To achieve an unmanned rice farm,in this study,a cotransporter system was developed using a tracked rice harvester and transporter for autonomous harvesting,unloading,and transportation.Additionally,two unloading and ...To achieve an unmanned rice farm,in this study,a cotransporter system was developed using a tracked rice harvester and transporter for autonomous harvesting,unloading,and transportation.Additionally,two unloading and transportation modes—harvester waiting for unloading(HWU)and transporter fol-lowing for unloading(TFU)—were proposed,and a harvesting-unloading-transportation(HUT)strategy was defined.By breaking down the main stages of the collaborative operation,designing module-state machines(MSMs),and constructing state-transition chains,a HUT collaborative operation logic frame-work suitable for the embedded navigation controller was designed using the concept and method of the finite-state machine(FSM).This method addresses the multiple-stage,nonsequential,and complex processes in HUT collaborative operations.Simulations and field-harvesting experiments were performed to evaluate the applicability of this proposed strategy and system.The experimental results showed that the HUT collaborative operation strategy effectively integrated path planning,path-tracking control,inter-vehicle communication,collaborative operation control,and implementation control.The cotrans-porter system completed the entire process of harvesting,unloading,and transportation.The field-harvesting experiment revealed that a harvest efficiency of 0.42 hm^(2)·h^(−1) was achieved.This study can provide insight into collaborative harvesting and solutions for the harvesting process of unmanned farms.展开更多
Lithium metal is considered as the most promising anode material for the next generation of secondary batteries due to its high theoretical specific capacity and low potential.However,undesirable parasitic reactions,p...Lithium metal is considered as the most promising anode material for the next generation of secondary batteries due to its high theoretical specific capacity and low potential.However,undesirable parasitic reactions,poor cycling stability and safety concerns could be caused by uncontrolled dendrite and high reactivity of Li metal,which hinder the practical application of Li-metal anode in high-energy rechargeable Li metal batteries(LMBs).Here,a facile way is reported to stabilize Li metal anode by building high lithiophilic Mg-Li-Cu alloy.Due to the delocalization of electrons on the deposited lithium enhanced by Cu self-diffusion into Mg-Li alloy,the growth of lithium dendrites could be inhibited by Mg-Li-Cu alloy.Moreover,the parasitic reactions with electrolyte could be avoided by the Mg-Li-Cu alloy anode.It is noteworthy that the symmetric battery life of Mg-Li-Cu alloy electrodes exceeds 9000 h at 1 m A cm^(-2)and 1 m Ah cm^(-2).The full cell(LiFePO_(4)|Mg-Li-Cu)exhibits a specific capacity of 148.2 m Ah g^(-1),with a capacity retention of 96.4%,at 1 C after 500 cycles.This work not only pave the way for application of flexible alloy anode in highly stable LMBs,but also provides novel strategies for preparation and optimization of Mg alloy.展开更多
Joining of aluminum to steel has attracted significant attention from the welding research community,automotive and rail transportation industries.Many current welding methods have been developed and applied,however,t...Joining of aluminum to steel has attracted significant attention from the welding research community,automotive and rail transportation industries.Many current welding methods have been developed and applied,however,they can not precisely control the heat input to work-piece,they are high costs,low efficiency and consist lots of complex welding devices,and the generated intermetallic compound layer in weld bead interface is thicker.A novel pulsed double electrode gas metal arc welding(Pulsed DE-GMAW)method is developed.To achieve a stable welding process for joining of aluminum to steel,a mathematical model of coupled arc is established,and a new control scheme that uses the average feedback arc voltage of main loop to adjust the wire feed speed to control coupled arc length is proposed and developed.Then,the impulse control simulation of coupled arc length,wire feed speed and wire extension is conducted to demonstrate the mathematical model and predict the stability of welding process by changing the distance of contact tip to work-piece(CTWD).To prove the proposed PSO based PID control scheme’s feasibility,the rapid prototyping