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Relative Broken Family Sensitivity

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Acta Mathematica Sinica,English Series 2024年第9期40卷 2297-2306页

作者： zhuo Wei liu Tao YU Department of Mathematics Shantou UniversityShantou 515063P.R.China

Letπ:(X,T)→(Y,S)be a factor map between two topological dynamical systems,and F_(a) Furstenberg family of *** introduce the notion of relative broken *** Fs(***,Finf)be the families consisting of all syndetic subsets(*** upper Banach density subsets,infinite subsets).We show that for a factor mapπ:(X,T)→(Y,S)between transitive systems,πis relatively broken F-sensitive for F=Fs or Fpubd if and only if there exists a relative sensitive pair which is an F-recurrent point of(R_(π),T^((2)));is relatively broken Finf-sensitive if and only if there exists a relative sensitive pair which is not *** a factor mapπ:(X,T)→(Y,S)between minimal systems,we get the structure of relative broken F-sensitivity by the factor map to its maximal equicontinuous factor.

关键词： Relative sensitivity recurrent points Furstenberg family relative sensitive pairs maximal equicontinuous factor

Mitigate noisy data for smart IoT via GAN based machine unlearning

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Science China(Information Sciences) 2024年第3期67卷 62-78页

作者： zhuo MA Yilong YANG Yang liu Xinjing liu Jianfeng MA School of Cyber Engineering Xidian University State Key Laboratory of Integrated Services Networks (ISN)

With the development of IoT applications, machine learning dramatically improves the utility of variable IoT systems such as autonomous driving. Although the pretrain-finetune framework can cope well with data heterogeneity in complex IoT scenarios, the data collected by sensors often contain unexpected noisy data, e.g., out-of-distribution(OOD) data, which leads to the reduced performance of fine-tuned models. To resolve the problem, this paper proposes Mu GAN, a method that can mitigate the side-effect of OOD data via the generative adversarial network(GAN)-based machine unlearning. Mu GAN follows a straightforward but effective idea to mitigate the performance loss caused by OOD data, i.e., “flashbacking” the model to the condition where OOD data are excluded from model training. To achieve the goal, we design an adversarial game, where a discriminator is trained to identify whether a sample belongs to the training set by observing the confidence score. Meanwhile, a generator(i.e., the target model) is updated to fool the discriminator into believing that the OOD data are not included in the training set but others do. The experimental results show that benefiting from the high unlearning rate(more than 90%) and retention rate(99%), Mu GAN succeeds in lowering the model performance degradation caused by OOD data from 5.88% to 0.8%.

关键词： machine unlearning generative adversarial network out of distribution data Internet of Thing neural network

Recent advances in the microfluidic generation of shape-controllable hydrogel microparticles and their applications

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Green Chemical Engineering 2024年第1期5卷 16-30页

作者： Yingzhe liu zhuo Chen Jianhong Xu The State Key Lab of Chemical Engineering Department of Chemical EngineeringTsinghua UniversityBeijing100084China

Hydrogel microparticles,generally accepted as significant green materials,have been widely used in chemical,biological,and biomedical fields owing to their excellent biocompatibility,biodegradability,and *** these,non-spherical hydrogel microparticles with diverse shape anisotropy have great potential in applications such as drug delivery,cellular interaction,micromotors,*** from their shapes,their functionalities in such fields cannot be satisfied by the typical spherical ***,microfluidics with precise control and domination of fluids at microflow sizes has emerged as a powerful method for synthesizing shape-controllable hydrogel microparticles with good monodispersity and unique *** this review,we tried to provide an overview of the production of non-spherical microparticles composed of green hydrogel materials,emphasizing the microfluidic ***,a brief introduction to their current applications is also presented.

