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硼的测定方法已有许多报导。为了配合盐湖的研究和开发利用,我们着重研究了硫酸盐型,碳酸盐型和氯化物型卤水,天然水和盐类矿物中硼的测定。由于我国盐湖卤水和盐类矿物中硼含量变化范围较大,常用的胭脂红法取样量受到限制,同时需要浓硫酸中显色,甚感不便。本法测硼较为理想,快速,准确,选择性好,可在水介质中直接测定。摩尔吸光系数为9×10~3。用于测定盐湖卤水和盐类矿物中的硼,其结 相似文献
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采用碱熔法分解电气石样品,研究了3种不同纯化分离方法对硼回收和同位素测定的影响。实验表明:电气石中富含的Fe3+和Al3+对甲亚胺-H酸分光光度法测定硼含量有较大干扰,并在硼特效树脂交换分离中形成氢氧化物沉淀,阻塞交换柱;同时吸附溶液中硼元素造成回收率降低。本实验依次采用阴/阳离子混合树脂,硼特效树脂和阴/阳离子混合树脂三步离子交换进行电气石样品的纯化分离方法,实现了复杂基体中硼的完全回收(回收率99%)。在TIMS(Triton TI)采用H3和H4法拉第杯,并通过优化Zoom Optics参数(Focus Quad:15;Dispersion Quad:-85)实现静态双接收硼同位素组成测定。本方法对NIST SRM 951标准样品测定结果为11B/10B=4.05044±0.00012(2σ,n=8,1μg B),测定内外精度优于传统的动态峰跳扫。NIST SRM951测定结果为-0.3‰,表明预处理过程中无硼同位素分馏效应。天然样品硼同位素组成分别采用静态多接收PTIMS-Cs2BO2+法和MC-ICP-MS测定,数据点基本分布在1:1线上,说明MC-ICP-MS测定结果与PTIMS方法结果相一致。 相似文献
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用双重柱子从浓盐溶液中离子交换分离锂 总被引:1,自引:0,他引:1
各种型号的阳离子交换树脂分离锂,已有很多文献报导。我们也曾作过萃取分离锂的工作,但均混有其他杂质。我所也曾研究了盐湖卤水中锂同位素丰度比值的质谱测定方法。该法在测定前要将锂从其他元素中分离出来,采用的是正1×12号强酸性阳离子交换树脂,加入有机溶剂作淋洗剂,洗脱时间仍需五小时。自从我们研究了无机离子交换剂—— 相似文献
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Jana Elias Dr. Elisabeth Kaifer Prof. Hans-Jörg Himmel 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(26):6553-6561
A new boron–boron dehydrocoupling strategy was established, providing convenient access to some diborane(4) compounds starting from simple borane adducts under mild conditions. In contrast to the traditional pathway using a reducing reagent, the reduction from BIII to BII was paradoxically initiated by the addition of the oxidation-reagent iodine. A reaction pathway for this unusual reaction was proposed based on quantum-chemical calculations. 相似文献
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硼原子因其半径小、缺电子、配位数大、价电子sp2杂化和三中心键等特点引起了科学家的高度关注。其团簇的电子结构、稳定性、芳香性和成键方式等性质的研究成为化学领域的一大热点。由于硼化物多样性的特点,其在光学、能源和储存工业气体方面具有潜在的应用价值。本文简述了近几年全硼团簇、硼烷及金属硼化物的研究现状。其中,分别从中性、阴离子和阳离子三种形式对全硼团簇和硼烷进行概括;金属掺杂硼化物主要包括金属掺杂的纯硼团簇和硼烷、过渡金属掺杂的三明治形式复合物以及金属中心硼分子轮。 相似文献
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微量枸椽酸溶硼测定是肥料检测中的常见项目,用以评估硼肥肥效。其测定方法大多复杂繁琐,操作条件苛刻。如用姜黄素或其他显色剂的分光光度法,体系中因有柠檬酸存在,产生的影响难以处理,测定结果重现性差,限制了测硼的快速和准确性。ICP-AES法较其它方法相比是一种精密度高、重现性好的方法[1],各元素对硼干扰较少,20 g·L-1柠檬酸在炬管处不会炭化引起阻塞,对硼的干扰也可得到校正,使得ICP-AES法测定稀柠檬酸有机溶液中硼成为可能。该方法操作简便、快速,检出限可达0.003 5%,回收率为86%,适用于硼镁肥中微量枸椽酸溶硼测定。枸椽酸溶… 相似文献
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A survey of novel classes of nanotubular materials based on boron is presented. Pure boron nanotubes are a consequence of a general Aufbau principle for boron clusters and solid boron phases, which postulates various novel boron materials besides the well-known bulk phases of boron based on boron icosahedra. Furthermore, several numerical studies suggest the existence of a large family of compound nanotubular materials derived from crystalline AlB2. We compare these novel boron-based nanotubular materials to standard nanotubular systems built from carbon, and point out a number of remarkable structural and electronic properties that make boron-based nanotubular materials an ideal component for composite nanodevices and extended nanotubular networks. 相似文献
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Toralf Peymann Axel Herzog Carolyn B. Knobler M. Frederick Hawthorne 《Angewandte Chemie (International ed. in English)》1999,38(8):1061-1064
No explosion , but per-B-hydroxylation occurs if the icosahedral boron hydrides [closo-B12H12]2− (see picture), [closo-CB11H12]−, or closo-1,12-(CH2OH)2-1,12-C2B10H10 are refluxed in 30 % hydrogen peroxide. Thus, the three isoelectronic species [closo-B12(OH)12]2−, [closo-1-H-1-CB11(OH)11]−, and closo-1,12-H2-1,12-C2B10(OH)10 were obtained. ○=BH, ○=BOH. 相似文献
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Polystyrene, cross-linked with 7.8% of divinylbenzene, formed a stable complex in chloroform with boron trifluoride containing 0.11% of boron, while cross-linked polystyrene-4-vinylpyridine resins containing 2–2.5% of pyridine rings formed a stable complex with boron trifluoride, containing 1.04% of boron. Both complexes catalyze conversions of aromatic aldehydes, ketones, and acids with alcohols into corresponding acetals, cyclic ketals, and esters; diphenylmethanol converts into ether. The structure of the alcohol plays an important role, with conversions decreasing in the order 1-butanol, 2-butanol, tert-butanol. Both complexes are very stable and in most cases more reactive than the cross-linked polystyrene-A1C13 complex. 相似文献
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