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Performances of fissured red sandstone after thermal treatment with constant-amplitude and low-cycle impacts

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第2期16卷 561-587页

作者： Yongjun chen Tubing Yin P.G.Ranjith Xibing Li qiang Li Dengdeng Zhuang School of Resources and Safety Engineering Central South UniversityChangsha410083China Department of Civil Engineering Monash UniversityMelbourne3800Australia Oulu Mining School University of OuluOuluFI-90014Finland

In the engineering practices,it is increasingly common to encounter fractured rocks perturbed by temperatures and frequent dynamic *** this paper,the dynamic behaviors and fracture characteristics of red sandstone considering temperatures(25℃,200℃,400℃,600℃,and 800℃)and fissure angles(0°,30°,60°,and 90°)were evaluated under constant-amplitude and low-cycle(CALC)impacts actuated by a modified split Hopkinson pressure bar(SHPB)***,fracture morphology and second-order statistics within the grey-level co-occurrence matrix(GLCM)were examined using scanning electron microscopy(SEM).Meanwhile,the deep analysis and discussion of the mechanical response were conducted through the synchronous thermal analyzer(STA)test,numerical simulations,one-dimensional stress wave theory,and material *** multiple regression models between response variables and interactive effects of independent variables were established using the response surface method(RSM).The results demonstrate the fatigue strength and life diminish as temperatures rise and increase with increasing fissure angles,while the strain rate exhibits an inverse ***,the peak stress intensification and strain rate softening observed during CALC impact exhibit greater prominence at increased fissure *** failure is dominated by tensile damage with concise evolution paths and intergranular cracks as well as the compressor-crushed zone which may affect the failure mode after 400℃.The second-order statistics of GLCM in SEM images exhibit a considerable dependence on the ***,thermal damage dominated by thermal properties controls the material structure and wave impedance and eventually affects the incident wave *** tensile wave reflected from the fissure surface is the inherent mechanism responsible for the angle effect exhibited by the fatigue strength and ***,the peak stress intensification and strain rate softening during impact are determ

关键词： Red sandstone Temperature Fissure Constant-amplitude and low-cycle(CALC) impact Fatigue failure Response surface method(RSM)

Deformation Characteristics of Hydrate-Bearing Sediments

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Journal of Ocean University of China 2024年第1期23卷 149-156页

作者： DONG Lin LI Yanlong ZHANG Yajuan HU Gaowei LIAO Hualin chen qiang WU Nengyou Key Laboratory of Gas Hydrate Ministry of Natural ResourcesQingdao Institute of Marine GeologyQingdao 266237China Laboratory for Marine Mineral Resources Laoshan LaboratoryQingdao 266237China College of Oceanography Hohai UniversityNanjing 210098China College of Petroleum Engineering China University of Petroleum(East China)Qingdao 266555China

The safe and efficient development of natural gas hydrate requires a deep understanding of the deformation behaviors of *** this study,a series of triaxial shearing tests are carried out to investigate the deformation properties of hydrate-bearing *** of volumetric and lateral strains versus hydrate saturation are analyzed *** indicate that the sediments with high hydrate saturation show dilative behaviors,which lead to strain-softening characteristics during *** volumetric strain curves have a tendency to transform gradually from dilatation to compression with the increase in effective confining *** easy prediction model is proposed to describe the relationship between volumetric and axial *** model coefficientβis the key dominating factor for the shape of volumetric strain curves and can be determined by the hydrate saturation and stress ***,a modified model is established for the calculation of lateral *** corresponding determination method is provided for the easy estimation of model coefficients for medium sand sediments containing *** study provides a theoretical and experimental reference for deformation estimation in natural gas hydrate development.

关键词： gas hydrate deformation characteristics volumetric strain lateral strain prediction model

Adaptive strategies of high and low nucleic acid prokaryotes in response to declining resource availability and selective grazing by protozoa

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Science China Earth Sciences 2024年第6期67卷 1872-1884页

