Sweet sorghum has become an important feedstock for bioethanol production. Total sugar yield and multiple harvests can directly affect ethanol production cost. Little is known about stem traits and multiple harvests t...Sweet sorghum has become an important feedstock for bioethanol production. Total sugar yield and multiple harvests can directly affect ethanol production cost. Little is known about stem traits and multiple harvests that contribute to sugar yield in sweet sorghum. Stem traits were evaluated from 25 sweet and grain sorghum accessions. Stems were harvested twice at the soft-dough stage and the stems were pressed with a hydraulic press. Sugars in the stem juice were quantified by high performance liquid chromatography. Sweet sorghum produced five times more fresh stem weight and dry stem mass (830 gand164 g) than grain sorghum (150 gand27g). Sweet sorghum produced a much higher volume of juice and higher yield of sugars (366 ml and42 g) per stem than grain sorghum (70 ml and4 g). Significant variability in fresh stem weight (72 - 1837 g), juice volume (31 - 753 ml), sugar yield (3 - 81 g), dry stem mass (14 - 383 g), and sugar yield/dry stem mass ratio (0.11 - 0.53) per stem was detected among sweet sorghum accessions. Stem sugar yield was significantly correlated with stem fresh weight and juice volume. Sorghum was harvested twice within one growing season resulting in some sweet sorghum accessions producing double amount of sugars. Sweet sorghum produced three times more dry mass weight (bagasse) than fermentable sugar weight. To reduce feedstock cost, methods have to be developed for efficiently utilizing bagasse. Our results showed high fresh stem weight, high ratio of sugar yield to dry stem mass, and double harvests are prime traits to boost sugar yield. Sweet sorghum may be suitable for multiple harvests in certain regions of theU.S.TheU.S.sweet sorghum collection needs to be screened for acces- sions that can be harvested twice with an extended feedstock-production season and used as a feedstock for sustainable and renewable bioenergy production.展开更多
Because of the complexity of social responses to climate change,as well as limitations of proxy data concerning interactions between climate change and human responses,the social impacts of past climate change and ass...Because of the complexity of social responses to climate change,as well as limitations of proxy data concerning interactions between climate change and human responses,the social impacts of past climate change and associated response mechanisms,thus,require further investigation.To shed light on the transmission of climate change impacts within historical Chinese society,we selected 30-year resolution sequences of temperature anomalies in eastern China and 10-year resolution sequences of grain harvest grades,famine indices,and frequencies of peasant uprisings in China over the past 2000 years.Using a food security perspective,we analyzed the impacts of temperature changes historically transmitted through Chinese production,population,and social subsystems,and differences in transmission characteristics between cold and warm units.Our results were as follows.(1)From 210 BC to 1910 AD,temperature changes in China were significantly positively correlated with grain harvest grades(correlation coefficient,0.338),and significantly negatively correlated with famine indices,and frequencies of peasant uprisings(correlation coefficients,-0.301 and-0.277,respectively).The correlation coefficients between famine indices and grain harvest grades or frequencies of peasant uprisings were very low.(2)There was a higher proportion of bumper or normal harvests(86.5%of the total decades),more moderate and mild famines(76%),and a lower proportion of peasant uprisings(33.3%)in the 30-year warm units.Conversely,there was a higher proportion of poor or normal harvests(70.7%),a greater proportion of moderate and severe famines(77.6%),and more peasant uprisings(51.7%)in the 30-year cold units.(3)Of the 23 main transmission pathways extending from temperature change to the social subsystem,13 occurred in cold units,of which 7 had an endpoint of peasant uprisings,and 10 occurred in warm units of which 3 had an endpoint of peasant uprisings.The main transmission pathways that were more likely to be associated with the impacts of temperature change were:Cold→poor harvests→severe famines→more uprisings;cold→poor harvests→moderate famines→more uprisings;warm→bumper harvests→mild famines→no uprisings;warm→bumper harvests→moderate harvests→no uprisings;warm→normal harvests→mild famines→no uprisings;and warm→normal harvests→moderate famines→no uprisings.(4)The transmission of the impacts of temperature change was a complex process.Within this process,famine was most prone to being modulated by human society.In the transmission pathways from the production to the social subsystem,there was a stepwise decrease in the occurrence rate of decades that were probably affected by climate change.In all cold units,10.4%of decades ending in more uprisings were most likely to be associated with the impacts of temperature change.In all warm units,47.9%of decades ending in no uprisings were most likely to be associated with the impacts of temperature change.This research can contribute a better understanding on the past interaction mechanisms and processes within the human-climate-ecosystem complex,as well as a better response to the impacts of the ongoing climate change.展开更多
Knee osteoarthritis(OA)is a debilitating condition with limited long-term treatment options.The therapeutic potential of mesenchymal stem cells(MSCs),particularly those derived from bone marrow aspirate concentrate,ha...Knee osteoarthritis(OA)is a debilitating condition with limited long-term treatment options.The therapeutic potential of mesenchymal stem cells(MSCs),particularly those derived from bone marrow aspirate concentrate,has garnered attention for cartilage repair in OA.While the iliac crest is the traditional site for bone marrow harvesting(BMH),associated morbidity has prompted the exploration of alternative sites such as the proximal tibia,distal femur,and proximal humerus.This paper reviews the impact of different harvesting sites on mesenchymal stem cell(MSC)yield,viability,and regenerative potential,emphasizing their relevance in knee OA treatment.The iliac crest consistently offers the highest MSC yield,but alternative sites within the surgical field of knee procedures offer comparable MSC characteristics with reduced morbidity.The integration of harvesting techniques into existing knee surgeries,such as total knee arthroplasty,provides a less invasive approach while maintaining thera-peutic efficacy.However,variability in MSC yield from these alternative sites underscores the need for further research to standardize techniques and optimize clinical outcomes.Future directions include large-scale comparative studies,advanced characterization of MSCs,and the development of personalized harvesting strategies.Ultimately,the findings suggest that optimizing the site of BMH can significantly influence the quality of MSC-based therapies for knee OA,enhancing their clinical utility and patient outcomes.展开更多
Smart farming with outdoor monitoring systems is critical to address food shortages and sustainability challenges.These systems facilitate informed decisions that enhance efficiency in broader environmental management...Smart farming with outdoor monitoring systems is critical to address food shortages and sustainability challenges.These systems facilitate informed decisions that enhance efficiency in broader environmental management.Existing outdoor systems equipped with energy harvesters and self-powered sensors often struggle with fluctuating energy sources,low durability under harsh conditions,non-transparent or non-biocompatible materials,and complex structures.Herein,a multifunctional hydrogel is developed,which can fulfill all the above requirements and build selfsustainable outdoor monitoring systems solely by it.It can serve as a stable energy harvester that continuously generates direct current output with an average power density of 1.9 W m^(-3)for nearly 60 days of operation in normal environments(24℃,60%RH),with an energy density of around 1.36×10^(7)J m^(-3).It also shows good self-recoverability in severe environments(45℃,30%RH)in nearly 40 days of continuous operation.Moreover,this hydrogel enables noninvasive and self-powered monitoring of leaf relative water content,providing critical data on evaluating plant health,previously obtainable only through invasive or high-power consumption methods.Its potential extends to acting as other self-powered environmental sensors.This multifunctional hydrogel enables self-sustainable outdoor systems with scalable and low-cost production,paving the way for future agriculture.展开更多
