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Acta Mechanica Solida Sinica 2024年第1期37卷 166-180页

作者： Zongxing liu Xiang Yang jun liu School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China COMAC Shanghai Aircraft Design and Research Institute Shanghai 201210China

To reduce the damage of the pressurizing panel structure of a fuselage caused by an explosion at the“least risk bomb location”in an aircraft structure,a new pre-separation panel structure was designed to resist blast ***,the dynamic strain response and morphology of impact damage of the new pre-separation panel were measured in an impact damage ***,the commercial software LS-DYNA was used to calculate the propagation of the blast shock wave,and the results were compared with empirical equations to verify the rationality of the numerical calculation ***,the fluid–structure coupling method was used to calculate the damage process of the pre-separation panel structure under the impact of an explosion wave and an impact *** calculated results were in good agreement with the test results,which showed the rationality of the calculation method and the *** residual strength of the damaged pre-separation panel was significantly higher than that of the original damaged *** results show that the new pre-separation panel structure is reasonable and has certain significance for guiding the design of plenum chambers with strong resistance to implosion for aircraft fuselages.

关键词： Pre-separation panel structure Explosive response Residual strength Aircraft plenum chamber Least risk bomb location

Evolution of pore systems in low-maturity oil shales during thermal upgrading--Quantified by dynamic SEM and machine learning

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Petroleum Science 2024年第3期21卷 1739-1750页

作者： jun liu Xue Bai Derek Elsworth Key Laboratory of Deep Underground Science and Engineering(Ministry of Education) Institute of New Energy and Low-Carbon TechnologySichuan UniversityChengdu610065SichuanChina International Quantum Academy Shenzhen518048GuangdongChina Shenzhen Institute of Advanced Electronic Materials Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen518055GuangdongChina Department of Energy and Mineral Engineering Pennsylvania State University ParkPA 16802USA

In-situ upgrading by heating is feasible for low-maturity shale oil,where the pore space dynamically *** characterize this response for a heated substrate concurrently imaged by *** systematically follow the evolution of pore quantity,size(length,width and cross-sectional area),orientation,shape(aspect ratio,roundness and solidity)and their anisotropy—interpreted by machine *** indicate that heating generates new pores in both organic matter and inorganic ***,the newly formed pores are smaller than the original pores and thus reduce average lengths and widths of the bedding-parallel pore ***,the average pore lengths and widths are increased in the bedding-perpendicular ***,heating increases the cross-sectional area of pores in low-maturity oil shales,where this growth tendency fluctuates at300℃.In addition,the orientation and shape of the newly-formed heating-induced pores follow the habit of the original pores and follow the initial probability distributions of pore orientation and ***,limited anisotropy is detected in pore direction and shape,indicating similar modes of evolution both bedding-parallel and *** propose a straightforward but robust model to describe evolution of pore system in low-maturity oil shales during heating.

关键词： Low-maturity oil shale Pore elongation Organic matter pyrolysis In-situthermal upgrading Scanning electron microscopy(SEM) Machine learning

Using vitamin C to improve both performance and stability of n-type organic semiconductors

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Science China Materials 2024年第11期67卷 3755-3756页

作者： Sizhe liu Xingxin Shao jun liu Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of Sciences School of Applied Chemistry and Engineering University of Science and Technology of China

Organic semiconductors(OSCs) have the great advantages of flexibility, light weight, low-cost and large-area processing [1].After intensively studied for several decades, OSCs are now considered to be the most promising candidate materials for next-generation electronic circuits. N-type OSCs are the vital component for the basic electronic element, such as p-n junctions, light-emitting diodes and complementary circuits [2].

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Equivalence between the internal observability and equation

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Applied Mathematics(A Journal of Chinese Universities) 2024年第1期39卷 89-97页

作者： liu Wen-jun TU Zhi-yu School of Mathematics and Statistics Nanjing University of Information Science and TechnologyNanjing 210044China

This paper is concerned with a third order in time linear Moore-Gibson-Thompson equation which describes the acoustic velocity potential in ultrasound wave *** by the work of Kaltenbacher,Lasiecka and Marchand(Control Cybernet.2011,40:971-988),we establish an observability inequality of the conservative problem,and then discuss the equivalence between the exponential stabilization of a dissipative system and the internal observational inequality of the corresponding conservative system.

