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Preface for the Special Issue on“Safety and Intelligent Maintenance of Offshore Structures”

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China Ocean Engineering 2024年第2期38卷 181-182页

作者： xu wan-hai State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation Tianjin UniversityTianjin 300072China

The ocean serves as a vital carrier for human resource development and economic growth and contains rich mineral resources such as oil,natural gas,polymetallic nodules,cobalt-rich ferromanganese crusts,polymetallic sulfides,and rare earth ore.Moreover,the ocean has wealthy reserves of wind,wave,tidal,and solar energy,making it an essential strategic space for sustainable future development.However,offshore structures are complex.

关键词： ocean offshore tidal

A Review on Vibration Control of Multiple Cylinders Subjected to FlowInduced Vibrations

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China Ocean Engineering 2024年第2期38卷 183-197页

作者： xu wan-hai MA Ye-xuan State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation Tianjin UniversityTianjin 300350China Institute of Mechanics Chinese Academy of SciencesBeijing 100190China

The fatigue damage caused by flow-induced vibration(FIV)is one of the major concerns for multiple cylindrical structures in many engineering applications.The FIV suppression is of great importance for the security of many cylindrical structures.Many active and passive control methods have been employed for the vibration suppression of an isolated cylinder undergoing vortex-induced vibrations(VIV).The FIV suppression methods are mainly extended to the multiple cylinders from the vibration control of the isolated cylinder.Due to the mutual interference between the multiple cylinders,the FIV mechanism is more complex than the VIV mechanism,which makes a great challenge for the FIV suppression.Some efforts have been devoted to vibration suppression of multiple cylinder systems undergoing FIV over the past two decades.The control methods,such as helical strakes,splitter plates,control rods and flexible sheets,are not always effective,depending on many influence factors,such as the spacing ratio,the arrangement geometrical shape,the flow velocity and the parameters of the vibration control devices.The FIV response,hydrodynamic features and wake patterns of the multiple cylinders equipped with vibration control devices are reviewed and summarized.The FIV suppression efficiency of the vibration control methods are analyzed and compared considering different influence factors.Further research on the FIV suppression of multiple cylinders is suggested to provide insight for the development of FIV control methods and promote engineering applications of FIV control methods.

关键词： flow-induced vibration vibration control multiple cylinders tandem side-by-side staggered

MODIFIED STOCHASTIC EXTRAGRADIENT METHODS FOR STOCHASTIC VARIATIONAL INEQUALITY

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Journal of Computational Mathematics 2024年第2期42卷 390-414页

作者： ling Zhang lingling xu School of Management and Economic Beijing Institute of TechnologyBeijing 100081China School of Mathematical Sciences Nanjing Normal UniversityNanjing 210023China School of Mathematical Sciences and Jiangsu Key Laboratory for NSLSCS Nanjing Normal UniversityNanjing 210023China

In this paper,we consider two kinds of extragradient methods to solve the pseudo-monotone stochastic variational inequality problem.First,we present the modified stochastic extragradient method with constant step-size(MSEGMC)and prove the convergence of it.With the strong pseudo-monotone operator and the exponentially growing sample sequences,we establish the R-linear convergence rate in terms of the mean natural residual and the oracle complexity O(1/ǫ).Second,we propose a modified stochastic extragradient method with adaptive step-size(MSEGMA).In addition,the step-size of MSEGMA does not depend on the Lipschitz constant and without any line-search procedure.Finally,we use some numerical experiments to verify the effectiveness of the two algorithms.

关键词： Stochastic variational inequality Pseudo-monotone Modified stochastic ex-tragradient methods Adaptive step-size

An overview and perspective of identifying lunar craters

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Science China Earth Sciences 2024年第5期67卷 1395-1416页

作者： Yan JIANG Changyi xu ling CHEN State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100029China Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100049China

The spatiotemporal evolution of lunar impact craters is crucial for investigating lunar interior structure,internal and external dynamic processes,and interplanetary impact history.Advances in lunar crater identification are reviewed based on topography and gravity data,and the features and mechanisms of topographic or buried craters are analyzed regarding morphology,gravity anomalies,gravity gradients,and the underlying crust-mantle interface relief.Based on the compiled crater catalog,the early lunar impact flux and thermal evolution are further discussed according to the basin ages and their interior structures.For some ancient impact basins,the crater size-frequency distribution measurements revealed age discrepancies from previous studies,suggesting that the lunar late heavy bombardment event started at~3.95 Ga.The degraded bulge structures of the crust-mantle interface beneath mare basins reveal that these basins formed on the lunar crust surface under high-temperature conditions and underwent prolonged relaxation compared to highland basins.Finally,we reveal that the up-to-date identification of lunar buried craters remains inaccurate and incomplete,preventing us from accurately reconstructing lunar and interplanetary impact histories.Therefore,we propose that a gravity model constructed using localized orthogonal basis functions can be useful for identifying lunar craters.

