Petroleum Science
·
2024
·
IF 6
Jian-Xun Wu,Shuo-Fan Li,Qi-Fu Li,Feng Yan,Qi-Lin Zhou,Shuai Ma,Ya-He Zhang,Suo-Qi Zhao,Quan Shi
Heavy oil is an important resource in current petroleum exploitation, and the chemical composition information of heavy oil is crucial for revealing its viscosity-inducing mechanism and solving practical exploitation issues. In this study, the techniques of high-temperature gas chromatography and high-resolution mass spectrometry equipped with an electrospray ionization source were applied to reveal the chemical composition of typical heavy oils from western, central, and eastern China. The results indicate that these heavy oils display significant variations in their bulk properties, with initial boiling points all above 200 °C. Utilizing pre-treatment and ESI high-resolution mass spectrometry, an analysis of the molecular composition of saturated hydrocarbons, aromatic hydrocarbons, acidic oxygen compounds, sulfur compounds, basic nitrogen compounds, and neutral nitrogen compounds within the heavy oil was conducted. Ultimately, a semi-quantitative analysis of the molecular composition of the heavy oil was achieved by integrating the elemental content. The semi-quantitative analysis results of Shengli-J8 heavy oil and a conventional Shengli crude oil show that Shengli-J8 heavy oil lacks alkanes and low molecular weight aromatic hydrocarbons, which contributes to its high viscosity. Additionally, characteristic molecular sets for different heavy oils were identified based on the semi-quantitative analysis of molecular composition. The semi-quantitative analysis of molecular composition in heavy oils may provide valuable reference data for establishing theoretical models on the viscosity-inducing mechanism in heavy oils and designing viscosity-reducing agents for heavy oil exploitation.
研究领域:
石油化学
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分析化学
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DOI
高影响因子
Russian Journal of Physical Chemistry A
·
2023
·Vol. 97
·期 6
·1239-1244
·
IF 0.7
Xiang Ji,Jin Hao,Ju Fan,Lu Yanzhen,Wang Fankuo
Abstract In this paper, we have synthesized a series of PdCu bimetallic nanoparticles (NPs) catalysts using the noble-metal-induced reduction process and investigated in detail by HRTEM, EDS mapping, XRD, and ICP-AES. More importantly, we also found that PdCu bimetallic NPs catalysts showed a compositional influence in the reaction of nitrobenzene reduction. When the palladium molar percentage of the PdCu NPs catalysts increases to more than 0.66, the main product is azoxybenzene. While the palladium molar percentage of the PdCu NPs catalysts dropped below 0.41, the main product is aniline. From the experimental results, the different catalytic results for nitrobenzene reduction could be attributed to the changes in the electronic structural and surface composition of the PdCu bimetallic NPs.
研究领域:
化学
·
催化材料科学
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DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2018
·
IF 3.909
Hongji Zhu,Li Tian,Lei Zhang,Jingxiu Bi,Qianqian Song,Hui Yang,Jianjun Qiao
This study explored the potential of spent Lentinus edodes substrate, a by-product of mushroom industries causing environmental pollution, serving as materials to produce antioxidant polysaccharide. The extraction process of spent Lentinus edodes substrate polysaccharide (SLSP) was optimized and the effects of drying methods on chemical composition, morphological property and antioxidant activity were investigated. Results showed that freeze-dried SLSP (SLSP-F) exhibited the best quality in terms of the polysaccharide yield (13.00%) and antioxidant activity. The EC 50 values of SLSP-F on DPPH, ABTS and superoxide anion radicals was 0.051 mg/mL, 0.379 mg/mL, 0.719 mg/mL, respectively, which was significantly lower than that of freeze-dried Lentinus edodes polysaccharide (LP-F). After purification by Sephadex G-150, the purified SLSP-F (PSP) has a molecular weight of 16.77 kDa. Compared with LP-F, PSP has more reducing sugars and uronic acids in chemical composition and higher contents of xylose, glucose and galactose in monosaccharide composition. FT-IR and NMR spectroscopy analysis revealed that PSP has both α and β glycosidic bonds and massive acetyl groups, which is different from LP-F mainly composed of 1, 3 linked α-D-Man p residue with some acetyl groups. The findings provided a reliable approach for the development of antioxidant polysaccharide from spent Lentinus edodes substrate.
