Analytical Methods
·
2014
·Vol. 7
·期 3
·1133-1139
·
IF 1.938
Zhengyu Yan,Yan Yu,Jianqiu Chen
A novel sensing system has been designed for the detection of m-phenylenediamine based on carbon quantum dots (CQDs)-improved chemiluminescence (CL) in a luminol–potassium permanganate (KMnO4) system. The CQDs were synthesized by pyrolyzing a mixture of citric acid (CA) and glycine (Gly). Under the action of CQDs and KMnO4, the luminol can be oxidized by synergy, which significantly increases the chemiluminescence intensity. In this work, it has been demonstrated that this facile methodology can offer a rapid, sensitive and reliable detection of m-phenylenediamine with a detection limit as low as 1.02 × 10−3 g L−1 and a dynamic range from 2.0 × 10−3 to 3.0 × 10−1 g L−1, which shows a promising application prospect.
研究领域:
分析化学
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材料科学
·
环境监测
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产品关联
DOI
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2018
·Vol. 135
·期 4
·2309-2316
·
IF 2.209
Yang Jianzhou,Jiang Jiajia,Jiang Juncheng,Pan Xuhai,Pan Yong,Ni Lei
m-Chloroperbenzoic acid (MCPBA) has been widely applied as an oxidant agent for various oxidations in organic chemistry. The understanding of thermal instability and kinetics is a prerequisite for safer storage and transportation. This study investigated the thermal decomposition characteristics of MCPBA under dynamic and adiabatic conditions by performing TG, DSC and ARC tests, respectively. Kinetic parameters were computed using Starink method and compensation effect. Thermal safety parameters, including critical temperature of thermal explosion ( T b ) and time to maximum rate under adiabatic conditions (TMR ad ), were determined to assess the thermal hazard of MCPBA. The experimental results showed two major thermal decomposition processes and a coupling phenomenon of heat absorption and generation. The mean value of E a was determined as 57.630 kJ mol −1 , and the best model to describe the overall reaction mechanism was three-dimensional diffusion model with integral form \(G\left( \alpha \right) = \left[ {1 - \left( {1 - \alpha } \right)^{1/3} } \right]^{2}\) for 0.05 < α < 0.80. The TMR ad was 24 h with an apparent onset temperature of 345.82 K. This study provided a guidance to determine the safety measures in MCPBA storage and transportation.
研究领域:
化学工程
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安全科学
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产品关联
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Xiao Yang,Zhuwei Yang,Linsen Li,Zhao Jiang,Guangxu Cheng
Dry methane reforming (DRM) represents a highly promising approach to greenhouse gas conversion (CO 2 and CH 4 ) to valuable byproducts. However, severe carbon deposition and catalyst deactivation inhibit large-scale applications. The work designed new catalysts with a yolk-shell structure using the water-in-oil microemulsion method. The catalysts were composed of a yolk-shell structure, with Ni-M as the active point and silica as the shell. The catalytic performance evaluation indicates that the Ni-M @SiO 2 catalysts show higher CH 4 and CO 2 conversion compared with the Ni@SiO 2 and conventional catalysts at 750 ℃, suggesting the yolk-shell structure and added M species enhance the DRM activity. The XRD, HRTEM, XPS, BET, H 2 -TPR, and CO 2 -TPD analysis confirmed the existence of yolk-shell configuration and evident electronic effect among Ni, M species, and SiO 2 . The long term measurements indicate that the added M species also bring higher carbon deposition tolerance for DRM, where Ni-Ce@SiO 2 and Ni-Zr@SiO 2 exhibit good structural and catalytic stability for DRM over 100 h. Through XRD, TEM, and TGA characterizations of the exhausted catalysts, it is determined that the coke deposition resistance of the catalyst is improved as a result of increased oxygen mobility and enhanced Ni dispersion on the catalytic surface, both of which are enhanced by the added Ce species. The structural analysis of the spent catalysts indicates that the tolerance of carbon deposition is improved by the yolk-shell samples. This study can offer valuable insights for the development of Ni-based catalysts with exceptional carbon deposition capability for DRM.
