IONICS
·
2022
·Vol. 28
·期 11
·4977-4987
·
IF 2.961
Shi Chonghua,Fu Hang,Nie Jiajin,Yao Shaowei
Bismuth-based material as a stable anode material for lithium-ion battery, which has the advantages of stable operating voltage and large volume energy density. In order to make the most of the theoretical specific capacity of 386 mAh g −1 bismuth-based materials, the carbon coating method will be used to obtain stable specific capacity. However, electrostatic spinning is great method of carbon coated precursor preparation. Here, the BiCl 3 reagent is added into the PAN-DMF spinning liquid to synthesize the fibrous Bi@C composites precursor, and the Bi@C fibre is obtained after heat treatment. Then the Bi@C fibres with different BiCl 3 content are used as anode materials for lithium-ion batteries to test the electrochemical performance of Bi@C. The results show that Bi@C fibre electrode can maintain the discharge capacity of 415.3 mAh g −1 at the current density of 100 mA g −1 for 100 cycles when the content of BiCl 3 is 1.5 g. When the current density is 500 mA g −1 , the specific capacity can still reach 415.7 mAh g −1 after 250 cycles and shows excellent electrochemical performance.
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DOI
高影响因子
Science China-Materials
·
2019
·Vol. 62
·期 6
·864-872
·
IF 5.636
Liu Shiyu,Yu Yao,Liu Lin,Wu Yue
When a liquid is supercooled, its structural equilibration time τ eq increases sharply approaching the glass transition temperature T g , below which it is kinetically arrested in the out of equilibrium glassy state. Upon annealing below T g , such glassy state relaxes toward the equilibrium state. There is growing evidence that such relaxation process is quite complex, influenced by the complexity of the potential energy landscape. Here we report the observation of a hierarchical aging pathway in the process of the glass-to-supercooled liquid transition in various molecular glass forming systems. Differential scanning calorimetry reveals that the glassy state upon annealing below T g firstly enters a transient metastable supercooled liquid state with slightly higher enthalpies than that of the equilibrium supercooled liquid state when extrapolated to below T g . This observation is also confirmed by structural measurements via Raman scattering. The dynamics of the transient metastable-to-stable supercooled liquid transition exhibits characteristics of thermodynamic transition at spinodal temperature T sp slightly above T g , leading to anomalous behaviors such as the appearance of a transition-like behavior in the plot of fragility measurements. These observations imply that the free energy landscape of the supercooled liquid develops complexity with qualitative changes approaching T g and could have strong influence on the process of the glass transition.
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DOI
高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2017
·Vol. 123
·期 3
·189
·
IF 1.455
Lin Yibing,Lin Yu,Wu Jihuai,Zhang Xiaolong,Fang Biaopeng
The composite photoanodes based on the ZnO/SnO 2 hierarchical structures with high photoelectricity properties have been successfully synthesized, and used in the CdS and CdSe quantum dots co-sensitized solar cells (QDSSCs). In this experiment, the ZnO/SnO 2 nanoparticles (ZS-NP) and hierarchical nanosheets-based microflowers (ZS-MF) were prepared by the one-step hydrothermal route and the morphologies of the products were controlled by the solvent variation. An improved power conversion efficiency of 4.98% was achieved for the cell based on the ZS-MF composite photoanodes, which showed an increase of 21.8% compared to the ZS-NP photoanodes (4.09%). This result is mainly connected to the unique superiority of the three-dimensional hierarchical microflower nanostructures for light scattering and quantum dots loading, which is responsible for the increase of photocurrent values and eventual PCE.
