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   

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   

Programmable deformation of patterned bimorph actuator swarm     

Jia-Nan Ma  Yong-Lai Zhang  Dong-Dong Han  Jiang-Wei Mao  Zhao-Di Chen  Hong-Bo Sun 《国家科学评论(英文版)》2020,7(4):775

Graphene-based actuators featuring fast and reversible deformation under various external stimuli are promising for soft robotics. However, these bimorph actuators are incapable of complex and programmable 3D deformation, which limits their practical application. Here, inspired from the collective coupling and coordination of living cells, we fabricated a moisture-responsive graphene actuator swarm that has programmable shape-changing capability by programming the SU-8 patterns underneath. To get better control over the deformation, we fabricated SU-8 micropattern arrays with specific geometries and orientations on a continuous graphene oxide film, forming a swarm of bimorph actuators. In this way, predictable and complex deformations, including bending, twisting, coiling, asymmetric bending, 3D folding, and combinations of these, have been achieved due to the collective coupling and coordination of the actuator swarm. This work proposes a new way to program the deformation of bilayer actuators, expanding the capabilities of existing bimorph actuators for applications in various smart devices.  相似文献   

Large-scale multiferroic complex oxide epitaxy with magnetically switched polarization enabled by solution processing     

Cong Liu  Feng An  Paria S M Gharavi  Qinwen Lu  Junkun Zha  Chao Chen  Liming Wang  Xiaozhi Zhan  Zedong Xu  Yuan Zhang  Ke Qu  Junxiang Yao  Yun Ou  Zhiming Zhao  Xiangli Zhong  Dongwen Zhang  Nagarajan Valanoor  Lang Chen  Tao Zhu  Deyang Chen  Xiaofang Zhai  Peng Gao  Tingting Jia  Shuhong Xie  Gaokuo Zhong  Jiangyu Li 《国家科学评论(英文版)》2020,7(1):84

Complex oxides with tunable structures have many fascinating properties, though high-quality complex oxide epitaxy with precisely controlled composition is still out of reach. Here we have successfully developed solution-based single-crystalline epitaxy for multiferroic (1-x)BiTi_(1-y)/2Fe_yMg_(1-y)/2O₃–(x)CaTiO₃ (BTFM–CTO) solid solution in large area, confirming its ferroelectricity at the atomic scale with strong spontaneous polarization. Careful compositional tuning leads to a bulk magnetization of 0.07 ± 0.035 μ_B/Fe at room temperature, enabling magnetically induced polarization switching exhibiting a large magnetoelectric coefficient of 2.7–3.0 × 10⁻⁷ s/m. This work demonstrates the great potential of solution processing in large-scale complex oxide epitaxy and establishes novel room-temperature magnetoelectric coupling in epitaxial BTFM–CTO film, making it possible to explore a much wider space of composition, phase, and structure that can be easily scaled up for industrial applications.  相似文献   

SA/rGO@CuS光热转化复合相变材料制备及性能研究的综合实验设计     

王静静  李泽超  孙建林  梁凯彦  梁贝星  王鹏宇  李旻咛 《实验技术与管理》2021,(2):68-72

结合科研工作热点和学科前沿方向,该文设计了“SA/rGO@CuS光热转化复合相变材料制备及性能研究”综合性实验.将具有光吸收能力的硫化铜(CuS)纳米粒子负载在具有高导热系数的还原氧化石墨烯(rGO)上,制备得到rGO@CuS复合物,以其为载体材料负载相变芯材十八酸(SA),设计制备出具有光捕集、光热转换和定形相变储能...  相似文献