JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2019
·
IF 2.298
Junshuai Chen,Ying Zhang,Taotao Zhan,Qi Zhou,Tian Lan,Maogang He
Methyl caprylate is expected to be one of the main components of biodiesel due to its high cetane number and good oxidation stability. Details of the experimental speeds of sound in methyl caprylate are very scarce, especially in high-temperature regions. Therefore, the speed of sound in liquid methyl caprylate was measured by the Brillouin light scattering method in the temperature range of 298.22–608.38 K and at pressures of up to 10 MPa. The relative expanded uncertainty of the speed of sound is estimated to be less than 1.32% (coverage factor k = 2). The variation of the speed of sound with the temperature and pressure was analyzed. Besides, the correlation for the speed of sound as a function of temperature and pressure is presented based on the experimental data. The absolute average of relative deviation between the experimental data and the calculated results is 0.29%.
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高影响因子
ANALYTICAL CHEMISTRY
·
2015
·
IF 5.636
Lu Li,Ping Li,Juan Fang,Qingling Li,Haibin Xiao,Hui Zhou,Bo Tang
Considering the important functions of cellular Na+ and K+ together with their cooperative efforts on various biological processes, it is significant to simultaneously detect Na+ and K+ at a single-cell level. Here, we present a novel method to discriminate and quantify simultaneously Na+ and K+ in single cells using a new near-infrared fluorescent probe associated with microchip electrophoresis. The fluorescent probe selectively responds to both Na+ and K+. The microchip electrophoresis allows accurate single-cell manipulation and effective distinction of Na+ and K+. Based on the method, the concentration of Na+ and K+ in single normal and cancer cells was compared, and the variation of Na+ and K+ in single cancer cells during the early stage of apoptotic volume decrease was monitored, which would help us to better understand the critical roles of Na+ and K+ in malignant cells and apoptosis. This method has paved a new way for the research of the synergistic function of Na+ and K+ in the regulation of various biological processes at a single-cell level.
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PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2015
·
IF 2.605
Renping Cao,Qingqiang Xiong,Wenjie Luo,Donglan Wu,Xiao Fen,Xiaoguang Yu
A series of SrAl [4−(4 x )/3] O 7 : x Mn 4+ (0≤ x ≤1.4 mol%) and Sr (1−0.06/2) Al [4−(4×0.008)/3] O 7 :0.008Mn 4+ ,0.06R + (R + =Li + , Na + , and K + ) phosphors are synthesized by a conventional solid-state reaction method in air. The PLE bands peaking at~325, 395, and 470 nm and the strongest PL band peaking at~660 nm are assigned to the 4 A 2 → 4 T 1 transition of Mn 4+ ion and O 2− –Mn 4+ change transfer band, 4 A 2 → 2 T 1 , 4 A 2 → 4 T 2 , and 2 E → 4 A 2 transitions, respectively. The optimum Mn 4+ doping concentration is about 0.8 mol%. Li + , Na + , and K + ions used as charge compensator can improve observably the PL intensity of SrAl 4 O 7 :Mn 4+ phosphor with excitation 325 nm. The fluorescence lifetimes of SrAl [4−(4×0.008)/3] O 7 :0.008Mn 4+ and Sr [1−0.06/2] Al [4−(4×0.008)/3] O 7 :0.008Mn 4+ ,0.06 R + (R + =Li + , Na + , and K + ) are 0.958, 0.97, 1.113 and 0.965 ms, respectively. The luminous mechanism is explained by schematic energy level diagram of Mn 4+ ion. These experiment results indicate that SrAl 4 O 7 :Mn 4+ ,R + (R + =Li + , Na + , and K + ) phosphors can be used as red emitting phosphor candidate for white LEDs based on a UV (~325 nm) and near UV (~395 nm) bands of LEDs chip.
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Petroleum Science
·
2024
·
IF 6
Jing Tan,Wei Zhang,Xiu-Ling Yan,Hao Zhou,Sher Bahadar Khan,Seitkhan Azat,Shi-You Yan,Hao-Jie Ma,Xin-Tai Su
Humic acids (HAs) are widely used as filtrate and viscosity reducers in drilling fluids. However, their practical utility is limited due to poor stability in salt resistance and high-temperature resistance. High-temperature coal pitch (CP) is a by-product from coal pyrolysis above 650 °C. The substance's molecular structure is characterized by a dense arrangement of aromatic hydrocarbon and alkyl substituents. This unique structure gives it unique chemical properties and excellent drilling performance, surpassing traditional humic acids in drilling operations. Potassium humate is prepared from CP (CP-HA-K) by thermal catalysis. A new type of high-quality humic acid temperature-resistant viscosity-reducer (Graft CP-HA-K polymer) is synthesized with CP-HA-K, hydrolyzed polyacrylonitrile sodium salt (Na-HPAN), urea, formaldehyde, phenol and acrylamide (AAM) as raw materials. The experimental results demonstrate that the most favorable conditions for the catalytic preparation of CP-HA-K are 1 wt% catalyst dosage, 30 wt% KOH dosage, a reaction temperature of 250 °C, and a reaction time of 2 h, resulting in a maximum yield of CP-HA-K of 39.58%. The temperature resistance of the Graft CP-HA-K polymer is measured to be 177.39 °C, which is 55.39 °C higher than that of commercial HA-K. This is due to the abundant presence of amide, hydroxyl, and amine functional groups in the Graft CP-HA-K polymer, which increase the length of the carbon chains, enhance the electrostatic repulsion on the surface of solid particles. After being aged to 120 °C for a specified duration, the Graft CP-HA-K polymer demonstrates significantly higher viscosity reduction (42.12%) compared to commercial HA-K (C-HA-K). Furthermore, the Graft CP-HA-K polymer can tolerate a high salt concentration of 8000 mg·L − 1 , measured after the addition of optimum amount of 3 wt% Graft CP-HA-K polymer. The action mechanism of Graft CP-HA-K polymer on high-temperature drilling fluid is that the Graft CP-HA-K polymer can increase the repulsive force between solid particles and disrupt bentonite's reticulation structure. Overall, this research provides novelty insights into the synthesis of artificial humic acid materials and the development of temperature-resistant viscosity reducers, offering a new avenue for the utilization of CP resources.
