CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Yongyang Zhu,Shaoyang Shen,Liuzhang Ouyang,Jiangwen Liu,Hui Wang,Zhenguo Huang,Min Zhu
Magnesium borohydride (Mg(BH 4 ) 2 ) is widely regarded as a promising hydrogen storage material due to its high capacity; however, it is still challenging to synthesize Mg(BH 4 ) 2 with low cost. Traditionally, Mg(BH 4 ) 2 has been mainly produced using other borohydride as the starting materials via exchange reactions. Herein, we report an economical method to synthesize Mg(BH 4 ) 2 by converting B-O bonds in widely available borates or boric acid to B-H. The borates or boric acid is ball-milled with MgH 2 under ambient conditions to form Mg(BH 4 ) 2 with high yield (>80%). Mg(BH 4 ) 2 was also successfully generated by reacting low-cost Mg with boric acid. Compared with previous approaches, this method avoids expensive boron sources such as LiBH 4 , NaBH 4 , and B 2 H 6 , and does not require high pressure H 2 gas and high temperatures, and therefore significantly reduces costs. This method could be an alternative to the current Mg(BH 4 ) 2 synthesis processes.
研究领域:
材料科学
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化学
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能源存储
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产品关联
DOI
高影响因子
CRYSTENGCOMM
·
2022
·Vol. 24
·期 46
·8060-8069
·
IF 3.756
Shu-Qin Qin,Wei Xu,Wen-Cai Ye,Ren-Wang Jiang
Guanidinium–naphthalenedisulfonic acid (GNPS) was used as a molecular catcher because (i) it contains a cavity and channel in the network; (ii) NH2+ can be used as a hydrogen bond donor, and SO3− can be used as a hydrogen bond acceptor; (iii) the co-planar naphthalene rings can form aromatic interactions with guest molecules. The liquid guests 1–8 [(−)-isopulegol (1), (−)-menthyl acetate (2), isoeugenol (3), 2,6-dimethylaniline (4), methyleugenol (5), 2,6-diisopropylaniline (6), methyl salicylate (7) and L(−)-carvone (8)] are successfully encapsulated in the cavity of GNPS and eight new crystals were obtained. Both aromatic and non-aromatic molecules form hydrogen bonds and C–H⋯π interactions with GNPS. Co-crystallization of 1–4 with GNPS led to stronger C–H⋯π interactions as compared to the previously reported GBPS. Furthermore, compounds 5–8 which were not co-crystallized with GBPS were found to be encapsulated in the cavity of GNPS. We found that the aromatic cavity of GNPS with hydrogen bonding and enhanced C–H⋯π interactions can be regarded as a useful tool for the structural determination of liquid molecules. Furthermore, the correct absolute configurations of 1, 2 and 8 can be assigned based on the small Flack parameters because of the presence of sulfur atoms in the host molecule GNPS.
研究领域:
化学晶体学
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分子结构分析
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材料科学
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DOI
高影响因子
BIOMEDICINE & PHARMACOTHERAPY
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2022
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IF 7.419
Xingzhuo Song,Yu Du,Cen Liu,Wei Wang,Jing Han,Xinlou Chai,Yonggang Liu
Oxidative stress disrupts the homeostasis of the redox state in cells and induces apoptosis. Prolonged oxidative stress can impair the normal function of cells, tissues, and organs and lead to the development of several diseases. H-2 was synthesized by derivatising N- Alkylamides (NAAs) from Anacyclus pyrethrum (L.) DC, which is commonly used in the treatment of vitiligo in Uyghurs. The antioxidant activity and potential molecular mechanisms of H-2 were investigated using Caenorhabditis elegans ( C. elegans ) and mouse melanoma cell B16-F10 models. The in vivo anti-vitiligo activity of H-2 was studied using C57BL/6 mice. The results showed that H-2 could increase the survival time of nematodes under oxidative stress, promote the nuclear localization of DAF-16, and enhance the expression of Superoxide Dismutase 3 (SOD-3) in nematodes thereby activating the antioxidant enzyme system. H-2 could affect the survival rate of age-1 and akt-1 mutants under oxidative stress. H-2 could reverse the oxidative stress damage by reducing the reactive oxygen species (ROS) content in the Hydrogen peroxide (H 2 O 2 ) -induced oxidative stress damage model of mouse melanoma cells B16-F10. In addition, it was also able to increase the number of melanocytes in the hair follicles of vitiligo model mice and improve the phenomenon of skin damage in mice. In conclusion, our findings suggest that H-2 can alleviate oxidative stress damage in C. elegans and B16-F10, which may be associated with oxidative stress, suppression of antioxidant defences, and transcription factors DAF-16/FOXO, providing beneficial evidence for the application of H-2 in the vitiligo treatment.
