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Adaptive Algorithms on Maximizing Monotone Nonsubmodular Functions

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Journal of the Operations Research Society of China 2024年第2期12卷 428-445页

作者： Bin liu Hui Su Shu-Fang Gong Qi-Zhi Fang School of Mathematical Sciences Ocean Universityof ChinaQingdao266100ShandongChina

Submodular optimization is widely used in large *** order to speed up the problems solving,it is essential to design low-adaptive algorithms to achieve acceleration in *** general,the function values are given by a value oracle,but in practice,the oracle queries may consume a lot of ***,how to strike a balance between optimizing them is *** this paper,we focus on maximizing a normalized and strictly monotone set function with the diminishing-return ratio under a cardinality constraint,and propose two algorithms to deal with *** apply the adaptive sequencing technique to devise the first algorithm,whose approximation ratio is arbitrarily close to 1-e^(-γ)in O(logn·log(log(k\γ))adaptive rounds,and requires O(logn^(2)·log(log(k\γ))*** by adding preprocessing and parameter estimation steps to the first algorithm,we get the second *** second algorithm trades a small sacrifice in adaptive complexity for a significant improvement in query *** the same approximation and adaptive complexity,the query complexity is improved *** the best of our knowledge,this is the first paper of designing adaptive algorithms for maximizing a monotone function using the diminishing-return ratio.

关键词： Approximation algorithm Adaptivity Nonsubmodular maximization:Cardinality constraint

In situ reduction strategy towards high conductivity,anti-freezing and super-stretchable rGO based hydrogel for diverse flexible electronics

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Nano Research 2024年第5期17卷 4016-4022页

作者： Xin Zhang Junhao Wang Mengyan Wang Dongxu liu Zhuo Wang College of Resources and Environment University of Chinese Academy of SciencesBeijing 101408China Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of ScienceBeijing 101400China

Hydrogels electrolytes with flexibility and high conductivity have been widely used in kinds of flexible ***,hydrogels always suffer from the inevitable freezing of water at subzero temperatures,which results in the sacrificing of their electrical ***,an anti-freezing,flexible hydrogel based on in situ reduction of graphene oxide(GO)and laponite has been developed as electrolyte for high performance supercapacitor and sensitive *** crosslinked GO and laponite in polyacrylamide(PAM)resulted in an enhanced mechanical property,while the in-situ reduction of GO in the hydrogel enhanced the conductivity and diminishes the aggregated of *** features guarantee a reliable electro signal as sensor and a high performance of the ***,in the process of preparation of reduced graphene oxide(rGO)hydrogel,the addition of ethylene glycol(EG)and KOH,endows the hydrogel antifreeze *** anti-freezing electrolyte can be stretched to a strain of 1600%and maintained a specific capacitance of 37.38 F·g^(-1) at-20℃.In addition,the photothermal conversion character of rGO in the hydrogel,endows it’s the potential application in wound *** overall merits of the hydrogel will open up a new avenue for sensitive sensor and energy storage device in practical applications.

关键词： hydrogel in-situ reduction flexible electronics low temperature tolerance photothermal therapy

Design and Performance Analysis of HMDV Dynamic Inertial Suspension Based on Active Disturbance Rejection Control

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Computer Modeling in Engineering & Sciences 2024年第8期140卷 1485-1506页

作者： Xiaofeng Yang Wei Wang Yujie Shen Changning liu Tianyi Zhang School of Automotive and Traffic Engineering Jiangsu UniversityZhenjiang212013China Automotive Engineering Research Institute Jiangsu UniversityZhenjiang212013China Chongqing Key Laboratory of Urban Rail Transit System Integration and Control Chongqing400074China State Key Laboratory of Advanced Design and Manufacturing Technology for Vehicle Hunan universityChangsha410082China

