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FlowGANAnomaly: Flow-Based Anomaly Network Intrusion Detection with Adversarial Learning

Chinese Journal of Electronics 2024年第1期33卷 58-71页

作者： Zeyi LI pan wang Zixuan wang School of Computer Science Nanjing University of Posts and Telecommunications School of Modern Posts Nanjing University of Posts and Telecommunications School of Internet of Things Nanjing University of Posts and Telecommunications

In recent years, low recall rates and high dependencies on data labelling have become the biggest obstacle to developing deep anomaly detection(DAD) techniques. Inspired by the success of generative adversarial networks(GANs) in detecting anomalies in computer vision and imaging, we propose an anomaly detection model called Flow GANAnomaly for detecting anomalous traffic in network intrusion detection systems(NIDS). Unlike traditional GAN-based approaches, which are composed of a flow encoder, a convolutional encoder-decoder-encoder, a flow decoder and a convolutional encoder, the architecture of this model consists of a generator(G) and a discriminator(D).Flow GANAnomaly maps the different types of traffic feature data from separate datasets to a uniform feature space,thus can capture the normality of network traffic data more accurately in an adversarial manner to mitigate the problem of the high dependence on data labeling. Moreover, instead of simply detecting the anomalies by the output of D, we proposed a new anomaly scoring method that integrates the deviation between the output of two Gs’ convolutional encoders with the output of D as weighted scores to improve the low recall rate of anomaly detection. We conducted several experiments comparing existing machine learning algorithms and existing deep learning methods(Auto Encoder and VAE) on four public datasets(NSL-KDD, CIC-IDS2017, CIC-DDo S2019, and UNSW-NB15). The evaluation results show that Flow GANAnomaly can significantly improve the performance of anomaly-based NIDS.

关键词： Anomaly detection Unsupervised learning Generative adversarial network Intrusion detection system

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Galerkin-based quasi-smooth manifold element(QSME)method for anisotropic heat conduction problems in composites with complex geometry

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Applied Mathematics and Mechanics(English Edition) 2024年第1期45卷 137-154页

作者： pan wang Xiangcheng HAN Weibin WEN Baolin wang Jun LIANG School of Civil Engineering Central South UniversityChangsha 410083China Institute of Advanced Structure Technology Beijing Institute of TechnologyBeijing 100081China School of Science Harbin Institute of TechnologyShenzhen 518055Guangdong ProvinceChina

The accurate and efficient analysis of anisotropic heat conduction problems in complex composites is crucial for structural design and performance evaluation. Traditional numerical methods, such as the finite element method(FEM), often face a trade-off between calculation accuracy and efficiency. In this paper, we propose a quasi-smooth manifold element(QSME) method to address this challenge, and provide the accurate and efficient analysis of two-dimensional(2D) anisotropic heat conduction problems in composites with complex geometry. The QSME approach achieves high calculation precision by a high-order local approximation that ensures the first-order derivative continuity.The results demonstrate that the QSME method is robust and stable, offering both high accuracy and efficiency in the heat conduction analysis. With the same degrees of freedom(DOFs), the QSME method can achieve at least an order of magnitude higher calculation accuracy than the traditional FEM. Additionally, under the same level of calculation error, the QSME method requires 10 times fewer DOFs than the traditional FEM. The versatility of the proposed QSME method extends beyond anisotropic heat conduction problems in complex composites. The proposed QSME method can also be applied to other problems, including fluid flows, mechanical analyses, and other multi-field coupled problems, providing accurate and efficient numerical simulations.

关键词： anisotropic heat conduction quasi-smooth manifold element(QSME) composite with complex geometry numerical simulation finite element method(FEM)

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Radiation build-up and dissipation in Raman random fiber laser

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Science China(Information Sciences) 2024年第1期67卷 254-260页

作者： Shengtao LIN Zinan wang Jiaojiao ZHANG pan wang Han WU Yifei QI Key Laboratory of Optical Fiber Sensing and Communications University of Electronic Science and Technology of China College of Electronics and Information Engineering Sichuan University

