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light(Science & Applications) 2024年第7期13卷 1427-1440页

作者： Shulang lin li Gong Zhiwei Huang Optical Bioimaging Laboratory Department of Biomedical EngineeringCollege of Design and EngineeringNational University of SingaporeSingapore 117576Singapore

We present a novel time-of-flight resolved Bessel light bullet-enabled stimulated Raman scattering(B2-SRS)microscopy for deeper tissue 3D chemical imaging with high resolution without a need for mechanical *** accomplish the tasks,we conceive a unique method to enable optical sectioning by generating the counterpropagating pump and Stokes Bessel light bullets in the sample,in which the group velocities of the Bessel light bullets are made ultraslow(e.g.,vg≈0.1c)and tunable by introducing programmable angular dispersions with a spatial light *** theoretically analyze the working principle of the collinear multicolor Bessel light bullet generations and velocity controls with the relative time-of-flight resolved detection for SRS 3D deep tissue *** have also built the B2-SRS imaging system and present the first demonstration of B2-SRS microscopy with Bessel light bullets for 3D chemical imaging in a variety of samples(e.g.,polymer bead phantoms,biological samples such as spring onion tissue and porcine brain)with high *** B2-SRS technique provides a>2-fold improvement in imaging depth in porcine brain tissue compared to conventional SRS *** method of optical sectioning in tissue using counter-propagating ultraslow Bessel light bullets developed in B2-SRS is generic and easy to perform and can be readily extended to other nonlinear optical imaging modalities to advance 3D microscopic imaging in biological and biomedical systems and beyond.

关键词： Bessel resolved propagating

Topological magnetoelectric response in ferromagnetic axion insulators

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National Science Review 2024年第2期11卷 8-14页

作者： Yuhao Wan Jiayu li Qihang liu Department of Physics and Shenzhen Institute for Quantum Science and Engineering(SIQSE) Southern University of Science and Technology Shenzhen key Laboratory of Advanced Quantum Functional Materials and Devices Southern University of Science and Technology Guangdong Provincial key Laboratory for computational Science and Material Design Southern University of Science and Technology

The topological magnetoelectric effect （TME） is a hallmark response of the topological field theory,which provides a paradigm shift in the study of emergent topological ***,its direct observation is yet to be realized due to the demanding magnetic configuration required to gap all surface ***,we theoretically propose that axion insulators with a simple ferromagnetic configuration,such as the MnBi2Te4/（Bi2Te3）nfamily,provide an ideal playground to realize the *** the designed triangular prism geometry,all the surface states are magnetically *** a vertical electric field,the surface Hall currents give rise to a nearly half-quantized orbital moment,accompanied by a gapless chiral hinge mode circulating in ***,the orbital magnetization from the two topological origins can be easily distinguished by reversing the electric *** work paves the way for direct observation of the TME in realistic axion-insulator materials.

关键词： topological magnetoelectric effect axion insulator magnetic topological materials

A new elastoplastic model for bolt-grouted fractured rock

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International Journal of Mining Science and Technology 2024年第7期34卷 995-1016页

作者： Haoyi li Shuangying Zuo Peiyuan lin State key Laboratory for Tunnel Engineering Sun Yat-Sen UniversityGuangzhou 510275China Southern Marine Science and Engineering Guangdong Laboratory Zhuhai 519082China School of civil Engineering Sun Yat-Sen UniversityGuangzhou 510275China college of Resources and Environmental Engineering Guizhou UniversityGuiyang 550025China

complexities in mechanical behaviours of rock masses mainly stem from inherent discontinuities,which calls for advanced bolt-grouting techniques for stability *** the mechanical properties of bolt-grouted fractured rock mass(BGFR)and developing accurate prediction methods are crucial to optimize the BGFR support *** paper establishes a new elastoplastic(E-P)model based on the orthotropic and the Mohr-coulomb(M-c)plastic-yielding *** elastic parameters of the model were derived through a meso-mechanical analysis of composite materials mechanics(cMM).Laboratory BGFR specimens were prepared and uniaxial compression test and variable-angle shear test considering different bolt arrangements were carried out to obtain the mechanical parameters of the *** showed that the anisotropy of BGFR mainly depends on the relative volume content of each component material in a certain ***,the mechanical parameters deduced from the theory of composite materials which consider the short fibre effect are shown to be in good agreement with those determined by laboratory experiments,and the variation rules maintained good ***,a case study of a real tunnel project is provided to highlight the effectiveness,validity and robustness of the developed E-P model in prediction of stresses and deformations.