In the applications such as food production,the environmental temperature should be measured continuously dur-ing the entire process,which requires an ultra-low-power temperature sensor for long-termly monitoring.Conv...In the applications such as food production,the environmental temperature should be measured continuously dur-ing the entire process,which requires an ultra-low-power temperature sensor for long-termly monitoring.Conventional tempera-ture sensors trade the measurement accuracy with power consumption.In this work,we present a battery-free wireless tempera-ture sensing chip for long-termly monitoring during food production.A calibrated oscillator-based CMOS temperature sensor is proposed instead of the ADC-based power-hungry circuits in conventional works.In addition,the sensor chip can harvest the power transferred by a remote reader to eliminate the use of battery.Meanwhile,the system conducts wireless bidirectional communication between the sensor chip and reader.In this way,the temperature sensor can realize both a high precision and battery-free operation.The temperature sensing chip is fabricated in 55 nm CMOS process,and the reader chip is imple-mented in 65 nm CMOS technology.Experimental results show that the temperature measurement error achieves±1.6℃ from 25 to 50℃,with battery-free readout by a remote reader.展开更多
The significance of water energy harvesting in the context of renewable energy utilization is steadily increasing.In response to the need for more efficient utilization of water resources,the nascent technology of liq...The significance of water energy harvesting in the context of renewable energy utilization is steadily increasing.In response to the need for more efficient utilization of water resources,the nascent technology of liquid-solid triboelectric nanogenerators(TENGs)has emerged as a prospective candidate for the harvesting of water energy.Liquid-solid TENGs show several distinct advantages,including their lightweight,low cost,and efficient energy harvesting capabilities.Herein,this review presents a comprehensive exposition of the latest advancements in the field of liquid-solid TENGs.It delves into the underlying principles and different operational modes while also addressing the factors influencing its output performance from a multifaceted perspective.The factors comprise the intrinsic properties of friction materials,the chemical properties of the liquid,and the ambient temperature of liquid-solid TENGs.Furthermore,this review delineates the applications of liquid-solid TENGs as self-powered sensors in physics,chemistry,and biomedical contexts,as well as their applications in various other fields such as corrosion resistance,and so on.Last but not least,it concludes by providing a forward-looking on the future developmental trends of liquid-solid TENGs.展开更多
Recycling plastic waste into triboelectric nanogenerators(TENGs)presents a sustainable approach to energy harvesting,self-powered sensing,and environmental remediation.This study investigates the recycling of polyviny...Recycling plastic waste into triboelectric nanogenerators(TENGs)presents a sustainable approach to energy harvesting,self-powered sensing,and environmental remediation.This study investigates the recycling of polyvinyl chloride(PVC)pipe waste polymers into nanofibers(NFs)optimized for TENG applications.We focused on optimizing the morphology of recycled PVC polymer to NFs and enhancing their piezoelectric properties by incorporating ZnO nanoparticles(NPs).The optimized PVC/0.5 wt%ZnO NFs were tested with Nylon-6 NFs,and copper(Cu)electrodes.The Nylon-6 NFs exhibited a power density of 726.3μWcm^(-2)—1.13 times higher than Cu and maintained 90%stability after 172800 cycles,successfully powering various colored LEDs.Additionally,a 3D-designed device was developed to harvest energy from biomechanical movements such as finger tapping,hand tapping,and foot pressing,making it suitable for wearable energy harvesting,automatic switches,and invisible sensors in surveillance systems.This study demonstrates that recycling polymers for TENG devices can effectively address energy,sensor,and environmental challenges.展开更多
Recently,one of the main challenges facing the smart grid is insufficient computing resources and intermittent energy supply for various distributed components(such as monitoring systems for renewable energy power sta...Recently,one of the main challenges facing the smart grid is insufficient computing resources and intermittent energy supply for various distributed components(such as monitoring systems for renewable energy power stations).To solve the problem,we propose an energy harvesting based task scheduling and resource management framework to provide robust and low-cost edge computing services for smart grid.First,we formulate an energy consumption minimization problem with regard to task offloading,time switching,and resource allocation for mobile devices,which can be decoupled and transformed into a typical knapsack problem.Then,solutions are derived by two different algorithms.Furthermore,we deploy renewable energy and energy storage units at edge servers to tackle intermittency and instability problems.Finally,we design an energy management algorithm based on sampling average approximation for edge computing servers to derive the optimal charging/discharging strategies,number of energy storage units,and renewable energy utilization.The simulation results show the efficiency and superiority of our proposed framework.展开更多
Wearable thermoelectric devices hold significant promise in the realm of self-powered wearable electron-ics,offering applications in energy harvesting,movement tracking,and health monitoring.Nevertheless,developing th...Wearable thermoelectric devices hold significant promise in the realm of self-powered wearable electron-ics,offering applications in energy harvesting,movement tracking,and health monitoring.Nevertheless,developing thermoelectric devices with exceptional flexibility,enduring thermoelectric stability,multi-functional sensing,and comfortable wear remains a challenge.In this work,a stretchable MXene-based thermoelectric fabric is designed to accurately discern temperature and strain stimuli.This is achieved by constructing an adhesive polydopamine(PDA)layer on the nylon fabric surface,which facilitates the subsequent MXene attachment through hydrogen bonding.This fusion results in MXene-based thermo-electric fabric that excels in both temperature sensing and strain sensing.The resultant MXene-based thermoelectric fabric exhibits outstanding temperature detection capability and cyclic stability,while also delivering excellent sensitivity,rapid responsiveness(60 ms),and remarkable durability in strain sens-ing(3200 cycles).Moreover,when affixed to a mask,this MXene-based thermoelectric fabric utilizes the temperature difference between the body and the environment to harness body heat,converting it into electrical energy and accurately discerning the body’s respiratory rate.In addition,the MXene-based ther-moelectric fabric can monitor the state of the body’s joint through its own deformation.Furthermore,it possesses the capability to convert solar energy into heat.These findings indicate that MXene-based ther-moelectric fabric holds great promise for applications in power generation,motion tracking,and health monitoring.展开更多
