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1.
丽水市茶叶及茶园土壤中重金属的测定 总被引：1，自引：0，他引：1
用火焰原子吸收光谱法测定浙江省丽水市不同茶叶产区的茶园土壤和茶叶样品中的重金属含量,结果表明:各茶园土壤中的铅、镉含量比较高,铜含量较低;茶叶中的铅、镉、铜的含量均较低,大部分符合我国无公害茶叶标准;测得铅、镉、铜的相对标准偏差分别为3.6%、5.2%、4.3%,回收率在95.2%～106.5%之间. 相似文献
2.
《大连大学学报》2016,(3)
检测了辽宁省营口市4个海蜇养殖池塘底泥的6项理化指标(p H、含盐量、硫化物、有机碳、总氮、总磷)和6项重金属指标(铜、锌、铅、铬、镉、汞),比较分析了这些底泥指标与海蜇亩产量之间的关系。结果发现,海蜇养殖池塘底泥理化指标中含盐量与海蜇亩产量之间相关性较高,J圈底泥含盐量最高,其海蜇亩产量也最高。重金属指标中铜和铬的含量与海蜇亩产量之间相关关系较为密切,J圈底泥铜和铬含量较高,其亩产量也较高,A15和C1圈底泥铜和铬含量较低,其亩产量也偏低。而其它理化指标和重金属指标与海蜇亩产量之间相关性不明显。综上,海蜇养殖池塘中底泥含盐量、铜和铬含量与海蜇亩产量之间存在较密切的相关性,其它指标与海蜇产量之间相关性不显著。 相似文献
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示波极谱法连续测定太湖流域大米中锌、铁、锰、铜、铅、镉含量 总被引：1，自引：0，他引：1
研究了示波极谱法在三乙醇胺-乙二胺-硫氰酸钾-乙酸-盐酸-碘化钾-十二烷基硫酸钠体系中连续测定太湖流域大米试样中锌、铁、锰、铜、铅、镉六种微量元素.在该体系中,六种微量元素分别在-1425mV、-1638mV、-1717mV、-508mV、-533mV、-668mV产生稳定的二阶导数极谱波.锌、铁、锰、铜和铅最低检出限为0.01μg·mL-1,镉最低检出限为0.005μg·mL-1,锌、铁、铜、铅的浓度在0.01～0.80μg·mL-1,镉在0.005～0.80μg·mL-1,锰在0.01～0.50μg·mL-1范围内与极谱波峰高成正比.六种微量元素回收率范围:94.4%～103.5%,RSD:0.14%～8.72%.该方法操作简便,灵敏度和精确度高.该方法应用于太湖流域18种大米中六种微量元素的测定,与原子吸收分光光度法测得的结果基本一致. 相似文献
4.
笔者采用火焰原子吸收光谱法测定了长江起点水域中的微量元素镉、铬、锰、锌、铜、镍6种元素，考察了不同种酸及酸度对硝化作用的影响和在体系中共存离子的相互干扰情况。用NH4H2PO4-Mg（NO3）2作为测定镉、铬的基体改进剂，得到了良好的测定结果，其标准加入回收率为96．5％-105％，相对标准偏差为1．1％-2．0％，检测限镉为0．040mg／L；铬为0．018mg／L；锰为0．020mg／L；锌0．096mg／mL；铜为0．064mg／mL；镍为0．035mg／mL。 相似文献
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利用植物监测手段对甘肃省兰州市南、北滨河路(安宁东段)道路两侧和兰州城市学院西校区的6种绿化植物带叶片进行了重金属含量的研究,采用原子吸收法,测定绿化带植物叶片中铅(Pb)、镉(Cd)、铬(Cr)、铜(Cu)的含量.结果表明,道路绿带化植物叶片中铅(Pb)、铬(Cr)、铜(Cu)的含量,滨河路段明显高于兰州城市学院西校区.并且未清洗叶片所测的铅(Pb)、镉(Cd)、铬(Cr)、铜(Cu)的含量又明显高于清洗过的叶片. 相似文献
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目的:测定注射用牡荆素中的铅、镉、砷、汞、铜等5种重金属元素的含量,探讨牡荆素注射剂重金属的质量控制方法。方法:经微波消解后的注射用牡荆素样品,加入铅、镉、砷、汞、铜等内标元素,ICPMS(电感耦合等离子体质谱)法测定样品中铅、镉、砷、汞、铜的含量。结果:铅、镉、砷、汞、铜的检出限分别为0.4、0.03、0.09、0.04及0.05ng/mL;且线性关系良好(r0.998);铅、镉、砷、汞、铜回收率分别为97.8%、97.2%、104.0%、91.2%和92.8%。结论:本方法操作简便、灵敏度高、专属性好,适用于注射用牡荆素中铅、镉、砷、汞、铜的质量控制。 相似文献