研究领域:
分子生物学
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药理学
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皮肤病学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHROMATOGRAPHIC SCIENCE
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2015
·Vol. 53
·期 8
·1361-1365
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IF 1.363
Zhou Fan,Zhou Yuxia,Zou Qiaogen,Sun Lili,Wei Ping
Liquid chromatographic separation of mirabegron enantiomers on Chiralpak AY-H, a column coated with amylose tris-(5-chloro-2-methylphenylcarbamate) as a chiral stationary phase, was studied under normal phase conditions. The influence of ethanol content (30–45%) and column temperature (20–40°C) on retention, resolution and separation were evaluated. Apparent thermodynamic parameters deduced from Van't Hoff plots were used to understand chiral separation mechanisms, and the chiral separation was enthalpy driven. The optimized chromatographic conditions were using a mixture solution of n-hexane, ethanol and diethyl amine (55 : 45 : 0.1, v/v/v) as a mobile phase at a flow rate of 1.0 mL/min. The column temperature and UV detector were set at 35°C and 254 nm, respectively. The method was validated to be simple, accuracy, sensitive and robust according to the ICH guidelines, and it was suitable for the routine quality control of mirabegron enantiomers for pharmaceutical industries.
研究领域:
药学
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分析化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2022
·
IF 6.364
Mao chen,Fan Zhang,Hailong Wang,Gang Shao,Bingbing Fan,Rui Zhang,Hongxia Li,Yongqiang Chen
The dense h-BN/ZrO 2 (30 wt%) composites without additives were rapidly fabricated by spark plasma sintering . The relative density, apparent porosity, fracture toughness, flexural strength , phase composition and microstructure of h-BN/ZrO 2 composites were systematically investigated. Besides, the corrosion resistance of h-BN/ZrO 2 composites in molten steel was also studied in detail. Especially, the h-BN/ZrO 2 composites were sintered at 1800 °C exhibiting a relative density of 96.6% and the flexural strength of ≈ 157 MPa. The corrosion of h-BN/ZrO 2 composites was mainly due to the oxidative decomposition of BN, and the corrosion process was clarified by a parabolic law. The excellent corrosion resistance of the h-BN/ZrO 2 composites was attributed to ZrO 2 residual layer formed at the interface. The corrosion thickness of h-BN/ZrO 2 composites was only ∼116 µm even using the longest corrosion time (80 min). The composites could be a promising candidate material applied to fabricated thin strip continuous casting side sealing plates.
研究领域:
材料科学
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陶瓷工程
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产品关联
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Mengjiao Xing,Yunlei Chen,Jian Cao,Yuanlong Han,Zhichao Tao,Fei Wang,Kun Hao,Ling Zhang,Wentao Zheng,Hongwei Xiang,Yong Yang,Yongwang Li,Xiaodong Wen
Understanding the catalytic structure–activity relationship over active sites is of fundamental importance in heterogeneous catalysis field. Herein, a series of H-ZSM-5 zeolites with Al pairs contents in the range of 31% to 82% are used to explore the structure sensitivity of olefin aromatization reaction. Compared with high reaction temperatures (385 ℃ and above), prominently different initial aromatic yields are observed over the samples at 150 ℃. In addition, the 1-octene temperature-programmed surface reaction (TPSR) and theoretical calculation results give a thorough understanding on active site dependent activation temperature (100 vs 150 ℃ over Al pairs and single Al). However, the catalytic cycle of olefin aromatization is not sustainable at low reaction temperature, which is due to the formation and blocking of big molecules in the micropores (e.g., trimethylbenzene etc.). In conclusion, the desorption of big molecules is the rate-determining step for olefin aromatization reaction over H-ZSM-5, which masks the structure sensitivity over Al pairs and single Al.
