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Rainfall-triggered waste dump instability analysis based on surface 3D deformation in physical model test
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作者 LI Hanlin JIN Xiaoguang +2 位作者 HE Jie XUE Yunchuan YANG Zhongping 《Journal of Mountain Science》 SCIE CSCD 2024年第5期1549-1563,共15页
Landslide is the second largest natural disaster after earthquake. It is of significance to study the evolution laws and failure mechanism of landslides based on its surface 3D deformation information. Based on the ra... Landslide is the second largest natural disaster after earthquake. It is of significance to study the evolution laws and failure mechanism of landslides based on its surface 3D deformation information. Based on the rainfall-triggered waste dump instability model test, we studied the failure mechanisms of the waste dump by integrating surface deformation and internal slope stress and proposed novel parameters for identifying landslide stability. We developed a noncontact measurement device, which can obtain millimeter-level 3D deformation data for surface scene in physical model test;Then we developed the similar materials and established a test model for a waste dump. Based on the failure characteristics of slope surface, internal stress of slope body and displacement contours during the whole process, we divided the slope instability process in model test into four stages: rainfall infiltration and surface erosion, shallow sliding, deep sliding, and overall instability. Based on the obtained surface deformation data, we calculated the volume change during slope instability process and compared it with the point displacement on slope surface. The results showed that the volume change can not only reflect the slow-ultra acceleration process of slope failure, but also fully reflect the above four stages and reduce the fluctuations caused by random factors. Finally, this paper proposed two stability identification parameters: the volume change rate above the slip surface and the relative velocity of volume change rate. According to the calculation of these two parameters in model test, they can be used for study the deformation and failure mechanism of slope stability. 展开更多
关键词 Waste dump stability Physical model test Surface 3D deformation Stability identification
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Physical model test and application of 3D printing rock-like specimens to laminated rock tunnels
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作者 Yun Tian Weizhong Chen +3 位作者 Hongming Tian Xiaoyun Shu Linkai He Man Huang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第11期4625-4637,共13页
Weak structural plane deformation is responsible for the non-uniform large deformation disasters in layered rock tunnels,resulting in steel arch distortion and secondary lining cracking.In this study,a servo biaxial t... Weak structural plane deformation is responsible for the non-uniform large deformation disasters in layered rock tunnels,resulting in steel arch distortion and secondary lining cracking.In this study,a servo biaxial testing system was employed to conduct physical modeling tests on layered rock tunnels with bedding planes of varying dip angles.The influence of structural anisotropy in layered rocks on the micro displacement and strain field of surrounding rocks was analyzed using digital image correlation(DIC)technology.The spatiotemporal evolution of non-uniform deformation of surrounding rocks was investigated,and numerical simulation was performed to verify the experimental results.The findings indicate that the displacement and strain field of the surrounding layered rocks are all maximized at the horizontal bedding planes and decrease linearly with the increasing dip angle.The failure of the layered surrounding rock with different dip angles occurs and extends along the bedding planes.Compressive strain failure occurs after excavation under high horizontal stress.This study provides significant theoretical support for the analysis,prediction,and control of non-uniform deformation of tunnel surrounding rocks. 展开更多
