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砂土强度变化测试控制系统设计与实现
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作者 李军 《现代电子技术》 北大核心 2018年第10期35-38,共4页
传统检测方法不能根据不同地质情况、砂土强度的具体变化趋势快速完成系统串行通信接口选择。为了解决此问题,设计砂土强度变化测试控制系统。通过系统集成框图设计、测试台结构设计、采集控制器设计,完成砂土强度变化测试控制系统硬件... 传统检测方法不能根据不同地质情况、砂土强度的具体变化趋势快速完成系统串行通信接口选择。为了解决此问题,设计砂土强度变化测试控制系统。通过系统集成框图设计、测试台结构设计、采集控制器设计,完成砂土强度变化测试控制系统硬件模块设计。通过软件框架设计、开发流程设计、串行程序设计,完成砂土强度变化测试控制系统软件模块设计。模拟新型系统的工作环境,设计对比实验。结果表明,在砂土强度由高转低、由低转高两种情况下,系统串行通信接口选择速度,都得到了明显提升。 展开更多
关键词 砂土强度 变化测试 系统集成 采集控制器 软件架构 开发流程 串行程序
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血乳酸测试仪对竞技运动员不同强度运动后血乳酸的变化测试分析
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作者 赵升 《电子测试》 2014年第5X期144-145,共2页
目的 :探讨分析采用血乳酸测试仪测试竞技运动员在不同强度的运动之后,机体内血乳酸的变化情况。
关键词 血乳酸测试 竞技运动 不同强度运动 血乳酸 变化测试
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对路面弯沉值及其变化测试的探讨
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作者 徐丽 吴迪 《中小企业管理与科技》 2011年第3期124-124,共1页
本文对路面弯沉值及其变化测试进行了分析探讨。
关键词 路面弯沉值 变化测试 探讨
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低频低压减载装置测试方法的研究
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作者 陈铸华 李晓 王帅夫 《数字技术与应用》 2014年第11期80-81,共2页
本项目针对低频低压减载装置的连续变化测试、多轮重复测试和固定步长连续测试方法进行了具体分析,并采用数字技术生成高精度频率、电压模拟校验df/dt和du/dt定值。文中详细介绍了实现方案、技术特点、测试系统的原理和硬软件构成。
关键词 低频低压减载装置 频率测试试验 电压变化测试
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高含CO_2凝析气相态测试及分析 被引量:6
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作者 余华杰 王星 +1 位作者 谭先红 田波 《石油钻探技术》 CAS CSCD 北大核心 2013年第2期104-108,共5页
为了制定高含CO2凝析气藏的合理开发方式、提高凝析油采收率,需要了解高含CO2的凝析气流体在开发过程中存在的复杂相变行为。采用高温高压多功能地层流体分析仪,对不同摩尔分数CO2凝析气体系样品进行了单次闪蒸实验、露点压力测试、等... 为了制定高含CO2凝析气藏的合理开发方式、提高凝析油采收率,需要了解高含CO2的凝析气流体在开发过程中存在的复杂相变行为。采用高温高压多功能地层流体分析仪,对不同摩尔分数CO2凝析气体系样品进行了单次闪蒸实验、露点压力测试、等组分膨胀实验和定容衰竭实验,对比分析了CO2摩尔分数对凝析气体系高压物性参数和相态特征的影响。研究结果表明,随着CO2摩尔分数的增加,凝析油的反凝析速度减缓,且最大反凝析液量减小约15%、凝析油的采出程度增加约20%、天然气采出程度为85%左右、相包络线向内收缩。富含CO2凝析气体系中的CO2既有利于抑制凝析油的反凝析,又有利于增强凝析油的反蒸发,对于提高凝析油采收率具有显著效果。 展开更多
关键词 高含CO2凝析气PVT测试相态变化规律
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近三年高考语文全国卷的坚持、变化及其教学启示 被引量:1
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作者 纪荣海 《福建基础教育研究》 2018年第8期4-8,共5页
近三年高考语文全国卷既有坚持,也有发展变化,其中隐含着一定的价值追求。文章在梳理近三年高考语文全国卷测试坚持与变化的基础上,探讨高考语文全国卷测试坚持与变化给教学带来的积极影响和意义,然后提出相应的教学策略与建议。
关键词 高考语文 全国卷 测试坚持 测试变化 教学启示
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基于SIFT技术的集成电路失效缺陷分析 被引量:3
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作者 刘迪 顾晓峰 +1 位作者 陆坚 梁海莲 《固体电子学研究与进展》 CAS CSCD 北大核心 2012年第4期336-340,共5页
激励源诱导故障测试(SIFT)是一种新型的失效定位技术,可用于集成电路和分立器件中漏电、击穿、短路等失效点的定位及失效机理的分析。在介绍SIFT技术工作原理的基础上,利用该技术进行了六反相器电路的深埋层缺陷、收发器电路中电源与地... 激励源诱导故障测试(SIFT)是一种新型的失效定位技术,可用于集成电路和分立器件中漏电、击穿、短路等失效点的定位及失效机理的分析。在介绍SIFT技术工作原理的基础上,利用该技术进行了六反相器电路的深埋层缺陷、收发器电路中电源与地之间漏电流失效和串行输出模数转换电路MOS器件欧姆短路的定位,并结合微结构观测分析了失效原因。研究结果表明,SIFT技术能有效分析光发射显微镜(EMMI)和激光光束诱导阻抗变化测试(OBIRCH)技术较难定位的缺陷,弥补了这些常规失效分析技术的不足。 展开更多
