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乙酸乙酯水解反应 被引量:1
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作者 陈毅贞 《实验教学与仪器》 1997年第10期12-12,共1页
关键词 乙酸乙水解 水浴加热 水浴温度 水解反应 课堂演示实验 催化剂 密封体系 的水解 碱性溶液 中性酯
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基于NGAL的模型在肝硬化急性肾损伤早期诊断和鉴别诊断中的意义 被引量:5
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作者 尹伟 李成忠 《肝脏》 2021年第3期247-251,共5页
目的明确早期检测NGAL对诊断肝硬化急性肾损伤的意义以及基于NGAL的模型在鉴别肝硬化急性肾损伤类型中的意义。方法对住院的肝硬化(失代偿期)患者按照入排标准进行前瞻性观察,一旦发生AKI,根据ICAAKI新指南进行诊断和治疗,在诊断AKI的2... 目的明确早期检测NGAL对诊断肝硬化急性肾损伤的意义以及基于NGAL的模型在鉴别肝硬化急性肾损伤类型中的意义。方法对住院的肝硬化(失代偿期)患者按照入排标准进行前瞻性观察,一旦发生AKI,根据ICAAKI新指南进行诊断和治疗,在诊断AKI的24 h内检测晨起的卧位醛固酮和血管紧张素Ⅱ、收集晨起尿液离心取上清检测uNGAL,评估NGAL对AKI诊断的意义,并根据收集到的数据设计早期鉴别诊断系统。结果纳入研究的肝硬化(失代偿期)患者共804例,住院期间并发AKI或入院时即存在AKI的患者为213例。肝硬化AKI患者uNGAL水平比未发生AKI的肝硬化患者高(t=11.439,P=0.000);不同类型的AKI患者uNGAL的表达水平不同,PRA、HRS、ATN分别为(323.08±106.93)、(486.27±164.67)和(882.43±440.92)ng/mL,差异有统计学意义(F=48.774,P<0.01)。uNGAL对AKI 2期以上的鉴别诊断有意义,特别是对ATN的鉴别,ROC曲线中根据约登指数确定的阈值为522.72 ng/mL,敏感度为0.938,特异度为0.655,采用621.73 ng/mL阈值(敏感度为0.750,特异度为0.800)更符合临床的需要。醛固酮和血管紧张素Ⅱ在不同类型的AKI中表达有差异,但组间分析和多因素分析显示对鉴别HRS和ATN意义不大。结论uNGAL作为新型标志物,可以作为肝硬化急性肾损伤患者诊断AKI的依据,早期检测对于鉴别ATN型AKI的有较大的意义。 展开更多
关键词 肝硬化急性肾损伤 中性粒明胶酶质转运体 鉴别诊断
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二次涂布对石油包装特种纸板性能的影响
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作者 高立敏 高玉杰 +1 位作者 袁晓娇 王伟 《天津科技大学学报》 CAS 北大核心 2016年第1期60-63,72,共5页
研究了以不同固含量的A号涂布剂为底涂原料,以23%,固含量的阳离子聚丙烯酸酯作为面涂原料对牛皮卡纸进行二次涂布,观察其对石油包装特种纸板抗水抗油性能及强度性能的影响.结果表明:随着A涂布剂固含量的增加,纸板的抗水性能和抗油性能... 研究了以不同固含量的A号涂布剂为底涂原料,以23%,固含量的阳离子聚丙烯酸酯作为面涂原料对牛皮卡纸进行二次涂布,观察其对石油包装特种纸板抗水抗油性能及强度性能的影响.结果表明:随着A涂布剂固含量的增加,纸板的抗水性能和抗油性能逐渐增加;纸板的强度性能除横向抗张强度无明显变化、纵向撕裂度有所减小外,其他强度性能都逐渐增加.当A号涂布剂的固含量为30%,时,石油包装特种纸板的各项性能较好,可以满足石油包装纸板的性能要求. 展开更多
关键词 石油包装特种纸板 抗水性能 抗油性能 防油剂 阳离子中性聚丙烯酸
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Neutral Complex Extraction and Synergistic Extraction of Macrolide Antibiotics 被引量:1
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作者 李洲 秦峰 +2 位作者 鲍浩 谷雪蔷 戴玲妹 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2000年第4期304-309,共6页
Based on the theory of reactive extraction, new solvent systems were developed to replace butylacetate for extraction of macrolide antibiotics (erythromycin, kitasamycin, spiramycin meleumycin etc.). A new neutral com... Based on the theory of reactive extraction, new solvent systems were developed to replace butylacetate for extraction of macrolide antibiotics (erythromycin, kitasamycin, spiramycin meleumycin etc.). A new neutral complex solvent extraction system, fatty alcohol-kerosene (marked by El), was used for extraction of erythromycin, one of the macrolide antibiotics. The extraction equilibrium equation is obtained, and the extraction distribution is as followsD = exp (-36.33×103/RT + 18.77)[B](o)1.1/(1 + 108.07-PH)The effects of several parameters on extraction equilibrium were investigated. Furthermore, a new synergistic extraction system (marked by E2) was developed, in which another solvent was used as synergistic agent to replace the diluent kerosene in the neutral complex extraction system. Based on these new extraction systems, an improved process for extraction of erythromycin was developed, showing remarkable advantages in technology and economics owing to its low solvent consumption of 3kg per billion unit compared with 9—10 for butylacetate. The recovery process of solvent from raffinate may be eliminated. 展开更多
关键词 macrolide antibiotics ERYTHROMYCIN neutral complex extraction synergistic extraction
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SYNTHESIS OF 1,2-ACEANTHRYLENEDIONE THROUGH ACYLATION OF ANTHRACENE WITH OXALYL CHLORIDE
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作者 ZHANG Chunyan CHEN Min +2 位作者 YU Long JIANG Deli YAN Yongsheng 《Chinese Journal of Reactive Polymers》 2007年第1期61-65,共5页
