Stochastic optical reconstruction microscopy(STORM),as a typical technique of single-molecule localization microscopy(SMLM),has overcome the diffraction limit by randomly switching fluorophores between fluorescent and...Stochastic optical reconstruction microscopy(STORM),as a typical technique of single-molecule localization microscopy(SMLM),has overcome the diffraction limit by randomly switching fluorophores between fluorescent and dark states,allowing for the precise localization of isolated emission patterns and the super-resolution reconstruction from millions of localized positions of single fluorophores.A critical factor influencing localization precision is the photo-switching behavior of fluorophores,which is affected by the imaging buffer.The imaging buffer typically comprises oxygen scavengers,photo-switching reagents,and refractive index regulators.Oxygen scavengers help prevent photobleaching,photo-switching reagents assist in facilitating the conversion of fluorophores,and refractive index regulators are used to adjust the refractive index of the solution.The synergistic interaction of these components promotes stable blinking of fluorophores,reduces irreversible photobleaching,and thereby ensures high-quality super-resolution imaging.This review provides a comprehensive overview of the essential compositions and functionalities of imaging buffers used in STORM,serving as a valuable resource for researchers seeking to select appropriate imaging buffers for their experiments.展开更多
Man-made superheavy elements(SHE)are produced as energetic recoils in complete-fusion reactions and need to be thermalized in a gas-filled chamber for chemical studies.The ever-shorter half-lives and decreasing produc...Man-made superheavy elements(SHE)are produced as energetic recoils in complete-fusion reactions and need to be thermalized in a gas-filled chamber for chemical studies.The ever-shorter half-lives and decreasing production rates of the elements beyond Fl(atomic number Z=114)-the heaviest element chemically studied today-require the development of novel techniques for quantitative thermalization and fast extraction efficiency.The Universal high-density gas stopping Cell(UniCell),currently under construction,was proposed to achieve this.Within this work,we propose an Ion Transfer by Gas Flow(ITGF)device,which serves as a UniCell ejector to interface with a gas chromatography detector array for chemical studies.Detailed parameter optimizations,using gas dynamics and Monte Carlo ion-trajectory simulations,promise fast(within a few ms)and highly efficient(up to 100%)ion extraction across a wide mass range.These ions can then be transmitted quantitatively through the ITGF into the high-pressure environment needed for further chemical studies.展开更多
The squeezing deformation of surrounding rock is an important factor restricting the safe construction and long-term operation of tunnels when a tunnel passes through soft strata with high ground stress.Under such sof...The squeezing deformation of surrounding rock is an important factor restricting the safe construction and long-term operation of tunnels when a tunnel passes through soft strata with high ground stress.Under such soft rock geological conditions,the large deformation of the surrounding rock can easily lead to the failure of supporting structures,including shotcrete cracks,spalling,and steel arch distortion.To improve the lining support performance during the large deformation of squeezed surrounding rock,this work selects aluminum foam with densities of 0.25 g/cm3,0.42 g/cm3 and 0.61 g/cm3 as the buffer layer material and carries out uniaxial confined compression tests.Through the evaluation and analysis of energy absorption and the comparison of the yield pressure of aluminum foam with those of other cushioning materials and yield pressure support systems,the strength,deformation and energy absorption of aluminum foam with a density of 0.25 g/cm3 meet the yield pressure performance requirements.The numerical model of the buffer layer yielding support system is then established via the finite element analysis software ABAQUS,and the influence of the buffer layer setting on the lining support is analyzed.Compared with the conventional support scheme,the addition of an aluminum foam buffer layer can reduce the stress and deformation of the primary support and secondary lining.The maximum and minimum principal stresses of the primary support are reduced by 13%and 15%,respectively.The maximum and minimum principal stresses of the secondary lining are reduced by 15%and 12%,respectively,and the displacement deformation of the secondary lining position is reduced by 15%.In summary,the application of aluminum foam buffer layer can reduce the stress and deformation of the primary support and secondary lining,improve the stress safety of the support and reduce the deformation of the support.展开更多
Photocatalytic hydrogen peroxide(H_(2)O_(2))production offers a sustainable route to convert water and oxygen into H_(2)O_(2)using solar energy.However,achieving long-term stability in photocatalysts remains a critica...Photocatalytic hydrogen peroxide(H_(2)O_(2))production offers a sustainable route to convert water and oxygen into H_(2)O_(2)using solar energy.However,achieving long-term stability in photocatalysts remains a critical challenge due to mismatched kinetics between oxygen reduction(ORR)and water oxidation(WOR),which leads to hole accumulation and oxidative degradation.Here,we report a redox-mediated strategy to address this bottleneck by designing a hydroquinone-embedded covalent organic framework(Tz-QH-COF)that enables reversible hole buffering and kinetic balance.The hydroquinone(QH)units act as dynamic hole reservoirs,capturing excess holes during ORR and converting to benzoquinone(Q),which is regenerated to QH via WOR,thereby preventing oxidative decomposition.This reversible QH/Q cycle,directly visualized through in situ attenuated total reflection surface-enhanced infrared absorption spectroscopy,ensures unmatched stability,achieving continuous H_(2)O_(2) production for 528 h(22 d)with an accumulated yield of 18.6 mmol L^(–1)—the highest reported duration for organic photocatalysts.Density functional theory calculations reveal that the QH units exhibit a strong oxygen adsorption energy and favorable two-electron ORR/WOR pathways with low energy barriers.The synergy between experimental and theoretical insights elucidates a redox-mediated charge-balance mechanism,advancing the design of robust photocatalysts for solar-driven H_(2)O_(2) synthesis.展开更多
The shop scheduling problem with limited buffers has broad applications in real-world production scenarios,so this research direction is of great practical significance.However,there is currently little research on th...The shop scheduling problem with limited buffers has broad applications in real-world production scenarios,so this research direction is of great practical significance.However,there is currently little research on the hybrid flow shop scheduling problem with limited buffers(LBHFSP).This paper deeply investigates the LBHFSP to optimize the goal of the total completion time.To better solve the LBHFSP,a multi-level subpopulation-based particle swarm optimization algorithm(MLPSO)is proposed,which is founded on the attributes of the LBHFSP and the shortcomings of the basic PSO(particle swarm optimization)algorithm.In MLPSO,firstly,considering the impact of the limited buffers on the process of subsequent operations,a specific circular decoding strategy is developed to accommodate the characteristics of limited buffers.Secondly,an initialization strategy based on blocking time is designed to enhance the quality and diversity of the initial population.Afterward,a multi-level subpopulation collaborative search is developed to prevent being trapped in a local optimum and improve the global exploration capability.Additionally,a local search strategy based on the first blocked job is designed to enhance the MLPSO algorithm’s exploitation capability.Lastly,numerous experiments are carried out to test the performance of the proposed MLPSO by comparing it with classical intelligent optimization and popular algorithms in recent years.The results confirm that the proposed MLPSO has an outstanding performance when compared to other algorithms when solving LBHFSP.展开更多
