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Recent Advances on Polyoxometalate-Based Ion-Conducting Electrolytes for Energy-Related Devices

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Energy & Environmental Materials 2023年第2期6卷 262-274页

作者： Dongming cheng Ke Li Hongying Zang jiajia chen Key Laboratory of Polyoxometalate and Reticular Material Chemistry of Ministry of Education at Universities of Jilin Province Faculty of ChemistryNortheast Normal UniversityChangchun 130024China State Key Laboratory of Physical Chemistry of Solid Surfaces Department of ChemistryCollege of Chemistry and Chemical EngineeringCollaborative Innovation Centre of Chemistry for Energy MaterialsXiamen UniversityXiamen 361005China

Solid-state electrolytes have attracted considerable attention in new energyrelated devices due to their high safety and broad application ***(POMs)are a kind of molecular-level cluster compounds with unique *** recent years,owing to their abundant physicochemical properties(including high ionic conductivity and reversible redox activity),POMs have shown great potential in becoming a new generation of solid-state *** this review,an overview is investigated about how POMs have evolved as ion-conducting materials from basic research to novel solid-state electrolytes in energy ***,some expressive POM-based ion-conducting materials in recent years are introduced and classified,mainly inspecting their structural and functional *** that,it is further focused on the application of these ionconducting electrolytes in the fields of proton exchange membranes,supercapacitors,and ion *** addition,some properties of POMs(such as inherent dimension,capable of forming stable hydrogen bonds,and reversible bonding to water molecules)enable these functional POM-based electrolytes to be employed in innovative applications such as ion selection,humidity sensing,and smart ***,some fundamental recommendations are given on the current opportunities and challenges of POM-based ion-conducting electrolytes.

关键词： energy devices ion conduction polyoxometalates solid-state electrolytes

Investigation on induction brazing of profiled cBN wheel for grinding of Ti-6Al-4V

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Chinese Journal of Aeronautics 2021年第4期34卷 132-139页

作者： Qilin LI Kai DING Weining LEI jiajia chen Qingshan HE Zhenzhen chen School of Mechanical Engineering Jiangsu University of TechnologyChangzhou 213001China Nanjing Forestry University Nanjing 210010China Henan University of Technology Zhenzhou 450007China Key Laboratory of Special Purpose Equipment and Advanced Processing Technology Ministry of Education&Zhejiang ProvinceZhejiang University of TechnologyHangzhou 310032China

Profiled monolayer cBN wheel was induction brazed for grinding of titanium dovetail slot in this *** at acquiring a uniform temperature distribution along the profiled surface and reducing the thermal deformation of the brazed wheel,a finite element model was established to investigate the temperature uniformity during induction brazing.A suitable induction coil and the related working parameters were designed and chosen based on the simulation ***-Cu-Ti alloy and cBN grains were applied in the induction brazing *** results showed geometric deformation of the brazed wheel was no more than 0.01 mm and chemical reaction layer were found on the brazed joint *** validation tests were carried out by grinding of Ti-6 Al-4 V *** to the electroplated wheel,the brazed wheel showed better performance such as low specific grinding energy and good ground quality in grinding of Ti-6 Al-4 V *** wear was found to be the main failure mode for the induction brazed wheel,while adhesion and grains pull-out were the main failure mode for the electroplated wheel.

关键词： Grinding performance Induction brazing Profiled cBN wheel Specific grinding energy Temperature uniformity

Interannual variability in the barrier layer and forcing mechanism in the eastern equatorial Indian Ocean and Bay of Bengal

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Acta Oceanologica Sinica 2020年第7期39卷 19-31页

作者： Tian Ma Xuhua cheng Yiquan Qi jiajia chen Key Laboratory of Marine Hazards Forecasting Ministry of Natural ResourcesHohai UniversityNanjing 210098China College of Oceanography Hohai UniversityNanjing 210098China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519000China

Interannual variability(IAV)in the barrier layer thickness(BLT)and forcing mechanisms in the eastern equatorial Indian Ocean(EEIO)and Bay of Bengal(BoB)are examined using monthly Argo data sets during 2002–*** BLT during November–January(NDJ)in the EEIO shows strong IAV,which is associated with the Indian Ocean dipole mode(IOD),with the IOD leading the BLT by two *** the negative IOD phase,the westerly wind anomalies driving the downwelling Kelvin waves increase the isothermal layer depth(ILD).Moreover,the variability in the mixed layer depth(MLD)is *** by the Wyrtki jet,the MLD presents negative anomalies west of 85°E and strong positive anomalies between 85°E and 93°***,the BLT shows positive anomalies except between 86°E and 92°E in the ***,the IAV in the BLT during December–February(DJF)in the BoB is also *** the eastern and northeastern BoB,the IAV in the BLT is remotely forced by equatorial zonal wind stress anomalies associated with the El Ni?o-Southern Oscillation(ENSO).In the western BoB,the regional surface wind forcing-related ENSO modulates the BLT variations.