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为了解渭南市售儿童小食品重金属污染情况,测定了9种儿童小食品中砷、汞、铅、镉、铜、锌、铝的含量.结果表明,所有样品中被测定的元素均未超标,检测合格率为100%.汞含量0.0087-0.0099 mg/Kg,镉含量0.06-0.08 mg/Kg,铅含量0.56-0.97 mg/Kg范围,铜含量9.2-9.4 mg/kg,锌含量41-48 mg/kg,铝含量80-97 mg/kg,砷含量0.03-0.06mg/kg.在七种金属中锌和铜为必需微量元素,其含量比砷、汞、铅、镉等重金属含量高,合理食用可以有效补充这两种元素.以上数据表明,这些小食品均无污染. 相似文献
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本文合成了8种金属（锰、钴、镍、铜、锌、镉、汞、铅）苦味酸配合物，并通过元素分析、红外光谱、紫外光谱和摩尔电导对该系列配合物进行了表征。 相似文献
10.
秦淮河底泥重金属污染评价 总被引：2，自引：0，他引：2
通过对秦淮河底泥中6种重金属元素:铜(Cu)、铅(Pb)、锌(Zn)、铬(Cr)、镉(Cd)、镍(Ni)的含量分析,并运用地累积指数法和潜在生态风险指数法对其污染程度和潜在生态风险进行评价.结果表明各种重金属的污染程度依次为:Pb>Cu>Cr>Zn>,Pb达到强污染;Cu为中-强度污染,Zn、Cr为中度污染,Cd、Ni未构成污染.总体上秦淮河底泥重金属污染表现为中度生态危害程度,其贡献因子为Pb和Cd两种元素. 相似文献
11.
巢宗祺 《华东师范大学学报(哲学社会科学版)》2000,32(4):111-116
根据粤、闽、湘、赣、客家等方言的资料以及一些书面资料,对与普通话里的"给…"和"相对应的词的语言形式、分布状况作一简要描写,可以初步窥见这些"对应词"之间的联系. 相似文献
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Simple, reliable and sensitive analytical methods to determine anticariogenic agents, preservatives, and artificial sweeteners contained in commercial gargles are necessary for evaluating their effectiveness, safety, and quality. An ion chromatography (IC) method has been described to analyze simultaneously eight anions including fluoride, chloride, sulfate, phosphate,monofluorophosphate, glycerophosphate (anticariogenic agents), sorbate (a preservative), and saccharin (an artificial sweetener)in gargles. In this IC system, we applied a mobile phased gradient elution with KOH, separation by IonPac AS18 columns, and suppressed conductivity detection. Optimized analytical conditions were further evaluated for accuracy. The relative standard deviations (RSDs) of the inter-day's retention time and peak area of all species were less than 0.938% and 8.731%, respectively,while RSDs of 5-day retention time and peak area were less than 1.265% and 8.934%, respectively. The correlation coefficients for targeted analytes ranged from 0.999 7 to 1.000 0. The spiked recoveries for the anions were 90%～102.5%. We concluded that the method can be applied for comprehensive evaluation of commercial gargles. 相似文献
13.
