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Determination of rock mass integrity coefficient using a non-invasive geophysical approach

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第6期15卷 1426-1440页

作者： Muhammad Hasan Yanjun Shang xuetao yi Peng Shao Meng He Key Laboratory of Shale Gas and Geoengineering(KLSGG) Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing100049China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing100029China

Determination of rock mechanical parameters is the most important step in rock mass quality evaluation and has significant impacts on geotechnical engineering *** mass integrity coefficient(KV)is one of the most efficient parameters,which is conventionally determined from *** approaches,however,are time-consuming and expensive,offer low data coverage of point measurements,require heavy equipment,and are hardly conducted in steep topographic ***,borehole approaches cannot assess the subsurface thoroughly for rock mass quality ***,use of geophysical methods is non-invasive,rapid and *** proposed geophysical approach makes useful empirical correlation between geophysical and geotechnical *** evaluated the rock mass quality via integration between KV measured from the limited boreholes and inverted resistivity obtained from electrical resistivity tomography(ERT).The borehole-ERT correlation provided KV along various geophysical profiles for more detailed 2D/3D(two-/three-dimensional)mapping of rock mass *** subsurface was thoroughly evaluated for rock masses with different engineering qualities,including highly weathered rock,semi-weathered rock,and fresh ***,ERT was integrated with induced polarization(IP)to resolve the uncertainty caused by water/clay *** results show that the proposed method,compared with the conventional approaches,can reduce the ambiguities caused by inadequate data,and give more accurate insights into the subsurface for rock mass quality evaluation.

关键词： Geotechnical engineering Rock mass integrity coefficient Rock mechanical parameters Geophysical parameters Electrical resistivity tomography(ERT) Induced polarization(IP)

Leakage Proof,Flame-Retardant,and Electromagnetic Shield Wood Morphology Genetic Composite Phase Change Materials for Solar Thermal Energy Harvesting

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Nano-Micro Letters 2024年第10期16卷 99-120页

作者： Yuhui Chen Yang Meng Jiangyu Zhang Yuhui Xie Hua Guo Mukun He xuetao Shi yi Mei Xinxin Sheng Delong Xie Yunnan Provincial Key Laboratory of Energy Saving in Phosphorus Chemical Engineering and New Phosphorus Materials The International Joint Laboratory for Sustainable Polymers of Yunnan ProvinceThe Higher Educational Key Laboratory for Phosphorus Chemical Engineering of Yunnan ProvinceFaculty of Chemical EngineeringKunming University of Science and TechnologyKunming 650500People's Republic of China Guangdong Provincial Key Laboratory of Functional Soft Condensed Matter School of Materials and EnergyGuangdong University of TechnologyGuangzhou 510006People's Republic of China Shaanxi Key Laboratory of Macromolecular Science and Technology School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi'anShaanxi 710072People's Republic of China

Phase change materials(PCMs)offer a promising solution to address the challenges posed by intermittency and fluctuations in solar thermal ***,for organic solid-liquid PCMs,issues such as leakage,low thermal conductivity,lack of efficient solar-thermal media,and flamma-bility have constrained their broad ***,we present an innova-tive class of versatile composite phase change materials(CPCMs)developed through a facile and environmentally friendly synthesis approach,leveraging the inherent anisotropy and unidirectional porosity of wood aerogel(nanowood)to support polyethylene glycol(PEG).The wood modification process involves the incorporation of phytic acid(PA)and MXene hybrid structure through an evaporation-induced assembly method,which could impart non-leaking PEG filling while concurrently facilitating thermal conduction,light absorption,and ***,the as-prepared wood-based CPCMs showcase enhanced thermal conductivity(0.82 W m^(-1)K^(-1),about 4.6 times than PEG)as well as high latent heat of 135.5 kJ kg^(-1)(91.5%encapsula-tion)with thermal durability and stability throughout at least 200 heating and cooling cycles,featuring dramatic solar-thermal conversion efficiency up to 98.58%.In addition,with the synergistic effect of phytic acid and MXene,the flame-retardant performance of the CPCMs has been significantly enhanced,showing a self-extinguishing ***,the excellent electromagnetic shielding of 44.45 dB was endowed to the CPCMs,relieving contemporary health hazards associated with electromagnetic ***,we capitalize on the exquisite wood cell structure with unidirectional transport inherent in the development of multifunctional CPCMs,showcasing the operational principle through a proof-of-concept prototype system.

