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1.
The current study examined the efficacy of graded doses of c9,t11 and t10,c12 CLA isomers on body composition, energy expenditure, hepatic and serum lipid liver biomarkers in hamsters. Animals (n = 105) were randomized to seven treatments (control, 1, 2, 3% of c9,t11; 1, 2, 3% of t10,c12) for 28 days. After 28 days treatment, 1–3% of t10,c12 lowered (p < 0.05) body fat mass compared to the control group. The 1–3% t10,c12 and 3% c9,t11 fed groups showed higher (p < 0.05) lean mass compared to other groups. We observed unfavorable changes in plasma total cholesterol and non-HDL cholesterol
levels in animals fed with 3% t10,c12 CLA isomers. The 2%, 3% t10,c12 groups presented elevated (p < 0.05) ALT levels. The present data suggest that a diet enriched with more than 2% t10, c12 led to liver malfunction and poses unfavorable changes on plasma lipid profiles. The 1% t10,c12 CLA lowered (p < 0.05) body fat mass and increased (p < 0.05) lean body mass. The c9,t11 CLA has less potent actions than t10,c12 CLA. We conclude that the actions of CLA on energy and lipid metabolism are form and dose dependent in the hamster model. 相似文献
2.
Olivier Berdeaux Robert L. Wolff 《Journal of the American Oil Chemists' Society》1996,73(10):1323-1326
The fatty acids from the seed oils of three Conifer species (one Pinaceae,Pinus pinaster, and two Cupressaceae,Chamaecyparis lawsoniana andBiota orientalis) have been analyzed as their 4,4-dimethyloxazoline (DMOX) derivatives by gas-liquid chromatography coupled with mass spectrometry.
The structures of six Δ5-unsaturated polymethylene-interrupted fatty acids (Δ5-UPIFA) were established, confirming previous
studies in which they were identified by their equivalent chainlengths (ECL) and by comparison with related authentic standards.
These acids were:cis-5,cis-9 18∶2,cis-5,cis-9,cis-12 18∶3 (P. pinaster),cis-5,cis-9,cis-12,cis-15 18∶4 (C.lawsoniana),cis-5,cis-11 20∶2,cis-5,cis-11,cis-14 20∶3 (all species),cis-5,cis-11,cis-14,cis-17 20∶4 (B. orientalis) acids. In addition,cis-9 18∶1,cis-9,cis-12 18∶2 (all species) andcis-9,cis-12,cis-15 18∶3 (Cupressaceae) acids, together with their elongation products [cis-11 20∶1,cis-11,cis-14 20∶2 (all species) andcis-11,cis-14,cis-17 20∶3 (B. orientalis) acids] were also identified. In the mass spectra, DMOX derivatives of all Δ5-UPIFA showed an intense peak atm/z 153, which is a diagnostic ion of fatty acid derivatives with a Δ5-ethylenic bond. Other double bonds were localized by ion
pairs that differed by 12 atomic mass units. The present study fully justifies the use of ECL to identify Δ5-UPIFA in Conifer
seed oils, in which they are ordinary components. 相似文献
3.
Forty-seven saturated synthetic diacyl PA, PC, PE, PG, and PS and five unsaturated diacyl phospholipids (PL) underwent normal-
and reversed-phase (RP) HPLC with isocratic isopropanol/hexane/water (5∶4∶1) and methanol/chloroform/acetonitrile/water (79.5∶9∶8∶3.5)
mobile phases, respectively. For normal-phase HPLC, capacity factors (k′
i
) decrease with chain length (n) of the two identical PL FA residues, whereas the opposite occurs with RP (C18)-HPLC. Plots of In k′
i
vs. n for individual PL classes are in general curved, violating the linear free-energy relationship. For PL of the same n but with different head groups, k′
i
with normal-phase HPLC varies as PE<PG<PA<PS<PC, except when n≥16, when the order is PE<PS≈PA≈PG<PC. For RP-HPLC, the order of k′
i
values is PG<_A≈PS≤PC≈PE until n≥16, when it is PA≈PG<PS≪PC≈PE. With normal-phase HPLC, k′
i
values of PL with unsaturated FA of n=18 are ordered as PE<PA<PC. Increasing degrees of unsaturation lead to increasing k′
i
. 相似文献
4.
