Polymer gels are widely used in water control and enhanced oil recovery in oil fields.However,the damage mechanism of polymer gels to layers with remaining oil and not requiring plugging and corresponding protective m...Polymer gels are widely used in water control and enhanced oil recovery in oil fields.However,the damage mechanism of polymer gels to layers with remaining oil and not requiring plugging and corresponding protective measures are unclear.In this paper,we investigated polymer gels'damage and protection performance through static gel-breaking experiments and dynamic plugging and oil recovery evaluations on rock cores.Moreover,nuclear magnetic resonance(NMR)technology was combined to analyze the damage performance of polymer gels on cores from the pore scale.In addition,a protective technique based on gel breakers for layers with remaining oil and not requiring plugging was proposed.Results showed that when polymer gels were injected into heterogeneous cores,they plugged high-permeability layers while also penetrating low-permeability layers.When the damage to the low-permeability layers was not alleviated,the conformance and oil displacement efficiency were significantly reduced.When the concentration of ammonium persulfate was 2%–5%,the gel-breaking time was shortest and the residue was very minimal.Therefore,ammonium persulfate could be used as a gel breaker and reservoir protective material.Furthermore,after injecting ammonium persulfate into heterogeneous reservoir cores,the gel damage on the face of low-permeability layers was relieved.Consequently,the improvement in sweep efficiency was achieved,showing the re-activation of the remaining oil in medium-low permeability layers.Therefore,the low-permeability layer protection process and core experiment study based on gel-breaking agents proposed in this study were suggested to provide a new technique for the field application of conformance modification agents,aiming to achieve higher recovery degrees.展开更多
Supercapacitors,comprising electrical double-layer capacitors(EDLCs)and pseudocapa-citors,are widely acknowledged as high-power energy storage devices.However,their local structures and fundamental mechanisms remain p...Supercapacitors,comprising electrical double-layer capacitors(EDLCs)and pseudocapa-citors,are widely acknowledged as high-power energy storage devices.However,their local structures and fundamental mechanisms remain poorly understood,and suitable experimental techniques for investigation are also lacking.Recently,nuclear magnetic resonance(NMR)has emerged as a powerful tool for addressing these fundamental issues with high local sensitivity and non-invasiveness.In this paper,we first review the limi-tations of existing characterization methods and highlight the advantages of NMR in investigating mechanisms of supercapacitors.Subsequently,we introduce the basic prin-ciple of ring current effect,NMR-active nuclei,and various NMR techniques employed in exploring energy storage mechanisms including cross polarization(CP)magic angle spinning(MAS)NMR,multiple-quantum(MQ)MAS,two-dimensional exchange spec-troscopy(2D-EXSY)NMR,magnetic resonance imaging(MRI)and pulsed-field gradient(PFG)NMR.Based on this,recent progress in investigating energy storage mechanisms in EDLCs and pseudocapacitors through various NMR techniques is discussed.Finally,an outlook on future directions for NMR research in supercapacitors is offered.展开更多
<span style="font-family:Verdana;">The present work encompasses identification and characterization of major degradation product (DP) of OSM observed in base hydrolytic stress study. The separation of ...<span style="font-family:Verdana;">The present work encompasses identification and characterization of major degradation product (DP) of OSM observed in base hydrolytic stress study. The separation of DP was carried out on a non-polar stationary phase by using high-performance liquid chromatography system (HPLC). Using waters X-bridge (250 mm × 4.6 mm, 5 μm) C18 column with gradient elution program. For the characterization study, stress samples were subjected to HPLC and UPLC-QTOF-MS/MS and based on mass fragmentation pattern</span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> plausible structure was deduced. Further</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> the DP was isolated using semi-prepara</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">- </span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;">tive liquid chromatography and concentrated the fractions using lyophiliza</span><span style="font-family:Verdana;">tion. The isolated DP was subjected to extensive 1D (1H, 13C, and</span><span style="font-family:Verdana;"> DEPT-135) and 2D (COSY, HSQC and HMBC) nuclear magnetic resonance (NMR) studies to authenticate the structure. The impurity was unambiguously named as N-(2-((2-(dimethylamino)ethyl)(methyl)amino)-4-metho</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;">xy-5-((4-(1-methyl-1H-indol-3-yl)pyrimidin-2-yl)amino)phenyl)-3-methoxy</span><span style="font-family:Verdana;">propanamide.