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Shear mechanical properties and fracturing responses of layered rough jointed rock-like materials

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International Journal of Minerals,Metallurgy and Materials 2024年第11期31卷 2417-2434页

作者： Xinxin Nie qian Yin Manchao He qi Wang Hongwen Jing Bowen Zheng Bo Meng Tianci Deng Zheng jiang jiangyu Wu State Key Laboratory for Geomechanics&Deep Underground Engineering China University of Mining and TechnologyXuzhou 221116China State Key Laboratory for Geomechanics&Deep Underground Engineering China University of Mining and Technology(Beijing)Beijing 100083China Key Laboratory of Shale Gas and Geoengineering Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Department of Materials University of OxfordOxford OX13PHUK

This study aims to investigate mechanical properties and failure mechanisms of layered rock with rough joint surfaces under direct shear *** layered samples with dimensions of 100 mm×100 mm×100 mm were casted using rock-like materials,with anisotropic angle(α)and joint roughness coefficient(JRC)ranging from 15°to 75°and 2-20,*** direct shear tests were conducted under the application of initial normal stress(σ_(n)) ranging from 1-4 *** test results indicate significant differences in mechanical properties,acoustic emission(AE)responses,maximum principal strain fields,and ultimate failure modes of layered samples under different test *** peak stress increases with the increasingαand achieves a maximum value atα=60°or 75°.As σ_(n) increases,the peak stress shows an increasing trend,with correlation coefficients R² ranging from 0.918 to 0.995 for the linear least squares *** JRC increases from 2-4 to 18-20,the cohesion increases by 86.32%whenα=15°,while the cohesion decreases by 27.93%whenα=75°.The differences in roughness characteristics of shear failure surface induced byαresult in anisotropic post-peak AE responses,which is characterized by active AE signals whenαis small and quiet AE signals for a largeα.For a given JRC=6-8 andσ_(n)=1 MPa,asαincreases,the accumulative AE counts increase by 224.31%(αincreased from 15°to 60°),and then decrease by 14.68%(αincreased from 60°to 75°).The shear failure surface is formed along the weak interlayer whenα=15°and penetrates the layered matrix whenα=60°.Whenα=15°,as σ_(n) increases,the adjacent weak interlayer induces a change in the direction of tensile cracks propagation,resulting in a stepped pattern of cracks *** increase in JRC intensifies roughness characteristics of shear failure surface for a smallα,however,it is not pronounced for a largeα.The findings will contribute to a better understanding of the mechanical responses and failure mechanisms of the layered roc

关键词： layered samples anisotropic angle joint roughness coefficient mechanical properties acoustic emission response fracturing evolution failure modes

铜催化实现1,3-二烯与二氧化碳不对称双羧基化反应

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有机化学 2024年第4期44卷 1368-1370页

作者：戚朝荣江焕峰华南理工大学化学与化工学院、广东省功能分子工程重点实验室广州510641

二元羧酸在有机合成、生物化学和高分子工业中具有重要的应用,在羧酸化合物中占有重要的地位.虽然二氧化碳(CO_(2))参与的双羧基化反应是构建二元羧酸最直接而且可持续的途径,但由于CO_(2)热力学的稳定性和动力学惰性,该方法极具挑战性。

关键词：有机合成二元羧酸二氧化碳动力学热力学铜催化生物化学可持续的

Frequency and risk factors of psychological distress among individuals with epilepsy before and during the outbreak of the SARS-CoV-2 Omicron variant in China:an online questionnaire survey

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Acta Epileptologica 2024年第1期7卷 36-43页

作者： Xiaoting Hao qi Zhang Chenxi Zhong Enzhi Li Yingqi jiang Jiajun Xu Yuanyuan Li Dong Zhou Bo Yan Department of Neurology West China HospitalSichuan University No37 Guoxue AlleyChengduSichuan Province610000China Department of Psychiatry and Mental Health West China HospitalSichuan University/West China School of Clinical MedicineSichuan UniversityChengdu610000China Department of Neurology Chengdu Shangjin Nanfu HospitalChengdu611730China West China School of Nursing Sichuan University Chengdu610000China Department of Clinical Research Management West China HospitalSichuan UniversityChengdu610000China