关键词： Wood PCMs MXene Solar thermal storage and conversion Flame-retardant Electromagnetic shielding

Axial Suspension Control for P.M.D with Pitch Stiffness Improvement

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Axial Suspension Control for P.M.D with Pitch Stiffness Impr...

Single Degree of Freedom Suspension Control for Permanent Magnet Disk with the Thickness Optimization

第30届中国控制与决策会议

作者： Chu Xiaoguang Wang Qiang Cai Bin Guo Dengpeng yi xuetao New Energy Technology Institute of Qufu Normal University

This paper proposed active and passive suspension control for permanent magnet disk（P.M.D）. The eddy current damping is introduced into suspension control for the improvement of the pitch stiffness and weak damping. Considering the deformation of the magnetic field and the centerline deviation of the suspension coils, the axial and pitch motion equations of the disk permanent magnet are constructed, with which the essence of the suspension shock is revealed, and then Pitch stiffness is improved by the eddy current damping. The single D.O.F axial suspension controller was designed with the consideration of suspension stability and measurement noise, and the stability domain of the controller was analyzed on the influence of eddy current damping. The experiment platform is builted to validate the active and passive suspension control strategy from the two operation condition on both the rated air gap and the variable air gap.

关键词： Disk permanent magnet Active and passive susp-endsion Eddy current damping Pitch stiffness

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Single Degree of Freedom Suspension Control for Permanent Ma...

高密度电法电性结构揭示天山天池堆积坝体厚度及其阻渗稳水功能分析

第30届中国控制与决策会议

作者： Chu Xiaoguang yi xuetao Cai Bin Wang Qiang Guo Dengpeng New Energy Technology Institute of Qufu Normal University

This paper proposed the single degree of freedom（D.O.F） suspension control with the thickness optimization for permanent magnet disk（P.M.D）, which reduces active suspension D.O.F and power consumption. Considering the winding edge effect and the gravity central deviation, two-degree-of-freedom dynamic model is constructed including axial suspension and pitching motion, with which structural constraints are deduced from the improvement of the pitching stiffness. Considering controllability, disturbance rejection, and structure constraints, Lagrange function method is applied to optimize the P.M.D thickness. State feedback axial active controller is applied to suspend the P.M.D, and then suspension performance is theoretically analyzed from the aspect of the controller stability margin, closed-loop stiffness and damping. Simulation results verify that the optimized thickness has the best air gap tracking and disturbance rejection through the comparison of three thickness P.M.D. Experimental results further validate that the thickness optimization can reduce active suspension D.O.F and improve asymptotic tracing ability with wider air gap operation range.

关键词： Structure optimization Pitching stiffness improvement Active suspension control

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现代地质 2023年第1期37卷 31-39页

作者：尚彦军金维浚伊学涛姜东廷 HASAN Muhammad 中国科学院地质与地球物理研究所页岩气与地质工程重点实验室北京100029 中国科学院大学地球与行星科学学院北京100049 新疆地质灾害防治重点实验室(新疆工程学院) 新疆乌鲁木齐830023

天山天池北堆积坝体结构受其成因和演化控制,影响其含水和渗流特性。对该坝体稳定至关重要的下伏基岩埋深、坝体结构阻渗水结构特征等需现场探测并给出科学判断。在地质调查基础上采用高密度电法对天池堆积坝体结构进行探测,首次获得深... 详细信息

