Enhancing the stability of supported noble metal catalysts emerges is a major challenge in both science and industry.Herein,a heterogeneous Pd catalyst(Pd/NCF)was prepared by supporting Pd ultrafine metal nanoparticle...Enhancing the stability of supported noble metal catalysts emerges is a major challenge in both science and industry.Herein,a heterogeneous Pd catalyst(Pd/NCF)was prepared by supporting Pd ultrafine metal nanoparticles(NPs)on nitrogen-doped carbon;synthesized by using F127 as a stabilizer,as well as chitosan as a carbon and nitrogen source.The Pd/NCF catalyst was efficient and recyclable for oxidative carbonylation of phenol to diphenyl carbonate,exhibiting higher stability than Pd/NC prepared without F127 addition.The hydrogen bond between chitosan(CTS)and F127 was enhanced by F127,which anchored the N in the free amino group,increasing the N content of the carbon material and ensuring that the support could provide sufficient N sites for the deposition of Pd NPs.This process helped to improve metal dispersion.The increased metal-support interaction,which limits the leaching and coarsening of Pd NPs,improves the stability of the Pd/NCF catalyst.Furthermore,density functional theory calculations indicated that pyridine N stabilized the Pd^(2+)species,significantly inhibiting the loss of Pd^(2+)in Pd/NCF during the reaction process.This work provides a promising avenue towards enhancing the stability of nitrogen-doped carbon-supported metal catalysts.展开更多
Combining the deviation between thin layers' adjacent surfaces with the confining potential method applied to the quantum curved systems,we derive the effective Schr?dinger equation describing the particle constra...Combining the deviation between thin layers' adjacent surfaces with the confining potential method applied to the quantum curved systems,we derive the effective Schr?dinger equation describing the particle constrained within a curved layer,accompanied by a general geometric potential V_(gq) composed of a compression-corrected geometric potential V_(gq)~*and a novel potential V_(gq)~(**) brought by the deviation.Applying this analysis to the cylindrical layer emerges two types of deviation-induced geometric potential,resulting from the the cases of slant deviation and tangent deviation,respectively,which strongly renormalizes the purely geometric potential and contribute to the energy spectrum based on a very substantial deepening of bound states they offer.展开更多
Bronchobiliary fistula(BBF) is a pathologic channel between the biliary tract and bronchial tree. In general, congenital BBF is relatively rare in adult patients. There are a few case reports suggesting that BBF is ma...Bronchobiliary fistula(BBF) is a pathologic channel between the biliary tract and bronchial tree. In general, congenital BBF is relatively rare in adult patients. There are a few case reports suggesting that BBF is mainly secondary to hepatobiliary diseases, such as biliary obstruction, tumor, surgery, or liver abscess, and liver tumor is the predominant causative factor [1]. In addition, with the increasing number of liver and biliary surgeries and interventional therapies in recent years, more cases of BBF were reported as a postoperative complication [ 2, 3 ]. In this case, we presented a patient who underwent interventional treatment for liver tumor and was treated for his respiratory symptoms but diagnosed with BBF finally. Here, we summarized the clinical features and main diagnostic procedures of the case, aiming to provide evidence for early identification and diagnosis of BBF.展开更多
Lithium-sulfur(Li-S)batteries are notable for their high theoretical energy density,but the‘shuttle effect’and the limited conversion kinetics of Li-S species can downgrade their actual performance.An essential stra...Lithium-sulfur(Li-S)batteries are notable for their high theoretical energy density,but the‘shuttle effect’and the limited conversion kinetics of Li-S species can downgrade their actual performance.An essential strategy is to design anchoring materials(AMs)to appropriately adsorb Li-S species.Herein,we propose a new three-procedure protocol,named InfoAd(Informative Adsorption)to evaluate the anchoring of Li_(2)S on two-dimensional(2D)materials and disclose the underlying importance of material features by combining high-throughput calculation workflow and machine learning(ML).In this paradigm,we calculate the anchoring of Li_(2)S on 12552D A_(x)B_(y)(B in the VIA/VIIA group)materials and pick out 44(un)reported nontoxic 2D binary A_(x)B_(y)AMs,in which the importance of the geometric features on the anchoring effect is revealed by ML for the first time.We develop a new Infograph model for crystals to accurately predict whether a material has a moderate binding with Li_(2)S and extend it to all 2D materials.Our InfoAd protocol elucidates the underlying structure-property relationship of Li_(2)S adsorption on 2D materials and provides a general research framework of adsorption-related materials for catalysis and energy/substance storage.展开更多
获取价值主体需要是开展高校在线开放课程教学质量认定标准研究的首要环节。该文通过文献梳理、学习者评价文本分析、问卷调查和访谈,全面收集了高校在线开放课程价值主体需要的原始资料,依照KJ法对资料抽取关键词、聚类去重、分组细化...获取价值主体需要是开展高校在线开放课程教学质量认定标准研究的首要环节。该文通过文献梳理、学习者评价文本分析、问卷调查和访谈,全面收集了高校在线开放课程价值主体需要的原始资料,依照KJ法对资料抽取关键词、聚类去重、分组细化、提炼总结,得到价值主体层次化需要列表,并利用专家评分法和层次分析法确定了各需要项的权重。为运用质量功能展开(QFD:Quality Function Deployment)技术,将多样化的价值主体需要转化为课程教学特性,进而形成教学质量标准和教学质量认定标准奠定了基础。展开更多
基金support by the National Natural Science Foundation of China(U21A20306,U20A20152)Natural Science Foundation of Hebei Province(B2022202077).
