The electro-hydraulic servo system was studied to cancel the amplitude attenuation and phase delay of its sinusoidal response,by developing a network using normalized least-mean-square (LMS) adaptive filtering algorit...The electro-hydraulic servo system was studied to cancel the amplitude attenuation and phase delay of its sinusoidal response,by developing a network using normalized least-mean-square (LMS) adaptive filtering algorithm.The command input was corrected by weights to generate the desired input for the algorithm,and the feedback was brought into the feedback correction,whose output was the weighted feedback.The weights of the normalized LMS adaptive filtering algorithm were updated on-line according to the estimation error between the desired input and the weighted feedback.Thus,the updated weights were copied to the input correction.The estimation error was forced to zero by the normalized LMS adaptive filtering algorithm such that the weighted feedback was equal to the desired input,making the feedback track the command.The above concept was used as a basis for the development of amplitude phase control.The method has good real-time performance without estimating the system model.The simulation and experiment results show that the proposed amplitude phase control can efficiently cancel the amplitude attenuation and phase delay with high precision.展开更多
Electro-thermal explosion directional spraying was used to prepare the stellite coating on substrate of the AISI 1045 steel. The morphologies of cross-section and worn scar, porosity, distribution of elements, micro- ...Electro-thermal explosion directional spraying was used to prepare the stellite coating on substrate of the AISI 1045 steel. The morphologies of cross-section and worn scar, porosity, distribution of elements, micro- hardness and wear resistance of the coating were determined by means of SEM, EDAX, micro-hardness tester and sliding wear tester. Because of the compact construction, good bonding and high hardness, the coating is characterized by good wear resistance. The results show that the mainly failure mode of the stellite coating is micro- plowing.展开更多
One of the thrust areas of research is to find an alternative fuel to meet the increasing demand for energy.Glucose is a good source of alternative fuel for clean energy and is easily available in abundance from both ...One of the thrust areas of research is to find an alternative fuel to meet the increasing demand for energy.Glucose is a good source of alternative fuel for clean energy and is easily available in abundance from both naturally occurring plants and industrial processes.Electrochemical oxidation of glucose in fuel cell requires high electro-catalytic surface of the electrode to produce the clean electrical energy w ith minimum energy losses in the cell.Pt and Pt based alloys exhibit high electro-catalytic properties but they are expensive.For energy synthesis at economically cheap price,non Pt based inexpensive high electro catalytic material is required.Electro synthesized Zn O-Al2O3composite is found to exhibit high electro-catalytic properties for glucose oxidation.The Cyclic Voltammetry and Chronoamperometry curves reflect that the material is very much comparable to Pt as far as the maximum current and the steady state current delivered from the glucose oxidation are concerned.XRD image confirms the mixed oxide composite.SEM images morphology show increased 3D surface areas at higher magnification.This attributed high current delivered from electrochemical oxidation of glucose on this electrode surface.展开更多
As a new spraying technology used in the remanufacturing engineering, electro-thermal explosion spraying holds a lot of advantages. Electro-thermal explosion spraying coating aliquation phenomena are reduced and non-c...As a new spraying technology used in the remanufacturing engineering, electro-thermal explosion spraying holds a lot of advantages. Electro-thermal explosion spraying coating aliquation phenomena are reduced and non-crystal, micro-crystal and millimicron-crystal and other microstructure are formed. The corrosion-resistance ability of electro-thermal explosion spraying coating in high temperature environment was surveyed respectively. SEM equipped with EDS was employed to analyze the microstructure of spraying coating before and after corrosion. The corrosion-resistance mechanism of the spraying coating was discussed.展开更多
To simulate the electro-hydrodynamics of wire-plate corona discharge at different voltages accurately,a simulation method,which relates the definite radius and initial velocity of a jet source to the amplitude of disc...To simulate the electro-hydrodynamics of wire-plate corona discharge at different voltages accurately,a simulation method,which relates the definite radius and initial velocity of a jet source to the amplitude of discharge voltage,is developed.Firstly,a model of the electro-hydrodynamics is established by the Matlab software using the governing equations discretized with the finite difference method.Secondly,the electric field strength and current density are simulated and the radius and initial velocity of a jet source at different voltages are determined.Finally,the discharge electro-hydrodynamics is simulated using the determined boundary conditions.Compared with using a conventional method,using the proposed method can obtain a wind velocity with smaller errors from the experimental and theoretical wind velocities: the errors between simulated wind velocity and its theoretical counter part at 45 kV and 50 kV decrease from 9% and 6.25% to 1.7% and 1.56%,respectively.Thus,the proposed method is feasible for the existing discharge models.展开更多
