The proportion of elderly patients in intensive care is increasing, and a significant proportion of them require mechanical ventilation. How to implement safe and effective mechanical ventilation for elderly patients,...The proportion of elderly patients in intensive care is increasing, and a significant proportion of them require mechanical ventilation. How to implement safe and effective mechanical ventilation for elderly patients, and when appropriate off-line is an important issue in the field of critical care medicine. Appropriate sedation can improve patient outcomes, but excessive sedation may lead to prolonged mechanical ventilation and increase the risk of complications. Elderly patients should be closely monitored and evaluated on an individual basis while offline, and the sedation regimen should be dynamically adjusted. This requires the healthcare team to consider the patient’s sedation needs, disease status, and pharmacodynamics and pharmacokinetics of the drug to arrive at the best strategy. Although the current research has provided valuable insights and strategies for sedation and off-line management, there are still many problems to be further explored and solved.展开更多
The effects of on-line solution, off-line solution and aging heat treatment on the microstructure and hardness of the die-cast AZ91D alloys were investigated. Brinell hardness of die-cast AZ91D alloy increases through...The effects of on-line solution, off-line solution and aging heat treatment on the microstructure and hardness of the die-cast AZ91D alloys were investigated. Brinell hardness of die-cast AZ91D alloy increases through on-line solution and off-line aging treatment but decreases after off-line solution treatment. By X-ray diffractometry, optical microscopy, differential thermal analysis, scanning electron microscopy and X-ray energy dispersive spectroscopy, it is found that the microstructures of the die-cast AZ91D magnesium alloy before and after on-line solution and off-line aging are similar, consisting of α-Mg and β-Al12Mg17. The precipitation of Al element is prevented by on-line solution so that the effect of solid solution strengthening is enhanced. The β-Al12Mg17 phases precipitate from supersaturated Mg solid solution after off-line aging treatment, and lead to microstructure refinement of AZ91D alloy, so the effect of precipitation hardening is enhanced. The β-Al12Mg17 phases dissolve in the substructure after off-line solution treatment, which leads to that the grain boundary strengthening phase is reduced significantly and the hardness of die cast AZ91D is reduced.展开更多
The IAP (Institute of Atmospheric Physics) land-surface model (IAP94) is described. This model is a comprehensive one with detailed description for the processes of vegetation, snow and soil. Particular attention has ...The IAP (Institute of Atmospheric Physics) land-surface model (IAP94) is described. This model is a comprehensive one with detailed description for the processes of vegetation, snow and soil. Particular attention has been paid to the cases with three water phases in the surface media. On the basis of the mixture theory and the theory of fluid dynamics of porous media, the system of universal conservational equations for water and heat of soil, snow and vegetation canopy has been constructed. On this background, all important factors that may affect the water and heat balance in media can be considered naturally, and each factor and term possess distinct physical meaning. In the computation of water content and temperature, the water phase change and the heat transportation by water flow are taken into account. Moreover, particular attention has been given to the water vapor diffusion in soil for arid or semi-arid cases, and snow compaction. In the treatment of surface turbulent fluxes, the difference between aerodynamic and thermal roughness is taken into account. The aerodynamic roughness of vegetation is calculated as a function of canopy density, height and zero-plane displacement. An extrapolation of log linear and exponential relationship is used when calculating the wind profile within canopy. The model has been validated against field measurements in off-line simulations. The desirable model′s performance leads to the conclusion that the IAP94 is able to reproduce the main physical mechanisms governing the energy and water balances in the global land surface. Part II of the present study will concern the validation in a 3-D experiment coupled with the IAP Two-Level AGCM.展开更多
Off-line programming (OLP) system becomes one of the most important programming modules for the robotic belt grinding process, however there lacks research on increasing the grinding dexterous space depending on the...Off-line programming (OLP) system becomes one of the most important programming modules for the robotic belt grinding process, however there lacks research on increasing the grinding dexterous space depending on the OLP system. A new type of grinding robot and a novel robotic belt grinding workcell are forwarded, and their features are briefly introduced. An open and object-oriented off-line programming system is developed for this robotic belt grinding system. The parameters of the trimmed surface are read from the initial graphics exchange specification (IGES) file of the CAD model of the workpiece. The deBoor-Cox basis function is used to sample the grinding target with local contact frame on the workpiece. The numerical formula of inverse kinematics is set up based on Newton's iterative procedure, to