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Chemical profiling of bioactive compounds in the methanolic extract of wild leaf and callus of Vitex negundo using gas chromatographymass spectrometry
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作者 Gunjan Garg Alok Bharadwaj +1 位作者 Shweta Chaudhary Veena Gupta 《World Journal of Experimental Medicine》 2024年第1期78-87,共10页
BACKGROUND The investigation of plant-based therapeutic agents in medicinal plants has revealed their presence in the extracts and provides the vision to formulate novel techniques for drug therapy.Vitex negundo(V.neg... BACKGROUND The investigation of plant-based therapeutic agents in medicinal plants has revealed their presence in the extracts and provides the vision to formulate novel techniques for drug therapy.Vitex negundo(V.negundo),a perennial herb belonging to the Varbanaceae family,is extensively used in conventional medication.AIM To determine the existence of therapeutic components in leaf and callus extracts from wild V.negundo plants using gas chromatography-mass spectrometry(GCMS).METHODS In this study,we conducted GC-MS on wild plant leaf extracts and correlated the presence of constituents with those in callus extracts.Various growth regulators such as 6-benzylaminopurine(BAP),2,4-dichlorophenoxyacetic acid(2,4-D),α-naphthylacetic acid(NAA),and di-phenylurea(DPU)were added to plant leaves and in-vitro callus and grown on MS medium.RESULTS The results clearly indicated that the addition of BAP(2.0 mg/L),2,4-D(0.2 mg/mL),DPU(2.0 mg/L)and 2,4-D(0.2 mg/mL)in MS medium resulted in rapid callus development.The plant profile of Vitex extracts by GC-MS analysis showed that 24,10,and 14 bioactive constituents were detected in the methanolic extract of leaf,green callus and the methanolic extract of white loose callus,respectively.CONCLUSION Octadecadienoic acid,hexadecanoic acid and methyl ester were the major constituents in the leaf and callus methanolic extract.Octadecadienoic acid was the most common constituent in all samples.The maximum concentration of octadecadienoic acid in leaves,green callus and white loose callus was 21.93%,47.79%and 40.38%,respectively.These findings demonstrate that the concentration of octadecadienoic acid doubles in-vitro compared to in-vivo.In addition to octadecadienoic acid;butyric acid,benzene,1-methoxy-4-(1-propenyl),dospan,tridecanedialdehyde,methylcyclohexenylbutanol,chlorpyrifos,n-secondary terpene diester,anflunine and other important active compounds were also detected.All these components were only available in callus formed in-vitro.This study showed that the callus contained additional botanical characteristics compared with wild plants.Due to the presence of numerous bioactive compounds,the medical use of Vitex for various diseases has been accepted and the plant is considered an important source of therapeutics for research and development. 展开更多
关键词 Leaf extracts Callus extracts Methanolic extract Octadecadienoic acid Hexadecanoic acid Methyl ester gas chromatography-mass spectrometry analysis
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Mutual regulation of microglia and astrocytes after Gas6 inhibits spinal cord injury
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作者 Jiewen Chen Xiaolin Zeng +6 位作者 Le Wang Wenwu Zhang Gang Li Xing Cheng Peiqiang Su Yong Wan Xiang Li 《Neural Regeneration Research》 SCIE CAS 2025年第2期557-573,共17页
Invasive inflammation and excessive scar formation are the main reasons for the difficulty in repairing nervous tissue after spinal cord injury.Microglia and astrocytes play key roles in the spinal cord injury micro-e... Invasive inflammation and excessive scar formation are the main reasons for the difficulty in repairing nervous tissue after spinal cord injury.Microglia and astrocytes play key roles in the spinal cord injury micro-environment and share a close interaction.However,the mechanisms involved remain unclear.In this study,we found that after spinal cord injury,resting microglia(M0)were polarized into pro-inflammatory phenotypes(MG1 and MG3),while resting astrocytes were polarized into reactive and scar-forming phenotypes.The expression of growth arrest-specific 6(Gas6)and its receptor Axl were significantly down-regulated in microglia and astrocytes after spinal cord injury.In vitro experiments showed that Gas6 had negative effects on the polarization of reactive astrocytes and pro-inflammatory microglia,and even inhibited the cross-regulation between them.We further demonstrated that Gas6 can inhibit the polarization of reactive astrocytes by suppressing the activation of the Yes-associated protein signaling pathway.This,in turn,inhibited the polarization of pro-inflammatory microglia by suppressing the activation of the nuclear factor-κB/p65 and Janus kinase/signal transducer and activator of transcription signaling pathways.In vivo experiments showed that Gas6 inhibited the polarization of pro-inflammatory microglia and reactive astrocytes in the injured spinal cord,thereby promoting tissue repair and motor function recovery.Overall,Gas6 may play a role in the treatment of spinal cord injury.It can inhibit the inflammatory pathway of microglia and polarization of astrocytes,attenuate the interaction between microglia and astrocytes in the inflammatory microenvironment,and thereby alleviate local inflammation and reduce scar formation in the spinal cord. 展开更多
