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Science China Chemistry 2024年第7期67卷 2199-2205页

作者： Hongyan Long Sha Zhao Chunyan jian Xiuli Wu Fengfei Lu Minghong liao Fengrui Che Xingxing Wu Yonggui Robin Chi State Key Laboratory of Green Pesticide Key Laboratory of Green Pesticide and Agricultural BioengineeringMinistry of EducationGuizhou UniversityGuiyang 550025China School of Chemistry Chemical Engineeringand BiotechnologyNanyang Technological UniversitySingapore 637371Singapore

Organoseleniums exhibit a diverse set of biological activities that are pivotal for drug discovery and are widely explored in synthetic chemistry and material *** many transformations have been developed for non-enantioselective C–Se bond formations,the catalyst-controlled stereoselective preparation of chiral organoseleniums continues to be of considerable *** particular,there are limited studies on the enantioselective seleno-Michael addition reactions to access chiral selenium functional ***,we disclose a carbene-catalyzed highly enantioselective nucleophilic C–Se bond construction through formal[3+3]annulations between selenocarboxamides and bromoenals,affording seleno-thiazinone products with good yields and excellent *** choice of a weak inorganic base was pivotal to suppressing the unproductive racemization and decomposition of the selenium ***,the catalytically generated chiral selenium-containing heterocyclic products feature remarkable antimicrobial activities that could serve as promising lead scaffolds for further agrochemical development.

关键词： seleno-Michael addition organocatalysis N-heterocyclic carbene seleno-heterocycles antimicrobial activity

DIELS-ALDER REACTIONS CATALYZED BY MISCH-LANTHANIDE CHLORIDES

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Chinese Chemical Letters 1994年第5期5卷 361-364页

作者： Shu Wen YU shi jian liao and Dao Rong YU (Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023)Lei shi Shu Zhen YU and Fang HONG (Department of Chemistry, liaoning Normal University, Dalian, 116022)Qi SHEN (Department of Che

Misch-lanthanide chlorides have ben found to be good catalysts for several DielsAlder reactions of industrial importance.

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Simultaneous Bulk-and Surface-initiated Living Polymerization Studied with a Heterogeneous Stochastic Reaction Model

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Chinese Journal of Polymer Science 2024年第3期42卷 364-372,I0008页

作者： Jia-Shu Ma Zhi-Ning Huang Jia-Hao Li Bang-Ping jiang Yan-Da liao shi-Chen Ji Xing-Can Shen State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources(Ministry of Education of China)School of Chemistry and Pharmaceutical SciencesGuangxi Normal UniversityGuilin 541004China School of Computer Science and Engineering&School of Software Guangxi Normal UniversityGuilin 541004China

To better characterize the properties of surface-initiated polymers, simultaneous bulk-and surface-initiated polymerizations are usually carried out by assuming that the properties of the surface-initiated polymers resemble those of the bulk-initiated polymers. Through a Monte Carlo simulation using a heterogeneous stochastic reaction model, it was discovered that the bulk-initiated polymers exhibit a higher molecular weight and a lower dispersity than the corresponding surface-initiated polymers, which indicates that the equivalent assumption is invalid. Furthermore, the molecular weight distributions of the two types of polymers are also different, suggesting different polymerization mechanisms. The results can be simply explained by the heterogeneous distributions of reactants in the system. This study is helpful to better understand surface-initiated polymerization.

