Presented in this paper is a semi active vibration control strategy based on the vibration absorber with adjustable clearance in elastic component. The control law of the clearance for alleviating the vibration of pr...Presented in this paper is a semi active vibration control strategy based on the vibration absorber with adjustable clearance in elastic component. The control law of the clearance for alleviating the vibration of primary system is derived by means of harmonic balancing technique so that the working frequency of the vibration absorber can trace the frequency variation of the harmonic excitation. The efficacy of the strategy is demonstrated by numerical simulations for attenuating the steady state vibration of a SDOF system and a 2 DOF system, which are under the harmonic excitation with slowly varied frequency in a wide range.展开更多
The numerical wave channel has been developed based on the volume of fluid method (VOF) in conjunction with the Navier-Stokes equations. The absorbing wave-maker boundary on the left side of the channel is presented b...The numerical wave channel has been developed based on the volume of fluid method (VOF) in conjunction with the Navier-Stokes equations. The absorbing wave-maker boundary on the left side of the channel is presented by prescribing velocity reference to linear wave-maker theory. The principle of which is that the numerical wave-maker is designed to move in a way that generates the required incident wave and cancels out any reflected wave that reach it at the same time. On the right side of the channel, the open boundary is set to permit incident waves to be transmitted freely. The parametric studies have been carried out at a range of ratios of water depth to wave length d/ L from 0.124 to 0.219, with wave height in the front of paddle/water depth ratio (H0 / d) from 0.1 to 0.3. Wave height, wave pressure distribution along the channel and velocity field are obtained for both open boundary condition and reflective boundary condition at the other end of the channel. For a reflective case, it is shown that the absorbing wave-maker is very effective in canceling out the reflected wave that reaches the numerical paddle and highly repeatable waves can be generated.展开更多
Significant structural vibration is an undesirable characteristic in helicopter flight that leads to structural fatigue, poor ride quality for passengers and high acoustic signature. Previous Individual Blade Control ...Significant structural vibration is an undesirable characteristic in helicopter flight that leads to structural fatigue, poor ride quality for passengers and high acoustic signature. Previous Individual Blade Control (IBC) techniques to reduce these effects have been hindered by electromechanical limitations of piezoelectric actuators. The Smart Spring is an active tunable vibration absorber using IBC approach to adaptively alter the 'structural impedance' at the blade root. In this paper, a mathematical model was developed to predict the response under harmonic excitations. An adaptive notch algorithm was designed and implemented on a TMS320c40 DSP platform. Reference signal synthesis techniques were used to automatically track the shifts in the fundamental vibratory frequency due to variations in flight conditions. Closed-loop tests performed on the proof-of-concept hardware achieved significant vibration suppression at harmonic peaks as well as the broadband reduction in vibration. The investigation verified the capability of the Smart Spring to suppress multiple harmonic components in blade vibration through active impedance control.展开更多
The purpose of this study is to compare the results of chemical analysis of two types of activated from the pyrolysis of bull horn and that of cow. Six samples were used to measure pH, carbon, calcium and to determine...The purpose of this study is to compare the results of chemical analysis of two types of activated from the pyrolysis of bull horn and that of cow. Six samples were used to measure pH, carbon, calcium and to determine adsorbent power. The pH was measured at a temperature of 20˚C using an “ANION 7010 ionomer” pH meter, the carbon (C) content was analyzed using a “EURO EA 3000” analyzer. and the electronic balance: “Sartorius CP-2P”, calcium (Ca) was analyzed using a DFS-8 spectrograph. For the adsorbency test, the 0.15% methylene blue R solution was used. At the end of this study, we found that the activated carbon from the bull horn demonstrated a carbon content that is higher than that of the cow horn (20.79% against 15.63%), activated carbon of cow horn is richer in calcium than that of bull horn (16.27% against 3.69%) and then the pH. The cow horn is higher than that of the bull horn (7.43 versus 6.5). For the adsorbent power, the sample (75% bull horn and 25% cow horn) was recorded with the greatest adsorbent power. Thus, from this study, it can be recommended as an activated carbon antidote to be used for poisonings treatment.展开更多