Fabrication and characterization of electro-optic modulators based on the novel organic electro-optic materials composed of self-assembled superlattices (SAS) were presented, both wet-dipping self-assembly and vapor p...Fabrication and characterization of electro-optic modulators based on the novel organic electro-optic materials composed of self-assembled superlattices (SAS) were presented, both wet-dipping self-assembly and vapor phase deposition approaches were discussed. Prototype waveguide electro-optic modulators were fabricated using SAS films integrated with low-loss polymeric materials functioning as partial guiding and cladding layers.Promising electro-optic thin film materials including DTPT and PEPCOOH grown from the vapor phase were used for fabrication and test of electro-optic prototype modulators. Finally,the EO coefficient of tens of pm/V was obtained,which can sufficiently support high-speed and small size EO modulators.展开更多
Objective:To investigate the effects of electro-acupuncture preconditioning on focal cerebral blood flow(CBF)in artery and vein of rats with middle cerebral artery occlusion(MCAO),and to provide experimental evidences...Objective:To investigate the effects of electro-acupuncture preconditioning on focal cerebral blood flow(CBF)in artery and vein of rats with middle cerebral artery occlusion(MCAO),and to provide experimental evidences for primary prevention of ischemic stroke.Method:Eighteen male Sprague-Dawley rats(two months old)were divided into 3 groups:electro-acupuncture preconditioning group(EA group),ischemia group(Is group)and Dazhui and Baihui sham group(six rats per group).The rats in the EA group were given electro-acupuncture preconditioning at Dazhui and Baihui with 2/15 density wave current for 30 minutes per day,5 days consecutively.After preconditioning,enhanced laser speckle contrast analysis was implemented to get false color images before making middle cerebral ischemia occlusion model.Then getting false color images two hours during ischemia by laser speckle contrast analysis again.Result:④Relative CBF in focal cortical artery:There were significant differences at every time point in EA group and Is group(P<0.01,P<0.05)comparing with that before occlusion respectively.Compared with that before ischemia,there was significant difference at 120 min after ischemia in sham group(P<0.05);compared with that at 30 min after occlusion,there was significant difference at every time point in EA group from the time point 60 min after occlusion;there was significant difference at every time point in EA group and Is group(P<0.05)comparing with sham group;Compared with sham group,there was significant difference at 30min and 60 min after ischemia in EA group(P<0.05).④Relative CBF in focal cortical vein:There was significant difference at every time point in sham group comparing with that before occlusion(P<0.05);compared with that before occlusion,there was significant difference from 45 min after occlusion in EA group(P<0.05);compared with that before occlusion,there was significant difference from 105 min after occlusion in sham group(P<0.05);there was significant difference at 120 min after occlusion comparing with 60 min after occlusion in EA group;compared with sham group,there was significant difference at every time point in EA group and Is group(except 30 min after occlusion)(P<0.05),respectively;compared with Is group,there was significant difference at 30,45,60 min after occlusion in EA group(P<0.05).④The infarct brain volume detected 24 h after reperfusion in EA group was significantly smaller comparing with that in Is group(P<0.05).Conclusion:Electro-acupuncture preconditioning could increase CBF velocity in artery and vein of focal cortex in rats with MCAO,which also had time-dependence.Additionally,electro-acupuncture preconditioning could decrease the infarct volume detected 24h after reperfusion,which possibly was correlated with the blood supply in ischemic penumbra.展开更多
Airborne electro-optical tracking and sighting system is a three-degree-of-freedom angular position servo system which is influenced by multi-disturbance,and its control system consists of stabilizing and tracking com...Airborne electro-optical tracking and sighting system is a three-degree-of-freedom angular position servo system which is influenced by multi-disturbance,and its control system consists of stabilizing and tracking components.Stabilizing control is applied to track angular velocity order and control multi-disturbance under airborne condition,and its robustness should be very good;tracking control is applied to compensate tracking error of angular position.A mathematical model is established by taking the control of yaw loop as example.H∞ stabilizing controller is designed by taking the advantage of H∞ control robustness and combining with Kalman filter.A fuzzy control is introduced in general PID control to design a decoupled fuzzy Smith estimating PID controller for tracking control.Simulation research shows that the control effect of airborne electro-optical tracking and sighting system based on fuzzy PID and H∞ control is good,especially when the model parameters change and the multi-disturbance exists,the system capability has little fall,but this system still can effectively track a target.展开更多