Raman random fiber laser(RRFL) is a complex physical system that arises from the distributed Raman amplification and the intrinsic stochasticity of fiber scattering.The analysis of the underlying lightwave kinetics at steady state has been the focus of considerable interest.However,the transient state,such as the RRFL build-up and dissipation,is particularly important for revealing the lightwave interaction process.Here,we investigate for the first time the RRFL dynamics at the transient state and track the RRFL temporal and spectral evolution theoretically and experimentally.Particularly,with the contribution of random distributed feedback,RRFL build-up exhibits continuous Verhulst logistic growth curves without cavity-related features,which is significantly different from the step-like growth curve of conventional fiber lasers.Furthermore,the radiation build-up duration is inversely related to the pump power,and the spectral evolution of the RRFL undergoes two phases,i.e.,from spectral density increase to spectral broadening.From the steady state to the pump switch-off state,the RRFL output power dissipates immediately,and the remaining Stokes lightwave from the Rayleigh scattering will gradually disappear after one round trip.This work provides new insights into the transient dynamic features of the RRFL.

关键词： random fiber laser stimulated Raman scattering transient phenomenon nonlinear optics łinebreak biological growth dynamics

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Evolution hydrothermal aging resistance mechanism study of zirconium and manganese doped CeO2 catalysts in soot catalytic combustion based on low Miller indices crystal surface effect

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Journal of Rare Earths 2024年第7期42卷 1272-1281页

作者： Zonglin Li pan wang Hong Ni Chengcheng Ao Lidong Zhang Hefeng Zhang Kai Li School of Automotive and Traffic Engineering Jiangsu University State Environmental Protection Key Laboratory of Vehicle Emission Control and Simulation Chinese Research Academy of Environmental Science National Synchrotron Radiation Laboratory University of Science and Technology of China

The thermogravimetric analysis（TGA） experiments were carried out to reveal the mechanism of Zr and Mn doping on catalytic activity of CeO2catalyst both fresh and after hydrothermal aging,and the lattice morphology and valence changes were characterized by means of Brunauer-Emmett-Teller（BET）method,X-ray diffraction（XRD）,X-ray photoelectron spectroscopy（XPS）,and H2-temperature programmed reduction（H2-TPR）.Density functional theory（DFT） and molecular thermodynamics calculations were applied to investigate the change in catalytic activity,crystal surface energy and crystal morphology caused by hydrothermal aging.The maximum reaction rate temperature of fresh Mn/CeO2（389℃） is similar to that of CeO2（371℃） and lower than that of Zr/CeO2（447℃）,but the catalytic performance of CeO2decreases more severely after hydrothermal aging.The catalyst crystals show different degrees of crystal surface migration after hydrothermal aging,which leads to the reduction of Ce3+/Ce4+ratio and the active sites shift.DFT calculations indicate that the doping of Zr and Mn reduces the surface energy of the low Miller indices surface and increases the oxygen vacancy formation energy,leading to better thermal stability and lower catalytic activity.The Zr and Mn doping also changes the adsorption energy and Gibbs free energy of H2O,which dominates the migration of（1 1 1） to（1 1 0） and（1 0 0） in the vapor environment.The crystal surface migration mechanism of CeO2catalysts doped with Zr and Mn induced by H2O molecules at high temperature obtained in this study can provide a valuable addition to the regeneration of CeO2catalysts in the after-treatment systems of diesel engines.

关键词： CDPF CeO2-based catalyst DFT calculations Rare earth metal oxides Soot

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Generating a nanoscale blade-like optical field in a coupled nanofiber pair

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Photonics Research 2024年第1期12卷 154-162页

作者： YUXIN YANG JIAXIN GAO HAO WU ZHANKE ZHOU LIU YANG XIN GUO pan wang LIMIN TONG Interdisciplinary Center for Quantum Information New Cornerstone Science LaboratoryState Key Laboratory of Extreme Photonics and InstrumentationCollege of Optical Science and EngineeringZhejiang UniversityHangzhou 310027China Jiaxing Key Laboratory of Photonic Sensing&Intelligent Imaging Intelligent Optics&Photonics Research CenterJiaxing Research Institute Zhejiang UniversityJiaxing 314000China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China

