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Chinese Journal of Aeronautics 2017年第4期30卷 1417-1426页

作者： Lijun GAO chengyu wang Zhanli LIU Zhuo ZHUANG Department of Engineering Mechanics School of Aerospace Engineering Tsinghua University Beo'ing 100084 China

Repeated Unit Cell（RUC）is a useful tool in micromechanical analysis of composites using Displacement-based Finite Element（DFE）method,and merely applying Periodic Displacement Boundary Conditions（PDBCs）to RUC is almost a standard practice to conduct such *** basic questions arising from this practice are whether Periodic Traction Boundary Conditions（PTBCs,also known as traction continuity conditions）are guaranteed and whether the solution is independent of selection of *** paper presents the theoretical aspects to tackle these questions,which unify the strong form,weak form and DFE method of the micromechanical problem ***,the solution’s independence of selection of RUCs is dealt with on the strong form side,PTBCs are derived from the weak form as natural boundary conditions,and the validity of merely applying PDBCs in micromechanical Finite Element（FE）analysis is proved by referring to its intrinsic connection to the strong form and weak *** points in the theoretical aspects are demonstrated by illustrative examples,and the merits of setting micromechanical FE analysis under the background of a clear theoretical framework are highlighted in the efficient selection of RUCs for Uni Directional（UD）fiber-reinforced composites.

关键词： Finite element method Micromechanics of composites Periodic boundary condition Repeated unit cell Theoretical aspect Traction continuity

Unsupervised Time Series Segmentation: A Survey on Recent Advances

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Computers, Materials & Continua 2024年第8期80卷 2657-2673页

作者： chengyu wang Xionglve Li Tongqing Zhou Zhiping Cai College of Computer National University of Defense TechnologyChangsha410073China

Time series segmentation has attracted more interests in recent years,which aims to segment time series into different segments,each reflects a state of the monitored *** there have been many surveys on time series segmentation,most of them focus more on change point detection(CPD)methods and overlook the advances in boundary detection(BD)and state detection(SD)*** this paper,we categorize time series segmentation methods into CPD,BD,and SD methods,with a specific focus on recent advances in BD and SD *** the scope of BD and SD,we subdivide the methods based on their underlying models/techniques and focus on the milestones that have shaped the development trajectory of each *** a conclusion,we found that:(1)Existing methods failed to provide sufficient support for online working,with only a few methods supporting online deployment;(2)Most existing methods require the specification of parameters,which hinders their ability to work adaptively;(3)Existing SD methods do not attach importance to accurate detection of boundary points in evaluation,which may lead to limitations in boundary point *** highlight the ability to working online and adaptively as important attributes of segmentation methods,the boundary detection accuracy as a neglected metrics for SD methods.

关键词： Time series segmentation time series state detection boundary detection change point detection

Sustainable Seawater Desalination and Energy Management:Mechanisms,Strategies,and the Way Forward

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Research 2024年第3期2023卷 595-611页

作者： Meng wang Yen Wei Ruoxin Li Xin wang chengyu wang Nanqi Ren Shih-Hsin Ho State Key Laboratory of Urban Water Resource and Environment School of EnvironmentHarbin Institute of TechnologyHarbin 150001China Department of Chemistry Tsinghua UniversityBeijing 100084China Key Laboratory of Bio-based Material Science&Technology(Northeast Forestry University) Ministry of EducationHarbin 150040China.

Solar-driven desalination systems have been recognized as an effective technology to address the water ***,evaporators prepared based on advanced manufacturing technologies have emerged as a promising tool in enhancing ocean energy *** this review,we discussed the thermal conversion,energy flow,salt deposition mechanisms,and design strategies for solar-driven desalination systems,and explored how to improve the desalination performance and energy use efficiency of the systems through advanced manufacturing *** future perspectives,we determined the feasibility of coupling solar-driven solar desalination systems with multi-stage energy utilization systems and emerging artificial intelligence technologies,for which conclusions are given and new directions for future desalination system development are ***,exciting opportunities and challenges in the face of basic research and practical implementation are discussed,providing promising solutions and blueprints for green and novel desalination technologies while achieving sustainable development.

