金属与硝酸反应题型的快速解法     

邹志洪 《铜仁学院学报》2001,3(3):103-105

金属与硝酸反应的计算是高中化学的重点和难点.由于金属与硝酸反应的复杂性,使得大多数学生在解决这一类型习题时大伤脑筋;要么过于繁琐,要么反应方程式写不出或根本束手无策.笔者在多年的教学中,摸索出一种解决这类题型的快速解法--关系式法,在某种程度上极大地方便了这类题的解答.  相似文献   

金属铝置换硝酸中氢的实验设计     

李大塘  唐建生 《株洲师范高等专科学校学报》2007,12(2):13-15,22

成功地设计了金属铝置换硝酸中氢的实验装置与方法，旨在探索金属铝与硝酸的化学性质以及深刘理解硝酸浓度影响其产物的规律．研究发现，室温下用去膜并经氯化汞溶液处理过的铝箔与一定浓度的稀硝酸作用可产生氢气，而未经氯化汞溶液处理的铝箔与稀硝酸作用几乎检测不到氢气的生成．进一步研究显示硝酸的最高浓度为1．6mol／L，产生氢气最快时硝酸浓度为0．07mol／L．  相似文献   

纳米氧化铁的结构性质及用途   总被引：3，自引：0，他引：3  

赵红丽  琚行松  芮玉兰  梁英华 《唐山师范学院学报》2005,27(5):1-4

纳米氧化铁是一种多功能材料，在催化、磁介质、医药等方面具有广泛的应用。本文综述了纳米氧化铁的结构性质及其用途。  相似文献   

PEMFC分散发电系统的压力控制研究     

张颖颖  曹广益  朱新坚 《上海大学学报(英文版)》2006,10(3):262-267

NomenclatureA-area ( m2)Dw-membrane water diffusivity ( m2/s)F-=96 487I-current (A)M-molecule mass (kg/mol)T-temperature (K)W-mass flowrate (kg/s)cw-water concentration in membrane ( mol/m3)m-mass (kg)n-cell numbernd-electro-osmotic drag coefficientp-pres…  相似文献   

浙南变质岩发育土壤中氧化铁组成及其发生学意义     

章明奎 《科技通报》1996,12(1):54-58

本文对浙南变质岩发育的１６个土壤剖面中氧化铁矿物的组成特性、红度与赤铁矿含量的关系及母质对铁矿物的影响等作了研究。结果表明，变质岩发育土壤的晶态氧化铁主要为针铁矿和赤铁矿，铁游离度较高（Ｂ层土壤为５１．６８％￣８５．５３％），活化度较低（Ｂ层土壤为０．９５％￣５．８３％）。土色常比同纬度同海拔的其它土壤红，粘一的赤铁矿含量较高，这与变革岩中矿物晶格能低、易风化、铁释放快等有关。土壤红度与赤铁矿含量  相似文献   

四川会理铅锌矿高碱度含泥尾矿氧化锌浮选生产实践     

周建琼 《大众科技》2016,(3):20-21

四川会理某铅锌矿选厂选别的是以铜铅锌银等硫化矿为主的多金属矿石,近年来,入选原矿含泥重、氧化率升高,选别指标有所下降,特别是选别后的硫化锌尾矿锌偏高,导致选矿的锌回收率大幅下降,因此对硫化锌尾矿氧化锌进行了再选。生产实践表明,高含泥低品位的氧化锌矿采用硫化后胺法浮选的方法时,脱泥作业至关重要。适当增加硫化时间有助于提高回收率。p H值太高不利于氧化锌的选别。  相似文献   

间接分光光度法测定药品中VC含量     

潘乐  孙瑞敏 《黄山学院学报》2011,13(3):47-49

利用VC的还原性,将Fe3+定量转化为Fe2+离子,产生的Fe2+与邻菲哆啉形成橘红色络合物,从而间接测定VC的含量。结果表明,络合物在510nm处有最大吸收峰,且显色物的浓度在2.0×10-6-5.0×10-5mol/L范围内与吸光度成正比,其相关系数R为0.9936,检出限为2.0×10-6mol/L,被测定样品的...  相似文献   

溅射法在不同O2／Ar比例下制备HfO2薄膜     

马紫微 《运城学院学报》2011,(5):25-28,35

作为一种性能稳定的绝缘体,HfO2在电子、光学以及能量相关的领域中有着重要的应用。在本工作中,我们使用反应溅射方法在不同O2／Ar比例下制备了HfO2薄膜。XRD结果显示,O2／At比例并不能明显的影响样品的结构。通过Debye—Schener公式估计,样品由纳米晶粒组成。在O2／Ar比例为0．06（功率12W）时制备的样品最接近化学配比。在可见光区域,样品具有很好的透光率,T〉85％。明显的吸收发生在波长小于220nm时。通过Tauc公式可以估算出,样品的带隙在5．051到5．547eV范围内变化。  相似文献   

Paving the road toward the use of β-Fe2O3 in solar water splitting: Raman identification,phase transformation and strategies for phase stabilization     

Ningsi Zhang  Xin Wang  Jianyong Feng  Huiting Huang  Yongsheng Guo  Zhaosheng Li  Zhigang Zou 《国家科学评论(英文版)》2020,7(6):1059

Although β-Fe₂O₃ has a high theoretical solar-to-hydrogen efficiency because of its narrow band gap, the study of β-Fe₂O₃ photoanodes for water splitting is elusive as a result of their metastable nature. Raman identification of β-Fe₂O₃ is theoretically and experimentally investigated in this study for the first time, thus clarifying the debate about its Raman spectrum in the literature. Phase transformation of β-Fe₂O₃ to α-Fe₂O₃ was found to potentially take place under laser and electron irradiation as well as annealing. Herein, phase transformation of β-Fe₂O₃ to α-Fe₂O₃ was inhibited by introduction of Zr doping, and β-Fe₂O₃ was found to withstand a higher annealing temperature without any phase transformation. The solar water splitting photocurrent of the Zr-doped β-Fe₂O₃ photoanode was increased by 500% compared to that of the pure β-Fe₂O₃ photoanode. Additionally, Zr-doped β-Fe₂O₃ exhibited very good stability during the process of solar water splitting. These results indicate that by improving its thermal stability, metastable β-Fe₂O₃ film is a promising photoanode for solar water splitting.  相似文献   

A highly alkaline-stable metal oxide@metal–organic framework composite for high-performance electrochemical energy storage     

Shasha Zheng  Qing Li  Huaiguo Xue  Huan Pang  Qiang Xu 《国家科学评论(英文版)》2020,7(2):305

Most metal–organic frameworks (MOFs) hardly maintain their physical and chemical properties after exposure to alkaline aqueous solutions, thus precluding their use as potential electrode materials for electrochemical energy storage devices. Here, we present the design and synthesis of a highly alkaline-stable metal oxide@MOF composite, Co₃O₄ nanocube@Co-MOF (Co₃O₄@Co-MOF), via a controllable and facile one-pot hydrothermal method under highly alkaline conditions. The obtained composite possesses exceptional alkaline stability, retaining its original structure in 3.0 M KOH for at least 15 days. Benefitting from the exceptional alkaline stability, unique structure, and larger surface area, the Co₃O₄@Co-MOF composite shows a specific capacitance as high as 1020 F g⁻¹ at 0.5 A  g⁻¹ and a high cycling stability with only 3.3% decay after 5000 cycles at 5 A g⁻¹. The as-constructed solid-state flexible device exhibits a maximum energy density of 21.6 mWh cm⁻³.  相似文献