研究领域:
催化化学
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材料科学
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产品关联
DOI
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
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2020
·Vol. 34
·期 11
·e5925
·
IF 3.14
Jie Yao,Yan Wang,Suleiman Sabo Bello,Guangwen Xu,Lei Shi
As it is well known, Brønsted acid sites in 8-MR of H-MOR (mordenite) are selective for dimethyl ether (DME) carbonylation to methyl acetate, whereas those in 12-MR are more prone to methanol to olefin reaction. Interestingly, we observed that the Brønsted acid sites in 12-MR of H-MOR are highly active for dimethoxymethane (DMM) carbonylation to methyl methoxyacetate (MMAc), whereas those in 8-MR led to the formation of DME. A series of modified H-MOR catalysts with accurate regulation of Brønsted acid sites in 12-MR or 8-MR were successfully synthesized by selective Na + exchange or pyridine (Py) adsorption. Fourier-transform infrared (FT-IR) spectra, NH 3 -temperature-programmed desorption, Py-FT-IR, and inductively coupled plasma analyses suggested that Na + first occupied Brønsted acid sites in 8-MR and then replaced those in 12-MR. All Na + -exchanged catalysts exhibited significant acceleration on MMAc selectivity, and the ratio of Brønsted acid amount in 12-MR/total had a positive correlation with MMAc selectivity. The MMAc selectivity (78%) of H-MOR-0.15Na was nearly 2.5 times more than that of untreated H-MOR (31%). However, H-MOR-Py showed almost no carbonylation activity (<1% MMAc) and a highest DME selectivity (98%), indicating that Brønsted acid sites in 12-MR were the only active sites for DMM carbonylation, whereas those in 8-MR tended to accelerate DMM disproportionation to DME.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
DYES AND PIGMENTS
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2015
·
IF 3.966
Bin Shan,Xing Tong,Wei Xiong,Wenzhu Qiu,Bingtao Tang,Rongwen Lu,Wei Ma,Yi Luo,Shufen Zhang
A new kind of reactive dyes containing both monoazo and anthraquinone chromophores was obtained by using 1,4-bis((4-aminophenyl)amino)anthrancene- 9,10-dione as diazo component and 1-amino-8-naphthol-3,6-disulfonicacid (H-acid) derivatives as coupling components. The dyes were characterized by UV–Vis, IR, MS, 1 H NMR and 13 C NMR. The results showed that the maximum absorption wavelengths of the dyes were all about 590 nm, which indicated that they were a kind of blue dyes. 1 H NMR and 13 C NMR results revealed that there were two kinds of tautomerisms in dye structure and a new conjugated system formed between the anthraquinone ring and the phenyl azo linkage. Density functional theory (DFT) calculations also proved the formation of the new larger conjugated system from which the blue colour was generated. The fixations of the dyes on cotton were over 88% and the light fastness reached 5 grade.
研究领域:
染料化学
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材料科学
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光谱学
✓ 已验证
产品关联
DOI
高影响因子
ICARUS
·
2022
·
IF 3.657
A. García Muñoz
Photoelectrons , the fast electrons produced in the photoionization of planetary atmospheres , drive transformations in the atmospheric gas that are often inhibited by energy considerations for thermal electrons. The transformations include excitation and ionization of atoms and molecules, which affect the detectability of these gases and constrain the fraction of incident stellar radiation that transforms into heat. To gain insight into these important questions, we build a Monte Carlo model that solves the slowing down of photoelectrons in a gas with arbitrary amounts of H and He atoms and thermal electrons. Our novel multi-score scheme differs from similar tools in that it efficiently handles rare collisional channels, as in the case of low-abundance excited atoms that undergo superelastic and inelastic collisions . The model is validated and its performance demonstrated. Further, we investigate whether photoelectrons might affect the population of the excited hydrogen H(2) detected at some exoplanet atmospheres by transmission spectroscopy in the H- α line. For the ultra-hot Jupiter HAT-P-32b, we find that photoelectron-driven excitation of H(2) is inefficient at the pressures probed by the line core but becomes significant (yet sub-dominant) deeper in the atmosphere where the line wings form. The contribution of photoelectrons to the destruction of H(2) either by collisional deexcitation or ionization is entirely negligible, a conclusion likely to hold for exoplanet atmospheres at large. Importantly, photoelectrons dominate the gas ionization at the altitudes probed by the H- α line, a fact that will likely affect, even if indirectly, the population of H(2) and other tracers such as metastable helium. Future modeling of these excited levels should incorporate photoelectron-driven ionization.
