Mussel aquaculture and large yellow croaker aquaculture areas and their environmental characteristics in Zhoushan were analyzed using satellite data and in-situ surveys.A new two-step remote sensing method was propose...Mussel aquaculture and large yellow croaker aquaculture areas and their environmental characteristics in Zhoushan were analyzed using satellite data and in-situ surveys.A new two-step remote sensing method was proposed and applied to determine the basic environmental characteristics of the best mussel and large yellow croaker aquaculture areas.This methodology includes the first step of extraction of the location distribution and the second step of the extraction of internal environmental factors.The fishery ranching index(FRI1,FRI2)was established to extract the mussel and the large yellow croaker aquaculture area in Zhoushan,using Gaofen-1(GF-1)and Gaofen-6(GF-6)satellite data with a special resolution of 2 m.In the second step,the environmental factors such as sea surface temperature(SST),chlorophyll a(Chl-a)concentration,current and tide,suspended sediment concentration(SSC)in mussel aquaculture area and large yellow croaker aquaculture area were extracted and analyzed in detail.The results show the following three points.(1)For the extraction of the mussel aquaculture area,FRI1 and FRI2 are complementary,and the combination of FRI1 and FRI2 is suitable to extract the mussel aquaculture area.As for the large yellow croaker aquaculture area extraction,FRI2 is suitable.(2)Mussel aquaculture and the large yellow croaker aquaculture area in Zhoushan are mainly located on the side near the islands that are away from the eastern open waters.The water environment factor template suitable for mussel and large yellow croaker aquaculture was determined.(3)This two-step remote sensing method can be used for the preliminary screening of potential site selection for the mussels and large yellow croaker aquaculture area in the future.the fishery ranching index(FRI1,FRI2)in this paper can be applied to extract the mussel and large yellow croaker aquaculture areas in coastal waters around the world.展开更多
Thermal energy storage(TES)solutions offer opportunities to reduce energy consumption,greenhouse gas emissions,and cost.Specifically,they can help reduce the peak load and address the intermittency of renewable energy...Thermal energy storage(TES)solutions offer opportunities to reduce energy consumption,greenhouse gas emissions,and cost.Specifically,they can help reduce the peak load and address the intermittency of renewable energy sources by time shifting the load,which are critical toward zero energy buildings.Thermochemical materials(TCMs)as a class of TES undergo a solid-gas reversible chemical reaction with water vapor to store and release energy with high storage capacities(600 kWh m^(-3))and negligible self-discharge that makes them uniquely suited as compact,stand-alone units for daily or seasonal storage.However,TCMs suffer from instabilities at the material(salt particles)and reactor level(packed beds of salt),resulting in poor multi-cycle efficiency and high-levelized cost of storage.In this study,a model is developed to predict the pulverization limit or Rcrit of various salt hydrates during thermal cycling.This is critical as it provides design rules to make mechanically stable TCM composites as well as enables the use of more energy-efficient manufacturing process(solid-state mixing)to make the composites.The model is experimentally validated on multiple TCM salt hydrates with different water content,and effect of Rcrit on hydration and dehydration kinetics is also investigated.展开更多
In fossil energy pollution is serious and the“double carbon”goal is being promoted,as a symbol of fresh energy in the electrical system,solar and wind power have an increasing installed capacity,only conventional un...In fossil energy pollution is serious and the“double carbon”goal is being promoted,as a symbol of fresh energy in the electrical system,solar and wind power have an increasing installed capacity,only conventional units obviously can not solve the new energy as the main body of the scheduling problem.To enhance the systemscheduling ability,based on the participation of thermal power units,incorporate the high energy-carrying load of electro-melting magnesiuminto the regulation object,and consider the effects on the wind unpredictability of the power.Firstly,the operating characteristics of high energy load and wind power are analyzed,and the principle of the participation of electrofusedmagnesiumhigh energy-carrying loads in the elimination of obstructedwind power is studied.Second,a two-layer optimization model is suggested,with the objective function being the largest amount of wind power consumed and the lowest possible cost of system operation.In the upper model,the high energy-carrying load regulates the blocked wind power,and in the lower model,the second-order cone approximation algorithm is used to solve the optimizationmodelwithwind power uncertainty,so that a two-layer optimizationmodel that takes into account the regulation of the high energy-carrying load of the electrofused magnesium and the uncertainty of the wind power is established.Finally,the model is solved using Gurobi,and the results of the simulation demonstrate that the suggested model may successfully lower wind abandonment,lower system operation costs,increase the accuracy of day-ahead scheduling,and lower the final product error of the thermal electricity unit.展开更多
