This paper studies a detection method of targets of high resolution radar operating at the band of millimeter-wave(32-38GHz) under the background of the clutters, and proposes a new nonparametric detection method, whi...This paper studies a detection method of targets of high resolution radar operating at the band of millimeter-wave(32-38GHz) under the background of the clutters, and proposes a new nonparametric detection method, which not only does less computation, but also is able to detect multiple extended targets radially distributed along distance "corridor", based on the position (range) correlation information of one-dimensional range images(or called range profiles) of high resolution radar targets. The experimental results, on the real echo data of tank illuminated by the millimeter-wave stepped frequency high resolution radar, have certified that such a method presented in this paper is a very effective detection method for multiple extended targets.展开更多
Four hierarchical cyclothems, superbundlesets, bundlesets, bundles and laminae, have been identified from the Devonian Frasnian-Famennian carbonate strata in Guangxi, South China. Their hierarchical structures, ratio ...Four hierarchical cyclothems, superbundlesets, bundlesets, bundles and laminae, have been identified from the Devonian Frasnian-Famennian carbonate strata in Guangxi, South China. Their hierarchical structures, ratio relationships and sequence in conodont zones are continuous and stable and can be traced across different facies zones and sedimentary basins. Our data show that hierarchically organized superbundlesets, bundlesets, bundles and laminae correspond to the long eccentricity, eccentricity, obliquity or precession and sub-Milankovitch cycles respectively. Their periods were 400,000, 100,000, 33,333, 16,667 and 8,000–17,000 a, respectively. The ratios of long eccentricity to eccentricity, eccentricity to obliquity, and eccentricity to precession in the Devonian are 1:4, 1:3 and 1:6 respectively. Using these hierarchical Milankovitch cyclothems, chronostratigraphical division and correlation can be realized at a resolution of 100 ka or 10 ka at the Frasnian-Famennian transition. The time intervals of the Upper rhenana Zone, linguiformis Zone, and the Lower, Middle and Upper triangularis Zone are 0.6, 0.8, 0.3, 0.3 and 0.3 Ma, respectively. Sea-level changes of the Frasnian-Famennian transition were not coherent and synchronous at the resolution of 100 ka or 10 ka in the basin-slope carbonate sequences of Guangxi, South China.展开更多
The phase change of lacustrine gravity flow deposition is fast and complex. In its reservoir division and correlation, the isochronous problem is very important. Taking the oil formation I of Es3 in Wuhaozhuang oilfie...The phase change of lacustrine gravity flow deposition is fast and complex. In its reservoir division and correlation, the isochronous problem is very important. Taking the oil formation I of Es3 in Wuhaozhuang oilfield as an example, through the analysis of stratigraphic drilling and logging data in the study area, according to the genetic types of different levels of base level cycle interfaces and the characteristics of high-resolution sequence stratigraphy, this paper subdivides the lacustrine gravity flow oil layer of lower Es3 in Wuhaozhuang Oilfield, divides it into four short-term base level cycle sequences, and establishes the high-resolution isochronous stratigraphic framework of this interval. It is found that the mid-term, short-term and ultra short-term base level cycles correspond to the oil formation, sand layer group and single layer in the oil layer correlation unit of the oilfield respectively. Based on this, the oil layer correlation unit of the interval is divided, and the sublayer correlation model is established according to the identification characteristics of the short-term base level cycle.展开更多
Characterizing material 3D deformation and damage is a key challenge in mechanical research. Digital volume correlation （DVC）, as a tool for quantifying the internal mechanical response, can comprehensively study th...Characterizing material 3D deformation and damage is a key challenge in mechanical research. Digital volume correlation （DVC）, as a tool for quantifying the internal mechanical response, can comprehensively study the extraction of key failure parameters. This review summarizes the recent progresses in the study of the internal movement of granular materials, inhomogeneous deformation of composite materials, and stress intensity factor around a crack front in static and fatigue states using DVC. To elaborate on the technique＇s potential, we discussed the accuracy and efficiency of the algorithm and the acquisition of real microstructure data within the material under a complex environment.展开更多
The Givetian-Frasnian boundary at Liujing, Guangxi, South China is for the first time recognized and correlated in high resolution using characteristic chemocycles of element abundance fluctuation integrated with cono...The Givetian-Frasnian boundary at Liujing, Guangxi, South China is for the first time recognized and correlated in high resolution using characteristic chemocycles of element abundance fluctuation integrated with conodont biostratignphy. The first appearance of Ancyrodella rotundiloba early form is as a biomarker, and the boundary of lowering fluctuation of element abundance followed by a sequence of characteristic chemocycles with a sequence of cmodonts is as an abiotic auxiliary marker. The error is not more than 0.10 Ma. The study indicates that in a quiet interval, characteristic chemocycles integrated with biomarkers can be used for boundary recognition and regional cormlation in high resolution, and this method has potential for intercontinental correlation展开更多
The statistical performance of AR high resolution array processor in presence of correlated sensor signal fluctuation is studied. Mean square inverse beam pattern and pointing error are examined. Special attention is ...The statistical performance of AR high resolution array processor in presence of correlated sensor signal fluctuation is studied. Mean square inverse beam pattern and pointing error are examined. Special attention is paid to the effects of reference sensor and correlation between sensors. It is shown that fluctuation causes broadening or even distortion of the mean square inverse beam pattern. Phase fluctuation causes pointing error. Its standard variance is proportional to that of fluctuation and is related to the number of sensors of the array. Correlation between sensors has important effects on pointing error.展开更多
文摘This paper studies a detection method of targets of high resolution radar operating at the band of millimeter-wave(32-38GHz) under the background of the clutters, and proposes a new nonparametric detection method, which not only does less computation, but also is able to detect multiple extended targets radially distributed along distance "corridor", based on the position (range) correlation information of one-dimensional range images(or called range profiles) of high resolution radar targets. The experimental results, on the real echo data of tank illuminated by the millimeter-wave stepped frequency high resolution radar, have certified that such a method presented in this paper is a very effective detection method for multiple extended targets.
