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Highly efficient room temperature phosphorescent liquid crystalline polymer optical waveguides for advanced optoelectronics

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Science China Chemistry 2024年第10期67卷 3450-3457页

作者： Jie Li Yan Guan Wei Xia Jin-Kang Chen Jiang Huang Yi Chen Qi Lin Er-Qiang Chen He-Lou Xie key laboratory of Environmentally Friendly Chemistry and Application of Ministry of Education and Key Laboratory of Advanced Functional Polymer Materials of CollegesUniversities of Hunan Province and College of ChemistryXiangtan UniversityXiangtan 411105China School of Physics and Optoelectronics Xiangtan UniversityXiangtan 411105China Beijing National laboratory for Molecular Sciences Key Laboratory of Polymer Chemistry and Physics of Ministry of EducationCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

Active organic optical waveguide materials(OOWMs)incorporating room temperature phosphorescence(RTP)hold significant promise for diverse applications in photonic and optoelectronic *** this potential,realizing active RTP optical waveguides with large-sized ordered structures and minimal light loss remains a formidable *** address this issue,we present a groundbreaking thermoplastic active OOWM with low light loss,leveraging room temperature phosphorescent liquid crystalline polymer(LCP).This innovative material can be easily synthesized through the copolymerization of phosphorescent and liquid crystalline *** resulting RTP copolymer exhibits a nematic liquid crystal phase with a phosphorescence lifetime of approximately 0.15 ms and an afterglow duration of around 1 *** the excellent processability of LCP,we successfully produce meter-scale fibers via melt *** RTP LCP fibers,characterized by a high orientation of mesogens along the fiber axis,demonstrate superior light confinement and efficient light conduction compared to unoriented samples,resulting in a low optical loss coefficient of 0.13 dB/***,the thermal responsiveness of the RTP LCP optical waveguide enables its use as a photo *** pioneering work paves the way for the design of new OOWMs tailored for advanced photonics and optoelectronics devices.

关键词： room temperature phosphorescence liquid crystalline polymer active optical waveguide

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Factors affecting land dissection density in geomorphological regions of China

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Journal of Mountain Science 2024年第4期21卷 1372-1387页

作者： SUN Xiaolin ZHAO Yinjun PENG Peihao CHENG Weiming WEI Yongping YANG Ronghao LI Jiaxu College of Earth Sciences Chengdu University of TechnologyChengdu 610059China School of Civil Engineering Guangxi Polytechnic of ConstructionNanning 530001China key laboratory of Environment Change and Resources use in Beibu Gulf Ministry of EducationNanning Normal UniversityNanning 530001China key laboratory of Earth Surface Process and Intelligent Simulation(Guangxi) Nanning Normal UniversityNanning 530001China State key laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China School of Earth and Environmental Sciences The University of QueenslandBrisbane 4702Australia School of Geography and Planning Nanning Normal UniversityNanning 530001China

land dissection density(LDD)provides morphological evidence regarding prior intense soil erosion and quantifies the distribution of land dissections.A comprehensive understanding of the potential factors influencing the spatial pattern and value of the LDD is vital in geological disasters,soil erosion,and other related *** dissection phenomena in China affects large areas with different morphological,pedological,and climatic *** studies have focused on the potential factors influencing the LDD at a watershed ***,these results are insufficient to reflect the status quo of dissection development and its primary influencing factors on a national ***’s spatial patterns and the dominant factors at a regional scale in millions of square kilometers remain to be *** study used the geomorphon-based method and the geographical detector model to quantify the spatial pattern of LDD over China and identify the dominant factors affecting this pattern in China’s six first-order geomorphological regions(GR1~GR6).The results yield the following findings:(1)LDD in China ranges from 0~4.55 km/km^(2),which is larger in central and eastern regions than in other regions of China;(2)dominant factors and their dominant risk subcategories vary with each geomorphological region’s primary internal and external forces;(3)the influence of natural factors is more significant on the large regional scale in millions of square kilometers compared to anthropogenic factors;relief degree of land surface(RDLS)is dominant in GR1,GR2,and GR5;the slope is dominant in GR6,soil type is dominant in GR3 and GR4,and lithology plays a critical role in the dominant interactions of GR3,GR4,and GR6;(4)the interactions between factors on LDD’s spatial pattern have a more significant effect than individual factors.

