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Probabilistic prediction on three-dimensional roughness of discontinuity based on two-dimensional traces under rock tunnel excavation based on Bayesian theory

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Underground Space 2024年第1期14卷 338-356页

作者： Qi Zhang Yuechao Pei Xiaojun Wang Xiaojun Li yixin Shen School of Civil Engineering Southeast UniversityNanjing 211189China Department of Geotechnical Engineering College of Civil EngineeringTongji UniversityShanghai 200092China

Three-dimensional(3D)roughness of discontinuity affects the quality of the rock mass,but 3D roughness is hard to be measured due to that the discontinuity is invisible in the ***-dimensional(2D)roughness can be calculated from the visible traces,but it is difficult to obtain enough quantity of the traces to directly derive 3D roughness during the tunnel *** this study,a new method using Bayesian theory is proposed to derive 3D roughness from the low quantity of 2D roughness *** more accurately calculating 3D roughness,a new regression formula of 2D roughness is established firstly based on wavelet *** new JRC3D prediction model based on Bayesian theory is then developed,and Markov chain Monte Carlo(MCMC)sampling is adopted to process JRC3D prediction *** discontinuity sample collected from the literature is used to verify the proposed *** groups with the sampling size of 2,3,4,and 5 of each group are randomly sampled from JRC2D values of 170 profiles of the discontinuity,*** research results indicate that 100%,90%,85%,and 60%predicting JRC3D of the sample groups corresponding to the sampling size of 5,4,3,and 2 fall into the tolerance interval[JRC_(true)–1,JRC_(true)+1].It is validated that the sampling size of 5 is enough for predicting *** sensitivities of sampling results are then analyzed on the influencing factors,which are the correlation function,the prior distribution,and the prior *** discontinuity across the excavation face at ZK78+67.5 of Daxiagu tunnel is taken as the tunnel engineering application,and the results further verify that the predicting JRC3D with the sampling size of 5 is generally in good agreement with JRC3D true values.

关键词： Rock discontinuity Joint roughness coefficient Tunnel excavation Bayesian theory Markov chain Monte Carlo sampling

Intelligent reflecting surface assisted untrusted NOMA transmissions: a secrecy perspective

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Science China(Information Sciences) 2023年第9期66卷 226-238页

作者： Dawei WANG Xuanrui LI yixin HE Fuhui ZHOU Qihui WU School of Electronics and Information Northwestern Polytechnical University Research & Development Institute of Northwestern Polytechnical University in Shenzhen College of Electronic and Information Engineering Nanjing University of Aeronautics and Astronautics Key Laboratory of Dynamic Cognitive System of Electromagnetic Spectrum Space Nanjing University of Aeronautics and Astronautics

In this paper, we investigate the intelligent reflecting surface(IRS) assisted secure transmissions for the untrusted non-orthogonal multiple access(NOMA) network threatened by an external eavesdropper,where the near user and two untrusted far users receive the privacy information from the transmitter assisted by the IRS’s passive reflection. To protect the privacy information against internal and external eavesdropping, we first provide a comprehensive analysis of the secrecy rates, which can offer suitable methods for separately handling the internal and external secrecy performance. Following the above results, we formulate a secrecy rate maximization problem by optimizing the transmission power allocation and phase shifts. To achieve this goal, we decouple the non-convex optimization problem into the external security problem and the internal security problem. Then, we propose a heuristic simulated annealing algorithm to iteratively solve the above problems, where the semi-definite relaxation(SDR) technique, the singular value decomposition(SVD) technique, and the Lagrange multiplier method are utilized to relax the problems and optimize the power allocation and phase shifts. Finally, numerical results show that the proposed scheme can improve the secrecy rate compared with the existing IRS-aided secure NOMA transmission schemes.

关键词： intelligent reflecting surface non-orthogonal multiple access security untrusted users.