This paper addresses the impact of vertical vibration negative effects,unbalanced radial forces generated by the static eccentricity of the hub motor,and road excitation on the suspension performance of Hub Motor Driven Vehicle(HMDV).A dynamic inertial suspension based on Active Disturbance Rejection Control(ADRC)is proposed,combining the vertical dynamic characteristics of dynamic inertial suspension with the features of ADRC,which distinguishes between internal and external disturbances and arranges the transition ***,a simulation model of the static eccentricity of the hub motor is established to simulate the unbalanced radial electromagnetic force generated under static eccentricity.A quarter-vehicle model of an HMDV with a controllable dynamic inertial suspension is then ***,the passive suspension model is studied under different grades of road excitation,and the impact mechanism of suspension performance at speeds of 0–20 m/s is ***,the three main components within the ADRC controller are designed for the second-order controlled system,and optimization algorithms are used to optimize its internal ***,the performance of the traditional passive suspension,the PID-based controllable dynamic inertial suspension,and the ADRC-based controllable dynamic inertial suspension are analyzed under different road *** results show that,under sinusoidal road input,the ADRC-based controllable dynamic inertial suspension exhibits a 52.3%reduction in the low-frequency resonance peak in the vehicle body acceleration gain diagram compared to the traditional passive suspension,with significant performance optimization in the high-frequency *** random road input,the ADRC-based controllable dynamic inertial suspension achieves a 29.53%reduction in the root mean square value of vehicle body acceleration and a 14.87%reduction in dynamic tire *** indicates that the designed controllable dynamic inertia

关键词： HMDV static eccentricity ADRC dynamic inertial suspension road excitation

Impact of Ni particle size on CO_(2)activation and CO formation during reforming process:A density functional theory study

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Frontiers in Energy 2024年第4期18卷 525-534页

作者： Juntian NIU Shengzhuo CHEN Xianrong ZHENG Haiyu liu Yan JIN Jingyu RAN College of Electrical and Power Engineering Taiyuan University of TechnologyTaiyuan 030024China Key Laboratory of Low-grade Energy Utilization Technologies and Systems(Ministry of Education) Chongqing UniversityChongqing 400044China

In recent years,the dry reforming of methane(DRM)reaction has gained widespread attention due to its effective utilization of two major greenhouse *** Ni-based catalysts for DRM exhibit a strong dependence on particle size,however,the reaction mechanisms involved remain *** this work,the effect of metal particle size on CO_(2)activation and CO formation was explored in the DRM reaction using the density functional ***/MgO(x=13,25,37)was constructed to investigate the CO_(2)activation and the formation of CO during the DRM *** is found that CO_(2)is more inclined to undergo chemisorption on Nix/MgO before *** the variation in particle size,the main activation pathway of CO_(2)on the catalyst *** the smallest Ni13/MgO,CO_(2)tends to directly dissociate,while on the larger Ni25/MgO and Ni37/MgO,the hydrogenation dissociation of CO_(2)is more kinetically *** to Ni13/MgO and Ni37/MgO,the oxidation of surface C atoms and the oxidation of CH occur more readily on Ni25/*** indicates that C atoms are less likely to form on Ni25 particle and are more easily to be *** some extent,the results suggest that Ni25/MgO exhibits superior resistance to carbon formation.

关键词： particle size Ni/MgO catalyst CO_(2)activation CO formation

The mechanisms of thermal solidification agent promoting steam diversion in heavy oil reservoirs

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Petroleum Science 2024年第3期21卷 1902-1914页

作者： Zhan-Xi Pang Qian-Hui Wang Qiang Meng Bo Wang Dong liu State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing102249China liaohe Oilfield Institute CNPC ChinaPanjin124000LiaoningChina Henan Oilfield Institute Sinopec ChinaNanyang473400HenanChina Tianjin Branch of China National Offshore Oil Company(CNOOC)Ltd. Tianjin300452China

At high cycles of steam huff&puff,oil distribution in reservoirs becomes stronger heterogeneity due to steam *** solidification agent can be used to solve this *** solution is a lowviscosity liquid at normal temperature,but it can be solidified above 80℃.The plugging degree is up to 99%at 250℃.The sweep efficiency reaches 59.2%,which is 7.3%higher than pure steam *** addition,simultaneous injection of viscosity reducer and/or nitrogen foams can further enhance oil *** mechanism of this technology depends on its strong plugging ability,which changes the flowing pattern of steam to effectively mobilize remaining *** reducer and nitrogen foams further expand the sweep range and extends the effective ***,thermal solidification agent can plug steam channeling paths and adjust steam flowing direction to significantly enhance oil recovery at high cycles of steam huff&puff.

