共查询到20条相似文献，搜索用时 62 毫秒
1.
采用HNO3——HClO4混合酸处理黑木耳试样,阳极溶出伏安法测定黑木耳中的镉和铅.同时,还对黑木耳中镉、铅元素进行回收实验,回收率为95%～98%. 相似文献
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采用3,5-二硝基水杨酸法和苯酚-硫酸法分别对溶剂法提取分离的金钱草叶的粗多糖进行分析,考察两种分析方法的可靠性和准确性.实验结果表明,多糖含量测定结果分别为11.70%和11.36%.平行测定6次,3,5-二硝基水杨酸法测定样品加标回收率在92.52%~104.49%之间,RSD%=3.98%,检出限为0.022 mg/mL;苯酚-硫酸法测定样品加标回收率在93.29%~114.82%之间,RSD%=3.36%,检出限为0.018 mg/mL.两种方法都比较灵敏、可靠. 相似文献
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采用湿法消解对冬苋菜样品进行处理,用原子吸收光谱法测定了冬苋菜中Ca,Mg,Fe,Mn,Zn,Cu,Pb,Cd 8种元素的含量.实验表明,冬苋菜中含有丰富的Ca和Fe,Pb,Cd未超过国家限量.该方法的标准曲线相关系数为0.9958～0.9999,相对标准偏差(RSD)为0.12%～1.93%. 相似文献
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陈雷 《淮南职业技术学院学报》2011,11(2)
为测定灵芝胶囊中灵芝多糖含量,采用UV法测定;通过具体实验,得出灵芝多糖线性范围为0.001509～0.015091 mg/ml,r=0.997,加样回收率为97.2%,RSD=1.50% (n=6);因此,该方法可实现对灵芝胶囊多糖含量的有效控制. 相似文献
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目的:建立女贞子及扶正女贞素片中多糖的含量测定方法.方法:采用苯酚-硫酸法测定总糖含量,采用水杨酸法测定单糖含量,从而准确测出多糖含量.结果:女贞子中多糖含量为2.712%,RSD=2.05%;扶正女贞素片中的多糖含量为3.952%,RSD=1.97%.结论:女贞子及扶正女贞素片中均含有大量多糖,该方法准确可靠,为扶正女贞素片的质量控制提供了依据. 相似文献
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原子吸收光谱法测定堆肥中铅、铬的含量 总被引：1，自引：0，他引：1
采用王水-高氯酸消解垃圾堆肥样品.用火焰原子吸收光谱法测定遵义市垃圾堆肥中铅、铬的含量.实验结果表明.遵义市垃圾堆肥中铅含量未超过国家土壤二级标准,而铬的含量比土壤环境质量标准值高.相对标准偏差均小于1.5%,回收率均大于90%. 相似文献
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实验模拟泡茶方式浸取得溪黄草的水提样品溶液,并用苯酚硫酸法测定了样品溶液的多糖浓度,计算了溪黄草的多糖含量,为3.72%,为科学服用溪黄草提供了客观依据. 相似文献
8.
火焰原子吸收法测定南果梨中的微量元素 总被引：1，自引：0，他引：1
研究了采用微波消解方法处理南果梨样品,以火焰原子吸收法测定南果梨中的K、Ca、Mg、Fe、Mn的方法.优化了火焰原子吸收的工作参数,考查了消解方法对测定结果的影响.实验结果表明,以微波消解方法对南果梨样品进行预处理,消解时间短,准确度高,5种元素的相对标准偏差RDS均小于7%,回收率为95.6%~103.6%.该方法用于南果梨中多种元素的元素测定,结果令人满意. 相似文献
9.
酶法提取虎杖中白藜芦醇和大黄素工艺研究 总被引：2，自引：0，他引：2
采用HPLC法,以白藜芦醇、大黄素的得率为指标,对虎杖原料经酶解处理后,对其中的有效成分进行了综合提取.通过正交实验,确定了最佳提取工艺条件为:95%乙醇,以液固比20:1,在40℃下提取40min,提取次效为1次.HPLC法测定结果表明,从虎杖中提取的有效成分的含量分别是:白藜芦醇为15.35mg/g,大黄素为18.11mg/g. 相似文献
10.
采用火焰原子吸收光谱法测定了电解钇-镁中间合金中杂质铁的含量.试验确定了最佳仪器工作条件,铁在0~10μg/mL范围内线性良好,研究了盐酸对溶液稳定性的影响,在标准溶液中加入等同于称样量的镁可消除基体镁和钇对铁测定的干扰.采用所确定方法应用于实际样品检测,RSD为0.75%,标准加入法测定回收率在100.2%~101.8%之间.与磺基水杨酸分光光度法测定结果一致性好. 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
13.
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
14.
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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Rajesh Kanoi 《海外英语》2007,(1):52
Today, Sunday morning, I sit thinking and typing at my computer. My thoughts are in my homeland, India and my body is in China. The body is here and mind there for a good reason. Mr. Hu is president and I am resident and both are in each other's countries (what a difference the absence of one small letter makes!). Mr. Hu will return in a few days and I will stay on longer. 相似文献
18.
正A One day a pig went to the stable(马棚)to see his good friend,an oldhorse,and was going to stay there forthenight.Night came and it was time forsleep.The pig went into the straw heap(稻草堆)and lay comfortably.A longtime passed,but the horse was stillstanding there and did not move.Thepig asked the horse why he did not go tosleep."Standing like this is the begin-ning ofsleeping,"answered the horse. 相似文献
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《今日中学生》2014,(9)
正1.Any fool can count the seeds in an apple.Only God can count all the apples in one seed.2.Happy families are all alike;every unhappy family is unhappy in its own way.3.Memories are the key not to the past,but to the future.4.Sometimes in the dark you see what you want to see.5.There is a great difference between 相似文献
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《重庆大学学报(英文版)》2014,(2)
正Scope and Policy The Journal of Chongqing University-English Edition(JCQU-E)is a peerreviewed journal publishing research articles in multiple disciplines of science and technology,covering civil and environmental engineering,chemical engineering,biotechnology,mechanical and electrical engineering,computer and data processing,mining,metallurgy,materials science,and interdisciplines thereof. 相似文献