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A general two-phase mixture model for sediment-laden flow in open channel

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Journal of Hydrodynamics 2022年第2期34卷 286-298页

作者： jia-xing li Xin Chen Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System China Agricultural UniversityBeijing100083China

This work extends the sediment-laden mixture model with consideration of the turbulence damping and particle wake effects under the framework of improved efficiency and *** mixture model consists of the continuity and momentum equations for the sediment-laden mixture,and the continuity equation for the sediment.A theoretical formula is derived for the relative velocity between the water and sediment phases,with consideration of the effects of the pressure gradient,the shear stress and the lift force.A modified expression of the particle wake effect,inducing the local turbulence enhancement around the sediment particle,is employed to improve the turbulent diffusion of the coarse *** k_(m)-ε_(m) model is proposed to close the mixture turbulence,with the turbulence damping effect due to the high sediment concentration expressed by the density-stratification term without an empirical *** k_(m)-ε_(m) turbulence model requires smaller computational work and offers better results than an empirical density-stratification turbulence model in high sediment concentration ***,with the proposed mixture model,the sediment transport in the open channel under a wide range of sediment sizes and concentrations can be revealed with the results in good agreement with experimental data for the velocity,the sediment concentration and the turbulent kinetic energy.

关键词： Sediment-laden flow two-phase mixture model particle wake effect turbulence damping effect density stratification

Cradle for the newborn Monochamus saltuarius:Microbial associates to ward off entomopathogens and disarm plant defense

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Insect Science 2023年第4期30卷 1165-1182页

作者： Si-Xun Ge jia-xing li Zhuo-Heng jiang Shi-Xiang Zong li-li Ren Bejing Key Laboratory for Forest Pest Control Bejing Forestry UniversityBeijingChina School of Science Westlake UniversityHangzhouChina Sino-French Joint Laboratory for Invasive Forest Pests in Eurasia Bejing Forestry University-French National Research Institute for AgricultureFood and Environment(INRAE)BejingChina

The Japanese pine sawyer,Monochamus saltuarius,as a beetle vector of Bur-saphelenchus xylophilus(pine wood nematode),is an economically important forest pest in *** feed on the phloem and xylem of conifers,*** needs to overcome various stress factors,including coping with entomopathogenic bacteria and also various plant secondary compounds(PSCs).As an important adaptation strategy to colonize host trees,*** deposit eggs in oviposition pits to shield their *** pits har-bor bacterial communities that are involved in the host adaptation of *** to the ***,the composition,origin,and functions of these oviposition pit bacteria are rarely *** this study,we investigated the bacterial community associated with *** oviposition pits and their ability to degrade *** showed that the bacterial community structure of *** oviposition pits significantly differed from that of uninfected ***,the oviposition pit bacteria were predicted to be enriched in PSC degradation *** microbial community also harbored a lethal strain of Serratia,which was significantly ***,metatranscriptome anal-ysis indicated that genes involved in PSCs degradation were expressed complementarily among the microbial communities of oviposition pits and *** vitro degrada-tion showed that bacteria cultured from oviposition pits degraded more monoterpenes and flavonoids than bacteria cultured from uninfected phloem *** of ovipo-sition pits increased the mortality of newly hatched larvae and resulted in a significant decrease in body weight in the early ***,our results reveal that *** construct oviposition pits that harbor a diverse microbial community,with stronger PSCs degradation abilities and a low abundance of entomopathogenic bacteria,resulting in the increased fitness of newly hatched larvae.

关键词： community structure entomopathogenic bacteria host plant adaptation plant secondary metabolites symbiotic bacteria

Long-term outcomes of endoscopic papillary large-balloon dilation(12-15 mm)with or without limited sphincterotomy for removal of bile duct stones

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Hepatobiliary & Pancreatic Diseases International 2023年第4期22卷 392-398页

作者： Tao li li-Xiao Hao Chan Lv xing-jia li Xiao-Dan Ji Meng Chen Chang liu li-Ke Bie Biao Gong Department of Gastroenterology Shuguang HospitalShanghai University of Traditional Chinese MedicineShanghai 201203China Department of Gastroenterology Ruijin HospitalShanghai Jiao Tong University School of MedicineShanghai 200025China

