JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2018
·
IF 2.196
Jian Yang,Xianyang Meng,Jiangtao Wu
As the important industrial raw materials, n-pentene, n-hexene, and n-heptene are widely used as gasoline additives to improve the combustion characteristics of gasoline and polymerized monomer to synthesize many important polymer compounds. Therefore, reliable density data are significant for these fluids to apply in industry. In this work, new experimental densities of n-pentene, n-hexene, and n-heptene have been measured at pressures up to 100 MPa along nine isotherms between 283 and 363 K by using a high pressure vibrating-tube densimeter. The experimental system was calibrated using water and a vacuum and was tested with R134a over the entire temperature and pressure ranges. The combined expanded uncertainties of the temperature, pressure, and density with a level of confidence of 0.95 (k = 2) are estimated to be 16 mK, 0.062 MPa (p ≤ 60 MPa), 0.192 MPa (60 MPa < p < 100 MPa), and up to 0.6 kg·m–3 depending on the temperature and pressure ranges. The density data were correlated with the Tait-like equation, and the average absolute deviations are 0.06, 0.04, and 0.05%. Furthermore, the isothermal compressibility and the isobaric thermal expansivity were derived from the Tait-like equation over the experimental temperature and pressure ranges.
研究领域:
化学工程
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2019
·
IF 3.771
Fuzhou Wang,Guoyong Xu,Qingshan Li,Ryo Tanaka,Yuushou Nakayama,Takeshi Shiono
The first example of a 3-alkene polymerization has been successfully achieved with 3-heptene in the presence of phenyl-substituted α- diimine nickel precatalysts activated by dMMAO, and compared with the corresponding linear alkenes, i.e., 1-pentene, 2-hexene and 4-octene polymerizations. The microstructures of the produced poly(3-heptene), which consists of ethyl , propyl and butyl branches indicated the 3,4- and 4,3-insertion, followed by chain-walking, with incorporation of a small fraction of long methylene sequences of 1,7-enchainment via monomer-isomerization. Late-transition metal catalyzed polymerization reactions of internal alkenes to synthesize novel polyolefin materials are highly important and also highly challenging. Upon activation with dried modified methylaluminoxane (dMMAO), the first example of a 3-alkene polymerization has been successfully achieved for 3-heptene catalyzed by phenyl-substituted α- diimine nickel complexes in comparison, and compared with the polymerizations of the corresponding linear alkenes, i.e., 1-pentene, 2-hexene and 4-octene. The results indicate that the polymerization of 3-heptene was achieved via chain-walking to generate branched amorphous polymers with glass transition temperature of ca. −68 °C. The microstructures of the produced poly(3-heptene) indicated the 3,4- and 4,3-insertion followed by chain-walking, the latter being predominant. The NMR analyses of the polymers showed that the obtained poly(3-heptene) possessed ethyl, propyl and butyl branches and a small amount of the long methylene sequence of 1,7-enchainment via monomer-isomerization. The branches structures were significantly dependent on the polymerization temperature, and the content of propyl branches derived from 3,4-insertion decreased with an increase in the polymerization temperature.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
Forensic Science Medicine and Pathology
·
2015
·Vol. 11
·期 4
·570-576
·
IF 1.983
Zhang Lin,Ma Jinghong,Li Shangxun,Xue Rui,Jin Ming,Zhou Yiwu
Diphenidol hydrochloride (DPN), a nonphenothiazinic antiemetic agent used primarily in patients with Meniere disease and labyrinthopathies to treat vomiting and vertigo, is considered to be a relatively safe drug. Since it was first approved in the United States in 1967, this drug has been widely used in Latin America and Asia and has contributed to sporadic suicidal and accidental poisonings in mainland China and Taiwan. However, its toxic or lethal concentration ranges have not yet been determined. We report a case of a 23-year-old female who suffered from DPN poisoning that resulted in death. At autopsy, there were no typical pathological findings, except for cerebral edema with high acetylcholinesterase expression. Postmortem analysis of DPN revealed 45 µg/ml in heart blood, 39 µg/ml in femoral vein blood, 141 µg/g in the liver, and 53 mg in the gastric contents. These concentrations indicated that the cause of death was DPN poisoning. The circumstances indicated that the manner of death was suicide. We also present a retrospective study, in which we review and summarize the literature from 1998 to 2014 and describe 16 cases of poisoning, including information from autopsy reports and postmortem drug concentrations. In forensic practice, drug residues at the scene, patients with convulsions and disturbance of consciousness, and rapidly occurring deaths, should draw attention to the possibility of this drug. Toxicological analysis and the exclusion of other diseases may ultimately be used to confirm DPN poisoning.
