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Neural Regeneration Research 2024年第11期19卷 2335-2336页

作者： Ibrahim Olabayode Saliu guoyan zhao Department of Genetics Washington University School of MedicineSt.LouisMOUSA Department of Neurology Department of Pathology and ImmunologyWashington University School of MedicineSt.LouisMOUSA

Astrocytes are a major glial cell type in the central nervous system,and they provide trophic and metabolic support to *** addition to these roles,they play crucial roles in modulating synaptic functions,development,and pruning(Brandebura et al.,2023).Astrocytes become reactive(activated)by undergoing morphological,molecular,and functional alterations in response to neuropathology such as in injuries and neurodegenerative diseases(NDs)(Escartin et al.,2021).

关键词： degenerative injuries

Novel stacking models based on SMOTE for the prediction of rockburst grades at four deep gold mines

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Underground Space 2024年第6期19卷 169-188页

作者： Peng Xiao Zida Liu guoyan zhao Pengzhi Pan State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan 430071China School of Resources and Safety Engineering Central South UniversityChangsha 410083China

Rockburst is a frequently encountered hazard during the production of deep gold *** prediction of rockburst is an important measure to prevent rockburst in gold *** study considers seven indicators to evaluate rockburst at four deep gold *** research and rock tests were performed at two gold mines in China to collect these seven indicators and rockburst *** collected database was oversampled by the synthetic minority oversampling technique(SMOTE)to balance the categories of rockburst *** models combining tree-based models and logistic regression(LR)were established by the balanced *** datasets from another two deep gold mines were implemented to verify the applicability of the predictive *** stacking model combining extremely randomized trees and LR based on SMOTE(SMOTE-ERT-LR)was the best model,and it obtained a training accuracy of 100%and an evaluation accuracy of 100%.Moreover,model evaluation suggested that SMOTE can enhance the prediction performance for weak rockburst,thereby improving the overall ***,sensitivity analysis was performed for *** results indicated that the SMOTE-ERT-LR model can achieve satisfactory performance when only depth,maximum tangential stress index,and linear elastic energy index were available.

关键词： Rockburst prediction Gold mine Stacking model SMOTE

Hybrid stacking ensemble algorithm and simulated annealing optimization for stability evaluation of underground entry-type excavations

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Underground Space 2024年第4期17卷 25-44页

作者： Leilei Liu guoyan zhao Weizhang Liang Zheng Jian School of Resources and Safety Engineering Central South UniversityChangsha 410083China

The stability of underground entry-type excavations(UETEs)is of paramount importance for ensuring the safety of mining *** more engineering cases are accumulated,machine learning(ML)has demonstrated great potential for the stability evaluation of *** this study,a hybrid stacking ensemble method aggregating support vector machine(SVM),k-nearest neighbor(KNN),decision tree(DT),random forest(RF),multilayer perceptron neural network(MLPNN)and extreme gradient boosting(XGBoost)algorithms was proposed to assess the stability of ***,a total of 399 historical cases with two indicators were collected from seven ***,to pursue better evaluation performance,the hyperparameters of base learners(SVM,KNN,DT,RF,MLPNN and XGBoost)and meta learner(MLPNN)were tuned by combining a five-fold cross validation(CV)and simulated annealing(SA)*** on the optimal hyperparameters configuration,the stacking ensemble models were constructed using the training set(75%of the data).Finally,the performance of the proposed approach was evaluated by two global metrics(accuracy and Cohen’s Kappa)and three within-class metrics(macro average of the precision,recall and F1-score)on the test set(25%of the data).In addition,the evaluation results were compared with six base learners optimized by *** hybrid stacking ensemble algorithm achieved better comprehensive performance with the accuracy,Kappa coefficient,macro average of the precision,recall and F1-score were 0.92,0.851,0.885,0.88 and 0.883,*** rock mass rating(RMR)had the most important influence on evaluation ***,the critical span graph(CSG)was updated based on the proposed model,representing a significant improvement compared with the previous *** study can provide valuable guidance for stability analysis and risk management of ***,it is necessary to consider more indicators and collect more extensive and balanced dataset to validate the model in futur

