A series of(R)-2-phenyl-4,5-dihydrothiazole-4-carboxamide derivatives containing a sulfur ether moiety were synthesized and characterized on the basis of NMR and elemental analysis(EA). The crystal structure of(R)-N-(...A series of(R)-2-phenyl-4,5-dihydrothiazole-4-carboxamide derivatives containing a sulfur ether moiety were synthesized and characterized on the basis of NMR and elemental analysis(EA). The crystal structure of(R)-N-(2-methyl-1-(methylthio)propan-2-yl)-2-(4-nitrophenyl)-4,5-dihydrothiazole-4-carboxamide(13 d) was determined to show R configuration. The bioasssy results indicated that most title compounds displayed good and broad spectrum antifungal activities against several phytopathogenic fungi. The structure activity relationships were discussed. Based on the antifungal activity of title compounds against Phytophthora capsici, a CoMSIA calculation was performed to establish a 3 D-QSAR model, which revealed that electrostatic and hydrophobic fields were the two most significant factors for antifungal activity. According to the established 3D-QSAR model, structure optimization was carried out to find(R)-N-((R)-1-(methylthio)propan-2-yl)-2-(p-tolyl)-4,5-dihydrothiazole-4-carboxamide(15 h)with excellent activity against Phytophthora capsici, thus emerging as a new lead compound for novel antiphytopathogenic fungus agent development.展开更多
The paper provides a review of the tribe Brachineurini first with subtribal arrangement （Brachineurina subtribe, nov. and Brachyneurina subtrib, nov.） and a key to the genera. A new genus and species, Pennaticoxita ...The paper provides a review of the tribe Brachineurini first with subtribal arrangement （Brachineurina subtribe, nov. and Brachyneurina subtrib, nov.） and a key to the genera. A new genus and species, Pennaticoxita tauricornuta Jiao ＆ Bu, gen. ＆ sp. nov. from China is described with generic diagnosis, illustration and photograph. The type specimens are deposited in the Institute of Entomology, College of Life Sciences, Nankai University, Tianjin, China （NKUM）.展开更多
Although the electromagnetic-coupling chemical vapor infiltration(E-CVI)has been proven of a highefficiency technique for producing carbon fiber reinforced pyrocarbon(Py C)matrix(C/C)composites,a deep understanding of...Although the electromagnetic-coupling chemical vapor infiltration(E-CVI)has been proven of a highefficiency technique for producing carbon fiber reinforced pyrocarbon(Py C)matrix(C/C)composites,a deep understanding of the deposition kinetics and mechanism of Py C matrix is still lack.In this work,a deposition model with uniform electric field but gradient magnetic field was set up by using unidirectional carbon fiber bundles as the substrates to investigate the deposition kinetics and mechanism.Meanwhile,the polarizability,and the chemical adsorption and dehydrogenation barriers of hydrocarbon were simulated based on the density functional theory(DFT)and the Climb-image nudged elastic band method,respectively.The E-CVI process exhibited extremely high Py C deposition rates of 8.7,11.5,16.5 and 22.7 nm/s at 700,750,800 and 850℃,respectively,together with a significantly low apparent activation energy of 57.9 k J/mol within the first 5 min.The Py C deposited at different temperatures with different time shows a smooth laminar structure with low coherent length and graphitization degree.The theoretical calculation and simulation results indicated that the electrons existing on the carbon fibers and the accelerated motion of radicals with preferred orientation forced by the derived magnetic field have reduced the energy barrier for the deposition process,thereby resulting in low apparent activation energy and high Py C deposition rate.The results of this work may shed a light on how to better direct the preparation of C/C composites by E-CVI process with high quality and efficiency.展开更多
C/SiC volume ratios in carbon fiber-reinforced carbon-silicon carbide(C_(f)/C-SiC)composites may influence greatly mechanical and oxidation properties of the composites,but have not been well investigated yet.Herein,C...C/SiC volume ratios in carbon fiber-reinforced carbon-silicon carbide(C_(f)/C-SiC)composites may influence greatly mechanical and oxidation properties of the composites,but have not been well investigated yet.Herein,C_(f)/C-SiC composites with different C/SiC volume ratios were fabricated by chemical vapor infiltration(CVI)technique through alternating the thickness of a pyrocarbon(PyC)interlayer.The composites with C/SiC volume ratios of 0.37 and 0.84 exhibited the better comprehensive mechanical properties.The CS0.37 showed the highest flexural strength of 340.6 MPa,and CS0.84 had the maximum tensile strength of 139.1 MPa.The excellent mechanical properties were closely related to the relatively low C/SiC volume ratios and porosities,optimum interfacial bonding and reduced matrix micro-cracks.The composite with a low C/SiC volume ratio of 0.10 showed the best anti-oxidation performance due to its high SiC content.The oxidation mechanisms at 1100℃and 1400℃were discussed by considering the effect of the C/SiC volume ratios,pores and matrix micro-cracks,oxidation of carbon phase and SiC.展开更多