研究领域:
农业科学
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食品科学
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生物技术
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药理学
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DOI
PubMed
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2016
·Vol. 125
·期 1
·155-162
·
IF 1.781
Liu Zhongguo,Wang Hui,Zhang Liyuan,Sun Daxin,Cheng Liang,Pang Cuicui
Sludge is an inevitable by-product of turbine oil during the operation of lubricating turbines. However, there are few reports of the detailed analytical results of the sludge. In addition, no global specification exists to evaluate the sludge formation from turbine oils. Hence, it is critical to analyze the contents of the sludge. In this study, we investigate both fresh and in-service (contains sludge) turbine oil based on ASTM standards. In-service turbine oil was first washed by petroleum ether to obtain the sludge and then characterized by FTIR, SEM, TG and EDAX. We found that the main compositions of sludge were C, O and N, while metals were <4 mass %. The analytical results show that antioxidant, defoamer, antirust and demulsifier are possible origins for the formation of sludge, which would be beneficial to decrease the sludge for the formulation of turbine oil.
研究领域:
化学工程
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环境科学
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产品关联
DOI
高影响因子
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
·
2022
·
IF 3.752
Hong-fu LIN,Wei WENG,Shui-ping ZHONG,Guan-zhou QIU
High-efficiency recovery of Zn and Pb from silicon-rich zinc leaching residues is realized in a rotary kiln. Characterizations by means of XRD, SEM, EDS and ICP reveal that the leaching residue contains 12.4 wt.% SiO 2 , 16.1 wt.% Zn, and 7.4 wt.% Pb. Thermodynamic analysis shows that metallic vapor of Zn and Pb can be easily generated from the zinc leaching residue at 1150−1250 °C inside the rotary kiln. Viscosities and melting points of 13 slag compositions were analyzed and three slag compositions (47wt.%SiO 2 −23wt.%CaO−30wt.%FeO, 40wt.%SiO 2 − 28wt.%CaO−32wt.%FeO, and 40wt.%SiO 2 −30wt.%CaO−30wt.%FeO) possessed the desirable physical properties, with the melting point and viscosity in the range of 1150−1280 °C and 0.2−0.5 Pa·s, respectively. The industrial tests show that adopting the optimized slag composition can contribute to very high recovery rates of Zn and Pb (97.3% for Zn and 94.5% for Pb), corresponding to slags with very low average contents of Zn and Pb (0.51 wt.% Zn and 0.45 wt.% Pb). The National-Standard leaching tests of the water-quenched slags result in 1.82 mg/L Zn, ~0.01 mg/L Cu, 0.0004 mg/L As, ~0.01 mg/L Cd, 0.08 mg/L Pb, and ~0.02 mg/L Hg in the leachate, verifying the detoxification of the zinc leaching residue at the same time.
研究领域:
冶金工程
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环境科学
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DOI
高影响因子
Foods
·
2021
·Vol. 10
·期 8
·1755
·
IF 4.35
Zhili Sheng,Junmei Liu,Bao Yang
Astragalus membranaceusis a functional food with multiple bioactivities. It presents differentiated health benefits due to origins. Polysaccharides (APS) are the leading bioactive macromolecules ofA. membranaceus, which are highly related to its health benefits. However, the effect of origin on the structural characteristics of APSs remains unclear. In this work, polysaccharides from four origins were isolated and identified by NMR. The results showed APSs of four origins had identical monosaccharide composition and glycosidic linkage. Rhamnogalacturonan II pectins and α-(1→4)-glucan were the dominant polysaccharides. However, the level of methyl ester in pectins varied to a large extent. The molecular weight profiles of APSs were also different. Inner Mongolia APS had the largest percentage of 20–40 kDa polysaccharides. Molecular weight and methyl ester level were two important parameters determining the difference of APSs from four origins. These results were helpful to recognize the origin-related quality ofA. membranaceus.Keywords:glycosidic linkage;monosaccharide composition;NMR;pectin
研究领域:
植物学
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食品科学
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药理学
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DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2020
·
IF 5.162
Yuanhao Qiu,Zahra Batool,Rui Liu,Guoqing Sui,Bulei Sheng,Xinhua Zheng,Dan Xu
Three novel polysaccharides (PCPW, PCPS1 and PCPS2) were isolated from Potentilla chinensis and subjected to structural analysis by using spectral and physicochemical methods. The molecular weights of PCPW, PCPS1 and PCPS2 were calculated to be 4.45 × 10 3 Da, 1.18 × 10 4 Da and 4.23 × 10 4 Da, respectively. Analysis of monosaccharides composition confirmed that PCPW was composed of mannose, rhamnose, glucose, galactose and arabinose, while the two acidic polysaccharides PCPS1 and PCPS2 were consisted of six monosaccharides, including mannose, rhamnose, galacturonic acid, glucose, galactose and arabinose respectively. In addition, the main linkages of glycosidic bonds of PCPS2 were 1, 4-linked-rha, 1, 4-linked-man,1, 4-linked-galA and 1, 6-linked-man. Immunological tests indicated that both PCPW and PCPS2 could increase NO production of RAW264.7 cells, and promote splenocyte proliferation. All three polysaccharides proved to be activators of NF-κB. Overall, three polysaccharides showed a good immunological activity and pose great potential as a novel food or drug additive.