Cai‐Xia Li Bin Yang Shan‐Tao Zhang Rui Zhang Ye Sun Hong‐Jun Zhang Wen‐Wu Cao 《Journal of the American Ceramic Society》2014,97(3):816-825
The structures, Curie temperature, dielectric relaxor behaviors, ferroelectricity, ferromagnetism, and magnetocapacitance of the (1?x)Ba0.70Ca0.30TiO3–xBiFeO3 [(1?x)BCT–xBF, x = 0–0.90] solid solutions have been systematically investigated. The ceramics have coexisted tetragonal (T) and orthorhombic (O) phases when x ≤ 0.06, coexisted pseudocubic (PC) and O phases when x = 0.065, coexisted cubic and O phases when 0.07 ≤ x ≤ 0.12, PC phase when 0.21 ≤ x ≤ 0.42, coexisted T and rhombohedral (R) phases when 0.52 ≤ x ≤ 0.70, and R phase when x ≥ 0.75. Significantly, composition‐dependent microstructures and Curie temperature are observed, the average grain size increases from 1.9 μm for x = 0, reaches 12.0 μm for x = 0.67, and then decreases to 1.3 μm for x = 0.90. At room temperature, the ceramics with x = 0.42–0.70 show piezoelectric properties and multiferroic behaviors, characterized by the polarization‐electric field, polarization current intensity–electric field, and magnetization–magnetic field curves, the composition with x = 0.67 has maximum polarization, remnant polarization, maximum magnetization, and remnant magnetization of 15.0 μC/cm2, 9.1 μC/cm2, 0.33 emu/g, and 0.14 emu/g, respectively. In addition, the magnetocapacitance is evidenced by the increased relative dielectric constant with increasing the applied magnetic field (H). With ΔH = 8 kOe, the composition with x = 0.67 shows the largest values of (εr(H) ? εr(0))/εr(0) = 2.96% at room temperature. The structure–property relationship is discussed intensively. 相似文献
5.
Chengcheng Ma Haitao Guo Yinsheng Xu Zhihao Wu Mingming Li Xiaomeng Jia Qiuhua Nie 《Journal of the American Ceramic Society》2019,102(11):6794-6801
In this work, Pr3+ ion-doped Ge20Ga15−xSbxSe65 (x = 0, 5, 10, in mol%), Ge20Sb15−yInySe65 (y = 5, 10, in mol%), Ge20Ga15−zInzSe65 (z = 0, 5, 10, in mol%), and Ge20Ga5Sb10Se60I5 glasses were prepared. The structural units, thermal properties, and optical properties of these glasses were analyzed. In addition, a comprehensive comparison study of the effects of metal ions (Sb, Ga, and In), S/Se ratio, and I content on the mid-infrared (MIR) luminescence of Pr3+ ions was conducted. Under a 1.55-μm laser pump, 0.2 mol% of Pr3+ ion-doped chalcogenide glasses performed strong photoluminescence in the wavelength range of 3.5-5.5 μm. Results indicated that the Sb-containing glass performed the strongest emission intensity among the studied glasses. Moreover, halogen element I can reduce the phonon energy of the matrix, which is beneficial to the luminescence of Pr3+ ions and provide significant possibilities for developing MIR lasers and amplifiers. 相似文献
6.
《Ceramics International》2022,48(4):4658-4664
Two garnet-structured Ca3MgBGe3O12 (B = Zr, Sn) ceramics with tetravalent cations at B-site were prepared by conventional solid state reaction. The crystal structure, microstructure evolution, and microwave dielectric performance were investigated using X-ray powder diffraction, Rietveld refinement, scanning electron microscopy, Raman spectroscopy, and infrared spectroscopy techniques. Dense Ca3MgZrGe3O12 and Ca3MgSnGe3O12 ceramics were obtained at sintering temperatures of 1420 and 1400 °C, respectively. The dielectric constant, unloaded quality factor, and temperature coefficient of resonance frequency of Ca3MgZrGe3O12 were 10.80 ± 0.2; 79,600 ± 1000 GHz (f = 12.61 GHz); and ?66.8 ± 1 ppm/°C, respectively, and the corresponding values for Ca3MgSnGe3O12 were 9.68 ± 0.2; 83,400 ± 1000 GHz (f = 14.19 GHz); and ?57.9 ± 1 ppm/°C, respectively. The dielectric performances of the two ceramics were compared by analyzing the ionic polarizability, packing fraction, and bond valence. The intrinsic dielectric properties were predicted by fitting the infrared reflectivity spectra. 相似文献
7.