experimental system is setup and the bead-on-plate control experiments are conducted to join aluminum to steel.The impulse control simulation shows that the established model can accurately represent the variation of coupled arc length,wire feed speed and the average main arc voltage when the welding process is disturbed,and the developed controller has a faster response and adjustment,only runs about 0.1 s.The captured electric signals show the main arc voltage gradually closes to the supposed arc voltage by adjusting the wire feed speed in 0.8 s.The obtained typical current waveform demonstrates that the main current can be reduced by controlling the bypass current under maintaining a relative large total current.The control experiment proves the accuracy of proposed model and feasibility of new control scheme further.The beautiful and smooth weld beads are also obtained by this method.Pulsed DE-GMAW can thus be considered as an alternative method for low cost,high efficiency joining of aluminum to steel.展开更多
High efficiency welding has always been one of the hot research subjects at home and overseas. Aiming at the problem of unstable droplet rotating spray transfer process in 450 A thin wire metal active gas arc(MAG) wel...High efficiency welding has always been one of the hot research subjects at home and overseas. Aiming at the problem of unstable droplet rotating spray transfer process in 450 A thin wire metal active gas arc(MAG) welding, a three-dimensional arc-droplet coupled model is established in this paper on the base of fluid dynamics to conduct numerical analysis for droplet transfer behavior with external magnetic controlled MAG welding, and used high-speed camera system to verify the simulation results. The results indicate that without external magnetic field, the droplet is transferred by the way of rotating spray, the arc is changeable and the spatter is serious. The electromagnetic force accelerates the radial liquid beam rotation under direct current(DC) magnetic field, and increases the angle between liquid beam and welding wire axis. Meanwhile, the rotation frequency of the liquid beam reaches 400 Hz, the area of arc column and heat loss increase under DC magnetic field. Based on the alternating magnetic field, the arc is the “bell shaped”, the arc stiffness raises, its temperature achieves 26 000 K, and the maximum speed of the liquid stream beam can reach 500 m/s. And the droplet transfer is more stable, the spatter significantly reduces, and welding quality is effectively improved.展开更多
The cathode spots are a common phenomenon in the TIG(tungsten inert gas)welding process.However,it is rarely observed in the activating TIG welding process.This research is mainly focused on the effect of activating f...The cathode spots are a common phenomenon in the TIG(tungsten inert gas)welding process.However,it is rarely observed in the activating TIG welding process.This research is mainly focused on the effect of activating flux on cathode spots in the activating TIG welding.The characteristics and behaviors of cathode spots were investigated in activating TIG welding by the high-speed camera and the spectrograph.Three kinds of oxide(TiO_(2),SiO_(2),MnO_(2))and two halide(MnCl_(2),CaF_(2))activating fluxes are used in the activating TIG welding process.The results show that differ from the TIG welding,the oxide activating flux increases the number of cathode spots and decreases the velocity.The effect is the opposite for the halide activating flux.Moreover,the number of spots no longer varies with the current except TiO2 activating flux.As the temperature of the weld pool surface increases the spot moves away from the center.But this rule is not valid when silica and manganese compounds activating fluxes are used.The variation of cathode spots is caused by the oxide film reformed and the distribution of weld slag.The formation mechanism of cathode spots might be the impact of ions on the cathode surface and the strong electric field formed near the cathode surface.展开更多