研究领域:
植物化学
·
免疫学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY
·
2019
·Vol. 96
·期 12
·1367-1377
·
IF 1.72
Zhong-Yuan Liu,Da-Yong Zhou,Kanyasiri Rakariyatham,Hong-Kai Xie,De-Yang Li,Bei-Wei Zhu,Fereidoon Shahidi
The current study shows the compositional changes and oxidation development of clam ( Ruditapes philippinarum , R. philippinarum ) lipids and frying oils when subjected to different processing conditions. Parameters measured include acid value, peroxide value (POV), thiobarbituric acid-reactive substances (TBARS), total oxidation (TOTOX), lipid classes, fatty acid composition, phosphatidylcholine (PC), and phosphatidylethanolamine (PE) contents together with major glycerophospholipid (GP) molecular species. Deep-fat frying increased triacylglycerol (TAG) content and decreased the contents of PC, PE, and GP molecular species in clam in a time-dependent manner. Meanwhile, minor amounts of free fatty acids, diacylglycerols, monoacylglycerols, and polar lipids were detected in frying oils, indicating lipid migration between the clam and frying oils. The time-dependent increase of POV, TBARS, and TOTOX in fried clams and frying oils with concurrent reduction of docosahexenoic acid and eicosapentaenoic acid indicates extensive oxidative degradation of clam lipids. Moreover, the moisture-rich clam aggravated the deterioration of frying oils. Consequently, deep-fat frying significantly altered the lipid profile and decreased the nutritional value of clams.
研究领域:
食品科学
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营养学
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生物化学
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2022
·Vol. 33
·期 15
·11625-11631
·
IF 2.779
Xing Zhuo,Weng Juhai,Ma Chi
A series of Ga 3+ -doped Zn 2 GeO 4 willemite ceramics, in a general formula Zn 2+0.5 x Ge 1− x Ga x O 4 (0.1 ≤ x ≤ 0.4), were prepared and the influence of Ga 3+ doping on the phase composition, structure, microstructure, and microwave dielectric properties were studied. XRD, SEM, and Raman analysis evidence that by moderate gallium substitution in the nominal Zn 2 GeO 4 , the unfavorable ZnO phase was suppressed, while a low-loss ZnGa 2 O 4 phase was induced. With increasing doping content, the ZnGa 2 O 4 phase increases in phase percentage and becomes dominant (~ 69%) after x = 0.3. Due to the mixture rule, both relative permittivity and quality factor were improved, which is related to the superior dielectric properties of ZnGa 2 O 4 compared to Zn 2 GeO 4 . The microwave dielectric properties show a remarkable dependence on the composition. Sintered at 1230 °C, a combination of dielectric performances with ε r ~ 9.4, Q × f ~ 97,000 GHz, and τ f ~ − 30.7 ppm/°C was accessed in the x = 0.4 composition.
