JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2026
·
IF 2.4
Zhao Lei,Yuhang Chen,Long Cheng,Maogang He,Ying Zhang
n-Dodecane is one of the key components of aviation kerosene. Although thermal conductivity data for n-dodecane is quite abundant, direct measurements of thermal diffusivity remain scarce, particularly in the vicinity of the aviation kerosene critical point. In this work, we measured the thermal diffusivity of n-dodecane using dynamic light scattering method in a temperature range of (290.15–633.15) K along seven isobars at p = (0.1, 1.0, 1.5, 1.8, 2.0 2.5 and 5.0) MPa and analyzed the thermal diffusivity as affected by temperature and pressure. The relative combined uncertainty of the thermal diffusivity experimental system is estimated to be 0.026 at a coverage factor of k = 2 with the level of confidence 0.95. The polynomial correlation of the thermal diffusivity against the temperature and pressure was proposed. The absolute average relative deviation and maximum relative deviation between the calculated results and experimental data are 0.68% and 2.98%, respectively. This study accurately measured the thermal diffusivity over a wide temperature range. It is expected to fill the gap in the existing literature and provide support for the exploration of the near-critical zone phenomenon.
✓ 已验证
DOI
高影响因子
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY
·
2024
·
IF 1.8
Jia-Yue Wang,Chen Yan,Han Sen-Jian,Guo Ya-Fei,Wang Shi-Qiang
To achieve efficient separation of alkali metal borate resources from the brines of the salt lake to provide a theoretical basis, this paper adopts the isothermal dissolution equilibrium method to study the solid-liquid phase equilibrium and phase diagram of the ternary system (LiB 5 O 8 + KB 5 O 8 + H 2 O) and (LiB 5 O 8 + NaB 5 O 8 + H 2 O) at 288.15 K. The study grasps the changing law of solubility and physicochemical properties of the system, as well as analyses and identifies the solid phase in stable equilibrium. The results show that the stable phase diagrams of the two ternary systems at 288.15 K are of the simple eutectic type, containing one invariant point, two univariate saturated solubility curves, and two crystalline regions. Among them, the crystalline region of LiB 5 O 8 ·5H 2 O is the smallest, indicating that it is not easy to precipitate from the saturated liquid phase, and the density and refractive index curves of each system show regular changes with the increase of LiB 5 O 8 content.
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2014
·
IF 2.045
Libin Chen,Ying Zhang,Sheng Wang,Xiong Zheng,Maogang He
The thermal diffusivities of 2-methoxy-2-methylpropane (MTBE, mass purity, > 0.990, GC) were measured by using the dynamic light scattering method at T = (303.15 to 493.15) K and p = (1.5 to 10) MPa, including saturated liquid, saturated vapor, and compressed liquid. The expanded relative uncertainty in thermal diffusivity was estimated to be less than 2.0 % over the entire investigated range. The polynomial representation for thermal diffusivity of MTBE was proposed by employing the experimental results. Comparing the calculated results with the experimental data, the average absolute deviations are 0.59 % for saturated liquid, 0.38 % for saturated vapor, and 0.43 % for compressed liquid.
研究领域:
化学工程
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2023
·
IF 2.6
Weichao Qin,Zenghui Li,Xinzi Zhou,Xiaolu Zhang,Xianyang Meng,Jiangtao Wu
Viscosity measurements for n-octane, ethylcyclohexane, and their binary mixtures were performed by using a vibrating-wire viscometer at temperatures between 283.15 and 363.15 K and pressures from 0.1 to 20 MPa. The combined expanded uncertainty (k = 2) of the experimental results is better than 0.02. The extended hard-sphere model was used to correlate the experimental results, and the relative deviations between the experimental data and calculated results were mostly within 1%. Moreover, the viscosity models of pure hydrocarbons combined with the mixing rules were applied to predict the viscosities of these binary mixtures. It is found that the deviations of the predicted results and the experimental viscosity data are generally within 4%.
研究领域:
化学工程
·
物理化学
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2023
·
IF 2.6
Jiale Wang,Guang Yao,Dong Hu,Sheng Huang,Junqi Liu,Quan Zhu
In order to investigate the interactive effect on the density of two-component mixtures, six mixtures of methylcyclohexane(1) + n-dodecane(2)/n-tetradecane(2)/n-hexadecane(2) and ethylcyclohexane(1) + n-dodecane(2)/n-tetradecane(2)/n-hexadecane(2) were measured by using the Anton Paar DMA 4200 M densimeter and a hand-operated pressure pump in the temperature and pressure ranges of T = 280 to 423.15 K and P = 0.1 to 9 MPa, respectively. Additionally, the combined standard uncertainty in the density of binary mixtures with n-hexadecane is uc(ρ) = 1.543 kg/m3, and for other mixtures, it is uc(ρ) = 1.541 kg/m3. The experimental data were successfully correlated with the empirically modified Toscani–Szwarc equation of state with a maximum regression deviation of less than 1.0630 kg/m3 for all the binary mixtures. On the basis of the experimental data and parameters of the regression model, isobaric thermal expansivity and isothermal compressibility were calculated and exhibited nonlinear behavior against the mole fraction, which is due to different molecular interactions between the two components.