关键词： barrier layer thickness interannual variability eastern equatorial Indian Ocean Bay of Bengal

Effective depolymerization of alkali lignin using an attapulgite-Ce_(0.75)Zr_(0.25)O_(2)(ATP-CZO)-supported cobalt catalyst in ethanol/isopropanol media

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Chinese Journal of Chemical Engineering 2023年第5期57卷 50-62页

作者： jiajia chen Xinyu Lu Dandan Wang Pengcheng Xiu Xiaoli Gu Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources College of Chemical EngineeringNanjing Forestry UniversityNanjing 210037China

Lignin is the world's greatest renewable aromatic biofeedstock,and it has promising applications in high value-added chemical ***,N-Co/ATP-CZO was used as a catalyst for the depolymerization of alkali lignin in ethanol and isopropanol systems,and explored the effects of formic acid(FA)amount,reaction time,reaction temperature and other factors on the depolymerization of alkali *** them,formic acid serves as both catalytic and in situ-hydrogen ***,the highest yield of bio-oil(59.28%(mass)),including 30.05%(mass)of monomer,was obtained after a reaction of FA to alkali lignin mass ratio of 4 and 240°C for 8 *** the monomers,the yield of Guaiacol was the highest(5.94%(mass)),followed by 2-methoxy-4-methylphenol(5.74%(mass)).This study,the modification of attapulgite was carried out to reduce the acidity while enhancing the catalytic activity for depolymerization,and the selection of hydrogen donor was investigated.A feasible pathway for lignin depolymerization research was opened.

关键词： Lignin Biofuel Catalyst support Mixing Ce_(0.75)Zr_(0.25)O_(2)solid solution

Measuring web page complexity by analyzing TCP flows and HTTP headers

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The Journal of China Universities of Posts and Telecommunications 2017年第6期24卷 1-13页

作者： cheng Weiqing Hu Yangyang Yin Qiaofeng chen jiajia School of Computer Science Nanjing University of Posts and Telecommunications Key Laboratory of Computer Network and Information Integration Southeast University Jiangsu Education Information Center Jiangsu Provincial Department of Education

To understand website complexity deeply, a web page complexity measurement system is developed. The system measures the complexity of a web page at two levels： transport-level and content-level, using a packet trace-based approach rather than server or client logs. Packet traces surpass others in the amount of information contained. Quantitative analyses show that different categories of web pages have different complexity characteristics. Experimental results show that a news web page usually loads much more elements at more accessing levels from much more web servers within diverse administrative domains over much more concurrent transmission control protocol （TCP） flows. About more than half of education pages each only involve a few logical servers, where most of elements of a web page are fetched only from one or two logical servers. The number of content types for web game traffic after login is usually least. The system can help web page designers to design more efficient web pages, and help researchers or Internet users to know communication details.

关键词： hyper text transfer protocol concurrent TCP flows world wide web web page complexity

Heat Transfer Characteristics outside the Condenser of a Rotating Heat Pipe Grinding Wheel with a Lateral Air Impinging Jet

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Journal of Thermal Science 2021年第2期30卷 493-503页

作者： chen jiajia ZHANG Liyong FU Yucan QIAN Ning JIANG Huafei YANG Lin College of Mechanical and Electronic Engineering Nanjing Forestry UniversityNanjing 210037China College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China Jiangsu Wind Power Generation Engineering&Technology Center Nanjing 210023China

This study numerically analyzed the heat transfer characteristics outside the condenser of a rotating heat pipe grinding wheel(RHP-GW).The goal of this investigation is to determine the optimal structure and parameters for the condenser section of *** fin height(f=0-7 mm),rotational Reynolds number(Rer=1602-6408)and jet Reynolds number(Rej=42379-108302)were analyzed under input heat flux of 4000 W/m2.A fully developed flow was imposed at the outlet of the *** showed that the optimal heat transfer rate was obtained for fin height of 5 mm,which improved the average Nusselt number by 84%compared to the structure without fins.A critical Rej for each Rer that the impinging jet can reach the condenser section was *** critical Rej value increases with Rer,which is in the range from 42379 to 61215 and 61215 to 80050 for Rer=6408 and Rer=9610,respectively.

关键词： rotating heat pipe grinding wheel impinging jet heat transfer numerical analysis

How graph convolutions amplify popularity bias for recommendation?

