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Mechanical property of cylindrical sandwich shell with gradient core of entangled wire mesh

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Defence Technology（防务技术） 2024年第1期31卷 510-522页

作者： Xin xue Chao Zheng Fu-qiang Lai xue-qian wu Institute of Metal-rubber&Vibration Noise School of Mechanical Engineering and AutomationFuzhou UniversityFuzhou350116China Fujian Metallurgical Industry Design Institute Fuzhou350116China

To explore the wide-frequency damping and vibration-attenuation performances in the application of aerospace components,the cylindrical sandwich shell structure with a gradient core of entangled wire mesh was proposed in this ***,the gradient cores of entangled wire mesh in the axial and radial directions were prepared by using an in-house Numerical Control weaving machine,and the metallurgical connection between skin sheets and the gradient core was performed using vacuum ***,to investigate the mechanical properties of cylindrical sandwich shells with axial or radial gradient cores,quasi-static and dynamic mechanical experiments were carried *** primary evaluations of mechanical properties include secant stiffness,natural frequency,Specific Energy Absorption(SEA),vibration acceleration level,and so *** results suggest that the vibration-attenuation performance of the sandwich shell is remarkable when the high-density core layer is at the end of the shell or abuts the inner *** axial gradient material has almost no influence on the vibration frequencies of the shell,whereas the vibration frequencies increase dramatically when the high-density core layer approaches the ***,compared to the conventional sandwich shells,the proposed functional grading cylindrical sandwich shell exhibits more potential in mass reduction,stiffness designing,and energy dissipation.

关键词： Entangled wire mesh Gradient cylindrical sandwich shell Vacuum brazing Secant stiffness Damping

Some Convergence Properties for Weighted Sums of Martingale Difference Random Vectors

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Acta Mathematica Sinica,English Series 2024年第4期40卷 1127-1142页

作者： Yi wu xue Jun WANG School of Big Data and Artificial Intelligence Chizhou UniversityChizhou 247000P.R.China School of Big Data and Statistics Anhui UniversityHefei 230601P.R.China

Let{X_(ni),F_(ni);1≤i≤n,n≥1}be an array of R^(d)martingale difference random vectors and{A_(ni),1≤i≤n,n≥1}be an array of m×d matrices of real *** this paper,the Marcinkiewicz-Zygmund type weak law of large numb... 详细信息

关键词： Martingale difference random vectors weighted sums Marcinkiewicz–Zygmund type weak law of large numbers complete convergence strong law of large numbers multivariate simple linear regression model

Distributed optical fiber acoustic sensor for in situ monitoring of marine natural gas hydrates production for the first time in the Shenhu Area,China

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China Geology 2022年第2期5卷 322-329页

作者： Xiang-ge He xue-min wu Lei Wang Qian-yong Liang Li-juan Gu Fei Liu Hai-long Lu Yi Zhang min Zhang Beijing International Center for Gas Hydrate Peking UniversityBeijing 100871China Guangzhou Marine Geological Survey China Geological SurveyMinistry of Natural ResourcesGuangzhou 510075China School of Earth and Space Sciences Peking UniversityBeijing 100871China Dongguan Institute of Optics and Electronics Peking UniversityDongguan 523000China Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) Guangzhou 511458China School of Computer and Communication Engineering University of Science and Technology BeijingBeijing 100083China SinoProbe Center Chinese Academy of Geological Sciences and China Geological SurveyMinistry of Natural ResourcesBeijing 100037China

The distributed acoustic sensor(DAS)uses a single optical cable as the sensing unit,which can capture the acoustic and vibration signals along the optical cable in *** it is suitable for monitoring downhole production activities in the process of oil and gas *** authors applied the DAS system in a gas production well in the South China Sea for in situ monitoring of the whole wellbore for the first time and obtained the distributed acoustic signals along the whole *** signals can clearly distinguish the vertical section,curve section,and horizontal production *** collected acoustic signal with the frequency of approximately 50 Hz caused by the electric submersible pump exhibit a signal-to-noise ratio higher than 27 *** analyzing the acoustic signals in the production section,it can be located the layers with high gas production *** an accurate physical model is built in the future,the gas production profile will be *** addition,the DAS system can track the trajectory of downhole tools in the wellbore to guide the *** the velocity analysis of the typical signals,the type of fluids in the wellbore can be *** successful application of the system provides a promising whole wellbore acoustic monitoring tool for the production of marine gas hydrate,with a good application prospect.

