Based on catastrophe theory,we used the catastrophe progression method to predict the risk of coal and gas outbursts in coal mines.According to the major factors affecting coal and gas outbursts,we built a comprehensi...Based on catastrophe theory,we used the catastrophe progression method to predict the risk of coal and gas outbursts in coal mines.According to the major factors affecting coal and gas outbursts,we built a comprehensive evaluation index system and a coal and gas outburst prediction model.In addition,we performed a standard transformation for each index system;based on the degree the various indices affect the risk of an outburst,to make the data dimensionless.Based on the outburst data from eight mines,we determined catastrophe progression values and verified these values.The results show that:1) converting multi-dimensional problems into one-dimensional problems using this catastrophe progression method can simplify the steps of predicting coal and gas outbursts;2) when pre-determined catastrophe progression values are used to predict coal and gas outbursts,the predicting accuracy rate can be as high as 87.5%;3) the various coal mines have different factors inducing outbursts with varying importance of these factors and 4) the catastrophe progression values,calculated based on these factors,can be used effectively to predict the risk of outbursts in coal mines.展开更多
Three major elements, carbon, hydrogen, and nitrogen, in twenty-four bituminous coal samples, were measured by laser-induced breakdown spectroscopy. Argon and helium were applied as ambient gas to enhance the signals ...Three major elements, carbon, hydrogen, and nitrogen, in twenty-four bituminous coal samples, were measured by laser-induced breakdown spectroscopy. Argon and helium were applied as ambient gas to enhance the signals and eliminate the interference of nitrogen from surrounding air. The relative standard deviation of the related emission lines and the performance in the partial least squares （PLS） modeling were compared for different ambient environments. The results showed that argon not only improved the intensity, but also reduced signal fluctuation. The PLS model also had the optimal performance in multi-element analysis using argon as ambient gas. The root mean square error of prediction of carbon concentration decreased from 4.25% in air to 3.49% in argon, while the average relative error reduced from 4.96% to 2.98%. Hydrogen line demonstrated similar improvement. Yet, the nitrogen lines were too weak to be detected even in an argon environment which suggested the nitrogen signal measured in air come from the breakdown of nitrogen molecules in the atmosphere.展开更多
目的建立基于质量源于生产(quality by production,Qb P)的广藿香质量标志物(Q-Marker),为规范广藿香饮片生产,合理提升广藿香饮片质量提供依据。方法对广藿香饮片生产过程中的质量风险点和饮片质量进行分析,发现饮片加工过程中存在广...目的建立基于质量源于生产(quality by production,Qb P)的广藿香质量标志物(Q-Marker),为规范广藿香饮片生产,合理提升广藿香饮片质量提供依据。方法对广藿香饮片生产过程中的质量风险点和饮片质量进行分析,发现饮片加工过程中存在广藿香叶加入不足的不规范生产现象,致使广藿香饮片质量下降。采用GC法同时测定广藿香饮片中挥发性成分百秋李醇和广藿香酮的含量,利用指纹图谱结合化学计量学对不同比例广藿香叶的样品中差异性成分进行筛选。结果百秋李醇含量与饮片中广藿香叶比例呈显著正相关,可作为控制饮片中广藿香叶比例的关键标志物之一。正交偏最小二乘-判别分析(OPLS-DA)结果显示,黄酮类成分对不同广藿香叶比例的饮片样品划分具有显著影响。通过同时测定雷杜辛黄酮醇和藿香黄酮醇2种主要黄酮类成分的含量并结合方差分析,结果显示雷杜辛黄酮醇和藿香黄酮醇含量在不同广藿香叶比例样品中具有显著性差异(P<0.05),并与广藿香叶比例呈显著性正相关,亦可作为广藿香生产规范性的Q-Marker。考虑饮片加工过程中广藿香叶的损失,以15%广藿香叶比例为标准,建议百秋李醇不低于0.24%,雷杜辛黄酮醇和藿香黄酮醇总量不低于0.045%。结论基于Qb P理念,确立百秋李醇、藿香黄酮醇和雷杜辛黄酮醇为广藿香生产规范化Q-Marker,为广藿香质量标准提升和保障饮片质量提供实验依据。展开更多
