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Evaluation on cutting performance of novel PDC cutter for pipe jacking machine

Underground Space 2024年第1期14卷 34-52页

作者： Long-Chuan Deng yi-Xiang Yuan Xiao-Zhao Li Qian-Wei Zhuang Chi Zhang yi-Wei Chen School of Earth Sciences and Engineering Nanjing UniversityNanjingJiangsu 210023China Shanghai Tunnel Engineering Co.Ltd. Shanghai 200232China State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and TechnologyXuzhouJiangsu 221116China School of Mechanics and Engineering Science Shanghai UniversityShanghai 200444China

It is inevitable to cut reinforced concrete(RC)appeared in cross passage of city metro by cutting tools when constructing in densely populated *** previous cutters employed to cut RC are insufficient and easily damaged,so a new polycrystalline diamond compact(PDC)cutter is used to solve this *** on the theoretical analysis of cutting mechanism,both circular and tapered PDC cutters with cutting edge angle of 90and negative front rack angle of 10are used to cut *** peeling and breaking patterns of cutting concrete are proposed,the nodular and grainy chips are the preferred modes in cutting steel *** LS-DYNA is employed to investigate the cutting performance in *** simulation results show that the average and peak cutting forces increase with the growth of penetration depth,cutting speed,and roundness,and subsequently the recommended penetration depth less than 1.2 mm is obtained to cut RC due to the existence of steel ***,the linear cutting platform is adopted to investigate the force ability and damage state of PDC *** is concluded that the cutting force increases abruptly and fluctuates heavily when cutting the coarse *** patterns occurred in both numerical and experimental results are generally ***,the steel bar is pulled out and the PDC cutter is damaged at the penetration depth of 0.8 mm,while a good cut occurs at the penetration depth of 0.3 *** tapered PDC cutter with a relatively low cutting force is prone to be broken compared with circular PDC *** is suggested that the circular PDC cutter at the penetration depth of 0.3 mm should be used to cut RC in practical engineering.

关键词： PDC cutter RC Pipe jacking machine Linear cutting tests Damage and wear LS-DYNA

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The critical role of energetic fluctuations in charge separation for efficient molecular doping of organic semiconductors

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Science China Chemistry 2024年第11期67卷 3675-3680页

作者： Yan Zeng Guangchao Han Yuanping yi Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Organic Solids Institute of Chemistry Chinese Academy of Sciences University of Chinese Academy of Sciences

Molecular doping is essential to improve the electrical conductivity of organic semiconductors for high-performance organic electronic devices. However, the doping efficiency is influenced by several factors, such as the energy levels, energetic fluctuations, dielectric properties, and molecular packing structures of the doped films, and the underlying mechanisms for highefficiency doping are still unclear. Here, through multi-level theoretical simulations on a series of fullerene derivatives, we identify that the energetic fluctuations can play a decisive role in activating charge separation for molecular doping. In particular,the doping efficiency appears to be exponentially increased with the fluctuation of charge polarization energies. Therefore,although the charge mobility is somewhat decreased, the experimental electrical conductivity is improved with the increased energetic fluctuation. Moreover, it has been found that polarization energy fluctuation can be effectively enhanced by simply introducing side chains with greater flexibility into organic semiconductors. This article paves the way towards high-efficiency molecular doping of organic semiconductors.

关键词： doping efficiency polarization energies energetic fluctuations organic semiconductors

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Can the integration between urban and rural areas be realized?A new theoretical analytical framework

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Journal of Geographical Sciences 2024年第1期34卷 3-24页

作者： WANG yi LU Yuqi ZHU yingming Research Base of Jiangsu Industrial Cluster School of Economics and ManagementNanjing University of Science and TechnologyNanjing 210094China School of Geography Nanjing Normal UniversityNanjing 210023China

