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Dielectric response of ANb_(2)O_(6)(A = Zn, Co, Mn, Ni) columbite niobates: From microwave to terahertz

Journal of Advanced Ceramics 2024年第8期13卷 1189-1197页

作者： Weijia Luo Shun Wang Siyong zheng jining Li Menglong Wang Yongzheng Wen ingxia Li ji Zhou State Key Laboratory of New Ceramics and Fine Processing School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China Institute of Laser and Optoelectronics School of Precision Instrument and Opto-Electronics EngineeringTianjin UniversityTianjin 300072China Shandong Inspur Artificial Intelligence Research Institute Co. Ltd.Jinan 250013China School of Microelectronics Tianjin UniversityTianjin 300072China

In the upcoming 6-generation(6G)revolution,the achievement of low power consumption has become a key objective in research concerning terahertz *** an important component of passive devices,there are very few low-loss dielectric ceramics in the terahertz *** elucidate the mechanism of loss and promote the application of microwave dielectric ceramics for future 6G technology(covering microwave and terahertz frequencies),the terahertz responses of ANb_(2)O_(6)(A=Zn,Co,Mn,and Ni)columbite niobates were *** influences of magnetic loss on the Qxf values in the microwave range with different transition metal ions in the A-site were reasonably ***,due to the weakened magnetic relaxation properties in the terahertz range,the samples all exhibited low loss and approximate transparency,especially for MnNb_(2)O_(6) and NiNb_(2)O_(6)(tano<0.01 and absorption coefficient<10 cm^(-1) below 1.2 THz),which subverted the definition of traditional low-loss microwave dielectric ***,based on Mie theory,we designed a prototypical broadband metamaterial reflector to validate the applicability of the ANb_(2)O_(6) system in the terahertz band,which is highly important for the development of terahertz ceramic-based passive devices.

关键词： columbite niobates terahertz response transition metal ions magnetic loss ceramic-based metamaterials

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Quality assessment of friction-stir-welded aluminum alloy welds via three-dimensional force signals

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Advances in Manufacturing 2024年第1期12卷 61-75页

作者： ji-Hong Dong Yi-Ming Huang jia-Lei Zhu Wei Guan Xu-Kai ren Huan-Wei Yu Lei Cui Beijing Institute of Petrochemical Technology Beijing102617People’s Republic of China Beijing Academy of Safety Engineering and Technology Beijing102617People’s Republic of China AVIC Manufacturing Technology Institute Beijing100024People’s Republic of China Tianjin Key Laboratory of Advanced Joining Technology School of Materials Science and EngineeringTianjin UniversityTianjin300350People’s Republic of China Shaoxing Special Equipment Testing Institute Shaoxing Key Laboratory of Special Equipment Intelligent Testing and EvaluationShaoxing312071ZhejiangPeople’s Republic of China

An online detection technology must be developed for realizing the real-time control of friction stir *** this study,the three-dimensional force exerted on a material during friction stir welding was collected synchronously and the relationship between the forces and welding quality was *** results indicated that the fluctuation period of the traverse force was equal to that of the lateral force during the stable welding *** phase difference between two horizontal forces wasπ/*** values of the horizontal forces increased with welding speed,whereas their amplitudes remained the *** proposed force model showed that the traverse and lateral forces conformed to an elliptical curve,and this result was consistent with the behavior of the measured *** variational mode decomposition was used to process the plunge *** intrinsic mode function that represented the real fluctuation in the plunge force varied at the same frequency as the spindle rotational *** tunnel defects occurred,the fluctuation period features were consistent with those obtained during normal welding,whereas the ratio parameter defined in this study increased significantly.

