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Base Stress of the Opened Bottom Cylinder Structures
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作者 刘建起 孟晓娟 《Transactions of Tianjin University》 EI CAS 2004年第2期133-137,共5页
The base stress of the opened bottom cylinder structure differs greatly from that of the structure with a closed bottom. By investigating the inner soil pressure on the cylinder wall and the base stress of the cylinde... The base stress of the opened bottom cylinder structure differs greatly from that of the structure with a closed bottom. By investigating the inner soil pressure on the cylinder wall and the base stress of the cylinder base, which were obtained from the model experiments, the interactions among the filler inside the cylinder, subsoil and cylinder are analyzed. The adjusting mechanism of frictional resistance between the inner filler and the wall of the cylinder during the overturning of the cylinder is discussed. Based on the experimental study, a method for calculating the base stress of the opened bottom cylinder structure is proposed. Meanwhile, the formulas for calculating the effective anti-overturning ratio of the opened bottom cylinder are derived. 展开更多
关键词 base stress opened bottom cylinder inner soil pressure adjusting mechanism
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Microstructural image based convolutional neural networks for efficient prediction of full-field stress maps in short fiber polymer composites
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作者 S.Gupta T.Mukhopadhyay V.Kushvaha 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第6期58-82,共25页
The increased demand for superior materials has highlighted the need of investigating the mechanical properties of composites to achieve enhanced constitutive relationships.Fiber-reinforced polymer composites have eme... The increased demand for superior materials has highlighted the need of investigating the mechanical properties of composites to achieve enhanced constitutive relationships.Fiber-reinforced polymer composites have emerged as an integral part of materials development with tailored mechanical properties.However,the complexity and heterogeneity of such composites make it considerably more challenging to have precise quantification of properties and attain an optimal design of structures through experimental and computational approaches.In order to avoid the complex,cumbersome,and labor-intensive experimental and numerical modeling approaches,a machine learning(ML)model is proposed here such that it takes the microstructural image as input with a different range of Young’s modulus of carbon fibers and neat epoxy,and obtains output as visualization of the stress component S11(principal stress in the x-direction).For obtaining the training data of the ML model,a short carbon fiberfilled specimen under quasi-static tension is modeled based on 2D Representative Area Element(RAE)using finite element analysis.The composite is inclusive of short carbon fibers with an aspect ratio of 7.5that are infilled in the epoxy systems at various random orientations and positions generated using the Simple Sequential Inhibition(SSI)process.The study reveals that the pix2pix deep learning Convolutional Neural Network(CNN)model is robust enough to predict the stress fields in the composite for a given arrangement of short fibers filled in epoxy over the specified range of Young’s modulus with high accuracy.The CNN model achieves a correlation score of about 0.999 and L2 norm of less than 0.005 for a majority of the samples in the design spectrum,indicating excellent prediction capability.In this paper,we have focused on the stage-wise chronological development of the CNN model with optimized performance for predicting the full-field stress maps of the fiber-reinforced composite specimens.The development of such a robust and efficient algorithm would significantly reduce the amount of time and cost required to study and design new composite materials through the elimination of numerical inputs by direct microstructural images. 展开更多
关键词 Micromechanics of fiber-reinforced composites Machine learning assisted stress prediction Microstructural image-based machine learning CNN based stress analysis
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Effect of Impurities and Cerium on Stress Concentration Sensitivity of Al-Li Based Alloys
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作者 孟亮 田丽 《Journal of Rare Earths》 SCIE EI CAS CSCD 2002年第1期51-55,共5页