Aqueous zinc-ion batteries(AZIBs)have developed rapidly in recent years but still face several challenges,including zinc dendrites growth,hydrogen evolution reaction,passivation and corrosion.The pH of the electrolyte...Aqueous zinc-ion batteries(AZIBs)have developed rapidly in recent years but still face several challenges,including zinc dendrites growth,hydrogen evolution reaction,passivation and corrosion.The pH of the electrolyte plays a crucial role in these processes,significantly impacting the stability and reversibility of Zn^(2+)deposition.Therefore,pH-buffer tris(hydroxymethyl)amino methane(tris)is chosen as a versatile electrolyte additive to address these issues.Tris can buffer electrolyte pH at Zn/electrolyte interface by protonated/deprotonated nature of amino group,optimize the coordination environment of zinc solvate ions by its strong interaction with zinc ions,and simultaneously create an in-situ stable solid electrolyte interface membrane on the zinc anode surface.These synergistic effects effectively restrain dendrite formation and side reactions,resulting in a highly stable and reversible Zn anode,thereby enhancing the electrochemical performance of AZIBs.The Zn||Zn battery with 0.15 wt%tris additives maintains stable cycling for 1500 h at 4 mA·cm^(−2) and 1120 h at 10 mA·cm^(−2).Furthermore,the Coulombic efficiency reaches~99.2%at 4 mA·cm^(−2)@1 mAh·cm^(−2).The Zn||NVO full batteries also demonstrated a stable specific capacity and exceptional capacity retention.展开更多
Optimizing the orientation of β-Ga_(2)O_(3) has emerged as an effective strategy to design high-performance β-Ga_(2)O_(3) device,but the orientation growth mechanism and approach have not been revealed yet.Herein,by...Optimizing the orientation of β-Ga_(2)O_(3) has emerged as an effective strategy to design high-performance β-Ga_(2)O_(3) device,but the orientation growth mechanism and approach have not been revealed yet.Herein,by employing AlN buffer layer,the highly preferred orientation of β-Ga_(2)O_(3)(100)film rather than(-201)film is realized on 4H-SiC substrate at low sputtering power and temperature.Because β-Ga_(2)O_(3)(100)film exhibits a slower growth speed than(-201)film,the former possesses the higher dangling bond density and the lower nucleation energy,and a large conversion barrier exists between these two ori-entations.Moreover,the AlN buffer layer can suppress the surface oxidation of the 4H-SiC substrate and eliminate the strain of β-Ga_(2)O_(3)(100)film,which further reduces the nucleation energy and en-larges the conversion barrier.Meanwhile,the AlN buffer layer can increase the oxygen vacancy formation energy and decrease the oxygen vacancy concentration of β-Ga_(2)O_(3)(100)film.Consequently,the solar-blind photodetector based on the oriented film exhibits the outstanding detectivity of 1.22×10^(12) Jones and photo-to-dark current ratio of 1.11×10^(5),which are the highest among the reported β-Ga_(2)O_(3) solar-blind photodetector on the SiC substrate.Our results offer in-depth insights into the preferred orientation growth mechanism,and provide an effective way to design high-quality β-Ga_(2)O_(3)(100)orientation film and high-performance solar-blind photodetector.展开更多
Attempts to remove environmentally harmful materials in mass production industries are always a major issue and draw attention if the substitution guarantees a chance to lower fabrication cost and to improve device pe...Attempts to remove environmentally harmful materials in mass production industries are always a major issue and draw attention if the substitution guarantees a chance to lower fabrication cost and to improve device performance,as in a wide bandgap Zn_(1-x)Mg_(x)O(ZMO)to replace the CdS buffer in Cu(In_(1-x),Ga_(x))Se_(2)(CIGSe)thin-film solar cell structure.ZMO is one of the candidates for the buffer material in CIGSe thin-film solar cells with a wide and controllable bandgap depending on the Mg content,which can be helpful in attaining a suitable conduction band offset.Hence,compared to the fixed and limited bandgap of a CdS buffer,a ZMO buffer may provide advantages in V_(oc) and J_(sc) based on its controllable and wide bandgap,even with a relatively wider bandgap CIGSe thin-film solar cell.In addition,to solve problems with the defect sites at the ZMO/CIGSe junction interface,a few-nanometer ZnS layer is employed for heterojunction interface passivation,forming a ZMO/ZnS buffer structure by atomic layer deposition(ALD).Finally,a Cd-free all-dry-processed CIGSe solar cell with a wider bandgap(1.25 eV)and ALD-grown buffer structure exhibited the best power conversion efficiency of 19.1%,which exhibited a higher performance than the CdS counterpart.展开更多
To detect the genome of viruses (in environmental and clinical samples), we use electrophoresis running buffer after PCR reaction. Also, electrophoresis buffers were used widely to separate any DNA molecule. In this p...To detect the genome of viruses (in environmental and clinical samples), we use electrophoresis running buffer after PCR reaction. Also, electrophoresis buffers were used widely to separate any DNA molecule. In this paper, we used four types of previously known electrophoresis buffers to compare which is easy for preparation, simple in structure, low cost and good performance in agarose gel electrophoresis. For this, we used two agarose concentration (1%, 2%) and two types of DNA ladder (100 bp, 1 kb) represent both smaller and larger sizes of molecule for each type of buffers, from the result we found in first level both supper buffer and TAE buffer with good performance and in second level we found bicarbonate buffer also with good performance also. Finally, we found the tang buffer cannot pose any electrophoretic activity on DNA agarose gel electrophoresis.展开更多
Soil acidification is a major threat to agricultural sustainability in tropical and subtropical regions.Biodegradable and environmentally friendly materials,such as calcium lignosulfonate(CaLS),calcium poly(aspartic a...Soil acidification is a major threat to agricultural sustainability in tropical and subtropical regions.Biodegradable and environmentally friendly materials,such as calcium lignosulfonate(CaLS),calcium poly(aspartic acid)(PASP-Ca),and calcium polyγ-glutamic acid(γ-PGA-Ca),are known to effectively ameliorate soil acidity.However,their effectiveness in inhibiting soil acidification has not been studied.This study aimed to evaluate the effect of CaLS,PASP-Ca,andγ-PGA-Ca on the resistance of soil toward acidification as directly and indirectly(i.e.,via nitrification)caused by the application of HNO_(3)and urea,respectively.For comparison,Ca(OH)_(2)and lignin were used as the inorganic and organic controls,respectively.Among the materials,γ-PGA-Ca drove the substantial improvements in the pH buffering capacity(pHBC)of the soil and exhibited the greatest potential in inhibiting HNO_(3)-induced soil acidification via protonation of carboxyl,complexing with Al~(3+),and cation exchange processes.Under acidification induced by urea,CaLS was the optimal one in inhibiting acidification and increasing exchangeable acidity during incubation.Furthermore,the sharp reduction in the population sizes of ammonia-oxidizing bacteria(AOB)and ammonia-oxidizing archaea(AOA)confirmed the inhibition of nitrification via CaLS application.Therefore,compared to improving soil pHBC,CaLS may play a more important role in suppressing indirect acidification.Overall,γ-PGA-Ca was superior to PASP-Ca and CaLS in enhancing the soil pHBC and the its resistance to acidification induced by HNO_(3) addition,whereas CaLS was the best at suppressing urea-driven soil acidification by inhibiting nitrification.In conclusion,these results provide a reference for inhibiting soil re-acidification in intensive agricultural systems.展开更多
An innovative metallic buffer consisting of series-connected hat-shaped entangled wire mesh damper(EWMD)and parallel springs are proposed in this work to enhance the reliability of engineering equipment.The impact res...An innovative metallic buffer consisting of series-connected hat-shaped entangled wire mesh damper(EWMD)and parallel springs are proposed in this work to enhance the reliability of engineering equipment.The impact response and the energy dissipation mechanism of hat-shaped EWMD under different quasi-static compression deformations(2-7 mm)and impact heights(100-200 mm)are investigated using experimental and numerical methods.The results demonstrate distinct stages in the quasi-static mechanical characteristics of hat-shaped EWMD,including stiffness softening,negative stiffness,and stiffness hardening.The loss factor gradually increases with increasing compression deformation before entering the stiffness hardening stage.Under impact loads,the hat-shaped EWMD exhibits optimal impact energy absorption when it enters the negative stiffness stage(150 mm),resulting in the best impact isolation effect of metallic buffer.However,the impact energy absorption significantly decreases when hat-shaped EWMD enters the stiffness hardening stage.Interestingly,quasi-static compression analysis after experiencing different impact loads reveals the disappearance of the negative stiffness phenomenon.Moreover,with increasing impact loads,the stiffness hardening point progressively shifts to an earlier stage.展开更多
