检索结果-南通市图书馆

Promotion effect of niobium on ceria catalyst for selective catalytic reduction of NO with NH3

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

Journal of Rare Earths 2022年第10期40卷 1535-1545页

作者： Bolin Zhang Lifeng Deng Michael Liebau Yingjie Ren Chunyun Luo Bo Liu Shengen Zhang roger glaser Institute for Advanced Materials and Technology University of Science and Technology BeijingBejing 100083China Shunde Graduate School University of Science and Technology BeijingFoshan 528399China Jiangsu Longkingcotech Co. Ltd.Yancheng224000China Institute of Chemical Technology Universit at LeipzigLeipzig04103Germany

The CeO_(2),Ce-Nb-O_(x) and Nb_(2)O_(5) catalysts were synthesized by citric acid method and the promotion effect of Nb on ceria for selective catalytic reduction(SCR)of NO with NH_(3) was *** catalytic activity measurements indicate that the mixed oxide Ce-Nb-O_(x) presents a higher SCR activity than the single oxide CeO_(2) or Nb_(2)O_(5) *** addition,the Ce-Nb-O_(x) catalyst shows high resistance towards H_(2)O and SO_(2) at 280℃.The Raman,X-ray photoelectron spectra and temperature programmed reduction with H_(2) results indicate that the incorporation of Nb provides abundant oxygen vacancies for capturing more surface adsorbed oxygen,which provides a superior redox capability and accelerates the renewal of active ***,the Fourier transform infrared spectra and temperature programmed desorption of NH_(3) results suggest that niobium pentoxide shows high surface acidity,which is partly retained in the Ce-Nb-O_(x) catalyst possessing a high content of Lewis and Br?nsted acid ***,the incorporation of Nb improves both the redox and acidic capacities of Ce-Nb-O_(x) catalyst for the SCR ***,the redox behavior is primarily taken on Ce and the acidity is well improved by Nb,so the synergistic effect should exist between Ce and *** terms of the reaction mechanism,in situ DRIFT experiments suggest that both NH_(3) on Lewis acid sites and NH_(4)^(+) on Bronsted acid sites can react with NO species,and adsorbed NO and NO_(2) species can both be reduced by NH_(3).In the SCR process,O_(2) primarily acts as the accelerant to improve the redox and acid cycles and plays an important *** work proves that the combination of redox and acidic properties of different constituents can be feasible for catalyst design to obtain a superior SCR performance.

关键词： Cerium-niobium Selective catalytic reduction Redox behavior Acid cycle Synergistic effect Rare earths

Synergistic effect of cobalt and niobium in Co_(3)-Nb-O_(x)on performance of selective catalytic reduction of NO with NH_(3)

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

Rare Metals 2022年第1期41卷 166-178页

作者： Bo-Lin Zhang Li-Feng Deng Bo Liu Chun-Yun Luo Michael Liebau Shen-Gen Zhang roger glaser Institute for Advanced Materials and Technology University of Science and Technology BeijingBeijing 100083China Shunde Graduate School University of Science and Technology BeijingFoshan 528399China Jiangsu Longkingcotech Co. Ltd.Yancheng 224000China Institute of Chemical Technology Universita¨t LeipzigLeipzig 04103Germany e-mail:roger.glaeser

Combining the redox properties of Co and the acid properties of Nb in a Co_(3)-Nb-O_(x)catalyst is shown to provide superior performance in the selective catalytic reduction of NO with NH_(3)(NH_(3)-SCR).Co_(3)O_(4)shows average activity,however,it exhibits a poor N_(2)***_(2)O_(5)is not active for NH_(3)-***,the mixed Co_(3)-Nb-O_(x) catalyst shows higher NO conversion and N_(2)selectivity than the single Co_(3)O_(4)and Nb_(2)O_(5)catalysts at 100–300℃.The results of temperature programmed reduction by H_(2)and X-ray photoelectron(XP)spectra indicate that the addition of Nb changes the chemical states of Co and decreases the concentration of Co^(3+) and Oa,adjusting the activity for catalytic oxidation to a moderate *** suppresses the formation of undesired N_(2)O from the over-oxidation of NH_(3).Incorporation of Co and Nb into one solid synergistically couples their redox behavior and surface acidity,ensuring the high catalytic activity and N2 selectivity in NH3-SCR.

