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Inter-stage performance and energy characteristics analysis of electric submersible pump based on entropy production theory

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Petroleum Science 2024年第2期21卷 1354-1368页

作者： hui wang Yang Yang Bin Xi Wei-Dong Shi Chuan wang Lei-Lei Ji Xiang-Yu Song zhao-Ming He College of Hydraulic Science and Engineering Yangzhou UniversityYangzhou225009JiangsuChina College of Electrical and Mechanical Engineering Nanchang Institute of TechnologyNanchang330044JiangxiChina College of Mechanical Engineering Nantong UniversityNantong226019JiangsuChina National Research Center of Pumps Jiangsu UniversityZhenjiang212013JiangsuChina Zhejiang Zhenxing Petrochemical Machinery Co. Ltd.Ruian325204ZhejiangChina Department of Mechanical Engineering of Texas Tech University Lubbock79411TXUSA

The electric submersible pump(ESP) is a crucial apparatus utilized for lifting in the oil extraction *** lifting capacity is enhanced by the multi-stage tandem structure, but variations in energy characteristics and internal flow across stages are also introduced. In this study, the inter-stage variability of energy characteristics in ESP hydraulic systems is investigated through entropy production(EP) analysis,which incorporates numerical simulations and experimental validation. The EP theory facilitates the quantification of energy loss in each computational subdomain at all ESP stages, establishing a correlation between microscopic flow structure and energy dissipation within the system. Furthermore, the underlying causes of inter-stage variability in ESP hydraulic systems are examined, and the advantages and disadvantages of applying the EP theory in this context are evaluated. Consistent energy characteristics within the ESP, aligned with the distribution of internal flow structure, are provided by the EP theory, as demonstrated by our results. The EP theory also enables the quantitative analysis of internal flow losses and complements existing performance analysis methods to map the internal flow structure to hydraulic losses. Nonetheless, an inconsistency between the energy characterization based on EP theory and the traditional efficiency index when reflecting inter-stage differences is identified. This inconsistency arises from the exclusive focus of the EP theory on flow losses within the flow field, disregarding the quantification of external energy input to the flow field. This study provides a reference for the optimization of EP theory in rotating machinery while deeply investigating the energy dissipation characteristics of multistage hydraulic system, which has certain theoretical and practical significance.

关键词： Electric submersible pump(ESP) Entropy production theory Energy characteristics Inter-stage differences

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Effects of N Forms and Rates on Vegetable Growth and Nitrate Accumulation

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Pedosphere 2003年第4期13卷 309-316页

作者： wang zhao-hui and LI Sheng-XiuCollege of Resources and Environmental Sciences, Northwestern Science and Technology University of Agriculture and Forestry, Yangling 712100 (China). E-mail: w-zhaohui@*** College of Resources and Environmental Sciences Northwestern Science and Technology University of Agriculture and Forestry Yangling 712100 (China)

Experiments were carried out on a vegetable field with Peking cabbage(Brassica pekinensis (Lour.) Rupr.), cabbage (Brassica, chinensis var. oleifcra Makino and nemoto),green cabbage (Brassica chinensis L.), spinach (Spinacia oleracea L.) and rape(Brassica campestrisL.) to study the effects of N forms and N rates on their growth and nitrate accumulation. Theresults indicated that application of ammonium chloride, ammonium nitrate, sodium nitrate and ureasignificantly increased the yields and nitrate concentrations of Peking cabbage and *** no significant difference was found in the yields after application of the 4 N forms,nitrate N increased nitrate accumulation in vegetables much more than ammonium N. The vegetableyields were not increased continuously with N rate increase, and oversupply of N reduced the plantgrowth, leading to a yield decline. This trend was also true for nitrate concentrations in somevegetables and at some sampling times. However, as a whole, the nitrate concentrations in vegetableswere positively correlated with N rates. Thus, addition of N fertilizer to soil was the major causefor increases in nitrate concentrations in vegetables. Nitrate concentrations were much higher inroots, stems and petioles than in blades at any N rate.