关键词 激励源诱导故障测试 失效分析 失效定位 光发射显微镜 激光光束诱导阻抗变化测试
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红外发光显微镜及其在集成电路失效分析中的应用 被引量:5
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作者 张滨海 方培源 王家楫 《分析仪器》 CAS 2008年第5期15-18,共4页
随着超大规模集成电路的发展,半导体芯片中元器件的特征尺寸越来越小,已经进入了深亚微米时代。近几年新发展起来的红外发光显微镜技术,能利用集成电路(IC)器件中大多数缺陷都呈现微弱红外发光的现象,迅速准确地定位失效点,成为对IC进... 随着超大规模集成电路的发展,半导体芯片中元器件的特征尺寸越来越小,已经进入了深亚微米时代。近几年新发展起来的红外发光显微镜技术,能利用集成电路(IC)器件中大多数缺陷都呈现微弱红外发光的现象,迅速准确地定位失效点,成为对IC进行失效缺陷定位的有力工具。本文介绍了半导体的发光机理,红外发光显微镜的基本结构、主要部件及技术特点。通过对两个IC失效样品的分析实例,介绍红外发光显微镜及其补充技术——激光束诱导电阻率变化测试技术在IC失效分析中的具体应用。 展开更多
关键词 集成电路 失效分析 红外发光显微镜 激光束诱导电阻率变化测试技术
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确定井漏层位的改进方法及其应用 被引量:12
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作者 陈钢花 尹成芳 +1 位作者 邱正松 王在明 《石油地质与工程》 CAS 2007年第3期101-103,共3页
为解决钻井过程中出现的井漏技术难题,对传统的立压变化测试法进行了改进,通过引入井径曲线,分段计算钻具组合和井身结构,使得立压变化测试法更趋完善,井漏层位判断更加准确。同时采用VB编制了相应的软件,该软件界面友好,操作简便。使... 为解决钻井过程中出现的井漏技术难题,对传统的立压变化测试法进行了改进,通过引入井径曲线,分段计算钻具组合和井身结构,使得立压变化测试法更趋完善,井漏层位判断更加准确。同时采用VB编制了相应的软件,该软件界面友好,操作简便。使用该软件对油田五口井的井漏层位进行了判断,经堵漏证实,井漏层位判断准确率为100%。另外对其它油田几口井的井漏层位也进行了判断,并取得了较好的应用效果。改进的确定井漏层位的立压变化测试方法为有效地防漏堵漏奠定了基础,缩短了堵漏作业时间,节约了钻井成本。 展开更多
关键词 井漏层位确定 立压变化测试 井径曲线 防漏堵漏
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Detecting Global Vegetation Changes Using Mann-Kendal(MK) Trend Test for 1982–2015 Time Period 被引量:10
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作者 GUO Meng LI Jing +2 位作者 HE Hongshi XU Jiawei JIN Yinghua 《Chinese Geographical Science》 SCIE CSCD 2018年第6期907-919,共13页
Vegetation is the main component of the terrestrial ecosystem and plays a key role in global climate change. Remotely sensed vegetation indices are widely used to detect vegetation trends at large scales. To understan... Vegetation is the main component of the terrestrial ecosystem and plays a key role in global climate change. Remotely sensed vegetation indices are widely used to detect vegetation trends at large scales. To understand the trends of vegetation cover, this research examined the spatial-temporal trends of global vegetation by employing the normalized difference vegetation index(NDVI) from the Advanced Very High Resolution Radiometer(AVHRR) Global Inventory Modeling and Mapping Studies(GIMMS) time series(1982–2015). Ten samples were selected to test the temporal trend of NDVI, and the results show that in arid and semi-arid regions, NDVI showed a deceasing trend, while it showed a growing trend in other regions. Mann-Kendal(MK) trend test results indicate that 83.37% of NDVI pixels exhibited positive trends and that only 16.63% showed negative trends(P < 0.05) during the period from 