关键词： Bolt-grouted fractured rock mass Elastoplastic model composite materials mechanics Laboratory experiment

Long Short-Term Memory Spiking Neural Networks for classification of Snoring and Non-snoring Sound Events

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chinese Journal of Electronics 2024年第3期33卷 793-802页

作者： Rulin ZHANG Ruixue li Jiakai liANG keqiang YUE Wenjun li Yilin li Electronics and Information college Hangzhou Dianzi University

Snoring is a widespread occurrence that impacts human sleep *** is also one of the earliest symptoms of many sleep *** is accurately detected,making further screening and diagnosis of sleep problems *** is frequently ignored because of its underrated and costly detection *** a result,this research offered an alternative method for snoring detection based on a long short-term memory based spiking neural network(LSTM-SNN) that is appropriate for large-scale home detection for *** designed acquisition equipment to collect the sleep recordings of 54 subjects and constructed the sleep sound database in the home *** Mel frequency cepstral coefficients(MFccs) were extracted from these sound signals and encoded into spike trains by a threshold encoding *** were classified automatically as non-snoring or snoring sounds by our LSTM-SNN *** used the backpropagation algorithm based on an alternative gradient in the LSTM-SNN to complete the parameter *** categorization percentage reached an impressive 93.4%,accompanied by a remarkable 36.9% reduction in computer power compared to the regular LSTM model.

关键词： costs Databases computational modeling Backpropagation algorithms Sleep apnea Encoding Recording

An extended numerical model of the first exothermic peak for three dimensional printed cement-based materials

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Frontiers of Structural and civil Engineering 2024年第1期18卷 80-88页

作者： Wei JIANG Wenqian li Xi cHEN School of Materials Science and Engineering Tongji UniversityShanghai 200092China School of civil Engineering Tongji UniversityShanghai 200092China

The first exothermic peak of cement-based material occurs a few minutes after mixing,and the properties of three dimensional(3D)printed concrete,such as setting time,are very sensitive to *** this background,based on the classical Park cement exothermic model of hydration,we propose and construct a numerical model of the first exothermic peak,taking into account the proportions of c_(3)S,c_(3)A and quicklime in *** calculated parameters are calibrated by means of relevant published exothermic test *** is found that this developed model offers a good simulation of the first exothermic peak of hydration for c_(3)S and c_(3)A proportions from 0 to 100% of cement clinker and reflects the effect of quicklime content at 8%-10%.The unique value of this research is provision of an important computational tool for applications that are sensitive to the first exothermic peak of hydration,such as 3D printing.

关键词： 3D printed cement-based materials cement hydration the first exothermic peak liquid quick-setting agent numerical model

High-lattice-adapted surface modifying Na_(4)MnV(PO_(4))_(3) for better sodium storage

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Nano Research 2024年第4期17卷 2728-2735页

作者： chongran Song Shiyu li Ying Bai International Joint Research Laboratory of New Energy Materials and Devices of Henan Province School of Physics and ElectronicsAcademy for Advanced Interdisciplinary StudiesHenan UniversityKaifeng 475004China

Sodium-ion batteries(SIBs)are required to possess long cycle life when used for large-scale energy *** polyanionic Na_(4)MnV(PO_(4))_(3)(NMVP)reveals good cyclic stability due to its unique three-dimensional(3D)frame structure,but it still faces the challenge of interfacial degradation in practical *** this work,NASIcON-type Na_(1.3)Al_(0.7)Ti_(1.3)(PO_(4))_(3)(NATP)was deposited on the surface of NMVP to promote interface stability by surface modification and gradient *** a result,the optimized NMVP@2%NATP released a capacity retention of 44.8%after 1000 cycles at 5 c,much higher than that of the initial NMVP(28.9%).The enhanced electrochemical performance was mainly attributed to NATP coating acting as a fast ion transport carrier and physical barrier,significantly facilitating the Na^(+)diffusion and isolating side reaction at the electrode/electrolyte *** the other hand,Ti_(4)^(+)and Al^(3+)cations from the NATP were partially doped inside the NMVP surface to boost the transport of Na^(+),and the perfect lattice matching of NVMP and NATP improved the interface and structural stability accompanying long *** work demonstrated the effectiveness of surface modification with high lattice match material and provided new perspectives for high energy density solid-state SIBs.