研究领域:
催化
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化学工程
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材料科学
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DOI
高影响因子
Journal of Superconductivity and Novel Magnetism
·
2022
·Vol. 36
·期 1
·327-341
·
IF 1.675
Li Pengwei,Li Jie,Wang Yonglun,Yao Kai,Shan Shuo,Suo Xing,Ma Saisai
Praseodymium (Pr)–aluminum (Al)-co-doped M-type barium ferrite with Ba 0.85 Pr 0.15 Fe 12-x Al x O 19 ( x = 0.0–1.0) was prepared by combining solid-phase sintering with high-energy ball milling. The samples were characterized using a thermogravimetric analyzer, X-ray diffractometer, field emission scanning electron microscopy, Fourier transform infrared spectroscopy, and vibrating sample magnetometer. Thermogravimetric analysis indicated that M-type barium ferrite was formed at 1250 °C. X-ray diffraction patterns showed that Al doping did not destroy the crystal structure of barium ferrite. Field emission scanning electron microscopy showed that the samples had a hexagonal crystal structure. The wave numbers of Fourier transform infrared spectroscopy in the 597–607 and 452–459 cm −1 bands represent tetrahedral and octahedral clusters, respectively. With the increase in the amount of Al doping ( x ) from 0.0 to 1.0, the saturation magnetization ( M s ) and residual magnetization ( M r ) decreased continuously, and the magnetic anisotropy field ( H a ) and coercivity ( H c ) increased significantly.
研究领域:
材料科学
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无机化学
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磁性材料
·
固体物理
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DOI
高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2025
·
IF 6.1
Xin Wang,Jie Zhao,Zehong Wu,Ling Wang,Wenjuan Zhang,Jie Zhang,Yong Liang
Bisphenol M (BPM), a structural analog of bisphenol A (BPA) commonly used in food packaging and consumer plastics, remains incompletely characterized in terms of its obesogenic potential and underlying molecular mechanisms, posing challenges for evidence-based risk assessment. To address this gap, we investigated the obesogenic effects and metabolic impacts of BPM exposure in male BALB/c mice through integrated liver untargeted metabolomics and gut microbiome analysis. Our results showed that BPM exposure significantly increased body fat percentage, enlarged the epididymal white adipose tissue volume, and induced hepatic steatosis. Untargeted metabolomics revealed that BPM disrupted hepatic metabolic pathways, such as riboflavin metabolism, glycerophospholipid metabolism and fatty acid degradation. Concurrently, BPM altered gut microbiota, increasing the Firmicutes/Bacteroidetes ratio and abundances of Staphylococcus and Jeotgalicoccus . Correlation networks linked these microbial shifts to hepatic lipid metabolites, specifically implicating linoleic acid metabolism as a potential mediator of gut-liver crosstalk in obesity development. These findings indicate that BPM promotes adiposity through liver-gut crosstalk, advancing the understanding of obesogenic risks associated with BPA alternatives.
研究领域:
毒理学
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代谢研究
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微生物组学
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产品关联
DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2022
·Vol. 46
·期 47
·22672-22685
·
IF 3.925
Jing Wang,Mei Zhang,Feng Li,Huan Wang,Yanguang Chen,Hua Song
To deeply understand the role of P in hydrodeoxygenation (HDO), SiO2-supported Ni and Ni–P catalysts with different P/Ni ratios (x) were prepared. The as-prepared samples were characterized by various characterization methods. The HDO activity and product distribution over the Ni/SiO2 and N–P/SiO2-x were compared and the effects of x on the structure, acidity, formation mechanism of active phases and HDO performance were studied taking m-cresol HDO as a model reaction. The results showed that the introduction of P promotes the formation of smaller active sites and contributes to the creation of weak and medium strength acid sites through the formation of P–OH groups and Niδ+ in Ni2P. HDO over the Ni/SiO2 catalyst occurs mainly via the hydrogenation (HYD) route with 3-methyl-cyclohexanol (3-MCHnol) as the main product. However, for Ni–P/SiO2-x catalysts, methyl-cyclohexane (MCH) selectivity increases first and then decreases with the increase of x, reaching a maximum of 95% at x = 1. The acidity generated by the introduction of P contributes to increased MCH selectivity, while the dehydration of 3-MCHnol to MCH occurs mainly on acid sites. However, the excessively high P content (x ≥ 2.0) leads to a significant increase of MB (toluene) selectivity, which is associated with the increase in Ni(I) sites. About 100% m-cresol conversion was achieved with Ni–P/SiO2-1.0 when the m-cresol (g)/catalyst (g) ratio was 3, with MCH (99.4%) as the major product, showing great promise for deep HDO catalysis.
