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Probabilistic analysis of tunnel face seismic stability in layered rock masses using Polynomial Chaos Kriging metamodel

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第7期16卷 2678-2693页

作者： jianhong Man Tingting zhang Hong{{2. Huang Daniel Dias Department of Geotechnical Engineering Key Laboratory of Geotechnical and Underground Engineering of Ministry of EducationCollege of Civil EngineeringTongji UniversityShanghai200092China Grenoble Alpes 3SR LabCNRS UMR 5521Grenoble38000France

Face stability is an essential issue in tunnel design and *** rock masses are typical and ubiquitous;uncertainties in rock properties always *** view of this,a comprehensive method,which combines the Upper bound Limit analysis of Tunnel face stability,the Polynomial Chaos Kriging,the Monte-Carlo Simulation and Analysis of Covariance method(ULT-PCK-MA),is proposed to investigate the seismic stability of tunnel faces.A two-dimensional analytical model of ULT is developed to evaluate the virtual support force based on the upper bound limit *** efficient probabilistic analysis method PCK-MA based on the adaptive Polynomial Chaos Kriging metamodel is then implemented to investigate the parameter uncertainty *** input parameters,including geological strength indices,uniaxial compressive strengths and constants for three rock formations,and the horizontal seismic coefficients,are treated as random *** effects of these parameter uncertainties on the failure probability and sensitivity indices are *** addition,the effects of weak layer position,the middle layer thickness and quality,the tunnel diameter,the parameters correlation,and the seismic loadings are investigated,*** results show that the layer distributions significantly influence the tunnel face probabilistic stability,particularly when the weak rock is present in the bottom *** efficiency of the proposed ULT-PCK-MA is validated,which is expected to facilitate the engineering design and construction.

关键词： Tunnel face stability Layered rock masses Polynomial Chaos Kriging(PCK) Sensitivity index Seismic loadings

Time-dependent model for two-phase flow in ultra-high water-cut reservoirs: Time-varying permeability and relative permeability

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Petroleum science 2024年第4期21卷 2536-2553页

作者： Shao-Chun Wang Na zhang Zhi-Hao Tang Xue-Fei zou Qian Sun {{2. Liu college of Energy Resources Chengdu University of Technology college of Petroleum Engineering Shandong Institute of Petroleum and Chemical Technology

For the ultra-high water-cut reservoirs, after long-term water injection exploitation, the physical properties of the reservoir change and the heterogeneity of the reservoir becomes increasingly severe, which further aggravates the spatial difference of the flow field. In this study, the displacement experiments were employed to investigate the variations in core permeability, porosity, and relative permeability after a large amount of water injection. A relative permeability endpoint model was proposed by utilizing the alternating conditional expectation(ACE) transformation to describe the variation in relative permeability based on the experimental data. Based on the time dependent models for permeability and relative permeability, the traditional oil-water two-phase model was improved and discretized using the mimetic finite difference method(MFD). The two cases were launched to confirm the validation of the proposed model. The impact of time-varying physical features on reservoir production performance was studied in a real water flooding reservoir. The experimental results indicate that the overall relative permeability curve shifts to the right as water injection increases. This shift corresponds to a transition towards a more hydrophilic wettability and a decrease in residual oil saturation. The endpoint model demonstrates excellent accuracy and can be applied to time-varying simulations of reservoir physics. The impact of variations in permeability and relative permeability on the reservoir production performance yields two distinct outcomes. The time-varying permeability of the reservoir results in intensified water channeling and poor development effects. On the other hand, the time-varying relative permeability enhances the oil phase seepage capacity, facilitating oil displacement. The comprehensive time-varying behavior is the result of the combined influence of these two parameters, which closely resemble the actual conditions observed in oil field expl

关键词： Mimetic finite difference Water flooding reservoir Time-varying physical properties Numerical simulation

The characteristics of arc beam shaping in hybrid plasma and laser deposition manufacturing

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science china(Technological sciences) 2006年第2期49卷 238-247页