基金Projects 50574072, 50874089 and 50534049 supported by the National Natural Science Foundation of China08JK366 by the Special Scientific Foundation of Educational Committee of Shaanxi Province
文摘Based on catastrophe theory,we used the catastrophe progression method to predict the risk of coal and gas outbursts in coal mines.According to the major factors affecting coal and gas outbursts,we built a comprehensive evaluation index system and a coal and gas outburst prediction model.In addition,we performed a standard transformation for each index system;based on the degree the various indices affect the risk of an outburst,to make the data dimensionless.Based on the outburst data from eight mines,we determined catastrophe progression values and verified these values.The results show that:1) converting multi-dimensional problems into one-dimensional problems using this catastrophe progression method can simplify the steps of predicting coal and gas outbursts;2) when pre-determined catastrophe progression values are used to predict coal and gas outbursts,the predicting accuracy rate can be as high as 87.5%;3) the various coal mines have different factors inducing outbursts with varying importance of these factors and 4) the catastrophe progression values,calculated based on these factors,can be used effectively to predict the risk of outbursts in coal mines.
基金Acknowledgements The authors are grateful for the financial support from the National Natural Science Foundation of China （Grant No. 51061130536）.
文摘Three major elements, carbon, hydrogen, and nitrogen, in twenty-four bituminous coal samples, were measured by laser-induced breakdown spectroscopy. Argon and helium were applied as ambient gas to enhance the signals and eliminate the interference of nitrogen from surrounding air. The relative standard deviation of the related emission lines and the performance in the partial least squares （PLS） modeling were compared for different ambient environments. The results showed that argon not only improved the intensity, but also reduced signal fluctuation. The PLS model also had the optimal performance in multi-element analysis using argon as ambient gas. The root mean square error of prediction of carbon concentration decreased from 4.25% in air to 3.49% in argon, while the average relative error reduced from 4.96% to 2.98%. Hydrogen line demonstrated similar improvement. Yet, the nitrogen lines were too weak to be detected even in an argon environment which suggested the nitrogen signal measured in air come from the breakdown of nitrogen molecules in the atmosphere.
文摘目的建立基于质量源于生产(quality by production,Qb P)的广藿香质量标志物(Q-Marker),为规范广藿香饮片生产,合理提升广藿香饮片质量提供依据。方法对广藿香饮片生产过程中的质量风险点和饮片质量进行分析,发现饮片加工过程中存在广藿香叶加入不足的不规范生产现象,致使广藿香饮片质量下降。采用GC法同时测定广藿香饮片中挥发性成分百秋李醇和广藿香酮的含量,利用指纹图谱结合化学计量学对不同比例广藿香叶的样品中差异性成分进行筛选。结果百秋李醇含量与饮片中广藿香叶比例呈显著正相关,可作为控制饮片中广藿香叶比例的关键标志物之一。正交偏最小二乘-判别分析(OPLS-DA)结果显示,黄酮类成分对不同广藿香叶比例的饮片样品划分具有显著影响。通过同时测定雷杜辛黄酮醇和藿香黄酮醇2种主要黄酮类成分的含量并结合方差分析,结果显示雷杜辛黄酮醇和藿香黄酮醇含量在不同广藿香叶比例样品中具有显著性差异(P<0.05),并与广藿香叶比例呈显著性正相关,亦可作为广藿香生产规范性的Q-Marker。考虑饮片加工过程中广藿香叶的损失,以15%广藿香叶比例为标准,建议百秋李醇不低于0.24%,雷杜辛黄酮醇和藿香黄酮醇总量不低于0.045%。结论基于Qb P理念,确立百秋李醇、藿香黄酮醇和雷杜辛黄酮醇为广藿香生产规范化Q-Marker,为广藿香质量标准提升和保障饮片质量提供实验依据。