关键词 Bedding plane Three-dimensional(3D)printing Physical model test Non-uniform deformation Digital imaging correlation(DIC)
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基于AdmiTest的CTCS-3级列控系统自动测试平台 被引量:3
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作者 贺广宇 范明 +1 位作者 程剑锋 黄宏福 《中国铁道科学》 EI CAS CSCD 北大核心 2013年第4期128-136,共9页
根据CTCS-3级列控系统的特点,结合欧洲列车运行控制系统(ETCS)测试经验,研发基于通用测试平台AdmiTest的CTCS-3级列控系统自动测试平台CARSTool。CARSTool采用激励-反馈机制实现单系统或多系统的闭环测试,包含测试对象、仿真系统、链路... 根据CTCS-3级列控系统的特点,结合欧洲列车运行控制系统(ETCS)测试经验,研发基于通用测试平台AdmiTest的CTCS-3级列控系统自动测试平台CARSTool。CARSTool采用激励-反馈机制实现单系统或多系统的闭环测试,包含测试对象、仿真系统、链路、消息、激励、响应和测试序列等基本元素,具有线路工程数据配置、通信链路配置、站场线路配置、PI Object、仿真系统、列车运行仿真和自动测试序列7个功能模块。以郑西客运专线列控数据为例,采用CARSTool对CTCS-3级列控系统进行仿真测试。测试结果表明:通过规范化语法严格卡控测试步骤,根据CTCS-3级列控系统测试案例库以及激励-反馈信息判断测试项目的执行状态,CARSTool实现了测试计划、执行过程和测试结果的闭环处理;说明CARSTool能够实现CTCS-3级列控系统的自动测试。 展开更多
关键词 CTCS-3级列控系统 激励-反馈机制 系统自动测试 测试平台
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Analysis of CET3 Based on Language Testing
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作者 张忠魁 《语言与文化研究》 2008年第2期104-107,共4页
In this paper,some basic theories and terms of language testing,like types of language tests and qualities of good tests were briefly discussed.Then CET3(College English Test Band3) in Beijing was analyzed from three ... In this paper,some basic theories and terms of language testing,like types of language tests and qualities of good tests were briefly discussed.Then CET3(College English Test Band3) in Beijing was analyzed from three perspectives:design principles,item formats and test content. In the end,some suggestions were given to improve this test. 展开更多
关键词 LANGUAGE testING CET3 RELIABILITY validity
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Test 3
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作者 贺云 《英语自学》 2007年第3期36-39,共4页
Part One:Quick Responses Please make a quick response to the sentence you will hear.1.I’m really sorry,but I can’t come to your party tonight.2.I’m so upset,Jean,I lost my bag on my way to the Science Museum.
关键词 SENTENCE REALLY PARTY 发话者 SOMETHING test 3 educati
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B/KNO_(3)点火药装药的烤燃特性研究
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作者 伍俊英 尚伊平 +4 位作者 郑富德 杜皓杰 姚雨乐 李钧剑 陈朗 《兵工学报》 EI CAS CSCD 北大核心 2024年第8期2828-2836,共9页
为研究B/KNO_(3)点火药的热安全性,建立多点测温烤燃实验装置,对不同升温速率、不同装药密度条件下的B/KNO_(3)点火药装药进行多点测温烤燃实验,以获得点火药装药发生点火的准确时间与烤燃过程中不同监测点的温度历程。建立B/KNO_(3)点... 为研究B/KNO_(3)点火药的热安全性,建立多点测温烤燃实验装置,对不同升温速率、不同装药密度条件下的B/KNO_(3)点火药装药进行多点测温烤燃实验,以获得点火药装药发生点火的准确时间与烤燃过程中不同监测点的温度历程。建立B/KNO_(3)点火药装药烤燃实验的数值计算模型并进行了数值模拟,计算中考虑了点火药的自热分解反应与相变吸热。通过与实验结果的对比,标定B/KNO_(3)点火药装药的热物性参数和反应动力学参数。研究结果表明:B/KNO_(3)点火药的指前因子为7.763×10^(13)s^(-1),活化能为2.0787×10^(5)J/mol;在点火药装药的烤燃过程中,随着升温速率的减小,点火延期时间逐渐增加,点火区域逐渐向中心移动,点火环境温度逐渐降低;在装药密度变化不太大的情况下,点火药的点火特征差别不大。 展开更多
关键词 B/KNO_(3)点火药 烤燃实验 热安全性 点火特性
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Expression of toxin-related human mono-ADP-ribosyltransferase 3 in human testes 被引量:6
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作者 Maik Friedrich Andreas Grahnert +3 位作者 Uwe Paasch Andrea Tannapfel Friedrich Koch-Nolte Sunna Hauschildt 《Asian Journal of Andrology》 SCIE CAS CSCD 2006年第3期281-287,共7页