In present paper, the metal vapour behavior in double electrodes TIG welding was investigated by a numerical model, including the arc plasma and weld pool. The thermodynamic parameters and transport coefficients of th...In present paper, the metal vapour behavior in double electrodes TIG welding was investigated by a numerical model, including the arc plasma and weld pool. The thermodynamic parameters and transport coefficients of the arc plasma were dependent on both the local temperature and the mass ratio of the metal vapour. A second viscosity approximation was used to formulate the diffusion coefficient of the metal vapour in the arc plasma. The temperature and flow fields together with the metal vapour concentration were simulated, and the influences of metal vapour on the arc plasma and the weld pool were analyzed. It was found that the metal vapour transport in the arc plasma was significantly influenced by the flow of the arc plasma, and the distribution of the metal vapour was more extended in the direction perpendicular to the line through the double electrodes tips. Both the arc plasma and the heat flux at the weld pool were constricted by the presence of the metal vapour, while the metal vapour had a minor effect on the total heat input to the work piece and the weld pool profile as a whole.展开更多
The physiological function of the gastrointestinal(GI)tract is based on the slow wave generated and transmitted by the interstitial cells of Cajal.Extracellular myoelectric recording techniques are often used to recor...The physiological function of the gastrointestinal(GI)tract is based on the slow wave generated and transmitted by the interstitial cells of Cajal.Extracellular myoelectric recording techniques are often used to record the characteristics and propagation of slow wave and analyze the models of slow wave transmission under physiological and pathological conditions to further explore the mechanism of GI dysfunction.This article reviews the application and research progress of electromyography,bioelectromagnetic technology,and high-resolution mapping in animal and clinical experiments,summarizes the clinical application of GI electrical stimulation therapy,and reviews the electrophysiological research in the biliary system.展开更多
The real-time detection and instance segmentation of strawberries constitute fundamental components in the development of strawberry harvesting robots.Real-time identification of strawberries in an unstructured envi-r...The real-time detection and instance segmentation of strawberries constitute fundamental components in the development of strawberry harvesting robots.Real-time identification of strawberries in an unstructured envi-ronment is a challenging task.Current instance segmentation algorithms for strawberries suffer from issues such as poor real-time performance and low accuracy.To this end,the present study proposes an Efficient YOLACT(E-YOLACT)algorithm for strawberry detection and segmentation based on the YOLACT framework.The key enhancements of the E-YOLACT encompass the development of a lightweight attention mechanism,pyramid squeeze shuffle attention(PSSA),for efficient feature extraction.Additionally,an attention-guided context-feature pyramid network(AC-FPN)is employed instead of FPN to optimize the architecture’s performance.Furthermore,a feature-enhanced model(FEM)is introduced to enhance the prediction head’s capabilities,while efficient fast non-maximum suppression(EF-NMS)is devised to improve non-maximum suppression.The experimental results demonstrate that the E-YOLACT achieves a Box-mAP and Mask-mAP of 77.9 and 76.6,respectively,on the custom dataset.Moreover,it exhibits an impressive category accuracy of 93.5%.Notably,the E-YOLACT also demonstrates a remarkable real-time detection capability with a speed of 34.8 FPS.The method proposed in this article presents an efficient approach for the vision system of a strawberry-picking robot.展开更多
Biodegradable plastic film mulch (PFM) is considered an alternative to non-biodegradable PFM to mitigate the negative impacts of residual film.However,the agronomic performance of biodegradable PFM in comparison to no...Biodegradable plastic film mulch (PFM) is considered an alternative to non-biodegradable PFM to mitigate the negative impacts of residual film.However,the agronomic performance of biodegradable PFM in comparison to non-biodegradable PFM still needs to be tested.In this study,we evaluated the effects of biodegradable and non-biodegradable PFM on soil physicochemical properties,microbial community,and enzyme activities,as well as maize growth performance.Biodegradable and non-biodegradable PFM both increased soil temperature,water content,N content,and microbial biomass and maize yield by up to 30%,but decreased soil enzyme activities as compared to no mulching (control,CK).Most soil physicochemical properties,microbial community,and enzyme activities were similar under non-biodegradable and biodegradable PFM at the early stages of maize growth.However,at the late stages,soil