APPLIED SPECTROSCOPY
·
2013
·
IF 1.942
Yunchang Fan,Sheli Zhang,Qiang Wang,Junhai Li,Haotian Fan,Dongkai Shan
The molecular mechanism of the interaction between pepsin and two typical ionic liquids (ILs), 1-butyl-3-methylimidazolium chloride ([C4mim]Cl) and 1-octyl-3-methylimidazolium chloride ([C8mim]Cl), was investigated with fluorescence spectroscopy, ultraviolet absorption, and circular dichroism spectroscopy at a pH value of 1.6. The results suggest that ILs could quench the intrinsic fluorescence of pepsin, probably via a dynamic quenching mechanism. The fluorescence quenching constants were determined by employing the classic Stern-Volmer equation. The constant values are very small, indicating that only a very weak interaction between ILs and pepsin exists. The Gibbs free-energy change, enthalpy change (ΔH), and entropy change (ΔS) during the interaction of pepsin and ILs were estimated. Positive values of ΔH and ΔS indicate that the interaction between ILs and pepsin is mainly driven by hydrophobic interaction. Synchronous and three-dimensional fluorescence spectra demonstrate that the addition of ILs (0–0.20 mol L−1 for each IL) does not bring apparent changes to the microenvironments of tyrosine and tryptophan residues. Activity experiments show that the activity of pepsin is concentration dependent; higher concentrations of ILs (>0.22 mol L−1 for [C8mim]Cl and >0.30 mol L−1 for [C4mim]Cl) cause the remarkable reduction of enzyme activity. The presence of ILs also does not improve the thermal stability of pepsin.
研究领域:
生物化学
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分子生物学
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DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2025
·
IF 9.7
Shihao Su,Xuyang Zou,Guojun Lv,Fuxin Wang,Yangbin Shen
Tandem catalysis reaction, which integrates two consecutive steps into a single one, can efficiently eliminate the separation of intermediate products, shortening the reaction time and decreasing energy expenditure. Therefore, the development of an efficient method for catalyzing tandem conversion of alkenes to prepare 1,2-diols is extremely fascinating. In this work, we reported the hydrothermal synthesis of tin-tungsten oxide catalysts at different pH values and their application as bifunctional catalyst for the one-pot tandem catalysis of alkenes to 1,2-diols. The SnWO 4 catalyst prepared at pH = 5 revealed the best tandem conversion performance and could attain a 95.4 % of cyclohexene conversion as well as a 77.2 % of 1,2-cyclohexanediol selectivity within 4 h of reaction. A possible mechanism corresponding to the tandem catalytic conversion of cyclohexene into 1,2-cyclohexanediol over SnWO 4 catalyst was proposed. Moreover, quenching experiments, density functional theory (DFT) calculations and in-situ infrared characterizations were further utilized to verify the reaction mechanism. Sn(II) could stabilize tungstate through the formation of W-O-Sn bonds and effectively reduced the energy of tungsten active centre binding to hydrogen peroxide, promoting the tandem catalysis reaction of cyclohexene to 1,2-cyclohexanediol. In addition, the one-pot tandem catalysis system could be further extended to the majority of linear and cyclic alkene substrates. This work can give a basis for the development of more green and efficient tandem conversion reaction of alkenes into 1,2-diols.