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2015
·Vol. 26
·期 12
·10201-10206
·
IF 1.569
Li Guanghao,Chen Jingjing,Mao Zhiyong,Song Weiwei,Sun Tao,Wang Dajian
In this work, red-emitting nitride phosphor, CaAlSiN 3 :Eu 2+ , was synthesized successfully by carbothermal method using CaH 2 , AlN, Si 3 N 4 , Eu 2 O 3 and graphite powder under the condition of atmospheric pressure with a moderate temperature of 1550 °C for 6 h. In particular, graphite powder was employed as efficient and robust reducing agent in an optimal C/O mol ratio of 0.86. The obtained CaAlSiN 3 :Eu 2+ phosphors were well crystallized and showed an intense red emission band with peaks in the range of 642–675 nm dependent on the Eu 2+ doping concentration. Excellent thermal stability for as-synthesized Ca 1−x AlSiN 3 :xEu 2+ (x = 0.02–0.10) phosphors with absolute quantum efficiency about 20 % were demonstrated. These results presented here indicated the promising prospect for this economic and facile carbothermal synthesis route in preparing CaAlSiN 3 :Eu 2+ phosphors , and the phosphors are highly promising candidates for warm white LEDs.
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DOI
高影响因子
Science China-Materials
·
2021
·Vol. 64
·期 12
·3069-3078
·
IF 8.273
Liu Xin,Zhang Qin,Jia Fei,Gao Guanghui
Wet-resistant flexible electronics have acquired increasing attention on applications in wet environments, such as sweaty skin, rainy weather, biological fluids, and underwater. However, it remains challenging to achieve non-swelling and underwater self-healing hydrogel sensors for the mechanical perception in aqueous solutions. Herein, a self-healing and non-swellable hydrogel is successfully fabricated, which presents an automatically healing behavior in various aquatic environments, including deionized water, seawater, sweat, alkali and acidic aqueous solutions. Moreover, the hydrogel demonstrates high stretchability and stable electromechanical sensing properties in water. Furthermore, an electronic skin is designed with the features of fast responsiveness, reliability, and high sensitivity for detecting breathing, speaking, coughing, and diverse body movements. The self-healing hydrogel sensors enable a brilliant mechanical sensibility for detecting a series of dynamic stimuli in air and underwater, even after the healing of fracture interface in water. The underwater self-healing and anti-swelling hydrogel would provide enticing potential on various stable electronic devices for aquatic environments, such as implantable electrodes, triboelectric nanogenerators, and underwater soft robotics.
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DOI
高影响因子
International Journal of Minerals Metallurgy and Materials
·
2025
·Vol. 32
·期 10
·2456-2468
·
IF 7.2
Chang Rende,Ding Chengyi,Jiang Feng,Long Hongming,Lü Xuewei,Chun Tiejun,Xu Xiaoqing,Yan Zhiming,Sun Yue,Lü Wei
With the gradual reduction in high-quality iron ore resources, the global steel industry faces long-term challenges. For example, the continuous increase in the Al 2 O 3 content of iron ore has led to a decrease in the metallurgical performance of sinter and fluctuations in slag properties. Considering calcium ferrite (CF) and composite CF (silico-ferrite of calcium and aluminum, SFCA) play a crucial role as a binding phase in high-alkalinity sinter and exhibit excellent physical strength and metallurgical performance, we propose incorporating excess Al 2 O 3 into SFCA to form a new binding phase with excellent properties for high-quality sinter preparation. In the synthesis of high-Al 2 O 3 SFCA, two high-Al 2 O 3 phases were identified as types A (Al 1.2 Ca 2.8 Fe 8.7 O 20 Si 0.8 ) and B (Ca 4 Al 4.18 Fe 1.82 Si 6 O 26 ). Results show that type A SFCA sample had a higher cell density (4.13 g/cm 3 ) and longer Fe–O bond length (2.2193 Å) than type B (3.46 g/cm 3 and 1.9415 Å), with a significantly greater lattice oxygen concentration (7.86% vs. 1.85%), which demonstrates advantages in strength and reducibility. Type A SFCA sample contained a lower proportion of silicates, was predominantly composed of SFCA, and exhibited minimal porosity. Melting point and viscosity simulation tests indicate that type A SFCA sample formed a liquid phase at 880°C with a viscosity range of 0–0.35 Pa·s, which is notably lower than that of type B SFCA sample (1220°C and 0–20 Pa·s). This finding suggests that type A SFCA sample has a low initial melting temperature and viscosity, which facilitates increasing liquid-phase generation and improving flow properties. Such a condition enhances the adhesion to surrounding ore particles. Compressive strength tests reveal that type A SFCA sample (36.83–42.48 MPa) considerably outperformed type B SFCA sample (5.98–12.79 MPa) and traditional sinter (5.02–13.68 MPa). In addition, at 900°C, type A SFCA sample achieved a final reducibility of 0.89, which surpassed that of type B SFCA sample (0.83). In summary, type A SFCA sample demonstrates superior structural, thermophysical, and metallurgical properties, which highlights its promising potential for industrial applications.