关键词： high-lattice-adapted cathode surface modification sodium-ion batteries

Trial application of the envelope method to the potential ambiguity problem

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Nuclear Science and Techniques 2024年第1期35卷 73-80页

作者： li-Yuan Hu Yu-Shou Song Fundamental Science on Nuclear Safety and Simulation Technology Laboratory Harbin Engineering UniversityHarbin 150001China college of Nuclear Science and Technology Harbin Engineering UniversityHarbin 150001China key Laboratory of Nuclear Safety and Advanced Nuclear Energy Technology Ministry of Industry and Information TechnologyHarbin 150001China

The optical potential ambiguity is a long-standing problem in the analysis of elastic scattering *** a specific collid-ing system,ambiguous potential families can lead to different behaviors in the nearside and farside scattering *** contrast,the envelope method can decompose the experimental data into two components with negative and positive deflection angles,***,a question arises as to whether the comparison between the calculated nearside(or farside)component and the derived positive-deflection-angle(or negative-deflection-angle)component can help analyze the potential ambiguity *** this study,we conducted a trial application of the envelope method to the potential ambiguity *** envelope method was improved by including uncertainties in the experimental *** colliding systems of 16O+28Si at 215.2 MeV and 12c+12c at 1016 MeV were considered in the *** each colliding system,the angular distribution experimental data were described nearly equally well by two potential sets,one of which is“surface transpar-ent”and the other is *** calculated angular distributions were decomposed into nearside and farside scattering *** the improved envelope method,the experimental data were decomposed into the positive-deflection-angle and negative-deflection-angle components,which were then compared with the calculated nearside and farside *** capability of the envelope method to analyze the potential ambiguities was also discussed.

关键词： Elastic scattering Optical potential ambiguities Envelope method Nearside/farside decomposition

Access to High-Molecular-Weight Polyethylenes through High Temperature Ethylene Polymerization catalysed by Ethylene-Bridged ansa-(3-R-cyclopentadienyl)(Fluorenyl) Zirconocene complexes

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chinese Journal of Polymer Science 2024年第1期42卷 42-51,I0007页

作者： Bo li Haiyan Ma Jiling Huang Shanghai key Laboratory of Functional Materials chemistry and Laboratory of Organometallic chemistry School of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China

A series of c1-symmetric ethylene-bridged ansa-(3-R-cyclopentadienyl)(fluorenyl) metallocene complexes(Zr: 1-5;Hf: 6) have been synthesized, characterized and investigated as catalyst precursors for the high temperature ethylene polymerization. Using methylaluminoxane(MAO) as the cocatalyst, zirconium complexes 1-5 bearing a bulky substituent on the 3-position of the cyclopendienyl ring showed high catalytic activities up to 1.48×10^(7) g PE·mol_(Zr)^(-1)·h^(-1) toward the polymerization of ethylene and afforded polyethylenes with high molecular weights(1.49×10^(5)-6.31×10^(5) g/mol), meanwhile exhibting great thermal stability at high temperatures up to 120 ℃ together with a long catalytic life time up to 2 h. By adopting low Al/Zr ratios, such as 125, polyethylenes with ultra high molecular weights up to 2.86×106 g/mol were obtained. It is worthy of noting that zirconium complexes 1-4 bearing a substituent with an aryl pendant showed temperature-dependent activities, which increased rapidly with the increase of polymerization temperature, thus weak interaction of the pendent aryl group with the cationic active center is proposed to account for the very low activities displayed at low temperatures. In contrast to zirconocene complexes 1-5, hafnocene complex 6 only displayed very low catalytic activities toward the polymerization of ethylene and afforded polyethylenes with molecular weights ten times smaller than those obtained by zirconocene complexes 1-5. Zirconocene complexes 1-5 were also able to catalyse the polymerization of propylene at high temperatures, but only afforded waxes with low molecular weights.

