ACS Nano
·
2025
·
IF 16
Hengdong Ren,Chensi Zhou,Ka Wang,Ximing Zhang,Lei Feng,Wenqing Wei,Yuqing Sun,Yukang Liu,Jun Dai,Xiaobing Xu,Zhiyong Zhang,Xinglong Wu
Interface polarization (one of the slow polarizations) is considered the primary mechanism driving microwave absorption (MA), but limitations in material composition and microstructure design often lead to weak interfacial polarization relaxation. In this work, we developed an interesting heterostructure consisting of carbon nanotube-encapsulated α-Fe2O3 nanocolumns (CNTs@α-Fe2O3). The curvature effects of CNTs induce a built-in electric field between CNTs and α-Fe2O3 nanocolumns, facilitating effective interface polarization. Under microwave irradiation, electron accumulation at the interfaces, driven by the energy-level mismatch between the two materials, further strengthens interface polarization, leading to a highly efficient MA performance. This heterostructured material achieves a minimum reflection loss of −74.1 dB at a thickness of 1.8 mm and an effective absorption bandwidth (reflection loss ≤ −10 dB) of 5.2 GHz (11.9 ∼ 17.1 GHz) at a thickness of only 1.5 mm. X-ray photoelectron spectroscopy and Raman scattering show a distinct blueshift in the Fe 2p binding energy and the A1g mode energy (exclusively associated with Fe atom vibrations), suggesting substantial charge transfer and redistribution at the interface associated with enhanced interface polarization. This work provides insights into interface polarization through the strategic design of energy levels and materials.
研究领域:
材料科学
·
物理学
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产品关联
DOI
PubMed
高影响因子
Molecular Catalysis
·
2024
·
IF 3.9
Tao Lv,Kexin Wei,Ting Wang,Xiao Wang,Zuguang Liu
A carbon-based acid was prepared by the sulfonation of activated carbon derived from eucalyptus wood waste, a solid waste from wood processing, and characterized by SEM, BET, FT-IR, Raman, XRD and XPS. Due to activation by phosphoric acid and subsequent sulfonation, the resultant carbon-based solid acid can obtain a porous structure, medium surface area and abundant functional groups including sulfonic groups, carboxyl, hydroxyl and other oxygen-containing groups, which provides excellent mass transfer channels and sufficient reactive sites for catalytic reactions. So, the carbon-based solid acid showed excellent catalytic performance for converting α -pinene to camphene with a conversion of up to 99.8 % and a selectivity of 51.2 %, respectively. Quantum chemical theoretical calculations (electrostatic potential, Gibbs free enthalpy of intermediates, molecular size) are used to further analyze the catalytic mechanism of carbon-based solid acids. Theoretical analysis of the carbon positive ions and their energies as well as experimental results under electron-donating co-catalysts suggests that oxygen-containing functional groups on carbon-based solid acids play an important role in improving α- pinene adsorption onto catalyst as well as camphene selectivity. This work provides a promising approach for converting α -pinene to camphene catalyzed by carbon-based solid catalyst.
研究领域:
化学工程
·
催化科学
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产品关联
DOI
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2015
·
IF 6.409
Chan Song,Guan-Yao Wang,De-Ming Kong
This work investigated the interactions of α-Fe 2 O 3 nanoparticles (NPs) with different structural nucleic acids and their fluorescence quenching ability towards fluorophore-labelled nucleic acid probes . Different from bulk α-Fe 2 O 3 samples, nanoscale α-Fe 2 O 3 particles exhibit the unique properties of strong adsorption and fluorescence quenching to fluorophore-labelled single-stranded DNA (ssDNA) probes. Based on these findings, a facile fluorescence method was developed for versatile quantification of nucleic acids. The size scale of NPs makes a significant impact on this sensing platform. Better selectivity was given by bigger NP (50–100 nm)-based nucleic acid-sensing platform compared with smaller NP (30 nm)-based one. In the 50–100 nm α-Fe 2 O 3 NP-based sensing platform, single nucleotide mismatch or single base-pair mismatch can even be effectively discriminated. The targets of micro-RNA (miRNA), ssDNA and double-stranded DNA (dsDNA) are sensitively detected with detection limits of 0.8 nM, 1.1 nM and 0.64 nM ( S / N =3), respectively. Significantly, α-Fe 2 O 3 NPs possess different affinities towards ssDNA probes with different lengths, and can be used as a universal quencher for ssDNA probes labelled with different fluorescent dyes . On the basis of these properties, the pristine α-Fe 2 O 3 NPs hold the potential to be widely utilized in the development of novel biosensors with signal amplification or simultaneous multiple target detection strategies.
