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Flow reconstructions and aerodynamic shape optimization of turbomachinery blades by POD-based hybrid models

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Science China(Technological Sciences) 2017年第11期60卷 1658-1673页

作者： luo JiaQi ZHU YaLu TANG xiao LIU Feng Department of Aeronautics and Astronautics Peking University Department of Mechanical and Aerospace Engineering University of CaliforniaIrvineCA 92697-3975USA

This study presented a hybrid model method based on proper orthogonal decomposition(POD) for flow field reconstructions and aerodynamic design optimization. The POD basis modes have better description performance in a system space compared to the widely used semi-empirical basis functions because they are obtained through singular value decomposition of the *** of the widely used linear regression, nonlinear regression methods are used in the function response of the coefficients of POD basis modes. Moreover, an adaptive Latin hypercube design method with improved space filling and correlation based on a multi-objective optimization approach was employed to supply the necessary samples. Prior to design optimization, the response performance of POD-based hybrid models was first investigated and validated through flow reconstructions of both single-and multiple blade rows. Then, an inverse design was performed to approach a given spanwise flow turning distribution at the outlet of a turbine blade by changing the spanwise stagger angle, based on the hybrid model method. Finally, the span wise blade sweep of a transonic compressor rotor and the spanwise stagger angle of the stator blade of a single low-speed compressor stage were modified to reduce the flow losses with the constraints of mass flow rate, total pressure ratio, and outlet flow *** results are presented in detail, demonstrating the good response performance of POD-based hybrid models on missing data reconstructions and the effectiveness of POD-based hybrid model method in aerodynamic design optimization.

关键词： flow reconstruction aerodynamic design optimization proper orthogonal decomposition turbomachinery hybrid model computational fluid dynamics transonic

Influence of electronic structure on Compton scattering through comparing Cu-Ni alloys with Cu-Ni powder mixtures

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Acta Metallurgica Sinica(English Letters) 2012年第1期25卷 55-64页

作者： Guang luo Xianquan HU Guangyu xiao Chunyang KONG College of Physics and Electronic Engineering Chongqing Normal UniversityChongqing 400047China

The application fields of Compton scattering have been further broadened through the studies of theories and experiments as well as the electronic structure of the scatters. The relationship between the contents of binary alloys （also binary powder mixtures） and the number of Compton scattered photons has been thoroughly examined. The linear expression of the relationship has been obtained approximately according to the Compton scattering theory. And the relationship has been validated well through the Compton scattering experiments with the scatters of Cu-Ni binary alloys or Cu- Ni binary powder mixtures. Furthermore, it is found that the slope of Cu-Ni powder mixture series is steeper than that of Cu-Ni alloy series, and through the pseudopotential plane wave theory of DFT the microscopic principles of Compton scattering of Cu-Ni alloy and Cu-Ni powder mixture series have been discussed and compared with each other. The results show that the electronic structure is the main reason for the difference of the linear slopes, and the line slope of Cu-Ni powder mixtures series is steeper than that of Cu-Ni alloy series.

关键词： Compton scattering Microscopic principle Cu-Ni Line slope

Temperature dependence in tensile properties and deformation behavior of GH4169 alloy

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Journal of Iron and Steel Research International 2023年第12期30卷 2566-2581页

作者： Qi Zheng Tian Liu Jia-bo Wei Rui luo Yi-ming Zhou Heng-nan ding Le-li Chen di Zhang xiao-nong Cheng School of Materials Science and Engineering Jiangsu UniversityZhenjiang212013JiangsuChina Yangtze Delta Region Institute of Advanced Materials Suzhou215100JiangsuChina State Key Laboratory of Advanced Metals and Materials University of Science and Technology BeijingBeijing100083China