关键词： Sustainable Solar directions

Effective purification of oily wastewater using lignocellulosic biomass:A review

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Chinese Chemical Letters 2022年第6期33卷 2807-2816页

作者： Meng wang Hsu-Sheng Tsai Chaofan Zhang chengyu wang Shih-Hsin Ho State Key Laboratory of Urban Water Resource and Environment School of EnvironmentHarbin Institute of TechnologyHarbin 150001China Laboratory for Space Environment and Physical Sciences Harbin Institute of TechnologyHarbin 150001China Key Laboratory of Bio-based Material Science& Technology(Northeast Forestry University) Ministry of EducationHarbin 150040China

Due to the frequent occurrence of oil spills and the large-scale production of oily wastewater, the treatment of oily sewage has become an important issue for sustainable development. Recently, materials prepared from lignocellulosic biomass(LCB) for oil-water separation have been found to be effective due to their high separation efficiency, good recyclability, and superior sustainability. However, few reviews have focused on the advantages and limitations of LCB for sewage treatment. This review summarizes the performance of modified LCB in oily wastewater treatment, in terms of the advanced modification methods applied and the structural dimensions of LCB materials according to the principle of superwetting oil-water separation. Research on the preparation technologies, separation mechanisms, and treatment efficiency of different LCB materials are briefly summarized, along with the characteristics of different LCB material types for oily wastewater treatment. Finally, the future prospects and challenges faced in the development of LCB materials are discussed.

关键词： Lignocellulosic biomass Superwetting Oily wastewater Wastewater treatment Oil-water separation

Accelerating BERT inference with GPU-efficient exit prediction

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Frontiers of Computer Science 2024年第3期18卷 31-42页

作者： Lei LI chengyu wang Minghui QIU Cen CHEN Ming GAO Aoying ZHOU Shanghai Engineering Research Center of Big Data Management School of Data Science and EngineeringEast China Normal UniversityShanghai 200062China Alibaba Group Hangzhou 311121China KLATASDS-MOE School of StatisticsEast China Normal UniversityShanghai 200062China

BERT is a representative pre-trained language model that has drawn extensive attention for significant improvements in downstream Natural Language Processing(NLP)*** complex architecture and massive parameters bring BERT competitive performance but also result in slow speed at model inference *** speed up BERT inference,FastBERT realizes adaptive inference with an acceptable drop in accuracy based on knowledge distillation and the early-exit ***,many factors may limit the performance of FastBERT,such as the teacher classifier that is not knowledgeable enough,the batch size shrinkage and the redundant computation of student *** overcome these limitations,we propose a new BERT inference method with GPU-Efficient Exit Prediction(GEEP).GEEP leverages the shared exit loss to simplify the training process of FastBERT from two steps into only one step and makes the teacher classifier more knowledgeable by feeding diverse Transformer outputs to the teacher *** addition,the exit layer prediction technique is proposed to utilize a GPU hash table to handle the token-level exit layer distribution and to sort test samples by predicted exit *** this way,GEEP can avoid batch size shrinkage and redundant computation of student *** results on twelve public English and Chinese NLP datasets prove the effectiveness of the proposed *** source codes of GEEP will be released to the public upon paper acceptance.

