<div style="text-align:justify;"> This study demonstrates mathematical analysis of biodegradation processes of xenobiotic polymers. A model for microbial population is based on the fact that growth rat...<div style="text-align:justify;"> This study demonstrates mathematical analysis of biodegradation processes of xenobiotic polymers. A model for microbial population is based on the fact that growth rate of microorganisms is proportional to the microbial population and consumption rate of parts of carbon sources. The model is paired with a model for weight distribution. Those models lead to inverse problems for a molecular factor and a time factor of degradation rate. Solution of the inverse problems allows us to simulate the biodegra-dation process. </div>展开更多
The next-generation gravity satellite mission equipped with the Cold Atom Interferometry(CAI)gradiometer has great potential for the Earth's gravity field estimation.Deploying a CAI gradiometer on the Chinese Tian...The next-generation gravity satellite mission equipped with the Cold Atom Interferometry(CAI)gradiometer has great potential for the Earth's gravity field estimation.Deploying a CAI gradiometer on the Chinese Tiangong Space Station launched for long-term Earth science research not only reduces the cost compared to a dual-satellite constellation but also enhances interdisciplinary collaboration in the Earth's gravity field detection.In this study,we conducted gravity gradient-based simulations to assess the contribution of deploying a CAI gradiometer on the Tiangong Space Station to collaboratively observe the Earth's gravity field with a polar-orbit gravity satellite.The simulation results demonstrate that whether utilizing V_(yy) component,three diagonal components or full components,the derived gravity field models show significant improvements within 100 degree and above 200 degree after incorporating Tiangong Space Station.In particular,the gravity field solution recovered from three diagonal components achieves the best accuracy.In the case of using diagonal components,the collaboration observation scheme effectively reduced the cumulative geoid height error by approximately 5.3 cm(300 d/o).In the spatial domain,the incorporation of the Tiangong Space Station primarily impacts the estimated gravity field within the orbital coverage area of the space station,and this effect is particularly pronounced when just employing V_(yy) component.However,due to the limitation of angular velocity observation inaccuracy associated with the CAI gradiometer in nadir mode,there is no substantial accuracy improvement observed above 200 degree when adding gradient components.展开更多
在遥感影像配准过程中,通常假设控制点是“完美的”。然而,在实际情况中,由于控制点本身不可避免的带有一定的误差导致这种假设在一定情况下并不成立,并且将会影响遥感影像几何校正的精度。普通最小二乘方法OLS(O rd inary Least Square...在遥感影像配准过程中,通常假设控制点是“完美的”。然而,在实际情况中,由于控制点本身不可避免的带有一定的误差导致这种假设在一定情况下并不成立,并且将会影响遥感影像几何校正的精度。普通最小二乘方法OLS(O rd inary Least Square)是遥感影像配准常用的校正估计模型,令人遗憾的是,在控制点存在误差的情况下,它的估计是有偏的,并且不能够正确传递和估计校正影像的误差大小。引入一致校正最小二乘方法CALS(ConsistentAd justed Least Squares),在此基础上提出的一个改进的方法,称之为松弛一致校正最小二乘方法RCALS(Relaxed ConsistentAd justed Least Squares)。这类回归模型具有改正控制点(解释变量)中的误差和跟踪回归模型中的误差传递的能力。为了验证CALS和RCALS模型的有效性,本文利用模拟影像进行分析。这里着重分析OLS,CALS和RCALS模型在几何校正过程中的比较。结果表明,RCALS和CALS的结果优于OLS估计结果。展开更多
文摘<div style="text-align:justify;"> This study demonstrates mathematical analysis of biodegradation processes of xenobiotic polymers. A model for microbial population is based on the fact that growth rate of microorganisms is proportional to the microbial population and consumption rate of parts of carbon sources. The model is paired with a model for weight distribution. Those models lead to inverse problems for a molecular factor and a time factor of degradation rate. Solution of the inverse problems allows us to simulate the biodegra-dation process. </div>
基金National Key R&D Program of China(2021YFB3900101)the National Natural Science Foundation of China(42174099 and 42192532)It is also partly supported by the Fundamental Research Funds for the Central Universities.
文摘The next-generation gravity satellite mission equipped with the Cold Atom Interferometry(CAI)gradiometer has great potential for the Earth's gravity field estimation.Deploying a CAI gradiometer on the Chinese Tiangong Space Station launched for long-term Earth science research not only reduces the cost compared to a dual-satellite constellation but also enhances interdisciplinary collaboration in the Earth's gravity field detection.In this study,we conducted gravity gradient-based simulations to assess the contribution of deploying a CAI gradiometer on the Tiangong Space Station to collaboratively observe the Earth's gravity field with a polar-orbit gravity satellite.The simulation results demonstrate that whether utilizing V_(yy) component,three diagonal components or full components,the derived gravity field models show significant improvements within 100 degree and above 200 degree after incorporating Tiangong Space Station.In particular,the gravity field solution recovered from three diagonal components achieves the best accuracy.In the case of using diagonal components,the collaboration observation scheme effectively reduced the cumulative geoid height error by approximately 5.3 cm(300 d/o).In the spatial domain,the incorporation of the Tiangong Space Station primarily impacts the estimated gravity field within the orbital coverage area of the space station,and this effect is particularly pronounced when just employing V_(yy) component.However,due to the limitation of angular velocity observation inaccuracy associated with the CAI gradiometer in nadir mode,there is no substantial accuracy improvement observed above 200 degree when adding gradient components.
文摘在遥感影像配准过程中,通常假设控制点是“完美的”。然而,在实际情况中,由于控制点本身不可避免的带有一定的误差导致这种假设在一定情况下并不成立,并且将会影响遥感影像几何校正的精度。普通最小二乘方法OLS(O rd inary Least Square)是遥感影像配准常用的校正估计模型,令人遗憾的是,在控制点存在误差的情况下,它的估计是有偏的,并且不能够正确传递和估计校正影像的误差大小。引入一致校正最小二乘方法CALS(ConsistentAd justed Least Squares),在此基础上提出的一个改进的方法,称之为松弛一致校正最小二乘方法RCALS(Relaxed ConsistentAd justed Least Squares)。这类回归模型具有改正控制点(解释变量)中的误差和跟踪回归模型中的误差传递的能力。为了验证CALS和RCALS模型的有效性,本文利用模拟影像进行分析。这里着重分析OLS,CALS和RCALS模型在几何校正过程中的比较。结果表明,RCALS和CALS的结果优于OLS估计结果。