Urban-rural integration is an advanced form resulting from the future evolution of urban-rural ***,little research has explored whether urban and rural areas can move from dual segmentation to integrated development from a theoretical or empirical *** on the research framework of welfare economics,which offers an appealing paradigm to frame the underlying game between cities and villages,this study clarifies the ideal state of urban-rural *** then proposes a series of basic assumptions,and constructs a corresponding objective function and its ***,it assesses the possibility of seeing the transmutation from division to integration between urban and rural areas with continuous socio-economic *** authors argue that the ideal state of urban-rural integration should be a Pareto-driven optimal allocation of urban-rural resources and outputs,and the maximization of social welfare in the entire *** on a systematic demonstration using mathematical models,the study proposes that urban and rural areas can enter this ideal integrated development pattern when certain parameter conditions are *** general,this study demonstrates the theoretical logic and scientific foundations of urban-rural integration,enriches theoretical studies about urban-rural relationships,and provides basic theoretical support for large developing countries to build a coordinated and orderly urban-rural community with a shared future.

关键词： urban-rural integration development ideal state parameter conditions welfare economics theoretical framework

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Switching on/off phosphorescent or non-radiative channels by aggregation-induced quantum interference

Aggregate

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Aggregate 2024年第1期5卷 175-184页

作者： yi Kong Yu-Chen Wang Xunkun Huang WanZhen Liang yi Zhao Department of Chemistry State Key Laboratory of Physical Chemistry of Solid SurfacesiChEMFujian Provincial Key Laboratory of Theoretical and Computational Chemistryand College of Chemistry and Chemical EngineeringXiamen UniversityXiamenPeople’s Republic of China

Pure organic materials with persistent and efficient room-temperature phosphorescence have recently aroused great research interest due to their vast potential in *** crucial design principle for such materials is to suppress as much as possible the non-radiative decay of the triplet exciton while maintaining a moderate phosphorescent radiative ***,molecular engineering often exhibits similar regulation trends for the two ***,we propose that the quantum interference caused by aggregation can be utilized to control the phosphorescent and non-radiative decay *** systematically analyze various constructive and destructive transition pathways in aggregates with different molecular packing types and establish clear relationships between the luminescence characters and the signs of the singlet and triplet excitonic *** is shown that the decay channels can be flexibly switched on or off by regulating the packing type and excitonic *** importantly,an enhanced phosphorescent decay and a completely suppressed non-radiative decay can be simultaneously realized in the aggregate packed with inversion *** work lays the theoretical foundation for future experimental realization of quantum interference effects in phosphorescence.

关键词： excitonic coupling intersystem crossing organic aggregates organic room temperature phosphorescence quantum interference

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Machine Learning Security Defense Algorithms Based on Metadata Correlation Features

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Computers, Materials & Continua 2024年第2期78卷 2391-2418页

作者： Ruchun Jia Jianwei Zhang yi Lin College of Computer Science Sichuan UniversityChengdu610065China

With the popularization of the Internet and the development of technology,cyber threats are increasing day by *** such as malware,hacking,and data breaches have had a serious impact on *** network security environment in the era of big data presents the characteristics of large amounts of data,high diversity,and high real-time *** security defense methods and tools have been unable to cope with the complex and changing network security *** paper proposes a machine-learning security defense algorithm based on metadata association *** control over unauthorized users through privacy,integrity,and *** user model is established and the mapping between the user model and the metadata of the data source is *** analyzing the user model and its corresponding mapping relationship,the query of the user model can be decomposed into the query of various heterogeneous data sources,and the integration of heterogeneous data sources based on the metadata association characteristics can be *** and classify customer information,automatically identify and perceive sensitive data,build a behavior audit and analysis platform,analyze user behavior trajectories,and complete the construction of a machine learning customer information security defense *** experimental results show that when the data volume is 5×103 bit,the data storage integrity of the proposed method is 92%.The data accuracy is 98%,and the success rate of data intrusion is only 2.6%.It can be concluded that the data storage method in this paper is safe,the data accuracy is always at a high level,and the data disaster recovery performance is *** method can effectively resist data intrusion and has high air traffic control *** can not only detect all viruses in user data storage,but also realize integrated virus processing,and further optimize the security defense effect of user big data.

