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Precise control of page cache for containers

Frontiers of Computer Science 2024年第2期18卷 17-30页

作者： Kun WANG Song WU Shengbang LI Zhuo HUANG Hao FAN Chen YU Hai JIN National Engineering research Center for Big Data technology and System Services Computing Technology and System LabCluster and Grid Computing Lab School of Computer Science and TechnologyHuazhong University of Science and TechnologyWuhan 430074China

Container-based virtualization isbecoming increasingly popular in cloud computing due to its efficiency and *** isolation is a fundamental property of *** works have indicated weak resource isolation could cause significant performance degradation for containerized applications and enhanced resource ***,current studies have almost not discussed the isolation problems of page cache which is a key resource for *** leverage memory cgroup to control page cache ***,existing policy introduces two major problems in a container-based ***,containers can utilize more memory than limited by their cgroup,effectively breaking memory ***,the Os kernel has to evict page cache to make space for newly-arrived memory requests,slowing down containerized *** paper performs an empirical study of these problems and demonstrates the performance impacts on containerized *** we propose pCache(precise control of page cache)to address the problems by dividing page cache into private and shared and controlling both kinds of page cache separately and *** do so,pCache leverages two new technologies:fair account(f-account)and evict on demand(EoD).F-account splits the shared page cache charging based on per-container share to prevent containers from using memory for free,enhancing memory *** EoD reduces unnecessary page cache evictions to avoid the performance *** evaluation results demonstrate that our system can effectively enhance memory isolation for containers and achieve substantial performance improvement over the original page cache management policy.

关键词： page cache memory cgroup container isolation cloud computing

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Optimal AP Deployment in Cell-Free Massive MIMO Systems with LoS/NLoS Transmissions:A Stochastic Geometry Approach

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China Communications 2024年第9期21卷 146-158页

作者： Jiang Ling Zhang Qi Zhu Hongbo Jiangsu Key Laboratory of wireless Communications Nanjing University of Posts and TelecommunicationsNanjing 210003China

Cell-free massive multiple-input multipleoutput(MIMO)is a promising technology for future wireless communications,where a large number of distributed access points(APs)simultaneously serve all users over the same time-frequency *** users and APs may locate close to each other,the line-of-sight(Lo S)transmission occurs more frequently in cell-free massive MIMO ***,in this paper,we investigate the cell-free massive MIMO system with Lo S and non-line-of-sight(NLo S)transmissions,where APs and users are both distributed according to Poisson point *** tools from stochastic geometry,we derive a tight lower bound for the user downlink achievable rate and we further obtain the energy efficiency(EE)by considering the power consumption on downlink payload transmissions and circuitry *** on the analysis,the optimal AP density and AP antenna number that maximize the EE are *** is found that compared with the previous work that only considers NLo S transmissions,the actual optimal AP density should be much smaller,and the maximized EE is actually much higher.

关键词： cell-free massive MIMO energy efficiency LoS/NLoS transmissions stochastic geometry

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Amorphous BaTiO_(3) Electron Transport Layer for Thermal Equilibrium-Governed γ-CsPbl_(3) Perovskite Solar Cell with High Power Conversion Efficiency of 19.96%

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Energy & Environmental Materials 2024年第3期7卷 291-302页

作者： Changhyun Lee Chanyong Lee Kyungjin Chae Taemin Kim Seaeun Park Yohan Ko Yongseok Jun Department of Energy Environment Policy and technology Graduate School of Energy and Environment(KU-KIST Green School)Korea UniversitySeoul 02841Republic of Korea Nano Electronic Materials and Components research Center Gumi Electronics and Information Technology Research Institute(GERI)Gumi 39171Republic of Korea Energy Materials research Center Clean Energy Research DivisionKorea Institute of Science and Technology(KIST)Seoul 02792Republic of Korea