A notch sensitivity factor was derived in order to evaluate the stress concentration sensitivity of Al Li based alloys. The factor values for the Al Li alloy sheets containing various contents of impurities and ceri... A notch sensitivity factor was derived in order to evaluate the stress concentration sensitivity of Al Li based alloys. The factor values for the Al Li alloy sheets containing various contents of impurities and cerium addition were evaluated by determining the mechanical properties. It is found that the impurities Fe, Si, Na and K significantly enhance the stress concentration sensitivity of the alloys 2090 and 8090, whereas cerium addition reduces the stress concentration sensitivity to a certain degree for the high strength alloys. However, an excess amount of cerium addition in the high ductility alloy 1420 can significantly increase the stress concentration sensitivity. As compared with conventional aluminum alloys, the Al Li based alloys generally show high stress concentration sensitivity. Therefore, a special attention must be paid to this problem in the practical application of Al Li based alloys. 展开更多
关键词 rare earths CERIUM IMPURITY Al Li based alloy stress concentration
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Influence of thermal exposure on microstructure and stress rupture properties of a new Re-containing single crystal Ni-based superalloy 被引量:2
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作者 Chen-guang Liu Yun-song Zhao +3 位作者 Jian Zhang Ding-zhong Tang Chun-zhi Li Zhen-ye Zhao 《China Foundry》 SCIE 2018年第1期51-57,共7页
In this study, the long-term thermal microstructural stability and related stress rupture lives of a new Re-containing Ni-based single-crystal superalloy, DD11, were investigated after high-temperature exposure for di... In this study, the long-term thermal microstructural stability and related stress rupture lives of a new Re-containing Ni-based single-crystal superalloy, DD11, were investigated after high-temperature exposure for different lengths of time. The results show that the γ' precipitates retained a cuboidal morphology and the γ' size increased after short thermal exposure for 50 h at 1,070℃. As the thermal exposure time was prolonged to 500 h, the cuboidal γ' gradually changed into irregular raft-like morphology due to particles coalescence, and the morphology of the microstructure was almost unchanged after further thermal exposure up to 3,000 h. The stress rupture experiments at 1,070℃ and a tensile stress of 140 MPa showed that the rupture lives increased significantly after thermal exposure for 50 h and dropped dramatically with increasing exposure time up to 500 h but decreased slowly after exposure for more than 500 h. These results imply that stress rupture properties did not decrease when the γ' remained cuboidal but degraded to different extents during the γ' coarsening process. The coarsening of the γ' precipitates and change in morphology were regarded as the main factors leading to the degradation of the stress rupture lives. This study provides fundamental information on the high-temperature longterm microstructural stability and mechanical performance, which will be of great help for DD11 alloy optimization and engineering aeroengine applications. 展开更多
关键词 Ni-based superalloy thermal exposure MICROSTRUCTURE COARSENING stress-rupture properties
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Identify Plant Drought Stress by 3D-Based Image 被引量:3
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作者 ZHAO Yan-dong SUN Yu-rui +2 位作者 CAI Xiang LIU He Peter Schulze Lammers 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2012年第7期1207-1211,共5页
Plants respond to drought stress with different physical manners, such as morphology and color of leaves. Thus, plants can be considered as a sort of living-sensors for monitoring dynamic of soil water content or the ... Plants respond to drought stress with different physical manners, such as morphology and color of leaves. Thus, plants can be considered as a sort of living-sensors for monitoring dynamic of soil water content or the stored water in plant body. Because of difficulty to identify the early wilting symptom of plants from the results in 2D (two-dimension) space, this paper presented a preliminary study with 3D (three-dimension)-based image, in which a laser scanner was used for achieving the morphological information of zucchini (Cucurbita pepo) leaves. Moreover, a leaf wilting index (DLWIF) was defined by fractal dimension. The experiment consisted of phase-1 for observing the temporal variation of DLWIF and phase-2 for the validation of this index. During the experiment, air temperature, luminous intensity, and volumetric soil water contents (VSWC) were simultaneously recorded over time. The results of both phases fitted the bisector (line: 1:1) with R2=0.903 and REMS=0.155. More significantly, the influence of VSWC with three levels (0.22, 0.30, and 0.36 cm3 cm-3) on the response of plant samples to drought stress was observed from separated traces of DLWIF. In brief, two conclusions have been made: (i) the laser scanner is an effective tool for the non-contact detection of morphological wilting of plants, and (ii) defined DLWIF can be a promising indicator for a category of plants like zucchini. 展开更多