研究领域:
催化化学
·
能源化学
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产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2022
·Vol. 46
·期 18
·8739-8751
·
IF 3.925
Quansheng Wu,Songhua Zhou,Chengbing Fu,Jiesong Zhang,Bo Chen,Hongyan Pan,Qian Lin
For the mono-metal Pd based catalysts, the O–O bond in O2 and H2O2 is easily dissociated due to the higher energy sites of Pd, which decreases the selectivity and productivity of H2O2. To address this issue, non-noble metals M (M = Sn, Fe, Co, Ni) were doped into palladium precursors to create a series of yolk–shell structure bimetallic catalysts Pd–M@HCS (H = hollow; C = carbon; S = sphere) with Pd–M as the core and porous carbon as the shell. The results indicated that the catalyst Pd–M@HCS doped with Sn, Fe, Co, and Ni has a weak dissociation ability for O2, and both the adsorption and dissociation ability for H2 are improved. Of these catalysts, the catalyst Pd–Sn@HCS gives the best performance, which is benefited by the suitable Pd–Sn nanoparticle size and the best Pd2+/Pd0 ratio. The influence of the nPd/nSn ratio in the Pd–Sn@HCS system on catalyst performance was further explored, and the findings revealed that Pd–Sn@HCS had the best catalytic activity and stability when the nPd/nSn ratio was 2. The catalyst's H2 conversion, H2O2 selectivity, and productivity were 35%, 97%, and 3961 mmol gPd−1 h−1, respectively. After 10 cycles, the H2O2 productivity of this catalyst remained at 92.1%, which was greater than the H2O2 productivity of the typical Pd-based catalyst Pd/C, which stayed at 37% under the same conditions.
研究领域:
催化
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化学工程
·
材料科学
·
无机化学
✓ 已验证
产品关联
DOI
高影响因子
FOOD CONTROL
·
2023
·
IF 6
Yanhua Xu,Huiyan Dong,Chenxi Liu,Haiwei Lou,Renyong Zhao
Aflatoxin B 1 (AFB 1 ) is the most common mycotoxin with the highest toxicity, posing a threat for food contamination. In this study, the bacterium Pseudomonas aeruginosa M-4 was isolated from rotten wood, and its culture supernatant showed a 56.79% AFB 1 degradation rate. Treatment with proteinase K, sodium dodecyl sulfate, and trichloroacetic acid decreased the AFB 1 degradation rate in the culture supernatant to 20.71%, 10.83%, and 19.62%, respectively. Moreover, heating the culture supernatant at 121 °C for 30 min increased in the AFB 1 degradation rate to 84.76%, indicating effective degradation by heat-resistant and inducible extracellular proteins or enzymes. P. aeruginosa M-4 reduced the content of AFB 1 in contaminated maize (90.57%, 14 d). Additionally, high-performance liquid chromatography and ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry analyses showed that AFB 1 was biotransformed into structurally different compounds, (C 17 H 16 O 6 ), (C 16 H 14 O 5 ), (C 17 H 14 O 5 ), and (C 16 H 10 O 6 ). According to the structure-activity relationship, these degradation products were produced by the destruction of partial toxic sites of AFB 1 , so the toxicity of these products may be lower than that of AFB 1 . Thus, P . aeruginosa M-4 has excellent potential for application in the detoxification of AFB 1 in food and feed.
研究领域:
食品科学
·
微生物学
·
毒理学
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产品关联
DOI
高影响因子
Catalysts
·
2016
·Vol. 6
·期 2
·19
·
IF 2.964
Guozhu Liu,Yunxia Zhao,Jinhua Guo
High selectively catalytic conversion of lignin-based phenols (m-cresol,p-cresol, and guaiacol) intopara-/m-xylene was performed over Pt/HZSM-5 through hydrodeoxygenation andin situmethylation with methanol. It is found that thep-/m-xylene selectivity is uniformly higher than 21%, and even increase up to 33.5% form-cresol (with phenols/methanol molar ratio of 1/8). The improvedp-/m-xylene selectivity in presence of methanol is attributed to the combined reaction pathways: methylation ofm-cresol into xylenols followed by HDO intop-/m-xylene, and HDO ofm-cresol into toluene followed by methylation intop-/m-xylene. Comparison of the product distribution over a series of catalysts indicates that both metals and supporters have distinct effect on thep-/m-xylene selectivity.Keywords:m-cresol;hydrodeoxygenation;methanol;p-/m-xylene;methylation
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2025
·
IF 4.9
Nana wang,Jiayu Teng,Yanmei Dai,Zijuan Tao,Changshun Huang,Liangli Luo,Zhimin Ou
To enhance the catalytic efficacy of nitroreductase and optimize the utilization of m-nitroacetophenone substrate, a novel nitroreductase, EcNTR, was isolated from Enterobacter cloacae ZJUT16 (CGMCC NO:28,310). The gene encoding EcNTR was successfully cloned and heterologously expressed. Through alanine scanning and site-saturation mutagenesis, two mutants, EcNTR-G20N/I54N and EcNTR-G20N/Y154D, were identified, exhibiting 5.01-fold and 4.69-fold higher specific activities, respectively, compared to wild-type EcNTR. At a substrate concentration of 80 mM, these mutants achieved a conversion rate of 98.52 %. Further optimization of the whole-cell catalytic conditions for mutant EcNTR-G20N/Y154D—specifically, a reaction time of 12 h, temperature of 30 °C, cell concentration of 100 g /L, use of DMSO as co-solvent, and 80 mM substrate—resulted in a yield of 99.2 %. These findings indicate that conformational changes in the active site region improved enzyme-substrate binding efficacy, thereby enhancing enzyme activity and catalytic ability. This study lays a foundation for the further development of nitroreductases for the efficient degradation of nitro-containing compounds.