As a complementary analysis tool to conventional high-field nuclear magnetic resonance(NMR),zero-to ultralow-field(ZULF)NMR detects nuclear magnetization signals in the sub-microtesla regime.Spin-exchange relaxation-f...As a complementary analysis tool to conventional high-field nuclear magnetic resonance(NMR),zero-to ultralow-field(ZULF)NMR detects nuclear magnetization signals in the sub-microtesla regime.Spin-exchange relaxation-free(SERF)atomic magnetometers provide a new generation of sensitive detectors for ZULF NMR.Owing to features such as low cost,high resolution,and portability,ZULF NMR has recently attracted considerable attention in chemistry,biology,medicine,and tests of fundamental physics.This review describes the basic principles,methodology,and recent experimental and theoretical development of ZULF NMR as well as its applications in spectroscopy,quantum control,imaging,NMR-based quantum devices,and tests of fundamental physics.The future prospects of ZULF NMR are also discussed.展开更多
This study has developed a novel sensing platform for the investigation of cell oxygen metabolism.With chitosan@TiO_(2) nanocomposites as supporting matrix which was decorated on the surface of indium tin oxide glass,...This study has developed a novel sensing platform for the investigation of cell oxygen metabolism.With chitosan@TiO_(2) nanocomposites as supporting matrix which was decorated on the surface of indium tin oxide glass,it can effectively absorb A549 cells and sensitize the electrochemiluminescence(ECL)of luminol.On this platform,the ECL output is dependent on the level of reactive oxygen species(ROSs),which was evidenced by the intervening of resveratrol,a typical ROSs’scavenger.The results indicated that the ECL signal was quenched by the resveratrol within its concentration range from 0.10 nM to 2.97μM.Thus,it is believable that the ECL of luminol sensitively responded upon oxygenic matters on this living cell platform would be powerful for cell oxygen metabolism monitoring.展开更多
The generic diagnosis of Brachineura is revised to give an accurate and adequate redescription by adding detailed characters. First records of Brachineura in China, including three new species, namely B. sphaerica Ji...The generic diagnosis of Brachineura is revised to give an accurate and adequate redescription by adding detailed characters. First records of Brachineura in China, including three new species, namely B. sphaerica Jiao ＆ Bu, sp. nov., B. physiphora Jiao ＆ Bu, sp. nov.and B. prodolichata Jiao ＆ Bu, sp. nov., are described and illustrated. The type specimens were deposited in the Institute of Entomology, College of Life Sciences, Nankai University, Tianjin, China（NKUM）.展开更多
基金financially supported by the Scientific Project of Tianjin Municipal Education Commission(No. 2018KJ008)Tianjin Natural Science Foundation(No. 16JCYBJC29400)
文摘A series of(R)-2-phenyl-4,5-dihydrothiazole-4-carboxamide derivatives containing a sulfur ether moiety were synthesized and characterized on the basis of NMR and elemental analysis(EA). The crystal structure of(R)-N-(2-methyl-1-(methylthio)propan-2-yl)-2-(4-nitrophenyl)-4,5-dihydrothiazole-4-carboxamide(13 d) was determined to show R configuration. The bioasssy results indicated that most title compounds displayed good and broad spectrum antifungal activities against several phytopathogenic fungi. The structure activity relationships were discussed. Based on the antifungal activity of title compounds against Phytophthora capsici, a CoMSIA calculation was performed to establish a 3 D-QSAR model, which revealed that electrostatic and hydrophobic fields were the two most significant factors for antifungal activity. According to the established 3D-QSAR model, structure optimization was carried out to find(R)-N-((R)-1-(methylthio)propan-2-yl)-2-(p-tolyl)-4,5-dihydrothiazole-4-carboxamide(15 h)with excellent activity against Phytophthora capsici, thus emerging as a new lead compound for novel antiphytopathogenic fungus agent development.
基金supported by Natural Science Foundation of China(31401995,J1210005)Tianjiin Science&Technology Development Fundation for Higher School(20140606)
文摘The paper provides a review of the tribe Brachineurini first with subtribal arrangement （Brachineurina subtribe, nov. and Brachyneurina subtrib, nov.） and a key to the genera. A new genus and species, Pennaticoxita tauricornuta Jiao ＆ Bu, gen. ＆ sp. nov. from China is described with generic diagnosis, illustration and photograph. The type specimens are deposited in the Institute of Entomology, College of Life Sciences, Nankai University, Tianjin, China （NKUM）.