Aim: To investigate wether the corresponding protein of mono-ADP-ribosyltransferase 3 (ART3) mRNA is expressed in human testes and, if so, whether the expression is cell type-specific. Methods: ART3 mRNA was deter... Aim: To investigate wether the corresponding protein of mono-ADP-ribosyltransferase 3 (ART3) mRNA is expressed in human testes and, if so, whether the expression is cell type-specific. Methods: ART3 mRNA was determined in human testes and sperm by reverse transcription-polymerase chain reaction (RT-PCR). The glycosylphosphatidylinositol linkage of ART3 was shown by treating ART3-transfected HEK-293-T cells with phospholipase C. Fluorescent activated cell sorter (FACS)-analyses were used to detect ART3 on mature spermatozoa and immunohistological studies to detect the protein in testes. Results: ART3 protein was shown to be present in testes. It was found on spermatocytes only. It was absent from spermatogonia, spermatids and spermatozoa. The absence of ART3 from spermatozoa was confirmed by FACS-analysis. ART3 protein was detected neither within a seminoma nor on Leydig cells. Conclusion: Here we show for the first time that ART3 protein is expressed in testes in particular on spermatocytes, indicating that ART3 exerts a specific function only required at a particular stage of spermatogenesis. 展开更多
关键词 mono-ADP-ribosyltransferase 3 testES human spermatocyte SPERMATOGENESIS
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3/4开口试验段汽车风洞的风阻测量误差分析与修正
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作者 庞加斌 《空气动力学学报》 CSCD 北大核心 2024年第7期112-117,I0002,共7页
汽车风洞用3/4开口试验段模拟真实道路气动环境,有限的试验段尺寸、地面边界层及射流剪切层会干扰流场,从而引起风阻测量误差。根据简化势流模型分析,3/4开口试验段存在模型实体阻塞、喷口阻塞、收集口阻塞以及水平压力梯度4项系统误差... 汽车风洞用3/4开口试验段模拟真实道路气动环境,有限的试验段尺寸、地面边界层及射流剪切层会干扰流场,从而引起风阻测量误差。根据简化势流模型分析,3/4开口试验段存在模型实体阻塞、喷口阻塞、收集口阻塞以及水平压力梯度4项系统误差源,其中模型实体阻塞让风阻测量值偏低,喷口和收集口阻塞让风阻测量值偏高,彼此平衡抵消机制使3/4开口试验段风洞具有能够适应更大尺寸模型的优势。利用Mercker-Wiedemann修正方法,结合同济大学整车气动声学风洞,计算修正了3辆不同尺寸车型的风阻系数。结果显示:设定风阻系数误差不超过1%为标准,3/4开口试验段汽车风洞最大阻塞比为15%;水平压力梯度对风阻系数误差的影响更大,风洞设计和验收标准应保证dC_(p)(x)/dx≤0.001/m。 展开更多
关键词 汽车风洞 3/4开口试验段 射流剪切层 阻塞效应 水平压力梯度
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Application of NaHCO_3/ DTPA Extractant-ICP Spectrometry Technique in Soil Test for Availability of Nutrients and Heavy Metals 被引量:4
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作者 CHEN TONG-BINBeifng Agroecosystem Experimental Station, Institute of Geography, Chinese Academy of Sciences, Beifng 100101 (China) 《Pedosphere》 SCIE CAS CSCD 1993年第4期377-382,共6页
Soil test for availability of nutrients and heavy metals is extensively served as a means for the evaluations of soil fertility, and environmental effects and phytotoxicity of pollutants in soils, and for the fertiliz... Soil test for availability of nutrients and heavy metals is extensively served as a means for the evaluations of soil fertility, and environmental effects and phytotoxicity of pollutants in soils, and for the fertilizer recommendation in agricultural and environmental sciences. Therefore, great attention has been paid to the measurement of elemental availability in soil test. 展开更多
关键词 calcareous soil elemental availability ICP spectrometry NaHCO3/ DTPA extractant soil test
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3D Particle Image Velocimetry Test of Inner Flow in a Double Blade Pump Impeller 被引量:5
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作者 LIU Houlin WANG Kai +3 位作者 YUAN Shouqi TAN Minggao WANG Yong RU Weimin 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2012年第3期491-497,共7页
The double blade pump is widely used in sewage treatment industry,however,the research on the internal flow characteristics of the double blade pump with particle image velocimetry(PIV) technology is very little at ... The double blade pump is widely used in sewage treatment industry,however,the research on the internal flow characteristics of the double blade pump with particle image velocimetry(PIV) technology is very little at present.To reveal inner flow characteristics in double blade pump impeller under off-design and design conditions,inner flows in a double blade pump impeller,whose specific speed is 111,are measured under the five off-design conditions and design condition by using 3D PIV test technology.In order to ensure the accuracy of the 