CERAMICS INTERNATIONAL
·
2017
·
IF 2.986
Zhiwu Jiang,Gaoming Zhu,Peizhong Feng,Farid Akhtar
Mo, Si and B 4 C powders were used to fabricate 0.4MoB-0.1SiC- x MoSi 2 composites by self-propagating high-temperature synthesis (SHS) and hot pressing (HP). The effects of MoSi 2 content ( x = 1, 0.75, 0.5 and 0.25) on phase composition, microstructure and properties of the composites were investigated. The results showed that the 0.4MoB-0.1SiC- x MoSi 2 composite exhibited Vickers hardness of 10.7–15.2 GPa, bending strength of 337–827 MPa and fracture toughness of 4.9–7.0 MPa m 1/2 . The fracture toughness increased with the increasing volume fraction of MoB and SiC particles which were promoted by the toughening mechanisms, such as crack bridging, cracks deflection and crack branching. Moreover, the electrical resistivity showed an increasing trend with decreasing volume fraction of MoSi 2 .
研究领域:
材料科学
·
复合材料
✓ 已验证
DOI
高影响因子
TREES-STRUCTURE AND FUNCTION
·
2021
·Vol. 36
·期 2
·711-721
·
IF 2.529
Xu Chenyi,Ma Yuandan,Tian Zhengfeng,Luo Qingyun,Zheng Tiefeng,Wang Bin,Zuo Zhaojiang
Key message The four chemotypes of adult C. camphora released different monoterpenes which protected these plants against high temperature by lowering ROS levels and maintaining photosynthetic abilities. Abstract High temperature seriously impacts plant growth and development, and terpenes are believed to improve plant thermotolerance through indoor experiments using seedlings. To uncover the actual protection effects of monoterpenes on outdoor adult plants, we investigated the monoterpene emissions, reactive oxygen species (ROS) metabolism, and photosynthetic abilities in four chemotypes of adult Cinnamomum camphora that were blocked monoterpene synthesis by fosmidomycin (Fos) under high temperature in summer (the mean highest temperature at about 38.2 °C). Eucalyptol (EuL), linalool (Lnl), borneol (BeL), and camphor (CmR) chemotypes of C. camphora released an abundance of monoterpenes, with eucalyptol, linalool, endo-borneol, and camphor as the typical monoterpene, respectively. When the four chemotypes of C. camphora were treated with Fos, their monoterpene emission was inhibited remarkably, with disappearance of some monoterpenes. In that case, the content of O 2 − , H 2 O 2 , and thiobarbituric acid reactive substance (TBARS) in the four chemotypes of C. camphora significantly increased although antioxidant enzyme activities remarkably increased, and the photosynthetic abilities significantly decreased by declining the quantum production and electron transport in photosystem II and increasing the dissipation of absorbed light energy. Among the four chemotypes, monoterpenes might play the maximum roles in CmR lowering ROS levels and in EuL maintaining photosynthesis. It can be speculated that monoterpenes can protect adult C. camphora against high temperature by lowering ROS levels and maintaining photosynthetic abilities.