This study aims to provide electricity to a remote village in the Union of Comoros that has been affected by energy problems for over 40 years. The study uses a 50 kW diesel generator, a 10 kW wind turbine, 1500 kW ph...This study aims to provide electricity to a remote village in the Union of Comoros that has been affected by energy problems for over 40 years. The study uses a 50 kW diesel generator, a 10 kW wind turbine, 1500 kW photovoltaic solar panels, a converter, and storage batteries as the proposed sources. The main objective of this study is to conduct a detailed analysis and optimization of a hybrid diesel and renewable energy system to meet the electricity demand of a remote area village of 800 to 1500 inhabitants located in the north of Ngazidja Island in Comoros. The study uses the Hybrid Optimization Model for Electric Renewable (HOMER) Pro to conduct simulations and optimize the analysis using meteorological data from Comoros. The results show that hybrid combination is more profitable in terms of margin on economic cost with a less expensive investment. With a diesel cost of $1/L, an average wind speed of 5.09 m/s and a solar irradiation value of 6.14 kWh/m<sup>2</sup>/day, the system works well with a proportion of renewable energy production of 99.44% with an emission quantity of 1311.407 kg/year. 99.2% of the production comes from renewable sources with an estimated energy surplus of 2,125,344 kWh/year with the cost of electricity (COE) estimated at $0.18/kWh, presenting a cost-effective alternative compared to current market rates. These results present better optimization of the used hybrid energy system, satisfying energy demand and reducing the environmental impact.展开更多
Learning progressions divide the logical system of a subject into ordered and continuously developing levels that are suitable for the cognitive development level of students,which plays an important role in understan...Learning progressions divide the logical system of a subject into ordered and continuously developing levels that are suitable for the cognitive development level of students,which plays an important role in understanding students’learning process.This paper focuses on the theme of“kinetic energy”in high school physics as the research object.Firstly,the concept map was used to represent the relationship between knowledge,and then five core concepts were selected based on the opinions of high school teachers.Secondly,the test tools were compiled and tested based on the relevant test questions.Finally,the paper analyzed the results based on the Rasch model,clarified students’cognitive development level of“kinetic energy”and constructed the learning progressions of“kinetic energy”based on the logical order of subject knowledge.The research provides theoretical and methodological support for the study of other subjects and learning progressions,and provides a valuable reference for high school teachers to effectively carry out the instruction of“kinetic energy.”展开更多
Objective: Given the unique cultural background, way of life, and physical environment of the Tibetan Plateau, this study aims to investigate the effects of health education using problem-based learning (PBL) approach...Objective: Given the unique cultural background, way of life, and physical environment of the Tibetan Plateau, this study aims to investigate the effects of health education using problem-based learning (PBL) approaches on the knowledge, attitude, practice, and coping skills of women with high-risk pregnancies in this region. Methods: 76 high-risk pregnancy cases were enrolled at Tibet’s Linzhi People’s Hospital between September 2023 and April 2024. 30 patients admitted between September 2023 and December 2023 were selected as the control group and were performed with regular patient education. 46 patients admitted between January 2024 and April 2024 were selected as the observation group and were performed regular patient education with problem-based learning approaches. Two groups’ performance on their health knowledge, attitude, practice and coping skills before and after interventions were evaluated, and patient satisfaction were measured at the end of the study. Results: There was no statistical significance (P P P Conclusions: Health education with problem-based learning approaches is worth promoting as it can help high-risk pregnant women in plateau areas develop better health knowledge, attitude and practice and healthier coping skills. Also, it can improve patient sanctification.展开更多
Extending the ionic conductivity is the pre-requisite of electrolytes in fuel cell technology for high-electrochemical performance.In this regard,the introduction of semiconductor-oxide materials and the approach of h...Extending the ionic conductivity is the pre-requisite of electrolytes in fuel cell technology for high-electrochemical performance.In this regard,the introduction of semiconductor-oxide materials and the approach of heterostructure formation by modulating energy bands to enhance ionic conduction acting as an electrolyte in fuel cell-device.Semiconductor(n-type;SnO_(2))plays a key role by introducing into p-type SrFe_(0.2)Ti_(0.8)O_(3-δ)(SFT)semiconductor perovskite materials to construct p-n heterojunction for high ionic conductivity.Therefore,two different composites of SFT and SnO_(2)are constructed by gluing p-and n-type SFT-SnO_(2),where the optimal composition of SFT-SnO_(2)(6∶4)heterostructure electrolyte-based fuel cell achieved excellent ionic conductivity 0.24 S cm^(-1)with power-output of 1004 mW cm^(-2)and high OCV 1.12 V at a low operational temperature of 500℃.The high power-output and significant ionic conductivity with durable operation of 54 h are accredited to SFT-SnO_(2)heterojunction formation including interfacial conduction assisted by a built-in electric field in fuel cell device.Moreover,the fuel conversion efficiency and considerable Faradaic efficiency reveal the compatibility of SFT-SnO_(2)heterostructure electrolyte and ruled-out short-circuiting issue.Further,the first principle calculation provides sufficient information on structure optimization and energy-band structure modulation of SFT-SnO_(2).This strategy will provide new insight into semiconductor-based fuel cell technology to design novel electrolytes.展开更多