Polymeric microwave actuators combining tissue-like softness with programmablemicrowave-responsive deformation hold great promise for mobile intelligentdevices and bionic soft robots. However, their application is cha...Polymeric microwave actuators combining tissue-like softness with programmablemicrowave-responsive deformation hold great promise for mobile intelligentdevices and bionic soft robots. However, their application is challenged by restricted electromagneticsensitivity and intricate sensing coupling. In this study, a sensitized polymericmicrowave actuator is fabricated by hybridizing a liquid crystal polymer with Ti3C2Tx(MXene). Compared to the initial counterpart, the hybrid polymer exhibits unique spacechargepolarization and interfacial polarization, resulting in significant improvements of230% in the dielectric loss factor and 830% in the apparent efficiency of electromagneticenergy harvest. The sensitized microwave actuation demonstrates as the shortenedresponse time of nearly 10 s, which is merely 13% of that for the initial shape memory polymer. Moreover, the ultra-low content of MXene (upto 0.15 wt%) benefits for maintaining the actuation potential of the hybrid polymer. An innovative self-powered sensing prototype that combinesdriving and piezoelectric polymers is developed, which generates real-time electric potential feedback (open-circuit potential of ~ 3 mV) duringactuation. The polarization-dominant energy conversion mechanism observed in the MXene-polymer hybrid structure furnishes a new approachfor developing efficient electromagnetic dissipative structures and shows potential for advancing polymeric electromagnetic intelligent devices.展开更多
Electrical energy can be harvested from the rotational kinetic energy of moving bodies,consisting of both mechanical and kinetic energy as a potential power source through electromagnetic induction,similar to wind ene...Electrical energy can be harvested from the rotational kinetic energy of moving bodies,consisting of both mechanical and kinetic energy as a potential power source through electromagnetic induction,similar to wind energy applications.In industries,rotational bodies are commonly present in operations,yet this kinetic energy remains untapped.This research explores the energy generation characteristics of two rotational body types,disk-shaped and cylinder-shaped under specific experimental setups.The hardware setup included a direct current(DC)motor driver,power supply,DC generator,mechanical support,and load resistance,while the software setup involved automation testing tools and data logging.Electromagnetic induction was used to harvest energy,and experiments were conducted at room temperature(25℃)with controlled variables like speed and friction.Results showed the disk-shaped body exhibited higher energy efficiency than the cylinder-shaped body,largely due to lower mechanical losses.The disk required only two bearings,while the cylinder required four,resulting in lower bearing losses for the disk.Additionally,the disk experienced only air friction,whereas the cylinder encountered friction from a soft,uneven rubber material,increasing surface contact losses.Under a 40 W resistive load,the disk demonstrated a 17.1%energy loss due to mechanical friction,achieving up to 15.55 J of recycled energy.Conversely,the cylinder body experienced a 48.05%energy loss,delivering only 51.95%of energy to the load.These insights suggest significant potential for designing efficient energy recycling systems in industrial settings,particularly in manufacturing and processing industries where rotational machinery is prevalent.Despite its lower energy density,this system could be beneficially integrated with energy storage solutions,enhancing sustainability in industrial practices.展开更多
High temperature piezoelectric energy harvester(HTPEH)is an important solution to replace chemical battery to achieve independent power supply of HT wireless sensors.However,simultaneously excellent performances,inclu...High temperature piezoelectric energy harvester(HTPEH)is an important solution to replace chemical battery to achieve independent power supply of HT wireless sensors.However,simultaneously excellent performances,including high figure of merit(FOM),insulation resistivity(ρ)and depolarization temperature(Td)are indispensable but hard to achieve in lead-free piezoceramics,especially operating at 250°C has not been reported before.Herein,well-balanced performances are achieved in BiFeO3–BaTiO3 ceramics via innovative defect engineering with respect to delicate manganese doping.Due to the synergistic effect of enhancing electrostrictive coefficient by polarization configuration optimization,regulating iron ion oxidation state by high valence manganese ion and stabilizing domain orientation by defect dipole,comprehensive excellent electrical performances(Td=340°C,ρ250°C>10^(7)Ωcm and FOM_(250°C)=4905×10^(–15)m^(2)N^(−1))are realized at the solid solubility limit of manganese ions.The HT-PEHs assembled using the rationally designed piezoceramic can allow for fast charging of commercial electrolytic capacitor at 250°C with high energy conversion efficiency(η=11.43%).These characteristics demonstrate that defect engineering tailored BF-BT can satisfy high-end HT-PEHs requirements,paving a new way in developing selfpowered wireless sensors working in HT environments.展开更多
Herein,we report a simple self-charging hybrid power system(SCHPS)based on binder-free zinc copper selenide nanostructures(ZnCuSe_(2) NSs)deposited carbon fabric(CF)(i.e.,ZnCuSe_(2)/CF),which is used as an active mate...Herein,we report a simple self-charging hybrid power system(SCHPS)based on binder-free zinc copper selenide nanostructures(ZnCuSe_(2) NSs)deposited carbon fabric(CF)(i.e.,ZnCuSe_(2)/CF),which is used as an active material in the fabrication of supercapacitor(SC)and triboelectric nanogenerator(TENG).At first,a binder-free ZnCuSe_(2)/CF was synthesized via a simple and facial hydrothermal synthesis approach,and the electrochemical properties of the obtained ZnCuSe_(2)/CF were evaluated by fabricating a symmetric quasi-solid-state SC(SQSSC).The ZCS-2(Zn:Cu ratio of 2:1)material deposited CF-based SQSSC exhibited good electrochemical properties,and the obtained maximum energy and power densities were 7.5 Wh kg^(-1)and 683.3 W kg^(-1),respectively with 97.6%capacitance retention after 30,000 cycles.Furthermore,the ZnCuSe_(2)/CF was coated with silicone rubber elastomer using a doctor blade technique,which is used as a negative triboelectric material in the fabrication of the multiple TENG(M-TENG).The fabricated M-TENG exhibited excellent electrical output performance,and the robustness and mechanical stability of the device were studied systematically.The practicality and applicability of the proposed M-TENG and SQSSC were systematically investigated by powering various low-power portable electronic components.Finally,the SQSSC was combined with the M-TENG to construct a SCHPS.The fabricated SCHPS provides a feasible solution for sustainable power supply,and it shows great potential in self-powered portable electronic device applications.展开更多
To further understand the performance of the energy harvesters under the influence of the wind force and the random excitation,this paper investigates the stochastic response of the bio-inspired energy harvesters subj...To further understand the performance of the energy harvesters under the influence of the wind force and the random excitation,this paper investigates the stochastic response of the bio-inspired energy harvesters subjected to Gaussian white noise and galloping excitation,simulating the flapping pattern of a seagull and its interaction with wind force.The equivalent linearization method is utilized to convert the original nonlinear model into the Itôstochastic differential equation by minimizing the mean squared error.Then,the second-order steady-state moments about the displacement,velocity,and voltage are derived by combining the moment analysis theory.The theoretical results are simulated numerically to analyze the stochastic response performance under different noise intensities,wind speeds,stiffness coefficients,and electromechanical coupling coefficients,time domain analysis is also conducted to study the performance of the harvester with different parameters.The results reveal that the mean square displacement and voltage increase with increasing the noise intensity and wind speed,larger absolute values of stiffness coefficient correspond to smaller mean square displacement and voltage,and larger electromechanical coupling coefficients can enhance the mean square voltage.Finally,the influence of wind speed and electromechanical coupling coefficient on the stationary probability density function(SPDF)is investigated,revealing the existence of a bimodal distribution under varying environmental conditions.展开更多
Piezoelectric transduction technology enables the direct conversion between mechanical and electrical energy,finding extensive applications in sensing,acoustics,imaging,actuation,and energy harvesting[1].Previous stud...Piezoelectric transduction technology enables the direct conversion between mechanical and electrical energy,finding extensive applications in sensing,acoustics,imaging,actuation,and energy harvesting[1].Previous studies on piezoelectric materials have primarily focused on ceramics or single-crystal materials characterized by wide band gaps(E_(g)>2.0 e V[2])and low electrical conductivity.In contrast,narrow-bandgap(E_(g)<0.5 eV[3])semiconductor materials typically exhibit high electrical conductivity,which is unfavorable for the effective accumulation of charges required to establish a stable voltage response.Consequently,experimental investigations into the piezoelectric effect of narrow-bandgap semiconductors are scarce.展开更多