研究领域:
化学工程
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催化科学
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DOI
PubMed
高影响因子
Catalysts
·
2022
·Vol. 12
·期 8
·809
·
IF 4.501
Yukai Zhao,Weichi Liang,Yihan Wang,Yan Tong,Zhanhong Li,Yuqian Liang,Xiaolong Liu,Jiuxing Jiang
As a solid acid, zeolite has been widely used in many fields such as tail gas treatment, petrochemical engineering, and the fine chemical industry. F−has been widely used in the synthesis of pure silica or high silica zeolites. To balance the charge of organic structure directing agents (OSDA), F−is often found located at the center of the double-4-rings (d4r) of the as-made zeolites. During calcination, fluorine ion is removed with the OSDA. We screened a series of composition building units and found thatd4ris capable to retain F−in zeolite structure. We introduce the F−back after the calcination to create an unprecedented type of acid site, i.e., F−@d4rin pure silica zeolites ITQ-12. The F−@d4rspecies is thermal stable up to 300 °C. ITQ-12 with F−@d4rshows substantial catalytic activity in Biginelli reaction. Furthermore, the catalytic performance is proved to be positive correlated with the presence of F−@d4r, indicating the mild acid catalytic property of F−@d4r.Keywords:zeolites;fluorine;double-4-rings
研究领域:
化学工程
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催化
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材料科学
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产品关联
DOI
高影响因子
PHYSICS OF THE SOLID STATE
·
2026
·Vol. 68
·期 7
·645-650
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IF 2.4
Huang Jinyan,Li Haichao,Guo Jianxia
Carbon nanomaterials, as pivotal representatives of forefront nanotechnologies, are advancing at a remarkable pace, driving global scientific, industrial, and socio-economic progress. To explore a straightforward yet effective route for the precise control over the morphology and dimensions of carbon nanostructures, this study employed a confined in-situ carbonization strategy. This approach successfully enabled the efficient synthesis of carbon nanosheets with tunable thicknesses under varied synthesis conditions. The resulting carbon nanosheets were systematically characterized using a comprehensive suite of analytical techniques. Scanning electron microscopy (SEM) was employed to examine their morphology and thickness, while Raman spectroscopy, X-ray diffraction (XRD), and Fourier-transform infrared (FTIR) spectroscopy provided insights into their graphitic structure, crystallinity, and surface functional groups, respectively. Additionally, energy-dispersive X-ray spectroscopy (EDS) was utilized for elemental analysis. The data collected from these techniques were integral in guiding and refining the subsequent experimental design. It was hypothesized that by carefully modulating key synthesis parameters—primarily the concentration of the surfactant SB3-12, but also other conditions such as reaction temperature—carbon nanosheets could be efficiently synthesized within a unique reaction environment created by the physical encapsulation of a concentrated potassium sulphate solution. This experimental investigation holds significant value, as it contributes meaningful insights into the development of controllable synthetic methodologies for carbon nanostructures and provides a foundation for future research and application developments in this promising field.
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DOI
高影响因子
PHYSICS OF THE SOLID STATE
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2026
·Vol. 68
·期 10
·880-885
·
IF 2.4
Li Chen,Zhang Huan,Zhen Zihan,Shi Chenglong
Carbon nanomaterials, owing to their unique properties, demonstrate indispensable application value in fields such as environmental science, biomedicine, and sensing technology. However, existing methods still face challenges in achieving precise and controllable preparation of morphology and structure, particularly exhibiting significant limitations in terms of green synthesis and mild conditions. This study proposes a novel and environmentally friendly strategy for the preparation of carbon nanomaterials: the confined in situ carbonization method. This method enables the in situ transformation and structurally directed growth of carbon sources within a confined environment, offering a new approach for morphology control of carbon materials. To comprehensively characterize the structure and properties of the as-prepared materials, various analytical techniques were employed for systematic investigation. Specifically, scanning electron microscopy (SEM) was used to observe the microscopic morphology and size distribution; X-ray diffraction (XRD) was employed to analyze the crystal structure; Raman spectroscopy was applied to assess the degree of graphitization and defect states of the carbon materials; Fourier-transform infrared spectroscopy (FTIR) was utilized to detect surface functional groups; and energy-dispersive X-ray spectroscopy (EDS) was combined to determine the elemental distribution.Using this method, carbon nanospheres with a diameter of approximately 10 nm were successfully prepared, and their structural properties were systematically analyzed.