To select or develop an appropriate actuator is one of the key and difficult issues in the study of semi-active controlled landing gear. Performance of the actuator may directly affect the effectiveness of semi-active...To select or develop an appropriate actuator is one of the key and difficult issues in the study of semi-active controlled landing gear. Performance of the actuator may directly affect the effectiveness of semi-active control. In this article, parallel high-speed solenoid valves are chosen to be the actuators for the semi-active controlled landing gear and being studied. A nonlinear high-speed solenoid valve model is developed with the consideration of magnetic saturation characteristics and verified by test. According to the design rule of keeping the peak load as small as possible while absorbing the specified shock energy, a fuzzy PD control rule is designed. By the rule controller parameters can be self-regulated. The simulation results indicate that the semi-active control based on high-speed solenoid valve can effectively improve the control performance and reduce impact load during landing.展开更多
A numerical irregular wave flume with active absorption of re-reflected waves is simulated by use of volume of fluid (VOF) method. An active 'absorbing wave-maker based on linear wave theory is set on the left boun...A numerical irregular wave flume with active absorption of re-reflected waves is simulated by use of volume of fluid (VOF) method. An active 'absorbing wave-maker based on linear wave theory is set on the left boundary of the wave flume. The progressive waves and the absorbing waves are generated simultaneously at the active wave generating-absorbing boundary. The absorbing waves are generated to eliminate the waves coming back to the generating boundary due to reflection from the outflow boundary and the structures. SIRW method proposed by Frigaard and Brorsen (1995) is used to separate the incident waves and reflected waves. The digital filters are designed based on the surface elevation signals of the two wave gauges. The corrected velocity of the wave-maker paddle is the output from the digital filter in real time. The numerical results of regular and irregular waves by the active absorbing-generating boundary are compared with the numerical results by the ordinary generating boundary to verify the performance of the active absorbing-generator boundary. The differences between the initial incident waves and the estimated incident waves are analyzed.展开更多
This paper investigates the feasibility of using an active dynamic vibration absorber(ADVA) for active vibration control of a flexible missile system through simulation.Based on the principles of a dynamic vibration a...This paper investigates the feasibility of using an active dynamic vibration absorber(ADVA) for active vibration control of a flexible missile system through simulation.Based on the principles of a dynamic vibration absorber(DVA),a ring-type ADVA is first designed to attenuate the elastic vibration of the flexible missile,and the design of the active controller adopts the proportional-integral-derivative(PID)control algorithm.The motion equations of a flexible missile with an ADVA,which is subjected to follower thrust at its aft end,are derived using the Lagrangian approach.Taking the minimum of the root mean square(RMS) of the lateral displacement response of the center of mass as the objective function,a genetic algorithm(GA) is used to optimize the parameter of the DVA and PID controller.The numerical calculations show that the ADVA and DVA are effective in suppressing the vibration and provide approximately 41.2% and 17.6% improvement,respectively,compa red with the case of no DVA,The ADVA has better performance than the DVA,When the missile is subjected to follower thrust,the effect of vibration reduction is more effective than the case without follower thrust.It is feasible to reduce vibration and improve the stability of flexible missiles by means of the ADVA.展开更多
Using lignite-based hypercoal as raw material, KOH as activator and CuO as microwave absorber, we prepared hypercoal-based activated carbons by microwave-assisted activation. The pore structure and the electrochemical...Using lignite-based hypercoal as raw material, KOH as activator and CuO as microwave absorber, we prepared hypercoal-based activated carbons by microwave-assisted activation. The pore structure and the electrochemical performance of the activated carbons were tested, and the effects of adding CuO in the activation reaction process were also investigated. The activated carbons prepared were characterized by nitrogen adsorption-desorption, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The specific surface area and mesoporous ratio of the hypercoal-based activated carbon are 1257 m2/g and 55.4%, respectively. When the activated carbons are used as the electrode materials, the specific capacitance reaches 309 F/g in 3 M KOH electrolyte. In comparison with those prepared without CuO absorber, the specific capacitance increases by 11.6%. It was proved that the addition of microwave absorber in microwave-assisted activation was a low-cost method for rapidly preparing activated carbon, and it could effectively promote the development of the pore structure and improve its electrochemical performance.展开更多