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DOI
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2011
·Vol. 110
·期 3
·1437-1442
·
IF 1.752
Lan X. Z.,Pei H. R.,Yan X.,Liu W. B.
Phase behavior of dodecane–tetradecane ( n -C 12 H 26 –C 14 H 30 , n -C 12 –C 14 ) binary system in bulk and confined in SBA-15 (pore diameters 8 nm; 15.9 nm) has been investigated by differential scanning calorimetry and transmission electron microscopy. The bulk system possesses some special phases relating to the rotator phase in normal alkanes. Dodecane–tetradecane mixtures confined in SBA-15 (8 nm) are a system miscible both in solid and liquid states with a phase diagram of a smooth curve. Dodecane–tetradecane system confined in SBA-15 (15.9 nm) exhibits not only solid–liquid (s–l) in all compositions but solid–solid transition in mole fractions of tetradecane 0.1–0.6, which forms a phase diagram of “loop line” shape. Melting temperatures of n -C 12 –C 14 /SBA-15 (8 nm) are lower than those of n -C 12 –C 14 /SBA-15 (15.9 nm) in all mole fractions. The evolution of the phase diagram of n -C 12 –C 14 confined in 8 nm, 15.9 nm pore sizes of SBA-15 and in bulk, respectively, shows a dramatic effect of confinement on phase behavior of normal alkane mixtures. The s–l phase boundary lines of n -C 12 –C 14 /SBA-15 (8, 15.9 nm) are fitted as \( T_{\text{m,r}}^{x} \) being [ \( xT_{{\text{m} ,r}}^{A} + \left( {1 - x} \right)T_{\text{m,r}}^{B} - D \) ], where D is a polynomial ∑ a
i
x
i , i = 1, 2,···, n ( A = C 14 , B = C 12 ).
研究领域:
物理化学
·
材料科学
·
纳米限域效应
·
热分析
·
软物质物理
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DOI
高影响因子
Journal of Food Measurement and Characterization
·
2020
·Vol. 14
·期 5
·2549-2558
·
IF 1.648
Hu Jun,Liu Yande,He Yong,Sun Xudong,Li Bin
Food safety has been an issue of common concern in today’s society. Excessive benzoic acid (BA) additives in wheat flour would pose a huge threat to human health. In this paper, terahertz (THz) time-domain spectroscopy was used to detect BA quantitatively, which is a preservative additive in flour. Samples were prepared by grinding, drying, weighing, mixing and performing successively according to the designed concentration gradient (concentration 0.04%, 0.08%, 0.1%, 0.2%, 0.4%, 0.5%, 1%, 1.5%, …, 10%), with the BA concentration ranging from 0.040% to 19.99%. Then the THz Spectra of wheat flour samples with different concentrations of BA were collected. After preprocessing the original terahertz spectra with multiple scattering correction and other methods, Competitive Adaptive Reweighted Sampling (CARS), Genetic Algorithm (GA), Principal Component Analysis (PCA) and Uninformative Variable Elimination (UVE) were used to select effective spectral bands, and then Partial Least Squares (PLS) and Least Square Support Vector Machine (LS-SVM) models were established respectively. It turned out that the absorption peak of BA was at 1.94 THz of terahertz absorption coefficient, which increased with the rise of BA concentration. The results also indicated that better modeling results could be obtained by using CARS method for variable selection. And the established CARS-PCA-LS-SVM model had the best prediction result by combining PCA with CARS, with the correlation coefficient of the prediction (R p ) of 0.9956 and Root Mean Square Error of Prediction (RMSEP) of 0.64%. Hence, it can be concluded that terahertz technology combined with LS-SVM model can well achieve the quantitative detection of BA concentration in flour. Although the model is not universal since samples size is not large enough, the research method provides a basis for the detection of BA additives in flour.
