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revealing the Structure-Property difference of Natural rubber Prepared by different Methods: Protein and Gel Content are key Factors

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Chinese Journal of Polymer Science 2024年第4期42卷 457-467页

作者： Shao-Qi Huang Jun-Qi Zhang Yong Zhu Ling-Min Kong Lu-Sheng Liao Fu-Quan Zhang Zheng-Tian Xie Jin-rong Wu State key Laboratory of Polymer Materials Engineering College of Polymer Science and EngineeringSichuan UniversityChengdu610065China Hainan Provincial key Laboratory of Natural rubber Processing Agricultural Products Processing Research Institute of Chinese Academy of Tropical Agricultural SciencesZhanjiang524001China

Natural rubber (Nr) is widely used in various fields including aerospace, military industry and transportation due to its superior elasticity and comprehensive mechanical properties. Nonetheless, the commercial Nr prepared by different methods usually exhibits different mechanical properties, primarily due to variations in processing conditions during the conversion from latex to bulk rubber material. Consequently, this poses challenges in scientific research and industrial production of Nr. In order to assess the properties of various commercially available Nr and identify key structural and compositional components, this study systematically compares and analyzes four representative Nr raw materials: air dried sheet (AdS), ribbed smoked sheets (rSS), constant viscidity Nr (CV), and whole field latex rubber (WF). The investigation focuses on evaluating their static mechanical behavior, SIC behavior, wear resistance, and fatigue resistance. The findings indicate that protein and gel content exhibit a crucial influence on the Nr properties. These constituents contribute to the formation of a high-crosslinking density region, generating a heterogeneous network structure within the rubber. This structure amplifies strains during deformation, leading to earlier and stronger strain-induced crystallization (SIC). Among the four commercial Nr brands, rSS demonstrates superior overall mechanical and dynamic properties owing to its high protein and gel content. This study serves as a valuable reference for comprehending the differences in properties among various commercial Nr, thereby offering guidance for the actual processing and selection of Nr.

关键词： Natural rubber Processingmethod Protein Gel content Property

AtrKd5 inhibits the parthenogenic potential mediated by AtBBM

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Journal of Integrative plant Biology 2024年第7期66卷 1517-1531页

作者： Qiyan Liu dongfen Han denghu Cheng Jinfan Chen Shujuan Tian Jiafa Wang Man Liu Li Yuan State key Laboratory of Crop Stress resistance and High‐Efﬁciency Production College of HorticultureNorthwest A&F UniversityYangling 712100China

Parthenogenesis,the development of unfertilized egg cells into embryos,is a key component of ***(BABY BOOM),a crucial regulator of embryogenesis in Arabidopsis,possesses the capacity to shift nutritional growth toward reproductive ***,the mechanisms underlying AtBBM-induced parthenogenesis remain largely unexplored in dicot *** findings revealed that in order to uphold the order of sexual reproduction,the embryo-specific promoter activity of AtBBM as well as repressors that inhibit its expression in egg cells combine to limiting its ability to induce ***,AtrKd5,a rWPrK domain-containing(rKd)transcription factor,binds to the 3'end of AtBBM and is identified as one of the inhibitory factors for AtBBM expression in the egg *** the atrkd5 mutant,we successfully achieved enhanced ectopic expression of AtBBM in egg cells,resulting in the generation of haploid offspring via parthenogenesis at a rate of 0.28%.Furthermore,by introducing chimeric Arabidopsis and rice BBM genes into the egg cell,we achieved a significant 4.6-fold enhancement in haploid induction through the atdmp8/9 *** findings lay a strong foundation for further exploration of the BBM-mediated parthenogenesis mechanism and the improvement of haploid breeding efficiency mediated by the dmp8/9 mutant.

关键词： AtBBM atdmp AtrKd5 haploid induction parthenogenesis

A Strong,Tough,and Self-Healing Strengthening Thioctic Acid-based Elastomer for Highly reliable Flexible Strain Sensor

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Chinese Journal of Polymer Science 2024年第10期42卷 1610-1618,I0016页

作者： Xin-Yu Chen Yu-Bing Fu Xue-Ling Yan Lan Liu School of Materials Science and Engineering Key Lab of Guangdong Province for High Property and Functional Polymer MaterialsSouth China University of TechnologyGuangzhou510641China

Elastomers with high strength and toughness,excellent self-healing properties,and biocompatibility have broad application prospects in wearable electronics and other fields,but preparing it remains a *** this work,we propose a highly adaptable strategy by introducing the small molecule crosslinking agent of triethanolamine(TEA)to the poly(thioctic acid)(PTA)chains and preparing the PAx Ey elastomers using a simple synthesis *** strategy stabilizes the PTA chains by constructing multiple non-covalent cross-linked dynamic networks,endowing materials with excellent strength and toughness(tensile strength of 288 kPa,toughness of 278.2 kJ/m3),admirable self-healing properties(self-healing efficiency of 121.6%within 7 h at 70℃),and good *** PAx Ey elastomers can also be combined with MWNTs to become flexible strain sensors,which can be used to monitor human joint movements with high sensitivity,repeatable responses,and stability.

