JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2022
·
IF 3.119
Hao Li,Fengyi Zhang,Qianlong Zhang,Hongjuan Li,Zhiying Wang,Chunli Li,Jing Fang
For some strongly non-ideal solution systems, there are often errors in predicting the phase equilibrium relationship of a multi-component system using the interaction parameters obtained by the regression of the phase equilibrium data of the binary system. The interaction parameters between the components obtained by directly determining the phase equilibrium of the multivariate system will bring the calculated values closer to the experimental values. Liquid–liquid equilibrium (LLE) data were determined for the system of n-butanol + n-pentanol + n-hexanol + water at 313.15, 323.15, and 333.15K under atmospheric pressure. LLE compositions were determined by gas chromatography. LLE data were correlated by the UNIQUAC model and the non-random two-liquid (NRTL) model. Both models were appropriate for describing the LLE of this quaternary equilibrium system. They provided accurate thermodynamic parameters for the phase equilibrium of C4–6 mixed alcohols in Fischer–Tropsch synthesis water.
研究领域:
化学工程
·
热力学
·
相平衡建模
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2017
·
IF 2.323
Shiming Xu,Wei Wang,Xi Wu,Jungyong Hu,Mengnan Jiang
Vapor–liquid equilibrium data of binary working pairs play a crucial part in the research of absorption process and absorption refrigeration technology. In this paper, the VLE data of binary mixtures, R124-NMP and R124-DMF, were measured in a temperature range from 303.15 to 363.15 K, using a VLE measurement apparatus. The activity coefficient model of five-parameter nonrandom two liquid (NRTL) was selected to correlate all the VLE data acquired by measurement. The maximum relative deviation of the pressure between the measurement data and calculated data for R124-NMP and R124-DMF were 3.80% and 3.27% respectively, and the average relative deviation of the pressure were 1.25% and 1.17% respectively. The correlated results coincide well with the measurement data and show that the VLE characteristics of R124-NMP and R124-DMF mixtures have a negative deviation from Raoul’s law. Comparing three absorbents, DMF, DMAC and NMP, the activity coefficient of R124 in DMF is largest, that in DMAC is second, and that in NMP is smallest.
研究领域:
热力学
·
制冷与空调
·
化学工程
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2022
·
IF 5.518
Ding Tingji,Wang Ruihe,Xu Jiafang,Ma Jiayue,Wang Xiaohui,Xue Jiawen,Yang Xiaolong
During deepwater drilling operation, the wellbore temperature decreases with the increase of water depth, and increases rapidly with the increase of formation depth. Temperature sensitive polymers can change the molecular conformation with temperature, and then change its hydrophobicity , to adjust the network structure between solid particles and polymer in drilling fluid. In this paper, a novel temperature sensitive copolymer poly(N-vinylcaprolactam- co -N,N-diethyl acrylamide) (PNVDE) was synthesized. Its molecular structure, molecular weight and molecular weight distribution were characterized. The effects of salinity, pH value and copolymer concentrations on lower critical solution temperature (LCST) were studied. Based on the temperature sensitive property of the copolymer, the ability to control the low-temperature rheology of water-based drilling fluid (WBDF) was studied. The results showed that PNVDE can effectively control the rheology of deepwater WBDF in the range of 4~ 60 ℃. At the same time, the experiments of temperature and salt resistance showed that the copolymer has strong ability of temperature resistance and salt resistance, and can withstand the temperature alternation of drilling fluid. The synergistic effect of PNVDE and bentonite made the rheology of deepwater drilling fluid stable, which can be explained by “SASA Hydrogen Bond Network”.