文摘Enhancing the stability of supported noble metal catalysts emerges is a major challenge in both science and industry.Herein,a heterogeneous Pd catalyst(Pd/NCF)was prepared by supporting Pd ultrafine metal nanoparticles(NPs)on nitrogen-doped carbon;synthesized by using F127 as a stabilizer,as well as chitosan as a carbon and nitrogen source.The Pd/NCF catalyst was efficient and recyclable for oxidative carbonylation of phenol to diphenyl carbonate,exhibiting higher stability than Pd/NC prepared without F127 addition.The hydrogen bond between chitosan(CTS)and F127 was enhanced by F127,which anchored the N in the free amino group,increasing the N content of the carbon material and ensuring that the support could provide sufficient N sites for the deposition of Pd NPs.This process helped to improve metal dispersion.The increased metal-support interaction,which limits the leaching and coarsening of Pd NPs,improves the stability of the Pd/NCF catalyst.Furthermore,density functional theory calculations indicated that pyridine N stabilized the Pd^(2+)species,significantly inhibiting the loss of Pd^(2+)in Pd/NCF during the reaction process.This work provides a promising avenue towards enhancing the stability of nitrogen-doped carbon-supported metal catalysts.
基金Project jointly supported by the National Natural Science Foundation of China(Grant No.11934008)funded by the Fund from National Laboratory of Solid State Microstructure of Nanjing University(Grant Nos.M35040 and M35053)the Youth Independent Innovation Fund(Grant No.KYJBJKQTZQ23006)。
文摘Combining the deviation between thin layers' adjacent surfaces with the confining potential method applied to the quantum curved systems,we derive the effective Schr?dinger equation describing the particle constrained within a curved layer,accompanied by a general geometric potential V_(gq) composed of a compression-corrected geometric potential V_(gq)~*and a novel potential V_(gq)~(**) brought by the deviation.Applying this analysis to the cylindrical layer emerges two types of deviation-induced geometric potential,resulting from the the cases of slant deviation and tangent deviation,respectively,which strongly renormalizes the purely geometric potential and contribute to the energy spectrum based on a very substantial deepening of bound states they offer.
文摘Bronchobiliary fistula(BBF) is a pathologic channel between the biliary tract and bronchial tree. In general, congenital BBF is relatively rare in adult patients. There are a few case reports suggesting that BBF is mainly secondary to hepatobiliary diseases, such as biliary obstruction, tumor, surgery, or liver abscess, and liver tumor is the predominant causative factor [1]. In addition, with the increasing number of liver and biliary surgeries and interventional therapies in recent years, more cases of BBF were reported as a postoperative complication [ 2, 3 ]. In this case, we presented a patient who underwent interventional treatment for liver tumor and was treated for his respiratory symptoms but diagnosed with BBF finally. Here, we summarized the clinical features and main diagnostic procedures of the case, aiming to provide evidence for early identification and diagnosis of BBF.
基金supported by National key research and development program of China(2022YFA1503101)National Natural Science Foundation of China(22173067,22203058)+4 种基金Science and Technology Project of Jiangsu Province(BK20200873,BZ2020011)the Science and Technology Development Fund,Macao SAR(0052/2021/A)Collaborative Innovation Center of Suzhou Nano Science&Technology,the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the 111 ProjectJoint International Research Laboratory of Carbon-Based Functional Materials and Devices。
文摘Lithium-sulfur(Li-S)batteries are notable for their high theoretical energy density,but the‘shuttle effect’and the limited conversion kinetics of Li-S species can downgrade their actual performance.An essential strategy is to design anchoring materials(AMs)to appropriately adsorb Li-S species.Herein,we propose a new three-procedure protocol,named InfoAd(Informative Adsorption)to evaluate the anchoring of Li_(2)S on two-dimensional(2D)materials and disclose the underlying importance of material features by combining high-throughput calculation workflow and machine learning(ML).In this paradigm,we calculate the anchoring of Li_(2)S on 12552D A_(x)B_(y)(B in the VIA/VIIA group)materials and pick out 44(un)reported nontoxic 2D binary A_(x)B_(y)AMs,in which the importance of the geometric features on the anchoring effect is revealed by ML for the first time.We develop a new Infograph model for crystals to accurately predict whether a material has a moderate binding with Li_(2)S and extend it to all 2D materials.Our InfoAd protocol elucidates the underlying structure-property relationship of Li_(2)S adsorption on 2D materials and provides a general research framework of adsorption-related materials for catalysis and energy/substance storage.
文摘获取价值主体需要是开展高校在线开放课程教学质量认定标准研究的首要环节。该文通过文献梳理、学习者评价文本分析、问卷调查和访谈,全面收集了高校在线开放课程价值主体需要的原始资料,依照KJ法对资料抽取关键词、聚类去重、分组细化、提炼总结,得到价值主体层次化需要列表,并利用专家评分法和层次分析法确定了各需要项的权重。为运用质量功能展开(QFD:Quality Function Deployment)技术,将多样化的价值主体需要转化为课程教学特性,进而形成教学质量标准和教学质量认定标准奠定了基础。
