This paper focuses on the use of the touchpad (key), STC89C51RC monolithic integrated circuit PWM control signal, which changed the traditional mechanical buttons as a DC motor rotational speed and steering control ...This paper focuses on the use of the touchpad (key), STC89C51RC monolithic integrated circuit PWM control signal, which changed the traditional mechanical buttons as a DC motor rotational speed and steering control method. Touch switch advantages compared with the traditional mechanical switches are: first, the quieter second, more sensitive; third, faster; four, long life and so on. Specialized chips are also used in the article the PWM signal system, and the principle of PWM signal, method and how the software adjust the duty cycle of the PWM signal to control its input signal waveforms are are described in detail. In addition, this article also introduced consisting of triode amplifier circuit of h-bridge amplifier as a DC motor driving module, enabling the control of DC motor speed. On the software side, PI was described in detail in the article arithmetic program initializes write ideas and specific programs such as program implementation.展开更多
After finishing picking the banana, how to tackle banana pesudostem has long been a thorny problem. According to banana pesudostem's characteristics of more crassitude stem, high moisture content and heavy fiber dens...After finishing picking the banana, how to tackle banana pesudostem has long been a thorny problem. According to banana pesudostem's characteristics of more crassitude stem, high moisture content and heavy fiber density, this paper proposes a efficient, energy-saving and low-loss device for crushing banana pesudostems and returning field.展开更多
Osmotic energy from the ocean,also called blue energy,serves as a clean,renewable,and vast energy source for the energy demands of the world.Reverse electrodialysis-based blue energy harvesting via ion-selective membr...Osmotic energy from the ocean,also called blue energy,serves as a clean,renewable,and vast energy source for the energy demands of the world.Reverse electrodialysis-based blue energy harvesting via ion-selective membranes,by the regulation and manipulation of directional ion transport,has been greatly developed recently.In particular,light has been employed to enhance directional ion transport for energy conversion through an increase in photo-induced surface charge.Here,the authors demonstrate a novel nanofluidic regulation strategy based on the phenomenon of light-induced heat-driven active ion transport through the lamellar MXene membrane.Due to the great light-induced heat effect,a temperature gradient appears as soon as illumination is applied to an off-center position,inducing an actively temperature gradient-driven ionic species transport.By employing this phenomenon,the authors conducted light-induced heat-enhanced osmotic energy conversion and doubled the osmotic energy conversion power density.This study has extended the scope of light-enhanced osmotic energy conversion and could further bring other photothermal materials into this field.Furthermore,the proposed system provides a new avenue of light-controlled ionic transport for ion gathering,desalination,and energy conversion applications.展开更多
Coupling low-grade heat(LGH)with salinity gradient is an effective approach to increase the efficiency of the nanofluidic-membrane-based power generator.However,it is a challenge to fabricate membranes with high charg...Coupling low-grade heat(LGH)with salinity gradient is an effective approach to increase the efficiency of the nanofluidic-membrane-based power generator.However,it is a challenge to fabricate membranes with high charge density that ensures ion permselectivity,while maintaining chemical and mechanical stability in this composite environment.Here,we develop a bis[2-(methacryloyloxy)ethyl]phosphate(BMAP)hydrogel membrane with good thermal stability and anti-swelling property through self-crosslinking of the selected monomer.By taking advantage of negative space charge and three-dimensional(3D)interconnected nanochannels,salinity gradient energy conversion efficiency is substantially enhanced by temperature difference.Theoretical and experimental results verify that LGH can largely weaken the concentration polarization,promoting transmembrane ion transport.As a result,such a hydrogel membrane delivers high-performance energy conversion with a power density of 11.53 W·m^(−2)under a negative temperature difference(NTD),showing a 193%increase compared with that without NTD.展开更多
Airflow speed is one of the three factors of air-assisted spraying.Optimizing the matching model between airflow speed and target canopy characteristics is an effective way to improve the orchard precision spraying te...Airflow speed is one of the three factors of air-assisted spraying.Optimizing the matching model between airflow speed and target canopy characteristics is an effective way to improve the orchard precision spraying technology,as airflow can significantly affect droplet deposition and drift loss.A simple model of airflow speed was established in this study.First,air-assisted spraying experiments were carried out on a standard simulation canopy to study the airflow speed depended on canopy width,leaf area index,and porosity rate.Second,determined by Ribbon Method and verified by droplet drift data,the airflow speed through the canopy was between 0.5 m/s and 0.7 m/s.Third,multiple tests were carried out under standard simulation canopy with different characteristics,and the airflow speed model was established ultimately:with a fixed leaf area index(LAI),the relationship between canopy upwind boundary airflow speed and canopy width satisfied the exponential model(y=ae^(bx)),and the coefficients a and b are well related to the density of branches and leaves in the canopy.When LAI=3.456,y=2.036e^(1.5887x),R^(2)=0.994;LAI=1.728,y=1.639e^(1.445x),R^(2)=0.972.Orchard growers can acquire needed airflow speed through this simple model,it is quick and precise and appropriate to most growth periods of a variety of fruit trees,such as apples,pears,and vines.展开更多
文摘This paper focuses on the use of the touchpad (key), STC89C51RC monolithic integrated circuit PWM control signal, which changed the traditional mechanical buttons as a DC motor rotational speed and steering control method. Touch switch advantages compared with the traditional mechanical switches are: first, the quieter second, more sensitive; third, faster; four, long life and so on. Specialized chips are also used in the article the PWM signal system, and the principle of PWM signal, method and how the software adjust the duty cycle of the PWM signal to control its input signal waveforms are are described in detail. In addition, this article also introduced consisting of triode amplifier circuit of h-bridge amplifier as a DC motor driving module, enabling the control of DC motor speed. On the software side, PI was described in detail in the article arithmetic program initializes write ideas and specific programs such as program implementation.
