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Dynamic collapse characteristics of the tunnel face induced by the shutdown of earth pressure balance shields(EPB):A 3D material point method study

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Underground Space 2024年第3期16卷 164-182页

作者： Shuying Wang Tingyu Liu Xiangcou Zheng Junsheng yang feng yang School of Civil Engineering Central South UniversityChangsha 410075HunanChina Tunnel and Underground Engineering Research Center of Central South University Changsha 410075HunanChina Hunan Provincial Key Laboratory for Disaster Prevention and Mitigation of Rail Transit Engineering Structures Central South UniversityChangsha 410075HunanChina

The collapse of the tunnel face is a prevalent geological disaster in *** study employs a three-dimensional(3D)material point method(MPM)to simulate the dynamic collapse process and post-failure mechanisms of the tunnel *** specific focus is on the scenario where the auxiliary air pressure balanced shield with a partially filled chamber is shut *** assess the suitability of the 3D MPM,numerical solutions are compared with the results from small-scale experimental ***,a series of large-scale numerical simulations is conducted to explore the dynamic collapse characteristics of the tunnel face induced by the shutdown of the EPB shield under various support air pressures and cutter head *** temporal evolution of the accumulated soil masses in the soil chamber and ground responses under different support air pressures,cutter head types and opening ratios are *** particular,the associated surface subsidence due to the tunnel face collapse is determined and compared with empirical *** results confirm the applicability of the 3D MPM for simulating the large-scale tunnel face collapse scenarios,spanning from small to large deformation analysis.

关键词： Large deformation Material point method Partially filled chamber Post-failure mechanism Shield tunnel Tunnel face collapse

Ag-doped CNT/HAP nanohybrids in a PLLA bone scaffold show significant antibacterial activity

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Bio-design and Manufacturing 2024年第2期7卷 105-120页

作者： Cijun Shuai Xiaoxin Shi Kai Wang Yulong Gu feng yang Pei feng State Key Laboratory of Precision Manufacturing for Extreme Service Performance College of Mechanical and Electrical EngineeringCentral South UniversityChangsha 410083China Institute of Additive Manufacturing Jiangxi University of Science and TechnologyNanchang 330013China College of Mechanical Engineering Xinjiang UniversityUrumqi 830017China

Bacterial infection is a major problem following bone implant ***,poly-l-lactic acid/carbon nanotube/hydroxyapatite(PLLA/CNT/HAP)bone scaffolds possess enhanced mechanical properties and show good ***,wesynthesizedsilver(Ag)-dopedCNT/HAP(CNT/Ag-HAP)nanohybrids via the partial replacing of calcium ions(Ca2+)in the HAP lattice with silver ions(Ag+)using an ion doping technique under hydrothermal ***ﬁcally,the doping process was induced using the special lattice structure of HAP and the abundant surface oxygenic functional groups of CNT,and involved the partial replacement of Ca2+in the HAP lattice by doped Ag+as well as the in situ synthesis of Ag-HAP nanoparticles on CNT in a hydrothermal *** result-ing CNT/Ag-HAP nanohybrids were then introduced into a PLLA matrix via laser-based powder bed fusion(PBF-LB)to fabricate PLLA/CNT/Ag-HAP scaffolds that showed sustained antibacterial *** then found that Ag+,which pos-sesses broad-spectrum antibacterial activity,endowed PLLA/CNT/Ag-HAP scaffolds with this activity,with an antibacterial effectiveness of 92.65%.This antibacterial effect is due to the powerful effect of Ag+against bacterial structure and genetic material,as well as the physical destruction of bacterial structures due to the sharp edge structure of *** addition,the scaffold possessed enhanced mechanical properties,showing tensile and compressive strengths of 8.49 MPa and 19.72 MPa,***,the scaffold also exhibited good bioactivity and cytocompatibility,including the ability to form apatite layers and to promote the adhesion and proliferation of human osteoblast-like cells(MG63 cells).

关键词： Ag-doped Carbon nanotube/hydroxyapatite(CNT/HAP) Antibacterial properties Bone scaffold

Plasma-etching on monolithic MOFs-based MIM filter boosted chemical sensing

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Nano Research 2024年第4期17卷 2800-2807页

作者： Jianxi Liu Li feng Zhihuan Li yang Wu feng Zhou Yadong Xu Research&development Institute Northwestern Polytechnical University in ShenzhenShenzhen 518057China State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal MaterialsSchool of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Yantai Zhongke Research Institute of Advanced Materials and Green Chemical Engineering Shandong Laboratory of Advanced Materials and Green Manufacturing at YantaiYantai 264006China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China

Metal-insulator-metal(MIM)cavity as a lithography-free structure to control light transmission and reflection has great potential in the field of optical ***,the dense top metal layer of the MIM prohibits any external medium from entering the dielectric insulation layer,which limits the application of the cavity in the sensing ***,we demonstrate a series of monolithic metal-organic frameworks(MOFs)based MIM cavities,which are treated by plasma etching to provide channels for chemical diffusion and to advance *** modulate the bandwidth of the MIM filters by controlling the MOF thickness as insulator *** plasma-etching is applied to build channels on the top metal layer without altering their saturation and brightness for chemical sensing *** etching time regulates the number and size of channels on the top metal *** behavior is demonstrated on the plasma-etched MOFs-based MIM cavity when external chemicals diffuse in the *** addition,we generate patterned structure of the MOFs-based MIM cavity via plasma-mask method,which can transfer to different substrates and produce a controllable structure color change for chemical *** MIM cavity may promote the advancement and applications of structural color in security imaging,color display,information anticounterfeiting,and color printing.