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JOURNAL OF CHEMICAL THERMODYNAMICS
·
2016
·
IF 2.196
Yunxue Gao,Shuni Li,Quanguo Zhai,Yucheng Jiang,Mancheng Hu
The (solid + liquid) phase equilibrium of the ternary system (NaCl + RbCl + H 2 O) at T = (288.15, 298.15 and 308.15) K was studied by the method of isothermal solution saturation. Moreover, the density and refractive index of the solution was also determined. The solid phase was studied by the Schreinemaker’s wet residue method and verified by X-ray diffraction. The results show that each of the phase diagrams contains one invariant point, two univariant curves, and three crystallization regions. The crystallization region of NaCl increased obviously with the temperature increasing, while the crystallization regions of RbCl and the mixed crystallization region of (NaCl + RbCl) decreased a little. Furthermore, there are break points at the invariant points for density and refractive index curves.
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高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2017
·
IF 2.323
Dong-Fang Zhao,Li-Sheng Wang,Jian Sun,Chuan-Ming Chen
A phosphorus flame retardant named N,N′-piperazinebis(neopentylglycol)phosphoramidate (PBNGP) was synthesized and characterized by elemental analysis, Fourier transform infrared spectroscopy, mass spectra, and nuclear magnetic resonance. Its thermal properties were evaluated via thermogravimetric analysis and differential scanning calorimetry. The solubilities of PBNGP in selected solvents at T = (293.15 to 333.15) K and atmospheric pressure were measured via a static-analytic method. The experimental data were correlated with Scatchard–Hildebrand, Buchowski-Ksiazczak, Wilson, nonrandom two liquid, and universal quasichemical equations. The calculated results showed that all of these models can reproduce the experimental data well, and the Wilson model gives the best correlation, with an overall relative standard deviation of 0.70%. The solubility parameter of PBNGP was calculated using the Scatchard–Hildebrand methodology.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2014
·
IF 2.045
Kelei Zhuo,Hao Ren,Yujing Wei,Yujuan Chen,Jingjing Ma
Activity coefficients of the 1-alkyl-3-methylimidazolium bromide [Cnmim]Br (n = 3 to 8) ionic liquids (ILs) in fructose + water mixed solvents at 298.15 K were determined by cell potential measurements. The molalities of [Cnmim]Br ranged from (0.005 to 0.1) mol·kg–1 and those of fructose from (0.2 to 0.8) mol·kg–1. Gibbs free energy interaction parameters were also obtained together with salt constants. The interactions between [Cnmim]Br and fructose are mainly controlled by electrostatic interactions. Gibbs free energy interaction parameters (gES) and salting constants (kS) are negative for the ILs (n = 3 to 6), indicating fructose are salted-in by the ILs in water, whereas fructose are salted-out by the ILs (n = 7 and 8).
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高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2013
·
IF 2.004
Shidong Tian,Shuhang Ren,Yucui Hou,Weize Wu,Wei Peng
Densities and viscosities of 1,1,3,3-tetramethylguanidium lactate ([TMG]L) (1) + H2O (2) with different compositions were determined at temperatures from (303.15 to 328.15) K. Densities of [TMG]L (1) + H2O (2) decrease with the increase of temperature. However, when the mole fraction of water is lower than 0.5, the water content does not have an obvious influence on the density of [TMG]L. When the mole fraction of water is greater than 0.5, the densities of [TMG]L (1) + H2O (2) decrease obviously with further increasing the mole fraction of water. Viscosity of [TMG]L decrease dramatically with the increase of temperature and the water content. Excess molar volumes (VE) and viscosity deviations (Δη) of the binary mixtures were calculated by the experimental data and fitted to the Redlich–Kister equation with four parameters. The result shows that the values of VE and Δη for the binary mixtures are negative over the whole composition range and temperatures from (303.15 to 328.15) K. The negative of the excess properties indicates a strong interaction between the ionic liquid and water. The partial molar volumes (V̅i), excess partial molar volumes (V̅iE), Gibbs energy of activation for viscous flow (ΔG*), and excess Gibbs energy of activation for viscous flow (ΔG*E) of the binary mixtures were also calculated based on the densities and viscosities data. Besides, the Jouyban–Acree model was used to correlate the densities and viscosities of the binary mixtures with respect to the mixture composition and temperature simultaneously.