关键词 WILTING 3D-based image laser scanner fractal dimension drought stress ZUCCHINI
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Influence of Co, W and Ti on the Stress-rupture Lives of a Single Crystal Nickel-base Superalloy 被引量:1
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作者 Dayun YANG Tao JIN Nairen ZHAO Zhihui WANG Xiaofeng SUN Hengrong GUAN Zhuangqi HU 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2006年第2期169-172,共4页
The influence of Co, W and Ti on stress-rupture lives of a Ni-Cr-AI-Mo-Ta-Co-W-Ti single crystal nickel-base superalloy has been investigated using a L9 (34) orthogonal array design (OAD) by statistical analysis. ... The influence of Co, W and Ti on stress-rupture lives of a Ni-Cr-AI-Mo-Ta-Co-W-Ti single crystal nickel-base superalloy has been investigated using a L9 (34) orthogonal array design (OAD) by statistical analysis. At a selected composition range, Ti content was the most important factor to the effect of the stress-rupture lives and then followed by Co content. W content had the minimum effect on stress-rupture lives. The optimal alloy should contain 10 wt pct Co, 8 wt pct W and zero Ti. The optimized alloy also had good microstructural stability during thermal exposure at 870℃ for 500 h. 展开更多
关键词 Nickel-base single crystal superalloy Orthogonal array design stress-RUPTURE
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Potential therapeutic interventions based on the role of the endoplasmic reticulum stress response in progressive neurodegenerative diseases
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作者 Basant K.Puri Gerwyn Morris 《Neural Regeneration Research》 SCIE CAS CSCD 2018年第11期1887-1889,共3页
In 1945,Porter et al.published an electon microscopy study of cultured chick fibroblasts in which they observed:'a granular background and details of a darker lacelike reticulum which in places appears to be made up... In 1945,Porter et al.published an electon microscopy study of cultured chick fibroblasts in which they observed:'a granular background and details of a darker lacelike reticulum which in places appears to be made up of chains of"vesicles"'(Porter et al.,1945).This constituted the first published observation of the endoplasmic reticulum(ER)and,while it was not evident at that time,this cytoplasmic system of interconnecting membrane-lined channels, comprising vesicles, tubules and cisternae, has numerous important functions. 展开更多
关键词 Potential therapeutic interventions based on the role of the endoplasmic reticulum stress response in progressive neurodegenerative diseases UPR NAC
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Effect of Heat Treatment on High Temperature Stress Rupture Strength of Brazing Seam for Nickel-base Superalloy 被引量:2
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作者 Junying Zhang, Zhongtai Zhang, Jisheng Sun, Xiaofang Liu, Wei Tian (State Key Laboratory of New Ceramics and Fine Processing, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084, China) (Beijing Institute of Aeronautical 《Journal of University of Science and Technology Beijing》 CSCD 2001年第2期123-125,共3页
In order to enhance the high-temperature stress rupture strength of brazing seam by heat treatment, it was diffusion treated, then solution heat treated, and finally aging treated. The microstructure of brazing seam e... In order to enhance the high-temperature stress rupture strength of brazing seam by heat treatment, it was diffusion treated, then solution heat treated, and finally aging treated. The microstructure of brazing seam especially morphology of gamma ' phase and boride was observed and the strength of brazing seam was measured in this process. The results show that heat treatment can enhance high-temperature stress rupture strength by improving the microstructure of brazing seam. The strength of brazing seam after solution heat treatment decreases in comparison with that only after diffusion treatment while aging treatment after solution heat treatment increases the strength of brazing seam. 展开更多
关键词 wide-gap brazing high temperature stress rupture strength MICROSTRUCTURE nickel-base superalloy
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A Displacement Based Analytical Model to Determine Residual Stress Components in a Finite Elastic Thin Plate with Hole-Drilling Method
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作者 Yuming Li Boussad Abbes +2 位作者 Fazilay Abbes Yingqiao Guo Xiaolu Gong 《Journal of Applied Mathematics and Physics》 2018年第8期1571-1580,共10页