关键词： metal-organic frameworks(MOFs) spin-coating metal-insulator-metal filter patterns sensing

A new method for identifying flow pattern of spouted fluidized bed by coupling Hilbert-Huang transform characteristics of differential pressure signals in different zones

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Particuology 2024年第6期89卷 67-78页

作者： Yongzhi Mei yang Wang Lihui Zhang feng Duan School of Energy and Environment Anhui University of TechnologyMaanshan243002China Wuhu Technology and Innovation Research Institute Wuhu241000China Wuhu Cigarette Factory of China Tobacco Anhui Industrial Co. Ldt.Wuhu241002China

On a cold spouted fluidized bed,this study compares the characteristic differences in intrinsic mode function(IMF)energy and Hilbert–Huang spectrum between the spout zone and annulus zone under different combinations of spouted gas and fluidized gas flow rates for five typical flow *** energy distribution characteristics under different flow patterns are also *** Hilbert–Huang spectrum and IMF energy of pressure difference signals exhibit distinct variations in different zones as the flow pattern ***,there exists a correlation between the energy in the middle-frequency range and the flow *** the K-means algorithm,the middle-frequency range energy of IMFs in the spout zone and annulus zone is subjected to clustering analysis,leading to the identification of partition boundaries for each flow *** on this,a flow pattern identification method of spouted fluidized bed coupled with middle-frequency range energy in spout zone and annulus zone is proposed,which has very high identification accuracy.

关键词： Spouted fluidized bed Flow pattern Zoning signal Flow pattern transition Hilbert-Huang transform

Efficient Monolithic Perovskite/Silicon Tandem Photovoltaics

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Energy & Environmental Materials 2024年第3期7卷 268-281页

作者： Yong Wang Yu Wang feng Gao deren yang State Key Laboratory of Silicon Materials and School of Materials Science and Engineering Zhejiang UniversityHangzhou 310027China ZJU-Hangzhou Global Scientific and Technological Innovation Center Zhejiang UniversityHangzhou 310014China department of Physics Chemistry and Biology(IFM)Linköping UniversityLinköping 58183Sweden

Tunable bandgaps make halide perovskites promising candidates for developing tandem solar cells(TSCs),a strategy to break the radiative limit of 33.7%for single-junction solar *** perovskites with market-dominant crystalline silicon(c-Si)is particularly attractive;simple estimates based on the bandgap matching indicate that the efficiency limit in such tandem device is as high as 46%.However,state-of-the-art perovskite/c-Si TSCs only achieve an efficiency of~32.5%,implying significant challenges and also rich *** this review,we start with the operating mechanism and efficiency limit of TSCs,followed by systematical discussions on wide-bandgap perovskite front cells,interface selective contacts,and electrical interconnection layer,as well as photon management for highly efficient perovskite/c-Si *** highlight the challenges in this field and provide our understanding of future research directions toward highly efficient and stable large-scale wide-bandgap perovskite front cells for the commercialization of perovskite/c-Si TSCs.

关键词： 2-terminal electrical interconnection perovskite/silicon tandem photovoltaics photon management wide-bandgap perovskites

Resilient sliding mode control for 2D CPSs under denial-of-service attacks

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Science China(Information Sciences) 2024年第6期67卷 262-278页

作者： Lingling LI Rongni yang Zhiguang feng Ligang WU College of Intelligent Systems Science and Engineering Harbin Engineering University School of Control Science and Engineering Shandong University School of Astronautics Harbin Institute of Technology

This study addresses the resilient sliding mode control(SMC) problem for two-dimensional cyber-physical systems(2D CPSs) characterized by the Roesser model under denial-of-service attack(DoSA), which can interfere with signal transmission over the communication network. First, the DoS-A model is established by introducing constraints on the Do S frequency and duration. Then, based on active or silent attack situations, the considered system is described as a switched mode. Furthermore, together with Lyapunov theory, the average dwell time technique is employed to deduce sufficient criteria that assure the existence of the desired sliding mode controller. Finally, verification examples are provided to show the validity of the established SMC scheme.