关键词： Moore-Gibson-Thompson equation internal observability exponential stability

A novel small-signal equivalent circuit model for GaN HEMTs incorporating a dual-field-plate

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Journal of Semiconductors 2024年第5期45卷 61-68页

作者： Jinye Wang jun liu Zhenxin Zhao School of Integrated Circuit Science and Engineering Hangzhou Dianzi UniversityHangzhou 310018China

An accurate and novel small-signal equivalent circuit model for GaN high-electron-mobility transistors(HEMTs)is proposed,which considers a dual-field-plate(FP)made up of a gate-FP and a *** equivalent circuit of the overall model is composed of parasitic elements,intrinsic transistors,gate-FP,and source-FP *** equivalent circuit of the gate-FP is identical to that of the intrinsic *** order to simplify the complexity of the model,a series combination of a resistor and a capacitor is employed to represent the *** analytical extraction procedure of the model parameters is presented based on the proposed equivalent *** verification is carried out on a 4×250μm GaN HEMT device with a gate-FP and a source-FP in a 0.45μm *** with the classic model,the proposed novel small-signal model shows closer agreement with measured S-parameters in the range of 1.0 to 18.0 GHz.

关键词： small-signal model dual field-plate(FP) GaN high-electron-mobility transistors(HEMT) parameter extraction

Microglia Suppresses Breast Cancer Brain Metastasis via a Pro-inflammatory Response

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Neuroscience Bulletin 2024年第7期40卷 1034-1036页

作者： Shengbo Chen Yi-jun liu Department of Neurobiology of Affiliated Mental Health Center and Hangzhou Seventh People's Hospital and School of Brain Science and Brain Medicine Zhejiang University School of MedicineHangzhou 310058China Liangzhu Laboratory MOE Frontier Science Center for Brain Science and Brain-machine IntegrationState Key Laboratory of Brain-machine IntelligenceZhejiang University1369 West Wenyi RoadHangzhou 311121China NHC and CAMS Key Laboratory of Medical Neurobiology Zhejiang UniversityHangzhou 310058China

Due to the obstacle of the blood-brain barrier(BBB)for drug delivery[1],breast cancer brain metastasis(BCBM)represents a worldwide health challenge with high *** BCBM formation and progression,brain metastases(BrMs)secret various factors,including cytokines and exosomes,and trigger the infiltration of tumours-associated macrophages(TAMs),which in turn become important components of brain tumour microenvironments(TME).

关键词： mortality tumour Breast

Adaptive coupled-sliding-variable-based finite-time control of composite formation for multi-robot systems

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Science China(Information Sciences) 2024年第10期67卷 244-260页

作者： Xinru MA Hengyu LI jun liu Yueying WANG Shaorong XIE jun LUO School of Mechatronic Engineering and Automation Shanghai University School of Mathematics and Computer Application Technology Jining University School of Computer Science Shanghai University College of Mechanical and Vehicle Engineering Chongqing University

This paper focuses on the finite-time control(FTC) of the composite formation consensus(CFC)problems for multi-robot systems(MRSs). The CFC problems are firstly proposed for MRSs under the complex network topology of cooperative or cooperative-competitive networks. Regarding the problems of FTC and CFC on multiple Lagrange systems(MLSs), coupled sliding variables are introduced to deal with the robustness and consistent convergence. Then, the adaptive finite-time protocols are given based on the displacement approaches. With the premised FTC, tender-tracking methods are further developed for the problems of tracking information disparity. Stability analyses of those MLSs mentioned above are clarified with Lyapunov candidates considering the coupled sliding vectors, which provide new verification for tender-tracking systems. Under the given coupled-sliding-variable-based finite-time protocols, MLSs distributively adjust the local formation error to achieve global CFC and perform uniform convergence in time-varying tracking. Finally, simulation experiments are conducted while providing practical solutions for the theoretical results.

关键词： composite formation time-vary tracking information disparity tender-tracking finite-time control nonlinear robots complex networks symmetry consensus

Sharp bilinear decomposition for products of both anisotropic Hardy spaces and their dual spaces with its applications to endpoint boundedness of commutators

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Science China Mathematics 2024年第9期67卷 2091-2152页

作者： jun liu Dachun Yang Mingdong Zhang School of Mathematics China University of Mining and TechnologyXuzhou 221116China Laboratory of Mathematics and Complex Systems(Ministry of Education of China) School of Mathematical SciencesBeijing Normal UniversityBeijing 100875China