Research on seismic behavior and shear strength of SRHC frame columns

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Earthquake Engineering and Engineering Vibration 2017年第2期16卷 349-364页

作者： Zheng Shansuo Qin Qing Zhang yixin Zhang Liang Yang Wei Department of Civil Engineering Xi’an University of Architecture and Technology Department of Civil and Architecture Engineering Xi'an University of Science and Technology

The seismic behavior of steel reinforced high strength and high performance concrete （SRHC） frame columns was investigated through pseudo-static experiments of 16 frame columns with various shear span ratios, axial compression ratios, concrete strengths, steel ratios and stirrup ratios. Three kinds of failure mechanisms are presented and the characteristics of experimental hysteretic curves and skeleton curves with different design parameters are discussed. The columns＇ ductility and energy dissipation were quantitatively evaluated based on seismic resistance. The research results indicate that SRHC frame columns can withstand extreme bearing capacity, but the abilities of ductility and energy dissipation are inferior because of SRHC＇s natural brittleness. As a result, the axial load ratio should be restricted and some construction measures adopted, such as increasing the stirrup ratio. This research established effect factors on the bearing capacity of SPHC columns. Finally, an algorithm for obtaining ultimate bearing capacity using the flexural failure mode is established based on a modified plane- section assumption. The authors also established equations to determine shearing baroclinic failure and shear bond failure based on the accumulation of the axial load force distribution ratio. The calculated results of shear bearing capacity for different failure modes were in good agreement with the experimental results.

关键词： SRHC flame columns seismic behavior ductility energy dissipation axial compression ratio shear bearingcapacity

Low complexity MIMO sonar imaging using a virtual sparse linear array

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Journal of Systems Engineering and Electronics 2016年第2期27卷 370-378页

作者： Xionghou Liu Chao Sun yixin Yang Jie Zhuo Yina Han School of Marine Science and Technology Northwestern Polytechnical University State Key Laboratory of Acoustics Institute of Acoustics Chinese Academy of Sciences

A multiple-input multiple-output（MIMO） sonar can synthesize a large-aperture virtual uniform linear array（ULA） from a small number of physical elements. However, the large aperture is obtained at the cost of a great number of matched filters with much heavy computation load. To reduce the computation load, a MIMO sonar imaging method using a virtual sparse linear array（SLA） is proposed, which contains the offline and online processing. In the offline processing, the virtual ULA of the MIMO sonar is thinned to a virtual SLA by the simulated annealing algorithm, and matched filters corresponding to inactive virtual elements are removed. In the online processing, outputs of matched filters corresponding to active elements are collected for further multibeam processing and hence, the number of matched filters in the echo processing procedure is effectively reduced. Numerical simulations show that the proposed method can reduce the computation load effectively while obtaining a similar imaging performance as the traditional method.

关键词： multiple-input multiple-output(MIMO) sonar simulated annealing sonar imaging sparse arrays

Dynamic failure risk of coal pillar formed by irregular shape longwall face:A case study

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International Journal of Mining Science and Technology 2018年第5期28卷 775-781页

作者： yixin Zhao Hao Wang Shimin Liu Zonglong Mu Zhiguo Lu Beijing Key Laboratory for Precise Mining of Intergrown Energy and Resources School of Resources and Safety Engineering China University of Mining & Technology Department of Energy and Mineral Engineering G3 Center and EMS Energy Institute Pennsylvania State University University Park School of Mines China University of Mining & Technology