徐从权 《安庆师范学院学报(社会科学版)》2018,37(5):36-43
上古韵部划分是上古音研究的核心部分,韵部划分至清代虽已渐臻完备,但学界对韵部进行再划分的工作一直未断。李新魁先生在二十九部基础上分出祭、废、至、队、曷、桓、戈七部,将上古韵部分为三十六部,其分部的依据不合理,故不必立祭、废、至、队、曷、桓、戈七部。 相似文献
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Marianna Papastephanou 《Educational Philosophy and Theory》2013,45(13-14):1493-1515
Many educational theoretical approaches to cosmopolitanism tend towards an unconditional appreciation of mobility, diversity and rootlessness. The recent interest of educational philosophy in the rhizome, de-territorialization and diversity contributes to this understanding of cosmopolitanism as movement across a borderless and imperfect world. Without downplaying such insights (and related political education), this article displaces and de-temporalizes them. It takes the form of a parody of the rhizome to view those insights from a different perspective and make them strike a different pedagogical note. 相似文献
15.
Simple, reliable and sensitive analytical methods to determine anticariogenic agents, preservatives, and artificial sweeteners contained in commercial gargles are necessary for evaluating their effectiveness, safety, and quality. An ion chromatography （IC） method has been described to analyze simultaneously eight anions including fluoride, chloride, sulfate, phosphate, monofluorophosphate, glycerophosphate （anticariogenic agents）, sorbate （a preservative）, and saccharin （an artificial sweetener） in gargles. In this IC system, we applied a mobile phased gradient elution with KOH, separation by IonPac AS18 columns, and suppressed conductivity detection. Optimized analytical conditions were further evaluated for accuracy. The relative standard deviations （RSDs） of the inter-day＇s retention time and peak area of all species were less than 0.938% and 8.731%, respectively, while RSDs of 5-day retention time and peak area were less than 1.265% and 8.934%, respectively. The correlation coefficients for targeted analytes ranged from 0.999 7 to 1.000 0. The spiked recoveries for the anions were 90%-102.5%. We concluded that the method can be applied for comprehensive evaluation of commercial gargles. 相似文献
16.
In this essay, I discuss three key ideas related to the construction and treatment of “difference” in and around schools and schooling. First, just as difference is most commonly located within marginalized populations at the intersections and along the lines of race, disability, social class, national origin, sexuality, sex, language, and religion, such “locating” is done by those socialized and reinforced to view themselves as normal and the norm against which they compare those different from them. Therefore, normalcy operates to maintain positions of superiority for some and inferiority for others. Next, the situation of disability at the intersection of non-dominant identities can be a powerful tool for disrupting normative spaces, practices, and beliefs. Finally, I call for critical action that exposes the negative construction of and consequences of difference in the academy, noting how epistemologies, methodologies, publication outlets and formats, and sentence structures that fall outside what we associate with normalcy, and those who employ them, are also sorted along lines of competence and incompetence, leading to the dismissal or exclusion of disabled scholars, scholars of color, and those scholars engaging in more public praxis outside the academy walls. 相似文献
17.
简单介绍了用王水、高氯酸处理高铬铸铁样品,分别进行Cr、P、Mn、Ni,Mo五元素含量测定的原理和方法.该方法准确度高、用量少、速度快,可以满足生产、科研的需要. 相似文献
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英、美、法、德、日中小学校教师法律地位的比较 总被引：23，自引：0，他引：23
英、美、法、德、日等国都非常重视用法律手段解决教师问题,但在以法规定政府、学校、社会、市场和法院等的教师管理权限,突出教师法律身份的公务性,健全教师权利保障机制,确保教师资格和工资待遇,保证教师具有一定程度的教学自由和建立完备的教师法律救济制度等方面,因各国国家体制的差异、所属法系的不同以及文化的多样性,上述各方面的法律规定又不尽一致.本文就此进行概要比较. 相似文献