1982 to 2015. The increasing NDVI trends primarily occurred in tree-covered regions because of forest growth and re-growth and also because of vegetation succession after a forest disturbance. The increasing trend of the NDVI in cropland regions was primarily because of the increasing cropland area and the improvement in planting techniques. This research describes the spatial vegetation trends at a global scale over the past 30+ years, especially for different land cover types. 展开更多
关键词 vegetation trend NDVI3g.v1 Mann-Kendall (MK) trend test land cover types
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Effects of Mechanical Impacts on Hatchability of Broiler Breeders
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作者 Timea Torma Katalin Gafil Kovhcsn 《Journal of Agricultural Science and Technology(A)》 2014年第6期535-540,共6页
Transporting hatching eggs from Hungary and incubating them abroad revealed lower hatchability compared to when the eggs were incubated in Hungary. Following transport, there were higher embryo losses and, notably, mo... Transporting hatching eggs from Hungary and incubating them abroad revealed lower hatchability compared to when the eggs were incubated in Hungary. Following transport, there were higher embryo losses and, notably, more malformed embryos. The aim of these initial trials was to determine if a testing device (crazy fit massage machine (CFM machine)) was able to replicate and model the mechanical impacts experienced during transport and reproduce the reduction in hatchability and increase the level of malformed embryos as observed in commercial practice. Tinytag~ high sensitivity shock and vibration loggers were used to monitor the impacts under field and trial conditions. Applying single 10 min treatments on the CFM machine, which used the same frequency (10-30 Hz) as the eggs experience under field conditions, induced the negative effect of transport, and lower hatching results were experienced. Three trials were conducted. Treated eggs in Trials 1 and 2 received automatically and periodical changing vibration in a range between 10-30 Hz for 10 min while in Trial 3 two different levels of impact were applied at 20 Hz and 30 Hz, respectively. Hatchability decreased due to the treatment significatly only in Trial 3. Significant differences were also detected in early dead levels in Trials 2 and 3 and the occurrences of malformation in Trials 1 and 3. All these results are in accordance with the field experience. Thus, the trials which examined the equipment were able to produce mechanical impacts that were repeatable in order to set up statistically reliable trials on hatching eggs. 展开更多
关键词 Mechanical impacts HATCHABILITY loggers.