</span></span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Add</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">- </span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;">itionally, the </span><i><span style="font-family:Verdana;">In-Silico</span></i><span style="font-family:Verdana;"> structure activity relation (QSAR) assessed through sta</span></span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;">tistical based software’s DEREK Nexus</span><sup><span style="font-family:Verdana;">TM</span></sup><span style="font-family:Verdana;">, and MultiCASE, Case Ultra</span><sup><span style="font-family:Verdana;">TM</span></sup></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> widely accepted and respected software’s for DP and OSM</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">.</span></span></span>展开更多
Two new phenylpropanoid glycosides, 9-O-[6-O-acetyl-β-D-glucopyranosyl]-4-hydroxycinnamic acid （1） and 8-O-β-D-glucopyranosyl-（R）-（＋）-3,4,8-trihydroxy methyl phenylpropionate （2） were isolated from the 80% ...Two new phenylpropanoid glycosides, 9-O-[6-O-acetyl-β-D-glucopyranosyl]-4-hydroxycinnamic acid （1） and 8-O-β-D-glucopyranosyl-（R）-（＋）-3,4,8-trihydroxy methyl phenylpropionate （2） were isolated from the 80% EtOH extract of the roots of Sanguisorba officinalis. Their slructures were characterized by spectroscopic analysis and chemical method, including 1D NMR, 2D NMR, and HR-ESI-MS. Compounds 1 and 2 exhibited the moderate antimicrobial activities against all Gram-positive and Gram-negative bacteria tested.展开更多
One new triterpenoid saponin, monepaloside K (1) was isolated from the water-soluble part of the whole plant of a famous Tibetan medicinal herb, morina nepalensis var. alba Hand.-Mazz.. Its structure was determined t...One new triterpenoid saponin, monepaloside K (1) was isolated from the water-soluble part of the whole plant of a famous Tibetan medicinal herb, morina nepalensis var. alba Hand.-Mazz.. Its structure was determined to be 3-O-a-L-arabinopyranosyl-(13)-b-D- xylopyranosyl siaresinolic acid on the basis of spectroscopic evidences, especially 2D NMR techniques.展开更多
Two new compounds. corialins A （1） and B （2） were isolated from Coriaria nepulensis Wall. These new compounds were established as 7-hydroxy-3-[2,3-acetonidc-（3-methylhutane）] coumarin （1） and 3-O-β-D-glucopyr...Two new compounds. corialins A （1） and B （2） were isolated from Coriaria nepulensis Wall. These new compounds were established as 7-hydroxy-3-[2,3-acetonidc-（3-methylhutane）] coumarin （1） and 3-O-β-D-glucopyranosyl-3,4,5-1rihydroxy-1-（3- methyl-2-butenyl）-benzene （2）. on the basis of ID and 2D NMR techniques.展开更多
Three vips with two moiety probes for different Cucurbit[n = 6—8]urils have been synthesized. They are N-(2-methylenethiophen)-adamataneamine, N-(2-methylene pyrrole)- adamataneamine and N-(2-methylenefurfuran)-ada...Three vips with two moiety probes for different Cucurbit[n = 6—8]urils have been synthesized. They are N-(2-methylenethiophen)-adamataneamine, N-(2-methylene pyrrole)- adamataneamine and N-(2-methylenefurfuran)-adamataneamine. The probes are methyle-nepyridyl typically for Q[6] and adamataneamine typically for Q[7]. The host-vip complexes of Cucurbit[n = 6—8]urils with these vips have been investigated by using NMR techniques and ESMS method. Also, thermoanalysis has been used for exploring relationship of enthalpy and stability of the host-vip complexes.展开更多
Cancer is one of the most serious diseases that cause an enormous number of deaths all over the world.Tumor metabolism has great discrimination from that of normal tissues.Exploring the tumor metabolism may be one of ...Cancer is one of the most serious diseases that cause an enormous number of deaths all over the world.Tumor metabolism has great discrimination from that of normal tissues.Exploring the tumor metabolism may be one of the best ways to find biomarkers for cancer detection,diagnosis and to provide novel insights into internal physiological state where subtle changes may happen in metabolite concentrations.Nuclear Magnetic Resonance(NMR)technique nowadays is a popular tool to analyze cell extracts,tissues and biological fluids,etc,since it is a relatively fast and an accurate technique to supply abundant biochemical information at molecular levels for tumor research.In this review,approaches in tumor metabolism are discussed,including sample collection,data profiling and multivariate data analysis methods etc.Some typical applications of NMR are also summarized in tumor metabolism.展开更多
基金supported by the Natural Science Foundation of Xinjiang Uygur Autonomous Region(No.2022D01A250)the Karamay Innovative Environment Construction Plan(Innovative Talents)project(No.20212022hjcxrc0015).
