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The utilisation of high CO2 content natural gas, such as that found at Natuna island in Indonesia, using methane dry reforming with carbon dioxide to synthesis gas is demonstrated. Highly active catalysts employed for coke-free, stable dry reforming include alumina-supported nickel, either as-prepared or doped with tungsten oxide or calcium oxide, and the supported group VIII metals. No deactivation was observed for the duration of any of the experiments (>70 h), and the methane conversion and product distributions were close to those predicted from thermodynamic equilibrium calculations. It is calculated that the application of dry reforming to the Natuna field alone, combined with known gas-to-liquids (GTL) technology, could provide liquid fuel to Indonesia for almost 18 years. 相似文献
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A class of 3s–5d–4f mixed metal substituted sandwich-type arsenotungstates [H2N(CH3)2]8H3[LnNa(H2O)4(OH)WO(H2O) (B-α-AsW9 O33)2]·8H2O [Ln = LaIII (1), CeIII (2), PrIII (3)] have been isolated from an aqueous solution reaction system (pH = 4) of Na2WO4·2H2O, C2H7N·HCl, NaAsO2 and Ln(NO3)3·6H2O and structurally characterized by elemental analyses, IR spectra, UV spectra and single-crystal X-ray diffraction. It is the most prominent in 1–3 that the [LnNa(H2O)4(OH) WO(H2O)(B-α-AsW9O33)2]11 − polyanion consists of two trivacant Keggin [B-α-AsW9O33]9 − moieties linked by one [WO(H2O)]4 + group and a dimeric [LnNa(H2O)4(OH)]3 + group resulting in the special 3s–5d–4f mixed metal substituted sandwich-type assembly. Interestingly, lanthanide and sodium ions simultaneously occupy the two positions located at the central belt of 1–3 with the site occupancy of 50% for each position. Moreover, the electrochemical and electrocatalytic properties of only 1 and 2 have been measured by cyclic voltammetry (CV) in 0.5 mol·L− 1 Na2SO4 + H2SO4 aqueous solution. 1 and 2 illustrate electrocatalytic activities for the hydrogen peroxide reduction. 相似文献
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Tao Cui Annan Yu Yangyu Zhang Jian Guo Xiongjie Li Shun Guo Ji Zhang Jing Wang Shan-Tao Zhang 《Journal of the American Ceramic Society》2022,105(10):6252-6261
Dielectric capacitors reveal great potential in the application of high power and/or pulsed power electronic devices owing to their ultrafast charge–discharge rate and ultrahigh power density. Among various dielectric capacitors, the environment-friendly lead-free dielectric ceramics have drawn extensive investigations in recent years. Nevertheless, the relatively small recoverable energy storage density (Wrec) is still an obstacle for their application. Herein, the (0.55−x)BiFeO3–0.45SrTiO3–xBaTiO3 ternary ceramics with 0.1 wt% MnO2 were prepared by the solid-state reaction, and achieved enhanced relaxor behavior as well as breakdown strength Eb. As a result, the x = 0.12 ceramic exhibited superior comprehensive energy storage performance of large Eb (50.4 kV/mm), ultrahigh Wrec (7.3 J/cm3), high efficiency η (86.3%), relatively fast charge–discharge speed (t0.9 = 6.1 μs) and outstanding reliability under different frequency, fatigue, and temperature, indicating that the BiFeO3-based relaxor ferroelectric ceramics are prospective alternatives for electrostatic energy storage. 相似文献
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Ming-xing Yang Shen Lin Li-juan Chen Xiao-feng Zhang Hui-hong Xu 《Inorganic chemistry communications》2009,12(6):566-568
A novel organic–inorganic hybrid compounds containing 12-tungstovanadate and 3d–4d heterometallic complex, [V1W12O40][VO2Ag(phen)3]2 (1), have been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction and IR analysis. The complex is an uncommon bisupporting polyoxometalate derivative in which the saturated Keggin type polyoxoanions are covalently linked by bimetallic complex [VO2Ag(phen)3]2+. The neighboring Ag+ and V5+ cations are bridged by the oxo atom forming heterometallic cations with the Ag–V distances of 3.556(2) Å in [VO2Ag(phen)3]2+ cations. Furthermore, the title compound shows good photocatalytic activity for reduction of Rhodamine B (RB) in a liquid–solid system. 相似文献