关键词： Friction stir welding(FSW) Three-dimensional force model Variational mode decomposition Tunnel defect

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High-excited-state splitting and multimode vibrational coupling in Mn^(4+)-activated fluoride phosphor

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Science China(Physics,Mechanics & Astronomy) 2024年第3期67卷 95-101页

作者： Debao Zhang Wanggui Ye Xuguang Cao ji Zhou Fei Tang Changcheng zheng jiqiang Ning Shijie Xu Department of Optical Science and Engineering School of Information Science and TechnologyFudan University Shanghai 200438China jiangsu Key Laboratory of Advanced Laser Materials and Devices Schoolof Physics and Electronic Engineering Jiangsu Normal UniversityXuzhou 221116China Division of Natural and Applied Sciences Duke Kunshan UniversityKunshan 215316China

Excited-states play a crucial role in the optical absorption and luminescence of solids and hence their accurate information is highly desired. Herein, we attempt to seize the excited-states information of Mn^(4+)ions in K_(2)SiF_(6) microcrystals via measuring and calculating their variable-temperature photoluminescence excitation(PLE) spectra. At cryogenic temperatures, an unpredicted splitting of the high-excited-state is observed. Moreover, the two-split high-excited-state levels are further revealed to primarily couple with the two hyperfine split modes of quasi-localized ν2 vibration in the distorted Mn-F_(6) octahedral configuration,whereas the coupling strengths are found to be substantially different from each other. The slightly split vibrational mode is firmly supported by the low-temperature Raman spectra. Jahn-Teller lattice distortion is believed to be responsible for the observed splitting of the electronic high-excited-state and the quasi-localized vibrational mode.

关键词： splitting of excited-state photoluminescence excitation spectrum electron-phonon coupling Jahn-Teller effect

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An improved installation of 2-hydroxy-4-methoxybenzyl(iHmb)method for chemical protein synthesis

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Chinese Chemical Letters 2024年第5期35卷 145-150页

作者： Ying Li Long-jie Wang Yong-Kang Zhou Jun Liang Bin Xiao ji-Shen zheng The First Affiliated Hospital of USTC MOE Key Laboratory for Membraneless Organelles and Cellular DynamicsDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefei 230001China Department of Chemistry University of Science and Technology of ChinaHefei 230027China

The 2-hydroxy-4-methoxybenzyl(Hmb)backbone modification can prevent amide bond-mediated sidereactions(e.g.,aspartimide formation,peptide aggregation)by installing the removable Hmb group into a peptide bond,thus improving the synthesis of long and challenging peptides and ***,its use is largely precluded by the limited Hmb’s installation *** this report,an improved installation of Hmb(iHmb)method was developed to achieve the flexible installation and the convenient removal of *** iHmb method involves two critical steps:(1)oxidative diazotization of the readily installed 2-hydroxy-4-methoxy-5-amino-benzyl(Hmab)to give 2-hydroxy-4-methoxy-5-diazonium-benzyl(Hmdab)by combining soamyl nitrite(IAN)/HBF_(4),and(2)reductive elimination of Hmdab to give the desired Hmb by 1,2-ethanedithiol(EDT).The iHmb method enables the installation of Hmb at any primary amino acid including the highly sterically hindered amino acids(e.g.,valine and isoleucine).The practicality and utility of the iHmb method was demonstrated by one-shot solid-phase synthesis of a challenging aspartimide-prone peptide,the mirror-image version of a hydrophobic peptide and a long-chain peptide up to ***,the iHmb method can be utilized to facilitate chemical protein ligation,as exemplified by the synthesis of the single-spanning membrane protein *** iHmb method expands the toolkit for peptide synthesis and ligation and facilitates the preparation of peptides/proteins.