Silicon(Si)is widely used as a lithium‐ion‐battery anode owing to its high capacity and abundant crustal reserves.However,large volume change upon cycling and poor conductivity of Si cause rapid capacity decay and p...Silicon(Si)is widely used as a lithium‐ion‐battery anode owing to its high capacity and abundant crustal reserves.However,large volume change upon cycling and poor conductivity of Si cause rapid capacity decay and poor fast‐charging capability limiting its commercial applications.Here,we propose a multilevel carbon architecture with vertical graphene sheets(VGSs)grown on surfaces of subnanoscopically and homogeneously dispersed Si–C composite nanospheres,which are subsequently embedded into a carbon matrix(C/VGSs@Si–C).Subnanoscopic C in the Si–C nanospheres,VGSs,and carbon matrix form a three‐dimensional conductive and robust network,which significantly improves the conductivity and suppresses the volume expansion of Si,thereby boosting charge transport and improving electrode stability.The VGSs with vast exposed edges considerably increase the contact area with the carbon matrix and supply directional transport channels through the entire material,which boosts charge transport.The carbon matrix encapsulates VGSs@Si–C to decrease the specific surface area and increase tap density,thus yielding high first Coulombic efficiency and electrode compaction density.Consequently,C/VGSs@Si–C delivers excellent Li‐ion storage performances under industrial electrode conditions.In particular,the full cells show high energy densities of 603.5 Wh kg^(−1)and 1685.5 Wh L^(−1)at 0.1 C and maintain 80.7%of the energy density at 3 C.展开更多
Finding sustainable energy resources is essential to face the increasing energy demand.Trees are an important part of ancient architecture but are becoming rare in urban areas.Trees can control and tune the pedestrian...Finding sustainable energy resources is essential to face the increasing energy demand.Trees are an important part of ancient architecture but are becoming rare in urban areas.Trees can control and tune the pedestrian-level wind velocity and thermal condition.In this study,a numerical investigation is employed to assess the role of trees planted in the windward direction of the building complex on the thermal and pedestrian wind velocity conditions around/inside a pre-education building located in the center of the complex.Compared to the previous studies(which considered only outside buildings),this work considers the effects of trees on microclimate change both inside/outside buildings.Effects of different parameters including the leaf area density and number of trees,number of rows,far-field velocity magnitude,and thermal condition around the main building are assessed.The results show that the flow velocity in the spacing between the first-row buildings is reduced by 30%-40% when the one-row trees with 2 m height are planted 15 m farther than the buildings.Furthermore,two rows of trees are more effective in higher velocities and reduce the maximum velocity by about 50%.The investigation shows that trees also could reduce the temperature by about 1℃around the building.展开更多
With the increasing spotlight in electric vehicles,there is a growing demand for high-energy-density batteries to enhance driving range.Consequently,several studies have been conducted on high-energy-density LiNi_(x)C...With the increasing spotlight in electric vehicles,there is a growing demand for high-energy-density batteries to enhance driving range.Consequently,several studies have been conducted on high-energy-density LiNi_(x)Co_(y)Mn_(z)O_(2)cathodes.However,there is a limit to permanent performance deterioration because of side reactions caused by moisture in the atmosphere and continuous microcracks during cycling as the Ni content to express high energy increases and the content of Mn and Co that maintain structural and electrochemical stabilization decreases.The direct modification of the surface and bulk regions aims to enhance the capacity and long-term performance of high-Ni cathode materials.Therefore,an efficient modification requires a study based on a thorough understanding of the degradation mechanisms in the surface and bulk region.In this review,a comprehensive analysis of various modifications,including doping,coating,concentration gradient,and single crystals,is conducted to solve degradation issues along with an analysis of the overall degradation mechanism occurring in high-Ni cathode materials.It also summarizes recent research developments related to the following modifications,aims to provide notable points and directions for post-studies,and provides valuable references for the commercialization of stable high-energy-density cathode materials.展开更多
The development of high-energy and long-lifespan NASICON-type cathode materials for sodium-ion batteries has always been a research hotspot but a daunting challenge.Although Na_(4)MnCr(PO_(4))_(3)has emerged as one of...The development of high-energy and long-lifespan NASICON-type cathode materials for sodium-ion batteries has always been a research hotspot but a daunting challenge.Although Na_(4)MnCr(PO_(4))_(3)has emerged as one of the most promising high-energy-density cathode materials owing to its three-electron reactions,it still suffers from serious structural distortion upon repetitive charge/discharge processes caused by the Jahn-Teller active Mn^(3+).Herein,the selective substitution of Cr by Zr in Na_(4)MnCr(PO_(4))_(3)was explored to enhance the structural stability,due to the pinning effect of Zr ions and the≈2.9-electron reactions,as-prepared Na_(3.9)MnCr_(0.9)Zr_(0.1)(PO_(4))_(3)/C delivers a high capacity retention of 85.94%over 500 cycles at 5 C and an ultrahigh capacity of 156.4 mAh g^(-1)at 0.1 C,enabling the stable energy output as high as 555.2 Wh kg^(-1).Moreover,during the whole charge/discharge process,a small volume change of only 6.7%was verified by in situ X-ray diffraction,and the reversible reactions of Cr^(3+)/Cr^(4+),Mn^(3+)/Mn^(4+),and Mn^(2+)/Mn^(3+)redox couples were identified via ex situ X-ray photoelectron spectroscopy analyses.Galvanostatic intermittent titration technique tests and density functional theory calculations further demonstrated the fast reaction kinetics of the Na_(3.9)MnCr_(0.9)Zr_(0.1)(PO_(4))_(3)/C electrode.This work offers new opportunities for designing high-energy and high-stability NASICON cathodes by ion doping.展开更多