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DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2024
·
IF 5.3
Huiwen Ren,Ruiqi Xie,Sheng Jian,Xiong Tong,Xian Xie,Zhihui Zhao,Xuelin Wei
The separation of spodumene and albite by the new collector 12-aminododecanoic acid (12-ADA) without an activator or depressant was investigated by single-mineral and artificially mixed-ore flotation test. The results showed that under the 12-ADA concentration of 314 mg/L, pH 5.0, and 10 °C, the recoveries of spodumene and albite were 12.85 % and 89.15 %, respectively. At the 12-ADA concentration of 114 mg/L, pH 4.5, and 10 ± 2 °C, Li 2 O grade of 4.56 % and recovery of 84.55 % were achieved. In addition, the interaction mechanism between minerals and 12-ADA was investigated. The results showed that 12-ADA could form an association complex, which could create hydrogen bonds with the Si-O bond on the albite surface through NH 2 , and form chemical bonds with Na through COOH. However, 12-ADA mainly adsorbed onto the spodumene surface through electrostatic attraction. With an increase in the concentration of 12-ADA, albite could preferentially adsorb 12-ADA as a monolayer, while the adsorption between spodumene and 12-ADA was small, when 12-ADA exceeded a certain amount, it became prone to multilayer adsorption. 12-ADA overcame the temperature limitation of traditional fatty acid reagents and had potential application value for the flotation of spodumene in cold areas. It also provided a theoretical basis for the research and development of low-temperature reagents for spodumene.
研究领域:
矿物加工工程
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材料科学与工程
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产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2020
·
IF 2.369
Yuanming Fu,Xianyang Meng,Ximei Liang,Jiangtao Wu
The density and viscosity of liquid 1-dodecanol and 1,12-dodecanediol were reported, which were obtained simultaneously by using a vibrating-wire viscometer. The measurements were determined at temperatures from 298.15 to 573.15 K for 1-dodecanol and 373.15 to 573.15 K for 1,12-dodecanediol and at pressures from 0.1 to 10 MPa. The combined expanded uncertainties (k = 2) of the reported data for density and viscosity were estimated to be 0.26% and 2.1%, respectively. The density and viscosity data obtained in this work were correlated with the Tait-type equation and Andrade–Tait equation, respectively. The average absolute percentage deviation of the density data from the correlations were 0.08% for 1-dodecanol and 0.06% for 1,12-dodecanediol, and the average absolute percentage deviation of the viscosity data from the correlations were 0.64% for 1-dodecanol and 0.67% for 1,12-dodecanediol. The correlations were also used to compare the present results with the available literature data. An acceptable agreement between the present results and the literature data was observed. Finally, the derived properties of isobaric expansibility and isothermal compressibility were derived based on the Tait-type equation of this work.
研究领域:
化学工程
·
物理化学
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DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 137
·期 23
·48766
·
IF 2.188
Lu Yang,Lequan Wang,Yinghong Chen
The selective laser sintering (SLS) is one of the most important 3D-printing technologies. However, the challenges in SLS could be in the limited high material cost and single material performance. Development of high-performance and multifunctional copowders suitable for SLS is of great importance. Here, polyamide 12 (PA12)/boron nitride (BN) thermal conductive copowders suitable for SLS were successfully prepared through solid state shear milling (S 3 M) technology in combination with cryogenic pulverization technology. The particle size, morphology, grafting reaction between PA12 and BN, rheology behavior, and coalescence behavior of the obtained PA12/BN copowders were carefully investigated. The optimal amount of silica flow additive (0.5 wt %) was determined to achieve the good powder flowability. Under the optimum 3D-printing conditions, the fabrication of parts with high BN loading could be achieved. When BN content was at 40 wt %, the flexural strength could reach 10.6 MPa and the thermal conductivity could reach 0.55 W/m·k, 77% higher than that of pure PA12. After treated with phenolic epoxy resin, the tensile strength and flexural strength of the printed parts with 40 wt % BN loading could reach 14.2 and 25.6 MPa, which were 130 and 115% higher than those of the untreated 3D-printed parts, respectively. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48766.
