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磁化率各向异性测量在沉积学中的应用 被引量:10
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作者 许峰宇 王力波 《沉积学报》 CAS CSCD 北大核心 1994年第2期94-100,共7页
本文利用磁化率各向异性来研究南京下蜀土的沉积组构。根据南京下蜀上的磁组构特征及其与华北黄土的对比分析,探讨了下蜀土的成因,并进而指出了磁化率各向异性测量对于沉积学的重要意义。
关键词 沉积学 磁化率 异性测量
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偶极各向异性测量中钻孔应力集中的效应
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作者 K. W. Winkler B. K. Sinha +2 位作者 T. J. Plona 董旭光 林怀存 《世界地震译丛》 1999年第2期63-70,共8页
由实验和理论给出了应力集中是如何影响钻孔周围速度场,以及速度场是如何影响偶极各向异性测量的。在低频率,偶极波主要易受远场应力的作用,即标准声波测井解释结果恰能得出最大应力方向。在高频率,偶极波主要受近场应力集中的影响,致... 由实验和理论给出了应力集中是如何影响钻孔周围速度场,以及速度场是如何影响偶极各向异性测量的。在低频率,偶极波主要易受远场应力的作用,即标准声波测井解释结果恰能得出最大应力方向。在高频率,偶极波主要受近场应力集中的影响,致使快速极化方向与最小构造应力的方向一致。这些效应使得在快速极化方向和慢速极化方向测得的偶极波散曲线产生了交叉。根据宽频带偶极资料,偶极波散曲线交叉可被用来作为应力诱发各向异性超过弱的固有各向异性的标志。 展开更多
关键词 偶极波 各向异性测量 钻孔 应力集 声波测井
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含裂隙储层中的天然气水合物分布:来自地震各向异性测量的启示 被引量:2
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作者 刘圣彪 韩同城 符力耘 《中国科学:地球科学》 CSCD 北大核心 2021年第5期725-733,共9页
不同的天然气水合物分布对储层地震性质的影响存在显著差异,深入认识储层中的水合物分布,对基于地震性质定量评价水合物资源具有重要意义.然而,目前对含裂隙储层中水合物分布的认识仍然严重不足.为此,文章设计并开展了针对性岩石物理实... 不同的天然气水合物分布对储层地震性质的影响存在显著差异,深入认识储层中的水合物分布,对基于地震性质定量评价水合物资源具有重要意义.然而,目前对含裂隙储层中水合物分布的认识仍然严重不足.为此,文章设计并开展了针对性岩石物理实验,测量了含硬币状定向裂隙岩石在水合物生成过程中的各向异性速度,并进一步分析了不同水合物饱和度条件下裂隙中的水合物分布,及其对各向异性速度和各向异性参数的影响.实验结果表明:随着水合物饱和度的增加,各向异性速度均呈现出整体增加的趋势;当水合物饱和度大于10%时,各向异性速度的增加幅度变得更大,且各向异性速度间的增加速率也表现出强烈差异,具体表现为,垂直于层理面与裂隙面传播的纵波速度和偏振方向垂直于层理面的横波速度分别比其他纵波和横波速度增加得更快.对各向异性结果的深入解释表明:在水合物饱和度小于10%时,水合物可能倾向于黏结在裂隙表面的矿物颗粒上,而当水合物饱和度大于10%时,以黏结矿物颗粒分布的水合物演化为连接裂隙上下表面的桥接分布.研究结果提出了对含裂隙储层水合物分布及其对各向异性地震性质影响的新认识,为含裂隙水合物储层的定量评价提供了重要依据. 展开更多
关键词 含裂隙水合物储层 水合物分布 地震各向异性 各向异性速度测量
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基于PACS测量实体瘤最长径的变异性分析 被引量:2
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作者 徐龙 刘文源 +4 位作者 段阳 邹明宇 徐森 谢晓冬 郑振东 《临床肿瘤学杂志》 CAS 北大核心 2018年第11期1005-1011,共7页
目的以非小细胞肺癌(NSCLC)的肺内靶病灶为例对当前临床实践中基于影像存档与通信系统(PACS)测量实体瘤最长径的变异性进行分析。方法收集2017年9月至2018年2月78个NSCLC肺内靶病灶。两名放射科医师通过PACS工作站分别独立测量肿瘤最长... 目的以非小细胞肺癌(NSCLC)的肺内靶病灶为例对当前临床实践中基于影像存档与通信系统(PACS)测量实体瘤最长径的变异性进行分析。方法收集2017年9月至2018年2月78个NSCLC肺内靶病灶。两名放射科医师通过PACS工作站分别独立测量肿瘤最长径,其中1名放射科医师间隔4周后重复测量1次。两名肿瘤科医师共同对测量图像进行复查和比较,记录测量结果并判定不同次测量之间是否选择了明显不一致的测量径线。应用Bland-Altman法计算观察者内及观察者间变异性,应用组内相关系数(ICC)评价相应两组测量结果的一致性。结果分别对肺窗和纵隔窗的病灶最长径进行3次测量,均值的差异均无统计学意义(P>0. 05)。对同一病灶测量时,不同观察者之间或同一观察者不同时间选择的最长径可能不同,不同观察者选择测量径线的变异性高于同一观察者。当最长径选择相同时,Bland-Altman散点图显示,肺窗测量的观察者内变异性为-7. 1%至7. 4%,观察者间变异性为-7. 4%至6. 8%;纵隔窗测量的观察者内变异性为-7. 6%至5. 8%,观察者间变异性为-5. 3%至7. 1%。测量绝对值的变异在±3 mm之间。无论是肺窗还是纵隔窗,每两组测量值的ICC均在0. 9至1. 0之间。结论由同一观察者对NSCLC肺内病灶最长径进行测量时,选择测量径线的变异性较低,肺窗最长径变化在-7. 1%至7. 4%之间,纵隔窗最长径变化在-7. 6%至5. 8%之间,同时测量值绝对值差异大于3 mm时可以认为是肿瘤的客观变化,而不是测量误差。 展开更多
关键词 实体瘤 非小细胞肺癌(NSCLC) 影像存档与通信系统(PACS) 疗效评价 测量异性
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符合模式下的γ射线各向异性度测量 被引量:4
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作者 郑勇 周小红 +6 位作者 柳敏良 刘忠 何建军 郭应祥 雷相国 张玉虎 罗万居 《高能物理与核物理》 EI CSCD 北大核心 2002年第9期909-913,共5页
介绍了符合模式下γ射线的各向异性度测量方法以及由此来指定γ射线跃迁多极性的原理 .结合在具体物理实验中的探测器布局 ,讨论了影响此方法准确性的因素 .通过提取已知跃迁多极性的γ射线的各向异性度系数 ,说明了各向异性度方法是可... 介绍了符合模式下γ射线的各向异性度测量方法以及由此来指定γ射线跃迁多极性的原理 .结合在具体物理实验中的探测器布局 ,讨论了影响此方法准确性的因素 .通过提取已知跃迁多极性的γ射线的各向异性度系数 ,说明了各向异性度方法是可靠的 .总结此方法与传统的角分布和DCO测量方法相比所具有的优越性 . 展开更多
关键词 符合模式 各向异性测量 Γ射线 γ跃迁多极性 重离子诱发 原子核 高自旋态 探测器
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Monitoring Seasonal Variations of Ionospheric TEC Using GPS Measurements 被引量:3
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作者 CAI Changsheng 《Geo-Spatial Information Science》 2007年第2期96-99,共4页
The regional ionospheric model is adopted to determine satellite-plus-receiver differential delay. The satellite-plus-receiver differential delay is estimated as constant values for each day. Dual-frequency GPS pseudo... The regional ionospheric model is adopted to determine satellite-plus-receiver differential delay. The satellite-plus-receiver differential delay is estimated as constant values for each day. Dual-frequency GPS pseudo-ranges observables are used to compute vertical TEC (VTEC). All the monthly mean VTEC profiles are represented by graphs using GPS data of the Beijing IGS site between 2000 and 2004. The monthly averaged values and amplitudes of VTEC are also represented by graphs. The results indicate that the VTEC has seasonal dependency. The monthly averaged values and amplitudes of VTEC in 2000 are about 2 times larger than that in 2004. The maximum VTEC values are observed in March and April, while the minimum VTEC values are observed in December. The seasonal variations trend is found to be similar after polynomial fitting between 2000 and 2004. 展开更多