temperature,water content,mineral N,NO_(3)^(-)-N,ammonia monooxygenase (AMO) activity,and total phospholipid fatty acids (PLFAs) decreased under biodegradable PFM owing to film fragmentation.White PFM increased soil temperature,water content,and total PLFAs at the early stages of maize growth but decreased soil mineral N and total PLFAs at the late stages,as compared to black PFM.As soil temperature and N availability were the major factors affecting soil microbial community,microbial activity decreased after the fragmentation of biodegradable PFM,owing to the decreased soil temperature,water content,and mineral N.Notably,biodegradable PFM could decrease NO_(3)^(-)-N accumulation in topsoil by decreasing N transformation due to the lower microbial and N-related enzyme (e.g.,AMO) activities,compared with non-biodegradable PFM,which may avoid negative environmental impacts,such as NO_(3)^(-)-N leaching or gas emission after harvest.Maize yield,height,aboveground biomass,and N uptake under biodegradable PFM were similar to those under non-biodegradable PFM during maize growth,implying that biodegradable PFM has no negative impact on crop growth and yield.In general,biodegradable PFM was equivalent to non-biodegradable PFM in terms of maize yield increase and N uptake,but was environmentally friendly.Therefore,biodegradable PFM can be used as an alternative to non-biodegradable PFM in semi-arid areas for sustainable agricultural practices.展开更多
Metabolic syndrome(MS)is a common metabolic disorder status and defined as a pathology characterized by abdominal obesity,insulin resistance,hypertension,and hyperlipidemia(atherosclerosis)status[1].Evidence suggests ...Metabolic syndrome(MS)is a common metabolic disorder status and defined as a pathology characterized by abdominal obesity,insulin resistance,hypertension,and hyperlipidemia(atherosclerosis)status[1].Evidence suggests that the underlying etiology of MS is multifactorial and includes environmental factors,tobacco use,high alcohol consumption,dietary risks,and low physical activity.Thus,a deeper understanding of MS and its risk factors will be beneficial for mitigating health damage and improving the quality of life in high-risk subpopulations.PM_(2.5)is an important environmental pollutant,poses a serious threat to human health,and is associated with various health problems.Several epidemiological studies have shown that exposure to PM_(2.5)may influence the development of diabetes[2],cardiovascular disease,obesity,and MS.Existing evidence also suggests that the components of MS are sensitive to environmental pollutants,especially PM_(2.5).However,most of them were observational studies or literature analyses based on epidemiology。展开更多
基金the National Key Research and Development Program of China(2021YFD2000600)the National Natural Science Foundation of China(32071914)+1 种基金the Modern Agricultural Industry Technology System of China(CARS-170405)the Key Research and Development Program(Science and Technology Demonstration Project)project of Shandong Province(2022SFGC0202).
文摘To achieve an unmanned rice farm,in this study,a cotransporter system was developed using a tracked rice harvester and transporter for autonomous harvesting,unloading,and transportation.Additionally,two unloading and transportation modes—harvester waiting for unloading(HWU)and transporter fol-lowing for unloading(TFU)—were proposed,and a harvesting-unloading-transportation(HUT)strategy was defined.By breaking down the main stages of the collaborative operation,designing module-state machines(MSMs),and constructing state-transition chains,a HUT collaborative operation logic frame-work suitable for the embedded navigation controller was designed using the concept and method of the finite-state machine(FSM).This method addresses the multiple-stage,nonsequential,and complex processes in HUT collaborative operations.Simulations and field-harvesting experiments were performed to evaluate the applicability of this proposed strategy and system.The experimental results showed that the HUT collaborative operation strategy effectively integrated path planning,path-tracking control,inter-vehicle communication,collaborative operation control,and implementation control.The cotrans-porter system completed the entire process of harvesting,unloading,and transportation.The field-harvesting experiment revealed that a harvest efficiency of 0.42 hm^(2)·h^(−1) was achieved.This study can provide insight into collaborative harvesting and solutions for the harvesting process of unmanned farms.