Influences of root-growing space of maize upon root physiological characteristics, nutrient uptake and crop yields were studied under conditions with and without supply of water and N. Results showed that limitation o...Influences of root-growing space of maize upon root physiological characteristics, nutrient uptake and crop yields were studied under conditions with and without supply of water and N. Results showed that limitation of the root-growing space greatly affected root growth, decreased total root-absorbing area and TTC-reductive amounts. However, it obviously increased the root active-absorbing area, specific absorbing area(absorbing area per gram root weight)and specific active-absorbing area(actively absorbing area per gram root weight)in addition to promoting the TTC-reductive intensity. This clearly showed that plants were not passively tolerant to stress, but actively regulated their physiological metabolic processes, and strengthened their absorbing ability to increase water and nutrient uptake so that root injury by the environmental stress could be reduced. Supply of water and N stimulated root growth, increased root-absorbing area and activity. promoted nutrient uptake, and therefore increased crop yield and decreased the detrimental effects resulting from the limitation of roots-growing space.展开更多
A simple, quick, sensitive, accurate and precise method has been developed for evaluating the catalytic active sites of titanium silicalite-1 (TS-1). The catalytic active sites of titanium silicalite zeolite depend on...A simple, quick, sensitive, accurate and precise method has been developed for evaluating the catalytic active sites of titanium silicalite-1 (TS-1). The catalytic active sites of titanium silicalite zeolite depend on the effectively active species (EAS) in TS-1 which react with specific substrates quickly. However, the EAS was hard to be evaluated with conventional instruments and techniques in the past. In this paper, the EAS was formed in TS-1 upon interaction with H2O2, and its presence could be confirmed by UV-vis spectroscopy which has an absorption peak at 385 nm. The absorbance at 385 nm was found to be linearly related to time, and when the absorbance and the increasing rate of absorbance (k) increased, the catalytic performance of TS-1 enhanced.展开更多
[Objective] This study aimed to improve comprehensive utilization value of glutinous rice straw and to develop new raw material for preparation of activated carbon. [Method] Using potassium hydroxide as activator and ...[Objective] This study aimed to improve comprehensive utilization value of glutinous rice straw and to develop new raw material for preparation of activated carbon. [Method] Using potassium hydroxide as activator and glutinous rice straw as raw material, activated carbon was prepared. [Result] The optimum technological conditions for preparation of activated carbon from glutinous rice straw were as fol- lows: activator concentration of 2 mol/L, activation time of 60 min, activation tem- perature of 600 ℃ and carbonization temperature of 450℃. The adsorption values of methylene blue and iodine by activated carbon prepared from glutinous rico straw were 10.21 ml/0.1 g and 920.74 mg/g respectively under the optimal conditions. The quality of the prepared activated carbon met the grade two of water quality purifica- tion-using activated carbon quality standard. [Conclusion] This study will provide certain references for comprehensive utilization of glutinous rice straw and preparation of high-performance activated carbon.展开更多
[Objective] The paper was to study the activity of tyrosinase,so as to provide reference for preventing browning of potatoes as well as fruits and vegetables containing tyrosinase.[Method] With potato as raw material ...[Objective] The paper was to study the activity of tyrosinase,so as to provide reference for preventing browning of potatoes as well as fruits and vegetables containing tyrosinase.[Method] With potato as raw material and Na2HPO4-HCl in buffer solution(pH=7.2)as system,spectrophotometer was used to measure the absorbance of potato extract at 480nm,the curve was established,and the activity of tyrosinase was obtained.[Result] The changes of data were little under the above conditions,and the stability of tyrosinase activity was high.[Conclusion] Using spectrophotometry to determine the tyrosinase activity in potato is simple with high accuracy.展开更多
植被吸收光合有效辐射(Absorbed Photosynthetically Active Radiation,APAR)是植被进行光合作用中实际吸收的太阳辐射量,是植被净第一性生产力的重要指标,也是生态系统的功能模型、作物生长模型、净初级生产力模型、气候模型等的重要...植被吸收光合有效辐射(Absorbed Photosynthetically Active Radiation,APAR)是植被进行光合作用中实际吸收的太阳辐射量,是植被净第一性生产力的重要指标,也是生态系统的功能模型、作物生长模型、净初级生产力模型、气候模型等的重要参数。因此高空间分辨率和精确性的植被吸收光合有效辐射对于高精度的区域生产力及光能利用率的研究具有重要意义。对CASA(Carnegie-Ames-Stanford Approach)模型进行了改进,利用30m×30m的数字高程模型(Digital Elevation Model,DEM)数据直接计算太阳辐射,从而将其作为CASA模型的输入参数。结合多源遥感数据、气象数据,研究2015-2020年江汉平原APAR的时空分布及其影响因素。顾及江汉平原的土地利用分布特点,着重分析了江汉平原农田APAR的时空特性,研究结果较好的反映了江汉平原APAR分布。实验结果表明:(1)2015-2020年APAR年总值在3.42×10^(13)MJ-3.73×10^(13)MJ之间,总体空间分布与植被类型的分布情况相符;(2)农田月均APAR值在4月、7月高于其他月份,表现出“双峰”的特征;(3)在空间分布上,水田APAR表现出明显的纬度地带性,而旱地APAR正好相反,这可能源于种植结构重心转移;(4)通过借助地理探测器,着重考虑与植被生长相关的12个因子(包括≧10℃积温、年总日照时数、年均气温、年总降雨量、农田种植结构、年散射辐射、农田施肥、土壤类型、土壤质地(砂土、粉砂土、黏土))进行分析,结果表明这12个因素对APAR空间变异性都具有很明显的影响。对CASA的改进方法可以适用于大范围高空间精度的计算。展开更多