3D PIV test,the external trigger synchronization system which makes use of fiber optic and equivalent calibration method are applied.The 3D PIV relative velocity synthesis procedure is compiled by using Visual C++ 2005.Then absolute velocity distribution and relative velocity distribution in the double blade pump impeller are obtained.Test results show that vortex exists in each condition,but the location,size and velocity of vortex core are different.Average absolute velocity value of impeller outlet increases at first,then decreases,and then increases again with increase of flow rate.Again average relative velocity values under 0.4,0.8,and 1.2 design condition are higher than that under 1.0 design condition,while under 0.6 and 1.4 design condition it is lower.Under low flow rate conditions,radial vectors of absolute velocities at impeller outlet and blade inlet near the pump shaft decrease with increase of flow rate,while that of relative velocities at the suction side near the pump shaft decreases.Radial vectors of absolute velocities and relative velocities change slightly under the two large flow rate conditions.The research results can be applied to instruct the hydraulic optimization design of double blade pumps. 展开更多
关键词 double blade pump IMPELLER inner flow 3D particle image velocimetry(PIV) test
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Deployment Reliability Test and Assessment for Landing Gear of Chang' E-3 Probe 被引量:1
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作者 吴琼 杨建中 +2 位作者 傅惠民 徐青华 满剑锋 《Journal of Donghua University(English Edition)》 EI CAS 2014年第6期782-784,800,共4页
Chang'E-3 probe incorporates four landing gears to assure the soft-landing,which are stowed while launching and deployed after separated from rocket. Deployment reliability is quite crucial for this mission. The d... Chang'E-3 probe incorporates four landing gears to assure the soft-landing,which are stowed while launching and deployed after separated from rocket. Deployment reliability is quite crucial for this mission. The deployment reliability test( DRT) method and assessment method were developed in this paper. Then DRT was conducted and the deployment reliability estimate of Chang'E-3probe was used to verify the proposed methods. 展开更多
关键词 Chang’E-3 landing gear DEPLOYMENT RELIABILITY test ASSESSMENT
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一种基于Al_(2)O_(3)/SiC气凝胶的热防护系统隔热性能研究
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作者 张兴丽 梁蒙康 马嘉 《航天器环境工程》 CSCD 2024年第5期595-601,共7页
飞行器再入大气层时,高速气流的冲刷作用会在其表面产生极高热流密度和压力,这种双重载荷可能对飞行器的结构材料造成严重的热损伤,甚至导致飞行事故。针对该问题,文章设计了以Al_(2)O_(3)/SiC复合气凝胶作为隔热层的轻质三明治结构热... 飞行器再入大气层时,高速气流的冲刷作用会在其表面产生极高热流密度和压力,这种双重载荷可能对飞行器的结构材料造成严重的热损伤,甚至导致飞行事故。针对该问题,文章设计了以Al_(2)O_(3)/SiC复合气凝胶作为隔热层的轻质三明治结构热防护系统,并通过氧−乙炔烧蚀试验对典型高温条件下该热防护系统的隔热性能进行测试,结果显示:热防护系统的线烧蚀率和质量烧蚀率随隔热层厚度的增加而逐渐减小,当系统厚度为14 mm时,线烧蚀率和质量烧蚀率分别为0.0019 mm·s^(-1)和0.0031 g·s^(-1),且烧蚀形貌整体性较好,说明热防护系统具有优异的隔热及力学性能。同时,通过有限元仿真方法对热防护系统进行热力耦合分析,对烧蚀试验结果进行了验证。 展开更多
关键词 Al_(2)O_(3)/SiC气凝胶 烧蚀试验 隔热性能 热力耦合 仿真分析 试验研究
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An optimal stacking order for mid-bond testing cost reduction of 3D IC 被引量:2
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作者 Ni Tianming Liang Huaguo +4 位作者 Nie Mu Bian Jingchang Huang Zhengfeng Xu Xiumin Fang Xiangsheng 《Journal of Southeast University(English Edition)》 EI CAS 2018年第2期166-172,共7页