The path planning of Unmanned Aerial Vehicle(UAV)is a critical issue in emergency communication and rescue operations,especially in adversarial urban environments.Due to the continuity of the flying space,complex buil...The path planning of Unmanned Aerial Vehicle(UAV)is a critical issue in emergency communication and rescue operations,especially in adversarial urban environments.Due to the continuity of the flying space,complex building obstacles,and the aircraft's high dynamics,traditional algorithms cannot find the optimal collision-free flying path between the UAV station and the destination.Accordingly,in this paper,we study the fast UAV path planning problem in a 3D urban environment from a source point to a target point and propose a Three-Step Experience Buffer Deep Deterministic Policy Gradient(TSEB-DDPG)algorithm.We first build the 3D model of a complex urban environment with buildings and project the 3D building surface into many 2D geometric shapes.After transformation,we propose the Hierarchical Learning Particle Swarm Optimization(HL-PSO)to obtain the empirical path.Then,to ensure the accuracy of the obtained paths,the empirical path,the collision information and fast transition information are stored in the three experience buffers of the TSEB-DDPG algorithm as dynamic guidance information.The sampling ratio of each buffer is dynamically adapted to the training stages.Moreover,we designed a reward mechanism to improve the convergence speed of the DDPG algorithm for UAV path planning.The proposed TSEB-DDPG algorithm has also been compared to three widely used competitors experimentally,and the results show that the TSEB-DDPG algorithm can archive the fastest convergence speed and the highest accuracy.We also conduct experiments in real scenarios and compare the real path planning obtained by the HL-PSO algorithm,DDPG algorithm,and TSEB-DDPG algorithm.The results show that the TSEBDDPG algorithm can archive almost the best in terms of accuracy,the average time of actual path planning,and the success rate.展开更多
Field-free spin-orbit torque(SOT)switching of perpendicular magnetization is essential for future spintronic devices.This study demonstrates the field-free switching of perpendicular magnetization in an HfO_(2)/Pt/Co/...Field-free spin-orbit torque(SOT)switching of perpendicular magnetization is essential for future spintronic devices.This study demonstrates the field-free switching of perpendicular magnetization in an HfO_(2)/Pt/Co/TaO_(x) structure,which is facilitated by a wedge-shaped HfO_(2)buffer layer.The field-free switching ratio varies with HfO_(2)thickness,reaching optimal performance at 25 nm.This phenomenon is attributed to the lateral anisotropy gradient of the Co layer,which is induced by the wedge-shaped HfO_(2)buffer layer.The thickness gradient of HfO_(2)along the wedge creates a corresponding lateral anisotropy gradient in the Co layer,correlating with the switching ratio.These findings indicate that field-free SOT switching can be achieved through designing buffer layer,offering a novel approach to innovating spin-orbit device.展开更多
Near-infrared(NIR)transparent inverted all-inorganic perovskite solar cells(PSCs)are excellent top cell candidates in tandem applications.An essential challenge is the replacement of metal contacts with transparent co...Near-infrared(NIR)transparent inverted all-inorganic perovskite solar cells(PSCs)are excellent top cell candidates in tandem applications.An essential challenge is the replacement of metal contacts with transparent conductive oxide(TCO)electrodes,which requires the introduction of a buffer layer to prevent sputtering damage.In this study,we show that the conventional buffers(i.e.,small organic molecules and atomic layer deposited metal oxides)used for organic-inorganic hybrid perovskites are not applicable to all-inorganic perovskites,due to non-uniform coverage of the vulnerable layers underneath,deterioration upon ion bombardment and moisture induced perovskite phase transition,A thin film of metal oxide nanoparticles by the spin-coating method serves as a non-destructive buffer layer for inorganic PSCs.All-inorganic inverted near-infrared-transparent PSCs deliver a PCE of 17.46%and an average transmittance of 73.7%between 780 and 1200 nm.In combination with an 18.56%Cu(In,Ga)Se_(2) bottom cell,we further demonstrate the first all-inorganic perovskite/CIGS 4-T tandem solar cell with a PCE of 24.75%,which exhibits excellent illumination stability by maintaining 86.7%of its initial efficiency after 1400 h.The non-destructive buffer lays the foundation for efficient and stable NIR-transparent inverted inorganic perovskite solar cells and perovskite-based tandems.展开更多
Anammox bacteria grow slowly and can be affected by large pH fluctuations.Using suitable buffers could make the start-up of anammox reactors easy and rapid.In this study,the effects of three kinds of buffers on the ni...Anammox bacteria grow slowly and can be affected by large pH fluctuations.Using suitable buffers could make the start-up of anammox reactors easy and rapid.In this study,the effects of three kinds of buffers on the nitrogen removal and growth characteristics of anammox sludge were investigated.Reactors with CO_(2)/NaHCO_(3)buffer solution(CCBS)performed the best in nitrogen removal,while 4-(2-hydroxyerhyl)piperazine-1-ethanesulfonic acid(HEPES)and phosphate buffer solution(PBS)inhibited the anammox activity.Reactors with 50 mmol/L CCBS could start up in 20 days,showing the specific anammox activity and anammox activity of 1.01±0.10 gN/(gVSS·day)and 0.83±0.06 kgN/(m^(3)·day),respectively.Candidatus Kuenenia was the dominant anammox bacteria,with a relative abundance of 71.8%.Notably,anammox reactors could also start quickly by using 50 mmol/L CCBS under nonstrict anaerobic conditions.These findings are meaningful for the quick start-up of engineered anammox reactors and prompt enrichment of anammox bacteria.展开更多
Two methods of irrigation,drip,and sprinkler were studied to determine the response of the Javits green roof to irrigation.The control study was dry unirrigated plots.Drip irrigation consisted of irrigation tubes runn...Two methods of irrigation,drip,and sprinkler were studied to determine the response of the Javits green roof to irrigation.The control study was dry unirrigated plots.Drip irrigation consisted of irrigation tubes running through the green roof that would water the soil throughout and sprinkler irrigation used a sprinkler system to irrigate the green roof from above.In all cases,the irrigated roofs had increased the soil moisture,reduced temperatures of both the upper and lower surfaces,reduced growing medium temperatures and reduced air temperatures above the green roof relative to the unirrigated roof.The buffered temperature fluctuations were also studied via air conditioner energy consumption.There was a 28%reduction in air conditioner energy consumption and a 33%reduction in overall energy consumption between dry and irrigated plots.Values of thermal resistance or S were determined for accuracy and for this study,there was little change which is ideal.A series of infra-red and thermal probe measurements were used to determine temperatures in the air and sedum.It was determined that the sprinkler irrigation did a better job than the drip irrigation in keeping cooler temperatures within the green roof.A Mann-Whitney U test was performed to verify the variation in moisture temperatures buffering energy consumption.By getting a p-value<0.05,it indicates that the model is accurate for prediction and medium temperatures were statistically different.展开更多
