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Identity-Preserving Adversarial Training for Robust Network Embedding

Journal of Computer science & technology 2024年第1期39卷 177-191页

作者：岑科廷沈华伟曹婍徐冰冰程学旗 Data Intelligence System Research Center Institute of Computing TechnologyChinese Academy of SciencesBeijing 100190China University of Chinese academy of sciences Beijing 101480China Beijing academy of Artificial Intelligence Beijing 100000China Chinese academy of sciences Key Laboratory of Network Data science and technology Institute of Computing Technology Chinese Academy of SciencesBeijing 100190China

Network embedding,as an approach to learning low-dimensional representations of nodes,has been proved extremely useful in many applications,e.g.,node classification and link ***,existing network embed-ding models are vulnerable to random or adversarial perturbations,which may degrade the performance of network em-bedding when being applied to downstream *** achieve robust network embedding,researchers introduce adversari-al training to regularize the embedding learning process by training on a mixture of adversarial examples and original ***,existing methods generate adversarial examples heuristically,failing to guarantee the imperceptibility of generated adversarial examples,and thus limit the power of adversarial *** this paper,we propose a novel method Identity-Preserving Adversarial Training(IPAT)for network embedding,which generates imperceptible adversarial exam-ples with explicit identity-preserving *** formalize such identity-preserving regularization as a multi-class classification problem where each node represents a class,and we encourage each adversarial example to be discriminated as the class of its original *** experimental results on real-world datasets demonstrate that our proposed IPAT method significantly improves the robustness of network embedding models and the generalization of the learned node representations on various downstream tasks.

关键词： network embedding identity-preserving adversarial training adversarial the example

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Experimental investigation of dynamic characteristics of leaching tubing for solution mining of salt cavern carbon and energy storage

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Petroleum science 2024年第4期21卷 2703-2722页

作者： Yin-Ping Li Xin-Bo Ge Xi-Lin Shi Hong-Ling Ma State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil Mechanics Chinese Academy of Sciences University of Chinese academy of sciences College of Energy and Mining Engineering Shandong University of Science and Technology State Key Laboratory of Mining Disaster Prevention and Control Co-founded by Shandong Province and the Ministry of science and technology Shandong University of Science and Technology

Salt caverns are extensively utilized for storing various substances such as fossil energy, hydrogen,compressed air, nuclear waste, and industrial solid waste. In China, when the salt cavern is leached through single-well water solution mining with oil as a cushion, engineering challenges arise with the leaching tubing, leading to issues like damage and instability. These problems significantly hinder the progress of cavern construction and the control of cavern shape. The primary cause of this is the flowinduced vibration instability of leaching tubing within a confined space, which results in severe bending or damage to the tubing. This study presents a model experimental investigation on the dynamic characteristics of leaching tubing using a self-developed liquid-solid coupling physical model experiment apparatus. The experiment utilizes a silicone-rubber pipe(SRP) and a polycarbonate pipe(PCP) to examine the effects of various factors on the dynamic stability of cantilevered pipes conveying fluid. These factors include external space constraint, flexural rigidity, medium outside the pipe, overhanging length, and end conditions. The experiments reveal four dynamic response phenomena: water hammer, static buckling, chaotic motion, and flutter instability. The study further demonstrates that the length of the external space constraint has a direct impact on the flutter critical flow velocity of the cantilevered pipe conveying fluid. Additionally, the flutter critical flow velocity is influenced by the end conditions and different external media.

关键词： Salt cavern storage Solution mining Leaching tubing Experimental investigation Flutter instability

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Design study of charge-stripping scheme of heavy ion beams for HIAF-BRing

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Nuclear science and Techniques 2024年第5期35卷 30-41页

作者： Jun-Jie Zhang Zhi-You Xu Jin-Quan Zhang Wen-Wen Ge Liang-Ting Sun Huan-Yu Zhao Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China School of Nuclear science and technology University of Chinese Academy of SciencesBeijing 100049China