Monika Wawrzkiewicz Zbigniew Hubicki 《Chemical engineering journal (Lausanne, Switzerland : 1996)》2009,150(2-3):509-515
The sorption of Tartrazine, Allura Red, Sunset Yellow and Indigo Carmine from aqueous solutions onto the strongly basic anion-exchanger (Lewatit MonoPlus M-600) of dimethylethanolamine functional groups and styrene–divinylbenzene matrix was investigated. The experimental data obtained at 50, 100, 200, 300 and 500 mg/dm3 initial concentrations at 20 °C were applied to the pseudo-first order, pseudo-second order and Weber–Morris kinetic models. The calculated sorption capacities (q1,cal) and the rate constant of the first-order adsorption (k1) were determined. The pseudo-second order kinetic constants (k2) and capacities (q2,cal) were calculated from the plots of t/qt vs. t, 1/qt vs. 1/t, 1/t vs. 1/qt, qt/t vs. qt and 1/q2 − qt vs. t for type 1, type 2, type 3, type 4 and type 5 of the pseudo-second order expression, respectively. 相似文献
8.
Bi substituted YCaZrVIG ferrites, Y2.3−xBixCa0.7Zr0.3V0.2Fe4.42O12 (x=0.1, 0.25, 0.4, 0.5, 0.75) ferrites were prepared by conventional oxide method. The addition of Bi2O3 promoted the sintering performance and lowered the sintering temperature from 1420–1230 °C. However, it also resulted in the formation of minor second phases and the decrease of grain size. With the increase of Bi concentration, the dielectric constant increases linearly and then remains unchanged. The dielectric loss decreased firstly and then increased. The saturation magnetization (4πMs) almost retained unchanged as the Bi concentration increased except for the sample with 0.75. The coercivity (Hc) decreased firstly and reached the minimum of 1.32 Oe at 0.25, and then rose when x>0.25, which was related to the facility of magnetic domain wall motion and magnetic moment reverse. Moderate addition of Bi also can increase the remanence (Br) by improving sintering process. Additionally, we got the optimum electromagnetic properties in the samples with x=0.25 at 1230 °C: RD>97%, εr=15.7, tan δe=2.48×10−4, Hc=1.32Oe, 4πMS=1663 Gs, Br=583.91 Gs. 相似文献
9.
Experimental data on the self‐diffusivities, Di,self, of a variety of gases (CH4, N2, Kr, C2H6, and C3H8) in three different zeolites, LTA, FAU, and MFI, show different dependences on the molar loading, qi. In LTA, Di,self appears to increase with qi for all molecules except N2. In FAU and in MFI the Di,self shows a sharp decrease with increasing qi. In order to gain insights into the causes behind the loading dependences, molecular dynamics (MD) simulations were carried out to determine the self‐diffusivities of seven gases (CH4, N2, Kr, C2H6, C3H8, Ar, and Ne) in six different all‐silica zeolite structures (MFI, AFI, FAU, CHA, DDR, and LTA). The simulation results show that the variation of Di,self with qi is determined by a variety of factors that include molecular size and shape, and degree of confinement within the zeolite. For one‐dimensional channels (AFI) and intersecting channel structures (MFI), the Di,self invariably decreases with increasing qi. For zeolite structures that consist of cages separated by windows (FAU, CHA, DDR, LTA), the size of the windows is an important determinant. When the windows are wide (FAU), the Di,self decreases with qi for all molecules. If the windows are narrow (CHA, DDR and LTA), the Di,self often exhibits a sharp increase with qi, reaches a maximum and reduces to near‐zero values at saturation. The sharpness with which Di,self increases with qi, is dictated by the degree of confinement at the window. Weakly confined molecules, such as Ne, do not exhibit an increase of Di,self with qi. 相似文献
10.
