A method of source depth estimation based on the multi-path time delay difference is proposed. When the minimum time arrivals in all receiver depths are snapped to a certain time on time delay-depth plane, time delay ...A method of source depth estimation based on the multi-path time delay difference is proposed. When the minimum time arrivals in all receiver depths are snapped to a certain time on time delay-depth plane, time delay arrivals of surface-bottom reflection and bottom-surface reflection intersect at the source depth. Two hydrophones deployed vertically with a certain interval are required at least. If the receiver depths are known, the pair of time delays can be used to estimate the source depth. With the proposed method the source depth can be estimated successfully in a moderate range in the deep ocean without complicated matched-field calculations in the simulations and experiments.展开更多
We develope a simple method to stabilize the beam during propagation. Combination of the self-developed control module and the large diameter mirrors reconstruct the beam stabilization system, and some important proce...We develope a simple method to stabilize the beam during propagation. Combination of the self-developed control module and the large diameter mirrors reconstruct the beam stabilization system, and some important procedures are presented, such as calibration arid average filter. The results show that the horizontal pointing and vertical pointing are stabilized to within 8.43 and 7.59 μrad, and the beam horizontal position and vertical position are stabilized to within 2.16 and 2.11 μm respectively. The regulating time is within 84 ms. Thus the method presented is effective for the current stabilization system applied in lithography tools.展开更多
The heart cannot regenerate muscle tissue after a heart attack has killed part of the muscle wall.That dead tissue can strain surrounding muscle,leading to a lethal heart enlargement.Biomedical engineers believe they ...The heart cannot regenerate muscle tissue after a heart attack has killed part of the muscle wall.That dead tissue can strain surrounding muscle,leading to a lethal heart enlargement.Biomedical engineers believe they can aid the failing heart by using pluripotent stem cells to grow heart muscle cells outside of the body,and then injecting those muscle cells or adding a patch made from those cells,at or near the site of the dead heart tissue.Experimental and clinical trial evidence with this approach has shown moderate improvement of the pumping ability of the heart's left ventricle.展开更多
A sequential deposition method is developed, where the hybrid organic-inorganic halide perovskite (CH3NH3Pb (I1-xBrx)3 ) is synthesized using precursor solutions containing CH3NH3I and PbBr2 with different mole ra...A sequential deposition method is developed, where the hybrid organic-inorganic halide perovskite (CH3NH3Pb (I1-xBrx)3 ) is synthesized using precursor solutions containing CH3NH3I and PbBr2 with different mole ratios and reaction times. The perovskite achieved here is quite stable in the atmosphere for a relatively long time without noticeable degradation, and the perovskite nanowires are proved to be single crystalline structure, based on transmission electron microscopy.Furthermore, strong red photoluminescence from perovskite is observed in the wavelength range from 746nm to 770nm with the increase of the reaction time, on account of the exchanges between I- ions and Br- ions in the perovskite crystal. Lastly, the influences of concentration and reaction time of the precursor solutions are discussed, which are important for evolution of hybrid perovskite from nanocuboid to nanowire and nanosheet.展开更多
A simple finite element method for the Reissner-Mindlin plate model in the primitive variables is presented and analyzed. The method uses conforming linear finite elements for both the transverse displacement and rota...A simple finite element method for the Reissner-Mindlin plate model in the primitive variables is presented and analyzed. The method uses conforming linear finite elements for both the transverse displacement and rotation. It is proved that the method converges with optimal order uniformly with respect to thickness.It is simpler and more economical than the Arnold-Falk element[1].展开更多
A simple data assimilation method for improving estimation of moderate resolution imaging spectroradiometer (MODIS) leaf area index (LAI) time-series data products based on the gradient inverse weighted filter and...A simple data assimilation method for improving estimation of moderate resolution imaging spectroradiometer (MODIS) leaf area index (LAI) time-series data products based on the gradient inverse weighted filter and object analysis is proposed. The properties and quality control (QC) of MODIS LAI data products are introduced. Also, the gradient inverse weighted filter and object analysis are analyzed. An experiment based on the simple data assimilation method is performed using MODIS LAI data sets from 2000 to 2005 of Guizhou Province in China.展开更多
Addition of fluoroalkyl iodides to olefins in the presence of hydrogen peroxide(H_2O_(?)) in acetone,acetonitrile or ethanol gave the corresponding 1:1 adducts in good yields.Reaction of fluoroalkyl iodide with dially...Addition of fluoroalkyl iodides to olefins in the presence of hydrogen peroxide(H_2O_(?)) in acetone,acetonitrile or ethanol gave the corresponding 1:1 adducts in good yields.Reaction of fluoroalkyl iodide with diallyl ether(DAE)yielded tetrahydrofuran derivatives,p-Hydroquinone (p-HQ)can partly suppress the reaction.A radical initiation mechanism is proposed.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 11174235
文摘A method of source depth estimation based on the multi-path time delay difference is proposed. When the minimum time arrivals in all receiver depths are snapped to a certain time on time delay-depth plane, time delay arrivals of surface-bottom reflection and bottom-surface reflection intersect at the source depth. Two hydrophones deployed vertically with a certain interval are required at least. If the receiver depths are known, the pair of time delays can be used to estimate the source depth. With the proposed method the source depth can be estimated successfully in a moderate range in the deep ocean without complicated matched-field calculations in the simulations and experiments.
