CERAMICS INTERNATIONAL
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2025
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IF 5.6
Zelai Cheng,Xingyu Huo,Zhen Zhao,Feng Qiao,Xiuling Yang,Ying Chen,Mingshan Qu,Hua Su
This work presents a miniaturization strategy for ferrite circulators by enhancing the dielectric constant ε r of NiCuZn ferrites and LTCC technology. Highly polarizable Cu 2+ and Ti 4+ substitutions for Ni 2+ and Fe 3+ increase dielectric constant, while non-magnetic Ti 4+ reduces magnetocrystalline anisotropy and narrows ferromagnetic resonance linewidth ΔH , with Cu 2+ concurrently lowering sintering temperatures. In the Ni 0.42-x/2 Cu 0.18+x Zn 0.4 Ti x/2 Fe 1.98-x O 4-δ system, the x = 0.1 composition (sintered at 975 °C) achieves minimal ΔH (82 Oe), ε r ≈ 14.6, and 4π M s ≈ 4219 G, whereas x = 0.6 (sintered at 925 °C) balances ε r ≈ 20.8 with magnetic performance ( ΔH ≈167 Oe, 4π M s ≈ 2117 G), confirming LTCC compatibility. A heterostructured substrate fabricated by co-firing Ni 0.12 Cu 0.78 Zn 0.4 Ti 0.3 Fe 1.38 O 4-δ ferrite (x = 0.6) with a microwave dielectric (50 wt.% SrCu 0.95 Mn 0.05 Si 4 O 10 + 50 wt.% Sr 3 V 2 O 8 ) exhibits controlled interfacial diffusion. HFSS simulations demonstrate that the integrated circulator-filter achieves significant miniaturization with >30 dB harmonic suppression (14-24 GHz) while maintaining in-band performance (| S 21 | < 1 dB, | S 11 | and | S 12 | < -20 dB at 7-12 GHz). The validates high- ε r NiCuZn ferrites and LTCC composite substrates for compact multifunctional microwave components.
研究领域:
微波工程
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材料科学
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电磁学
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铁氧体技术
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集成电路设计
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陶瓷工艺
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
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IF 8.1
Almire Dolkun,Turghun Muhammad,Junxia Gao,Yuanyuan Chen,Yan Zhang,Defu Zhi,Shubiao Zhang
Accurate and real-time measurement of flavonoid concentration during the adsorption process is vital for understanding its adsorption mechanism. In this study, a new merging-zone flow injection analysis (FIA) method based on the NaNO 2 -AlCl 3 -NaOH colorimetric reaction was developed for automatic determination of flavonoid concentration in plant extracts and in adsorption solution during batch adsorption process. The method parameters were optimized using a univariate experimental design, and rutin standard solutions in the concentration range of 25–800 mg/L showed good linearity (R 2 = 0.9994) with the FIA signal. The sample throughput was 40 h -1 and the limit of detection was 4.888 mg/L. The adsorption kinetics, isotherms, and thermodynamics of flavonoids from Dracocephalum Moldavia onto HPD 300 resin were investigated at varying initial concentrations and temperatures. The pseudo-first-order kinetic model was found to be suitable at 25 and 35 ℃, while the pseudo-second-order model exhibited superior performance at 45 ℃. The Freundlich model was found to be appropriate for describing the adsorption isotherm. The thermodynamic parameters ΔG and ΔH were both negative, and ΔS was positive, indicating that the adsorption process of flavonoids onto the HPD 300 resin is spontaneous and exothermic. The FIA method can effectively decrease the errors arising from the big adsorption volume change in conventional method during the batch adsorption. The developed method enables rapid and online determination of total flavonoids, reducing both time and labor costs, suitable for routine measurements as well as online monitoring of adsorption processes.
研究领域:
分析化学
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药学
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植物化学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
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2019
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IF 3.771
Chao Lv,Ruiyang Wang,Jia Gao,Ning Ding,Shunni Dong,Jingjing Nie,Junting Xu,Binyang Du
Enhanced phase separation and inverse order-to-order phase transition with increasing temperature was observed for a series of poly (acrylic acid)- b -poly (propylene oxide)- b -poly (acrylic acid) triblock copolymers with various block lengths by temperature-variable synchrotron small-angle X-ray scattering (SAXS). This abnormal phase behavior was attributed to the change of hydrogen (H)-bonding interaction in block copolymers upon increasing temperature and theoretically explained from thermodynamic viewpoint. The temperature-dependent FTIR analysis revealed that increasing temperature led to the weakening of overall H-bonding interactions and the increase of free C O and C–O–C groups. The Flory-Huggins interaction parameter χ of PAA and PPO blocks was positive and increased with increasing temperature as determined from the SAXS profiles of disordered block copolymer. The thermodynamic calculation indicated that the increase of Δ H was larger than the decrease of – T Δ S with increasing temperature because of the relatively large value of χ , leading to the increase of overall Δ G mix and hence the enhanced phase separation at higher temperature.
研究领域:
高分子科学
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材料科学
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热力学
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物理化学
✓ 已验证
DOI
高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
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2016
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IF 3.13
Qiang Liu,Qinze Liu,Zining Ruan,Xiaoqing Chang,Jinshui Yao
A novel poly(catechol-diethylenetriamine-pphenylenediamine)(PCEA) adsorbent was synthesized in methanol, with chelating groups supplied by catechol and diethylenetriamine, which showed a strong removal performance and efficient adsorption toward Cu(II) ions in aqueous solution. The adsorbent was characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). Besides, factors such as adsorbent dosage, pH, initial ionic and metal concentrations, contact time, and temperature on the adsorption of Cu(II) were studied. The data revealed that the adsorption followed a pseudo-second order kinetic model and the adsorption rate was influenced by the intra-particle diffusion. Furthermore, the adsorption process followed the Langmuir isotherm model, and the maximum adsorption capacity ( Q m ) was 44.2 mg/g at 298 K in simulated wastewater. The value of Δ G (kJ/mol) and Δ H (kJ/mol) also demonstrated that the adsorption process was spontaneous and endothermic. Studies revealed that PCEA particles were powerful and stable for the removal of Cu(II) in water, and it could be directly applied to the Cu(II)-contaminated water.
研究领域:
环境科学
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材料科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）