Compared to organic-inorganic hybrid perovskites,the cesium-based allinorganic lead halide perovskite(CsPbI_(3))is a promising light absorber for perovskite solar cells owing to its higher resistance to thermal ***,additional research is required to reduce the nonradiative recombination to realize the full potential of CsPbI_(3).Here,the diffusion of Cs ions participating in ion exchange is proposed to be an important factor responsible for the bulk defects inγ-CsPbI_(3)*** based on first-principles density functional theory reveal that the[PbI_(6)]^(4-)octahedral tilt modifies the perovskite crystallographic properties inγ-CsPbI_(3),leading to alterations in its bandgap and crystal *** addition,by substituting amorphous barium titanium oxide(a-BaTiO_(3))for TiO_(2)as the electron transport layer,interfacial defects caused by imperfect energy levels between the electron transport layer and perovskite are ***-resolution transmission electron microscopy and electron energy loss spectroscopy demonstrate that a-BaTiO_(3)forms entirely as a single phase,as opposed to Ba-doped TiO_(2)hybrid nanoclusters or separate domains of TiO_(2)and BaTiO_(3)***,inorganic perovskite solar cells based on the a-BaTiO_(3)electron transport layer achieved a power conversion efficiency of 19.96%.

关键词： amorphous BaTiO_(3) electron transport layer moisture γ-CsPbI_(3)

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Coordination-environment regulation of atomic Co-Mn dual-sites for efficient oxygen reduction reaction

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Nano research 2024年第8期17卷 6841-6848页

作者： Caiting Sun Yarong Liu Zunhang Lv Rui Liu Changli Wang Liuhua Li Jinming Wang Yu Zhang Wenxiu Yang Bo Wang Key Laboratory of Cluster Science(Ministry of Education) Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion MaterialsAdvanced Technology Research Institute(Jinan)Advanced Research Institute of Multidisciplinary ScienceSchool of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing 100081China Beijing Institute of technology Library Beijing Institute of TechnologyBeijing 100081China

Precisely designing atomic metal-nitrogen-carbon(M-N-C)catalysts with asymmetric diatomic configurations and studying their structure–activity relationships for oxygen reduction reaction(ORR)are important for zinc-air batteries(ZABs).Herein,a dualatomic-site catalyst(DASC)with CoN_(3)S-MnN_(2)S_(2) configuration was prepared for the cathodes of *** with Co-N-C(Mn-free)and CoMn-N-C(S-free doping),CoMn-N/S-C exhibits excellent half-wave potential(0.883 V)and turnover frequency(1.54 e·s^(−1)·site^(−1)),surpassing most of the reported state-of-the-art Pt-free ORR *** CoMn-N/S-C-based ZABs achieve extremely high specific capacity(959 mAh·g^(−1))and good stability(350 h@5 mA·cm^(−2)).Density functional theory(DFT)calculation shows that the introduction of Mn and S can break the electron configuration symmetry of the original Co 3d orbital,lower the dband center of the Co site,and optimize the desorption behavior of*OH intermediate,thereby increasing the ORR activity.

关键词： metal organic frameworks oxygen reduction reaction dual-atom catalyst coordination-environment regulation zinc-air batteries

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Answering reachability queries with ordered label constraints over labeled graphs

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Frontiers of Computer Science 2024年第1期18卷 105-117页

作者： Daoliang HE Pingpeng YUAN Hai JIN National Engineering research Center for Big Data technology and System Services Computing Technology and System LabCluster and Grid Computing LabSchool of Computer Science&TechnologyHuazhong University of Science and TechnologyWuhan 430074China