研究领域:
生物化学
·
酶工程
·
合成生物学
✓ 已验证
DOI
高影响因子
JOURNAL OF THERMAL SPRAY TECHNOLOGY
·
2021
·Vol. 30
·期 4
·873-885
·
IF 2.757
Ye Fuxing,Yang Wenqi,Yan Shuai,Yu Jianxing
CMAS corrosion is one of the significant failure mechanisms for thermal barrier coatings (TBCs). In this work, the corrosion behaviors and wettability of CMAS on M-YTaO 4 at 1350 °C are studied to evaluate the M-YTaO4 ceramics’ potential to replace YSZ. The results show that the contact angles of CMAS on M-YTaO 4 with different time (1 min, 0.5 h, 4 h, 10 h and 24 h) are around 14.3° (14.4°14.4°, 14.4°, 14.3° and 14.2°, respectively), and larger than that on YSZ (8.0°, 1 min), which means the wettability of CMAS on M-YTaO 4 is worse than that on YSZ and which is benefit to improve its corrosion resistance. The thickness of reaction layer is increasing with elapsed time, but the increasing rate is decreased, and the maximum reaction thickness is 31.42 μm at 24 h. There are four main phases after reaction, which are M-YTaO 4 , M’-YTaO 4 , Ca 2 Ta 2 O 7 and Y 2 Si 2 O 7 . For the effects of lattice distortion and thermodynamics reason, M’-YTaO 4 can retain steadily at room temperature. Besides, the chemical reaction process between CMAS and yttrium tantalite is also be discussed.
研究领域:
材料科学
·
陶瓷
·
腐蚀工程
·
热障涂层
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Haifeng Li,Lu Zheng,Dongdong Deng,Xialin Yi,Xiaohong Zhang,Xiang Luo,Yubo Wu,Wenjun Luo,Meijie Zhang
BaFe 12–2 x (Mn 0.5 Co 0.5 Ti) x O 19 ( x = 0, 0.5, 1.0, 2.0) powders were synthesized by a solid-state reaction (SSR) technique and its microwave absorption bandwidth was broadened by multiple magnetic resonances. The crystalline phases, microstructure, magnetic properties , and microwave (MW) absorption properties of substituted M-type barium hexaferrites (BaM, BaFe 12 O 19 ) were investigated. The refined X-ray diffraction (XRD) patterns and scanning electron microscope (SEM) images showed that all prepared samples consisted of single-phase flake shaped particles. With an increase of substitution x , the saturation magnetization ( M s ) and coercivity ( H c ) changed, resulting in a transition from hard magnetic to soft magnetic samples. The dielectric spectra and magnetic spectra of the substituted samples presented resonance at almost the same position, and multiple resonances of magnetic spectra were observed with an increase in the doping amount x , which enhanced the MW absorption and broadened the effective absorption bandwidth ( EAB ). For the x = 0.5 sample, the minimum reflection loss ( RL min ) arrived −40.2 dB, and the EABs of RL <−10 dB and RL <−20 dB widened to 7.0 GHz and 4.2 GHz respectively, with a corresponding coating thickness of 2.3 mm. The energy dissipation mechanism of all substituted samples was dominated by a dielectric resonance and natural resonance, including the contribution of exchange resonance. The BaFe 11 (Mn 0.5 Co 0.5 Ti) 0.5 O 19 is therefore a desirable candidate for electromagnetic wave (EMW) absorber applications.
研究领域:
材料科学
·
电磁学
·
物理学
✓ 已验证
DOI
高影响因子
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