The effect of temperature on the tensile properties and deformation mechanism of GH4169 alloy has been systematically studied over a wide range of room temperature(RT)to 1000℃.The results indicate that the stress–strain curve of the alloy shows serrations at 200–600℃,and the character of the serrations changes from type A to type B and then to type C at different *** ultimate tensile strength of the alloy decreases gradually from RT to 600℃.The yield strength decreases slowly from RT to 700℃ but decreases rapidly above 800℃.Transmission electron microscopy analysis relieves that the primary deformation mechanism of the alloy below 500℃ is Orowan bypass *** temperatures between 600 and 700℃,the coordinated deformation of twins and cross-slip of dislocations are *** transformation of\upgamma^{\prime\prime}phase toδphase above 650℃ will decrease the *** primary deformation mechanism above 800℃ transforms into the repeated shearing of\upgamma^{\prime\prime}by dislocations to form multiple stacking *** grains were observed above 800℃,and continuous dynamic recrystallization and discontinuous dynamic recrystallization were *** stress concentration caused by Nb-rich carbides is the cause of intracrystalline crack *** 700℃,grain boundary crack sprouting is caused by the combined effect of slip band impact on grain boundaries and grain boundary dislocation *** relationship between the serrated flow behavior and the deformation mechanism has been discussed based on the experimental results.

关键词： GH4169 alloy Tensile property Deformation mechanism Serrated flow

Strategic games on a hierarchical network model

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第2期9卷 271-278页

作者： Yi-xiao LI xiao-gang JIN Fan-sheng KONG Hui-lan luo Institute of Artificial Intelligence Zhejiang University Hangzhou 310027 China Ningbo Institute of Technology Zhejiang University Ningbo 315100 China

Among complex network models,the hierarchical network model is the one most close to such real networks as world trade web,metabolic network,WWW,actor network,and so *** has not only the property of power-law degree distribution,but also the scaling clustering coefficient property which Barabási-Albert(BA)model does not *** model is a model of network growth based on growth and preferential attachment,showing the scale-free degree distribution *** this paper,we study the evolution of cooperation on a hierarchical network model,adopting the prisoner's dilemma(PD)game and snowdrift game(SG)as metaphors of the interplay between connected *** model provides a unifying framework for the emergence of *** interestingly,we found that on hierarchical model,there is no sign of cooperation for PD game,while the fre-quency of cooperation decreases as the common benefit decreases for *** comparing the scaling clustering coefficient prop-erties of the hierarchical network model with that of BA model,we found that the former amplifies the effect of *** different performances of PD game and SG on complex network,we also found that common benefit leads to cooperation in the *** our study may shed light on the emergence of cooperation in both natural and social environments.

关键词： Complex network Hierarchical network model Barabási-Albert (BA) model Prisoner's dilemma (PD) game Snowdrift game (SG)

Analysis of hospitalization costs related to fall injuries in elderly patients

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World Journal of Clinical Cases 2021年第6期9卷 1271-1283页

作者： Fei-Yue Su Mei-Ling Fu Qing-Hua Zhao Huan-Huan Huang di luo Ming-Zhao xiao Department of Urology The First Affiliated Hospital of Chongqing Medical UniversityChongqing 400016China Department of Medical Insurance The First Affiliated Hospital of Chongqing Medical UniversityChongqing 400016China Department of Nursing The First Affiliated Hospital of Chongqing Medical UniversityChongqing 400016China

BACKGROUND With the aging world population,the incidence of falls has intensified and fallrelated hospitalization costs are *** are one type of event studied in the health economics of patient safety,and many developed countries have conducted such research on fall-related hospitalization ***,China,a developing country,still lacks large-scale studies in this *** To investigate the factors related to the hospitalization costs of fall-related injuries in elderly inpatients and establish factor-based,cost-related *** A retrospective study was *** information and cost data for elderly inpatients(age≥60 years,n=3362)who were hospitalized between 2016 and 2019 due to falls was collected from the medical record systems of two grade-A tertiary hospitals in *** regression(QR)analysis was used to identify the factors related to fall-related hospitalization costs.A decision tree model based on the chi-squared automatic interaction detector algorithm for hospitalization cost grouping was built by setting the factors in the regression results as separation *** The total hospitalization cost of fall-related injuries in the included elderly patients was 180479203.03 RMB,and the reimbursement rate of medical benefit funds was 51.0%(92039709.52 RMB/180479203.03 RMB).The medical material costs were the highest component of the total hospitalization cost,followed(in order)by drug costs,test costs,treatment costs,integrated medical service costs and blood transfusion costs The QR results showed that patient age,gender,length of hospital stay,payment method,wound position,wound type,operation times and operation type significantly influenced the inpatient cost(P<0.05).The cost grouping model was established based on the QR results,and age,length of stay,operation type,wound position and wound type were the most important influencing factors in the ***,the cost of each combination varied significan