关键词： land dissection density Influencing factors Regional scale Spatial pattern Geographical detector model Geomorphon-based method China

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Identification of the cytochrome P450s responsible for the biosynthesis of two types of aporphine alkaloids and their de novo biosynthesis in yeast

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Journal of Integrative Plant Biology 2024年第8期66卷 1703-1717页

作者： Qishuang Li Xiang Jiao Xinyi Li Wenlong Shi Ying Ma Xiangmei Tan Jingyi Gan Jimei Liu Jian Yang Jian Wang Baolong Jin Tong Chen Ping Su Yujun Zhao Yifeng Zhang Jinfu Tang Guanghong Cui Yun Chen Juan Guo Luqi Huang School of Traditional Chinese Pharmacy China Pharmaceutical UniversityNanjing 211198China State key laboratory for Quality Ensurance and Sustainable use of Dao-di Herbs National Resource Center for Chinese Materia MedicaChina Academy of Chinese Medical SciencesBeijing 100700China Department of Life Sciences Chalmers University of TechnologyGothenburg SE-41296Sweden State key laboratory of Natural and Biomimetic Drugs School of Pharmaceutical SciencesPeking UniversityBeijing 100191China State key laboratory of Bioactive Substance and Function of Natural Medicines Institute of Materia MedicaThe Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100050China

Aporphine alkaloids have diverse pharmacological activities;however,our understanding of their biosynthesis is relatively *** studies have classified aporphine alkaloids into two categories based on the configuration and number of substituents of the D-ring and have proposed preliminary biosynthetic pathways for each *** this study,we identified two specific cytochrome P450 enzymes(CYP80G6 and CYP80Q5)with distinct activities toward(S)-configured and(R)-configured substrates from the herbaceous perennial vine Stephania tetrandra,shedding light on the biosynthetic mechanisms and stereochemical features of these two aporphine alkaloid ***,we characterized two CYP719C enzymes(CYP719C3 and CYP719C4)that catalyzed the formation of the methylenedioxy bridge,an essential pharmacophoric group,on the A-and D-rings,respectively,of aporphine *** the functional characterization of these crucial cytochrome P450 enzymes,we reconstructed the biosynthetic pathways for the two types of aporphine alkaloids in budding yeast(Saccharomyces cerevisiae)for the de novo production of compounds such as(R)-glaziovine,(S)-glaziovine,and *** study provides key insight into the biosynthesis of aporphine alkaloids and lays a foundation for producing these valuable compounds through synthetic biology.

关键词： aporphine alkaloids biosynthesis CYP719C CYP80 engineered yeast

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Underoil superhydrophilic flame-retardant 3D porous composite for efficient on-demand emulsion separation:Interface engineering design on sphagnum moss

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Friction 2024年第10期12卷 2222-2240页

作者： Yuyan GUO Peng LIU Wenhao ZHANG Zhiguang GUO Weimin LIU Ministry of Education key laboratory for the Green Preparation and Application of Functional Materials Hubei UniversityWuhan 430062China State key laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou730000China

Oil pollution and the energy crisis make oil-water separation an urgent for human *** widespread use of materials with a single emulsion separation capability is *** on-demand separation materials can adapt to a wide range of application scenarios,thus having a wider range of *** underoil superhydrophilic surface is of great significance for realizing the on-demand separation of oil/water emulsions through the removal of water in the oil and oil in the water.A 3D porous emulsion separation material based on the superhydrophilic principle of sphagnum moss was *** material was prepared in a simple step by taking advantage of the adhesion of polydopamine and the introduction of the as-prepared superhydrophilic BaSO4 nanoparticles to achieve superhydrophilicity with a water contact angle(WCA)of 0°and an oil contact angle(OCA)of 157.3°,resulting in excellent separation performance for both water-in-oil and oil-in-water *** superhydrophilic porous composite(OSPC)can complete two kinds of emulsion separations by filtration or *** adsorbs water from water-in-oil emulsion to achieve separation,with a good adsorption capacity of 74.38 g/g and efficiency up to 99%.It can also filter oil-in-water emulsions with an efficiency of 99.92%.The separation efficiencies are all almost unchanged after ten separation ***,the material has excellent flame retardancy,which reduces the possibility of secondary *** three-dimensional porous sponge has excellent on-demand separation performance for multiple *** provides a new preparation strategy for underoil superhydrophilic materials and a new idea for the design direction of special wetting materials for the on-demand separation of oil/water emulsions.