Let a:=(a_(1),...,a_(n))2[1,∞)^(n),p∈(0,1),andα:=1/*** any x∈R^(n)and t∈[0,∞),letΦ_(p)(x,t):={t/1+(t[x]_(a)^(ν))^(1-p)if να■N,t/1+(t[x]_(a)^(ν))^(1-p)[log(e+|x|a)]^(p)if να∈N,let where [·]a:=1+|·|a,|·|a denotes the anisotropic quasi-homogeneous norm with respect to a,and ν:=a_(1)+…+a_(n).Let H_(a)^(p)(R^(n)),L_(a)^(a)(R^(n)),and H_(a)^(Φ_(p))(R^(n))be,respectively,the anisotropic Hardy space,the anisotropic Campanato space,and the anisotropic Musielak-Orlicz Hardy space associated with Φ_(p) on R^(n).In this article,via first establishing the wavelet characterization of anisotropic Campanato spaces,we prove that for any f∈H_(a)^(p)(R^(n))and g∈L_(a)^(a)(R^(n)),the product of f and g can be decomposed into S(f,g)+T(f,g) in the sense of tempered distributions,where S is a bilinear operator bounded from H_(a)^(p)(R^(n))*L_(a)^(a)(R^(Φ_(p))) to L^(1)(R^(n)) and T is a bilinear operator bounded from H_(a)^(p)(R^(n))*L_(a)^(a)(R^(n)) to H_(a)^(Φ_(p))(R^(n)) .Moreover,this bilinear decomposition is sharp in the dual sense that any y■H_(a)^(Φ_(p))(R^(n)) that fits into the above bilinear decomposition should satisfy(L^(1)(R^(n))+y)*=(L^(1)(R^(n)+H_(a)^(Φ_(p))(R^(n))*.As applications,for any non-constant b∈L_(a)^(a)(R^(n)) and any sublinear operator T satisfying some mild bounded assumptions,we find the largest subspace of H_(a)^(p)(R^(n)),denoted by H_(a,b)^(p)(R^(n)),such that the commutator [b,T] is bounded from H_(a,b)^(p)(R^(n))to L^(1)(R^(n)).In addition,when T is an anisotropic CalderónZygmund operator,the boundedness of [b,T] from H_(a,b)^(p)(R^(n))to L^(1)(R^(n))(or to H_(a)^(1)(R^(n)) is also *** key of their proofs is the wavelet characterization of function spaces under consideration.

关键词： anisotropic Euclidean space bilinear decomposition Hardy space Campanato space Musielak-Orlicz Hardy space commutator wavelet

Quantum-enhanced microscopic imaging technology [Invited]

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Chinese Optics Letters 2024年第6期22卷 68-76页

作者： jun liu Xiaolong Su State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Opto-ElectronicsShanxi UniversityTaiyuan 030006China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China

Microscopes are indispensable tools in modern biology and medicine. With the development of microscopy, the signal-tonoise ratio of microscopes is now limited by the shot noise. Recently, quantum-enhanced microscopic imaging provides a feasible approach for improving the signal-to-noise ratio since it can beat the shot-noise limit by using quantum light. In this review, we first briefly introduce quantum states applied in quantum-enhanced microscopic imaging, and then we provide an overview of the principle and progress of quantum-enhanced stimulated Raman scattering microscopy, entangled twophoton microscopy,and quantum-enhanced differential interference contrast microscopy.

关键词： squeezed state entangled state imaging microscopy

Suppression of low-frequency ultrasound broadband vibration using star-shaped single-phase metamaterials

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Defence Technology（防务技术） 2024年第4期34卷 217-224页

作者： Rui Zhao Jian Zheng Jin Guo Yunbo Shi Hengzhen Feng jun Tang jun liu Science and Technology on Electronic Test&Measurement Laboratory North University of ChinaTaiyuan 030051ShanxiChina School of Mechatronical Engineering Beijing Institute of TechnologyBeijing 100081China

In order to suppress the low-frequency ultrasound vibration in the broadband range of 20 k Hz—100 k Hz,this paper proposes and discusses an acoustic metamaterial with low-frequency ultrasound vibration attenuation properties,which is configured by hybrid arc and sharp-angle convergent star-shaped *** effect of the dispersion relation and the bandgap characteristic for the scatterers in star-shaped are simulated and *** target bandgap width is extended by optimizing the geometry parameters of arc and sharp-angle convergent *** proposed metamaterial configured by optimized hybrid lattices exhibits remarkable broad bandgap characteristics by bandgap complementarity,and the simulation results verify a 99%vibration attenuation amplitude can be obtained in the frequency of20 k Hz—100 k *** the fabrication of the proposed hybrid configurational star-shaped metamaterial by 3D printing technique,the transmission loss experiments are performed,and the experimental results indicate that the fabricated metamaterial has the characteristics of broadband vibration attenuation and an amplitude greater than 85%attenuation for the target *** results demonstrate that the hybrid configurational star-shaped metamaterials can effectively widen the bandgap and realize high efficiency attenuation,which has capability for the vibration attenuation in the application of highprecise equipment.

关键词： Star-shaped metamaterials Broadband Vibration attenuation Low-frequency ultrasound vibration Transmission loss