calculate the grinding robot configurations corresponding to the grinding targets. After the grinding path is obtained, the OLP system turns to be more effective than the teach-by-showing system. In order to improve the grinding workspace, an optimization algorithm for dynamic tool frame is proposed and performed on the special robotic belt grinding system. The initial tool frame and the interval of neighboring tool frames are defined as the preparation of the algorithm. An optimized tool local frame can be selected to grind the complex surface for a maximum dexterity index of the robot. Under the optimization algorithm, a simulation of grinding a vane is included and comparison of grinding workspace is done before and after the tool frame optimization. By the algorithm, the grinding workspace can be enlarged. Moreover the dynamic tool frame can be considered to add one degree-of-freedom to the grinding kinematical chain, which provides the theoretical support for the improvement of robotic dexterity for the complex surface grinding.展开更多
In order to further understand the land surface processes over the northern Tibetan Plateau, this study produced an off-line simulated examination at the Bujiao site on the northern Tibetan Plateau from June 2002 to A...In order to further understand the land surface processes over the northern Tibetan Plateau, this study produced an off-line simulated examination at the Bujiao site on the northern Tibetan Plateau from June 2002 to April 2004, using the Noah Land Surface Model (Noah LSM) and observed data from the CAMP/Tibet experiment. The observed data were neces- sarily corrected and the number of soil layers in the Noah LSM was changed from 4 to 10 to enable this off-line simulation and analysis. The main conclusions are as follows: the Noah LSM performed well on the northern Tibetan Plateau. The simulated net radiation, upward longwave radiation, and upward shortwave radiation demonstrated the same remarkable annual and seasonal variation as the observed data, especially the upward longwave radiation. The simulated soil temperatures were acceptably close to the observed temperatures, especially in the shallow soil layers. The simulated freezing and melting processes were shown to start from the surface soil layer and spread down to the deep soil layers, but they took longer than the observed processes. However, Noah LSM did not adequately simulate the soil moisture. Therefore, additional high-quality, long-term observations of land surface-atmosphere processes over the Tibetan Plateau will be a key factor in proper adiustments of the model parameters in the future.展开更多
Segmentation of cursive text has been one of the major problems in Arabic writing. The problem is the shape of the letter which is context sensitive, depending on it’s location within a word. Many text recognition sy...Segmentation of cursive text has been one of the major problems in Arabic writing. The problem is the shape of the letter which is context sensitive, depending on it’s location within a word. Many text recognition systems recognize text imagery at the character level and assemble words from the recognized characters. Unfortunately this approach does not work with Arabic text. In this paper we describe a new approach to segment Arabic text imagery at a word level, without analyzing individual characters. This approach avoids the problem of individual characters segmentation, and can overcome local errors in character recognition.展开更多
A study of the interference simulation based on robot welding of the radar pedestal was carried out by using the KUKA Sim Pro simulation software and off-line program technology. Compared with the actual robot welding...A study of the interference simulation based on robot welding of the radar pedestal was carried out by using the KUKA Sim Pro simulation software and off-line program technology. Compared with the actual robot welding process, it was found that the trajectory of the simulated robot welding process in line with that recorded in the actual welding process, and the actual limit and interference appeared at the same place as the simulation process. There was no interference phenomenon on the outside weld-seam; on the internal weld-seam, especially on the weld-joint of support plate connected to the cylinder, a phenomenon of interference appeared. It was helpful to use the simulation method to guide the actual robot welding so as to protect robot from impacting and reduce the weld defects.展开更多
Thick walled curve welding are usually joined by multi-layer and multi-pass welding, which quality and efficiency could be improved by off-line programming of robot welding. However, the precision of off-line programm...Thick walled curve welding are usually joined by multi-layer and multi-pass welding, which quality and efficiency could be improved by off-line programming of robot welding. However, the precision of off-line programming welding path was decreased due to the deviation between the off-line planned welding path and the actual welding path. A path planning algorithm and a path compensation algorithm of multi-layer and multi-pass curve welding seam for off-line programming of robot welding are developed in this paper. Experimental results show that the robot off-line programming improves the welding efftcieney and precision for thick walled curve welding seam.展开更多
In this paper we present some of our recent results on applications of spectral techniques over finite fields to the problems of testing and diagnosis of computer systems.
