Yaw control system plays an important role in helping large-scale horizontal wind turbines capture the wind energy.To track the stochastic and fast-changing wind direction,the nacelle is rotated by the yaw control sys...Yaw control system plays an important role in helping large-scale horizontal wind turbines capture the wind energy.To track the stochastic and fast-changing wind direction,the nacelle is rotated by the yaw control system.Therein,a difficulty consists in the variation speed of the wind direction much faster than the rotation speed of the nacelle.To deal with this difficulty,model predictive control has been recently proposed in the literature,in which the previewed wind direction is employed into the predictive model,and the estimated captured energy and yaw actuator usage are two contradictive objectives.Since the performance of the model predictive control strat-egy relies largely on the weighting factor that is designed to balance the two objectives,the weighting factor should be carefully selected.In this study,a fuzzy-deduced scheme is proposed to derive the weighting factor of the mod-el predictive yaw control.For the proposed fuzzy-deduced strategy,the variation degree and the increment of the wind direction during the predictive horizon are used as the inputs,and the weighting factor is the output,which is dynamically adjusted.The proposed model predictive yaw control is demonstrated by some simulations using real wind data and its performance is compared with the conventional model predictive control with thefixed weighting factor.Comparison results confirm the outweighing performance of the proposed control strategy over the conventional one.展开更多
The biomimetic construction of a microstructural–mechanical–electrical anisotropic microenvironment adaptive to the native cardiac tissue is essential to repair myocardial infarction(MI).Inspired by the 3D anisotrop...The biomimetic construction of a microstructural–mechanical–electrical anisotropic microenvironment adaptive to the native cardiac tissue is essential to repair myocardial infarction(MI).Inspired by the 3D anisotropic characteristic of the natural fish swim bladder(FSB),a novel flexible,anisotropic,and conductive hydrogel was developed for tissue-specific adaptation to the anisotropic structural,conductive,and mechanical features of the native cardiac extracellular matrix.The results revealed that the originally stiff,homogeneous FSB film was tailored to a highly flexible anisotropic hydrogel,enabling its potential as a functional engineered cardiac patch(ECP).In vitro and in vivo experiments demonstrated the enhanced electrophysiological activity,maturation,elongation,and orientation of cardiomyocytes(CMs),and marked MI repair performance with reduced CM apoptosis and myocardial fibrosis,thereby promoting cell retention,myogenesis,and vascularization,as well as improving electrical integration.Our findings offer a potential strategy for functional ECP and provides a novel strategy to bionically simulate the complex cardiac repair environment.展开更多
从蓝花黄芩内生真菌土曲霉(Aspergillusterreus)HQ100X-1发酵产物中分离得到2个新化合物[terrustone(1)和asperteretone G (2)], 10个已知化合物(3~12), terrustone (1)为具有4个连续手性中心的三羟基环戊酮类化合物,它们的结构以及绝...从蓝花黄芩内生真菌土曲霉(Aspergillusterreus)HQ100X-1发酵产物中分离得到2个新化合物[terrustone(1)和asperteretone G (2)], 10个已知化合物(3~12), terrustone (1)为具有4个连续手性中心的三羟基环戊酮类化合物,它们的结构以及绝对构型是通过1D/2D NMR结合电子圆二色谱(ECD)计算来确定.抗菌实验表明,化合物rbrolide R (4)对金黄色葡萄球菌有一定的抑菌活性,其最低抑菌浓度(MIC)值为2.5μg/mL.展开更多
In order to clarify the formation mechanism and conditions for akaganeite in long-term exposure, the influence of the former corrosion results on akaganeite formation was investigated by simulated experi- ments in lab...In order to clarify the formation mechanism and conditions for akaganeite in long-term exposure, the influence of the former corrosion results on akaganeite formation was investigated by simulated experi- ments in laboratory. The combination of XRD, FTIR, SEM and EPMA enabled the identification of the rust layer formed on the surface. Accordingly, the nature of the rust layer and the amount of the corrosive species in the rust layer varied with the extension of the exposure. Among them, comparing with the corrosion condition in initial stage, the structure of rust layer after repeated wet-dry cycles was disad- vantage for akaganeite formation. Element CI aggregated at the interface between rust and substrate in the thick part can participate in the formation of akaganeite after the rust layer covered removed. The accumulation effect of salt deposited contributed to akaganeite formation under the condition that salt deposition rate was relatively low.展开更多
基金supported by the National Natural Science Foundation of China under Grant 61803393project supported by the Natural Science Foundation of Hunan Province(No.2020JJ4751)the Innovation-Driven Project of Central South University(No.2020CX031).
