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Towards rational design in electrochemical denitrification by analyzing pH dependence

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National Science Review 2024年第6期11卷 223-232页

作者： Huan Li Dong luan Jun Long Xiaoyan Fu Jianping Xiao State Key Laboratory of Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences University of Chinese Academy of Sciences

A small fraction of NOx（<1%） always exists in CO2feedstock（e.g. exhausted gas）, which can significantly reduce the efficiency of CO2electroreduction by ～30%. Hence, electrochemical denitrification is the precondition of CO2electroreduction. The pH effect is a key factor, and can be used to tune the selectivity between N2and N2O production in electrochemical denitrification. However, there has been much controversy for many years about the origin of pH dependence in electrocatalysis. To this end, we present a new scheme to accurately model the pH dependence of the electrochemical mechanism. An extremely small pH variation from pH 12.7 to pH 14 can be accurately reproduced for N2O production. More importantly,the obviously different pH dependence of N2production, compared to N2O, can be attributed to a cascade path. In other words, the N2was produced from the secondary conversion of the as-produced N2O molecule（the major product）, instead of the original reactant NO. This is further supported by more than 35 experiments over varying catalysts（Fe, Ni, Pd, Cu, Co, Pt and Ag）, partial pressures（20%, 50% and100%） and potentials（from -0.2 to 0.2 V vs. reversible hydrogen electrode）. All in all, the insights herein overturn long-lasting views in the field of NO electroreduction and suggest that rational design should steer away from catalyst engineering toward reactor optimization.

关键词： electrocatalysis denitrification pH-dependence nitric oxide reduction reaction mechanism

Recent advances in periodontal regeneration: A biomaterial perspective

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Bioactive Materials 2020年第2期5卷 297-308页

作者： Yongxi Liang Xianghong luan Xiaohua Liu Department of Biomedical Sciences Texas A&M University College of DentistryDallasTX75246USA Department of Periodontics Texas A&M University College of DentistryDallasTX75246USA

Periodontal disease(PD)is one of the most common inflammatory oral diseases,affecting approximately 47%of adults aged 30 years or older in the United *** not treated properly,PD leads to degradation of periodontal tissues,causing tooth movement,and eventually tooth *** clinical therapy for PD aims at eliminating infectious sources,and reducing inflammation to arrest disease progression,which cannot achieve the regeneration of lost periodontal *** the past two decades,various regenerative periodontal therapies,such as guided tissue regeneration(GTR),enamel matrix derivative,bone grafts,growth factor delivery,and the combination of cells and growth factors with matrix-based scaffolds have been developed to target the restoration of lost tooth-supporting tissues,including periodontal ligament,alveolar bone,and *** review discusses recent progresses of periodontal regeneration using tissue-engineering and regenerative medicine ***,we focus on the advances of biomaterials and controlled drug delivery for periodontal regeneration in recent *** attention is given to the development of advanced bio-inspired scaffolding biomaterials and temporospatial control of multi-drug delivery for the regeneration of cementum-periodontal ligament-alveolar bone *** and future perspectives are presented to provide inspiration for the design and development of innovative biomaterials and delivery system for new regenerative periodontal therapy.

关键词： periodontal eventually properly

Radial growth and non-structural carbohydrate partitioning response to resin tapping of slash pine(Pinus elliottii ***)

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Journal of Forestry Research 2022年第2期33卷 423-433页

作者： Baoguo Du Qifu luan Zhanglin Ni Honggang Sun Jingmin Jiang College of Life Science and Biotechnology Ecological and Security Key Laboratory of Sichuan ProvinceMianyang Normal UniversityMianyang 621000People’s Republic of China Chair of Tree Physiology Institute of Forest SciencesAlbert Ludwigs-Universitat FreiburgGeorges-Köhler-Allee 5379110 FreiburgGermany Institute of Subtropical Forestry Research of the Chinese Academy of Forestry Fuyang 311400People’s Republic of China

