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Variation of stress intensity factors for several interface crack problems under arbitrary material combinations

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Science China(Physics,Mechanics & Astronomy) 2012年第11期55卷 2128-2134页

作者： ZHANG Yu NODA nao-Aki LAN Xin TAKAISHI Ken-Taro Department of Mechanical Engineering Kyushu Institute of Technology1-1 Sensui-choTobata-kuKitakyushu-shiFukuoka804-8550Japan

In this paper the variation of interface stress intensity factors is considered under arbitrary material combinations for several problems such as central internal interface cracks, periodic interface cracks, and edge interface cracks. The stress intensity factors for all these problems have been determined in terms of Dundurs＇ parameters a, b by the application of FEM in the authors＇ previous papers. In this paper, the variations of the stress intensity factors for all these problems are discussed under arbitrary a, b, then the maximum and minimum values of dimensionless stress intensity factors FI,max, FII,max, FI,min, FII,max are indicated on the map of a, b. As an example, it is found that FI,max always appears when （a, b）= （0.2,0.3）, and FI,min always appears when （a, b）= （1,0）, for the central internal interface cracks independent of crack length.

关键词： Interface crack Stress intensity factor Fracture mechanics

Quantifying compliance with COVID-19 mitigation policies in the US: A mathematical modeling study

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Infectious Disease Modelling 2021年第1期6卷 503-513页

作者： nao Yamamoto Bohan Jiang Haiyan Wang School of Human Evolution and Social Change Arizona State UniversityTempeAZ85287USA School of Computing Informaticsand Decision Systems EngineeringArizona State UniversityTempeAZ85287USA School of Mathematical and Natural Sciences Arizona State UniversityPhoenixAZ85069USA

The outbreak of COVID-19 disrupts the life of many people in the *** response to this global pandemic,various institutions across the globe had soon issued their prevention *** in the US had also implemented social distancing ***,those policies,which were designed to slow the spread of COVID-19,and its compliance,have varied across the states,which led to spatial and temporal heterogeneity in COVID-19 *** paper aims to propose a spatio-temporal model for quantifying compliance with the US COVID-19 mitigation policies at a regional *** achieve this goal,a specific partial differential equation(PDE)is developed and validated with shortterm *** proposed model describes the combined effects of transboundary spread among state clusters in the US and human mobilities on the transmission of *** model can help inform policymakers as they decide how to react to future outbreaks.

关键词： COVID-19 Partial differential equation Validation Social distancing Google Community Mobility Reports

Genome-Wide Association Study Reveals Host Genetic Factors for Liver Diseases

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Journal of Clinical and Translational Hepatology 2013年第1期1卷 45-50页

作者： nao Nishida Katsushi Tokunaga Masashi Mizokami The Research Center for Hepatitis&Immunology National Center for Global Health and Medicine Ichikawa Chiba Japan Department of Human Genetics The University of Tokyo Bunkyo-ku Tokyo Japan Department of Human Genetics The University of Tokyo Bunkyo-ku Tokyo Japan The Research Center for Hepatitis&Immunology National Center for Global Health and Medicine Ichikawa Chiba Japan

A number of disease-associated genetic markers for common liver diseases have been identified using genome-wide association studies (GWASs). The GWAS strategy is based on genome-wide single-nucleotide polymorphism typing technologies, which are now commercially available, accom-panied by statistical methods to identify host genetic factors that are associated with target diseases or complex genetic traits. One of the most striking features of the GWAS strategy is the ability to identify unexpected disease-associated genetic markers across the entire human genome. Here, we describe the technological aspects of the GWAS strategy with examples from actual GWAS reports related to hepatitis research, including drug response for patients with chronic hepatitis C, susceptibility to primary biliary cirrhosis, and hepatitis-B-related hepatocellular carcinoma.

关键词： GWAS Hepatitis B infection Hepatitis C infection Primary biliary cirrhosis HLA-DP Hepatocellular carcinoma Host genetic factors

Dynamic recrystallization behavior and strengthening mechanism of a novel Mo-Ti_(3)AlC_(2) alloy at ultrahigh temperature

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Rare Metals 2024年第8期43卷 3946-3960页

作者： Lu Yang Xin-Yuan Zheng Yang Zhao Xi-Ran Wang Fang-nao Xiao Shi-Zhong Wei School of Materials Science and Engineering Henan University of Science and TechnologyLuoyang 471023China National Joint Engineering Research Center for Abrasion Control and Molding of Metal Materials Henan University of Science and TechnologyLuoyang 471003China Department of Applied Mechanics Univ.Bourgogne FrancheComteFEMTO-ST InstituteCNRS/UF/ENSMM/UTBM25000BesangonFrance