关键词 GPS differential delay IONOSPHERE TEC
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An Intelligent Household Heart Rate Meter
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作者 张付有 卢晓 王海霞 《Journal of Measurement Science and Instrumentation》 CAS 2011年第3期293-296,共4页
The measuring instrument which uses Sunplus SPCE061A MCU as the controller is a practical intelligent household heart rate meter.It can serve all people timely and effectively to detect the heart rate.It rings some vo... The measuring instrument which uses Sunplus SPCE061A MCU as the controller is a practical intelligent household heart rate meter.It can serve all people timely and effectively to detect the heart rate.It rings some voice alarm if the HRV is abnormal.Then it is decided whether to see a doctor at a convenient time for further diagnosis.The instrument has a feature of voice guidance that can save keyboard steps,which extends the scope of use.All people,old and young,the blind and the deaf,can use it by themselves. 展开更多
关键词 SCM HRV heart rate voice guidance
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Micro-failure process and failure mechanism of brittle rock under uniaxial compression using continuous real-time wave velocity measurement 被引量:3
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作者 WU Zhi-jun WANG Zhi-yang +2 位作者 FAN Li-feng WENG Lei LIU Quan-sheng 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第2期556-571,共16页
In this study,the micro-failure process and failure mechanism of a typical brittle rock under uniaxial compression are investigated via continuous real-time measurement of wave velocities.The experimental results indi... In this study,the micro-failure process and failure mechanism of a typical brittle rock under uniaxial compression are investigated via continuous real-time measurement of wave velocities.The experimental results indicate that the evolutions of wave velocities became progressively anisotropic under uniaxial loading due to the direction-dependent development of micro-damage.A wave velocity model considering the inner anisotropic crack evolution is proposed to accurately describe the variations of wave velocities during uniaxial compression testing.Based on which,the effective elastic parameters are inferred by a transverse isotropic constitutive model,and the evolutions of the crack density are inversed using a self-consistent damage model.It is found that the propagation of axial cracks dominates the failure process of brittle rock under uniaxial loading and oblique shear cracks develop with the appearance of macrocrack. 展开更多
关键词 elastic wave velocity brittle rock failure uniaxial compression test continuous real-time measurement anisotropic damage evolution theory and modelling
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Pitfalls of microseismic data inversion in the case of strong anisotropy
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作者 Sergey Yaskevich Georgy Loginov +1 位作者 Anton Duchkov Alexandr Serdukov 《Applied Geophysics》 SCIE CSCD 2016年第2期326-332,418,419,共9页
In downhole microseismic monitoring, anisotropic models are presently useful for obtaining the locations of events and give realistic description of the media. In anisotropic media, the wavefield structure is complex ... In downhole microseismic monitoring, anisotropic models are presently useful for obtaining the locations of events and give realistic description of the media. In anisotropic media, the wavefield structure is complex because of shear-wave splitting and singularities. We show the results of conventional processing and kinematic inversion using velocity model calibrations for strongly anisotropic VTI media and double-couple seismic sources. The small traveltime misfits, typical quality assessment criteria, are not always accurate. The artificial addition of isotropic layers may reduce the misfit but it may also produce nonphysical model, negative Poisson ratios, shifted locations. 展开更多