Mobile edge computing (MEC) has a vital role in various delay-sensitive applications. With the increasing popularity of low-computing-capability Internet of Things (IoT) devices in industry 4.0 technology, MEC also fa...Mobile edge computing (MEC) has a vital role in various delay-sensitive applications. With the increasing popularity of low-computing-capability Internet of Things (IoT) devices in industry 4.0 technology, MEC also facilitates wireless power transfer, enhancing efficiency and sustainability for these devices. The most related studies concerning the computation rate in MEC are based on the coordinate descent method, the alternating direction method of multipliers (ADMMs) and Lyapunov optimization. Nevertheless, these studies do not consider the buffer queue size. This research work concerns the computation rate maximization for wireless-powered and multiple-user MEC systems, specifically focusing on the computation rate of end devices and managing the task buffer queue before computation at the terminal devices. A deep reinforcement learning (RL)-based task offloading algorithm is proposed to maximize the computation rate of end devices and minimizes the buffer queue size at the terminal devices.Precisely, considering the channel gain, the buffer queue size and wireless power transfer, it further formalizes the task offloading problem. The mode selection for task offloading is based on the individual channel gain, the buffer queue size and wireless power transfer maximization in a particular time slot.The central idea of this work is to explore the best optimal mode selection for IoT devices connected to the MEC system. The proposed algorithm optimizes computation delay by maximizing the computation rate of end devices and minimizing the buffer queue size before computation at the terminal devices. Then, the current study presents a deep RL-based task offloading algorithm to solve such a mixed-integer and non-convex optimization problem, aiming to get a better trade-off between the buffer queue size and the computation rate. The extensive simulation results reveal that the presented algorithm is much more efficient than the existing work to maintain a small buffer queue for terminal devices while simultaneously achieving a high-level computation rate.展开更多
Aqueous Zn-based batteries(AZBs)are hindered by issues associated with the Zn electrodeposition process(ZEDP)on electrode surfaces,including passivation,dendrite formation,and hydrogen evolution.One of the important r...Aqueous Zn-based batteries(AZBs)are hindered by issues associated with the Zn electrodeposition process(ZEDP)on electrode surfaces,including passivation,dendrite formation,and hydrogen evolution.One of the important reasons is the drastic fluctuation in the concentration of Zn^(2+)ions on the electrode surface during the charging and discharging process.In this work,an electrolyte with Zn^(2+)ion buffer layer(EZIBL)is proposed to regulate the ZEDP.First,numerical simulations and corresponding experiments are conducted to assess the impact of different thicknesses of the Zn^(2+)ion buffer layer(ZIBL)on the variation in Zn^(2+)ion concentration,from which the optimal thickness of the ZIBL is determined.Then,the regulation role of EZIBL in the cycling process is demonstrated by a Zn-Cu half cell.Further,combined with the potential profile of the symmetric cell and the experimental phenomena,the regulation role of EZIBL in ZEDP is systematically explained at the mechanistic level through the analysis of key parameters.Finally,a full battery composed of Zn-LiMn2O4 is assembled to evaluate the practical applicability of the EZIBL in real battery cycles,which shows great enhancement in capacity retention and coulombic efficiency.This work proposes the design of the EZIBL used to regulate the ZEDP and provides a simple,low-cost regulation method for the development of high-performance AZBs.展开更多
Virtual Reality(VR)is a key industry for the development of the digital economy in the future.Mobile VR has advantages in terms of mobility,lightweight and cost-effectiveness,which has gradually become the mainstream ...Virtual Reality(VR)is a key industry for the development of the digital economy in the future.Mobile VR has advantages in terms of mobility,lightweight and cost-effectiveness,which has gradually become the mainstream implementation of VR.In this paper,a mobile VR video adaptive transmission mechanism based on intelligent caching and hierarchical buffering strategy in Mobile Edge Computing(MEC)-equipped 5G networks is proposed,aiming at the low latency requirements of mobile VR services and flexible buffer management for VR video adaptive transmission.To support VR content proactive caching and intelligent buffer management,users’behavioral similarity and head movement trajectory are jointly used for viewpoint prediction.The tile-based content is proactively cached in the MEC nodes based on the popularity of the VR content.Second,a hierarchical buffer-based adaptive update algorithm is presented,which jointly considers bandwidth,buffer,and predicted viewpoint status to update the tile chunk in client buffer.Then,according to the decomposition of the problem,the buffer update problem is modeled as an optimization problem,and the corresponding solution algorithms are presented.Finally,the simulation results show that the adaptive caching algorithm based on 5G intelligent edge and hierarchical buffer strategy can improve the user experience in the case of bandwidth fluctuations,and the proposed viewpoint prediction method can significantly improve the accuracy of viewpoint prediction by 15%.展开更多
This study explored the performances of CZTS-based thin-film solar cell with three novel buffer layer materials ZnS, CdS, and CdZnS, as well as with variation in thickness of buffer and absorber-layer, doping concentr...This study explored the performances of CZTS-based thin-film solar cell with three novel buffer layer materials ZnS, CdS, and CdZnS, as well as with variation in thickness of buffer and absorber-layer, doping concentrations of absorber-layer material and operating temperature. Our aims focused to identify the most optimal thin-film solar cell structure that offers high efficiency and lower toxicity which are desirable for sustainable and eco-friendly energy sources globally. SCAPS-1D, widely used software for modeling and simulating solar cells, has been used and solar cell fundamental performance parameters such as open-circuited voltage (), short-circuited current density (), fill-factor() and efficiency() have been optimized in this study. Based on our simulation results, it was found that CZTS solar cell with Cd<sub>0.4</sub>Zn<sub>0.6</sub>S as buffer-layer offers the most optimal combination of high efficiency and lower toxicity in comparison to other structure investigated in our study. Although the efficiency of Cd<sub>0.4</sub>Zn<sub>0.6</sub>S, ZnS and CdS are comparable, Cd<sub>0.4</sub>Zn<sub>0.6</sub>S is preferable to use as buffer-layer for its non-toxic property. In addition, evaluation of performance as a function of buffer-layer thickness for Cd<sub>0.4</sub>Zn<sub>0.6</sub>S, ZnS and CdS showed that optimum buffer-layer thickness for Cd<sub>0.4</sub>Zn<sub>0.6</sub>S was in the range from 50 to 150nm while ZnS offered only 50 – 75 nm. Furthermore, the temperature dependence performance parameters evaluation revealed that it is better to operate solar cell at temperature 290K for stable operation with optimum performances. This study would provide valuable insights into design and optimization of nanotechnology-based solar energy technology for minimizing global energy crisis and developing eco-friendly energy sources sustainable and simultaneously.展开更多
基金funded by the National Natural Science Foundation of China(No.62305041)the Natural Science Foundation of Liaoning Province(No.2023-MS-103)。
文摘Stochastic optical reconstruction microscopy(STORM),as a typical technique of single-molecule localization microscopy(SMLM),has overcome the diffraction limit by randomly switching fluorophores between fluorescent and dark states,allowing for the precise localization of isolated emission patterns and the super-resolution reconstruction from millions of localized positions of single fluorophores.A critical factor influencing localization precision is the photo-switching behavior of fluorophores,which is affected by the imaging buffer.The imaging buffer typically comprises oxygen scavengers,photo-switching reagents,and refractive index regulators.Oxygen scavengers help prevent photobleaching,photo-switching reagents assist in facilitating the conversion of fluorophores,and refractive index regulators are used to adjust the refractive index of the solution.The synergistic interaction of these components promotes stable blinking of fluorophores,reduces irreversible photobleaching,and thereby ensures high-quality super-resolution imaging.This review provides a comprehensive overview of the essential compositions and functionalities of imaging buffers used in STORM,serving as a valuable resource for researchers seeking to select appropriate imaging buffers for their experiments.