关键词 ASTROCYTES AXL cell polarization gas6 Hippo signal inflammatory micro-environment intercellular interaction MICROGLIA single-cell sequencing spinal cord injury
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GaSb单晶研究进展 被引量:1
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作者 刘京明 杨俊 +3 位作者 赵有文 杨成奥 蒋洞微 牛智川 《人工晶体学报》 北大核心 2024年第1期1-11,共11页
近年来,锑化物红外技术发展迅速,成为半导体技术的重要发展方向之一。锑化镓(GaSb)作为典型的Ⅲ-Ⅴ族化合物半导体,凭借优异的性能成为锑化物红外光电器件的关键衬底材料。随着锑化物红外技术逐步成熟和应用逐渐开展,人们对GaSb单晶片... 近年来,锑化物红外技术发展迅速,成为半导体技术的重要发展方向之一。锑化镓(GaSb)作为典型的Ⅲ-Ⅴ族化合物半导体,凭借优异的性能成为锑化物红外光电器件的关键衬底材料。随着锑化物红外技术逐步成熟和应用逐渐开展,人们对GaSb单晶片的需求日益剧增的同时也对其质量提出更高的要求。GaSb单晶片质量直接影响着外延材料和器件性能,这就要求GaSb单晶片具有大尺寸、更低的缺陷密度、更好的表面质量和一致性。本文就GaSb晶体材料的性质、制备方法、国内外机构的研究进展及其应用情况进行了综述,并对其发展前景和趋势进行了展望。 展开更多
关键词 锑化镓 化合物半导体 锑化物 晶体 红外光电器件
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Diagnosing gastrointestinal illnesses using fecal headspacevolatile organic compounds 被引量:5
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作者 Daniel K Chan Cadman L Leggett Kenneth K Wang 《World Journal of Gastroenterology》 SCIE CAS 2016年第4期1639-1649,共11页
Volatile organic compounds(VOCs) emitted from stool are the components of the smell of stool representing the end products of microbial activity and metabolism that can be used to diagnose disease. Despite the abundan... Volatile organic compounds(VOCs) emitted from stool are the components of the smell of stool representing the end products of microbial activity and metabolism that can be used to diagnose disease. Despite the abundance of hydrogen, carbon dioxide, and methane that have already been identified in human flatus, the small portion of trace gases making up the VOCs emitted from stool include organic acids, alcohols, esters, heterocyclic compounds, aldehydes, ketones, and alkanes, among others. These are the gases that vary among individuals in sickness and in health, in dietary changes, and in gut microbial activity. Electronic nose devices are analytical and pattern recognition platforms that can utilize mass spectrometry or electrochemical sensors to detect these VOCs in gas samples. When paired with machine-learning and pattern recognition algorithms, this can identify patterns of VOCs, and thus patterns of smell, that can be used to identify disease states. In this review, we provide a clinical background of VOC identification, electronic nose development, and review gastroenterology applications toward diagnosing disease by the volatile headspace analysis of stool. 展开更多
关键词 Electronic NOSE Volatile organic compounds FECES Mass spectrometry Odors
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Rapid and simultaneous determination of ten off-flavor compounds in water by headspace solid phase microextraction and gas chromatography-mass spectrometry 被引量:3
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作者 邹攀 王琳 +2 位作者 杨兆光 李小婉 李海普 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第1期59-67,共9页
A simple and sensitive analytical procedure for the determination of multi-component compounds in water samples was developed and optimized using the headspace solid-phase microextraction(HSSPME) coupled with gas chro... A simple and sensitive analytical procedure for the determination of multi-component compounds in water samples was developed and optimized using the headspace solid-phase microextraction(HSSPME) coupled with gas chromatography-mass spectrometry(GC-MS). Ten off-flavor compounds, including geosmin(GSM), 2-methylisoborneol(2-MIB), 2-isopropyl-3-methoxypyrazine(IPMP), 2-isobutyl-3-methoxypyrazine(IBMP), β-ionone, trans-2,cis-6-nonadienal(NDE), 2,3,4-trichloroanisole(2,3,4-TCA), 2,3,6-trichroloanisole(2,3,6-TCA), 2,4,6-trichloroanisole(2,4,6-TCA), and 2,4,6-tribromoanisole(2,4,6-TBA) were used as the target analytes. The optimization of extraction parameters including fibers types, extraction time, extraction temperature, stirring rate, sample volume, and ionic strength was carried out through the univariate approach. Ten off-flavor compounds were quantified within 50 min under the optimal conditions. Calibration curves with good linearity(r^2=0.990-0.998) were obtained in the range 1.0/2.0-100 ng/L, while the limits of detection for all compounds were lower than or close to the odor threshold concentration. Furthermore, the proposed method was applied to analyzing and determining the off-flavor compounds in real water samples from water-treatment plants. 展开更多