研究领域:
法医学
·
毒理学
·
临床医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POSTHARVEST BIOLOGY AND TECHNOLOGY
·
2025
·
IF 6.8
Lijun Ling,Rongxiu Mo,Wenyue Zhang,Yijuan Jiang,Fanjin Kong,Lijun Feng,Yao Li,Rui Yue,Yongpeng Zhou
The antifungal activity of six microbial-derived volatile organic compounds (VOCs) [ 3-hepten-2-one (Hep), cis-3-octen-1-ol, 3-methylvalerate, isovalerate, 1-octen-3-ol (Oct), and 2-methylbutyrate] against Aspergillus flavus was investigated by determining the minimum inhibitory concentration (MIC) and the fractional inhibitory concentration index (FICI). The results demonstrated that all 15 binary combinations of the VOCs presented additive effects against A. flavus . Among them, the combination of Hep and Oct, refers to C OH , with concentrations of 2 μL L −1 and 2.5 μL L −1 , respectively, displayed the most potent antifungal effect with the lowest concentration, in contrast to the individual MIC of Hep or Oct, which were reduced to 1/8 and 1/2. C OH can induce membrane lipid peroxidation, enhance cell membrane permeability, and cause leakage of nucleic acids and proteins within the cell, and 1-octen-3-ol might play a leading role. Finally, applying C OH at a concentration of 1/2 MIC Oct + 1/4 MIC Hep could effectively restrain the spread of A. flavus on wolfberries and exhibit excellent preservation effects. This study validates the antifungal effect of C OH and may serve as a natural alternative to antimicrobial agents for post-harvest agricultural products.
研究领域:
食品科学
·
微生物学
·
植物保护
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Tongtong Ren,Suli Liu,Hong Li,Angui Zhang,Xingang Li,Wei Yuan,Xin Gao
Utilization of F-T synthetic to produce value-added C 8 linear α-olefin is a promising alternative approach, however, the purification of α-olefin from F-T synthetic products is a great challenge, especially for removing 2-methyl-1-heptene (MH). This article addresses the novel method of etherification reaction to remove MH from F-T synthetic products, and develop by far the most efficiency reactive distillation (RD) method to intensified the etherification process. The scarcity of thermodynamic data was measured and regressed by the activity coefficient models, furthermore, kinetics of the etherification reaction of MH with methanol was explored using an ion exchange resin as catalyst, and then fitted by a pseudo-homogeneous model. The pilot-scale RD experimental results show that the conversion of MH reaches 91.83 % and the purity of α-olefin increases by 14.9 wt% (percentage points). Process analysis method was used to realize the optimization of design and operating parameters of etherification RD column based on the developed rigorous model. The optimization results show that the conversion of MH achieves 99.74 % and the purity of α-olefin achieves 96.87 wt%, which is also illustrated that the novel method for removing MH is proposed paving the way for purification of α-olefin from F-T synthetic products.
研究领域:
化学工程
·
石油化学
✓ 已验证
DOI
高影响因子
SYNTHESIS-STUTTGART
·
2015
·Vol. 47
·期 19
·3049-3060
·
IF 2.689
Jialin Wang,Jiaqi Liu,Hao Lan,Wenyi Chu,Zhizhong Sun
Intramolecular Friedel–Crafts acylation reactions of 2-arylphenoxyacetic acids are accomplished using trifluoroacetic anhydride or trifluoromethanesulfonic acid at 0 °C or room temperature. Depending on the reaction conditions, dibenzoxepines or arylcoumaranones are obtained in good yields and with high selectivities (83–100%). Plausible mechanistic pathways for the selective formation of the different reaction products are discussed.
