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A seismic elastic moduli module for the measurements of low-frequency wave dispersion and attenuation of fluid-saturated rocks under different pressures

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Petroleum Science 2024年第1期21卷 162-181页

作者： Yan-xiao He Shang-Xu Wang Gen-Yang Tang Chao Sun Hong-Bing Li San-Yi Yuan Xian Wei Li-Deng Gan xiao-feng dai Qiang Ge Peng-Peng Wei Hui-Qing Zhang National Key Laboratory of Petroleum Resources and Engineering CNPC Key Lab of Geophysical ExplorationCollege of GeophysicsChina University of Petroleum(Beijing)Beijing102249China School of Resources and Geosciences China University of Mining and TechnologyXuzhou221116JiangsuChina Research Institute of Petroleum Exploration and Development CNPCBeijing100083China Beijing Vocational College of Labour and Social Security Beijing100029China PetroChina Dagang Oilfield Exploration and Development Research Institute CNPCTianjin300280China

Knowledge about the seismic elastic modulus dispersion,and associated attenuation,in fluid-saturated rocks is essential for better interpretation of seismic observations taken as part of hydrocarbon identification and time-lapse seismic surveillance of both conventional and unconventional reservoir and overburden performances.A Seismic Elastic Moduli Module has been developed,based on the forced-oscillations method,to experimentally investigate the frequency dependence of Young's modulus and Poisson's ratio,as well as the inferred attenuation,of cylindrical samples under different confining pressure *** with three standard samples showed that the measured elastic moduli were consistent with the published data,indicating that the new apparatus can operate reliably over a wide frequency range of f∈[1-2000,10^(6)]*** Young's modulus and Poisson's ratio of the shale and the tight sandstone samples were measured under axial stress oscillations to assess the frequency-and pressure-dependent *** dry condition,both samples appear to be nearly frequency independent,with weak pressure dependence for the shale and significant pressure dependence for the *** particular,it was found that the tight sandstone with complex pore microstructure exhibited apparent dispersion and attenuation under brine or glycerin saturation conditions,the levels of which were strongly influenced by the increased effective *** addition,the measured Young's moduli results were compared with the theoretical predictions from a scaled poroelastic model with a reasonably good agreement,revealing that the combined fluid flow mechanisms at both mesoscopic and microscopic scales possibly responsible for the measured dispersion.

关键词： Low-frequency measurements Dispersion and attenuation Rock physics Fluid flow

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Jackson-type inequalities on high-dimensional spheres

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Science China Mathematics 2024年第11期67卷 2571-2586页

作者： Yeli Niu feng dai Department of Mathematics Shanghai Normal University Department of Mathematical and Statistical Sciences University of Alberta

We study Jackson's inequality on high-dimensional spheres with respect to the modulus of smoothness defined via the rotation *** obtain a version of Jackson's inequality with a dimensionfree constant,extending Newman and Shapiro's well-known results in 1964 from the case of r = 1 and p = ∞ to more general *** results partially overcome the curse of *** also establish similar results on the equivalence of the K-functional and modulus of smoothness.

关键词： modulus of smoothness $K$-functional Jackson's inequality high-dimensional approximation

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Fast nuclear-spin gates and electrons−nuclei entanglement of neutral atoms in weak magnetic fields

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Frontiers of physics 2024年第2期19卷 179-203页

作者： xiao-feng Shi School of Physics Xidian UniversityXi’an 710071China

We present a novel class of Rydberg-mediated nuclear-spin entanglement in divalent atoms with global laser ***,we show a fast nuclear-spin controlled phase gate of an arbitrary phase realizable either with two laser pulses when assisted by Stark shifts,or with three ***,we propose to create an electrons−nuclei-entangled state,which is named a super bell state(SBS)for it mimics a large Bell state incorporating three small Bell ***,we show a protocol to create a three-atom electrons-nuclei entangled state which contains the three-body W and Greenberger−Horne−Zeilinger(GHZ)states *** protocols possess high intrinsic fidelities,do not require single-site Rydberg addressing,and can be executed with large Rydberg Rabi frequencies in a weak,Gauss-scale magnetic *** latter two protocols can enable measurement-based preparation of Bell,hyperentangled,and GHZ states,and,specifically,SBS can enable quantum dense coding where one can share three classical bits of information by sending one particle.