关键词 off-flavor compounds MICROEXTRACTION gas chromatography-mass spectrometry (GC-MS) water quality
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Production of aryl oxygen-containing compounds from catalytic pyrolysis of bagasse lignin over LaTixFe1xO3 被引量:4
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作者 Haiying Wang Hongjing Han +5 位作者 Enhao Sun Yanan Zhang Jinxin Li Yanguang Chen Hua Song Hongzhi Zhao 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2019年第8期1939-1944,共6页
A new approach,named production of aryl oxygen-containing compounds from the catalytic pyrolysis of bagasse lignin(BL) over perovskite oxide,was proposed,A series of LaTixFe1-xO3(LTF-x) samples were prepared by the so... A new approach,named production of aryl oxygen-containing compounds from the catalytic pyrolysis of bagasse lignin(BL) over perovskite oxide,was proposed,A series of LaTixFe1-xO3(LTF-x) samples were prepared by the solid state reaction method.The crystal phase and morphology of LTF-x were characterized by XRD and SEM respectively.Catalytic pyrolysis performance of LTF-x was performed by TG-DTG and the distribution patterns of gaseous,liquid and solid products from BL was investigated using a fixed-bed micro-reactor.The optimal reaction conditions were determined:the pyrolysis temperature was 600℃,the mass ratio of mBL:mLTF-0.2 was 3:1,the veloeity of earrier gas was 100 ml·min-1.The gaseous produets were mainly eomposed of CO2,CO,CH4 and CnHm(n=2-4,m=2 n+2 or m=2 n),The main aryl oxygen-containing compounds in liquid products were phenolics,guaiacols,syringols and phenylates,the rest were benzenes,furans,esters and carboxylic acid.The total contents of aryl oxygencontaining compounds were from 62% up to more than 72% under the action of the perovskite.Moreover,the LTF-0.2 sample had nice regenerability. 展开更多
关键词 BAgasSE LIGNIN Perovskite Catalytic pyrolysis ARYL oxygen-containing compounds
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Composition of phenolic compounds in wastewater from the fixed-bed gasification of Baishihu coal 被引量:2
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作者 Yuan Zhao 《International Journal of Coal Science & Technology》 EI CAS CSCD 2021年第6期1461-1467,共7页
Crude phenols extracted using organic solvent from the wastewater of a typical fixed-bed gasification process was used as a raw material,and the distillation range was analyzed.The wide and narrow fractions of the raw... Crude phenols extracted using organic solvent from the wastewater of a typical fixed-bed gasification process was used as a raw material,and the distillation range was analyzed.The wide and narrow fractions of the raw material derived from distillation range analysis were cut using a real boiling point distillation device.The phenolic compounds in the different fractions were then qualitatively and quantitatively analyzed by gas chromatography after derivatization pretreatment.The yield of the<290℃fraction was 68.50%(mass fraction).A total of 33 effective phenolic compounds were identified in this fraction,and the percentage of identified phenols was nearly 80%.The contents of eight phenolic compounds were high,with phenol being the most abundant(26.34%)followed by catechol(13.44%).The contents of the remaining six abundant phenols ranged from 4%to 8%.The sum of the contents of m-cresol and p-cresol exceeded 12%,and the content of 5-indenol was nearly 8%.The yield of the fraction rich in low-grade phenols(<230℃)was 35.40%.The content of phenol in this fraction was more than 40%,the total content of cresol was over 23%,and the total content of m-cresol and p-cresol was nearly 20%.At room temperature,the 235-245℃and 245-260℃fractions were white crystals in which the catechol content was approximately 50%,and the 5-indenol content was more than 10%.The contents of these two high-value-added phenolic compounds are low in typical coal tar,making them difficult to extract.However,due to their strong polarity and good water solubility,catechol and 5-indenol are enriched in gasification wastewater by water selection,allowing their further extraction. 展开更多
关键词 gasification wastewater Phenolic compounds Derivatization pretreatment gas chromatography
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Characterization of aroma compounds of Pu-erh ripen tea using solvent assisted flavor evaporation coupled with gas chromatography-mass spectrometry and gas chromatography-olfactometry 被引量:7
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作者 Bei Wang Qing Meng +8 位作者 Lin Xiao Ruili Li Chunhai Peng Xueli Liao Jingna Yan Honglin Liu Guanhua Xie Chi-Tang Ho Huarong Tong 《Food Science and Human Wellness》 SCIE 2022年第3期618-626,共9页