关键词： Co-Nb Selective catalytic reduction Lowtemperature Acid property Redox behavior

An adaptive Markov chain algorithm applied over map-matching of vehicle trip GPS data

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

Geo-Spatial Information Science 2021年第3期24卷 484-497页

作者： Bilge Kaan Karamete Louai Adhami Eli glaser Engineering GeospatialKinetica DB IncArlingtonVAUSA

Markov chains have frequently been applied to match the probable routes with a set of GPS trip data that a pilot vehicle is emitting over a specific graph road network. This class of mapmatching (MM) algorithms presently demonstrates and involve statistical and ad-hoc measures to drive the Markov chain transitional probabilities in picking the best route combinations constrained over the graph road network. In this study, we have devised an adaptive scheme to modify the Markov Chain (MC) kernel window as we move along the GPS samples to reduce the mistakes that can happen by the use of narrower MC widths. The measure for temporarily increasing the MC window width is chosen to be the ratio between the geodesic distance of current route to the actual geodesic distance between each pair of GPS samples. This adaptive use of MC has shown to have hardened the results significantly with tolerable computational cost increase. The details of the overall algorithm are depicted by the example routes extracted from various vehicle trips and the results are shown to validate the usefulness of the algorithm in practice.

关键词： Hidden Markov chain(HMC) map-matching(MM) graph networks

Strengthening the scientific evidence base of a new climate agreement

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Ecosystem Health and Sustainability 2015年第9期1卷 18-22页

作者： Gisbert glaser International Council for Science(ICSU) 5 Rue Auguste VacquerieParisFrance 75116

Ahead of the forthcoming global intergovernmental climate meeting in Paris,scientists met in Paris in July at a large scientific conference calling for an ambitious agreement aimed at holding global warming to 2℃.With agriculture,forestry,and other land use contributing 24%of total greenhouse gas(GHG)emissions(2000-2009),there is potential for significant ecosystem-based mitigation ***,maintaining healthy ecosystems represents,in many situations,the most efficient way of *** paper highlights some scientific aspects,as presented at the conference,related to ecosystem-based adaptation and *** calls for enhanced cooperation between scientists,policy makers,and other stakeholders.

关键词： adaptation agriculture climate change ecosystems international agreements mitigation science–policy links stakeholder cooperation sustainable development

Import Determinants of Organelle-Specific and Dual Targeting Peptides of Mitochondria and Chloroplasts in Arabidopsis thaliana

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Molecular Plant 2014年第1期7卷 121-136页

作者： Changrong Ge Erika Spanning Elzbieta glaser Ake Wieslander Department of Biochemistry and Biophysics Center for Biomembrane Research Stockholm University SE-106 91 Stockholm Sweden Medical Inflammation Research Department of Medical Biochemistry and Biophysics Karolinska Institute SE-171 77 Stockholm Sweden