文摘After finishing picking the banana, how to tackle banana pesudostem has long been a thorny problem. According to banana pesudostem's characteristics of more crassitude stem, high moisture content and heavy fiber density, this paper proposes a efficient, energy-saving and low-loss device for crushing banana pesudostems and returning field.
基金This study was supported by the National Key R&D Program of China(nos.2017YFA0206904 and 2017YFA0206900)the National Natural Science Foundation of China(nos.21625303,21905287,51673206,and 21988102)+2 种基金the Beijing Natural Science Foundation(no.2194088)the Strategic Priority Research Program of the Chinese Academy of Science(no.XDA21010213)the Key Research Program of the Chinese Academy of Sciences(no.QYZDY-SSW-SLH014).
文摘Osmotic energy from the ocean,also called blue energy,serves as a clean,renewable,and vast energy source for the energy demands of the world.Reverse electrodialysis-based blue energy harvesting via ion-selective membranes,by the regulation and manipulation of directional ion transport,has been greatly developed recently.In particular,light has been employed to enhance directional ion transport for energy conversion through an increase in photo-induced surface charge.Here,the authors demonstrate a novel nanofluidic regulation strategy based on the phenomenon of light-induced heat-driven active ion transport through the lamellar MXene membrane.Due to the great light-induced heat effect,a temperature gradient appears as soon as illumination is applied to an off-center position,inducing an actively temperature gradient-driven ionic species transport.By employing this phenomenon,the authors conducted light-induced heat-enhanced osmotic energy conversion and doubled the osmotic energy conversion power density.This study has extended the scope of light-enhanced osmotic energy conversion and could further bring other photothermal materials into this field.Furthermore,the proposed system provides a new avenue of light-controlled ionic transport for ion gathering,desalination,and energy conversion applications.
基金supported by the National Key R&D Program of China(Nos.2022YFB3805904,2022YFB3805900,and 2020YFA0710401)the National Natural Science Foundation of China(Nos.22122207,21988102,and 52075138)+2 种基金CAS Key Laboratory of Bio-inspired Materials and Interfacial Science,Technical Institute of Physics and Chemistry(No.BMIS202102)China Postdoctoral Science Foundation(Nos.2022TQ0345,2022M723229,and 2022M713226)Postdoctoral International Exchange Talent-Introducing Program(No.YJ20220199).
文摘Coupling low-grade heat(LGH)with salinity gradient is an effective approach to increase the efficiency of the nanofluidic-membrane-based power generator.However,it is a challenge to fabricate membranes with high charge density that ensures ion permselectivity,while maintaining chemical and mechanical stability in this composite environment.Here,we develop a bis[2-(methacryloyloxy)ethyl]phosphate(BMAP)hydrogel membrane with good thermal stability and anti-swelling property through self-crosslinking of the selected monomer.By taking advantage of negative space charge and three-dimensional(3D)interconnected nanochannels,salinity gradient energy conversion efficiency is substantially enhanced by temperature difference.Theoretical and experimental results verify that LGH can largely weaken the concentration polarization,promoting transmembrane ion transport.As a result,such a hydrogel membrane delivers high-performance energy conversion with a power density of 11.53 W·m^(−2)under a negative temperature difference(NTD),showing a 193%increase compared with that without NTD.
基金financially supported by the National Natural Science Foundation of China(Grant No.2016YFD020070).
文摘Airflow speed is one of the three factors of air-assisted spraying.Optimizing the matching model between airflow speed and target canopy characteristics is an effective way to improve the orchard precision spraying technology,as airflow can significantly affect droplet deposition and drift loss.A simple model of airflow speed was established in this study.First,air-assisted spraying experiments were carried out on a standard simulation canopy to study the airflow speed depended on canopy width,leaf area index,and porosity rate.Second,determined by Ribbon Method and verified by droplet drift data,the airflow speed through the canopy was between 0.5 m/s and 0.7 m/s.Third,multiple tests were carried out under standard simulation canopy with different characteristics,and the airflow speed model was established ultimately:with a fixed leaf area index(LAI),the relationship between canopy upwind boundary airflow speed and canopy width satisfied the exponential model(y=ae^(bx)),and the coefficients a and b are well related to the density of branches and leaves in the canopy.When LAI=3.456,y=2.036e^(1.5887x),R^(2)=0.994;LAI=1.728,y=1.639e^(1.445x),R^(2)=0.972.Orchard growers can acquire needed airflow speed through this simple model,it is quick and precise and appropriate to most growth periods of a variety of fruit trees,such as apples,pears,and vines.