Pu-erh ripen tea becomes popular worldwide owing to its unique taste and aroma.In the present study,volatile compounds from Pu-erh ripen tea were extracted using a solvent assisted flavor evaporation(SAFE)and analyzed... Pu-erh ripen tea becomes popular worldwide owing to its unique taste and aroma.In the present study,volatile compounds from Pu-erh ripen tea were extracted using a solvent assisted flavor evaporation(SAFE)and analyzed with a gas chromatography-mass spectrometry(GC-MS)and a gas chromatography olfactometry(GC-O).Results demonstrated that 58 major volatile compounds and 24 aroma active substances of Pu-erh ripen tea were identified by GC-MS and GC-O analysis.Among volatile compounds identified,methoxyphenyl compounds were considered as the dominate compounds in the aroma of Pu-erh ripen tea.Further investigation showed that 6 methoxybenzenes were responsible for the aging aroma in Pu-erh ripen tea;α-ionone,3,4-dimethoxytoluene,1,3-dimethoxybenzene,etc.were responsible for the wood-like aroma.Linalool,α-terpineol,α-ionone,β-ionone,and benzeneacetaldehyde were responsible for the floral odor.Compared the odor detection threshold(ODT)among the 8 methoxyphenyl compounds in water,1,2,3-trimethoxybenzene showed the highest ODT,followed by 3,4-dimethoxyphenol.1,3-dimethoxybenzene(105μg/L)and 1,2,3-trimethoxy-5-methylbenzene(100μg/L)were present at relatively low odor threshold values.The result indicated that methoxyphenyl compounds play a vital role in the unique flavor of Pu-erh ripen tea. 展开更多
关键词 Pu-erh ripen tea SAFE GC-MS GC-O Methoxyphenyl compounds
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Simultaneous Determination of Halogen Compounds and Sulfur Oxides in Flue Gas by Ion Chromatography 被引量:1
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作者 Makoto Nonomura Keiko Kurita 《Journal of Chemistry and Chemical Engineering》 2011年第4期289-295,共7页
Ion chromatography (IC) is a suitable analytical method for the determination of anions. As analytical methods for the halogen compounds in flue gas, those of bromine compound, fluorine compound, chlorine (Cl2) an... Ion chromatography (IC) is a suitable analytical method for the determination of anions. As analytical methods for the halogen compounds in flue gas, those of bromine compound, fluorine compound, chlorine (Cl2) and hydrogen chloride (HCI) are listed in JIS. However, IC has not been adopted in JIS except for HCI and C12. Because the carbon dioxide in flue gas is absorbed in a 0.1 M sodium hydroxide solution as an absorber, it is interfered with the measurement of F^- and Cl^- ions. This paper describes the development of the pretreatment equipment for the flue gas analysis by IC, and its applications to real flue gas analysis. The F^-, Cl^-, Br^- and SO4^2- in the absorbing solution can be clearly separated by IC using the pretreatment equipment. The halogen compounds and sulfur oxides in flue gas can be simultaneously determined by IC. 展开更多
关键词 Fluorine compound chloride compound sulfur oxide flue gas analysis ion chromatography
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Study on Reaction of Thiophene Compounds and Olefins for Deep Desulfurization of Gasoline 被引量:1
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作者 Xu Yun 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2019年第3期53-60,共8页
The HY,Hβ,HZSM-5,and SAPO-11 zeolites were investigated in the alkylation reaction of thiophene and olefins.As a result,some sulfur-containing impurities could be converted to higher molecular weight components with ... The HY,Hβ,HZSM-5,and SAPO-11 zeolites were investigated in the alkylation reaction of thiophene and olefins.As a result,some sulfur-containing impurities could be converted to higher molecular weight components with their boiling point being in the range of diesel fraction.HZSM-5 had the highest activity and selectivity of desulfurization.At the same time,extensive oligomerization of olefins was not found and coke yield was very low,which could lead to high yield of gasoline products.The main reaction mechanism verifies that the second order alkylation reaction can be carried out on the outer surface and/or pores of the catalyst.The catalytic performance of the HZSM-5 catalyst which is poisoned by 2,4-dimethylquinoline during alkylation to form larger molecules of sulfur compounds is obviously weakened due to the decrease of the acid sites on the outer surface and at the mouth of pores. 展开更多
关键词 FCC gasOLINE HZSM-5 zeolite DESULFURIZATION THIOPHENE compounds
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Simultaneous Removal of H_2S and Organosulfur Compounds from Liquefied Petroleum Gas Using Formulated Solvents: Solubility Parameter Investigation and Industrial Test 被引量:6