关键词： Underground entry-type excavations(UETEs) Hybrid stacking ensemble Machine learning Simulated annealing Critical span graph Base and meta learners

Effect of injection scheme on asymmetric phenomenon in rectangular and circular scramjets

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Chinese Journal of Aeronautics 2023年第1期36卷 216-230页

作者： Guangwei MA Mingbo SUN guoyan zhao Changhai LIANG Hongbo WANG Jiangfei YU Science and Technology on Scramjet Laboratory National University of Defense TechnologyChangsha 410073China

The asymmetric separation has a crucial effect on the performance of the *** this study,the asymmetric separation and combustion in both rectangular and circular scramjets are investigated numerically,and the effect of injection scheme is *** characteristics of the flow field are analyzed based on sufficient code *** the rectangular scramjet,the separation tends to occur in the corner due to the corner boundary-layer *** separation is asym-metric and only two corners have serious *** fuel penetration depth in the separation zone increases and the combustion is *** the injection scheme is uniform,both the combustion and separation become *** the circular scramjet,the separation and combustion are basically axisymmetric in the scramjet with one-row injection *** asymmetric combustion becomes obvious in cases with multi-row injection *** the injection orifices distribute intensively on the top and bottom sides,the strongest and weakest separations occur near these two sides *** the distribution of orifices becomes uniform,the direction of separation cannot be *** multi-row cases,the nonuniform injection scheme could result in violent combustion and asymmetric flow structures compared with the uniform injection scheme.

关键词： Asymmetric phenomenon Cavity Combustion Injection scheme Scramjet Supersonic

Review and Evaluate the Bioinformatics Analysis Strategies of ATAC-seq and CUT&Tag Data

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Genomics, Proteomics & Bioinformatics 2024年第3期22卷 11-27页

作者： Siyuan Cheng Benpeng Miao Tiandao Li guoyan zhao Bo Zhang Department of Developmental Biology Center of Regenerative MedicineWashington University School of MedicineSt.LouisMO 63108USA Department of Genetics Washington University School of MedicineSt.LouisMO 63108USA Department of Neurology Washington University School of MedicineSt.LouisMO 63108USA Department of Pathology and Immunology Washington University School of MedicineSt.LouisMO 63108USA

Efficient and reliable profiling methods are essential to study ***5,one of the first identified prokaryotic transposases with high DNA-binding and tagmentation efficiency,is widely adopted in different genomic and epigenomic protocols for high-throughputly exploring the genome and *** on Tn5,the Assay for Transposase-Accessible Chromatin using sequencing(ATAC-seq)and the Cleavage Under Targets and Tagmentation(CUT&Tag)were developed to measure chromatin accessibility and detect DNA–protein *** methodologies can be applied to large amounts of biological samples with low-input levels,such as rare tissues,embryos,and sorted single ***,fast and proper processing of these epigenomic data has become a bottleneck because massive data production continues to increase ***,inappropriate data analysis can generate biased or misleading ***,it is essential to evaluate the performance of Tn5-based ATAC-seq and CUT&Tag data processing bioinformatics tools,many of which were developed mostly for analyzing chromatin immunoprecipitation followed by sequencing(ChIP-seq)***,we conducted a comprehensive benchmarking analysis to evaluate the performance of eight popular software for processing ATAC-seq and CUT&Tag *** compared the sensitivity,specificity,and peak width distribution for both narrow-type and broad-type peak *** also tested the influence of the availability of control IgG input in CUT&Tag data ***,we evaluated the differential analysis strategies commonly used for analyzing the CUT&Tag *** study provided comprehensive guidance for selecting bioinformatics tools and recommended analysis strategies,which were implemented into Docker/Singularity images for streamlined data analysis.

