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A stable staggered-grid finite-difference scheme for acoustic modeling beyond conventional stability limit

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Petroleum Science 2024年第1期21卷 182-194页

作者： Jing-yi Xu yang Liu National Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing 102249China China University of Petroleum(Beijing) Karamay CampusKaramay 834000XinjiangChina

Staggered-grid finite-difference(SGFD)schemes have been widely used in acoustic wave modeling for geophysical *** improved methods are proposed to enhance the accuracy of numerical ***,these methods are inevitably limited by the maximum Courant-Friedrichs-Lewy(CFL)numbers,making them unstable when modeling with large time sampling intervals or small grid *** solve this problem,we extend a stable SGFD scheme by controlling SGFD dispersion relations and maximizing the maximum CFL ***,to improve modeling stability,we minimize the error between the FD dispersion relation and the exact relation in the given wave-number region,and make the FD dispersion approach a given function outside the given wave-number area,thus breaking the conventional limits of the maximum CFL ***,to obtain high modeling accuracy,we use the SGFD scheme based on the Remez algorithm to compute the FD *** addition,the hybrid absorbing boundary condition is adopted to suppress boundary reflections and we find a suitable weighting coefficient for the proposed *** derivation and numerical modeling demonstrate that the proposed scheme can maintain high accuracy in the modeling process and the value of the maximum CFL number of the proposed scheme can exceed that of the conventional SGFD scheme when adopting a small maximum effective wavenumber,indicating that the proposed scheme improves stability during the modeling.

关键词： Acoustic wave Staggered-grid finite-difference(SGFD) modeling Courant-friedrichs-lewy(CFL)number Stability

Low-Frequency Stability Analysis of Power Electronic Traction Transformer Based Train-Network System

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CSEE Journal of Power and Energy Systems 2024年第4期10卷 1608-1617页

作者： yi Hong yang Li Zhikang Shuai Hanyu yang College of Electrical and Information Engineering Hunan University and the Advanced Energy Technology Center of State Grid Shanghai Energy Interconnection Research Institute Co.Ltd.Shanghai 201203China College of Electrical and Information Engineering Hunan UniversityChangsha 410082China College of Electrical Engineering and Controal Science in Nanjing Tech University Nanjing 211816China

Power electronic traction transformers(PETTs)will be increasingly applied to locomotives in the future for their small volume and light ***,similar to conventional trains,PETTs behave as constant power loads and may cause low-frequency oscillation(LFO)to the train-network *** solve this issue,a mathematical model of the PETT is firstly proposed and verified based on the extended describing function(EDF)method in this *** the proposed model,the LLC converter is simplified to an equivalent circuit consisting of a capacitor and a resistor in *** is further demonstrated that the model can apply to various LLC converters with different topologies and ***,when the parameter differences between cells are not obvious,the PETT can be simplified to a single-phase rectifier(i.e.,conventional train)by equivalent *** on the model of PETT,the system low-frequency stability and influential factors are analyzed by using the generalized Nyquist ***,the correctness and accuracy of theoretical analyses are validated by off-line and hardware-in-the-loop simulation results.

关键词： Extended describing function method impedance model low-frequency oscillation power electronic traction transformer train-network system

Enhancing Low-Frequency Microwave Absorption Through Structural Polarization Modulation of MXenes

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Nano-Micro Letters 2024年第10期16卷 435-452页

作者： Bo Shan yang Wang Xinyi Ji yi Huang College of Light Industry Science and Engineering State Key Laboratory of Biobased Fiber Manufacturing TechnologyTianjin University of Science and TechnologyTianjin 300457People's Republic of China National Institute for Advanced Materials Tianjin Key Laboratory of Metal and Molecule Based Material ChemistryKey Laboratory of Functional Polymer MaterialsCollaborative Innovation Center of Chemical Science and Engineering(Tianjin)School of Materials Science and EngineeringNankai UniversityTianjin 300350People's Republic of China

Two-dimensional carbon-based materials have shown promising electromagnetic wave absorption capabilities in mid-and high-frequency ranges,but face challenges in low-frequency absorption due to limited control over polarization response mecha-nisms and ambiguous resonance *** this study,we pro-pose a novel approach to enhance absorption efficiency in aligned three-dimensional(3D)MXene/CNF(cellulose nanofibers)cavities by modifying polarization properties and manipulating resonance response in the 3D MXene *** controlled polarization mechanism results in a significant shift of the main absorption region from the X-band to the S-band,leading to a remarkable reflection loss value of-47.9 dB in the low-frequency ***,our findings revealed the importance of the oriented electromagnetic coupling in influencing electromagnetic response and microwave absorption *** present study inspired us to develop a generic strategy for low-frequency tuned absorption in the absence of magnetic element participation,while orientation-induced polarization and the derived magnetic resonance coupling are the key controlling factors of the method.