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Tests for Parameter Changes in Time Series
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作者 JIN Hao YANG Yun-feng 《Chinese Quarterly Journal of Mathematics》 CSCD 2011年第1期120-124,共5页
The paper considers the problem of testing for a change point in the parameters of AR(p) models.It is shown that the asymptotically limiting distribution of the residual CUSUM of squares test(RCUSQ) is still the s... The paper considers the problem of testing for a change point in the parameters of AR(p) models.It is shown that the asymptotically limiting distribution of the residual CUSUM of squares test(RCUSQ) is still the sup of a standard Brownian bridge under null hypothesis.We also show via simulations that our asymptotic results provide good approximations in finite samples. 展开更多
关键词 change point Brownian bridge RCUSQ test
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The Correlation between Density and Low-Temperature Creep Property of Asphalt 被引量:2
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作者 Zhang Xiaoying Xu Chuanjie 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2012年第2期31-38,共8页
The density of asphalt was measured with the pycnometer and densitometer. Creep properties of the asphalt were investigated with the bending beam rheometer at temperatures ranging from 0 ~C to -36 ~C. The asphalt dens... The density of asphalt was measured with the pycnometer and densitometer. Creep properties of the asphalt were investigated with the bending beam rheometer at temperatures ranging from 0 ~C to -36 ~C. The asphalt density data used to correlate with the creep properties were calculated from the regression equation of density and temperature. The asphalt sample used to determine the creep property was aged by the standard RTFOT test and the PAV test. The test results showed that the asphalt density had a linear relationship with temperature changes. The logarithm of the creep stiffness and the slope of the logarithm of the stiffness at 60 seconds all demonstrated a linear relationship with the density, and the regression coefficient of these data was around 0.99. The creep stiffness and the slope of the creep stiffness can be calculated from the asphalt density at the same temperature. 展开更多
关键词 ASPHALT DENSITY creep stiffness low-temperature property
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New real-time-PCR method to identify single point mutations in hepatitis C virus 被引量:1
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作者 Qian Chen Irene Belmonte +11 位作者 Maria Buti Leonardo Nieto Damir Garcia-Cehic Josep Gregori Celia Perales Laura Ordeig Meritxell Llorens Maria Eugenia Soria Rafael Esteban Juan Ignacio Esteban Francisco Rodriguez-Frias Josep Quer 《World Journal of Gastroenterology》 SCIE CAS 2016年第43期9604-9612,共9页
AIM To develop a fast, low-cost diagnostic strategy to identify single point mutations in highly variable genomes such as hepatitis C virus(HCV).METHODS In patients with HCV infection, resistance-associated amino acid... AIM To develop a fast, low-cost diagnostic strategy to identify single point mutations in highly variable genomes such as hepatitis C virus(HCV).METHODS In patients with HCV infection, resistance-associated amino acid substitutions within the viral quasispecies prior to therapy can confer decreased susceptibility to direct-acting antiviral agents and lead to treatment failure and virological relapse. One such naturally occurring mutation is the Q80 K substitution in the HCV-NS3 protease gene, which confers resistance to PI inhibitors, particularly simeprevir. Low-cost, highly sensitive techniques enabling routine detection of these single point mutations would be useful to identify patients at a risk of treatment failure. Light Cycler methods, based on real-time PCR with sequencespecific probe hybridization, have been implemented in most diagnostic laboratories. However, this technique cannot identify single point mutations in highly variable genetic environments, such as the HCV genome. To circumvent this problem, we developed a new method to homogenize all nucleotides present in a region except the point mutation of interest. RESULTS Using nucleotide-specific probes Q, K, and R substitutions at position 80 were clearly identified at a sensitivity of 10%(mutations present at a frequency of at least 10% were detected). The technique was successfully applied to identify the Q80 K substitution in 240 HCV G1 serum samples, with performance comparable to that of direct Sanger sequencing, the current standard procedure for this purpose. The new method was then validated in a Catalonian population of 202 HCV G1-infected individuals. Q80 K was detected in 14.6% of G1 a patients and 0% of G1 b in our setting. CONCLUSION A fast, low-cost diagnostic strategy based on real-time PCR and fluorescence resonance energy transfer probe melting curve analysis has been successfully developed to identify single point mutations in highly variable genomes such as hepatitis C virus. This technique can be adapted to detect any single point mutation in highly variable genomes. 展开更多
