Traditional matrix does not allow matrix-assisted laser desorption/ionization mass spectrometry(MALDI MS) to analyze volatile compounds,because volatile analytes may vaporize during the sample preparation process or i...Traditional matrix does not allow matrix-assisted laser desorption/ionization mass spectrometry(MALDI MS) to analyze volatile compounds,because volatile analytes may vaporize during the sample preparation process or in the high vacuum circumstance of ion source.Herein,we reported a Co and N doped porous carbon material(Co-NC) which were synthesized by pyrolysis of a Schiff base coordination compound.Co-NC could simultaneously act as adsorbent of volatile compounds and as matrix of MALDI MS,to provide the capability of MALDI MS to analyze volatile compounds.As adsorbent,Co-NC could stro ngly adsorb and enrich the volatile compounds in perfume and herbs,and hold them even in the high vacuum circumstance.On the other hand,Co-NC could absorb the energy of the laser,and then transfer the energy to the analyte for desorption and ionization of analyte in both negative and positive ionization modes.Additionally,the background interferences were avoided in the low-mass region(<500 Da) when using Co-NC as matrix,overcoming the challenges of MALDI MS analysis of small molecule compounds.In summary,Co-NC as matrix tremendously extended the application of MALDI MS.展开更多
本论文基于传统聚合物基炭材料合成原理,通过选择合适结构的前驱体分子,在聚合过程中分子水平锚定Co原子,同时引入TiO_(2)纳米颗粒,再经高温焙烧后制得一种双金属氮氧化物(Co_(m)Ti_(n)O_(x)N_(y))-Co单原子(Co-NC)复合催化剂。该催化...本论文基于传统聚合物基炭材料合成原理,通过选择合适结构的前驱体分子,在聚合过程中分子水平锚定Co原子,同时引入TiO_(2)纳米颗粒,再经高温焙烧后制得一种双金属氮氧化物(Co_(m)Ti_(n)O_(x)N_(y))-Co单原子(Co-NC)复合催化剂。该催化剂在酸性(E_(onset)=0.755 V vs.RHE,0.5 mol/LH_(2)SO_(4);0.760 V vs.RHE,0.1mol/LHClO_(4))、中性(E_(onset)=0.787 V vs.RHE,0.1 mol/L PBS)、碱性(E_(onset)=0.880 V vs.RHE,0.1 mol/L KOH)电解液中的氧气还原(ORR)性能(pH=0-13)均优于纯氮杂碳纳米管、氮杂碳纳米管负载的金属氮氧化物和Co单原子催化剂,表明,Co_(m)Ti_(n)O_(x)N_(y)与Co单原子的协同效应使得复合催化剂具有更好的ORR活性,同时复合催化剂的稳定性和选择性显著优于商品Pt/C催化剂。这为开发高性能低成本氧气还原电催化剂提供了新的思路。展开更多
针对网络控制系统(NCS)中网络带宽等网络资源受限制的情况,对目前NCS信息调度的研究现状进行了综述.首先介绍了NCS的背景和基本概念,阐述了网络的引入带来的各种影响.然后研究了NCS的动态特性,对现有的信息调度策略和调度方法进行了总...针对网络控制系统(NCS)中网络带宽等网络资源受限制的情况,对目前NCS信息调度的研究现状进行了综述.首先介绍了NCS的背景和基本概念,阐述了网络的引入带来的各种影响.然后研究了NCS的动态特性,对现有的信息调度策略和调度方法进行了总结与分析.进一步分析了在资源受限时如何进行有效的信息调度以保证较高的网络服务质量QoS(Quality ofService)和较好的控制品质QoC(Quality of Control),对一些控制与调度协同设计的研究进行了说明.最后,结合前面的研究分析,讨论了该领域今后进一步的研究方向.展开更多
Selenium(Se)is a promising cathode material for lithium batteries due to its high volumetric energy density(2528 Wh·L^(-1)).However,its practical application is restricted by rapid capacity fading resulting from ...Selenium(Se)is a promising cathode material for lithium batteries due to its high volumetric energy density(2528 Wh·L^(-1)).However,its practical application is restricted by rapid capacity fading resulting from the shuttle effect and slow reaction kinetics.Herein,a N/Co co-doped three-dimensional porous carbon(Co-NC)is prepared and used as Se host for lithium-selenium batteries(LSeBs).Co-NC displays a high specific surface area of1201 m^(2)·g^(-1)which benefits from N and Co doping.The N and Co not only enhance the electrical conductivity of porous carbon but also possess an adsorption effect on polyselenide.Thus,Se/Co-NC electrode exhibits excellent cycling performance(a stable specific capacity of 480 mAh·g^(-1)after 200 cycles at 1.0C with a much lowcapacity decay of 0.028%per cycle)and outstanding rate performance(a high specific capacity of 414 mAh·g^(-1)at5.0C).This work inspires highly stable Se cathode design for LSeBs.展开更多
