  相似文献   

11.
Phosphorylation of 2,7-dihydroxynaphthalene derivatives, containing different amine components was performed by full amides of phosphorous acid. A substantial effect of the intramolecular hydrogen bond on the process of phosphorylation was shown. Cyclophosphorylation was performed and principal possibility of the synthesis of naphthophosphacrownaphanes having aminomethyl linkers was shown. Mannich aminomethylation of naphthophosphacyclophanes was found to be impossible.  相似文献   

12.
提出了电感耦合等离子体原子发射光谱法(ICP-AES)测定钒铁中硅、磷、铝、锰、镍、铬、铜、钛共8个杂质元素含量的方法。钒铁样品(0.5000g),先后加入50%(体积分数)硝酸溶液20mL及50%(体积分数)盐酸溶液10mL,在100℃左右加热溶解,溶解过程中应注意保持溶液体积在25mL左右。将溶液过滤并置于200mL容量瓶中作为母液留用。将滤纸及不溶物一并移入铂坩埚中,置于马弗炉中,先于250℃灰化20min,稍冷后加入无水碳酸钠和硼酸(质量比2∶1)组成的混合熔剂0.3g,升温至950℃融熔15min。冷却,用体积比1∶10的盐酸溶液10mL浸出熔块,将此溶液与上述母液合并并加水定容至200mL。此溶液供ICP-AES在仪器工作条件下进行分析。绘制校准曲线时,加入纯铁和五氧化二钒作为基体,以消除基体干扰,然后加入上述8种元素的标准溶液,并按上述溶液最终稀释体积条件和仪器工作条件制作曲线(R大于0.999)。为验证所提出的分析方法的测定数据的精密度,约请了10个实验室对8个不同含量水平的钒铁样品对方法作协同试验,按GB/T 6379.2-2004所规定的方法求算了重复性标准偏差Sr和重复性限r,以及再现性标准偏差SR和再现性限R,并求得所测定的8种元素在各自的测定范围内的r与w之间和R与w之间的函数关系,说明该方法有较好的稳定性和准确性,而且证明此方法是可行的。  相似文献   

13.
In an effort to understand the mechanism of cardiovascular actions of Ganoderma lucidum which was cultivated in Korea, the mycelium was isolated for a large-scale culture. Water extract of the mycelia was evaluated for its cardiovascular activity in anesthetized rabbits and rats. The left femoral artery and vein were cannulated for the measurement of arterial pressure and subsequent delivery of drugs. The left kidney was exposed retroperitoneally and a branch of the renal nerve was used to integrate renal efferent or afferent nerve activities. The extract decreased systolic and diastolic blood pressure, which was accompanied by an inhibition of renal efferent sympathetic nerve activity. The extract did not decrease heart rate in these animals, although there was clear hypotension in the extract dose dependent manner. This suggests that the hypotension induced by the treatment of the extract was secondary to the primary effect of the extract in the central nerve system, which suppressed the sympathetic outflow. Therefore we concluded that the mechanism of hypotensive action of Ganoderma lucidum was due to its central inhibition of sympathetic nerve activity.  相似文献   

14.
以11种炼焦煤为研究对象,分别进行FT-IR和黏结指数G测试。采用Peak Fit软件对FT-IR谱峰进行分峰拟合和定量计算,研究炼焦煤特征官能团含量与其黏结性间的关系。结果表明,煤黏结性大小与其FT-IR吸收峰密切相关,特别是3 000-2 800和3 700-3 000 cm-1两个吸收带;脂肪族结构是煤黏结性形成的主要决定因素,通常脂肪链越短或支链化程度越高,越有利于煤的黏结性形成;含-OH(或-NH)的氢键缔合结构可以与脂肪链协同作用,共同决定煤的黏结性能。不论煤分子有多大,只要是结构单元缩合度较小而作为桥键的脂肪链较多的结构形式,在热解过程中就会生成大量适度分子量、以结构单元为基元的液相物质。氢键是煤中主要的分子间作用形式,当若干形成氢键的官能团聚集缔合时,其相互作用会更强,甚至会形成类似超分子的结构;在形成胶质体阶段,这类氢键缔合的结构也会被打破,并形成以胶质体液相为主的物质。这些液相物质的存在,有利于胶质体的流动、黏连和固化成为半焦,从而最终获得优越的黏结性。  相似文献   