关键词： Surface-initiated polymerization Polymer brush Stochastic reaction model Heterogeneous polymerization Simultaneous polymerization

How variable progenitor clones construct a largely invariant neocortex

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National Science Review 2024年第1期11卷 129-144页

作者： Zhongfu Shen Jiajun Yang Qiangqiang Zhang Kuiyu Wang Xiaohui Lv Xiaolin Hu jian Ma Song-Hai shi New Cornerstone Science Laboratory IDG/McG overn Institute for Brain Research Tsinghua-Peking Center for Life Sciences Beijing Frontier Research Center for Biological Structure School of Life Sciences Tsinghua University Department of Computer Sciences Tsinghua University College of Life Sciences Nankai University Chinese Institute for Brain Research

The neocortex contains a vast collection of diverse neurons organized into distinct layers. While nearly all neocortical neurons are generated by radial glial progenitors(RGPs), it remains largely unclear how a complex yet organized neocortex is constructed reliably and robustly. Here, we show that the division behavior and neuronal output of RGPs are highly constrained with patterned variabilities to support the reliable and robust construction of the mouse neocortex. The neurogenic process of RGPs can be well-approximated by a consistent Poisson-like process unfolding over time, producing deep to superficial layer neurons progressively. The exact neuronal outputs regarding layer occupation are variable; yet, this variability is constrained systematically to support all layer formation, largely reflecting the variable intermediate progenitor generation and RGP neurogenic entry and exit timing differences. Together, these results define the fundamental features of neocortical neurogenesis with a balanced reliability and variability for the construction of the complex neocortex.

关键词： neocortex radial glial progenitor intermediate progenitor neurogenesis clonal variability layer formation

Feasibility of low-intensity ultrasound treatment with hydroxylamine to accelerate the initiation of partial nitrification and allow operation under intermittent aeration

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Journal of Environmental Sciences 2024年第5期139卷 446-459页

作者： jianxiong jian Xiaojian liao Zhihua Mo Shoupeng Li Lei Li Shaojin Chen Zhenhua Huang Junhao Chen Wencan Dai Shuiyu Sun Guangzhou Key Laboratory Environmental Catalysis and Pollution Control Guangdong Key Laboratory of Environmental Catalysis and Health Risk ControlSchool of Environmental Science and EngineeringInstitute of Environmental Health and Pollution ControlGuangdong University of TechnologyGuangzhou 510006China Guangdong Province Solid Waste Recycling and Heavy Metal Pollution Control Engineering Technology Research Center Guangdong Polytechnic of Environmental Protection EngineeringFoshan 528216China Analysis and Test Center Guangdong University of TechnologyGuangzhou 510006China

Partial nitrification is a key aspect of efficient nitrogen removal,although practically it suf-fers from long start-up cycles and unstable long-term operational *** address these drawbacks,this study investigated the effect of low intensity ultrasound treatment combined with hydroxylamine(NH2OH)on the performance of partial *** showthat compared with the control group,low-intensity ultrasound treatment(0.10W/mL,15 min)combined with NH2OH(5 mg/L)reduced the time required for partial nitrification initiation by 6 days,increasing the nitrite accumulation rate(NAR)and ammonia nitro-gen removal rate(NRR)by 20.4% and 6.7%,respectively,achieving 96.48% ***-tic analysis showed that NH2OH enhanced ammonia oxidation,inhibited nitrite-oxidizing bacteria(NOB)activity and shortened the time required for partial nitrification ***,ultrasonication combined with NH2OH dosing stimulated EPS(extracellular polymeric substances)secretion,increased carbonyl,hydroxyl and amine functional group abundances and enhanced mass *** addition,16S rRNA gene sequencing results showed that ultrasonication-sensitive Nitrospira disappeared from the ultrasound+NH_(2)OH system,while Nitrosomonas gradually became the dominant ***,the results of this study provide valuable insight into the enhancement of partial nitrification start-up during the process of wastewater nitrogen removal.