关键词： Data-oriented architecture metadata correlation features machine learning security defense data source integration

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Synthesis of Diverse Oxetane Amino Acids via Visible-Light-Induced Photocatalytic Decarboxylative Giese-Type Reaction

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Chinese Journal of Chemistry 2024年第12期42卷 1341-1346页

作者： Haoliang Shi yi Wan Yongqiang Zhang Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism Shanghai Key Laboratory of New Drug Designand School of PharmacyEast China University of Science and TechnologyShanghai200237 China

The divergent synthesis of versatile 3,3′-disubstituted oxetane amino acids by utilizing visible-light-induced photocatalytic decarboxylative Giese-type reaction has been demonstrated.3-Methyleneoxetane-derived substrates are readily available in a single-step and highly reactive as radical acceptors,allowing the production of versatile oxetaneγ-andα-amino acids in high yields.A distinct ring strain release-driven radical addition mechanism was preliminarily *** preparative power was further highlighted by the application in the synthesis of oxetane-containing dipeptides and azetidine amino acids,as well as the transformation of the product into novel oxetane-containing spiro-heterocycle pharmacophore.

关键词： Photoredox catalysis Decarboxylative Giese-type reaction Oxetane amino acids Amino acids Synthesis Radical reactions

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Ultrasonic enhancement of persulfate oxidation system governs emerging pollutants decontamination

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GREEN ENERGY & ENVIRONMENT 2024年第11期9卷 1666-1678页

作者： Li, Yanpan Zhou, Yanbo Zhou, yi East China Univ Sci & Technol Natl Engn Res Ctr Ind Wastewater Detoxicat & Resou State Environm Protect Key Lab Environm Risk Asses 130 Meilong Rd Shanghai 200237 Peoples R China East China Univ Sci & Technol Shanghai Engn Res Ctr Multimedia Environm Catalysi 130 Meilong Rd Shanghai 200237 Peoples R China Shanghai Inst Pollut Control & Ecol Secur Shanghai 200092 Peoples R China

Emerging contaminants (ECs) are widely present in aquatic environments, posing potential risks to both ecosystems and human health. The ultrasound-assisted persulfate oxidation process has attracted considerable attention in the degradation of ECs due to its ability to generate both sulfate radicals and cavitation effects, enhancing degradation effects. In this paper, the principle of ultrasonic synergistic Fenton-like oxidation system for degrading organic pollutants was reviewed, divided into homogeneous system, non-homogeneous system, and single-atom system to explore the synergistic effect of ultrasound-enhanced persulfate technology in three aspects, and the effects of environmental factors such as ultrasonic frequency and power, system pH, temperature, and initial oxidant concentration on the system's decontamination performance were discussed. Finally, future research on ultrasonically activated persulfate technology is summarized and prospected. (c) 2024 Institute of Process Engineering, Chinese Academy of Sciences. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co., Ltd. This is an open access article under the CC BY-NC-ND license (http://***/licenses/by-nc-nd/4.0/).

关键词： Ultrasound Persulfate Emerging contaminants Reaction mechanism Synergistic effects NAPHTHOL BLUE BLACK SONOCATALYTIC DEGRADATION ACTIVATED PERSULFATE WASTE-WATER SONOCHEMICAL DEGRADATION REMOVAL NANOPARTICLES KINETICS PEROXYMONOSULFATE NANOCOMPOSITE

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Seismic risk assessment and damage analysis: Emerging trends and new developments

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JOURNAL OF SAFETY SCIENCE AND RESILIENCE 2024年第3期5卷 365-381页

作者： Liu, yi Gu, yin Zhang, Hui Tsinghua Univ Inst Publ Safety Res Dept Engn Phys Beijing 100084 Peoples R China Tsinghua Univ Sch Safety Sci Beijing 100084 Peoples R China Beijing Key Lab City Integrated Emergency Response Beijing 100084 Peoples R China

Earthquakes are major catastrophes that cause great life and economic losses to human society and environment. This paper reviews and synthesizes relevant studies, drawing from a systematic examination of 4229 articles from the Web of Science core collection (1982-2023). Employing the CiteSpace visualization and analysis tool, current research and emerging trends in seismic risk assessment are discussed and analyzed. This paper provides a holistic overview of principal contributions, knowledge sources, interdisciplinary characteristics, and principal research topics in this field. Additionally, we propose key technologies that are in urgent need of enhancement, including data availability, quantity and quality of data, interpretability of machine learning models, performance improvement of machine learning methods and application of foundation models, as well as real-time risk assessment techniques. These insights support both theoretical understanding and practical applications of seismic risk assessment and damage analysis.