基金This work was supported by the German BMBF (No.05P21UMFN2)
文摘Man-made superheavy elements(SHE)are produced as energetic recoils in complete-fusion reactions and need to be thermalized in a gas-filled chamber for chemical studies.The ever-shorter half-lives and decreasing production rates of the elements beyond Fl(atomic number Z=114)-the heaviest element chemically studied today-require the development of novel techniques for quantitative thermalization and fast extraction efficiency.The Universal high-density gas stopping Cell(UniCell),currently under construction,was proposed to achieve this.Within this work,we propose an Ion Transfer by Gas Flow(ITGF)device,which serves as a UniCell ejector to interface with a gas chromatography detector array for chemical studies.Detailed parameter optimizations,using gas dynamics and Monte Carlo ion-trajectory simulations,promise fast(within a few ms)and highly efficient(up to 100%)ion extraction across a wide mass range.These ions can then be transmitted quantitatively through the ITGF into the high-pressure environment needed for further chemical studies.
基金the support of the National Natural Science Foundation of China(Grant No.42207199)Scientific Research Project of Education of Zhejiang Province(No.Y202351343)+1 种基金Zhejiang Postdoctoral Scientific Research Project(Grant Nos.ZJ2022155,ZJ2022156)Zhejiang Province International Science and Technology Cooperation Base Open Fund Project(IBGDP-2023-01)。
文摘The squeezing deformation of surrounding rock is an important factor restricting the safe construction and long-term operation of tunnels when a tunnel passes through soft strata with high ground stress.Under such soft rock geological conditions,the large deformation of the surrounding rock can easily lead to the failure of supporting structures,including shotcrete cracks,spalling,and steel arch distortion.To improve the lining support performance during the large deformation of squeezed surrounding rock,this work selects aluminum foam with densities of 0.25 g/cm3,0.42 g/cm3 and 0.61 g/cm3 as the buffer layer material and carries out uniaxial confined compression tests.Through the evaluation and analysis of energy absorption and the comparison of the yield pressure of aluminum foam with those of other cushioning materials and yield pressure support systems,the strength,deformation and energy absorption of aluminum foam with a density of 0.25 g/cm3 meet the yield pressure performance requirements.The numerical model of the buffer layer yielding support system is then established via the finite element analysis software ABAQUS,and the influence of the buffer layer setting on the lining support is analyzed.Compared with the conventional support scheme,the addition of an aluminum foam buffer layer can reduce the stress and deformation of the primary support and secondary lining.The maximum and minimum principal stresses of the primary support are reduced by 13%and 15%,respectively.The maximum and minimum principal stresses of the secondary lining are reduced by 15%and 12%,respectively,and the displacement deformation of the secondary lining position is reduced by 15%.In summary,the application of aluminum foam buffer layer can reduce the stress and deformation of the primary support and secondary lining,improve the stress safety of the support and reduce the deformation of the support.
文摘Photocatalytic hydrogen peroxide(H_(2)O_(2))production offers a sustainable route to convert water and oxygen into H_(2)O_(2)using solar energy.However,achieving long-term stability in photocatalysts remains a critical challenge due to mismatched kinetics between oxygen reduction(ORR)and water oxidation(WOR),which leads to hole accumulation and oxidative degradation.Here,we report a redox-mediated strategy to address this bottleneck by designing a hydroquinone-embedded covalent organic framework(Tz-QH-COF)that enables reversible hole buffering and kinetic balance.The hydroquinone(QH)units act as dynamic hole reservoirs,capturing excess holes during ORR and converting to benzoquinone(Q),which is regenerated to QH via WOR,thereby preventing oxidative decomposition.This reversible QH/Q cycle,directly visualized through in situ attenuated total reflection surface-enhanced infrared absorption spectroscopy,ensures unmatched stability,achieving continuous H_(2)O_(2) production for 528 h(22 d)with an accumulated yield of 18.6 mmol L^(–1)—the highest reported duration for organic photocatalysts.Density functional theory calculations reveal that the QH units exhibit a strong oxygen adsorption energy and favorable two-electron ORR/WOR pathways with low energy barriers.The synergy between experimental and theoretical insights elucidates a redox-mediated charge-balance mechanism,advancing the design of robust photocatalysts for solar-driven H_(2)O_(2) synthesis.
基金supported in part by the National Natural Science Foundation of China under Grant No.52175490.
文摘The shop scheduling problem with limited buffers has broad applications in real-world production scenarios,so this research direction is of great practical significance.However,there is currently little research on the hybrid flow shop scheduling problem with limited buffers(LBHFSP).This paper deeply investigates the LBHFSP to optimize the goal of the total completion time.To better solve the LBHFSP,a multi-level subpopulation-based particle swarm optimization algorithm(MLPSO)is proposed,which is founded on the attributes of the LBHFSP and the shortcomings of the basic PSO(particle swarm optimization)algorithm.In MLPSO,firstly,considering the impact of the limited buffers on the process of subsequent operations,a specific circular decoding strategy is developed to accommodate the characteristics of limited buffers.Secondly,an initialization strategy based on blocking time is designed to enhance the quality and diversity of the initial population.Afterward,a multi-level subpopulation collaborative search is developed to prevent being trapped in a local optimum and improve the global exploration capability.Additionally,a local search strategy based on the first blocked job is designed to enhance the MLPSO algorithm’s exploitation capability.Lastly,numerous experiments are carried out to test the performance of the proposed MLPSO by comparing it with classical intelligent optimization and popular algorithms in recent years.The results confirm that the proposed MLPSO has an outstanding performance when compared to other algorithms when solving LBHFSP.
基金supported by the Fund of Xuzhou Science and Technology Key R&D Program(Social Development)Project(No.KC22289)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX22_2783).
文摘Aqueous zinc-ion batteries(AZIBs)have developed rapidly in recent years but still face several challenges,including zinc dendrites growth,hydrogen evolution reaction,passivation and corrosion.The pH of the electrolyte plays a crucial role in these processes,significantly impacting the stability and reversibility of Zn^(2+)deposition.Therefore,pH-buffer tris(hydroxymethyl)amino methane(tris)is chosen as a versatile electrolyte additive to address these issues.Tris can buffer electrolyte pH at Zn/electrolyte interface by protonated/deprotonated nature of amino group,optimize the coordination environment of zinc solvate ions by its strong interaction with zinc ions,and simultaneously create an in-situ stable solid electrolyte interface membrane on the zinc anode surface.These synergistic effects effectively restrain dendrite formation and side reactions,resulting in a highly stable and reversible Zn anode,thereby enhancing the electrochemical performance of AZIBs.The Zn||Zn battery with 0.15 wt%tris additives maintains stable cycling for 1500 h at 4 mA·cm^(−2) and 1120 h at 10 mA·cm^(−2).Furthermore,the Coulombic efficiency reaches~99.2%at 4 mA·cm^(−2)@1 mAh·cm^(−2).The Zn||NVO full batteries also demonstrated a stable specific capacity and exceptional capacity retention.