Slash pine(Pinus elliottii ***)is a resin-producing species grown worldwide for significant economic benefits for wood *** tapping cre-ates a carbon sink at the expense of carbon allocation for growth and consequently,wood production may be ***-structural carbohydrates comprising starch and sugars stored in plant organs,may serve as intermediate pools between assimilation and ***,the effect of resin tapping between tree growth and non-structural carbo-hydrates is not well *** study investigated(1)the effects of resin tapping on radial growth,(2)the effects of resin tapping on non-structural carbohydrate pools in different compartments,and(3)the feasibility of resin pro-duction without disruption of tree *** one-year-old slash pines were subjected to resin tapping over two suc-cessive ***-structural carbohydrate concentrations in needles,branches,stem phloem,and roots of tapped and untapped trees in summer and winter were determined after the second year of resin *** results showed that tapping had no significant effects on annual *** was the dominant non-structural carbohydrate frac-tion,regardless of tissues and season,and constituted up to 99%of the total non-structural carbohydrates in the phloem and *** and fructose were the dominant sugars;sucrose was *** with the controls,tapped trees showed 26%lower non-structural carbohydrate concen-tration in the phloem above the tapping wound in summer,which was attributable to the decreased abundance of starch,glucose,fructose,and *** winter,the altered non-structural carbohydrate profiles in the phloem above the tap-ping wounding were minimised as a result of recovery of the sugar *** contrast to free sugars,which accu-mulated substantially in needles and branches during winter,starch was enriched in the phloem,roots,and current-year *** results provide evidence fo

关键词： Slash pine Localised effects Non-structural carbohydrate Resin tapping Radial growth

Genomic differentiation with isolation by distance along a latitudinal gradient in the spotted-leg treefrog Polypedates megacephalus

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Integrative Zoology 2023年第3期18卷 569-580页

作者： Long JIN Yuchi ZHENG Xiaofeng luan Wenbo LIAO Key Laboratory of Southwest China Wildlife Resources Conservation(Ministry of Education) China West Normal UniversityNanchongChina Chengdu Institute of Biology Chinese Academy of SciencesChengduChina School of Ecology and Nature Conservation Beijing Forestry UniversityBeijingChina

The patterns of isolation by distance(IBD)entailing increased genetic differentiation among populations have aroused extensive concerns for evolutionary *** the IBD may act on spatial processes contribut-ing to the genetic differentiation among populations in anuran species,the factors shaping the IBD of frogs among populations in natural systems are largely ***,we studied the genetic differentiation among six popula-tions with 24 individuals of the spotted-leg treefrog along a latitudinal gradient(1860.31 km)based on 1020 single nucleotide polymorphisms from restriction site-associated DNA *** results showed that the genetic diversity differed signiﬁcantly among populations and that the insular populations had higher genetic diversity than the mainland ***,we also found a signiﬁcant genetic differentiation among populations(FST=0.277)and no sign of inbreeding(FUNI=-0.145).The IBD was detected for all populations,and a higher degree of the IBD was indicated when controlling for the effects of the isolation between Hainan and mainland populations caused by the Qiongzhou ***ﬁndings suggest that the form of the Qiongzhou Strait plays a key role in shaping the genetic diversity and population differentiation in treefrogs.

关键词： genetic diversity isolation by distance Polypedates megacephalus population differentiation single nucleotide polymorphisms

TianmaGouteng yin attenuates ischemic stroke-induced brain injury by inhibiting the AGE/RAGE pathway

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BIOCELL 2023年第6期47卷 1345-1352页

作者： LUOJUN ZHENG luan WENG DIWEN SHOU Department of TCM Pharmacy The First Affiliated Hospital of Zhejiang Chinese Medical University(Zhejiang Provincial Hospital of Chinese Medicine)Hangzhou310003China

Background:Ischemic stroke is characterized by permanent or transient obstruction of blood flow,leading to a growing risk factor and health *** yin(TMG)is commonly used in Chinese medicine to treat cerebral *** aim of this study was to investigate the neuroprotective effects of TMG against ischemic ***:Either permanent middle cerebral artery occlusion(pMCAO)or sham operation was performed on anesthetized Wistar male rats(n=36).Results:Results demonstrated that TMG administration reduced the infarction volume and mitigated the neurobehavioral *** and eosin(HE)staining and Prussian blue staining revealed that TMG attenuated tissue disruption and microbleeds in hippocampus *** addition,TMG down-regulated the receptor of advanced glycation end products(RAGE)and *** also inhibited the concentrations of advanced glycation end products(AGEs),ferritin,malondialdehyde(MDA),and reactive oxygen species(ROS).Conclusion:As repetitive clinical trials of neuroprotectants targeting stroke have failed previously,our results suggested that the natural product,TMG,can probably help in the vicious cycles of ischemic stroke pathology.