关键词 Hepatitis C virus Resistance-associated amino acid substitutions Low-cost test Single-point mutations Q80K
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Grain crushing and its effects on rheological behavior of weathered granular soil
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作者 陈晓斌 张家生 《Journal of Central South University》 SCIE EI CAS 2012年第7期2022-2028,共7页
To disclose the grain crushing effects on the weathered granular soil rheological behavior,a series of rheological tests (odometer compression and triaxial shearing) were carried out.At the same time,the sieving analy... To disclose the grain crushing effects on the weathered granular soil rheological behavior,a series of rheological tests (odometer compression and triaxial shearing) were carried out.At the same time,the sieving analysis tests of these specimens were also executed before and after tests,and the grain crushing degree,Br and n5,were collectively adopted to estimate the grain crushing.The grain crushing degree depends on the stress path,stress level,and load time,especially,the longer load time and more intensive gradient shearing path will increase the grain crushing quantity.The Hardin crushing degrees Br are 0.191,0.118 and 0.085 in the ordinary compression,rheological compression and triaxial rheological shearing,respectively;The grain crushing degrees n5 are 1.9,1.4 and 1.32,respectively.The strain softening phase indicates the grain crushing and diffusive collapse,and the strain hardening phase indicates the rearrangement of these crushed grains and formation of new bearing soil skeleton.The rheological deformation of granular soil can be attributed to the coarse grain crushing and the filling external porosity with crushed fragments. 展开更多
关键词 grain crushing degree rheological behavior weathered granular soil tri-axial rheological tests odometer compressiontest
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Multi-environmental Evaluation of Triticale, Wheat and Barley Genotypes by GGE Biplot Analysis
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作者 Oguz Bilgin Alpay Balkan +1 位作者 Zahit Kayihan Korkut Ismet Baser 《Journal of Life Sciences》 2018年第1期13-23,共11页
The research was carried out with 9 triticale, 3 bread wheat, 3 durum wheat and 3 barley varieties and advanced lines in Tekirdag, Edime and Silivri locations during three years. In the study, the data obtained from c... The research was carried out with 9 triticale, 3 bread wheat, 3 durum wheat and 3 barley varieties and advanced lines in Tekirdag, Edime and Silivri locations during three years. In the study, the data obtained from combined variance analysis were performed and the significance of the differences between the averages was determined by LSD multiple comparison test. GGE biplot analysis and graphics were made by using the statistical package program. The genotypes G2 and G3 for thousand kernel weight, genotype G1 for the heading time and test weight, genotypes G14 and G15 for the maturation time, number of spikelets per spike and grain weight per spike and G13 for the plant height, spike length and grain yield per hectare decare revealed the highest values. The genotypes G6, GS, G4, G14, G9, G8 and G7 gave lower values than the average in terms of grain yield, whereas the other genotypes gave higher values than the general average. According to biplot graphical results, while locations 1 and 8 were closely related, locations 9, 2 and 7 were positively related to these environments. Although the location 7 is slightly different from the other 4 locations, these 5 locations can be seen as a mega environment. Genotypes G12, G2, G3 and G10 for this mega-environment showed the best performances. According to the results of grain yields obtained from 9 different locations, the location 5 was the most discriminating area while the location 1 was the least discriminating. Location 2 was the best representative location, while locations 4 and 7 were with the lowest representation capability. The locations that are both descriptive and representative are good test locations for the selection of adapted genotypes. Test environments, such as location 8, with low ability to represent are useful for selecting genotypes that perform well in specific regions if the target environments can be subdivided into sub-environments. 展开更多
关键词 GGE biplot genotype mega-environment descriptive location and representative.
