LA-ICPMS zircon U-Pb dating has been greatly advanced and widely applied in the past decade because it is a cheap and fast technique.The internal error of LA-ICPMS zircon U-Pb dating can be better than 1%,but reproduc...LA-ICPMS zircon U-Pb dating has been greatly advanced and widely applied in the past decade because it is a cheap and fast technique.The internal error of LA-ICPMS zircon U-Pb dating can be better than 1%,but reproducibility(accuracy)is relatively poor.In order to quantitatively assess the accuracy of this technique,zircons from two dioritic rocks,a Mesozoic dioritic microgranular enclave(FS06)and a Neoproterozoic diorite(WC09-32),were dated independently in eight laboratories using SIMS and LA-ICPMS.Results of three SIMS analyses on FS06 and WC09-2 are indistinguishable within error and give a best estimate of the crystallization age of 132.2 and 760.5 Ma(reproducibility is^1%,2RSD),respectively.Zircon U-Pb ages determined by LA-ICPMS in six laboratories vary from 128.3±1.0 to 135.0±0.9 Ma(2SE)for FS06 and from 742.9±3.1 to777.8±4.7 Ma(2SE)for WC09-32,suggesting a reproducibility of^4%(2RSD).Uncertainty produced during LA-ICPMS zircon U-Pb analyses comes from multiple sources,including uncertainty in the isotopic ratio measurements,uncertainty in the fractionation factor calculation using an external standard,uncertainty in the age determination as a result of common lead correction,age uncertainty of the external standards and uncertainty in the data reduction.Result of our study suggests that the uncertainty of LA-ICPMS zircon U-Pb dating is approximately 4%(2RSD).The uncertainty in age determination must be considered in order to interpret LA-ICPMS zircon U-Pb data rationally.展开更多
The recent advent of deep artificial neural networks has resulted in a dramatic increase in performance for object classification and detection.While pre-trained with everyday objects,we find that a state-of-the-art o...The recent advent of deep artificial neural networks has resulted in a dramatic increase in performance for object classification and detection.While pre-trained with everyday objects,we find that a state-of-the-art object detection architecture can very efficiently be fine-tuned to work on a variety of object detection tasks in a high-power laser laboratory.In this paper,three exemplary applications are presented.We show that the plasma waves in a laser±plasma accelerator can be detected and located on the optical shadowgrams.The plasma wavelength and plasma density are estimated accordingly.Furthermore,we present the detection of all the peaks in an electron energy spectrum of the accelerated electron beam,and the beam charge of each peak is estimated accordingly.Lastly,we demonstrate the detection of optical damage in a high-power laser system.The reliability of the object detector is demonstrated over1000 laser shots in each application.Our study shows that deep object detection networks are suitable to assist online and offline experimental analysis,even with small training sets.We believe that the presented methodology is adaptable yet robust,and we encourage further applications in Hz-level or kHz-level high-power laser facilities regarding the control and diagnostic tools,especially for those involving image data.展开更多
基金supported by the State Key Laboratory of Lithospheric EvolutionThe analyses at the University of Newcastle were financially supported by the Analytical&Biomolecular Research Facility(ABRF)unitsupported by the National Basic Research Program of China(Grant Nos.2012CB416702)
文摘LA-ICPMS zircon U-Pb dating has been greatly advanced and widely applied in the past decade because it is a cheap and fast technique.The internal error of LA-ICPMS zircon U-Pb dating can be better than 1%,but reproducibility(accuracy)is relatively poor.In order to quantitatively assess the accuracy of this technique,zircons from two dioritic rocks,a Mesozoic dioritic microgranular enclave(FS06)and a Neoproterozoic diorite(WC09-32),were dated independently in eight laboratories using SIMS and LA-ICPMS.Results of three SIMS analyses on FS06 and WC09-2 are indistinguishable within error and give a best estimate of the crystallization age of 132.2 and 760.5 Ma(reproducibility is^1%,2RSD),respectively.Zircon U-Pb ages determined by LA-ICPMS in six laboratories vary from 128.3±1.0 to 135.0±0.9 Ma(2SE)for FS06 and from 742.9±3.1 to777.8±4.7 Ma(2SE)for WC09-32,suggesting a reproducibility of^4%(2RSD).Uncertainty produced during LA-ICPMS zircon U-Pb analyses comes from multiple sources,including uncertainty in the isotopic ratio measurements,uncertainty in the fractionation factor calculation using an external standard,uncertainty in the age determination as a result of common lead correction,age uncertainty of the external standards and uncertainty in the data reduction.Result of our study suggests that the uncertainty of LA-ICPMS zircon U-Pb dating is approximately 4%(2RSD).The uncertainty in age determination must be considered in order to interpret LA-ICPMS zircon U-Pb data rationally.
基金support by the operating resources of the Centre for Advanced Laser Applications(CALA)support from the Alexander von Humboldt Stiftung+1 种基金support from the BMBF under contract number 05K19WMBsupport from the German Research Agency,DFG Project No.453619281
文摘The recent advent of deep artificial neural networks has resulted in a dramatic increase in performance for object classification and detection.While pre-trained with everyday objects,we find that a state-of-the-art object detection architecture can very efficiently be fine-tuned to work on a variety of object detection tasks in a high-power laser laboratory.In this paper,three exemplary applications are presented.We show that the plasma waves in a laser±plasma accelerator can be detected and located on the optical shadowgrams.The plasma wavelength and plasma density are estimated accordingly.Furthermore,we present the detection of all the peaks in an electron energy spectrum of the accelerated electron beam,and the beam charge of each peak is estimated accordingly.Lastly,we demonstrate the detection of optical damage in a high-power laser system.The reliability of the object detector is demonstrated over1000 laser shots in each application.Our study shows that deep object detection networks are suitable to assist online and offline experimental analysis,even with small training sets.We believe that the presented methodology is adaptable yet robust,and we encourage further applications in Hz-level or kHz-level high-power laser facilities regarding the control and diagnostic tools,especially for those involving image data.