关键词： Ischemic stroke Tianmagouteng yin Brain injury Neuroprotection AGE/RAGE pathway pMCAO

Below-Cloud Aerosol Scavenging by Different-Intensity Rains in Beijing City

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Journal of Meteorological Research 2019年第1期33卷 126-137页

作者： Tian luan Xueliang GUO Tianhang ZHANG Lijun GUO State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesChina Meteorological Administration Key Laboratory for Cloud Physics Chinese Academy of Meteorological SciencesChina Meteorological Administration Collaborative Innovation Center for Meteorological Disasters Forecast Early Warning and AssessmentNanjing University of Information Science &Technology National Meteorological Center China Meteorological Administration

Below-cloud aerosol scavenging process by precipitation is important for cleaning the polluted aerosols in the atmosphere, and is also a main process for acid rain formation. However, the related physical mechanism has not been well documented and clarified yet. In this paper, we investigated the below-cloud PM_(2.5)(particulate matter with aerodynamic diameter being 2.5 μm or less) scavenging by different-intensity rains under polluted conditions characterized by high PM_(2.5) concentrations, based on in-situ measurements from March 2014 to July 2016 in Beijing city. It was found that relatively more intense rainfall events were more efficient in removing the polluted aerosols in the atmosphere. The mean PM_(2.5) scavenging ratio and its standard deviation(SD) were 5.1% ± 25.7%, 38.5% ± 29.0%,and 50.6% ± 21.2% for light, moderate, and heavy rain events, respectively. We further found that the key impact factors on below-cloud PM_(2.5) scavenging ratio for light rain events were rain duration and wind speed rather than raindrop size distribution. However, the impacts of rain duration and wind speed on scavenging ratio were not important for moderate and heavy rain events. To our knowledge, this is the first statistical result about the effects of rain intensity, rain duration, and raindrop size distribution on below-cloud scavenging in China.

关键词： PM2.5 below-cloud scavenging rain intensity impact factors

A programmable approach to revising knowledge bases

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Science in China(Series F) 2005年第6期48卷 681-692页

作者： luan Shangmin DAI Guozhong LI Wei Institute of Software Chinese Academy of Sciences Beijing 100080 China Department of Computer Science and Technology Beijing-University of Aeronautics and Astronautics Beijing 100083 China

This paper presents a programmable approach to revising knowledge bases consisting of clauses. Some theorems and lemmas are shown in order to give procedures for generating maximally consistent subsets. Then a complete procedure and an incomplete procedure for generating the maximal consistent subsets are presented, and the correctness of the procedures is also shown. Furthermore, a way to implement knowledge base revision is presented, and a prototype system is introduced. Compared with related works, the main characteristic of our approach is that the approach can be implemented by a computer program.

关键词： knowledge base knowledge base revision rules predicate logic propositional logic

Strengthened and toughened SiHfBCN-based hightemperature resistant adhesive with SiC NWs

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Chinese Journal of Aeronautics 2024年第7期37卷 539-549页

作者： Xingang luan Xiyue ZHU Xichao DONG Min LI Laifei CHENG Science and Technology on Thermostructural Composite Materials Laboratory Northwestern Polytechnical UniversityXi’an 710072China

To further improve the performance of binders,a SiHfBCN-based high-temperature resistant adhesive was successfully synthesized by Polymer-Derived Ceramics(PDC)route using TiB2,Polysiloxane(PSO)and short SiC nanowires as *** effect of short SiC nanowires on the adhesive strength at room temperature and high temperature,as well as the reinforcing mechanism was *** with the adhesive without SiC nanowires,after curing(at 170℃)and pyrolysis(at 1000℃)in air,the appropriate adding of SiC nanowires upgrades the room temperature and high temperature(at 1000℃ in air)adhesive strength to(12.50±0.67)MPa(up by about 32%)and(13.11±0.79)MPa(up by about 106%),***,under the synergistic impact of the nanowire bridging,nanowire breaking,nanowire drawing and crack deflection,the optimized adhesive exhibits multi-stage fracture,causing the increscent fracture displacement.

关键词： High-temperature resistant adhesive SiHfBCN SiC NWs Strengthening Toughening

Freeze-thaw Durability of Recycled Aggregate Concrete:An Overview

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Journal of Wuhan University of Technology(Materials Science) 2021年第1期36卷 58-69页

作者： luan Haoxiang WU Jin PAN Jiayu Department of Civil Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China College of Civil and Architecture Guangxi University of Science and TechnologyLiuzhou 545006China Jiangsu Huangjiang Construction Group Co. Ltd.Yangzhou 225200China

The characteristics of surface appearances,mass loss,relative dynamic modulus of elasticity and strength loss of different recycled aggregate concretes(RAC) exposed to freeze-thaw cycles were *** was found that the freeze-thaw resistance of RAC could be determined by the recycled aggregate compositions and *** the saturation degree and the air void structure were the key factors influencing the freeze-thaw damage on *** major proposed freeze-thaw deterioration mechanisms were utilized to interpret the freeze-thaw damage on recycled aggregate ***,some potential measures to enhance the freeze-thaw resistance of concrete were summarized and discussed.

关键词： recycled aggregate concrete freeze-thaw durability aggregate composition deterioration mechanism improvement measures