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Long-term performance and Microstructural Characterization of Dam Concrete in the three gorges project

Engineering 2024年第2期33卷 237-262页

作者： Chen Lyu cheng yu Chao Lu Li pan Wenwei Li jiaping Liu school of Materials science and Engineering Southeast UniversityNanjing 211189China state Key Laboratory of high performance Civil Engineering Materials Sobute New Materials Co.Ltd.Nanjing 211103China China three gorges Corporation Wuhan 430010China

this study investigates the long-term performance of laboratory dam concrete in different curing environments over ten years and the microstructure of 17-year-old laboratory concrete and actual concrete cores drilled from the three gorges *** mechanical properties of the laboratory dam concrete,whether cured in natural or standard environments,continued to improve over ***,the laboratory dam concrete exhibited good resistance to diffusion and a refined microstructure after 17 ***,curing and long-term exposure to the local natural environment reduced the frost *** analyses of the laboratory concrete samples demonstrated that moderate-heat cement and fine fly ash(FA)particles were almost fully hydrated to form compact micro structures consisting of large quantities of homogeneous calcium(alumino)silicate hydrate(C-(A)-s-h)gels and a few *** obvious interfacial transition zones were observed in the microstructure owing to the longterm pozzolanic *** dense and homogenous microstructure was the crucial reason for the excellent long-term performance of the dam concrete.A high FA volume also played a significant role in the microstructural densification and performance growth of dam concrete at a later *** concrete drilled from the dam surface exhibited a loose microstructure with higher microporosity,indicating that concrete directly exposed to the actual service environment suffered degradation caused by water and wind *** this study,both macro-performance and microstructural analyses revealed that the application of moderate-heat cement and FA resulted in a dense and homogenous microstructure,which ensured the excellent long-term performance of concrete from the three gorges Dam after 17 ***-term exposure to an actual service environment may lead to microstructural degradation of the concrete ***,the retained long-term dam concrete samples need to be further researched to

关键词： three gorges Dam Long-term performance Microstructural analysis Moderate-heat cement Fly ash

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Learning-based user association and dynamic resource allocation in multi-connectivity enabled unmanned aerial vehicle networks

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Digital Communications and Networks 2024年第1期10卷 53-62页

作者： Zhipeng cheng Minghui Liwang Ning Chen Lianfen huang Nadra guizani Xiaojiang Du Department of Information and Communication Engineering Xiamen UniversityXiamen361005China school of Electrical and Computer Engineering University of Texas at ArlingtonArlingtonTX76019USA Department of Electrical and Computer Engineering Stevens Institute of TechnologyHobokenNJ07030USA

Unmanned Aerial Vehicles(UAvs)as aerial base stations to provide communication services for ground users is a flexible and cost-effective paradigm in ***,dynamic resource allocation and multi-connectivity can be adopted to further harness the potentials of UAVs in improving communication capacity,in such situations such that the interference among users becomes a pivotal disincentive requiring effective *** this end,we investigate the joint UAV-User Association,Channel Allocation,and transmission power Control(j-UACApC)problem in a multi-connectivity-enabled UAV network with constrained backhaul links,where each UAV can determine the reusable channels and transmission power to serve the selected ground *** goal was to mitigate co-channel interference while maximizing long-term system *** problem was modeled as a cooperative stochastic game with hybrid discrete-continuous action space.A Multi-Agent hybrid Deep Reinforcement Learning(MAhDRL)algorithm was proposed to address this *** simulation results demonstrated the effectiveness of the proposed algorithm and showed that it has a higher system utility than the baseline methods.