关键词 microseismic monitoring ANISOTROPY location quality
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Effect of Water Salinity on the Spatial Variability of Soil and Plant Parameters
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作者 Ali Ajeel Ali Saeed +3 位作者 Giovanna Dragonetti Alessandro Comegna Nicola Lamaddalena AntonioCoppola 《Journal of Life Sciences》 2015年第11期549-555,共7页
Spatial pattern and interdependence of different soil and plant parameters were examined in green bean field experiment carried out at the Mediterranean Agronomic Institute of Bari (MAIB), Italy. The study aimed to ... Spatial pattern and interdependence of different soil and plant parameters were examined in green bean field experiment carried out at the Mediterranean Agronomic Institute of Bari (MAIB), Italy. The study aimed to identify the spatial distribution of soil and plant parameters and their relationship at transects scale. The experiment consisted of three transects of 30 m length and 4.2 m width, irrigated with three different salinity levels (1 dSm"1, 3 dSm1, 6 dSml). Soil measurements (electrical conductivity and soil water content) were monitored along each transect in 24 sites, using TDR probe installed vertically at soil surface. Water storage was measured by using Diviner sensor for calculating directly the evapotranspiration fluxes along the whole soil profile under the different salinity levels imposed during the experiment. In the same 24 sites, crop monitoring involved measurements of Leaf Area Index (LAI), Osmotic Potential (OP), Root length Density (RID) and Evapotranspiration fluxes (ET). Soil and plant properties were analyzed using both classical and geostatistical methods which included descriptive statistics, semivariograms and cross-semivariograms. Results indicated that moderate to large spatial variability existed across the field for soil and plant parameters, especially under the 6 dSm1 salinity treatment. A relatively satisfactory fit of the experimental cross-semivariogram was obtained for the 6 dS1, thus indicating similar spatial structures of the pairs of compared variables. By contrast, the experimental cross-semivariograms observed under the 3 dS~ treatment indicated no significant correlation structure between the compared variables. Overall, the results observed in the 3 dSm-1 were not significantly different from those obtained in the 1 dSm-1 transect and suggested a general insensitivity of the crop response to those levels of salinity. 展开更多
关键词 Soil and crop properties spatial variability SEMIVARIOGRAM cross-semivariogram.
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Measuring IP Performance Metrics on Mobile Network with Heterogeneous Wireless Technologies
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作者 Pyung-soo KIM Jeong-hun CHOI 《Journal of Measurement Science and Instrumentation》 CAS 2010年第3期289-292,共4页
The new measurement scheme of IP performance metrics is for the mobile network in heterogeneous wireless network environment. In the proposed scheme, when Mobile Nodes (MNs) inside the mobile network needs to under... The new measurement scheme of IP performance metrics is for the mobile network in heterogeneous wireless network environment. In the proposed scheme, when Mobile Nodes (MNs) inside the mobile network needs to understand the condition of multiple comrmunicatinn paths outside the mobile netwtrk, they can get IP performance metrics, such as delay, jitter, bandwidth, packet loss, etc., irrespective of the preserre or absence of measurement functionality. At the same time, the proposed scheme dees not require the MN to he involved in measuring IP performance metrice. The Multihomed Mobile Router (MMR) with heterogeneons wireless interfaces measures IP performance metrics on behalf of the MNs inside the mobile network. Then, MNs can get measured IP perfonmnce metries from the MMR using L3 messages. The proposed scheme can reduce burden and power consumption of MNs with limited resource and batty power since MNs don' t measure IP performance metrics directly. In addition, it can reduce considerably traffic overhead over wireless links on multiple measurement paths since signaling messages and injeeted testing traffic are reduced. 展开更多