关键词： Hierarchical structure MXene Microwave absorption Low-frequency

NFHP-RN:AMethod of Few-Shot Network Attack Detection Based on the Network Flow Holographic Picture-ResNet

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Computer Modeling in Engineering & Sciences 2024年第7期140卷 929-955页

作者： Tao yi Xingshu Chen Mingdong yang Qindong Li yi Zhu School of Cyber Science and Engineering Sichuan UniversityChengdu610065China CyberScience Research Institute Sichuan UniversityChengdu610065China Chengdu Fengwei Technology Co. Ltd.Chengdu610041China

Due to the rapid evolution of Advanced Persistent Threats(APTs)attacks,the emergence of new and rare attack samples,and even those never seen before,make it challenging for traditional rule-based detection methods to extract universal rules for effective *** the progress in techniques such as transfer learning and meta-learning,few-shot network attack detection has ***,challenges in few-shot network attack detection arise from the inability of time sequence flow features to adapt to the fixed length input requirement of deep learning,difficulties in capturing rich information from original flow in the case of insufficient samples,and the challenge of high-level abstract *** address these challenges,a few-shot network attack detection based on NFHP(Network Flow Holographic Picture)-RN(ResNet)is ***,leveraging inherent properties of images such as translation invariance,rotation invariance,scale invariance,and illumination invariance,network attack traffic features and contextual relationships are intuitively represented in *** addition,an improved RN network model is employed for high-level abstract feature extraction,ensuring that the extracted high-level abstract features maintain the detailed characteristics of the original traffic behavior,regardless of changes in background ***,a meta-learning model based on the self-attention mechanism is constructed,achieving the detection of novel APT few-shot network attacks through the empirical generalization of high-level abstract feature representations of known-class network attack *** results demonstrate that the proposed method can learn high-level abstract features of network attacks across different traffic detail *** state-of-the-artmethods,it achieves favorable accuracy,precision,recall,and F1 scores for the identification of unknown-class network attacks through cross-validation onmultiple datasets.

关键词： APT attacks spatial pyramid pooling NFHP(network flow holo-graphic picture) ResNet self-attention mechanism meta-learning

Odorant-binding protein 19 in Monochamus alternatus involved in the recognition of a volatile strongly emitted from ovipositing host pines

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Insect Science 2024年第1期31卷 134-146页

作者： Ruinan yang Dongzhen Li Shancheng yi yi Wei Manqun Wang Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina Key Laboratory of Forest Protection of National Forestry and Grassland Administration Ecology and Nature Conservation InstituteChinese Academy of ForestryBeijingChina

Monochamus alternatus is the primary carrier of pine wood nematodes,which pose a serious threat to Pinus *** many *** emerging *** adults feed on heathy host pines,while matured adults transfer to stressed host pines for mating and *** odorant-binding proteins(OBPs)of *** have been proved to aid in the complex process of host *** clarify the corresponding relations between OBPs and pine volatiles,more OBPs need to be *** this research,MaltOBP19 showed a specific expression in the antennae and mouthparts of ***,and it was marked in 4 types of antenna sensilla by *** binding assays demonstrated the high binding affinity of MaltOBP19 with camphene and myrcene in *** Y-tube olfactory experiments,*** adults were attracted by camphene and RNAi of OBP19 via microinjection significantly decreased their attraction *** induced phobotaxis,but RNAi had no significant effect on this ***,we found that ingesting dsOBP19 produced by a bacteria-expressed system with a newly constructed vector could lead to the knockdown of *** results suggest that MaltOBP19 may play a role in the process of host conversion via the recognition of camphene,which has been identified to be strongly released in stressed host *** addition,it is proved that knockdown of OBP can be achieved by oral administration of bacteria-expressed double-stranded RNA in *** adults,providing a new perspective in the control of ***.

关键词： bacteria-expressed dsRNA camphene Japanese pine sawyer beetle MaltOBP19 RNAi stressed host pines

Application of a microscopic optical potential of chiral effective field theory in (p, d) transfer reactions

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Nuclear Science and Techniques 2024年第1期35卷 134-144页

作者： yi-Ping Xu Si-Lu Chen Dan-yang Pang School of Nuclear Science and Engineering North China Electric Power UniversityBeijing 102206China School of Physics Beihang UniversityBeijing 100191China

The microscopic global nucleon–nucleus optical model potential(OMP)proposed by Whitehead,Lim,and Holt,the WLH potential(Whitehead et al.,Phys Rev Lett 127:182502,2021),which was constructed in the framework of many-body per-turbation theory with state-of-the-art nuclear interactions from chiral effective field theory(EFT),was tested with(p,d)transfer reactions calculated using adiabatic wave *** target nuclei included both stable and unstable nuclei,and the incident energies reached 200 *** results were compared with experimental data and predictions using the phenomenological global optical potential of Koning and Delaroche,the KD02 ***,we found that the micro-scopic WLH potential described the(p,d)reaction angular distributions similarly to the phenomenological KD02 potential;however,the former was slightly better than the latter for radioactive *** average,the obtained spectroscopic factors(SFs)using both microscopic and phenomenological potentials were similar when the incident energies were below approxi-mately 120 ***,their difference tended to increase at higher incident energies,which was particularly apparent for the doubly magic target nucleus 40Ca.