Li-Xiang Wu Lin-Lin Zhu Yang You Rui-Lin Lin Qing-Qing Liu Wei-Ming Guo Hua-Tay Lin Kevin Paul Plucknett 《Ceramics International》2021,47(1):935-942
Dense pressure-sintered reaction-bonded Si3N4 (PSRBSN) ceramics were obtained by a hot-press sintering method. Precursor Si powders were prepared with Eu2O3–MgO–Y2O3 sintering additive. The addition of Eu2O3–MgO–Y2O3 was shown to promote full nitridation of the Si powder. The nitrided Si3N4 particles had an equiaxial morphology, without whisker formation, after the Si powders doped with Eu2O3–MgO–Y2O3 were nitrided at 1400 °C for 2 h. After hot pressing, the relative density, Vickers hardness, flexural strength, and fracture toughness of the PSRBSN ceramics, with 5 wt% Eu2O3 doping, were 98.3 ± 0.2%, 17.8 ± 0.8 GPa, 697.0 ± 67.0 MPa, and 7.3 ± 0.3 MPa m1/2, respectively. The thermal conductivity was 73.6 ± 0.2 W m?1 K?1, significantly higher than the counterpart without Eu2O3 doping, or with ZrO2 doping by conventional methods. 相似文献
11.
La0.85DxSr0.15–xGa0.8Mg0.2O2.825 (D = Ba and Ca, x?=?0, 0.01, 0.03, 0.05, and 0.07) electrolytes were synthesized using a solid-state reaction method, calcined at 1400?°C for 5?h, and sintered at 1400?°C for 5?h. The microstructures, electrical properties, and cell performances of the electrolytes and fuel cells were analyzed by X-ray diffraction, scanning electron microscopy, impedance analysis, and electrochemical analysis. La0.85BaxSr0.15–xGa0.8Mg0.2O2.825 (LBSGM) and La0.85CaxSr0.15–xGa0.8Mg0.2O2.825 (LCSGM) exhibit a dense structure and a cubic perovskite phase. Further, they contain small amounts of a secondary phase. The lattice constants of LBSGM and LCSGM are 0.3913–0.3914?nm and 0.3906–0.3909?nm, respectively. The average grain size of the sample increases with increasing Ba2+ or Ca2+ content. The conductivity of LCSGM (0.197–0.174?S/cm) is usually higher than that of LBSGM (0.181–0.162?S/cm) at 800?°C. The cells with La0.85Sr0.15Ga0.8Mg0.2O2.825 and La0.85Ca0.03Sr0.12Ga0.8Mg0.2O2.825 electrolytes exhibit high open-circuit voltages and maximum power densities of 0.96?V and 542?mW/cm2 and 0.94?V and 567?mW/cm2, respectively, at 800?°C. 相似文献
12.
ZnBO-doped (Ba, Sr)TiO3 ceramics were investigated for low-temperature co-fired ceramics (LTCCs) applications. Until now, B2O3 and Li2CO3 dopants have been commonly employed as the low-temperature sintering aids. In this paper, we suggest ZnBO as an alternative dopant to the B2O3 and Li2CO3. To reduce the sintering temperature of (Ba, Sr)TiO3, we have added 1–5 wt.% of ZnBO to (Ba, Sr)TiO3. ZnBO-doped (Ba, Sr)TiO3 ceramics were respectively sintered from 750 to 1350 °C by 50 °C to confirm the sintering temperature with different dopant contents. By adding 5 wt.% of ZnBO to the (Ba, Sr)TiO3 ceramics, the sintering temperature of (Ba, Sr)TiO3 ceramics can be reduced to 1100 °C. From the XRD analysis, ZnBO-doped (Ba, Sr)TiO3 has no pyro phase. By adding ZnBO dopants to (Ba, Sr)TiO3 ceramics, both of relative dielectric permittivity and loss tangent were decreased. From the frequency dispersion of dielectric properties, the relative dielectric permittivity and loss tangent of 5 wt.% ZnBO-doped (Ba, Sr)TiO3 were 1180 and 3.3 × 10−3, while those of BST were 1585 and 4.8 × 10−3, respectively. 相似文献
13.