基金supported by Shandong Provincial Natural Science Foundation,China(ZR2022QE014)Basic Scientific Research Fund for Central Universities(202112018)Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education)。
文摘Lithium metal is considered as the most promising anode material for the next generation of secondary batteries due to its high theoretical specific capacity and low potential.However,undesirable parasitic reactions,poor cycling stability and safety concerns could be caused by uncontrolled dendrite and high reactivity of Li metal,which hinder the practical application of Li-metal anode in high-energy rechargeable Li metal batteries(LMBs).Here,a facile way is reported to stabilize Li metal anode by building high lithiophilic Mg-Li-Cu alloy.Due to the delocalization of electrons on the deposited lithium enhanced by Cu self-diffusion into Mg-Li alloy,the growth of lithium dendrites could be inhibited by Mg-Li-Cu alloy.Moreover,the parasitic reactions with electrolyte could be avoided by the Mg-Li-Cu alloy anode.It is noteworthy that the symmetric battery life of Mg-Li-Cu alloy electrodes exceeds 9000 h at 1 m A cm^(-2)and 1 m Ah cm^(-2).The full cell(LiFePO_(4)|Mg-Li-Cu)exhibits a specific capacity of 148.2 m Ah g^(-1),with a capacity retention of 96.4%,at 1 C after 500 cycles.This work not only pave the way for application of flexible alloy anode in highly stable LMBs,but also provides novel strategies for preparation and optimization of Mg alloy.
基金Supported by National Natural Science Foundation of China(Grant No.51165023)Project of International Cooperation and Exchanges of National Natural Science Foundation of China(Grant No.51210105024)+1 种基金Financial Commission of Gansu Province of Chinathe Hong Liu Outstanding Talent Training Plan of Lanzhou University of Technology,China(Grant No.J201201)
文摘Joining of aluminum to steel has attracted significant attention from the welding research community,automotive and rail transportation industries.Many current welding methods have been developed and applied,however,they can not precisely control the heat input to work-piece,they are high costs,low efficiency and consist lots of complex welding devices,and the generated intermetallic compound layer in weld bead interface is thicker.A novel pulsed double electrode gas metal arc welding(Pulsed DE-GMAW)method is developed.To achieve a stable welding process for joining of aluminum to steel,a mathematical model of coupled arc is established,and a new control scheme that uses the average feedback arc voltage of main loop to adjust the wire feed speed to control coupled arc length is proposed and developed.Then,the impulse control simulation of coupled arc length,wire feed speed and wire extension is conducted to demonstrate the mathematical model and predict the stability of welding process by changing the distance of contact tip to work-piece(CTWD).To prove the proposed PSO based PID control scheme’s feasibility,the rapid prototyping experimental system is setup and the bead-on-plate control experiments are conducted to join aluminum to steel.The impulse control simulation shows that the established model can accurately represent the variation of coupled arc length,wire feed speed and the average main arc voltage when the welding process is disturbed,and the developed controller has a faster response and adjustment,only runs about 0.1 s.The captured electric signals show the main arc voltage gradually closes to the supposed arc voltage by adjusting the wire feed speed in 0.8 s.The obtained typical current waveform demonstrates that the main current can be reduced by controlling the bypass current under maintaining a relative large total current.The control experiment proves the accuracy of proposed model and feasibility of new control scheme further.The beautiful and smooth weld beads are also obtained by this method.Pulsed DE-GMAW can thus be considered as an alternative method for low cost,high efficiency joining of aluminum to steel.
基金Major Scientific and Technological Project of Gansu Province(No.22ZD6GA008)the National Natural Science Foundation of China(No.51775256).
文摘High efficiency welding has always been one of the hot research subjects at home and overseas. Aiming at the problem of unstable droplet rotating spray transfer process in 450 A thin wire metal active gas arc(MAG) welding, a three-dimensional arc-droplet coupled model is established in this paper on the base of fluid dynamics to conduct numerical analysis for droplet transfer behavior with external magnetic controlled MAG welding, and used high-speed camera system to verify the simulation results. The results indicate that without external magnetic field, the droplet is transferred by the way of rotating spray, the arc is changeable and the spatter is serious. The electromagnetic force accelerates the radial liquid beam rotation under direct current(DC) magnetic field, and increases the angle between liquid beam and welding wire axis. Meanwhile, the rotation frequency of the liquid beam reaches 400 Hz, the area of arc column and heat loss increase under DC magnetic field. Based on the alternating magnetic field, the arc is the “bell shaped”, the arc stiffness raises, its temperature achieves 26 000 K, and the maximum speed of the liquid stream beam can reach 500 m/s. And the droplet transfer is more stable, the spatter significantly reduces, and welding quality is effectively improved.
