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Optimization of anchorage support parameters for soft rock tunnel based on displacement control theory

Journal of Mountain Science 2023年第7期20卷 2076-2092页

作者： LI Gan MA Wei-bin yu chang-yi TAO Zhi-gang WANG Feng-nian School of Civil&Environmental Engineering and Geography Science Rock mechanics Research InstituteNingbo UniversityNingbo 315000China Railway Engineering Research Institute China Academy of Railway Sciences Corporation LimitedBeijing 100081China CCCC First Harbor Engineering Company Co.Ltd.Tianjin 300461 CCCC-Tianjin Port Engineering Institute Co.Ltd.Tianjin 300222 State Key Laboratory for Geomechanics&Deep Underground Engineering Beijing 100083China Shanxi Transportation Technology Research and Development Co. LTDTaiyuan 030032China

In the construction of a soft rock tunnel,it is critical to accurately estimate the pre-stressed anchor support parameters for surrounding rock reinforcement;otherwise,engineering disasters may *** paper presents a support parameter selection method that aims to allow deformation as a control objective,which was applied to the tunnel located in Muzailing Highway,Min County,Dingxi City,Gansu Province,*** theoretical analysis,we have identified five factors that influence pre-stressing *** selection of mechanical parameters for the rock mass was carried out using an inverse analysis *** with the measured data,the maximum displacement error of the numerical simulation results was only 0.07 *** length of anchor cable,circumferential spacing of anchor cable,longitudinal spacing,and pre-stress index are adopted as the input parameters for the support vector machine neural network model based on particle swarm optimization(PSO-LSSVM).Besides,the vault subsidence and the maximum deformation of surrounding rock are considered as output values(performance indices).The goodness of fit between the predicted values and the simulated values exceeds ***,all support parameters within the acceptable deformation range are *** optimal support variables are derived by considering the construction cost and *** field application results show that it is feasible to construct the sample database utilizing the numerical simulation approach by taking the displacement as the control target and using the neural network to specify the appropriate support parameters.

关键词： Displacement control theory Anchorage support parameters Numerical simulation PSOLSSVM Tunnel construction

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Self-Driven Photo-Polarized Water Molecule-Triggered Graphene-Based Photodetector

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Research 2024年第2期2023卷 273-283页

作者： Shisheng Lin chang Liu Xin Chen yi Zhang Hongtao Lin Xutao yu yujiao Bo Yanghua Lu College of Information Science and Electronic Engineering Zhejiang UniversityHangzhou 310027P.R.China Hangzhou Gelanfeng Technology Co.Ltd Hangzhou 310051P.R.China State Key Laboratory of Modern Optical Instrumentation Zhejang UniversityHangzhou 310027P.R.China Key Laboratory of Wide Bandgap Semiconductor Materials and Devices HCSemitek CorporationYiwu 322009P.R.China Smart Materials for Architecture Research Lab Innovation Center of Yangtze River DeltaZhejiang UniversityJiaxing 314100P.R.China

Flowing water can be used as an energy source for generators,providing a major part of the energy for daily ***,water is rarely used for information or electronic ***,we present the feasibility of a polarized liquid-triggered photodetector in which polarized water is sandwiched between graphene and a *** to the polarization and depolarization processes of water molecules driven by photogenerated carriers,a photo-sensitive current can be repeatedly produced,resulting in a high-performance *** response wavelength of the photodetector can be fine-tuned as a result of the free choice of semiconductors as there is no requirement of lattice match between graphene and the *** zero voltage bias,the responsivity and specific detectivity of Gr/NaCl(0.5 M)W/N-GaN reach values of 130.7 mA/W and 2.3×10^(9)Jones under 350 nm illumination,***,using a polar liquid photodetector can successfully read the photoplethysmography signals to produce accurate oxygen blood saturation and heart *** with the commercial pulse oximetry sensor,the average errors of oxygen saturation and heart rate in the designed photoplethysmography sensor are~1.9%and~2.1%,*** study reveals that water can be used as a high-performance photodetector in informative industries.