Off line programming provides an essential link between CAD and CAM, whose development will result in greater use of robotic arc welding. An arc welding system with a robot and a rotating/tilting positioner is one of...Off line programming provides an essential link between CAD and CAM, whose development will result in greater use of robotic arc welding. An arc welding system with a robot and a rotating/tilting positioner is one of the most typical workcells. The inverse kinematics of robot and positioner is the foundation of the off line programming system. The previous researchers only focused on a special solution of the positioner inverse kinematics, which is the solution at down hand welding position. In this paper, we introduce a method for representing welding position. Then a general algorithm of rotating/tilting positioner inverse kinematics is presented, and an approach to find the unique solution of the inverse kinematics is discussed. The simulation experiment results show that the general algorithm can improve the ability of robotic arc welding off line programming system to program all types of welding positions.展开更多
This paper puts forward a communication programming method between robot and external computer based on RPC (Remote Produce Call) communication method, which realizes robot distributed controlling network system model...This paper puts forward a communication programming method between robot and external computer based on RPC (Remote Produce Call) communication method, which realizes robot distributed controlling network system model. And a new Robot off line programming method is built based on this communication method and network model. Further more, as an example, robot auto marking and auto cutting of shipbuilding profile system is developed, which proves the ideas of author’s off line programming and development methods of robot flexible automation system. As a result, this paper presents a new method for developing robot flexible automation system.展开更多
Objective: To identify phytochemical constituents present in the extract of flowers of Xanthoceras sorbifolia and evaluate their anti-oxidant and anti-hyperglycemic capacities.Methods: The AlCl3colorimetric method and...Objective: To identify phytochemical constituents present in the extract of flowers of Xanthoceras sorbifolia and evaluate their anti-oxidant and anti-hyperglycemic capacities.Methods: The AlCl3colorimetric method and Prussian Blue assay were used to determine the contents of total flavonoids and total phenolic acids in extraction layers, and the bioactive layers was screened through anti-oxidative activity in vitro. The Waters ACQUITY UPLC system and a Waters ACQUITY UPLC BEH C18column(2.0 mm × 150 mm, 5 μm) were used to identify the ingredients. And anti-oxidative ingredients were screened by off-line UPLC-QTOF-MS/MS-free radical scavenging. The ameliorative role of it was further evaluated in a high-fat, streptozotocin-induced type 2 diabetic rat model and the study was carried out on NADPH oxidase(PDB ID: 2CDU) by molecular docking.Results: Combined with the results of activity screening in vitro, the anti-oxidative part was identified as the ethyl acetate layer. A total of 24 chemical constituents were identified by liquid chromatographymass spectrometry in the ethyl acetate layer and 13 main anti-oxidative active constituents were preliminarily screened out through off-line UPLC-QTOF-MS/MS-free radical scavenging. In vivo experiments showed that flowers of X. sorbifolia could significantly reduce the blood glucose level of diabetic mice and alleviate liver cell damage. Based on the results of docking analysis related to the identified phytocompounds and oxidase which involved in type 2 diabetes, quercetin 3-O-rutinoside, kaempferol-3-O-rhamnoside, isorhamnetin-3-O-glucoside, and isoquercitrin showed a better inhibitory profile.Conclusion: The ethyl acetate layer was rich in flavonoids and phenolic acids and had significant anti-oxidant activity, which could prevent hyperglycemia. This observed activity profile suggested X. sorbifolia flowers as a promising new source of tea to develop alternative natural anti-diabetic products with a high safety margin.展开更多
To overcome the shortcomings of model-driven state estimation methods, this paper proposes a data-driven robust state estimation (DDSE) method through off-line learning and on-line matching. At the off-line learning s...To overcome the shortcomings of model-driven state estimation methods, this paper proposes a data-driven robust state estimation (DDSE) method through off-line learning and on-line matching. At the off-line learning stage, a linear regression equation is presented by clustering historical data from supervisory control and data acquisition (SCADA), which provides a guarantee for solving the over-learning problem of the existing DDSE methods;then a novel robust state estimation method that can be transformed into quadratic programming (QP) models is proposed to obtain the mapping relationship between the measurements and the state variables (MRBMS). The proposed QP models can well solve the problem of collinearity in historical data. Furthermore, the off-line learning stage is greatly accelerated from three aspects including reducing historical categories, constructing tree retrieval structure for known topologies, and using sensitivity analysis when solving QP models. At the on-line matching stage, by quickly matching the current snapshot with the historical ones, the corresponding MRBMS can be obtained, and then the estimation values of the state variables can be obtained. Simulations demonstrate that the proposed DDSE method has obvious advantages in terms of suppressing over-learning problems, dealing with collinearity problems, robustness, and computation efficiency.展开更多