Since the first laser was invented,the pursuit of high-energy lasers(HELs)has always been enthusiastic.The first revolution of HELs was pushed by the fusion of laser and aerospace in the 1960s,with the chemical rocket...Since the first laser was invented,the pursuit of high-energy lasers(HELs)has always been enthusiastic.The first revolution of HELs was pushed by the fusion of laser and aerospace in the 1960s,with the chemical rocket engines giving fresh impetus to the birth of gas flow and chemical lasers,which finally turned megawatt lasers from dream into reality.Nowadays,the development of HELs has entered the age of electricity as well as the rocket engines.The properties of current electric rocket engines are highly consistent with HELs’goals,including electrical driving,effective heat dissipation,little medium consumption and extremely light weight and size,which inspired a second fusion of laser and aerospace and motivated the exploration for potential HELs.As an exploratory attempt,a new configuration of diode pumped metastable rare gas laser was demonstrated,with the gain generator resembling an electric rocket-engine for improved power scaling ability.展开更多
The environmental characteristics of hypothermia and hypoxia exert great selective pressure on the energy metabolism of high-altitude animals,especially the ectotherms.Current research on energy-limited adaptation of ...The environmental characteristics of hypothermia and hypoxia exert great selective pressure on the energy metabolism of high-altitude animals,especially the ectotherms.Current research on energy-limited adaptation of high-altitude ectotherms has focused on energy expenditures.However,the mechanisms of increasing energy intake in high-altitude ectotherms have been studied rarely.In order to investigate the adaptation mechanism of the small intestine,the key part of energy acquisition for animals,to energy limitation at high altitude in ectotherms,the gut proteins of Phrynocephalus vlangalii from high-and low-altitude populations were compared using label free proteomics.GO enrichment and KEGG pathway analysis showed that proteins associated with energy intake,such as those involved in oxidation-reduction processes,glutathione metabolism,oxidoreductase activity,cofactor binding,catalytic activity and metabolic pathways,were significantly up-regulated in high-altitude populations;while proteins associated with energy expenditure,such as immune responses and processes,membrane attack complexes,natural killer pathway and other immune-related processes,were significantly down-regulated in expression.展开更多
Herein,we report the design,fabrication,and performance of two wireless energy harvesting devices based on highly flexible graphene macroscopic films(FGMFs).We first demonstrate that benefiting from the high conductiv...Herein,we report the design,fabrication,and performance of two wireless energy harvesting devices based on highly flexible graphene macroscopic films(FGMFs).We first demonstrate that benefiting from the high conductivity of up to 1×10^(6)S m^(-1)and good resistive stability of FGMFs even under extensive bending,the FGMFs-based rectifying circuit(GRC)exhibits good flexibility and RF-to-DC efficiency of 53%at 2.1 GHz.Moreover,we further expand the application of FGMFs to a flexible wideband monopole rectenna and a 2.45 GHz wearable rectenna for harvesting wireless energy.The wideband rectenna at various bending conditions produces a maximum conversion efficiency of 52%,46%,and 44%at the 5th Generation(5G)2.1 GHz,Industrial Long-Term Evolution(LTE)2.3 GHz,and Scientific Medical(ISM)2.45 GHz,respectively.A 2.45 GHz GRC is optimized and integrated with an AMC-backed wearable antenna.The proposed 2.45 GHz wearable rectenna shows a maximum conversion efficiency of 55.7%.All the results indicate that the highly flexible graphene-film-based rectennas have great potential as a wireless power supplier for smart Internet of Things(loT)applications.展开更多
Developing a simple scalable method to fabricate electrodes with high capacity and wide voltage range is desired for the real use of electrochemical supercapacitors.Herein,we synthesized amorphous NiCo-LDH nanosheets ...Developing a simple scalable method to fabricate electrodes with high capacity and wide voltage range is desired for the real use of electrochemical supercapacitors.Herein,we synthesized amorphous NiCo-LDH nanosheets vertically aligned on activated carbon cloth substrate,which was in situ transformed from Co-metal-organic framework materials nano-columns by a simple ion exchange process at room temperature.Due to the amorphous and vertically aligned ultrathin structure of NiCo-LDH,the NiCo-LDH/activated carbon cloth composites present high areal capacities of 3770 and 1480 mF cm^(-2)as cathode and anode at 2 mA cm^(-2),and 79.5%and 80%capacity have been preserved at 50 mA cm^(-2).In the meantime,they all showed excellent cycling performance with negligible change after>10000 cycles.By fabricating them into an asymmetric supercapacitor,the device achieves high energy densities(5.61 mWh cm^(-2)and 0.352 mW cm^(-3)).This work provides an innovative strategy for simplifying the design of supercapacitors as well as providing a new understanding of improving the rate capabilities/cycling stability of NiCo-LDH materials.展开更多