Background:limited endoscopic sphincterotomy with large balloon dilation(ES-LBD)and endoscopic papillary large-balloon dilation(EPLBD)have been proven safe and effective for removal of bile duct ***,the long-term outcomes are not *** aim of this study was to assess the long-term outcomes of EPLBD(12-15 mm)with or without limited sphincterotomy for removal of common bile duct(CBD)***:Patients with EPLBD or ES-LBD referred for the removal of bile-duct stones between June 2008 and August 2020 were retrospectively *** stone clearance,endoscopic retrograde cholangiopancreatography(ERCP)-related adverse events,and late biliary complications during long-term follow-up were ***:Basic patient characteristics were not significantly different between the groups that underwent EPLBD(n=168)and ES-LBD(n=57).EPLBD compared with ES-LBD resulted in similar outcomes in terms of overall successful stone removal(99.4%vs.100%,P=1.00)and ERCP-related adverse events(7.7%vs.5.3%,P=0.77).The mean duration of the follow-up were 113.6 months and 106.7 months for patients with EPLBD and ES-LBD,respectively(P=0.13).There was no significant difference between EPLBD and ES-LBD in the incidence of stone recurrence[20(11.9%)vs.9(15.8%);P=0.49].Multivariate analysis showed that a diameter of CBD≥15 mm(OR=3.001;95%CI:1.357-6.640;P=0.007)was an independent risk factor for stone ***:The application of a large balloon(12-15 mm)via EPLBD is an effective and safe alternative to ES-LBD for extraction of large CBD *** sphincterotomy prior to EPLBD may be unnec-essary.A diameter of CBD≥15 mm is a risk factor of stone recurrence.

关键词： Endoscopic papillary large-balloon dilation Endoscopic sphincterotomy Bile duct stone

Surface decoration of mesocarbon microbeads with multifunctional TiNbO_(4-x)@C coating layer as high rate and stable anode of li-ion batteries

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Rare Metals 2024年第5期43卷 2053-2066页

作者： jia-Mei Lai Zhi-Min Zou Yu Bai Yu-Tao xing Chun-Hai jiang Fujian Provincial Key Laboratory of Functional Materials and Applications Institute of Advanced Energy MaterialsSchool of Materials Science and EngineeringXiamen University of TechnologyXiamen 361024China Shanghai XFH Science and Technology Development Co. Ltd.Shanghai 200949China Fujian XFH New Energy Materials Co. Ltd.Yong'an 366000China Shenzhen XFH Science and Technology Co. Ltd.Shenzhen 518071China Laboratorio de Microscopia Eletronica de Alta Resolucao Centro de Caracterizagao Avangada Para a Industria de Petroleo(LaMAR/CAIPE)Universidade Federal FluminenseNiteroiRJ 24210-346Brazil

Surface modification of graphite anode with electroactive matters has been proven of a more practical strategy in enhancing the performance of li-ion batteries than exploring alternative novel anode ***,rutile TiNbO_(4-x) nanoparticles with a tunnel structure are employed as multifunctional decoration substances in combination with a carbon coating layer to improve the rate and cycle properties of mesocarbon microbeads(MCMBs).As compared to pristine MCMB,the li^(+)diffusion coefficients of the composite anodes are enhanced due to the synergistic effect of TiNbO_(4-x)@***,the overcharge and voltage polarization of the composite anodes at high rate are obviously minimized due to the current sharing effect of the high-potential TiNbO_(4-x).Moreover,the amorphous li_(y)TiNbO_(4-x) converted from TiNbO_(4-x) in the initial lithiation process can deliver pseudocapacitive capacity to the composite anodes from the second *** of these functions of TiNbO_(4-x)@Ccoating layer have directly contributed to the improved rate and cycle performance of the MCMB/TiNbO_(4-x)@C composite *** one containing 12.0 wt%TiNbO_(4-x) exhibits a high reversible specific capacity of 118 m Ah·g^(-1)at 10C(1C=372 m A·g^(-1)),together with a high capacity retention of 90.9%after 300 cycles at 3C,which are all much superior to those of pristine MCMB.