关键词： Earthquake Vulnerability Seismic risk assessment Seismic damage analysis CiteSpace HISTORICAL MASONRY TOWERS VULNERABILITY ASSESSMENT FRAGILITY CURVES TYPICAL BRIDGES RESILIENCE EARTHQUAKE MODEL FRAMEWORK BUILDINGS NETWORK

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Molecular evolution of Toll-like receptors in rodents

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Integrative Zoology 2024年第3期19卷 371-386页

作者： Qianqian SU yi CHEN Hongxuan HE College of Forestry Central South University of Forestry and TechnologyChangshaChina National Research Center for Wildlife-Borne Diseases Institute of ZoologyChinese Academy of SciencesBeijingChina

Toll-like receptors(TLRs),the key sensor molecules in vertebrates,trigger the innate immunity and prime the adaptive immune *** TLR family of rodents,the largest order of mammals,typically contains 13 TLR ***,a clear picture of the evolution of the rodent TLR family has not yet emerged and the TLR evolutionary patterns are unclear in rodent ***,we analyzed the natural variation and the evolutionary processes acting on the TLR family in rodents at both the interspecific and population *** results showed that rodent TLRs were dominated by purifying selection,but a series of positively selected sites(PSSs)primarily located in the ligand-binding domain was also *** numbers of PSSs differed among TLRs,and nonviralsensing TLRs had more PSSs than those in viral-sensing ***-conversion events were found between TLR1 and TLR6 in most rodent *** genetic analyses showed that TLR2,TLR8,and TLR12 were under positive selection in Rattus norvegicus and ***,whereas positive selection also acted on TLR5 and TLR9 in the former species,as well as TLR1 and TLR7 in the latter ***,we found that the proportion of polymorphisms with potentially functional change was much lower in viral-sensing TLRs than in nonviral-sensing TLRs in both of these rat *** findings revealed the first thorough insight into the evolution of the rodent TLR genetic variability and provided important novel insights into the evolutionary history of TLRs over long and short timescales.

关键词： adaptive evolution gene conversion positive selection rodents Toll-like receptors

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Disposal of zinc extraction residues via iron ore sintering process:an innovative resource utilization

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Journal of Iron and Steel Research International 2024年第7期31卷 1636-1645页

作者： Chun-long Fan Cheng-yi Ding Tao Yang Yun-fei Luo yi-fan Wang Qian Li Hong-ming Long School of Metallurgical Engineering Anhui University of TechnologyMa'anshan 243002AnhuiChina Zhongye Changtian International Engineering Co. Ltd.Changsha 410205HunanChina Key Laboratory of Metallurgical Emission Reduction and Resources Recycling(Ministry of Education) Anhui University of TechnologyMa'anshan 243002AnhuiChina

Zinc extraction residue,a solid waste generated from the treatment of zinc-containing dust in rotary kilns,is commonly stockpiled in steel companies for extended *** poses significant disposal challenges and environmental pollution *** far,research on the treatment of zinc extraction residues has been slow,inadequate,and *** this gap,a novel approach was proposed to effectively treat the zinc extraction residue via the iron ore sintering *** was feasible to add 1 wt.%of zinc extraction residues to the sintering raw *** more adequate mineralization reaction resulted in higher yield and tumbler indexes,despite a slight decrease in sintering *** this may result in a slight decrease in sintering speed,the more complete mineralization reaction leads to improved sintering yield and tumbler ***,the addition of zinc extraction residues reduced the CO and NO_(x) concentrations in the sintering flue ***,the iron ore sintering process provided a viable solution for resource utilization and environmentally friendly treatment of zinc extraction residues.

关键词： Zinc extraction residue Iron ore sintering Co-processing Waste utilization Gas pollutant reduction

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