关键词： BERT FastBERT inference acceleration model distillation early exit text classification

Leveraging Active Decremental TTL Measuring for Flexible and Efficient NAT Identification

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Computers, Materials & Continua 2022年第3期70卷 5179-5198页

作者： Tao Yang chengyu wang Tongqing Zhou Zhiping Cai Kui Wu Bingnan Hou National University of Defense Technology Changsha410073China Department of Computer Science University of VictoriaCanada

Malicious attacks can be launched by misusing the network address translation technique as a *** mitigate such threats,network address translation identification is investigated to identify network address translation devices and detect abnormal ***,existingmethods in this field are mainly developed for relatively small-scale networks and work in an offline manner,which cannot adapt to the real-time inference requirements in high-speed network *** this paper,we propose a flexible and efficient network address translation identification scheme based on actively measuring the distance of a round trip to a target with decremental time-tolive *** basic intuition is that the incoming and outgoing traffic froma network address translation device usually experiences the different number of hops,which can be discovered by probing with dedicated time-to-live *** explore a joint effort of parallel transmission,stateless probes,and flexible measuring reuse to accommodate the efficiency of the measuring *** further accelerate statistical countingwith a new sublinear space data structure *** implement a prototype and conduct real-world deployments with 1000 volunteers in 31 Chinese provinces,which is believed to bring insight for ground truth collection in this *** onmulti-sources datasets show that our proposal can achieve as high precision and recall as 95%with a traffic handling throughput of over 106 pps.

关键词： Network address translation NAT security NAT identification active measurement

Internet Inter-Domain Path Inferring:Methods,Applications,and Future Directions

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Computers, Materials & Continua 2024年第10期81卷 53-78页

作者： Xionglve Li chengyu wang Yifan Yang Changsheng Hou Bingnan Hou Zhiping Cai College of Computer National University of Defense TechnologyChangsha410000China

The global Internet is a complex network of interconnected autonomous systems(ASes).Understanding Internet inter-domain path information is crucial for understanding,managing,and improving the *** path information can also help protect user privacy and ***,due to the complicated and heterogeneous structure of the Internet,path information is not publicly *** path information is challenging due to the limited measurement probes and ***,inferring Internet inter-domain paths from the limited data is a supplementary approach to measure Internet inter-domain *** purpose of this survey is to provide an overview of techniques that have been conducted to infer Internet inter-domain paths from 2005 to 2023 and present the main lessons from these *** this end,we summarize the inter-domain path inference techniques based on the granularity of the paths,for each method,we describe the data sources,the key ideas,the advantages,and the *** help readers understand the path inference techniques,we also summarize the background techniques for path inference,such as techniques to measure the Internet,infer AS relationships,resolve aliases,and map IP addresses to ASes.A case study of the existing techniques is also presented to show the real-world applications of inter-domain path ***,we discuss the challenges and opportunities in inferring Internet inter-domain paths,the drawbacks of the state-of-the-art techniques,and the future directions.

关键词： Internet inter-domain paths path inference network measurement network modeling

Recent advances in visible light-mediated chemical transformations of enaminones

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Chinese Chemical Letters 2024年第2期35卷 4-15页

作者： Yu Han Liyun Zhou chengyu wang Shangti Feng Rong Ma Jie-Ping Wan College of Chemistry and Chemical Engineering Jiangxi Normal UniversityNanchang 330022China School of Chemistry and Chemical Engineering Linyi UniversityLinyi 276000China Linyi Sanfeng Chemical Co. Ltd.Linyi 276000China

Enaminones,which possesses both the nucleophilic enamine as well as electrophilic enone structures,are well known versatile building blocks in organic ***,visible light-mediated reactions have emerged as useful synthetic strategy with enhanced *** the last decade,various photochemical transformations of enaminones have been developed to construct cyclic or acyclic *** this review,we describe the recent advances in visible light-mediated chemical transformations of *** discussion on the reaction mechanism of the related reactions is given to provide guide to the ***,a summary on the existing challenges and the future outlook towards the development of practical photocatalytic reactions of enaminones is also presented.