Increasing the recrystallization temperature to achieve better high-temperature performance is critical in the development of molybdenum alloys for ultrahightemperature applications,such as the newest generation of multitype high-temperature nuclear *** this study,an innovative strategy was proposed to improve the performance of molybdenum alloys at high temperature by using the two-dimensional MAX(where M is an early transition metal,A is an A-group element and X is C or N)ceramic material Ti_(3)AlC_(2).The relationships between flow stress,strain rate and temperature were *** microstructure,distribution of misorientation and evolution of dislocations in the Mo-Ti_(3)AlC_(2) alloy were *** microscopic mechanism of the Ti_(3)AlC_(2) phase in the molybdenum alloy at high temperatures was *** experimental results showed that the peak flow stress of Mo-Ti_(3)AlC_(2) at 1600℃ reached 155 MPa,which was161.8% greater than that of pure *** activation energy of thermal deformation of Mo-Ti_(3)AlC_(2) was as large as537 kJ·mol~(-1),which was 17.6% more than that of pure *** recrystallization temperature reached 1600℃ or even *** topological reaction of the Ti_(3)AlC_(2) phase consumed a large amount of energy at high temperatures,resulting in increases in the deformation activation *** structures of AlTi_3 and Ti-O Magneli-phase oxides(Ti_nO_(2n-1)) were formed in-situ,which relied on kink bands and interlayer slip,resulting in many dislocations during ***,the special two-dimensional of the structure Ti_(3)AlC_(2) ceramic inhibited the recrystallization behavior of the Mo *** results of this study can provide theoretical guidance for the development of a new generation of molybdenum alloys for use in ultrahigh-temperature environments.

关键词： Mo alloy Two-dimensional reinforcement Dynamic recrystallization behavior Hot deformation Mechanical properties

Visible-light-driven enhanced antibacterial and biofilm elimination activity of graphitic carbon nitride by embedded Ag nanoparticles

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Nano Research 2015年第5期8卷 1648-1658页

作者： Wei Bing Zhaowei Chen Hanjun Sun Peng Shi nao Gao Jinsong Ren Xiaogang Qu Laboratory of Chemical Biology Division of Biological Inorganic Chemistry State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied Chemistry University of Chinese Academy of Sciences Chinese Academy of Sciences Changchun Jilin 130022 China College of Life Science Jilin University Changchun Jilin 130012 China

Semiconductor nanomaterials with photocatalytic activity have potential for many applications. An effective way of promoting photocatalytic activity is depositing noble metal nanoparticles （NPs） on a semiconductor, since the noble metal NPs act as excellent electron acceptors which inhibit the quick recombination of the photoexcited electron-hole pairs and thereby enhance the generation of reactive oxygen species （ROS）. Herein, a highly effective platform, graphitic carbon nitride （g-C3N4） nanosheets with embedded Ag nanopartides （Ag/g-C3N4）, was synthesized by a facile route. Under visible light irradiation, the ROS production of Ag/g-C3N4 nanohybrids was greatly improved compared with pristine g-C3N4 nanosheets, and moreover, the nanohybrids showed enhanced antibacterial efficacy and ability to disperse bacterial biofilms. We demonstrate for the first time that the Ag/g-C3N4 nanohybrids are efficient bactericidal agents under visible light irradiation, and can also provide a new way for biofilm elimination. The enhanced antibacterial properties and biofilm-disrupting ability of Ag/g-C3N4 nanohybrids may offer many biomedical applications.

关键词： graphitic carbon nitride Ag/g-C3N4 nanohybrids antibacterial platform reactive oxygen species(ROS) biofilm

基于临界应力强度因子的胶接对接接头抗拉强度简便预测方法

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工程力学 2017年第11期34卷 218-224页

作者：李戎梁斌 NODA nao-Aki 河南科技大学土木工程学院河南洛阳471023 九州工业大学机械系日本北九州市804-8550

为了能够对胶接对接接头进行抗拉强度预测,该文以有限元分析方法为基础,通过利用参考问题的无量纲应力强度因子、接头模型与参考问题模型之间应力值的比值以及接头抗拉强度的试验数值,得到了胶接对接接头的临界应力强度因子数值,从而提... 详细信息

为了能够对胶接对接接头进行抗拉强度预测,该文以有限元分析方法为基础,通过利用参考问题的无量纲应力强度因子、接头模型与参考问题模型之间应力值的比值以及接头抗拉强度的试验数值,得到了胶接对接接头的临界应力强度因子数值,从而提出了一个基于临界应力强度因子的胶接对接接头抗拉强度的简便预测新方法。该方法能够在保证精确度的基础上快速计算出胶接对接接头的应力强度因子,通过使用任意某一胶层厚度时的抗拉强度试验数值预测出其他胶层厚度时对接接头的抗拉强度数值。通过三种胶接对接接头的算例对比分析,证明了该方法的预测结果与实际结果非常接近,预测精度良好,便于工程应用。

关键词：胶接对接接头粘结抗拉强度预测有限元分析方法临界应力强度因子胶层厚度

Influence of sampling on three-dimensional surface shape measurement

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中国光学（中英文） 2024年第6期17卷 1512-1520页

