NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
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2014
·
IF 1.186
M.M. Mikhailov,Chundong Li,V.V. Neshchimenko
Diffuse reflection spectra and absorption spectra of titanium dioxide (anatase) micro- and nanopowders induced by exposure to 100 keV protons and electrons were analyzed at wavelengths between 250 and 2500 nm. It is established that the radiation stability of the nanopowders is higher than the micropowders in the absorption region λ > 500 nm for proton and electron exposure. This effect is caused by the high concentration of radiation defects in micropowders, which is associated with defects of interstitial titanium ions ( Ti i , Ti i ), titanium vacancies ( V Ti ⁗ , V Ti ‴ ) and oxygen vacancies V O X .
研究领域:
材料科学
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物理学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2019
·Vol. 137
·期 5
·1615-1620
·
IF 2.471
Yang Hongtao,Liu Yunfei,Huang Haitao,Zhao Yu,Song Kuanguang,Wang Haiyang,Xie Wuxi,Cheng Yi,Fan Xuezhong
In this study, an advanced electrospray process was successfully used to fabricate aluminum nanopowders (Al)/iron oxide nanopowders (Fe 2 O 3 )/hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX)/nitrocellulose (NC) composite materials containing different RDX contents. Differential scanning calorimetric analysis indicates that the decomposition temperature of the RDX in the composition prepared by electrospray has a decrease of about 20 °C compared with the raw RDX. Combustion performances in air show that the RDX decreases combustion performance of nanothermites, and the combustion intensity decreases as the RDX content increases. Furthermore, the combustion cell test indicates that the maximum pressure peak has been greatly improved for the Al/Fe 2 O 3 /RDX/NC composites. The amount of released gas can be adjusted by the RDX content in Al/Fe 2 O 3 /RDX/NC composite.
研究领域:
材料科学
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燃烧与爆炸
✓ 已验证
产品关联
DOI
高影响因子
SURFACE & COATINGS TECHNOLOGY
·
2020
·
IF 3.784
Mikhailov Mikhail,Iurina Victoria,Neshchimenko Vitaly,Li Chundong
The effects of proton (E = 100 keV, F = 5 × 10 15 сm −2 ) exposure on the reflective spectra of Al 2 O 3 , CeO 2 , TiO 2 , Y 2 O 3 , ZrO 2 , ZnO micro- and nanopowders in wavelength range from 250 to 2500 nm have been investigated. It has been established that titanium dioxide nanopowders have higher radiation stability to protons exposure in comparison with the other white powders (TiO 2 , Y 2 O 3 , Al 2 O 3 , ZnO, ZrO 2 ) used as pigments for coatings. This effect is caused by high specific surface area of the nanoparticle causing fast recombination processes of electrons and holes in various surface drains.
研究领域:
材料科学
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核物理学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
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2011
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IF 1.472
Xinghong Zhang,Yang Hou,Ping Hu,Wenbo Han,Junting Luo
The dispersion and co-dispersion behavior of ZrB 2 and SiC nanopowders in ethanol solution was studied by sedimentation test, particle size measurement and transmission electron microscope (TEM) analysis. The dispersion behavior of ZrB 2 and SiC nanopowders in ethanol solution was strongly dependent on the pH values, types and amounts of dispersant. PEI was found to be effective for the dispersion of both ZrB 2 and SiC nanopowders in ethanol solution. With the addition of PEI, the isoelectric points of ZrB 2 and SiC nanopowders in ethanol solution were at pH 10 and pH 9.5, and shift to pH 13 and pH 12.3, respectively. The stability of ZrB 2 suspension increased with the dispersant content increasing until reached 0.7 wt% and well-dispersed SiC slurry can be obtained with more than 2.5 wt% PEI. The suitable pH value for the dispersion of ZrB 2 and SiC nanopowders should be lower than 12 and 10, respectively. The well co-dispersed ZrB 2 and SiC nanocomposite powders can be achieved by using 1 wt% or more PEI below pH 10.
