Highly efficient and selective carbon-carbon double bond aerobic cleavage of olefins catalyzed by metallopor- phyrins was investigated, and carbonyl compounds and epoxide were produced as the main products. CoTPP （co...Highly efficient and selective carbon-carbon double bond aerobic cleavage of olefins catalyzed by metallopor- phyrins was investigated, and carbonyl compounds and epoxide were produced as the main products. CoTPP （co- balt meso-tetraphenyl porphyrin） showed excellent activity for the oxidative cleavage of carbon-carbon double bond by using styrene as model compound, in which the TOF （turnover frequency） and selectivity toward benzaldehyde was obtained with 2×10^4h-1 and 86%,respectively.展开更多
One novel discrete coordination molecule with Ag^(I) centers,namely[Ag_(3)(L)_(3)(ClO_(4))_(3)]·3CH_(2)Cl_(2)·6CH_(3)OH·1.5H_(2)O (1),has been synthesized based on the double Schiff-base ligand,3,6-bis[...One novel discrete coordination molecule with Ag^(I) centers,namely[Ag_(3)(L)_(3)(ClO_(4))_(3)]·3CH_(2)Cl_(2)·6CH_(3)OH·1.5H_(2)O (1),has been synthesized based on the double Schiff-base ligand,3,6-bis[2-(4-oxidequinoxaline)-yl]-4,5-diaza-3,5-octadiene (L) and AgClO_4.The obtained Ag(I) compound was fully characterized by infrared spectroscopy,elemental analysis,and single-crystal X-ray diffraction.1 is of trigonal system space group P-31c with a=16.320(2),b=16.320(2),c=20.108(6)?,T=173(2) K,V=4638.2(16) A^(3),D_(c)=1.645 g/cm^(3),M_(r)=2297.33,Z=2,F(000)=2334,μ=0.970 mm~(–1),Goodness-of-fit=1.109,the final R=0.0776,wR=0.1813,Rindices (all data)=0.1196,wR=0.2011.The compound exhibits a triple-helical[Ag_(3)L_(3)]^(3+)crown-like trimer,in which three Ag(I) atoms form an equilateral triangle with the Ag···Ag distance of 4.7 A.Uncoordinated counterions ClO_(4)^(–) and solvent molecules methanol generate the hydrogen-bonded frameworks based on discrete molecular complex building blocks.展开更多
采用双层辉光离子渗金属技术,在工业纯铁和20钢表面进行W、Mo、Co多元共渗,形成Fe W Mo Co型渗镀复合层.对渗镀层进行了金相组织观察、成分及硬度测量,重点研究了镀层的相组成及镀层与基体间的结合强度.结果表明:纯铁和20钢表面镀层以...采用双层辉光离子渗金属技术,在工业纯铁和20钢表面进行W、Mo、Co多元共渗,形成Fe W Mo Co型渗镀复合层.对渗镀层进行了金相组织观察、成分及硬度测量,重点研究了镀层的相组成及镀层与基体间的结合强度.结果表明:纯铁和20钢表面镀层以金属钨、钼为基体,其上分布大量μ相,并有少量Laves相;镀层硬度高达1000～1400HV,固溶和时效处理对硬度提高影响不大;纯铁表面镀层在渗金属、固溶、时效状态下,持续加载100N未发生镀层剥落现象;20钢表面镀层经固溶处理后,所加载荷在100N内未发生剥落现象,但在渗金属及时效态,当载荷加至80N时,镀层开始剥落.展开更多
Lipids play an important role in platelet integrity and function.However,most of lipid molecular compositions in platelets still remain unknown,especially for phospholipids.In this work,we characterized detailed struc...Lipids play an important role in platelet integrity and function.However,most of lipid molecular compositions in platelets still remain unknown,especially for phospholipids.In this work,we characterized detailed structures of different classes of phospholipids in human platelets.Using a flow microreactor,the acetone Paternò-Büchi reaction was introduced for online derivatization of carbon-carbon double bond(C=C)of lipids right after separation by liquid chromatography(LC).Tandem mass spectrometry(MS/MS)methods were developed for multi-level structural identification of phospholipids,including head group,chain composition,and C=C locations in the fatty acyl/alkyl chains.After optimization of the workflow,a total of 110 molecular species of phospholipids were identified in the human platelet samples,including many C=C location isomers.At lipid class level,phosphatidylserine was found more abundant in the platelet samples than that of the plasma samples;at isomer level,the relative ratio of C18:1(Δ9)vs C18:1(Δ11)also increased in platelet samples comparing with that of the plasma samples.The detailed structural information of phospholipids and their C=C isomers ratios would be useful for investigation of potential functions of human platelets potentially associated with phospholipid isomers.展开更多
文摘Highly efficient and selective carbon-carbon double bond aerobic cleavage of olefins catalyzed by metallopor- phyrins was investigated, and carbonyl compounds and epoxide were produced as the main products. CoTPP （co- balt meso-tetraphenyl porphyrin） showed excellent activity for the oxidative cleavage of carbon-carbon double bond by using styrene as model compound, in which the TOF （turnover frequency） and selectivity toward benzaldehyde was obtained with 2×10^4h-1 and 86%,respectively.
