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A CSMA/CA based MAC protocol for hybrid Power-line/Visible-light communication networks:Design and analysis

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Digital Communications and Networks 2024年第2期10卷 481-497页

作者： Sheng hao Huyin Zhang fei Yang Chenghao li Jing Wang School of Computer Science Central China Normal UniversityWuhan430079PR China Hubei Key Laboratory of intelligent Robot(Wuhan Institute of Technology) Wuhan430079PR China School of Computer Science Wuhan UniversityWuhan430079China School of Information Science and Engineering Shandong Normal UniversityJinan250000China School of Computer Science Hubei University of TechnologyWuhan430079China

Hybrid Power-line/Visible-light Communication(HPVC)network has been one of the most promising Cooperative Communication(CC)technologies for constructing Smart Home due to its superior communication reliability and hardware *** research on HPVC networks focuses on the performance analysis and optimization of the Physical(PHY)layer,where the Power line Communication(PLC)component only serves as the backbone to provide power to light Emitting Diode(LED)*** designing a Media Access Control(MAC)protocol remains a great challenge because it allows both PLC and Visible light Communication(VLC)components to operate data transmission,i.e.,to achieve a true HPVC network *** solve this problem,we propose a new HPC network MAC protocol(HPVC MAC)based on Carrier Sense Multiple Access/Collision Avoidance(CSMA/CA)by combining IEEE 802.15.7 and IEEE 1901 ***,we add an Additional Assistance(AA)layer to provide the channel selection strategies for sensor stations,so that they can complete data transmission on the selected channel via the specified CSMA/CA mechanism,*** on this,we give a detailed working principle of the HPVC MAC,followed by the construction of a joint analytical model for mathematicalmathematical validation of the HPVC *** the modeling process,the impacts of PHY layer settings(including channel fading types and additive noise feature),CSMA/CA mechanisms of 802.15.7 and 1901,and practical configurations(such as traffic rate,transit buffer size)are comprehensively taken into ***,we prove the proposed analytical model has the ***,through extensive simulations,we characterize the HPVC MAC performance under different system parameters and verify the correctness of the corresponding analytical model with an average error rate of 4.62%between the simulation and analytical results.

关键词： Hybrid power-line/Visible light communication (HPVC)networks MAC protocol CSMA/CA IEEE 802.15.7 IEEE 1901 Performance analysis

Temperature prediction model in multiphase flow considering phase transition in the drilling operations

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Petroleum Science 2024年第3期21卷 1969-1979页

作者： Yang Zhang Yong-An li Xiang-Wei Kong hao liu Teng-fei Sun College of Mechanical and Electrical Engineering Beijing University of Chemical TechnologyBeijing 100027China School of Petroleum Engineering Yangtze UniversityWuhan430000HubeiChina

The study considers gas compression properties,gas slippage,back pressure(BP),phase transition(PT),well depth,and differences in gas-liquid physical properties.A new temperature model for multiphase flow is proposed by considering phase transition in the drilling *** mathematical model of multiphase flow is solved using the finite difference method with annulus mesh division for grid nodes,and a module for multiphase flow calculation and analysis is *** results indicate that the temperature varies along the annulus with the variation of gas influx at the bottom of the *** the process of controlled pressure drilling,as gas slips along the annulus to the wellhead,its volume continuously expands,leading to an increase in the gas content within the annulus,and consequently,an increase in the pressure drop caused by gas *** temperature increases with the increase in BP and decreases in gas influx rate and wellbore *** gas influx,the thermal conductivity coefficient for the gas-drilling mud two phases is significantly weakened,resulting in a considerable change in temperature along the *** the context of MPD,the method of slightly changing the temperature along the annulus by controlling the back pressure is feasible.