Charge strippers play an essential role in heavy-ion accelerators by stripping the projectile ions to higher charge states to enhance the acceleration efficiency downstream of the *** the high-energy mode of the booster ring(BRing)of the high-intensity heavy-ion accelerator facility,the pre-accelerated ions from the iLinac will be stripped by a carbon foil to higher charge states and then injected into the *** key parameters of the stripper and stripped ions were calculated,and the influence of stripping on the beam quality was *** get high stripping efficiencies,the foil thicknesses and resultant charge state distributions for the typical ions were determined by the code *** equilibrium thickness was obtained for the U beam,while the stripper thicknesses for the Xe and Kr beams were determined based on a compromise between the stripped charge states and the stripping *** energy loss,energy straggling,and emittance growth due to stripping have a non-negligible impact on the transport of the stripped beams and the injection of the ***,these parameters were simulated by *** addition,the foil’s temperature evolution,which greatly affects the foil lifetime,was simulated by *** maximum temperature of the foil bombarded by the U and Xe beams with the nominal parameters will exceed the safe value in terms of the impact of evaporation on the foil’s *** the foil temperature constraint,the highest tolerable beam intensity and the injected ion number into the ring were derived for different beam *** results of this paper will present important reference data for the optimization design and commissioning of the beamline and injection to the BRing for the stripped ions.

关键词： High-intensity heavy-ion accelerator facility Charge stripper Energy spread Thermal analysis Emittance growth Injection turns

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Convex-up Style of Deformation within Grabens in Regions of Incomplete Crossing Conjugate Normal Faults: A Numerical Simulation Investigation and Case Study

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Journal of Earth science 2024年第3期35卷 839-849页

作者： Zheng Li Kai Wang Xiong Xiong Bing Zhou School of Geophysics and Geomatics China University of GeosciencesWuhan 430074China State Key Laboratory of Geodesy and Earth’s Dynamics Innovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhan 430077China Department of Earth Sicences Khalifa UniversityAbu DhabiUnited Arab Emirates

Crossing conjugate normal faults(CCNFs)are extensively developed in many hydrocarbon-producing basins,generally existing in the form of incomplete ***,the effect of the non-conjugate zone of the CCNFs on the conjugate relay zone post late tectonic action has not been previously *** use 3D elastic-plastic modeling to investigate the influence of incomplete(i.e.,partially intersecting)CCNFs on the pattern of deformation of strata in the intersection region.A series of model simulations were performed to examine the effects of horizontal tectonic extension,fault size,and fault depth on the deformation of conjugate relay zones of incomplete *** analyses yielded the following results.(1)The model of incomplete conjugation predicts a convex-up style of deformation in the conjugate graben region superimposed on overall subsidence under applied horizontal tectonic extension.(2)The degree of convex-up deformation of the conjugate graben depends on the influence of the non-conjugate zone on the conjugate relay zone,which varies with the amount of horizontal tectonic extension,fault size,and fault burial depth.(3)Our results indicate that incomplete CCNFs can form convex-up deformation,similar to that in the Nanpu Sag area and provide a sound understanding of hydrocarbon migration and accumulation.

关键词： incomplete conjugate normal fault conjugate graben convex-up deformation hydrocarbons Nanpu Sag tectonics.

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Assessment of natural and anthropogenic impacts on terrestrial water storage in the Loess Plateau based on different types of GRACE/GRACE-FO solutions

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Journal of Mountain science 2024年第7期21卷 2173-2192页

作者： ZHANG Cheng CHEN Peng ZHU Chengchang LU Jierui ZHANG Yuchen YANG Xinyue WU Mengyan College of Geomatics Xi'an University of Science and TechnologyXi'an 710054China State Key Laboratory of Geodesy and Earth’s Dynamics Innovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhan 430077China