Reachability query plays a vital role in many graph analysis *** researches proposed many methods to efficiently answer reachability queries between vertex *** many real graphs are labeled graph,it highly demands Label-Constrained Reachability(LCR)query inwhich constraint includes a set of labels besides vertex *** researches proposed several methods for answering some LCR queries which require appearance of some labels specified in constraints in the *** that constraint may be a label set,query constraint may be ordered labels,namely OLCR(Ordered-Label-Constrained Reachability)queries which retrieve paths matching a sequence of ***,no solutions are available for ***,we propose DHL,a novel bloom filter based indexing technique for answering OLCR *** can be used to check reachability between vertex *** the answers are not no,then constrained DFS is ***,we employ DHL followed by performing constrained DFS to answer OLCR *** show that DHL has a bounded false positive rate,and it's powerful in saving indexing time and *** experiments on 10 real-life graphs and 12 synthetic graphs demonstrate that DHL achieves about 4.8-22.5 times smaller index space and 4.6-114 times less index construction time than two state-of-art techniques for LCR queries,while achieving comparable query response *** results also show that our algorithm can answer OLCR queries effectively.

关键词： graph ordered-label-constrained reachability partial index bloom filter query processing

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Enrichment of anammox biomass during mainstream wastewater treatment driven by achievement of partial denitrification through the addition of bio-carriers

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Journal of Environmental Sciences 2024年第3期137卷 181-194页

作者： Yuqing Ma Bo Wang Xiaodi Li Shuo Wang Wen Wang Yongzhen Peng National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse technology Engineering Research Center of BeijingBeijing University of TechnologyBeijing 100124China

Anammox is widely considered as the most cost-effective and sustainable process for nitrogen ***,how to achieve the enrichment of anammox biomass remains a challenge for its large-scale application,especially in mainstream wastewater *** this study,the feasibility of enrichment of anammox biomass was explored through the realization of partial denitrification and the addition of *** using ordinary activated sludge,a sequencing batch reactor(SBR)followed by an up-fow anaerobic sludge bed(UASB)was operated at 25±2℃ for 214 *** long-term operation was divided into five phases,in which SBR and UASB were started-up in Phases I and II,*** eliminating oxygen and adjusting the infow ratios in Phases III-V,advanced nitrogen removal was achieved with the effuent total nitrogen being 4.7 mg/L and the nitrogen removal efficiency being 90.5%in Phase *** in-situ and ex-situ activity tests demonstrated the occurrence of partial denitrification and ***,16S rRNA high-throughput sequencing analysis revealed that Candidatus Brocadia was enriched from below the detection limit to in biofilms(0.4%in SBR,2.2%in UASB)and the foc sludge(0.2%in SBR,1.3%in UASB),while Thauera was mainly detected in the foc sludge(8.1%in SBR,8.8%in UASB),which might play a key role in partial ***,this study provides a novel strategy to enrich anammox biomass driven by rapid achievement of partial denitrification through the addition of bio-carriers,which will improve large-scale application of anammox processes in mainstream wastewater treatment.

关键词： Enrichment Anammox biomass Bio-carriers Partial denitrification Mainstream wastewater

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Single-atomic activation on ZnIn_(2)S_(4)basal planes boosts photocatalytic hydrogen evolution

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Nano research 2024年第7期17卷 5949-5955页

作者： Jianpeng Cui Ying Wang Luxue Lin Xiaotian Yang Xuyu Luo Shiying Guo Xiaoyong Xu College of Physics Science and technology and Center for Interdisciplinary ResearchYangzhou UniversityYangzhou 225002China

The use of single-atom cocatalysts plays a crucial role in enhancing artificial photocatalysis,where the precise construction of stable and efficient single-atom configuration is essential but remains ***,we report a simple one-step hydrothermal method for preparing single-atomic Mo modified ZnIn_(2)S_(4)(Mo-ZIS)nanosheets as a highly active photocatalytic hydrogen evolution(PHE)*** Mo substituting for portion of In atoms in ZIS nanosheets induces the spatial charge redistribution,which not only promotes the separation of photogenerated charge carriers but also optimizes the Gibbs free energy of adsorbing H*on S atoms at basal *** a result,Mo-ZIS exhibits an impressive PHE rate as high as 6.71 mmol·g^(−1)·h^(−1),over 10 times that of the pristine ZIS,with an apparent quantum efficiency(AQE)up to 38.8%at 420 *** study gains insights into the coordination configuration and electronic modulation resulting from single-atomic decoration,providing mechanistic cognitions for the development of advanced photocatalysts via non-precious metal atomic modification.

