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Visualization Experiments of a Specific Fuel Flow Through Quartz-glass Tubes Under both Sub- and Supercritical Conditions

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Chinese Journal of Aeronautics 2012年第3期25卷 372-380页

作者： DENG Hongwu zhang Chunben XU Guoqiang tao Zhi ZHU kun wang Yingjie National Key Laboratory of Science and Technology on Aero-Engine Aero-thermodynamics School of Jet Propulsion Beihang University Beo'ing 100191 China Xi'an Aerospace Propulsion Institute Xi 'an 710100 China

The present work is a visualization study of a typical kerosene （RP-3） flowing through vertical and horizontal quartz-glass tubes under both sub- and supercritical conditions by a high speed camera. The experiments are accomplished at temperatures of 300-730 K under pressures from 0.107-5 MPa. Six distinctive two-phase flow patterns are observed in upward flow and the critical point of RP-3 is identified as critical pressure pc=2.33 MPa and critical temperature Tc=645.04 K and it is found that when the fluid pressure exceeds 2.33 MPa the flow can be considered as a single phase flow. The critical opalescence phenomenon of RP-3 is observed when the temperature is between 643.16 K and 648.61 K and the pressure is between 2.308 MPa and 2.366 MPa. The region filled by the critical opalescence in the upward flow is clearly larger than that in the downward flow due to the interaction between the buoyancy force and fluid inertia. Morecover, obvious layered flow phenomenon is observed in horizontal flow under supercritical pressures due to the differences of gravity and density.

关键词： visualization flow patterns critical opalescence supercritical layered fuel

Photocatalyst-controlled and visible light-enabled selective oxidation of pyridinium salts

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Science China Chemistry 2021年第5期64卷 753-760页

作者： xiang-Jun Peng Hai-Ping He qian Liu kun She Bao-qi zhang Heng-Shan wang Hai-tao Tang Ying-Ming Pan State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources School of Chemistry and Pharmaceutical Sciences of Guangxi Normal UniversityGuilin 541004China Key Laboratory of Prevention and Treatment of Cardiovascular and Cerebrovascular Diseases of Ministry of Education Gannan Medical UniversityGanzhou 341000China

This study proposes two different methods of photocatalytic-controlled and visible light-induced selective oxidation of pyridiniums with air as the terminal *** key to these transformations is to choose the appropriate light source and *** are successfully converted into pyrroles through oxygen-mediated cycloaddition,proton-coupled electron transfer(PCET),pyridine ring opening,and *** other route is that pyridiniums selectively form 4-carbonyl pyridines through free radical rearrangement/aerobic oxidation under the catalysis of cobalt(Ⅱ).

关键词： photocatalytic-controlled reaction proton-coupled electron transfer ring opening/recyclization process rearrangement/aerobic oxidation the Ladenburg rearrangement pyridinium

Alternative splicing and related RNA binding proteins in human health and disease

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Signal Transduction and Targeted Therapy 2024年第3期9卷 839-871页

作者： Yining tao qi zhang Haoyu wang Xiyu Yang Haoran Mu Department of Orthopedics Shanghai General HospitalShanghai Jiao Tong University School of Medicine200000 ShanghaiChina Shanghai Bone Tumor Institution 200000 ShanghaiChina Department of Biochemistry and Molecular Cell Biology Shanghai Key Laboratory for Tumor Microenvironment and InflammationShanghai Jiao Tong University School of Medicine200000 ShanghaiChina

Alternative splicing(AS)serves as a pivotal mechanism in transcriptional regulation,engendering transcript diversity,and modifications in protein structure and *** varying tissues,developmental stages,or under specific conditions,AS gives rise to distinct splice *** implies that these isoforms possess unique temporal and spatial roles,thereby associating AS with standard biological activities and *** these,AS-related RNA-binding proteins(RBPs)play an instrumental role in regulating alternative splicing *** physiological conditions,the diversity of proteins mediated by AS influences the structure,function,interaction,and localization of proteins,thereby participating in the differentiation and development of an array of tissues and *** pathological conditions,alterations in AS are linked with various diseases,particularly *** changes can lead to modifications in gene splicing patterns,culminating in changes or loss of protein *** instance,in cancer,abnormalities in AS and RBPs may result in aberrant expression of cancer-associated genes,thereby promoting the onset and progression of *** and RBPs are also associated with numerous neurodegenerative diseases and autoimmune ***,the study of AS across different tissues holds significant *** review provides a detailed account of the recent advancements in the study of alternative splicing and AS-related RNA-binding proteins in tissue development and diseases,which aids in deepening the understanding of gene expression complexity and offers new insights and methodologies for precision medicine.