This study focuses on wave energy harvesting by leveraging the impact-induced frequency of sea waves.It introduces a novel double-buoyed model based on the existing single-buoyed system to address the shortcomings of ...This study focuses on wave energy harvesting by leveraging the impact-induced frequency of sea waves.It introduces a novel double-buoyed model based on the existing single-buoyed system to address the shortcomings of previous systems.Notably,the traditional single-buoyed system,which is characterized by a long beam extending to the sea floor,proves impractical in deep-sea environments,especially in distant offshore regions.The proposed double-buoyed model replaces the long beam with a second buoy to increase energy harvesting efficiency.A parametric analysis that included the density and height of the first buoy and wave period was conducted to enhance the proposed model further.Results indicated that with the selection of optimal parameters,the power output of the double-buoyed system increased by approximately 13-fold,thereby enhancing the viability and efficiency of wave energy harvesting.展开更多
Smart actuators and wearable and implantable devices have attracted much attention in healthcare and environmental sensing.Flexible electronic and ionic materials are the two main approaches used to construct these de...Smart actuators and wearable and implantable devices have attracted much attention in healthcare and environmental sensing.Flexible electronic and ionic materials are the two main approaches used to construct these devices.Among them,hydrogel-based ionic materials offer unique advantages,such as biocompatibility and adaptable mechanical properties.However,ionic hydrogels encounter challenges in achieving wirelessly powered and noncontact sensing.To address this,we introduce MXene nanosheets to construct ionotronic hydrogels.Leveraging the rich surface charges and electronic conductivity of MXene nanosheets,ionotronic hydrogels can harvest vibrational and electromagnetic waves as electrical energy and enable noncontact sensing.Under ultrasound,it can continuously generate voltages up to 85 V and light up lightemitting diodes,promising wireless charging of implanted devices.In addition,it achieves an absorption coefficient of 0.2 for 915 MHz electromagnetic waves,enabling noncontact sensing through radio frequency identification.Notably,the physically crosslinked network of the MXenebased hydrogels maintained structural and performance stability under ultrasonic stimulation and exhibited self-healing properties.Even when cut into two halves,the self-healing hydrogel fully regenerates its original performance.This study provides insight into the development of ionotronic hydrogels for wirelessly powered and noncontact sensing in smart actuators and wearable and implantable applications.展开更多
The shortage of freshwater has become a global challenge,exacerbated by global warming and the rapid growth of the world’s population.Researchers across various fields have made numerous attempts to efficiently colle...The shortage of freshwater has become a global challenge,exacerbated by global warming and the rapid growth of the world’s population.Researchers across various fields have made numerous attempts to efficiently collect freshwater for human use.These efforts include seawater desalination through reverse osmosis or distillation,sewage treatment technologies,and atmospheric water harvesting.However,after thoroughly exploring traditional freshwater harvesting methods,it has become clear that bio-inspired fog harvesting technology offers new prospects due to its unique advantages of efficiency and sustainability.This paper systematically introduces the current principles of fog harvesting and wettability mechanism found in nature.It reviews the research status of combining bionic fog harvesting materials with textile science from two distinct dimensions.Additionally,it describes the practical applications of fog harvesting materials in agriculture,industry,and domestic water use,analyzes their prospects and feasibility in engineering projects,discusses potential challenges in practical applications,and envisions future trends and directions for the development of these materials.展开更多
Unmanned Aerial Vehicles(UAVs)have been considered to have great potential in supporting reliable and timely data harvesting for Sensor Nodes(SNs)from an Internet of Things(IoT)perspective.However,due to physical limi...Unmanned Aerial Vehicles(UAVs)have been considered to have great potential in supporting reliable and timely data harvesting for Sensor Nodes(SNs)from an Internet of Things(IoT)perspective.However,due to physical limitations,UAVs are unable to further process the harvested data and have to rely on terrestrial servers,thus extra spectrum resource is needed to convey the harvested data.To avoid the cost of extra servers and spectrum resources,in this paper,we consider a UAV-based data harvesting network supported by a Cell-Free massive Multiple-Input-Multiple-Output(CF-mMIMO)system,where a UAV is used to collect and transmit data from SNs to the central processing unit of CF-mMIMO system for processing.In order to avoid using additional spectrum resources,the entire bandwidth is shared among radio access networks and wireless fronthaul links.Moreover,considering the limited capacity of the fronthaul links,the compress-and-forward scheme is adopted.In this work,in order to maximize the ergodically achievable sum rate of SNs,the power allocation of ground access points,the compression of fronthaul links,and also the bandwidth fraction between radio access networks and wireless fronthaul links are jointly optimized.To avoid the high overhead introduced by computing ergodically achievable rates,we introduce an approximate problem,using the large-dimensional random matrix theory,which relies only on statistical channel state information.We solve the nontrivial problem in three steps and propose an algorithm based on weighted minimum mean square error and Dinkelbach’s methods to find solutions.Finally,simulation results show that the proposed algorithm converges quickly and outperforms the baseline algorithms.展开更多
文摘Sweet sorghum has become an important feedstock for bioethanol production. Total sugar yield and multiple harvests can directly affect ethanol production cost. Little is known about stem traits and multiple harvests that contribute to sugar yield in sweet sorghum. Stem traits were evaluated from 25 sweet and grain sorghum accessions. Stems were harvested twice at the soft-dough stage and the stems were pressed with a hydraulic press. Sugars in the stem juice were quantified by high performance liquid chromatography. Sweet sorghum produced five times more fresh stem weight and dry stem mass (830 gand164 g) than grain sorghum (150 gand27g). Sweet sorghum produced a much higher volume of juice and higher yield of sugars (366 ml and42 g) per stem than grain sorghum (70 ml and4 g). Significant variability in fresh stem weight (72 - 1837 g), juice volume (31 - 753 ml), sugar yield (3 - 81 g), dry stem mass (14 - 383 g), and sugar yield/dry stem mass ratio (0.11 - 0.53) per stem was detected among sweet sorghum accessions. Stem sugar yield was significantly correlated with stem fresh weight and juice volume. Sorghum was harvested twice within one growing season resulting in some sweet sorghum accessions producing double amount of sugars. Sweet sorghum produced three times more dry mass weight (bagasse) than fermentable sugar weight. To reduce feedstock cost, methods have to be developed for efficiently utilizing bagasse. Our results showed high fresh stem weight, high ratio of sugar yield to dry stem mass, and double harvests are prime traits to boost sugar yield. Sweet sorghum may be suitable for multiple harvests in certain regions of theU.S.TheU.S.sweet sorghum collection needs to be screened for acces- sions that can be harvested twice with an extended feedstock-production season and used as a feedstock for sustainable and renewable bioenergy production.