研究领域:
材料科学
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复合材料
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3D打印技术
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产品关联
DOI
高影响因子
Heliyon
·
2024
·
IF 3.4
Bingxuan Du,Haichao Li,Conglin Zhang,Qingsong Ji
Nanocarbons have potential applications in almost all areas of materials science. While we have appreciated the various discoveries and applications of many nanocarbons, we recognize that the field remains challenging in terms of tunability. In this research, we report a new strategy for the self-assembly of surfactant @ salt from the concept of carbon nanostructure design, and introduce the concept of “separator”. On the one hand, it allows the core and shell to be formed in one step. On the other hand, it allows the ordered aggregates to remain in their original shape under thermal action. The surface morphology, degree of graphitization, elemental composition and surface chemical state, formation mechanism, and specific luminescent properties of carbon nanomaterials were investigated. TEM reveals that (dodecyldimethyl betaine) BS-12 @ LiCl carbon nanospheres with tunable size (from 55 nm to 70 nm) can be successfully synthesized. Raman and XRD show that the structure of carbon nanospheres has some defects and disordered carbon. XPS and FTIR analyses indicate that the defects present in the carbon nanosphere structure are related to the N and O elements. The detailed growth mechanism shows that the micelle structure in the system can be well adjusted by changing the concentration of surfactant. PL research demonstrates that the synthesized carbon nanospheres have UV luminescent properties. Most importantly, the method can be further developed into a general strategy for self-assembly using a variety of surfactants and “separators” as promising candidates for future practical applications of nanocarbon materials.
研究领域:
材料科学
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纳米技术
·
化学工程
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2020
·
IF 2.369
Jinbo Ouyang,Jian Chen,Limin Zhou,Zhirong Liu,Chuntao Zhang
The solubility data of propylparaben in polar and apolar solvents were first measured at T = (283.15–323.15) K using the shake flask method. The results show that solubility of propylparaben in all selected solvents increases proportionally with temperature, and at a high temperature (323.15 K), propylparaben is most soluble in acetone, followed by isopropanol, 1-propanol, ethanol, methanol, ethyl acetate, 1-butanol, butyl acetate, methyl acetate, isobutanol, acetonitrile, and water. To mathematically represent the experimentally measured solubility data, the modified Apelblat model, Wilson model, and NRTL model were applied. The difference between experimentally measured and predicted values was described by the percentage of averaged relative deviation. The best correlation of solubility versus temperature with the highest accuracy was obtained using the modified Apelblat model. Dissolution thermodynamics of propylparaben in different solvents at different temperatures were calculated and discussed to study the dissolution mechanism of propylparaben in different solvents.
研究领域:
药学
·
物理化学
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DOI
高影响因子
FULLERENES NANOTUBES AND CARBON NANOSTRUCTURES
·
2025
·
IF 1.8
Jianxia Guo,Hai-chao Li,Xiaofei Kang
Carbon nanostructures have emerged as a promising component in modern technology and production due to their distinctive properties and varied carbonation states. In this paper, a novel preparation method, termed the ‘bound in situ carbonization’, is proposed to achieve the complete carbonization process by employing the encapsulation of concentrated salt. The morphology and properties of the prepared carbon nanostructures were investigated using a range of analytical methods, including SEM, XPS, XRD, FTIR and Raman. The experimental results yielded carbon nanostructures in the form of small particles, short rods, and sheet-like structures. The experimental preparation method is of significance for the synthesis of carbon nanostructures with tunable morphology and size.
研究领域:
材料科学
·
纳米科技
·
物理化学
·
功能材料
✓ 已验证
产品关联
DOI
高影响因子
Educational Research and Evaluation
·
2026
·
IF 1.3
Tzu-Hua Wang,Ence Surahman
Studies on assessment for STEM learning practices have reported several forms of meaningful assessment, however, few systematic reviews have evaluated assessment trends in K–12 context. Hence, in this study, assessment practices in K-12 STEM education were systematically reviewed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. A total of 56 empirical research articles published between 2013 and 2025 on the Web of Science were carefully selected. Notable trends were observed in the research context, educational grade levels, course subjects, assessment methods and objectives, research methods, sample size, findings, and future research directions reported in the included studies. Reported assessment methods included surveys, questionnaires, examinations, and peer-based, authentic, and game-based assessments. Overall, the findings offer insights for K-12 STEM educators regarding the development of appropriate assessment methods tailored to the unique requirements of each STEM field.
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DOI
高影响因子
危险品化学品经营许可证（带存储）