研究领域:
食品科学
·
分析化学
·
光谱学
·
食品安全
·
计算生物学
·
分子检测技术
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DOI
高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2023
·Vol. 129
·期 11
·758
·
IF 2.7
Hao Lifeng,Lin Liyu,Jiang Zewen,Zhou Yang,Fang Yujie
Inspired by the fact that nanostructured expandable graphite (denoted as EG), when functionalized with silicon (Si) and boron (B) elements, can significantly enhance thermal insulation performance and improve the strength of char residue layers, the study controllably synthesizes EG supported with boron acid (H 3 BO 3 ) or polyhedral oligomeric silsesquioxane (POSS), using polydopamine (PDA) as a bridging agent. The resulting composites possess specific particle sizes of 80–90 nm and 100–120 nm for H 3 BO 3 -PDA-EG and POSS-PDA-EG, respectively. By formulating ablative-resistant coatings incorporating these composites, significant improvements are achieved in the mechanical properties of the resulting ceramic layers formed during ablation compared to control formulation. The compressive strength of the char residue layer is 0.13 MPa for EG alone, 8.85 MPa for H 3 BO 3 -PDA-EG, and 12.86 MPa for POSS-PDA-EG. Additionally, it is observed that the back surface of the coating with POSS-PDA-EG is approximately 180 ℃, while the back surface of the coating with H 3 BO 3 -PDA-EG is approximately 300 ℃ in a thermal test by a FD-04D/E Wind Tunnel, and compared to the coating with H 3 BO 3 -PDA-EG, the coating with POSS-PDA-EG yields more uniformly expanded and dense residue, which indicated that the coating with POSS-PDA-EG is characterized by better heat insulation and heat-resistant parameters. This is attributed to the improved silicon-boron coordination effect facilitated by the presence of POSS-PDA-EG and boron oxide, promoting ceramization. The resulting graphitized carbon layer, formed through fusion with porous expanded graphite at high temperatures, effectively resists high heat flow erosion over an extended duration. This work introduces an effective approach for enhancing ablation resistance by synergistically catalyzing boric acid or POSS-modified EG with a PDA bridge. The initial decomposition temperature was increased from 189 to 223 ℃, the maximum decomposition temperature was increased from 282 to 287℃, and the residual weight was increased from 51.6 to 63.6%. This can be concluded that the mixture of epoxy resin with either H 3 BO 3 -PDA-EG or POSS-PDA-EG demonstrates outstanding thermal resistance. The utilization of these novel composites and the insights gained from their performance contribute to advancements in the field of ablation-resistant coatings.