We deposited indium-tin-oxide(ITO)films on silicon and quartz substrates by magnetron sputtering technology in pure argon.Using electrostatic quadrupole plasma diagnostic technology,we investigate the effects of disch...We deposited indium-tin-oxide(ITO)films on silicon and quartz substrates by magnetron sputtering technology in pure argon.Using electrostatic quadrupole plasma diagnostic technology,we investigate the effects of discharge power and discharge pressure on the ion flux and energy distribution function of incidence on the substrate surface,with special attention to the production of high-energy negative oxygen ions,and elucidate the mechanism behind its production.At the same time,the structure and properties of ITO films are systematically characterized to understand the potential effects of high energy oxygen ions on the growth of ITO films.Combining with the kinetic property analysis of sputtering damage mechanism of transparent conductive oxide(TCO)thin films,this study provides valuable physical understanding of optimization of TCO thin film deposition process.展开更多
This article reviews the current status on the dynamic behavior of highly stressed rocks under disturbances.Firstly,the experimental apparatus,methods,and theories related to the disturbance dynamics of deep,high-stre...This article reviews the current status on the dynamic behavior of highly stressed rocks under disturbances.Firstly,the experimental apparatus,methods,and theories related to the disturbance dynamics of deep,high-stress rock are reviewed,followed by the introduction of scholars’research on deep rock deformation and failure from an energy perspective.Subsequently,with a backdrop of highstress phenomena in deep hard rock,such as rock bursts and core disking,we delve into the current state of research on rock microstructure analysis and residual stresses from the perspective of studying the energy storage mechanisms in rocks.Thereafter,the current state of research on the mechanical response and the energy dissipation of highly stressed rock formations is briefly retrospected.Finally,the insufficient aspects in the current research on the disturbance and failure mechanisms in deep,highly stressed rock formations are summarized,and prospects for future research are provided.This work provides new avenues for the research on the mechanical response and damage-fracture mechanisms of rocks under high-stress conditions.展开更多
The tireless pursuit of supercapacitors with high energy density entails the parallel advancement of wellsuited electrode materials and elaborately engineered architectures.Polypyrrole(PPy)emerges as an exceedingly co...The tireless pursuit of supercapacitors with high energy density entails the parallel advancement of wellsuited electrode materials and elaborately engineered architectures.Polypyrrole(PPy)emerges as an exceedingly conductive polymer and a prospective pseudocapacitive materials for supercapacitors,yet the inferior cyclic stability and unpredictable polymerization patterns severely impede its real-world applicability.Here,for the first time,an innovative seed-induced in-situ polymerization assisted 3D printing strategy is proposed to fabricate PPy-reduced graphene oxide/poly(vinylidene difluoride-cohexafluoropropylene)(PVDF-HFP)(PPy-rGO/PH)electrodes with controllable polymerization behavior and exceptional areal mass loading.The preferred active sites uniformly pre-planted on the 3D-printed graphene substrates serve as reliable seeds to induce efficient polypyrrole deposition,achieving an impressive mass loading of 185.6 mg cm^(-2)(particularly 79.2 mg cm^(-2)for polypyrrole)and a superior areal capacitance of 25.2 F cm^(-2)at 2 mA cm^(-2)for a 12-layer electrode.In agreement with theses appealing features,an unprecedented areal energy density of 1.47 mW h cm^(-2)for a symmetrical device is registered,a rarely achieved value for other PPy/rGO-based supercapacitors.This work highlights a promising route to preparing high energy density energy storage modules for real-world applications.展开更多
The high-energy photon source(HEPS)is the first fourth-generation synchrotron light source facility in China.The HEPS injector consists of a linear accelerator(Linac)and a full energy booster.The booster captures the ...The high-energy photon source(HEPS)is the first fourth-generation synchrotron light source facility in China.The HEPS injector consists of a linear accelerator(Linac)and a full energy booster.The booster captures the electron beam from the Linac and increases its energy to the value required for the storage ring.The full-energy beam could be injected to the storage ring directly or after“high-energy accumulation.”On November 17,2023,the key booster parameters successfully reached their corresponding target values.These milestone results were achieved based on numerous contributions,including nearly a decade of physical design,years of equipment development and installation,and months of beam commissioning.As measured at the extraction energy of 6 GeV,the averaged beam current and emittance reached 8.57 mA with 5 bunches and 30.37 nm rad with a single-bunch charge of 5.58 nC,compared with the corresponding target values of 6.6 mA and 35 nm rad,respectively.This paper presents the physical design,equipment development,installation,and commissioning process of the HEPS booster.展开更多