作者： QIAO nao-sheng Shang Xue International College Hunan University of Arts and ScienceChangde 415000China Mathematics and Physics Science College Hunan University of Arts and ScienceChangde 415000China

In order to accurately measure an object’s three-dimensional surface shape,the influence of sampling on it was ***,on the basis of deriving spectra expressions through the Fourier transform,the generation of CCD pixels was analyzed,and its expression was ***,based on the discrete expression of deformation fringes obtained after sampling,its Fourier spectrum expression was derived,resulting in an infinitely repeated"spectra island"in the frequency ***,on the basis of using a low-pass filter to remove high-order harmonic components and retaining only one fundamental frequency component,the inverse Fourier transform was used to reconstruct the signal strength.A method of reducing the sampling interval,i.e.,reducing the number of sampling points per fringe,was proposed to increase the ratio between the sampling frequency and the fundamental frequency of the *** was done to reconstruct the object’s surface shape more accurately under the condition of m>*** basic principle was verified through simulation and *** the simulation,the sampling intervals were 8 pixels,4 pixels,2 pixels,and 1 pixel,the maximum absolute error values obtained in the last three situations were 88.80%,38.38%,and 31.50%in the first situation,respectively,and the corresponding average absolute error values are 71.84%,43.27%,and 32.26%.It is demonstrated that the smaller the sampling interval,the better the recovery *** the same four sampling intervals in the experiment as in the simulation can also lead to the same *** simulated and experimental results show that reducing the sampling interval can improve the accuracy of object surface shape measurement and achieve better reconstruction results.

关键词： three-dimensional surface shape measurement sampling interval spectra overlapping measurement accuracy

A patient with spinal metastasis from hepatocellular carcinoma discovered from neurological findings

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World Journal of Gastroenterology 2007年第19期13卷 2758-2760页

作者： Katsuyoshi Tamaki Ichiro Shimizu Mari Urata nao Kohno Hiroshi Fukuno Susumu Ito Nobuya Sano Department of Digestive and Cardiovascular Medicine Institute of Health Biosciences The University of Tokushima Graduate School Japan Division of Pathology Tokushima University Hospital Tokushima Japan

Although spinal tumors are uncommon, they may reduce survival or cause serious functional disorders in the extremities. Metastatic spinal tumors from malignant tumors can induce symptoms of spinal cord compression, such as paraplegia, quadriplegia, and vesicorectal disturbance, which are aggravated with progression of the diseases and time. We report a patient with hepatocellular carcinoma (HCC) who was suspected of having spinal lesions based on neurological findings, and a metastatic spinal tumor was found by imaging examination. Assuming that metastasis had occurred at the time lumbar pain developed, the patient reached the level of gait disturbance within only 4 mo, showing a rapid advancement of symptoms. If early diagnosis had been possible, treatment could be performed before acute myelopathy progressed to complete paralysis. We speculate that the terminal stage of HCC is not only liver failure associated with intrahepatic lesions but also metastasis to other regions, treatment for individual pathologies therefore, will be needed, which constitutes an important issue.

关键词： Hepatocellular carcinoma Spinal cord metastasis Brain metastasis

基于裂纹尖端应力比值的含裂纹功能梯度材料圆筒应力强度因子计算方法

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工程力学 2020年第4期37卷 22-29页

作者：李戎杨萌梁斌 NODA nao-Aki 河南科技大学土木工程学院河南洛阳471023 九州工业大学机械系日本北九州市804-8550

由于功能梯度材料(FGM)性质的特殊性,现有含裂纹FGM结构应力强度因子计算方法难以避免复杂的矩阵运算以及数值积分。该文针对含外表面环向裂纹FGM圆筒,利用FGM圆筒与均匀材料圆筒裂纹尖端应力之间的比例关系,将复杂的FGM圆筒应力强度因... 详细信息

由于功能梯度材料(FGM)性质的特殊性,现有含裂纹FGM结构应力强度因子计算方法难以避免复杂的矩阵运算以及数值积分。该文针对含外表面环向裂纹FGM圆筒,利用FGM圆筒与均匀材料圆筒裂纹尖端应力之间的比例关系,将复杂的FGM圆筒应力强度因子求解问题转化为简单的应力值提取问题以及经验公式计算问题,仅由均匀材料圆筒应力强度因子经验公式、均匀材料圆筒和FGM圆筒裂纹尖端应力比值即可得到任意含裂纹FGM圆筒应力强度因子。该方法仅需建立2D轴对称模型即可满足计算要求,在保证精度的基础上成功回避了传统方法中的复杂矩阵运算以及数值积分,且适用于不同FGM、筒体尺寸、裂纹深度等情况下的应力强度因子计算。通过多组算例对比分析,证明该方法计算精度高、计算过程简便,便于工程应用。

关键词：功能梯度材料圆筒应力强度因子有限元分析方法裂纹尖端应力比值