Changes in water resource storage are inevitable due to climate change and human activities,thus understanding alterations in water storage within a specific region is imperative for the planning and management of water *** from the Gravity Recovery and Climate Experiment(GRACE)satellite mission are extensively employed to analyze large-scale total terrestrial water storage anomalies(TWSA).In this study,we derived a more reliable TWSA using different types of GRACE gravity models,which served as the basis for evaluating spatial and temporal variations in total terrestrial water storage and its hydrological components(soil moisture and groundwater)across the Loess ***,we analyzed the impact of natural and anthropogenic influences on water storage in the Loess Plateau,categorizing them into primary and secondary influences,utilizing data on climate and human *** findings revealed a declining trend in the overall TWSA of the Loess Plateau,with a rate of decrease at-0.65±0.05 cm/yr from 2003 to 2020(P<0.01).As the direct factors affecting TWSA,soil moisture dominated the change of TWSA before 2009,and groundwater dominated the change of TWSA after ***,there was variability in the changes of TWSA in the Loess *** in-depth studies showed that soil moisture changes in the study area were primarily driven by evapotranspiration and temperature,with precipitation and vegetation cover status playing a secondary *** activities had a secondary effect on soil moisture in some *** change and agricultural development were major factors in altering groundwater storage in the study *** than that,groundwater was influenced by natural factors to a limited *** findings provided valuable insights for local governments to implement proactive water management policies.

关键词： GRACE Terrestrial water storage Human activity Loess Plateau

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STGNN-LMR:A Spatial–Temporal Graph Neural Network Approach Based on sEMG Lower Limb Motion Recognition

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Journal of Bionic Engineering 2024年第1期21卷 256-269页

作者： Weifan Mao Bin Ma Zhao Li Jianxing Zhang Yizhou Lu Zhuting Yu Feng Zhang Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201210China University of Chinese academy of sciences Beijing 101408China University of science and technology of China Hefei 230026China Shanghai Zhongyan Jiuyi technology Co. Ltd.Shanghai 201821China academy of Military science Bejing 100091China

Lower limb motion recognition techniques commonly employ Surface Electromyographic Signal(sEMG)as input and apply a machine learning classifier or Back Propagation Neural Network(BPNN)for ***,this artificial feature engineering technique is not generalizable to similar tasks and is heavily reliant on the researcher’s subject *** contrast,neural networks such as Convolutional Neural Network(CNN)and Long Short-term Memory Neural Network(LSTM)can automatically extract features,providing a more generalized and adaptable approach to lower limb motion *** this approach overcomes the limitations of human feature engineering,it may ignore the potential correlation among the sEMG *** paper proposes a spatial–temporal graph neural network model,STGNN-LMR,designed to address the problem of recognizing lower limb motion from multi-channel ***-LMR transforms multi-channel sEMG into a graph structure and uses graph learning to model spatial–temporal *** 8-channel sEMG dataset is constructed for the experimental stage,and the results show that the STGNN-LMR model achieves a recognition accuracy of 99.71%.Moreover,this paper simulates two unexpected scenarios,including sEMG sensors affected by sweat noise and sudden failure,and evaluates the testing results using hypothesis *** to the experimental results,the STGNN-LMR model exhibits a significant advantage over the control models in noise scenarios and failure *** experimental results confirm the effectiveness of the STGNN-LMR model for addressing the challenges associated with sEMG-based lower limb motion recognition in practical scenarios.

关键词： Lower limb motion recognition Exoskeleton sEMG.Graph neural network Noise Sensor failure

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Influence of acceleration stage electrode voltage on the performance of double-stage Hall effect thruster with adjustable zero magnetic point

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Plasma science and technology 2024年第6期26卷 60-69页

作者：陈龙高维富崔作君段萍许雪松阚子晨檀聪琦陈俊宇 School of science Dalian Maritime UniversityDalian 116026People’s Republic of China

The configuration of electrode voltage and zero magnetic point position has a significant impact on the performance of the double-stage Hall effect thruster. A 2D-3V model is established based on the two-magnetic peak type double-stage Hall thruster configuration, and a particle-in-cell simulation is carried out to investigate the influences of both acceleration electrode voltage value and zero magnetic point position on the thruster discharge characteristics and *** results indicate that increasing the acceleration voltage leads to a larger potential drop in the acceleration stage, allowing ions to gain higher energy, while electrons are easily absorbed by the intermediate electrode, resulting in a decrease in the anode current and ionization rate. When the acceleration voltage reaches 500 V, the thrust and efficiency are maximized, resulting in a 15%increase in efficiency. After the acceleration voltage exceeds 500 V, a potential barrier forms within the channel, leading to a decrease in thruster efficiency. Further study shows that as the second zero magnetic point moves towards the outlet of the channel, more electrons easily traverse the zero magnetic field region, participating in the ionization. The increase in the ionization rate leads to a gradual enhancement in both thrust and efficiency.