关键词： nuclear-spin qubit electrons−nuclei entanglement super Bell state Greenberger−Horne−Zeilinger state Rydberg-mediated entanglement quantum dense coding

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Refractory autoimmune hemolytic anemia in a patient with systemic lupus erythematosus and ulcerative colitis:A case report

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World Journal of Clinical Cases 2024年第13期12卷 2286-2292页

作者： dai-Xing Chen Yue Wu Sui-feng Zhang xiao-Jun Yang Department of Digestive System Chongqing Traditional Chinese Medicine HospitalChongqing 400021China

BACKGROUND Ulcerative colitis(UC)and systemic lupus erythematosus(SLE)are both systemic immunoreactive diseases,and their pathogenesis depends on the interaction between genes and environmental *** are no reports of UC with SLE in China,but six cases of SLE with UC have been reported in *** combination of these two diseases has distinct effects on the pathogenesis of both *** SUMMARY A female patient(30 years old)came to our hospital due to dull umbilical pain,diarrhea and mucous bloody stool in August 2018 and was diagnosed with *** symptoms were relieved after oral administration of mesalazine(1 g po tid)or folic acid(5 mg po qd),and the patient were fed a control *** June 24,2019,the patient was admitted for treatment due to anemia and *** hospitalization,the patient had repeated low-grade fever and a progressively decreased Hb *** tests revealed positive antinuclear antibody test,positive anti-dsDNA antibody,0.24 g/L C3(0.9-1.8 g/L),0.04 g/L C4(0.1-0.4 g/L),32.37 g/L immunoglobulin(8-17 g/L),and 31568.1 mg/24 h total 24-h urine protein(0-150 mg/24 h).The patient was diagnosed with SLE involving the joints,kidneys and blood *** reported cases of SLE were retrieved from PubMed to characterize clinicopathological features and identify prognostic factors for *** The patient was discharged in remission after a series of treatments,such as intravenous methylprednisolone sodium succinate,intravenous human immunoglobulin,cyclophosphamide injection,and plasma *** discharge,the patient took oral prednisone acetate tablets,cyclosporine capsules,hydroxychloroquine sulfate tablets and other treatments for symptoms and was followed up regularly for 1 month,after which the patient's condition continued to improve and stabilize.

关键词： Plasma exchange Autoimmune hemolytic anemia Systemic lupus erythematosus Ulcerative colitis Case report

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A Trust Evaluation Mechanism Based on Autoencoder Clustering Algorithm for Edge Device Access of IoT

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Computers, Materials & Continua 2024年第2期78卷 1881-1895页

作者： xiao feng Zheng Yuan Cyber Security Academy Beijing University of Posts and TelecommunicationsBeijing100876China Department of Cyberspace Security Beijing Electronic Science and Technology InstituteBeijing100070China State Grid Info-Telecom Great Power Science and Technology Co. Ltd.Beijing102211China

First,we propose a cross-domain authentication architecture based on trust evaluation mechanism,including registration,certificate issuance,and cross-domain authentication processes.A direct trust evaluation mechanism based on the time decay factor is proposed,taking into account the influence of historical interaction *** weight the time attenuation factor to each historical interaction record for updating and got the new historical record *** refer to the beta distribution to enhance the flexibility and adaptability of the direct trust assessment model to better capture time trends in the historical *** we propose an autoencoder-based trust clustering *** perform feature extraction based on *** leibler(KL)divergence is used to calculate the reconstruction *** constructing a convolutional autoencoder,we introduce convolutional neural networks to improve training efficiency and introduce sparse constraints into the hidden layer of the *** sparse penalty term in the loss function measures the difference through the KL *** clustering is performed based on the density based spatial clustering of applications with noise(DBSCAN)clustering *** the clustering process,edge nodes have a variety of trustworthy attribute *** assign different attribute weights according to the relative importance of each attribute in the clustering process,and a larger weight means that the attribute occupies a greater weight in the calculation of ***,we introduced adaptive weights to calculate comprehensive trust *** experiments prove that our trust evaluation mechanism has excellent reliability and accuracy.