Simulation studies of the electronic structure, interatomic bonds, chemical composition, and atomic ordering in solid solutions Si6–x MgxO2x N8–2x of the β-Si3N4 – Mg – O system and solid solutions Si6–x MgxOxN8–2x Xx (X = S, Se) and Si6–x Mg x/2M x/2OxN8–x (M = C, Si, Ti, Ge, Zr, Sn, and Pb) are carried out using the strong-coupling energy-band method. Stabilization of solid solutions Si6–x MgxO2x N8–2x is accomplished in the presence of S, Se or Zr. In these solutions, Mg and O atoms are capable of forming quasi-unidimensional structures (dopant, or impurity, channels) similar to those predicted for β-sialons. 相似文献
14.
Yixiao Ren Fu-Zhi Dai Huimin Xiang Xiaohui Wang Luchao Sun Yanchun Zhou 《Journal of the American Ceramic Society》2020,103(10):5939-5951
Al5BO9 is a promising thermal sealing material for hypersonic vehicles due to its low density, theoretically predicted low shear modulus, and low thermal conductivity. However, experimental investigations on the mechanical and thermal properties of bulk Al5BO9 have not been carried out. Herein, we report the mechanical and thermal properties of bulk Al5BO9 prepared by spark plasma sintering of solid-state reaction synthesized Al5BO9 powders. The bulk (B), shear (G), and Young's (E) moduli are 148 GPa, 85 GPa, and 214 GPa, respectively, which are close to the theoretical values. The Pugh's ratio G/B is 0.574, indicating its intrinsic damage tolerance, which is also revealed by Hertzian contact test. The Vickers hardness (Hv) is 10.8 GPa, being lower than mullite. The flexural strength, compressive strength, and fracture toughness are, respectively, 277 ± 35 MPa, 814 ± 75 MPa, and 2.4 ± 0.3 MPa·m1/2, which are close to those of mullite. Al5BO9 has anisotropic coefficient of thermal expansion (CTE) in three crystallographic directions, ie αa = (4.40 ± 0.21) × 10−6 K−1, αb = (7.11 ± 0.18) × 10−6 K−1, αc = (6.70 ± 0.29) × 10−6 K−1 from Debye temperature to 1473 K, which are underpinned by its structural feature, ie lower αa is resulted from the edge-shared AlO6 octahedron chains along the [100] direction. The average CTE is (6.05 ± 0.06) × 10−6 K−1. The thermal conductivity declines with temperature as κ = 1336.39/T + 1.97, consisting with predicted trend from Slack's model. The low thermal conductivity and low density guarantee Al5BO9 a promising candidate as ceramic wafer in the seal structure for hypersonic vehicles. 相似文献
15.
Male Sprague-Dawley rats were fed a cholesterol-free (Exp. 1) or cholesterol-supplemented (Exp. 2) diet containing 20% casein
(control group) or 15% defatted squid and 5% casein (defatted squid group), as protein, for 14 d. Serum and hepatic cholesterol
concentrations were lower in rats fed defatted squid than in those fed casein in both cholesterol-free (−20%, P<0.05 and −15%, P<0.05, respectively) and cholesterol-supplemented (−25%, P<0.05 and −15%, P<0.05, respectively) diets. Hepatic triglyceride concentration was lower in the defatted squid than in the control groups
in both cholesterol-free (−51%, P<0.05) and cholesterol-supplemented diets (−38%, P<0.01). The activities of cytosolic fatty acid synthase and the NADPH-generating enzymes, malic enzyme and glucose-6-phosphate
dehydrogenase, in the liver were lower in the defatted squid than in the control groups in both cholesterol-free (−21%, P<0.01, −33%, P<0.05, and −33%, P<0.01, respectively) and cholesterol-supplemented diets (−34%, P<0.05, −57%, P<0.05, and −67%, P<0.05, respectively). The activity of mitochondrial carnitine palmitoyltransferase in the liver was comparable between the
control and defatted squid groups. The activity of Mg2+-dependent phosphatidate phosphohydrolase in the liver cytosol was lower in the defatted squid (−9%, P<0.05) than in the control groups only in the cholesterol-free diet. Fecal excretion of total steroids was stimulated by the
feeding of defatted squid in both cholesterol-free (+77%, P<0.005) and cholesterol-supplemented diets (+29%, P<0.01). These results suggest that the nonlipid fraction of squid exerts a hypocholesterolemic effect by increasing the excretion
of total steroids in feces. The fraction also induces a triglyceride-lowering activity in the liver by decreasing hepatic
lipogenesis. 相似文献
16.
