To analyze the stress wave propagation associated with the vortex-induced vibration（VIV） of a marine riser, this paper employed a multi-signal complex exponential method. This method is an extension of the classical...To analyze the stress wave propagation associated with the vortex-induced vibration（VIV） of a marine riser, this paper employed a multi-signal complex exponential method. This method is an extension of the classical Prony＇s method which decomposes a complicated signal into a number of complex exponential components. Because the proposed method processes multiple signals simultaneously, it can estimate the “global” dominating frequencies（poles） shared by those signals.The complex amplitude（residues） corresponding to the estimated frequencies for those signals is also obtained in the process. As the signals were collected at different locations along the axial direction of a marine riser, the phenomena of the stress wave propagation could be analyzed through the obtained residues of those signals. The Norwegian Deepwater Program（NDP） high mode test data were utilized in the numerical studies, including data sets in both the in-line（IL） and cross-flow（CF） directions. It was found that the most dominant component in the IL direction has its stress wave propagation along the riser being dominated by a standing wave, while that in the CF direction dominated by a traveling wave.展开更多
Fertile topsoil was added onto the surface of barren slope land in Three Gorges Reservoir region of China in an anthropogenic process known as the foreign soil reconstruction project. The main goal of this paper was t...Fertile topsoil was added onto the surface of barren slope land in Three Gorges Reservoir region of China in an anthropogenic process known as the foreign soil reconstruction project. The main goal of this paper was to reveal the influence of anthropogenic activities on pedogenic processes and soil classifications. Chemical weathering indices and comparative analysis were applied to discuss changes in geochemical compositions and weathering features of purplish soils(Cambisols) before and after the project. Results showed that:(1) The foreign soil reconstruction project slightly altered the major element composition of topsoil and improved the soil structure. Although the distributions of major elements in the original topsoil, original subsoil, foreign topsoil and newly constructed topsoil were all similar to that in upper continental crust, newly constructed topsoil was the most similar soil.(2) The chemical index of alteration was more sensitive than the weathering index of Parker at indicating chemical weathering status of purplish soil. The chemical weathering status of newly constructed topsoil was higher than that of the original topsoil and lower than that of foreign topsoil.(3) Anthropogenic activities may provide a promising new thought for the anthropogenic soil classification system. The scope and subgroups of Anthrosols should be extended and strengthened. Or there may be a need to combine Anthrosols and Technosols orders to create a new soil order. The results may be used for optimizing soil mellowing engineering activities and enriching the soil classification system.展开更多
Post-war Iraq is a mix of potential opportunities, promising intentions, and difficult challenges. After 2003, the government adopted a program to manage the housing crisis and satisfy housing needs. Through a fieldwo...Post-war Iraq is a mix of potential opportunities, promising intentions, and difficult challenges. After 2003, the government adopted a program to manage the housing crisis and satisfy housing needs. Through a fieldwork survey, we aimed to present this program by reviewing the government targets, main housing problems, governmental legislations, and construction process. We found that the government abandoned its centralized role in its National Housing Project as it opened the door of Iraqi housing market to foreign and local investors. We also found that, considering the enormous need for housing the occupancy rate of the governmental housing units are so low and construction is also generally slow. We deduced that the pricing model of the government＇s national housing project is far from our general notion of public housing for low-income post-war people. Moreover, it is necessary for the government to formulate a clearer strategic vision and to adopt more innovative approaches to address effectively and rapidly the trade-offs of the short and long terms objectives of the reconstruction process in post-war Iraq.展开更多
The existing terrain models that describe the local lunar surface have limited resolution and accuracy, which can hardly meet the needs of rover navigation,positioning and geological analysis. China launched the lunar...The existing terrain models that describe the local lunar surface have limited resolution and accuracy, which can hardly meet the needs of rover navigation,positioning and geological analysis. China launched the lunar probe Chang＇e-3 in December, 2013. Chang＇e-3 encompassed a lander and a lunar rover called ＂Yutu＂（Jade Rabbit）. A set of panoramic cameras were installed on the rover mast. After acquiring panoramic images of four sites that were explored, the terrain models of the local lunar surface with resolution of 0.02 m were reconstructed. Compared with other data sources, the models derived from Chang＇e-3 data were clear and accurate enough that they could be used to plan the route of Yutu.展开更多