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作者 Zhang Feng Shen Benxian +2 位作者 Sun Hui Liu Jichang Shang Jianfeng 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2015年第1期75-81,共7页
The performance of four formulated solvents(labeled as UDS-I, UDS-II, UDS-III, and UDS-IV) for removing methyl mercaptan from liquefied petroleum gas was predicted based on a two-dimensional solubility parameter theor... The performance of four formulated solvents(labeled as UDS-I, UDS-II, UDS-III, and UDS-IV) for removing methyl mercaptan from liquefied petroleum gas was predicted based on a two-dimensional solubility parameter theory. The calculation results show that UDS-IV has the closest solubility parameter to that of methyl mercaptan as compared with other tested solvents, indicating the strongest affinity and the highest solubility for methyl mercaptan. The industrial tests at a plant for desulfurization of LPG produced from the delayed coker have shown that the UDS solvents have the excellent performance for removal of organosulfur compounds(mainly methyl mercaptan). Although the sulfur loading dramatically increases, the total sulfur content of LPG treated with UDS-IV can be reduced by about 50% in comparison with N-methyl diethanolamine. In addition, UDS-IV has superior regeneration performance and selectivity for sulfur compounds over hydrocarbons. The industrial test and the solubility parameter calculation results are in good agreement with each other. 展开更多
关键词 liquefied petroleum gas DESULFURIZATION SOLVENT SOLUBILITY parameter METHYL MERCAPTAN ORGANOSULFUR
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Characterization of the key aroma compounds in four varieties of pomegranate juice by gas chromatography-mass spectrometry(GC-MS),gas chromatography-olfactometry(GC-O),odor activity value(OAV),aroma recombination,and omission tests 被引量:5
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作者 Cong Lu Yuyu Zhang +2 位作者 Ping Zhan Peng Wang Honglei Tian 《Food Science and Human Wellness》 SCIE CSCD 2023年第1期151-160,共10页
P omegranate(Punica granatum L.)has attracted considerable attention in world markets due to its valuable nutrients and highly appreciated sensory properties.The aroma profiles of 4 varieties of pomegranate juice,incl... P omegranate(Punica granatum L.)has attracted considerable attention in world markets due to its valuable nutrients and highly appreciated sensory properties.The aroma profiles of 4 varieties of pomegranate juice,including Dahongtian(DP),Jingpitian(JP),Luyudan(LP),and Tianhonngdan(TP),were investigated via gas chromatography-mass spectrometry(GC-MS)and gas chromatography-olfactometry(GC-O)analyses.A total of 43 volatile compounds were identified by using GC-MS.Among these compounds,16 were considered as potential aroma-active compounds as detected by GC-O.These compounds belonged to the classes of terpinenes,alcohols,and aldehydes.Eleven volatile compounds were defined as the main contributors to the overall aroma of pomegranate juice due to their high odor activity values(OAVs≥1).Aroma recombination and omission tests confirmed thatβ-myrcene,1-hexanol,and(Z)-3-hexen-1-ol were the key aroma compounds,and limonene,1-octen-3-ol,linalool,and hexanal were important aroma-active compounds in DP samples. 展开更多
关键词 Pomegranate juice Aroma-active compounds GC-MS GC-O Odor active value(OAV) Omission tests
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Modeling Gas Chromatographic Retention Indices of Oxygen-containing Compounds by Novel Atom-type Topological Indices 被引量:1
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作者 Xiao-fang Hu Chun-hui Lu Chun-sheng Yin 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 北大核心 2006年第3期243-247,共5页
Quantitative structure-retention relationship (QSRR) model for the estimation of retention indices (RIs) of 39 oxygen-containing compounds containing ketones and esters was established by our newly introduced dist... Quantitative structure-retention relationship (QSRR) model for the estimation of retention indices (RIs) of 39 oxygen-containing compounds containing ketones and esters was established by our newly introduced distance-based atom-type indices DAI. The useful application of the novel DAI indices has been demonstrated by developing accurate predictive equations for gas chromatographic retention indices. The statistical results of the multiple linear regression for the final model are τ=0.9973 and s=8.23. Furthermore, an external test set of 10 oxo-containing compounds can be accurately predicted with the final equation giving the following statistical results: τpred:0.9966 and spred=8.56. 展开更多
关键词 Topological indices Retention indices Oxygen-containing compounds
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Identification of the toxic compounds produced by Sargassum thunbergii to red tide microalgae 被引量:3