关键词： Cross-domain authentication trust evaluation autoencoder

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Impact of continuous low water stage on the breeding environment of Oncomelania hupensis: a case study of Poyang Lake area in China

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Infectious Diseases of Poverty 2020年第4期9卷 156-157页

作者： Fei Hu Qi-Yue Li xiao-feng dai Zhao-Jun Li Shang-Biao Lv Chun-Fang Lu Yi-feng Li Min Yuan Yue-Ming Liu Ying Liu Dan-Dan Lin Jiangxi Provincial Institute of Parasitic Diseases No.239First Gaoxin Rd.Gaoxin District330096NanchangJiangxi ProvincePeople’s Republic of China Jiangxi Province Key Laboratory of Schistosomiasis Prevention and Control Nanchang330096People’s Republic of China Jiangxi Normal University No.99Ziyang AvenueNanchang330022Jiangxi provincePeople’s Republic of China

Background Oncomelania hupensis is the only intermediate host of Schistosoma japonicum and plays a decisive role in its *** variation of water level greatly affects the reproduction and growth of ***,in this paper,we analyze the variations of water level in the Poyang Lake region from 1993 to 2016 combined with satellite imagery to elucidate the evolution of the snail breeding *** By employing remote sensing data from 1993 to 2016(April–June and September–November),the vegetation area of Poyang Lake and the vegetation area at different elevations were extracted and ***,the average daily water level data from the four hydrological stations(Hukou station,Xingzi station,Tangyin station and Kangshan station)which represent the typical state of Poyang Lake were collected from 1993 to *** variance of the monthly mean water level,inundation time and the average area were analyzed by variance to find a significance level ofα=*** According to hydrological data before and after 2003,the average water level after 2003 is significantly lower than that before 2003 in Poyang *** 2003,the time of inundateing the snail breeding period was later in April to June than that before 2003,while the time of wate-falling stage in September to November moved forward after 2003 than before *** them,the lowest water level affecting the breeding and growing period of *** in the northern part of Poyang Lake decreased from 11 m to 9 *** 2003,the expansion of meadow area in the north part of Poyang Lake was mainly concentrated in the elevation of 9–11 m,and the newly increased infested-meadow in the lake area was mainly concentrated in the north part of Poyang *** By comparing the change of water level characteristics in different parts of the Poyang Lake area as well as changes in meadow area before and after 2003,it is found that the water level changes mainly affect the snail breeding are

关键词： Oncomelania hupensis Water level Lake meadow Snail control Poyang Lake China

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Plasma-assisted ammonia synthesis under mild conditions for hydrogen and electricity storage:Mechanisms,pathways,and application prospects

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Frontiers in Energy 2024年第4期18卷 418-435页

作者： feng GONG Yuhang JING Rui xiao Key Laboratory of Energy Thermal Conversion and Process Measurement and Control of the Ministry of Education School of Energy and EnvironmentSoutheast UniversityNanjing 210096China

Ammonia,with its high hydrogen storage density of 17.7 wt.%(mass fraction),cleanliness,efficiency,and renewability,presents itself as a promising zero-carbon ***,the traditional Haber−Bosch(H−B)process for ammonia synthesis necessitates high temperature and pressure,resulting in over 420 million tons of carbon dioxide emissions annually,and relies on fossil fuel *** contrast,dielectric barrier discharge(DBD)plasma-assisted ammonia synthesis operates at low temperatures and atmospheric pressures,utilizing nitrogen and hydrogen radicals excited by energetic electrons,offering a potential alternative to the H−B *** method can be effectively coupled with renewable energy sources(such as solar and wind)for environmentally friendly,distributed,and efficient ammonia *** review delves into a comprehensive analysis of the low-temperature DBD plasma-assisted ammonia synthesis technology at atmospheric pressure,covering the reaction pathway,mechanism,and catalyst system involved in plasma nitrogen *** from current research,it evaluates the economic feasibility of the DBD plasmaassisted ammonia synthesis technology,analyzes existing dilemmas and challenges,and provides insights and recommendations for the future of nonthermal plasma ammonia processes.