关键词： Gas hydrate production monitoring Optical fiber sensor Distributed acoustic sensor In situ monitoring Fluid type NGHs exploration trial engineering Oil and gas exploration engineering Shenhu Area South China Sea

Consistency of Tropospheric Water Vapor between Reanalyses and Himawari-8/AHI Measurements over East Asia

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Advances in Atmospheric Sciences 2024年第1期41卷 19-38页

作者： Di DI Jun LI Yunheng xue min min Bo LI Zhenglong LI Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and TechnologyNanjing 210044China Key Laboratory for Aerosol-Cloud-Precipitation China Meteorological AdministrationSchool of Atmospheric PhysicsNanjing University of Information Science and TechnologyNanjing 210044China FYSIC National Satellite Meteorological CenterChina Meteorological AdministrationBeijing 100081China Chengdu University of Information Science and Technology Chengdu 610225China School of Atmospheric Sciences and Guangdong Province Key laboratory for Climate Change and Natural Disaster Studies Sun Yat-sen University and Southern Laboratory of Ocean Science and EngineeringZhuhai 519082China Cooperative Institute for Meteorological Satellite Studies University of Wisconsin–MadisonMadison WI 53706WisconsinUSA wuxi University Wuxi 214105China

High spatiotemporal resolution radiances from the advanced imagers onboard the new generation of geostationary weather satellites provide a unique opportunity to evaluate the abilities of various reanalysis datasets to depict multilayer tropospheric water vapor(WV),thereby enhancing our understanding of the deficiencies of WV in reanalysis *** on daily measurements from the Advanced Himawari Imager(AHI)onboard the Himawari-8 satellite in 2016,the bias features of multilayer WV from six reanalysis datasets over East Asia are thoroughly *** assessments show that wet biases exist in the upper troposphere in all six reanalysis datasets;in particular,these biases are much larger in ***,we find better depictions of WV in the middle troposphere than in the upper *** accuracy of WV in the ERA5 dataset is the highest,in terms of the bias magnitude,dispersion,and pattern *** characteristics of the WV bias over the Tibetan Plateau are significantly different from those over other parts of East *** addition,the reanalysis datasets all capture the shift of the subtropical high very well,with ERA5 performing better overall.

关键词： AHI reanalysis dataset multilayer water vapor assessment radiative transfer model

Two polyoxovanadoborates with over 100 nuclei assembled from a {V_(14)Co_(12)B_(72)} cluster

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Science China Chemistry 2024年第8期67卷 2578-2585页

作者： Shuang-xue wu Yu-Jiao Dong Yang Yang Chao Qin Chun-Yi Sun Wei Guan Xin-Long Wang Zhong-min Su Key Laboratory of Polyoxometalate and Reticular Material Chemistry of ministry of Education Northeast Normal UniversityChangchun 130024China School of Chemistry and Environmental Engineering Changchun University of Science and TechnologyChangchun 130013China Key Laboratory of Advanced Materials of Tropical Island Resources Hainan UniversityHaikou 570228China