文摘Yaw control system plays an important role in helping large-scale horizontal wind turbines capture the wind energy.To track the stochastic and fast-changing wind direction,the nacelle is rotated by the yaw control system.Therein,a difficulty consists in the variation speed of the wind direction much faster than the rotation speed of the nacelle.To deal with this difficulty,model predictive control has been recently proposed in the literature,in which the previewed wind direction is employed into the predictive model,and the estimated captured energy and yaw actuator usage are two contradictive objectives.Since the performance of the model predictive control strat-egy relies largely on the weighting factor that is designed to balance the two objectives,the weighting factor should be carefully selected.In this study,a fuzzy-deduced scheme is proposed to derive the weighting factor of the mod-el predictive yaw control.For the proposed fuzzy-deduced strategy,the variation degree and the increment of the wind direction during the predictive horizon are used as the inputs,and the weighting factor is the output,which is dynamically adjusted.The proposed model predictive yaw control is demonstrated by some simulations using real wind data and its performance is compared with the conventional model predictive control with thefixed weighting factor.Comparison results confirm the outweighing performance of the proposed control strategy over the conventional one.
基金the National Natural Science Foundation of China(U21A20173,52003113,31922043,82102228,and 32071363)Guangdong Basic and Applied Basic Research Foundation(2021A1515010745 and 2020A1515110356)+3 种基金Medical Research Project of Guangdong Province(A2021462)Science and Technology Planning Project of Guangdong Province(2020B1212060037)Key Research&Development Program of Guangzhou Regenerative Medicine and Health Guangdong Laboratory(2018GZR110104002)Shenzhen Fundamental Research Key Project(JCYJ20200109150641992).
文摘The biomimetic construction of a microstructural–mechanical–electrical anisotropic microenvironment adaptive to the native cardiac tissue is essential to repair myocardial infarction(MI).Inspired by the 3D anisotropic characteristic of the natural fish swim bladder(FSB),a novel flexible,anisotropic,and conductive hydrogel was developed for tissue-specific adaptation to the anisotropic structural,conductive,and mechanical features of the native cardiac extracellular matrix.The results revealed that the originally stiff,homogeneous FSB film was tailored to a highly flexible anisotropic hydrogel,enabling its potential as a functional engineered cardiac patch(ECP).In vitro and in vivo experiments demonstrated the enhanced electrophysiological activity,maturation,elongation,and orientation of cardiomyocytes(CMs),and marked MI repair performance with reduced CM apoptosis and myocardial fibrosis,thereby promoting cell retention,myogenesis,and vascularization,as well as improving electrical integration.Our findings offer a potential strategy for functional ECP and provides a novel strategy to bionically simulate the complex cardiac repair environment.
文摘从蓝花黄芩内生真菌土曲霉(Aspergillusterreus)HQ100X-1发酵产物中分离得到2个新化合物[terrustone(1)和asperteretone G (2)], 10个已知化合物(3~12), terrustone (1)为具有4个连续手性中心的三羟基环戊酮类化合物,它们的结构以及绝对构型是通过1D/2D NMR结合电子圆二色谱(ECD)计算来确定.抗菌实验表明,化合物rbrolide R (4)对金黄色葡萄球菌有一定的抑菌活性,其最低抑菌浓度(MIC)值为2.5μg/mL.
基金This work was supported by the National Natural Science Foundation of China （No. 51222104） and the Fundamental Research Funds for the Central Universities.
基金financially supported by the National Natural Science Foundation of China under the contract Nos.51301182 and 51671198the National Basic Research Program of China and Ministry of Science and Technology China under the contract No.2014CB643303
文摘In order to clarify the formation mechanism and conditions for akaganeite in long-term exposure, the influence of the former corrosion results on akaganeite formation was investigated by simulated experi- ments in laboratory. The combination of XRD, FTIR, SEM and EPMA enabled the identification of the rust layer formed on the surface. Accordingly, the nature of the rust layer and the amount of the corrosive species in the rust layer varied with the extension of the exposure. Among them, comparing with the corrosion condition in initial stage, the structure of rust layer after repeated wet-dry cycles was disad- vantage for akaganeite formation. Element CI aggregated at the interface between rust and substrate in the thick part can participate in the formation of akaganeite after the rust layer covered removed. The accumulation effect of salt deposited contributed to akaganeite formation under the condition that salt deposition rate was relatively low.
