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Integrated approach of predicting rock stability in high mountain valley underground caverns

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Underground Space 2024年第6期19卷 317-341页

作者： Fuyuan Tan Haosen Guo Pengzhi Pan Zhaofeng Wang xufeng Liu Yangyi Zhou East China Jiaotong University Nanchang 467200China State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan 430071China Key Laboratory of Liaoning Province on Deep Engineering and Intelligent Technology Northeastern UniversityShenyang 110819China University of Chinese Academy of Sciences Beijing 100049China

High mountain valleys are characterized by the development of intricate ground stress fields due to geological processes such as tectonic stress,river erosion,and rock *** processes introduce considerable stability concerns in the surrounding rock formations for underground engineering projects in these regions,highlighting the imperative need for rigorous stability assessments during the design phase to ensure construction *** paper introduces an innovative approach for the pre-evaluation of the stability of surrounding rocks in underground caverns situated within high mountain *** methodology comprises several pivotal ***,we conduct inverse calculations of the ground stress field in complex geological terrains,combining field monitoring and numerical ***,we ascertain stress-strength ratios of the surrounding rocks using various rock strength *** assess the stability characteristics of the surrounding rocks in the 1.(#)spillway cave within our project area,we employ numerical simulations to compute stress-strength ratios based on different rock strength ***,we undertake a comparative analysis,utilizing data from the 5^(#)Underground Laboratory(Lab 5)of Jinping II Hydropower Station,aligning the chosen rock strength criterion with the damage characteristics of Lab 50s surrounding *** analysis serves as the cornerstone for evaluating other mechanical responses of the surrounding rocks,thereby validating the pre-evaluation *** pre-evaluation method takes into account the intricate geological evolution processes specific to high mountain *** also considers the influence of the initial geostress field within the geological range of underground *** comprehensive approach provides a robust foundation for the analysis and assessment of the stability of surrounding rocks,especially in high mountain valley areas,during the design phase of underground engi

关键词： High mountain valley Underground cavern Stability of surrounding rock On-site monitoring Stress-strength ratio Numerical simulation

A novel indirect optical method for rock stress measurement using microdeformation field analysis

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第9期16卷 3616-3628页

作者： Yujie Feng Peng-Zhi Pan Zhaofeng Wang xufeng Liu Shuting Miao State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China University of Chinese Academy of Sciences Beijing100049China

Stress measurement plays a crucial role in geomechanics and rock engineering,especially for the design and construction of large-scale rock *** paper presents a novel method,based on the traditional stress relief approach,for indirectly measuring rock stress using optical *** proposed method allows for the acquisition of full-field strain evolution on the borehole’s inner wall before and after disturbance,facilitating the determination of three-dimensional(3D)stress information at multiple points within a single *** study focuses on presenting the method’s theoretical framework,laboratory validation results,and equipment design *** theoretical framework comprises three key components:the optical imaging method of the borehole wall,the digital image correlation(DIC)method,and the stress calculation *** validation tests investigate strain field distribution on the borehole wall under varying stress conditions,with stress results derived from DIC strain ***,the optical method demonstrates better measurement accuracy during the unloading stage compared to conventional strain gauge *** relatively high stress levels,the optical method demonstrates a relative error of less than 7%and an absolute error within 0.5 ***,a comparative analysis between the optical method and the conventional contact resistance strain gauge method highlights the optical method’s enhanced accuracy and stability,particularly during the unloading *** proposed optical stress measurement device represents a pioneering effort in the application of DIC technology to rock engineering,highlighting its potential to advance stress measurement techniques in the field.

