INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
·
2020
·
IF 3.407
Longqing Chen,Wenbin Qiu,Hao Deng,Xiaoliang Yang,Yangyipeng Song,Jun Zhu,Jun Tang
The shrinkages presented in sintering process of tungsten alloys are extremely detrimental to their practical applications in fusion reactors. Positively in this work, we effectively reduced the shrinkages via synergistically applying Ti-doping and annealing process on tungsten‑potassium (WK) alloys. This shrinkage-fill effect only works in the one with trace amount of titanium doping, such as 0.05 wt%Ti or 0.5 wt%Ti. Due to such effect, the compressive strength was improved by ~18%. Based on morphological and elementary analyses, we speculated that the Ti-rich particles along the grain boundaries of WK alloys were activated and migrated into shrinkages during annealing. Further Ti doping (e.g. 1wt.%Ti) led to nanoscale grain refinement in WK alloys, which almost doubled the compressive strength. In this case, an unconventional grain-refinement model was proposed. Furthermore, anomalous grain growth was observed in WK-3wt.%Ti, which was attributed to the formation of Ti-rich regions and the corresponding raise of energy in grain boundaries. The fabricating strategies in this work may benefit the design of refractory tungsten alloys with less shrinkages and ultra-fine grains.
研究领域:
材料科学
·
核能工程
✓ 已验证
产品关联
DOI
高影响因子
SOLID STATE IONICS
·
2024
·
IF 3
Xunshuai Yan,Ying Li,Caihong Li,Hongqiang Wang,Tengda Wang,Yihan Ma,Shihui Zhang,Xu Zhang,Weiyan He
The problems of enhancing tap density and electrochemical performance of LiFePO 4 /C were studied when FePO 4 was prepared by in-situ polymerization-precipitation method and LiFePO 4 /C was prepared by carbothermal reduction method. The morphology of LiFePO 4 /C can be controlled by adjusting the preparation conditions of precursor FePO 4 . Spherical morphology of particles is beneficial to improve the tap density and high rate performance of LiFePO 4 /C. Although the high compactness of LiFePO 4 particles results in high tap density, high compactness of particles is not conducive to improving the electrochemical performance of the materials. Therefore, when improving the compactness of materials to increase their tap density, it is necessary to consider their negative impact on electrochemical performance. The influence of filling effects between different particles on improving the tap density was studied. With LiFePO 4 /C prepared by in-situ polymeration-coprecipitation method as the first principal particle size, and LiFePO 4 /C prepared by in-situ polymeration-hydrothermal method as the second principal particle size, when particle size and mass ratios conform to Hudon and Horsfield filling theory, small particles can fill the void formed by the accumulation of large particles. The tap density of LiFePO 4 is 1.3649 g cm −3 , and the specific capacity is 94.85 mA h g −1 at 5C.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Advanced Optical Materials
·
2024
·
IF 8
Peipei Ma,Jinhai Si,Lihe Yan,Jiayi Wu,Jin Xu,Xun Hou
In semiconductor-based microlasers, the generated excited carriers can affect both the optical absorption coefficient and refractive index, influencing the lasing behavior and device performance. In this study, the lasing behavior of individual MAPbBr 3 microrods pumped by femtosecond laser pulses is investigated using an ultrafast optical Kerr gating technique. By analyzing the spectral and temporal evolution of the lasing behavior, it is found that the band-filling (BF) effect can cause a significant change in the refractive index of the material, which results in an unfavorable red-shift and broadening of the resonant modes, deteriorating the laser linewidth and quality factor. The hot carrier cooling process can provide a buffer for alteration of the energy level occupation state, resulting in a small transient refractive index change and slight red-shift. These results offer insights into the lasing behavior driven by photogenerated carrier dynamics and provide an optimization strategy for semiconductor-based microlasers.