Strong glass-ceramics (GCs) have been envisaged and widely researched for various applications, including large architectural panels, ballistic impact protection, bioactive medical implants, and odontological prostheses. Here, we report on the development and characterization of a novel hard, strong and tough enstatite-zirconia (MgSiO3-ZrO2) glass-ceramic derived from a 51SiO2–35MgO–6Na2O–4ZrO2–4TiO2 (mol%) glass. The best GC was developed by treating glass samples for nucleation at 700°C for 12 hours, followed by crystal growth at 1090°C for 3 minutes. It was characterized by X-ray fluorescence (XRF), differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HR-TEM), and contained plate-like enstatite, zirconia, and Ti-containing crystals. We investigated the nucleating ability of ZrO2 and TiO2 in inducing internal nucleation. In the early stage of crystallization, enstatite spherulites were observed, which were precipitated by heterogeneous nucleation on previously nucleated ZrO2 nano-crystals. At more advanced stages, at high temperatures, they transformed into plate-like crystals. The ball-on-three-balls strength, elastic modulus, and Vickers micro-hardness of the GC are 323 ± 26 MPa, 146 ± 13 GPa, and 6.9 ± 0.1 GPa (load = 5N), respectively. The indentation (KC), single-edge notched beam bending (KIC), and crack tip (Ktip) fracture toughness are 2.8 ± 0.6 MP.m0.5, 2.2 ± 0.3 MP.m0.5, 1.9 ± 0.3 MP.m0.5, respectively. The crack propagation profile after a controlled Vickers indentation was quite intricate. The enstatite and zirconia crystals enhanced crack deflection, bridging and branching, hindering crack propagation. According to the ISO 6872 for dental materials, the chemical solubility of our GC is 80 ± 5 μg/cm2. Due to this positive combination of high strength, toughness, hardness, and chemical durability, this new glass-ceramic is envisioned as a candidate for several applications and could be further developed for memory disc substrates, architectural cladding and tiles, ceramic glazes, and dental materials. 相似文献
17.
Résumé L'électrodissolution de sulfure de plomb obtenu par fusion ou par frittage, a été étudiée dans l'acide sulfamique par les méthodes cyclovoltammétrique, potentiocinétique et potentiostatique. Les paramètres examinés sont: la température, la vitesse de rotation de l'électrode, l'oxygène, le pH et la concentration de l'acide. L'identification par voie chimique, l'analyse par rayonsX et l'observation par la microscopie électronique à balayage ont permis de définir les produits de la polarisation anodique. Le comportement anodique de PbS en milieu sulfamique a été discuté et précisé davantage.
The electrodissolution of lead sulphide, prepared by fusion or by sintering in sulphamic acid, was studied by cyclic voltammetric, potentiodynamic and potentiostatic methods. The parameters examined were: temperature, rotation speed of the electrode, oxygen concentration, pH and the acid concentration. The chemical identification,X-ray analysis and scanning electron microscope observations permitted the definition of the anodic polarization products. The anodic behaviour of PbS in sulphamic medium was critically discussed and is explained in more detail.相似文献
18.