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Frontiers of Computer Science 2024年第5期18卷 121-132页

作者： jiajia chen Jiancan WU Jiawei chen Xin XIN Yong LI Xiangnan HE School of Information Science and Technology University of Science and Technology of ChinaHefei 230026China School of Computer Science and Technology Zhejiang UniversityHangzhou 310058China School of Computer Science and Technology Shandong UniversityQingdao 250100China Department of Electronic Engineering Tsinghua UniversityBeijing 100084China

Graphconvolutional networks(GCNs)have become prevalent in recommender system(RS)due to their superiority in modeling collaborative *** improving the overall accuracy,GCNs unfortunately amplify popularity bias-tail items are less likely to be *** effect prevents the GCN-based RS from making precise and fair recommendations,decreasing the effectiveness of recommender systems in the long *** this paper,we investigate how graph convolutions amplify the popularity bias in *** theoretical analyses,we identify two fundamental factors:(1)with graph convolution(i.e.,neighborhood aggregation),popular items exert larger influence than tail items on neighbor users,making the users move towards popular items in the representation space;(2)after multiple times of graph convolution,popular items would affect more high-order neighbors and become more *** two points make popular items get closer to almost users and thus being recommended more *** rectify this,we propose to estimate the amplified effect of popular nodes on each node's representation,and intervene the effect after each graph ***,we adopt clustering to discover highly-influential nodes and estimate the amplification effect of each node,then remove the effect from the node embeddings at each graph convolution *** method is simple and generic-it can be used in the inference stage to correct existing models rather than training a new model from scratch,and can be applied to various GCN *** demonstrate our method on two representative GCN backbones LightGCN and UltraGCN,verifying its ability in improving the recommendations of tail items without sacrificing the performance of popular *** are open-sourced^(1)).

关键词： recommendation graph convolution networks popularity bias

Rational design and biomedical applications of DNA-functionalized upconversion nanoparticles

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Chinese Chemical Letters 2018年第9期29卷 1321-1332页

作者： Xinwen Liu Meng Liu jiajia chen Zhihao Li Quan Yuan Key laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education) College of Chemistry and Molecular Sciences Wuhan University

Lanthanide-doped upconversion nanoparticles （UCNPs） offer unique advantages in term of low autofluorescence, high signal-to-noise ratio and deep tissue penetration, and have attracted considerable attention in biomedical applications. DNA, beyond the properties of self-assembly, also exhibits multiple functions such as molecular recognition, drug loading capacity and therapeutic effect. In this regard, the combination of UCNPs and DNA offers a promising and powerful platform for potential applications in biosensing, bioimaging and disease therapy. In this review, we mainly introduce recent progresses of DNA-functionalized upconversion materials, providing an overview of the design and applications in biosensing, bioimaging and therapy. The challenges and future perspectives are also discussed, aiming to promote their applications in material science and biomedicine.

关键词： Lanthanide-doped upconversion nanoparticles DNA Biosensor Bioimaging Disease therapy

Li_(2)ZnTi_(3)O_(8)as the host–separator modifier with efficient polysulfides trapping and fast Li^(+)diffusion for lithium-sulfur batteries

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Nano Research 2024年第7期17卷 6087-6094页

作者： Mao Qian Yakun Tang Lang Liu Yue Zhang Xiaohui Li jiajia chen State Key Laboratory of Chemistry and Utilization of Carbon Based Energy Resources Xinjiang UniversityUrumqi 830017China State Key Laboratory of Physical Chemistry of Solid Surfaces Xiamen UniversityXiamen 361005China

The diffusion and loss of lithium polysulfides(LiPSs)in lithium-sulfur batteries(LSBs)reduce the sulfur utilization rate and the catalytic conversion efficiency of sulfur species,resulting in early battery ***_(2)ZnTi_(3)O_(8)(LZTO),characterized by its stable spinel structure,exhibits high Li+conductivity and holds great potential as an effective adsorbent for *** study proposes a collaborative design concept of LZTO host–separator modifier,which offers a complementary and matching approach in the cathode side,effectively addressing the challenges associated with dissolution and inadequate conversion of *** functional theory(DFT)calculation substantiates the pronounced chemical affinity of LZTO towards *** importantly,the high efficiency ion transport channels are achieved in separator coating due to the presence of the LZTO ***,the catalytic efficacy of LZTO is validated through meticulous analysis of symmetric batteries and Tafel ***,the LZTO host–separator modifier-based cell displays satisfactory rate capability(1449 and 1166 mAh·g^(−1)at 0.1 and 0.5 C)and an impressively capacity(606 mAh·g^(−1)after 500 cycles at 1 C).The coordinated strategy of host–separator modifier is supposed to have wide applications in LSBs.

关键词： Li_(2)ZnTi_(3)O_(8) lithium-sulfur batteries host-separator modifier catalytic conversion diffusion and loss of LiPSs