关键词： Chemical protein synthesis Solid-phase peptide synthesis Removable backbone modification 2-Hydroxy-4-methoxybenzyl(Hmb)group Aspartimide-prone peptides Difficult peptides Membrane proteins

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Intelligent extraction of road cracks based on vehicle laser point cloud and panoramic sequence images

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Journal of Road Engineering 2024年第1期4卷 69-79页

作者： Ming Guo Li Zhu Ming Huang jie ji Xian ren Yaxuan Wei Chutian Gao School of Geomatics and Urban Spatial Informatics Beijing University of Civil Engineering and ArchitectureBeijing 102616China Engineering Research Centre of Representative Building and Architectural Heritage Database Ministry of EducationBeijing 100044China Key Laboratory of Modern Urban Surveying and Mapping National Administration of SurveyingBeijing 102616China School of Civil and Transportation Engineering Beijing University of Civil Engineering and ArchitectureBeijing 102616China

In light of the limited efficacy of conventional methods for identifying pavement cracks and the absence of comprehensive depth and location data in two-dimensional photographs,this study presents an intelligent strategy for extracting road *** methodology involves the integration of laser point cloud data obtained from a vehicle-mounted system and a panoramic sequence of *** study employs a vehicle-mounted LiDAR measurement system to acquire laser point cloud and panoramic sequence image data simultaneously.A convolutional neural network is utilized to extract cracks from the panoramic sequence *** extracted sequence image is then aligned with the laser point cloud,enabling the assignment of RGB information to the vehicle-mounted three dimensional(3D)point cloud and location information to the two dimensional(2D)panoramic ***,a threshold value is set based on the crack elevation change to extract the aligned roadway point *** three-dimensional data pertaining to the cracks can be *** experimental findings demonstrate that the use of convolutional neural networks has yielded noteworthy outcomes in the extraction of road *** utilization of point cloud and image alignment techniques enables the extraction of precise location data pertaining to road *** approach exhibits superior accuracy when compared to conventional ***,it facilitates rapid and accurate identification and localization of road cracks,thereby playing a crucial role in ensuring road maintenance and traffic ***,this technique finds extensive application in the domains of intelligent transportation and urbanization *** technology exhibits significant promise for use in the domains of intelligent transportation and city development.

关键词： Road crack extraction Vehicle laser point cloud Panoramic sequence images Convolutional neural network

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A low-swelling hydrogel as a multirole sealant for efficient dural defect sealing and prevention of postoperative adhesion

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National Science Review 2024年第6期11卷 294-307页

作者： Xueliang Cheng Zhen Zhang Hui ren zheng Zou Yu Zhang Yang Qu Xuesi Chen jianwu Zhao Chaoliang He CAS Key Laboratory of Polymer Ecomaterials Changchun Institute of Applied ChemistryChinese Academy of Sciences Department of Orthopedics The Second Norman Bethune Hospital of Jilin University School of Applied Chemistry and Engineering University of Science and Technology of China

Dural defects and subsequent complications, including cerebrospinal fluid（CSF） leakage, are common in both spine surgery and neurosurgery, and existing clinical treatments are still unsatisfactory. In this study, a tissue-adhesive and low-swelling hydrogel sealant comprising gelatin and o-phthalaldehyde（OPA）-terminated 4-armed poly（ethylene glycol）(4aPEG-OPA) is developed via the OPA/amine condensation reaction. The hydrogel shows an adhesive strength of 79.9 ± 12.0 k Pa on porcine casing and a burst pressure of 208.0 ± 38.0 cm H2O. The hydrogel exhibits a low swelling ratio at physiological conditions, avoiding nerve compression in the limited spinal and intracranial spaces. In rat and rabbit models of lumbar and cerebral dural defects, the 4aPEG-OPA/gelatin hydrogel achieves excellent performance in dural defect sealing and preventing CSF leakage. Moreover, local inflammation, epidural fibrosis and postoperative adhesion in the defect areas are markedly reduced. Thus, these findings establish the strong potential of the hydrogel sealant for the effective watertight closure of dural defects.