To support withdrawing and storing money from all levels of the bank for the customers in the real world, in this paper, we propose a proxy blind signature scheme and an off-line e-cash scheme based on the new proxy b...To support withdrawing and storing money from all levels of the bank for the customers in the real world, in this paper, we propose a proxy blind signature scheme and an off-line e-cash scheme based on the new proxy blind signature scheme. The pro- posed proxy blind signature is proven secure in the random oracle model under chosen-target computational Diffie-Hellman assump- tions, and the e-cash scheme can satisfy the security requirements of unforgeability, anonymity, and traceability.展开更多
Based on the existing land-surface schemes and models,an improved Land-surface Process Model(LPM-ZD)has been developed.It has the following major characteristics:(1)The combination of physical equations and empirical ...Based on the existing land-surface schemes and models,an improved Land-surface Process Model(LPM-ZD)has been developed.It has the following major characteristics:(1)The combination of physical equations and empirical analytical formulae are used to construct the governing equations of soil temperature and moisture.Higher resolution of model level and physical equations are adopted for the upper soil layers,and for the lower soil layers,lower resolution of model level is adopted and empirical analytical formulae are used.(2)In land surface hydrological process,the sub-grid distribution of rainfall and its effects are taken into account. (3)A simple snow cover submodel has been used,which includes effects of snow cover on soil thermodynamics and hydrology,as well as albedo. By use of this model and three groups of point observation data,a series of“off-line”tests have been carried out.The simulation results indicate that land-surface process model has good performance and can well simulate diurnal and seasonal variation of land surface processes for many kinds of land surface covers(forest,grass,crops and desert)in different climate zone.The results simulated by the model are consistent with the observations.Later,by use of one group of observation data and the model,a series of sensitivity experiments have been done.It is shown that the model is much sensitive to some parameters,such as initial soil moisture,vegetation physical parameters as well as the proportion of the grid covered with rain.Therefore it is much important for land-surface process model to define these parameters as accurately as possible.展开更多
文摘The proportion of elderly patients in intensive care is increasing, and a significant proportion of them require mechanical ventilation. How to implement safe and effective mechanical ventilation for elderly patients, and when appropriate off-line is an important issue in the field of critical care medicine. Appropriate sedation can improve patient outcomes, but excessive sedation may lead to prolonged mechanical ventilation and increase the risk of complications. Elderly patients should be closely monitored and evaluated on an individual basis while offline, and the sedation regimen should be dynamically adjusted. This requires the healthcare team to consider the patient’s sedation needs, disease status, and pharmacodynamics and pharmacokinetics of the drug to arrive at the best strategy. Although the current research has provided valuable insights and strategies for sedation and off-line management, there are still many problems to be further explored and solved.
基金Projects (2011BAE22B01, 2011BAE22B06) supported by the National Key Technologies R&D Program During the 12th Five-Year Plan Period of ChinaProject (2010NC018) supported by the Innovation Fund of Inner Mongolia University of Science and Technology, China
文摘The effects of on-line solution, off-line solution and aging heat treatment on the microstructure and hardness of the die-cast AZ91D alloys were investigated. Brinell hardness of die-cast AZ91D alloy increases through on-line solution and off-line aging treatment but decreases after off-line solution treatment. By X-ray diffractometry, optical microscopy, differential thermal analysis, scanning electron microscopy and X-ray energy dispersive spectroscopy, it is found that the microstructures of the die-cast AZ91D magnesium alloy before and after on-line solution and off-line aging are similar, consisting of α-Mg and β-Al12Mg17. The precipitation of Al element is prevented by on-line solution so that the effect of solid solution strengthening is enhanced. The β-Al12Mg17 phases precipitate from supersaturated Mg solid solution after off-line aging treatment, and lead to microstructure refinement of AZ91D alloy, so the effect of precipitation hardening is enhanced. The β-Al12Mg17 phases dissolve in the substructure after off-line solution treatment, which leads to that the grain boundary strengthening phase is reduced significantly and the hardness of die cast AZ91D is reduced.
