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Performance improvement of Ethylene-Vinyl Acetate Copolymer Pour Point Depressant(EVA PPD)by adding small dosages of Laurylamine(LA)

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Petroleum Science 2022年第5期19卷 2472-2482页

作者： Xue Xia chuan-xian li Guang-Yu Sun Ke-Ke Zhao Jie Zhang Bo Yao Fei Yang College of Pipeline and Civil Engineering China University of PetroleumQingdaoShandong266580PR China Shandong Provincial Key Laboratory of Oil&Gas Storage and Transportation Safety QingdaoShandong266580PR China China Petroleum Engineering&Construction Corp.Beijing Company PR China

Lauramine is widely considered to be an asphaltene flocculant,but its effect on the modification of crude oil by PPDs has been little *** this paper,the effect of LA dosage on the rheology improvement of EVA PPDs(100 ppm)on Qinghai waxy crude oil was investigated through rheological measurement,wax precipitating analysis,granularity test and resins/asphaltenes FTIR *** with pure EVA,the compounding of LA and EVA obviously enhances the agglomeration degree and reduces the number of fine wax crystals,thus further enhancing the rheology of the oil samples,and the best performance is at the LA dosage of 200 *** relatively small LA dosages,the LA facilitates the adsorption of EVA molecules on the asphaltene surfaces,which favors the becoming of EVA/asphaltenes composite particles;but at relatively high LA dosages,the LA makes the asphaltenes more aggregated and disturbs the EVA adsorption on the asphaltenes,which is adverse for the formation of EVA/asphaltenes compound *** compound particles can serve as wax precipitating templates and significantly influence its morphology,thus further improving the crude oil *** consequence,the rheology improvement of EVA PPDs on Qinghai waxy crude oil first increases and then decreases with increasing the LA dosage.

关键词： Waxy crude oil EVA PPD Laurylamine Asphaltenes Synergistic effect

Pre-heating temperature induced flowability and wax deposition characteristics of crude oil adding wax inhibitors

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Petroleum Science 2023年第4期20卷 2468-2478页

作者： Bo Yao Hao-Ran Zhu Bao-Dong Yan chuan-xian li Fei Yang Guang-Yu Sun Hong-Bo Zeng College of Pipeline and Civil Engineering China University of PetroleumQingdaoShandong266580People's Republic of China Department of Chemical and Materials Engineering University of AlbertaEdmontonABT6G 1H9Canada School of Petroleum Engineering Changzhou UniversityChangzhouJiangsu213164People's Republic of China China Oil&Gas Pipeline Network Corporation Beijing100020China

This paper investigated the effects of pre-heating treatment temperatures(T_(pre))on the flowability and wax deposition characteristics of a typical waxy crude oil after adding wax *** is found that there is little difference in wax precipitation exothermic characteristics of crude oils at different T_(pre),as well as the wax crystal solubility coefficient in the temperature range of 25-30℃.For the undoped crude oil,the flowability after wax precipitation gets much improved and the wax deposition is alleviated as T_(pre)*** T_(pre)=50℃,the viscosity and wax deposition rate of crude oil adding wax inhibitors are higher than those of the undoped crude *** the T_(pre)increases to 60,70,and 80℃,the flowability of the doped crude oil are largely improved and the wax deposition is suppressed with the T_(pre)increase,but the wax content of wax deposit increases *** is speculated that,on the one hand,the T_(pre)increase helps the dispersion of asphaltenes into smaller sizes,which facilitates the co-crystallization with paraffin waxes and generates more aggregated wax crystal *** weakens the low-temperature gel structure and increases the solid concentration required for the crosslink to form the wax *** the other hand,the decrease in viscosity increases the diffusion rate of wax molecules and accelerates the aging of wax *** experimental results have important guiding significance for the pipeline transportation of doped crude oils.