研究领域:
植物生理学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Kaichen Wang,Tianying Zhang,Tieying Wang,Chao Xu,Feng Ye,Zhirong Liao
Metallic phase change materials (PCMs) have the advantages of large phase change latent heat, high heat storage density and broad application prospects in various high temperature industrial waste heat recovery and utilization. However, due to the strong corrosion of molten metal at high temperature, appropriate packaging technology is the prerequisite for the promotion and application of metallic PCMs. In this research, a high temperature PCM microencapsulating technology with SiCN shell and a new microencapsulation method was proposed. The high temperature microencapsulated phase change materials (MEPCMs) with the core–shell mass ratios of 5:1, 4:1 and 3:1 were prepared by “solvent evaporation-heating curing” method, using SiCN cured by organic polysilazane (OPSZ) as heat resistant shell material and Al-Si particles as core PCMs. The mechanisms of shell formation and coating of OPSZ were studied experimentally, as well as the material properties and thermal performance of MEPCMs. With the increase of temperature, OPSZ gradually formed a dense SiCN shell on the surface of Al-Si particles. The experimental results showed that MEPCMs with the core–shell mass ratio of 4:1 had a high phase change temperature (571.9 °C-573.7 °C) and good heat storage capability (281.2 J/g-282.9 J/g). SiCN shell was conducive to maintain a complete core–shell structure, and exhibited excellent thermal resistance and oxidation resistance to protect inner core materials during thermal cycles. Therefore, the prepared microcapsule was a potential heat storage material, which provided a new idea for developing microencapsulation method of high temperature PCMs.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
Minerals
·
2022
·Vol. 12
·期 8
·963
·
IF 2.818
Dongsheng Ren
Quartz is an important component of the Earth. In this study, experiments were conducted at temperatures between 600 to 700 °C, confining pressures between 1.5 and 1.8 GPa, and differential stress conditions. It was found that coesite production is closely related to differential stress, reaction time, and reaction temperature, with coesite formation being a multifactorial coupling process.Keywords:high temperature;high pressure;differential stress;coesite;phase transition
研究领域:
地质学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2022
·Vol. 12
·期 8
·926
·
IF 4.501
Chunling Wu,Linge Ma,Yufei Zhu,Xuqiang Guo,Yongli Wu,Zhen Wu,Xian Zhang,Lihua Hou
In this paper, the extraction residue of direct coal liquefaction residue-DCLR(ER)was used as raw material. The high-temperature reaction mechanism of Mo compound in DCLR(ER)was investigated using a synchronous thermal analyzer and the Factsage database. The high temperature reaction of DCLR(ER)-MoO3in an oxygen atmosphere consists of pyrolysis of organic components at 400–600 °C, molybdenum trioxide sublimation at 747–1200 °C, and a stable stage at 600–747 °C. The thermal reaction process of the DCLR(ER)-MoS2system in the oxygen atmosphere involves the pyrolysis of unreacted coal and asphaltene, the oxidation of molybdenum sulfide at 349–606/666 °C, the diffusion of MoO3at 606/666–85 °C, and the sublimation reaction process of MoO3at 854–1200 °C. The results show that the lower heating rate can promote the oxidation of the Mo compound and the sublimation of molybdenum trioxide. On the other hand, the oxides of aluminum, calcium, and iron in DCLR(ER)can inhibit the oxidative pyrolysis efficiency of the DCLR(ER)-MoS2system.Keywords:direct coal liquefaction residue;molybdenum;high temperature;reaction mechanism
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CORROSION SCIENCE
·
2022
·
IF 7.72
Jin Huang,Jian Zhang,Tingting Luo,Ruxia Liu,QinQin Wei,Guoqiang Luo,Qiang Shen
Corrosion test of Mo in LiF-LiCl-LiBr salt with different SO 4 2 content have been studied. MoO 2 , Mo 3 S 4 and MoS 2 was formed after corrosion. The SO 4 2- will corrode the grain boundary of Mo and lead to the decomposition of large Mo grain. Moreover, the formation of different corrosion products will lead to significant changes in volume and destroy the stable oxide layer which could be protective. The Mo will be severely corroded in LiF-LiCl-LiBr molten salt with a higher content of SO 4 2- .