关键词 performance metrics network mobility HETEROGENEOUS
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Subtyping Animal Influenza Virus with General Multiplex RT-PCR and Liquichip High Throughput (GMPLex) 被引量:8
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作者 Zhi-feng Qin Jie Sun +11 位作者 Ti-kang Lu Shao-ling Zeng Qun-yi Hua Qing-yan Ling Shu-kun Chen Jian-qiang Lv Cai-hong Zhang Bing Cheng Zhou-xi Ruan Ying-zuo Bi Joseph J Giambrone Hong-zhuan Wu 《Virologica Sinica》 CAS CSCD 2012年第2期120-131,共12页
This study developed a multiplex RT-PCR integrated with luminex technology to rapidly subtype simultaneously multiple influenza viruses. Primers and probes were designed to amplify NS and M genes of influenza A viruse... This study developed a multiplex RT-PCR integrated with luminex technology to rapidly subtype simultaneously multiple influenza viruses. Primers and probes were designed to amplify NS and M genes of influenza A viruses HA gene of ill, H3, H5, HT, H9 subtypes, and NA gene of the N1 and N2 subtypes. Universal super primers were introduced to establish a multiplex RT-PCR (GM RT-PCR). It included three stages of RT-PCR amplification, and then the RT-PCR products were further tested by LiquiChip probe, combined to give an influenza virus (IV) rapid high throughput subtyping test, designated as GMPLex. The IV GMPLex rapid high throughput subtyping test presents the following features: high throughput, able to determine the subtypes of 9 target genes in H1, H3, H5, H7, H9, N1, and N2 subtypes of the influenza A virus at one time; rapid, completing the influenza subtyping within 6 hours; high specificity, ensured the specificity of the different subtypes by using two nested degenerate primers and one probe, no cross reaction occurring between the subtypes, no non-specific reactions with other pathogens and high sensitivity. When used separately to detect the product of single GM RT-PCR for single H5 or N1 gene, the GMPLex test showed a sensitivity of 10-5(= 280ELDs0) forboth tests and the Luminex qualitative ratio results were 3.08 and 3.12, respectively. When used to detect the product of GM RT-PCR for H5N1 strain at the same time, both showed a sensitivity of 10-4(=2800 ELD50). The GMPLex rapid high throughput subtyping test can satisfy the needs of influenza rapid testing. 展开更多
关键词 Influenza Virus General multiplex RT-PCR Iuminex assay SUBTYPING HA and NA genes
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A Variation Account of Divergent Thinking
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作者 Leonid Dorfman Vera Gassimova 《Journal of Literature and Art Studies》 2017年第8期1039-1053,共15页
A variation account was applied to divergent thinking accommodated as a kind of creative thinking. To provide control (contrast) condition the variation account was applied to psychometric intelligence. Guilford's ... A variation account was applied to divergent thinking accommodated as a kind of creative thinking. To provide control (contrast) condition the variation account was applied to psychometric intelligence. Guilford's (1956, 1967, 1988) theory of divergent-----convergent thinking served the background of our study. The main premise was that creative variation represents "thought trials" with diverse ways to find a solution to the problem. Task demands and the respective creative problem solving reveal advantageous sources that suggest the variation. Probably, uncertainty, information search, and finding alternatives extracted from memory precede, entail and provide variety of seeking, as well. A principal hypothesis to be tested was that divergent thinking enables its variation rather than intelligence does that to its variation. As predicted, the divergent thinking and its variation were related. Compared to uncreative, creative persons were characterized by larger variation. Apart from the mathematical intelligence, other kinds of intelligence and their variation did not correlate. Mainly, the data obtained, thus, lend support to the claimed hypothesis. 展开更多