基金supported by the National Natural Science Foundation of China(Grant No.51965036).
文摘The cathode spots are a common phenomenon in the TIG(tungsten inert gas)welding process.However,it is rarely observed in the activating TIG welding process.This research is mainly focused on the effect of activating flux on cathode spots in the activating TIG welding.The characteristics and behaviors of cathode spots were investigated in activating TIG welding by the high-speed camera and the spectrograph.Three kinds of oxide(TiO_(2),SiO_(2),MnO_(2))and two halide(MnCl_(2),CaF_(2))activating fluxes are used in the activating TIG welding process.The results show that differ from the TIG welding,the oxide activating flux increases the number of cathode spots and decreases the velocity.The effect is the opposite for the halide activating flux.Moreover,the number of spots no longer varies with the current except TiO2 activating flux.As the temperature of the weld pool surface increases the spot moves away from the center.But this rule is not valid when silica and manganese compounds activating fluxes are used.The variation of cathode spots is caused by the oxide film reformed and the distribution of weld slag.The formation mechanism of cathode spots might be the impact of ions on the cathode surface and the strong electric field formed near the cathode surface.
基金supported by the National Natural Science Foundation of China(Grant No.51705054)Scientific and Technological Research Program of Chongqing Municipal Education Commission(Grant No.KJ 1600903)
文摘In present paper, the metal vapour behavior in double electrodes TIG welding was investigated by a numerical model, including the arc plasma and weld pool. The thermodynamic parameters and transport coefficients of the arc plasma were dependent on both the local temperature and the mass ratio of the metal vapour. A second viscosity approximation was used to formulate the diffusion coefficient of the metal vapour in the arc plasma. The temperature and flow fields together with the metal vapour concentration were simulated, and the influences of metal vapour on the arc plasma and the weld pool were analyzed. It was found that the metal vapour transport in the arc plasma was significantly influenced by the flow of the arc plasma, and the distribution of the metal vapour was more extended in the direction perpendicular to the line through the double electrodes tips. Both the arc plasma and the heat flux at the weld pool were constricted by the presence of the metal vapour, while the metal vapour had a minor effect on the total heat input to the work piece and the weld pool profile as a whole.
文摘The physiological function of the gastrointestinal(GI)tract is based on the slow wave generated and transmitted by the interstitial cells of Cajal.Extracellular myoelectric recording techniques are often used to record the characteristics and propagation of slow wave and analyze the models of slow wave transmission under physiological and pathological conditions to further explore the mechanism of GI dysfunction.This article reviews the application and research progress of electromyography,bioelectromagnetic technology,and high-resolution mapping in animal and clinical experiments,summarizes the clinical application of GI electrical stimulation therapy,and reviews the electrophysiological research in the biliary system.
基金funded by Anhui Provincial Natural Science Foundation(No.2208085ME128)the Anhui University-Level Special Project of Anhui University of Science and Technology(No.XCZX2021-01)+1 种基金the Research and the Development Fund of the Institute of Environmental Friendly Materials and Occupational Health,Anhui University of Science and Technology(No.ALW2022YF06)Anhui Province New Era Education Quality Project(Graduate Education)(No.2022xscx073).
文摘The real-time detection and instance segmentation of strawberries constitute fundamental components in the development of strawberry harvesting robots.Real-time identification of strawberries in an unstructured envi-ronment is a challenging task.Current instance segmentation algorithms for strawberries suffer from issues such as poor real-time performance and low accuracy.To this end,the present study proposes an Efficient YOLACT(E-YOLACT)algorithm for strawberry detection and segmentation based on the YOLACT framework.The key enhancements of the E-YOLACT encompass the development of a lightweight attention mechanism,pyramid squeeze shuffle attention(PSSA),for efficient feature extraction.Additionally,an attention-guided context-feature pyramid network(AC-FPN)is employed instead of FPN to optimize the architecture’s performance.Furthermore,a feature-enhanced model(FEM)is introduced to enhance the prediction head’s capabilities,while efficient fast non-maximum suppression(EF-NMS)is devised to improve non-maximum suppression.The experimental results demonstrate that the E-YOLACT achieves a Box-mAP and Mask-mAP of 77.9 and 76.6,respectively,on the custom dataset.Moreover,it exhibits an impressive category accuracy of 93.5%.Notably,the E-YOLACT also demonstrates a remarkable real-time detection capability with a speed of 34.8 FPS.The method proposed in this article presents an efficient approach for the vision system of a strawberry-picking robot.
