In the present work,Ru@CeO_(2) catalysts similar in their core-shell morphology but different in nanoparticle sizes(95,150 and 225 nm)were obtained by varying the hydrothermal time for the preparation of colloidal car...In the present work,Ru@CeO_(2) catalysts similar in their core-shell morphology but different in nanoparticle sizes(95,150 and 225 nm)were obtained by varying the hydrothermal time for the preparation of colloidal carbon spheres to be used as templates.The surface areas of these catalysts are in the range of 111-146 m^(2) g^(-1).After in situ H_(2) treatment at 450℃ for 4 h,the Ru@CeO_(2)-9 catalyst with a nanoparticle size of 225 nm has an ammonia synthesis rate of 13504μmol gNH_(3)^(-1) h^(-1) at 1 MPa(N_(2):H_(2)=1:3)and 425℃.The results of XAS,Raman and XPS investigations reveal the active sites in the form of Ru-hydride and Ru0 clusters of the Ru@CeO_(2) catalysts for ammonia synthesis.Moreover,H_(2) treatment results in the strengthening of the ruthenium-ceria interaction,which is beneficial for ammonia formation.It is demonstrated that the size of the nanoparticle has a strong effect on the strength of the ruthenium-ceria interaction,which influences the reduction degree of ruthenium and cerium and the amount of the generated Ru-hydride species.The outcomes of DFT calculations provide evidence that the strength of the ruthenium-cerium interaction is associated with the N_(2) adsorption energy.In comparison with Ru/CeO_(2)-CP synthesized by the co-precipitation method,the core-shell structure of Ru@CeO_(2) affords a larger surface area,stronger metal-support interactions and more reductive species,and the consequence is a higher ammonia synthesis rate.展开更多
This paper describes the design and performance of the tender energy spectroscopy beamline(BL16U1),a phase Ⅱ beamline,at the Shanghai Synchrotron Radiation Facility.The beamline,based on an in-vacuum undulator source...This paper describes the design and performance of the tender energy spectroscopy beamline(BL16U1),a phase Ⅱ beamline,at the Shanghai Synchrotron Radiation Facility.The beamline,based on an in-vacuum undulator source with 26 mm period,provides an operable energy range between 2.1 keV and 16 keV,covering the K-edges of P to Rb and L3-edges of Zr to Bi.The principal optical elements of the beamline are a toroidal mirror,a liquid nitrogen-cooled double-crystal monochromator,a high-harmonic-rejection mirror,and two pairs of Kirkpatrick–Baez(KB)mirrors.Three end-stations,including non-focusing,microprobe,and sub-microprobe types,are installed on the beamline.X-ray fluorescence(XRF)and X-ray absorption spectroscopy(XAS),including X-ray absorption near-edge structure(XANES)and extended X-ray absorption fine structure(EXAFS),are performed under vacuum or He atmosphere at the non-focusing end-station(with a beam spot size of∼670μm×710μm).Using two KB mirrors systems,micro-XRF(μXRF)mapping and micro-XANES(μXANES)studies can be performed with a spot size of approximately∼3.3μm×1.3μm at the microprobe end-station and with a smaller spot size of∼0.5μm×0.25μm at the sub-microprobe end-station.The non-focusing end-station was officially opened to users in January 2024.The microprobe and sub-microprobe end-stations will be opened to users in the near future.This paper presents the characteristics,short-term technical developments,and early experimental results of this new beamline.展开更多