关键词 VARIATION CREATIVITY divergent thinking INTELLIGENCE SCATTERING
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Overhead shoulder press - In-front of the head or behind the head?
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作者 Mark R. McKean Brendan J. Burkett 《Journal of Sport and Health Science》 SCIE 2015年第3期250-257,共8页
Background: Using a cross-sectional design comparison, two overhead press techniques (in-front of the head or behind the head) were compared. The purpose of this study was to determine the impact of behind the head... Background: Using a cross-sectional design comparison, two overhead press techniques (in-front of the head or behind the head) were compared. The purpose of this study was to determine the impact of behind the head or in-front of the head overhead pressing technique on shoulder range of movement (ROM) and spine posture. The overhead press is commonly prescribed exercise. The two techniques (in-front of the head or behind the head) may influence joint mechanics and therefore require an objective analysis. Methods: Passive shoulder ROM quantified using goniometric measures, dynamic ROM utilised three-dimensional (3D) biomechanical mea- sures (120 Hz) of 33 participants performing overhead pressing in a seated position. The timing and synchronisation of the upper limb shoulder and spine segments were quantified and influence of each technique was investigated. Results: The in-front technique commenced in lordotic position, whilst behind the head technique commenced in kyphotic position. Behind the head technique started with less thoracic extension than in-front condition. The thoracic spine remained extended and moved between 12~ and 15~ regardless of gender or technique. The techniques resulted in a significant difference between genders. Males were able to maintain a flat or normal lumbar lordosis, whereas females tended to kyphotic. Conclusion: Shoulder ROM was within passive ROM for all measures except external rotation for males with the behind the head technique. To avoid possible injury passive ROM should be increased prior to behind the head protocol. Females showed greater spine movements, suggesting trunk strengthening may assist overhead pressing techniques. For participants with normal trunk stability and ideal shoulder ROM, overhead pressing is a safe exercise (for the shoulder and spine) when performed either in-front of or behind the head. 展开更多
关键词 3RM HEAD ROM Shoulder flexibility Shoulder press Spine flexion
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Quantitative analysis of deformation in hollow cylinder tests on anisotropic clay formations
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作者 You Shuang Ji Hongguang +2 位作者 Labiouse Vincent Hall Stephen A. Viggiani Gioacchino 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2015年第2期299-303,共5页
A series of triaxial laboratory experiments are performed on thick-walled hollow cylindrical samples of boom clay.The aim of this testing program is to better understand the anisotropic deformation during the excavati... A series of triaxial laboratory experiments are performed on thick-walled hollow cylindrical samples of boom clay.The aim of this testing program is to better understand the anisotropic deformation during the excavation.The testing conditions are similar to those to be experienced by host rocks around disposal galleries for radioactive waste.X-ray computed tomography is performed at different steps for each test with the samples remaining inside the loading cell.Initial analysis of the tomography images allows of the observation of the deformation of the central hole.In addition,particles manual tracking and 3D volumetric digital image correlation processing methods are considered being used to analyze the particles displacements and the boundary deformation of the sample quantitatively.An unsymmetrical damaged zone is induced around the hole,with a reverse deformation trend being found at the boundary after unloading,which indicates that the significant anisotropic deformation of boom clay can be induced by mechanical unloading. 展开更多