文摘Polymer gels are widely used in water control and enhanced oil recovery in oil fields.However,the damage mechanism of polymer gels to layers with remaining oil and not requiring plugging and corresponding protective measures are unclear.In this paper,we investigated polymer gels'damage and protection performance through static gel-breaking experiments and dynamic plugging and oil recovery evaluations on rock cores.Moreover,nuclear magnetic resonance(NMR)technology was combined to analyze the damage performance of polymer gels on cores from the pore scale.In addition,a protective technique based on gel breakers for layers with remaining oil and not requiring plugging was proposed.Results showed that when polymer gels were injected into heterogeneous cores,they plugged high-permeability layers while also penetrating low-permeability layers.When the damage to the low-permeability layers was not alleviated,the conformance and oil displacement efficiency were significantly reduced.When the concentration of ammonium persulfate was 2%–5%,the gel-breaking time was shortest and the residue was very minimal.Therefore,ammonium persulfate could be used as a gel breaker and reservoir protective material.Furthermore,after injecting ammonium persulfate into heterogeneous reservoir cores,the gel damage on the face of low-permeability layers was relieved.Consequently,the improvement in sweep efficiency was achieved,showing the re-activation of the remaining oil in medium-low permeability layers.Therefore,the low-permeability layer protection process and core experiment study based on gel-breaking agents proposed in this study were suggested to provide a new technique for the field application of conformance modification agents,aiming to achieve higher recovery degrees.
基金supported by the National Natural Science Foundation of China(Grant No.22075064)National Key Laboratory Projects(No.SYSKT20230056).
文摘Supercapacitors,comprising electrical double-layer capacitors(EDLCs)and pseudocapa-citors,are widely acknowledged as high-power energy storage devices.However,their local structures and fundamental mechanisms remain poorly understood,and suitable experimental techniques for investigation are also lacking.Recently,nuclear magnetic resonance(NMR)has emerged as a powerful tool for addressing these fundamental issues with high local sensitivity and non-invasiveness.In this paper,we first review the limi-tations of existing characterization methods and highlight the advantages of NMR in investigating mechanisms of supercapacitors.Subsequently,we introduce the basic prin-ciple of ring current effect,NMR-active nuclei,and various NMR techniques employed in exploring energy storage mechanisms including cross polarization(CP)magic angle spinning(MAS)NMR,multiple-quantum(MQ)MAS,two-dimensional exchange spec-troscopy(2D-EXSY)NMR,magnetic resonance imaging(MRI)and pulsed-field gradient(PFG)NMR.Based on this,recent progress in investigating energy storage mechanisms in EDLCs and pseudocapacitors through various NMR techniques is discussed.Finally,an outlook on future directions for NMR research in supercapacitors is offered.