The reduction of low-concentration carbon dioxide with water to organic fuels is still a huge challenge. In this study, we successfully designed the partially oxidized cobalt nanoparticles coated by the nitrogendoped ...The reduction of low-concentration carbon dioxide with water to organic fuels is still a huge challenge. In this study, we successfully designed the partially oxidized cobalt nanoparticles coated by the nitrogendoped carbon layer(Co@NC) of 2-8 nm via a facile method and then interspersed with different amount of Pt nanoparticles. The Co@NC decorated with 1 wt% Pt exhibits the best ability for COreduction to CHand a CHproduction rate of 14.4 μmol·g·his achieved. It is worth noting that the system is carried out under low-concentration CO(400 ppm) circumstance without any sacrificial agent, which could be meaningful to the design of catalysts for atmospheric COreduction.展开更多
The self-assembly reactions of Co(NCS) 2 with diester-bridged pyridine-based ligands pyCO 2-(CH 2) m-O 2Cpy (py=4-pyridyl; m=2, 3, 4) have been studied. Interestingly, while Co^(NCS) 2 reacted with pyCO 2-(CH ...The self-assembly reactions of Co(NCS) 2 with diester-bridged pyridine-based ligands pyCO 2-(CH 2) m-O 2Cpy (py=4-pyridyl; m=2, 3, 4) have been studied. Interestingly, while Co^(NCS) 2 reacted with pyCO 2-(CH 2) 2-O 2Cpy (La) in MeOH/H 2O or THF/MeCN to yield two coordination polymers [Co^(NCS) 2(La) 2] n(1) and [Co(NCS) 2(La) 2·2THF] n(2), reactions of Co(NCS) 2 with pyCO 2-(CH 2) 3-O 2Cpy (Lb) in MeOH/MeCN and Co(NCS) 2 with pyCO 2-(CH 2) 4-O 2Cpy (Lc) in EtOH/H 2O afforded [Co(NCS) 2(Lb) 2· 0.5MeOH] n(3) and [Co(NCS) 2(Lc) 2·2H 2O] n(4), respectively. The X-ray diffraction analyses indicated that polymers 1-4 consist of a one-dimensional Co(II) chain in which each of the two adjacent Co(II) ions is bridged by two pyCO 2-(CH 2) m-O 2Cpy ligands to form a macrocycle. In addition, the structures of polymers 1-4 were also characterized by infrared spectroscopy, thermogravimetry and elemental analysis.展开更多
基金supported by the National Key R&D Program of China(No.2018YFA0506900)National Natural Science Foundation of China(Nos.21635008 and 21621062)the Military Medicine and Healthy Major Project,China(No.AWS16J016)。
文摘Traditional matrix does not allow matrix-assisted laser desorption/ionization mass spectrometry(MALDI MS) to analyze volatile compounds,because volatile analytes may vaporize during the sample preparation process or in the high vacuum circumstance of ion source.Herein,we reported a Co and N doped porous carbon material(Co-NC) which were synthesized by pyrolysis of a Schiff base coordination compound.Co-NC could simultaneously act as adsorbent of volatile compounds and as matrix of MALDI MS,to provide the capability of MALDI MS to analyze volatile compounds.As adsorbent,Co-NC could stro ngly adsorb and enrich the volatile compounds in perfume and herbs,and hold them even in the high vacuum circumstance.On the other hand,Co-NC could absorb the energy of the laser,and then transfer the energy to the analyte for desorption and ionization of analyte in both negative and positive ionization modes.Additionally,the background interferences were avoided in the low-mass region(<500 Da) when using Co-NC as matrix,overcoming the challenges of MALDI MS analysis of small molecule compounds.In summary,Co-NC as matrix tremendously extended the application of MALDI MS.