基金supported by the Major State Basic Research Development Program of China (Grant No. 2010CB950103)the National Natural Science Foundation of China (Grant No. 41371201)the Strategic Project of Science and Technology of the Chinese Academy of Sciences (Grant No. XDA05080102)
文摘Because of the complexity of social responses to climate change,as well as limitations of proxy data concerning interactions between climate change and human responses,the social impacts of past climate change and associated response mechanisms,thus,require further investigation.To shed light on the transmission of climate change impacts within historical Chinese society,we selected 30-year resolution sequences of temperature anomalies in eastern China and 10-year resolution sequences of grain harvest grades,famine indices,and frequencies of peasant uprisings in China over the past 2000 years.Using a food security perspective,we analyzed the impacts of temperature changes historically transmitted through Chinese production,population,and social subsystems,and differences in transmission characteristics between cold and warm units.Our results were as follows.(1)From 210 BC to 1910 AD,temperature changes in China were significantly positively correlated with grain harvest grades(correlation coefficient,0.338),and significantly negatively correlated with famine indices,and frequencies of peasant uprisings(correlation coefficients,-0.301 and-0.277,respectively).The correlation coefficients between famine indices and grain harvest grades or frequencies of peasant uprisings were very low.(2)There was a higher proportion of bumper or normal harvests(86.5%of the total decades),more moderate and mild famines(76%),and a lower proportion of peasant uprisings(33.3%)in the 30-year warm units.Conversely,there was a higher proportion of poor or normal harvests(70.7%),a greater proportion of moderate and severe famines(77.6%),and more peasant uprisings(51.7%)in the 30-year cold units.(3)Of the 23 main transmission pathways extending from temperature change to the social subsystem,13 occurred in cold units,of which 7 had an endpoint of peasant uprisings,and 10 occurred in warm units of which 3 had an endpoint of peasant uprisings.The main transmission pathways that were more likely to be associated with the impacts of temperature change were:Cold→poor harvests→severe famines→more uprisings;cold→poor harvests→moderate famines→more uprisings;warm→bumper harvests→mild famines→no uprisings;warm→bumper harvests→moderate harvests→no uprisings;warm→normal harvests→mild famines→no uprisings;and warm→normal harvests→moderate famines→no uprisings.(4)The transmission of the impacts of temperature change was a complex process.Within this process,famine was most prone to being modulated by human society.In the transmission pathways from the production to the social subsystem,there was a stepwise decrease in the occurrence rate of decades that were probably affected by climate change.In all cold units,10.4%of decades ending in more uprisings were most likely to be associated with the impacts of temperature change.In all warm units,47.9%of decades ending in no uprisings were most likely to be associated with the impacts of temperature change.This research can contribute a better understanding on the past interaction mechanisms and processes within the human-climate-ecosystem complex,as well as a better response to the impacts of the ongoing climate change.
文摘Knee osteoarthritis(OA)is a debilitating condition with limited long-term treatment options.The therapeutic potential of mesenchymal stem cells(MSCs),particularly those derived from bone marrow aspirate concentrate,has garnered attention for cartilage repair in OA.While the iliac crest is the traditional site for bone marrow harvesting(BMH),associated morbidity has prompted the exploration of alternative sites such as the proximal tibia,distal femur,and proximal humerus.This paper reviews the impact of different harvesting sites on mesenchymal stem cell(MSC)yield,viability,and regenerative potential,emphasizing their relevance in knee OA treatment.The iliac crest consistently offers the highest MSC yield,but alternative sites within the surgical field of knee procedures offer comparable MSC characteristics with reduced morbidity.The integration of harvesting techniques into existing knee surgeries,such as total knee arthroplasty,provides a less invasive approach while maintaining thera-peutic efficacy.However,variability in MSC yield from these alternative sites underscores the need for further research to standardize techniques and optimize clinical outcomes.Future directions include large-scale comparative studies,advanced characterization of MSCs,and the development of personalized harvesting strategies.Ultimately,the findings suggest that optimizing the site of BMH can significantly influence the quality of MSC-based therapies for knee OA,enhancing their clinical utility and patient outcomes.