Abrupt near-surface temperature changes in mountainous areas are a special component of the mountain climate system.Fast and accurate measurements of the locations,intensity,and width of the near-surface changes are n...Abrupt near-surface temperature changes in mountainous areas are a special component of the mountain climate system.Fast and accurate measurements of the locations,intensity,and width of the near-surface changes are necessary but highly difficult due to the complicated environmental conditions and instrumental issues.This paper develops a spatial pattern recognition method to measure the near-surface high temperature increase(NSHTI),one of the lesser-attended changes.First,raster window measurement was proposed to calculate the temperature lapse rate using MODIS land surface temperature and SRTM DEM data.It fully considers the terrain heights of two neighboring cells on opposite or adjacent slopes with a moving window of 3×3 cell size.Second,a threshold selection was performed to identify the NSHTI cells using a threshold of-0.65℃/100 m.Then,the NSHTI strips were parameterized through raster vectorization and spatial analysis.Taking Yunnan,a mountainous province in southwestern China,as the study area,the results indicate that the NSHTI cells concentrate in a strip-like pattern along the mountains and valleys,and the strips are almost parallel to the altitude contours with a slight northward uplift.Also,they are located mostly at a 3/5 height of high mountains or within 400 m from the valley floors,where the controlling topographic index is the altitude of the terrain trend surface but not the absolute elevation and the topographic uplift height and cutting depth.Additionally,the NSHTI intensity varies with the geographic locations and the proportions increase with an exponential trend,and the horizontal width has a mean of about 1000 m and a maximum of over 5000 m.The result demonstrates that the proposed method can effectively recognize NSHTI boundaries over mountains,providing support for the modeling of weather and climate systems and the development of mountain resources.展开更多
基金The National Key Research and Development Program of China under contract Nos 2023YFD2401900 and 2020YFD09008004the National Natural Science Foundation of China Key International(Regional)Cooperative Research Project under contract No.42020104009the Basic Public Welfare Research Program of Zhejiang Province under contract No.LGF21D010004.
文摘Mussel aquaculture and large yellow croaker aquaculture areas and their environmental characteristics in Zhoushan were analyzed using satellite data and in-situ surveys.A new two-step remote sensing method was proposed and applied to determine the basic environmental characteristics of the best mussel and large yellow croaker aquaculture areas.This methodology includes the first step of extraction of the location distribution and the second step of the extraction of internal environmental factors.The fishery ranching index(FRI1,FRI2)was established to extract the mussel and the large yellow croaker aquaculture area in Zhoushan,using Gaofen-1(GF-1)and Gaofen-6(GF-6)satellite data with a special resolution of 2 m.In the second step,the environmental factors such as sea surface temperature(SST),chlorophyll a(Chl-a)concentration,current and tide,suspended sediment concentration(SSC)in mussel aquaculture area and large yellow croaker aquaculture area were extracted and analyzed in detail.The results show the following three points.(1)For the extraction of the mussel aquaculture area,FRI1 and FRI2 are complementary,and the combination of FRI1 and FRI2 is suitable to extract the mussel aquaculture area.As for the large yellow croaker aquaculture area extraction,FRI2 is suitable.(2)Mussel aquaculture and the large yellow croaker aquaculture area in Zhoushan are mainly located on the side near the islands that are away from the eastern open waters.The water environment factor template suitable for mussel and large yellow croaker aquaculture was determined.(3)This two-step remote sensing method can be used for the preliminary screening of potential site selection for the mussels and large yellow croaker aquaculture area in the future.the fishery ranching index(FRI1,FRI2)in this paper can be applied to extract the mussel and large yellow croaker aquaculture areas in coastal waters around the world.
基金supported by the Energy Efficiency and Renewable Energy,Building Technologies Program,of the US Department of Energy,under contract no.DE-AC02-05CH11231the support on the DSC/TGA 3+supported by the Office of Science,Office of Basic Energy Sciences,of the U.S.Department of Energy under Contract No.DE-AC02-05CH11231
文摘Thermal energy storage(TES)solutions offer opportunities to reduce energy consumption,greenhouse gas emissions,and cost.Specifically,they can help reduce the peak load and address the intermittency of renewable energy sources by time shifting the load,which are critical toward zero energy buildings.Thermochemical materials(TCMs)as a class of TES undergo a solid-gas reversible chemical reaction with water vapor to store and release energy with high storage capacities(600 kWh m^(-3))and negligible self-discharge that makes them uniquely suited as compact,stand-alone units for daily or seasonal storage.However,TCMs suffer from instabilities at the material(salt particles)and reactor level(packed beds of salt),resulting in poor multi-cycle efficiency and high-levelized cost of storage.In this study,a model is developed to predict the pulverization limit or Rcrit of various salt hydrates during thermal cycling.This is critical as it provides design rules to make mechanically stable TCM composites as well as enables the use of more energy-efficient manufacturing process(solid-state mixing)to make the composites.The model is experimentally validated on multiple TCM salt hydrates with different water content,and effect of Rcrit on hydration and dehydration kinetics is also investigated.