Low efficiency, negative impacts on the environment and non-profitable operations are the main shortcomings of out-dated industrial processes. Such systems can be reconstructed and improved in the direction of multi-p...Low efficiency, negative impacts on the environment and non-profitable operations are the main shortcomings of out-dated industrial processes. Such systems can be reconstructed and improved in the direction of multi-product operations. The study of this article focuses on the development of a method for multi-product operations by reconstructing out-dated industrial processes. This article contains the theory of a developed method that enables the updating of existing process units and integrated systems on the basis of reconstruction scenarios and pathways. The goals of the set out method are: 1) to maintain the existing process units and chemical plants to a greater extent, 2) to enable the potential for finding new process alternatives and technological solutions, 3) to provide a streamlined operation for all subsystems and total systems, 4) to promote environmental and social responsibilities, and 5) to apply the concept of the presented reconstruction method to non-profitable industrial processes. In regard to multi-product operations, a conceptual model is a suitable tool for the reconstruction of industrial processes. It connects several software tools and so enables quick decision-making between process alternatives. A reconstruction method provides foresight into the possible improvements to existing industrial processes. In comparison with the indirect synthesis of DME (simple reconstruction pathway), the lower operating costs from the direct synthesis of DME (complex reconstruction pathway) were confirmed.展开更多
Compressed ultrafast photography(CUP)is a computational imaging technique that can simultaneously achieve an imaging speed of 10^(13)frames per second and a sequence depth of hundreds of frames.It is a powerful tool f...Compressed ultrafast photography(CUP)is a computational imaging technique that can simultaneously achieve an imaging speed of 10^(13)frames per second and a sequence depth of hundreds of frames.It is a powerful tool for observing unrepeatable ultrafast physical processes.However,since the forward model of CUP is a data compression process,the reconstruction process is an ill-posed problem.This causes inconvenience in the practical application of CUP,especially in those scenes with complex temporal behavior,high noise level and compression ratio.In this paper,the CUP system model based on spatial-intensity-temporal constraints is proposed by adding an additional charge-coupled device(CCD)camera to constrain the spatial and intensity behaviors of the dynamic scene and an additional narrow-slit streak camera to constrain the temporal behavior of the dynamic scene.Additionally,the unsupervised deep learning CUP reconstruction algorithm with low-rank tensor embedding is also proposed.The algorithm enhances the low-rankness of the reconstructed image by maintaining the low-rank structure of the dynamic scene and effectively utilizes the implicit prior information of the neural network and the hardware physical model.The proposed joint learning model enables high-quality reconstruction of complex dynamic scenes without training datasets.The simulation and experimental results demonstrate the application prospect of the proposed joint learning model in complex ultrafast physical phenomena imaging.展开更多
Three-dimensional structured illumination microscopy(3DSIM)is a popular method for observing subcellular/cellular structures or animal/plant tissues with gentle phototoxicity and 3D super-resolution.However,its time-c...Three-dimensional structured illumination microscopy(3DSIM)is a popular method for observing subcellular/cellular structures or animal/plant tissues with gentle phototoxicity and 3D super-resolution.However,its time-consuming reconstruction process poses challenges for high-throughput imaging and real-time observation.Moreover,traditional 3DSIM typically requires more than six z layers for successful reconstruction and is susceptible to defocused backgrounds.This poses a great gap between single-layer 2DSIM and 6-layer 3DSIM,and limits the observation of thicker samples.To address these limitations,we developed FO-3DSIM,a novel method that integrates spatial-domain reconstruction with optical-sectioning SIM.FO-3DSIM enhances reconstruction speed by up to 855.7 times with superior performance with limited z layers and under high defocused backgrounds.It retains the high-fidelity,low-photon reconstruction capabilities of our previously proposed Open-3DSIM.Utilizing fast reconstruction and optical sectioning,we achieved large field-of-view(FOV)3D super-resolution imaging of mouse kidney actin,covering a region of 0.453 mm×0.453 mm×2.75μm within 23 min of acquisition and 13 min of reconstruction.Near real-time performance was demonstrated in live actin imaging with FO-3DSIM.Our approach reduces photodamage through limited z layer reconstruction,allowing the observation of ER tubes with just three layers.We anticipate that FO-3DSIM will pave the way for near real-time,large FOV 6D imaging,encompassing xyz super-resolution,multi-color,long-term,and polarization imaging with less photodamage,removed defocused backgrounds,and reduced reconstruction time.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant Nos.51490675,51379197 and 51522906)