关键词： polarization polarized saturation

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Risk assessment of oil and gas investment environment in countries along the Belt and Road Initiative

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Petroleum Science 2024年第2期21卷 1429-1443页

作者： Bao-Jun Tang chang-Jing Ji yu-Xian Zheng Kang-Ning Liu yi-Fei Ma Jun-yu Chen Center for Energy and Environmental Policy Research Beijing Institute of TechnologyBeijing100081China School of Management and Economics Beijing Institute of TechnologyBeijing100081China Collaborative Innovation Center of Electric Vehicles in Beijing BeijingChina Sustainable Development Research Institute for Economy and Society of Beijing BeijingChina Institute of Carbon Neutrality ShanghaiTech UniversityShanghai201210China

With the implementation of the Belt and Road Initiative, China is deepening its cooperation in oil and gas resources with countries along the Initiative. In order to better mitigate risks and enhance the safety of investments, it is of significant importance to research the oil and gas investment environment in these countries for China's overseas investment macro-layout. This paper proposes an indicator system including 27 indicators from 6 dimensions. On this basis, game theory models combined with global entropy method and analytic hierarchy process are applied to determine the combined weights, and the TOPSIS-GRA model is utilized to assess the risks of oil and gas investment in 76 countries along the Initiative from 2014 to 2021. Finally, the GM(1,1) model is employed to predict risk values for 2022-2025. In conclusion, oil and gas resources and political factors have the greatest impact on investment environment risk, and 12 countries with greater investment potential are selected through cluster analysis in conjunction with the predicted results. The research findings may provide scientific decisionmaking recommendations for the Chinese government and oil enterprises to strengthen oil and gas investment cooperation with countries along the Belt and Road Initiative.

关键词： Belt and Road Initiative Oil and Gas Investment Risk assessment

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The Logarithmic Sobolev Inequality for a Submanifold in Manifolds with Nonnegative Sectional Curvature

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Chinese Annals of Mathematics,Series B 2024年第3期45卷 487-496页

作者： Chengyang yi yu ZHENG School of Mathematical Sciences East China Normal UniversityShanghai 200241China

The authors prove a sharp logarithmic Sobolev inequality which holds for compact submanifolds without boundary in Riemannian manifolds with nonnegative sectional curvature of arbitrary dimension and *** the Michael-Simon Sobolev inequality,this inequality includes a term involving the mean *** extends a recent result of Brendle with Euclidean setting.

关键词： Logarithmic Sobolev inequality Nonnegative sectional curvature Submanifold

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Dual modification of LiNi_(0.83)Co_(0.11)Mn_(0.06)O_(2) cathode materials by K^(+) doping and Li_(3)PO_(4) coating for lithium ions batteries

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Rare Metals 2024年第7期43卷 3007-3018页

作者： Wei Xiao Jia-Le Wang Zhi-Cheng yi Cheng-Jin Liu chang Miao yu Xin Shu-Qing Nie College of Chemistry and Environmental Engineering Yangtze UniversityJingzhou 434023China

Li_(3)PO_(4)@Li_(0.99)K_(0.01)Ni_(0.83)Co_(0.11)Mn_(O.06)O_(2)(NCM-KP) cathode powders are synthesized via K^(+)doping in calcination processes and H_3PO_4 coating in sol-gel processes.K^(+) precisely enters into the lattice to widen the(003) plane to 0.4746 nm with a lower cationic disordered degree of 1.87%.Moreover,the surface residual lithium salts are treated by H_3PO_4 to generate a uniform Li_(3)PO_(4) coating layer of approximately 11.41 nm,which completely covers on the surface of secondary spherical particles to improve the interfacial *** 25℃,the NCM-KP electrode delivers a discharge specific capacity of 148.9 mAh·g^(-1) with a remarkable capacity retention ratio of 84.1% after 200 cycles at 1.0C and retains a high reversible specific capacity of 154.4 mAh·g^(-1) at *** at 1.0C and 60℃,it can maintain a reversible discharge specific capacity of 114.6 mAh·g^(-1) with 0.21% of capacity decay per cycle after 200 cycles,which is significantly lower than 0.40% for the pristine NCM ***,the charge transfer resistance of 238.89 Ω for the NCM-KP electrode is significantly lower than 947.41 Ω for the pristine NCM one by restricting the interfacial side ***,combining K+doping and Li_(3)PO_(4) coating is an effective strategy to enable the significant improvement of the electrochemical property of high-nickel cathode materials,which may be mainly attributed to the widened diffusion pathway and the formed Li_(3)PO_(4) protective layer,thus promoting Li~+diffusion rate and preventing the erosion of HF.