基金funded by the National Key R&D Program of China,Grant Number 2019YFB1505400.
文摘In fossil energy pollution is serious and the“double carbon”goal is being promoted,as a symbol of fresh energy in the electrical system,solar and wind power have an increasing installed capacity,only conventional units obviously can not solve the new energy as the main body of the scheduling problem.To enhance the systemscheduling ability,based on the participation of thermal power units,incorporate the high energy-carrying load of electro-melting magnesiuminto the regulation object,and consider the effects on the wind unpredictability of the power.Firstly,the operating characteristics of high energy load and wind power are analyzed,and the principle of the participation of electrofusedmagnesiumhigh energy-carrying loads in the elimination of obstructedwind power is studied.Second,a two-layer optimization model is suggested,with the objective function being the largest amount of wind power consumed and the lowest possible cost of system operation.In the upper model,the high energy-carrying load regulates the blocked wind power,and in the lower model,the second-order cone approximation algorithm is used to solve the optimizationmodelwithwind power uncertainty,so that a two-layer optimizationmodel that takes into account the regulation of the high energy-carrying load of the electrofused magnesium and the uncertainty of the wind power is established.Finally,the model is solved using Gurobi,and the results of the simulation demonstrate that the suggested model may successfully lower wind abandonment,lower system operation costs,increase the accuracy of day-ahead scheduling,and lower the final product error of the thermal electricity unit.
文摘This study aims to provide electricity to a remote village in the Union of Comoros that has been affected by energy problems for over 40 years. The study uses a 50 kW diesel generator, a 10 kW wind turbine, 1500 kW photovoltaic solar panels, a converter, and storage batteries as the proposed sources. The main objective of this study is to conduct a detailed analysis and optimization of a hybrid diesel and renewable energy system to meet the electricity demand of a remote area village of 800 to 1500 inhabitants located in the north of Ngazidja Island in Comoros. The study uses the Hybrid Optimization Model for Electric Renewable (HOMER) Pro to conduct simulations and optimize the analysis using meteorological data from Comoros. The results show that hybrid combination is more profitable in terms of margin on economic cost with a less expensive investment. With a diesel cost of $1/L, an average wind speed of 5.09 m/s and a solar irradiation value of 6.14 kWh/m<sup>2</sup>/day, the system works well with a proportion of renewable energy production of 99.44% with an emission quantity of 1311.407 kg/year. 99.2% of the production comes from renewable sources with an estimated energy surplus of 2,125,344 kWh/year with the cost of electricity (COE) estimated at $0.18/kWh, presenting a cost-effective alternative compared to current market rates. These results present better optimization of the used hybrid energy system, satisfying energy demand and reducing the environmental impact.
基金Jilin Province Education Science“14th Five Year Plan”2021 Annual Project“Research on Middle School Physics Teaching Based on STEM Education Concept”(GH21032).
文摘Learning progressions divide the logical system of a subject into ordered and continuously developing levels that are suitable for the cognitive development level of students,which plays an important role in understanding students’learning process.This paper focuses on the theme of“kinetic energy”in high school physics as the research object.Firstly,the concept map was used to represent the relationship between knowledge,and then five core concepts were selected based on the opinions of high school teachers.Secondly,the test tools were compiled and tested based on the relevant test questions.Finally,the paper analyzed the results based on the Rasch model,clarified students’cognitive development level of“kinetic energy”and constructed the learning progressions of“kinetic energy”based on the logical order of subject knowledge.The research provides theoretical and methodological support for the study of other subjects and learning progressions,and provides a valuable reference for high school teachers to effectively carry out the instruction of“kinetic energy.”
文摘Objective: Given the unique cultural background, way of life, and physical environment of the Tibetan Plateau, this study aims to investigate the effects of health education using problem-based learning (PBL) approaches on the knowledge, attitude, practice, and coping skills of women with high-risk pregnancies in this region. Methods: 76 high-risk pregnancy cases were enrolled at Tibet’s Linzhi People’s Hospital between September 2023 and April 2024. 30 patients admitted between September 2023 and December 2023 were selected as the control group and were performed with regular patient education. 46 patients admitted between January 2024 and April 2024 were selected as the observation group and were performed regular patient education with problem-based learning approaches. Two groups’ performance on their health knowledge, attitude, practice and coping skills before and after interventions were evaluated, and patient satisfaction were measured at the end of the study. Results: There was no statistical significance (P P P Conclusions: Health education with problem-based learning approaches is worth promoting as it can help high-risk pregnant women in plateau areas develop better health knowledge, attitude and practice and healthier coping skills. Also, it can improve patient sanctification.
