共查询到19条相似文献，搜索用时 328 毫秒
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苦参不同器官中的生物碱含量分析 总被引：2，自引：0，他引：2
[目的]探讨苦参不同器官中的生物碱含量,为该资源植物的合理应用提供依据.[方法]用薄层色谱法(TLC)分析测定了辽宁产苦参不同器官中苦参碱及氧化苦参碱含量.[结果]各类器官,除叶片外,氧化苦参碱含量均显著超过苦参碱含量;苦参碱含量以种子中的为最高,占干重的0.065%,其次为茎(0.034%)、根(0.016%)、叶(0.013%);氧化苦参碱含量以根最高,占干重的3.847%,其次为种子(1.982%)、茎(0.140%),叶中未检测到;粗老根(直径大于1 cm)与细嫩根(直径在0.5~1.0 cm)中的两种生物碱含量差别不大.[结论]达到一定生长年限后,生物碱积累不再有明显增加而趋于饱和;大部分器官中,氧化苦参碱含量高于苦参碱含量;种子及茎更适合作为苦参碱的提取器官. 相似文献
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濒危植物桫椤叶和茎干中可溶性糖和总黄酮含量的研究 总被引：1，自引：0，他引：1
采用分光光度法测定了桫椤叶和茎干中可溶性糖和总黄酮的含量,其中桫椤叶中可溶性糖为21.42%,总黄酮含量为6.24%;桫椤茎干中可溶性糖为4.08%,总黄酮含量为5.39%。 相似文献
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贵州矮杨梅叶总黄酮的提取工艺和测定方法 总被引：1，自引：0，他引：1
目的:建立矮杨梅叶总黄酮的提取工艺和含量测定方法。方法:利用L9(34)进行矮杨梅叶总黄酮提取影响因素即乙醇浓度、提取时间、料液比的优化组合;应用分光光度计考察其含量测定方法。结果:矮杨梅叶总黄酮的提取工艺为提取时间为1.5h,乙醇浓度为50%,材液比为1:35,提取率为4.88%;总黄酮提取液在0-60min内测定,线性关系良好(0.9996),仪器较为稳定,测定结果准确、重现性好,回收率高。结论:矮杨梅叶总黄酮的提取工艺可行、测定方法可信。这一研究结果对于杨梅属植物中总黄酮的提取和测定具有可操作性和推广应用价值。 相似文献
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濒危植物桫椤叶和茎干中可溶牲糖和总黄酮含量的研究 总被引：1，自引：0，他引：1
采用分光光度法测定了桫椤叶和茎干中可溶性糖和总黄酮的含量,其中桫椤叶中可溶性糖为21.42%,总黄酮含量为6.24%;桫椤茎干中可溶性糖为4.08%,总黄酮含量为5.39%. 相似文献
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紫外分光光度法测定雪菊中总黄酮的含量 总被引：1，自引：0，他引：1
目的:测定雪菊中总黄酮含量。方法:将雪菊分别用60%乙醇加热回流提取三次,以芦丁为标准品,用紫外分光光度法测定雪菊中总黄酮的含量。结果:利用紫外分光光度法测得总黄酮含量为20.74%。结论:雪菊的总黄酮含量比其它菊花要高。 相似文献
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目的：测定粉花月见草中总黄酮的含量。方法：以无水乙醇作为回流提取溶剂,在375nm处用紫外可见分光光度法测定粉花月见草中总黄酮的含量。结果：测得粉花月见草中总黄酮的含量为1.4435mg/g,精密度RSD=0.14%（n=5）,回收率为90.87%～98.98%。结论：该方法操作简便、准确、可靠,可用于植物中总黄酮的含量测定。 相似文献
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目的 :从油菜蜂花粉中提取总黄酮 ,并测定其含量。方法 :采用超声技术提取总黄酮 ,用比色法测定总黄酮含量。结果 :油菜蜂花粉中总黄酮含量为 (30 .5 0± 1.0 0 ) % ,平均回收率为 99.6 0 % ,RSD =2 .95 % (n =6 )。结论 :运用超声技术从油菜蜂花粉中提取总黄酮 ,可提高提取率 ,节省提取时间。 相似文献
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李洁 《温州职业技术学院学报》2002,2(3):32-32,44
应用薄层扫描法测定孩儿茶中消旋儿茶素的含量，方法简便，重现性好，结果准确。在4．0－8．0μg/ml范围内呈线性关系，r=0．9992。回收率为99．6％－102．8％，RSD为1．2％－4．2％。 相似文献
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采用添加促发剂和增素剂的方法,对城市污水厂污泥进行了除臭去水增有机质效果研究。结果表明,随着促发剂的添加,污泥粘稠度明显下降,水分含量降低近50％。气味由腐臭味慢慢转变为无臭味,但最后现出酸臭味;在24％的促发剂条件下,随着增素剂的量逐渐增加,污泥变得越来越松散;气味由酸腐味转变为泥草味,直至带有氨味的转变。在养分上,处理后有机质、全氮、五氧化二磷、氧化钾的含量范围分别为49．68％-63．89％,2．216％-3．630％,1．428％-1．696％,1．077％-1．467％。综合各种堆肥处理,以污泥＋24％促发剂＋16％-24％增素剂处理效果较好。 相似文献
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目的:评价酶循环法(ECM)定量检测血清同型半胱氨酸(Hcy)的技术性能。方法:参考NCCLS评价方案,评价ECM定量检测血清Hcy的准确度、精密度、线性范围和干扰因素。结果:ECM定量检测低、高水平定值质控血清Hcy的相对偏差分别为2.52%和4.28%;正常值和高值血清测定的批内变异系数(CV)和总CV分别为1.63%~1.58%和4.65%~3.88%;3.12~49.98 umol/L范围内测定的线性相关系数(r2)达到0.9971;胆红素(20 mg/dL)、乳糜(1000 mg/dL)和维生素C(10 mg/dL)对该检测方法无显著性干扰(P>0.05)。结论:酶循环法不仅实用性高,而且可靠性强,因此在各级医疗机构的检验科均可普及使用。 相似文献
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Signature pedagogies [Shulman, L. 2005. “Signature pedagogies in the professions.” Daedalus 134 (3): 52–59.] are a focus of teacher educators seeking to improve teaching and teacher education. The purpose of this paper is to present a preliminary common language of signature pedagogies for teacher professional development (PD). In all, 24 papers from the study of physical education PD projects with clearly articulated pedagogical objectives and documentation on achieving those objectives were included in the analysis. In total 479 teachers and 48 facilitators across the US and Europe were interviewed and/or surveyed. Three discrete PD signature