Combining theoretical prediction and experimental exploration, the first sandwich-type polyoxovanadoborate(POVB) with an odd number of nuclei, [V_(11)B_(26)O_(73)(OH)_(10)]^(8-)(1), was discovered under hydrothermal conditions. Density-functional theory(DFT)gives a rationalization for the existence of this structure and the structural feature is consistent with the {V_NB_(2N+X)}(X = 2, 4, 6, 8)general formula. Excitingly, when Co and 1,10-phenanthroline(phen) are introduced into the synthesis of vanadoborates system,a 100-nuclei [Co_6(phen)_(10)(H_(2)O)_8][V_(14)Co_(12)B_(72)O_(144)(OH)_(20)]·28H_(2)O(2) and a 102-nuclei [Co_6(phen)_(14)(H_(2)O)_(4)][V_(14)Co_(12)B_(72)O_(144)(OH)_(20)]·23H_(2)O(3) with the same core structure of [V_(14)Co_(12)B_(72)]^(12-)are obtained. The vase-shaped [V_(14)Co_(12)B_(72)] polyanion is a multilayered sandwich-type structure containing seven distinct structural layers and is the largest known POVB. Furthermore, 2demonstrates exceptional thermal and chemical stability and serves as an efficient and stable catalyst for the photoreduction of carbon dioxide.

关键词： boronate metallic materials polyoxovanadoborates density functional theory photocatalysis CO_(2)reduction

Application of the monitoring and early warning system for internal solitary waves:Take the second natural gas hydrates production test in the South China Sea as an example

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China Geology 2023年第4期6卷 676-684页

作者： Dan-yi Su Bin-bin Guo Qian-yong Liang Chu-jin Liang Fei-long Lin Su-meng Jiang Yi-fei Dong xue-min wu Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) Guangzhou 511458China National Engineering Research Center of Gas Hydrate Exploration and Development Guangzhou 510075China Guangzhou Marine Geological Survey China Geological SurveyMinistry of Natural ResourcesGuangzhou 510075China Second Institute of Oceanography Ministry of Natural ResourcesHangzhou 310012China Nanjing University of Information Science and Technology Nanjing 210044China

Internal solitary waves(ISWs) contain great energy and have the characteristics of emergency and concealment. To avoid their damage to offshore engineering, a new generation of monitoring and early warning system for ISWs was developed using technologies of double buoys monitoring, intelligent realtime data transmission, and automatic software identification. The system was applied to the second natural gas hydrates(NGHs) production test in the Shenhu Area, South China Sea(SCS) and successfully provided the early warning of ISWs for 173 days(from October 2019 to April 2020). The abrupt changes in the thrust force of the drilling platform under the attack of ISWs were consistent with the early warning information, proving the reliability of this system. A total of 93 ISWs were detected around the drilling platform. Most of them occurred during the spring tides in October–December 2019 and April 2020, while few of them occurred in winter. As suggested by the theoretical model, the full-depth structure of ISWs was a typical current profile of mode-1, and the velocities of wave-induced currents can reach 80 cm/s and30 cm/s, respectively, in the upper ocean and near the seabed. The ISWs may be primarily generated from the interactions between the topography and semidiurnal tides in the Luzon Strait, and then propagate westward to the drilling platform. This study could serve as an important reference for the early warning of ISWs for offshore engineering construction in the future.

关键词： Internal solitary wave Early warning Offshore engineering Drilling platform Natural gas hydrates production test Shenhu Area South China Sea

Impact response and energy absorption of metallic buffer with entangled wire mesh damper

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Defence Technology（防务技术） 2024年第5期35卷 137-150页

作者： Chao Zheng Jun wu Mangong Zhang Xin xue Institute of Metal Rubber&Vibration Noise School of Mechanical Engineering and AutomationFuzhou UniversityFuzhou 350116China wuhan Second Ship Design and Research Institute Wuhan 430205China

An innovative metallic buffer consisting of series-connected hat-shaped entangled wire mesh damper(EWMD)and parallel springs are proposed in this work to enhance the reliability of engineering *** impact response and the energy dissipation mechanism of hat-shaped EWMD under different quasi-static compression deformations(2-7 mm)and impact heights(100-200 mm)are investigated using experimental and numerical *** results demonstrate distinct stages in the quasi-static mechanical characteristics of hat-shaped EWMD,including stiffness softening,negative stiffness,and stiffness *** loss factor gradually increases with increasing compression deformation before entering the stiffness hardening *** impact loads,the hat-shaped EWMD exhibits optimal impact energy absorption when it enters the negative stiffness stage(150 mm),resulting in the best impact isolation effect of metallic ***,the impact energy absorption significantly decreases when hat-shaped EWMD enters the stiffness hardening ***,quasi-static compression analysis after experiencing different impact loads reveals the disappearance of the negative stiffness ***,with increasing impact loads,the stiffness hardening point progressively shifts to an earlier stage.