关键词： Heavy oil reservoir Steam huff&puff Steam channeling Steam diversion Plugging performance Mechanism analysis

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Characteristics,origins,and significance of pyrites in deep-water shales

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Science China Earth Sciences 2024年第2期67卷 313-342页

作者： Chao liANG Shichao JI Yingchang CAO Keyu liu Jing WU Fang HAO National Key Laboratory of Deep Oil and Gas China University of Petroleum(East China)Qingdao266580China School of Geosciences China University of PetroleumQingdao266000China Laboratory for Marine Mineral Resource Qingdao National Laboratory for Marine Science and TechnologyQingdao266071China College of Earth Science and Engineering Shandong University of Science and TechnologyQingdao266590China

As important metal sulfides in the geochemical cycle of sulfur,the characteristics and formation processes of pyrites can provide useful clues regarding their *** on previous findings,shale pyrites were divided into three major classes(euhedral pyrites,framboidal pyrites(framboids)and metasomatic pyrites)and six sub-classes in this *** the microscopic scale,each type of pyrite is associated with a different formation *** are formed by burst nucleation in environments with a homogeneous distribution of nutrients while euhedral pyrites are usually formed on pre-existing sites(such as=FeS on the minerals surface)in the heterogeneous *** pyrites formed by the replacement of other ions in accountable material by iron ions and hydrogen sulfide ions in hydrothermal *** morphology and isotope value of pyrite provide information to track the origins of their nutrient and characteristics of sulfur and iron *** addition,the trace element content of pyrite can serve as a proxy for paleo-ocean trace element abundance,indicating changes in atmospheric oxygen ***,pyrite can also serves as an indicator of shale gas reservoirs.

关键词： Shale Pyrite Sulfate reduction reaction Isotope fractionation Pyrite element

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Prediction model establishment and validation for enteral nutrition aspiration during hospitalization in patients with acute pancreatitis

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World Journal of Gastrointestinal Surgery 2024年第8期16卷 2583-2591页

作者： Ping Hou Hao-Jun Wu Tang li Jia-Bin liu Quan-Qing Zhao Hong-Jiang Zhao Zi-Ming liu Division II of General Surgery West China Hospital-Chengdu Shangjin NanfuWest China HospitalSichuan UniversityChengdu 611730Sichuan ProvinceChina Division of Biliary Tract Surgery West China HospitalSichuan UniversityChengdu 610041Sichuan ProvinceChina Department of Hepatobiliary and Pancreatic Surgery West China Hospital-Chengdu Shangjin NanfuWest China HospitalSichuan UniversityChengdu 611730Sichuan ProvinceChina Department of Thyroid Surgery West China HospitalSichuan UniversityChengdu 610041Sichuan ProvinceChina Department of Oncology West China Hospital-Chengdu Shangjin NanfuWest China HospitalSichuan UniversityChengdu 611730Sichuan ProvinceChina Division of Biliary Tract Surgery Department of General SurgeryWest China HospitalSichuan UniversityChengdu 610041Sichuan ProvinceChina

BACKGROUND Acute pancreatitis(AP)is a disease caused by abnormal activation of pancreatic enzymes and can lead to self-digestion of pancreatic tissues and dysfunction of other *** nutrition plays a vital role in the treatment of AP because it can meet the nutritional needs of patients,promote the recovery of intestinal function,and maintain the barrier and immune functions of the ***,the risk of aspiration during enteral nutrition is high;once aspiration occurs,it may cause serious complications,such as aspiration pneumonia,and suffocation,posing a threat to the patient’s *** study aims to establish and validate a prediction model for enteral nutrition aspiration during hospitalization in patients with *** To establish and validate a predictive model for enteral nutrition aspiration during hospitalization in patients with *** A retrospective review was conducted on 200 patients with AP admitted to Chengdu Shangjin Nanfu Hospital,West China Hospital of Sichuan University from January 2020 to February *** data were collected from the electronic medical record *** were randomly divided into a validation group(n=40)and a modeling group(n=160)in a 1:4 ratio,matched with 200 patients from the same time *** modeling group was further categorized into an aspiration group(n=25)and a non-aspiration group(n=175)based on the occurrence of enteral nutrition aspiration during *** and multivariate logistic regression analyses were performed to identify factors influencing enteral nutrition aspiration in patients with AP during hospitalization.A prediction model for enteral nutrition aspiration during hospitalization was constructed,and calibration curves were used for *** operating characteristic curve analysis was conducted to evaluate the predictive value of the *** There was no statistically significant difference in general data between the validation and mode

关键词： Acute pancreatitis Hospitalization Enteral nutrition Predictive model Aspiration

A residual denoising and multiscale attention-based weighted domain adaptation network for tunnel boring machine main bearing fault diagnosis

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Science China Technological Sciences 2024年第8期67卷 2594-2618页