关键词： on-demand emulsion separation porous absorption filtration underoil hydrophilicity superwettability

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Catalyst design and structure control for photocatalytic refineries of cellulosic biomass to fuels and chemicals

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Journal of Energy Chemistry 2024年第7期94卷 102-127页

作者： Lulu Sun Nengchao Luo State key laboratory of Catalysis Dalian National Laboratory for Clean EnergyDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina

Lignocellulosic biomass is the largest renewable hydrocarbon resource on *** cellulose,one of the major components of lignocellulose,powered by solar energy is a promising way of providing lowcarbon-footprint energy chemicals such as H_(2),HCOOH,CO,and transportation ***-of-the-art biorefineries target the full use of biomass feedstocks as they have a maximum collection radius of 75-100 km,requesting efficient and selective photocatalysts that significantly influence the outcome of photocatalytic ***-performed photocatalysts can harvest a broad solar spectrum and are active in breaking the chemical bonds of cellulose,decreasing the capital investments of ***,photocatalysts should control the selectivity of cellulose conversion,originating target products to level down separation *** separation in photocatalysts and interfacial charge transfer between photocatalysts and cellulose affect the activity and selectivity of cellulose refineries to H2 and carbonaceous *** account for the challenges above,this review summarizes photocatalysts for the refineries of cellulose and downstream platform molecules based on the types of products,with the structure features of different types of photocatalysts discussed in relation to the targets of either improving the activity or product *** addition,this review also sheds light on the methods for designing and regulating photocatalyst structures to facilitate photocatalytic refineries of cellulose and platform molecules,meanwhile summarizing proposed future research challenges and opportunities for designing efficient photocatalysts.

关键词： Photocatalysts Biorefineries Cellulose Fuels Hydrogen

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Receptivity of Mack modes to localized unsteady blowing and suction in a chemical non-equilibrium hypersonic boundary layer

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Acta Mechanica Sinica 2024年第7期40卷 1-18页

作者： Qingjiang Yuan Runjie Song Ming Dong State key laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing 100190China

This paper studies the local receptivity of the Mack-mode instability to localized unsteady blowing and suction(UBS)in a chem-ical non-equilibrium(CNE)hypersonic boundary *** five-species CNE model is employed,and the receptivity efficiency is formulated by use of the residual *** with the results for the calorically perfect gas(CPG)model,we find that the real-gas effect enhances the receptivity efficiency remarkably in the majority of the second-mode frequency band,and the enhancement is mainly attributed to the modification of the base flow due to the CNE effect,which is akin to the cold-wall effect in hypersonic boundary *** with the destabilizing role of the CNE effect on the Mack second mode,it is concluded that the CNE effect would lead to a greater linearly accumulated perturbation amplitude,implying premature of transition to turbulence in a high-enthalpy hypersonic boundary layer subject to localized perturbations.

关键词： Chemical non-equilibrium flow Boundary-layer instability Hypersonic Receptivity Transition to turbulence

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Dynamics modeling and electromechanical coupling characteristics analysis of cage induction motors

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Science China(Technological Sciences) 2024年第3期67卷 709-724页

作者： ZHOU ZiWei CHEN ZaiGang ZHAI WanMing State key laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu 610031China

Induction motors, as typical electromechanical energy conversion devices, have received limited attention in previous studies on electromechanical coupling vibrations, precise modeling, and the use of electromechanical coupling effects for fault diagnosis and condition assessment in motor drive systems. This study proposes a comprehensive model of cage induction motors that integrates the multiple coupled circuit model with a rotor-bearing dynamics model. The model accounts for the linear increase in the magnetomotive force across the slot and incorporates the skidding characteristics of bearings in the rotor-bearing system. By calculating the time-varying mutual inductance parameters based on the air-gap distribution in the vibration environment, the electromechanical coupling vibration of the cage motor is investigated. Furthermore, this study examines the electromechanical coupling vibration characteristics influenced by various factors, including bearing clearances, radial loads, and the vertical excitation frequencies of the stators. The results show that the proposed model improves the excitation inputs for the electrical and mechanical systems of the motor compared with conventional models. Increased bearing clearance and radial load affect the current and torque similarly but have opposite effects on the slip ratio. This study provides a deeper understanding of electromechanical coupling mechanisms and facilitates the use of such phenomena for fault diagnosis and condition assessment in motor-driven systems.

关键词： cage induction motors rotor-bearing dynamics mutual inductance electromechanical testing current signal analysis

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A review of rock macro-indentation:Theories,experiments,simulations,and applications

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 2351-2374页

作者： Weiqiang Xie Xiaoli Liu Xiaoping Zhang Xinmei Yang Xiaoxiong Zhou State key laboratory of Hydroscience and Engineering Tsinghua UniversityBeijing100084China Yunlong Lake laboratory of Deep Underground Science and Engineering Xuzhou221116China State key laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan430072China