关键词： N form N rate nitrate accumulation vegetable yield

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Butterfly taxonomic and functional diversity in the urban green spaces of Hefei city

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Journal of Forestry Research 2024年第5期35卷 47-62页

作者： Haicong Zeng Yan Zhu Junyao Zhang Chenliang Li Jian Zhang hui Liu Jianan wang Dexian zhao The College of Forestry and Landscape Architecture Anhui Agricultural UniversityHefei 230036People’s Republic of China Anhui Hefei Urban Ecosystem National Observation and Research Station Hefei 230036People’s Republic of China School of Urban Construction Anhui Xinhua UniversityHefei 230001People’s Republic of China

Urbanization has profound impacts on ecological environments. Green spaces are a vital component of urban ecosystems and play a crucial role in maintaining ecological balance and enhancing sustainability. This study aimed to investigate the community composition characteristics of butterflies in urban green spaces within the context of rapid urbanization. Simultaneously, it explored the status and differences in butterfly taxonomic diversity, functional diversity, and functional traits among different types of urban green spaces, regions, and urban gradients to provide relevant insights for further improving urban green space quality and promoting biodiversity conservation. We conducted a year-long survey of 80 green spaces across different urban regions and ring roads within Hefei City, Anhui Province, with monthly sampling intervals over 187 transects. A total of 4822 butterflies, belonging to 5 families, 17 subfamilies, 40 genera, and 55 species were identified. The species richness, Shannon, Simpson, functional richness, and Rao's quadratic entropy indices of butterflies in urban park green spaces were all significantly higher than those in residential and street green spaces(P < 0.05). Differences in butterfly diversity and functional traits among different urban regions and ring roads were relatively minor, and small-sized, multivoltine, and long flying duration butterflies dominated urban green spaces. Overall, these spaces offer more favorable habitats for butterflies. However, some residential green spaces and street green spaces demonstrate potential for butterfly conservation.

关键词： Urban green space planning Rapid urbanization Butterfly functional traits Green space types Urban biodiversity

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Microstructure evolution and mechanical properties of brazing joint for ultra-thin-walled Inconel 718 considering grain size effect and brazing temperature

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Chinese Journal of Aeronautics 2024年第2期37卷 541-556页

作者： Rui zhao Yueshuai SONG hui KANG Min WAN School of Mechanical Engineering and Automation Beihang UniversityBeijing 100191China Jiangxi Research Institute of Beihang University Jiangxi 330000China

The systematic investigation of the mechanical properties and microstructure evolution process of ultra-thin-walled Inconel 718 capillary brazing joints is of great significance because of the exceptionally high demands on its *** achieve this objective,this study investigates the impact of three distinct brazing temperatures and five typical grain sizes on the brazed joints’mechanical properties and microstructure evolution *** evolution analysis was conducted based on Electron Back Scatter Diffraction(EBSD),Scanning Electron Microscopy(SEM),X-Ray Diffraction(XRD),High-Resolution Transmission Electron Microscopy(HRTEM),and Focused Ion Beam(FIB).Besides,the mechanical properties and fracture behavior were studied based on the uniaxial tension tests and in-situ tension *** findings reveal that the brazing joint’s strength is higher for the fine-grain capillary than the coarse-grain one,primarily due to the formation of a dense branch structure composed of G-phase in the brazing *** effects of grain size,such as pinning and splitting,are amplified at higher brazing ***,micro-cracks initiate around brittle intermetallic compounds and propagate through the eutectic zone,leading to a cleavage fracture *** fracture stress of fine-grain specimens is higher than that of coarse-grain due to the complex micro-crack ***,this study contributes significantly to the literature by highlighting the crucial impact of grain size on the brazing properties of ultra-thin-walled Inconel 718 structures.

关键词： EYWORDS Ultra-thin-walled structure Brazing Inconel 718 Grain size effect Brazing temperature

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Formation of free-surface vortex and vortex suppression by rotating stopper-rod at end of tundish casting

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Journal of Iron and Steel Research International 2024年第5期31卷 1104-1116页

作者： Qing Fang Peng zhao Hua Zhang Wen-hao Zhou Gang Yu Jia-hui wang Hong-wei Ni The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan430081HubeiChina Hunan Valin Xiangtan Iron and Steel Co. Ltd.Xiangtan411101HunanChina Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking Wuhan University of Science and TechnologyWuhan430081HubeiChina

A rotating stopper-rod technique was proposed to suppress the formation of free-surface vortex in the *** large eddy simulation model coupled with volume of fluid model was developed to study the steel–slag–gas three-phase flow *** critical slag entrapment height of the free-surface vortex and mass of residual steel were predicted at different rotating speeds(30,60,90 and 120 r/min)of the rotating *** numerical model was verified by water model *** results showed that by rotating the stopper-rod in the opposite direction of the vortex above the submerged entry nozzle,the formation of vortex can be effectively disturbed and the critical height of the free-surface vortex can be *** for the 2nd strand,when the rotating speeds are 30,60,90 and 120 r/min,the critical height of the free-surface vortex above the 2nd strand is 7.3,4.7,6.3 and 7.4 cm,respectively.A reasonable rotating speed should be 60 r/min,which can reduce about 2 tons of residual *** rotating speeds just can reduce about 1.6 tons of residual steel.