关键词： Thioctic acid Ion clusters Multiple dynamic networks Self-healing strengthening Flexible strain sensor

Effective integration of highly-efficient focusing apodized grating and quantum dots on a solid substrate for scalable quantum photonic circuits

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Science China(Physics,Mechanics & Astronomy) 2024年第9期67卷 99-107页

作者： Beimeng Yao rongbin Su Shunfa Liu Changkun Song Ying Yu Jin Liu Xuehua Wang State key Laboratory of Optoelectronic Materials and Technologies School of PhysicsSun Yat-sen UniversityGuangzhou 510275China State key Laboratory of Optoelectronic Materials and Technologies School of Electronics and Information TechnologySun Yat-sen UniversityGuangzhou 510275China

recent advancements in quantum photonic circuits have significantly influenced the field of quantum information *** pursuit of an integrated quantum photonic circuit that offers an active,stable platform for large-scale integration and high processing efficiency remains a key *** grating coupler,as a crucial element for an efficient transformation output interface in the integrated quantum photonic circuits,presents significant potential for practical ***,we demonstrate the integration block of a highly efficient shallow-etched focusing apodized grating coupler with indium arsenide(InAs)quantum dots(Qds)in gallium arsenide(GaAs)on a SiO2substrate for active quantum photonic *** designed grating couplers possess a high efficiency over 90% in the broadband(900-930 nm)from the circuit to free space,and a nearly-perfect match with the fiber ***,the efficiency to free space reaches 81.8%,and the match degree with the fiber mode is high up to 92.1%.The proposed integration block offers the potential for large-scale integration of active quantum photonic circuits due to its stable solid substrate and highly performant output for quantum measurements.

关键词： quantum dot grating coupler wafer bonding quantum photonic circuit

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Synthetic auxotrophs accelerate cell factory development through growth-coupled models

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Frontiers of Chemical Science and Engineering 2024年第9期18卷 73-87页

作者： Liangpo Li Linwei Yu Xinxiao Sun Qipeng Yuan Xiaolin Shen Jia Wang State key Laboratory of Chemical resource Engineering Beijing University of Chemical TechnologyBeijing 100029China

The engineering of microbial cell factories for the production of high-value chemicals from renewable resources presents several challenges,including the optimization of key enzymes,pathway fluxes and metabolic *** these challenges involves the development of synthetic auxotrophs,a strategy that links cell growth with enzyme properties or biosynthetic *** linkage allows for the improvement of enzyme properties by in vivo directed enzyme evolution,the enhancement of metabolic pathway fluxes under growth pressure,and remodeling of metabolic networks through directed strain *** advantage of employing synthetic auxotrophs lies in the power of growth-coupled selection,which is not only high-throughput but also labor-saving,greatly simplifying the development of both strains and *** auxotrophs play a pivotal role in advancing microbial cell factories,offering benefits from enzyme optimization to the manipulation of metabolic networks within single ***,this strategy extends to coculture systems,enabling collaboration within microbial *** review highlights the recently developed applications of synthetic auxotrophs as microbial cell factories,and discusses future perspectives,aiming to provide a practical guide for growth-coupled models to produce value-added chemicals as part of a sustainable biorefinery.

关键词： synthetic auxotrophs growth-coupled directed enzyme evolution pathway flux directed strain evolution coculture

Strategy of preparing SmCo based films with high coercivity and remanence ratio achieved by temperature and chemical optimization

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Journal of rare Earths 2024年第7期42卷 1289-1297,I0004页

作者： Yansong Gong Zhaoguo Qiu Sizhe Liang Xinrui Zheng Hongxia Meng Zhigang Zheng deyang Chen Shengfu Yuan Weixing Xia dechang Zeng J.P.Liu School of Materials Science and Engineering South China University of TechnologyGuangzhou510640China Zhongshan r&d Center for Materials Surface and Thin Films Technology of the South China University of Technology Gent Materials Surface Technology(Guangdong)Co.Ltd.Zhongshan528437China Institute for Advanced Materials South China Academy of Advanced OptoelectronicsSouth China Normal UniversityGuangzhou510006China Yangjiang Branch Guangdong Laboratory Materials Science and Technology Yangjiang Advanced Alloys LaboratoryYangjiang529500China Laboratory of rare-Earth Magnetic Functional Materials Ningbo Institute of Material Technology and EngineeringChinese Academy of SciencesNingbo315201China department of Physics University of Texas at ArlingtonArlingtonTX76019USA