1 Results Lithium ion batteries have been widely used in modern portable electronics,such as cellular phones and notebook computers,because of their low cost,long life,and high energy density.In the lithium ion batter...1 Results Lithium ion batteries have been widely used in modern portable electronics,such as cellular phones and notebook computers,because of their low cost,long life,and high energy density.In the lithium ion batteries,the cathode provides lithium ion source and plays a critical role to determinate the performance of battery.Lithium transition metal oxides have been investigated as active cathode materials due to their high potential versus Li/Li+ and large proportion of the lithium ions can be insert...展开更多
In-situ observation of the charge transfer plays a key role in understanding the working mechanism of hematite for solar water oxidation.Here by using in-situ X-ray absorption spectroscopy(XAS),the electron injection ...In-situ observation of the charge transfer plays a key role in understanding the working mechanism of hematite for solar water oxidation.Here by using in-situ X-ray absorption spectroscopy(XAS),the electron injection from illuminated hematite(photon-excited electron)to the surface carbon layer can be clearly identified,which can facilitate the charge separation and then improve the performance.As a result,the carbon-coated and Sn-doped hematite photoanode(C-Sn-Fe_(2)O_(3))shows a greatly enhanced photocurrent density of 2.3 mA/cm^(2) at 1.23 VRHE,which is 2.3 times that of the pristine hematite.The injected electron can modify the chemical state of surface groups in the carbon layer and be quickly transferred to the electrode due to the high conductivity of the carbon layer,leaving behind the high-valence Fe^(4+)with high oxidation capability to enhance the performance.By coupling with the FeNiOOH co-catalyst,the photoanode can finally achieve a high photocurrent density of 3.0 mA/cm^(2) at 1.23 VRHE with a low onset potential of 0.76 VRHE.The understanding of the charge migration route by using in-situ XAS offers a novel way for the design of highly efficient solar water oxidation materials.展开更多
目的通过筛选真实世界中非瓣膜性房颤(NVAF)合并肾功能不全[15<肌酐清除率(CL_(cr))≤60 mL·min^(-1)]患者联用利伐沙班致出血风险增加的药代动力学相互作用(PK-DDI)药品,以促进临床合理用药。方法通过检索文献(PubMed、Web of ...目的通过筛选真实世界中非瓣膜性房颤(NVAF)合并肾功能不全[15<肌酐清除率(CL_(cr))≤60 mL·min^(-1)]患者联用利伐沙班致出血风险增加的药代动力学相互作用(PK-DDI)药品,以促进临床合理用药。方法通过检索文献(PubMed、Web of Science、中国知网、万方数据、维普网)、说明书、2021年欧洲心律协会指南、Lexicomp数据库总结利伐沙班PK-DDI目录;采用回顾性队列研究,收集2022年11月1日至2023年10月31日在首都医科大学宣武医院住院并服用利伐沙班的NVAF合并肾功能不全患者,根据是否使用利伐沙班PK-DDI药品分为PK-DDI组和非PK-DDI组。其中PK-DDI药品限定为P-gp和/或CYP3A4抑制剂,随访3个月,比较2组患者有效性和安全性结局。结果共计22类141种药品,根据是否需调整剂量分类,需要禁用、慎用药品65种和无需调整剂量药品76种。研究共纳入患者143例,PK-DDI组出血发生率高于非PK-DDI组(P<0.05),PK-DDI组与非PK-DDI组的缺血性卒中发生率差异无统计学意义(P>0.05)。PK-DDI组主要的出血性事件为临床相关非大出血(8例,61.5%),用药后30 d内出血发生率为38.7%,涉及药品包含胺碘酮、银杏叶提取物、氟康唑、伏立康唑、奥希替尼。结论利伐沙班PK-DDI涉及多种药品,主要靶点为P-gp和CYP3A4。肾功能不全患者服用利伐沙班时,联用P-gp和/或CYP3A4抑制剂增加出血风险。利伐沙班应避免与银杏叶提取物、伏立康唑联用。利伐沙班与胺碘酮、氟康唑、奥希替尼联用需严密监测,如凝血酶原时间、抗凝血(Xa)因子水平或利伐沙班血药浓度。展开更多
现代汉语中“雪白、稀烂、稀糟”等状态词在词法上包括状中式复合词和附加前缀的派生词,“稀”这样的成分属于表增量的评价性前缀。经历时考察发现,XA式状态词经历了如下演变过程:如/若/似+XP+A(比拟结构)/Ad+A(状中短语)/A 1 A 2(并列...现代汉语中“雪白、稀烂、稀糟”等状态词在词法上包括状中式复合词和附加前缀的派生词,“稀”这样的成分属于表增量的评价性前缀。经历时考察发现,XA式状态词经历了如下演变过程:如/若/似+XP+A(比拟结构)/Ad+A(状中短语)/A 1 A 2(并列式复合词)→XA式复合词→xA式派生词。XA式复合词的形成是词汇化的过程,具体的复合词有不同的词汇化来源。xA式派生词是词法化的结果,增量前缀是复合词的构成成分经类推扩展而来。XA式复合词在明清时期出现了一系列词法变化形式,在现代汉语中出现了主观义磨损的趋势,这些变化均可以通过评价性形态的演变规律得到解释。展开更多
基金supported by the National Key Research and Development Program(2016YFC0203900 and 2016YFC0203902)the National Natural Science Foundation of China(21703037 and 21825801)+1 种基金leading project of Fujian Province(2017H0049)Natural Science Foundation of Fujian(2018J10691).