文摘The IAP (Institute of Atmospheric Physics) land-surface model (IAP94) is described. This model is a comprehensive one with detailed description for the processes of vegetation, snow and soil. Particular attention has been paid to the cases with three water phases in the surface media. On the basis of the mixture theory and the theory of fluid dynamics of porous media, the system of universal conservational equations for water and heat of soil, snow and vegetation canopy has been constructed. On this background, all important factors that may affect the water and heat balance in media can be considered naturally, and each factor and term possess distinct physical meaning. In the computation of water content and temperature, the water phase change and the heat transportation by water flow are taken into account. Moreover, particular attention has been given to the water vapor diffusion in soil for arid or semi-arid cases, and snow compaction. In the treatment of surface turbulent fluxes, the difference between aerodynamic and thermal roughness is taken into account. The aerodynamic roughness of vegetation is calculated as a function of canopy density, height and zero-plane displacement. An extrapolation of log linear and exponential relationship is used when calculating the wind profile within canopy. The model has been validated against field measurements in off-line simulations. The desirable model′s performance leads to the conclusion that the IAP94 is able to reproduce the main physical mechanisms governing the energy and water balances in the global land surface. Part II of the present study will concern the validation in a 3-D experiment coupled with the IAP Two-Level AGCM.
基金supported by National Hi-tech Research and Development Program of China (863 Program, Grant No. 2007AA04Z2443)State Key Laboratory for Man ufacturing Systems Engineering of Xi’an Jiaotong University of China
文摘Off-line programming (OLP) system becomes one of the most important programming modules for the robotic belt grinding process, however there lacks research on increasing the grinding dexterous space depending on the OLP system. A new type of grinding robot and a novel robotic belt grinding workcell are forwarded, and their features are briefly introduced. An open and object-oriented off-line programming system is developed for this robotic belt grinding system. The parameters of the trimmed surface are read from the initial graphics exchange specification (IGES) file of the CAD model of the workpiece. The deBoor-Cox basis function is used to sample the grinding target with local contact frame on the workpiece. The numerical formula of inverse kinematics is set up based on Newton's iterative procedure, to calculate the grinding robot configurations corresponding to the grinding targets. After the grinding path is obtained, the OLP system turns to be more effective than the teach-by-showing system. In order to improve the grinding workspace, an optimization algorithm for dynamic tool frame is proposed and performed on the special robotic belt grinding system. The initial tool frame and the interval of neighboring tool frames are defined as the preparation of the algorithm. An optimized tool local frame can be selected to grind the complex surface for a maximum dexterity index of the robot. Under the optimization algorithm, a simulation of grinding a vane is included and comparison of grinding workspace is done before and after the tool frame optimization. By the algorithm, the grinding workspace can be enlarged. Moreover the dynamic tool frame can be considered to add one degree-of-freedom to the grinding kinematical chain, which provides the theoretical support for the improvement of robotic dexterity for the complex surface grinding.
基金the National Natural Science Foundation of China (Nos. 41075053 and 41275016)
文摘In order to further understand the land surface processes over the northern Tibetan Plateau, this study produced an off-line simulated examination at the Bujiao site on the northern Tibetan Plateau from June 2002 to April 2004, using the Noah Land Surface Model (Noah LSM) and observed data from the CAMP/Tibet experiment. The observed data were neces- sarily corrected and the number of soil layers in the Noah LSM was changed from 4 to 10 to enable this off-line simulation and analysis. The main conclusions are as follows: the Noah LSM performed well on the northern Tibetan Plateau. The simulated net radiation, upward longwave radiation, and upward shortwave radiation demonstrated the same remarkable annual and seasonal variation as the observed data, especially the upward longwave radiation. The simulated soil temperatures were acceptably close to the observed temperatures, especially in the shallow soil layers. The simulated freezing and melting processes were shown to start from the surface soil layer and spread down to the deep soil layers, but they took longer than the observed processes. However, Noah LSM did not adequately simulate the soil moisture. Therefore, additional high-quality, long-term observations of land surface-atmosphere processes over the Tibetan Plateau will be a key factor in proper adiustments of the model parameters in the future.
