5-羟甲基糠醛(HMF)是在果葡糖浆生产过程中可能产生的一种物质,会对产品的口感风味和人身健康带来一定的影响。本论文通过单因素实验和正交实验设计,对影响果葡糖浆中HMF产生的影响因素进行了研究。实验表明:温度越高HMF越易产生;pH控制...5-羟甲基糠醛(HMF)是在果葡糖浆生产过程中可能产生的一种物质,会对产品的口感风味和人身健康带来一定的影响。本论文通过单因素实验和正交实验设计,对影响果葡糖浆中HMF产生的影响因素进行了研究。实验表明:温度越高HMF越易产生;pH控制在4~5 HMF产生较少,酸性较强容易产生HMF;干物浓度较高时(】70%),HMF产生的速度较快;操作时间与HMF的产生量成正比关系。正交实验显示,各个影响因素中对HMF产生的影响:温度 】 时间 】 干物浓度 】 pH。本论文还对颗粒活性炭去除HMF的方法进行了简单介绍和研究,为公司生产工艺的控制提供了必要的依据。5-Hydroxymethylfurfural (HMF) is a substance generated in the producing process of high fructose corn syrup, which is harmful to the flavor of products and human healthy. Single factor experiment and orthogonal experi- ment design were adopted to investigate the factors influencing the generation of 5-HMF. The results indicated that 5-HMF increases as the temperature rises. 5-HMF produces less at pH 4 - 5. The stronger acidity of the syrup leads to generate more 5-HMF. The 5-HMF increases faster at higher concentrations (DS 】 70%). The reaction time is propor- tional to 5-HMF generation. Orthogonal experiments showed that the influencing effects of factor were followed as: temperature 】 time 】 concentrations 】 pH value. Moreover, the removing method of 5-HMF by using granular acti- vated carbons was also studied in the work. The results might be very meaningful to provide evidence for process con- trol of high fructose corn syrup.展开更多
目的:评价十二导联常规心电图对冠脉缺血性心脏病的诊断与冠脉造影检查结果的一致性。方法:收集、对比2011年~2015年期间华北石油管理局总医院心内科109例行冠脉造影检查住院患者的术前常规十二导联心电图与其冠脉造影结果。将术前常规...目的:评价十二导联常规心电图对冠脉缺血性心脏病的诊断与冠脉造影检查结果的一致性。方法:收集、对比2011年~2015年期间华北石油管理局总医院心内科109例行冠脉造影检查住院患者的术前常规十二导联心电图与其冠脉造影结果。将术前常规心电图结果按其具体表现分为:完全正常心电图;非特异性异常心电图(包括各种心律失常,非特异性ST-T改变)以及特异性改变心电图(包括异常Q波,典型ST抬高或压低,明显T波改变)。冠脉造影结果按照冠脉斑块阻塞程度也分为三组:冠脉斑块阻塞小于50%;冠脉斑块阻塞50%~75%;冠脉斑块阻塞大于75%。对数据进行汇总,并做一致性分析统计。结果:109例中,常规心电图为完全正常窦性心律的有17例,非特异性异常心电图(包括心律失常11例,非特异性ST-T改变9例)20例,特异性改变心电图(包括异常Q波10例,ST-T改变40例,单纯ST压低12例,单纯T波倒置10例)72例;冠脉造影结果无斑块及阻塞小于50%共19例,冠脉斑块阻塞50%~75%的共11例,冠脉斑块阻塞大于75%的共79例。经分析后得出,两种检查结果有相关性(卡方 = 40.7520,P = 0.0000),可以用Kappa指数描述其一致性。Kappa指数 = 0.286195,说明此两种检查的一致性较差。结论:常规十二导联心电图是诊断冠脉缺血性心脏病的重要方法,但由于受采集时机等因素影响,其表现与实际冠脉病变程度一致性较差,不能单纯依此作为判断冠状动脉狭窄程度的依据,需要通过运动实验,24小时动态心电监测等检查来提高检测的敏感度和准确率。Aims: To analyze the consistency between coronary arteriography and electrocardiogram in ischemic heart disease. Methods: Between 2011 and 2015, 109 patients who received both arteriography and electrocardiogram in Cardiology Department, Huabei Petroleum General Hospital, were registered. We divided arteriography results into 3 groups by the degree of stenosis of coronary a展开更多
由于风能具有随机性、间歇性与波动性等特点,致使当大规模风电场接入电力系统后,会给系统造成不可忽视的负面影响,从而给电网的安全稳定运行带来风险。本文基于运行风险评估框架理论体系,建立了相应的运行风险评估指标体系,分别从局部...由于风能具有随机性、间歇性与波动性等特点,致使当大规模风电场接入电力系统后,会给系统造成不可忽视的负面影响,从而给电网的安全稳定运行带来风险。本文基于运行风险评估框架理论体系,建立了相应的运行风险评估指标体系,分别从局部级和系统级两个层面反映系统的短期运行风险水平。最后,基于IEEE-RTS79验证上述所建评估框架理论体系的正确性。Due to the randomness, intermittent and fluctuation characteristics of wind energy, the negative effects brought by large-scale wind farms when they are connected to the power system cannot be neglected. Large scale wind farm connected to power grid will bring operational risk to the grid. Based on the theoretical framework of operational risk assessment, this paper established the corresponding operational risk assessment index system, which reflects the system’s short-term level of the operational risk from the local and system level respectively. At last, the accuracy of the established assessment index system is proved based on the IEEE-RTS79 system.展开更多