关键词： UAV-user association Multi-connectivity Resource allocation power control Multi-agent deep reinforcement learning

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Non-synchronous vibration of rotor blade in a six-stage transonic compressor

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Chinese journal of Aeronautics 2024年第8期37卷 36-48页

作者： Ronghui cheng Zhuo WANg huawei yU Lin DU yi ZhANg Xiaofeng sUN Aeroengine Research Institute Beihang UniversityBeijing 102206China school of Energy and power Engineering Beihang UniversityBeijing 102206China

this paper presents an experimental study on the Non-synchronous Vibration(NsV)in a six-stage transonic *** first part of the paper describes the NsV phenomenon of Rotor 1,which occurs when both stator 1(s1)and stator 2(s2)or s1 only are *** measurements and analysis are carried out for the former case through the unsteady wall pressure and the Blade strain(Bs).the spinning mode theory used in the rotor/stator interaction noise is employed to explain the relation between the circumferential wave number of the aerodynamic disturbance and the Nodal Diameter(ND)of the blade *** variations of the vibration amplitudes of different blades and the Inter-Blade phase Angles(IBpAs)at different moments suggest that the evolution of NsV is a highly nonuniform phenomenon along the circumferential *** addition,the difference between the wall-pressure spectra generated by the NsV and the classic flutter has been *** the second part,the variations of aerodynamic loading due to the adjustment of the staggers of the Inlet guide Vane(IgV),s1 and s2 have been *** is found that closing s1 only can result in a great fluctuation to the performance of the front stages,which might be detrimental to the flow organization and increase the risk of *** contrast,the effect of closing s2 only on the performance of the first two stages appears to be slighter relatively.

关键词： transonic compressor Non-synchronous vibration Modal analysis Aerodynamic loading Nodal diameter

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Reactive molecular dynamics insight into the thermal decomposition mechanism of 2,6-Bis(picrylamino)-3,5-dinitropyridine

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Defence technology（防务技术） 2024年第3期33卷 134-146页

作者： jianbo Fu hui Ren Xinzhou Wu yongjin Chen Mi Zhang yazhi cheng state Key Laboratory of Explosion science and technology Beijing Institute of TechnologyBeijing 100081China

2,6-bis(picrylamino)-3,5-dinitropyridine(pyX)has excellent thermostability,which makes its thermal decomposition mechanism receive much *** this paper,the mechanism of pyX thermal decomposition was investigated thoroughly by the ReaxFF-lg force field combined with DFt-B3Lyp(6-311++g)*** detailed decomposition mechanism,small-molecule product evolution,and cluster evolution of pyX were mainly *** the initial stage of decomposition,the intramolecular hydrogen transfer reaction and the formation of dimerized clusters are earlier than the denitration *** the progress of the reaction,one side of the bitter amino group is removed from the pyridine ring,and then the pyridine ring is *** final products produced in the thermal decomposition process are CO_(2),h_(2)O,N_(2),and h_(2).Among them,h_(2)O has the earliest generation time,and the reaction rate constant(k_(3))is the *** clusters are formed during the decomposition of pyX,and the formation,aggregation,and decomposition of these clusters are strongly affected by *** low temperatures(2500 K-2750 K),many clusters are *** high temperatures(2750 K-3250 K),the clusters aggregate to form larger *** 3500 K,the large clusters decompose and become *** the late stage of the reaction,h and N in the clusters escaped almost entirely,but more O was trapped in the clusters,which affected the auto-oxidation process of ***'s initial decomposition activation energy(E_(a))was calculated to be 126.58 kj/*** work contributes to a theoretical understanding of pyX's entire thermal decomposition process.

关键词： pyX thermal decomposition ReaxFF-lg MD simulations Excellent thermostable explosives

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solid Bronsted acidity boosts adsorption reactivity of nano-adsorbent for water decontamination

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Frontiers of Environmental science & Engineering 2024年第7期18卷 23-34页

作者： sikai cheng Zhixian Li Kaisheng Zhang Qingrui Zhang Xiaolin Zhang Bingcai pan state Key Laboratory of pollution Control and Resource Reuse School of the EnvironmentNanjing UniversityNanjing 210023China Environmental Materials and pollution Control Laboratory Institute of Solid State PhysicsHFIPSChinese Academy of SciencesHefei 230031China state Key Laboratory of Metastable Materials science and technology Yanshan UniversityQinhuangdao 066004China hebei Key Laboratory of heavy Metal Deep-remediation in Water and Resource Reused Qinhuangdao 066004China Research Center for Environmental Nanotechnology(ReCENt) Nanjing UniversityNanjing 210023China