基金funded by the National Natural Science Foundation of China(No.41877086)the Natural Science Basic Research Plan in Shaanxi Province of China(No.2020JZ-16)+1 种基金the UK Global Research Challenges Fundthe UK Natural Environment Research Council Project(No.NE/V005871/1)。
文摘Biodegradable plastic film mulch (PFM) is considered an alternative to non-biodegradable PFM to mitigate the negative impacts of residual film.However,the agronomic performance of biodegradable PFM in comparison to non-biodegradable PFM still needs to be tested.In this study,we evaluated the effects of biodegradable and non-biodegradable PFM on soil physicochemical properties,microbial community,and enzyme activities,as well as maize growth performance.Biodegradable and non-biodegradable PFM both increased soil temperature,water content,N content,and microbial biomass and maize yield by up to 30%,but decreased soil enzyme activities as compared to no mulching (control,CK).Most soil physicochemical properties,microbial community,and enzyme activities were similar under non-biodegradable and biodegradable PFM at the early stages of maize growth.However,at the late stages,soil temperature,water content,mineral N,NO_(3)^(-)-N,ammonia monooxygenase (AMO) activity,and total phospholipid fatty acids (PLFAs) decreased under biodegradable PFM owing to film fragmentation.White PFM increased soil temperature,water content,and total PLFAs at the early stages of maize growth but decreased soil mineral N and total PLFAs at the late stages,as compared to black PFM.As soil temperature and N availability were the major factors affecting soil microbial community,microbial activity decreased after the fragmentation of biodegradable PFM,owing to the decreased soil temperature,water content,and mineral N.Notably,biodegradable PFM could decrease NO_(3)^(-)-N accumulation in topsoil by decreasing N transformation due to the lower microbial and N-related enzyme (e.g.,AMO) activities,compared with non-biodegradable PFM,which may avoid negative environmental impacts,such as NO_(3)^(-)-N leaching or gas emission after harvest.Maize yield,height,aboveground biomass,and N uptake under biodegradable PFM were similar to those under non-biodegradable PFM during maize growth,implying that biodegradable PFM has no negative impact on crop growth and yield.In general,biodegradable PFM was equivalent to non-biodegradable PFM in terms of maize yield increase and N uptake,but was environmentally friendly.Therefore,biodegradable PFM can be used as an alternative to non-biodegradable PFM in semi-arid areas for sustainable agricultural practices.
基金funded by the National Natural Science Foundation of China[12061058]National Natural Science Foundation of Ningxia[2023AAC02033]and the Key Research and Development Plan Project of Ningxia[2021BEG02026].
文摘Metabolic syndrome(MS)is a common metabolic disorder status and defined as a pathology characterized by abdominal obesity,insulin resistance,hypertension,and hyperlipidemia(atherosclerosis)status[1].Evidence suggests that the underlying etiology of MS is multifactorial and includes environmental factors,tobacco use,high alcohol consumption,dietary risks,and low physical activity.Thus,a deeper understanding of MS and its risk factors will be beneficial for mitigating health damage and improving the quality of life in high-risk subpopulations.PM_(2.5)is an important environmental pollutant,poses a serious threat to human health,and is associated with various health problems.Several epidemiological studies have shown that exposure to PM_(2.5)may influence the development of diabetes[2],cardiovascular disease,obesity,and MS.Existing evidence also suggests that the components of MS are sensitive to environmental pollutants,especially PM_(2.5).However,most of them were observational studies or literature analyses based on epidemiology。