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流动性过剩问题最近已成为学术界争论的焦点,本文在别人研究的基础上对流动性问题产生的根源进行探讨,得出了流动性过剩的根源在于外汇占款过多,并在此研究的基础上提出了相应的政策建议。 相似文献
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J. Reichen J. T. M. Buters Z. Sojcic F. J. Roos 《Cellular and molecular life sciences : CMLS》1992,48(5):482-486
We determined to what extent a change in the lipid composition of the smooth endoplasmic reticulum contributes to altered microsomal function in cirrhosis. Rats were rendered cirrhotic either by chronic exposure to phenobarbital/CCl4 (MCIR) or by bile duct ligation (BCIR). Microsomal function was tested in vivo by the aminopyrine breath test (ABT), then microsomes were prepared and their phospholipid and cholesterol composition analysed. ABT was reduced by 35 and 41% in BCIR and MCIR, respectively. Cholesterol in microsomes was increased in both cirrhotic groups. (BCIR +154%, MCIR +75%) while total phospholipid content was not affected. As shown in other membrane systems, the phospholipid/cholesterol (PL/XOL) ratio showed an excellent inverse correlation with fluorescence anisotropy determined by diphenylhexatriene fluorescence polarization (r=–0.896). The PL/XOL ratio was significantly correlated with aminopyrine N-demethylation in vivo (r=0.649). Alterations in the composition of phospholipid groups (an increase in sphingomyelin in both cirrhotic groups, and a decrease in phosphatidylcholine and an increase in phosphatidylethanolamine in BCIR) also contributed to increased membrane rigidity. We conclude that altered membrane fluidity contributes to diminished microsomal function but that other factors must also be involved since the PL/XOL ratio explained only 42% of the variance in aminopyrine N-demethylation. 相似文献
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采用丙烯酸(AA)和聚乙二醇单甲醚(MPEG)为主要反应原料,通过逐步滴加带水剂甲苯的方法,研究其主要反应条件对酯化率的影响。在温度为90℃的条件下,制备的聚羧酸减水剂的活性大单体聚乙二醇单甲醚丙烯酸酯(MPEGAA)酯化率高达99.6%,双键保留率高达91.5%。测试了应用该大单体所合成的聚羧酸减水剂与几种水泥的适应性和分散保持性。 相似文献
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张永钿 《广西大学学报(自然科学版)》1988,(2)
本文论述糖液的浓度、纯度、粘度和温度对过饱和度的影响。评述当前国内测量糖液过饱和度主要采用的方法,如电导率法,流变度法和沸点升高法及其优缺点。提出间歇煮糖最适控制模型和在煮糖生产实际中正确控制过饱和度的具体措施,综述对过饱和度测量方法的改进。最后,指出确保在最适过饱和度条件下进行煮糖监控是有益的。 相似文献
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