关键词： Pre-heating treatment Wax inhibitor Flowability Wax deposition Waxy crude oil

Co-adsorption behavior of aggregated asphaltenes and silica nanoparticles at oil/water interface and its effect on emulsion stability

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Petroleum Science 2022年第4期19卷 1793-1802页

作者： Guang-Yu Sun Hao Zhang Dai-Wei liu chuan-xian li Fei Yang Bo Yao Ze Duan Xin-Ya Chen Fu-Jun Sheng College of Pipeline and Civil Engineering China University of Petroleum(East China)Qingdao266580ShandongPeople's Republic of China Shandong Key Laboratory of Oil&Gas Storage and Transportation Safety Qingdao266580ShandongPeople's Republic of China

In petroleum industry, crude oil emulsions are commonly formed in oilfields. The asphaltenes and fine particles in crude oil may affect the stability of the emulsions by adsorbing at the water/oil interface. In this research, the effect of silica nanoparticles and asphaltenes on emulsion stability is explored first. The asphaltenes are proved to benefit emulsion stability. Unlike the asphaltenes, however, the modified silica nanoparticles may have positive or negative effect on emulsion stability, depending on the asphaltene concentration and aggregation degree in the emulsions. Further, it is confirmed by conducting interfacial experiment that the asphaltenes and particles can adsorb at the interface simultaneously and determine the properties of the interfacial layer. More in-depth experiments concerning contact angle and asphaltene adsorption amount on the particles indicate that the asphaltenes can modify the wettability of the particles. Higher concentration and lower aggregation degree of the asphaltenes can increase their adsorption amount on the surface of particles and then improve the modification effectiveness of the particles. Resultantly, the particles with good modification effectiveness can enhance the emulsion stability while the particles with poor modification effectiveness will weaken the emulsion stability.

关键词： Asphaltene Silica nanoparticle Co-adsorption behavior Modification effectiveness Emulsion stability

Elimination of methicillin‑resistant Staphylococcus aureus biofilms on titanium implants via photothermally‑triggered nitric oxide and immunotherapy for enhanced osseointegration

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Military Medical Research 2024年第2期11卷 157-179页

作者： Yong‑lin Yu Jun‑Jie Wu chuan‑chuan lin xian Qin Franklin R.Tay li Miao Bai‑Long Tao Yang Jiao Department of Pathology Affiliated Hospital of Zunyi Medical UniversityZunyi 563003GuizhouChina Laboratory Research Center the First Affiliated Hospital of Chongqing Medical UniversityChongqing 400016China Department of Blood Transfusion Laboratory of Radiation Biologythe Second Affiliated HospitalArmy Military Medical UniversityChongqing 400037China Department of Reproductive Endocrinology Chongqing Health Center for Women and ChildrenChongqing 401147China The Graduate School Augusta UniversityAugustaGA 30912USA Department of Stomatology the Seventh Medical Center of PLA General HospitalBeijing 100700China

Background:Treatment of methicillin-resistant Staphylococcus aureus(MRSA)biofilm infections in implant placement surgery is limited by the lack of antimicrobial activity of titanium(Ti)*** is a need to explore more effective approaches for the treatment of MRSA biofilm ***:Herein,an interfacial functionalization strategy is proposed by the integration of mesoporous polydopamine nanoparticles(PDA),nitric oxide(NO)release donor sodium nitroprusside(SNP)and osteogenic growth peptide(OGP)onto Ti implants,denoted as Ti-PDA@*** physical and chemical properties of Ti-PDA@SNP-OGP were assessed by scanning electron microscopy,X-ray photoelectron spectroscope,water contact angle,photothermal property and NO release *** synergistic antibacterial effect and elimination of the MRSA biofilms were evaluated by 2′,7′-dichlorofluorescein diacetate probe,1-N-phenylnaphthylamine assay,adenosine triphosphate intensity,O-nitrophenyl-β-D-galactopyranoside hydrolysis activity,bicinchoninic acid *** staining,assays for alkaline phosphatase activity,collagen secretion and extracellular matrix mineralization,quantitative real‑time reverse transcription‑polymerase chain reaction,and enzyme-linked immunosorbent assay(EliSA)were used to evaluate the inflammatory response and osteogenic ability in bone marrow stromal cells(MSCs),RAW264.7 cells and their co-culture *** staining,EliSA,micro-CT,hematoxylin and eosin,Masson's trichrome and immunohistochemistry staining were used to evaluate the eradication of MRSA biofilms,inhibition of inflammatory response,and promotion of osseointegration of Ti-PDA@SNP-OGP in ***:Ti-PDA@SNP-OGP displayed a synergistic photothermal and NO-dependent antibacterial effect against MRSA following near-infrared light(NIR)irradiation,and effectively eliminated the formed MRSA biofilms by inducing reactive oxygen species(ROS)-mediated oxidative stress,destroying bacterial membrane integrity and

关键词： Polydopamine nanoparticles Methicillin-resistant Staphylococcus aureus Nitric oxide Osseointegration Osteo-immunomodulation Photothermal effect Titanium implants