关键词： photocatalytic hydrogen evolution ZnIn_(2)S_(4) single-atom activation Gibbs free energy

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Amphipathic Janus Nanofibers Aerogel for Efficient Solar Steam Generation

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Energy & Environmental Materials 2024年第4期7卷 422-432页

作者： Rui Wang Jinshuo Deng Ping Wu Qianli Ma Xiangting Dong Wensheng Yu Guixia Liu Jinxian Wang Lei Liu Chongqing research Institute Changchun University of Science and Technology Key Laboratory of Applied Chemistry and Nanotechnology at Universities of Jilin Province Changchun University of Science and Technology

Solar steam generation is a promising water purification technology due to its low-cost and environmentally friendly applications in water purification and ***,hydrophilic or hydrophobic materials alone are insufficient in achieving necessary characteristics for constructing highquality solar steam generators with good comprehensive properties.

关键词： aerogels electrospinning photothermal materials solar desalination solar steam generation

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Structure and dynamical properties during solidification of liquid aluminum induced by cooling and compression

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Chinese Physics B 2024年第7期33卷 476-481页

作者：吴旻杨永琪王垚 College of Materials Science and Engineering Zhejiang University of TechnologyHangzhou 310014China Shaoxing research Institute Zhejiang University of TechnologyShaoxing 312000China

The structural transformation from a liquid into a crystalline solid is an important subject in condensed matter physics and materials science. In the present study, first-principles molecular dynamics calculations are performed to investigate the structure and properties of aluminum during the solidification which is induced by cooling and compression. In the cooling process and compression process, it is found that the icosahedral short-range order is initially enhanced and then begin to decay, the face-centered cubic short-range order eventually becomes dominant before it transforms into a crystalline solid.

关键词： first-principles method molecular dynamics short-range order liquid aluminum

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Fault diagnosis of HVAC system with imbalanced data using multi-scale convolution composite neural network

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Building Simulation 2024年第3期17卷 371-386页

作者： Rouhui Wu Yizhu Ren Mengying Tan Lei Nie School of Mechanical Engineering Hubei University of TechnologyWuhan430068China Industrial research Institute of Xiangyang Hubei University of technology Xiangyang441100China

Accurate fault diagnosis of heating,ventilation,and air conditioning(HVAC)systems is of significant importance for maintaining normal operation,reducing energy consumption,and minimizing maintenance ***,in practical applications,it is challenging to obtain sufficient fault data for HVAC systems,leading to imbalanced data,where the number of fault samples is much smaller than that of normal ***,most existing HVAC system fault diagnosis methods heavily rely on balanced training sets to achieve high fault diagnosis ***,to address this issue,a composite neural network fault diagnosis model is proposed,which combines SMOTETomek,multi-scale one-dimensional convolutional neural networks(M1DCNN),and support vector machine(SVM).This method first utilizes SMOTETomek to augment the minority class samples in the imbalanced dataset,achieving a balanced number of faulty and normal ***,it employs the M1DCNN model to extract feature information from the augmented ***,it replaces the original Softmax classifier with an SVM classifier for classification,thus enhancing the fault diagnosis *** the SMOTETomek-M1DCNN-SVM method,we conducted fault diagnosis validation on both the ASHRAE RP-1043 dataset and experimental dataset with an imbalance ratio of 1:*** results demonstrate the superiority of this approach,providing a novel and promising solution for intelligent building management,with accuracy and F1 scores of 98.45%and 100%for the RP-1043 dataset and experimental dataset,respectively.

关键词： fault diagnosis chiller imbalanced data SMOTETomek multi-scale neural networks

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