研究领域:
光学
·
材料科学
·
半导体物理
✓ 已验证
DOI
高影响因子
POLYMER
·
2025
·
IF 4.5
Shuai Li,Junliang He,Shitian Han,Fei Chen,Yuhang Zhang,Yang Chen,Huawei Zou
The free volume within an epoxy resin curing system is recognized as a critical determinant of its modulus. This study introduces a "hydrogen bond-driven rigid filling effect," achieved by incorporating rigid anchored groups of varying sizes into the epoxy resin system. These groups enhance network densification through conformational transitions and Π-Π stacking interactions, effectively reducing free volume while improving the glass transition temperature (T g ), mechanical properties, and thermal stability of the cured system. Notably, smaller benzene ring groups within the RAE complex system demonstrate greater efficacy in filling network voids. This study elucidates the role of rigid filling in epoxy resin networks, highlighting the enhancement of hydrogen bonding sites within attached groups. These findings present a novel approach for designing high-performance epoxy resin materials.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMISTRY OF MATERIALS
·
2016
·
IF 9.407
Jun Shao,Songwang Yang,Lei Lei,Qipeng Cao,Yu Yu,Yan Liu
Pore size and porosity of the porous materials play an important role in catalysis, dye-sensitized solar cells and mesoscopic perovskite solar cells (PSC), etc. Increasing pore size and porosity of mesoporous TiO2 is crucial for facilitating pore-filling of perovskite, charge extraction on TiO2/CH3NH3PbI3 interface and thus cell performance enhancement. Highly porous TiO2 films (TFs) with a large pore size that extends the limit of particle size have been achieved through a novel TiO2 paste using copolymer P123 as a pore-adjusting agent and 2-butoxyethyl acetate as a solvent. A highly porous structure with the pore size of 34.2 nm and porosity of 73.5% has been obtained, the porosity of which is the largest that has ever been reported in the screen-printed TiO2 thick films. The pore size and porosity of TFs can be successively adjusted in a certain range by tuning the P123 content in the pastes. As particle size and surface area of TFs are kept almost constant, the specific investigation on the effect of varied pore size on the performance of bilayer-structured PSCs becomes possible. The hysteresis phenomenon, the notorious problem of PSCs, is found to depend greatly on pore size and porosity of TFs, that is, pore-filling of perovskite. The suppressing effect of highly porous TFs on hysteresis by avoiding charges accumulation on the interface due to enhanced interfacial contact is proved by the invariable photocurrent response after prebias treatment. A hysteresis-free solar cell with an efficiency of 15.47% was achieved by depositing a 242 nm-thick perovskite capping layer upon 350 nm-thick TF with a pore size of 34.2 nm. This method developed for the preparation of highly porous TFs provides a new way to fabricate hysteresis-free PSCs and is widely applicable for the fabrication of other mesoporous metal oxide films with large pore sizes.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Hua Zhong,Guangju Zhu,Zhuozhuo Wang,Xiaochang Liu,Hua Zhang,Yanling Qiu,Daqiang Yin,Zhiliang Zhu
The decontamination of trace micropollutants from water environments is a widely concerned issue, and developing green and efficient adsorbent serves as an effective solution. In this study, using dual-activator modification method, an efficient hydrochar adsorbent was prepared through a two-step sequential process combining H 3 PO 4 hydrothermal treatment with K 2 CO 3 pyrolysis activation for carbamazepine (CBZ) adsorption removal. The results indicated that H 3 PO 4 facilitated the K 2 CO 3 activation process. The prepared hydrochar exhibited excellent adsorption properties due to its high specific surface area (1265.08 m 2 ·g −1 ) and aromatic porous mesh structure, with the maximum and dynamic adsorption capacity for CBZ of 376.11 and 296.98 mg·g −1 , respectively. The adsorption mechanism primarily involved pore-filling effects, π-π electron-donor–acceptor (EDA) interactions and hydrophobic interactions. Additionally, the obtained hydrochar material showed high adsorption efficiency for various pollutants and performed well in actual water samples. This study may provide theoretical and technical support for the development and application of high-efficiency hydrochar-based adsorbents.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
WATER AIR AND SOIL POLLUTION
·
2024
·Vol. 235
·期 2
·1-18
·
IF 3.8
Deng Yu,Chen Jingfan,Xiao Zhidan,Liu Jiaying,Zhang Jie,Zhu Bingqi,You Xiaotong,Ni Fuquan,Ao Tianqi,Tan Yanping
N self-doped porous biochars (KBCs) were synthesized through high-temperature carbonization and KHCO 3 activation using chicken feathers as biomass. Subsequently, it was employed for the remediation of tetracycline hydrochloride (TC)-contaminated water and soil. The properties of KBCs were analyzed by various characterization techniques. The results verified that KBC 800-2 exhibited outstanding specific surface area (1648.89 m 2 g −1 ) and pore volume (0.806 cm 3 g −1 ). The maximum adsorption capacity of KBC 800-2 for TC was 147.8 mg g −1 , which was superior to that of raw biochar (15.5 mg g −1 ). The results of pseudo-second-order and Freundlich indicated that the process was dominated by chemisorption. Moreover, the adsorption capacity of KBC 800-2 was stable over a wide pH range of 3–12 and high coexisting ionic strength. The consequences proved that the enhancement of pore filling effect and π-π electron interactions between TC and N self-doped adsorbent were the predominant driving forces to improve the adsorption efficiency of TC. Notably, compared to T50 (soil and 50 mg kg −1 TC), the properties of organic carbon, total nitrogen, and sucrase, urease, and catalase activities in TKBC 800-2 (soil, 50 mg kg −1 TC, and 2% KBC 800-2 ) were increased by 108.57%, 4.98%, 886.08%, 89.52%, and 78.08% respectively. KBC 800-2 as a low-cost and highly effective adsorbent for antibiotic pollution has enormous application potential. Graphical
研究领域:
环境科学
·
材料工程
·
化学工程
·
污染修复
·
吸附技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）