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采用原子吸收分光光度法对中国一些常用茶叶和银杏叶中的钾和不同方法冲泡的茶、银杏叶饮料中的钾进行了测定,结果表明,茶叶、银杏叶中的钾含量丰富,为14 035~38 924 mg/kg。饮茶和银杏叶茶对人体健康有益。 相似文献
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颜卿 《广东微量元素科学》2009,16(4):61-61
茶叶是备受我国人民及世界人民欢迎的饮料,饮茶不仅仅是能得到味觉的享受,还能得到保健身体的效果,茶还提供人体组织正常运转所不可缺少的矿物质元素,茶叶的保健效果主要取决于它的抗氧化和含有多种丰富的人体所必需的宏量元素和微量元素。经过国内外科学家的研究发现,茶叶中所含的必需宏量元素和微量元素约有40种之多,含有较丰富的必需微量元素有铁、锌、锰、铬、氟和硒等等。 相似文献
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马国军 《理化检验(化学分册)》2014,(6):766-768
近年来,随着人们生活水平的提高,饮料成为人们日常生活的必备饮品,为改善饮料的品质,提高其色、香、味等感官质量,延长其保存期和提高产品质量,生产厂家通常会在产品生产过程中加入一些食品添加剂,而这些食品添加剂大多为人工合成,过量使用对人体会造成一定的危害。国家标准GB 2760《食品添加剂使用卫生标准》中对各种添加剂的使用限量进行了严格控制[1]。山梨酸、苯甲酸、脱氢乙酸、甜蜜素、糖精钠、安 相似文献
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通过密度法巧妙地定量测定了市售常见的22种饮料的含糖量并进行比较分析,激发了学生学习化学的兴趣,培养了学生利用所学知识解决生活实际问题的能力。整个实验中所用试剂价格低廉、易得,对人体和环境没有任何污染。 相似文献
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甲醛是一种环境污染物.室内装修材料、家具、化纤材料、食品、饮料等包装材料生产过程都不同程度地用了甲醛,这些物质释放的微量甲醛会给人体健康造成极大危害.国际癌症研究所(IARC)已建议将其列为一种可疑致癌物. 相似文献
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溴酸钾氧化靛红催化光度法测定痕量甲醛 总被引:4,自引:0,他引:4
甲醛对人体有不同程度的危害,对人体呼吸道黏膜和皮肤有强烈的刺激作用.吸人过量甲醛,可导致流泪、流涕等症状,并发生呼吸道疾病.慢性吸入低浓度甲醛,可导致持续头疼、无力、失眠等症状.长期皮肤接触,会导致皮炎,过敏者还会发生皮疹.国际癌症研究所已将其列为可疑致癌物质[1].因此,对食品、饮料及室内空气中所含甲醛的测定,具有非常重要的实际意义. 相似文献
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桑色素褪色光度法测定茶叶中的锰 总被引:2,自引:1,他引:1
锰是人体必需的微量元素,具有重要的生理功能和营养作用.茶树对锰有富集现象,茶叶是人们常用的饮料[1].因此,建立一种灵敏而又简便的测定痕量锰的分析方法,具有重要的实用价值. 相似文献
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A redox hydrogel with an apparent electron diffusion coefficient (D(app)) of (5.8 +/- 0.5) x 10(-)(6) cm(2) s(-)(1) is described. The order of magnitude increase in D(app) relative to previously studied redox hydrogels results from the tethering of redox centers to the backbone of the cross-linked redox polymer backbone through 13 atom spacer arms. The long and flexible tethers allow the redox centers to sweep electrons from large-volume elements and to collect electrons of glucose oxidase efficiently. The spacer arms make the collection of electrons from glucose oxidase so efficient that glucose is electrooxidized already at -0.36 V versus Ag/AgCl, the reversible potential of the redox potential of the FAD/FADH(2) centers of the enzyme at pH 7.2. The limiting current density of 1.15 mA cm(-)(2) is reached at a potential as low as -0.1 V versus Ag/AgCl. The novel redox center of the polymer is a tris-dialkylated N,N'-biimidazole Os(2+/3+) complex. Its redox potential, -0.195 V versus Ag/AgCl, is 0.8 V reducing relative to that of Os(bpy)(2+/3+), its 2,2'-bipyridine analogue. 相似文献
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Jean Nahmias Hervé Téphany Philippe Méjanelle 《Journal of colloid and interface science》1997,190(2):497
Using a rotating magnet device, we observe the noncoalescence of droplets of certain liquids slightly put in contact with the surface of the same liquid. The droplets go into the vortex and coalesce, the resulting drop staying in equilibrium in this position. If the rotation of the liquid is stopped, the drop rests at the surface for more than 20 s, as if it were immiscible, without any relative motion. 相似文献
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200 nm-thick super bundles showing a novel polygonization and densely aligned arrangement are found in long single-walled carbon nanotube (SWNT) strands prepared by the vertical floating catalytic method. 相似文献
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By the study of the pressure dependence of the fluorescence and phosphorescence yields of pyrazine vapors in the pressure range of 10−2-10 torr it was established that the fluorescence decay is not exponential but contains a long component (τ ≈ 10−6–10−7 sec) corresponding to the “dilution” of the singlet radiative properties in the dense manifold of triplet levels. The phosphorescence is due exclusively to the collisionally induced relaxation from the quasi-stationary state to the pure triplet state. 相似文献
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M. Fülöp N. Patzeltová P. Ragan L. Mátel 《Journal of Radioanalytical and Nuclear Chemistry》1996,209(2):291-293
The long-term effect of the plutonium to the human organism after Chernobyl accident was traced. Nine years after the accident the level of plutonium in the urine of the patients was in the order of tenths mBq. 相似文献
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