基金Project(50905037) supported by the National Natural Science Foundation of ChinaProject(20092304120014) supported by Specialized Research Fund for the Doctoral Program of Higher Education of China+2 种基金 Project(20100471021) supported by the China Postdoctoral Science Foundation Project(LBH-Q09134) supported by Heilongjiang Postdoctoral Science-Research Foundation,China Project (HEUFT09013) supported by the Foundation of Harbin Engineering University,China
文摘The electro-hydraulic servo system was studied to cancel the amplitude attenuation and phase delay of its sinusoidal response,by developing a network using normalized least-mean-square (LMS) adaptive filtering algorithm.The command input was corrected by weights to generate the desired input for the algorithm,and the feedback was brought into the feedback correction,whose output was the weighted feedback.The weights of the normalized LMS adaptive filtering algorithm were updated on-line according to the estimation error between the desired input and the weighted feedback.Thus,the updated weights were copied to the input correction.The estimation error was forced to zero by the normalized LMS adaptive filtering algorithm such that the weighted feedback was equal to the desired input,making the feedback track the command.The above concept was used as a basis for the development of amplitude phase control.The method has good real-time performance without estimating the system model.The simulation and experiment results show that the proposed amplitude phase control can efficiently cancel the amplitude attenuation and phase delay with high precision.
文摘Electro-thermal explosion directional spraying was used to prepare the stellite coating on substrate of the AISI 1045 steel. The morphologies of cross-section and worn scar, porosity, distribution of elements, micro- hardness and wear resistance of the coating were determined by means of SEM, EDAX, micro-hardness tester and sliding wear tester. Because of the compact construction, good bonding and high hardness, the coating is characterized by good wear resistance. The results show that the mainly failure mode of the stellite coating is micro- plowing.
基金"TEQIP,COE Phase Ⅱ "in Jadavpur University for the support of this work
文摘One of the thrust areas of research is to find an alternative fuel to meet the increasing demand for energy.Glucose is a good source of alternative fuel for clean energy and is easily available in abundance from both naturally occurring plants and industrial processes.Electrochemical oxidation of glucose in fuel cell requires high electro-catalytic surface of the electrode to produce the clean electrical energy w ith minimum energy losses in the cell.Pt and Pt based alloys exhibit high electro-catalytic properties but they are expensive.For energy synthesis at economically cheap price,non Pt based inexpensive high electro catalytic material is required.Electro synthesized Zn O-Al2O3composite is found to exhibit high electro-catalytic properties for glucose oxidation.The Cyclic Voltammetry and Chronoamperometry curves reflect that the material is very much comparable to Pt as far as the maximum current and the steady state current delivered from the glucose oxidation are concerned.XRD image confirms the mixed oxide composite.SEM images morphology show increased 3D surface areas at higher magnification.This attributed high current delivered from electrochemical oxidation of glucose on this electrode surface.
文摘As a new spraying technology used in the remanufacturing engineering, electro-thermal explosion spraying holds a lot of advantages. Electro-thermal explosion spraying coating aliquation phenomena are reduced and non-crystal, micro-crystal and millimicron-crystal and other microstructure are formed. The corrosion-resistance ability of electro-thermal explosion spraying coating in high temperature environment was surveyed respectively. SEM equipped with EDS was employed to analyze the microstructure of spraying coating before and after corrosion. The corrosion-resistance mechanism of the spraying coating was discussed.
基金Project supported by National Natural Science Foundation of China （10875036）, Hebei Provincial Natural Science Foundation of China （A2010000182）, Hebei Provincial Science and Technology Supporting Program of China （09276712D）.
文摘To simulate the electro-hydrodynamics of wire-plate corona discharge at different voltages accurately,a simulation method,which relates the definite radius and initial velocity of a jet source to the amplitude of discharge voltage,is developed.Firstly,a model of the electro-hydrodynamics is established by the Matlab software using the governing equations discretized with the finite difference method.Secondly,the electric field strength and current density are simulated and the radius and initial velocity of a jet source at different voltages are determined.Finally,the discharge electro-hydrodynamics is simulated using the determined boundary conditions.Compared with using a conventional method,using the proposed method can obtain a wind velocity with smaller errors from the experimental and theoretical wind velocities: the errors between simulated wind velocity and its theoretical counter part at 45 kV and 50 kV decrease from 9% and 6.25% to 1.7% and 1.56%,respectively.Thus,the proposed method is feasible for the existing discharge models.