基金supported by the National Key Research and Development Program of China(No.2021YFA0715600)the National Natural Science Foundation of China(Nos.62274125,52192611)+2 种基金the Guangdong Basic and Applied Basic Research Fund(No.2023A1515030084)the Key Research and Development Program of Shaanxi Province(Grant No.2024GX-YBXM-410)the fund of the State Key Laboratory of Solidification Processing in NWPU(No.SKLSP202220).
文摘Optimizing the orientation of β-Ga_(2)O_(3) has emerged as an effective strategy to design high-performance β-Ga_(2)O_(3) device,but the orientation growth mechanism and approach have not been revealed yet.Herein,by employing AlN buffer layer,the highly preferred orientation of β-Ga_(2)O_(3)(100)film rather than(-201)film is realized on 4H-SiC substrate at low sputtering power and temperature.Because β-Ga_(2)O_(3)(100)film exhibits a slower growth speed than(-201)film,the former possesses the higher dangling bond density and the lower nucleation energy,and a large conversion barrier exists between these two ori-entations.Moreover,the AlN buffer layer can suppress the surface oxidation of the 4H-SiC substrate and eliminate the strain of β-Ga_(2)O_(3)(100)film,which further reduces the nucleation energy and en-larges the conversion barrier.Meanwhile,the AlN buffer layer can increase the oxygen vacancy formation energy and decrease the oxygen vacancy concentration of β-Ga_(2)O_(3)(100)film.Consequently,the solar-blind photodetector based on the oriented film exhibits the outstanding detectivity of 1.22×10^(12) Jones and photo-to-dark current ratio of 1.11×10^(5),which are the highest among the reported β-Ga_(2)O_(3) solar-blind photodetector on the SiC substrate.Our results offer in-depth insights into the preferred orientation growth mechanism,and provide an effective way to design high-quality β-Ga_(2)O_(3)(100)orientation film and high-performance solar-blind photodetector.
基金conducted under the framework of the research and development program of the Korea Institute of Energy Research(C4-2412 and C4-2413)supported by the National Research Foundation of Korea(grant number 2022M3J1A1063019)funded by the Ministry of Science and ICT.
文摘Attempts to remove environmentally harmful materials in mass production industries are always a major issue and draw attention if the substitution guarantees a chance to lower fabrication cost and to improve device performance,as in a wide bandgap Zn_(1-x)Mg_(x)O(ZMO)to replace the CdS buffer in Cu(In_(1-x),Ga_(x))Se_(2)(CIGSe)thin-film solar cell structure.ZMO is one of the candidates for the buffer material in CIGSe thin-film solar cells with a wide and controllable bandgap depending on the Mg content,which can be helpful in attaining a suitable conduction band offset.Hence,compared to the fixed and limited bandgap of a CdS buffer,a ZMO buffer may provide advantages in V_(oc) and J_(sc) based on its controllable and wide bandgap,even with a relatively wider bandgap CIGSe thin-film solar cell.In addition,to solve problems with the defect sites at the ZMO/CIGSe junction interface,a few-nanometer ZnS layer is employed for heterojunction interface passivation,forming a ZMO/ZnS buffer structure by atomic layer deposition(ALD).Finally,a Cd-free all-dry-processed CIGSe solar cell with a wider bandgap(1.25 eV)and ALD-grown buffer structure exhibited the best power conversion efficiency of 19.1%,which exhibited a higher performance than the CdS counterpart.
文摘To detect the genome of viruses (in environmental and clinical samples), we use electrophoresis running buffer after PCR reaction. Also, electrophoresis buffers were used widely to separate any DNA molecule. In this paper, we used four types of previously known electrophoresis buffers to compare which is easy for preparation, simple in structure, low cost and good performance in agarose gel electrophoresis. For this, we used two agarose concentration (1%, 2%) and two types of DNA ladder (100 bp, 1 kb) represent both smaller and larger sizes of molecule for each type of buffers, from the result we found in first level both supper buffer and TAE buffer with good performance and in second level we found bicarbonate buffer also with good performance also. Finally, we found the tang buffer cannot pose any electrophoretic activity on DNA agarose gel electrophoresis.
基金supported by the Major project of Ministry of Agriculture and Rural Affairs of the People’s Republic of China(No.NK2022180401)the major project of Ministry of Agriculture and Rural Affairs of the People’s Republic of China(No.NK2022180404)。
文摘Soil acidification is a major threat to agricultural sustainability in tropical and subtropical regions.Biodegradable and environmentally friendly materials,such as calcium lignosulfonate(CaLS),calcium poly(aspartic acid)(PASP-Ca),and calcium polyγ-glutamic acid(γ-PGA-Ca),are known to effectively ameliorate soil acidity.However,their effectiveness in inhibiting soil acidification has not been studied.This study aimed to evaluate the effect of CaLS,PASP-Ca,andγ-PGA-Ca on the resistance of soil toward acidification as directly and indirectly(i.e.,via nitrification)caused by the application of HNO_(3)and urea,respectively.For comparison,Ca(OH)_(2)and lignin were used as the inorganic and organic controls,respectively.Among the materials,γ-PGA-Ca drove the substantial improvements in the pH buffering capacity(pHBC)of the soil and exhibited the greatest potential in inhibiting HNO_(3)-induced soil acidification via protonation of carboxyl,complexing with Al~(3+),and cation exchange processes.Under acidification induced by urea,CaLS was the optimal one in inhibiting acidification and increasing exchangeable acidity during incubation.Furthermore,the sharp reduction in the population sizes of ammonia-oxidizing bacteria(AOB)and ammonia-oxidizing archaea(AOA)confirmed the inhibition of nitrification via CaLS application.Therefore,compared to improving soil pHBC,CaLS may play a more important role in suppressing indirect acidification.Overall,γ-PGA-Ca was superior to PASP-Ca and CaLS in enhancing the soil pHBC and the its resistance to acidification induced by HNO_(3) addition,whereas CaLS was the best at suppressing urea-driven soil acidification by inhibiting nitrification.In conclusion,these results provide a reference for inhibiting soil re-acidification in intensive agricultural systems.
基金the financial support by the National Natural Science Foundation of China(No.12272094)the Natural Science Foundation of Fujian Province of China(No.2022J01541)Natural Science Foundation of Hubei Province of China(No.2022CFB441)。
文摘An innovative metallic buffer consisting of series-connected hat-shaped entangled wire mesh damper(EWMD)and parallel springs are proposed in this work to enhance the reliability of engineering equipment.The impact response and the energy dissipation mechanism of hat-shaped EWMD under different quasi-static compression deformations(2-7 mm)and impact heights(100-200 mm)are investigated using experimental and numerical methods.The results demonstrate distinct stages in the quasi-static mechanical characteristics of hat-shaped EWMD,including stiffness softening,negative stiffness,and stiffness hardening.The loss factor gradually increases with increasing compression deformation before entering the stiffness hardening stage.Under impact loads,the hat-shaped EWMD exhibits optimal impact energy absorption when it enters the negative stiffness stage(150 mm),resulting in the best impact isolation effect of metallic buffer.However,the impact energy absorption significantly decreases when hat-shaped EWMD enters the stiffness hardening stage.Interestingly,quasi-static compression analysis after experiencing different impact loads reveals the disappearance of the negative stiffness phenomenon.Moreover,with increasing impact loads,the stiffness hardening point progressively shifts to an earlier stage.
