海洋科学的发展离不开精确的数据,然而各种海洋观测仪器在复杂的海洋环境中作业难免产生测量误差,导致观测数据需要进行实时(或延时)质量控制。中国Argo计划在搭载多个航次布放剖面浮标的同时,对航次中获取的船载CTD(conductivity, temp...海洋科学的发展离不开精确的数据,然而各种海洋观测仪器在复杂的海洋环境中作业难免产生测量误差,导致观测数据需要进行实时(或延时)质量控制。中国Argo计划在搭载多个航次布放剖面浮标的同时,对航次中获取的船载CTD(conductivity, temperature, and depth)仪观测资料、自动剖面浮标观测资料以及实验室高精度盐度计测量数据进行了实时比对。分析结果显示,利用实验室高精度盐度计对现场观测数据尤其是船载CTD仪观测资料进行质量控制,于温盐数据(特别是深层)的实时/延时校正非常重要;如某航次未经标定的船载CTD仪所测1000dbar以深范围内海水盐度,与实验室高精度盐度计的差值达到±0.1左右,远远落后于国内海洋调查规范对盐度准确度±0.02的一级测量要求,该具体实例更加突显了船载CTD仪在航次前后送往权威部门进行检测的必要性和重要性,从而确保每个航次获取的CTD资料的质量。建议有条件的情况下,在进行深海大洋船载CTD仪观测时要进行现场实验室高精度盐度计的质量控制工作及比对试验,以提高我国深海大洋观测数据的质量。展开更多
In order to deal with modeling problem of a pressure balance system with time-delay, nonlinear, time-varying and uncertain characteristics, an intelligent modeling procedure is proposed, which is based on artificial n...In order to deal with modeling problem of a pressure balance system with time-delay, nonlinear, time-varying and uncertain characteristics, an intelligent modeling procedure is proposed, which is based on artificial neural network(ANN) and input-output data of the system during shield tunneling and can overcome the precision problem in mechanistic modeling(MM) approach. The computational results show that the training algorithm with Gauss-Newton optimization has fast convergent speed. The experimental investigation indicates that, compared with mechanistic modeling approach, intelligent modeling procedure can obviously increase the precision in both soil pressure fitting and forecasting period. The effectiveness and accuracy of proposed intelligent modeling procedure are verified in laboratory tests.展开更多
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
文摘海洋科学的发展离不开精确的数据,然而各种海洋观测仪器在复杂的海洋环境中作业难免产生测量误差,导致观测数据需要进行实时(或延时)质量控制。中国Argo计划在搭载多个航次布放剖面浮标的同时,对航次中获取的船载CTD(conductivity, temperature, and depth)仪观测资料、自动剖面浮标观测资料以及实验室高精度盐度计测量数据进行了实时比对。分析结果显示,利用实验室高精度盐度计对现场观测数据尤其是船载CTD仪观测资料进行质量控制,于温盐数据(特别是深层)的实时/延时校正非常重要;如某航次未经标定的船载CTD仪所测1000dbar以深范围内海水盐度,与实验室高精度盐度计的差值达到±0.1左右,远远落后于国内海洋调查规范对盐度准确度±0.02的一级测量要求,该具体实例更加突显了船载CTD仪在航次前后送往权威部门进行检测的必要性和重要性,从而确保每个航次获取的CTD资料的质量。建议有条件的情况下,在进行深海大洋船载CTD仪观测时要进行现场实验室高精度盐度计的质量控制工作及比对试验,以提高我国深海大洋观测数据的质量。
基金Project(2013CB035402) supported by the National Basic Research Program of ChinaProjects(51105048,51209028) supported by the National Natural Science Foundation of China
文摘In order to deal with modeling problem of a pressure balance system with time-delay, nonlinear, time-varying and uncertain characteristics, an intelligent modeling procedure is proposed, which is based on artificial neural network(ANN) and input-output data of the system during shield tunneling and can overcome the precision problem in mechanistic modeling(MM) approach. The computational results show that the training algorithm with Gauss-Newton optimization has fast convergent speed. The experimental investigation indicates that, compared with mechanistic modeling approach, intelligent modeling procedure can obviously increase the precision in both soil pressure fitting and forecasting period. The effectiveness and accuracy of proposed intelligent modeling procedure are verified in laboratory tests.
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.