Crystalline-amorphous M@MN_x(M=Co,Fe,Ni)encapsulated in nitrogen-doped carbon for enhanced efficient and durable hydrogen evolution reaction

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Rare Metals 2024年第4期43卷 1547-1556页

作者： Yang Yang Xiao-chuan Duan Shao-Hui Guo xian-Ming Zhang College of Materials Science and Engineering College of ChemistryKey Laboratory of Interface Science and Engineering in Advanced MaterialsTaiyuan University of TechnologyYuci030600China

Developing earth-abundant electrocatalysts for hydrogen evolution reaction(HER)is important for the sustainable energy ***,efficient and stable heterocatalysts consisting of crystalline-amorphous M@MN_(x)(M=Co,Fe,Ni)encapsulated in N-doped carbon layers supported with N-doped graphene sheets(denoted as M@MN_(x)@NC-NG)are synthesized by facile hydrothermal reaction and nitridation *** the nitriding process,metal ions in M(tzbc)_2(H_(2)O)_4(tzbc=4-(1H-1,2,4-triazol-1-yl)benzoic acid)complexes are reduced to crystalline M cores,accompanied by the formation of amorphous MN_(x)shells;the tzbc ligands are insitu carbonized to form outermost N-doped carbon(NC)layers that connect with inner MN_(x)via M-N-C motifs inherited from the complex precursors and inhibit the transition of MN_(x)from amorphous to crystalline *** Co@CoN_(x)@NC-NG catalyst exhibits excellent HER activity with small overpotentials of 45 and 64 mV at a cathode current density of 10 mA·cm^(-2)and low Tafel slopes of 40 and 85 mV·dec^(-1)in 0.5 mol·L^(-1)H_(2)SO_4 and1.0 mol·L^(-1)KOH electrolytes,*** Co@CoN_(x)@NC-NG retains 97%of the initial overpotential after 100,000 s in both acidic and alkaline *** outstanding HER performance originates from the crystalline-amorphous Co@CoN_(x)that redistributes electrons around the heterointerfaces,facilitating the conversion process of H^(+)/H_(2)O to hydrogen and thereby promoting HER *** outermost NC layers serve as the armor of Co@CoN_(x),and graphene nanosheets act as carriers of egg-like Co@CoN_(x)@NC and conduction paths for electron shuttles,ensuring stable and continuous electrocatalytic hydrogen production.

关键词： Hydrogen evolution reaction Electrocatalysts Iron group metals Heterojunction Crystalline-amorphous structure

Theoretical Design of Defects as a Driving Force for Ion Transport in li3OBr Solid Electrolyte

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Energy & Environmental Materials 2024年第3期7卷 147-157页

作者： Xingyun Luo Yanlu li xian Zhao State Key Lab of Crystal Materials and Institute of Crystal Materials Shandong University Center for Optics Research and Engineering Shandong University

Due to ever-increasing concerns about safety issues in using li ionic batteries,solid electrolytes have extensively *** li-rich antiperovskite li3OBr has been considered as a promising solid electrolyte candidate,but it still suffers challenges to achieve a high ionic conductivity owing to the high intrinsic symmetry of the crystal ***,we presented a design strategy that introduces various point defects and grain boundaries to break the high lattice symmetry of li3OBr crystal,and their effect and microscopic mechanism of promoting the migration of li-ion were explored *** has been found that liiare the dominant defects responsible for the fast li-ion diffusion in bulk li3OBr and its surface,but they are easily trapped by the grain boundaries,leading to the annihilating of the Frenkel defect pair V'li+li,and thus limits the V'lidiffusion at the grain *** VBrdefect near the grain boundaries can effectively drive V'liacross the grain boundary,thereby converting the carrier of li+migration from li,in the bulk and surface to V'liat the grain boundary,and thus improving the ionic conductivity in the whole li3OBr *** work provides a comprehensive insight into the li+transport and conduction mechanism in the li3OBr *** opens a new way of improving the conductivity for all-solid-state li electrolyte material through the defect design.