关键词： ansa-Metallocene Ethylene Propylene Polymerization High temperature

Ultrasound-responsive spherical nucleic acid against c-Myc/PD-L1 to enhance anti-tumoral macrophages in triple-negative breast cancer progression

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Science china(life Sciences) 2024年第4期67卷 698-710页

作者： Runtian Wang Gaigai li Fangyan Gao Feng Xu Xintong li Jian Zhang Jinbo li Xiaoxiang Guan Department of Oncology The First Affiliated Hospital of Nanjing Medical UniversityNanjing 210029China State key Laboratory of Analytical chemistry for life Sciences Jiangsu Key Laboratory of Advanced Organic MaterialsSchool of Chemistry and Chemical EngineeringChemistry and Biomedicine Innovation Center(ChemBIC)Nanjing UniversityNanjing 210023China Department of Medical Oncology Fudan University Shanghai Cancer CenterDepartment of OncologyShanghai Medical CollegeFudan UniversityShanghai 200032China Jiangsu key Lab of cancer Biomarkers Prevention and TreatmentCollaborative Innovation Center for Cancer Personalized MedicineNanjing Medical UniversityNanjing 211166China

Triple-negative breast cancer(TNBc)is the most challenging breast cancer subtype because of its aggressive behavior and limited therapeutic targets.c-Myc is hyperactivated in the majority of TNBc tissues,however,it has been considered an“undruggable”target due to its disordered ***,we developed an ultrasound-responsive spherical nucleic acid(SNA)against c-Myc and PD-L1 in *** is a self-assembled and carrier-free system composed of a hydrophilic small-interfering RNA(si RNA)shell and a hydrophobic core made of a peptide nucleic acid(PNA)-based antisense oligonucleotide(ASO)and a *** accomplished significant enrichment in the tumor by enhanced permeability and retention(EPR)effect,the controllable release of effective elements by ultrasound activation,and the combination of targeted therapy,immunotherapy and *** study demonstrated significant anti-tumoral effects in vitro and in *** cytometry showed an invigorated tumor microenvironment(TME)characterized by a significant alteration in the composition of tumor-associated macrophages(TAM)and decreased proportion of PD-1-positive(PD-1+)T effector cells after appropriate treatment of the ultrasound-responsive SNA(USNA).Further experiments verified that tumor-conditioned macrophages residing in the TME were transformed into the anti-tumoral *** finding offers a novel therapeutic strategy against the“undruggable”c-Myc,develops a new targeted therapy for c-Myc/PD-L1 and provides a treatment option for the TNBc.

关键词： triple-negative breast cancer c-Myc spherical nucleic acid self-assembly

current-carrying tribological behavior of c/cu contact pairs in extreme temperature and humidity environments for railway catenary systems

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Science china(Technological Sciences) 2024年第8期67卷 2537-2548页

作者： SHEN MingXue JI DeHui HU Qiang XIAO li li QiuPing State key Laboratory of Performance Monitoring and Protecting of Rail Transit Infrastructure East China Jiaotong UniversityNanchang 330013China School of Materials Science and Engineering East China Jiaotong UniversityNanchang 330013China Institute of Applied Physics Jiangxi Academy of SciencesNanchang 330095China

Many current-carrying contact pairs, such as those found in pantograph-catenary systems, operate in open environments and are susceptible to significant external interference from temperature and humidity variations. This study investigated the evolution of the friction coefficient and contact resistance of c/cu contact pairs under alternating temperature, humidity, and current conditions. Through experimentation, the wear rate and microtopography of the worn surface were analyzed under various constant parameters. Subsequently, the differences in tribological behavior and current-carrying characteristics of the contact pairs under these three parameters were explored. The results revealed that the decrease in temperature resulted in a significant increase in the friction coefficient of the contact pairs, carbon wear, and copper surface roughness. Additionally, the surface oxidation rate was lower at lower temperatures. Moreover, contact resistance did not consistently increase with decreasing temperature, owing to the combined action of the contact area and the oxide film. compared with temperature, humidity fluctuations at room temperature exerted less influence on the friction coefficient and contact resistance of the contact pairs. Dry environments rendered carbon materials vulnerable to oxidation and cracking, while excessive humidity fostered abrasive wear and arcing. High-current conditions generally degraded the tribological properties of c/cu contacts. In the absence of current, the friction coefficient was extremely high, and the copper transfer was high. Under excessive current, copper was susceptible to plowing by carbon micro-bumps and abrasive particles, resulting in a decrease in the friction coefficient. The release of lipids from the carbon surface due to temperature elevation weakened the electrical contact performance and increased the occurrence of arc erosion, thereby exacerbating carbon wear.

关键词： temperature/humidity pantograph-catenary system c/cu wear current-carrying friction sliding electrical contact

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