The newly discovered iron-based superconductors have triggered renewed enormous research interest in the condensed matter physics community. Nuclear magnetic resonance （NMR） is a low-energy local probe for studying ...The newly discovered iron-based superconductors have triggered renewed enormous research interest in the condensed matter physics community. Nuclear magnetic resonance （NMR） is a low-energy local probe for studying strongly correlated electrons, and particularly important for high-Tc superconductors. In this paper, we review NMR studies on the structural transition, antiferromagnetic order, spin fluctuations, and superconducting properties of several iron-based high-Tc superconductors, including LaFeAsOl_xFx, LaFeAsOl_x, BaFe2As2, Bal_xKxFe2As2, Cao.23Nao.67Fe2As2, BaFe2（Asl_xPx）2, Ba（Fel_xRux）2As2, Ba（Fel_xCox）2As2, Lil＋xFeAs, LiFel_xCoxAs, NaFeAs, NaFel_xCoxAs, KyFe2_xSe2, and （T1,Rb）yFe2_xSe2.展开更多
BACKGROUND Several studies have demonstrated a correlation between esophageal cancer(EC)and perturbed urinary metabolomic profiles,but none has described the correlation between urine metabolite profiles and those of ...BACKGROUND Several studies have demonstrated a correlation between esophageal cancer(EC)and perturbed urinary metabolomic profiles,but none has described the correlation between urine metabolite profiles and those of the tumor and adjacent esophageal mucosa in the same patient.AIM To investigate how urinary metabolic phenotypes were linked to the changes in the biochemical landscape of esophageal tumors.METHODS Nuclear magnetic resonance-based metabolomics were applied to esophageal tumor tissues and adjacent normal mucosal tissues alongside patient-matched urine samples.RESULTS Analysis revealed that specific metabolite changes overlapped across both metrics,including glucose,glutamate,citrate,glycine,creatinine and taurine,indicating that the networks for metabolic pathway perturbations in EC,potentially involved in but not limited to disruption of fatty acid metabolism,glucose and glycolytic metabolism,tricarboxylic acid cycle and glutaminolysis.Additionally,changes in most urinary biomarkers correlated with changes in biomarker candidates in EC tissues,implying enhanced energy production for rapid cell proliferation.CONCLUSION Overall,these associations provide evidence for distinct metabolic signatures and pathway disturbances between the tumor tissues and urine of EC patients,and changes in urinary metabolic signature could reflect reprogramming of the aforementioned metabolic pathways in EC tissues.Further investigation is needed to validate these initial findings using larger samples and to establish the underlying mechanism of EC progression.展开更多
针对海上油田中油基泥浆滤液侵入导致的储层核磁共振(Nuclear Magnetic Resonance,NMR)测井横向弛豫时间(Transverse Relaxation Time,T_(2))谱“拖尾”现象,提出了一种基于储层物性约束的T_(2)谱分段校正方法,并研发了可挂接于CIFLog...针对海上油田中油基泥浆滤液侵入导致的储层核磁共振(Nuclear Magnetic Resonance,NMR)测井横向弛豫时间(Transverse Relaxation Time,T_(2))谱“拖尾”现象,提出了一种基于储层物性约束的T_(2)谱分段校正方法,并研发了可挂接于CIFLog测井综合解释平台的插件模块。该方法以渗透率为校正判别阈值,按孔隙度分段构建多级物性区间,结合流体类型特征建立校正系数数据库,并在算法中引入积分面积守恒约束,确保校正前后T_(2)谱总面积一致,从物理层面保持孔隙度的真实性。模块采用插件化设计,实现了数据自动匹配、系数管理、计算可视化及结果输出等功能。南海北部湾盆地两口油基泥浆井的应用结果表明,校正后T_(2)谱“拖尾”现象得到明显抑制,长弛豫时间端幅值较原始T_(2)谱平均降低6.86%~10.61%,谱形与储层物性特征更加一致,测井解释结果与常规曲线及岩心资料匹配良好,验证了所建方法的稳定性与工程适用性。研究成果为复杂钻井条件下的核磁测井定量解释提供了可靠的技术支撑。展开更多
New Schiff base polymers poly[4,4＇-methylenebis（cinnamaldehyde）ethylenediimine] （PMBCen）, poly[4,4＇- methylenebis（cinnamaldehyde）1,2-propylenediimine] （PMBCPn）, poly[4,4＇-methylenebis（cinnamaldehyde）1,3-p...New Schiff base polymers poly[4,4＇-methylenebis（cinnamaldehyde）ethylenediimine] （PMBCen）, poly[4,4＇- methylenebis（cinnamaldehyde）1,2-propylenediimine] （PMBCPn）, poly[4,4＇-methylenebis（cinnamaldehyde）1,3-propylenediimine] （PMBCPR）, poly[4,4＇-methylenebis（cinnamaldehyde） 1,2-phenylenediimine] （PMBCPh）, poly[4,4＇-methylenebis（cinnamaldehyde）meso-stilbenediimine] （PMBCS）, poly[4,4＇-methylenebis（cinnamaldehyde）urea] （PMBCUR）, poly[4,4＇- methylenebis（cinnamaldehyde）semicarbazone] （PMBCSc）, poly[4,4＇-methylenebis（cinnamaldehyde）thiosemicarbazone] （PMBCTSc） and poly[4,4＇-methylenebis（cinnamaldehyde）hydrazone] （PMBCH） were formed by polycondensation of 4,4＇- methylenebis（cinnamaldehyde） with ethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, 1,2-phenylenediamine, meso-stilbenediamine, urea, semicarbazide, thiosemicarbazide and hydrazine, respectively. The dialdehyde and polymers have been characterized through elemental micro-analysis, IR, UV-Vis and ^1H-NMR spectroscopic techniques. Thermoanalytical studies and viscous flow of dilute solutions of dialdehyde and its polymers have been examined and compared.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.11074304 and 11222433)the National Basic Research Program of China(Grant Nos.2010CB923004 and 2011CBA00112)
文摘The newly discovered iron-based superconductors have triggered renewed enormous research interest in the condensed matter physics community. Nuclear magnetic resonance （NMR） is a low-energy local probe for studying strongly correlated electrons, and particularly important for high-Tc superconductors. In this paper, we review NMR studies on the structural transition, antiferromagnetic order, spin fluctuations, and superconducting properties of several iron-based high-Tc superconductors, including LaFeAsOl_xFx, LaFeAsOl_x, BaFe2As2, Bal_xKxFe2As2, Cao.23Nao.67Fe2As2, BaFe2（Asl_xPx）2, Ba（Fel_xRux）2As2, Ba（Fel_xCox）2As2, Lil＋xFeAs, LiFel_xCoxAs, NaFeAs, NaFel_xCoxAs, KyFe2_xSe2, and （T1,Rb）yFe2_xSe2.