研究领域:
材料科学
·
聚合物涂层
·
热防护系统
·
烧蚀材料
·
纳米复合材料
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DOI
高影响因子
Science China-Materials
·
2016
·Vol. 59
·期 5
·337-347
·
IF 0
Zhang Guoxin,Jin Xiuyan,Li Haoyuan,Wang Lin,Hu Cejun,Sun Xiaoming
The crumpled graphene (CrG) was fabricated by applying defluorination of polyvinylidenefluoride (PVDF) on highly curved surface of CaC 2 particle through bottom-up synthetic strategy. The limited reaction depth between PVDF and CaC 2 leads to the formation of CrG with thin layer (3−6 layer graphene) and reasonable high specific surface area (~324.8 m 2 g −1 ). CrG with N incorporation (N-CrG) was applied as electrode material for reducing oxygen (i.e., oxygen reduction reaction, ORR) in alkaline, showing close onset potential to that of Pt/C and better mass-diffusion behavior. Surprisingly, with increased mass loading of catalysts, N-CrG exhibits steady current increase while Pt/C shows clear current plateau. Meanwhile, the N-CrG sample reveals high cycling stability and tolerance to contaminant, demonstrating its high potential for practical applications. Additionally, the bottom-up synthetic pathway to CrG via polymer dehalogenation on solid alkaline may find more applications which require controlled morphology and thickness of deposited thin graphitic carbon layers.
研究领域:
材料科学
·
电化学
·
纳米材料
·
能量存储与转换
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DOI
CHEMICAL PAPERS
·
2018
·Vol. 72
·期 11
·2871-2877
·
IF 0.963
Wang Yazhen,Li Rifang,Jia Hongge,Yang Guoxing,Di Yutao,Xu Chenxi,Ma Liqun,Zhang Hui,Zhou Yongli,Zang Yu,Xu Shuangping,Sun Zhaoyang,Zu Liwu,Yue Chenge,Lan Tianyu
A novel peroxy group-containing silane coupling agent was synthesized and anchored on the surface of titanium dioxide nanoparticles (nano-TiO 2 ) to form an immobilized-initiator-modified nano-TiO 2 species. In this study, the kinetic parameters of the peroxy group-containing silane were tested and assessed using DSC. The pre-exponential factor ( A d ) was 8.973 × 10 8 and the activation energy ( E a ) was 80.736 kJ mol −1 . Moreover, the empirical Arrhenius equation was determined to be ln K d = − 80.736/ RT + ln(8.973 × 10 8 ). To obtain continuous polymers, acrylonitrile (AN) and methyl methacrylate (MMA) were polymerized using the novel peroxy group-containing silane and FeSO 4 as an initiator system. The number average molecular weights ( M n of PAN = 3×10 4 and M n of PMMA = 1.4 × 10 5 ) and polydispersity indexes (PDI of PAN = 2.76 and PDI of PMMA = 1.65) were determined by GPC. It was suggested that the redox initiation system can generate highly reactive species on the surfaces of inorganic nanoparticles. The nano-TiO 2 -grafted polymers were successfully obtained.
研究领域:
高分子化学
·
材料科学
·
纳米技术
·
表面改性
·
引发剂设计
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DOI
高影响因子
APPLIED PHYSICS B-LASERS AND OPTICS
·
2024
·Vol. 130
·期 3
·38
·
IF 2
Ran Qiu-Yue,Lian Yu-Long,Tang Yong,Hao Jian-Hong,Bai Yun-Feng
FIR temperature measurement based on thermally coupled levels of rare earth ions has been widely studied, but its sensitivity is limited by the thermal coupling levels’ spacing. In this letter, a transition from non-thermally coupled levels of Ho 3+ to thermally coupled levels is reported for the first time. It can effectively improve the sensitivity of temperature measurement based on thermal coupling levels. The Ho 3+ /Yb 3+ co-doped Y 2 O 3 millimeter crystals have been prepared by laser annealing. The fluorescence properties of laser-annealed Ho 3+ /Yb 3+ co-doped Y 2 O 3 millimeter crystals were investigated as a function of temperature. It was found that the I 667nm / I 549nm show non-thermal coupling below 453K, but changes to thermal coupling above 453K. The maximum relative sensitivity of I 667nm / I 549nm in thermal coupling is greater than the relative sensitivity of any known thermal coupling energy levels of Ho 3+ . It provides a new way to improve the sensitivity of thermally coupled FIR temperature measurement.
研究领域:
材料科学
·
光学传感
·
稀土掺杂
·
激光加工
·
温度测量
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DOI
高影响因子
危险品化学品经营许可证（带存储）