关键词： Rock stress measurement Optical technology Digital image correlation(DIC)technology Micro-deformation field

Random Terpolymer of Carbon Dioxide,Butadiene and Epoxides:Synthesis,Functionalization and Degradability

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Chinese Journal of Chemistry 2024年第14期42卷 1630-1636页

作者： Zi Wang Wuyi Zheng Sicong Yue Kaihao Chen Jun Ling xufeng Ni MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang UniversityHangzhouZhejiang310058 China Westlake Electronics Group Co. Ltd.HangzhouZhejiang310012 China

The utilization of carbon dioxide(CO_(2))as a C1.feedstock is consistently attractive,especially in the preparation of sustainable polymeric *** this contribution,a terpolymer of CO_(2),1.3-butadiene(BD)and epoxide is synthesized by scandium triflate catalyzed cationic ring-opening copolymerization ofα-ethylidene-δ-vinyl-δ-valerolactone(EVL),an intermediate derived from CO_(2)and BD,with *** obtained terpolymer with a CO_(2)content of 22 mol%has a number-average molecular weight(M_(n))up to 7.8 kg/mol and a dispersity(Đ)of *** reactivity ratios of EVL and cyclohexene oxide(CHO)are determined as 0.01.and 1.07,respectively,suggesting random characteristic of the *** preserved C=C double bonds from BD allow for the further modification of the terpolymer by photoinitiated *** yielded networks are fluorescent and *** method offers enhanced versatility to the synthesis and additional functionalization of CO_(2)-based polymers.

关键词： Ring-opening polymerization Copolymerization Carbon dioxide Butadiene Scandium triflate Fluorescence

Modulation on electrostatic potential to build a firm bridge at NiO_(x)/perovskite interface for efficient and stable perovskite solar cells

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Journal of Energy Chemistry 2024年第9期96卷 249-258页

作者： Xiangbao Yuan xufeng Ling Hongyu Wang Chengxia Shen Ru Li Yehao Deng Shijian Chen Chongqing Key Laboratory of Interface Physics in Energy Conversion College of PhysicsChongqing UniversityChongqing 401331China Key Laboratory of Optoelectronic Technology&Systems(Ministry of Education) College of Optoelectronic EngineeringChongqing UniversityChongqing 400044China Center of Modern Physics Institute for Smart City of Chongqing University in LiyangLiyang 213300JiangsuChina

The NiO_(x)/perovskite interface in NiO_(x)-based inverted perovskite solar cells(PSCs)is one of the main issues that restrict device performance and long-term stability,as the unwanted interfacial defects and undesirable redox reactions cause severe interfacial non-radiative recombination and open-circuit voltage(Voc)***,a series of self-assembled molecules(SAMs)are employed to bind,bridge,and stabilize the NiO_(x)/perovskite interface by regulating the electrostatic *** on systematically theoretical and experimental studies,4-pyrazolecarboxylic acid(4-PCA)is proven as an efficient molecule to simultaneously passivate the NiO_(x)and perovskite surface traps,release the interfacial tensile stress as well as quench the detrimental interface redox reactions,thus effectively suppressing the interfacial non-radiative recombination and enhancing the quality of perovskite ***,the PSCs with 4-PCA treatment exhibited an eminently increased Voc,leading to a significant increase in power conversion efficiency from 21.28%to 23.77%.Furthermore,the unencapsulated devices maintain 92.6%and 81.3%of their initial PCEs after storing in air with a relative humidity of 20%–30%for 1.00 h and heating at 65℃for 500 h in a N_(2)-filled glovebox,respectively.

关键词： Perovskite solar cells Nickel oxide Interface defects passivation Redox reaction Nonradiative recombination

Suppress oxygen evolution of lithium-rich manganese-based cathode materials via an integrated strategy

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Green Energy & Environment 2024年第1期9卷 138-151页

作者： Wenhua Yu Yanyan Wang Aimin Wu Aikui Li Zhiwen Qiu xufeng Dong Chuang Dong Hao Huang Key Laboratory of Energy Materials and Devices(Liaoning Province) School of Materials Science and EngineeringDalian University of TechnologyDalian116024Liaoning ProvinceChina Dalian Engineering Research Center for New Electric Power Systerms School of Electrical EngineeringDalian University of TechnologyDalian116024Liaoning ProvinceChina