研究领域:
物理化学
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
ACS Omega
·
2026
·Vol. 11
·期 35
·53469-53476
·
IF 5.2
Lu Xin,Yuan Fangfang,Han Xiaojie,Qin Tingting,Wang Qianqian,Li Zengli,Ge Chuanjun,Shi Wenqing,Bai Haijiao,Wang Pei
Desmopressin, a synthetic
analog of vasopressin widely used in
the treatment of diabetes insipidus and bleeding disorders, is a representative
disulfide-containing peptide therapeutic prepared by Fmoc-based solid-phase
peptide synthesis (SPPS). Its unique sequence architecture, particularly
the spatial proximity between the N-terminal mercaptopropionic acid
residue Mpa(1) and the Tyr(2) residue, provides a distinct structural
environment for investigating sequence-dependent side reactions during
peptide manufacturing. The tert- butyl ( t- Bu) protecting group is widely employed for side-chain protection
in Fmoc-based solid-phase peptide synthesis (SPPS). However, under
certain reaction conditions, the highly reactive t- Bu + carbocation generated during acidic deprotection can
participate in nonspecific alkylation, leading to challenging process-related
impurities. In this study, we investigated a unique and highly site-selective
+56 Da impurity observed during side-chain deprotection. High-resolution
MS/MS analysis unambiguously identified this species as a site-selective
product arising from the migration of t- Bu from the
Tyr(2) side chain to the thiol group of Mpa(1). Based on the structural
features of desmopressin, in particular, the spatial proximity between
Tyr(2) and Mpa(1), we propose that the formation of this impurity
most plausibly proceeds via a vicinal-thiol-induced intramolecular
migration mechanism, which competes significantly with the conventional
diffusion-controlled carbocation intermediate intermolecular pathway.
Strengthening the scavenger conditions failed to eliminate this impurity,
further supporting the intramolecular migration mechanism induced
by vicinal thiol. This finding accounts for the observed site selectivity
that cannot be explained by the conventional carbocation intermediate
pathway alone. Guided by these mechanistic insights, we re-evaluated
the necessity of Tyr side-chain protection and proposed a “source-elimination”
strategy. Experimental validation demonstrated that the use of unprotected
Fmoc-Tyr-OH (free phenolic hydroxyl) completely suppressed the formation
of the t- Bu migration impurity and improved the crude
peptide purity to 93.5%. Overall, this study elucidates the formation
mechanism of t- Bu migration impurities and provides
a broadly applicable, mechanism-driven strategy for process optimization
in solid-phase peptide synthesis. While this study focuses on the
desmopressin system, the findings highlight a proximity-driven reactivity
pattern that may be relevant to other thiol-containing peptide sequences.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2025
·
IF 2.1
Xinyu Liu,Yuhang Chen,Zhao Lei,Long Cheng,Maogang He,Ying Zhang
Isooctane is an ideal gasoline component with a high octane number and low volatility. However, there is a lack of research on the thermal properties of isooctane, especially near the critical point. This work uses dynamic light scattering to measure the thermal diffusivity of isooctane in the temperature range of (298.15–583.15) K, along 8 isobaric lines p = (0.1, 2.0, 2.5, 2.7, 3.0, 3.5, 5.0, 7.5) MPa, and analyzes the trend of thermal diffusivity with temperature and pressure. The average relative combined expanded uncertainty of the thermal diffusivity is 0.0214. Meanwhile, the experimental data were compared with the calculated values from thermal conductivity, and the absolute average values of the relative deviation and maximum deviation were 2.88 and 8.22%, respectively.
研究领域:
物理化学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2020
·
IF 2.888
Qi Zhou,Taotao Zhan,Junshuai Chen,Maogang He,Ying Zhang
n -Decane is a major ingredient of many transportation fuels, and is widely used as the additive in engineering domain. To supplement the existing database, the speed of sound in n -decane was measured along five isobaric lines from (0.1 to 10) MPa and at temperatures between (298.32 and 653.93) K by the Brillouin light scattering method. With the level of confidence of 0.95 (coverage factor k = 2), the relative expanded uncertainty of our measurement system and that of the experimental speed of sound in n -decane were estimated to be less than 1.1% and 1.7%, respectively. Besides, the absolute average percentage deviation and the maximum deviation of the experimental results from values calculated with the recommended fundamental equation in the NIST Standard Reference Database 23 were found to be 1.0% and 4.4%, respectively. At the end, for temperatures between (303.15 and 373.15) K and at pressures up to 10 MPa, the derived properties of n -decane including density, isobaric heat capacity, isobaric thermal expansion, isothermal compressibility, isentropic compressibility and internal pressure were studied.
