JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2018
·Vol. 29
·期 19
·17047-17053
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IF 2.324
Peng Sen,Zhao Chenglin,Huang Guohua,Wang Shaojie,Xu Jianming,Li Xingliang,Yu Shengquan
A novel Ca x Y 3−x Al 5−x Ti x O 12 (0 ≤ x ≤ 2.0) solid solution with garnet structure was synthesized by solid-state reaction technique. Ca 2+ and Ti 4+ substituted for Y 3+ and Al 3+ , respectively. Ca 2+ /Ti 4+ doping reduced the sintering temperature of Ca x Y 3−x Al 5−x Ti x O 12 ceramics to 1450 °C, and it also improved corresponding densification process. Meanwhile, the doping strongly influenced microwave dielectric properties. For the samples sintered at 1550 °C for 3 h, the dielectric constant (ε r ) increased from 7.2 to 34.7 by increasing Ca 2+ /Ti 4+ content, and at the same time the quality factor (Q × f) values increased from 12,000 to 45,200 GHz and then slightly declined to 41,000 GHz. The temperature coefficient of resonant frequency (τ f ) values of these samples increased monotonically from − 40 to + 31 ppm/°C by increasing Ca 2+ /Ti 4+ content. Therefore, Ca x Y 3−x Al 5−x Ti x O 12 solid solution ceramics with x = 1.5 sintered at 1550 °C for 3 h showed optimum microwave dielectric properties: ε r = 32.6, Q × f = 45,200 GHz and τ f = + 7 ppm/°C. Ca x Y 3−x Al 5−x Ti x O 12 (0 ≤ x ≤ 2.0) solid solution ceramics with garnet structure were new promising aluminate ceramics for microwave dielectric application.
研究领域:
材料科学
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电子工程
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产品关联
DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 104
·60025-60033
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IF 3.708
Juan Chen,Lihua Jia,Xiangfeng Guo,Lijun Xiang,Shengfeng Lou
A series of KF-modified Ca–Al hydrotalcite (xKF/HTL-M) solid base catalysts was prepared in methanol, and characterized by thermogravimetry analysis (TG-DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM) and carbon dioxide temperature-programmed desorption (CO2-TPD). The catalytic activity was investigated in the transesterification of ethylene glycol monomethyl ether (EGME) with methyl laurate (ML) to produce a novel biodiesel of ethylene glycol monomethyl ether monolaurate (EGMEML). The effect of the mass content of KF and the main reaction parameters such as EGME to ML molar ratio, amount of catalyst, reaction time and temperature on the yield of EGMEML were examined. The results indicate that a new phase of KCaF3 formed in xKF/HTL-M, and acted as the main active sites for the transesterification. In addition, xKF/HTL-M has excellent catalytic performance in the production of EGMEML. The highest yield of 97.7% was obtained over 24.7KF/HTL-M at EGME/ML molar ratio of 3.0, catalyst amount of 5 wt%, and reaction time of 4 h at 120 °C. Moreover, the catalyst displays a good stability and reutilization. A satisfactory yield of 90% was obtained after use for five consecutive cycles without significant deactivation. Finally, the activation energy (Ea) of the reaction of EGME with ML over 24.7KF/HTL-M was obtained as 27.11 kJ mol−1.
研究领域:
化学工程
·
催化材料
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DOI
高影响因子
Science China-Physics Mechanics & Astronomy
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2018
·Vol. 61
·期 9
·1-4
·
IF 2.754
Zhang Yue,Liu Wenhao,Si Jin,Zhu Xiyu,He Chengping,Zhao Haonan,Wen Hai-Hu
Superconductivity is observed in a new nontoxic cuprate system Ga-Ba-Ca-Cu-O, with T c = 82 K for GaBa 2 Ca 5 Cu 6 O 14 + δ ( 5 (Ga-1256) and T c = 116 K probably for GaBa 2 Ca 3 Cu 4 O 10+δ (Ga-1234) or GaBa 2 Ca 2 Cu 3 O 8+δ (Ga-1223), respectively. All compounds are fabricated by solid state reaction method under high pressure and high temperature. Samples are characterized by resistivity, magnetization and X-ray diffraction (XRD) measurements. The temperature dependence of magnetization measured in both zero-field-cooled and field-cooled processes on one sample (S1) shows two superconducting transitions at about 82 K and 113 K. The estimated shielding fraction for the phase with T c of 82 K is about 67%, while the fraction for another phase with T c of 113 K is quite small. The XRD Rietveld refinement for S1 indicates two main phases existing in the sample, Ga-1256 with fraction of about 58% and non-superconducting Ca 0.85 CuO 2 with fraction of about 42% respectively. Thus, we can conclude the superconducting phase with transition temperature of 82 K is due to Ga-1256. The resistivity measurement also confirms the superconductivity for S1, and the resistivity reaches zero at about 82 K. The temperature dependence of magnetization for another sample (S2) shows much higher superconducting shielding fraction for the phase with T c of 116 K, which may be a promising prospective for the synthesis of Ga-1234 or Ga-1223 phase.