In order to solve the problem that the testing cost of the three-dimensional integrated circuit(3D IC)is too high,an optimal stacking order scheme is proposed to reduce the mid-bond test cost.A new testing model is bu... In order to solve the problem that the testing cost of the three-dimensional integrated circuit(3D IC)is too high,an optimal stacking order scheme is proposed to reduce the mid-bond test cost.A new testing model is built with the general consideration of both the test time for automatic test equipment(ATE)and manufacturing failure factors.An algorithm for testing cost and testing order optimization is proposed,and the minimum testing cost and optimized stacking order can be carried out by taking testing bandwidth and testing power as constraints.To prove the influence of the optimal stacking order on testing costs,two baselines stacked in sequential either in pyramid type or in inverted pyramid type are compared.Based on the benchmarks from ITC 02,experimental results show that for a 5-layer 3D IC,under different constraints,the optimal stacking order can reduce the test costs on average by 13%and 62%,respectively,compared to the pyramid type and inverted pyramid type.Furthermore,with the increase of the stack size,the test costs of the optimized stack order can be decreased. 展开更多
关键词 three-dimensional integrated circuit(3D IC) mid-bond test cost stacking order sequential stacking failed bonding
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功能性状和立地条件与树木根系NO_(3)^(-)吸收能力的关系 被引量:2
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作者 于淼 张碧嘉 +6 位作者 王泽锦 于凤珍 赵新航 杨佳绒 李品 樊大勇 徐程扬 《北京林业大学学报》 CAS CSCD 北大核心 2024年第1期35-43,共9页
【目的】养分是干旱瘠薄立地中树木生长的重要限制因素,树木对干旱瘠薄立地中养分的吸收利用方式决定其生态适应对策。本研究通过野外原位测定,探究根系氮吸收动力学及其与根系形态性状间的耦合关系,为揭示林木根系在干旱瘠薄环境中的... 【目的】养分是干旱瘠薄立地中树木生长的重要限制因素,树木对干旱瘠薄立地中养分的吸收利用方式决定其生态适应对策。本研究通过野外原位测定,探究根系氮吸收动力学及其与根系形态性状间的耦合关系,为揭示林木根系在干旱瘠薄环境中的生理功能奠定基础。【方法】以北京市百望山森林公园内的山桃、栓皮栎和元宝枫为对象,采用以硝态氮(NO_(3)^(-))为唯一氮源的改良型梯度霍格兰营养液,在一般程度的干旱瘠薄立地和极端程度的干旱瘠薄立地中分别开展野外原位测定根系NO_(3)^(-)吸收动力学研究,并通过Pearson相关性分析和通径分析研究根系NO_(3)^(-)吸收速率与根系功能性状间的关系。【结果】树种、立地条件和两者的交互效应对NO_(3)^(-)吸收速率和动力学参数均有显著或极显著的影响。3个树种对氮的亲和性均较高,元宝枫根系对NO_(3)^(-)的吸收速率偏低,在2种立地条件中均显著低于山桃和栓皮栎。生长在更加干旱瘠薄立地中的速生树种对NO_(3)^(-)的吸收具有补偿性。根系功能性状与NO_(3)^(-)的吸收速率有很好的耦合关系,比根长和比根表面积对根系NO_(3)^(-)吸收速率有显著正效应,根直径和根组织密度则相反。分支结构性状中,分支强度和链接数对根系NO_(3)^(-)吸收速率的作用较弱。【结论】生长速度较快的山桃和栓皮栎根系的NO_(3)^(-)吸收速率在极端干旱瘠薄立地胁迫下显著降低,元宝枫则相反。采取提高最大吸收速率和降低氮亲和力的“速度策略”可保障速生树种根系对NO_(3)^(-)的补偿性吸收。高比根长、高比根表面积、低根直径和低根组织密度的形态性状组合,可有效提高根系在干旱瘠薄立地中对NO_(3)^(-)的吸收速率。 展开更多
关键词 原位测定 立地条件 种间差异 NO_(3)^(-)吸收 功能性状 吸收动力学
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Chair-rising and 3-min walk: A simple screening test for functional mobility
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作者 Tae-Woong Oh Izumi Tabata +2 位作者 Jin-Hwan Kim Tae-Hyun Lee Tatsuki Naka 《Open Journal of Preventive Medicine》 2012年第1期93-97,共5页
Aging induces decrease of locomotor capacity and its decrease is associated with an increased risk of falls. Several lines of evidence indicate that both change in muscle power and aerobic fitness are causative. Mobil... Aging induces decrease of locomotor capacity and its decrease is associated with an increased risk of falls. Several lines of evidence indicate that both change in muscle power and aerobic fitness are causative. Mobility tests are usually based on a maximal exercise stress test;however, this test is often difficult and sometimes frightening to older persons. Therefore, the objective of this study was to examine age and gender differences in 3-min walk distance test (3WDT), and time of chair-rising test (CRT) of functional mobility. 153 men and 159 women aged from 20 to 78 years were recruited as subjects of the present study. The body composition measured the height, body mass (BM), body mass index (BMI), lean tissue mass (LTM), and waist circumference (WC). The Functional mobility tests measured the peak oxygen uptake (VO2peak), 3WDT, leg extension strength (LES), and times of CRT. Both in men and women, height and BMI, WC decreased and increased, respectively, with age. Height, BM, LTM, WC in men are higher than in women. We found no correlation between ages and 3WDT in women and a significant, negative correlation in men. All parameters of fitness performance were negatively correlated with age. Both in men and women, all parameters of fitness performance were positively correlated with sex. Both in men and women, VO2peak, 3WDT, and LES decreased with age. All parameters of fitness performance in men are higher than in women. Both in men and women were observed for the correlation between 3WDT and VO2peak, LES and CRT respectively. Although as the correlation coefficient between 3WTD and VO2peak, LES and CRT were low (r = 0.28 - 0.38), an error may occur, this study shows that 3WDT and CRT test can be a feasible method of providing the information for muscle power and aerobic fitness, possibly avoiding the need for a maximal stress test. 展开更多