关键词： Microscopic optical model potential (p,d)transfer Spectroscopic factors

Hematite-facilitated microbial ammoxidation for enhanced nitrogen removal in constructed wetlands

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Frontiers of Environmental Science & Engineering 2024年第7期18卷 35-45页

作者： Hao Qin Wenbo Nie Duo yi Dongxu yang Mengli Chen Tao Liu yi Chen Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment(Ministry of Education) Chongqing UniversityChongqing 400045China College of Environment and Ecology Chongqing UniversityChongqing 400045China Faculty of Geosciences and Environmental Engineering Southwest Jiaotong UniversityChengdu 610031China

Constructed wetlands(CWs)are widely applied for decentralized wastewater ***,achieving efficient removal of ammonia(NH+-N)has proven challenging due to insufficient *** this study,natural hematite(Fe,O3)was employed as a CW substrate(H-CWs)for the first time to drive anaerobic ammonia oxidation coupled with iron(I)reduction(Feammox).Compared to gravel constructed wetlands(G-CWs),ammonia removal was enhanced by 38.14%to 54.03%and nitrous oxide(N_(2)0)emissions were reduced by 34.60%in *** synergistic removal of ammonia and nitrate by H-CWs also resulted in the absence of ammoxidation *** and 15N isotope tracer incubations showed that Feammox accounting for approximately 40%of all ammonia removal in the *** enrichment of iron phosphate(Fe_(3)Fe_(4)(PO_(4))_(6))promoted the accumulation of the Feammox intermediate compound *** nanowires were observed on the surface of H-CW substrates as well,suggesting that the observed biological ammoxidation was most likely related to extracellular electron transfer(EET).Microbial and metagenomics analysis revealed that H-CWs elevated the integrity and enhanced the abundance of functional microorganisms and genes associated with nitrogen ***,the efficient ammonia removal in the absence of O2 together with a reduction in N_(2)O emissions as described in this study may provide useful guidance for hematite-mediated anaerobic ammonia removal in CWs.

关键词： Constructed wetlands Nitrogen removal Feammox Hematite Iron cycle

Understanding the Interfacial Energy Structure and Electron Extraction Process in Inverted Organic Solar Cells with Phosphine-Doped Cathode Interlayers

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Chinese Journal of Chemistry 2024年第12期42卷 1347-1354页

作者： yi yang Jingwen Wang yang Xiao Bowei Xu Jianhui Hou State Key Laboratory of Polymer Physics and Chemistry Beijing National Laboratory for Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China State Key Laboratory of Chemical Resource Engineering College of Materials Science and EngineeringBeijing University of Chemical TechnologyBejing 100029China University of Chinese Academy of Sciences Beijing 100049China

Comprehensive Summary Cathode interlayers(CILs)play an essential role in achieving efficient organic solar cells(OSCs).However,the electronic structure at the electrode/CIL/active layer interfaces and the underlying mechanisms for electron collection remain unclear,which becomes a major obstacle to develop high-performance ***,we investigate the relationship of the electron collection abilities of four cross-linked and n-doped CILs(c-NDI:P0,c-NDI:P1,c-NDI:P2,c-NDI:P3)with their electronic structure of space charge region at heterojunction *** accurately calculating the depletion region width according to the barrier height,doping density and permittivity,we put forward that the optimal thickness of CIL should be consistent with the depletion region width to realize the minimum energy *** a result,the depletion region width is largely reduced from 13 nm to 0.8 nm at the indium tin oxide(ITO)/c-NDI:P0 interface,resulting in a decent PCE of 17.7%for the corresponding inverted OSCs.

关键词： Organic solar cells Cathode interlayer Depletion region width Electric conductivity Electron transport Electron transfer Electron extraction process

Stem Cell Transplantation Represents a New Strategy for the Treatment of Epilepsy

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Neuroscience Bulletin 2024年第5期40卷 673-676页

作者： Yuan Zhou yi Wang Lin yang Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province School of Pharmaceutical Sciences and First Affiliated HospitalZhejiang Chinese Medical UniversityHangzhou310053China Zhejiang Rehabilitation Medical Center Department The Third Affiliated HospitalZhejiang Chinese Medical UniversityHangzhou310013China

Epilepsy is a neurological disorder characterized by faulty neuronal synchronization and repeated *** balance between glutamatergic excitatory neurons and gammaaminobutyric acid inhibitory neurons is critical for opti... 详细信息

关键词： epilepsy Transplantation Strategy