基金supported in part by the Hubei Provincial Science and Technology Major Project of China(Grant No.2020AEA011)in part by the National Ethnic Affairs Commission of the People’s Republic of China(Training Program for Young and Middle-aged Talents)(No:MZR20007)+4 种基金in part by the National Natural Science Foundation of China(Grant No.61902437)in part by the Hubei Provincial Natural Science Foundation of China(Grant No.2020CFB629)in part by the Application Foundation Frontier Project of Wuhan Science and Technology Program(Grant No.2020020601012267)in part by the Fundamental Research Funds for the Central Universities,South-Central MinZu University(No:CZQ21026)in part by the Special Project on Regional Collaborative Innovation of Xinjiang Uygur Autonomous Region(Plan to Aid Xinjiang with Science and Technology)(2022E02035)。
文摘The path planning of Unmanned Aerial Vehicle(UAV)is a critical issue in emergency communication and rescue operations,especially in adversarial urban environments.Due to the continuity of the flying space,complex building obstacles,and the aircraft's high dynamics,traditional algorithms cannot find the optimal collision-free flying path between the UAV station and the destination.Accordingly,in this paper,we study the fast UAV path planning problem in a 3D urban environment from a source point to a target point and propose a Three-Step Experience Buffer Deep Deterministic Policy Gradient(TSEB-DDPG)algorithm.We first build the 3D model of a complex urban environment with buildings and project the 3D building surface into many 2D geometric shapes.After transformation,we propose the Hierarchical Learning Particle Swarm Optimization(HL-PSO)to obtain the empirical path.Then,to ensure the accuracy of the obtained paths,the empirical path,the collision information and fast transition information are stored in the three experience buffers of the TSEB-DDPG algorithm as dynamic guidance information.The sampling ratio of each buffer is dynamically adapted to the training stages.Moreover,we designed a reward mechanism to improve the convergence speed of the DDPG algorithm for UAV path planning.The proposed TSEB-DDPG algorithm has also been compared to three widely used competitors experimentally,and the results show that the TSEB-DDPG algorithm can archive the fastest convergence speed and the highest accuracy.We also conduct experiments in real scenarios and compare the real path planning obtained by the HL-PSO algorithm,DDPG algorithm,and TSEB-DDPG algorithm.The results show that the TSEBDDPG algorithm can archive almost the best in terms of accuracy,the average time of actual path planning,and the success rate.
基金Project supported by the National Natural Science Foundation of China (Grant No.12274108)the Natural Science Foundation of Zhejiang Province,China (Grant Nos.LY23A040008 and LY23A040008)the Basic Scientific Research Project of Wenzhou,China (Grant No.G20220025)。
文摘Field-free spin-orbit torque(SOT)switching of perpendicular magnetization is essential for future spintronic devices.This study demonstrates the field-free switching of perpendicular magnetization in an HfO_(2)/Pt/Co/TaO_(x) structure,which is facilitated by a wedge-shaped HfO_(2)buffer layer.The field-free switching ratio varies with HfO_(2)thickness,reaching optimal performance at 25 nm.This phenomenon is attributed to the lateral anisotropy gradient of the Co layer,which is induced by the wedge-shaped HfO_(2)buffer layer.The thickness gradient of HfO_(2)along the wedge creates a corresponding lateral anisotropy gradient in the Co layer,correlating with the switching ratio.These findings indicate that field-free SOT switching can be achieved through designing buffer layer,offering a novel approach to innovating spin-orbit device.
基金financially supported by the National Natural Science Foundation of China (22279083,22109166,52202183)Guangdong Basic and Applied Basic Research Foundation (Grant No.2019A1515011136,2022B1515120006,2023B1515120041,2414050001473)+3 种基金Guangdong Province Higher Vocational Colleges and Schools Pearl River Scholar Funded SchemeGuangdong Provincial Key Laboratory Program (2021B1212040001)from the Department of Science and Technology of Guangdong ProvinceBeijing Institute of TechnologySongshan Lake Materials Laboratory。
文摘Near-infrared(NIR)transparent inverted all-inorganic perovskite solar cells(PSCs)are excellent top cell candidates in tandem applications.An essential challenge is the replacement of metal contacts with transparent conductive oxide(TCO)electrodes,which requires the introduction of a buffer layer to prevent sputtering damage.In this study,we show that the conventional buffers(i.e.,small organic molecules and atomic layer deposited metal oxides)used for organic-inorganic hybrid perovskites are not applicable to all-inorganic perovskites,due to non-uniform coverage of the vulnerable layers underneath,deterioration upon ion bombardment and moisture induced perovskite phase transition,A thin film of metal oxide nanoparticles by the spin-coating method serves as a non-destructive buffer layer for inorganic PSCs.All-inorganic inverted near-infrared-transparent PSCs deliver a PCE of 17.46%and an average transmittance of 73.7%between 780 and 1200 nm.In combination with an 18.56%Cu(In,Ga)Se_(2) bottom cell,we further demonstrate the first all-inorganic perovskite/CIGS 4-T tandem solar cell with a PCE of 24.75%,which exhibits excellent illumination stability by maintaining 86.7%of its initial efficiency after 1400 h.The non-destructive buffer lays the foundation for efficient and stable NIR-transparent inverted inorganic perovskite solar cells and perovskite-based tandems.
基金supported by the National Natural Science Foundation of China(No.52070162)。
文摘Anammox bacteria grow slowly and can be affected by large pH fluctuations.Using suitable buffers could make the start-up of anammox reactors easy and rapid.In this study,the effects of three kinds of buffers on the nitrogen removal and growth characteristics of anammox sludge were investigated.Reactors with CO_(2)/NaHCO_(3)buffer solution(CCBS)performed the best in nitrogen removal,while 4-(2-hydroxyerhyl)piperazine-1-ethanesulfonic acid(HEPES)and phosphate buffer solution(PBS)inhibited the anammox activity.Reactors with 50 mmol/L CCBS could start up in 20 days,showing the specific anammox activity and anammox activity of 1.01±0.10 gN/(gVSS·day)and 0.83±0.06 kgN/(m^(3)·day),respectively.Candidatus Kuenenia was the dominant anammox bacteria,with a relative abundance of 71.8%.Notably,anammox reactors could also start quickly by using 50 mmol/L CCBS under nonstrict anaerobic conditions.These findings are meaningful for the quick start-up of engineered anammox reactors and prompt enrichment of anammox bacteria.