In order to measure the residual stress components in an elastic thin plate, the hole-drilling strain-gage method has been used. This method enables to determine the relation between the magnitudes and directions of t... In order to measure the residual stress components in an elastic thin plate, the hole-drilling strain-gage method has been used. This method enables to determine the relation between the magnitudes and directions of the principal stresses and the strain relaxation about the hole. In the existing analytical models based on stress field, the formulations associated with the hole-drilling method are based on the assumption of an infinite plate, this may cause some errors for a finite plate and it’s difficult to validate these solutions by FE methods. Furthermore, in the composite, the displacement field is continuous but the stress field is not necessarily continuous, the displacement field based method has to be used. In the present paper an analyt-ical model based on a displacement field described by a function with coefficients to determine for a finite round thin plate is presented. The coefficients used in the displacement field are independent on the three residual stress components, and they are determined by minimization of the internal strain energy during the hole-drilling process. Once the coefficients in the dis-placement field are determined, three strains measured in three radial directions are utilized to determine the three residual stress components. The proposed analytical model can be also adapted to infinite plate by assuming that the diameter of the round plate tends to infinite. 展开更多
关键词 RESIDUAL stress HOLD DRILLING DISPLACEMENT based Internal Strain Energy Analytical Model
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Stress Corrosion Cracking of Pressure Vessel Steel and Countermeasures by Titanium-Based & Cerium-Based Inhibitors in Subcritical Aqueous Environment
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作者 沈长斌 韩冬云 +1 位作者 杨怀玉 王福会 《Journal of Rare Earths》 SCIE EI CAS CSCD 2003年第S1期1-4,共4页
An overview of a severe kind of environmentally-assisted cracking-stress corrosion cracking (SCC) of pressure vessel steel (PVS),such as stainless steel 304, alloy 600,690 and other nickel-based alloys in subcritical ... An overview of a severe kind of environmentally-assisted cracking-stress corrosion cracking (SCC) of pressure vessel steel (PVS),such as stainless steel 304, alloy 600,690 and other nickel-based alloys in subcritical (~300 ℃) aqueous environment was given. The mechanisms of SCC of metals under this inclement surrounding were briefly generalized. Herein,some pragmatic solutions to mitigate the SCC susceptibility and retard its propagation were presented. The titanium and cerium-based inhibitors addition countermeasure was highlighted. 展开更多
关键词 pressure vessel steel subcritical aqueous environment stress corrosion titanium & cerium-based inhibitors-addition rare earths
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Friction Shear Stress on the Surface of Iron-Based Coating/HSS during Sliding Wear of Pin Disk
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作者 Huajun Wang Kangkang Gan +2 位作者 Xiaoguang Zhou Songshan Yan Longfei Niu 《Journal of Applied Mathematics and Physics》 2017年第9期1694-1701,共8页
With the increasing demand for lightweight and lower fuel consumption and safety of automobile industry, lightweight materials of high strength steel (HSS) are more and more widely used. The hot stamping technology, w... With the increasing demand for lightweight and lower fuel consumption and safety of automobile industry, lightweight materials of high strength steel (HSS) are more and more widely used. The hot stamping technology, which is determined by the inherent mechanical properties of high strength steel, makes molds prone to wear failure in the harsh service environments. In this paper, a finite element model is proposed for analyzing the value and distributions law of friction shear stress of contact surface of the pin disk. Through the simulation process of sliding wear, two kinds of different cladding materials of the pin specimens including H13 and Fe65, were experimented under three different loads by using the software ABAQUS. And then the pin-on- disk wear test at elevated temperature was conducted to verify the effectiveness of the simula-tion results. The results showed that the friction shear stress of pin with iron-based cladding and H13 steel was different under different loads, but the distribution was basically the same;the normal friction shear stress increased gradually along the direction of the pin movement, and the tangential shear stress increased gradually from the center of the pin to the outside of the circle;the value of the friction shear stress of the normal joints on the contact surface was periodically fluctuating in the whole dynamic analysis step, while it was basically stable in the tangential direction. 展开更多
关键词 High Strength Steel IRON-baseD CLADDING SLIDING Wear FRICTION SHEAR stress Finite Element Analysis
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Brain structure in post-traumatic stress disorder A voxel-based morphometry analysis