关键词： Managed pressure drilling Phase transition Temperature Gas-drilling mud two phase

CFD-DEM study of impacts of the porous distributor medium on fluidization characteristics of a 2D-fluidized bed

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Particuology 2024年第4期87卷 54-73页

作者： fei Wang Yishan Zeng hao Yan School of Mechanical Engineering Hefei University of TechnologyHefei230009China

Gas-solid bubbling fluidized beds are widely used in chemical,energy,construction,and other industrial fields due to their excellent fluidization performance.2D-fluidized beds with planar rectangular columns of finite thickness are widely used in fluidized bed studies,and it is essential for understanding the hydrodynamics of gas-particle ***,the distributor(porous medium)at the bottom of the bed has a crucial influence on the fluidization performance of the 2D-fluidized *** this work,the fluidization mechanism and gas-solid dynamic characteristics of the fluidized bed under three porous media are studied by CFD-DEM coupled with the porous medium model,and the accuracy of numerical simulation is verified by a high-speed photography *** show that with the increase in the flow resistance of the porous medium,the average and standard deviation of the bubble diameter decrease,and the time and position of particles in the dead zone to participate in the core-annular flow *** a low fluidization velocity,the dead zone in the bed can be considerably reduced by increasing the flow resistance.

关键词： Fluidized bed CFD-DEM Porous medium Bubble dynamics Solid mixing

Visualizing Wallerian degeneration in the corticospinal tract after sensorimotor cortex ischemia in mice

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Neural Regeneration Research 2024年第3期19卷 636-641页

作者： Jiao Mu liufang hao Zijue Wang Xuyang Fu Yusen li fei hao Hongmei Duan Zhaoyang Yang Xiaoguang li Beijing Key Laboratory for Biomaterials and Neural Regeneration School of Biological Science and Medical EngineeringBeihang UniversityBeijingChina Department of Neurobiology School of Basic Medical SciencesCapital Medical UniversityBeijingChina

Stroke can cause Wallerian degeneration in regions outside of the brain,particularly in the corticospinal *** investigate the fate of major glial cells and axons within affected areas of the corticospinal tract following stroke,we induced photochemical infarction of the sensorimotor cortex leading to Wallerian degeneration along the full extent of the corticospinal *** first used a routine,sensitive marker of axonal injury,amyloid precursor protein,to examine Wallerian degeneration of the corticospinal *** antibody to amyloid precursor protein mapped exclusively to proximal axonal segments within the ischemic cortex,with no positive signal in distal parts of the corticospinal tract,at all time *** improve visualization of Wallerian degeneration,we next utilized an orthograde virus that expresses green fluorescent protein to label the corticospinal tract and then quantitatively evaluated green fluorescent protein-expressing *** this approach,we found that axonal degeneration began on day 3 post-stroke and was almost complete by 7 days after *** addition,microglia mobilized and activated early,from day 7 after stroke,but did not maintain a phagocytic state over ***,astrocytes showed relatively delayed mobilization and a moderate response to Wallerian ***,no anterograde degeneration of spinal anterior horn cells was observed in response to Wallerian degeneration of the corticospinal *** conclusion,our data provide evidence for dynamic,pathogenic spatiotemporal changes in major cellular components of the corticospinal tract during Wallerian degeneration.

关键词： corticospinal tract green fluorescent protein microglia spinal anterior horn cells stroke virus trace Wallerian degeneration

Hydrolysis mechanism of YbB_(2)C_(2)and the microstructure of the carbon derived from the hydrolysis reaction

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Journal of Materials Science & Technology 2024年第4期171卷 209-221页

作者： Zhihui li hao Zhang Jixin Chen Jiemin Wang Xiaohui Wang Jinxing Yang Chao Zhang Zerong Zhang Hongyang liu fei Huang Meishuan li fei li Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Shanghai Key Laboratory for High Temperature Materials and Precision Forming School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Carbide-derived carbon(CDC)materials have gained great attention due to the excellent properties for various potential ***,graphite crystal is formed during a room-temperature hydrolysis pro-cess of layered compound YbB_(2)C_(2).The formation mechanism can be demonstrated by a YbB_(2)C_(2)molecular cell:Yb^(3+)acts as a cathode where H_(2)O molecule is reduced to H atom and OH^(−)ion,while(B_(2)C_(2))^(3−)acts as an anode where OH−ion is oxidized to O ***,YbB_(2)C_(2)molecular cell begins to disintegrate,i.e.,Yb^(3+)ion,B and C atoms dissociate from the molecular *** as-produced C atoms combine to form graphite *** initial graphite crystal is a cabbage-like microsphere,and then it gradually disintegrates and transforms into layered *** addition,YbB_(6),Yb_(3)(OH)_(3)n(BO_(3))_((3-n))sol,hydrogen,hydrocarbons,and carbon oxides form *** method provides a general and inexpensive route to obtain carbide-derived graphite crystal.