基金supported by the Research Platform for biomedical and Health Technology, NUS (Suzhou) Research Institute (RP-BHT-Prof. LEE Chengkuo)RIE Advanced Manufacturing and Engineering (AME) Programmatic Grant (Grant A18A4b0055)+1 种基金RIE 2025-Industry Alignment Fund – Industry Collaboration Projects (IAF-ICP) (Grant I2301E0027)Reimagine Research Scheme projects, National University of Singapore, A-0009037-03-00 and A-0009454-01-00 and Reimagine Research Scheme projects, National University of Singapore, A-0004772-00-00 and A-0004772-01-00。
文摘Smart farming with outdoor monitoring systems is critical to address food shortages and sustainability challenges.These systems facilitate informed decisions that enhance efficiency in broader environmental management.Existing outdoor systems equipped with energy harvesters and self-powered sensors often struggle with fluctuating energy sources,low durability under harsh conditions,non-transparent or non-biocompatible materials,and complex structures.Herein,a multifunctional hydrogel is developed,which can fulfill all the above requirements and build selfsustainable outdoor monitoring systems solely by it.It can serve as a stable energy harvester that continuously generates direct current output with an average power density of 1.9 W m^(-3)for nearly 60 days of operation in normal environments(24℃,60%RH),with an energy density of around 1.36×10^(7)J m^(-3).It also shows good self-recoverability in severe environments(45℃,30%RH)in nearly 40 days of continuous operation.Moreover,this hydrogel enables noninvasive and self-powered monitoring of leaf relative water content,providing critical data on evaluating plant health,previously obtainable only through invasive or high-power consumption methods.Its potential extends to acting as other self-powered environmental sensors.This multifunctional hydrogel enables self-sustainable outdoor systems with scalable and low-cost production,paving the way for future agriculture.
基金supported by the National Key R&D Program of China under Grant 2024YFE0203500Xiaomi Young Talents Program。
文摘In the applications such as food production,the environmental temperature should be measured continuously dur-ing the entire process,which requires an ultra-low-power temperature sensor for long-termly monitoring.Conventional tempera-ture sensors trade the measurement accuracy with power consumption.In this work,we present a battery-free wireless tempera-ture sensing chip for long-termly monitoring during food production.A calibrated oscillator-based CMOS temperature sensor is proposed instead of the ADC-based power-hungry circuits in conventional works.In addition,the sensor chip can harvest the power transferred by a remote reader to eliminate the use of battery.Meanwhile,the system conducts wireless bidirectional communication between the sensor chip and reader.In this way,the temperature sensor can realize both a high precision and battery-free operation.The temperature sensing chip is fabricated in 55 nm CMOS process,and the reader chip is imple-mented in 65 nm CMOS technology.Experimental results show that the temperature measurement error achieves±1.6℃ from 25 to 50℃,with battery-free readout by a remote reader.
基金supported by the National Natural Science Foundation Project of China(No.52201056)the funding of postdoctoral researchers in Anhui Province(No.2022B613)the College Excellent Young Foundation of Anhui Province(No.2023AH030029).
文摘The significance of water energy harvesting in the context of renewable energy utilization is steadily increasing.In response to the need for more efficient utilization of water resources,the nascent technology of liquid-solid triboelectric nanogenerators(TENGs)has emerged as a prospective candidate for the harvesting of water energy.Liquid-solid TENGs show several distinct advantages,including their lightweight,low cost,and efficient energy harvesting capabilities.Herein,this review presents a comprehensive exposition of the latest advancements in the field of liquid-solid TENGs.It delves into the underlying principles and different operational modes while also addressing the factors influencing its output performance from a multifaceted perspective.The factors comprise the intrinsic properties of friction materials,the chemical properties of the liquid,and the ambient temperature of liquid-solid TENGs.Furthermore,this review delineates the applications of liquid-solid TENGs as self-powered sensors in physics,chemistry,and biomedical contexts,as well as their applications in various other fields such as corrosion resistance,and so on.Last but not least,it concludes by providing a forward-looking on the future developmental trends of liquid-solid TENGs.
基金supported by the research projects AP23486880 from the Ministry of Higher EducationScience of the Republic of Kazakhstan and 111024CRP2010,20122022FD4135 from Nazarbayev University.
文摘Recycling plastic waste into triboelectric nanogenerators(TENGs)presents a sustainable approach to energy harvesting,self-powered sensing,and environmental remediation.This study investigates the recycling of polyvinyl chloride(PVC)pipe waste polymers into nanofibers(NFs)optimized for TENG applications.We focused on optimizing the morphology of recycled PVC polymer to NFs and enhancing their piezoelectric properties by incorporating ZnO nanoparticles(NPs).The optimized PVC/0.5 wt%ZnO NFs were tested with Nylon-6 NFs,and copper(Cu)electrodes.The Nylon-6 NFs exhibited a power density of 726.3μWcm^(-2)—1.13 times higher than Cu and maintained 90%stability after 172800 cycles,successfully powering various colored LEDs.Additionally,a 3D-designed device was developed to harvest energy from biomechanical movements such as finger tapping,hand tapping,and foot pressing,making it suitable for wearable energy harvesting,automatic switches,and invisible sensors in surveillance systems.This study demonstrates that recycling polymers for TENG devices can effectively address energy,sensor,and environmental challenges.
基金supported in part by the National Natural Science Foundation of China under Grant No.61473066in part by the Natural Science Foundation of Hebei Province under Grant No.F2021501020+2 种基金in part by the S&T Program of Qinhuangdao under Grant No.202401A195in part by the Science Research Project of Hebei Education Department under Grant No.QN2025008in part by the Innovation Capability Improvement Plan Project of Hebei Province under Grant No.22567637H
文摘Recently,one of the main challenges facing the smart grid is insufficient computing resources and intermittent energy supply for various distributed components(such as monitoring systems for renewable energy power stations).To solve the problem,we propose an energy harvesting based task scheduling and resource management framework to provide robust and low-cost edge computing services for smart grid.First,we formulate an energy consumption minimization problem with regard to task offloading,time switching,and resource allocation for mobile devices,which can be decoupled and transformed into a typical knapsack problem.Then,solutions are derived by two different algorithms.Furthermore,we deploy renewable energy and energy storage units at edge servers to tackle intermittency and instability problems.Finally,we design an energy management algorithm based on sampling average approximation for edge computing servers to derive the optimal charging/discharging strategies,number of energy storage units,and renewable energy utilization.The simulation results show the efficiency and superiority of our proposed framework.
基金supported by the National Natural Science Foundation of China(No.21975107)the China Scholarship Council(No.202206790046).
文摘Wearable thermoelectric devices hold significant promise in the realm of self-powered wearable electron-ics,offering applications in energy harvesting,movement tracking,and health monitoring.Nevertheless,developing thermoelectric devices with exceptional flexibility,enduring thermoelectric stability,multi-functional sensing,and comfortable wear remains a challenge.In this work,a stretchable MXene-based thermoelectric fabric is designed to accurately discern temperature and strain stimuli.This is achieved by constructing an adhesive polydopamine(PDA)layer on the nylon fabric surface,which facilitates the subsequent MXene attachment through hydrogen bonding.This fusion results in MXene-based thermo-electric fabric that excels in both temperature sensing and strain sensing.The resultant MXene-based thermoelectric fabric exhibits outstanding temperature detection capability and cyclic stability,while also delivering excellent sensitivity,rapid responsiveness(60 ms),and remarkable durability in strain sens-ing(3200 cycles).Moreover,when affixed to a mask,this MXene-based thermoelectric fabric utilizes the temperature difference between the body and the environment to harness body heat,converting it into electrical energy and accurately discerning the body’s respiratory rate.In addition,the MXene-based ther-moelectric fabric can monitor the state of the body’s joint through its own deformation.Furthermore,it possesses the capability to convert solar energy into heat.These findings indicate that MXene-based ther-moelectric fabric holds great promise for applications in power generation,motion tracking,and health monitoring.
