Graphic correlation method has been proved to be very useful in correlating sections in different places. In this study, we have selected five sections from the Western Interior Basin, USA and applied graphic correlat...Graphic correlation method has been proved to be very useful in correlating sections in different places. In this study, we have selected five sections from the Western Interior Basin, USA and applied graphic correlation method to correlate them. The selected five sections are located from the eastern to the western margins of the Western Interior Basin, USA. The cross-basinal high-precision chronostratigraphic correlation provides geologists a better understanding about how facies and depositional environments evolved across the mid-Cretaceous Western Interior Basin during the mid-Cretaceous. In addition, our data fits well with the previous understandings about mid- Cretaceous Western Interior Seaway, which characterized by slow depositional rates and higher organic matter concentration.展开更多
Three dimensional-digital image correlation （3D-DIC） is a widely used optical metrology in the experimental mechanics community because of its reliability, practicality, and flexibility. Although the precision of di...Three dimensional-digital image correlation （3D-DIC） is a widely used optical metrology in the experimental mechanics community because of its reliability, practicality, and flexibility. Although the precision of digital image correlation （DIC） has been thoroughly studied theoretically and numerically, verification experiments have seldom been performed, especially fbr complex surfaces with a small field of view （FOV）. In this work, the shape of a 1-yuan coin was measured using 3D-DIC; the shape was complex due to the presence of many fine details, and the FOV was relatively small because the coin diameter was only 25 mm. During the experiment, a novel strategy for speckle production was developed： white paint was simply sprayed onto the surface. Black paint was not used; instead, taking advantage of the reflective nature of the coin surface, polarized light and a Polaroid filter were introduced, and the polarization direction was carefully adjusted, ensuring that the spray pattern was extremely thin and that high-quality speckle images with significant contrast were captured. The three-dimensional coin shape was also successfully determined for comparison using a stylus profiler. The results demonstrate that 3D-DIC provides high precision in shape measurement even for complex surfaces with small FOV. The precision of 3D-DIC can reach 1/7000 of the field of view, corresponding to about 6 ~tm in this experiment.展开更多
With a three-dimensional semiclassical ensemble method, we theoretically investigated the nonsequential double ionization of Ar driven by the spatially inhomogeneous few-cycle negatively chirped laser pulses. Our resu...With a three-dimensional semiclassical ensemble method, we theoretically investigated the nonsequential double ionization of Ar driven by the spatially inhomogeneous few-cycle negatively chirped laser pulses. Our results show that the recollision time window can be precisely controlled within an isolated time interval of several hundred attoseconds, which is useful for understanding the subcycle correlated electron dynamics. More interestingly, the correlated electron momentum distribution (CEMD) exhibits a strong dependence on laser intensity. That is, at lower laser intensity, CEMD is located in the first quadrant. As the laser intensity increases,CEMD shifts almost completely to the second and fourth quadrants, and then gradually to the third quadrant.The underlying physics governing the CEMD's dependence on laser intensity is explained.展开更多