文摘本论文基于传统聚合物基炭材料合成原理,通过选择合适结构的前驱体分子,在聚合过程中分子水平锚定Co原子,同时引入TiO_(2)纳米颗粒,再经高温焙烧后制得一种双金属氮氧化物(Co_(m)Ti_(n)O_(x)N_(y))-Co单原子(Co-NC)复合催化剂。该催化剂在酸性(E_(onset)=0.755 V vs.RHE,0.5 mol/LH_(2)SO_(4);0.760 V vs.RHE,0.1mol/LHClO_(4))、中性(E_(onset)=0.787 V vs.RHE,0.1 mol/L PBS)、碱性(E_(onset)=0.880 V vs.RHE,0.1 mol/L KOH)电解液中的氧气还原(ORR)性能(pH=0-13)均优于纯氮杂碳纳米管、氮杂碳纳米管负载的金属氮氧化物和Co单原子催化剂,表明,Co_(m)Ti_(n)O_(x)N_(y)与Co单原子的协同效应使得复合催化剂具有更好的ORR活性,同时复合催化剂的稳定性和选择性显著优于商品Pt/C催化剂。这为开发高性能低成本氧气还原电催化剂提供了新的思路。
文摘针对网络控制系统(NCS)中网络带宽等网络资源受限制的情况,对目前NCS信息调度的研究现状进行了综述.首先介绍了NCS的背景和基本概念,阐述了网络的引入带来的各种影响.然后研究了NCS的动态特性,对现有的信息调度策略和调度方法进行了总结与分析.进一步分析了在资源受限时如何进行有效的信息调度以保证较高的网络服务质量QoS(Quality ofService)和较好的控制品质QoC(Quality of Control),对一些控制与调度协同设计的研究进行了说明.最后,结合前面的研究分析,讨论了该领域今后进一步的研究方向.
基金financially supported by the National Key Research and Development Project(No.2018YFE0124800)the Research Project of Education Department of Jiangxi Province(No.GJJ190310)Natural Science Foundation of Jiangxi Province(No.20212BAB204006)。
文摘Selenium(Se)is a promising cathode material for lithium batteries due to its high volumetric energy density(2528 Wh·L^(-1)).However,its practical application is restricted by rapid capacity fading resulting from the shuttle effect and slow reaction kinetics.Herein,a N/Co co-doped three-dimensional porous carbon(Co-NC)is prepared and used as Se host for lithium-selenium batteries(LSeBs).Co-NC displays a high specific surface area of1201 m^(2)·g^(-1)which benefits from N and Co doping.The N and Co not only enhance the electrical conductivity of porous carbon but also possess an adsorption effect on polyselenide.Thus,Se/Co-NC electrode exhibits excellent cycling performance(a stable specific capacity of 480 mAh·g^(-1)after 200 cycles at 1.0C with a much lowcapacity decay of 0.028%per cycle)and outstanding rate performance(a high specific capacity of 414 mAh·g^(-1)at5.0C).This work inspires highly stable Se cathode design for LSeBs.
基金financially supported by the National Natural Science Foundation of China(Nos.51772312 and 51472260)the Environmental Functional Materials Innovation Team of Ministry of Education(IRT 16R49)the International Joint Laboratory on Resource Chemistry(IJLRC)
文摘The reduction of low-concentration carbon dioxide with water to organic fuels is still a huge challenge. In this study, we successfully designed the partially oxidized cobalt nanoparticles coated by the nitrogendoped carbon layer(Co@NC) of 2-8 nm via a facile method and then interspersed with different amount of Pt nanoparticles. The Co@NC decorated with 1 wt% Pt exhibits the best ability for COreduction to CHand a CHproduction rate of 14.4 μmol·g·his achieved. It is worth noting that the system is carried out under low-concentration CO(400 ppm) circumstance without any sacrificial agent, which could be meaningful to the design of catalysts for atmospheric COreduction.
文摘The self-assembly reactions of Co(NCS) 2 with diester-bridged pyridine-based ligands pyCO 2-(CH 2) m-O 2Cpy (py=4-pyridyl; m=2, 3, 4) have been studied. Interestingly, while Co^(NCS) 2 reacted with pyCO 2-(CH 2) 2-O 2Cpy (La) in MeOH/H 2O or THF/MeCN to yield two coordination polymers [Co^(NCS) 2(La) 2] n(1) and [Co(NCS) 2(La) 2·2THF] n(2), reactions of Co(NCS) 2 with pyCO 2-(CH 2) 3-O 2Cpy (Lb) in MeOH/MeCN and Co(NCS) 2 with pyCO 2-(CH 2) 4-O 2Cpy (Lc) in EtOH/H 2O afforded [Co(NCS) 2(Lb) 2· 0.5MeOH] n(3) and [Co(NCS) 2(Lc) 2·2H 2O] n(4), respectively. The X-ray diffraction analyses indicated that polymers 1-4 consist of a one-dimensional Co(II) chain in which each of the two adjacent Co(II) ions is bridged by two pyCO 2-(CH 2) m-O 2Cpy ligands to form a macrocycle. In addition, the structures of polymers 1-4 were also characterized by infrared spectroscopy, thermogravimetry and elemental analysis.