关键词： High-nickel cathode material Residual lithium K^(+)doping Li_(3)PO_(4)coating Lithium ions battery

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Cross section determination of^(27)Al(n,2n)^(26)Al reaction induced by 14-MeV neutrons uniting with D-T neutron activation and AMS techniques

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Nuclear Science and Techniques 2024年第6期35卷 78-89页

作者： Xian-Lin Yang chang-Lin Lan yu-Ting Wei yi Zhang Gong Jiang Bo Xie yu Liu Hong-Tao Shen Xiao-Jun Sun School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China MOE Frontiers Science Center for Rare Isotopes Lanzhou UniversityLanzhou 730000China State Key Laboratory of Environmental Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China Guangxi Key Laboratory of Nuclear Physics and Nuclear Technology Guangxi Normal UniversityGuilin 541004China

Aluminum is the primary structural material in nuclear engineering,and its cross section induced by 14-MeV neutrons is of great *** address the issue of insufficient accuracy for the^(27)Al(n,2n)^(26)Al reaction cross section,the activation method and accelerator mass spectrometry(AMS)technique were used to determine the^(27)Al(n,2n)^(26)Al cross section,which could be used as a D-T plasma ion temperature monitor in fusion *** the China Academy of Engineering Physics,neutron activation was performed using a K-400 neutron generator produced by the T(d,n)4He ***^(26)Al∕^(27)Al isotope ratios were measured using the newly installed GyiG 1 MV AMS at the Institute of Geochemistry,Chinese Academy of *** neutron flux was monitored by measuring the activity of 92mNb produced by the 93Nb(n,2n)92mNb *** measured results were compared with available data in the experimental nuclear reaction database,and the measured values showed a reasonable degree of consistency with partially available literature *** newly acquired cross-sectional data at 12 neutron energy points through systematic measurements clarified the divergence,which has two different growth trends from the existing experimental *** obtained results are also compared with the corresponding evaluated database,and the newly calculated excitation functions with TALYS−1.95 and EMPIRE−3.2 codes,the agreement with CENDL−3.2,TENDL-2021 and EMPIRE−3.2 results are generally acceptable.A substantial improvement in the knowledge of the^(27)Al(n,2n)^(26)Al reaction excitation function was obtained in the present work,which will lay the foundation for the diagnosis of the fusion ion temperature,testing of the nuclear physics model,evaluation of nuclear data,etc.

关键词： 14-MeV neutron ^(27)Al(n,2n)^(26)Al Cross section AMS

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A homopolymolybdate-supported plate-like 2D cobalt network constructed from a new pyrazole-amide-pyridyl ligand: highly electrochemical activity in both capacitive performance and the detection of Cr(Ⅵ)

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Tungsten 2024年第2期6卷 422-427页

作者： Xiu-Li Wang Yong-Zhen Chen Zhi-Han chang yu-Chun Lin Jing-yi Ma College of Chemistry and Materials Engineering Bohai UniversityJinzhou 121013China Professional Technology Innovation Center of Liaoning Province for Conversion Materials of Solar Cell Jinzhou 121013China

By employing a new semi-rigid pyrazole-amide-derived bis(pyridyl)ligand[N,N'-bis(4-picolylamine)-1-hydropyrazole(4-dpap)],a new homopolymolybdate-based two-dimensional(2D)plate-like complex[Co(4-dpap)(H_(2)O)(β-Mo_(8)O_(2)6)1/2](1)has been prepared under solvothermal condition and structurally ***β-Mo_(8)anions are fi xed between the 2D metal–organic networks[Co(4-dpap)(H_(2)O)]n 2n+via hydrogen-bonding *** 1 possesses satisfactory specifi c capacitance of 1512.4 F·g^(−1)(current density:1 A·g^(−1))and good cycling stability(90.8%after 1000 cycles).Moreover,1 represents a promising amperometric sensor for measurement of Cr(Ⅵ)with low detection limit(0.042μmol·L^(−1))and high *** insertion ofβ-Mo_(8)anions between the unique 2D metal−organic networks improves the active area of polyoxometalates,which further promotes electrochemical performance.

关键词： Homopolymolybdate Metal–organic network Pyrazole-amide-derived bis(pyridyl)ligand Supercapacitor Electrochemical sensor

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Optimal Cooperative Secondary Control for Islanded DC Microgrids via a Fully Actuated Approach

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IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 405-417页

作者： yi yu Guo-Ping Liu yi Huang Peng Shi IEEE Shenzhen Key Laboratory of Control Theory and Intelligent Systems Southern University of Science and TechnologyShenzhen 518055China School of Electrical Engineering and Automation Wuhan UniversityWuhan 430072China School of Electrical and Mechanical Engineering the University of AdelaideSA 5005Australia Research and Innovation Centre Obuda University1034 BudapestHungary

DC-DC converter-based multi-bus DC microgrids(MGs) in series have received much attention, where the conflict between voltage recovery and current balancing has been a hot topic. The lack of models that accurately portray the electrical characteristics of actual MGs while is controller design-friendly has kept the issue active. To this end, this paper establishes a large-signal model containing the comprehensive dynamical behavior of the DC MGs based on the theory of high-order fully actuated systems, and proposes distributed optimal control based on this. The proposed secondary control method can achieve the two goals of voltage recovery and current sharing for multi-bus DC MGs. Additionally, the simple structure of the proposed approach is similar to one based on droop control, which allows this control technique to be easily implemented in a variety of modern microgrids with different configurations. In contrast to existing studies, the process of controller design in this paper is closely tied to the actual dynamics of the MGs. It is a prominent feature that enables engineers to customize the performance metrics of the system. In addition, the analysis of the stability of the closed-loop DC microgrid system, as well as the optimality and consensus of current sharing are given. Finally, a scaled-down solar and battery-based microgrid prototype with maximum power point tracking controller is developed in the laboratory to experimentally test the efficacy of the proposed control method.