文摘Segmentation of cursive text has been one of the major problems in Arabic writing. The problem is the shape of the letter which is context sensitive, depending on it’s location within a word. Many text recognition systems recognize text imagery at the character level and assemble words from the recognized characters. Unfortunately this approach does not work with Arabic text. In this paper we describe a new approach to segment Arabic text imagery at a word level, without analyzing individual characters. This approach avoids the problem of individual characters segmentation, and can overcome local errors in character recognition.
基金Funded by Anhui Provincial Natural Science Foundation of China(GFKJ2015B002)Quality Engineering Project of Anhui province(2014zy122)
文摘A study of the interference simulation based on robot welding of the radar pedestal was carried out by using the KUKA Sim Pro simulation software and off-line program technology. Compared with the actual robot welding process, it was found that the trajectory of the simulated robot welding process in line with that recorded in the actual welding process, and the actual limit and interference appeared at the same place as the simulation process. There was no interference phenomenon on the outside weld-seam; on the internal weld-seam, especially on the weld-joint of support plate connected to the cylinder, a phenomenon of interference appeared. It was helpful to use the simulation method to guide the actual robot welding so as to protect robot from impacting and reduce the weld defects.
文摘Thick walled curve welding are usually joined by multi-layer and multi-pass welding, which quality and efficiency could be improved by off-line programming of robot welding. However, the precision of off-line programming welding path was decreased due to the deviation between the off-line planned welding path and the actual welding path. A path planning algorithm and a path compensation algorithm of multi-layer and multi-pass curve welding seam for off-line programming of robot welding are developed in this paper. Experimental results show that the robot off-line programming improves the welding efftcieney and precision for thick walled curve welding seam.
基金This work was supported by the National Science Foundation(USA)under grant MIP 9630096the NATO under Grant 910411Volkswagen Foundation(Germany)
文摘In this paper we present some of our recent results on applications of spectral techniques over finite fields to the problems of testing and diagnosis of computer systems.
基金ThispaperissupportedbyNationalNatureScienceFoundation (No .5 96 35 16 0 )AdvancedUniversityDoctoralSubjectFoundation (No .980 2 1311)
文摘Off line programming provides an essential link between CAD and CAM, whose development will result in greater use of robotic arc welding. An arc welding system with a robot and a rotating/tilting positioner is one of the most typical workcells. The inverse kinematics of robot and positioner is the foundation of the off line programming system. The previous researchers only focused on a special solution of the positioner inverse kinematics, which is the solution at down hand welding position. In this paper, we introduce a method for representing welding position. Then a general algorithm of rotating/tilting positioner inverse kinematics is presented, and an approach to find the unique solution of the inverse kinematics is discussed. The simulation experiment results show that the general algorithm can improve the ability of robotic arc welding off line programming system to program all types of welding positions.
文摘This paper puts forward a communication programming method between robot and external computer based on RPC (Remote Produce Call) communication method, which realizes robot distributed controlling network system model. And a new Robot off line programming method is built based on this communication method and network model. Further more, as an example, robot auto marking and auto cutting of shipbuilding profile system is developed, which proves the ideas of author’s off line programming and development methods of robot flexible automation system. As a result, this paper presents a new method for developing robot flexible automation system.