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作者 王仁君 王悠 唐学玺 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2012年第5期778-785,共8页
The inhibitory effects of methanol extracts from the tissues of three macroalgal species on the growths of three marine red tide microalgae were assessed under laboratory conditions.Extracts of Sargassum thunbergii(Me... The inhibitory effects of methanol extracts from the tissues of three macroalgal species on the growths of three marine red tide microalgae were assessed under laboratory conditions.Extracts of Sargassum thunbergii(Mertens ex Roth) Kuntz tissue had stronger inhibitory effects than those of either Sargassum pallidum(Turner) C.Agardh or Sargassum kjellmanianum Yendo on the growths of Heterosigma akashiwo(Hada) Hada,Skeletonema costatum(Grev.) Grev,and Prorocentrum micans Ehrenberg.Methanol extracts of S.thunbergii were further divided into petroleum ether,ethyl acetate,butanol,and distilled water phases by liquid-liquid fractionation.The petroleum ether and ethyl acetate fractions had strong algicidal effects on the microalgae.Gas chromatography-mass spectrometry analyses of these two phases identified nine fatty acids,most of which were unsaturated fatty acids.In addition,pure compounds of four of the nine unsaturated fatty acids had effective concentrations below 5 mg/L.Therefore,unsaturated fatty acids are a component of the allelochemicals in S.thunbergii tissue. 展开更多
关键词 allelopathic effects Heterosigma akashiwo Skeletonema costatum Prorocentrum micans unsaturated fatty acids gas chromatography-mass spectrometry (GC-MS)
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Ultra-deep adsorptive removal of thiophenic sulfur compounds from FCC gasoline over the specific active sites of CeHY zeolite 被引量:2
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作者 Yun Zu Chang Zhang +5 位作者 Yucai Qin Xiaotong Zhang Li Zhang Honghai Liu Xionghou Gao Lijuan Song 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2019年第12期256-267,共12页
Adsorption desulfurization performance of Na Y,HY and Ce HY zeolites is evaluated in a miniature fixedbed flow by model gasoline containing with thiophene,tetrahydrothiophene,2-methylthiophene,benzothiophene or mixed ... Adsorption desulfurization performance of Na Y,HY and Ce HY zeolites is evaluated in a miniature fixedbed flow by model gasoline containing with thiophene,tetrahydrothiophene,2-methylthiophene,benzothiophene or mixed sulfur compounds.The structural properties of adsorbents are characterized by XRD,N2-adsorption and XPS techniques.Adsorption desulfurization mechanisms of these sulfur compounds over the specific active sites of adsorbents as a major focus of this work,have been systematically investigated by using in situ FT-IR spectroscopy with single and double probing molecules.Desulfurization experimental results show that the Ce HY adsorbent exhibits superior adsorption sulfur capacity at breakthrough point of zero sulfur for ultra-deep removal of each thiophenic sulfur compound,especially in the capture of aromatic 2-methylthiophene(about ca.28.6 mgS/gadsorbent).The results of in situ FT-IR with single probing molecule demonstrate an important finding that high oligomerization ability of thiophene or 2-methylthiophene on the CeHY can promote the breakthrough adsorption sulfur capacity,mainly resulting from the synergy between Br?nsted acid sites and Ce(III)hydroxylated species active sites located in the supercages of Ce HY.Meanwhile,the result of in situ FT-IR with double probing molecules further reveals the essence of oligomerization reactions of thiophene and 2-methylthiophene molecules on those specific active sites.By contrast,the oligomerization reaction of benzothiophene molecules on the active sites of Ce HY cannot occur due to the restriction of cavity size of supercages,but they can be adsorbed on the Br?nsted acid sites via protonation,and on Ce(III)hydroxylated species and extra-framework aluminum hydroxyls species via direct"S-M"bonding interaction.As to the tetrahydrothiophene,adsorption mechanism is similar to that of benzothiophene,except in the absence of protonation.The paper can provide a new design idea of specific adsorption active sites in excellent desulfurization adsorbents for elevating higher quality of FCC gasoline in the future. 展开更多
关键词 CeHY zeolite Active sites Thiophenic sulfur compounds Adsorption desulfurization Oligomerization ability In situ FT-IR spectroscopy
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Relationship between Symptoms, Use of PPE and Habits Related to Occupational Exposure to BTEX Compounds in Workers of Gas Stations in Bahia, Brazil 被引量:1