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
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Weichao Wang,Gu Liu,Liuying Wang,Chaoqun Ge,Long Wang,Bin Wang,Jie Huang
The advancement of absorption materials and coating preparation technology is crucial to address the challenges posed by electromagnetic interference and pollution in high-temperature extreme environments. Here, by using a granulation and plasma spraying strategy, we successfully fabricated a series of La 0.8 Sr 0.2 MnO 3 /Al 2 O 3 –13%TiO 2 (LSMO/AT13) high-temperature microwave absorption coatings that have excellent dielectric properties and extremely thermal stability. The results showed that the LSMO/AT13 coatings exhibited remarkable oxidation resistance , withstanding high-temperature aerobic environments of up to 1000 °C. Based on the temperature-dependent permittivity of the coatings, the establishment process of polarization and the transformation of loss mechanism were observed and explained. With the increase of temperature, the main dielectric loss mechanism of the coatings transitions from polarization loss to conductive loss. Thanks to the coordinated effects of impedance and loss, the coatings are capable of effectively absorbing microwave over a wide temperature range. When the LSMO content was 30 wt% and the thickness was 1.9 mm, the effective bandwidth ranged from 1.7 GHz to 2.4 GHz at temperatures below 773 K. This study demonstrates the promising application of LSMO/AT13 microwave absorption coatings for ultra-high temperature environment, and provides a reference for the design and optimization of high-temperature microwave absorption coatings.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Storage
·
2025
·
IF 9.8
Meng Jia,Fan Zhang,Aimin Sha,Zhe Li,Wentong Wang,Wenxiu Jiao
Phase change materials (PCMs) hold promising potential for regulating asphalt pavement temperatures during the summer. To enhance the suitability of polyurethane-based solid–solid phase change materials (PUSSPCMs), this study focuses on optimizing their structure and performance. A series of PUSSPCMs were synthesized with varying soft-to-hard segment ratios and soft segment molecular weights. Their high-temperature leakage resistance, phase change behavior and thermal stability were systematically evaluated, to identify the optimal formulations. Subsequently, a SMA-13 phase change asphalt mixture incorporating a selected PUSSPCM was designed. The effect of the PUSSPCM, as a functional filler, on both the pavement and thermal properties of the mixture was evaluated. Results indicate that the PUSSPCM structure critically affects leakage resistance at elevated temperatures. Increasing the hard segment content significantly improves leakage resistance, enabling the PUSSPCM to maintain structural integrity during the high-temperature paving of phase change asphalt mixtures. A higher molecular weight of polyethylene glycol (PEG) requires a correspondingly higher proportion of hard segments for leakage prevention. An increase in PEG molecular weight or soft-to-hard segment ratio usually leads to elevated phase change temperature and enthalpy. Irrespective of the composition, PUSSPCMs can perform excellent volumetric, chemical, and phase transition stability during hot-mix asphalt construction. P8000–6 as a preferred PUSSPCM enhances high-temperature stability and low-temperature crack resistance, but reduces the moisture resistance of the asphalt mixture. The phase change asphalt mixture exhibits a reduced heating rate, maintaining a temperature difference of over 3 °C for up to 250 min, with a maximum difference of 3.7 °C. The addition of P8000–6 functional filler has minimal impact on the thermal conductivity of the asphalt mixture. However, it effectively moderates temperature fluctuations during heating by increasing the heat absorption capacity.
研究领域:
土木工程
·
材料科学
·
高分子科学
·
热工学
·
交通基础设施
✓ 已验证
产品关联
DOI
高影响因子
FEBS Open Bio
·
2020
·Vol. 10
·期 12
·2733-2739
·
IF 2.231
Sai-sai Ding,Jin-peng Zhu,Yang Wang,Bin Wu,Zongpei Zhao
In the paper industry, chlorine is often used to treat the pulp for bleaching. After pulping, a large amount of xylan is present in the fiber. Xylanase can be used to degrade xylan in an eco-friendly process called biobleaching, which can help minimize the usage of chlorine in the delignification process. However, a bottleneck in the adoption of biobleaching is the cost of xylanase and the requirement that xylanase be active and stable at extreme conditions. Here, we investigated whether using sodium alginate beads to immobilize an extracellular xylanase from Bacillus subtilis (Lucky9) can reduce the potential cost of enzyme usage. The optimal pH and the activity of the immobilized enzyme were increased at optimal temperature compared with the free enzyme. In addition, immobilized xylanase was shown to be more stable than free xylanase. The results of this study suggest that the immobilized xylanase has potential applications in the biobleaching industry.
