排序方式: 共有136条查询结果,搜索用时 15 毫秒
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GC/MS分析铝箔轧制基础油组成 总被引:2,自引:0,他引:2
用GC/MS技术分析铝箔轧制基础油,得到了基础油的组成成分。并提出了采用计算机检索和参考标准物质的相对保留时间,结合各物质的物理化学性质的方法来解析石油产品色谱图。 相似文献
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论偏最小二乘校正方法的稳定性 总被引:1,自引:0,他引:1
研究了多元校正方法--偏最小二乘(PLS)在波长色散X射线荧光光谱分析中的应用,并将该法与传统的经验系数法(ECM)进行了比较,其考察对象为一组转炉渣文献数据,一组不锈钢样和一组锌精矿样。结果表明,PLS比ECM准确、稳定、经分析探讨,认为其主要原因是PLS能滤除噪音,文中建立了描述浓度和强度本质的关系式。 相似文献
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Optimization of extraction and determination of emodin from Polygonum cuspidatum Sieb. et Zucc. products by HPLC-DAD 总被引:1,自引:0,他引:1
A uniform experimental design procedure was used to investigate the effects of some operating parameters on the extraction of emodin from Polygonum cuspidatum Sieb. et Zucc. products. Variables tested were volume ratio of material to solvent, size of material, extraction time and temperature and composition of extraction solvent (mixtures of acetone-water). Each variable was tested at seven levels; 7 experiments were performed in random order. Analyses of the extracts were performed by high-performance liquid chromatography with diode array detection(HPLC-DAD). Analytical responses were processed by using a forward regression analysis, in order to find polynomial function describing the relationship between variables and responses. For all the analytes the experimental conditions for providing the highest extraction yield inside the experimental domain considered were found. Finally, a simple, rapid and accurate analytical method was developed for the determination of emodin by high performance liquid chromatography. The separation is achieved within 25 rain on an ODS column using methanol and water as gradient mobiles. Emodin can be quantified by using external standard method detecting at 436 nm. Good linearity is obtained with correlation coefficient exceeding 0.9986 and the detection limit and the quantification limit are 1.53 and 3.23 mg/L respectively. This method shows good reproducibility for the quantification of the emodin with intra-day and inter-day relative standard deviation less than 2.3% and 5.6% respectively. Under optimized extraction conditions, the recovery of the standard is 96.5%. The validated method is successfully applied to quantify the emodin in seven Polygonum cuspidatum sieb. Et zucc. products, which provided an idea for the pre-treatment of determination of active compounds in traditional Chinese medicines. 相似文献
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五水硫酸铜的催化氧化制备 总被引:1,自引:0,他引:1
研究了空气鼓泡--催化氧用紫杂铜制备五水硫酮铜生产方法,考察了温度、酸度、空气鼓入量、催化剂用量等影响。实验结果表明,在硫酸浓度为3%(V/V)、反应温度为60℃,空气流量为3601/h时,铜片溶解速率为0.0288g/cm^2.h,产品的物含量为98.5%。 相似文献
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燕麦秸秆还原浸出低品位软锰矿及其动力学 总被引:1,自引:0,他引:1
以燕麦秸秆为还原剂,在硫酸介质中直接浸出某低品位软锰矿,研究浸出过程的工艺条件和动力学。结果表明:在硫酸浓度为150 g/L、液固比为9 mL/g、麦秆与软锰矿质量比为0.3、浸出温度90℃、浸出60 min的条件下,锰浸出率可达96.1%,此时,铁浸出率为46.8%,浸出液化学需氧量(COD)值为6.2 g/L。动力学研究表明:锰的浸出过程在333~363 K内符合未反应核缩减模型,浸出过程主要受界面化学反应步骤控制,其浸出表观活化能为69.4 kJ/mol。 相似文献
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电解浸出废旧锂电池中钴的热力学和动力学 总被引:1,自引:0,他引:1
以废旧锂电池正极条为阴极,以铅板作阳极,在稀硫酸溶液中,电解浸出正极材料中的钴,从热力学和动力学两方面对钴的电解浸出过程进行研究。实验及热力学数据分析表明:LiCoO2主要通过Co(OH)3还原浸出得到Co2+,考查浸出温度和时间表明在电解前期5~30 min电解浸出由缩核模型的化学反应过程控制,浸出率α与时间t满足未反应核收缩模型1-(1-α)1/3=Kt,其表观活化能为7.32 kJ/mol;中期是混合控制;后期75~180 min符合内扩散控制模型1-2α/3-(1-α)2/3=Kt,表观活化能17.05 kJ/mol。浸出液中的铝主要是铝箔表面氧化铝层不受阴极保护而溶于硫酸溶液,正极材料从铝箔上剥离与氧化铝层的溶解有关,剥离时间影响钴的浸出率。 相似文献
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