关键词： li-ion batteries MCMB TiNbO_(4-x)@C Surface decoration Rate capability

Effects of combustion temperature on the optical properties of brown carbon from biomass burning

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Journal of Environmental Sciences 2024年第3期137卷 302-309页

作者： Peng Gao Rule Deng Song jia Yue li Xuefei Wang Qian xing School of Chemistry Sciences University of Chinese Academy of SciencesBeijing 100049China College of Chemistry and Materials Engineering Beijing Technology and Business UniversityBeijing 100048China

Biomass burning has been known as one of main sources of Brown Carbon(BrC)in *** this study,by controlling the combustion temperature at 250℃,350℃,and 450℃,the methanol soluble organic carbon(MSOC)and methanol insoluble carbon(MISC)from pine wood burning was collected by ***–Vis,excitation emission matrix(EEM),TEM and FTIR spectra were applied to investigate the properties of BrC *** MSOC at 250℃ and 350℃,all the spectral profiles of UV–Vis absorption and excitation emission matrix are almost the same,while the EEM of MSOC at 450℃ are different from that of the other *** MISC fuorescence was observed only in the case of 450℃.In the FTIR spectra,with the temperature increasing the peaks associated to the oxygen-contained functions was weakened,indicating the formation of the fuorophores with larger conjugated system,especially aromatic *** results show that biomass combustion at low temperature produces more oxygen-riched BrC,which possesses relatively lower light absorption,while at high temperature produces more aromatics hydrocarbons with relatively strong light *** results of this work are helpful to trace the source of brown carbon and optimize biomass energy utilization.

关键词： Biomass burning Combustion temperature Methanol-soluble brown carbon EEM Impinger

High-sensitive state perception method for inverter-fed machine turn insulation based on FrFT-Mel

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Global Energy Interconnection 2024年第2期7卷 155-165页

作者： Ruitian Fan xing Lei Tao jia Menglong Qin Hao li Dawei Xiang College of Electrical Power Engineering Shanghai University of Electric PowerShanghai 200090P.R.China State Grid Shanghai Municipal Electric Power Company Shanghai 200437P.R.China State Grid Technology College Shandong 250002P.R.China College of Electronics and Information Engineering Tongji UniversityShanghai 201804P.R.China

Amidst the swift advancement of new power systems and electric vehicles,inverter-fed machines have progressively materialized as a pivotal apparatus for efficient energy *** winding turn insulation failure is the root cause of inverter-fed machine *** online monitoring of turn insulation health can detect potential safety risks promptly,but faces the challenge of weak characteristics of turn insulation *** study proposes an innovative method to evaluate the turn insulation state of inverter-fed machines by utilizing the fractional Fourier transform with a Mel filter(FrFT-Mel).First,the sensitivity of the high-frequency(HF)switching oscillation current to variations in turn insulation was analyzed within the fractional ***,an improved Mel filter is introduced,and its structure and parameters are specifically designed based on the features intrinsic to the common-mode impedance resonance point of the electrical ***,an evaluation index was proposed for the turn insulation state of inverter-fed *** results on a 3kW permanent magnet synchronous machine(PMSM)demonstrate that the proposed FrFT-Mel method significantly enhances the sensitivity of turn insulation state perception by approximately five times,compared to the traditional Fourier transform method.

关键词： State perception Turn insulation Switching oscillation Fractional Fourier transform Mel filter

Challenges in li-ion battery high-voltage technology and recent advances in high-voltage electrolytes

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Journal of Energy Chemistry 2024年第4期91卷 73-98页

作者： jianguo liu Baohui li Jinghang Cao Xiao xing Gan Cui Shandong Key Laboratory of Oil&Gas Storage and Transportation Safety College of Pipeline and Civil EngineeringChina University of Petroleum(East China)Qingdao 266580ShandongChina