Despite the development of various Lewis acidic nano-adsorbents for fluoride removal through innersphere coordination,strong competition for hydroxyl ions still hinders efficient water *** addition,the critical issue of polysilicate scaling that results from the ubiquitous silicates must be *** tackle these issues,an alternative approach to enhancing adsorption reactivity by modifying nano-adsorbents with dual Lewis and Bronsted acidity is *** feasibility of this approach is demonstrated by growing zirconium phosphate(Zrp)inside a gel-type anion exchanger,N201,to produce nanocomposite Zrp@N201,in which the confined Zrp contained an otherwise metastable amorphous phase with Lewis acidic Zr^(4+) sites and Bronsted acidic monohydrogen phosphate groups(-O_(3)pOh).Compared with the Lewis acidic nano-zirconium oxide analog(hZ0@N201),Zrp@N201 exhibited a greatly improved adsorption capacity(117.9 vs.52.3 mg/g-Zr)and mass transfer rate(3.56×10^(-6) vs.4.55×10^(-7) cm/s),while bulk Zrp produced a thermodynamically stableα-phase with Bronsted acidity that exhibited negligible adsorption capability toward *** enhanced defluoridation activity of Zrp@N201 is attributed to Bronsted acidity and the increased outer electron density of ZA+sites,as corroborated using Xps and solid-state NMR ***,Bronsted acidity strengthens the resistance of Zrp@N201 to silicate,allowing its full regeneration during cyclic *** tests demonstrated 3-10 times the amount of clean water from(waste)for Zrp@N201 as compared to both hZO@N201 and the widely used activated aluminum *** study highlights the potential of developing nano-adsorbents with dual acidities for various environmental remediation applications.

关键词： Nanocomposite selective adsorption Fluoride removal Dual Lewis and Bronsted acidity Regeneration

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Functional Optical Fiber sensors Detecting Imperceptible physical/Chemical Changes for smart Batteries

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Nano-Micro Letters 2024年第8期16卷 268-308页

作者： yiding Li Li Wang youzhi song Wenwei Wang cheng Lin Xiangming he Institute of Nuclear and New Energy technology Tsinghua UniversityBeijing 100084People’s Republic of China National Engineering Research Center of Electric Vehicles Beijing Institute of Technology(BIT)Beijing 100081People’s Republic of China shenzhen Automotive Research Institute of BIt(shenzhen Research Institute of National Engineering Research Center of Electric Vehicles) Shenzhen 518118People’s Republic of China

the battery technology progress has been a contradictory process in which performance improvement and hidden risks *** the battery is still a“black box”,thus requiring a deep understanding of its internal *** battery should“sense its internal physical/chemical conditions”,which puts strict requirements on embedded sensing *** paper summarizes the application of advanced optical fiber sensors in lithium-ion batteries and energy storage technologies that may be mass deployed,focuses on the insights of advanced optical fiber sensors into the processes of one-dimensional nano-micro-level battery material structural phase transition,electrolyte degradation,electrode-electrolyte interface dynamics to three-dimensional macro-safety *** paper contributes to understanding how to use optical fiber sensors to achieve“real”and“embedded”*** the inherent advantages of the advanced optical fiber sensor,it helps clarify the battery internal state and reaction mechanism,aiding in the establishment of more detailed *** advancements can promote the development of smart batteries,with significant importance lying in essentially promoting the improvement of system ***,with the help of smart batteries in the future,the importance of consistency can be weakened or even *** application of advanced optical fiber sensors helps comprehensively improve the battery quality,reliability,and life.