作者： zhang Hai’ou1, QIAN Yingping1,3. WANG Guilan1 & ZHENG Qiguang2.1. School of Material {2. and {2., Huazhong university of {2. and {2., Wuhan 43.074, china 2. Institute of Laser {2. and Engineering, Huazhong university of {2. and {2., Wuhan 43.074, china 3. Mechanical Engineering {12., Hubei university of {2., Wuhan 43.068, china 1. School of Material science and technology Huazhong University of Science and Technology Wuhan 430074 China 3. Mechanical Engineering college Hubei University of Technology Wuhan 430068 China 2. Institute of Laser technology and Engineering Huazhong University of Science and Technology Wuhan 430074 China

As a new direct metal prototyping technology,the hybrid plasma and laser deposition manufacturing (PLDM) is proposed in this paper. In order to figure out the characteristics of plasma arc beam and mould in the PLDM process of high temperature alloy, the high speed CCD camera is used to obtain the picture around the plasma arc. Afterwards the sketch of picture is clearly obtained. And the effect of laser parameter, such as average power, pulse width, pulse repetition frequency and the angle between laser beam and plasma arc beam on the plasma arc appearance, is studied experimentally. The results show that the modality of plasma arc beam is markedly influenced by laser beam. And the improvements of shape precision and surface state of the layer deposited by PLDM are confirmed.

关键词： plasma hybrid laser, direct deposition, plasma arc beam, molding character, high-temperature alloy.

A new family of windows——convolution windows and their applications

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science china(Technological sciences) 2005年第4期48卷 468-480页

作者： zhang Jieqiu1,2. LIANG Changhong1 & CHEN Yanpu{2.. Department of Applied Math. & Phys., {2. of science, Airforce Engineering university, Xi’an 710051, china 2. National Key Laboratory of Antennas and Microwave technology, Xidian university, Xi’an 710071, china 3. Computer Center, Xi’an Communication {2., Xi’an 710106, china 1. Department of Applied Math. & Phys. College of Science Airforce Engineering University 710051 Xi’an China 2. National Key Laboratory of Antennas and Microwave technology Xidian University 710071 Xi’an China 3. Computer Center Xi’an Communication College 710106 Xi’an China

A new family of windows is constructed by convolutions via a few rectangular windows with same time width and is thus referred to as convolution windows. The expressions of the second-order up to the eighth-order convolution windows in both the time and frequency domains are derived. Their applications in high accuracy harmonic analysis of periodic signals are investigated. Comparisons between the proposed windows and some known windows with the same width shows that, when the synchronous deviation of data sampling is slight, the proposed ones have the least effect of spectral leakage. Therefore, the new windows are well suited for high accuracy harmonic analysis and parameter estimation for periodic signals. The error analysis and computer simulations show that the estimation errors, corresponding to frequency, amplitude and phase of every harmonic component of a signal, are proportional to the pth power of the relative frequency deviation in case of the pth-order convolution window is applied to windowing signal of approximately p cycles. By introducing real time adjustment in sampling interval, the proposed algorithm can adaptively trace signal frequency and lead to less sampling synchronous deviation. The proposed approach has the advantages of easy implementation and high measure precision and can be used in harmonic analysis of quasi-periodic signals whose fundamental frequency drifts slowly with time.

关键词： signal processing harmonic analysis window function convolution window synchronous error spoctral leakage

Surface Nanocrystallization of Magnesium Alloy AZ91D by High-Energy Shot Peening

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Journal of Wuhan university of technology(Materials {{2.) 2009年第4期24卷 515-519页

作者：张津 School of Materials science & Engineering University of Science and Technology Beijing college of Materials science & Engineering Chongqing University of Technology

High-energy shot peening （HESP）, a method to produce severe plastic deformation by high velocity flying balls, was applied on die cast magnesium alloy AZ91D. Effects of surface nanocrystallization by HESP and heat treatment at different temperatures were investigated. The mi- crostructure evolution was conducted using X-ray diffraction （XRD） and field emission scanning electronic microscopy （FESEM）. The hardness was measured by microhardness tester. The experimental results show that surface nanocrystrallization of AZ91D obtained by HESP would lead to the increase of microhardness. Low temperature heated at 100℃ for 1 h do not change the property obviously. However, both the microstructure and microhardness vary greatly after heat treatment at 400℃ for 1 h.