In this paper,an active tunable terahertz bandwidth absorber based on single-layer graphene is proposed,which consists of a graphene layer,a photo crystal plate,and a gold substrate.When the Fermi energy(Ef)of graphen...In this paper,an active tunable terahertz bandwidth absorber based on single-layer graphene is proposed,which consists of a graphene layer,a photo crystal plate,and a gold substrate.When the Fermi energy(Ef)of graphene is 1.5 eV,the absorber shows high absorption in the range of 3.7 THz–8 THz,and the total absorption rate is 96.8%.By exploring the absorption mechanism of the absorber,the absorber shows excellent physical regulation.The absorber also shows good adjustability by changing the Efof graphene.This means that the absorber exhibits excellent tunability by adjusting the physical parameters and Efof the absorber.Meanwhile,the absorber is polarization independent and insensitive to the incident angle.The fine characteristics of the absorber mean that the absorber has superior application value in many fields such as biotechnology and space exploration.展开更多
文摘Presented in this paper is a semi active vibration control strategy based on the vibration absorber with adjustable clearance in elastic component. The control law of the clearance for alleviating the vibration of primary system is derived by means of harmonic balancing technique so that the working frequency of the vibration absorber can trace the frequency variation of the harmonic excitation. The efficacy of the strategy is demonstrated by numerical simulations for attenuating the steady state vibration of a SDOF system and a 2 DOF system, which are under the harmonic excitation with slowly varied frequency in a wide range.
文摘The numerical wave channel has been developed based on the volume of fluid method (VOF) in conjunction with the Navier-Stokes equations. The absorbing wave-maker boundary on the left side of the channel is presented by prescribing velocity reference to linear wave-maker theory. The principle of which is that the numerical wave-maker is designed to move in a way that generates the required incident wave and cancels out any reflected wave that reach it at the same time. On the right side of the channel, the open boundary is set to permit incident waves to be transmitted freely. The parametric studies have been carried out at a range of ratios of water depth to wave length d/ L from 0.124 to 0.219, with wave height in the front of paddle/water depth ratio (H0 / d) from 0.1 to 0.3. Wave height, wave pressure distribution along the channel and velocity field are obtained for both open boundary condition and reflective boundary condition at the other end of the channel. For a reflective case, it is shown that the absorbing wave-maker is very effective in canceling out the reflected wave that reaches the numerical paddle and highly repeatable waves can be generated.
文摘Significant structural vibration is an undesirable characteristic in helicopter flight that leads to structural fatigue, poor ride quality for passengers and high acoustic signature. Previous Individual Blade Control (IBC) techniques to reduce these effects have been hindered by electromechanical limitations of piezoelectric actuators. The Smart Spring is an active tunable vibration absorber using IBC approach to adaptively alter the 'structural impedance' at the blade root. In this paper, a mathematical model was developed to predict the response under harmonic excitations. An adaptive notch algorithm was designed and implemented on a TMS320c40 DSP platform. Reference signal synthesis techniques were used to automatically track the shifts in the fundamental vibratory frequency due to variations in flight conditions. Closed-loop tests performed on the proof-of-concept hardware achieved significant vibration suppression at harmonic peaks as well as the broadband reduction in vibration. The investigation verified the capability of the Smart Spring to suppress multiple harmonic components in blade vibration through active impedance control.
文摘The purpose of this study is to compare the results of chemical analysis of two types of activated from the pyrolysis of bull horn and that of cow. Six samples were used to measure pH, carbon, calcium and to determine adsorbent power. The pH was measured at a temperature of 20˚C using an “ANION 7010 ionomer” pH meter, the carbon (C) content was analyzed using a “EURO EA 3000” analyzer. and the electronic balance: “Sartorius CP-2P”, calcium (Ca) was analyzed using a DFS-8 spectrograph. For the adsorbency test, the 0.15% methylene blue R solution was used. At the end of this study, we found that the activated carbon from the bull horn demonstrated a carbon content that is higher than that of the cow horn (20.79% against 15.63%), activated carbon of cow horn is richer in calcium than that of bull horn (16.27% against 3.69%) and then the pH. The cow horn is higher than that of the bull horn (7.43 versus 6.5). For the adsorbent power, the sample (75% bull horn and 25% cow horn) was recorded with the greatest adsorbent power. Thus, from this study, it can be recommended as an activated carbon antidote to be used for poisonings treatment.