关键词： defects density functional theory ionic migration solid electrolyte

A mixed-valence polyoxometalate-based 3D inorganic framework cathode material for high-efficiency rechargeable AZIBs

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Rare Metals 2024年第8期43卷 3677-3691页

作者： Qing Han Hao-Ran Xiao Tao Zhou Bing-chuan li liu Yang ling-ling Xie Xue-Jing Qiu xian-Yong Wu li-Min Zhu Xiao-Yu Cao School of Chemistry and Chemical Engineering Henan University of TechnologyZhengzhou 450001China Key Laboratory of High Specific Energy Materials for Electrochemical Power Sources of Zhengzhou City Zhengzhou 450001China College of Materials Engineering Henan University of EngineeringZhengzhou450007China School of Environmental Engineering Henan University of TechnologyZhengzhou 450001China Department of Chemistry University of Puerto Rico-Rio Piedras CampusSan JuanPR 00925USA

The global trend towards new energy storage systems has stimulated the development of electrochemical energy storage *** these technologies,rechargeable aqueous zinc-ion batteries(AZIBs)have attracted considerable interest as a potential alternative to lithium-ion batteries(liBs)due to their affordable cost,environmental compatibility and high safety *** this study,a high-quality electrode for AZIBs has been successfully developed using a dehydrated mixed-valence polyoxometalate-based three-dimensional(3D)inorganic framework material known as[H_6Mn_(3)V^Ⅳ_(15)V-^Ⅴ_(4O)_(46)(H_2O)_(12)](3D-MnVO).This innovative 3D-MnVO material is built from the alternate connections of{V_(19)O_(46)}"sphere-shaped"clusters andμ_(2)-{Mn(H_(2)O)_(4)}bridges,where each{V_(19)O_(46)}cluster is surrounded by three pairs of vertically distributed{Mn(H_(2)O)_(4)}units,thus resulting in the 3D interpenetrating grid-like network from the infinite[-{V_(19)O_(46)}-μ_(2)-Mn(H_(2)O)_(4)-{V_(19)O_(46)}]_∞chains in three mutually perpendicular *** 3D framework structure of 3D-MnVO possesses abundant oxygen vacancies,spacious and multi-level interconnected channels for ion transport,which facilitates the efficient intercalation/deintercalation of hydrated Zn^(2+)into the pores of the primary structure via the intercalation capacitance *** a result,the 3D-MnVO electrode exhibits excellent diffusion rates and minimal interfacial *** a current density of 0.1 A·g^(-1),the 3D-MnVO cathode delivers a commendable discharge capacity of170.5 mAh·g^(-1)with 81.6%capacity retention after100 charge/discharge ***,even at a high current density of 1.0 A·g^(-1),the 3D-MnVO electrode delivers a remarkable reversible capacity of198.9 mAh·g^(-1).Our research results provide valuable insights into the development of advanced polyoxometalate-based 3D inorganic framework electrode materials for high-performance rechargeable AZIBs.

关键词： Cathode Polyoxometalate 3D inorganic framework Zinc-ion batteries Energy storage mechanism

Trace formula of the integro-differential operator on a quantum graph

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Applied Mathematics(A Journal of Chinese Universities) 2024年第2期39卷 311-318页

作者： WEI li-xiao YANG chuan-fu School of Mathematics and Statistics Nanjing University of Science and TechnologyNanjing 210094China.

In this paper we study the eigenvalue problem for integro-differential operators on a lasso *** trace formula of the operator is established by applying the residual technique in complex analysis.

关键词： integro-differential operators eigenvalue trace formula

Physiological and pathological functions of circular RNAs in the nervous system

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Neural Regeneration Research 2024年第2期19卷 342-349页

作者： Min Zhou Shi li chuan Huang School of life Sciences Chongqing UniversityChongqingChina

Circular RNAs(circRNAs)are a class of covalently closed single-stranded RNAs that are expressed during the development of specific cells and *** play crucial roles in physiological and pathological processes by sponging microRNAs,modulating gene transcription,controlling the activity of certain RNA-binding proteins,and producing functional peptides.A key focus of research at present is the functionality of circRNAs in the nervous system and several advances have emerged over the last 2 ***,the precise role of circRNAs in the nervous system has yet to be comprehensively *** this review,we first summarize the recently described roles of circRNAs in brain development,maturity,and ***,we focus on the involvement of circRNAs in various diseases of the central nervous system,such as brain cancer,chronic neurodegenerative diseases,acute injuries of the nervous system,and neuropathic pain.A better understanding of the functionality of circRNAs will help us to develop potential diagnostic,prognostic,and therapeutic strategies to treat diseases of the nervous system.

关键词： Alzheimer’s disease amyotrophic lateral sclerosis brain development circRNAs neuropathic pain Parkinson’s disease