✓ 已验证
产品关联
DOI
高影响因子
Chinese Physics C
·
2023
·Vol. 47
·期 3
·034001
·
IF 3.6
Long He,Junhua Luo,Li Jiang
Measurement of the cross-sections of the 79Br(n, 2n)78Br, 81Br(n, p)81mSe, 81Br(n, α)78As, and 79Br(n, α)76As reactions was performed at specific neutron energies, precisely, 13.5±0.2, 14.1±0.2, 14.4±0.2, and 14.8±0.2 MeV, relative to the standard 93Nb(n, 2n)92mNb and 27Al(n, α)24Na reference reactions using offline γ-ray spectrometry and neutron activation. Monoenergetic neutrons were generated at the China Academy of Engineering Physics via a 3H(d, n)4He reaction using the K-400 Neutron Generator equipped with a solid 3H-Ti based target. The activity of the reaction produce was obtained using a high-purity germanium detector. The cross-sections of the (n, 2n), (n, p), and (n, α) reactions on the bromine isotopes were measured in the 13–15 MeV neutron energy range. The covariance analysis approach was employed for a thorough inspection of any uncertainties within the measured cross-section data. A discussion and comparison of the observed outcome were carried out with previously published data, especially with the results of the JENDL-4.0, JEFF-3.3, TENDL-2019, and ENDF/B-VIII.0 data libraries, along with the theoretical excitation function curve derived by employing the TALYS-1.95 program. Improved cross-section restrictions for the investigated processes in the 13–15 MeV neutron energy range will be obtained using the current findings, which will help to raise the caliber of associated databases. Furthermore, the parameters of relevant nuclear reaction models can be verified using this data.
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2026
·
IF 6
Xiao-Dong Kang,Guo-Hua Zhang
To address the challenge of balancing hardness, toughness, and strength in Ti(C, N)-based cermets, existing research predominantly focused on composition design and sintering optimization, while comparatively less attention was paid to the critical role of initial Ti(C, N) powder characteristics in determining properties. In this study, high-quality Ti(C, N) powders with varying C/N ratios were synthesized via carbothermal reduction-nitridation (CRN) coupled with Ca treatment, followed by the fabrication of Ti(C, N)-20WC-5Mo-5Ni-5Co (wt%) cermets using vacuum pre-sintering assisted spark plasma sintering (SPS). The prepared powders were characterized by the absence of free carbon, low oxygen content, uniform morphology, superior crystallinity, and excellent dispersibility. After sintering, all samples achieved high densification, comprising the (Ti, W, Mo)(C, N) hard phase, (Co, Ni) binder phase, and trace residual WC. The ceramic grains mainly displayed black core-gray rim, black core-rimless, and white core-gray rim structures, characterized by overall thin rims. As the C/N ratio decreased, the dissolution-precipitation process during sintering was inhibited. Accordingly, hardness exhibited an initial decline followed by an increase, whereas the fracture toughness ( K IC ) showed an opposite trend. Transverse rupture strength (TRS) peaked at an intermediate C/N ratio. Cermet derived from Ti(C 0.44 , N 0.56 ) powder achieved an optimal combination of properties, with hardness, K IC , and TRS values of 1867 ± 12 HV 30 , 9.13 ± 0.21 MPa m 1/2 , and 1748 ± 75 MPa, respectively. The synthesized high-quality Ti(C, N) powders provided a crucial foundation for microstructural control and improved overall properties of cermets, and adjusting the C/N ratio served to further optimize the balance among hardness, toughness, and strength.
✓ 已验证
DOI
高影响因子
LANGMUIR
·
2026
·
IF 4.4
Wenchao Ma,Na Du,Wanguo Hou
Surfactant-free microemulsions (SFMEs) are unique microemulsions, which form from immiscible liquids (generally called oil and water components) in the presence of amphi-solvents rather than traditional surfactants. Our understanding of SFMEs is still limited. One of the questions to be explored is whether the surfactant-free systems can form the middle-phase (or Winsor III) microemulsions like the surfactant-containing systems. In the current work, the phase behavior of the ternary mixture of n-hexadecane (HDA), n-butanol (BuOH), and water was investigated at different temperatures (20–90 °C), where amphi-solvent BuOH is completely miscible with HDA (oil) but partially miscible with water. The single-phase, two-phase, and three-phase patterns were observed for the ternary mixture, depending on its composition. The area of the three-phase region in the ternary phase diagram decreases with an increase in T (20–55 °C). The mesoscale structuring of the ternary mixture samples with different existing states was determined using dynamic light scattering, electrical conductivity, and cryogenic and negative-staining transmission electron microscopy techniques. The middle phase of the three-phase systems was identified as the bicontinuous (BC) microemulsion, demonstrating that the middle-phase (or Winsor III) microemulsion can be formed without traditional surfactants. In addition, the Winsor I, II, and IV microemulsion systems were also identified in the ternary mixture. This work provides a better understanding of the features of SFMEs.