研究领域:
物理化学
·
工程热力学
✓ 已验证
产品关联
DOI
高影响因子
FLUID PHASE EQUILIBRIA
·
2019
·
IF 2.514
Ying Zhang,Qi Zhou,Taotao Zhan,Junshuai Chen,Maogang He
n -Pentane is one of the main components in many industrial fluids, and is widely used as the fuel. The speed of sound can be used for developing the Helmholtz energy formulation and calculating other thermodynamic properties, which has not been reported yet for supercritical n -pentane. In this paper, the speed of sound in supercritical n -pentane was measured by the Brillouin light scattering (BLS) technique within the temperature limits of (422.69–653.53) K along four isobars at p = (3.5, 6.0, 8.0, and 10.0) MPa. The relative uncertainty of our BLS experimental system is estimated to be less than 0.6% and the relative uncertainty of the reported speed of sound values is estimated to be 0.85% considering the influence of impurities in the sample. The dependences of the speed of sound on temperature and pressure were also analyzed. At the end, we compared the experimental data with the calculated values from the multiparameter EOS proposed by Span and Wagner and the Modified BWR EOS proposed by J. Ratanapisit and J.F. Ely. The AARD is 1.3% for the multiparameter EOS and 1.5% for the Modified BWR EOS, respectively.
研究领域:
物理化学
·
工程热物理
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2020
·Vol. 13
·期 5
·1135
·
IF 3.057
Lei Zha,Heping Li,Ning Wang
TC11 alloy is a promising structural material, and has a wide range of applications in many corrosive and high temperature hydrothermal systems. The passive film has an important influence on its electrochemical behavior. In this study, in-situ electrochemical methods (that is, open circuit potential (OCP), linear polarization (LP) and electrochemical impedance spectroscopy (EIS)) were used to monitor the long period electrochemical behavior of TC11 alloy in 0.01 M Na2SO4solution at 300 °C/10 MPa. The growth kinetics of the passive film was mainly studied. The correlation between the evolution of the electrochemical behavior and the growth of the oxide film was discussed. The results showed that although the OCP gradually stabilized after twenty thousand seconds, henceforth the polarization resistance (Rp) was still increasing due to the thickening of the passive film. An equivalent circuit was proposed to fit the EIS experimental data, leading to determination of film capacitance and film resistance. Besides, the electrochemical data was interpreted in terms of the point defect model (PDM). The EIS results are consistent with theRpresults.Keywords:TC11 alloy;passive film;time;high temperature and pressure;EIS;PDM
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FLUID PHASE EQUILIBRIA
·
2019
·
IF 2.514
Taotao Zhan,Ying Zhang,Junshuai Chen,Xiangyang Liu,Maogang He
n -Hexane is a significant component of industrial fluids. The speed of sound in supercritical n –hexane was measured by Brillouin light scattering (BLS) technique in the temperature range from (509.17–637.99) K along five isobars at p = (3.5, 4.5, 5.5, 6.5 and 7.5) MPa. The relative expanded measurement uncertainty in the speed of sound at the 95% confidence level is estimated to be 0.018. For the studied supercritical n –hexane, the change regularities of the speed of sound with increasing temperature and pressure are illustrated. Moreover, the well-known equation of state (EOS) proposed by Span and Wagner is assessed, and the absolute average deviation (AAD) between the experimental results and the calculated values is 0.89% for the whole examined p – T region.
研究领域:
物理化学
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2017
·
IF 3.648
Jing Zhang,Taotao Fu,Chunying Zhu,Youguang Ma
Densities and viscosities of glycine, L-alanine, L-valine, L-threonine and L-arginine in aqueous (0.1–0.5) mol·kg − 1 myo -inositol solutions were measured at T = (293.15, 303.15, 313.15 and 323.15) K and p = 0.101 MPa. The volumetric properties such as the apparent molar volume ( V φ ), the limiting partial molar volume ( V φ 0 ), the limiting partial molar volumes of transfer (Δ tr V φ 0 ), the limiting apparent molar expansibility ( E 2 0 ), Hepler's constant and the isobaric thermal expansion coefficient ( α 2 ) were calculated through density. The viscometric properties such as the B -coefficient, the free energies of activation per mole of solvent (Δ μ 1 0 ≠ ) and solute (Δ μ 2 0 ≠ ) were obtained from the experimental viscosity data. The derived parameters hydration number and solvation number were also calculated through apparent molar volume and B -coefficient. From the volumetric and viscometric properties, the solute-solute and solute-solvent interactions in the studied systems were analyzed on the basis of co-sphere overlap model and transition state theory . Finally, the group contribution method was applied to calculate the contribution of (NH 3 + , COO − ), CH 2 , OH and CNHNHNH 2 of amino acids to V φ 0 , B -coefficient and Δ μ 2 0 ≠ .
研究领域:
物理化学
·
热力学
·
溶液化学
✓ 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）