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1.
目的:探讨一种同时测定唇齿清胃丸中黄芩苷和盐酸小檗碱含量的高效液相色谱法。方法以 Kromasil100-5 C18柱(4.6 mm×150.0 cm,5μm)为色谱柱;以乙腈为流动相A,以0.05 mol/L磷酸二氢钾溶液为流动相B,采用梯度洗脱;检测波长278 nm,柱温30℃,流速为1.0 ml/min。结果盐酸小檗碱进样量在0.0124~0.3100μg,进样量0.0217~0.5425μg范围内有良好的线性关系,平均回收率分别为99.1%、99.04%,RSD分别为0.94%、0.85%(n=6)。结论该方法准确可靠专属性强、结果稳定,重复性好。  相似文献   

2.
目的建立测试咳尔康口服液中盐酸麻黄碱含量的高效液相方法,并对此方法进行系统的方法学验证,以确保应用该方法测试的结果准确、可靠。方法采用色谱柱:Agilent TC-C18柱(4.6×250mm,5μm,Agilent,美国),流动相:甲醇-0.02mol/L磷酸二氢钾溶液(以磷酸调至PH2.5)(5:95),检测波长为210nm。结果盐酸麻黄碱在2.048mg?L-~500mg?L-1范围内线性关系良好,得到线性回归方程为Y=1.0818X+0.0011,相关系数为0.9993(n=7);低、中、高浓度的精密度RSD值分别为0.27%、0.76%、0.53%;重复性RSD为0.67%;平均加样回收率为99.31%,RSD为0.90%;供试品溶液室温放置8h稳定。结论本方法测定咳尔康口服液盐酸麻黄碱的含量准确、可靠,操作简单、用时短,可用于咳尔康口服液中盐酸麻黄碱的含量测定。  相似文献   

3.
不同产地桂郁金中吉马酮含量测定   总被引:1,自引:0,他引:1  
目的 对桂郁金中的有效成分吉马酮进行含量测定,为科学评价和有效控制桂郁金的质量提供实验依据.方法 采用高效液相色谱法,色谱柱美国Welch XB-C 18柱(5μm,4.6mm×250mm),流动相:乙腈-水(70:30),流速:1mL/min,柱温:35℃,检测波长:210nm,进样量:5μL.结果桂郁金的线性范围为14.9~84.5μg/mL之间,平均回收率为102.8%.结论 该方法稳定线好、可靠,可应用于桂郁金的吉马酮的含量测定.  相似文献   

4.
目的建立测定蒿鳖养阴软坚方中大黄素含量的高效液相色谱(HPLC)方法。方法采用HPLC法,色谱柱Hypersil ODS2(250mm×4.6mm,5μm),流动相:甲醇-0.1%磷酸(75:25);流速:1.0ml·min^-1;检测波长:254nm。结果大黄素在2.64-26.4μg·ml^-1范围内呈良好线性关系,r=0.9998,平均加样回收率为99.7%,RSD为2.7%(n=6)。结论该方法可将大黄素从复方中充分提取分离,专属性强,结果准确,可用于蒿鳖养阴软坚方的质量控制。  相似文献   

5.
目的采用高效液相色谱法测定烟酰胺的含量。方法色谱柱,日本资生堂(A4AD04276)C18柱(250mm×4.6mm,5μm);以甲醇:水(35:65)为流动相;流速为:1.0ml/min;检测波长为261nm;柱温:室温。结果烟酰胺在10.0~60.0μg/ml范围内线性关系良好,r=0.9991(n=6);平均回收率为99.0%(n=6)。结论本方法测定烟酰胺含量专属性强、快速、灵敏,结果准确可靠。  相似文献   

6.
目的 采用柱前衍生高效液相色谱法测定克拉霉素血药浓度.方法 克拉霉素血浆样品以正己烷-正丁醇混合溶液萃取后,与9-芴甲氧羰酰氯(FMOC-CL)衍生化后进样.色谱柱为Hypersil TMODS2柱(4.6mm×250mm,5μm),柱温:62℃;流动相:0.05mol/L NH4H2PO4缓冲液(PH6.72)-乙腈=38:62 (v/v),流速2.5 mL/min;激发波长:265nm,发射波长:315nm.结果 克拉霉素血药浓度在50~3000ng/mL范围内,浓度与峰面积比有良好的线性关系,最低检测浓度为30ng/mL,平均回收率为97.9~100.2%,日内RSD≤4.1%,日间RSD≤6.8%.结论 本方法简单、快速、准确,可用于克拉霉素临床药动学研究.  相似文献   