研究领域:
有机化学
·
合成化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF FOOD COMPOSITION AND ANALYSIS
·
2025
·
IF 4.6
Shuwei Wang,Tianyu Dong,Ruijia Liu,Jie Sun,Haitao Chen
Pork is one of the meats widely consumed all over the world, while stewing is preferred because it can retain the nutritional content of the meat. After stewing, pork still retains some odors, such as bloody aroma, which affects the flavor quality. Therefore, people often add spices during the stewing process to reduce the off-flavor, but the mechanism of the effect of spices on the off-flavor has not been clarified. This study examined the pork broth before and after the addition of spices and determined the off-flavor compounds ( (E) -2-nonenal, (E) -2-heptenal, acetic acid, and valeric acid) in pork broth and key spice compounds (linalool, 1,8-cineole, and (E) -anethole) in pork broth with spices. The mechanism of the influence of spices on the off-flavor compounds of pork broth was clarified through the sensory perceptual interaction between off-flavor compounds and key spice compounds. The S-curve method was used to analyze the perceptual interactions between off-flavor compounds and key spice compounds. The results showed that linalool, 1,8-cineole, and (E) -anethole all had a masking effect on the aroma of off-flavor compounds (S-curve ratios = 1.58, 2.21, and 5.84, respectively), and the inhibitory effect was strongest when the three compounds acted together (S-curve ratio = 42.49).
研究领域:
食品化学
·
风味科学
·
感官分析
·
食品加工
✓ 已验证
产品关联
DOI
高影响因子
GREEN CHEMISTRY
·
2022
·Vol. 25
·期 3
·1056-1066
·
IF 11.034
Fengan Han,Yanting Liu,Guangyi Li,Lin Yuan,Aiqin Wang,Feng Wang,Tao Zhang,Ning Li
Selective hydrodeoxygenation (HDO) of lignocellulose-derived ketones to olefins is a promising method for upgrading lignocellulosic biomass-derived molecules. Herein, zinc molybdate (ZnMoO4–E) with a disordered layered stacking structure was first prepared using a facile and environmentally friendly evaporation method and it exhibited outstanding catalytic performance for the selective HDO of lignocellulose-derived ketones to olefins. Using it, 4-heptanone, a representative of lignocellulose-derived ketones, was totally converted, and a high carbon yield of heptene (90%) was achieved at 673 K. On the basis of the characterization results, the outstanding catalytic performance of ZnMoO4–E was attributed to its porous structure, higher oxygen vacancy (or the Mo5+ species) concentration and higher acidity. Analogously, ZnMoO4–E also exhibited good catalytic performances for the selective HDO of other lignocellulose-derived ketones (such as acetone, butanone, 2-pentanone, 3-pentanone, cyclohexanone, acetophenone and 5-nonanone) to their corresponding olefins.
研究领域:
催化
·
化学工程
·
材料科学
·
可再生能源
✓ 已验证
产品关联
DOI
高影响因子
EUROPEAN FOOD RESEARCH AND TECHNOLOGY
·
2016
·Vol. 243
·期 2
·203-214
·
IF 1.433
Liu Tao,Zhu Wei,Huang Jing,Chen Huahan,Nie Rongzu,Li Chun-mei
The influence of the planting season on the nutritional as well as the aromatic composition of Hezuo 903 tomato was investigated by combining use of nutrition analysis, sensory evaluation, electronic nose and electronic tongue analysis, gas chromatography–mass spectrometry (GC–MS) and GC–MS–olfactometry (GC–MS–O) method. The results suggested that in-season tomato contained higher levels of reducing sugar, vitamin C and lycopene than off-season tomato. In-season tomato showed a better overall flavor and acceptability than off-season tomato. Significant difference was observed in both composition and concentration of the typical volatile and aroma-active compounds in two samples. E-2-Hexenal and methyl salicylate were only found in off-season tomato, and phenylacetaldehyde detected merely in in-season tomato. In addition, significantly higher levels of 6-methyl-5-hepten-2-one ( P < 0.01) and 2-isobutylthiazole ( P < 0.01) were detected in off-season tomato than in-season tomato, which showed a negative effect on the overall flavor of tomato. Our result indicated that the planting season affected the composition and concentration of both non-volatile and volatile compounds of tomato fruit.