关键词： Metallic buffer Hat-shaped EWMD Drop impact Energy absorption characteristics Mechanical behavior

Mutations in the SARS-CoV-2 spike receptor binding domain and their delicate balance between ACE2 affinity and antibody evasion

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Protein & Cell 2024年第6期15卷 403-418页

作者： Song xue Yuru Han Fan wu Qiao Wang Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS) Shanghai Institute of Infectious Disease and BiosecurityShanghai Frontiers Science Center of Pathogenic Microorganisms and InfectionSchool of Basic Medical SciencesShanghai Medical CollegeFudan UniversityShanghai 200032China

Intensive selection pressure constrains the evolutionary trajectory of SARS-CoV-2 genomes and results in various novel variants with distinct mutation *** mutations,particularly those within the receptor binding domain(RBD)of SARS-CoV-2 spike(S)protein,lead to the functional alteration in both receptor engagement and monoclonal antibody(mAb)***,we review the data of the RBD point mutations possessed by major SARS-CoV-2 variants and discuss their individual effects on ACE2 affinity and immune *** single amino acid substitutions within RBD epitopes crucial for the antibody evasion capacity may conversely weaken ACE2 binding ***,this weakened effect could be largely compensated by specific epistatic mutations,such as N501Y,thus maintaining the overall ACE2 affinity for the spike protein of all major *** predominant direction of SARS-CoV-2 evolution lies neither in promoting ACE2 affinity nor evading mAb neutralization but in maintaining a delicate balance between these two ***,this review interprets how RBD mutations efficiently resist antibody neutralization and meanwhile how the affinity between ACE2 and spike protein is maintained,emphasizing the significance of comprehensive assessment of spike mutations.

关键词： ACE2 affinity maintained

Underlying anti-hypertensive mechanism of the Mizuhopecten yessoensis derived peptide NCW in spontaneously hypertensive rats via widely targeted kidney metabolomics

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Food Science and Human Wellness 2024年第1期13卷 472-481页

作者： Wenjun xue Wenzhu Zhao Sijia wu Zhipeng Yu School of Food Science and Engineering Hainan UniversityHaikou 570228China College of Food Science and Engineering Bohai UniversityJinzhou 121013China Lab of Nutrition and Functional Food Jilin UniversityChangchun 130062China

The angiotensin-converting enzyme(ACE)inhibitory peptide NCW derived from Mizuhopecten yessoensis has been demonstrated to have significant in vivo anti-hypertensive effects,however,its anti-hypertensive mechanism is still not fully *** study established a UPLC-Q-TRAP-MS/MS-based widely targeted kidney metabolomics approach to explore the changes of kidney metabolic profiles and to clarify the antihypertensive mechanism of peptide NCW in spontaneously hypertensive rats(SHRs).Multivariate statistical analysis indicated that the kidney metabolic profiles were clearly separated between the SHR-NCW and SHRUntreated groups.A total of 85 metabolites were differentially regulated,and 16 metabolites were identified as potential kidney biomarkers,e.g.,3-hydroxybutyrate,malonic acid,deoxycytidine,and L-aspartic *** peptide NCW might regulate kidney metabolic disorder of SHRs to alleviate hypertension by suppressing inflammation and improving nitric oxide production under the regulation of linoleic acid metabolism,folate related pathways,synthesis and degradation of ketone bodies,pyrimidine metabolism,β-alanine metabolism,and retinal metabolism.

关键词： ACE inhibitory peptide Kidney Mechanism Metabolomics Spontaneously hypertensive rats