文摘Two methods of irrigation,drip,and sprinkler were studied to determine the response of the Javits green roof to irrigation.The control study was dry unirrigated plots.Drip irrigation consisted of irrigation tubes running through the green roof that would water the soil throughout and sprinkler irrigation used a sprinkler system to irrigate the green roof from above.In all cases,the irrigated roofs had increased the soil moisture,reduced temperatures of both the upper and lower surfaces,reduced growing medium temperatures and reduced air temperatures above the green roof relative to the unirrigated roof.The buffered temperature fluctuations were also studied via air conditioner energy consumption.There was a 28%reduction in air conditioner energy consumption and a 33%reduction in overall energy consumption between dry and irrigated plots.Values of thermal resistance or S were determined for accuracy and for this study,there was little change which is ideal.A series of infra-red and thermal probe measurements were used to determine temperatures in the air and sedum.It was determined that the sprinkler irrigation did a better job than the drip irrigation in keeping cooler temperatures within the green roof.A Mann-Whitney U test was performed to verify the variation in moisture temperatures buffering energy consumption.By getting a p-value<0.05,it indicates that the model is accurate for prediction and medium temperatures were statistically different.
基金National Natural Science Foundation of China(No.61902060)Shanghai Sailing Program,China(No.19YF1402100)+1 种基金Fundamental Research Funds for the Central Universities,China(No.2232019D3-51)Open Foundation of State Key Laboratory of Networking and Switching Technology(Beijing University of Posts and Telecommunications,China)(No.SKLNST-2021-1-06)。
文摘Mobile edge computing (MEC) has a vital role in various delay-sensitive applications. With the increasing popularity of low-computing-capability Internet of Things (IoT) devices in industry 4.0 technology, MEC also facilitates wireless power transfer, enhancing efficiency and sustainability for these devices. The most related studies concerning the computation rate in MEC are based on the coordinate descent method, the alternating direction method of multipliers (ADMMs) and Lyapunov optimization. Nevertheless, these studies do not consider the buffer queue size. This research work concerns the computation rate maximization for wireless-powered and multiple-user MEC systems, specifically focusing on the computation rate of end devices and managing the task buffer queue before computation at the terminal devices. A deep reinforcement learning (RL)-based task offloading algorithm is proposed to maximize the computation rate of end devices and minimizes the buffer queue size at the terminal devices.Precisely, considering the channel gain, the buffer queue size and wireless power transfer, it further formalizes the task offloading problem. The mode selection for task offloading is based on the individual channel gain, the buffer queue size and wireless power transfer maximization in a particular time slot.The central idea of this work is to explore the best optimal mode selection for IoT devices connected to the MEC system. The proposed algorithm optimizes computation delay by maximizing the computation rate of end devices and minimizing the buffer queue size before computation at the terminal devices. Then, the current study presents a deep RL-based task offloading algorithm to solve such a mixed-integer and non-convex optimization problem, aiming to get a better trade-off between the buffer queue size and the computation rate. The extensive simulation results reveal that the presented algorithm is much more efficient than the existing work to maintain a small buffer queue for terminal devices while simultaneously achieving a high-level computation rate.
基金funding support from National Innovative Talents Program(GG2090007001)USTC Startup Program(KY2090000044).
文摘Aqueous Zn-based batteries(AZBs)are hindered by issues associated with the Zn electrodeposition process(ZEDP)on electrode surfaces,including passivation,dendrite formation,and hydrogen evolution.One of the important reasons is the drastic fluctuation in the concentration of Zn^(2+)ions on the electrode surface during the charging and discharging process.In this work,an electrolyte with Zn^(2+)ion buffer layer(EZIBL)is proposed to regulate the ZEDP.First,numerical simulations and corresponding experiments are conducted to assess the impact of different thicknesses of the Zn^(2+)ion buffer layer(ZIBL)on the variation in Zn^(2+)ion concentration,from which the optimal thickness of the ZIBL is determined.Then,the regulation role of EZIBL in the cycling process is demonstrated by a Zn-Cu half cell.Further,combined with the potential profile of the symmetric cell and the experimental phenomena,the regulation role of EZIBL in ZEDP is systematically explained at the mechanistic level through the analysis of key parameters.Finally,a full battery composed of Zn-LiMn2O4 is assembled to evaluate the practical applicability of the EZIBL in real battery cycles,which shows great enhancement in capacity retention and coulombic efficiency.This work proposes the design of the EZIBL used to regulate the ZEDP and provides a simple,low-cost regulation method for the development of high-performance AZBs.
基金supported in part by the Chongqing Municipal Education Commission projects under Grant No.KJCX2020035,KJQN202200829Chongqing Science and Technology Commission projects under grant No.CSTB2022BSXM-JCX0117 and cstc2020jcyjmsxmX0339+1 种基金supported in part by National Natural Science Foundation of China under Grant No.(62171072,62172064,62003067,61901067)supported in part by Chongqing Technology and Business University projects under Grant no.(2156004,212017).
文摘Virtual Reality(VR)is a key industry for the development of the digital economy in the future.Mobile VR has advantages in terms of mobility,lightweight and cost-effectiveness,which has gradually become the mainstream implementation of VR.In this paper,a mobile VR video adaptive transmission mechanism based on intelligent caching and hierarchical buffering strategy in Mobile Edge Computing(MEC)-equipped 5G networks is proposed,aiming at the low latency requirements of mobile VR services and flexible buffer management for VR video adaptive transmission.To support VR content proactive caching and intelligent buffer management,users’behavioral similarity and head movement trajectory are jointly used for viewpoint prediction.The tile-based content is proactively cached in the MEC nodes based on the popularity of the VR content.Second,a hierarchical buffer-based adaptive update algorithm is presented,which jointly considers bandwidth,buffer,and predicted viewpoint status to update the tile chunk in client buffer.Then,according to the decomposition of the problem,the buffer update problem is modeled as an optimization problem,and the corresponding solution algorithms are presented.Finally,the simulation results show that the adaptive caching algorithm based on 5G intelligent edge and hierarchical buffer strategy can improve the user experience in the case of bandwidth fluctuations,and the proposed viewpoint prediction method can significantly improve the accuracy of viewpoint prediction by 15%.
文摘This study explored the performances of CZTS-based thin-film solar cell with three novel buffer layer materials ZnS, CdS, and CdZnS, as well as with variation in thickness of buffer and absorber-layer, doping concentrations of absorber-layer material and operating temperature. Our aims focused to identify the most optimal thin-film solar cell structure that offers high efficiency and lower toxicity which are desirable for sustainable and eco-friendly energy sources globally. SCAPS-1D, widely used software for modeling and simulating solar cells, has been used and solar cell fundamental performance parameters such as open-circuited voltage (), short-circuited current density (), fill-factor() and efficiency() have been optimized in this study. Based on our simulation results, it was found that CZTS solar cell with Cd<sub>0.4</sub>Zn<sub>0.6</sub>S as buffer-layer offers the most optimal combination of high efficiency and lower toxicity in comparison to other structure investigated in our study. Although the efficiency of Cd<sub>0.4</sub>Zn<sub>0.6</sub>S, ZnS and CdS are comparable, Cd<sub>0.4</sub>Zn<sub>0.6</sub>S is preferable to use as buffer-layer for its non-toxic property. In addition, evaluation of performance as a function of buffer-layer thickness for Cd<sub>0.4</sub>Zn<sub>0.6</sub>S, ZnS and CdS showed that optimum buffer-layer thickness for Cd<sub>0.4</sub>Zn<sub>0.6</sub>S was in the range from 50 to 150nm while ZnS offered only 50 – 75 nm. Furthermore, the temperature dependence performance parameters evaluation revealed that it is better to operate solar cell at temperature 290K for stable operation with optimum performances. This study would provide valuable insights into design and optimization of nanotechnology-based solar energy technology for minimizing global energy crisis and developing eco-friendly energy sources sustainable and simultaneously.