研究领域:
天文学
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行星科学
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DOI
高影响因子
JOURNAL OF ORGANIC CHEMISTRY
·
2024
·
IF 3.3
Jin Yan,Suijie Zhong,Xu Chen,Yihuan Luo,Hua Cao,Xiang Liu,Limin Zhao
Here, we report controlled and site-selective C–H alkenylation and dialkenylation of indolizines and pyrrolo[1,2-a]quinolines with β-alkoxyvinyl trifluoromethylketones under simple and practical conditions. Moreover, this direct C–H alkenylation strategy can also be extended to imidazo[1,2-a]pyridines. Notably, without a transition metal and external oxidant, efficient dehydrogenative β-alkenylation of tertiary amines with β-alkoxyvinyl trifluoromethylketones is presented.
研究领域:
有机化学
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合成化学
✓ 已验证
DOI
高影响因子
ACS Applied Energy Materials
·
2024
·
IF 5.4
Cuicui Li,Tongtong Gao,Wanzhen Wu,Xinpu Zhou,Shuyu Zhang,Guangpeng Ma,Xianfeng Guan,Shuang Wang
A series of composite membranes (sPBIp3-CAUX) are prepared by using modified sulfonated polybenzimidazole with an optimal side link grafting degree of 30% as a polymer matrix and then doping with CAU-10-H. The hydrophobic alkyl side chains and hydrophilic sulfonic acid groups easily form microphase separated structures due to the polarity difference, which is conducive to the enhancement of proton conductivity. The introduction of CAU-10-H into the polymer effectively prevents the passage of vanadium ions because the vanadium ion transport path becomes more tortuous. The sPBIp3-CAU2 membrane has low vanadium permeability (3.1 × 10–9 cm2 min–1) and excellent ion selectivity (9.16 × 106 S min cm–3). In addition, the sPBIp3-CAU2 membrane shows good cell performance at 60 mA cm–2 with CE of 93.32% and EE of 83.03% compared with those of Nafion 117.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Qiuxia Zou,Hongshen He,Jie Xie,Shibo Han,Weijie Lin,Ajoy Kanti Mondal,Fang Huang
In this study, Sn modified molecular sieves with Lewis (L) acid center and Al modified molecular sieves with Brönsted (B) acid center were prepared by post-synthesis method. They were applied to the catalytic pyrolysis of Kraft lignin for the preparation of bio-oil. The acid properties of acid modified zeolites were systematically investigated by XRD, SEM, EDS and Py-FT-IR, and the bio-oil is analyzed by heteronuclear single quantum coherent nuclear magnetic resonance (HSQC-NMR). By separating L acid and B acid from zeolite molecular sieves, the conformational relationships between these two acids on the oxygen-containing functional groups in Kraft lignin bio-oil are investigated separately. The results show that acid modified molecular sieves’ L acid and B acid can effectively improve the cleavage of aromatic C-O bonds including methoxy and ether bonds. The L acid of Sn modified molecular sieve tends to break the O-C 4 bond and the natural methoxy bond, while the B acid of Al modified molecular sieve generates aliphatic hydrocarbon intermediates and phenolic compounds by breaking the C β -O bond and rearranging the methoxy bond. By chemical characterization of the acid modified molecular sieves and the bio-oil, the conformational relationship between the L acid and B acid of zeolite molecular sieves on the deoxygenation efficiency of Kraft lignin pyrolysis bio-oil is established.
研究领域:
化学工程
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材料科学
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能源科学
✓ 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）