关键词： Carbide-derived carbon YbB_(2)C_(2) Hydrolysis Molecular cell First-principles calculations

Distribution and bioavailability of mercury in size-fractioned atmospheric particles around an ultra-low emission power plant in Southwest China

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Journal of Environmental Sciences 2024年第4期138卷 141-152页

作者： Wei Zhang Jinjuan li hao Qiu Xingqiang Guo Zhijun fei Yi Xing Deliang Yin College of Resources and Environmental Engineering Guizhou UniversityGuiyang 550025China College of Resources and Environmental Engineering Guizhou Institute of TechnologyGuiyang 550003China Key Laboratory of Karst Georesources and Environment(Guizhou University) Ministry of EducationGuiyang 550025China School of Energy and Environmental Engineering University of Science&Technology BeijingBeijing 100083China

Ultra-low emission(ULE)technology retrofits significantly impact the particulate-bound mercury(Hg)emissions from coal-fired power plants(CFPPs);however,the distribution and bioavailability of Hg in size-fractioned particulate matter(PM)around the ULE-retrofitted CF-PPs are less ***,total Hg and its chemical speciation in TSP(total suspended particles),PM_(10)(aerodynamic particle diameter≤10μm)and PM_(2.5)(aerodynamic particle diameter≤2.5μm)around a ULE-retrofitted CFPP in Guizhou Province were *** PM_(2.5)concentration was higher around this ULE-retrofitted CFPP than that in the intra-regional urban cities,and it had higher mass Hg concentration than other sizefractioned *** Hg concentrations in PM had multifarious sources including CFPP,vehicle exhaust and biomass combustion,while they were significantly higher in autumn and winter than those in other seasons(P40%).Mass concentrations of exchangeable,HCl-soluble,elemental,and residual Hg in PM_(2.5)were higher than those in other size-fractioned PM,and were markedly elevated in autumn and winter(P<0.05).In PM_(2.5),HCl-soluble Hg presented a significantly positive relationship with elemental Hg(P<0.05),while residual Hg showed the significantly positive relationships with HCl-soluble Hg and elemental Hg(P<0.01).Overall,these results suggested that atmospheric PM-bound Hg around the ULE-retrofitted CFPP tends to accumulate in finer PM,and has higher bioavailable fractions,while has potential transformation between chemical speciation.

关键词： Size-fractioned particles Mercury Chemical speciation Coal-fired power plant Ultra-low emission

RNA modifications in cellular metabolism:implications for metabolism-targeted therapy and immunotherapy

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Signal Transduction and Targeted Therapy 2024年第4期9卷 1565-1594页

作者： Wei-Wei liu Si-Qing Zheng Tian li Yun-fei fei Chen Wang Shuang Zhang fei Wang Guan-Min Jiang hao Wang Department of Laboratory Medicine The First Affiliated Hospital of USTCDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiChina School of Clinical Medicine Shandong UniversityJinanChina Core Unit of National Clinical Research Center for Laboratory Medicine HefeiChina Neurosurgical Department The First Affiliated Hospital of USTCDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiChina Department of Clinical Laboratory The Fifth Affiliated HospitalSun Yat-sen UniversityZhuhaiChina