An optical field with sub-nm confinement is essential for exploring atomic-or molecular-level light-matter interaction.While such fields demonstrated so far have typically point-like cross-sections,an optical field having a higher-dimensional cross-section may offer higher flexibility and/or efficiency in applications.Here,we propose generating a nanoscale blade-like optical field in a coupled nanofiber pair(CNP)with a 1-nm-width central slit.Based on a strong mode coupling-enabled slit waveguide mode,a sub-nm-thickness blade-like optical field can be generated with a cross-section down to~0.28 nm×38 nm at 1550 nm wavelength(i.e.,a thickness of~λ_(0)∕5000)and a peak-to-background intensity ratio(PBR)higher than 20 d B.The slit waveguide mode of the CNP can be launched from one of the two nanofibers that are connected to a standard optical fiber via an adiabatical fiber taper,in which a fundamental waveguide mode of the fiber can be converted into a high-purity slit mode with high efficiency(>98%)within a CNP length of less than 10μm at 1550 nm wavelength.The wavelengthdependent behaviors and group velocity dispersion in mode converting processes are also investigated,showing that such a CNP-based design is also suitable for broadband and ultrafast pulsed operation.Our results may open up new opportunities for studying light-matter interaction down to the sub-nm scale,as well as for exploring ultra-high-resolution optical technology ranging from super-resolution nanoscopy to chemical bond manipulation.

关键词： fiber waveguide optical

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Experimental study of the influencing factors and mechanisms of the pressure-reduction and augmented injection effect by nanoparticles in ultra-low permeability reservoirs

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Petroleum Science 2024年第3期21卷 1915-1927页

作者： pan wang Yu-Hang Hu Liao-Yuan Zhang Yong Meng Zhen-Fu Ma Tian-Ru wang Zi-Lin Zhang Ji-Chao Fang Xiao-Qiang Liu Qing You Yan Zhang Beijing Key Laboratory of Unconventional Natural Gas Geological Evaluation and Development Engineering China University of Geosciences (Beijing) School of Energy Resources China University of Geosciences (Beijing) Petroleum Engineering Technology Research Institute Sinopec Shengli Oilfield Company Hekou Oil Production Plant Sinopec Shengli Oilfield Company Petroleum Exploration and Production Research Institute SINOPEC CNPC Engineering Technology R&D Company Limited

Nanoparticles(NPs) have gained significant attention as a functional material due to their ability to effectively enhance pressure reduction in injection processes in ultra-low permeability reservoirs. NPs are typically studied in controlled laboratory conditions, and their behavior in real-world, complex environments such as ultra-low permeability reservoirs, is not well understood due to the limited scope of their applications. This study investigates the efficacy and underlying mechanisms of NPs in decreasing injection pressure under various injection conditions(25—85°C, 10—25 MPa). The results reveal that under optimal injection conditions, NPs effectively reduce injection pressure by a maximum of 22.77% in core experiment. The pressure reduction rate is found to be positively correlated with oil saturation and permeability, and negatively correlated with temperature and salinity. Furthermore, particle image velocimetry(PIV) experiments(25°C, atmospheric pressure) indicate that the pressure reduction is achieved by NPs through the reduction of wall shear resistance and wettability change. This work has important implications for the design of water injection strategies in ultra-low permeability reservoirs.

关键词： Nanoparticle Pressure reduction Augmented injection Ultra-low permeability reservoir

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Potentiation of the lateral habenula-ventral tegmental area pathway underlines the susceptibility to depression in mice with chronic pain

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Science China(Life Sciences) 2024年第1期67卷 67-82页