文摘Fabrication and characterization of electro-optic modulators based on the novel organic electro-optic materials composed of self-assembled superlattices (SAS) were presented, both wet-dipping self-assembly and vapor phase deposition approaches were discussed. Prototype waveguide electro-optic modulators were fabricated using SAS films integrated with low-loss polymeric materials functioning as partial guiding and cladding layers.Promising electro-optic thin film materials including DTPT and PEPCOOH grown from the vapor phase were used for fabrication and test of electro-optic prototype modulators. Finally,the EO coefficient of tens of pm/V was obtained,which can sufficiently support high-speed and small size EO modulators.
基金supported by the Natural Science Foundation of China(NSFC,NO.81171856,81171855)the Development Program of China(863 program,NO.2007AA02Z482)the Key projects of Shanghai Science and Technology on Biomedicine(NO.10DZ1950800)
文摘Objective:To investigate the effects of electro-acupuncture preconditioning on focal cerebral blood flow(CBF)in artery and vein of rats with middle cerebral artery occlusion(MCAO),and to provide experimental evidences for primary prevention of ischemic stroke.Method:Eighteen male Sprague-Dawley rats(two months old)were divided into 3 groups:electro-acupuncture preconditioning group(EA group),ischemia group(Is group)and Dazhui and Baihui sham group(six rats per group).The rats in the EA group were given electro-acupuncture preconditioning at Dazhui and Baihui with 2/15 density wave current for 30 minutes per day,5 days consecutively.After preconditioning,enhanced laser speckle contrast analysis was implemented to get false color images before making middle cerebral ischemia occlusion model.Then getting false color images two hours during ischemia by laser speckle contrast analysis again.Result:④Relative CBF in focal cortical artery:There were significant differences at every time point in EA group and Is group(P<0.01,P<0.05)comparing with that before occlusion respectively.Compared with that before ischemia,there was significant difference at 120 min after ischemia in sham group(P<0.05);compared with that at 30 min after occlusion,there was significant difference at every time point in EA group from the time point 60 min after occlusion;there was significant difference at every time point in EA group and Is group(P<0.05)comparing with sham group;Compared with sham group,there was significant difference at 30min and 60 min after ischemia in EA group(P<0.05).④Relative CBF in focal cortical vein:There was significant difference at every time point in sham group comparing with that before occlusion(P<0.05);compared with that before occlusion,there was significant difference from 45 min after occlusion in EA group(P<0.05);compared with that before occlusion,there was significant difference from 105 min after occlusion in sham group(P<0.05);there was significant difference at 120 min after occlusion comparing with 60 min after occlusion in EA group;compared with sham group,there was significant difference at every time point in EA group and Is group(except 30 min after occlusion)(P<0.05),respectively;compared with Is group,there was significant difference at 30,45,60 min after occlusion in EA group(P<0.05).④The infarct brain volume detected 24 h after reperfusion in EA group was significantly smaller comparing with that in Is group(P<0.05).Conclusion:Electro-acupuncture preconditioning could increase CBF velocity in artery and vein of focal cortex in rats with MCAO,which also had time-dependence.Additionally,electro-acupuncture preconditioning could decrease the infarct volume detected 24h after reperfusion,which possibly was correlated with the blood supply in ischemic penumbra.
基金Sponsored by Foundation for Excellent Young Teachers in Universities of Henan Province of China(2002[121])
文摘Airborne electro-optical tracking and sighting system is a three-degree-of-freedom angular position servo system which is influenced by multi-disturbance,and its control system consists of stabilizing and tracking components.Stabilizing control is applied to track angular velocity order and control multi-disturbance under airborne condition,and its robustness should be very good;tracking control is applied to compensate tracking error of angular position.A mathematical model is established by taking the control of yaw loop as example.H∞ stabilizing controller is designed by taking the advantage of H∞ control robustness and combining with Kalman filter.A fuzzy control is introduced in general PID control to design a decoupled fuzzy Smith estimating PID controller for tracking control.Simulation research shows that the control effect of airborne electro-optical tracking and sighting system based on fuzzy PID and H∞ control is good,especially when the model parameters change and the multi-disturbance exists,the system capability has little fall,but this system still can effectively track a target.