作者： ZHONG Tao QIN ChengJin SHI Gang ZHANG ZhiNan TAO JianFeng liu Chengliang State Key Laboratory of Mechanical System and Vibration School of Mechanical Engineering Shanghai Jiao Tong University

As a critical component of a tunnel boring machine(TBM), the precise condition monitoring and fault analysis of the main bearing is essential to guarantee the safety and efficiency of the TBM cutter drive. Currently, under conditions of strong noise and complex working environments, traditional signal decomposition and machine learning methods struggle to extract weak fault features and achieve high fault classification accuracy. To address these issues, we propose a novel residual denoising and multiscale attention-based weighted domain adaptation network(RDMA-WDAN) for TBM main bearing fault diagnosis. Our approach skillfully designs a deep feature extractor incorporating residual denoising and multiscale attention modules, achieving better domain adaptation despite significant domain interference. The residual denoising component utilizes a convolutional block to extract noise features, removing them via residual connections. Meanwhile, the multiscale attention module uses a 4-branch convolution and 3 pooling strategy-based channel–spatial attention mechanism to extract multiscale features, concentrating on deep fault features. During training, a weighting mechanism is introduced to prioritize domain samples with clear fault features. This optimizes the deep feature extractor to obtain common features, enhancing domain adaptation. A low-speed and heavy-loaded bearing testbed was built, and fault data sets were established to validate the proposed method. Comparative experiments show that in noise domain adaptation tasks, proposed the RDMA–WDAN significantly improves target domain classification accuracy by 42.544%, 23.088%, 43.133%, 16.344%, 5.022%, and 9.233% over dense connection network(DenseNet), squeeze–excitation residual network(SE-ResNet), antinoise multiscale convolutional neural network(ANMSCNN), multiscale attention module-based convolutional neural network(MSAMCNN), domain adaptation network, and hybrid weighted domain adaptation(HWDA). In combined no

关键词： tunnel boring machine (TBM) main bearing fault diagnosis domain adaptation antinoise cross working RDMA-WDAN

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Decoupled water electrolysis:Flexible strategy for pure hydrogen production with small voltage inputs

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Journal of Energy Chemistry 2024年第7期94卷 340-356页

作者： Kexin Zhou Jiahui Huang Daili Xiang Aijiao Deng Jialei Du Hong liu Institute for Advanced Interdisciplinary Research(iAIR) Collaborative Innovation Center of Technology and Equipment for Biological Diagnosis and Therapy in Universities of ShandongUniversity of JinanJinan 250022ShandongChina State Key Laboratory of Crystal Materials Shandong UniversityJinan 250100ShandongChina Zhengzhou Vocational College of Industrial Safety Zhengzhou 451192HenanChina

Hydrogen gas is widely regarded as an ideal green energy carrier and a potential alternative to fossil fuels for coping with the aggravating energy crisis and environmental ***,the vast majority of the world's hydrogen is produced by reforming fossil fuels;however,this hydrogen-making technology is not sustainable or environmentally friendly because ofits high energy consumption and large carbon ***-driven water splitting(2H_(2)0-2H_(2)+0_(2))becomes an extensively studied scheme for sustain-able hydrogen *** water electrolysis requires an input voltage higher than 1.23 V and forms a gas mixture of H_(2)/O_(2),which results in high electricity consumption,potential safety hazards,and harmful reactive oxygen *** virtue of the auxiliary redox mediators(RMs)as the robust H^(+)/e^(-)reservoir,decoupled electrolysis splits water at a much lower potential and evolves O_(2)(H_(2)O+RMS_(ox)-O_(2)+H-RMS_(red))and H_(2)(H-RMS_(red)-H_(2)+RMS_(ox))at separate times,rates,and spaces,thus pro-ducing the puretarget hydrogen gas *** electrolysis has accelerated the development ofwater electrolysis technology for H_(2) ***,itis still lack of a comprehensive and in-depth review in this field based on different types of *** review highlights the basic principles and critical progress of this emerging water electrolysis mode over the past *** representative examples are then dis-played in detail according to the differences in the *** rational choice and design of RMs have also been ***,novel applications of decoupled water splitting are briefly discussed,including the manufacture of valuable chemicals,Cl_(2) production,pollutant degradation,and other half-reactions in artificial ***,thekey characteristics and disadvantages of each type of mediator are sum-marized in *** addition,we present an outlook for future directions in decoupled

关键词： Hydrogen production Conventional water splitting Decoupled water splitting Redox mediators Biomimetics

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