Irregular shape workface would result in the presence of coal pillar, which leads to high stress concentration and possibly induces coal bumps. In order to study the coal bump mechanism of pillars, static and dynamic stress overlapping(SDSO) method was proposed to explain the impacts of static stress concentration and tremors induced by mining activities. The stress and deformation in surrounding rock of mining face were analyzed based on the field case study at 1303 workface in Zhaolou Coal Mine in *** results illustrate that the surrounding rock of a workface could be divided into four different zones,i.e., residual stress zone, stress decrease zone, stress increase zone and original stress zone. The stress increase zone is prone to failure under the SDSO impact loading conditions and will provide elastic energy for inducing coal bump. Based on the numerical modelling results, the evolution of static stress in coal pillar as the size of gob increasing was studied, and the impact of dynamic stress was investigated through analyzing the characteristics of tremor activities. The numerical results demonstrate the peak value of vertical stress in coal pillar rises from about 30 MPa with mining distance 10 m to 52.6 MPa with mining distance 120 m, and the location of peak stress transfers to the inner zone of coal pillars as the workface moves forward. For the daily tremor activities, tremors with high energy released indicate high dynamic stress disturbance on the surrounding rock, therefore, the impact of dynamic stressing is more serious during workface extension period because the tremor frequency and average energy after workface extension are higher than those before the workface extension.

关键词： Coal bump Coal pillar Tremor Irregular shape longwall face Static and dynamic stress overlapping

Double-layer probiotic encapsulation for enhanced bacteriotherapy against inflammatory bowel disease

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Nano Research 2024年第10期17卷 9103-9110页

作者： yixin Wang Jun Liu Sichen Yuan Yawen You Quanyin Hu Pharmaceutical Sciences Division School of PharmacyUniversity of Wisconsin-MadisonMadisonWI 53705USA Carbone Cancer Center School of Medicine and Public HealthUniversity of Wisconsin-MadisonMadisonWI 53705USA Wisconsin Center for NanoBioSystems School of PharmacyUniversity of Wisconsin-MadisonMadisonWI 53705USA

Inflammatory bowel disease(IBD)is inflammatory intestinal disorders associated with dysregulated gut *** that leverages bacteria as therapeutics has shown tremendous promise in resolving gut dysbiosis and reducing inflammatory mediators to treat *** delivered probiotics,such as Escherichia coli Nissle 1917(EcN),can produce beneficial ingredients,competitively inhibit the proliferation of pathogens,and promote the restoration of gut microbiome ***,environmental stresses(such as gastric acids)in the gastrointestinal(GI)tract pose an enormous challenge to the probiotics following oral administration,leading to decreases in viability and activity of ***,the inferior mucoadhesive capability of probiotics results in low colonization efficacy,further compromising their therapeutic *** probiotics with functional biomaterials may protect them from elimination and prolong their retention in the GI ***,we developed a facile double-layer electrostatic assembly technique to encapsulate EcN bacteria in protective layers of mucoadhesive chitosan(CS)and immunomodulatory hyaluronic acid(HA)to generate *** biomaterials confer the coated EcN resistance to environmental assault and enhanced mucoadhesion in the GI *** probiotics equipped with the multifunctional shield can thus suppress inflammation and reshape the intestinal microenvironment to enhance therapeutic efficacy for the prevention and treatment of ***,this study presents a novel probiotic coating strategy to augment the outcome of bacteriotherapy to combat IBD.

关键词： probiotics biomaterial coating inflammatory bowel disease mucoadhesion oral administration

Planning method of droplet fusion scheduling based on mixedinteger programming

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Science China(Technological Sciences) 2024年第1期67卷 157-171页

作者： XIONG JiaCong CHEN JianKui WANG yixin YIN ZhouPing LI YiQun State Key Laboratory of Intelligent Manufacturing Equipment and Technology School of Mechanical Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China

The emergence of new display devices,such as organic light-emitting diodes,has brought about numerous advantages,including high material utilization,low cost,and high *** devices are manufactured using inkjet printing and possess the potential to become a key technology for display ***,a challenge in achieving this is the display effect that reveals uneven brightness and darkness,which can be avoided by controlling the volume of ink solution in a pixel to within 5%.Currently,the volume difference among the nozzles of commercial printheads does not meet the requirements for volume uniformity,thus challenging the printing ***,designing a suitable printing method that allows for the fusion of different volumes of ink droplets,ultimately reducing the error of the post fusion process,is *** this study,we propose a print display droplet fusion scheduling method comprising two main ***,we use a dichotomous trust domain algorithm to obtain a feasible range of printhead docking point spacings for different nozzle and pixel panel ***,we model the printing process as a droplet fusion scheduling model based on mixed integer programming,with the optimization objective of achieving intra pixel volume uniformity via ensuring the volume uniformity of ink droplets within all *** verified this method through numerical simulations and printing experiments using 394 pixels per inch(ppi)pixel panels and successfully reduced the volume uniformity error among pixels to within 5%.