关键词： Partial nitrification Low-intensity ultrasound Hydroxylamine Ammonia oxidizing bacteria Nitrite oxidizing bacteria

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

The exploration and practice of low-altitude airspace flight service and traffic management in China

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Green Energy and Intelligent Transportation 2024年第2期3卷 1-8页

作者： Xiangmin Guan Hongxia shi Dongsong Xu Binhua Zhang jian Wei Jun Chen CAAC Key Laboratory of General Aviation Operation Department of General AviationCivil Aviation Management Institute of ChinaBeijing 100102China Research Institute of Civil Aviation Regulations and Standardization China Academy of Civil Aviation Science and TechnologyBeijing 100028China Department of Technology Platform Phoenix Wings Technology(Shen zhen)Co.LtdShenZhen 518054China Shenzhen Highgreat Innovation Technology Development Co. Ltd dShenzhen 518000China School of Engineering and Materials Science Queen Mary University of LondonLondonE14NSUK

Due to the inherent nature of being highly digitalized,networked and intelligent,Unmanned Aerial System(UAS)operations pose a huge challenge to traditional aviation regulation and technical *** to keep safe,efficient and integrated operation for different Airspace users has become a pressing issue faced by civil aviation around the *** paper focuses on the main operational scenarios and characteristics of unmanned aviation development in *** operational characteristics and associated challenges due to diverse low-altitude users are analyzed,including operation concepts,UAS traffic management,technological test and verification,and *** light on the practices in Europe and the United States,this paper summarizes China's practices and progress in low-altitude operations management,and analyzes future technological development needs and trends,as well as feasible implementation pathways and measures based on actual needs.

关键词： UAS Low-altitude airspace UAS traffic management Exploration and practice

Electro-reductive carboxylation of acyclic C(sp^(3))–C(sp^(3))bonds in aromatic hydrocarbons with CO_(2)

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Science China Chemistry 2024年第10期67卷 3366-3372页

作者： Chuan-Kun Ran Quan Qu Yang-Yi Tao Yi-Fei Chen Li-Li liao jian-Heng Ye Da-Gang Yu Key Laboratory of Green Chemistry&Technology of Ministry of Education College of ChemistrySichuan UniversityChengdu 610064China West China School of Public Health and West China Fourth Hospital Sichuan UniversityChengdu 610064China

Despite the recent advances in the selective functionalization of C–C bonds in specific substrates,cleavage and functionalization of C–C bonds in acyclic substrates,such as ethane derivatives,remains *** contrast to the well-developed functionalization of one carbon fragment after C–C bond cleavage,herein,we report a novel electro-reductive carboxylation of C(sp^(3))–C(sp^(3))bond in multi-aryl ethanes with carbon dioxide(CO_(2))by utilizing both carbon ***,this reaction exhibits an atom-,step-economic approach for the synthesis of carboxylic acids,fulfilling principal aspirations of organic ***,this method features mild reaction conditions,broad substrate scope,and good functional group *** and asymmetric substrates bearing primary,secondary,or tertiary C(sp^(3))–C(sp^(3))bonds are all amenable to this strategy,enabling one or two structurally different carboxylic acids to be facilely constructed at the same *** investigations indicate that carbanions might be the key intermediates in this reaction,which could be captured by CO_(2)efficiently.

关键词： carbon dioxide electrochemistry C(sp^(3))–C(sp^(3))bonds cleavage reductive carboxylation

Enhancing Log Anomaly Detection with Semantic Embedding and Integrated Neural Network Innovations

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Computers, Materials & Continua 2024年第9期80卷 3991-4015页

作者： Zhanyang Xu Zhe Wang jian Xu Hongyan shi Hong Zhao School of Computer and Software Nanjing University of Information Science and TechnologyNanjing210044China