作者： Chun-Kui Zhang pan wang Yuan-Yuan Ji Jian-Shuai Zhao Jun-Xiang Gu Xian-Xia Yan Hong-Wei Fan Ming-Ming Zhang Yu Qiao Xiao-Die Liu Bao-Juan Li Ming-Hui wang Hai-Long Dong Hao-Hong Li Peng-Cheng Huang Yun-Qing Li Wu-Gang Hou Jin-Lian Li Tao Chen Department of Anatomy and K.K.Leung Brain Research Centre Fourth Military Medical UniversityXi’an 710032China Beijing Institute of Basic Medical Sciences Beijing 100850China Key Laboratory of Ministry of Public Health for Forensic Science Xi’an Jiaotong UniversityXi’an 710061China Department of Anesthesiology Xijing HospitalFourth Military Medical UniversityXi’an 710032China Department of Neurosurgery the Second Affiliated Hospital of Xian Jiaotong UniversityXi’an 710004China School of Biomedical Engineering Fourth Military Medical UniversityXi’an 710032China Affiliated Mental Health Centre and Hangzhou Seventh People’s Hospital Zhejiang University School of MedicineHangzhou 310013China The MOE Frontier Research Center of Brain&Brain-machine Integration Zhejiang University School of Brain Science and Brain MedicineHangzhou 310058China Department of Neurology The First Affiliated Hospital of Nanchang UniversityNanchang 330006China Department of Anatomy School of MedicineNorthwest UniversityXi’an 710069China

Chronic pain often develops severe mood changes such as depression.However,how chronic pain leads to depression remains elusive and the mechanisms determining individuals’responses to depression are largely unexplored.Here we found that depression-like behaviors could only be observed in 67.9%of mice with chronic neuropathic pain,leaving 32.1%of mice with depression resilience.We determined that the spike discharges of the ventral tegmental area(VTA)-projecting lateral habenula(LHb)glutamatergic(Glu)neurons were sequentially increased in sham,resilient and susceptible mice,which consequently inhibited VTA dopaminergic(DA)neurons through a LHbGlu-VTAGABA-VTADA circuit.Furthermore,the LHbGlu-VTADA excitatory inputs were dampened via GABAB receptors in a pre-synaptic manner.Regulation of LHb-VTA pathway largely affected the development of depressive symptoms caused by chronic pain.Our study thus identifies a pivotal role of the LHb-VTA pathway in coupling chronic pain with depression and highlights the activity-dependent contribution of LHbGlu-to-VTADA inhibition in depressive behavioral regulation.

关键词： chronic pain depression lateral habenula ventral tegmental area dopamine susceptibility

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Efficacy of scraping therapy on blood pressure and sleep quality in stage Ⅰ and Ⅱ essential hypertension: A systematic review and meta-analysis

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Journal of Integrative Medicine 2024年第1期22卷 12-21页

作者： Zheng-gang Zhu Jian-ru wang Xiao-yan pan School of Nursing Hunan University of Chinese MedicineChangsha 410208Hunan ProvinceChina School of Health Sciences Universiti Sains MalaysiaKubang Kerian 16150KelantanMalaysia Department of Cardiovascular Medicine the First Affiliated Hospital of Henan University of Chinese MedicineZhengzhou 450000Henan ProvinceChina

Background Scraping therapy is widely used in treating stage I and II essential hypertension in China.However,there has been no systematic evaluation of the efficacy of scraping therapy on blood pressure and sleep quality in stage I and II essential hypertension.Search strategy Seven electronic databases(PubMed,Scopus,Cochrane Library,Web of Science,EBSCO,China National Knowledge Infrastructure and Wanfang Data electronic databases)were searched from inception to December 2022.Based on the principle of combining subject words with text words,the search strategy was constructed around search terms for“scraping therapy,”“scraping,”“Guasha,”“Gua sha,”“hypertension,”and“high blood pressure”during the database searches.Inclusion criteria Randomized controlled trials(RCTs)were included if they recruited patients with stage I and II essential hypertension and included a scraping therapy intervention.The intervention group received antihypertensive drugs and scraping therapy,while the control group only took antihypertensive drugs.Data extraction and analysis Review Manager 5.4.0 and STATA 15.1 were used to enter all the relevant outcome variables to conduct the meta-analysis.The quality of the selected RCTs was assessed using the PEDro scale.The sensitivity analysis was carried out by iteratively excluding individual studies and repeating the analysis to determine the stability of the findings and identify any studies with greater influence on the outcome.Subgroup analysis was performed to find the source of heterogeneity.Funnel plots were used to evaluate the publication bias of included studies.Results Nine RCTs including 765 participants were selected.Meta-analysis showed that scraping therapy combined with medication had an advantage over the use of medication alone in lowering systolic blood pressure(mean difference[MD]=?5.09,95%confidence interval[CI]=?6.50 to?3.67,P<0.001)and diastolic blood pressure(MD=?2.66,95%CI=?3.17 to?2.14,P<0.001).Subgroup analysis showed that scraping therapy improved sleep quality in mid