基金the Fourth National Investigation of Chinese materia medica resources in Liaoning Province (LN2018017, LN2019019)Career Development Support Plan for Young and Middle-aged Teachers in Shenyang Pharmaceutical University (No. ZQN2021014)Key Laboratory of Marine Biogenetic Resources, Ministry of Natural Resources (No. HY202105)
文摘Objective: To identify phytochemical constituents present in the extract of flowers of Xanthoceras sorbifolia and evaluate their anti-oxidant and anti-hyperglycemic capacities.Methods: The AlCl3colorimetric method and Prussian Blue assay were used to determine the contents of total flavonoids and total phenolic acids in extraction layers, and the bioactive layers was screened through anti-oxidative activity in vitro. The Waters ACQUITY UPLC system and a Waters ACQUITY UPLC BEH C18column(2.0 mm × 150 mm, 5 μm) were used to identify the ingredients. And anti-oxidative ingredients were screened by off-line UPLC-QTOF-MS/MS-free radical scavenging. The ameliorative role of it was further evaluated in a high-fat, streptozotocin-induced type 2 diabetic rat model and the study was carried out on NADPH oxidase(PDB ID: 2CDU) by molecular docking.Results: Combined with the results of activity screening in vitro, the anti-oxidative part was identified as the ethyl acetate layer. A total of 24 chemical constituents were identified by liquid chromatographymass spectrometry in the ethyl acetate layer and 13 main anti-oxidative active constituents were preliminarily screened out through off-line UPLC-QTOF-MS/MS-free radical scavenging. In vivo experiments showed that flowers of X. sorbifolia could significantly reduce the blood glucose level of diabetic mice and alleviate liver cell damage. Based on the results of docking analysis related to the identified phytocompounds and oxidase which involved in type 2 diabetes, quercetin 3-O-rutinoside, kaempferol-3-O-rhamnoside, isorhamnetin-3-O-glucoside, and isoquercitrin showed a better inhibitory profile.Conclusion: The ethyl acetate layer was rich in flavonoids and phenolic acids and had significant anti-oxidant activity, which could prevent hyperglycemia. This observed activity profile suggested X. sorbifolia flowers as a promising new source of tea to develop alternative natural anti-diabetic products with a high safety margin.
基金This work was supported in part by National Natural Science Foundation of China(No.52077076)in part by the State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources(No.LAPS2021-18).
文摘To overcome the shortcomings of model-driven state estimation methods, this paper proposes a data-driven robust state estimation (DDSE) method through off-line learning and on-line matching. At the off-line learning stage, a linear regression equation is presented by clustering historical data from supervisory control and data acquisition (SCADA), which provides a guarantee for solving the over-learning problem of the existing DDSE methods;then a novel robust state estimation method that can be transformed into quadratic programming (QP) models is proposed to obtain the mapping relationship between the measurements and the state variables (MRBMS). The proposed QP models can well solve the problem of collinearity in historical data. Furthermore, the off-line learning stage is greatly accelerated from three aspects including reducing historical categories, constructing tree retrieval structure for known topologies, and using sensitivity analysis when solving QP models. At the on-line matching stage, by quickly matching the current snapshot with the historical ones, the corresponding MRBMS can be obtained, and then the estimation values of the state variables can be obtained. Simulations demonstrate that the proposed DDSE method has obvious advantages in terms of suppressing over-learning problems, dealing with collinearity problems, robustness, and computation efficiency.
基金Supported by the National Natural Science Foundation of China(61272501)the National Key Basic Research Program(973Program)(2012CB315905)the Specialized Research Fund for the Doctoral Program of Higher Education(20091102110004)
文摘To support withdrawing and storing money from all levels of the bank for the customers in the real world, in this paper, we propose a proxy blind signature scheme and an off-line e-cash scheme based on the new proxy blind signature scheme. The pro- posed proxy blind signature is proven secure in the random oracle model under chosen-target computational Diffie-Hellman assump- tions, and the e-cash scheme can satisfy the security requirements of unforgeability, anonymity, and traceability.
文摘Based on the existing land-surface schemes and models,an improved Land-surface Process Model(LPM-ZD)has been developed.It has the following major characteristics:(1)The combination of physical equations and empirical analytical formulae are used to construct the governing equations of soil temperature and moisture.Higher resolution of model level and physical equations are adopted for the upper soil layers,and for the lower soil layers,lower resolution of model level is adopted and empirical analytical formulae are used.(2)In land surface hydrological process,the sub-grid distribution of rainfall and its effects are taken into account. (3)A simple snow cover submodel has been used,which includes effects of snow cover on soil thermodynamics and hydrology,as well as albedo. By use of this model and three groups of point observation data,a series of“off-line”tests have been carried out.The simulation results indicate that land-surface process model has good performance and can well simulate diurnal and seasonal variation of land surface processes for many kinds of land surface covers(forest,grass,crops and desert)in different climate zone.The results simulated by the model are consistent with the observations.Later,by use of one group of observation data and the model,a series of sensitivity experiments have been done.It is shown that the model is much sensitive to some parameters,such as initial soil moisture,vegetation physical parameters as well as the proportion of the grid covered with rain.Therefore it is much important for land-surface process model to define these parameters as accurately as possible.