文摘In the present work,Ru@CeO_(2) catalysts similar in their core-shell morphology but different in nanoparticle sizes(95,150 and 225 nm)were obtained by varying the hydrothermal time for the preparation of colloidal carbon spheres to be used as templates.The surface areas of these catalysts are in the range of 111-146 m^(2) g^(-1).After in situ H_(2) treatment at 450℃ for 4 h,the Ru@CeO_(2)-9 catalyst with a nanoparticle size of 225 nm has an ammonia synthesis rate of 13504μmol gNH_(3)^(-1) h^(-1) at 1 MPa(N_(2):H_(2)=1:3)and 425℃.The results of XAS,Raman and XPS investigations reveal the active sites in the form of Ru-hydride and Ru0 clusters of the Ru@CeO_(2) catalysts for ammonia synthesis.Moreover,H_(2) treatment results in the strengthening of the ruthenium-ceria interaction,which is beneficial for ammonia formation.It is demonstrated that the size of the nanoparticle has a strong effect on the strength of the ruthenium-ceria interaction,which influences the reduction degree of ruthenium and cerium and the amount of the generated Ru-hydride species.The outcomes of DFT calculations provide evidence that the strength of the ruthenium-cerium interaction is associated with the N_(2) adsorption energy.In comparison with Ru/CeO_(2)-CP synthesized by the co-precipitation method,the core-shell structure of Ru@CeO_(2) affords a larger surface area,stronger metal-support interactions and more reductive species,and the consequence is a higher ammonia synthesis rate.
基金supported by the National Key R&D Program of China(No.2021YFA1601003)the financial support of the SSRF PhaseⅡproject.
文摘This paper describes the design and performance of the tender energy spectroscopy beamline(BL16U1),a phase Ⅱ beamline,at the Shanghai Synchrotron Radiation Facility.The beamline,based on an in-vacuum undulator source with 26 mm period,provides an operable energy range between 2.1 keV and 16 keV,covering the K-edges of P to Rb and L3-edges of Zr to Bi.The principal optical elements of the beamline are a toroidal mirror,a liquid nitrogen-cooled double-crystal monochromator,a high-harmonic-rejection mirror,and two pairs of Kirkpatrick–Baez(KB)mirrors.Three end-stations,including non-focusing,microprobe,and sub-microprobe types,are installed on the beamline.X-ray fluorescence(XRF)and X-ray absorption spectroscopy(XAS),including X-ray absorption near-edge structure(XANES)and extended X-ray absorption fine structure(EXAFS),are performed under vacuum or He atmosphere at the non-focusing end-station(with a beam spot size of∼670μm×710μm).Using two KB mirrors systems,micro-XRF(μXRF)mapping and micro-XANES(μXANES)studies can be performed with a spot size of approximately∼3.3μm×1.3μm at the microprobe end-station and with a smaller spot size of∼0.5μm×0.25μm at the sub-microprobe end-station.The non-focusing end-station was officially opened to users in January 2024.The microprobe and sub-microprobe end-stations will be opened to users in the near future.This paper presents the characteristics,short-term technical developments,and early experimental results of this new beamline.
文摘1 Results Lithium ion batteries have been widely used in modern portable electronics,such as cellular phones and notebook computers,because of their low cost,long life,and high energy density.In the lithium ion batteries,the cathode provides lithium ion source and plays a critical role to determinate the performance of battery.Lithium transition metal oxides have been investigated as active cathode materials due to their high potential versus Li/Li+ and large proportion of the lithium ions can be insert...
