检索结果-南通市图书馆

Analysis of Dimer Impurity in Polyamidoamine Dendrimer Solutions by Small-angle Neutron Scattering

Chinese j.urnal of Polymer Science 2019年第8期37卷 827-833页

作者： Tian-Fu Li Yi-Yun Cheng Yu Wang Hui Wang Dong-Feng Chen Yun-Tao Liu Li Zhang Wen-Ze Han Rong-Deng Liu Zi-j.n Wang Chun-Ming Yang charl j. jafta Daniel Clemens Uwe Keiderling China Institute of Atomic Energy Beijing 102413 China Key Laboratory of Regulatory Biology School of Life Sciences East China Normal University Shanghai 200062 China Shanghai Synchrotron Radiation Facility Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai 201204 China Helmholtz-Zentrum Berlin fürMaterialien und Energie Lise-Meitner-Campus Berlin 14109 Germany

Dimer impurity in the solution of a generation five(G5) polyamidoamine(PAMAM) dendrimer has been investigated by small-angle neutron scattering(SANS). The existence of dimer impurity in dendrimer solution was evidenced by indirect Fourier transform(IFT) analysis of the SANS data, in which the maximum dimension of particles in solution was found to be about twice the diameter of G5 dendrimer. We then developed an analytical model which accounts for the scattering contribution from both dendrimer monomer and dimer. The experimental data were well fitted by using the established model. The results showed that the amount of dimer impurities is significant for the measured three batches of G5 PAMAM dendrimers.

关键词： PAMAM dendrimer Dimer impurity Small-angle neutron scattering Scattering model

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Demonstration of no catalytical activity of Fe-N-C and Nb-N-C electrocatalysts toward nitrogen reduction using in-line quantification

引用

SusMat 2022年第4期2卷 476-486页

作者： Arnar Sveinbj.rnsson Anna Berglj.t Gunnarsdóttir Erin B.Creel Camila Pía Canales Barr Zulevi Xiang Lyu charl j.jafta Egill Skúlason Alexey Serov Helga Dögg Flosadóttir Atmonia ehf. ReykjavíkIceland Faculty of Industrial Engineering Mechanical Engineering and Computer ScienceUniversity of IcelandVR-IIIReykjavíkIceland Electrification and Energy Infrastructures Division Oak Ridge National LaboratoryOak RidgeTennesseeUSA Paj.rito Powder LLC(PPC)AlbuquerqueNew MexicoUSA Science Institute University of IcelandVR-IIIReykjavíkIceland

Ammonia(NH3)production via the electrochemical nitrogen reduction reaction(NRR)is a promising method for sustainable generation of this important *** are ongoing in finding an efficient,stable,and selective catalyst that will enable the ***,progress is hindered in the field due to lack of reproducibility,most likely a consequence of reports of false-positive results due to improper measurement control and *** this study,we explore the NRR activity of a promising class of single atom catalysts,transition metal-nitrogen-carbon(M-N-C)*** a state-of-the-art in-line ammonia quantification methodology,with detection limit as low as 1 ppb for ammonia,we show that single atom Nb and Fe embedded in a stable carbon and nitrogen framework do not electrochemically reduce N_(2) to NH_(3).Critically,this demonstrates that our experimental setup with in-line sequential inj.ction analysis successfully excludes ammonia contamination from the gas supply and atmospheric sources,allowing for thorough and high-throughput examination of potential NRR catalysts.

关键词： ammonia synthesis electrocatalysis nitrogen electroreduction NRR single atom catalyst

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Saving One Smile at a Time: Oral Health Promotion in Pediatric Primary Care Practice

引用

Open j.urnal of Nursing 2014年第6期4卷 402-408页

作者： Deborah j. Mattheus charl Mattheus University of Florida Gainesville USA

Oral health continues to be a maj.r issue affecting children these days. Early childhood caries are considered to be the most common chronic childhood disease in the United States. Despite the availability of Medicaid, millions of children can still not access a dental provider to receive proper care. Getting children in for dental care early in their lives saves money. Children that do not receive proper oral health care during their childhood are at higher risk for more complex and restorative care as they age. Plans to reduce childhood caries include more creative interventions such as oral assessment, education and fluoride varnish application in primary care practices. Pediatric primary care providers are trusted by parents to care for their children and have an ideal opportunity to make a lasting impression and create behavioral changes in oral health during their frequent contacts with children and families. Integrating oral health promotion is a simple task with numerous benefits for children and families, as well as primary care doctors’ offices. With proper professional and governmental support oral health promotion programs in primary care practice can further increase in number which can ultimately improve oral health outcomes, save time and prevent costly dental repairs, as well as benefit the practice through proper reimbursement.

关键词： Early Childhood Caries Oral Health Promotion Primary Care Practice

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Metal-free Synthesis of Pyridyl Conj.gated Microporous Polymers for Photocatalytic Hydrogen Evolution

引用

Chinese j.urnal of Polymer Science 2021年第8期39卷 1004-1012,I0006页

作者： Qin-Ruo Zeng Zhong-Hua Cheng Chen Yang Yan He Nan Meng charl F.j.Faul Yao-Zu Liao State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and EngineeringDonghuo UniversityShanghai 201620China School of Chemistry University of BristolBS8 ITS BristolU.K.

Developing efficient,stable and sustainable photocatalysts for water splitting is one of the most significant methods for generating *** microporous polymers,as a new type of organic semiconductor photocatalyst,have adj.stable bandgaps and high specific surface areas,and can be synthesized using diverse *** this work,we report the design and synthesis of a series of pyridyl conj.gated microporous polymers(PCMPs)utilizing polycondensation of aromatic aldehydes and aromatic ketones in the presence of ammonium *** with different chemical structures were synthesized via adj.sting monomers with different geometries and contents of nitrogen element,which could adj.st the bandgap and photocatalytic *** hydrogen evolution rate(HER)up to 1198.9μmol·h^(-1)·g^(-1) was achieved on the optimized polymer with a specific surface area of 312 m^(2)·g^(-1) under UV-Vis light irradiation(A>320 nm).This metal-free synthetic method provides a new avenue to preparing an efficient photocatalyst for hydrogen evolution.

关键词： Pyridyl conj.gated microporous polymer Metal-free synthesis Adj.stable bandgaps Photocatalytic hydrogen evolution

来源：

维普期刊数据库

同方期刊数据库评论