文摘To analyze the stress wave propagation associated with the vortex-induced vibration（VIV） of a marine riser, this paper employed a multi-signal complex exponential method. This method is an extension of the classical Prony＇s method which decomposes a complicated signal into a number of complex exponential components. Because the proposed method processes multiple signals simultaneously, it can estimate the “global” dominating frequencies（poles） shared by those signals.The complex amplitude（residues） corresponding to the estimated frequencies for those signals is also obtained in the process. As the signals were collected at different locations along the axial direction of a marine riser, the phenomena of the stress wave propagation could be analyzed through the obtained residues of those signals. The Norwegian Deepwater Program（NDP） high mode test data were utilized in the numerical studies, including data sets in both the in-line（IL） and cross-flow（CF） directions. It was found that the most dominant component in the IL direction has its stress wave propagation along the riser being dominated by a standing wave, while that in the CF direction dominated by a traveling wave.
基金the National Key Technology Research and Development Program of the Ministry of Science and Technology of China (Grant No. 2012BAD05B06)
文摘Fertile topsoil was added onto the surface of barren slope land in Three Gorges Reservoir region of China in an anthropogenic process known as the foreign soil reconstruction project. The main goal of this paper was to reveal the influence of anthropogenic activities on pedogenic processes and soil classifications. Chemical weathering indices and comparative analysis were applied to discuss changes in geochemical compositions and weathering features of purplish soils(Cambisols) before and after the project. Results showed that:(1) The foreign soil reconstruction project slightly altered the major element composition of topsoil and improved the soil structure. Although the distributions of major elements in the original topsoil, original subsoil, foreign topsoil and newly constructed topsoil were all similar to that in upper continental crust, newly constructed topsoil was the most similar soil.(2) The chemical index of alteration was more sensitive than the weathering index of Parker at indicating chemical weathering status of purplish soil. The chemical weathering status of newly constructed topsoil was higher than that of the original topsoil and lower than that of foreign topsoil.(3) Anthropogenic activities may provide a promising new thought for the anthropogenic soil classification system. The scope and subgroups of Anthrosols should be extended and strengthened. Or there may be a need to combine Anthrosols and Technosols orders to create a new soil order. The results may be used for optimizing soil mellowing engineering activities and enriching the soil classification system.
文摘Post-war Iraq is a mix of potential opportunities, promising intentions, and difficult challenges. After 2003, the government adopted a program to manage the housing crisis and satisfy housing needs. Through a fieldwork survey, we aimed to present this program by reviewing the government targets, main housing problems, governmental legislations, and construction process. We found that the government abandoned its centralized role in its National Housing Project as it opened the door of Iraqi housing market to foreign and local investors. We also found that, considering the enormous need for housing the occupancy rate of the governmental housing units are so low and construction is also generally slow. We deduced that the pricing model of the government＇s national housing project is far from our general notion of public housing for low-income post-war people. Moreover, it is necessary for the government to formulate a clearer strategic vision and to adopt more innovative approaches to address effectively and rapidly the trade-offs of the short and long terms objectives of the reconstruction process in post-war Iraq.
基金Supported by the National Natural Science Foundation of China
文摘The existing terrain models that describe the local lunar surface have limited resolution and accuracy, which can hardly meet the needs of rover navigation,positioning and geological analysis. China launched the lunar probe Chang＇e-3 in December, 2013. Chang＇e-3 encompassed a lander and a lunar rover called ＂Yutu＂（Jade Rabbit）. A set of panoramic cameras were installed on the rover mast. After acquiring panoramic images of four sites that were explored, the terrain models of the local lunar surface with resolution of 0.02 m were reconstructed. Compared with other data sources, the models derived from Chang＇e-3 data were clear and accurate enough that they could be used to plan the route of Yutu.