关键词： Tundish Free-surface vortex Stopper-rod Numerical simulation Multiphase flow

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Flexible and multifunctional triboelectric nanogenerator based on liquid metal/polyvinyl alcohol hydrogel for energy harvesting and self-powered wearable human-machine interaction

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Rare Metals 2024年第3期43卷 1186-1196页

作者： Hou-wang Zhou Cong zhao Ze-Yu zhao Jun-Chen Jiang hui-Le Jin Shun wang Shuang Pan Min-Yi Xu Yi-Huang Chen Hai-Ming Jin Department of Orthopaedics The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical UniversityWenzhou325027China College of Chemistry and Materials Engineering Wenzhou UniversityWenzhou325035China Dalian Key Laboratory of Marine Micro/Nano Energy and Self-Powered Systems Marine Engineering CollegeDalian Maritime UniversityDalian116026China

Hydrogel-based triboelectric nanoge nerator(TENG)has a promising applied prospect in wearable electronic ***,its low performance,poor stability,insufficient recyclability and inferior self-healing seriously hinder its ***,we report a robust route to a liquid metal(LM)/polyvinyl alcohol(PVA)hydrogel-based TENG(LP-TENG).Owing to the intrinsically liquid feature of conductive LM within the flexible PVA hydrogel,the as-prepared LP-TENG exhibited comprehensiye advantages of adaptability,biocompatibility,outstanding electrical performance,superior stability,recyclability and diverse applications,which were unattainable by traditional ***,the LP-TENG delivered appealing open circuit voltage of 250 V,short circuit current of 4μA and transferred charge of 120 nC with high stability,outperforming most advanced TENG *** LP-TENG was successfully employed for versatile applications with multifunctionality,including human motion detection,handwriting recognition,energy collection,message transmission and human-machine *** work presents significant prospects for crafting advanced materials and devices in the fields of wearable electronics,flexible skin and smart robots.

关键词： Liquid metal Hydrogel Wearable TENG Multifunctionality Human-machine interaction

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Organic ligand nanoarchitectonics for BiVO_(4) photoanodes surface passivation and cocatalyst grafting

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Nano Research 2024年第5期17卷 3667-3674页

作者： Jingyi Lin Xin Li Zhiliang wang Runlu Liu hui Pan Yixin zhao Lingti Kong Yao Li Shenmin Zhu Lianzhou wang State Key Laboratory of Metal Matrix Composites School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China Nanomaterials Centre School of Chemical Engineering and Australian Institute for Bioengineering and Nanotechnologythe University of QueenslandQLD 4072Australia School of Environmental Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China Hubei Key Laboratory of Plasma Chemistry and Advanced Materials Wuhan Institute of TechnologyWuhan 430205China

Bismuth vanadate(BiVO_(4))is a promising photoanode material for efficient photoelectrochemical(PEC)water splitting,whereas its performance is inhibited by detrimental surface *** solve the problem,herein,a low-cost organic molecule 1,3,5-benzenetricarboxylic acid(BTC)is selected for surface passivation of BiVO_(4) photoanodes(BVOs),which also provides bonding sites for Co^(2+)to anchor,resulting in a Co-BTC-BVO *** to its strong coordination with metal ions,BTC not only passivates surface states of BVO,but also provides bonding between BVO and catalytic active sites(Co^(2+))to form a molecular *** study and interfacial charge kinetic investigation reveal that chemical bonding formed at the interface greatly suppresses charge recombination and accelerates charge *** obtained Co-BTC-BVO photoanode exhibits a photocurrent density of 4.82 mA/cm^(2) at 1.23 V *** hydrogen electrode(RHE)and a low onset potential of 0.22 VRHE under AM 1.5 G illumination,which ranks among the best photoanodes coupled with Co-based *** work presents a novel selection of passivation layers and emphasizes the significance of interfacial chemical bonding for the construction of efficient photoanodes.