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作者 Lidmary P. Alves Daniela S. P. Vieira +6 位作者 Luís Sérgio S. Nunes Lícia P. S. Cruz Ana Caroline S. Reis ícaro V. S. Gomes Sameque R. Luz Akácia V. S. Santos Mabel B. Esteves 《Journal of Environmental Protection》 2017年第5期650-661,共12页
To show the risks and harm caused by the occupational exposure to the benzene, toluene, ethylbenzene and xylenes compounds (BTEX), the working conditions of 113 persons employed at gas stations in the cities of Riach?... To show the risks and harm caused by the occupational exposure to the benzene, toluene, ethylbenzene and xylenes compounds (BTEX), the working conditions of 113 persons employed at gas stations in the cities of Riach?o do Jacuipe, Feira de Santana and Salvador in the state of Bahia, Brazil were investigated by experts who correlated protection measures required by law and those applied to the workers. Data collection was performed by help of a questionnaire and non-participant observation record. The age groups of the workers in the three cities surveyed were between 18 to 25 years (30.08%) and 26 to 33 years (34.51%) of the total. The study revealed an association between occupational habits of workers at gas stations and the prevalence of symptoms due to the exposure to the BTEX compounds. Regarding the use of Personal Protective Equipment (PPE) most workers wear boots. The data show that these workers reported symptoms such as headache, rhinitis, leg pain, drowsiness, cough, fatigue, insomnia, tremors and palpitations. These disorders are related back to previous exposure to BTEX compounds which is associated with inadequate occupational habits of the workers which potentiate chemical contamination in their respective environment. 展开更多
关键词 BTEX gas Stations OCCUPATIONAL Exposure SYMPTOMS
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Geochemistry and origins of hydrogen-containing natural gases in deep Songliao Basin,China:Insights from continental scientific drilling 被引量:3
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作者 Shuang-Biao Han Chao-Han Xiang +3 位作者 Xin Du Lin-Feng Xie Jie Huang Cheng-Shan Wang 《Petroleum Science》 SCIE EI CAS CSCD 2024年第2期741-751,共11页
The different reservoirs in deep Songliao Basin have non-homogeneous lithologies and include multiple layers with a high content of hydrogen gas.The gas composition and stable isotope characteristics vary significantl... The different reservoirs in deep Songliao Basin have non-homogeneous lithologies and include multiple layers with a high content of hydrogen gas.The gas composition and stable isotope characteristics vary significantly,but the origin analysis of different gas types has previously been weak.Based on the geochemical parameters of gas samples from different depths and the analysis of geological settings,this research covers the diverse origins of natural gas in different strata.The gas components are mainly methane with a small amount of C_(2+),and non-hydrocarbon gases,including nitrogen(N_(2)),hydrogen(H_(2)),carbon dioxide(CO_(2)),and helium(He).At greater depth,the carbon isotope of methane becomes heavier,and the hydrogen isotope points to a lacustrine sedimentary environment.With increasing depth,the origins of N_(2)and CO_(2)change gradually from a mixture of organic and inorganic to inorganic.The origins of hydrogen gas are complex and include organic sources,water radiolysis,water-rock(Fe^(2+)-containing minerals)reactions,and mantle-derived.The shales of Denglouku and Shahezi Formations,as source rocks,provide the premise for generation and occurrence of organic gas.Furthermore,the deep faults and fluid activities in Basement Formation control the generation and migration of mantle-derived gas.The discovery of a high content of H_(2)in study area not only reveals the organic and inorganic association of natural-gas generation,but also provides a scientific basis for the exploration of deep hydrogen-rich gas. 展开更多
关键词 gas compositions Stable isotopes gas origins Hydrogen gas Songliao Basin
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Gas sensitivity of polyaniline/SnO_2 hybrids to volatile organic compounds
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作者 耿丽娜 《中国有色金属学会会刊:英文版》 CSCD 2009年第S3期678-683,共6页
Polyaniline (PAn) was prepared by chemical oxidation polymerization and characterized by FT-IR. PAn/SnO2 materials with different mass fractions of PAn were prepared by mechanical mixing. Compared with single PAn and ... Polyaniline (PAn) was prepared by chemical oxidation polymerization and characterized by FT-IR. PAn/SnO2 materials with different mass fractions of PAn were prepared by mechanical mixing. Compared with single PAn and SnO2, the gas sensitivity of PAn/SnO2 materials to volatile organic compounds (VOCs, methanol, ethanol and acetone) was studied. The possible response mechanism of PAn/SnO2 materials to VOCs was also discussed. It is found that PAn/SnO2 materials have gas sensitivity to VOCs at 90 ℃ among the four operating temperatures (room temperature, 30, 60 and 90 ℃), but PAn and SnO2 have no gas sensitivity at the above temperatures. The sensitivity of PAn/SnO2 materials shows linear increase with the increase of methanol concentration, but saturation with the increase of ethanol and acetone concentrations. PAn/SnO2 materials have high selectivity, fast response-recovery time and low operation temperature to VOCs, but pure PAn and SnO2 do not have. 展开更多