The recruitment of the Low Earth Orbit(LEO)constellation is recognized as an effective way to augment Global Navigation Satellite System(GNSS)Precise Point Positioning(PPP)in the near future.Its potential to accelerat...The recruitment of the Low Earth Orbit(LEO)constellation is recognized as an effective way to augment Global Navigation Satellite System(GNSS)Precise Point Positioning(PPP)in the near future.Its potential to accelerate PPP convergence has been proved with simulated data.However,the mechanism of how the geometric change of LEO accelerates the convergence of GNSS PPP has not been studied from a theoretical perspective,which hampers the understanding and exploitation of the enhancement of LEO.In this article,the convergence mechanism of LEO enhanced GNSS PPP is investigated in terms of theoretical analysis and simulated verification.To show the characteristics of the ambiguities during convergence,eigenvalue decomposition is used to divide the ambiguities into orthogonal components,named geometric-related component,clock-error-related component,and independent component.The results show that the precision of geometric-related components of ambiguities,which correlates with position parameters,is low at a single epoch,while the precision can be greatly improved with the fast geometric change of LEO.On the other hand,the precision of clock-error-related components of ambiguities,which correlates with clock errors,cannot be improved by fast geometric change of LEO constellation due to its irrelevance to geometry,which causes the precision of each ambiguity to be low.Further investigations show that single-differenced ambiguities could overcome this drawback and are beneficial to ambiguity resolution.展开更多
目的分析比較高效液相色譜法與免疫比濁法測定糖化血紅蛋白的相關性和偏倚的可接受性,並對兩種原理的不精密度、準確度及攜帶污染率進行評估。方法以日本東曹HLC-723 G11儀器為比較方法(設為X機),羅氏Cobas c 503儀器為實驗方法(設為Y...目的分析比較高效液相色譜法與免疫比濁法測定糖化血紅蛋白的相關性和偏倚的可接受性,並對兩種原理的不精密度、準確度及攜帶污染率進行評估。方法以日本東曹HLC-723 G11儀器為比較方法(設為X機),羅氏Cobas c 503儀器為實驗方法(設為Y機),採用EP9-A2、EP5-A2、EP15-A3等實驗方案,比較分析兩儀器測定結果的相關性、精密度,準確度及攜帶污染率。結果兩儀器測定結果的相關性比較:r=0.997、平均相對偏倚1.83%、預期偏倚0.17;不精密度CV(Coefficient variation,CV)值:X機的高值、低值批内CV值分别為0.48%、0.89%,天間CV值分别為0.80%、0.36%,總CV值分别為0.97%、0.73%;Y機的高值、低值批内CV值分别為0.82%、1.17%,天間CV值分别為0.34%、0.48%,總CV值分别為0.67%、0.86%。準確度實驗:X機的相對偏倚-3.95%~-0.58%;Y機相對偏倚-2.63%~1.84%,兩機的偏差符合率均為100%。結論兩種原理測定糖化血紅蛋白的不精密度良好,準確度實驗中,測定結果與靶值的偏倚在可接受範圍内;兩種原理結果間的相關性良好,其偏倚可接受,能實現檢驗結果的可比性。展开更多
文摘Graphic correlation method has been proved to be very useful in correlating sections in different places. In this study, we have selected five sections from the Western Interior Basin, USA and applied graphic correlation method to correlate them. The selected five sections are located from the eastern to the western margins of the Western Interior Basin, USA. The cross-basinal high-precision chronostratigraphic correlation provides geologists a better understanding about how facies and depositional environments evolved across the mid-Cretaceous Western Interior Basin during the mid-Cretaceous. In addition, our data fits well with the previous understandings about mid- Cretaceous Western Interior Seaway, which characterized by slow depositional rates and higher organic matter concentration.
基金supported by the National Natural Science Foundation of China(Grant Nos.11332010,51271174,11372300,11127201,11472266&11428206)
文摘Three dimensional-digital image correlation （3D-DIC） is a widely used optical metrology in the experimental mechanics community because of its reliability, practicality, and flexibility. Although the precision of digital image correlation （DIC） has been thoroughly studied theoretically and numerically, verification experiments have seldom been performed, especially fbr complex surfaces with a small field of view （FOV）. In this work, the shape of a 1-yuan coin was measured using 3D-DIC; the shape was complex due to the presence of many fine details, and the FOV was relatively small because the coin diameter was only 25 mm. During the experiment, a novel strategy for speckle production was developed： white paint was simply sprayed onto the surface. Black paint was not used; instead, taking advantage of the reflective nature of the coin surface, polarized light and a Polaroid filter were introduced, and the polarization direction was carefully adjusted, ensuring that the spray pattern was extremely thin and that high-quality speckle images with significant contrast were captured. The three-dimensional coin shape was also successfully determined for comparison using a stylus profiler. The results demonstrate that 3D-DIC provides high precision in shape measurement even for complex surfaces with small FOV. The precision of 3D-DIC can reach 1/7000 of the field of view, corresponding to about 6 ~tm in this experiment.