基金This research work was funded by the Public Agency for the Development of the Republic of Slovenia(ADRS),the Ministry of Education,Science,Culture and Sport,for which we sincerely thank them.
文摘Low efficiency, negative impacts on the environment and non-profitable operations are the main shortcomings of out-dated industrial processes. Such systems can be reconstructed and improved in the direction of multi-product operations. The study of this article focuses on the development of a method for multi-product operations by reconstructing out-dated industrial processes. This article contains the theory of a developed method that enables the updating of existing process units and integrated systems on the basis of reconstruction scenarios and pathways. The goals of the set out method are: 1) to maintain the existing process units and chemical plants to a greater extent, 2) to enable the potential for finding new process alternatives and technological solutions, 3) to provide a streamlined operation for all subsystems and total systems, 4) to promote environmental and social responsibilities, and 5) to apply the concept of the presented reconstruction method to non-profitable industrial processes. In regard to multi-product operations, a conceptual model is a suitable tool for the reconstruction of industrial processes. It connects several software tools and so enables quick decision-making between process alternatives. A reconstruction method provides foresight into the possible improvements to existing industrial processes. In comparison with the indirect synthesis of DME (simple reconstruction pathway), the lower operating costs from the direct synthesis of DME (complex reconstruction pathway) were confirmed.
基金National Natural Science Foundation of China(11975184)。
文摘Compressed ultrafast photography(CUP)is a computational imaging technique that can simultaneously achieve an imaging speed of 10^(13)frames per second and a sequence depth of hundreds of frames.It is a powerful tool for observing unrepeatable ultrafast physical processes.However,since the forward model of CUP is a data compression process,the reconstruction process is an ill-posed problem.This causes inconvenience in the practical application of CUP,especially in those scenes with complex temporal behavior,high noise level and compression ratio.In this paper,the CUP system model based on spatial-intensity-temporal constraints is proposed by adding an additional charge-coupled device(CCD)camera to constrain the spatial and intensity behaviors of the dynamic scene and an additional narrow-slit streak camera to constrain the temporal behavior of the dynamic scene.Additionally,the unsupervised deep learning CUP reconstruction algorithm with low-rank tensor embedding is also proposed.The algorithm enhances the low-rankness of the reconstructed image by maintaining the low-rank structure of the dynamic scene and effectively utilizes the implicit prior information of the neural network and the hardware physical model.The proposed joint learning model enables high-quality reconstruction of complex dynamic scenes without training datasets.The simulation and experimental results demonstrate the application prospect of the proposed joint learning model in complex ultrafast physical phenomena imaging.
基金supported by the National Key R&D Program of China(2022YFC3401100)the National Natural Science Foundation of China(624B2009,62405010,62335008,62025501,92150301,and 62411540238).
文摘Three-dimensional structured illumination microscopy(3DSIM)is a popular method for observing subcellular/cellular structures or animal/plant tissues with gentle phototoxicity and 3D super-resolution.However,its time-consuming reconstruction process poses challenges for high-throughput imaging and real-time observation.Moreover,traditional 3DSIM typically requires more than six z layers for successful reconstruction and is susceptible to defocused backgrounds.This poses a great gap between single-layer 2DSIM and 6-layer 3DSIM,and limits the observation of thicker samples.To address these limitations,we developed FO-3DSIM,a novel method that integrates spatial-domain reconstruction with optical-sectioning SIM.FO-3DSIM enhances reconstruction speed by up to 855.7 times with superior performance with limited z layers and under high defocused backgrounds.It retains the high-fidelity,low-photon reconstruction capabilities of our previously proposed Open-3DSIM.Utilizing fast reconstruction and optical sectioning,we achieved large field-of-view(FOV)3D super-resolution imaging of mouse kidney actin,covering a region of 0.453 mm×0.453 mm×2.75μm within 23 min of acquisition and 13 min of reconstruction.Near real-time performance was demonstrated in live actin imaging with FO-3DSIM.Our approach reduces photodamage through limited z layer reconstruction,allowing the observation of ER tubes with just three layers.We anticipate that FO-3DSIM will pave the way for near real-time,large FOV 6D imaging,encompassing xyz super-resolution,multi-color,long-term,and polarization imaging with less photodamage,removed defocused backgrounds,and reduced reconstruction time.