基金Aeronautical Science Foundation of China (04B52012, 98B52023)
文摘To select or develop an appropriate actuator is one of the key and difficult issues in the study of semi-active controlled landing gear. Performance of the actuator may directly affect the effectiveness of semi-active control. In this article, parallel high-speed solenoid valves are chosen to be the actuators for the semi-active controlled landing gear and being studied. A nonlinear high-speed solenoid valve model is developed with the consideration of magnetic saturation characteristics and verified by test. According to the design rule of keeping the peak load as small as possible while absorbing the specified shock energy, a fuzzy PD control rule is designed. By the rule controller parameters can be self-regulated. The simulation results indicate that the semi-active control based on high-speed solenoid valve can effectively improve the control performance and reduce impact load during landing.
基金supported by the‘New Century Outstanding Talent’Scheme of the Ministry of Education of China(Grant No.NCET-07-0135)
文摘A numerical irregular wave flume with active absorption of re-reflected waves is simulated by use of volume of fluid (VOF) method. An active 'absorbing wave-maker based on linear wave theory is set on the left boundary of the wave flume. The progressive waves and the absorbing waves are generated simultaneously at the active wave generating-absorbing boundary. The absorbing waves are generated to eliminate the waves coming back to the generating boundary due to reflection from the outflow boundary and the structures. SIRW method proposed by Frigaard and Brorsen (1995) is used to separate the incident waves and reflected waves. The digital filters are designed based on the surface elevation signals of the two wave gauges. The corrected velocity of the wave-maker paddle is the output from the digital filter in real time. The numerical results of regular and irregular waves by the active absorbing-generating boundary are compared with the numerical results by the ordinary generating boundary to verify the performance of the active absorbing-generator boundary. The differences between the initial incident waves and the estimated incident waves are analyzed.
基金supported by the National Natural Science Foundation of China(10972033)。
文摘This paper investigates the feasibility of using an active dynamic vibration absorber(ADVA) for active vibration control of a flexible missile system through simulation.Based on the principles of a dynamic vibration absorber(DVA),a ring-type ADVA is first designed to attenuate the elastic vibration of the flexible missile,and the design of the active controller adopts the proportional-integral-derivative(PID)control algorithm.The motion equations of a flexible missile with an ADVA,which is subjected to follower thrust at its aft end,are derived using the Lagrangian approach.Taking the minimum of the root mean square(RMS) of the lateral displacement response of the center of mass as the objective function,a genetic algorithm(GA) is used to optimize the parameter of the DVA and PID controller.The numerical calculations show that the ADVA and DVA are effective in suppressing the vibration and provide approximately 41.2% and 17.6% improvement,respectively,compa red with the case of no DVA,The ADVA has better performance than the DVA,When the missile is subjected to follower thrust,the effect of vibration reduction is more effective than the case without follower thrust.It is feasible to reduce vibration and improve the stability of flexible missiles by means of the ADVA.
基金Funded by the National Natural Science Foundation of China(No.51874136)Natural Science Foundation of Hebei Province(No.B2017209240)。
文摘Using lignite-based hypercoal as raw material, KOH as activator and CuO as microwave absorber, we prepared hypercoal-based activated carbons by microwave-assisted activation. The pore structure and the electrochemical performance of the activated carbons were tested, and the effects of adding CuO in the activation reaction process were also investigated. The activated carbons prepared were characterized by nitrogen adsorption-desorption, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The specific surface area and mesoporous ratio of the hypercoal-based activated carbon are 1257 m2/g and 55.4%, respectively. When the activated carbons are used as the electrode materials, the specific capacitance reaches 309 F/g in 3 M KOH electrolyte. In comparison with those prepared without CuO absorber, the specific capacitance increases by 11.6%. It was proved that the addition of microwave absorber in microwave-assisted activation was a low-cost method for rapidly preparing activated carbon, and it could effectively promote the development of the pore structure and improve its electrochemical performance.
基金part of the projects(49890330,30230230,30070429 and 40201028)supported by the National Natural Science Foundation of China(NSFC)project(G1999011707)supported by the National Key Basic Research Support Funds(NKBRSF).