研究领域:
生物化学
·
分子生物学
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分析化学
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产品关联
DOI
PubMed
高影响因子
Energies
·
2017
·Vol. 10
·期 9
·1296
·
IF 2.262
Yizhi Yan,Haolin Tang,Fan Wu,Rui Wang,Mu Pan
A cocoon-like α-Fe2O3nanocomposite with a novel carbon-coated structure was synthesized via a simple one-step hydrothermal self-assembly method and employed as supercapacitor electrode material. It was observed from electrochemical measurements that the obtained α-Fe2O3@C electrode showed a good specific capacitance (406.9 Fg−1at 0.5 Ag−1) and excellent cycling stability, with 90.7% specific capacitance retained after 2000 cycles at high current density of 10 Ag−1. These impressive results, presented here, demonstrated that α-Fe2O3@C could be a promising alternative material for application in high energy density storage.Keywords:one-step;self-assembly;α-Fe2O3;carbon coating;supercapacitors
研究领域:
材料科学
·
电化学
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产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2021
·Vol. 32
·期 10
·13941-13947
·
IF 2.478
Liu Ying,Cao Bo,Zhang Xu,Luo Rong,Luo Chunhua,Lin Hechun,Peng Hui
Layered Co(OH) 2 has been regarded as a potential candidate for pseudocapacitor electrode material, but it is limited by its poor conductivity and low surface area. Herein, carbonated multi-walled carbon nanotubes (MWCNTs-COOH) were used to improve the conductivity of α-Co(OH) 2 nanocomposites. α-Co(OH) 2 nanoflowers were successfully grown and tangled with MWCNTs-COOH to form a randomly oriented network structure mediated by ammonia using water-methanol as co-solvent at room temperature. The capacitance performances of the obtained α-Co(OH) 2 @MWCNT-COOH composites were investigated to find that MWCNT-COOH improved the specific capacitance efficiently. Especially, in the presence of 20% in mole of MWCNT-COOH, the composite gave rise to the high specific capacitance of 1027 F/g at the current density of 2 A/g with good cycle stability, whose specific capacitance remained 78% of its original even after 5000 cycles at 30 A/g current. The large surface area and strengthening the conductivity of the composites lead to the improvement of efficiency in charge/discharge process.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2013
·
IF 2.072
Hongtao Guan,Jianbin Xie,Gang Chen,Yude Wang
One-dimensional α-MnO 2 nanorods were fabricated by using low-temperature water-bathing chemical precipitation method at 80 °C. The crystalline structures, morphological evolution process and microwave absorption properties were systematically investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and measurement of electromagnetic parameters. The results show that the morphological structures and electromagnetic properties have close relationship with the reaction time. With the prolonging of the treatment time, the as-synthesized products turn from microspheres constituted of tiny dendrites to nanorods with diameters of 20–30 nm and lengths up to 1–2 μm. The electromagnetic characterization shows that the dielectric constants and magnetic permeability values show decreasing trends with the increasing frequency, however, the dielectric and magnetic loss tangents all increase with frequency. The electromagnetic absorption properties of the products have close relationship with the morphologies and thicknesses of the samples. With a thickness of 3 mm, an absorbing peak value of −25 dB was achieved for the sample treated for 24 h. The microwave absorption properties of MnO 2 can be attributed mainly to interfacial polarization, space charge polarization and relaxation phenomena.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
FOOD CHEMISTRY
·
2017
·
IF 4.529