✓ 已验证
DOI
PubMed
高影响因子
ACTA PHYSICO-CHIMICA SINICA
·
2026
·
IF 13.5
Youjian Chen,Yuxin Liu,Xu Yang,Lanchao Wen,Haifeng Li,Hongcheng Shang,Siyao Cheng,Wei Dong,Aming Xie
N-doped carbon materials are promising electromagnetic wave (EMW) absorbers, yet the distinct roles of N configurations (Graphitic-N, Pyridinic-N, and Pyrrolic-N) in dielectric loss remain unclear. This work introduces a ligand-centered molecular design strategy using 2-methylimidazole and 4-dimethylaminopyridine to precisely modulate N configurations. Systematic characterization reveals that 4-dimethylaminopyridine stabilizes Pyrrolic-N, increasing its content to 42.95% while reducing Graphitic-N to 9.57%, which introduces defects and enhanced polarization centers. Combining Debye relaxation theory and first-principles calculations, we quantitatively decouple dielectric contributions: Graphitic-N enhances conduction loss via improved carrier mobility, whereas Pyrrolic-N governs polarization loss. As a result, the Graphitic-N rich NC-M sample achieves a minimum reflection loss (RL) of −70.82 dB at 1.97 mm, while the Pyrrolic-N-rich NC-D sample extends the effective absorption bandwidth (EAB) to 5.9 GHz. This work establishes a clear structure-activity relationship, offering a rational pathway for designing configuration-controlled EMW absorbers. This work systematically elucidates the influence of different nitrogen configurations on the electromagnetic response mechanisms of materials by modulating the arrangement of nitrogen atoms, providing theoretical guidance and practical foundations for designing and constructing high-performance nitrogen-doped carbon-based materials for electromagnetic wave absorption. Download: Download high-res image (298KB) Download: Download full-size image
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2011
·
IF 2.089
Lina Dong,Min Liu,Guangqian Li,Lili Wang,Dezhi Sun,Xilian Wei,Youying Di
Densities (ρ) of N,N′-hexamethylenebisacetamide (HMBA) in pure water and aqueous glucose and sucrose solutions have been measured at T = (288.15, 293.15, 298.15, 303.15, and 308.15) K with a quartz vibrating-tube densimeter. These experimental data have been used to calculate some important physical parameters, including apparent molar volumes (Vϕ), limiting partial molar volumes (Vϕ0), and transfer partial molar volumes (ΔtrsVϕ0). Another physical parameter, molar refraction at the sodium-D line (RD), has been computed from the refractive index (nD) measured by a refractometer at 298.15 K. The variations of all above parameters are discussed in terms of interactions occurring in the solutions.
研究领域:
溶液化学
·
物理化学
·
热力学
·
分子间相互作用
✓ 已验证
DOI
高影响因子
Vietnam Journal of Chemistry
·
2021
·Vol. 59
·期 3
·389-394
·
IF 0
Nguyen Thi Ngoc Mai,Nguyen Van Dat,Trinh Thi Huan,Duong Quoc Hoan
A reasonable and chemoselective approach for N -formylation of various amines with N , N -dimethylformamide in presence of acetic acid has been improved under irradiation of a domestic microwave oven. The method was found to be compatible with primary, secondary, aromatic and aliphatic amines with electron withdrawing and electron donating groups as well but did not support to form N -formate derivatives. N -formamides 1 , 2 , and 3 did not exhibit antibacterial activity on Gram(+), Gram(-) and fungi but compounds 1 , 2 , 18 and 19 showed weak antioxidant activity with SC: 36.8 %, 38.3 %, 45.7 %, respectively. Compound 18 exhibited antioxidant activity with SC 50 : 47.2 μg/mL.