关键词： Microfluidics Hydrogel Microparticles Non-spherical Anisotropic Green materials

Bulging Distortion of Austenitic Stainless Steel Sheet on the Partially Penetrated Side of Non-Penetration Lap Laser Welding Joint

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Chinese Journal of Mechanical Engineering 2024年第1期37卷 286-295页

作者： Chengwu Yao Enze liu Jiaming ni Binying nie Shanghai Key Laboratory of Materials Laser Processing and Modification School of Material Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China Shanghai Aerospace Precision Machinery Institute Shanghai 201600China Chemical and Biological Engineering College Yichun UniversityYichun 336000China

Non-penetration laser welding of lap joints in austenitic stainless steel sheets is commonly preferred in fields where the surface quality is of utmost ***,the application of non-penetration welded austenitic stainless steel parts is limited owing to the micro bulging distortion that occurs on the back surface of the partial penetration *** this paper,non-penetration lap laser welding experiments,were conducted on galvanized and SUS304 austenitic stainless steel plates using a fiber laser,to investigate the mechanism of bulging distortion.A comparative experiment of DC01 galvanized steel-Q235 carbon steel lap laser welding was carried out,and the deflection and distortion profile of partially penetrated side of the sheets were measured using a noncontact laser *** addition,the cold-rolled SUS304 was subjected to heat holding at different temperatures and water quenching after bending to characterize its microstructure under tensile and compressive *** results show that,during the heating stage of the thermal cycle of laser lap welding,the partial penetration side of the SUS304 steel sheet generates compressive stress,which extrudes the material in the heat-affected zone to the outside of the back of the SUS304 steel sheet,thereby forming a *** findings of these experiments can be of great value for controlling the distortion of the partial penetrated side of austenitic stainless steel sheet during laser non-penetration lap welding.

关键词： Non-penetration lap laser welding Bulging distortion Austenitic stainless steel Compressive stress Tension stress

Prediction on Failure Pressure of Pipeline Containing Corrosion Defects Based on ISSA-BPNNModel

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Energy Engineering 2024年第3期121卷 821-834页

作者： Qi Zhuang Dong liu zhuo Chen PetroChina Changqing Oilfield Company The Second Gas Production PlantXi’an710000China PetroChina Changqing Oilfield Company Safety and Environmental Supervision Department Co.Ltd.Xi’an710000China Sinopec Northwest Oilfield Company The Second Oil Production Plant Co.Ltd.Urumqi830016China

Oil and gas pipelines are affected by many factors,such as pipe wall thinning and pipeline *** prediction of failure pressure of oil and gas pipelines can provide technical support for pipeline safety *** at the shortcomings of the BP Neural Network(BPNN)model,such as low learning efficiency,sensitivity to initial weights,and easy falling into a local optimal state,an Improved Sparrow Search Algorithm(ISSA)is adopted to optimize the initial weights and thresholds of BPNN,and an ISSA-BPNN failure pressure prediction model for corroded pipelines is *** 61 sets of pipelines blasting test data as an example,the prediction model was built and predicted by MATLAB software,and compared with the BPNN model,GA-BPNN model,and SSA-BPNN *** results show that the MAPE of the ISSA-BPNN model is 3.4177%,and the R2 is 0.9880,both of which are superior to its comparison *** the ISSA-BPNN model has high prediction accuracy and stability,and can provide support for pipeline inspection and maintenance.

关键词： Oil and gas pipeline corrosion defect failure pressure prediction sparrow search algorithm BP neural network logistic chaotic map

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

Strong hetero-interface interaction in 2D/2D WSe_(2)/Znin_(2)S_(4) heterostructures for highly-efficient photocatalytic hydrogen generation

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Journal of Energy Chemistry 2024年第10期97卷 379-387,I0008页

作者： Xu Guo Xing liu jing Shan zhuo Xu Zhiming Fang Lu Wang Shengzhong liu School of Energy Powerand Mechanical EngineeringNorth China Electric Power UniversityBeijing 102206China Shaanxi Key Laboratory for Advanced Energy Devices School of Materials Science and EngineeringShanxi Normal UniversityXi'an 710119ShanxiChina Qinghai Advanced Energy Storage Laboratory SPIC Qinghai Photovoltaic Industry Innovation Center Co.Ltd.State Power Investment CorporationXining 810oo7QinghaiChina Key Laboratory of Photoelectric Conversion and Utilization of Solar Energy Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