The electrolyte directly contacts the essential parts of a lithium-ion battery,and as a result,the electrochemical properties of the electrolyte have a significant impact on the voltage platform,charge discharge capacity,energy density,service life,and rate discharge *** raising the voltage at the charge/discharge plateau,the energy density of the battery is ***,this causes transition metal dissolution,irreversible phase changes of the cathode active material,and parasitic electrolyte oxidation *** article presents an overview of these concerns to provide a clear explanation of the issues involved in the development of electrolytes for high-voltage lithium-ion ***,solidstate electrolytes enable various applications and will likely have an impact on the development of batteries with high energy *** is necessary to improve the high-voltage performance of electrolytes by creating solvents with high thermal stabilities and high voltage resistance and additives with superior film forming performance,multifunctional capabilities,and stable lithium *** offer suggestions for the future development of high-energy lithium-ion batteries,we conclude by offering our own opinions and insights on the current development of lithium-ion batteries.

关键词： lithium-ion battery High voltage Electrolyte additive Solid electrolyte

Simultaneous Bulk-and Surface-initiated living Polymerization Studied with a Heterogeneous Stochastic Reaction Model

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Chinese Journal of Polymer Science 2024年第3期42卷 364-372,I0008页

作者： jia-Shu Ma Zhi-Ning Huang jia-Hao li Bang-Ping jiang Yan-Da liao Shi-Chen Ji xing-Can Shen State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources(Ministry of Education of China)School of Chemistry and Pharmaceutical SciencesGuangxi Normal UniversityGuilin 541004China School of Computer Science and Engineering&School of Software Guangxi Normal UniversityGuilin 541004China

To better characterize the properties of surface-initiated polymers, simultaneous bulk-and surface-initiated polymerizations are usually carried out by assuming that the properties of the surface-initiated polymers resemble those of the bulk-initiated polymers. Through a Monte Carlo simulation using a heterogeneous stochastic reaction model, it was discovered that the bulk-initiated polymers exhibit a higher molecular weight and a lower dispersity than the corresponding surface-initiated polymers, which indicates that the equivalent assumption is invalid. Furthermore, the molecular weight distributions of the two types of polymers are also different, suggesting different polymerization mechanisms. The results can be simply explained by the heterogeneous distributions of reactants in the system. This study is helpful to better understand surface-initiated polymerization.

关键词： Surface-initiated polymerization Polymer brush Stochastic reaction model Heterogeneous polymerization Simultaneous polymerization

Vocal repertoire of the critically endangered whiteheaded langur(Trachypithecus leucocephalus): Call types, acoustic structures, and related social-ecological contexts

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Zoological Research 2022年第5期43卷 875-879页

作者： Peng-Lai Fan jia-xing li li-Ting Yang Tao Sun Shi-Jun Wu Cyril CGrueter Cheng-Ming Huang Qi-Hai Zhou Ming li CAS Key Lab Animal Ecology&Conservation Biology Institute of ZoologyChinese Academy of SciencesBeijing 100101China Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection(Guangxi Normal University) Ministry of EducationGuilinGuangxi 541006China Guangxi Key Laboratory of Rare and Endangered Animal Ecology College of Life SciencesGuangxi Normal UniversityGuilinGuangxi 541006China Guangxi Chongzuo White-headed Langur National Nature Reserve ChongzuoGuangxi 532200China Department of Anatomy Physiologyand Human BiologySchool of Human SciencesUniversity of Western AustraliaPerth WA 6009Australia Centre for Evolutionary Biology School of Biological SciencesUniversity of Western AustraliaPerth WA 6009Australia International Center of Biodiversity and Primate Conservation Dali UniversityDaliYunnan 671003China Center for Excellence in Animal Evolution and Genetics Chinese Academy of SciencesKunmingYunnan 650223China

DEAR EDITOR,We examined the vocal repertoire of the critically endangered white-headed langur(Trachypithecus leucocephalus)inhabiting karst limestone forests in *** identified 17 call types across all age/sex classes based on human auditory perception,spectrogram assessment,and quantitative analysis of 25 acoustic parameters extracted from 409 high-quality *** total,11 types of calls produced by adults corresponded to the simple one-male multi-female social groups of white-headed langurs.

关键词： white critically karst