研究领域:
有机化学
·
绿色化学
·
药物化学
·
微波辅助合成
✓ 已验证
DOI
POLYMER SCIENCE SERIES B
·
2014
·Vol. 56
·期 6
·799-806
·
IF 0.633
Xu Yewei,Sun Yi,Huo Jichuan,Lei Yonglin,Zhang Lin
A new bis(benzimidazolyl) monomer containing biphenyl group, 4,4′-bis(2-benzimidazolyl) diphenyl, was successfully synthesized from 4,4′-biphenyldicarboxylic acid and 1,2-phenylenddiamine. The corresponding biphenyl-containing poly( N -arylenebenzimidazole)s were prepared using C-N coupling reaction that removed the N-H sites from the novel bis(benzimidazolyl) derivative with activated aromatic difluorides in sulfolane. The reaction was carried out at 210°C in the presence of anhydrous potassium carbonate. All resulting polymers showed essentially amorphous patterns. This was consistent with the calculated results. Differential scanning calorimetry and thermogravimetric measurements showed that the polymers had high glass transition temperatures (>253°C) and good thermal stability with high decomposition temperatures (>457°C). These novel polymers also showed easy solubility.
研究领域:
高分子化学
·
材料科学
·
有机合成
·
高性能聚合物
·
热分析
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Qiannan Wu,Qijing Bu,Shuo Li,Yanhong Lin,Xiaoxin Zou,Dejun Wang,Tengfeng Xie
Inevitable drawbacks on α-Fe 2 O 3 photoanodes , such as poor conductivity, short hole diffusion length , high electron-hole recombination rate, limit their photoelectrochemical (PEC) performance for water oxidation . The construction of heterojunction is an effective approach to improve the PEC performance of photoanodes. Herein, we report the design of the WO 3 /Ti–Fe 2 O 3 heterojunction photoanodes, which are synthesized by two simple hydrothermal method . The optimized WO 3 /Ti–Fe 2 O 3 photoanode shows remarkably improved photocurrent of 2.15 mA/cm 2 at 1.23 V versus reversible hydrogen electrode (RHE) without additional cocatalyst , which is higher than that of previous literatures. The improvement benefits from reduced charge transfer resistance in the bulk of Ti–Fe 2 O 3 photoanode and improved charge separation efficiency, which can been further confirmed by electrochemical impedance spectroscopy (EIS), the transient photovoltage (TPV) and the work function (WF) measurement. The present work also provide new opportunities in developing high performance photoanodes for PEC water splitting .
研究领域:
材料科学
·
物理化学
·
能源科学
·
半导体光电化学
·
纳米材料
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2026
·
IF 8.8
Xiang Jin,Jie Xie,Zuojun Ding,Zhi Li,Xuerui Wang,Xuechao Gao,Xuehong Gu
N, N-dimethylacetamide (DMAc) is a typical strongly polar aprotic organic solvent, and its recovery by pervaporation (PV) dehydration is important for production sustainability. However, maintaining a stable permeation flux remains challenge because of the pronounced competitive adsorption of DMAc versus water on membrane surfaces. To address this issue, hollow fiber supported T-type zeolite membrane was modified in AgNO 3 solution to tune its intrinsic pore structure and surface properties. The optimal modification conditions were determined as 0.5 M AgNO 3 concentration with an 8 h exchange time. The PV results demonstrated that the Ag + -modulated membrane could effectively improve the stability in DMAc dehydration. Compared to a dramatic 69% flux loss observed in the original membrane at 373 K, the flux loss of the Ag + -modulated membrane was only 7% after 30 h in dehydrating a 5 wt% water/DMAc mixture. At a lower operation temperature of 353 K, the dehydration flux remained completely stable. The improvement is attributed to the weakened competitive adsorption of DMAc molecules, achieved by reducing surface polarity after Ag + modulation. In addition, the simulated results further revealed that Ag + modulation enhanced water adsorption, thereby creating a steric hindrance for DMAc molecules near the pore entrances. These results suggested that Ag + modulation effectively improves the long-term stability of T-type zeolite membrane for DMAc dehydration, and presents a promising strategy for dehydrating the similar solvents.
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）