关键词： Falls Elderly Hospitalization costs Quantile regression model Decision tree model Prevention

5-Aza-2'-deoxycytidine inhibits retinoblastoma cell by reactivating epigenetically silenced RASSF1A gene

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International Journal of Ophthalmology(English edition) 2014年第1期7卷 51-56页

作者： Ru Liu xiao-Huan Zhang Kun Zhang Wei Li Wen-Jun Wang di-Xian luo Ling Gao Department of Ophthalmology the Second Xiangya Hospital Central South University Department of Ophthalmology the First People's Hospital of Chenzhou City Institute of Translational Medicine the First People's Hospital of Chenzhou City

AIM: To investigate the effect of 5-Aza-2’-deoxycytidine(5-Aza-CdR),a DNA methyltransferase(DNMT) inhibitor,on the growth and survival of the Chinese retinoblastoma(RB) cell line HXO-RB44. ·METHODS: The DNA methylation status of the Ras association domain family(RASSF1A) promoter in the presence of 5-Aza-CdR at different concentrations was analyzed by methylation-specific polymerase chain reaction(MSP). RASSF1A mRNA and protein levels were measured by semiquantitative RT-PCR and immunohistochemistry staining,respectively,when cells were treated with 5.0μmol/L of 5-Aza-CdR. The effect of 5.0μmol/L 5-Aza-CdR on the proliferation and viability of HXO-RB44 cells was examined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay and flow cytometry. ·RESULTS: 5-Aza-CdR efficiently induced cell cycle arrest at G0 /G1 and apoptotic death in HXO-RB44 cells. MSP analysis showed that unmethylated RASSF1A DNA increased and methylated RASSF1A decreased in a dose-dependent manner in a range of 0.5-5.0μmol/L 5-Aza-CdR. Accordingly,RASSF1A expression was reactivated at both mRNA and protein levels. Incubation time of 5-Aza-CdR treatment also functioned as a factor for the demethylation status of RASSF1A promoter DNA,with a plateau on day four. 5-Aza-CdR at 5.0μmol/L completely demethylated the RASSF1A promoter in HXORB44 cells on day four,and as a result,RASSF1A expression increased significantly from day 4 to day 7.·CONCLUSION: 5-Aza-CdR inhibits the growth of the HXO-RB44 RB cell line and induces apoptosis by demethylating the RASSF1A gene.

关键词： 5-Aza-2'-deoxycytidine retinoblastoma methylation apoptosis Ras association domain family

Hybrid model for muon tomography and quantitative analysis of image quality

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Nuclear Science and Techniques 2022年第7期33卷 1-13页

作者： Si-Yuan luo Yu-He Huang Xuan-Tao Ji Lie He Wan-Cheng xiao Feng-Jiao luo Song Feng Min xiao xiao-Dong Wang School of Nuclear Science and Technology University of South ChinaHengyang 421001China