作者： chen HU Liuqian YU Xiaowei chen Jihua LIU Yao ZHANG John BATT Xilin XIAO qiang SHI Rui ZHANG Tingwei LUO Nianzhi JIAO Dapeng XU College of the Environment and Ecology Xiamen UniversityXiamen 361102China State Key Laboratory of Marine Environmental Science College of Ocean and Earth SciencesFujian Key Laboratory of Marine Carbon SequestrationXiamen UniversityXiamen 361102China Joint Lab for Ocean Research and Education(LORE)of Dalhousie University Canadaand Shandong University and Xiamen UniversityXiamen 361102China Earth Ocean and Atmospheric Sciences ThrustThe Hong Kong University of Science and Technology(Guangzhou)Guangzhou 510000China Institute of Marine Science and Technology Shandong UniversityQingdao 266237China Department of Oceanography Dalhousie UniversityHalifaxNova Scotia B3H 4R2Canada Institute for Advanced Study Shenzhen UniversityShenzhen 518060China Carbon Neutral Innovation Research Center Xiamen UniversityXiamen 361102China

Prokaryotes play a fundamental role in global ocean biogeochemical ***,how the abundance and metabolic activity of ecologically distinct subgroups(i.e.,high nucleic acid(HNA)and low nucleic acid(LNA)cells),and their regulating factors,change in response to changing marine environmental conditions remains poorly ***,we delved into the time-evolving dynamic responses of the HNA and LNA prokaryotic subgroups to declining resource availability and selective grazing by protozoa by conducting a 73-day incubation experiment in a large-volume(117,000 L)macrocosm that facilitates community-level *** found that the metabolic activity of the HNA subgroup was higher than that of the LNA subgroup when the macrocosm was resource replete but that the HNA subgroup declined more rapidly than the LNA subgroup as the resources became increasingly scarce,leading to a steadily increasing contribution of LNA cells to prokaryotic ***,as resources in the macrocosm became limited,protozoan grazing preference shifted from the HNA to the LNA subgroup and the contributions of the LNA subgroup to the carbon flow within the macrocosm *** findings highlight the resilience of LNA cells in resource-limited environments,illuminate the critical role of selective grazing by protozoa in balancing distinct prokaryotic subgroups under changing resource conditions,and demonstrate the complex and adaptive interactions between protozoa and prokaryotes across diverse environmental contexts.

关键词： Microbial loop Macrocosm experiment Prokaryote Top-down and bottom-up controls Carbon flow

Moisture‑Electric–Moisture‑Sensitive Heterostructure Triggered Proton Hopping for Quality‑Enhancing Moist‑Electric Generator

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Nano-Micro Letters 2024年第3期16卷 351-366页

作者： Ya’nan Yang Jiaqi Wang Zhe Wang Changxiang Shao Yuyang Han Ying Wang Xiaoting Liu Xiaotong Sun Liru Wang Yuanyuan Li qiang guo Wenpeng Wu Nan chen Liangti Qu Key Laboratory of Cluster Science Ministry of Education of ChinaKey Laboratory of Photoelectronic/Electrophotonic Conversion MaterialsSchool of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing 100081People’s Republic of China Yangtze Delta Region Academy of Beijing Institute of Technology Jiaxing 314019People’s Republic of China Department of Chemistry Key Laboratory of Organic Optoelectronics&Molecular EngineeringMinistry of EducationTsinghua UniversityBeijing 100084People’s Republic of China

Moisture-enabled electricity(ME)is a method of converting the potential energy of water in the external environment into electrical energy through the interaction of functional materials with water molecules and can be directly applied to energy harvesting and signal ***,ME can be unreliable in numerous applications due to its sluggish response to moisture,thus sacrificing the value of fast energy harvesting and highly accurate information ***,by constructing a moisture-electric-moisture-sensitive(ME-MS)heterostructure,we develop an efficient ME generator with ultra-fast electric response to moisture achieved by triggering Grotthuss protons hopping in the sensitized ZnO,which modulates the heterostructure built-in interfacial potential,enables quick response(0.435 s),an unprecedented ultra-fast response rate of 972.4 mV s^(−1),and a durable electrical signal output for 8 h without any *** research provides an efficient way to generate electricity and important insight for a deeper understanding of the mechanisms of moisture-generated carrier migration in ME generator,which has a more comprehensive working scene and can serve as a typical model for human health monitoring and smart medical electronics design.