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作者 Liwen Tan Li Zhang +4 位作者 Rongfeng Qi Guangming Lu Lingjiang Li Jun Liu Weihui Li 《Neural Regeneration Research》 SCIE CAS CSCD 2013年第26期2405-2414,共10页
This study compared the difference in brain structure in 12 mine disaster survivors with chronic post-traumatic stress disorder, 7 cases of improved post-traumatic stress disorder symptoms, and 14 controls who experie... This study compared the difference in brain structure in 12 mine disaster survivors with chronic post-traumatic stress disorder, 7 cases of improved post-traumatic stress disorder symptoms, and 14 controls who experienced the same mine disaster but did not suffer post-traumatic stress disorder, using the voxel-based morphometry method. The correlation between differences in brain structure and post-traumatic stress disorder symptoms was also investigated. Results showed that the gray matter volume was the highest in the trauma control group, followed by the symptoms-improved group, and the lowest in the chronic post-traumatic stress disorder group. Compared with the symptoms-improved group, the gray matter volume in the lingual gyrus of the right occipital lobe was reduced in the chronic post-traumatic stress disorder group. Compared with the trauma control group, the gray matter volume in the right middle occipital gyrus and left middle frontal gyrus was reduced in the symptoms-improved group. Compared with the trauma control group, the gray matter volume in the left superior parietal lo- bule and right superior frontal gyrus was reduced in the chronic post-traumatic stress disorder group. The gray matter volume in the left superior parietal Iobule was significantly positively correlated with the State-Trait Anxiety Inventory subscale score in the symptoms-improved group and chronic post-traumatic stress disorder group (r = 0.477, P = 0.039). Our findings indicate that (1) chronic post-traumatic stress disorder patients have gray matter structural damage in the prefrontal lobe, oc- cipital lobe, and parietal lobe, (2) after post-traumatic stress, the disorder symptoms are improved and gray matter structural damage is reduced, but cannot recover to the trauma-control level, and (3) the superior parietal Iobule is possibly associated with chronic post-traumatic stress disorder. Post-traumatic stress disorder patients exhibit gray matter abnormalities. 展开更多
关键词 neural regeneration NEUROIMAGING MRI post-traumatic stress disorder voxel-based morphometry pre-frontal lobe parietal lobe occipital lobe follow-ups grants-supported paper NEUROREGENERATION
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Research Findings Using Mindfulness-Based Interventions for Chronic Pain 被引量:2
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作者 Tracy L. Skaer 《Pain Studies and Treatment》 2015年第4期38-45,共8页
Chronic pain is a complex condition that is very detrimental to physical and psychological wellbeing. It carries a significant level of disability and economic burden. Pain patients frequently experience comorbid ment... Chronic pain is a complex condition that is very detrimental to physical and psychological wellbeing. It carries a significant level of disability and economic burden. Pain patients frequently experience comorbid mental illness (e.g. depression, anxiety, PTSD, insomnia) and often require psychotherapeutic interventions in addition to medication management. Mindfulness-based interventions (MBIs) have emerged as a means to treat several chronic conditions (e.g. chronic pain, depression, anxiety, substance abuse, stress, insomnia). The objective of this review is to evaluate the current research on the use of MBIs in chronic pain managment. Although there are several controlled trials on the use of MBIs in chronic pain management, only a few studies were found that demonstrated significant effects on pain intensity, quality of life, as well as physical and psychological functioning. Therefore, the current evidence is mixed and there are insufficient data to definitively confirm the full impact of the use of MBIs in chronic pain conditions such as fibromyalgia, chronic low back pain, rheumatoid arthritis, and chronic musculoskeletal pain. The lack of compelling evidence at this time signals a demand for higher quality investigations in this area. Research examining MBIs and concomitant CBT may be of great value in order to synergize and strengthen patient outcomes. 展开更多
关键词 CHRONIC PAIN FIBROMYALGIA CHRONIC Low Back PAIN Mindfulness-based stress Reduction Acceptance and Commitment Therapy Depression Anxiety Quality of Life Psychiatric COMORBIDITIES
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Reliability analysis of GaN-based light emitting diodes for solid state illumination 被引量:1
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作者 杨凌 马晓华 +1 位作者 冯倩 郝跃 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第7期2696-2700,共5页