基金supported by grants from NSFC(Nos.21671122 and 21475078)。
文摘One novel discrete coordination molecule with Ag^(I) centers,namely[Ag_(3)(L)_(3)(ClO_(4))_(3)]·3CH_(2)Cl_(2)·6CH_(3)OH·1.5H_(2)O (1),has been synthesized based on the double Schiff-base ligand,3,6-bis[2-(4-oxidequinoxaline)-yl]-4,5-diaza-3,5-octadiene (L) and AgClO_4.The obtained Ag(I) compound was fully characterized by infrared spectroscopy,elemental analysis,and single-crystal X-ray diffraction.1 is of trigonal system space group P-31c with a=16.320(2),b=16.320(2),c=20.108(6)?,T=173(2) K,V=4638.2(16) A^(3),D_(c)=1.645 g/cm^(3),M_(r)=2297.33,Z=2,F(000)=2334,μ=0.970 mm~(–1),Goodness-of-fit=1.109,the final R=0.0776,wR=0.1813,Rindices (all data)=0.1196,wR=0.2011.The compound exhibits a triple-helical[Ag_(3)L_(3)]^(3+)crown-like trimer,in which three Ag(I) atoms form an equilateral triangle with the Ag···Ag distance of 4.7 A.Uncoordinated counterions ClO_(4)^(–) and solvent molecules methanol generate the hydrogen-bonded frameworks based on discrete molecular complex building blocks.
文摘采用双层辉光离子渗金属技术,在工业纯铁和20钢表面进行W、Mo、Co多元共渗,形成Fe W Mo Co型渗镀复合层.对渗镀层进行了金相组织观察、成分及硬度测量,重点研究了镀层的相组成及镀层与基体间的结合强度.结果表明:纯铁和20钢表面镀层以金属钨、钼为基体,其上分布大量μ相,并有少量Laves相;镀层硬度高达1000～1400HV,固溶和时效处理对硬度提高影响不大;纯铁表面镀层在渗金属、固溶、时效状态下,持续加载100N未发生镀层剥落现象;20钢表面镀层经固溶处理后,所加载荷在100N内未发生剥落现象,但在渗金属及时效态,当载荷加至80N时,镀层开始剥落.
基金Financial support from the National Natural Science Foundation of China(Grant nos.21722506 and 21621003)National Institutes of Health(Project R01GM118484)is greatly appreciated.
文摘Lipids play an important role in platelet integrity and function.However,most of lipid molecular compositions in platelets still remain unknown,especially for phospholipids.In this work,we characterized detailed structures of different classes of phospholipids in human platelets.Using a flow microreactor,the acetone Paternò-Büchi reaction was introduced for online derivatization of carbon-carbon double bond(C=C)of lipids right after separation by liquid chromatography(LC).Tandem mass spectrometry(MS/MS)methods were developed for multi-level structural identification of phospholipids,including head group,chain composition,and C=C locations in the fatty acyl/alkyl chains.After optimization of the workflow,a total of 110 molecular species of phospholipids were identified in the human platelet samples,including many C=C location isomers.At lipid class level,phosphatidylserine was found more abundant in the platelet samples than that of the plasma samples;at isomer level,the relative ratio of C18:1(Δ9)vs C18:1(Δ11)also increased in platelet samples comparing with that of the plasma samples.The detailed structural information of phospholipids and their C=C isomers ratios would be useful for investigation of potential functions of human platelets potentially associated with phospholipid isomers.