基金the support from NSRL for the XAS experiments.This work was financially supported by the National Key R&D Program of China(No.2020YFA0406103)the National Natural Science Foundation of China(No.U1932211)+1 种基金the Collaborative Innovation Center of Suzhou Nano Science&Technology,the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the 111 Project.
文摘In-situ observation of the charge transfer plays a key role in understanding the working mechanism of hematite for solar water oxidation.Here by using in-situ X-ray absorption spectroscopy(XAS),the electron injection from illuminated hematite(photon-excited electron)to the surface carbon layer can be clearly identified,which can facilitate the charge separation and then improve the performance.As a result,the carbon-coated and Sn-doped hematite photoanode(C-Sn-Fe_(2)O_(3))shows a greatly enhanced photocurrent density of 2.3 mA/cm^(2) at 1.23 VRHE,which is 2.3 times that of the pristine hematite.The injected electron can modify the chemical state of surface groups in the carbon layer and be quickly transferred to the electrode due to the high conductivity of the carbon layer,leaving behind the high-valence Fe^(4+)with high oxidation capability to enhance the performance.By coupling with the FeNiOOH co-catalyst,the photoanode can finally achieve a high photocurrent density of 3.0 mA/cm^(2) at 1.23 VRHE with a low onset potential of 0.76 VRHE.The understanding of the charge migration route by using in-situ XAS offers a novel way for the design of highly efficient solar water oxidation materials.
文摘目的通过筛选真实世界中非瓣膜性房颤(NVAF)合并肾功能不全[15<肌酐清除率(CL_(cr))≤60 mL·min^(-1)]患者联用利伐沙班致出血风险增加的药代动力学相互作用(PK-DDI)药品,以促进临床合理用药。方法通过检索文献(PubMed、Web of Science、中国知网、万方数据、维普网)、说明书、2021年欧洲心律协会指南、Lexicomp数据库总结利伐沙班PK-DDI目录;采用回顾性队列研究,收集2022年11月1日至2023年10月31日在首都医科大学宣武医院住院并服用利伐沙班的NVAF合并肾功能不全患者,根据是否使用利伐沙班PK-DDI药品分为PK-DDI组和非PK-DDI组。其中PK-DDI药品限定为P-gp和/或CYP3A4抑制剂,随访3个月,比较2组患者有效性和安全性结局。结果共计22类141种药品,根据是否需调整剂量分类,需要禁用、慎用药品65种和无需调整剂量药品76种。研究共纳入患者143例,PK-DDI组出血发生率高于非PK-DDI组(P<0.05),PK-DDI组与非PK-DDI组的缺血性卒中发生率差异无统计学意义(P>0.05)。PK-DDI组主要的出血性事件为临床相关非大出血(8例,61.5%),用药后30 d内出血发生率为38.7%,涉及药品包含胺碘酮、银杏叶提取物、氟康唑、伏立康唑、奥希替尼。结论利伐沙班PK-DDI涉及多种药品,主要靶点为P-gp和CYP3A4。肾功能不全患者服用利伐沙班时,联用P-gp和/或CYP3A4抑制剂增加出血风险。利伐沙班应避免与银杏叶提取物、伏立康唑联用。利伐沙班与胺碘酮、氟康唑、奥希替尼联用需严密监测,如凝血酶原时间、抗凝血(Xa)因子水平或利伐沙班血药浓度。
文摘现代汉语中“雪白、稀烂、稀糟”等状态词在词法上包括状中式复合词和附加前缀的派生词,“稀”这样的成分属于表增量的评价性前缀。经历时考察发现,XA式状态词经历了如下演变过程:如/若/似+XP+A(比拟结构)/Ad+A(状中短语)/A 1 A 2(并列式复合词)→XA式复合词→xA式派生词。XA式复合词的形成是词汇化的过程,具体的复合词有不同的词汇化来源。xA式派生词是词法化的结果,增量前缀是复合词的构成成分经类推扩展而来。XA式复合词在明清时期出现了一系列词法变化形式,在现代汉语中出现了主观义磨损的趋势,这些变化均可以通过评价性形态的演变规律得到解释。