System logs,serving as a pivotal data source for performance monitoring and anomaly detection,play an indispensable role in assuring service stability and *** this,the majority of existing log-based anomaly detection methodologies predominantly depend on the sequence or quantity attributes of logs,utilizing solely a single Recurrent Neural Network(RNN)and its variant sequence models for *** approaches have not thoroughly exploited the semantic information embedded in logs,exhibit limited adaptability to novel logs,and a single model struggles to fully unearth the potential features within the log *** these challenges,this article proposes a hybrid architecture based on amultiscale convolutional neural network,efficient channel attention and mogrifier gated recurrent unit networks(LogCEM),which amalgamates multiple neural network *** on the superior performance of robustly optimized BERT approach(RoBERTa)in the realm of natural language processing,we employ RoBERTa to extract the original word vectors from each word in the log *** conjunction with the enhanced Smooth Inverse Frequency(SIF)algorithm,we generate more precise log sentence vectors,thereby achieving an in-depth representation of log ***,these log vector sequences are fed into a hybrid neural network,which fuses 1D Multi-Scale Convolutional Neural Network(MSCNN),Efficient Channel Attention Mechanism(ECA),and Mogrifier Gated Recurrent Unit(GRU).This amalgamation enables themodel to concurrently capture the local and global dependencies of the log sequence and autonomously learn the significance of different log sequences,thereby markedly enhancing the efficacy of log anomaly *** validate the effectiveness of the LogCEM model,we conducted evaluations on two authoritative open-source *** experimental results demonstrate that LogCEM not only exhibits excellent accuracy and robustness,but also outperfo

关键词： Deep learning log analysis anomaly detection natural language processing

Stratigraphic framework and sedimentary evolution during the Cryogenian-Ediacaran transition in northeastern Sichuan Basin,South China

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Petroleum Science 2024年第2期21卷 823-835页

作者： Yi Zhang Hong-Wei Kuang Yong-Qing Liu Qiang shi Dong-Ge Wang Ke-Ning Qi Yu-Chong Wang Da-Wei Qiao Xiao-Shuai Chen Li-Zhi Wu Meng Tian Long Chen Yi Wei liao-Yuan Song jian Li Zi-Gang Wu Yun-Qian Liu Xuan-Chun Liu An-Qing Chen Zhi-Wei liao Institute of Geology Chinese Academy of Geological SciencesBeijing100037China State Key Laboratory of Coal Mine Disaster Dynamics and Control School of Resources and Safety EngineeringChongqing UniversityChongqing400044China No.205 Geological Team Chongqing Bureau of Geology and Minerals ExplorationChongqing401121China Chongqing Institute of Geological Survey Chongqing401122China Key Laboratory of Deep-time Geography and Environment Reconstruction and Applications of Ministry of Natural Resources Chengdu University of TechnologyChengdu610059SichuanChina

The northeastern Sichuan area in the northern Yangtze margin has unique Ediacaran geological records,especially the Doushantuo Formation(DST),and become a hot research area in recent ***,the Cryogenian-Ediacaran(C-E)boundary has not been precisely identified,which restricts the in-depth study of geological information during this crucial transitional period and is unfavorable for a systematic and complete understanding of the Yangtze Block and even the global paleogeographic *** study conducted stratigraphy,sedimentology,and chronostratigraphy to establish the stratigraphic framework and sedimentary evolution of the C-E transition strata in northeastern *** results showed that the Ediacaran sediments,without the cap dolomite,unconformably overlaid the Cryogenian sediments in the studied *** Member II of the DST,characterized by 50-160 m of red-green sandstone(approximately equivalent to the original Chengkou“Guanyinya Formation”),directly overlaid the Cryogenian sediments and displayed a 623±2.3 Ma maximum depositional age from the detrital zircon U-Pb *** stratigraphic correlations indicate that the C-E transition strata in northeastern Sichuan had a consistent lithological association and sedimentary sequence characteristics but differed from the Three ***,the upper Nantuo massive glacial diamictites transition to the icebergs rafted lonestone-bearing mudstones at the top,then change upward to DST barrier coast *** proposed DST of the northeastern Sichuan Basin was divided into three lithostratigraphic members without the regional Member I cap dolomite:(i)Member II purple-red,gray-green sandstone strata,(ii)MemberⅢblack mudstone strata,and(iii)Member IV P-Mn bearing *** the C-E transition,the study area experienced(i)the global deglaciation stage in the terminal Marinoan glaciation and(ii)the filling-leveling up stage with clastic rocks in the early ***,the early Ediacaran

关键词： Marinoan glaciation Doushantuo formation Cap dolomite Deglacial and coastal deposits Detrital zircon U-Pb dating