文摘<span style="font-family:Verdana;">The present work encompasses identification and characterization of major degradation product (DP) of OSM observed in base hydrolytic stress study. The separation of DP was carried out on a non-polar stationary phase by using high-performance liquid chromatography system (HPLC). Using waters X-bridge (250 mm × 4.6 mm, 5 μm) C18 column with gradient elution program. For the characterization study, stress samples were subjected to HPLC and UPLC-QTOF-MS/MS and based on mass fragmentation pattern</span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> plausible structure was deduced. Further</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> the DP was isolated using semi-prepara</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">- </span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;">tive liquid chromatography and concentrated the fractions using lyophiliza</span><span style="font-family:Verdana;">tion. The isolated DP was subjected to extensive 1D (1H, 13C, and</span><span style="font-family:Verdana;"> DEPT-135) and 2D (COSY, HSQC and HMBC) nuclear magnetic resonance (NMR) studies to authenticate the structure. The impurity was unambiguously named as N-(2-((2-(dimethylamino)ethyl)(methyl)amino)-4-metho</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;">xy-5-((4-(1-methyl-1H-indol-3-yl)pyrimidin-2-yl)amino)phenyl)-3-methoxy</span><span style="font-family:Verdana;">propanamide.</span></span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Add</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">- </span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;">itionally, the </span><i><span style="font-family:Verdana;">In-Silico</span></i><span style="font-family:Verdana;"> structure activity relation (QSAR) assessed through sta</span></span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;">tistical based software’s DEREK Nexus</span><sup><span style="font-family:Verdana;">TM</span></sup><span style="font-family:Verdana;">, and MultiCASE, Case Ultra</span><sup><span style="font-family:Verdana;">TM</span></sup></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> widely accepted and respected software’s for DP and OSM</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">.</span></span></span>
基金Key Projects in Scientific Research of Qujing Normal University(No.2011ZD003)
文摘Two new phenylpropanoid glycosides, 9-O-[6-O-acetyl-β-D-glucopyranosyl]-4-hydroxycinnamic acid （1） and 8-O-β-D-glucopyranosyl-（R）-（＋）-3,4,8-trihydroxy methyl phenylpropionate （2） were isolated from the 80% EtOH extract of the roots of Sanguisorba officinalis. Their slructures were characterized by spectroscopic analysis and chemical method, including 1D NMR, 2D NMR, and HR-ESI-MS. Compounds 1 and 2 exhibited the moderate antimicrobial activities against all Gram-positive and Gram-negative bacteria tested.
文摘One new triterpenoid saponin, monepaloside K (1) was isolated from the water-soluble part of the whole plant of a famous Tibetan medicinal herb, morina nepalensis var. alba Hand.-Mazz.. Its structure was determined to be 3-O-a-L-arabinopyranosyl-(13)-b-D- xylopyranosyl siaresinolic acid on the basis of spectroscopic evidences, especially 2D NMR techniques.
基金supported by the Major State Basic Research Development Program of China(Nos. 2009CB522303 and 2009CB940900)the foundation of State Key Laboratory of Phytochemistry and Plant Resources in West China(No.P2008-ZZ13)
文摘Two new compounds. corialins A （1） and B （2） were isolated from Coriaria nepulensis Wall. These new compounds were established as 7-hydroxy-3-[2,3-acetonidc-（3-methylhutane）] coumarin （1） and 3-O-β-D-glucopyranosyl-3,4,5-1rihydroxy-1-（3- methyl-2-butenyl）-benzene （2）. on the basis of ID and 2D NMR techniques.
文摘Three vips with two moiety probes for different Cucurbit[n = 6—8]urils have been synthesized. They are N-(2-methylenethiophen)-adamataneamine, N-(2-methylene pyrrole)- adamataneamine and N-(2-methylenefurfuran)-adamataneamine. The probes are methyle-nepyridyl typically for Q[6] and adamataneamine typically for Q[7]. The host-vip complexes of Cucurbit[n = 6—8]urils with these vips have been investigated by using NMR techniques and ESMS method. Also, thermoanalysis has been used for exploring relationship of enthalpy and stability of the host-vip complexes.
文摘Cancer is one of the most serious diseases that cause an enormous number of deaths all over the world.Tumor metabolism has great discrimination from that of normal tissues.Exploring the tumor metabolism may be one of the best ways to find biomarkers for cancer detection,diagnosis and to provide novel insights into internal physiological state where subtle changes may happen in metabolite concentrations.Nuclear Magnetic Resonance(NMR)technique nowadays is a popular tool to analyze cell extracts,tissues and biological fluids,etc,since it is a relatively fast and an accurate technique to supply abundant biochemical information at molecular levels for tumor research.In this review,approaches in tumor metabolism are discussed,including sample collection,data profiling and multivariate data analysis methods etc.Some typical applications of NMR are also summarized in tumor metabolism.