基金supported by the National Natural Science Foundation of China (Grant No. 12074329)Nanhu Scholars Program for Young Scholars of Xinyang Normal University。
文摘With a three-dimensional semiclassical ensemble method, we theoretically investigated the nonsequential double ionization of Ar driven by the spatially inhomogeneous few-cycle negatively chirped laser pulses. Our results show that the recollision time window can be precisely controlled within an isolated time interval of several hundred attoseconds, which is useful for understanding the subcycle correlated electron dynamics. More interestingly, the correlated electron momentum distribution (CEMD) exhibits a strong dependence on laser intensity. That is, at lower laser intensity, CEMD is located in the first quadrant. As the laser intensity increases,CEMD shifts almost completely to the second and fourth quadrants, and then gradually to the third quadrant.The underlying physics governing the CEMD's dependence on laser intensity is explained.
基金supported by the National Natural Science Funds of China[grant numbers 42104013 and 42225401]the Innovation Program of Shanghai Municipal Education Commission[grant number 2021-01-07-00-07-E00095]+3 种基金Natural Science Fund of Shanghai[grant number 21ZR1465600]the Scientific and Technological Innovation Plan from Shanghai Science and Technology Committee[grant numbers 21511103902 and 22511103003]the industrial Collaborative Innovation Project(Technology)of Shanghai Municipality[grant numbers XTCX-KJ-2023-35 and XTCX-KJ-2022-09]the Fundamental Research Funds for the Central Universities.
文摘The recruitment of the Low Earth Orbit(LEO)constellation is recognized as an effective way to augment Global Navigation Satellite System(GNSS)Precise Point Positioning(PPP)in the near future.Its potential to accelerate PPP convergence has been proved with simulated data.However,the mechanism of how the geometric change of LEO accelerates the convergence of GNSS PPP has not been studied from a theoretical perspective,which hampers the understanding and exploitation of the enhancement of LEO.In this article,the convergence mechanism of LEO enhanced GNSS PPP is investigated in terms of theoretical analysis and simulated verification.To show the characteristics of the ambiguities during convergence,eigenvalue decomposition is used to divide the ambiguities into orthogonal components,named geometric-related component,clock-error-related component,and independent component.The results show that the precision of geometric-related components of ambiguities,which correlates with position parameters,is low at a single epoch,while the precision can be greatly improved with the fast geometric change of LEO.On the other hand,the precision of clock-error-related components of ambiguities,which correlates with clock errors,cannot be improved by fast geometric change of LEO constellation due to its irrelevance to geometry,which causes the precision of each ambiguity to be low.Further investigations show that single-differenced ambiguities could overcome this drawback and are beneficial to ambiguity resolution.
文摘目的分析比較高效液相色譜法與免疫比濁法測定糖化血紅蛋白的相關性和偏倚的可接受性,並對兩種原理的不精密度、準確度及攜帶污染率進行評估。方法以日本東曹HLC-723 G11儀器為比較方法(設為X機),羅氏Cobas c 503儀器為實驗方法(設為Y機),採用EP9-A2、EP5-A2、EP15-A3等實驗方案,比較分析兩儀器測定結果的相關性、精密度,準確度及攜帶污染率。結果兩儀器測定結果的相關性比較:r=0.997、平均相對偏倚1.83%、預期偏倚0.17;不精密度CV(Coefficient variation,CV)值:X機的高值、低值批内CV值分别為0.48%、0.89%,天間CV值分别為0.80%、0.36%,總CV值分别為0.97%、0.73%;Y機的高值、低值批内CV值分别為0.82%、1.17%,天間CV值分别為0.34%、0.48%,總CV值分别為0.67%、0.86%。準確度實驗:X機的相對偏倚-3.95%~-0.58%;Y機相對偏倚-2.63%~1.84%,兩機的偏差符合率均為100%。結論兩種原理測定糖化血紅蛋白的不精密度良好,準確度實驗中,測定結果與靶值的偏倚在可接受範圍内;兩種原理結果間的相關性良好,其偏倚可接受,能實現檢驗結果的可比性。