关键词： smart battery Advanced embedded optical fiber sensor Battery internal physical/chemical state Quality-reliability-life characteristic

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gas film/regenerative composite cooling characteristics of the liquid oxygen/liquid methane (LOX/LCh4) rocket engine

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journal of Zhejiang University-science A(Applied physics & Engineering) 2024年第8期25卷 631-649页

作者： Xinlin LIU jun sUN Zhuohang jIANg Qinglian LI peng cheng jie sONg science and technology on scramjet Laboratory College of Aerospace Science and EngineeringNational University of Defense TechnologyChangsha 410073China

the thermal protection of rocket engines is a crucial aspect of rocket engine *** this paper,the gas film/regenerative composite cooling of the liquid oxygen/liquid methane(LOX/LCh4)rocket engine thrust chamber was investigated.A gas film/regenerative composite cooling model was developed based on the grisson gas film cooling efficiency formula and the one-dimensional regenerative cooling *** accuracy of the model was validated through experiments conducted on a 6 kg/s level gas film/regenerative composite cooling thrust ***,key parameters related to heat transfer performance were *** results demonstrate that the model is sufficiently accurate to be used as a preliminary design *** temperature rise error of the coolant,when compared with the experimental results,was found to be less than 10%.Although the pressure drop error is relatively large,the calculated results still provide valuable guidance for heat transfer *** addition,the performance of composite cooling is observed to be superior to regenerative *** the gas film flow rate results in higher cooling efficiency and a lower gas-side wall ***,the position at which the gas film is introduced greatly impacts the cooling *** optimal introduction position for the gas film is determined when the film is introduced from a single row of *** optimal introduction position results in a more uniform wall temperature distribution and reduces the peak ***,it is observed that a double row of holes,when compared to a single row of holes,enhances the cooling effect in the superposition area of the gas film and further lowers the gas-side wall *** results provide a basis for the design of gas film/regenerative composite cooling systems.

关键词： Liquid oxygen/liquid methane(LOX/LCh4)rocket engine gas film cooling Regenerative cooling heat transfer characteristics

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ZNF554 Inhibits Endometrial Cancer progression via Regulating RBM5 and Inactivating WNt/β-Catenin signaling pathway

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Current Medical science 2024年第2期44卷 406-418页

作者： cheng-cheng ZhU heng-liang sUN teng-fei LONg yuan-yuan LyU jiang-li LIU guan-tai NI Anhui Medical University Hefei 230032China Department of Obstetrics and gynecology The First Affiliated Hospital of Wannan Medical CollegeWuhu 241001China

Objective:Uterine corpus endometrial carcinoma(UCEC),a kind of gynecologic malignancy,poses a significant risk to women’s *** precise mechanism underlying the development of UCEC remains *** finger protein 554(ZNF554),a member of the Krüppel-associated box domain zinc finger protein superfamily,was reported to be dysregulated in various illnesses,including malignant *** study aimed to examine the involvement of ZNF554 in the development of ***:the expression of ZNF554 in UCEC tissues and cell lines were examined by qRt-pCR and Western blot *** with stably overexpressed or knocked-down ZNF554 were established through lentivirus ***-8,wound healing,and transwell invasion assays were employed to assess cell proliferation,migration,and *** iodide(pI)staining combined with fluorescence-activated cell sorting(FACs)flow cytometer was utilized to detect cell cycle ***-pCR and Western blotting were conducted to examine relative mRNA and protein *** immunoprecipitation assay and luciferase reporter assay were used to explore the regulatory role of ZNF554 in RNA binding motif 5(RBM5).Results:the expression of ZNF554 was found to be reduced in both UCEC samples and cell *** expression of ZNF554 was associated with higher tumor stage,decreased overall survival,and reduced disease-free survival in ***554 overexpression suppressed cell proliferation,migration,and invasion,while also inducing cell cycle *** contrast,a decrease in ZNF554 expression resulted in the opposite ***,ZNF554 transcriptionally regulated RBM5,leading to the deactivation of the Wingless(WNt)/β-catenin signaling ***,the findings from rescue studies demonstrated that the inhibition of RBM5 negated the impact of ZNF554 overexpression onβ-catenin and p-glycogen synthase kinase-3β(p-gsK-3β).similarly,the deliberate activation of RBM5 reduced the increase inβ-catenin and

关键词： zinc finger protein 554 endometrial carcinoma RNA binding motif 5 Wingless/β-catenin signaling pathway

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A disk I/O optimized system for concurrent graph processing jobs