关键词 Boom clay Hollow cylinder test Deformation X-ray computed tomography Particles manual tracking
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A consensus linkage map of common carp (Cyprinus carpio L.) to compare the distribution and variation of QTLs associated with growth traits 被引量:4
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作者 ZHENG XianHu KUANG YouYi +5 位作者 LV WeiHua CAO DingChen ZHANG XiaoFeng LI Chao LU CuiYun SUN XiaoWen 《Science China(Life Sciences)》 SCIE CAS 2013年第4期351-359,共9页
The ability to detect and identify quantitative trait loci (QTLs) in a single population is often limited. Analyzing multiple populations in QTL analysis improves the power of detecting QTLs and provides a better unde... The ability to detect and identify quantitative trait loci (QTLs) in a single population is often limited. Analyzing multiple populations in QTL analysis improves the power of detecting QTLs and provides a better understanding of their functional allelic variation and distribution. In this study, a consensus map of the common carp was constructed, based on four populations, to compare the distribution and variation of QTLs. The consensus map spans 2371.6 cM across the 42 linkage groups and comprises 257 microsatellites and 421 SNPs, with a mean marker interval of 3.7 cM/marker. Sixty-seven QTLs affecting four growth traits from the four populations were mapped to the consensus map. Only one QTL was common to three populations, and nine QTLs were detected in two populations. However, no QTL was common to all four populations. The results of the QTL comparison suggest that the QTLs are responsible for the phenotypic variability observed for these traits in a broad array of common carp germplasms. The study also reveals the different genetic performances between major and minor genes in different populations. 展开更多
关键词 common carp consensus map comparative QTL analysis growth-related traits
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Quantum Correlations in Heisenberg XY Chain
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作者 朱银燕 张勇 《Communications in Theoretical Physics》 SCIE CAS CSCD 2013年第4期407-410,共4页
Quantum correlations measured by quantum discord (QD), measurement-induced distance (MID), and geometric measure of quantum discord (GMQD) in two-qubit Heisenberg XY spin chain are investigated. The effects of D... Quantum correlations measured by quantum discord (QD), measurement-induced distance (MID), and geometric measure of quantum discord (GMQD) in two-qubit Heisenberg XY spin chain are investigated. The effects of DM interaction and anisotropic on the three correlations are considered. Characteristics of various correlation measures for the two-qubit states are compared. The increasing Dz increases QD, MID and GMQD monotonously while the increasing anisotropy both increases and decreases QD and GMQD. The three quantum correlations are always existent at very high temperature. MID is always larger than QD, but there is no definite ordering between QD and GMQD. PACS numbers: 03.65.Ta, 03.67.Mn 展开更多
关键词 quantum discord measurement=induced distance geometric measure of quantum discord
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New Metrics from a Fractional Gravitational Field
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作者 Rami Ahmad El-Nabulsi 《Communications in Theoretical Physics》 SCIE CAS CSCD 2017年第9期309-312,共4页
Agop et al. proved in Commun. Theor. Phys. (2008) that, a Reissner-Nordstrom type metric is obtained, if gauge gravitational field in a fractal spacetime is constructed by means of concepts of scale relativity. We p... Agop et al. proved in Commun. Theor. Phys. (2008) that, a Reissner-Nordstrom type metric is obtained, if gauge gravitational field in a fractal spacetime is constructed by means of concepts of scale relativity. We prove in this short communication that similar result is obtained if gravity in D-spacetime dimensions is fractionalized by means of the Glaeske-Kilbaz Saigo fractional. Besides, non-singular gravitational fields are obtained without using extra-dimensions. We present few examples to show that these gravitational fields hold a number of motivating features in spacetime physics. 展开更多