关键词： Moon Gravity field Craters Impact flux Early evolution

Whispering-gallery-mode barcode-based broadband sub-femtometer-resolution spectroscopy with an electro-optic frequency comb

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Advanced Photonics 2024年第1期6卷 115-125页

作者： Bingxin xu Yangyang wan Xinyu Fan Zuyuan He Shanghai Jiao Tong University State Key Laboratory of Advanced Optical Communication Systems and NetworksDepartment of Electronic EngineeringShanghaiChina Max-Planck Institute of Quantum Optics Hans-Kopfermann-Straûe 185748 GarchingGermany

Spectroscopy is the basic tool for studying molecular physics and realizing biochemical sensing.However,it is challenging to realize sub-femtometer resolution spectroscopy over broad bandwidth.Broadband and high-resolution spectroscopy with calibrated optical frequency is demonstrated by bridging the fields of speckle pattern and electro-optic frequency comb.A wavemeter based on a whispering-gallery-mode barcode is proposed to link the frequencies of a probe continuous-wave laser and an ultrastable laser.The ultrafine electro-optic comb lines are generated from the probe laser to record spectrum of sample with sub-femtometer resolution.Measurement bandwidth is a thousandfold broader than comb bandwidth,by sequentially tuning the probe laser while its wavelength is determined.This approach fully exploits the advantages of two fields to realize 0.8-fm resolution with a fiber laser and 80-nm bandwidth with an external cavity diode laser.The spectroscopic measurements of an ultrahigh Q-factor cavity and gas molecular absorption are experimentally demonstrated.The compact system,predominantly constituted by few-gigahertz electronics and telecommunication components,shows enormous potential for practical spectroscopic applications.

关键词： frequency comb reconstructive wavemeter spectroscopy

Challenging anticoagulation therapy for multiple primary malignant tumors combined with thrombosis:A case report and review of literature

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World Journal of Clinical Cases 2024年第9期12卷 1704-1711页

作者： Jia-Xin Chen ling-ling xu Jing-Ping Cheng xun-Hua xu Department of Gerontology China Resources and Wisco General HospitalWuhan University of Science and TechnologyWuhan 430080Hubei ProvinceChina Medical College Wuhan University of Science and TechnologyWuhan 430065Hubei ProvinceChina Department of Gerontology China Resources and Wisco General HospitalWuhan 430080Hubei ProvinceChina Department of Radiology China Resources and Wisco General HospitalWuhan 430080Hubei ProvinceChina

BACKGROUND Venous thromboembolism significantly contributes to patient deterioration and mortality.Management of its etiology and anticoagulation treatment is intricate,necessitating a comprehensive consideration of various factors,including the bleeding risk,dosage,specific anticoagulant medications,and duration of therapy.Herein,a case of lower extremity thrombosis with multiple primary malignant tumors and high risk of bleeding was reviewed to summarize the shortcomings of treatment and prudent anticoagulation experience.CASE SUMMARY An 83-year-old female patient was admitted to the hospital due to a 2-wk history of left lower extremity edema that had worsened over 2 d.Considering her medical history and relevant post-admission investigations,it was determined that the development of left lower extremity venous thrombosis and pulmonary embolism in this case could be attributed to a combination of factors,including multiple primary malignant tumors,iliac venous compression syndrome,previous novel coronavirus infection,and inadequate treatment for prior thrombotic events.However,the selection of appropriate anticoagulant medications,determination of optimal drug dosages,and establishment of an appropriate duration of anticoagulation therapy were important because of concurrent thrombocytopenia,decreased quantitative fibrinogen levels,and renal insufficiency.CONCLUSION Anticoagulant prophylaxis should be promptly initiated in cases of high-risk thrombosis.Individualized anticoagulation therapy is required for complex thrombosis.

关键词： Venous thromboembolism Cancer-associated thrombosis Anticoagulation therapy iliac vein compression syndrome COVID-19 Thrombocytopenia Case report

A promising approach to steady-state fusion: High-temperature superconducting strong-field stellarator with precise omnigenity

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The Innovation 2024年第1期5卷 23-25页

作者： Guosheng xu Zhiyuan Lu Dehong Chen Baonian wan Institute of Plasma Physics Chinese Academy of SciencesHefei 230031China

The stellarator has inherent advantages over the tokamak in achieving steady-state operation,especially due to its absence of disruptions and lack of need for current drive and the associated recirculating power.In recent years,there have been remarkable advances in the field of stellarator optimization,where precisely quasi-symmetric and precisely quasi-isodynamic magnetic configurations have been achieved with coils,allowing the neoclassical transport and energetic particle losses of stellarators to be reduced to levels comparable to those of tokamaks.At the same time,the development of high-temperature superconducting magnet technology will potentially double the magnetic field strength of stellarators.While these strong fields are expected to introduce new challenges,and while turbulent transport remains a common challenge for both stellarators and tokamaks,the combination of these physical and technological advances results in the expectation that stellarators will become a competitive approach to tokamaks for realizing steady-state fusion.