Muon tomography is a novel method for the non-destructive imaging of materials based on muon rays,which are highly penetrating in natural background ***,the most commonly used imaging methods include muon radiography and muon tomography.A previously studied method known as coinciding muon trajectory density tomography,which utilizes muonic secondary particles,is proposed to image low and medium atomic number(Z)***,scattering tomography is mostly used to image high-Z materials,and coinciding muon trajectory density tomography exhibits a hollow phenomenon in the imaging results owing to the self-absorption *** address the shortcomings of the individual imaging methods,hybrid model tomography combining scattering tomography and coinciding muon trajectory density tomography is proposed and *** addition,the peak signal-to-noise ratio was introduced to quantitatively analyze the image *** imaging models were simulated using the Geant4 toolkit to confirm the advantages of this innovative *** simulation results showed that hybrid model tomography can image centimeter-scale materials with low,medium,and high Z *** high-Z materials with similar atomic numbers,this method can clearly distinguish those with apparent differences in *** to the peak signal-to-noise ratio of the analysis,the reconstructed image quality of the new method was significantly higher than that of the individual imaging *** study provides a reliable approach to the compatibility of scattering tomography and coinciding muon trajectory density tomography.

关键词： Monte Carlo simulation Muon tomography Image reconstruction

Seminal Plasma Biochemical Components Mediate the Inverse Association of Microcystin Exposure with Sperm Motility:A Mediation Analysis in Chinese Men

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Biomedical and Environmental Sciences 2023年第5期36卷 463-468页

作者： XU di Hui MA Yu Han YU Wen ZHOU Xue luo Yang CHEN Ya Bing HAN xiao Dong Immunology and Reproduction Biology Laboratory&State Key Laboratory of Analytical Chemistry for Life Science Medical SchoolNanjing UniversityNanjing 210093JiangsuChina Jiangsu Key Laboratory of Molecular Medicine Nanjing UniversityNanjing 210093JiangsuChina Department of Andrology Affliated Drum Tower HospitalSchool of MedicineNanjing UniversityNanjing 210008JiangsuChina

Epidemiological studies suggest a global decline in male fertility, which accounts for approximately50% of infertility cases in couples. Male infertility is a multifactorial and complex issue that may arise due to con... 详细信息

关键词： infertility congenital fertility

Low-field NMR inversion based on low-rank and sparsity restraint of relaxation spectra

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Petroleum Science 2022年第6期19卷 2741-2756页

作者： Si-Hui luo Li-Zhi xiao Yan Jin Jiang-Feng Guo xiao-Bo Qu Zhang-Ren Tu Gang luo Can Liang College of Artificial Intelligence and College of Petroleum Engineering China University of PetroleumBeijing102249China State Key Laboratory of Petroleum Resources and Prospecting China University of PetroleumBeijing102249China School of Electronic Science and Engineering(National Model Microelectronics College) Xiamen UniversityFujian361005China School of Electronic Science and Engineering National Model Microelectronics College Xiamen University Changzhou Institute of Technology ChangzhouJiangsu213000China

In this paper,we proposed a novel method for low-field nuclear magnetic resonance(NMR)inversion based on low-rank and sparsity restraint(LRSR)of relaxation spectra,with which high quality construction is made possible for one-and two-dimensional low-field and low signal to noise ratio NMR *** this method,the low-rank and sparsity restraints are introduced into the objective function instead of the smoothing *** low-rank features in relaxation spectra are extracted to ensure the local characteristics and morphology of *** sparsity and residual term are contributed to the resolution and precision of spectra,with the elimination of the redundant relaxation *** process of the objective function is designed with alternating direction method of multiples,in which the objective function is decomposed into three subproblems to be independently *** optimum solution can be obtained by alternating iteration and updating *** first,numerical simulations are conducted on synthetic echo data with different signal-to-noise ratios,to optimize the desirable regularization parameters and verify the feasibility and effectiveness of proposed ***,NMR experiments on solutions and artificial sandstone samples are conducted and analyzed,which validates the robustness and reliability of the proposed *** results from simulations and experiments have demonstrated that the suggested method has unique advantages for improving the resolution of relaxation spectra and enhancing the ability of fluid quantitative identification.

关键词： Low-field NMR Inversion method Low-rank and sparsity restraint Relaxation spectra Data processing