15.
多相光催化是一种非常有效的降解各种水污染物的方法.本文以稀土(镝和镨)掺杂的TiO2为光催化剂,考察了制备条件对其物理性质和光催化性能的影响.采用溶胶-凝胶法和不同条件(反应温度450,550,650oC;反应时间4,8,12 h)的固态反应法制备了TiO2样品.运用X射线衍射分析了该样品的晶相,发现只存在锐钛矿相,并得到Raman光谱的证实.同时采用扫描电镜观察了样品的结构和粒径;以BET法计算了其比表面积;运用紫外-可见光漫反射光谱测得了样品的带隙能量.通过测量紫外光照射下常用除草剂吡唑草胺的降解速率评价了样品的光催化活性,反应过程中吡唑草胺的浓度用高效液相色谱分析.结果表明,稀土掺杂使得TiO2吸收边红移,并提高了其光催化活性;制备时最优的固态反应条件为550oC反应8 h.  相似文献   

16.
Introduction Theliverisoneoftheorgansthathaspotentialre generativecapabilityinmammaliananimals[1].Studies oncaninemodelshaveindicatedthatthelivercanre generate,inonlytwoweeks,toitsoriginalsize,after70%hepatectomy[2].Therefore,theresearchoncellu larandmole…  相似文献   

17.
碳纤维预浸料挥发分的测试对于复合材料的工艺成型和制品的使用性能至关重要。为了解决碳纤维预浸料挥发分测试数据偏离理论值的问题,根据基体类型的差异,对挥发分测试方法进行了改进。对烘焙温度和烘焙时间进行考察试验。通过试验确定4211体系预浸料烘焙温度为160℃,烘焙时间为20 min,;氰酸酯体系预浸料烘焙温度为180℃,烘焙时间为60 min,并且需在金属网的下面加入恒重的收集皿。测试方法改进后,测试结果与理论值接近,且测定结果的标准偏差从0.75下降至0.12,提高了挥发分测试结果的精密度和准确度。  相似文献   

18.
分别将酮洛芬与牛血清白蛋白(BSA)及卵清蛋白(OVA)偶联制得免疫原和包被原,经过免疫新西兰白兔制备多克隆抗体,抗体经纯化后效价为1:128000。使用自制的抗体,建立了测定酮洛芬的间接竞争酶联免疫吸附(ic-ELISA)新方法。ic-ELISA的线性范围为0.010~10.0μg/L,IC50为0.235μg/L,最低检测限为0.0040μg/L,线性回归方程为y=-22.97ρ+104.5(R2=0.980),与布洛芬、双氯酚酸的交叉反应率均小于4%,方法可用于水体中酮洛芬的检测。  相似文献   

19.
Mechanism of Thermal Decomposition of Barium Benzoate   总被引:4,自引:0,他引:4  
Barium benzoate was synthesized in a hydrothermal reaction. The complex was characterized by elemental analysis, IR spectroscopy and X-ray powder diffraction. It was monoclinic and had a layered structure. The mechanism of thermal decomposition of the barium benzoate was studied by using TG, DTA, IR and gas chromatography-mass spectrometry. In a nitrogen atmosphere, the barium benzoate decomposed to form BaCO3 and organic compounds: mainly benzophenone, triphenylmethane, etc.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

20.
Morphological structure of native and extruded starches of varied biological origin was studied, their X-ray phase analysis was made, and their solubility in cold water was examined.  相似文献   

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