关键词： Tn5 transposase Epigenetic Bioinformatics ATAC-seq CUT&Tag

Mixing and combustion characteristics in a scramjet combustor with different distances between cavity and backward-facing step

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Chinese Journal of Aeronautics 2023年第7期36卷 400-411页

作者： Mingjiang LIU Mingbo SUN Daoning YANG guoyan zhao Tao TANG Bin AN Hongbo WANG Science and Technology on Scramjet Laboratory National University of Defense TechnologyChangsha 410073China Department of Aerospace Science and Technology Space Engineering UniversityBeijing 101416China

The mixing and combustion characteristics in a cavity flameholding combustor under inlet Mach number 2.92 are numerically investigated with ethylene *** distance is defined as the ratio of the actual distance to the height of the combustor *** cavity shear-layer mode,the lifted cavity shear-layer mode,and jet wake mode with upstream separation are observed respectively with dimensionless distance equals to 1.5,4.5,and *** both non-reacting and reacting flow fields,the numerical results are essentially in agreement with the schlieren photography,flame chemiluminescence images,and wall pressure,which verify the reliability of the numerical *** results of non-reacting flow fields show that the BackwardFacing Step(BFS)can promote the flow separation downstream at a fixed *** more forward the separation position is,the larger the separation zone is in the non-reacting flow ***,the larger the separation zone is,the higher the intensity of combustion in the reacting flow field is.A reasonable distance can reduce the total pressure loss generated by the shock waves in the *** flame presents remarkable three-dimensional characteristics in the reacting flow *** dimensionless distance equals to 4.5,there are flames near the side wall above the cavity and it is difficult for the flame stabilization in the center of the combustor,while the combustion intensity in the center of the combustor is higher than that near the side wall when dimensionless distance equals to *** the cavity flameholding combustors with a backward-facing step,the higher combustion intensity may bring much total pressure loss to the ***,it is a good choice to achieve better thrust performance when dimensionless distance equals to 4.5 compared to the other two combustors.

关键词： Backward-facing step Cavity Combustion Scramjet combustor Supersonic flow

SMART/ASTC dynamic soft reduction technology and its application on the bloom continuous caster at Pangang

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Journal of University of Science and Technology Beijing 2006年第2期13卷 121-124页

作者： Guijun Li Kaijian Zhang Chuanfi Han Yong Chen guoyan zhao Kaike Cai Metallurgical and Ecological Engineering School University of Science and Technology Beijing Beijing 100083 China Panzhihua Iron ＆ Steel Co. Panzhihua Sichuan 617000 China

The SMART/ASTC dynamic soft reduction technology of VAI and its application on the 6-strand bloom continuous caster at Pangang, China are presented. The operation results show that soft reduction technology is effective to improve the inner quality of continuously cast blooms. At Pangang, both the central porosity and the central segregation ratings are no more than 1.0, the central shrinkage cavity rating is no more than 0.5, and the central segregation index of carbon is no more than 1.05. Rails made from the blooms have excellent quality and are used for high-speed tracks.

关键词： bloom continuous casting dynamic soft reduction heavy rail steel

Flamelet-like models applied in scramjet combustors:A state of art and prospect

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Chinese Journal of Aeronautics 2023年第10期36卷 24-43页

作者： Tao TANG Zhenguo WANG Yuhui HUANG Mingbo SUN Hongbo WANG guoyan zhao Jiangfei YU College of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073China Equipment Project Management Center Equipment Development DepartmentBeijing 100089China

Developing supersonic combustion models with efficiency,accuracy and practicality is important foundation to deeply understand the complex combustion processes in scramjet *** by efficiency and intuition,the flamelet-like models are widely used models in computational combustion ***,the supersonic combustion flow field has the nature of strong compressibility,multiple modality,and multiple scales,which poses a great challenge to the traditional flamelet-like models with fixed boundary conditions,and then the complex chemical reaction mechanisms that may face will impose additional computational *** this context,this paper reviews the flamelet-like models used in scramjet engines,and summarizes prominent issues in the application practice,including modeling partially premixed combustion,defining progress variable,solving temperature efficiently,evaluating assumed Probability Density Function(PDF)models,and treating mixture fraction ***,possible prospects and directions of improvements are proposed and highlighted for the flamelet-like *** fully describe the physicochemical scenario and address the raised challenges,these improvements are dedicated to dealing with the compressibility,temperature rise,time-scales,species of interest,multi-inlet combustion,the progress variable definition,and the higher Mach number flight condition.