Jian-Qiang Zhao,Yan-Ming Wang,Yan-Long Yang,Ying Zeng,Li-Juan Mei,Yan-Ping Shi,Yan-Duo Tao
The young leaves and shoots of Sibiraea laevigata , known as “Liucha”, are used as tea by Tibetans to improve digestion after meals. Long-term consumption of “Liucha” will cause weight loss. In present work, we reported on the isolation and NMR and chemical analysis-based elucidation of seven new sorbitol O -caffeic acid ester derivatives named sorbitol esters A–G ( 1 – 7 ) and eighteen known phenolic compounds from S. laevigata . All of the isolates were evaluated for their antioxidant and α -glucosidase inhibitory activities. Among them sorbitol ester A ( 1 ), sorbitol ester D ( 4 ), sorbitol ester F ( 6 ), sorbitol ester G ( 7 ), isoferulic acid ( 15 ), methyl caffeate ( 18 ), trans - p -hydroxycinnamic acid ( 19 ), and kaempferol 3- O - β - d -(6″- E - p -coumaroyl)-glucopyranoside ( 25 ) showed more potent α -glucosidase inhibitory activity than the clinical drug acarbose.
研究领域:
植物化学
·
药理学
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食品科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2017
·
IF 3.181
Fa Xu,Dongyu Gu,Miao Wang,Lin Zhu,Tingting Chu,Yuna Cui,Jing Tian,Yi Wang,Yi Yang
The present study was performed to screen the α-amylase inhibitor in the essential oil from Cedrus deodara cones. For this purpose, a fast and efficient method based on GC–MS and molecular docking was established for identification chemical compositions and prediction their activity in the essential oil with the potential α-amylase inhibitory activity. A total of 28 compounds were identified from the essential oil through GC–MS, which were individually docked with α-amylase as the target through molecular docking. Longipinene with the lowest binding energy of −5.93 kcal/mol was completely enfolded in the active site of α-amylase, which indicated that longipinene possessed the potential α-amylase inhibitory activity. The experimental verification exhibited that longipinene with an IC 50 value of 34.47 ± 0.54 μg/mL, indicating that it is the active ingredient responsible for the activity of this essential oil. The result revealed that the present strategy can facilely screen the active compounds from the complex natural plant extract.
研究领域:
植物化学
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药理学
·
食品科学
✓ 已验证
产品关联
DOI
高影响因子
Foods
·
2023
·Vol. 12
·期 24
·4425
·
IF 5.2
Xiaosan Zhang,Guangrong Huang,Hua Liu,Wenwei Chen,Jing Zhao,Zhenbao Jia,Fei Tao
Inhibiting α-amylase can lower postprandial blood glucose levels and delay glucose absorption, offering an effective approach for the development of antidiabetic diets. In this study, an active constituent with inhibitory activity against α-amylase was isolated and purified by bioassay-guided fractionation fromCarya cathayensisSarg. peel (CCSP). The active constituent was identified by NMR and Q-Exactive Orbitrap Mass Spectrometry as 5-O-p-coumaroylquinic acid (5-CQA). 5-CQA possessed strong inhibitory activity against α-amylase, with an IC50 value of 69.39 µM. In addition, the results of the kinetic study indicated that 5-CQA was a potent, reversible, noncompetitive inhibitor against α-amylase. The findings indicate that 5-CQA derived from CCSP has potential as a novel inhibitor against α-amylase, which can help mitigate postprandial blood sugar spikes, making it suitable for inclusion in antidiabetic diets.Keywords:Carya cathayensisSarg. Peel;postprandial hyperglycemia;5-O-p-coumaroylquinic acid;α-amylase inhibitor
研究领域:
植物化学
·
代谢病学
·
食品科学
✓ 已验证
DOI
PubMed
高影响因子
ACS Applied Nano Materials
·
2021
·
IF 5.097
Xiaobo Zhu,Qingqing Yan,Yue Yu,Haichao Zhao,Qunji Xue,Liping Wang