关键词： printing display droplet fusion mixed-integer programming dichotomous trust domain

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Crocetin Potentiates Neurite Growth in Hippocampal Neurons and Facilitates Functional Recovery in Rats with Spinal Cord Injury

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Neuroscience Bulletin 2017年第6期33卷 695-702页

作者： Xiqian Wang Xiejia Jiao Zhonghao Liu yixin Li Orthopaedics Department The Second Hospital of Shandong UniversityJinan 250012China Imaging Department The Second Hospital of Shandong UniversityJinan 250012China

Crocetin is an ingredient of traditional Chinese medicine and has therapeutic potential in various diseases due to its pharmacological properties, such as neuroprotection, anti-oxidative stress, and anti-inflammation. These properties might benefit the treatment of spinal cord *** the present study, we tested the effect of crocetin on neurite growth and sensorimotor dysfunction in a rat model of spinal cord injury. We evaluated the viability of cultured hippocampal neurons with tetrazolium dye and lactate dehydrogenase assays, visualized neurites and axons with antibody staining, and monitored motor and sensorimotor functions in rats with spinal cord injury using the Basso,Beattie, and Bresnahan assay and the contact plantar placement test, respectively, and measured cytokine expression using enzyme-linked immuno-absorbent *** found that crocetin（1） did not alter the viability of cultured hippocampal neurons;（2） accelerated neurite growth with preference for the longest process in individual hippocampal neurons;（3） reversed the inhibition of neurite growth by chondroitin sulfate proteoglycan and Nogo A;（4） facilitated the recovery of motor and sensorimotor functions after spinal cord injury; and（5） did not inhibit pro-inflammatory responses, but restored the innervation of the descending 5-HT system in injured spinalcord. Crocetin promotes neurite growth and facilitates the recovery of motor and sensorimotor functions after spinal cord injury, likely through repairing neuronal connections.

关键词： Crocetin Spinal cord injury Hippocampal neurons Inflammation

Tuning graphene thermal modulator by rotating

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International Journal of Smart and Nano Materials 2020年第3期11卷 310-323页

作者： Ning Wei yixin Zhang Yang Chen Yingyan Zhang Jiangsu Key Laboratory of Advanced Food Manufacturing Equipment and Technology Jiangnan UniversityWuxiChina College of Water Resources and Architectural Engineering Northwest A&F UniversityYanglingChina Shanghai Institute of Applied Mathematics and Mechanics Shanghai Key Laboratory of Mechanics in Energy EngineeringShanghai UniversityShanghaiChina School of Engineering RMIT UniversityBundooraAustralia

Exploring the thermal transport of graphene is significant for the application of its thermal ***,it is still a challenge to regulate the thermal conductivity of graphene *** study the interfacial thermal transport mechanism of the bilayer graphene by utilizing the molecular dynamics *** the simulation,the interfacial thermal conductivity is regulated and controlled by lattice matching and *** lattice mismatched bilayer graphene model,combining the straining and torsion,can increase the interfacial thermal resistance(ITR)about 3.7 *** variation trend of the ITR is explained by utilizing the vibrational spectra and the overlap ***,the thermal conductivity is proportional to the overlapping *** results show that the tailoring models can regularly control the thermal conductivity in a wide range by twisting the angle between upper and lower *** findings can provide a guideline for thermoelectric manage-ment and device design of thermal switch.

关键词： Interfacial thermal resistance bilayer graphene torsion