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Yun-Zhi Tang He-Rui Wen Zan Cao Xiao-Wei Wang Shuai Huang Chang-Lin Yu 《Inorganic chemistry communications》2010,13(8):924-928
The 3D heterometallic polymeric complex 1 {[Nd2Cu2(L)2 (OXA)4·2(2H2O)]·2(3H2O)}n (HL = 2, 2′-bipyridine-3-carboxyic acid, OXA = oxalate) was obtained from hydrothermal reaction of Nd2O3, Cu(ClO4)2, HL and oxalic acid in the presence of ethanol and water. X-ray single crystal diffraction investigation of the polymeric complexes {[Nd2Cu2(L)2(OXA)4·2(2H2O)]·2(3H2O)}n exhibits an interesting and novel topological structure. 相似文献
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《硅酸盐学报》2016,(6)
计算了CaO–Al–Al_2O_3–CaCO_3–O_2体系燃烧合成铝酸钙的绝热温度,运用物质自由能函数理论,对主要反应进行了热力学计算,分析了燃烧合成铝酸钙的物相生成过程。结果表明:体系绝热温度随产物中CA_2含量的增加而降低,但均大于1800K,说明反应可自持;在反应初期,C_(12)A7的生成驱动力最大,其次是CA、CA_2的生成驱动力,C_(12)A_7为主要生成物相;随着反应的进行,铝酸钙不同物相间会发生转化,C_(12)A_7转化CA_2的驱动力最大,其次是C_(12)A_7转化为CA;C_(12)A_7和CA2共同转化成CA的驱动力最小,因此形成以CA、CA_2为主要物相的产物,且CA的含量大于CA_2的含量。燃波前端C_(12)A_7特征峰强度最大;反应区C_(12)A_7的特征峰强度减小,而CA、CA_2的特征峰强度增加;产物区C_(12)A_7特征峰强度消失,且CA的特征峰强度大于CA2的特征峰强度,表明产物中CA的含量大于CA2的,与热力学分析结果一致。在反应区有片状CA和颗粒状CA_2生成;在产物区CA_2弥散在CA中。 相似文献
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《Ceramics International》2017,43(14):11132-11141
Dy3+ doped calcium bismuth borate glasses were synthesized in the composition range of xLiCl-(30 − x)CaO-20Bi2O3-50B2O3 + 1 mol% Dy2O3 (x = 0, 2, 5, 7, 10 and 15 mol%, LC0, LC2, LC5, LC7, LC10 and LC15 respectively) using conventional melt-quench technique. Broad XRD profiles confirmed non-crystalline nature of synthesized compositions. The compositional dependencies of structural changes (using FTIR spectra), thermal behavior (using DSC thermographs) and optical band gap (using UV–Vis–NIR spectra) were discussed. Photoluminescence (PL) excitation spectra recorded at 577 nm yielded six different excitation peaks belonging to Dy3+ ions. The PL emission spectra recorded at 451 nm were analyzed to extract different light emission parameters viz. Y/B ratio, color coordinates, correlated color temperature (CCT) following CIE 1931 chromaticity diagram. The emission colors were found to lie in white light region and lies very close to standard white light emission. The CCT of sample LC10 (5335 K) is closest to CCT of standard white light (5615 K) which depicted the optimized concentration of LiCl for application of these glasses in WLED application. 相似文献
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《Inorganic chemistry communications》2008,11(11):1409-1411
The self-assembly of nicotinic acid and sodium oxalate with mixed 3d–4f metal salts under hydrothermal conditions gave three isostructural 3D 3d–4f coordination polymers, [LnCu(nic)2(ox)] · xH2O [Ln = La, x = 1 (1); Ln = Eu, x = 2 (2); Ln = Gd, x = 2 (3)] [ox = oxalate, nic = nicotinate]. All three structures exhibit same unusual 3D microporous heterometallic coordination frameworks that are built up by rare tetranuclear Ln2Cu2 clusters and mixed ox and nic linkers. Furthermore, the luminescent property of complex 2 has also been investigated. 相似文献
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H3BO3–NaCl–MgCl2–H2O体系相平衡及工艺分析 总被引:1,自引:0,他引:1
测定了25, 100℃下H3BO3–NaCl–MgCl2–H2O体系的溶解度数据,并依据绘制的相图对我国西藏含钠镁的硼矿资源采用盐酸分解法制备硼酸的生产工艺进行了讨论. 相似文献
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3D打印技术是以计算机数学模型为基础,开展的多种材料可黏合打印技术,主要通过二维平面的逐层打印,完成三维物体的增材制造。在全球3D打印技术快速发展情况下,3D打印技术成熟度、准确性与适用范围随着资金投入及技术研发而不断优化,3D打印成本也不断下降。主要探讨了3D打印的技术现状,以及3D打印中涉及的关键技术,并对3D打印实现原理进行论述与探讨。 相似文献
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以苯并三氮唑和2–氯–3–硝基–吡啶为原料,合成出1–(3–硝基–2–吡啶)–1H–苯并三唑。采用元素分析、核磁共振光谱等手段鉴定了目标产物结构,并用DSC测定了产物的熔点。考察了反应溶剂、溶剂用量、缚酸剂种类、缚酸剂用量对该反应收率和产品纯度的影响。确定的最佳工艺条件为:以工业乙醇为反应溶剂,溶剂与反应物的原料比为200 mL∶0.1 mol,Na2CO3为反应缚酸剂,缚酸剂与苯并三氮唑的摩尔比为1∶1,反应时间为12 h。 相似文献