研究领域:
凝聚态物理
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超导物理
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材料科学
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2020
·
IF 6.155
Shuaihang Qiu,Mingliang Li,Gang Shao,Hailong Wang,Jinpeng Zhu,Wen Liu,Bingbing Fan,Hongliang Xu,Hongxia Lu,Yanchun Zhou,Rui Zhang
A novel entropy-stabilized (ES) (Ca,Sr,Ba)ZrO 3 ceramic has been designed and synthesized by pressureless sintering of CaZrO 3 , SrZrO 3 and BaZrO 3 powders mixtures at 1450 °C, 1500 °C and 1550 °C for 3 h. X-ray diffraction, scanning electron microscopy and transmission electron microscopy analyses collectively indicate that a single solid solution is formed with a homogeneous distribution of metal elements after sintering at 1550 °C. The relative density and hardness of the ES (Ca,Sr,Ba)ZrO 3 ceramic sintered at 1550 °C are 97.79 % and 10.84 ± 0.33 GPa, respectively. This ES (Ca,Sr,Ba)ZrO 3 exhibits lower thermal conductivity from 373 K to 1073 K than their constituting zirconates , CaZrO 3 , SrZrO 3 and BaZrO 3 . Most importantly, the ES (Ca,Sr,Ba)ZrO 3 ceramic possesses good corrosion resistance to TiNi alloy melt and no distinct reaction layer exists between TiNi alloy and ES (Ca,Sr,Ba)ZrO 3 ceramic in the contact region. The combination of these properties indicates that ES (Ca,Sr,Ba)ZrO 3 ceramic is promising for use as a novel crucible material for the melting of titanium alloys .
研究领域:
材料科学
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陶瓷
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冶金学
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热工工程
✓ 已验证
DOI
高影响因子
PHYSICA B-CONDENSED MATTER
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2017
·
IF 1.405
Xiaoping Qi,Lihong Bao,Luomeng Chao,O. Tegus
Nanocrystalline Ca-doped CeB 6 powders have been synthesized via a solid-state reaction of CaO and CeO 2 with NaBH 4 under a vacuum condition. The Ca doping effects on phase composition, grain morphology and optical absorption properties of nanocrystalline CeB 6 were investigated. As a result, all the synthesized nanocrystalline hexaborides are composed by single phase of CsCl -type structure. The grain size and morphology are very sensitive to the reaction temperature. The optical absorption result indicates that the absorption valley of nanocrystalline CeB 6 shows a red-shift from 619 nm to 685 nm with increasing Ca doping content, which means the tunable optical absorption of nanocrystalline Ca-doped CeB 6 . In addition, a first-principles calculation has been used to reveal the origin of the tunable optical properties. It is found that Ca doping reduces the total kinetic energy of the electrons of CeB 6 and leads to the absorption valleys shift to longer wavelength direction.
研究领域:
材料科学
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光学
✓ 已验证
DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
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2021
·
IF 5.161
Jinhe Dou,Jing Wang,Yupeng Lu,Chuanzhong Chen,Huijun Yu,Robin Lok-Wang Ma
MAO/CS composite coatings were generated on Mg-1.75Zn-0.56Ca alloy surface for protection and improving biocompatibility of Mg -Zn- Ca alloy in the physiological environment. The microstructure, surface analysis and corrosion resistance of samples were evaluated by scanning electronic microcopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) in SBF solution. In addition, in vitro cell cytotoxicity test was performed by MTT tests. The findings of this work indicated that MAO/CS composite coatings were smooth and defect-free. The MAO/CS coatings retained a low degradation rate and the solution pH value at a moderate level (≤7.5) during immersion test. The corrosion resistance and cell proliferation were greatly enhanced by the composite coating. Furthermore, the different cell cytotoxicity on Mg alloy, MAO and MAO/CS coating was discussed.