关键词： field approach precise

An effective catalyst carrier SiO_(2):Enhancing catalytic and combustion properties of CuFe_(2)O_(4)on energetic components

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Defence Technology（防务技术） 2024年第2期32卷 383-392页

作者： Li Ding Chong wan Suhang Chen Zhao Qin Kangzhen xu School of Chemical Engineering/Xi'an Key Laboratory of Special Energy Materials Northwest UniversityXi'an710069China Xi’an Modern Chemistry Research Institute Xi'an710065China

To enhance the catalytic activity of copper ferrite(CuFe_(2)O_(4))nanoparticle and promote its application as combustion catalyst,a low-cost silicon dioxide(SiO_(2))carrier was employed to construct a novel CuFe_(2)O_(4)/SiO_(2)binary composites via solvothermal method.The phase structure,morphology and catalytic activity of CuFe_(2)O_(4)/SiO_(2)composites were studied firstly,and thermal decomposition,combustion and safety performance of ammonium perchlorate(AP)and 1,3,5-trinitroperhydro-1,3,5-triazine(RDX)with it affecting were then systematically analyzed.The results show that CuFe_(2)O_(4)/SiO_(2)composite can remarkably either advance the decomposition peak temperature of AP and RDX,or reduce the apparent activation energy at their main decomposition zone.Moreover,the flame propagation rate of RDX was promoted by about 2.73 times with SiO_(2)content of 3 wt%,and safety property of energetic component was also improved greatly,in which depressing the electrostatic discharge sensitivity of pure RDX by about 1.89 times.In addition,the effective range of SiO_(2)carrier content in the binary catalyst is found to be 3 to 5 wt%.Therefore,SiO_(2)opens a new insight on the design of combustion catalyst carrier and will promote the application of CuFe_(2)O_(4)catalyst in solid propellant.

关键词： Copper ferrite Silicon dioxide Combustion catalyst Thermal decomposition Laser ignition

Global trend of nondrug and nonsedativehypnotic treatment forinsomnia: a bibliometric study

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Journal of Traditional Chinese Medicine 2024年第3期44卷 595-608页

作者： LEI Hanzhou xu Guixing WEI Zepeng ZHAO ling LIANG Fanrong Acupuncture and Tuina School Chengdu University of Traditional Chinese Medicine Department of Haematology Royal North Shore Hospital

OBJECTIVE: To present a bibliometric analysis of global scientific publications on the nondrug and nonsedative hypnotic treatment of insomnia with regard to influential institutions, publications, countries, research hotspots,trends, and frontiers. METHODS: A literature review was conducted by searching the Web of Science Core Collection(Wo SCC) and China National Knowledge Infrastructure(CNKI) databases to identify all publications related to the nondrug and nonsedative hypnotic treatment of insomnia from 2000 to 2021. Eligible publications were reviewed, including annual publication increments, citation analyses, international collaborations, and keyword analyses. The data were analysed using Cite Space(vers5.8.R3, 6.1.R2 and 6.1.6, College of Computing and Informatics, Philadelphia, PA, USA) and virtualized by knowledge maps. RESULTS:In total, 9832 publications were included in this analysis. The results from the WoSCC showed that the United States of America(Count = 2268, 40.33%), Stanford University(Count = 141, 2.51%), and the United States Department of Health and Human Services were the leading country, institute, and funding agency regarding the number of publications, respectively. “Cognitive-behavioural therapy” was the most popular research topic generated from the cocited reference. The most frequently co-occurring keywords were insomnia, cognitive behavioural therapy, disorder, depression, quality of life, Meta-analysis, older adult, sleep, prevalence and efficacy, while keywords including clinical practice guideline, guideline, and Tai Chi remained popular after 2021. Circadian rhythm was the strongest research frontier for 2000-2021. In China, Chengdu University of Traditional Chinese Medicine(Count = 69, 4.79%) was the most productive institute in this field. The most frequently co-occurring keywords from Chinese literature were sleep disorder, sleep quality, acupuncture and moxibustion, Parkinson's disease, transcranial magnetic stimulation, health education, music therapy, chronic insomnia, qua

关键词： CiteSpace bibliometrics cognitive behavioral therapy complementary therapies hypnotics and sedatives scientometrics visualization analysis