In this paper, we have discussed the effect of electrical stress on GaN light emitting diode (LED). With the lapse of time, the LED with an applied large current stress can reduce its current more than without such ... In this paper, we have discussed the effect of electrical stress on GaN light emitting diode (LED). With the lapse of time, the LED with an applied large current stress can reduce its current more than without such a stress under a large forward-voltage drop. Its scanning electron microscopy (SEM) image shows that there exist several pits on the surface of the p-metal. With an electrical stress applied, the number of pits greatly increases. We also find that the degradation of GaN LED is related to the oxidized Ni/Au ohmic contact to p-GaN. The electrical activation of H-passivated Mg acceptors is described in detail. Annealing is performed in ambient air for 10 min and the differential resistances at a forward-voltage drop of 5 V are taken to evaluate the activation of the Mg acceptors. These results suggest some mechanisms of degradation responsible for these phenomena, which are described in the paper. 展开更多
关键词 GaN based LED electrical stress PITS ANNEALING mechanism of degradation
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Research and development of nickle-based OCTG used in severe sour oil and gas fields 被引量:1
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作者 ZHANG Zhonghua,ZHANG Chunxia,PAN Dagang and SHAO Weidong Baoshan Iron & Steel Co.,Ltd.,Shanghai 201900,China 《Baosteel Technical Research》 CAS 2010年第S1期66-,共1页
With an alloy content as high as 80%or more,Ni-based OCTG is a strategic products related to the state energy security,mainly applied in the exploitation and development of sour gas fields with complicate geological f... With an alloy content as high as 80%or more,Ni-based OCTG is a strategic products related to the state energy security,mainly applied in the exploitation and development of sour gas fields with complicate geological formation,high temperature,high pressure and severe corrosive well conditions.Ni-based OCTG is regarded as the pipe product with most high technologies due to the complexity and great difficulty in manufacturing and rigorous requirements in quality control.In this paper,the technical features and quality requirements of Ni-based OCTG are summarized,and the quality and properties of the Ni-based OCTG products of Baosteel are introduced in detail.With the help of SEM,XPS and TEM,the corrosion mechanism of Nickle-based OCTG in the environments containing H_2S,CO_2,Cl^- and elementary suifur are also analyzed. 展开更多
关键词 nickle-based alloys OCTG stress crossion cracking
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Microstructures and properties of transient liquid phase diffusion bonded joints of Ni_3Al-base superalloy 被引量:8
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作者 李晓红 毛唯 程耀永 《中国有色金属学会会刊:英文版》 CSCD 2001年第3期405-408,共4页
An investigation of transient liquid phase (TLP) diffusion bonding of a Ni 3Al base directionally solidified superalloy, IC6 alloy, was presented. The interlayer alloy employed was Ni Mo Cr B powder alloy. The results... An investigation of transient liquid phase (TLP) diffusion bonding of a Ni 3Al base directionally solidified superalloy, IC6 alloy, was presented. The interlayer alloy employed was Ni Mo Cr B powder alloy. The results show that the microstructure of the TLP diffusion bonded joints is a combination of γ solid solution (or a γ+γ′ structure) and borides. With the bonding time increasing, the quantity of the borides both in bonding seam and adjacent zones is gradually reduced, and the joint stress rupture property is improved. The obtained stress rupture property of the TLP bonded joints is on a level with the transverse property of IC6 base materials. [ 展开更多
关键词 Ni 3Al base superalloy TLP diffusion bonding stress rupture property
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Reliability Based Design Optimization of Aero-Engine Spindle Ball Bearings 被引量:2
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作者 杨静 孟德彪 +2 位作者 张小玲 汪忠来 许焕卫 《Journal of Donghua University(English Edition)》 EI CAS 2014年第6期853-855,共3页
Aero-engine spindle ball bearings work in harsh conditions which are affected by relatively complex stresses. One of the key factors which affects bearing performance is its structure. In this paper,we used reliabilit... Aero-engine spindle ball bearings work in harsh conditions which are affected by relatively complex stresses. One of the key factors which affects bearing performance is its structure. In this paper,we used reliability based design optimization method to solve the structure design problem of aero-engine spindle ball bearings.Compared with the optimization design method, the value of equivalent dynamic load using reliability optimization design method was the least by MATLAB simulation. Also the design solutions show that the optimized structure possesses higher reliability than the original solution. 展开更多