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New double yield surface model for coarse granular materials incorporating nonlinear unified failure criterion 被引量:3
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作者 刘萌成 刘汉龙 高玉峰 《Journal of Central South University》 SCIE EI CAS 2012年第11期3236-3243,共8页
A new double-yield-sarface (DYS) model was developed to characterize the strength and deformation behaviors of coarse granular materials (CGMs). Two kinds of deformation mechanisms, including the shear and compres... A new double-yield-sarface (DYS) model was developed to characterize the strength and deformation behaviors of coarse granular materials (CGMs). Two kinds of deformation mechanisms, including the shear and compressive plastic deformation, were taken into account in this model, These two deformation mechanisms were described by the shear and compressive yield functions, respectively. The Lode angle dependent formulations of proposed model were deduced by incorporating a 3D nonlinear unified failure criterion. Some comparisons were presented between the numerical predictions of proposed model and test data of true triaxial tests on the modeled rockfills. The model predictions are in good agreement with the test data and capture the strain hardening and plastic volumetric dilation of CGMs. These findings verify the reasonability of current DYS model, and indicate that this model is well suited to reproduce the stress-strain-volume change behavior of CGMs in general. 展开更多
关键词 constitutive model coarse granular material failure criterion DILATANCY yield surface
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An Extreme Value Approach to Test the Effect of Price Limits on Volatility
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作者 Haitham Nobanee Khalil Hilu 《Journal of Modern Accounting and Auditing》 2013年第10期1382-1391,共10页
Many stock exchanges around the world enforcing daily price limits on the amount asset prices can change to prevent the market from overreacting and to reduce volatility. Price limits are artificial boundaries set by ... Many stock exchanges around the world enforcing daily price limits on the amount asset prices can change to prevent the market from overreacting and to reduce volatility. Price limits are artificial boundaries set by market regulators who restrict price changes of a stock to a pre-specified range during a trading day or a single trading session. The primary aim of price limit rules is to stabilize the markets during panic trading, to moderate vitality by repressing excessive speculation, and to allow stocks to be traded at prices close to their fair value. However, their impact on the market is a somewhat unresolved issue (Harris, 1998). Using a methodology of comparing volatility based on the extreme value technique, the authors empirically investigate the impact of price limits on the volatility of the Stock Exchange of Thailand. The empirical results support price limits advocates, suggesting that price limits rules moderate stock price volatility. 展开更多
关键词 price limits extreme value theory VOLATILITY Stock Exchange of Thailand
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Examination of Archival Data for Inhomogeneities and Determination of Climate Change in North America
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作者 William A. van Wijngaarden 《Journal of Earth Science and Engineering》 2013年第11期776-783,共8页
Numerous articles have examined archival weather observations and attributed climate changes on time scales ranging from centuries to decades and in one case even days to human activity. This article gives examples sh... Numerous articles have examined archival weather observations and attributed climate changes on time scales ranging from centuries to decades and in one case even days to human activity. This article gives examples showing how climate variability and sudden changes in instruments affect trend determination. In particular, surface temperature and water vapor pressure trends in North America during 1948-2010 are discussed. Over 1/4 billion hourly observations taken at 309 stations, were first carefully examined for inhomogeneities. Positive and negative steps, for both temperature and water vapor pressure were found to not be evenly distributed in time. Inclusion of such data in a trend analysis would overstate decadal changes in temperature and water vapor. Time series free of such discontinuities show a statistically significant warming has primarily affected the western Arctic, Canadian prairies and the Midwestern U.S. during winter. Increases in water vapor pressure are most pronounced in summer in the eastern U.S. The decadal water vapor pressure trends are somewhat smaller than found in other studies that examined data for far shorter time periods. The claim of a change in the DTR (diurnal temperature range) during the 3 day flight ban following Sept. 11, 2011, is not substantiated. The observed change in the DTR was likely caused by a reduction in cloudiness during the flight ban. 展开更多
关键词 Climate change INHOMOGENEITIES TEMPERATURE humidity trends diurnal temperature range.
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Self-adaptive learning based immune algorithm 被引量:1
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作者 许斌 庄毅 +1 位作者 薛羽 王洲 《Journal of Central South University》 SCIE EI CAS 2012年第4期1021-1031,共11页
A self-adaptive learning based immune algorithm (SALIA) is proposed to tackle diverse optimization problems, such as complex multi-modal and ill-conditioned prc,blems with the high robustness. The SALIA algorithm ad... A self-adaptive learning based immune algorithm (SALIA) is proposed to tackle diverse optimization problems, such as complex multi-modal and ill-conditioned prc,blems with the high robustness. The SALIA algorithm adopted a mutation strategy pool which consists of four effective mutation strategies to generate new antibodies. A self-adaptive learning framework is implemented to select the mutation strategies by learning from their previous performances in generating promising solutions. Twenty-six state-of-the-art optimization problems with different characteristics, such as uni-modality, multi-modality, rotation, ill-condition, mis-scale and noise, are used to verify the validity of SALIA. Experimental results show that the novel algorithm SALIA achieves a higher universality and robustness than clonal selection algorithms (CLONALG), and the mean error index of each test function in SALIA decreases by a factor of at least 1.0×10^7 in average. 展开更多
关键词 immune algorithm multi-modal optimization evolutionary computation immtme secondary response self-adaptivelearning
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