研究领域:
生物材料
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医学工程
·
腐蚀科学
✓ 已验证
DOI
高影响因子
Biomaterials Advances
·
2026
·
IF 6.7
Han Wang,Zhenlin Fan,Jingdi Zhang,Lei Zhang,Xinyv Gao,Yingying Zhu,Wei Zhang,Wenjie Ren,Xiansong Wang
Novel dissolving microneedles transdermally deliver Ca-MOF-encapsulated collagenase. • Ca-MOF shields collagenase and releases Ca 2+ /gallic acid to scavenge ROS. • Synergistically degrades pathological collagen and inhibits myofibroblast activation. • Effectively reduces scar thickness and restores organized collagen in vivo. • Provides a painless, minimally invasive platform for clinical scar therapy. Hypertrophic scars resulting from pathological fibrosis and excessive collagen deposition cause significant functional and aesthetic impairment. Conventional therapies often fail to address the underlying molecular mechanisms of collagen overproduction. To overcome these limitations, we developed a novel layered dissolving microneedle system (MOF-CCH-MN) capable of delivering a synergistic therapeutic payload. This system incorporates Clostridium histolyticum collagenase (CCH) loaded within a calcium-based metal-organic framework (Ca-MOF), embedded in a γ-polyglutamic acid (γ-PGA) matrix. Characterization studies demonstrate that the microneedles possess a uniform pyramidal structure, penetrate the stratum corneum effectively, and dissolve within 25 min. Mechanistically, the Ca-MOF acts as a smart reservoir, protecting enzymatic activity while releasing Ca 2+ and gallic acid to scavenge reactive oxygen species(ROS) and inhibit fibroblast – to - myofibroblast transition. In vitro assays confirmed that the system significantly downregulates pro-inflammatory cytokines (TNF-α, IL-1β) and suppresses fibrogenic gene expression (α-SMA, COL1A1, TGF-β). In vivo evaluation in a rabbit ear hypertrophic scar model demonstrated that a 20-day treatment regimen with MOF-CCH-MN significantly reduced scar thickness and promoted the reorganization of collagen fibers. These findings establish MOF-CCH-MN as a safe, effective, and minimally invasive platform for clinical scar management. To address pathological fibrosis in hypertrophic scars, we developed a synergistic dissolving microneedle platform (MOF-CCH-MN) that integrates γ-PGA microneedles with a Ca-MOF reservoir encapsulating Clostridium histolyticum collagenase (CCH). This system functions through a coordinated three-stage mechanism: transdermal delivery via microneedles, sustained release of CCH for collagen degradation, and co-release of Ca 2+ /gallic acid to scavenge ROS and modulate inflammation. The platform overcomes key limitations of conventional therapies by ensuring efficient penetration and enzyme stability. Download: Download high-res image (206KB) Download: Download full-size image
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DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Xiaoshuai Zhang,Wen Xiong,Chengrun Liu,Zixuan Wang,Xiaoyan Yu,Xiaojie Li,Guodong Zhang,Panlai Li,Zhijun Wang
Exploring oxide-based deep red light-emitting phosphors is crucial for indoor plant lighting applications. In particular, designing Eu 2+ deep red emission in inorganic solids is challenging. In this paper, a cation substitution strategy was used to replace the Ca 2+ ions in the matrix with a certain concentration of Sr 2+ ions. A series of spectrally red-shifted Ca 1-x Sr x Sc 2 O 4 :Eu 2+ deep red phosphors were obtained under 460 nm light excitation. The substitution of Sr 2+ ions changes the local crystal field environment of Eu 2+ . The spectral shift from 656 nm to 702 nm was achieved by changing the centroid shift, the degree of polyhedral distortion and the lattice disorder. Combined with the need for practical applications, Ca 0.5 Sr 0.5 Sc 2 O 4 :0.01Eu 2+ phosphor and blue chip have been made into phosphor-converted light-emitting diodes for plant lighting, and the results of plant lighting experiments show that Ca 0.5 Sr 0.5 Sc 2 O 4 :0.01Eu 2+ phosphor has a certain application potential in plant lighting. In addition, this study will guide the exploration of new oxide-based deep red phosphors with Eu 2+ activation and for the realization of tunable emission through cation substitution.