《Journal of the European Ceramic Society》2023,43(14):6098-6106
Herein, the sintering behavior, structural evolution, microstructure, and dielectric properties of Li2+xMgTiO4Fx (0 ≤ x ≤ 5) ceramics were investigated. At x ≤ 0.75, Li2+xMgTiO4Fx ceramics formed a continuous solid solution with a cubic rock salt structure. Subsequently, a composite ceramic of Li2+xMgTiO4Fx and LiF was formed. It was found that the maximum mass percentage of LiF required to fully form a solid solution was between 11% and 13%. The Li2.75MgTiO4F0.75 exhibited the best dielectric properties: εr = 16.52, Q × f = 123,574 GHz, and τf = −18.11 ppm/°C. The substitution of F- for O2- resulted in a lower sintering temperature of 875 °C, which slightly suppressed the volatilization of Li, and thus optimized the dielectric properties. The decrease in lattice vibration damping behavior and the increase in electron cloud density resulted in lower dielectric losses. The reduction in molecular polarization rate led to a reduction in εr, and the increase in bond energy optimized τf. Good chemical compatibility with Ag electrode was demonstrated, indicating that Li2+xMgTiO4Fx ceramics have unlimited potential for LTCC applications. 相似文献
19.
Shun Xu Xuping Lin Ben Ge Desheng Ai Jingtao Ma Zhijian Peng 《International Journal of Applied Ceramic Technology》2019,16(1):108-118
(100-x) wt.% La0.9Sr0.1 Ga0.8Mg0.2O2.85 - x wt.% Ce0.8Gd0.2O1.9 (x = 0, 5, 10, 20) electrolytes were prepared by solid-state reaction. The composition, microstructure, and electrical conductivity of the samples were investigated. At 300 ~ 600°C, the pure La0.9Sr0.1 Ga0.8Mg0.2O2.85 electrolyte has a higher conductivity compared to the composite electrolytes, but at 650 ~ 800°C the 95 wt.% La0.9Sr0.1 Ga0.8Mg0.2O2.85 - 5 wt.% Ce0.8Gd0.2O1.9 composite electrolyte presents the highest conductivity, reaching 0.035 S cm−1 at 800°C. The cell performances based on La0.9Sr0.1 Ga0.8Mg0.2O2.85-Ce0.8Gd0.2O1.9 electrolytes were measured using Sr2CoMoO6-La0.9Sr0.1 Ga0.8Mg0.2O2.85 as anode and Sr2Co0.9Mn0.1NbO6 -La0.9Sr0.1 Ga0.8Mg0.2O2.85 as cathode, respectively. At 800°C, the measured open-circuit voltages are higher than 1.08 V, and the maximum power density and current density of the fuel cell prepared with 95 wt.% La0.9Sr0.1 Ga0.8Mg0.2O2.85 - 5 wt.% Ce0.8Gd0.2O1.9 electrolyte reach 192 mW cm−2 and 720 mA cm−2, respectively. 相似文献
20.
《Ceramics International》2022,48(24):36802-36813
X-type samarium-cadmium co-substituted hexaferrite with compositions Ba2-xSmxCo2CdyFe28-yO46 (0.00 ≤ x ≤ 0.08, and 0 ≤ y ≤ 0.4) were prepared at 1340 °C using a simple heat treatment technique. All heated samples were characterized using FTIR, XRD, SEM, VSM, M?ssbauer, and low-frequency dielectric measurements. XRD analysis of prepared samples shows the formation of X as a major phase along with hematite. The MS value varied from 67.01 Am2/kg to 50.43 Am2/kg; whereas the Hc value changed from 2.95 kA/m to 6.17 kA/m, A high value of MS (67.01 Am2/kg) is observed in the pure sample, and a very low value of Hc (2.95 kA/m) is observed for x = 0.06, y = 0.3 compositions, but Mr/Ms < 0.5 confirm the multi-domain nature of prepared hexaferrites. Hysteresis loops of all samples are narrow, and confirmed that formed samples belong to magnetically soft. Mössbauer spectra of the three samples (S1, S3, and S5) show the existence of doublets. Significantly low values of coercivity, retentivity, and loss tangent in Sm–Cd substituted samples signified those prepared materials can be used to design electromagnets, transformer cores, electric motors, and maybe a potential candidate for lossless low-frequency applications. 相似文献