关键词： Enaminone Visible light C-H functionalization C=C bond cleavage Cyclization Multicomponent reactions

Chemical and Isotopic Characters of the Water and Suspended Particulate Materials in the Yellow River and Their Geological and Environmental Implications

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Acta Geologica Sinica(English Edition) 2016年第1期90卷 285-351页

作者： DING Tiping GAO Jianfei TIAN Shihong wang Huaibai LI Ming wang chengyu LUO Xurong HANG Dan MLR Key Laboratory of Metallogeny and Mineral Assessment Institute of Mineral ResourcesCAGSBeijing 100037China MLR Key Laboratory of Isotope Geology CAGSBeijing 100037China Hydrological Bureau YRCCZhengzhou 450004China

The chemical and isotopic characteristics of the water and suspended particulate materials （SPM） in the Yellow River were investigated on the samples collected from 29 hydrological monitoring stations in the mainstem and several major tributaries during 2004 to 2007. The JD and δ^18O values of the Yellow River water vary in large ranges from -32%0 to -91‰ and from -3.1‰ to -12.5‰, respectively. The characters of H and O isotope variations indicate that the major sources of the Yellow River water are meteoric water and snow melting water, and water cycle in the Yellow River basin is affected strongly by evaporation process and human activity. The average SPM content （9.635 g/L） of the Yellow River is the highest among the world large rivers. Compared with the Yangtze River, the Yellow River SPM has much lower clay content and significantly higher contents of clastic silicates and carbonates. In comparison to the upper crust rocks, the Yellow River SPM contains less SiO2, CaO, K2O and Na2O, but more TFe203, Co, Ni, Cu, Zn, Pb and Cd. The abnormal high Cd contents found in some sample may be related to local industrial activity. The REE contents and distribution pattern of the Yellow River SPM are very close to the average value of the global shale. The average δ^30Sisp in the Yellow River （-0.11‰） is slightly higher than the average value （-0.22‰） of the Yangtze River SPM. The major factors controlling the δ^30Si SPM of the Yellow River are the soil supply, the isotopic composition of the soil and the climate conditions. The TDS in the Yellow River are the highest among those of world large rivers. Fair correlations are observed among Cl, Na^＋, K^＋, and Mg^2＋ contents of the Yellow River water, indicating the effect of evaporation. The Ca^2＋ and Sr^2＋ concentrations show good correlation to the SO42 concentration rather than HCO3-concentration, reflecting its origin from evaporates. The NO3-contents are affected by farmland fertilization. The Cu, Zn and Cd contents in

关键词： Yellow River stable isotopes water chemistry suspended particulate materials (SPM) hydrology environmental implication

Facile designing a superhydrophobic anti-icing surface applied for reliable long-term deicing

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Chinese Chemical Letters 2023年第11期34卷 269-274页

作者： Feng Liu Xin wang Meng wang Yao Li Zishuai Jiang Wenbo Zhang Haiyue Yang chengyu wang Shih-Hsin Ho Key Laboratory of Bio-based Material Science&Technology of Ministry of Education Northeast Forestry UniversityHarbin 150040China State Key Laboratory of Urban Water Resource and Environment School of EnvironmentHarbin Institute of TechnologyHarbin 150001China Center for Composite Materials and Structure Harbin Institute of TechnologyHarbin 150001China

While superhydrophobic coatings have shown promise as potential anti-icing coatings, the surface roughness of these coatings is prone to damage during repeated icing-deicing cycles. Herein, two kinds of superhydrophobic anti-icing coatings are prepared from organic resin and micro-nano particles using two strategies, and their excellent anti-icing properties are also investigated. However, superhydrophobic surface Ⅰ(SF1), prepared by first strategy, cannot be used for extended periods of time due to irreversible damage to the surface roughness during the icing–deicing process. Finite element simulations and experimental studies are preformed to investigate the fatal issue of such roughness damage. In contrast,the anti-icing properties of superhydrophobic surface Ⅱ(SF2), prepared by second strategy, can easily regain through a simple sandpaper abrasion treatment even the surface roughness was damaged during the icing–deicing process. These exploratory results and SF2 preparation strategy provide a facile design of anti-icing coating, and the derived restorable anti-icing coating is expected to be useful for a wide application.

关键词： Anti-icing Superhydrophobic Roughness Restorable Sandpaper abrasion