关键词： Moist-electric generators Grotthuss proton hopping Fast response Durable electrical output Personal health monitoring

Copper-catalyzed C(sp)-H aryl amination enables modular synthesis of quinolines and 2-quinolinones

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Science China Chemistry 2024年第2期67卷 595-603页

作者： Yang Gao Haixia Li Simin Yang Yanping Huo Qian chen Xianwei Li Zhe Wang Xiao-qiang Hu School of Chemical Engineering and Light Industry Guangdong University of TechnologyGuangzhou510006China Jieyang Branch of Chemistry and Chemical Engineering Guangdong Laboratory Jieyang515200China Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education&Hubei Key Laboratory of Catalysis and Materials Science School of Chemistry and Materials ScienceSouth-Central University for NationalitiesWuhan430074China

Herein,we disclose a novel copper-catalyzed C(sp)-H aryl amination of terminal alkynes with anthranils,enabling the rapid generation of highly reactive secondary N-aryl ynamines for the modular synthesis of structurally diverse C2-substituted quinolines and *** in-situ formed carbonyl-ynamines are prone to tautomerize to carbonyl-ketenimines,which can efficiently react with a series of nucleophiles,including amines,alcohols,phenols,thiols,thiophenols,active-methylene compounds,and even water to produce various quinoline derivatives with the generation of H_(2)O as a sole and green *** method also unlocks a practical route to create various quinoline-fused heterocycles and can be successfully applied to the late-stage modification of complex molecules and the concise synthesis of bioactive *** studies reveal a coppercatalyzed inner-sphere nitrene transfer process by using anthranils as novel aryl nitrene precursors.

关键词： copper catalysis anthranils C(sp)-H aryl amination carbonyl-ketenimines quinolines

Arbitrarily rotating polarization direction and manipulating phases in linear and nonlinear ways using programmable metasurface

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Light(Science & Applications) 2024年第9期13卷 1789-1800页

作者： Wei Liu Si Ran Wang Jun Yan Dai Lei Zhang Qiao chen qiang cheng Tie Jun Cui State Key Laboratory of Millimeter Waves Southeast UniversityNanjing 210096China Institute of Electromagnetic Space Southeast UniversityNanjing 210096China Frontiers Science Center for Mobile Information Communication and Security Southeast UniversityNanjing 210096China Electrical Engineering Department Chalmers University of TechnologyGothenburg 41258Sweden

Independent controls of various properties of electromagnetic(EM)waves are crucially required in a wide range of *** metasurface is a promising candidate to provide an advanced platform for manipulating EM ***,we propose an approach that can arbitrarily control the polarization direction and phases of reflected waves in linear and nonlinear ways using a stacked programmable ***,we extend the space-timecoding theory to incorporate the dimension of polarization,which provides an extra degree of freedom for manipulating EM *** proof-of-principle application examples,we consider polarization rotation,phase manipulation,and beam steering at linear and nonlinear *** validation,we design,fabricate,and measure a metasurface *** experimental results show good agreement with theoretical predictions and *** proposed approach has a wide range of applications in various areas,such as imaging,data storage,and wireless communication.

关键词： surface. nonlinear rotating

A review of solid-state lithium metal batteries through in-situ solidification

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Science China Chemistry 2024年第1期67卷 67-86页

作者： Pan Xu Zong-Yao Shuang chen-Zi Zhao Xue Li Li-Zhen Fan Aibing chen Haoting chen Elena Kuzmina Elena Karaseva Vladimir Kolosnitsyn Xiaoyuan Zeng Peng Dong Yingjie Zhang Mingpei Wang qiang Zhang Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology Department of Chemical EngineeringTsinghua UniversityBeijing 100084China National and Local Joint Engineering Laboratory for Lithium-ion Batteries and Materials Preparation Technology Key Laboratory of Advanced Battery Materials of Yunnan ProvinceFaculty of Metallurgical and Energy EngineeringKunming University of Science and TechnologyKunming 650093China Institute of Advanced Materials and Technology University of Science and Technology BeijingBeijing 100083China College of Chemical and Pharmaceutical Engineering Hebei University of Science and TechnologyShijiazhuang 050018China Ordos Carbon Neutral Research and Application Co. Ltd.Ordos City 017010China Ufa Institute of Chemistry UFRC RAS Ufa 450054Russia Institute for Carbon Neutrality Tsinghua UniversityBeijing 100084China Shanxi Research Institute for Clean Energy Tsinghua UniversityTaiyuan 030032China