7.
目的采用反相高效液相色谱法同时测定清热通淋片中苦参碱和氧化苦参碱的含量。方法使用Capcel C18色谱柱(4.6mm×250mm,5μm),流动相为甲醇-磷酸盐缓冲液(PH3.0)(7:93)(磷酸盐缓冲液配制:准确量取磷酸二氢钾3.402g溶解于1000mL水中,用磷酸调PH值至3.0),流速为0.8mL?min-1,检测波长220nm,柱温为40℃。结果苦参碱和氧化苦参碱进样量在0.3118~4.6770μg和0.02976~0.44640μg范围内,线性关系良好;平均回收率(n=6)分别为97.1%和98.4%, RSD分别为0.24%和1.48%。结论本法简便、准确,重复性好,可为清热通淋片的质量控制提供实验依据。  相似文献   

8.
目的建立克霉唑阴道片中克霉唑含量的测定方法。方法采用高效液相色谱法,以HYPERSIL ODS C18柱(Φ4.6 mm×250.0 mm),粒度5μm为分析柱,磷酸氢二钾溶液(取磷酸氢二钾4.35 g,加水溶解并稀释至1 000 ml)-甲醇(1:3)为流动相,流速为1.0 ml/min,检测波长为254 nm。结果克霉唑在0.1~5.0μg/ml范围内具有良好的线性关系。r=0.9999,平均回收率为99.0%。结论本测定方法简便,准确,可有效测定克霉唑阴道片中克霉唑的含量。  相似文献   

9.
目的建立包头市中心医院临床验方中药制剂活血胶囊的质量标准.方法采用薄层色谱法,对活血胶囊中红花、黄芪、川芎进行定性鉴别,采用高效液相色谱法测定羟基红花黄色素A含量.色谱柱采用Agilent TC-C18柱(150mm ×4.6mm,5μm);以甲醇-乙腈-0.7%磷酸溶液(26:2:72)为流动相;检测波长为403.0nm.结果检测的结果是羟基红花黄色素A呈良好的线性关系,条件是在0.1372-0.9601μg范围内,r=1,平均回收率99.0%,RSD=0.8%(n=6).结论该方法简便、准确、可靠,可作为活血胶囊的质量控制方法.  相似文献   

10.
目的:建立头痛定胶囊中葛根素的高效液相含量测定法。方法:采用HPLC-DAD法,色谱柱为Diamonsil C18(250×4.6mm,5μm);流动相为甲醇-水(25:75);检测波长为255nm;流速为1.0 ml/min;柱温为30℃。结果:葛根素在19.4-310.4μg/ml范围内呈良好线性关系,r=0.9999,平均回收率为99.24%,RSD=1.38%。结论:本方法操作简便、灵敏度高、准确性和重现性好,可作为头痛定胶囊的质量控制方法。  相似文献   

11.
John Stuart Mill has traditionally been portrayed as self-contradictory and failing to construct a unified social theory. Recent scholarship, however, has challenged this view, finding Mill's work to be creatively synthetic in bridging the antinomies inherent in liberal democratic thought. This revisionist interpretation of Mill is advanced by an understanding of his theory of justice and its role in shaping his policy positions on issues such as welfare, education, voting rights, property rights, taxation, government intervention, and the future of capitalism.  相似文献   

12.
Arik Hesseldahl In the aftermath of the September 11 attacks, U.S. officials quickly turned their attention to other potential targets, including California's Golden Gate Bridge. What would happen if terrorists took down the bridge between San Francisco and Marin County? How much of the region would be affected and for how long?  相似文献   

13.
This article seeks to evaluate the appropriateness of a variety of existing forecasting techniques (17 methods) at providing accurate and statistically significant forecasts for gold price. We report the results from the nine most competitive techniques. Special consideration is given to the ability of these techniques to provide forecasts which outperforms the random walk (RW) as we noticed that certain multivariate models (which included prices of silver, platinum, palladium and rhodium, besides gold) were also unable to outperform the RW in this case. Interestingly, the results show that none of the forecasting techniques are able to outperform the RW at horizons of 1 and 9 steps ahead, and on average, the exponential smoothing model is seen providing the best forecasts in terms of the lowest root mean squared error over the 24-month forecasting horizons. Moreover, we find that the univariate models used in this article are able to outperform the Bayesian autoregression and Bayesian vector autoregressive models, with exponential smoothing reporting statistically significant results in comparison with the former models, and classical autoregressive and the vector autoregressive models in most cases.  相似文献   

14.
Abstract

The purpose of this paper is to introduce explicitly pleasure and belief in what aims at being a Humean theory of decision, like the one developed in Diaye and Lapidus (2005a). Although we support the idea that Hume was in some way a hedonist – evidently different from Bentham's or Jevons' way – we lay emphasis less on continuity than on the specific kind of hedonism encountered in Hume's writings (chiefly the Treatise, the second Enquiry, the Dissertation, or some of his Essays). Such hedonism clearly contrasts to its standard modern inheritance, expressed by the relation between preferences and utility.

The reason for such a difference with the usual approach lies in the mental process that Hume puts to the fore in order to explain the way pleasure determines desires and volition. Whereas pleasure is primarily, in Hume's words, an impression of sensation, it takes place in the birth of passions as reflecting an idea of pleasure, whose “force and vivacity” is precisely a “belief”, transferred to the direct passions of desire or volition that come immediately before action. As a result, from a Humean point of view, “belief” deals with decision under risk or uncertainty, as well as with intertemporal decision and indiscrimination problems.