关键词： plasma catalysis nitrogen fixation ammonia synthesis hydrogen storage catalyst carbon neutralization

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A Denoiser for Correlated Noise Channel Decoding: Gated-Neural Network

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China Communications 2024年第2期21卷 122-128页

作者： xiao Li Ling Zhao Zhen dai Yonggang Lei School of Electronic and Information Engineering Beihang UniversityBeijing 100191China Beijing Institute of Tracking and Telecommunications Technology BITTT

This letter proposes a sliced-gated-convolutional neural network with belief propagation(SGCNN-BP) architecture for decoding long codes under correlated noise. The basic idea of SGCNNBP is using Neural Networks(NN) to transform the correlated noise into white noise, setting up the optimal condition for a standard BP decoder that takes the output from the NN. A gate-controlled neuron is used to regulate information flow and an optional operation—slicing is adopted to reduce parameters and lower training complexity. Simulation results show that SGCNN-BP has much better performance(with the largest gap being 5dB improvement) than a single BP decoder and achieves a nearly 1dB improvement compared to Fully Convolutional Networks(FCN).

关键词： belief propagation channel decoding correlated noise neural network

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Precisely modulating covalent and coordination bonds in the porous network for highly selective metal ion extraction

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Science China Chemistry 2024年第4期67卷 1039-1040页

作者： Jie Li xiao feng Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials Key Laboratory of Cluster ScienceMinistry of EducationAdvanced Technology Research Institute(Jinan)Frontiers Science Center for High Energy MaterialSchool of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing 100081China

Scandium(Sc)is recognized as a“strategic”and“critical”element by several countries,including the *** Russia,owing to its wide range of applications in high-tech fields such as superconductivity,alloys,lasers,nucle... 详细信息

关键词： alloys coordination network

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Unraveling the modulation essence of p bands in Co-based oxide stability on acidic oxygen evolution reaction

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Nano Research 2024年第7期17卷 5922-5929页

作者： Yafei Yang Yihao Xu Haiquan Liu Qi Zhang Boling Liu Menghua Yang Huan dai Zunjian Ke Dong He xiaobo feng Xiangheng xiao Department of Physics Zhongnan Hospital of Wuhan UniversityWuhan UniversityWuhan 430072China School of Physics and Electronic Information Yunnan Normal UniversityKunming 650500China Yunnan Key Laboratory of Opto-electronic Information Technology Kunming 650500China

The oxygen evolution reaction(OER)electrocatalysts,which can keep active for a long time in acidic media,are of great significance to proton exchange membrane water ***,Ru-Co_(3)O_(4)electrocatalysts with transition metal oxide Co_(3)O_(4)as matrix and the noble metal Ru as doping element have been prepared through an ion exchange–pyrolysis process mediated by metal-organic framework,in which Ru atoms occupy the octahedral sites of Co_(3)O_(4).Experimental and theoretical studies show that introduced Ru atoms have a passivation effect on lattice *** strong coupling between Ru and O causes a negative shift in the energy position of the O p-band ***,the bonding activity of oxygen in the adsorbed state to the lattice oxygen is greatly passivated during the OER process,thus improving the stability of matrix *** addition,benefiting from the modulating effect of the introduced Ru atoms on the metal active sites,the thermodynamic and kinetic barriers have been significantly reduced,which greatly enhances both the catalytic stability and reaction efficiency of Co_(3)O_(4).

关键词： p-band modulation oxygen evolution reaction stability acidic oxygen evolution reaction(OER)

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