关键词 Peak Oxygen UPTAKE 3-Min WALK Distance test LEG Extension Strength Chair-Rising test Mobility
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<i>Inmap-t</i>: Leveraging TTCN-3 to Test the Security Impact of Intra Network Elements
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作者 Antonino Vitale Marc Dacier 《Journal of Computer and Communications》 2021年第6期174-190,共17页
This paper rejuvenates the notion of conformance testing in order to assess the security of networks. It leverages the Testing and Test Control Notation Version 3 (TTCN-3) by applying it to a redefined notion of <i... This paper rejuvenates the notion of conformance testing in order to assess the security of networks. It leverages the Testing and Test Control Notation Version 3 (TTCN-3) by applying it to a redefined notion of <i>System under Test</i> (<i>SUT</i>). Instead of testing, as it is classically done, a software/firmware/ hardware element, an intangible object, namely the network, is tested in order to infer some of its security properties. After a brief introduction of TTCN-3 and Titan, its compilation and execution environment, a couple of use cases are provided to illustrate the feasibility of the approach. The pros and cons of using TTCN-3 to implement a scalable and flexible network testing environment are discussed. 展开更多
关键词 TTCN-3 Network Security Conformance testing Deep Packet Inspection FIREWALL
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利用SSR标记鉴定西瓜杂交种新喜3号纯度
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作者 任艺慈 刘喜存 +4 位作者 王文英 高展 王向东 郭春江 李江伟 《中国瓜菜》 CAS 北大核心 2024年第8期131-135,共5页
为了提高杂交种筛选效率,从23对西瓜简单重复序列(simple sequence repeat,SSR)引物中筛选适用于西瓜杂交种新喜3号及其亲本的特异性引物并进行种子纯度鉴定。结果表明,1对引物BVWS00208在亲本间具有多态性且在杂交后代中兼具双亲条带,... 为了提高杂交种筛选效率,从23对西瓜简单重复序列(simple sequence repeat,SSR)引物中筛选适用于西瓜杂交种新喜3号及其亲本的特异性引物并进行种子纯度鉴定。结果表明,1对引物BVWS00208在亲本间具有多态性且在杂交后代中兼具双亲条带,属于共显性标记。将该引物在98个杂交后代中进行验证,纯度鉴定结果为98.9%,通过传统田间纯度鉴定结果为98.0%,二者误差≤1%。综上,SSR引物BVWS00208能够作为特异引物对西瓜杂交种新喜3号进行种子纯度鉴定,且该方法便捷经济,能为该品种的制种和推广提供技术支持。 展开更多
关键词 西瓜 新喜3 SSR分子标记 纯度鉴定
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Effects of 3D deformation and nonlinear stress–strain relationship on the Brazilian test for a transversely isotropic rock
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作者 Juhyi Yim Yoonsung Lee +1 位作者 Seungki Hong Ki-Bok Min 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第12期3221-3229,共9页
To improve the accuracy of indirect tensile strength for a transversely isotropic rock in the Brazilian test, this study considered the three-dimensional (3D) deformation and the nonlinear stress–strain relationship.... To improve the accuracy of indirect tensile strength for a transversely isotropic rock in the Brazilian test, this study considered the three-dimensional (3D) deformation and the nonlinear stress–strain relationship. A parametric study of a numerical Brazilian test was performed for a general range of elastic constants, revealing that the 3D modeling evaluated the indirect tensile strength up to 40% higher than the plane stress modeling. For the actual Asan gneiss, the 3D model evaluated the indirect tensile strength up to 10% higher and slightly enhanced the accuracy of deformation estimation compared with the plane stress model. The nonlinearity in stress–strain curve of Asan gneiss under uniaxial compression was then considered, such that the evaluated indirect tensile strength was affected by up to 10% and its anisotropy agreed well with the physical intuition. The estimation of deformation was significantly enhanced. The further validation on the nonlinear model is expected as future research. 展开更多