基金supported by the National Natural Science Foundation of China(No.52373280,52177014,51977009,52273257)。
文摘Polymeric microwave actuators combining tissue-like softness with programmablemicrowave-responsive deformation hold great promise for mobile intelligentdevices and bionic soft robots. However, their application is challenged by restricted electromagneticsensitivity and intricate sensing coupling. In this study, a sensitized polymericmicrowave actuator is fabricated by hybridizing a liquid crystal polymer with Ti3C2Tx(MXene). Compared to the initial counterpart, the hybrid polymer exhibits unique spacechargepolarization and interfacial polarization, resulting in significant improvements of230% in the dielectric loss factor and 830% in the apparent efficiency of electromagneticenergy harvest. The sensitized microwave actuation demonstrates as the shortenedresponse time of nearly 10 s, which is merely 13% of that for the initial shape memory polymer. Moreover, the ultra-low content of MXene (upto 0.15 wt%) benefits for maintaining the actuation potential of the hybrid polymer. An innovative self-powered sensing prototype that combinesdriving and piezoelectric polymers is developed, which generates real-time electric potential feedback (open-circuit potential of ~ 3 mV) duringactuation. The polarization-dominant energy conversion mechanism observed in the MXene-polymer hybrid structure furnishes a new approachfor developing efficient electromagnetic dissipative structures and shows potential for advancing polymeric electromagnetic intelligent devices.
基金The APC was funded by Research Management Center, Multimedia University, Malaysia.
文摘Electrical energy can be harvested from the rotational kinetic energy of moving bodies,consisting of both mechanical and kinetic energy as a potential power source through electromagnetic induction,similar to wind energy applications.In industries,rotational bodies are commonly present in operations,yet this kinetic energy remains untapped.This research explores the energy generation characteristics of two rotational body types,disk-shaped and cylinder-shaped under specific experimental setups.The hardware setup included a direct current(DC)motor driver,power supply,DC generator,mechanical support,and load resistance,while the software setup involved automation testing tools and data logging.Electromagnetic induction was used to harvest energy,and experiments were conducted at room temperature(25℃)with controlled variables like speed and friction.Results showed the disk-shaped body exhibited higher energy efficiency than the cylinder-shaped body,largely due to lower mechanical losses.The disk required only two bearings,while the cylinder required four,resulting in lower bearing losses for the disk.Additionally,the disk experienced only air friction,whereas the cylinder encountered friction from a soft,uneven rubber material,increasing surface contact losses.Under a 40 W resistive load,the disk demonstrated a 17.1%energy loss due to mechanical friction,achieving up to 15.55 J of recycled energy.Conversely,the cylinder body experienced a 48.05%energy loss,delivering only 51.95%of energy to the load.These insights suggest significant potential for designing efficient energy recycling systems in industrial settings,particularly in manufacturing and processing industries where rotational machinery is prevalent.Despite its lower energy density,this system could be beneficially integrated with energy storage solutions,enhancing sustainability in industrial practices.
基金supported by the National Natural Science Foundation of China(Grant Nos.52272103 and 52072010)Beijing Natural Science Foundation(Grant Nos.2242029 and JL23004).
文摘High temperature piezoelectric energy harvester(HTPEH)is an important solution to replace chemical battery to achieve independent power supply of HT wireless sensors.However,simultaneously excellent performances,including high figure of merit(FOM),insulation resistivity(ρ)and depolarization temperature(Td)are indispensable but hard to achieve in lead-free piezoceramics,especially operating at 250°C has not been reported before.Herein,well-balanced performances are achieved in BiFeO3–BaTiO3 ceramics via innovative defect engineering with respect to delicate manganese doping.Due to the synergistic effect of enhancing electrostrictive coefficient by polarization configuration optimization,regulating iron ion oxidation state by high valence manganese ion and stabilizing domain orientation by defect dipole,comprehensive excellent electrical performances(Td=340°C,ρ250°C>10^(7)Ωcm and FOM_(250°C)=4905×10^(–15)m^(2)N^(−1))are realized at the solid solubility limit of manganese ions.The HT-PEHs assembled using the rationally designed piezoceramic can allow for fast charging of commercial electrolytic capacitor at 250°C with high energy conversion efficiency(η=11.43%).These characteristics demonstrate that defect engineering tailored BF-BT can satisfy high-end HT-PEHs requirements,paving a new way in developing selfpowered wireless sensors working in HT environments.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIP)(No.2018R1A6A1A03025708)partly supported by the GRRC program of Gyeonggi province(GRRCKyungHee2023-B03).
文摘Herein,we report a simple self-charging hybrid power system(SCHPS)based on binder-free zinc copper selenide nanostructures(ZnCuSe_(2) NSs)deposited carbon fabric(CF)(i.e.,ZnCuSe_(2)/CF),which is used as an active material in the fabrication of supercapacitor(SC)and triboelectric nanogenerator(TENG).At first,a binder-free ZnCuSe_(2)/CF was synthesized via a simple and facial hydrothermal synthesis approach,and the electrochemical properties of the obtained ZnCuSe_(2)/CF were evaluated by fabricating a symmetric quasi-solid-state SC(SQSSC).The ZCS-2(Zn:Cu ratio of 2:1)material deposited CF-based SQSSC exhibited good electrochemical properties,and the obtained maximum energy and power densities were 7.5 Wh kg^(-1)and 683.3 W kg^(-1),respectively with 97.6%capacitance retention after 30,000 cycles.Furthermore,the ZnCuSe_(2)/CF was coated with silicone rubber elastomer using a doctor blade technique,which is used as a negative triboelectric material in the fabrication of the multiple TENG(M-TENG).The fabricated M-TENG exhibited excellent electrical output performance,and the robustness and mechanical stability of the device were studied systematically.The practicality and applicability of the proposed M-TENG and SQSSC were systematically investigated by powering various low-power portable electronic components.Finally,the SQSSC was combined with the M-TENG to construct a SCHPS.The fabricated SCHPS provides a feasible solution for sustainable power supply,and it shows great potential in self-powered portable electronic device applications.