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Frontiers of Computer science 2024年第3期18卷 13-29页

作者： Xianghao XU Fang WANg hong jIANg yongli cheng Dan FENg peng FANg school of Computer science and Engineering Nanjing University of Science and TechnologyNanjing 210094China Wuhan National Laboratory for Optoelectronics Huazhong University of Science and TechnologyWuhan 430074China Department of Computer science&Engineering University of Texas at ArlingtonArlingtonTX 76019USA College of Computer and Data science Fuzhou UniversityFuzhou 350108China Zhejiang Lab Hangzhou 311121China

In order to analyze and process the large graphs with high cost efficiency,researchers have developed a number of out-of-core graph processing systems in recent years based on just one commodity *** the other hand,with the rapidly growing need of analyzing graphs in the real-world,graph processing systems have to efficiently handle massive concurrent graph processing(Cgp)***,due to the inherent design for single graph processing job,existing out-of-core graph processing systems usually incur unnecessary data accesses and severe competition of I/O bandwidth when handling the Cgp *** this paper,we propose graphCp,a disk I/O optimized out-of-core graph processing system that efficiently supports the processing of Cgp *** proposes a benefit-aware sharing execution model to share the I/O access and processing of graph data among the Cgp jobs and adaptively schedule the graph data loading based on the states of vertices,which efficiently overcomes above challenges faced by existing out-of-core graph processing ***,graphCp adopts a dependency-based future-vertex updating model so as to reduce disk I/Os in the future *** addition,graphCp organizes the graph data with a source-sorted sub-Block graph representation for better processing capacity and I/O access *** evaluation results show that graphCp is 20.5×and 8.9×faster than two out-of-core graph processing systems gridgraph and graphZ,and 3.5×and 1.7×faster than two state-of-art concurrent graph processing systems seraph and graphsO.

关键词： graph processing disk I/O concurrent jobs

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persistent radical anion of perylene dianhydride:an emerging metal-free photocatalyst for near-infrared photocontrolled RAFt polymerization

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science China Chemistry 2024年第2期67卷 677-686页

作者： haitao Zhao guoqing Bian Xiang Xu Weiwei he Lifen Zhang Zhenping cheng state and Local joint Engineering Laboratory for Novel Functional polymeric Materials Jiangsu Key Laboratory of Advanced Functional Polymer Design and ApplicationSuzhou Key Laboratory of Macromolecular Design and Precision SynthesisCollege of ChemistryChemical Engineering and Materials ScienceSoochow UniversitySuzhou215123China

Developing a new type of photocatalyst(pC) and catalytic mechanism for near-infrared(NIR) photocontrolled reversibledeactivation radical polymerization(RDRp) system is charming but ***,a novel pC of the persistent radical anion(pRA)(possessing the properties of both radical and anion) was developed for NIR photocontrolled reversible additionfragmentation chain transfer(RAFt) polymerization,enabling successful polymerization while gaining a deep insight into the mechanism of photo-induced electron transfer RAFt(pEt-RAFt) *** from the conventional and wellaccepted reductive quenching(RQ) pathway,in which the radical anion intermediates of pCs(pCs^(·-)) must be generated in an excited state(Es),here,the pRA(3,4,9,10-perylenetetracarboxylic dianhydride radical anion(ptCDA^(·-))) could generate conveniently in situ in the ground state(gs) and subsequently serve as highly efficient pC in the NIR region(740–850 nm).the successful implementation of this strategy elucidates the peculiar role played by light and the real way of electron transfer *** fact,the transfer of a single electron from pRA to chain transfer agent(CtA) and cleavage of the C–s bonds is a process from Es to gs,rather than always from gs(pCs^(·-)) to gs(CtA) in the RQ pathway as is well known to *** addition,the excellent spatial-temporal control and powerful penetration ability of the NIR light were also confirmed by this pRAcatalyzed polymerization system.

关键词： photocatalyst persistent radical anion(pRA) near-infrared(NIR)light reversible-deactivation radical polymerization(RDRp) photo-induced electron transfer RAFt(pEt-RAFt)polymerization

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