Background The COVID-19 pandemic substantially increases the risk of severe psychological distress among people with epilepsy(PWE),especially those with monthly household income12 should consult a psychiatrist,especially during major *** study was aimed to compare the frequency of psychological distress among Chinese PWE before and during the outbreak of the SARS-CoV-2 Omicron variant,and to identify risk factors for such *** In this prospective study,we collected sociodemographic data of PWE aged>14 years,who were treated at our center during December 1 to 15,*** participants completed the 6-item Kessler Psychological Distress Scale before the outbreak and again during the *** visitors who were unrelated to those patients during the outbreak were included as a *** logistic regression analysis was performed to identify risk factors of severe psychological distress and its *** Of the 223 PWE,127 were tested positive for SARS-CoV-2,while 174 of 218 controls were positive for *** neurological symptoms were similar between PWE and controls with *** average Kessler score of PWE was significantly higher during the outbreak than before it(9.93±3.98 vs.8.52±0.23,P<0.001).The average score of controls during the outbreak(5.146±0.35,P<0.001)was significantly lower than that of the *** identified three independent predictors for severe psychological distress in PWE during the outbreak,i.e.,monthly household income<5000 RMB(OR=0.252,95%CI 0.064–0.998,P=0.048),severe psychological distress before the outbreak(OR=0.067,95%CI 0.026–0.174,P<0.001),and seizure onset within 30 days before the assessment during the outbreak(OR=0.356,95%CI 0.157–0.805,P=0.013).Of the three predictors,the last one was also an independent predictor for exacerbation of psychological distress during the outbreak(OR=0.302,95%CI 0.123–0.741,P

关键词： Epilepsy Neurological symptoms Psychological distress COVID-19 pandemic

Computed tomography radiomic features and clinical factors predicting the response to first transarterial chemoembolization in intermediate-stage hepatocellular carcinoma

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Hepatobiliary & Pancreatic Diseases International 2024年第4期23卷 361-369页

作者： Zhong-Xing Shi Chang-Fu Li Li-Feng Zhao Zhong-qi Sun Li-Ming Cui Yan-Jie Xin Dong-qing Wang Tan-Rong Kang Hui-Jie jiang Department of Interventional Radiology the Second Affiliated Hospital of Harbin Medical UniversityHarbin 150086China Department of Digestive Medicine Daqing Longnan HospitalDaqing 163453China Department of Radiology Daqing Longnan HospitalDaqing 163453China Department of Radiology the Second Affiliated Hospital of Harbin Medical UniversityHarbin 150086China

Background:According to clinical practice guidelines,transarterial chemoembolization(TACE)is the standard treatment modality for patients with intermediate-stage hepatocellular carcinoma(HCC).Early prediction of treatment response can help patients choose a reasonable treatment *** study aimed to investigate the value of the radiomic-clinical model in predicting the efficacy of the first TACE treatment for HCC to prolong patient ***:A total of 164 patients with HCC who underwent the first TACE from January 2017 to September 2021 were *** tumor response was assessed by modified response evaluation criteria in solid tumors(mRECIST),and the response of the first TACE to each session and its correlation with overall survival were *** radiomic signatures associated with the treatment response were identified by the least absolute shrinkage and selection operator(LASSO),and four machine learning models were built with different types of regions of interest(ROIs)(tumor and corresponding tissues)and the model with the best performance was *** predictive performance was assessed with receiver operating characteristic(ROC)curves and calibration ***:Of all the models,the random forest(RF)model with peritumor(+10 mm)radiomic signatures had the best performance[area under ROC curve(AUC)=0.964 in the training cohort,AUC=0.949 in the validation cohort].The RF model was used to calculate the radiomic score(Rad-score),and the optimal cutoff value(0.34)was calculated according to the Youden’s *** were then divided into a high-risk group(Rad-score>0.34)and a low-risk group(Rad-score≤0.34),and a nomogram model was successfully established to predict treatment *** predicted treatment response also allowed for significant discrimination of Kaplan-Meier *** Cox regression identified six independent prognostic factors for overall survival,including male[hazard ratio(HR)=0.500,95%confidence interva

关键词： Hepatocellular carcinoma Transarterial chemoembolization Radiomics Treatment response Prediction

Gut microbial interactions based on network construction and bacterial pairwise cultivation

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Science China(Life Sciences) 2024年第8期67卷 1751-1762页

作者： Min-Zhi jiang Chang Liu Chang Xu He jiang Yulin Wang Shuang-jiang Liu State Key Laboratory of Microbial Technology Shandong UniversityQingdao 266000China State Key Laboratory of Microbial Resources and Environmental Microbiology Research Center(EMRC)Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

Association networks are widely applied for the prediction of bacterial interactions in studies of human gut ***,the experimental validation of the predicted interactions is challenging due to the complexity of gut microbiomes and the limited number of cultivated *** this study,we addressed this challenge by integrating in vitro time series network(TSN)associations and cocultivation of TSN taxon *** samples were collected and used for cultivation and enrichment of gut microbiome on YCFA agar plates for 13 *** cells were harvested for DNA extraction and metagenomic sequencing.A total of 198 metagenome-assembled genomes(MAGs)were *** dynamics of bacteria growing on the YCFA agar were used to infer microbial association *** experimentally validate the interactions of taxon pairs in networks,we selected 24 and 19 bacterial strains from this study and from the previously established human gut microbial biobank,respectively,for pairwise *** co-culture experiments revealed that most of the interactions between taxa in networks were identified as neutralism(51.67%),followed by commensalism(21.67%),amensalism(18.33%),competition(5%)and exploitation(3.33%).Genome-centric analysis further revealed that the commensal gut bacteria(helpers and beneficiaries)might interact with each other via the exchanges of amino acids with high biosynthetic costs,short-chain fatty acids,and/or *** also validated 12 beneficiaries by adding 16 additives into the basic YCFA medium and found that the growth of 66.7%of these strains was significantly *** approach provides new insights into the gut microbiome complexity and microbial interactions in association *** work highlights that the positive relationships in gut microbial communities tend to be overestimated,and that amino acids,short-chain fatty acids,and vitamins are contributed to the positive relationships.