Green hydrogen is urgently required for sustainable development of human beings and rational construction of heterostructures holds great promising for photocatalytic hydrogen ***,2D/2D WSe_(2)/Znin_(2)S_(4) heterostructures with strong hetero-interface interaction and abundant contact were constructed via an impregnation-annealing *** charge transfer from Znin_(2)S_(4) to WSe_(2)was evidenced by transient absorption spectroscopy in crafted heterostructures owing to the tight and2D face-to-face *** a result,the prepared WSe_(2)/Znin_(2)S_(4) heterostructures exhibited boosted photocatalytic performance and a highest hydrogen evolution rate of 3.377 mmol/(g h)was achieved with an apparent quantum yield of 45.7%at 420 *** work not only provides new strategies to achieve efficient 2D/2D heterostructures but also paves the way for the development of green hydrogen in the future.

关键词： Strong hetero-interface interaction in 2D/2D WSe_(2)/Znin_(2)S_(4) heterostructures for highly-efficient photocatalytic hydrogen generation

Ecological Network Resilience of Shiyang River Basin: An Arid Inland Watershed of Northwest China

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Chinese Geographical Science 2024年第5期34卷 951-966页

作者： HE Yangxi liu Chunfang ni Bowen LIAN Hugang School of Management Northwest Normal UniversityLanzhou 730070China Research Center of Land Use and Comprehensive Improvement Engineering of Gansu Province Lanzhou 730070China

Due to the uncertainties posed by climate change,resilience has become an increasingly important variable for evaluating regional ecosystem *** assessment of Ecological Network Resilience(ENR)is crucial for establishing mitigation strategies and sustainable socioeconomic development in arid *** River Basin is an arid watershed in Northwest China with complex characteristics,its ENR and spatial differentiation characteristics in 2020 were investigated in this work based on the Complex Adaptive System(CAS)*** results indicated that the mean Ecological Network Resilience Index(ENRI)value for the Shiyang River Basin was 0.390 in 2020,and the mean values in the southern mountainous,middle oasis,and northern desert regions of the basin were 0.598,0.461,and 0.237,respectively,demonstrating evident spatial ***,the ENR of the basin exhibited distinct distribution characteristics across different dimension,whereas the trend of the integrated ENR of the basin was consistent with that of elemental,structural,and functional resilience,indicating the constructed three-region ENR model based on the logical relationship of element-structure-function was suitable for evaluation of the ENR in arid inland river ***,strategies for enhancing regional ENR were proposed from the perspective of adapting to climate change.

关键词： Ecological Network Resilience(ENR) Complex Adaptive System(CAS) element-structure-function Shiyang River Basin Northwest China

Review on frost resistance and anti-clogging of pervious concrete

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Journal of Traffic and Transportation Engineering(English Edition) 2024年第3期11卷 481-496页

作者： zhuo Wang Zhichen liu Feng Zeng Kun He Shuaicheng Guo China Railway Construction Group Co. Ltd.Beijing 100040China State Key Laboratory of Bridge Safety and Resilience College of Civil EngineeringHunan UniversityChangsha 410082China

Pervious concrete is a special type of concrete that is of high porosity and contains no or a small amount of fine aggregate,and it is an important basic material for sponge city *** presence of a large number of connected pores inside pervious concrete leads to a marked difference in durability failure mechanism compared with that of ordinary *** this study,the frost resistance and anti-clogging of pervious concrete were introduced in detail,and the methods to improve their performance were summarized *** cracking pattern of pervious concrete is influenced by geometric characteristics and three-dimensional morphological features of pores,resulting in its crack generation,development,and geometry being significantly different from those of ordinary concrete,thus leading to different freeze-thaw cycle *** addition,due to its different pore structure compared to ordinary concrete,three types of clogging mechanisms,affecting the long-term permeability of pervious concrete were elaborated systematically(i.e.,physical clogging,biological clogging,and chemical clogging).And the ways to improve the anti-clogging of pervious concrete are systematically presented from multiple ***,in order to broaden the engineering applications of pervious concrete,some research proposals are presented in this study.

关键词： Pervious concrete Connected pore Frost resistance Clogging mechanism