文摘To further understand the performance of the energy harvesters under the influence of the wind force and the random excitation,this paper investigates the stochastic response of the bio-inspired energy harvesters subjected to Gaussian white noise and galloping excitation,simulating the flapping pattern of a seagull and its interaction with wind force.The equivalent linearization method is utilized to convert the original nonlinear model into the Itôstochastic differential equation by minimizing the mean squared error.Then,the second-order steady-state moments about the displacement,velocity,and voltage are derived by combining the moment analysis theory.The theoretical results are simulated numerically to analyze the stochastic response performance under different noise intensities,wind speeds,stiffness coefficients,and electromechanical coupling coefficients,time domain analysis is also conducted to study the performance of the harvester with different parameters.The results reveal that the mean square displacement and voltage increase with increasing the noise intensity and wind speed,larger absolute values of stiffness coefficient correspond to smaller mean square displacement and voltage,and larger electromechanical coupling coefficients can enhance the mean square voltage.Finally,the influence of wind speed and electromechanical coupling coefficient on the stationary probability density function(SPDF)is investigated,revealing the existence of a bimodal distribution under varying environmental conditions.
文摘Piezoelectric transduction technology enables the direct conversion between mechanical and electrical energy,finding extensive applications in sensing,acoustics,imaging,actuation,and energy harvesting[1].Previous studies on piezoelectric materials have primarily focused on ceramics or single-crystal materials characterized by wide band gaps(E_(g)>2.0 e V[2])and low electrical conductivity.In contrast,narrow-bandgap(E_(g)<0.5 eV[3])semiconductor materials typically exhibit high electrical conductivity,which is unfavorable for the effective accumulation of charges required to establish a stable voltage response.Consequently,experimental investigations into the piezoelectric effect of narrow-bandgap semiconductors are scarce.
文摘This study focuses on wave energy harvesting by leveraging the impact-induced frequency of sea waves.It introduces a novel double-buoyed model based on the existing single-buoyed system to address the shortcomings of previous systems.Notably,the traditional single-buoyed system,which is characterized by a long beam extending to the sea floor,proves impractical in deep-sea environments,especially in distant offshore regions.The proposed double-buoyed model replaces the long beam with a second buoy to increase energy harvesting efficiency.A parametric analysis that included the density and height of the first buoy and wave period was conducted to enhance the proposed model further.Results indicated that with the selection of optimal parameters,the power output of the double-buoyed system increased by approximately 13-fold,thereby enhancing the viability and efficiency of wave energy harvesting.
基金financially supported by the National Natural Science Foundation of China(No.22305033 received by Z.Y.L.,No.52161135102 received by P.Y.W.)the Fundamental Research Funds for the Central Universities(No.2232024A-05 received by Z.Y.L.)。
文摘Smart actuators and wearable and implantable devices have attracted much attention in healthcare and environmental sensing.Flexible electronic and ionic materials are the two main approaches used to construct these devices.Among them,hydrogel-based ionic materials offer unique advantages,such as biocompatibility and adaptable mechanical properties.However,ionic hydrogels encounter challenges in achieving wirelessly powered and noncontact sensing.To address this,we introduce MXene nanosheets to construct ionotronic hydrogels.Leveraging the rich surface charges and electronic conductivity of MXene nanosheets,ionotronic hydrogels can harvest vibrational and electromagnetic waves as electrical energy and enable noncontact sensing.Under ultrasound,it can continuously generate voltages up to 85 V and light up lightemitting diodes,promising wireless charging of implanted devices.In addition,it achieves an absorption coefficient of 0.2 for 915 MHz electromagnetic waves,enabling noncontact sensing through radio frequency identification.Notably,the physically crosslinked network of the MXenebased hydrogels maintained structural and performance stability under ultrasonic stimulation and exhibited self-healing properties.Even when cut into two halves,the self-healing hydrogel fully regenerates its original performance.This study provides insight into the development of ionotronic hydrogels for wirelessly powered and noncontact sensing in smart actuators and wearable and implantable applications.
基金Shandong Provincial Key Research and Development Program(Major Scientific and Technological Innovation Project)(2021CXGC011001)Huafon Microfibre(Jiangsu)Co.Ltd.(2021120011000234)+1 种基金Textile Vision Basic Research Program(J202306)China Postdoctoral Science Foundation(No.2023M732103).
文摘The shortage of freshwater has become a global challenge,exacerbated by global warming and the rapid growth of the world’s population.Researchers across various fields have made numerous attempts to efficiently collect freshwater for human use.These efforts include seawater desalination through reverse osmosis or distillation,sewage treatment technologies,and atmospheric water harvesting.However,after thoroughly exploring traditional freshwater harvesting methods,it has become clear that bio-inspired fog harvesting technology offers new prospects due to its unique advantages of efficiency and sustainability.This paper systematically introduces the current principles of fog harvesting and wettability mechanism found in nature.It reviews the research status of combining bionic fog harvesting materials with textile science from two distinct dimensions.Additionally,it describes the practical applications of fog harvesting materials in agriculture,industry,and domestic water use,analyzes their prospects and feasibility in engineering projects,discusses potential challenges in practical applications,and envisions future trends and directions for the development of these materials.
基金supported in part by the Jiangsu Provincial Key Research and Development Program(No.BE2022068-2)in part by the National Natural Science Foundation of China under Grant 62201285+1 种基金in part by Young Elite Scientists Sponsorship Program by CAST under Grant 2022QNRC001in part by the Postgraduate Research&Practice Innovation Program of Jiangsu Province under Grant KYCX23_1012.
文摘Unmanned Aerial Vehicles(UAVs)have been considered to have great potential in supporting reliable and timely data harvesting for Sensor Nodes(SNs)from an Internet of Things(IoT)perspective.However,due to physical limitations,UAVs are unable to further process the harvested data and have to rely on terrestrial servers,thus extra spectrum resource is needed to convey the harvested data.To avoid the cost of extra servers and spectrum resources,in this paper,we consider a UAV-based data harvesting network supported by a Cell-Free massive Multiple-Input-Multiple-Output(CF-mMIMO)system,where a UAV is used to collect and transmit data from SNs to the central processing unit of CF-mMIMO system for processing.In order to avoid using additional spectrum resources,the entire bandwidth is shared among radio access networks and wireless fronthaul links.Moreover,considering the limited capacity of the fronthaul links,the compress-and-forward scheme is adopted.In this work,in order to maximize the ergodically achievable sum rate of SNs,the power allocation of ground access points,the compression of fronthaul links,and also the bandwidth fraction between radio access networks and wireless fronthaul links are jointly optimized.To avoid the high overhead introduced by computing ergodically achievable rates,we introduce an approximate problem,using the large-dimensional random matrix theory,which relies only on statistical channel state information.We solve the nontrivial problem in three steps and propose an algorithm based on weighted minimum mean square error and Dinkelbach’s methods to find solutions.Finally,simulation results show that the proposed algorithm converges quickly and outperforms the baseline algorithms.