关键词： hydrogel sealant watertight closure low swelling o-phthalaldehyde chemistry dural sealing

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Magnetism of NaYbS_(2):From finite temperatures to ground state

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Science China(Physics,Mechanics & Astronomy) 2024年第10期67卷 92-104页

作者： Weizhen Zhuo zheng Zhang Mingtai Xie Anmin Zhang jianting ji Feng jin Qingming Zhang School of Physical Science and Technology Lanzhou UniversityLanzhou 730000China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China

Rare-earth chalcogenide compounds ARECh_(2)(A=alkali or monovalent metal,RE=rare earth,Ch=O,S,Se,Te)are a large family of quantum spin liquid(QSL)candidate ***2is a representative member of the *** key issues on NaYbS_(2),particularly how to determine the highly anisotropic spin Hamiltonian and describe the magnetism at finite temperatures and the ground state,remain to be *** this paper,we conducted an in-depth and comprehensive study on the magnetism of NaYbS_(2) from finite temperatures to the ground ***,we successfully detected three crystalline electric field(CEF)excitation energy levels using low-temperature Raman scattering *** them with the CEF theory and magnetization data,we worked out the CEF parameters,CEF energy levels,and CEF *** further determined a characteristic temperature of~40 K,above which the magnetism is dominated by CEF excitations while below which the spinexchange interactions play a main *** characteristic temperature has been confirmed by the temperature-dependent electron spin resonance(ESR)***-temperature ESR experiments on the dilute magnetic doped crystal of NaYb_(0.1)Lu_(0.9)S_(2) further helped us to determine the accurate ***,we quantitatively obtained the spin-exchange interactions in the spin Hamiltonian by consistently simulating the magnetization and specific heat ***,the above studies allow us to explore the ground state magnetism of NaYbS_(2) by using the density matrix renormalization *** combined numerical calculations and experimental results to demonstrate that the ground state of NaYbS_(2) is a Dirac-like QSL.

关键词： rare-earth chalcogenide anisotropic spin Hamiltonian quantum spin liquid

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Nanophase separated,grafted alternate copolymer styrene-maleic anhydride as an efficient room temperature solid state lithium ion conductor

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Chinese Chemical Letters 2024年第7期35卷 491-496页

作者： Qian Wang Ting Gao Xiwen Lu Hangchao Wang Minggui Xu Longtao ren zheng Chang Wen Liu Institute of Science and Technology China Three Gorges CorporationBeijing 100038China State Key Laboratory of Chemical Resource Engineering Beijing Advanced Innovation Center for Soft Matter Science and EngineeringCollege of ChemistryBeijing University of Chemical TechnologyBeijing 100029China

All solid-state lithium metal batteries(ASSLMBs)based on polymer solid electrolyte and lithium metal anode have attracted much attention due to their high energy density and intrinsic ***,the low ionic conductivity at room temperature and poor mechanical properties of the solid polymer electrolyte result in increased polarization and poor cycling stability of the Li metal *** order to improve the ionic conductivity at room temperature while maintaining mechanical strength,we combine the conductivity of short chain polyethylene oxide(PEO)and strength of styrene-maleic anhydride copolymer(SMA)to obtain a grafted block copolymer with nanophase separation structure,which has room temperature ionic conductivity up to 1.14×10^(-4)S/cm and tensile strength up to 1.4 ***||Li symmetric cell can work stably for more than 1500 h under the condition of 0.1 mA/cm^(2).Li||LiFePO_(4)full cells can deliver a high capacity of 151.4 mAh/g at 25℃and 0.2 C/0.2 C charge/discharge conditions,showing 85.6%capacity retention after 400 ***,the all solid state Li||LiFePO_(4)pouch cell shows excellent safety performance under different abuse *** results demonstrate that the nanophase separated,grafted alternate copolymer electrolyte has huge potential for application in Li metal batteries.