关键词 ANISOTROPY Transversely isotropy Brazilian test Indirect tensile strength NONLINEARITY 3D modeling
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3-D Modelling of the Confederation Bridge Using Data of Full Scale Tests
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作者 Lan Lin 《Open Journal of Civil Engineering》 2013年第3期18-25,共8页
Long-span bridges are special structures that require advanced analysis techniques to examine their performance. This paper presents a procedure developed to model the Confederation Bridge using 3-D beam elements. The... Long-span bridges are special structures that require advanced analysis techniques to examine their performance. This paper presents a procedure developed to model the Confederation Bridge using 3-D beam elements. The model was validated using the data collected before the opening of the bridge to the public. The bridge was instrumented to conduct fullscale static and dynamic tests. The static tests were to measure the deflection of the bridge pier while the dynamic tests to measure the free vibrations of the pier due to a sudden release of the static load. Confederation Bridge is one of the longest reinforced concrete bridges in the world. It connects the province of Prince Edward Island and the province of New Brunswick in Canada. Due to its strategic location and vital role as a transportation link between these two provinces, it was designed using higher safety factors than those for typical highway bridges. After validating the present numerical model, a procedure was developed to evaluate the performance of similar bridges subjected to traffic and seismic loads. It is of interest to note that the foundation stiffness and the modulus of elasticity of the concrete have significant effects on the structural responses of the Confederation Bridge. 展开更多
关键词 3-D Numerical Modeling Finite Element Technique Static testS Dynamic testS ACCELERATION Time HISTORY FOURIER Analysis Full Scale test SEISMIC Evaluation Confederation BRIDGE
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Finite element and experimental analysis of Vickers indentation testing on Al_2O_3 with diamond-like carbon coating
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作者 ZHAI Jian-guang WANG Yi-qi +1 位作者 KIM Tae-gyu SONG Jung-il 《Journal of Central South University》 SCIE EI CAS 2012年第5期1175-1181,共7页
Numerical simulation and experimental study of the Vickers indentation testing of the Al2O3 ceramic coated by diamond-like carbon(DLC) layer were conducted.The numerical analysis was implemented by a two-dimensional f... Numerical simulation and experimental study of the Vickers indentation testing of the Al2O3 ceramic coated by diamond-like carbon(DLC) layer were conducted.The numerical analysis was implemented by a two-dimensional finite element(FE) axis symmetry model.FE analysis results gave insight into the fracture mechanism of DLC films coated on brittle ceramic(Al2O3) substrates.The maximum principal stress field was used to locate the most expected area for crack formation and propagation during the Vickers indentation testing.The results show that the median crack initiates in the interface under indenter,before ring crack occurs as the indenter presses down.Finally,the plastic deformation appears when the indenter penetrates into the substrate.The thicker DLC coating increases the Vickers hardness and fracture toughness. 展开更多
关键词 Vickers indentation testing finite element diamond-like carbon AL2O3 fracture toughness
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