The in vitro degradation rate of polyanhydride （poly（sebacic acid）, diacetoxy terminated）, also known as PSADT, was investigated. PSADT tablets with a circular cross-section were formed using a compression molding...The in vitro degradation rate of polyanhydride （poly（sebacic acid）, diacetoxy terminated）, also known as PSADT, was investigated. PSADT tablets with a circular cross-section were formed using a compression molding device, and then immersed into phosphate buffer saline （PBS） for in vitro degradation experiments. The mechanisms of degradation and the degradation rate were characterized by the change in molecular weight and reduction in specimen mass. In addition, the effects of processing temperature and the geometry of the formed PSADT tablets on the rate of degradation were studied. The surface morphology at different degradation times was observed by scanning electron microscopy （SEM）. The experimental results showed that PSADT exhibited sur^hce erosion due to the fact that near zero-order degradation kinetics was observed during its degradation process. Moreover, it is found that the geometry of tablets played an important role on the rate of degradation, while the processing temperature had no significant effect on the PSADT degradation rate.展开更多
The compressive sensing （CS） theory allows people to obtain signal in the frequency much lower than the requested one of sampling theorem. Because the theory is based on the assumption of that the location of sparse...The compressive sensing （CS） theory allows people to obtain signal in the frequency much lower than the requested one of sampling theorem. Because the theory is based on the assumption of that the location of sparse values is unknown, it has many constraints in practical applications. In fact, in many cases such as image processing, the location of sparse values is knowable, and CS can degrade to a linear process. In order to take full advantage of the visual information of images, this paper proposes the concept of dimensionality reduction transform matrix and then se- lects sparse values by constructing an accuracy control matrix, so on this basis, a degradation algorithm is designed that the signal can be obtained by the measurements as many as sparse values and reconstructed through a linear process. In comparison with similar methods, the degradation algorithm is effective in reducing the number of sensors and improving operational efficiency. The algorithm is also used to achieve the CS process with the same amount of data as joint photographic exports group （JPEG） compression and acquires the same display effect.展开更多
The multistage triaxial compression test was mainly utilized in this research to investigate the degradation in the strength of swelling shale under different wetting conditions.Shale samples were tested in four diffe...The multistage triaxial compression test was mainly utilized in this research to investigate the degradation in the strength of swelling shale under different wetting conditions.Shale samples were tested in four different conditions:(1)under their natural moisture content denoted as intact,and after soaking in,(2)water,(3)polymer solution,and(4)bentonite solution,separately.The experimental results showed that a considerable decrease in the shale’s strength was noted after soaking in water and the lubricant fluids(LFs).The polymer solution caused the least decrease in the strength compared to other fluids.Strength envelopes of the tested shale were constructed for intact and soaked states.These envelopes showed fair agreement between the single stage and the multistage triaxial compression test results,indicating suitability of the multistage triaxial compression test for the tested swelling shale.展开更多
基金Project supported by the UK Engineering and Physical Sciences Research Council(No.EP/E041965)the National Basic Research Program(973 Program)of China(No.2012CB719800)the Zhejiang Provincial Natural Science Foundation of China(No.LY17E080021)
基金Funded by the China Scholarship Council and Wisconsin Institute for Discovery(WID)the Scientific Research Staring Foundation,Fujian University of Technology,China(No.GY-Z13028)+1 种基金the Programfor New Century Excellent Talents in Fujian Province University(NCETFJ-2010)the Research Fund for Fujian Provincial University(JK-2010038)
文摘The in vitro degradation rate of polyanhydride （poly（sebacic acid）, diacetoxy terminated）, also known as PSADT, was investigated. PSADT tablets with a circular cross-section were formed using a compression molding device, and then immersed into phosphate buffer saline （PBS） for in vitro degradation experiments. The mechanisms of degradation and the degradation rate were characterized by the change in molecular weight and reduction in specimen mass. In addition, the effects of processing temperature and the geometry of the formed PSADT tablets on the rate of degradation were studied. The surface morphology at different degradation times was observed by scanning electron microscopy （SEM）. The experimental results showed that PSADT exhibited sur^hce erosion due to the fact that near zero-order degradation kinetics was observed during its degradation process. Moreover, it is found that the geometry of tablets played an important role on the rate of degradation, while the processing temperature had no significant effect on the PSADT degradation rate.
基金supported by the National Natural Science Foundation of China (61077079)the Specialized Research Fund for the Doctoral Program of Higher Education (20102304110013)the Program Ex-cellent Academic Leaders of Harbin (2009RFXXG034)
文摘The compressive sensing （CS） theory allows people to obtain signal in the frequency much lower than the requested one of sampling theorem. Because the theory is based on the assumption of that the location of sparse values is unknown, it has many constraints in practical applications. In fact, in many cases such as image processing, the location of sparse values is knowable, and CS can degrade to a linear process. In order to take full advantage of the visual information of images, this paper proposes the concept of dimensionality reduction transform matrix and then se- lects sparse values by constructing an accuracy control matrix, so on this basis, a degradation algorithm is designed that the signal can be obtained by the measurements as many as sparse values and reconstructed through a linear process. In comparison with similar methods, the degradation algorithm is effective in reducing the number of sensors and improving operational efficiency. The algorithm is also used to achieve the CS process with the same amount of data as joint photographic exports group （JPEG） compression and acquires the same display effect.
文摘The multistage triaxial compression test was mainly utilized in this research to investigate the degradation in the strength of swelling shale under different wetting conditions.Shale samples were tested in four different conditions:(1)under their natural moisture content denoted as intact,and after soaking in,(2)water,(3)polymer solution,and(4)bentonite solution,separately.The experimental results showed that a considerable decrease in the shale’s strength was noted after soaking in water and the lubricant fluids(LFs).The polymer solution caused the least decrease in the strength compared to other fluids.Strength envelopes of the tested shale were constructed for intact and soaked states.These envelopes showed fair agreement between the single stage and the multistage triaxial compression test results,indicating suitability of the multistage triaxial compression test for the tested swelling shale.