Rock macro-indentation plays a fundamental role in mechanical rock breaking for various rock engineering application,such as drilling,tunneling,cutting,and *** the past decades,extensive research has been conducted to understand the indentation mechanisms and responses through various *** review aims to provide an overview of the current status and recent advancements in theories,experiments,numerical simulations,and applications of macro-indentation in rock *** starts with elaborating on the mechanisms of macro-indentation,followed by a discussion of the merits and limitations of commonly used *** factors and their effects on indentation test results are then *** numerical simulation methods for rock macro-indentation are highlighted,along with their advantages and ***,the applications of indentation tests and indentation indices in characterizing rock properties are *** reveals that compression-tension,compression-shear,and composite models are widely employed in rock *** the compression-tension model is straightforward to use,it may overlook the anisotropic properties of *** the other hand,the composite model provides a more comprehensive description of rock indentation but requires complex ***,factors,such as indentation rate,indenter geometry,rock type,specimen size,and confining pressure,can significantly influence the indentation *** methods for macro-indentation encompass continuous medium,discontinuous medium,and continuous-discontinuous medium methods,with selection based on their differences in ***,rock macro-indentation can be practically applied to mining engineering,tunneling engineering,and petroleum drilling *** indices serve as valuable tools for characterizing rock strength,brittleness,and *** review sheds light on the development of rock macro-inde

关键词： Rock macro-indentation Indentation test Indentation indices Mechanism Rock breaking

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Comparison of nitrification inhibitors for mitigating cadmium accumulation in pakchoi and their associated microbial mechanisms

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2024年第9期25卷 773-788页

作者： Wenxin DU Qingyang ZHU Xiangting JING Wejie HU Yao ZHUANG Yijie JIANG Chongwei JIN State key laboratory of Plant Environmental Resilience Zhejiang UniversityHangzhou 310058China

The use of nitrification inhibitors has been suggested as a strategy to decrease cadmium(Cd)accumulation in ***,the most efficient nitrification inhibitor for mitigating crop Cd accumulation remains to be elucidated,and whether and how changes in soil microbial structure are involved in this process also remains *** address these questions,this study applied three commercial nitrification inhibitors,namely,dicyandiamide(DCD),3,4-dimethylpyrazole phosphate(DMPP),and nitrapyrin(NP),to *** results showed that both DCD and DMPP(but not NP)could efficiently decrease Cd concentrations in pakchoi in urea-and ammonium-fertilized *** addition,among the three tested nitrification inhibitors,DMPP was the most efficient in decreasing the Cd concentration in *** nitrification inhibitors decreased pakchoi Cd concentrations by suppressing acidification-induced Cd availability and reshaping the soil microbial structure;the most effective nitrification inhibitor was *** oxidation generates the most protons during nitrification and is inhibited by nitrification *** in environmental factors and predatory bacterial abundance caused by the nitrification inhibitors changed the soil microbial structure and increased the potential participants in plant Cd *** summary,our study identified DMPP as the most efficient nitrification inhibitor for mitigating crop Cd contamination and observed that the soil microbial structural changes caused by the nitrification inhibitors contributed to decreasing Cd concentration in pakchoi.

关键词： Cadmium(Cd) Nitrification inhibitor Soil microbial structure Safe crop production

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Soil microbial ecology through the lens of metatranscriptomics

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Soil Ecology Letters 2024年第3期6卷 1-15页

作者： Jingjing Peng Xi Zhou Christopher Rensing Werner Liesack Yong-Guan Zhu State key laboratory of Nutrient use and Management College of Resources and Environmental SciencesNational Academy of Agriculture Green DevelopmentKey Laboratory of Plant-Soil InteractionsMinistry of EducationChina Agricultural UniversityBeijing 100193China Institute of Environmental Microbiology College of Resource and EnvironmentFujian Agriculture and Forestry UniversityFuzhou 350002China Max Planck Institute for Terrestrial Microbiology Marburg 35043Germany State key laboratory of Urban and Regional Ecology Research Centre for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China key laboratory of Urban Environment and Health Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China

Metatranscriptomics is a cutting-edge technology for exploring the gene expression by,and functional activities of,the microbial community across diverse ecosystems at a given time,thereby shedding light on their metabolic responses to the prevailing environmental *** double-RNA approach involves the simultaneous analysis of rRNA and mRNA,also termed structural and functional *** contrast,mRNA-centered metatranscriptomics is fully focused on elucidating community-wide gene expression profiles,but requires either deep sequencing or effective rRNA *** this review,we critically assess the challenges associated with various experimental and bioinformatic strategies that can be applied in soil microbial ecology through the lens of functional *** particular,we demonstrate how recent methodological advancements in soil metatranscriptomics catalyze the development and expansion of emerging research fields,such as rhizobiomes,antibiotic resistomes,methanomes,and *** review provides a framework that will help to design advanced metatranscriptomic research in elucidating the functional roles and activities of microbiomes in soil ecosystems.

关键词： metatranscriptomics mRNA MAGs rhizobiont resistome virome

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