Improving the reversibility of anionic redox and inhibiting irreversible oxygen evolution are the main challenges in the application of high reversible capacity Li-rich Mn-based cathode materials.A facile synchronous lithiation strategy combining the advantages of yttrium doping and LiYO_(2) surface coating is *** doping effectively suppresses the oxygen evolution during the delithiation process by increasing the energy barrier of oxygen evolution reaction through strong Y–O bond ***_(2) nanocoating has the function of structural constraint and protection,that protecting the lattice oxygen exposed to the surface,thus avoiding irreversible *** an Li^(+) conductor,LiYO_(2) nano-coating can provide a fast Li^(+) transfer channel,which enables the sample to have excellent rate *** synergistic effect of Y doping and nano-LiYO_(2) coating integration suppresses the oxygen release from the surface,accelerates the diffusion of Li^(+)from electrolyte to electrode and decreases the interfacial side reactions,enabling the lithium ion batteries to obtain good electrochemical *** lithium-ion full cell employing the Y-1.sample(cathode)and commercial graphite(anode)exhibit an excellent specific energy density of 442.9 Wh kg^(-1. at a current density of 0.1.,with very stable safety performance,which can be used in a wide temperature range(60 to-1.℃)stable *** result illustrates a new integration strategy for advanced cathode materials to achieve high specific energy density.

关键词： Lithium-rich manganese-based cathodes Lithium ion batteries Oxygen redox Oxygen evolution Integrated strategy

Annulation Cascades of Cyclosulfonium Salts and Alkenes towards Sulfur-Containing N-Heterocycles by Visible Light/Copper Catalysis

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Chinese Journal of Chemistry 2024年第14期42卷 1637-1643页

作者： Jie Ma xufeng Li Yuqing Chen Yongjia Shi Xiuyan Song Jian Lv Daoshan Yang Key Laboratory of Optic-electric Sensing and Analytical Chemistry for Life Science MOECollege of Chemistry and Molecular EngineeringQingdao University of Science and TechnologyQingdaoShandong266042 China Zhejiang Wansheng Co. Ltd.LinhaiZhejiang317000 China National Engineering Research Center of Low-Carbon Processing and Utilization of Forest Biomass Nanjing Forestry UniversityNanjingJiangsu210037 China

Although,great achievements have been made in the synthesis of heterocycles using radical addition/cyclization strategy,developing versatile alkyl radical precursors,especially the non-stabilized long chain alkyl radicals for this strategy still remains a huge ***,we report an efficient annulation cascade reaction between cyclosulfonium salts and alkenes for the synthesis of sulfur-containing N-heterocycles by visible light/copper catalysis under mild *** C—S bond cleavage/radical cascade reaction delivers a variety of corresponding N-heterocycles containing aryl alkyl thioether motifs with good functional group ***,the current system could be used for the late-stage functionalization of complex bioactive molecules.

关键词： Visible light Radical reactions C-C coupling Sulfur heterocycles Photoredox catalysis

Silica-modified Pt/TiO_(2) catalysts with tunable suppression of strong metal-support interaction for cinnamaldehyde hydrogenation

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Chinese Journal of Chemical Engineering 2024年第6期70卷 189-198页

作者： Zhengjian Hou Yuanyuan Zhu Hua Chi Li Zhao Huijie Wei Yanyan Xi Lishuang Ma Xiang Feng xufeng Lin College of Chemistry and Chemical Engineering China University of Petroleum(East China)Qingdao 266580China Advanced Chemical Engineering and Energy Materials Research Center China University of Petroleum(East China)Qingdao 266580China State Key Laboratory of Heavy Oil Processing China University of Petroleum(East China)Qingdao 266580China

Tuning Strong Metal-support Interactions(SMSI)is a key strategy to obtain highly active catalysts,but conventional methods usually enable TiO_(x) encapsulation of noble metal components to minimize the exposure of noble *** study demonstrates a catalyst preparation method to modulate a weak encapsulation of Pt metal nanoparticles(NPs)with the supported TiO_(2),achieving the moderate suppression of SMSI *** introduction of silica inhibits this encapsulation,as reflected in the characterization results such as XPS and HRTEM,while the Ti^(4+) to Ti^(3+) conversion due to SMSI can still be found on the support ***,the hydrogenation of cinnamaldehyde(CAL)as a probe reaction revealed that once this encapsulation behavior was suppressed,the adsorption capacity of the catalyst for small molecules like H_(2) and CO was enhanced,which thereby improved the catalytic activity and facilitated the hydrogenation of ***,the introduction of SiO_(2) also changed the surface structure of the catalyst,which inhibited the occurrence of the acetal reaction and improved the conversion efficiency of C=O and C=C *** manipulation of SMSI formation and its consequence on the performance in catalytic hydrogenation reactions are discussed.