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Jaeyeop Chung Hiroyuki Inoue Kohei Yoshimoto Atsunobu Masuno Yasuhiro Watanabe 《Journal of the American Ceramic Society》2021,104(8):3963-3972
Oxyfluoride glasses of xLaF3–(60 − x)LaO3/2–40NbO5/2 (x = 0, 5, 10, 35) and xLaF3–(60 − x)LaO3/2–30NbO5/2–10AlO3/2 (x = 0, 10, 20, 30) were prepared using a levitation technique. Both the glass-transition temperature, Tg, and onset crystallization temperature, Tc, were lowered by substituting a part of the oxygen with fluorine in the glasses. An appropriate amount of fluorine maximized the difference between the temperatures, ΔT (= Tc − Tg), indicating the improvement in the glass-forming ability. The atomic packing densities of the glasses were approximately 60%, which gradually increased with the fluorine content. The absorption edge of the glasses shifted toward the shorter wavelength region in the ultraviolet spectra and toward the longer region in the infrared spectra by fluorine substitution. In addition, in one of the oxyfluoride glasses, a wide transparency from 307 nm to 9.2 µm was realized. Furthermore, the glass exhibited superior optical properties, with a combination of a high refractive index, nd, of 2.020 and low wavelength dispersion, vd, of 30.1. The effect of fluorine substitution on the nd and its vd was analyzed using the Lorentz–Lorenz dispersion formula. 相似文献
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Xiao-Ming Lin Yin Ying Li Chen Hua-Cai Fang Zheng-Yuan Zhou Qing-Guang Zhan Yue-Peng Cai 《Inorganic chemistry communications》2009,12(4):316-320
Three 4d–4f heterometallic polymers, Ln2Ag2(Hpydc)2(pydc)2(ox) · 4H2O (Ln = Nd (1), Eu (2) and Er (3); H2Pydc = pyridine-3,5-dicarboxylic acid, H2ox = oxalic acid), have been successfully synthesized under hydrothermal condition and structurally characterized. Single-crystal X-ray diffraction analyses reveal that three compounds are isomorphous and exhibit 3D pillar-layered coordination frameworks constructed from two-dimensional lanthanide-carboxylate layers and [Ag(pydc)]? pillars. Furthermore, the luminescent property of compound 2 was studied. 相似文献
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《Journal of the European Ceramic Society》2003,23(5):721-728
The pyroelectric, dielectric and DC resistive properties of Sb and Cr-doped ceramics with a base composition of Pb(Mg1/3Nb2/3)0.025(Zr0.825Ti0.175)0.975O3 have been studied. Sb doping has been shown to produce a linear reduction in Curie temperature (TC=−22z+294 °C) with concentration (z) and to give an increase in pyroelectric coefficient from 250 to 310 μCm−2 K−1 for z increasing from 0 to 3 at.%. It also produces first a reduction and then an increase in both dielectric constant and loss, so that the 33 Hz pyroelectric figures of merit (FOM's) are as follows: FV peaks at 3.8×10−2 m2 C−1 and FD peaks at 1.2×10−5 Pa−1/2. The resistivity is increased substantially from 1.1×1011 to ca 6×1011 Ωm with 1 at.% Sb, thereafter changing little. The behaviour has been explained in terms of Sb acting as a donor ion, reducing oxygen vacancy concentrations up to 1 at.%, with conductivity dominated by hole hopping between traps (Ea=0.59±0.05 eV) that are not changed by the Sb doping. It is concluded that additions of higher levels of Sb do not produce electron-mediated hopping conduction. The Cr additions have no effect upon TC, but reduce dielectric constant and loss, pyroelectric coefficient and resistivity at doping levels up to 3 at.%. The FOM FV peaks at 3.6×10−2 m2 C−1 and FD at 1.9×10−5 Pa−1/2. The behaviour of the electrical resistivity as a function of dopant level is shown to produce a linear ln(σo) vs z−1/3 dependence (σo=DC conductivity), as would be expected for hole hopping conduction between Cr3+ sites, with an Ea=0.38±0.03 eV. 相似文献