研究领域:
材料科学
·
电子工程
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产品关联
DOI
高影响因子
Separations
·
2023
·Vol. 11
·期 1
·2
·
IF 2.6
Meijuan Zhao,Fengyan Kuang,Yingyue Zhang,Guangping Lv
Monosaccharide composition analysis is essential to the structural characterization and research into the biological activity of polysaccharides. In this study, a systematic comparison was performed among commonly used monosaccharide composition analysis methods, including colorimetric and chromatographic methods. These were tested on 16 aldoses, ketoses, alditols, amino sugars, and uronic acids. Furthermore, the effect of hydrolysis methods was also investigated. The results showed that the phenol sulfuric acid method is greatly affected by the type of monosaccharide that is used as the reference substance. The determination of uronic acid using sulfuric acid carbazole is less affected by neutral sugars than that method using m-hydroxybiphenyl. The high-performance thin-layer chromatography (HPTLC) method can simultaneously analyze multiple samples and accurately determine the type of uronic acid. High-performance liquid chromatography (HPLC) can provide a good qualitative and quantitative analysis of aldose, amino sugars, and uronic acids, while gas chromatography–mass spectrometry (GC-MS) can detect aldose, ketose, and alditols. Fructose was detected in a large amount in inulin andCodonopsis pilosulaafter one-step hydrolysis, while it was totally destroyed in two-step hydrolysis. The release of galacturonic acid significantly increased after two-step hydrolysis in pectin andLycium barbarum, which indicated that one-step hydrolysis is not enough for acidic polysaccharides. The results of this study are beneficial for selecting appropriate hydrolysis and analysis methods in order to accurately analyze the monosaccharide compositions of natural polysaccharides.Keywords:polysaccharide;monosaccharide composition;hydrolysis condition;detection method
研究领域:
分析化学
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生物化学
·
食品科学
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产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Jianqi Cao,Lei Zhang,Wanlin Wang,Daoyuan Huang,Yongqi Sun
As a dominant resource for vanadium extraction, roasting of vanadium-bearing slags involves the destruction of vanadium-containing phases, mainly including iron-vanadium spinels and liquid phase, and the formation of soluble vanadate. Extraction of vanadium from iron-vanadium spinels determines the efficiency of the whole process due to their ultrastabilities. Here the phase and composition evolutions of iron-vanadium spinels containing chromium were investigated by both advanced experimental characterizations (EPMA, XRD and XPS, etc.) and thermodynamic analysis. The roles of roasting conditions were clarified, including roasting temperature, time and the presence of chromium. It was found that, upon roasting, the iron-vanadium spinels underwent a phase transition to form two distinct phases, namely a vanadium-enriched phase and a Me 2 O 3 solid solution phase. A relatively high roasting temperature with a relatively long roasting time could enhance the completeness of the roasting reaction and improve the separation of vanadium from iron and chromium. The evolution of iron-vanadium spinels with the current compositions (n(FeO): n(V 2 O 3 ): n(CaO): n(Cr 2 O 3 ) = 4: 1: 2: 0.2) followed a three-step mechanism under the current roasting conditions, i.e., an initial step of the oxidation decomposition of spinels, a reaction between CaO and V 2 O 5 to form CaV 2 O 6 , and a final reaction between residual CaO and CaV 2 O 6 to form a Ca 2 V 2 O 7 phase. Moreover, the presence of chromium resulted in an increase in the Fe 2 O 3 concentration within the vanadium-enriched phase due the formation of a solid solution with an infinite miscibility between Cr 2 O 3 and Fe 2 O 3 . The findings of this study offer not only scientific insight with regard to the evolution of iron-vanadium spinels upon roasting but also significant guidance for the optimization of roasting conditions toward target vanadium extraction from iron-vanadium spinels.
研究领域:
冶金学
·
材料科学
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产品关联
DOI
高影响因子
JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
·
2025
·
IF 3.1
Baojie Zhu,Cunwu Chen,Jiaxian He,Shaoping Li,Jing Zhao
The interpretation of the chemical quality differences during Dendrobium huoshanense ( D. huoshanense ) traditional processing into ‘Fengdou’ is critical for scientifically evaluating the medicinal value, optimizing the processing methods, and ensuring the stability and predictability of its efficacy. In this study, the quality differences of polysaccharides during the processing of D. huoshanense were conducted utilizing high performance size exclusion chromatography coupled with multi-angle laser light scattering and refractive index detector (HPSEC-MALLS-RID), nuclear magnetic resonance (NMR) and saccharide mapping based on polysaccharides analysis by using carbohydrate gel electrophoresis (PACE) and high-performance anion exchange chromatography-pulsed amperometric detection (HPAEC-PAD). The results showed that the concentration of non-starch D. huoshanense polysaccharides (NDHP) rose and exhibited greater stability during the processing. The molecular weight (Mw), molecular weight distribution, cumulative molar mass, radius of gyration (Rz), and monosaccharide composition molar ratio of NDHP did not have significant changes during the processing, and these parameters would be affected by the presence of starch. The NMR investigation indicated that the primary glycosidic linkages of β -1,4-Man p and β -1,4-Glc p , together with the acetyl group substitutions at O-2 and O-3 of 1,4-linked Man p , were unaltered. Additionally, the PACE and HPAEC-PAD profiles of acidic and enzymatic hydrolysates of NDHP were similar. These findings contribute to a deeper understanding of the changes in bioactive polysaccharides during the processing of D. huoshanense into ‘Fengdou’, providing theoretical support for improving its processing techniques.
研究领域:
中药学
·
分析化学
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）