关键词： human gut microbiome gut microbial pairwise interaction co-culture association network microbial community

Hybrid Block Diagonalization Precoding for Multi-User Weighted Sum-Rate Maximization

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China Communications 2024年第8期21卷 127-141页

作者： Su Xiaofeng jiang Yi Key Laboratory for Information Science of Electromagnetic Waves(MoE) Department of Communication Science and EngineeringFudan UniversityShanghai 200433China

This paper studies large-scale multi-input multi-output(MIMO)orthogonal frequency division multiplexing(OFDM)communications in a broadband frequency-selective channel,where a massive MIMO base station(BS)communicates with multiple users equipped with *** develop a hybrid precoding design to maximize the weighted sum-rate(WSR)of the users by optimizing the digital and the analog precoders *** the digital part,we employ block-diagonalization to eliminate inter-user interference and apply water-filling power allocation to maximize the *** the analog part,the optimization of the PSN is formulated as an unconstrained problem,which can be efficiently solved by a gradient descent *** results show that the proposed block-diagonal hybrid precoding algorithm can outperform the existing works.

关键词： block-diagonal gradient descent hybrid precoding iterative optimization MIMO-OFDM multi-user water-filling power allocation weighted sum-rate maximization

CONVERGENCE OF MODIFIED TRUNCATED EULER-MARUYAMA METHOD FOR STOCHASTIC DIFFERENTIAL EQUATIONS WITH HOLDER DIFFUSION COEFFICIENTS

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Journal of Computational Mathematics 2024年第4期42卷 1109-1123页

作者： Guangqiang Lan Yu jiang College of Mathematics and Physics Beijing University of Chemical TechnologyBeijing 100029China

Convergence of modified truncated Euler-Maruyama(MTEM)method for stochastic differential equations(SDEs)with(1/2+α)-Holder continuous diffusion coefficients are investigated in this *** prove that the MTEM method for... 详细信息

关键词： Stochastic differential equations Modified truncated Euler-Maruyama method Strong convergence One-sided Lipschitz Holder continuous

Sounding the alarm:Functionally referential signaling in Azure-winged Magpie

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Avian Research 2024年第1期15卷 35-41页

作者： Xingyi jiang Yanyun Zhang Ministry of Education Key Laboratory for Biodiversity and Ecological Engineering College of Life SciencesBeijing Normal UniversityBeijing 100875China

Functionally referential signals are a complex form of communication that conveys information about the external *** signals have been found in a range of mammal and bird species and have helped us understand the complexities of animal *** are well known for their extraordinary cognitive abilities,but relatively little attention has been paid to their vocal ***,we investigated the functionally referential signals of a cooperatively breeding corvid species,Azure-winged Magpie(Cyanopica cyanus).Through field observations,we suggest that Azure-winged Magpie uses referential alarm calls to distinguish two types of threats:’rasp’ calls for terrestrial threats and ’chatter’ calls for aerial threats.A playback experiment revealed that Azure-winged Magpies responded to the two call types with qualitatively different *** sought cover by flying into the bushes in response to the ’chatter’ calls,and flew to or stayed at higher positions in response to ’rasp’ calls,displaying a shorter response time to ’chatter’ *** differences in acoustic structure were found between the two types of *** the extensive cognitive abilities of corvids and the fact that referential signals were once thought to be unique to primates,these findings are important for expanding our understanding of social communication and language evolution.

关键词： Alarm call Animal communication Azure-winged Magpie Referential signal

General formalism for dirty extreme-mass-ratio inspirals

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Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 22-29页

作者： Ye jiang Wen-Biao Han Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China Shanghai Frontiers Science Center for Gravitational Wave Detection Shanghai 200240China

Detecting the environment around the supermassive black holes and tests of general relativity are important applications of extreme-mass-ratio inspirals(EMRIs).There is still a challenge to efficiently describe various“dirty”impacts on the inspirals,such as dark matter,gas,dipole radiation,and electromagnetic *** this study,we find the inherent linearity of the asymptotic solution of the inhomogeneous Teukolsky *** the basis of this property,we completely decouple the factors of the perturber and the background spacetime in the energy fluxes and *** the new decoupling form,the waveforms of EMRIs with non-geodesic motion in Kerr spacetime can be conveniently *** will help to resolve the environment(including gas,field,dark matter,electromagnetic interaction)around supermassive black holes and test general relativity.

关键词： gravitational wave Teukolsky equation extreme-mass-ratio inspirals