关键词： Solid polymer electrolyte All solid-state battery Li metal battery Copolymers Nanophase separation

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Reorganization of 3D genome architecture provides insights into pathogenesis of early fatty liver disease in laying hens

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Journal of Animal Science and Biotechnology 2024年第3期15卷 1086-1100页

作者： Yanli Liu Zhuqing zheng Chaohui Wang Yumeng Wang Xi Sun Zhouzheng ren Xin Yang Xiaojun Yang College of Animal Science and Technology Northwest A&F UniversityYangling 712100China Institute of Agricultural Biotechnology Jingchu University of TechnologyJingmen 448000China

Background Fatty liver disease causes huge economic losses in the poultry industry due to its high occurrence and lethality ***-dimensional(3D)chromatin architecture takes part in disease processing by regulating tran-scriptional *** study is carried out to investigate the alterations of hepatic 3D genome and H3K27ac profiling in early fatty liver(FLS)and reveal their effect on hepatic transcriptional reprogramming in laying *** Results show that FLS model is constructed with obvious phenotypes including hepatic visible lipid deposi-tion as well as higher total triglyceride and cholesterol in serum.A/B compartment switching,topologically associat-ing domain(TAD)and chromatin loop changes are identified by high-throughput/resolution chromosome conforma-tion capture(HiC)*** genes of these alternations in hepatic 3D genome organization significantly enrich pathways related to lipid metabolism and hepatic damage.H3K27ac differential peaks and differential expres-sion genes(DEGs)identified through RNA-seq analysis are also enriched in these ***,certain DEGs are found to correspond with changes in 3D chromatin structure and H3K27ac binding in their *** motif analysis reveals that candidate transcription factors are implicated in regulating transcriptional ***,disturbed folate metabolism is observed,as evidenced by lower folate levels and altered enzyme *** Our findings establish a link between transcriptional reprogramming changes and 3D chromatin struc-ture variations during early FLS formation,which provides candidate transcription factors and folate as targets for FLS prevention or treatment.

关键词： 3D chromatin architecture Fatty liver disease Folate H3K27ac profiling Transcription reprogramming

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A nitroreductase-responsive nanoprobe with homogeneous composition and high loading for preoperative non-invasive tumor imaging and intraoperative guidance

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Chinese Chemical Letters 2024年第7期35卷 313-318页

作者： jingqi Xin Shupeng Han Meichen zheng Chenfeng Xu Zhongxi Huang Bin Wang Changmin Yu Feifei An Yu ren Institute of Medical Engineering Department of BiophysicsSchool of Basic Medical ScienceHealth Science CenterXi'an Jiaotong UniversityXi'an 710061China School of Public Health Health Science CenterXi'an Jiaotong UniversityXi'an 710061China Key Laboratory of Flexible Electronics(KLOFE)&Institute of Advanced Materials(IAM) Nanjing Tech UniversityNanjing 211816China Department of Breast Surgery the First Affiliated Hospital of Xi'an Jiaotong UniversityXi'an 710061China

Tumor microenvironment(TME)-activatable probes have been proven to effectively increase signal-tobackground ratios(SBRs)and improve the success rate of complete tumor ***,many fluorescence probes have to be loaded into a nanocarrier for tumor targeted delivery,which consequently encounters poor drug loading,heterogeneous composition and non-encapsulated drug aggregates occurred during nanoformulation ***,a nitroreductase(NTR)-activated“OFF-ON”near-infrared fluorescence nanoprobe,named Nano Bodipy,was synthesized by the spontaneous self-assembling of NTRresponsive dye-polyethylene glycol(PEG)amphiphilic polymer in *** NTR-responsive dye acted as the hydrophobic segment in the amphiphilic polymer,yielding a homogeneous composition and a high loading of 12.2 wt%(according to calculation)in the synthesized Nano *** synthesized Nano Bodipy can efficiently accumulate in tumors via the enhanced permeability and retention(EPR)effect,enabling non-invasive tumor-targeted fluorescence imaging and guiding complete tumor *** the synthesized Nano Bodipy entered the tumor cells,they dissociated and were activated by overexpressed *** the real-time fluorescence guide of Nano Bodipy,complete tumor resection surgery was performed successfully.

关键词： Nitroreductase Tumor diagnosis Intraoperative guidance Self-assembly Nanoprobe

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