文摘Influences of root-growing space of maize upon root physiological characteristics, nutrient uptake and crop yields were studied under conditions with and without supply of water and N. Results showed that limitation of the root-growing space greatly affected root growth, decreased total root-absorbing area and TTC-reductive amounts. However, it obviously increased the root active-absorbing area, specific absorbing area(absorbing area per gram root weight)and specific active-absorbing area(actively absorbing area per gram root weight)in addition to promoting the TTC-reductive intensity. This clearly showed that plants were not passively tolerant to stress, but actively regulated their physiological metabolic processes, and strengthened their absorbing ability to increase water and nutrient uptake so that root injury by the environmental stress could be reduced. Supply of water and N stimulated root growth, increased root-absorbing area and activity. promoted nutrient uptake, and therefore increased crop yield and decreased the detrimental effects resulting from the limitation of roots-growing space.
文摘A simple, quick, sensitive, accurate and precise method has been developed for evaluating the catalytic active sites of titanium silicalite-1 (TS-1). The catalytic active sites of titanium silicalite zeolite depend on the effectively active species (EAS) in TS-1 which react with specific substrates quickly. However, the EAS was hard to be evaluated with conventional instruments and techniques in the past. In this paper, the EAS was formed in TS-1 upon interaction with H2O2, and its presence could be confirmed by UV-vis spectroscopy which has an absorption peak at 385 nm. The absorbance at 385 nm was found to be linearly related to time, and when the absorbance and the increasing rate of absorbance (k) increased, the catalytic performance of TS-1 enhanced.
基金Supported by Guizhou Provincial College Students’ Innovative Entrepreneurial Training Program in 2014(201414440004)~~
文摘[Objective] This study aimed to improve comprehensive utilization value of glutinous rice straw and to develop new raw material for preparation of activated carbon. [Method] Using potassium hydroxide as activator and glutinous rice straw as raw material, activated carbon was prepared. [Result] The optimum technological conditions for preparation of activated carbon from glutinous rice straw were as fol- lows: activator concentration of 2 mol/L, activation time of 60 min, activation tem- perature of 600 ℃ and carbonization temperature of 450℃. The adsorption values of methylene blue and iodine by activated carbon prepared from glutinous rico straw were 10.21 ml/0.1 g and 920.74 mg/g respectively under the optimal conditions. The quality of the prepared activated carbon met the grade two of water quality purifica- tion-using activated carbon quality standard. [Conclusion] This study will provide certain references for comprehensive utilization of glutinous rice straw and preparation of high-performance activated carbon.
文摘[Objective] The paper was to study the activity of tyrosinase,so as to provide reference for preventing browning of potatoes as well as fruits and vegetables containing tyrosinase.[Method] With potato as raw material and Na2HPO4-HCl in buffer solution(pH=7.2)as system,spectrophotometer was used to measure the absorbance of potato extract at 480nm,the curve was established,and the activity of tyrosinase was obtained.[Result] The changes of data were little under the above conditions,and the stability of tyrosinase activity was high.[Conclusion] Using spectrophotometry to determine the tyrosinase activity in potato is simple with high accuracy.
基金support from the National Natural Science Foundation of China (No.51606158,11604311,12074151)funding from the Scientific Research Fund of Sichuan Provincial Science and Technology Department (2020YJ0137+7 种基金2020YFG04672021JDRC0019)funding from the Opening Project of Key Laboratory of Microelectronic Devices&Integrated Technology,Institute of Microelectronics,Chinese Academy of Sciencesfunding from the College Students’innovation and entrepreneurship training program (S202110619073S202110619069)funding from the undergraduate Innovation Fund Project of SWUST (CX 21-099LX2020010CX21-008)。
文摘In this paper,an active tunable terahertz bandwidth absorber based on single-layer graphene is proposed,which consists of a graphene layer,a photo crystal plate,and a gold substrate.When the Fermi energy(Ef)of graphene is 1.5 eV,the absorber shows high absorption in the range of 3.7 THz–8 THz,and the total absorption rate is 96.8%.By exploring the absorption mechanism of the absorber,the absorber shows excellent physical regulation.The absorber also shows good adjustability by changing the Efof graphene.This means that the absorber exhibits excellent tunability by adjusting the physical parameters and Efof the absorber.Meanwhile,the absorber is polarization independent and insensitive to the incident angle.The fine characteristics of the absorber mean that the absorber has superior application value in many fields such as biotechnology and space exploration.