关键词： bismuth vanadate photoanode water splitting surface passivation bridging ligands

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Light People:Professor Manijeh Razeghi

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Light(Science & Applications) 2024年第8期13卷 1451-1462页

作者： hui wang Cun Yu Changchun Institute of Optics Fine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China

The sense of light is the first sensation the human body *** importance of light is ***,we all know that the light we can see and perceive covers only a small section of the ***,for Light People,we feature a researcher who is committed to exploring different spectral bands of light ranging from deep ultraviolet to terahertz waves and working on quantum semiconductor technology,*** Razeghi of the Northwestern University in the United *** for her quick thinking and witty remarks,*** is passionate about life and always kind to *** a scientist,she does not limit her research to a single focus,instead,she works on the entire process from material selection,device design,processing,and manufacturing,all the way to product *** has a strong passion for education,a commitment unwavered by fame or *** her students,she is both a reliable source of knowledge and a motherly figure with a caring *** firmly believes that all things in nature can give her energy and *** science,she is a true“pioneer”in research and a“miner”of scientific *** advises young scientists to enjoy and love what they do,and turn their research into their *** a female scientist,she calls on all women to realize their true value and ***,let’s hear from Professor Manijeh Razeghi,a true star who radiates energy and light.

关键词： mother instead passion

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Tirofiban combined with Aspirin in the Treatment of Acute Penetrating Artery Territory Infarction (STRATEGY): protocol for a multicentre, randomised controlled trial

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Stroke & Vascular Neurology 2024年第1期9卷 75-81,I0047-I0052页

作者： Xiaoling Liao Shuo Feng Yicong wang Yuesong Pan Weiqi Chen hui Qu Xingquan zhao Liping Liu Yongjun wang Yilong wang Department of Neurology Beijing Tiantan HospitalCapital Medical UniversityBeijingChina China National Clinical Research Center for Neurological Diseases Beijing TiantanHospitalCapital Medical UniversityBeijingChina Chinese Institute for Brain Research BeijingChina National Center for Neurological Diseases BeijingChina Advanced Innovation Center for Human Brain Protection Capital Medical UniversityBeijingChina Beijing Laboratory of Oral Health Capital Medical UniversityBeijingChina

Background Perforating artery territorial infarction(PAI)caused by branch atheromatous disease(BAD)is prone to recurrence and early progression without an effective and well-documented antiplatelet treatment ***,an adjunctive antiplatelet agent,has shown great potential to treat acute ischaemic ***,whether the combination of tirofiban and aspirin can improve the prognosis of PAI remains *** To explore an effective and safe antiplatelet regimen for reducing the risk of recurrence and early neurological deterioration(END)in PAI caused by BAD by comparing the tirofiban and aspirin combination with placebo and aspirin *** Tirofiban combined with Aspirin in the Treatment of Acute Penetrating Artery Territory Infarction(STRATEGY)trial is an ongoing multicentre,randomised,placebo-controlled trial in *** patients shall be randomly assigned to receive standard aspirin with tirofiban or placebo on the first day and standard aspirin from days 2 to *** primary endpoint is a new stroke or END within 90 *** primary safety endpoint is severe or moderate bleeding within 90 *** The STRATEGY trial will assess whether tirofiban combined with aspirin is effective and safe in preventing recurrence and END in patients with *** registration number NCT05310968.

关键词： Aspirin regimen centre

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Experimental Study of Electrical‑Assisted Nanomachining of Monocrystalline Copper Using Customized Tungsten Tip

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Nanomanufacturing and Metrology 2024年第2期7卷 60-75页

作者： Tao wang Yanling Tian Zhilai Lu Weijie wang zhao Zhang Guangwei Zhu hui Tang Dawei Zhang Key Laboratory of Mechanism Theory and Equipment Design of Ministry of Education Tianjin UniversityTianjin 300072China School of Engineering University of WarwickCoventry CV47ALUK State Key Laboratory of High Performance Complex Manufacturing Central South UniversityChangsha 410083China State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment Guangdong University of TechnologyGuangzhou 510006China

As a promising micro/nanofabrication method,electrical-assisted nanomachining has obtained substantial attention due to its high material removal rate and attainable superior surface *** this study,a rectangular wave electrical signal was applied for nanomachining by a customized tungsten *** to the coupling effect between the electric field and mechanical force,the cutting depth of the machined grooves can be *** electrical-assisted groove processing,a depth of 270 nm and an aspect ratio of 0.6 on the copper sample can be *** influence of operation parameters including applied voltage,frequency,duty ratio,normal force and cutting speed on the machining performance was investigated in terms of the groove depth,width,aspect ratio,and surface *** potential machining mechanisms should be a combination of electric field force,nanoscale electric discharge,electric contact thermal effects,possible annealing behavior,and scraping and plowing actions induced by mechanical forces.

关键词： Tip-based nanofabrication Electrical-assisted machining Nanoscale scratching Machining parameters

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