High-energy-density lithium metal batteries are the next-generation battery systems of choice,and replacing the flammable liquid electrolyte with a polymer solid-state electrolyte is a prominent conduct towards realizing the goal of high-safety and high-specific-energy ***,the inherent intractable problems of poor solid-solid contacts between the electrode/electrolyte and the growth of Li dendrites hinder their practical *** in-situ solidification has demonstrated a variety of advantages in the application of polymer electrolytes and artificial interphase,including the design of integrated polymer electrolytes and asymmetric polymer electrolytes to enhance the compatibility of solid–solid contact and compatibility between various electrolytes,and the construction of artificial interphase between the Li anode and cathode to suppress the formation of Li dendrites and to enhance the high-voltage stability of polymer *** review firstly elaborates the history of in-situ solidification for solid-state batteries,and then focuses on the synthetic methods of solidified ***,the recent progress of in-situ solidification technology from both the design of polymer electrolytes and the construction of artificial interphase is summarized,and the importance of in-situ solidification technology in enhancing safety is ***,prospects,emerging challenges,and practical applications of in-situ solidification are envisioned.

关键词： in-situ solidification polymer electrolyte artificial solid electrolyte interphase rechargeable lithium metal batteries dendrite-free lithium metal anode

Effect and mechanism of reductive polyaniline on the stability of nitrocellulose

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Defence Technology（防务技术） 2024年第8期38卷 217-225页

作者： Wenjiang Li Binbin Wang Huimin chen Aoao Lu chenguang Li qiang Li Fengqiang Nan Ping Du School of Chemistry and Chemical Engineering Nanjing University of Science and TechnologyNanjing 210094China Key Laboratory of Special Energy Materials Ministry of EducationNanjing 210094China

The search for new green and efficient stabilizers is of great importance for the stabilization of nitrocellulose(NC). This is due to the shortcomings of traditional stabilizers, such as high toxicity. In this study, reduced polyaniline(r-PANI), which has a similar functional structure to diphenylamine(DPA) but is non-toxic, was prepared from PANI based on the action with N_(2)H_(4) and NH_(3)-H_(2)O, and used for the first time as a potential stabilizer for NC. XPS, FTIR, Raman, and SEM were used to characterize the reduced chemical structure and surface morphology of r-PANI. In addition, the effect of r-PANI on the stabilization of NC was characterized using DSC, VST, isothermal TG, and MMC. Thermal weight loss was reduced by 83% and 68% and gas pressure release by 75% and 49% compared to pure NC and NC&3%DPA, *** and XPS were used to characterize the structural changes of r-PANI before and after reaction with NO_(2). The 1535 cm^(-1) and 1341 cm^(-1) of the FTIR and the 404.98 eV and 406.05 eV of the XPS showed that the -NO_(2) was generated by the absorption of NO_(2). Furthermore, the quantum chemical calculation showed that NO_(2) was directly immobilized on r-PANI by forming -NO_(2) in the neighboring position of the benzene ring.

关键词： Nitrocellulose Green stabilizer Polyaniline Mechanism of stability

Research on feed-pulse collaborative control method in micro-electrical discharge machining

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Advances in Manufacturing 2024年第2期12卷 270-287页

作者： qiang Gao Ya-Ou Zhang Xue-cheng Xi Yuan-Ding Wang Xiao-Fei chen Wan-Sheng Zhao School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai200240People’s Republic of China State Key Laboratory of Mechanical System and Vibration Shanghai200240People’s Republic of China Shanghai Institute of Space Propulsion Shanghai201112People’s Republic of China

Reducing the short-circuit rate and increasing the effective discharge rate are important targets for improving the servo control effect of micro-electrical discharge machining(micro-EDM),as these two indicators are closely related to the machining efficiency and *** this study,a feed-pulse collaborative control(FPCC)method is proposed for micro-EDM based on two dimensions(space and time).In the spatial dimension,a feed control strategy with a discharge holding process is ***,in the time dimension,a forward-looking pulse control strategy is adopted,in which the pulse interval is adjusted based on a sequence analysis of feed commands and discharge *** experiments are carried out to determine the key parameters used in this method,including the discharge holding threshold and pulse interval adjustment value(T_(off_(adj))).The feed smoothness and discharge sufficiency analyses of the experimental results show that compared to the traditional double threshold average voltage method,the FPCC method reduces the number of long-distance retreats by 64%and improves the effective discharge time by 40%.

关键词： Micro-electrical discharge machining(micro-EDM) Electrode feed control Discharge pulse control Machining surface quality