天山天池北堆积坝体结构受其成因和演化控制,影响其含水和渗流特性。对该坝体稳定至关重要的下伏基岩埋深、坝体结构阻渗水结构特征等需现场探测并给出科学判断。在地质调查基础上采用高密度电法对天池堆积坝体结构进行探测,首次获得深达下伏基岩的堆积坝体纵向和横向电性剖面。结合光释光测年、水化学成分对比、水量平衡计算等手段,分析坝体堆积物形成时代以及坝体水文地质结构特征。结果显示:天池坝堆积体厚度大于100 m并可分为3层,上部浅表层滑坡形成的巨大块石层厚30~40 m且基本不含水,其下松散含水层厚度为30~50 m;下部为较低电阻率弱透水的冰碛物,主要分布在坝体下游和东端;底部为高电阻率不透水的石炭系火山岩。坝体中间部位地下水集中下渗补给了西小天池。同时靠坝体东侧发育排泄通道,呈现多处溢水点,控制了飞龙涧左岸下降泉季节性发育,同河谷冲刷作用一起影响并导致下游左岸冰碛物中发育4处滑坡体。电法剖面揭示出与坝体轴向近平行的2条隐伏断层,其中堆积坝高堤处气象台所在山丘上游一侧发育一条近东西走向并倾向上游的断层F1,构成地下水阻隔带而使天池堆积坝上游潜水水位呈现一定雍高,同坝体下伏基岩和弱透水冰碛物联合组成的坝体结构致使旱季天池水不会大量溢出,夏季丰水时浅表泉水渗漏,保证了天池水满而不溢、结构松而不垮。由此构建该堆积体内断层和地层结构组成的浅表导水模型,计算得出天池堆积体地下水排泄量约为1200 m^(3)/d,天池总下泄水量为52×10^(4)~113×10^(4)m^(3)/d(从冬季到夏季),维持了天池湖水动态稳定。

关键词：天池坝体结构高密度电法电性结构阻渗水功能

Shor's algorithm does not factor large integers in the presence of noise

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Science China(Information Sciences) 2024年第7期67卷 305-320页

作者： Jin-yi CAI College of Letters and Science University of Wisconsin

We consider Shor's quantum factoring algorithm in the setting of noisy quantum gates. Under a generic model of random noise for(controlled) rotation gates, we prove that the algorithm does not factor integers of the form pq when the noise exceeds a vanishingly small level in terms of n—the number of bits of the integer to be factored, where p and q are from a well-defined set of primes of positive density. We further prove that with probability 1-o(1) over random prime pairs(p, q), Shor's factoring algorithm does not factor numbers of the form pq, with the same level of random noise present.

关键词： random noise Shor's algorithm rotation gates quantum computing prime factorization

How to build a habitable planet:an interview with Charles H. Langmuir

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National Science Review 2024年第6期11卷 76-80页

作者： yi-Gang Xu the Guangzhou Institute of Geochemistry Chinese Academy of Sciences

Earth is the only known habitable planet in the solar system. Understanding how Earth developed its unique habitability has been the frontier of Earth sciences and has become one of the main themes of current deep-space explorations. What are the decisive factors that led to a habitable planet? What is the role of solid Earth processes in the origin of life and in modulating the surface environment? Are Earth’s habitability studies relevant to current challenges that human beings face? These questions have attracted the interest of both scientists and the public alike.

关键词： Earth (planet)

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

Self-assembly of perovskite nanocrystals:From driving forces to applications

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Journal of Energy Chemistry 2024年第1期88卷 561-578,I0013页

作者： yi Li Fei Zhang School of Chemical Engineering and Technology Tianjin UniversityTianjin 300072China Collaborative Innovation Center of Chemical Science and Engineering(Tianjin) Tianjin 300072China

Self-assembly of metal halide perovskite nanocrystals(NCs)into superlattices can exhibit unique collective properties,which have significant application values in the display,detector,and solar cell *** review discusses the driving forces behind the self-assembly process of perovskite NCs,and the commonly used self-assembly methods and different self-assembly structures are ***,we summarize the collective optoelectronic properties and application areas of perovskite superlattice ***,we conclude with an outlook on the potential issues and future challenges in developing perovskite NCs.

关键词： Self-assembly Metal halide perovskite Nanocrystals Driving forces