关键词： organs alterations thereby

Effects of MOx(M=Mn,Cu,Sb,La)on V-Mo-Ce/Ti selective catalytic reduction catalysts

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Journal of Rare Earths 2020年第2期38卷 157-166页

作者： Daojun zhang Ziran Ma Baodong wang qi Sun Wenqiang Xu tao Zhu State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China National Institute of Clean-and-Low-Carbon Energy Beijing 102211China School of Chemical&Environmental Engineering China University of Mining&Technology(Beijing)Beijing 100083China

A series of MOx-V2O5-MoO3-CeO2/TiO2(M=Mn,Cu,Sb,and La) catalysts were prepared via an impregnation *** physico-chemical properties of the catalysts were characterized and their NH3-SCR of NO performance was *** Mn-loaded catalyst(Mn5V1Mo3Ce7/Ti) exhibits a large number of acid sites of varying strength,and together with good reducibility of the catalyst,contributes to the optimal SCR *** sulphate species formed in the presence of SO2 significantly enhance the H2O and SO2 tolerance of Mn5V1Mo3Ce7/*** Cu-loaded catalyst(Cu5V1Mo3Ce7/Ti)demonstrates potential in flue gas applications in the absence of SO2 at low temperatures because of the excellent redox ability observed and the high degree of weak acid *** Sb and La loaded catalysts(Sb5V1Mo3Ce7/Ti and La5V1Mo3Ce7/Ti),especially La5V1Mo3 Ce7/Ti,exhibit the largest number of acid sites and the lowest reducibility,and therefore,may be suitable for use in high temperature denitrification applications.

关键词： Selective catalytic reduction Vanadium Manganese Copper Antimony Rare earths

Investigation of the Corrosion and Passive Behavior of HP-13Cr Stainless Steel in Formate Annulus Protection Fluid

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Acta Metallurgica Sinica(English Letters) 2024年第6期37卷 1087-1103页

作者： Jidong wang Tengfei Yin Wenlong qi Xuanpeng Li Yang Zhao tao zhang Fuhui wang Shenyang National Laboratory for Materials Science Northeastern UniversityShenyang110819China State Key Laboratory of Performance and Structural Safety for Petroleum Tubular Goods and Equipment Materials Tubular Goods Research InstituteCNPCXi’an710077China

The corrosion and passive behavior of HP-13Cr stainless steel(HP-13Cr SS)in formate annulus protection fluid was ***-13Cr SS exhibited good passive behavior in clean formate annulus protection fluid,which was attributed to a thinner and more dense passive film mainly composed of Cr_(2)O_(3).In the formation water solution,the passive film was composed of metastable Cr(OH)3,which was explained by the isoelectric point theory,resulting in the deterioration of the passive behavior of HP-13Cr *** the formation water penetrated the formate annulus protection fluid,a large number of loose FeCO_(3)particles formed in the corrosion scales,thus HP-13Cr SS suffered severe ***,avoiding formation water penetrating the formate annulus protection fluid is conducive to improving the service life of HP-13Cr SS oil tubes in extremely aggressive environment.

关键词： HP-13Cr SS Passive behavior Formate annulus protection fluid Isoelectric point

Analysis of gas transport behavior in organic and inorganic nanopores based on a unified apparent gas permeability model

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Petroleum Science 2020年第1期17卷 168-181页

作者： qi zhang Wen-Dong wang Yilihamu Kade Bo-tao wang Lei Xiong Key Laboratory of Tectonics and Petroleum Resources China University of GeosciencesWuhan 430074HubeiChina School of Petroleum Engineering China University of Petroleum(East China)Qingdao 266580ShandongChina Institute of Ground Engineering Engineering Technology Research Institute of PetroChina Xinjiang Oilfield CompanyKaramay 834000XinjiangChina Oil Production Plant 5 of PetroChina Changqing Oilfield Company Changqing OilfieldXi’an 710200ShaanxiChina Oil Production Plant 1 of PetroChina Xinjiang Oilfield Company Karamay 834000XinjiangChina

Different from the conventional gas reservoirs,gas transport in nanoporous shales is complicated due to multiple transport mechanisms and reservoir *** this work,we presented a unified apparent gas permeability model for real gas transport in organic and inorganic nanopores,considering real gas effect,organic matter(OM)porosity,Knudsen diffusion,surface diffusion,and stress ***,the effects of monolayer and multilayer adsorption on gas transport are ***,we validated the model by experimental *** influences of pore radius,pore pressure,OM porosity,temperature,and stress dependence on gas transport behavior and their contributions to the total apparent gas permeability(AGP)were *** results show that the adsorption effect causes Kn(OM)>Kn(IM)when the pore pressure is larger than 1 MPa and the pore radius is less than 100 *** ratio of the AGP over the intrinsic permeability decreases with an increase in pore radius or pore *** nanopores with a radius of less than 10 nm,the effects of the OM porosity,surface diffusion coefficient,and temperature on gas transport cannot be ***,the surface diffusion almost dominates in nanopores with a radius less than 2 nm under high OM porosity *** the small-radius and low-pressure conditions,gas transport is governed by the Knudsen diffusion in *** study focuses on revealing gas transport behavior in nanoporous shales.