基金the National Science and Technology Major Project of China(No.2011ZX02402)the International Science & Technology Cooperation Program of China(No.2011DFR10010)
文摘We develope a simple method to stabilize the beam during propagation. Combination of the self-developed control module and the large diameter mirrors reconstruct the beam stabilization system, and some important procedures are presented, such as calibration arid average filter. The results show that the horizontal pointing and vertical pointing are stabilized to within 8.43 and 7.59 μrad, and the beam horizontal position and vertical position are stabilized to within 2.16 and 2.11 μm respectively. The regulating time is within 84 ms. Thus the method presented is effective for the current stabilization system applied in lithography tools.
文摘The heart cannot regenerate muscle tissue after a heart attack has killed part of the muscle wall.That dead tissue can strain surrounding muscle,leading to a lethal heart enlargement.Biomedical engineers believe they can aid the failing heart by using pluripotent stem cells to grow heart muscle cells outside of the body,and then injecting those muscle cells or adding a patch made from those cells,at or near the site of the dead heart tissue.Experimental and clinical trial evidence with this approach has shown moderate improvement of the pumping ability of the heart's left ventricle.
文摘A sequential deposition method is developed, where the hybrid organic-inorganic halide perovskite (CH3NH3Pb (I1-xBrx)3 ) is synthesized using precursor solutions containing CH3NH3I and PbBr2 with different mole ratios and reaction times. The perovskite achieved here is quite stable in the atmosphere for a relatively long time without noticeable degradation, and the perovskite nanowires are proved to be single crystalline structure, based on transmission electron microscopy.Furthermore, strong red photoluminescence from perovskite is observed in the wavelength range from 746nm to 770nm with the increase of the reaction time, on account of the exchanges between I- ions and Br- ions in the perovskite crystal. Lastly, the influences of concentration and reaction time of the precursor solutions are discussed, which are important for evolution of hybrid perovskite from nanocuboid to nanowire and nanosheet.
文摘A simple finite element method for the Reissner-Mindlin plate model in the primitive variables is presented and analyzed. The method uses conforming linear finite elements for both the transverse displacement and rotation. It is proved that the method converges with optimal order uniformly with respect to thickness.It is simpler and more economical than the Arnold-Falk element[1].
基金This work was supported by the China Postdoctoral Science Foundation(No.20060390326)the key international S&T cooperation project of China(No.2004DFA06300).
文摘A simple data assimilation method for improving estimation of moderate resolution imaging spectroradiometer (MODIS) leaf area index (LAI) time-series data products based on the gradient inverse weighted filter and object analysis is proposed. The properties and quality control (QC) of MODIS LAI data products are introduced. Also, the gradient inverse weighted filter and object analysis are analyzed. An experiment based on the simple data assimilation method is performed using MODIS LAI data sets from 2000 to 2005 of Guizhou Province in China.
基金This project was supported by the National Natural Science Foundation of China.
文摘Addition of fluoroalkyl iodides to olefins in the presence of hydrogen peroxide(H_2O_(?)) in acetone,acetonitrile or ethanol gave the corresponding 1:1 adducts in good yields.Reaction of fluoroalkyl iodide with diallyl ether(DAE)yielded tetrahydrofuran derivatives,p-Hydroquinone (p-HQ)can partly suppress the reaction.A radical initiation mechanism is proposed.