The latter are explored within a formal framework, and it is shown that the relation of pleasure is transformed by belief into a non-empty class of relations of desire, among which at least one is a preorder.  相似文献   

15.
中国拥有世界五分之一强的人口 ,收入又在迅速增长。因此 ,国际上很自然地会考虑或推测她在今后的几十年是否有能力养活自己。中国的人口预计将从 2 0 0 0年的 1 2 8亿增长到 2 0 2 0年的 1 4 6亿 ,和 2 0 3 0年的 1 4 9亿。与此同时 ,人均收入的增长将导致对家畜和鱼类产品更大的需求 ,因而对饲料的需求也将有很大的增长  相似文献   

16.
In principle, we want regulatory programs to be based on current realities, as reflected for example in the best knowledge of relevant experts. That would imply that old rules now on the books should be consistent with today's knowledge base, not just what was known when a rule or standard was originally set. This paper reports on a survey of US programs, examining how often existing rules are actually updated in light of better knowledge, and identifies five programs that attempt to make policy routinely adaptive. These programs exhibit what we term Planned Adaptation: they both revise rules when relevant new knowledge appears, and take steps to produce such improved knowledge. While Planned Adaptation is rare, it is used in several nationally prominent programs, including air pollution, airplane safety, and drug safety. Planned Adaptation is a policy tool that deserves more attention.  相似文献   

17.
Synopsis Classification is an important activity that facilitates theory development in many academic disciplines. Scholars in fields such as organizational science, management science and economics and have long recognized that classification offers an approach for ordering and understanding the diversity of organizational taxa (groups of one or more similar organizational entities). However, even the most prominent organizational classifications have limited utility, as they tend to be shaped by a specific research bias, inadequate units of analysis and a standard neoclassical economic view that does not naturally accommodate the disequilibrium dynamics of modern competition. The result is a relatively large number of individual and unconnected organizational classifications, which tend to ignore the processes of change responsible for organizational diversity. Collectively they fail to provide any sort of universal system for ordering, compiling and presenting knowledge on organizational diversity. This paper has two purposes. First, it reviews the general status of the major theoretical approaches to biological and organizational classification and compares the methods and resulting classifications derived from each approach. Definitions of key terms and a discussion on the three principal schools of biological classification (evolutionary systematics, phenetics and cladistics) are included in this review. Second, this paper aims to encourage critical thinking and debate about the use of the cladistic classification approach for inferring and representing the historical relationships underpinning organizational diversity. This involves examining the feasibility of applying the logic of common ancestry to populations of organizations. Consequently, this paper is exploratory and preparatory in style, with illustrations and assertions concerning the study and classification of organizational diversity.  相似文献   

18.
19.
Neoliberal political movements advocate privatization of public pension systems. Globalization imposes pressure on nations to conform to neoliberal policy views with respect to the design and structure of social insurance, including public pension systems. The paper begins with an investigation of the economic, ethical and ideological dimensions of the privatization debates in the U.S.; it argues that privatization advocates may be largely moved by ideology, since the other reasons advanced appear weak or unfounded. The second part discusses the history of Social Security, the purposes for its creation, and some of its economic effects. Differences between public and private pension systems are considered. A brief international comparison of some aspects of public pension system finance and benefit structures is presented. The final section considers the ethical, macroeconomic and distributional implications of privatization, prefunding and payroll tax funding, and argues for a pay as you go system financed with income taxes. In order to promote equity, economic security, community, and social cohesion, public pension systems should be universal in coverage. In order to reduce the inequality, income insecurity, and aged poverty generated by market economies, public pension systems ought to be progressive: benefit/contribution ratios should be inversely proportional to income, and progressive income taxes should finance the system. To promote economic growth, the systems should be financed on a pay-as-you-go basis, and should not be prefunded except for an emergency reserve. The fiscal policy recommendations partially depend upon the theory developed by Abba Lerner in the 1940s, and recently advanced by Wynne Godley and Randy Wray: Lerner's “principle of functional finance.”  相似文献   

20.
Although he was much influenced by David Ricardo when he wrote the classical part of his Principles , John Stuart Mill was not a Ricardian when he penned his theories of wealth and distribution. They are based on a triple foundation. First, a belief that economics is a moral discipline. Second a theory of custom-driven human behavior. Third, an empirically formed conviction that the institutions of state, education and business cooperate to structure the distribution of income. On the basis of these presuppositions, Mill formulated 1) an institutional theory of the formation of human and non-human wealth and 2) an even more institutional theory of distribution demonstrating how the aforementioned institutions malignantly skew the distribution of income to the advantage of the propertied classes and to the extreme disadvantage of the working class. As a social economist, Mill recommended institutional reforms designed to eradicate the poverty of the working class.  相似文献   

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