基金supported by the National Key R&D Program of China(Grant No.2018YFF01013600)the National Natural Science Foundations of China(Grant No.U1537204,U20A20242,52022101,51802313&51902315)+1 种基金the National Science and Technology Major Project(2017-VI-0020-0093)Liaoning Revitalization Talents Program and the Research Fund of Youth Innovation Promotion Association of CAS,China(Grant No.Y201830&2021190)。
文摘Although the electromagnetic-coupling chemical vapor infiltration(E-CVI)has been proven of a highefficiency technique for producing carbon fiber reinforced pyrocarbon(Py C)matrix(C/C)composites,a deep understanding of the deposition kinetics and mechanism of Py C matrix is still lack.In this work,a deposition model with uniform electric field but gradient magnetic field was set up by using unidirectional carbon fiber bundles as the substrates to investigate the deposition kinetics and mechanism.Meanwhile,the polarizability,and the chemical adsorption and dehydrogenation barriers of hydrocarbon were simulated based on the density functional theory(DFT)and the Climb-image nudged elastic band method,respectively.The E-CVI process exhibited extremely high Py C deposition rates of 8.7,11.5,16.5 and 22.7 nm/s at 700,750,800 and 850℃,respectively,together with a significantly low apparent activation energy of 57.9 k J/mol within the first 5 min.The Py C deposited at different temperatures with different time shows a smooth laminar structure with low coherent length and graphitization degree.The theoretical calculation and simulation results indicated that the electrons existing on the carbon fibers and the accelerated motion of radicals with preferred orientation forced by the derived magnetic field have reduced the energy barrier for the deposition process,thereby resulting in low apparent activation energy and high Py C deposition rate.The results of this work may shed a light on how to better direct the preparation of C/C composites by E-CVI process with high quality and efficiency.
基金financially supported by the National Key R&D Program of China(Grant No.2018YFF01013600)the National Natural Science Foundations of China(Grant Nos.U20A20242,52022101,51802313,51902315)+1 种基金the Research Fund of Youth Innovation Promotion Association of Chinese Academy of Sciences,China(Grant Nos.Y201830 and 2021190)the Liaoning Revitalization Talents Program and the National Science and Technology Major Project(No.2017-VI-0020-0093)。
文摘C/SiC volume ratios in carbon fiber-reinforced carbon-silicon carbide(C_(f)/C-SiC)composites may influence greatly mechanical and oxidation properties of the composites,but have not been well investigated yet.Herein,C_(f)/C-SiC composites with different C/SiC volume ratios were fabricated by chemical vapor infiltration(CVI)technique through alternating the thickness of a pyrocarbon(PyC)interlayer.The composites with C/SiC volume ratios of 0.37 and 0.84 exhibited the better comprehensive mechanical properties.The CS0.37 showed the highest flexural strength of 340.6 MPa,and CS0.84 had the maximum tensile strength of 139.1 MPa.The excellent mechanical properties were closely related to the relatively low C/SiC volume ratios and porosities,optimum interfacial bonding and reduced matrix micro-cracks.The composite with a low C/SiC volume ratio of 0.10 showed the best anti-oxidation performance due to its high SiC content.The oxidation mechanisms at 1100℃and 1400℃were discussed by considering the effect of the C/SiC volume ratios,pores and matrix micro-cracks,oxidation of carbon phase and SiC.
基金This work was supported by National Key Research and Development Program of China(Grant no.2018YFA0306600)National Natural Science Foun-dation of China(Grants nos.11661161018,11927811)+1 种基金Anhui Initia-tive in Quantum Information Technologies(Grant No.AHY050000)USTC Research Funds of the Double First-Class Initiative(Grant no.YD3540002002).
文摘As a complementary analysis tool to conventional high-field nuclear magnetic resonance(NMR),zero-to ultralow-field(ZULF)NMR detects nuclear magnetization signals in the sub-microtesla regime.Spin-exchange relaxation-free(SERF)atomic magnetometers provide a new generation of sensitive detectors for ZULF NMR.Owing to features such as low cost,high resolution,and portability,ZULF NMR has recently attracted considerable attention in chemistry,biology,medicine,and tests of fundamental physics.This review describes the basic principles,methodology,and recent experimental and theoretical development of ZULF NMR as well as its applications in spectroscopy,quantum control,imaging,NMR-based quantum devices,and tests of fundamental physics.The future prospects of ZULF NMR are also discussed.
基金the National Natural Science Foundation of China(21675115 and 21375091).
文摘This study has developed a novel sensing platform for the investigation of cell oxygen metabolism.With chitosan@TiO_(2) nanocomposites as supporting matrix which was decorated on the surface of indium tin oxide glass,it can effectively absorb A549 cells and sensitize the electrochemiluminescence(ECL)of luminol.On this platform,the ECL output is dependent on the level of reactive oxygen species(ROSs),which was evidenced by the intervening of resveratrol,a typical ROSs’scavenger.The results indicated that the ECL signal was quenched by the resveratrol within its concentration range from 0.10 nM to 2.97μM.Thus,it is believable that the ECL of luminol sensitively responded upon oxygenic matters on this living cell platform would be powerful for cell oxygen metabolism monitoring.
基金supported by National Natural Science Foundation of China(31401995,J1210005)Tianjiin Science&Technology Development Fundation for Higher School(20140606)
文摘The generic diagnosis of Brachineura is revised to give an accurate and adequate redescription by adding detailed characters. First records of Brachineura in China, including three new species, namely B. sphaerica Jiao ＆ Bu, sp. nov., B. physiphora Jiao ＆ Bu, sp. nov.and B. prodolichata Jiao ＆ Bu, sp. nov., are described and illustrated. The type specimens were deposited in the Institute of Entomology, College of Life Sciences, Nankai University, Tianjin, China（NKUM）.