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
Analytical Methods
·
2016
·Vol. 8
·期 33
·6313-6322
·
IF 1.915
Yanan Wu,Rong He,Zhigao Wang,Jian Yuan,Changrui Xing,Lifeng Wang,Xingrong Ju
Rice (Oryza sativa L.), an important cereal crop, has been seriously contaminated by cadmium (Cd) in the world. In this study, we compared the effects of three organic acids (citric acid, malic acid and tartaric acid) which are all approved food additives on the removal of Cd and developed a safe, efficient and simple technique to remove Cd from contaminated brown rice flour using citric acid (CA). The optimal conditions for citric acid removal of Cd were determined by a three-level Box–Behnken design with three factors (CA concentration, treatment temperature and treatment time) under the condition that the liquid–solid ratio was 12 mL g−1 and the shaking speed was 150 rpm, and the results were as follows: CA concentration, 0.08 mol L−1; treatment temperature, 45 °C; and treatment time, 53.09 min. Under these conditions, the removal efficiency of Cd was 94.28 ± 0.06%, which agreed well with the predicted value of 94.75%. Moreover, the contents of the main chemical components such as protein, starch and fat in the brown rice flour were still very high after citric acid treatment, indicating that this technique did not affect the quality of brown rice flour. This technique was also used in other brown rice flour samples and satisfactory results were obtained. Therefore, this technique is efficient in removing Cd and may have the potential to be used in the food industry to solve the Cd-rich rice problem in the world.
研究领域:
食品安全
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环境科学
·
农业科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF RARE EARTHS
·
2016
·
IF 2.188
Siyuan CHEN,Jintai FAN,Liangjie PAN,Benxue JIANG,Xiaojian MAO,Rihong LI,Xinqiang YUAN,Xiongwei JIANG,Long ZHANG
Yb:Lu 3 Al 5 O 12 (Yb:LuAG) nano powders were synthesized with the co-precipitation method from cation (Lu 3+ , Yb 3+ , Al 3+ ) solution of different concentrations using NH 4 HCO 3 as the precipitant. The influence of cation concentration on the morphology and purity of the calcined powders was studied. Contrary to the conventional suggestion that recommends thin solution to obtain loosely agglomerated nano powders, results showed that thin cation (Lu+Yb+Al) concentration ≤0.08 mol/L led to formation of Al 2 O 3 and LuAP impurities in the obtained nano powders. By means of Tg/(DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM), the cause was revealed to be re-dissolution of Lu at high pH value that resulted from the decomposition of NH 4 HCO 3 . (Lu+Yb+Al) concentration of ∼0.24 mol/L was recommended to achieve pure Yb:LuAG nano powders. Transparent Yb:LuAG ceramics were fabricated with the prepared Yb:LuAG nano powders. The transmittance around 800 nm was 77.5%.
研究领域:
材料科学
·
光学材料
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2016
·
IF 3.014
Jiang Tan,Yuchang Su,Hongbo Tang,Te Hu,Qiushan Yu,Rabigul Tursun,Xiangyu Zhang
10Sc1CeSZ (10 mol% Sc 2 O 3 –1 mol% CeO 2 –89 mol% ZrO 2 ) nanopowders were prepared by hydrothermal and calcinations . The calcined powders were uniaxially compacted into pellets and sintered at 1400 °C for 2 h. The calcined powders and sintered pellets were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared transmission spectroscopy (FTIR) and impedance spectroscopy . The powders calcined at 800 °C for 2 h (and below 800 °C) was beneficial to pellets densification. After the powders were calcined at 800 °C for 2 h, the sintered pellets showed relative density of 97.5%, and its conductivity was 0.108 S cm −1 at 800 °C. The powders calcined at 800 °C for 24 h showed the better conductivity of 0.131 S cm −1 at 800 °C. The microstructure, bulk density and electrical properties of the sintered pellets can be tuned using different calcined parameters.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
KEY ENGINEERING MATERIALS
·
2012
·
IF 0
Yang Hou,Ping Hu,Wen Bo Han
The dispersion of SiC nanopowders in ethanol solution was studied by sedimentation test, particle size measurement and TEM analysis. The dispersion behavior of SiC nanopowders in ethanol solution was strongly dependent on the pH values, types and amounts of dispersant. PEI was found to be effective for the dispersion of SiC nanopowders in ethanol solution. With the addition of PEI, the isoelectric points of SiC nanopowders in ethanol solution were at pH 9.5, and shift to pH 12.3. The stability of SiC suspension increased with the dispersant content increasing until reached 2.5 wt% PEI. The suitable pH value for the dispersion of SiC nanopowders should lower than 10.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2024
·Vol. 35
·期 19
·1-8
·
IF 2.8
Yan Shuai,Hu Wencai,Wang Sen,Liu Gaobin