Acylation of anthracene and oxalyl chloride in the presence of anhydrous AlCl3 was investigated. Pure 1,2-aceanthrylenedione, which is used as new functional macromolecule, was prepared by extraction and recrystallati... Acylation of anthracene and oxalyl chloride in the presence of anhydrous AlCl3 was investigated. Pure 1,2-aceanthrylenedione, which is used as new functional macromolecule, was prepared by extraction and recrystallation. The structure of 1,2-aceanthrylenedione was identified by measure of melting point, GC/MS, FTIR and 1HNMR analyses. The influences of various parameters, such as solvent, dosage of catalyst, molar ratio of anthracene to oxalyl chloride, reaction temperature, and reaction time were studied. The anhydrous AlCl3 was found to catalyze the reaction with high yeild and good selectivity. When the reaction temperature is 303K, reaction time is 5h and molar ratio of anthracene to oxalyl chloride is 1:2, the yield and selectivity of 1,2-aceanthrylenedione is 83.8 % and 92.3% respectively. 展开更多
关键词 Functional macromolecule intermediate 1 2-aeanthrylenedione Anthracene ACYLATION Anhydrous AlCl3.
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Efficient Method to Achieve Enhanced Thermal Dimensional Stability and Desired Dimensions of Hollow Polyester Fiber
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作者 刘奎 周晖 +3 位作者 章倩 孙宝忠 张瑞云 黄莉茜 《Journal of Donghua University(English Edition)》 EI CAS 2016年第4期670-672,共3页
This study has developed an efficient method to achieve excellent thermal dimensional stability and desired dimensions of hollow polyester fiber. Firstly,the influence of thermal treatment temperate( 140-180 ℃) on th... This study has developed an efficient method to achieve excellent thermal dimensional stability and desired dimensions of hollow polyester fiber. Firstly,the influence of thermal treatment temperate( 140-180 ℃) on the degree of shrinkage of fiber was investigated. The influence was also analyzed with a 2nd heating to simulate the application situation. It was discovered that the heat treatment at a temperature which was above the application temperature( 2nd heating) would efficiently remove the internal stress in the fiber and improve the thermal dimensional stability.Secondly,the impact of heat treatment temperature on the fiber diameter and the degree of hollowness were studied. The results implied that with a fixed fiber length, higher treatment temperature led to thinner fiber and a lower degree of hollowness.Last but not least,key parameters that could further influence the fiber dimensions were investigated. The results suggested that the fiber diameters and the degree of hollowness could be further controlled by tuning the drawing speed,the spinning meter pump output and cooling status while the spinneret parameters were fixed. 展开更多
关键词 hollow diameters heating shrinkage desired dimensions spinning polyester length thinner
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Ordered mesoporous Ba CO_3/C-catalyzed synthesis of glycerol carbonate from glycerol and dimethyl carbonate 被引量:1
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作者 Yin Wang Chunling Liu +2 位作者 Jihong Sun Rongzhen Yang Wensheng Dong 《Science China Chemistry》 SCIE EI CAS CSCD 2015年第4期708-715,共8页
Ordered mesoporous BaCO3/C composites were synthesized by a multi-component co-assembly method combined with a carbonization process using phenolic resol as carbon source, barium nitrate as barium precursor, and tribl... Ordered mesoporous BaCO3/C composites were synthesized by a multi-component co-assembly method combined with a carbonization process using phenolic resol as carbon source, barium nitrate as barium precursor, and triblock copolymer Pluronic F127 as template. The synthesized materials were characterized by X-ray diffraction, transmission electron microscopy, N2 physical adsorption, thermogravimetric analysis, and temperature-programmed desorption of CO〉 When BaCO3 contents were increased from 9.1 wt% to 44.7 wt%, pore size increased from 3.1 to 4.3 nm and the BET (Brunauer-Emmett-Teller) surface area initially increased to a maximum value of 390 m2 g^-1 (at a BaCO3 content of 18.5 wt%) before subsequently decreasing. BaCO3 was well dispersed in the amorphous carbon framework, and no phase separation was observed. The mesoporous BaCO3/C composites exhibited high catalytic activities toward the transesterification of glycerol and dimethyl carbonate into glycerol carbonate. A glycerol conversion of 97.8% and a glycerol carbonate selectivity of 98.5% were obtained under the optimized reaction conditions. 展开更多
关键词 NANOCOMPOSITES MESOPOROUS CARBON barium carbonate glycerol carbonate
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