研究领域:
生物技术
·
酶工程
·
制浆造纸工业
✓ 已验证
DOI
PubMed
高影响因子
Chinese Physics B
·
2022
·Vol. 31
·期 6
·066206
·
IF 1.652
Yao Wang,Dan Xu,Shan Gao,Qi Chen,Dayi Zhou,Xin Fan,Xin-Jian Li,Lijie Chang,Yuewen Zhang,Hongan Ma,Xiao-Peng Jia
Pyrite tailings are the main cause of acid mine wastewater. We propose an idea to more effectively use pyrite, and it is modified by exploiting the reducibility of metal represented by Al under high-pressure and high-temperature (HPHT) conditions. Upon increasing the Al addition, the conductivity of pyrite is effectively improved, which is nearly 734 times higher than that of unmodified pyrite at room temperature. First-principles calculations are used to determine the influence of a high pressure on the pyrite lattice. The high pressure increases the thermal stability of pyrite, reduces pyrite to high-conductivity Fe7S8 (pyrrhotite) by Al. Through hardness and density tests the influence of Al addition on the hardness and toughness of samples is explored. Finally we discuss the possibility of using other metal-reducing agents to improve the properties of pyrite.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
POLYMER
·
2024
·
IF 4.1
Qin Zhang,Guo-Rui Zhu,Xiang-Xin Xiao,Min Jiang,Feng-Ming He,Xin Li,De-Ming Guo,Hai-Bo Zhao,Ze-Yong Zhao,Li Chen,Bo-Wen Liu,Yu-Zhong Wang
With the increasing public awareness of safety and the ongoing global legislation on the use of flame retardants, the development of eco-friendly flame-retardant methods has become an urgent issue. In this study, we utilized the room-temperature hydrogen-bonding effect and the high-temperature rearrangement inherent in the functional hydroxyl-containing phenylimide structure to engineer a flame-retardant, high-performance aliphatic polyamide. Remarkably, the obtained polyamide copolymer was exclusively composed of the elemental constituents inherent to polyamide itself, i.e., carbon, hydrogen, oxygen, and nitrogen. As expected, the high-temperature rearrangement along with the corresponding char-forming and end-group-capturing effect significantly improved the flame retardancy of the copolymer, characterized by an UL-94 V-0 rating with great anti-dripping performance, 41% reduction in peak heat release rate and 50% reduction in total heat release. The room-temperature hydrogen bonding largely mitigated the deterioration of the chain symmetry and regularity caused by the incorporation of the monomer, thus resulting in substantial preservation of mechanical properties. Furthermore, the copolymer exhibited low dielectric properties and high heat resistance, thereby broadening its potential application domains. This work presented a novel flame-retardant-free strategy for achieving both flame retardancy and high performance in polymeric materials, meeting the increasingly stringent demands for environmental protection and safety.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Longfei Li,Yunguang Yin,Chenyu Mi,Youmei Wang,Yongshuai Xie,Luyi Zhu,Xinqiang Wang,Benxue Liu,Guanghui Zhang
In this paper, DyTaO 4 fiber membrane and fiber sponge were successfully prepared by electrospinning for the first time from new precursors of Dy and Ta. DyTaO 4 fibers were crystallized at only 430 °C from amorphous precursor fibers and without phase transformation up to 1600 °C. The fiber membranes have tensile strength (0.75 ± 0.20 MPa @ 800 °C) and flexibility, exhibits excellent flexural and compressive resilience properties, which can replace thermal insulation layer in firefighting suits and exhibit excellent thermal insulation properties and ablation resistance. The fiber sponge with the density of about 65 mg·cm −3 has low thermal conductivity of 23.5 and 86.4 mW·m −1 ·K −1 at room temperature and 1000 °C, respectively. Butane gun flame as heat source, the sample with the thickness of 25 mm can reduce the temperature from 1300 °C to 150 °C. After 600 s, the surface hardness of the fiber sponges was increased, but the sample still maintained excellent flexibility. This work provides a new way for rare-earth tantalates to meet high-temperature flexible applications by fully utilizing their advantages
研究领域:
材料科学
·
热力学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）