关键词： Scraping therapy Essential hypertension Efficacy Blood pressure Sleep quality Systematic review Meta-analysis

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Automatic calculation of the magnetometer zero offset using the interplanetary magnetic field based on the wang-pan method

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Earth and Planetary Physics 2022年第1期6卷 52-60页

作者： XiaoWen Hu GuoQiang wang ZongHao pan Chinese Academy of Sciences Key Laboratory of Geospace Environment School of Earth and Space SciencesUniversity of Science and Technology of ChinaHefei 230026China Institute of Space Science and Applied Technology Harbin Institute of TechnologyShenzhen 518055China

The space-borne fluxgate magnetometer(FGM)requires regular in-flight calibration to obtain its zero offset.Recently,wang GQ and pan ZH(2021a)developed a new method for the zero offset calibration based on the properties of Alfvén waves.They found that an optimal offset line(OOL)exists in the offset cube for a pure Alfvén wave and that the zero offset can be determined by the intersection of at least two nonparallel OOLs.Because no pure Alfvén waves exist in the interplanetary magnetic field,calculation of the zero offset relies on the selection of highly Alfvénic fluctuation events.Here,we propose an automatic procedure to find highly Alfvénic fluctuations in the solar wind and calculate the zero offset.This procedure includes three parts:(1)selecting potential Alfvénic fluctuation events,(2)obtaining the OOL,and(3)determining the zero offset.We tested our automatic procedure by applying it to the magnetic field data measured by the FGM onboard the Venus Express.The tests revealed that our automatic procedure was able to achieve results as good as those determined by the Davis-Smith method.One advantage of our procedure is that the selection criteria and the process for selecting the highly Alfvénic fluctuation events are simpler.Our automatic procedure could also be applied to find fluctuation events for the Davis-Smith method.

关键词： fluxgate magnetometer in-flight calibration zero offset highly Alfvénic fluctuations automatic procedure

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Developmental Impairments of Synaptic Refinement in the Thalamus of a Mouse Model of Fragile X Syndrome

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Neuroscience Bulletin 2024年第4期40卷 439-450页

作者： Xiaotong Wu Yali Liu Xiaomeng wang Lu Zheng Libiao pan Hao wang Department of Neurosurgery of Second Affiliated Hospital and School of Brain Science and Brain Medicine Key Laboratory for Biomedical Engineering of Education MinistryZhejiang University School of MedicineHangzhou310058China Nanhu Brain-computer Interface Institute Hangzhou311100China NHC and CAMS Key Laboratory of Medical Neurobiology MOE Frontier Science Center for Brain Research and Brain Machine IntegrationKey Laboratory of Precise Treatment and Clinical Translational Research of Neurological DiseasesSchool of Brain Science and Brain MedicineZhejiang UniversityHangzhou310058China Lingang Laboratory Shanghai200031China

While somatosensory over-reactivity is a common feature of autism spectrum disorders such as fragile X syndrome(FXS),the thalamic mechanisms underlying this remain unclear.Here,we found that the developmental elimination of synapses formed between the principal nucleus of V(PrV)and the ventral posterior medial nucleus(VPm)of the somatosensory system was delayed in fragile X mental retardation 1 gene knockout(Fmr1 KO)mice,while the developmental strengthening of these synapses was disrupted.Immunohistochemistry showed excessive VGluT2 puncta in mutants at P12–13,but not at P7–8 or P15–16,confirming a delay in somatic pruning of PrV-VPm synapses.Impaired synaptic function was associated with a reduction in the frequency of quantal AMPA events,as well as developmental deficits in presynaptic vesicle size and density.Our results uncovered the developmental impairment of thalamic relay synapses in Fmr1 KO mice and suggest that a thalamic contribution to the somatosensory over-reactivity in FXS should be considered.

关键词： Fragile X syndrome Synaptic refinement VPm Sensory over-reactivity

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