文摘5-羟甲基糠醛(HMF)是在果葡糖浆生产过程中可能产生的一种物质,会对产品的口感风味和人身健康带来一定的影响。本论文通过单因素实验和正交实验设计,对影响果葡糖浆中HMF产生的影响因素进行了研究。实验表明:温度越高HMF越易产生;pH控制在4~5 HMF产生较少,酸性较强容易产生HMF;干物浓度较高时(】70%),HMF产生的速度较快;操作时间与HMF的产生量成正比关系。正交实验显示,各个影响因素中对HMF产生的影响:温度 】 时间 】 干物浓度 】 pH。本论文还对颗粒活性炭去除HMF的方法进行了简单介绍和研究,为公司生产工艺的控制提供了必要的依据。5-Hydroxymethylfurfural (HMF) is a substance generated in the producing process of high fructose corn syrup, which is harmful to the flavor of products and human healthy. Single factor experiment and orthogonal experi- ment design were adopted to investigate the factors influencing the generation of 5-HMF. The results indicated that 5-HMF increases as the temperature rises. 5-HMF produces less at pH 4 - 5. The stronger acidity of the syrup leads to generate more 5-HMF. The 5-HMF increases faster at higher concentrations (DS 】 70%). The reaction time is propor- tional to 5-HMF generation. Orthogonal experiments showed that the influencing effects of factor were followed as: temperature 】 time 】 concentrations 】 pH value. Moreover, the removing method of 5-HMF by using granular acti- vated carbons was also studied in the work. The results might be very meaningful to provide evidence for process con- trol of high fructose corn syrup.
文摘目的:评价十二导联常规心电图对冠脉缺血性心脏病的诊断与冠脉造影检查结果的一致性。方法:收集、对比2011年~2015年期间华北石油管理局总医院心内科109例行冠脉造影检查住院患者的术前常规十二导联心电图与其冠脉造影结果。将术前常规心电图结果按其具体表现分为:完全正常心电图;非特异性异常心电图(包括各种心律失常,非特异性ST-T改变)以及特异性改变心电图(包括异常Q波,典型ST抬高或压低,明显T波改变)。冠脉造影结果按照冠脉斑块阻塞程度也分为三组:冠脉斑块阻塞小于50%;冠脉斑块阻塞50%~75%;冠脉斑块阻塞大于75%。对数据进行汇总,并做一致性分析统计。结果:109例中,常规心电图为完全正常窦性心律的有17例,非特异性异常心电图(包括心律失常11例,非特异性ST-T改变9例)20例,特异性改变心电图(包括异常Q波10例,ST-T改变40例,单纯ST压低12例,单纯T波倒置10例)72例;冠脉造影结果无斑块及阻塞小于50%共19例,冠脉斑块阻塞50%~75%的共11例,冠脉斑块阻塞大于75%的共79例。经分析后得出,两种检查结果有相关性(卡方 = 40.7520,P = 0.0000),可以用Kappa指数描述其一致性。Kappa指数 = 0.286195,说明此两种检查的一致性较差。结论:常规十二导联心电图是诊断冠脉缺血性心脏病的重要方法,但由于受采集时机等因素影响,其表现与实际冠脉病变程度一致性较差,不能单纯依此作为判断冠状动脉狭窄程度的依据,需要通过运动实验,24小时动态心电监测等检查来提高检测的敏感度和准确率。Aims: To analyze the consistency between coronary arteriography and electrocardiogram in ischemic heart disease. Methods: Between 2011 and 2015, 109 patients who received both arteriography and electrocardiogram in Cardiology Department, Huabei Petroleum General Hospital, were registered. We divided arteriography results into 3 groups by the degree of stenosis of coronary a
文摘由于风能具有随机性、间歇性与波动性等特点,致使当大规模风电场接入电力系统后,会给系统造成不可忽视的负面影响,从而给电网的安全稳定运行带来风险。本文基于运行风险评估框架理论体系,建立了相应的运行风险评估指标体系,分别从局部级和系统级两个层面反映系统的短期运行风险水平。最后,基于IEEE-RTS79验证上述所建评估框架理论体系的正确性。Due to the randomness, intermittent and fluctuation characteristics of wind energy, the negative effects brought by large-scale wind farms when they are connected to the power system cannot be neglected. Large scale wind farm connected to power grid will bring operational risk to the grid. Based on the theoretical framework of operational risk assessment, this paper established the corresponding operational risk assessment index system, which reflects the system’s short-term level of the operational risk from the local and system level respectively. At last, the accuracy of the established assessment index system is proved based on the IEEE-RTS79 system.