Most of the mitochondrial and chloroplastic proteins are synthesized in the cytosol as precursor proteins carrying an N-terminal targeting peptide （TP） directing them specifically to a correct organelle. However, there is a group of proteins that are dually targeted to mitochondria and chloroplasts using an ambiguous N-terminal dual targeting peptide （dTP）. Here, we have investigated pattern properties of import determinants of organelle-specific TPs and dTPs combining mathematical multivariate data analysis （MVDA） with in vitro organellar import studies. We have used large datasets of mitochondrial and chloroplastic proteins found in organellar proteomes as well as manually selected data sets of experimentally confirmed organelle-specific TPs and dTPs from Arabidopsis thaliana. Two classes of organelle-specific TPs could be distinguished by MVDA and potential patterns or periodicity in the amino acid sequence contributing to the separation were revealed, dTPs were found to have intermediate sequence features between the organelle-specific TPs. Interestingly, introducing positively charged residues to the dTPs showed clustering towards the mitochondrial TPs in silico and resulted in inhibition of chloroplast, but not mitochondrial import in in vitro organellar import studies. These findings suggest that positive charges in the N-terminal region of TPs may function as an ＇avoidance signal＇ for the chloroplast import.

关键词： dual targeting ambiguous targeting signal mitochondria chloroplast protein import partial least square discriminant analysis Arabidopsis thaliana.

Effect of biochar fertilizers on amino acid variability of Secale cereale and Lupinus angustifolius

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Biochar 2019年第2期1卷 187-201页

作者： Katja Wiedner Corinna Schimpf Steven Polifka Bruno glaser Soil Biogeochemistry Institute of Agronomy and Nutritional SciencesMartin Luther University Halle-WittenbergVon-Seckendorff-Platz 306120 Halle(Saale)Germany

Little is known on the effects of biochar on N uptake and amino acid variability in crops such as winter rye and narrow-leafed lupine despite the fact that amino acids are important indicators,for food quality and plant stress.N uptake of both crops showed contrasting results when treated with different biochar *** amino acid contents referred to total nitro-gen generally tend to decrease in rye grains in the presence of biochar;whereas lupine seeds were more or less unaffected by biochar combined with mineral fertilizer or *** lupine seeds,total amino acid contents significantly increased when biochar was mixed with digestate but decreased when mixed with fermented ***,one of the most limiting amino acids in cereals,reached the recommended value of 4 g kg^(−1) in rye grain for most biochar *** lupine seeds,lysine decreased when biochar had been applied but were still in the recommended range when used as animal ***,an indicator for plant stress,significantly decreased(−49%)in rye when 2 Mg biochar ha^(−1) was added in combination with mineral *** contrast,proline increased when biochar was added to organic(digestate and compost)fertilizers(up to 43%).Further biochar research should focus much more on food quality,which is a key challenge for global food production.

关键词： Food quality Protein Lupine Winter rye Yield

Bile acid interactions with cholangiocytes

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2006年第22期12卷 3553-3563页

作者： Xuefeng Xia Heather Francis Shannon glaser Gianfranco Alpini Gene LeSage University of Texas at Houston Medical School Houston TX United States Division of Research and Education Scott & White Hospital and The Texas A&M University System Health Science Center College of Medicine Temple TX United States Department of Medicine Division of Research and Education Scott & White Hospital and The Texas A&M University System Health Science Center College of MedicineTemple TX United States Central Texas Vctcrans Health Care System and Department of Medicine and Systems Biology and Translational Medicine United States

Cholangiocytes are exposed to high concentrations of bile acids at their apical membrane. A selective transporter for bile acids, the Apical Sodium Bile Acid Cotransporter （ASBT）（also referred to as Ibat; gene name Slc10a2） is localized on the cholangiocyte apical membrane. On the basolateral membrane, four transport systems have been identified （t-ASBT, multidrug resistance （MDR）3, an unidentified anion exchanger system and organic solute transporter （Ost） heteromeric transporter, Ostα- Ostβ. Together, these transporters unidirectionally move bile acids from ductal bile to the circulation. Bile acids absorbed by cholangiocytes recycle via the peribiliary plexus back to hepatocytes for re-secretion into bile. This recycling of bile acids between hepatocytes and cholangiocytes is referred to as the cholehepatic shunt pathway. Recent studies suggest that the cholehepatic shunt pathway may contribute in overall hepatobiliary transport of bile acids and to the adaptation to chronic cholestasis due to extrahepatic obstruction. ASBT is acutely regulated by an adenosine 3＇, 5＇monophosphate （cAMP）-dependent translocation to the apical membrane and by phosphorylation-dependent ubiquitination and proteasome degradation. ASBT is chronically regulated by changes in gene expression in response to biliary bile acid concentration and inflammatory cytokines. Another potential function of cholangiocyte ASBT is to allow cholangiocytes to sample biliary bile acids in order to activate intracellular signaling pathways. Bile acids trigger changes in intracellular calcium, protein kinase C （PKC）, phosphoinositide 3-kinase （PI3K）, mitogenactivated protein （MAP） kinase and extracellular signalregulated protein kinase （ERK） intracellular signals. Bile acids significantly alter cholangiocyte secretion,proliferation and survival. Different bile acids have differential effects on cholangiocyte intracellular signals,and in some instances trigger opposing effects on cholangiocyte secretion, pro