关键词： Gas transport Apparent gas permeability model Gas adsorption Surface diffusion Stress dependence

Modeling and Parameter Sensitivity Analysis of Valve‑Controlled Helical Hydraulic Rotary Actuator System

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Chinese Journal of Mechanical Engineering 2022年第6期35卷 257-274页

作者： kun zhang Junhui zhang Minyao Gan Huaizhi Zong Ximeng wang Hsinpu Huang qi Su Bing Xu State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310027China Shanghai Marine Equipment Research Institute Shanghai 200031China

As a type of hydraulic rotary actuator,a helical hydraulic rotary actuator exhibits a large angle,high torque,and compact structure;hence,it has been widely used in various ***,its core technology is proprietary to several companies and thus has not been ***,the relevant reports are primarily limited to the component *** dynamic characteristics of the output when a helical rotary actuator is applied to a closed-loop system are investigated from the perspective of driving system *** main aspects are considered:one is to establish a reliable mathematical model and the other is to consider the effect of system parameter perturbation on the *** this study,a detailed mechanical analysis of a helical rotary hydraulic cylinder is first performed,factors such as friction and load are considered,and an accurate dynamic model of the actuator is ***,considering the nonlinear characteristics of pressure flow and the dynamic characteristics of the valve,a dynamic model of a valve-controlled helical rotary actuator angle closed-loop system is described based on sixth-order nonlinear state equations,which has never been reported *** deriving the system model,a sensitivity analysis of 23 main parameters in the model with a perturbation of 10%is performed under nine operating ***,the system dynamics model and sensitivity analysis results are verified via a prototype experiment and co-simulation,which demonstrate the reliability of the theoretical results obtained in this *** results provide an accurate mathematical model and analysis basis for the structural optimization or control compensation of similar systems.

关键词： Helical hydraulic rotary actuator Dynamic model Closed-loop system Sensitivity analysis Prototype experiment Co-simulation

Full-scale site evaluation of ventilation expressway embankments underlain by warm permafrost along the Gonghe−Yushu Expressway

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Frontiers of Structural and Civil Engineering 2023年第7期17卷 1047-1059页

作者： Shuangjie wang qi zhang Yuanhong DONG kun YUAN Binhua HU Huilong ZHAO Nanlu ZHAO CCCC First Highway Consultants Co. Ltd.Xi’an 710065China State Key Laboratory of Road Engineering Safety and Health in Cold and High-Altitude Regions Xi’an 710065China qinghai Huashixia Permafrost Highway Engineering Safety National Observation and Research Station Xi’an 710065China

Ventilation embankments,including those with forced ventilation,natural ventilation,and combination of these,were adopted for the construction of the Gonghe−Yushu Expressway in warm permafrost *** evaluate the actual thermal performance of ventilation embankment in the qinghai−Tibet Plateau,four types of ventilation embankments were selected as objects,and their long-term thermal characteristics were analyzed based on monitoring *** was found that:1)under the strong scale effect of a wide embankment,the crushed-rock embankment(CRE)was warming up and the permafrost table was declining year by ***,the combined ventilated slab and CRE and ventilated ducts embankment can effectively decrease the ground temperature and raise permafrost table in the year with a colder winter;2)transverse temperature difference caused by the shady–sunny slope effect existed in all the four ***,it was weakened by the combined ventilated slab and CRE and the ventilated ducts embankment due to their stronger cooling effect;and 3)the pre-existing embankment had a remarkable thermal disturbance to the adjacent newly-built embankment,so a reasonable embankment spacing should be considered in practical *** findings would provide a reference for construction of expressway embankments in permafrost regions.

关键词： warm permafrost expressway ventilation embankments temperature field

An Ant Colony Algorithm Based on Cross-Layer Design for Routing and Wavelength Assignment in Optical Satellite Networks

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China Communications 2017年第8期14卷 63-75页

作者： Guoli Wen qi zhang Houtian wang qinghua Tian Ying tao School of Electronic Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China Beijing Key Laboratory of Space-ground Interconnection and Convergence Beijing University of Posts and TelecommunicationsBeijing 100876China China Academy of Space Technology Beijing 100094China

This paper introduces an ant colony routing and wavelength assignment algorithm based on cross-layer design(CL-ACRWA),which can overcome the adverse effects of Doppler wavelength shift on data transmission in optical satellite networks. Firstly, a cross-layer optimization model is built, which considers the Doppler wavelength shift, the transmission delay as well as wavelength-continuity constraint. Then an ant colony algorithm is utilized to solve the cross-layer optimization model, resulting in finding an optimal light path satisfying the above constraints for every connection request. The performance of CL-ACRWA is measured by the communication success probability, the convergence property and the transmission delay. Simulation results show that CL-ACRWA performs well in communication success probability and has good global search ability as well as fast convergence speed. Meanwhile, the transmission delay can meet the basic requirement of real-time transmission of business.

关键词： optical satellite network routing and wavelength assignment ant colony optimization cross-layer design Doppler wavelength shift