掩蔽锶-铬酸钡-碘量法测定碳酸锶中钡

采用乙二胺四乙酸二钠掩蔽锶,在ＰＨ值为５．９条件下,钡离子重铬酸钾生成铬酸钡沉淀,分离后,用碘量法测定。相对标准偏差１．０２％－２．１７％,加标回收率９５％－１０３％。     

Novel synthesis method and microstructure evolution of Ti3C2(OH)2/K2Ti8O17 nanocomposites as an effective surface enhanced Raman scattering substrate

In this paper, we have developed a mild and facile approach using KOH solution as etchants to corrode Ti₃SiC₂ at room temperature, fabricating novel Ti₃C₂(OH)₂/K₂Ti₈O₁₇ nanocomposites with open network structures and abundant surface functional groups. The as-produced products obtain the excellent surface enhanced Raman scattering (SERS) performance in the determination of crystal violet (CV), rhodamine 6G (R6G) and methylene blue (MB) dye molecules. The enhancement factors of the three can be calculated to be 3.98 × 10⁵, 1.78 × 10⁵ and 5.27 × 10⁵, and the Raman signals can be detected at the concentrations as low as 10^?6 M, 10^?8 M and 10^?6 M, respectively, suggesting the potential for reliable SERS substrates. In this regard, this work provides a new strategy for exploring and synthesizing MAX phase-derived nanomaterials as promising SERS substrates for high-sensitive molecular detection.     

复分解法硝酸钾生产中的相图分析

文章对硝酸铵和氯化钾复分解生产硝酸钾的生产中的配料过程及其影响因素 ,以K+ ,NH+ 4∥Cl-,NO-3 -H2 O四元水盐体系相图为依据作了理论分析 ,指出以相图理论为基础 ,利用物料衡算的方法确定各配盐量来指导操作是非常必要的。     

Facile ion-exchanged synthesis of Sn incorporated potassium titanate nanoribbons and their visible-light-responded photocatalytic activity

Sn²⁺-incorporated potassium titanate (K₂Ti₆O₁₃) nanoribbons were prepared by a facile acid-free ion-exchanged method in a dehydrated methanol solution at room temperature. XRD patterns suggested that K₂Ti₆O₁₃ (KTO) and Sn²⁺-incorporated KTO (SKTO) are well crystallized with monoclinic phase structures. The mole ratio of incorporated Sn²⁺ to K⁺ in SKTO was estimated to be 2. X-ray photoelectron spectrum showed that the Sn species of SKTO consisted of 90% of Sn²⁺ and 10% of Sn⁴⁺, suggesting that part of Sn²⁺ was oxidized to Sn⁴⁺ in the incorporation process. The band gap of SKTO was 0.7 eV narrower than that of KTO, which was derived from lift of the top of the valence band due to the hybridization of Sn5s and O2p orbitals. The SKTO nanoribbons showed remarkable photocatalytic activities for H₂ evolution and rhodamine B degradation under visible light irradiation (λ ≥ 420 nm). The photocatalytic mechanism and durability were studied in detail. The advantage of this acid-free ion-exchange method is ease of ion-exchange of K⁺ with H⁺ and maintenance of the integrity of the 1D nanoribbon structures. This method can be applied to preparation of other Sn²⁺-incorporated compounds with special nanostructures.     

Potassium promoted Ru/meso-macroporous SiO2 catalyst for the preferential oxidation of CO in H2-rich gases

A series of potassium promoted Ru/meso-macroporous SiO₂ catalysts were prepared and used for the preferential oxidation of CO (CO-PROX) in H₂-rich gases. The catalysts were characterized by using techniques of TEM, SEM TPR, XPS, and N₂ adsorption/desorption. The catalytic activity of Ru/meso-macroporous SiO₂ was markedly improved by the introduction of potassium. The catalyst of K-5 wt.% Ru/meso-macroporous SiO₂ with molar ratio of K:Ru = 5:7 exhibited relatively high activity and selectivity for CO-PROX. Nanoparticles of ruthenium species can be highly dispersed on the meso-macroporous SiO₂ support by the simple impregnation method. The addition of potassium weakened the interaction between metallic Ru and the silica support. Lowering the reduction temperature of ruthenium ions could keep ruthenium in the state of metallic Ru, and it was proposed that potassium acted as an electron donating agent. The electron donating effect of potassium improved the low temperature activity for CO oxidation and increased the selectivity of O₂ for CO oxidation, thus K-modified Ru/meso-macroporous SiO₂ catalyst showed obviously a wide temperature window for CO elimination from H₂-rich gases, meanwhile the related mechanism was discussed.     

离子选择电极法测定马口铁钝化,漂洗含铬废水中氯的研究

用氯离子选择电极,通过多次标准添加作图法测定马口铁钝化、漂洗含铬废水中的氯离子,用乙醇－乙酸 氧化氢还原来消除对测定有干扰的大量铬酸根。该法简单快速,相对标准偏差小于２．０％,加料回收率为９６％－１０４％,最低可测定氯离子含量约为０．２μｇ／ｍＬ。     

氨法生产硫酸钾的工艺研究

实验研究了氨作为硫酸钾结晶助剂,在常温常压下石膏和氯化钾在水盐相体系中有选择地结晶硫酸钾的原理及工艺流程。该流程具有节省热能,操作维护容易,效率高等优点。     

利用硫铁矿烧渣制硫酸钾的工艺研究

考察了诸多因素对利用硫铁矿烧渣制取硫酸钾的影响,确定了最佳工艺条件,并对添加有机胺试剂以提高K+的转化率进行了探索。     

苦味酸钾点火药在电点火头中的应用

通过理论分析和试验,从机械感度、燃烧精度、热安定性、性能、长贮等方面,对比分析了苦味酸钾点火药与DDNP点火药.结果表明:在电点火头制造中,采用苦味酸钾作为点火药的主要组分,具有热稳定性好、药头机械强度高、生产过程废品少、无环境污染等优点,尤其有利于提高电雷管的发火可靠性和一致性.     

离子选择电极法测定镀铬液中氯的研究

用氯离子选择电极,通过多次标准添加作图法测定镀铬液中的氯离子,用乙醇-乙酸及过氧化氢还原来消除对测定有干扰的大量铬酸根,该法简单快速,相对标准偏差小于2.0%,加料回送率为96%~104%,最低可测定氯离子含量为0.2μg/mL。