关键词： DC microgrids distributed control high-order fully actuated system approach linear quadratic regulator microgrid modeling secondary control

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Characteristics of the HIV/AIDS Epidemic among People Aged≥50 Years in China during 2018–2021

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Biomedical and Environmental Sciences 2024年第4期37卷 399-405页

作者： HOU yu Shan JIN yi Chen CAI chang TANG Hou Lin QIN Qian Qian Lyu Fan National Center for AIDS/STD Control and Prevention Chinese Center for Disease Control and PreventionBeijing 102206China

Objective This study aimed to determine the current epidemiological status of PLWHA aged≥50 years in China from 2018 to *** also aimed to recommend targeted interventions for the prevention and treatment of HIV/AIDS in elderly *** Data on newly reported cases of PLWHA,aged≥50 years in China from 2018 to 2021,were collected using the *** tests and spatial analyses were also *** Between 2018 and 2021,237,724 HIV/AIDS cases were reported among patients aged≥50 years in *** main transmission route was heterosexual transmission(91.24%).Commercial heterosexual transmission(CHC)was the primary mode of transmission among males,while non-marital non-CHC([NMNCHC];60.59%)was the prevalent route in *** proportion of patients with CHC decreased over time(Z=67.716,P<0.01),while that of patients with NMNCHC increased(Z=153.05,P<0.01).The sex ratio varied among the different modes of infection,and it peaked at 17.65 for *** spatial analysis indicated spatial clustering,and the high-high clustering areas were mainly distributed in the southwestern and central-southern *** In China,PLWHA,aged≥50 years,were predominantly infected through heterosexual *** primary modes of infection were CHC and *** were variations in the sex ratio among different age groups,infected through various sexual ***/AIDS cases exhibited spatial *** on these results,the expansion of HIV testing,treatment,and integrated behavioral interventions in high-risk populations is recommended to enhance disease detection in key regions.

关键词： HIV/AIDS Aged≥50 years China

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Nitrogen and phosphorus fertilization leads to soil arbuscular mycorrhizal fungal diversity changes and rainfed crop yield increase on the Loess Plateau of China:A 37-year study

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Pedosphere 2024年第2期34卷 328-338页

作者： yi WANG Wenting ZHANG Chunyue LI Shun chang yu MIAO Qianxue LI Zhaoyang KOU Tinghui DANG State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy of SciencesXi'an 710061China School of Geography and Tourism Shaanxi Normal UniversityXi'an 710119China Institute of Soil and Water Conservation Northwest A&F UniversityYangling 712100China

More than 80%of plants form mutualistic symbiotic relationships with arbuscular mycorrhizal fungi(AMF),and the application of fertilizers,such as nitrogen(N)and phosphorus(P)fertilizers,is a common agricultural management practice to improve crop yield and ***,the potential effects of long-term N and P fertilization on the AMF community in the rainfed agricultural system of the Loess Plateau of China are still not well *** this study,a long-term field experiment was conducted based on orthogonal design,with three N levels(0,90,and 180 kg ha^(-1)year^(-1))and three P levels(0,90,and 180 kg ha^(-1)year^(-1))for wheat *** in AMF community and correlations between AMF community composition,soil environmental factors,and wheat yield component traits were analyzed using traditional biochemical methods and high-throughput sequencing *** results showed that long-term N and P addition had a significant effect on the AMF community structure and *** application alone significantly reduced the richness and diversity of AMF community,whereas the combined application of N and P significantly increased the richness and diversity of AMF *** AMF community was driven mainly by soil available P,total P,and *** was a significant positive correlation between Glomus abundance and wheat yield and a significant negative correlation between Paraglomus abundance and wheat ***-term N and P addition directly increased crop yield and affected yield indirectly by influencing soil chemical properties and the AMF *** application of N and P both at90 kg ha^(-1)year^(-1)could improve the ecological and physiological functions of the AMF community and benefit the sustainable development of rainfed agriculture.

关键词： Glomus long-term fertilization microbial community Paraglomus rainfed agriculture wheat

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