关键词： two-dimensional systems cyber-physical systems denial-of-service attack resilient sliding mode control

Advances in the study of gastric organoids as disease models

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World Journal of Gastrointestinal Oncology 2024年第5期16卷 1725-1736页

作者： Yi-yang Liu de-Kun Wu Ji-Bing Chen You-Ming Tang feng Jiang Graduate School Guangxi University of Chinese MedicineNanning 530011Guangxi Zhuang Autonomous RegionChina Teaching Experiment and Training Center Guangxi University of Chinese MedicineNanning 530011Guangxi Zhuang Autonomous RegionChina Central Laboratory Ruikang Hospital Affiliated to Guangxi University of Traditional Chinese MedicineNanning 530011Guangxi Zhuang Autonomous RegionChina department of Digestive Disease Ruikang Hospital Affiliated to Guangxi University of Traditional Chinese MedicineNanning 530011Guangxi Zhuang Autonomous RegionChina AIDS Research Center Ruikang Hospital Affiliated to Guangxi University of Traditional Chinese MedicineNanning 530011Guangxi Zhuang Autonomous RegionChina

Gastric organoids are models created in the laboratory using stem cells and sophisticated three-dimensional cell culture *** models have shown great promise in providing valuable insights into gastric physiology and advanced disease *** review comprehensively summarizes and analyzes the research advances in culture methods and techniques for adult stem cells and induced pluripotent stem cell-derived organoids,and patient-derived *** potential value of gastric organoids in studying the pathogenesis of stomach-related diseases and facilitating drug screening is initially *** construction of gastric organoids involves several key steps,including cell extraction and culture,three-dimensional structure formation,and functional *** the structure and function of the human stomach by disease modeling with gastric organoids provides a platform to study the mechanism of gastric cancer induction by Helicobacter *** addition,in drug screening and development,gastric organoids can be used as a key tool to evaluate drug efficacy and toxicity in preclinical *** can also be used for precision medicine according to the specific conditions of patients with gastric cancer,to assess drug resistance,and to predict the possibility of adverse ***,despite the impressive progress in the field of gastric organoids,there are still many unknowns that need to be addressed,especially in the field of regenerative ***,the reproducibility and consistency of organoid cultures are major challenges that must be *** challenges have had a significant impact on the development of gastric ***,as technology continues to advance,we can foresee more comprehensive research in the construction of gastric *** research will provide better solutions for the treatment of stomach-related diseases and personalized medicine.

关键词： Organoids Stomach neoplasms Helicobacter pylori Drug evaluation Preclinical Precision

On the Probability of Generating a Primitive Matrix

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Journal of Systems Science & Complexity 2024年第4期37卷 1755-1771页

作者： CHEN Jingwei feng Yong LIU yang WU Wenyuan Chongqing Key Laboratory of Automated Reasoning and Cognition Chongqing Institute of Green and Intelligent TechnologyChinese Academy of SciencesChongqing 400714China Chongqing College University of Chinese Academy of SciencesChongqing 400714China Key Laboratory of Advanced Manufacturing Technology of Ministry of Education Guizhou UniversityyGuiyang 550025China Information Science and Engineering Chongqing Jiaotong UniversityChongqing 400074China

Given a k×n integer primitive matrix A(i.e.,a matrix can be extended to an n×n unimodular matrix over the integers)with the maximal absolute value of entries‖A‖bounded by an integer λ from above,the authors study the probability that the m×n matrix extended from A by appending other m-k row vectors of dimension n with entries chosen randomly and independently from the uniform distribution over{0,1,…,λ-1}is still *** authors present a complete and rigorous proof of a lower bound on the probability,which is at least a constant for fixed m in the range[k+1,n-4].As an application,the authors prove that there exists a fast Las Vegas algorithm that completes a k×n primitive matrix A to an n×n unimodular matrix within expected O(n^(ω)log‖A‖)bit operations,where O is big-O but without log factors,ω is the exponent on the arithmetic operations of matrix multiplication.

关键词： Integer matrix matrix completion probabilistic algorithm unimodular matrix

Stability Analysis of a Class of Nonlinear Fractional Differential Systems With Riemann-Liouville derivative

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IEEE/CAA Journal of Automatica Sinica 2024年第8期11卷 1883-1885页

作者： Ruoxun Zhang Shiping yang Shiwen feng College of Teacher Education Xingtai UniversityXingtai 054001China College of Physics and Information Engineering Hebei Normal UniversityShijiazhuang 050016China

dear Editor,This letter investigates the stability of n-dimensional nonlinear fractional differential systems with Riemann-Liouville *** using the Mittag-Leffler function,Laplace transform and the Gronwall-Bellman lemma,one sufficient condition is attained for the asymptotical stability of a class of nonlinear fractional differential systems whose order lies in(0,2).According to this theory,if the nonlinear term satisfies some conditions,then the stability condition for nonlinear fractional differential systems is the same as the ones for corresponding linear *** examples are provided to illustrate the applications of our result.

关键词： Liouville Riemann nonlinear