基金The study was jointly supported by the National Natural Science Foundation of China(Grants 49472086 and 40072041)the Ministry of Science and Technology(the SSER project).
文摘Four hierarchical cyclothems, superbundlesets, bundlesets, bundles and laminae, have been identified from the Devonian Frasnian-Famennian carbonate strata in Guangxi, South China. Their hierarchical structures, ratio relationships and sequence in conodont zones are continuous and stable and can be traced across different facies zones and sedimentary basins. Our data show that hierarchically organized superbundlesets, bundlesets, bundles and laminae correspond to the long eccentricity, eccentricity, obliquity or precession and sub-Milankovitch cycles respectively. Their periods were 400,000, 100,000, 33,333, 16,667 and 8,000–17,000 a, respectively. The ratios of long eccentricity to eccentricity, eccentricity to obliquity, and eccentricity to precession in the Devonian are 1:4, 1:3 and 1:6 respectively. Using these hierarchical Milankovitch cyclothems, chronostratigraphical division and correlation can be realized at a resolution of 100 ka or 10 ka at the Frasnian-Famennian transition. The time intervals of the Upper rhenana Zone, linguiformis Zone, and the Lower, Middle and Upper triangularis Zone are 0.6, 0.8, 0.3, 0.3 and 0.3 Ma, respectively. Sea-level changes of the Frasnian-Famennian transition were not coherent and synchronous at the resolution of 100 ka or 10 ka in the basin-slope carbonate sequences of Guangxi, South China.
文摘The phase change of lacustrine gravity flow deposition is fast and complex. In its reservoir division and correlation, the isochronous problem is very important. Taking the oil formation I of Es3 in Wuhaozhuang oilfield as an example, through the analysis of stratigraphic drilling and logging data in the study area, according to the genetic types of different levels of base level cycle interfaces and the characteristics of high-resolution sequence stratigraphy, this paper subdivides the lacustrine gravity flow oil layer of lower Es3 in Wuhaozhuang Oilfield, divides it into four short-term base level cycle sequences, and establishes the high-resolution isochronous stratigraphic framework of this interval. It is found that the mid-term, short-term and ultra short-term base level cycles correspond to the oil formation, sand layer group and single layer in the oil layer correlation unit of the oilfield respectively. Based on this, the oil layer correlation unit of the interval is divided, and the sublayer correlation model is established according to the identification characteristics of the short-term base level cycle.
基金supported by the National Natural Science Foundation of China (11722221, 11272305, and 11472265)the National Key Research and Development Program of China (2017YFA0403800 and 2017YFB0702000)the Anhui Provincial Natural Science Foundation (1508085MA17)
文摘Characterizing material 3D deformation and damage is a key challenge in mechanical research. Digital volume correlation （DVC）, as a tool for quantifying the internal mechanical response, can comprehensively study the extraction of key failure parameters. This review summarizes the recent progresses in the study of the internal movement of granular materials, inhomogeneous deformation of composite materials, and stress intensity factor around a crack front in static and fatigue states using DVC. To elaborate on the technique＇s potential, we discussed the accuracy and efficiency of the algorithm and the acquisition of real microstructure data within the material under a complex environment.
文摘The Givetian-Frasnian boundary at Liujing, Guangxi, South China is for the first time recognized and correlated in high resolution using characteristic chemocycles of element abundance fluctuation integrated with conodont biostratignphy. The first appearance of Ancyrodella rotundiloba early form is as a biomarker, and the boundary of lowering fluctuation of element abundance followed by a sequence of characteristic chemocycles with a sequence of cmodonts is as an abiotic auxiliary marker. The error is not more than 0.10 Ma. The study indicates that in a quiet interval, characteristic chemocycles integrated with biomarkers can be used for boundary recognition and regional cormlation in high resolution, and this method has potential for intercontinental correlation
文摘The statistical performance of AR high resolution array processor in presence of correlated sensor signal fluctuation is studied. Mean square inverse beam pattern and pointing error are examined. Special attention is paid to the effects of reference sensor and correlation between sensors. It is shown that fluctuation causes broadening or even distortion of the mean square inverse beam pattern. Phase fluctuation causes pointing error. Its standard variance is proportional to that of fluctuation and is related to the number of sensors of the array. Correlation between sensors has important effects on pointing error.