关键词： Hall thruster particle-in-cell simulation intermediate electrode zero magnetic point

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Effect of ion stress on properties of magnetized plasma sheath

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Plasma science and technology 2024年第2期26卷 1-12页

作者：陈龙崔作君高维富段萍阚子晨檀聪琦陈俊宇 School of science Dalian Maritime UniversityDalian 116026People's Republic of China

In the plasma sheath, there is a significant gradient in ion velocity, resulting in strong stress on ions treated as a fluid. This aspect has often been neglected in previous sheath studies. This study is based on the Braginskii plasma transport theory and establishes a 1D3V sheath fluid model that takes into account the ion stress effect. Under the assumption that ions undergo both electric and diamagnetic drift in the presheath region, self-consistent boundary conditions,including the ion Bohm velocity, are derived based on the property of the Sagdeev ***, assuming that the electron velocity at the wall follows a truncated Maxwell distribution, the wall floating potential is calculated, leading to a more accurate sheath thickness estimation. The results show that ion stress significantly reduces the sheath thickness, enhances ion Bohm velocity, wall floating potential, and ion flux at the wall. It hinders the acceleration of ions within the sheath, leading to notable alterations in the particle density profiles within the sheath. Further research indicates that in ion stress, bulk viscous stress has the greatest impact on sheath properties.

关键词： magnetized plasma sheath ion stress Bohm criterion

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Enhancing leaching efficiency of ion adsorption rare earths by ameliorating mass transfer effect of rare earth ions by applying an electric field

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Journal of Rare Earths 2024年第1期42卷 172-180,I0006页

作者： Lingbo Zhou Jie Yang Shijie Kang Xiaojun Wang Hongdong Yu Yinhua Wan Rare Earth Institute University of Science and Technology of ChinaHefei230000China Ganjiang Innovation academy Chinese Academy of SciencesGanzhou341000China Jiangxi Institute of Rare Earths Chinese Academy of SciencesGanzhou341000China School of Resources and Environment Engineering Jiangxi University of Science and TechnologyGanzhou341000China

Improving the seepage of leaching solution in the ore body and strengthening the mass transfer process of rare earth ions during in-situ leaching are two critical methods to improve the leaching efficiency of rare *** this study,2 wt%MgSO_(4)solution was used for the indoor simulated column leaching experiment on rare earth samples and an electric field was applied at both ends of the *** the effects of different intensities,initial application time and duration of the electric field on the rare earth leaching system and its mechanism were *** results show that compared with the single MgSO_(4)solution leaching,applying an electric field with a strength of 6 V/cm can save the leaching time of 30 min and increase the flow velocity of the rare earth leachate by 26.98%.Under the optimal conditions of applying an electric field with a strength of 6 V/cm for 20 min to the leaching system after10 min of the rare earth leachate flowing out,the leaching efficiency of sample increases from 81.20% to 86.05% with the increase of 4.85%.The mechanism analysis shows that when a direct current electric field is applied to the rare earth leaching system,rare earth ions rapidly change from disorderly movement with the seepage into faster and directional *** addition,the seepage of the leaching solution is also improved due to the increase of the cross-sectional area of the seepage channel,the polarized water molecules migrate directionally by force from the negative pole,and the movement of the hydrogen is generated by the electrolytic *** impo rtantly,based on the principle of in-situ leaching process,the layout of injection holes and deflector holes in this process provides a natural site for the electrode layout of the electric *** the simple equipme nt and the ope ration,the rare earth leaching process with the applied electric field has high feasibility in industrial application.

关键词： Ion adsorption rare earths Leaching system Electric field Mass transfer process Seepage

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Graph-decomposed k-NN searching algorithm on road network

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Frontiers of Computer science 2024年第3期18卷 243-245页

作者： Wei JIANG Bo NING Guanyu LI Mei BAI Xiao JIA Fangliang WEI Faculty of Information science and technology Dalian Maritime UniversityDalian 116026China Jiangxing Intelligence Inc. Shenzhen 518100China

1 Introduction The k-NN(k Nearest Neighbors)searching problem on road network constitutes a crucial aspect of location-oriented services,which has boasted the practical implications.

关键词： services searching network

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