关键词： Cholangiocytes Bile acid Liver

Microwave-assisted combustion to produce benzene polycarboxylic acids as molecular markers for biochar identification and quantification

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Biochar 2021年第4期3卷 407-418页

作者： Bruno glaser Marie Guenther Heike Maennicke Tobias Bromm Institute of Agricultural and Nutritional Sciences Soil BiogeochemistryMartin Luther University Halle-Wittenbergvon-Seckendorff-Platz 306120 HalleGermany

Biochar is a promising carbon dioxide removal(CDR)technology for climate change *** procedures for its determination are lengthy,labor-intensive,and difficult to *** polycarboxylic acids(BPCA)are the most promising molecular markers for identification and quantification of biochar and its quality as they specifically represent the stable polyaromatic backbone of ***,using the BPCA method,its stability and,thus,its C sequestration potential could be used for CDR *** current BPCA method relies on a specific high-pressure digestion apparatus,which is not available around the ***,the aims of the present work were(i)to compare the conventional high-pressure nitric acid oxidation with a microwave-assisted digestion technique and optimize the oxidation conditions in such a way that previous results are comparable with future ones,and(ii)to significantly reduce the digestion time of soil samples of 8 h and to develop a suitable routine method that produces comparable and reproducible *** this purpose,soil and control sample series were prepared for different *** results were compared with the values of the conventional method both for individual samples and for the whole dataset *** ensure the representative-ness of the results,in addition to various soil samples with different properties,we included two reference materials into our data set,one without biochar(wheat flour)and a biochar *** results showed that conventional nitric acid oxidation in the BPCA determination at 170°C and 8 h can be substituted by digestion in a microwave reaction system(CEM Mars6)at 190°C and 1 *** results further showed that this condition needs to be strictly matched,because,otherwise,over-or underestimation of biochar quantity and/or quality will be the *** goal of a less time-consuming BPCA extrac-tion from soil samples was achieved by reducing the extraction t

关键词： Biochar Black carbon Pyrogenic carbon Analysis Molecular marker Microwave-assisted combustion

Epidemiology and clinical characteristics of pediatric osteomyelitis in northern California

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Pediatrics 2023年第6期19卷 609-613页

作者： Xiao Ben Wang Navendu Samant Justin Searns Carol glaser Department of Pediatrics UCLA Medical Center10833 Le Conte AvenueA2-383 MDCCLos AngelesCA 90095USA Division of Research Kaiser Permanente Northern CaliforniaOaklandCAUSA Department of Pediatrics University of ColoradoChildren's Hospital ColoradoAuroraCOUSA California Department of Public Health CARichmondUSA

Pediatric osteomyelitis is a serious infection in children leading to significant morbidity and hospitalization[1].Infections most commonly occur in the long bones,and 52%-70% are caused by Staphylococcus aureus(***)[2-4].Methicillin-resistant Staphylococcus aureus(MRSA)has been associated with higher rates of complications for children with acute osteomyelitis.

关键词： Epidemiology myelitis acute