pedagogies holding potential to enhance teacher growth and learning within the context of PD were identified: critical dialogue (process of acquiring knowledge through communicative interactions), public sharing of work (testing out practices in classrooms and share ideas with larger audiences), and communities of learners (collective learning around a shared concern or a passion). It is our hope in providing the beginnings of a common vocabulary for pedagogies of teacher professional learning we have encouraged additional steps toward developing signature pedagogies for learning across different PD settings and content areas. 相似文献
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Canbaz H Dirlik M Colak T Ocal K Akca T Bilgin O Tasdelen B Aydin S 《Journal of Zhejiang University. Science. B》2008,9(6):482-488
Objective: To investigate the effect of recurrent laryngeal nerve (RLN) identification on the complications after total thyroidectomy and lobectomy. Methods: Total 134 consecutive patients undergoing total thyroidectomy or thyroid lobectomy from January 2003 to November 2004 were investigated retrospectively. Patients were divided into two groups: RLN identified (Group A) or not (Group B). The two groups were compared for RLN injury and hypocalcaemia. Results: The numbers of patients and nerves at risk were 71 and 129 in Group A, and 63 and 121 in Group B, respectively. RLN injury in Group A (0) was significantly lower than that in Group B (5[7.9%]) patients, 7 [5.8%] nerves) for the numbers of patients (P=-0.016) and nerves at risk (P=0.006). Temporary hypocalcaemia was significantly higher in Group A than in Group B (14 [24.1%] vs 6 [10.3%], P=0.049).Permanent complications in Group B were significantly higher than those in Group A (13 [20.6%] vs 4 [5.6%], P=0.009). Conclusion: RLN injury was prevented and permanent complications were decreased by identifying the whole course and branches of the recurrent laryngeal nerve during total thyroidectomy. 相似文献
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Tom Davies 《The International Journal of Art & Design Education》2000,19(3):332-344
This research is part of an on-going investigation into student teachers' perceptions of theory and practice within Initial Teacher Training [ITT] and beyond. Respondents were drawn from a number of specialist ITT providers, and supple-mented from other sources. [1] The enquiry grew out of earlier research into examination courses in Key Stage 4 and teachers' dependency on 'orthodox' approaches and content. [2] The likelihood of challenging or breaking down this dependency seemed to rely on student teachers' ability to critique current practices and speculate as to alternatives, which is made more problem- atic because of the drastic reduction of time allocation in ITT. [3] This report in part is predicated on the belief that the enforced, crude division of time spent in, and out, of schools polarises theory and practice in the minds of students. This, in turn, tends to undermine the opportunities to explore and experiment with teaching and learning styles, and the degree to which students value and employ theory and make use of, and extend, their subject knowledge. [4] 相似文献
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研究1-甲基-3-丁基咪唑对甲苯磺酸盐（[bmim][p-CH3C6H4SO3]）离子液体/水体系促进室温下碱催化芳醛与芳酮Aldol缩合反应.实验结果显示,在室温下,离子液体体积分数为25%,离子液体/水体系对苯甲醛与苯乙酮间Aldol缩合反应具有更明显的加速作用,缩合产物收率达到81%以上;该方法具有条件温和、操作简单、反应时间短、产率高等特点. 相似文献