关键词： Combustion model Flamelet-like model Model improvements Supersonic combustion Scramjet

A novel Lactococcus lactis L-arabinose isomerase for D-tagatose production from lactose

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Food Bioscience 2022年第4期48卷 339-348页

作者： Susu Zhang Zhenshang Xu Ming Ma guoyan zhao Runlei Chang Hongli Si Meixue Dai College of Life Science Shandong Normal UniversityJinan250014PR China State Key Laboratory of Biobased Material and Green Papermaking Qilu University of TechnologyShandong Academy of ScienceJinan250353PR China Shandong Provincial Key Laboratory of Microbial Engineering Department of BioengineeringQilu University of TechnologyShandong Academy of ScienceJinan250353PR China

A new strain of Lactococcus lactis producing D-tagatose was isolated and *** L-arabinose isomerase coding gene was cloned and expressed in Escherichia coli BL21(DE3).The optimal temperature and pH of the purified enzyme were 50◦C and *** produce D-tagatose from lactose,β-D-galactosidases from ***,Lactiplantibacillus plantarum,and Streptococcus thermophilus were further incorporated into *** by two ***β-D-galactosidases were fused to L-arabinose isomerase coupled with a peptide linker(GGGGS)***,they were co-expressed with L-arabinose isomerase using pETDuet-1 *** these recombinant strains,the cell co-expressing L-arabinose isomerase and ***β-D-galactosidase showed maximal ***-PAGE results confirmed that exogenous enzymes had the maximum soluble expression level in this *** the optimal condition,the conversion rate of D-tagatose from 300 g/L lactose achieved to 42.4%,and the volumetric productivity reached 4.28 g/L/h at 15 *** research established a highly efficient biotransformation system to produce D-tagatose from lactose.

关键词： Lactose D-tagatose Lactic acid bacteria L-arabinose isomerase β-D-galactosidase

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平行黏结模型中细观参数对宏观特性影响研究

岩石力学与工程学报 2012年第7期31卷 1491-1498页

作者：赵国彦戴兵马驰中南大学资源与安全工程学院湖南长沙410083

采用理论分析与数值模拟相结合的方法,对平行黏结模型中细观参数对宏观特性的影响进行系统研究。首先通过理论研究,定性提出细观参数与宏观特性的理论公式,然后运用PFC2D数值模拟,定量地给出两者之间的关系式。研究表明:(1)计算模型宏... 详细信息

采用理论分析与数值模拟相结合的方法,对平行黏结模型中细观参数对宏观特性的影响进行系统研究。首先通过理论研究,定性提出细观参数与宏观特性的理论公式,然后运用PFC2D数值模拟,定量地给出两者之间的关系式。研究表明:(1)计算模型宏观弹性模量主要由颗粒接触杨氏模量和颗粒黏结杨氏模量决定,且与二者均呈线性关系,同时受颗粒接触法向刚度与切向刚度之比、颗粒黏结法向刚度与切向刚度之比及颗粒尺寸的影响,且均呈对数关系;(2)泊松比主要由颗粒刚度决定,且呈对数关系,受颗粒尺寸的影响较小;(3)抗压强度由颗粒黏结应力比τb,m/σb,m决定,受颗粒摩擦因数的影响轻微,当0<τb,m/σb,m<2时,抗压强度主要受τb,m的影响,当τb,m/σb,m≥2时,抗压强度主要受σb,m的影响。并给出具有一定参考意义的相关关系式,结合实例进一步对相关分析式的可靠性进行论证。研究成果对快速、合理确定PFC模型细观参数具有指导意义。

关键词：数值分析平行黏结模型细观参数宏观特性