SmCo based films with excellent intrinsic magnetic properties have promising applications in micro-electro-mechanical system(MEMS).However,due to the complexity of phase composition and uncontrollable crystallization degree of SmCo hard magnetic phase in the film,both the coercivity(Hc)and remanence(Mr)of films are difficult to enhance *** this paper,SmCo based films were deposited with a Cr underlayer and capping layer on single crystal Si substrates via magnetron sputtering *** effects of annealing parameters and Sm/Co atomic ratio on the phase structure and coercivity of films are *** adjusting the Sm/Co atomic ratio from 1:5 to 1:4,Co soft magnetic phase disappears and the single phase SmCo5 is obtained,leading to the increase of coercivity of the films from 30 to 34 *** influence of deposition temperature and Cu doping on magnetic properties of SmCo based films was *** the deposition temperature increases from room temperature to 250℃,the coercivity will further increase from 34 to 51 ***,a severe kink is observed in the demagnetization curves due to the poor exchanged *** analysis of transmission electron microscopy(TEM)confirms that the average size of non-hard magnetic amorphous phase exceeds the effective exchanged coupling length of SmCo5,which contributes to the decoupling and low remanence ***,doping Cu and applying a post-annealing process can significantly improve the crystallization degree of the *** the coercivity and the remanence ratio of the demagnetization curves are greatly *** propose a plausible strategy to prepare the SmCo based films with high coercivity and remanence ratio by temperature and chemical optimization,which can be utilized in high performed MEMS devices.

关键词： rare earths SmCo based films Phase composition Crystallization conditions Coercivity remanence ratio

Machine learning-based performance predictions for steels considering manufacturing process parameters:a review

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Journal of Iron and Steel research International 2024年第7期31卷 1555-1581页

作者： Wei Fang Jia-xin Huang Tie-xu Peng Yang Long Fu-xing Yin Tianjin key Laboratory of Materials Laminating Fabrication and Interface Control Technology School of Materials Science and EngineeringHebei University of TechnologyTianjin 300132China Institute of New Materials Guangdong Academy of ScienceGuangzhou 510651GuangdongChina

Steels are widely used as structural materials,making them essential for supporting our lives and ***,further improving the comprehensive properties of steel through traditional trial-and-error methods becomes challenging due to the continuous development and numerous processing parameters involved in steel *** address this challenge,the application of machine learning methods becomes crucial in establishing complex relationships between manufacturing processes and steel *** review begins with a general overview of machine learning methods and subsequently introduces various performance predictions in steel *** classification of performance pre-diction was used to assess the current application of machine learning model-assisted *** important issues,such as data source and characteristics,intermediate features,algorithm optimization,key feature analysis,and the role of environmental factors,were summarized and *** insights will be beneficial and enlightening to future research endeavors in this field.

关键词： Steel Manufacturing process Machine learning Performance prediction Algorithm

Optical scattering imaging with sub-nanometer precision based on position-ultra-sensitive giant Lamb shift

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Science China(Physics,Mechanics & Astronomy) 2024年第6期67卷 96-105页

作者： Zeyang Liao Yu-Wei Lu Wei Li Xue-Hua Wang State key Laboratory of Optoelectronic Materials and Technologies School of PhysicsSun Yat-sen UniversityGuangzhou 510275China Quantum Science Center of guangdong-Hong Kong-Macao Greater Bay area(guangdong) Shenzhen 518045China

The Lamb shift of a quantum emitter in close proximity to a plasmonic nanostructure can be three or more orders of magnitude larger than that in the free space and is ultra-sensitive to the emitter position and *** demonstrate that this large Lamb shift can be sensitively observed from the scattering or absorption spectrum dip shift of the coupled system when the plasmonic nanoparticle or tip scans the *** these observations,we propose a scanning optical scattering imaging method based on the plasmonic-enhanced Lamb shift with achieves sub-nanometer *** method is based on the scattering or absorption spectrum of the plasmon-emitter coupling system,which is free of the fluorescence quenching problem and easier to implement in a plasmon-emitter coupling *** addition,our scheme works even if the quantum emitter is slightly below the dielectric surface,which can bring about broader applications,such as detecting atoms and molecules or quantum dots above or under a surface.

关键词： Lamb shift plasmon optical scattering imaging

An NMOS output-capacitorless low-dropout regulator with dynamic-strength event-driven charge pump

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Journal of Semiconductors 2024年第6期45卷 23-34页

作者： Yiling Xie Baochuang Wang dihu Chen Jianping Guo School of Electronics and Information Technology Sun Yat-sen UniversityGuangzhou 510006China School of Microelectronics University of Science and Technology of ChinaHefei 230000China

In this paper,an NMOS output-capacitorless low-dropout regulator(OCL-LdO)featuring dual-loop regulation has been proposed,achieving fast transient response with low power *** event-driven charge pump(CP)loop with the dynamic strength control(dSC),is proposed in this paper,which overcomes trade-offs inherent in conventional *** presented design addresses and resolves the large signal stability issue,which has been previously overlooked in the event-driven charge pump *** breakthrough allows for the full exploitation of the charge-pump structure's poten-tial,particularly in enhancing transient ***,a dynamic error amplifier is utilized to attain precise regulation of the steady-state output voltage,leading to favorable static characteristics.A prototype chip has been fabricated in 65 nm CMOS *** measurement results show that the proposed OCL-LdO achieves a 410 nA low quiescent current(IQ)and can recover within 30 ns under 200 mA/10 ns loading change.

关键词： output-capacitorless low-dropout regulator fast transient low quiescent current event-driven charge pump