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高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2015
·
IF 2.133
Yunsheng Liu,Dajiang Mei,Jingli Xu,Yuandong Wu
New alkali metal zinc selenites, A 2 Zn 3 (SeO 3 ) 4 · X H 2 O (A=Li, Na, K; X =2 or 0) were prepared through hydrothermal reactions . Li 2 Zn 3 (SeO 3 ) 4 ·2H 2 O ( 1 ) crystallizes in the monoclinic space group P 2 1 / c with lattice parameters a =8.123(4), b =9.139(4), c =7.938(3) Å, β =112.838(9)°. Na 2 Zn 3 (SeO 3 ) 4 ·2H 2 O ( 2 ) crystallizes in the monoclinic space group C2/c with lattice parameters a =15.7940(18), b =6.5744(8), c =14.6787(17) Å, β =107.396(3)°. K 2 Zn 3 (SeO 3 ) 4 ( 3 ) crystallizes in the monoclinic space group C2/c with lattice parameters a =11.3584(12), b =8.6091(9), c =13.6816(14) Å, β =93.456(2)°. The anionic structures are composed of [Zn 3 O 12 ] 18− sheets, chains, and “isolated” units in compound 1, 2, 3, respectively, and trigonal pyramids SeO 3 2− . The compounds were characterized by the solid state UV–vis–NIR diffuse reflectance spectroscopy , infrared spectra and thermogravimetric analysis .
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高影响因子
JOURNAL OF SOLUTION CHEMISTRY
·
2013
·Vol. 42
·期 10
·1879-1887
·
IF 1.128
Guo Song,Yang Wenge,Hu Yonghong,Wang Kai,Luan Yuanyuan
The solubility of N -acetylglycine was measured in methanol, ethanol, propanol, isopropanol, n -butanol and ethyl formate in the temperature range between 278.15 and 319.15 K under atmospheric pressure by a gravimetric method. The solubility of N -acetylglycine in those selected solvents increases with increasing temperature. The solubility data were correlated with the van’t Hoff equation, the modified Apelblat equation and the λh equation to obtain the corresponding model parameters. The experimental results could be useful for optimizing the industrial process of purification of N -acetylglycine.
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高影响因子
JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
·
2015
·
IF 2.979
Hui Liu,Yong-Sheng Wang,Xian Tang,Hui-Xian Yang,Si-Han Chen,Hui Zhao,Shan-Du Liu,Yu-Feng Zhu,Xiao-Feng Wang,Yan-Qin Huang
A sensitive, lable-free and low cost fluorescence aptasensor was developed for detecting 8-hydroxy-2′-deoxyguanosine (8-OHdG) by using 8-OHdG aptamer (Apt) as a recognition probe and N-methyl mesoporphyrin IX (NMM) as a reporter. The method is based on the conformational switching of a K + -stabilized G-quadruplex to a 8-OHdG-stabilized one. NMM can selectively bind to K + -stabilized G-quadruplex instead of 8-OHdG-stabilized one. The addition of 8-OHdG in the solution of Apt - K + ions leads to a sharp change in fluorescence intensity, which showed a good linear response toward 8-OHdG concentration ranging from 3.96 nM to 211 nM with a detection limit of 1.19 nM. The relative standard deviation and the recovery were 1.23–3.26% ( n = 11) and 94.8–106.7%, respectively. The proposed aptasensor consists of only an aptamer probe and a specific dye NMM, avoiding the complex and expensive labeling procedure. Thus it is much cheaper and more applicable.
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PubMed
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2017
·
IF 2.323
Yunxue Gao,Shuni Li,Quanguo Zhai,Yucheng Jiang,Mancheng Hu
Complete phase diagrams and physico-chemical properties for the ternary system (CsCl + NaCl + H2O) were determined at T = (298.15, 308.15, and 318.15) K, respectively. The X-ray diffraction method and Schreinemaker’s wet residue method were used to verify the solid phase. The phase diagrams show this ternary system is a complex type. Three crystallization regions were found corresponding to the single salt NaCl, a compound CsCl·2NaCl·2H2O, and a solid solution series [Cs1–x(Na·H2O)x]Cl (x in [Cs1–x(Na·H2O)x]Cl changed from 0 to 0.43 (298.15 K), 0.39 (308.15 K), and 0.36 (318.15 K) at each temperature. With rising temperature, the crystallization area of NaCl increased, but CsCl·2NaCl·2H2O and [Cs1–x(Na·H2O)x]Cl decreased simultaneously. However, density and refractive index increased with increasing CsCl concentration.
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高影响因子
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