研究领域:
材料科学
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光学工程
·
植物学
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产品关联
DOI
高影响因子
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
·
2025
·
IF 7.8
Daoqing Liu,Qing Wang,Biao Wei,Shaoxia Yang,Qianwei Li,Huazhang Zhao
Phosphates and organic matter usually coexist in secondary effluent, adversely affecting the stable control of water quality. Therefore, achieving the simultaneous removal of phosphates and organic matter from water bodies is significant. This study reports an excellent Fe₃Ce₁Oₓ(CA) functional material synthesized via a simple one-step co-precipitation method for hydroquinone (HQ) degradation through a Fenton-like reaction while simultaneously adsorbing phosphate. Experimental results show that the Fe₃Ce₁Oₓ(CA) materials exhibit a 92 % HQ degradation efficiency and an 80 % phosphate adsorption efficiency. Systematic characterization confirms that the Fe–Ce synergistic effect enhances the Fe(II) content, significantly promoting H₂O₂ activation. Electron paramagnetic resonance and radical scavenger experiments reveal that ¹O₂, O₂ • ⁻, and •OH play essential roles in organic degradation, with •OH being the dominant reactive species. Introducing citric acid increases the Ce(III) content in the Fe–Ce bimetallic oxide composite, enhancing its phosphate adsorption performance. This material successfully achieves both HQ degradation and phosphate removal, and these findings suggest that the Fe₃Ce₁Oₓ(CA)/H₂O₂ system can potentially treat wastewater with combined organic and phosphate pollution. This approach, which achieves multifunctionality in water treatment by regulating the composition of environmental functional materials, enhances the practical application potential of such materials.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
Sustainability
·
2025
·Vol. 17
·期 11
·5049
·
IF 3.3
Qi Wang,Guanghui Zhuo,Dongxin Xue,Guangcan Zhu,Chu-Ya Wang
Elevated phosphorus levels in aquatic ecosystems have been identified as a critical driver of eutrophication processes, necessitating resource-recovery remediation strategies. Adsorption techniques show particular promise for nutrient recovery due to their selective binding capacities and operational feasibility. In this study, the Mg- and Ca-modified biogas residue-based biochar (Ca-Mg/BC) was successfully prepared via a “bimetallic loading-pyrolysis” modification strategy. The optimum temperature for the calcination of the material and the salt solution impregnation concentrations were determined experimentally through optimization of the synthesis conditions. Structural and chemical analyses of Ca–Mg/BC demonstrated that the material contains MgO and CaO. The specific surface area of Ca–Mg/BC was 8.49 times higher than that of the unmodified biochar (BC). The optimized Ca–Mg/BC achieved 95% phosphate removal rate (157.13 mg/g adsorption capacity). FTIR and XPS characterization results indicated the importance of Ca/Mg loading in phosphate capture. MgO and CaO were mainly loaded on the surface of the material and adsorbed phosphate through a chemical reaction. Crucially, the phosphate-laden biochar exhibited potential as a nutrient-enriched soil amendment, opening the material loop from wastewater treatment to agricultural applications. This sustainable strategy simultaneously addresses water pollution control and sustainable development, providing environmentally benign solutions compatible with industrial effluent treatment and sustainable agriculture practices.
研究领域:
环境科学
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材料科学
·
农业资源利用
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DOI
高影响因子
Materials
·
2024
·Vol. 17
·期 24
·6159
·
IF 3.1
Qidong Liu,Hongmei Chen,Xiumei Wu,Junjie Yan,Biaobiao Yang,Chenying Shi,Yunping Li,Shu Yu
Silicon oxycarbide (SiOC), Ca- and Mg-modified silicon oxycarbide (SiCaOC and SiMgOC) were synthesized via sol–gel processing with subsequent pyrolysis in an inert gas atmosphere. The physicochemical structures of the materials were characterized by XRD, SEM, FTIR, and29Si MAS NMR. Biocompatibility and in vitro bioactivity were detected by MTT, cell adhesion assay, and simulated body fluid (SBF) immersion test. Mg and Ca were successfully doped into the network structure of SiOC, and the non-bridging oxygens (NBO) were formed. The hydroxycarbonate apatite (HCA) was formed on the modified SiOC surface after soaking in simulated body fluid (SBF) for 14 days, and the HCA generation rate of SiCaOC was higher than that of SiMgOC. Accompanying the increase of bioactivity, the network connectivity (NC) of the modified SiOC decreased from 6.05 of SiOC to 5.80 of SiCaOC and 5.60 of SiMgOC. However, structural characterization and biological experiments revealed the nonlinear relationship between the biological activity and NC of the modified SiOC materials.
研究领域:
材料科学
·
生物医学工程
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产品关联
DOI
PubMed
高影响因子
Polymers
·
2024
·Vol. 16
·期 24
·3454
·
IF 4.7
Yang Peng,Chuxuan Zhang,Xiaomin Li,Tianyi Feng,Xun Gong
Adsorption is one of the most promising strategies for heavy metal removal. For Hg(II) removal, mineralized Ca-based shell-type self-assembly beads (MCABs) using alginate as organic polymer template were synthesized in this work. The adsorbent preparation consists of gelation of a Ca-based spherical polymer template (CAB) and rate-controlled self-assembly mineralization in bicarbonate solution with various concentrations. The comparative study demonstrates that 1% (MCAB-1) is the optimal concentration of bicarbonate. Based on this condition, the maximum adsorption capacity (48 ± 4 mg/g) of MCAB-1 was observed at pH = 5 in a batch test, which was 2.67 times more than that of the unmodified one, CAB, at 18 ± 1 mg/g. Long-duration (10 h) adsorption tests showed that MCAB-1 exhibited remarkable performance stability and anti-wear ability (43.2% removal efficiency and 74.3% mass retention, compared to 2.7% and 38.6% for CAB at pH = 3, respectively). The morphology determination showed that a shell-type porous amorphous carbonate layer was formed at the surface of the organic polymer template by rate-controlled self-assembly mineralization. This transition not only promotes the pore structure and activated cation binding functional sites, but also improves the anti-wear ability of materials effectively.
研究领域:
环境科学
·
材料科学
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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）