Two-dimensional layered materials have attracted wide attention owing to their many desirable properties. In particular, its outstanding barrier properties can effectively improve the impermeability of organic polymer coatings. However, the barrier properties of the coating depend to a large extent on the dispersion and orientation of the nanosheets in the coating. Here, monoamine-capped poly(etheramine) is inserted into the synthesized α-zirconium phosphate (α-ZrP) to obtain water-dispersible nanosheets with regular shapes and controllable thicknesses. In addition, the effects of the orientation (random and parallel) of α-ZrP nanosheets on the permeability and corrosion resistance of waterborne epoxy coatings have been systematically studied, and the results are in good agreement with the theoretical model. Compared with the pure coating, the impedance of the coating with high aspect ratio nanosheets and the coating with high aspect ratio nanosheets arranged in parallel increased by 83.5 and 221.7 times, respectively, after immersion for 60 days. This provides a strategy and theoretical basis for the two-dimensional nanosheet to improve the long-term service of anticorrosion coatings.
研究领域:
材料科学
·
腐蚀与防护
✓ 已验证
DOI
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2015
·
IF 6.409
Juan Zhang,Ying Liu,Xiaonan Wang,Yangyang Chen,Genxi Li
An electrochemical method is established in this work for the assay of α-glucosidase activity and the inhibitor screening through one-step displacement reaction, which can be directly used in cell medium. The displacement reaction can be achieved via strong binding of 4-aminophenyl-α- d -glucopyranoside (pAPG)/magnetic nanoparticles (MNPs) to pyrene boric acid (PBA) immobilized on the surface of graphite electrode (GE), compared to that of dopamine (DA)/sliver nanoparticles (AgNPs). Since α-glucosidase can specifically catalyze MNPs/pAPG into MNPs/pAP which has no binding capacity with PBA, the activity of both isolated and membrane bound enzyme can be well evaluated by using this proposed method. Meanwhile, signal amplification can be accomplished via the immobilization of DA at the outer layer of AgNPs , and the accuracy can be strengthened through magnetic separation. Moreover, this method can also be utilized for inhibitor screening not only in the medium containing the enzyme but also in cell medium. With good precision and accuracy, it may be extended to other proteases and their inhibitors as well.
研究领域:
生物化学
·
医学检测
·
药物开发
✓ 已验证
DOI
PubMed
高影响因子
Molecular Catalysis
·
2024
·
IF 3.9
Fukun Li,Ronghe Yang,Jinhang Dai,Hanyue Deng,Junjun Shi,Wucheng Xie,Juanhua Kong,Tingwang Guo
Biomass upgrading, which supplies important biomaterials, chemicals and fuels, is considered as an efficient way to realize the goal of carbon neutralization. Recently, γ-valerolactone (GVL) has gained increasing attention due to its wide applications. In this work, a novel protocol of microwave-assisted cascade catalytic upgrading of α-angelicalactone (α-AL) to GVL over metal triflate using alcohol as the hydrogen donor was proposed. The yield of GVL production from α-AL upgrading is strongly influenced by the Lewis acid strength of the metal triflate and the reduction potential of the employed alcohol. Among all tests, Sc (OTf) 3 showed the best catalytic performance in isopropanol media, giving 96.4 % GVL yield and 100 % α-AL conversion at 433 K within 3.0 h. Meanwhile, kinetic study indicated transfer hydrogenation of isopropyl levulinate to isopropyl 4-hydroxyvalerate was the rate-limited step with the apparent activation energy of 94.5 kJ/mol. This Sc (OTf) 3 catalyst was highly stable and could be reused for five cycles by simple vacuum distillation. In a word, this work provides an alternative for GVL production from biomass upgrading.
研究领域:
生物质化学
·
催化科学
·
可再生资源
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）