关键词 aero-engine spindle ball bearing complex stresses reliability based design optimization structure design
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Research on China's high-grade highway design index of asphalt pavement with granular base 被引量:2
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作者 XiuShan Wang TaoTao Fan +1 位作者 YanXu Gao Yi Hu 《Research in Cold and Arid Regions》 CSCD 2013年第4期498-502,共5页
Based on the 2006 Chinese asphalt pavement deflection value design index, we used KENLAYER Pavement Analysis and Design software and lstOpt statistical analysis software to can-y on the nonlinear regression, this pape... Based on the 2006 Chinese asphalt pavement deflection value design index, we used KENLAYER Pavement Analysis and Design software and lstOpt statistical analysis software to can-y on the nonlinear regression, this paper establish high-grade highway design equations for the compressive slrain of soil sub-base top (CSSBT) and the radial compressive stress of semi-rigid base top (RCSRBT). The correlation coefficients inspection standard to get precise proof, which means that our granular base design equations have high credibility and can be used in the Chinese design index of asphalt pavement with granular base (APGB). 展开更多
关键词 granular base semi-rigid base compressive strain radial compressive stress
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Induction of Oxidative Stress in Male Rats Subchronically Exposed to Electromagnetic Fields at Non-Thermal Intensities
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作者 Albert Achudume Bill Onibere +1 位作者 Funso Aina Paschal Tchokossa 《Journal of Electromagnetic Analysis and Applications》 2010年第8期482-487,共6页
To investigate the oxidative stress-inducing potential of non-thermal electromagnetic fields in rats. Male Wister rats were exposed to electrical field intensity of 2.3 ± 0.82 μV/m . Exposure was in three forms:... To investigate the oxidative stress-inducing potential of non-thermal electromagnetic fields in rats. Male Wister rats were exposed to electrical field intensity of 2.3 ± 0.82 μV/m . Exposure was in three forms: continuous waves, or modulated at 900 MHz or modulated GSM-nonDTX. The radio frequency radiation (RFR) was 1800 MHz, specific absorption radiation (SAR) (0.95-3.9 W/kg) for 40 and/or 60 days continuously. Control animals were located > 300 m from base station, while sham control animals were located in a similar environmental conditions, but in the vicinity of a non-functional base station. The rats were assessed for thiobarbituric and reactive species (TBARS), reduced glutathione (GSH) content, catalase activity, glutathione reductase (GR) and glucose residue after 40 and 60 days of exposure. At 40 days, electromagnetic radiation failed to induce any significant alterations. However, at 60 days of exposure various attributes evaluated decreased. The respective decreases in both nicotinamide adenine dinucleotide phosphate (NADPH) and Ascorbate- linked lipid peroxidation (LPO) with concomitant diminution in enzymatic antioxidative defense systems resulted in decreased glucose residue. The present studies showed some biochemical changes that may be associated with a prolong exposure to electromagnetic fields and its relationship to the activity of antioxidant system in rat Regular assessment and early detection of antioxidative defense system among people working around the base stations are recommended. 展开更多
关键词 Electromagnetic field TELECOMMUNICATION base station OXIDATIVE stress ANTIOXIDANT system
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Corrosion performance and applicability evaluation of nickel-based alloys for oil and gas production tubing applications
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作者 ZHOU Qingjun ZHANG Zhonghua YANG Jianqiang 《Baosteel Technical Research》 CAS 2015年第4期52-56,共5页
The sulfide stress corrosion cracking( SSC) performance of G3 and 028 nickel-based alloys w as studied using slow strain rate test( SSRT) and the four-point bend( FPB) test under simulated dow nhole conditions. ... The sulfide stress corrosion cracking( SSC) performance of G3 and 028 nickel-based alloys w as studied using slow strain rate test( SSRT) and the four-point bend( FPB) test under simulated dow nhole conditions. The effect of high temperature,high H2 S / CO2 partial pressure,and the presence of sulfur on SSC susceptibility w as investigated. The G3 alloy w as found to have a higher SSC resistance than the 028 alloy. Presence of sulfur and temperature bear a strong influence on the SSC performance of the metals,particularly on the 028 alloy. The applicability of 028 and G3 alloys may be expanded and both could safely be used beyond the limits set by the ISO15156-3 standard. 展开更多
关键词 nickel-based alloy sulfide stress corrosion oil tubing
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