研究领域:
农业
·
食品科学
·
营养学
·
植物生理学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2022
·
IF 5.895
Mu Zhao,Hairan Ma,Yaqiong Hou,Jie Li,Tingting Zou,Dongjie Zhang,Rong Wen,Hongliang Li,Huanlu Song
The purpose of this study was to determine the key odor-active compounds contributing to the off-flavor of aged pasteurized yogurt (APY) using sensory-directed flavor analysis. Additionally, different extraction methods were compared to determine their effects on the volatile compounds, including dynamic headspace sampling (DHS), solid-phase microextraction, and stir bar sorptive extraction, and DHS was found to be suitable for this study. The results showed that comprehensive two-dimensional gas chromatography–olfactometry–mass spectrometry analysis (GC × GC–O–MS) had more advantages in separating and identifying the volatile compounds than the traditional GC–O–MS. A total of 17 odor-active compounds were determined in the fresh pasteurized yogurt and APY samples by DHS coupled with GC × GC–O–MS. The dynamic headspace dilution analysis demonstrated that 2-heptanone and hexanal were the most vital components in APY with the highest flavor dilution factor. Furthermore, the spiking and omission experimental results revealed that the odor-active compounds, such as 2-heptanone, butanoic acid, pentanoic acid, hexanal, and (E)-2-heptenal, were the key odor-active off-flavor contributors in APY. Therefore, these compounds could be used as potential indicators to determine the freshness of pasteurized yogurt.
研究领域:
食品科学
·
分析化学
·
感官科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MOLECULES
·
2022
·Vol. 27
·期 2
·352
·
IF 4.927
Shiqing Song,Feiting Zheng,Xiaoyan Tian,Tao Feng,Lingyun Yao,Min Sun,Lei Shi
To explore the role of fatty acids as flavor precursors in the flavor of oxidized tallow, the volatile flavor compounds and free fatty acid (FFAs) in the four oxidization stages of tallow were analyzed via gas chromatography (GC)–mass spectrometry (MS), the aroma characteristics of them were analyzed by GC–olfactory (GC-O) method combined with sensory analysis and partial least-squares regression (PLSR) analysis. 12 common FFAs and 35 key aroma-active compounds were obtained. Combined with the results of odor activity value (OAV) and FD factor, benzaldehyde was found to be an important component in unoxidized tallow. (E,E)-2,4-Heptadienal, (E,E)-2,4-decadienal, (E)-2-nonenal, octanal, hexanoic acid, hexanal and (E)-2-heptenal were the key compounds involved in the tallow flavor oxidation. The changes in FFAs and volatile flavor compounds during oxidation and the metabolic evolution of key aroma-active compounds are systematically summarized in this study. The paper also provides considerable guidance in oxidation control and meat flavor product development.Keywords:oxidized tallow;aroma-active compounds;solvent-assisted flavor evaporation;gas chromatography-olfactometry;partial least-squares regression
研究领域:
食品科学
·
分析化学
·
农业化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2019
·
IF 3.714
Ping Yang,Chen Liu,Huanlu Song,Lijin Wang,Xueqing Wang,Jiacai Hua
Off-flavor compounds in IF-DHMP were identified using sensory-directed analysis. In total, 56 types of aroma-active compounds were identified in the off-flavor (OF) samples, positive control (PC) samples, and accelerated oxidation (AO) samples. The Aroma Extraction Dilution Analysis (AEDA) results showed that methional, generated via Maillard reaction , was the most important component with the highest dilution factor in OF. The results of aroma recombination, omission and spiking experiment revealed that compounds such as pentanal, methional, ( E )-2-nonenal, 3-methylbutanal, ( E )-2-heptenal, nonanal, ( E,E )-2,4-heptadienal, 1-penten-3-one, 1-octen-3-one, and ( E,E )-2,4-nonadienal were the major sources of off-flavor in OF. We observed that the off-flavor in OF samples originated due to proteolysis, Maillard reaction, or lipid oxidation during processing rather than due to lipid oxidation during storage.
研究领域:
食品科学
·
化学感官科学
·
分析化学
·
婴幼儿营养
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）