关键词： Pt catalyst Silica modification Hydrogenation Cinnamaldehyde Strong metal-support interaction

Unveiling evapotranspiration patterns and energy balance in a subalpine forest of the Qinghai-Tibet Plateau:observations and analysis from an eddy covariance system

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Journal of Forestry Research 2024年第3期35卷 175-188页

作者： Niu Zhu Jinniu Wang Dongliang Luo xufeng Wang Cheng Shen Ning Wu Ning Zhang Binghui Tian Aihong Gai Chengdu Institute of Biology Chinese Academy of SciencesChengdu 610041People's Republic of China College of Resources and Environmental Sciences Gansu Agricultural UniversityLanzhou 730070People's Republic of China Mangkang Ecological Monitoring Station Tibet Ecological Security Barrier Ecological Monitoring NetworkQamdo 854500People's Republic of China Northwest Institute of Eco Environmental Resources Chinese Academy of SciencesLanzhou 730000People's Republic of China

Evapotranspiration is an important parameter used to characterize the water cycle of *** under-stand the properties of the evapotranspiration and energy balance of a subalpine forest in the southeastern Qinghai-Tibet Plateau,an open-path eddy covariance system was set up to monitor the forest from November 2020 to October 2021.in a core area of the Three Parallel Rivers in the Qing-hai-Tibet *** results show that the evapotranspira-tion peaked daily,the maximum occurring between 1.:00 and 1.:*** factors had significant effects on evapotranspiration,among them,net radiation the greatest(R^(2)=0.487),and relative humidity the least(R^(2)=0.001..The energy flux varied considerably in different seasons and sensible heat flux accounted for the main part of turbulent *** energy balance ratio in the dormant season was less than that in the growing season,and there is an energy imbalance at the site on an annual time scale.

关键词： Evapotranspiration Energy balance Subalpine forest Three Parallel Rivers region Southeast Qinghai-Tibet Plateau

Bone tissue engineering scaffold materials: Fundamentals, advances, and challenges

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Chinese Chemical Letters 2024年第2期35卷 176-186页

作者： Chang Xu Zhize Liu Xi Chen Yang Gao Wenjun Wang Xijing Zhuang Hao Zhang xufeng Dong Department of Cardiovascular Surgery Central Hospital of Dalian University of TechnologyDalian 116089China School of Materials Science and Engineering Dalian University of TechnologyDalian 116024China Department of Orthopaedics Central Hospital of Dalian University of TechnologyDalian 116089China Department of Dermatology Allergologyand VenereologyUniversity of LübeckLübeck 23562Germany

Bone damage caused by trauma and tumors is a serious problem for human health, therefore, three-dimensional (3D) scaffolding materials that stimulate and promote the regeneration of broken bone tissues have become the focus of current research in the field of bone damage *** this regard, a preferential combination of materials and preparation techniques is considered crucial for the preparation of advanced bone tissue engineering scaffolds to better facilitate the regeneration of broken *** this review, current research advances and challenges in bone tissue engineering scaffolds are discussed and analyzed in ***, we elucidated the structure and self-healing mechanism of bone ***, the main applications of different materials, including inorganic and organic materials, in bone tissue engineering scaffolds are ***, we overview the latest research progress of the mainstream preparation strategies of bone tissue engineering scaffolds, and provide an in-depth analysis of the different advantages of each ***, promising future directions and challenges of bone tissue engineering scaffolds are systematically discussed.

关键词： Biomaterials Bone defects Tissue engineering Scaffolds Osteogenesis