关键词： AZ91 D surface nanocrystallization HESP microhardnss corrosion resistance

Down-regulation of microRNA-2.a promotes pancreatic ductal adenocarcinoma initiation and progression by up-regulation of FOXM1 expression

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Genes & Diseases 2024年第5期11卷 456-469页

作者： Lixin Liang Tian Cai Xiaojia Li jianhong An Sen Yu Yang zhang Fengjie Guo Fang {{2. Jie He Keping Xie Tingting Jiang Center for Pancreatic Cancer Research South China University of Technology School of MedicineGuangzhouGuangdong 510006China Department of Laboratory Medicine The Sixth Affiliated Hospital and Nanhai People’s HospitalSouth China University of Technology School of MedicineFoshanGuangdong 528200China The Second Affiliated Hospital and Guangzhou First People’s Hospital South China University of Technology School of MedicineGuangzhouGuangdong 510006China

Transcriptional factor Forkhead box M1(FOXM1)plays an important role in pancreatic ductal adenocarcinoma(PDAC)development and *** molecular mechanisms underlying its dysregulation remain *** identified and functionally validated the microRNAs(miRNAs)that critically regulate FOXM1 expression in *** expression levels of miRNA-2.a(miR-2.a-3. and-5p)were altered in PDAC cell lines and their effects on FOXM1 signaling and cell proliferation and migration and tumorigenesis were examined in vitro and in vivo using mouse PDAC *** with non-tumor pancreatic tissues,PDAC tissues and cell lines exhibited significantly reduced levels of miR-2.a *** miR-2.a expression and concomitant increase in FOXM1 expression were also observed in acinar-toductal metaplasia and pancreatic intraepithelial neoplasia,the major premalignant lesions of *** expression of miR-2.a reduced the expression of FOXM1 and suppressed cell proliferation and migration in PDAC cells,whereas the inhibitors of miR-2.a did the *** or reduced levels of miR-2.a increased the levels of FOXM1 expression,while increased expression of FOXM1 down-regulated miR-2.a expression,suggesting that miR-2.a and FOXM1 were mutual negative regulators of their expression in PDAC ***,the miR-2.a/FOXM1 signaling axis is important in PDAC initiation and progression and could serve as an interventional or therapeutic target for patients with early or late stages of PDAC.

关键词： FOXM1 Gene expression Gene regulation MicroRNA Pancreatic cancer Targeted therapy

Neuroglobin mutation associated with hypoxia adaptation in Tibet chicken

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Progress in Natural science:Materials International 2007年第12期17卷 1419-1424页

作者： zhang Lifan1, Liu Chong2. Lian Linsheng3. Zhao Chunjiang1, Bao Haigang1 and Wu Changxin1(1. {2. of Animal {2. and technology, china Agricultural university, Beijing 100094, china 2. {2. of Biological {2., china Agricultural university, Beijing 100094, china 3. {2. of Animal {2. and technology, Yunnan Agricultural university, Kunming 6502.1, china) college of Animal science and {{2. China Agricultural University Beijing 100094 China college of Biological science China Agricultural University Beijing 100094 China college of Animal science and {{2. Yunnan Agricultural University Kunming 650201 China