关键词 gas sensitivity polyaniline/SnO2 VOLATILE organic compounds
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Modern approaches for detection of volatile organic compounds in metabolic studies focusing on pathogenic bacteria:Current state of the art 被引量:1
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作者 Karolina Zuchowska Wojciech Filipiak 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2024年第4期483-505,共23页
Pathogenic microorganisms produce numerous metabolites,including volatile organic compounds(VOCs).Monitoring these metabolites in biological matrices(e.g.,urine,blood,or breath)can reveal the presence of specific micr... Pathogenic microorganisms produce numerous metabolites,including volatile organic compounds(VOCs).Monitoring these metabolites in biological matrices(e.g.,urine,blood,or breath)can reveal the presence of specific microorganisms,enabling the early diagnosis of infections and the timely implementation of tar-geted therapy.However,complex matrices only contain trace levels of VOCs,and their constituent com-ponents can hinder determination of these compounds.Therefore,modern analytical techniques enabling the non-invasive identification and precise quantification of microbial VOCs are needed.In this paper,we discuss bacterial VOC analysis under in vitro conditions,in animal models and disease diagnosis in humans,including techniques for offline and online analysis in clinical settings.We also consider the advantages and limitations of novel microextraction techniques used to prepare biological samples for VOC analysis,in addition to reviewing current clinical studies on bacterial volatilomes that address inter-species in-teractions,the kinetics of VOC metabolism,and species-and drug-resistance specificity. 展开更多
关键词 Volatile organic compounds Pathogenic bacteria metabolites Metabolomics Microextraction techniques gas chromatography-mass spectrometry In vivo breath analysis In vitro model
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Constraints on Characteristics and Distribution of Gas Hydrate and Free Gas Using Broad-Band Processing of Three-Dimensional Seismic Data 被引量:2
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作者 WANG Xiujuan ZHOU Jilin +7 位作者 LI Sanzhong LI Lixia LI Jie LI Yuanping WANG Linfei SU Pibo JIN Jiapeng GONG Zhi 《Journal of Ocean University of China》 SCIE CAS CSCD 2024年第5期1233-1247,共15页
Gas hydrate drilling expeditions in the Pearl River Mouth Basin,South China Sea,have identified concentrated gas hydrates with variable thickness.Moreover,free gas and the coexistence of gas hydrate and free gas have ... Gas hydrate drilling expeditions in the Pearl River Mouth Basin,South China Sea,have identified concentrated gas hydrates with variable thickness.Moreover,free gas and the coexistence of gas hydrate and free gas have been confirmed by logging,coring,and production tests in the foraminifera-rich silty sediments with complex bottom-simulating reflectors(BSRs).The broad-band processing is conducted on conventional three-dimensional(3D)seismic data to improve the image and detection accuracy of gas hydratebearing layers and delineate the saturation and thickness of gas hydrate-and free gas-bearing sediments.Several geophysical attributes extracted along the base of the gas hydrate stability zone are used to demonstrate the variable distribution and the controlling factors for the differential enrichment of gas hydrate.The inverted gas hydrate saturation at the production zone is over 40% with a thickness of 90 m,showing the interbedded distribution with different boundaries between gas hydrate-and free gas-bearing layers.However,the gas hydrate saturation value at the adjacent canyon is 70%,with 30-m-thick patches and linear features.The lithological and fault controls on gas hydrate and free gas distributions are demonstrated by tracing each gas hydrate-bearing layer.Moreover,the BSR depths based on broad-band reprocessed 3D seismic data not only exhibit variations due to small-scale topographic changes caused by seafloor sedimentation and erosion but also show the upward shift of BSR and the blocky distribution of the coexistence of gas hydrate and free gas in the Pearl River Mouth Basin. 展开更多
关键词 gas hydrate free gas shift of BSR broad-band processing
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