基金Supported by the National Natural Science Foundation of China,No.81471729 and No.81101102the Science and Technology and Planning Project of Guangdong Province,No.2016A020216025+2 种基金the Research Award Fund for Outstanding Young Teachers in Higher Education Institutions,Guangdong Province,No.YQ2015245the National Natural Science Foundation of Guangdong Province,No.S2011010004973the Department of Education of Guangdong Province,No.2017KTSCX071
文摘BACKGROUND Several studies have demonstrated a correlation between esophageal cancer(EC)and perturbed urinary metabolomic profiles,but none has described the correlation between urine metabolite profiles and those of the tumor and adjacent esophageal mucosa in the same patient.AIM To investigate how urinary metabolic phenotypes were linked to the changes in the biochemical landscape of esophageal tumors.METHODS Nuclear magnetic resonance-based metabolomics were applied to esophageal tumor tissues and adjacent normal mucosal tissues alongside patient-matched urine samples.RESULTS Analysis revealed that specific metabolite changes overlapped across both metrics,including glucose,glutamate,citrate,glycine,creatinine and taurine,indicating that the networks for metabolic pathway perturbations in EC,potentially involved in but not limited to disruption of fatty acid metabolism,glucose and glycolytic metabolism,tricarboxylic acid cycle and glutaminolysis.Additionally,changes in most urinary biomarkers correlated with changes in biomarker candidates in EC tissues,implying enhanced energy production for rapid cell proliferation.CONCLUSION Overall,these associations provide evidence for distinct metabolic signatures and pathway disturbances between the tumor tissues and urine of EC patients,and changes in urinary metabolic signature could reflect reprogramming of the aforementioned metabolic pathways in EC tissues.Further investigation is needed to validate these initial findings using larger samples and to establish the underlying mechanism of EC progression.
文摘针对海上油田中油基泥浆滤液侵入导致的储层核磁共振(Nuclear Magnetic Resonance,NMR)测井横向弛豫时间(Transverse Relaxation Time,T_(2))谱“拖尾”现象,提出了一种基于储层物性约束的T_(2)谱分段校正方法,并研发了可挂接于CIFLog测井综合解释平台的插件模块。该方法以渗透率为校正判别阈值,按孔隙度分段构建多级物性区间,结合流体类型特征建立校正系数数据库,并在算法中引入积分面积守恒约束,确保校正前后T_(2)谱总面积一致,从物理层面保持孔隙度的真实性。模块采用插件化设计,实现了数据自动匹配、系数管理、计算可视化及结果输出等功能。南海北部湾盆地两口油基泥浆井的应用结果表明,校正后T_(2)谱“拖尾”现象得到明显抑制,长弛豫时间端幅值较原始T_(2)谱平均降低6.86%~10.61%,谱形与储层物性特征更加一致,测井解释结果与常规曲线及岩心资料匹配良好,验证了所建方法的稳定性与工程适用性。研究成果为复杂钻井条件下的核磁测井定量解释提供了可靠的技术支撑。
文摘New Schiff base polymers poly[4,4＇-methylenebis（cinnamaldehyde）ethylenediimine] （PMBCen）, poly[4,4＇- methylenebis（cinnamaldehyde）1,2-propylenediimine] （PMBCPn）, poly[4,4＇-methylenebis（cinnamaldehyde）1,3-propylenediimine] （PMBCPR）, poly[4,4＇-methylenebis（cinnamaldehyde） 1,2-phenylenediimine] （PMBCPh）, poly[4,4＇-methylenebis（cinnamaldehyde）meso-stilbenediimine] （PMBCS）, poly[4,4＇-methylenebis（cinnamaldehyde）urea] （PMBCUR）, poly[4,4＇- methylenebis（cinnamaldehyde）semicarbazone] （PMBCSc）, poly[4,4＇-methylenebis（cinnamaldehyde）thiosemicarbazone] （PMBCTSc） and poly[4,4＇-methylenebis（cinnamaldehyde）hydrazone] （PMBCH） were formed by polycondensation of 4,4＇- methylenebis（cinnamaldehyde） with ethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, 1,2-phenylenediamine, meso-stilbenediamine, urea, semicarbazide, thiosemicarbazide and hydrazine, respectively. The dialdehyde and polymers have been characterized through elemental micro-analysis, IR, UV-Vis and ^1H-NMR spectroscopic techniques. Thermoanalytical studies and viscous flow of dilute solutions of dialdehyde and its polymers have been examined and compared.