In this paper, Sr-doped BaTiO 3 nanoparticles were synthesized via electrochemical method, leading to the successful preparation of Ba 0.67 Sr 0.33 TiO 3 (BST) powders. The phase composition and microstructure of the powders were characterized using X-ray diffraction small angle X-ray scattering, scanning electron microscopy (SEM), and transmission electron microscopy. The results show that the average grain size of the nanoparticles is in the range of 10–20 nm, and the particles with good crystallinity are obtained under the environment of 3 mol.L −1 NaOH concentration. Sintering at 1250 ℃ for 3 h yields nanoscale BST ceramics with a dense structure and an average grain size of about 300 nm. These fine-grained ceramic samples exhibit superior temperature stability compared to relatively coarser BST ceramics. Furthermore, due to their nanoscale grain size, extensive phase transitions result in a low dielectric constant as observed from the dielectric property data. This work presents a novel approach for preparing nanoscale powders and homogeneous ceramics applicable in various electronic applications.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED ENGINEERING MATERIALS
·
2022
·Vol. 25
·期 5
·2200175
·
IF 4.122
Meiqin Zeng,Youtao Pan,Weifeng Liu,Jie Cui,Zhongchen Lu,Min Zhu
This work prepares nanocrystalline tungsten carbide (WC) powder using conventional ball milling or plasma milling (P-milling) to process tungsten trioxide (WO 3 )–carbon (C) mixtures, with subsequent carbothermal reduction. The aim is to assess the effects of a discharge plasma on the microstructure of these materials. The results indicates that WC powders with particle sizes of less than 100 nm could be fabricated through heating at a relatively low temperature of 1150 °C for 1 h under vacuum after P-milling. This process is found to allow a lower processing temperature and provided more complete carburization in comparison with conventional ball milling. P-milling is determined to produce more loosely adhering WO 3 nanoparticles and a higher surface area, resulting in more reactive sites and a larger contact area between WO 3 nanoparticles and C atoms. This technique simultaneously generates more oxygen vacancies and defects on the surfaces of the WO 3 and C, respectively, based on the use of a plasma discharge. It is evident that this new technology permits nanocrystalline WC to be readily obtained from WO 3 and C in a reduced time span and at a lower cost and greater efficiency. This technique could also be used to fabricate WC nanopowders on an industrial scale.
研究领域:
材料科学
·
纳米技术
✓ 已验证
DOI
高影响因子
JOURNAL OF FOOD SCIENCE AND TECHNOLOGY-MYSORE
·
2019
·Vol. 56
·期 2
·1027-1036
·
IF 1.85
Yang Shuang,Liu Jingsheng,Zheng Mingzhu,Zhao Chengbin,Cao Yong,Dong Yanjiao,Yaqoob Sanabil,Xiao Yu,Xu Xiuying
Cordyceps militaris ( C. militaris ) was utilized to ferment cornmeal by solid state fermentation. The main objective of this study was to investigate effect of fermentation on the dynamic state of water and microstructure distribution of water within cornmeal with Low-field nuclear magnetic resonance, as well as the effect on composition and microstructure properties. The spin–spin relaxation time (T 2 ) showed significant changes in solid-state fermented cornmeal. Principal component analysis further revealed that the variations within different fermentation stage could be discriminated by the T 2 parameters. Bulk water (T 22 ) was the main form of water present and lost in substrates. The weights of different indicators, as assessed by multiple regression analysis, demonstrated that there was a strong correlation between starch and T 2 relaxation. Scanning electron microscopy demonstrated that fermentation can cause the appearance of micropores. The longer relaxation time of T 22 during logarithmic period can be interpreted as a loosening of the structure at the starch hydrolysis, introducing more water into the structure. Thus, the differences in composition and structure of the substrate at different fermentation time produce different T 2 values.
研究领域:
食品科学
·
微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
OPTICAL MATERIALS
·
2019
·
IF 2.687
Penghui Chen,Qiang Liu,Yagang Feng,Xiaoying Li,Xiaopu Chen,Yumin Liu,Jiang Li
Y 0.16 Zr 0.84 O 1.92 transparent ceramics were successfully fabricated by air pre-sintering combined with HIP post-treatment from the nanopowder synthesized by the co-precipitation method. Fine and low-agglomerated Y 0.16 Zr 0.84 O 1.92 powder with the average particle size of 14.8 nm was obtained by calcining the precursor at 800 °C for 4 h. The influences of pre-sintering temperature on the microstructure and optical quality of Y 0.16 Zr 0.84 O 1.92 ceramics were investigated. It is found that the relative density of pre-sintered Y 0.16 Zr 0.84 O 1.92 ceramics increases from 82.1% to 96.1% and the average grain size increases from 0.6 μm to 6.0 μm with the pre-sintering temperature increasing from 1250 °C to 1500 °C. The Y 0.16 Zr 0.84 O 1.92 ceramic sample pre-sintered at 1300 °C for 2 h and HIP post-treated at 1800 °C for 3 h without sintering additives exhibits the best transparency. In-line transmittance of Y 0.16 Zr 0.84 O 1.92 ceramics with the thickness of 1.0 mm reaches 72.4% at 800 nm, which is near to the theoretical transmittance.
研究领域:
材料科学
·
光学工程
✓ 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）