关键词 D-spacetime dimensions fractional gravitational field
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INFERENCE FOR REPEATED MEASURES MODELS UNDER HETEROSCEDASTICITY
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作者 Weiyan MU Xingzhong XU 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2012年第6期1158-1170,共13页
This paper considers a widely used mixed effects model in repeated measures under het- eroscedasticity. Hypotheses of the equality of the fixed effects and the simultaneous confidence intervals for all pair-wise diffe... This paper considers a widely used mixed effects model in repeated measures under het- eroscedasticity. Hypotheses of the equality of the fixed effects and the simultaneous confidence intervals for all pair-wise differences are discussed. A generalized F-test has been proposed to test the equality of the fixed effects in the model, but simulation results for evaluating its performance have not been shown in the literature. Moreover, the generalized F-test cannot be used to deduce the simultaneous confidence intervals for all pair-wise differences of the fixed effects. The authors propose two new p-values to test the hypotheses of equality of the fixed effects and simultaneous confidence intervals of the differences of the effects based on the generalized pivotal quantities derived in this paper. The authors also compare the empirical performances of the proposed tests and the generalized F-test. The type I error rates and powers of these tests are evaluated using the Monte Carlo simulation. The simulation studies show that the generalized F-test does not perform well in terms of type I error rate under various sample size and parameter combinations. However, the type I error probabilities of the proposed tests are always close to the nominal value. It can also be seen that the simultaneous confidence intervals perform well. 展开更多
关键词 Generalized p-values HETEROSCEDASTICITY mixed effect repeated measures models simul-taneous confidence intervals.
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Thickness-driven spin reorientation transition in ultrathin films
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作者 MIAO BingFeng MILLEV YonkoTimtchev +3 位作者 SUN Liang YOU Biao ZHANG Wei DING HaiFeng 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2013年第1期70-84,共15页
We review recent studies by different experimental means of ultrathin films,exhibiting thickness-driven spin reorientation transitions(SRTs).The stage is set by determining,via phenomenological thermodynamic descripti... We review recent studies by different experimental means of ultrathin films,exhibiting thickness-driven spin reorientation transitions(SRTs).The stage is set by determining,via phenomenological thermodynamic description,of the relevant phase diagrams for the possible types of SRT with and without applied magnetic field.Suitable representation may be chosen such that best use is made of the linear character(under thickness variation) of the system's path in anisotropy space.The latter involves higher-order bulk and surface anisotropies in a substantial way.We examine sensitive experimental techniques for the detection and quantification of SRTs,such as hysteresis measurements with magneto-optical Kerr effect(MOKE),micromagnetic studies utilizing scanning electron microscopy with polarization analysis(SEMPA),photoemission electron microscopy(PEEM) and spin-polarized low-energy electron microscopy(SPLEEM) as well as ac magnetic susceptibility measurements via MOKE.Key issues are conclusively discussed including the identification of reliable experimental fingerprints about whether a given SRT proceeds via a phase of coexistence or via a cone(canted) phase.We demonstrate how the application of the general theoretical ideas to carefully designed measurements leads to the determination of the most important material parameters in any ultrathin-film SRT,namely,the surface(interface) magnetic anisotropy constants.The review concludes by our personal outline for future promising work on SRTs. 展开更多
关键词 ultrathin magnetic films spin reorientation transitions magnetic anisotropy
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