Cellular metabolism is an intricate network satisfying bioenergetic and biosynthesis requirements of *** studies have been constantly making inroads in our understanding of pathophysiology,and inspiring development of *** a crucial component of epigenetics at post-transcription level,RNA modification significantly determines RNA fates,further affecting various biological processes and cellular *** be noted,immunometabolism defines the metabolic alterations occur on immune cells in different stages and immunological *** this review,we characterize the distribution features,modifying mechanisms and biological functions of 8 RNA modifications,including N6-methyladenosine(m6A),N6,2'-O-dimethyladenosine(m6Am),N1-methyladenosine(m1A),5-methylcytosine(m5C),N4-acetylcytosine(ac4C),N7-methylguanosine(m7G),Pseudouridine(V),adenosine-to-inosine(A-to-l)editing,which are relatively the most studied *** regulatory roles of these RNA modification on metabolism in diverse health and disease contexts are comprehensively described,categorized as glucose,lipid,amino acid,and mitochondrial *** we highlight the regulation of RNA modifications on immunometabolism,further influencing immune *** all,we provide a thorough discussion about clinical implications of RNA modification in metabolism-targeted therapy and immunotherapy,progression of RNA modification-targeted agents,and its potential in RNAtargeted ***,we give legitimate perspectives for future researches in this field from methodological requirements,mechanistic insights,to therapeutic applications.

关键词： metabolism targeted alterations

Self-assembly of perovskite nanocrystals:From driving forces to applications

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Journal of Energy Chemistry 2024年第1期88卷 561-578,I0013页

作者： Yi li fei Zhang School of Chemical Engineering and Technology Tianjin UniversityTianjin 300072China Collaborative Innovation Center of Chemical Science and Engineering(Tianjin) Tianjin 300072China

Self-assembly of metal halide perovskite nanocrystals(NCs)into superlattices can exhibit unique collective properties,which have significant application values in the display,detector,and solar cell *** review discusses the driving forces behind the self-assembly process of perovskite NCs,and the commonly used self-assembly methods and different self-assembly structures are ***,we summarize the collective optoelectronic properties and application areas of perovskite superlattice ***,we conclude with an outlook on the potential issues and future challenges in developing perovskite NCs.

关键词： Self-assembly Metal halide perovskite Nanocrystals Driving forces

Frequency and size change of ice–snow avalanches in the central Himalaya:A case from the Annapurna II glacier

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Advances in Climate Change Research 2024年第3期15卷 464-475页

作者： Yao li Yi-fei CUI Jian-Sheng hao Zheng-Tao ZHANG hao WANG Jian GUO Shuo-Fan WANG State Key Laboratory of Hydroscience and Engineering Department of Hydraulic EngineeringTsinghua UniversityBeijing 100084China Key Laboratory of Hydrosphere Sciences of the Ministry of Water Resources Beijing 100084China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China School of National Safety and Emergency Management Beijing Normal UniversityBeijing 100875China Key Laboratory of Mountain Hazards and Earth Surface Process Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610041China

Glaciers have retreated and shrunk in High Mountain Asia since the mid-20th century because of global warming,leading to glacier instability and hazardous iceesnow ***,the complex relationship between iceesnow avalanches and factors such as climate and potential triggers are difficult to understand because of the lack of observational ***,we addressed iceesnow avalanches on the Annapurna II glacier in Nepal,Central *** constructed an iceesnow avalanche history using long-term multi-source remote sensing images(1988-2021)and mapped the velocity fields of glaciers using cross-correlation analysis on SAR and optical ***,we investigated the impact of climate change and earthquakes on the frequency and size of iceesnow *** results demonstrate that the frequency of iceesnow avalanches has increased from 10 in 1988 to 27 in 2020,but the average area of iceesnow avalanche deposits has decreased by approximately 70%,from 3.4×10^(5) m^(2) in 1988 to 1.2×10^(5) m^(2) in *** evolutionary characteristic of ice avalanches is linked to the impact of glacier retreat(reduction in ice material supply)and increased activity under climate *** glacier movement velocity controls the size of iceesnow avalanches and can be set as an indicator for iceesnow avalanche *** the Annapurna Ⅱ glacier,an iceesnow avalanche occurred when the glacier velocities were greater than 1.5 m d^(-1).These results offer insights into iceesnow avalanche risk assessment and prediction in high-mountain areas,particularly in regions characterised by dense glacier distribution.

关键词： Iceesnow avalanche Glacier instability Climate change Central Himalaya Remote sensing