Globin protein family plays an important role in storing and transporting oxygen. As a newly reported globin, the revealed function of neuroglobin includes binding and storing oxygen as well as facilitating the utilization of oxygen in neuronal cells. In the present study, mutations in exons of chicken Ngb gene were identified with the method of sequencing and created restriction site PCR in Tibet chicken and other four lowland chicken breeds. The mutations of Lys-2.2.(E4)-Asn and Ser-2.79(E4)-Gly were identified in exon 4 of the gene. The Lys-2.2.(E4)-Asn mutation existed only in Tibet chicken and the mutation frequencies increased with increasing altitude. Analysis of the haplotype and diplotype of the two mutations in Tibet chicken populations of different altitudes showed that the frequencies of TG haplotype and TTGG diplotype also increased with increasing altitude, while the reverse tendency was found on GGAA diplotype. Under the hypoxic simulation incubation, the main haplotype was TG in living embryos and GA in dead embryos. The results showed that the Lys-2.2.(E4)-Asn mutation may be a specific mutation associated with hypoxia adaptation in Tibet chicken.

关键词： Tibet chicken neuroglobin hypoxia adaptation Ngb gene mutation.

High-resolution spatiotemporal mapping:a comprehensive view of eukaryotic cell cycle proteome dynamics

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Signal Transduction and Targeted Therapy 2024年第6期9卷 2354-2356页

作者： Jing zou Ziran Qin Long zhang Life sciences Institute Second Affiliated Hospital of the Zhejiang University School of MedicineThe MOE Key Laboratory of Biosystems Homeostasis&Protection and Zhejiang Provincial Key Laboratory for Cancer Molecular Cell BiologyZhejiang UniversityHangzhouZhejiangChina The MOE Basic Research and Innovation Center for the Targeted Therapeutics of Solid Tumors The First Affiliated HospitalJiangxi Medical CollegeNanchang UniversityNanchangChina Cancer Center Zhejiang UniversityHangzhouZhejiangChina

In a recent study published in Cell,Litsios et *** a highresolution spatiotemporal map of the eukaryotic cell cycle proteome.1 They identified proteome-level changes in both abundance and spatial distribution throughout the cell cycle and provided a valuable resource for future exploration into the global proteome dynamics that drive cell cycle progression(https://***/cellcycle).

关键词： al. cycle dynamics

Regulation of eight avr genes by hrpG and hrpX in Xanthomonas campestris pv. campestris and their role in pathogenicity

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Progress in Natural science:Materials International 2006年第12期16卷 1288-1294页

作者： XU Rongqi~ 1,3., LI Xianzhen~3. wei Hongyu~3. JIANG Bole~2. LI Kai~3. HE Yongqiang~ 2.3., FENG Jiaxun~ 1,3.and TANG Jiliang~ 1,2.**(1. Guangxi Key Laboratory of Subtropical Bioresources Conservation and Utilization 2. The Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering 3. college of Life {2. and technology, Guangxi university, Nanning 53.004, china) Guangxi Key Laboratory of Subtropical Bioresources Conservation and Utilization Guangxi University Nanning 530004 China college of Life science and {{2. Guangxi University Nanning 530004 China The Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering Guangxi University Nanning 530004 China

Eight putative avirulence genes in Xanthomonas campestris pv. campestris (Xcc) strain 8004 were characterized by Tn5gusA5 mutagenesis and gene expression analysis. The virulence test of mutants on Chinese radish showed that all mutants in individual avr genes except avrBs2.mutant were not significantly different from the wild type in virulence. The avrBs2.mutant showed reduced virulence and bacterial growth in planta. Gene expression analysis using β-glucuronidase as reporter indicated that avrBs1.1,avrBs1,avrXccB,avrXccC,avrXccE1 were regulated by hrpG, whereas avrXccA1, avrXccA2.and avrBs2.were not. RT-PCR analysis showed that all hrpG-regulated genes except avrBs1 were also regulated by hrpX. In addition, it was demonstrated that avrBs1 was responsible for elicitation of a type III dependent hypersensitive reaction (HR) on nonhost plant pepper ECW-10R, and wild type Xcc 8004 was unable to cause HR on pepper ECW-2.R.

关键词： Xanthomonas campestris pv. campestris avirulence gene virulence expression analysis.