共查询到20条相似文献，搜索用时 62 毫秒
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建立了高效液相色谱法检测鳗鱼中恩诺沙星、环丙沙星、诺氟沙星等合成抗菌剂残留的方法。样品以乙腈为提取剂,经脱脂、净化、浓缩,用流动相溶解。用高效液相色谱荧光检测器测定恩诺沙星、环丙沙星、诺氟沙星。各标准曲线线性范围0．05—1．20μg／ml,线性相关系数r=0．9911—0．9943,实验回收率为55．0％～85．9％,RSD在5．58％～7．38％（n=5）,检坝4低限分别为1μg／kg,2μg／kg,2μg／kg。 相似文献
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比色法测定珠芽蓼中多糖的含量 总被引：4，自引：0，他引：4
用苯酚——硫酸比色法测定珠芽蓼中多糖的含量，测定波长490nm，多糖换算因子f=5．036，在2-20ug／ml范围内吸光度与多糖含量具有良好的线性关系，r=0．9999，多糖的含量为7．0％． 相似文献
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采用苯酚一硫酸分光光度法测定茵陈蒿中多糖的含量，测定波长为4‰，多糖换算因子f=1．3124,在1050ug／ml范围内吸光度与多糖含量具有良好的线性关系，r=0．9998，平均回收率为99．76％，精密度RSD％为1．24％，多糖的含量为7．0％． 相似文献
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以连续回流及超声提取方法,采用NaNO2-Al（NO3）3-NaOH分光光度法,测定了长白山区野生毛茛总黄酮含量．结果表明,芦丁在11．60～58．00μg／ml范围内呈良好线性关系（r=0．9996）,平均加样回收率为99．27％（n=5,RSD=0．91％）,测得毛茛总黄酮含量为1．81％．该方法简便、灵敏、准确,可用于毛茛中总黄酮的含量测定． 相似文献
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研究了钛铁试剂分光光度法测定土壤中铁的方法,探讨了方法的最佳条件。结果表明,以钛铁试剂为显色剂,可于560nm处测定土壤中铁的含量,铁含量在0-3mg／L范围内服从比尔定律,线性回归方程为Y=0．0889x,相关系数1=0．9984,表观摩尔吸光系数为K560=5．12×10^4L·mol^-1·cm^-1。该方法简便,选择性好,灵敏度高。此法用于土壤中铁的测定,结果与磺基水杨酸法相符。样品标准加入回收率分别为95．6％～99．9％,相对标准偏差为0．34％-0．53％（n=6）。 相似文献
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灿烂甲酚蓝标记分光光度法测定核酸 总被引：3，自引：0，他引：3
研究了灿烂甲酚蓝与小牛胸腺DNA相互作用，提出了测定ctDNA的新的光度分析法。室温、pH8．1tris-HCl的条件下，ctDNA的加入使灿烂甲酚蓝在其最大吸收波长636nm处的吸光度明显下降，下降的程度与ctDNA的含量呈线性关系，ctDNA质量浓度在0～3．0μg／ml范围内与△A呈线性关系，线性回归方程为△A=0．0032 0．0984C(μg/ml）(r=0．9987)，方法的检出限（3σ／k)为0．125μg/ml。该方法具有仪器简单，快速，选择性好等特点，对合成样品中ctDNA测定，RSD％=1．5～1．9，回收率在101％～104％，结果令人满意。 相似文献
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间苯三酚分光光度法测定小麦戊聚糖新方法及其应用 总被引：5，自引：0，他引：5
时侠清 《安徽技术师范学院学报》2005,19(3):6-10
水溶性戊聚糖能满意地进行间苯三酚分光光度测定。但小麦中的戊聚糖以非水溶性为主，不同于水溶性戊聚糖，因此用测定水溶性戊聚糖的方法不适合用来测定小麦戊聚糖。本文以小麦作为实际样品，在优化其测定条件下建立起间苯三酚光度测定小麦戊聚糖的新方法。方法的线性范围为15．4～34．6mg／L，线性方程为y=-226．0 989．8x(吸光差)，r=0．9915，样品添加标准木糖溶液测定的回收率为92．1％～102．6％，方法的检出限为0．03mg/L，对戊聚糖含量为4．76％的小麦样品进行6次平行测定，测得方法的精密度RSD为2．18％。方法应用与于260多个小麦实际样品的测定，在研究小麦品质及小麦育种等方面结果满意。 相似文献
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以乙腈-甲醇-0．05mol／L磷酸二氢钾溶液（10：20：70）（用磷酸调节pH值为4．0）为流动相．采用迪马钻石C18（250mm×4．6mm，5μm）色谱柱及紫外检测器，建立了甲钴胺注射液中甲钴胺含量的反相高效液相色谱检测方法．柱温：40℃：检测波长为264nm；流速：1．0mL／min．本方法测定的日内精密度为0．59％，日间精密度为0．67％，回收率为99．7％～100．5％，在160～240μg／mL范围内线性关系满足要求（r=-0．9999）；结果表明方法准确、操作简单、专属性强，可用于定量测定甲钴胺注射液含量． 相似文献
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比较安徽省3种药用菊花总黄酮含量差异,为药用菊花应用开发提供依据。以芦丁为标准品,检测波长为506nm,采用紫外一可见分光光度法测定总黄酮含量。结果表明,总黄酮在0mg／L-100mg／L与吸光值呈良好线性关系,回归方程A=0．0133C-0．0131,R^2=0．9993。3种药用菊花总黄酮含量滁菊〉贡菊〉亳菊。 相似文献
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《海外英语》2007,(5):10-11
Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help? 相似文献
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《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love. 相似文献
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Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject. 相似文献
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Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities. 相似文献
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RUZBEHANI Mohsen 《重庆大学学报(英文版)》2004,3(1):20-25
1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec… 相似文献
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唐芳 《读与写:教育教学刊》2008,5(6)
During interview with English majors, it was found that a majority of students expressed disappointment with their experience of English literature classes. Students' dislike of learning English literature appears to be the major problem of teaching English literature in China. Reader response approach is a good way to solve this problem. In this paper, I explain the rationale behind the reader response approach, such as its origin, definition, features, assumptions, and strategies. Then I illustrate how reader response approach works as a teaching strategy by presenting several teaching models. At last I evaluate its usefuiness for teachers and present the advantages of reader response approach in Chinese context. 相似文献