基金supported by the National Natural Science Foundation of China(Grant No.32250410309 and 52105582)Natural Science Foundation of Guangdong Province(Grant No.2022A1515010894 and 2022B0303040002)+1 种基金Fundamental Research Foundation of Shenzhen(JCYJ20210324095210030 and JCYJ20220818095810023)Shenzhen-Hong Kong-Macao S&T Program(Category C:SGDX20210823103200004)
文摘Extending the ionic conductivity is the pre-requisite of electrolytes in fuel cell technology for high-electrochemical performance.In this regard,the introduction of semiconductor-oxide materials and the approach of heterostructure formation by modulating energy bands to enhance ionic conduction acting as an electrolyte in fuel cell-device.Semiconductor(n-type;SnO_(2))plays a key role by introducing into p-type SrFe_(0.2)Ti_(0.8)O_(3-δ)(SFT)semiconductor perovskite materials to construct p-n heterojunction for high ionic conductivity.Therefore,two different composites of SFT and SnO_(2)are constructed by gluing p-and n-type SFT-SnO_(2),where the optimal composition of SFT-SnO_(2)(6∶4)heterostructure electrolyte-based fuel cell achieved excellent ionic conductivity 0.24 S cm^(-1)with power-output of 1004 mW cm^(-2)and high OCV 1.12 V at a low operational temperature of 500℃.The high power-output and significant ionic conductivity with durable operation of 54 h are accredited to SFT-SnO_(2)heterojunction formation including interfacial conduction assisted by a built-in electric field in fuel cell device.Moreover,the fuel conversion efficiency and considerable Faradaic efficiency reveal the compatibility of SFT-SnO_(2)heterostructure electrolyte and ruled-out short-circuiting issue.Further,the first principle calculation provides sufficient information on structure optimization and energy-band structure modulation of SFT-SnO_(2).This strategy will provide new insight into semiconductor-based fuel cell technology to design novel electrolytes.
基金Guangdong Basic and Applied Basic Research Foundation,Grant/Award Number:2020A1515110762Research Grants Council of the Hong Kong Special Administrative Region,China,Grant/Award Number:R6005‐20Shenzhen Key Laboratory of Advanced Energy Storage,Grant/Award Number:ZDSYS20220401141000001。
文摘Silicon(Si)is widely used as a lithium‐ion‐battery anode owing to its high capacity and abundant crustal reserves.However,large volume change upon cycling and poor conductivity of Si cause rapid capacity decay and poor fast‐charging capability limiting its commercial applications.Here,we propose a multilevel carbon architecture with vertical graphene sheets(VGSs)grown on surfaces of subnanoscopically and homogeneously dispersed Si–C composite nanospheres,which are subsequently embedded into a carbon matrix(C/VGSs@Si–C).Subnanoscopic C in the Si–C nanospheres,VGSs,and carbon matrix form a three‐dimensional conductive and robust network,which significantly improves the conductivity and suppresses the volume expansion of Si,thereby boosting charge transport and improving electrode stability.The VGSs with vast exposed edges considerably increase the contact area with the carbon matrix and supply directional transport channels through the entire material,which boosts charge transport.The carbon matrix encapsulates VGSs@Si–C to decrease the specific surface area and increase tap density,thus yielding high first Coulombic efficiency and electrode compaction density.Consequently,C/VGSs@Si–C delivers excellent Li‐ion storage performances under industrial electrode conditions.In particular,the full cells show high energy densities of 603.5 Wh kg^(−1)and 1685.5 Wh L^(−1)at 0.1 C and maintain 80.7%of the energy density at 3 C.
文摘Finding sustainable energy resources is essential to face the increasing energy demand.Trees are an important part of ancient architecture but are becoming rare in urban areas.Trees can control and tune the pedestrian-level wind velocity and thermal condition.In this study,a numerical investigation is employed to assess the role of trees planted in the windward direction of the building complex on the thermal and pedestrian wind velocity conditions around/inside a pre-education building located in the center of the complex.Compared to the previous studies(which considered only outside buildings),this work considers the effects of trees on microclimate change both inside/outside buildings.Effects of different parameters including the leaf area density and number of trees,number of rows,far-field velocity magnitude,and thermal condition around the main building are assessed.The results show that the flow velocity in the spacing between the first-row buildings is reduced by 30%-40% when the one-row trees with 2 m height are planted 15 m farther than the buildings.Furthermore,two rows of trees are more effective in higher velocities and reduce the maximum velocity by about 50%.The investigation shows that trees also could reduce the temperature by about 1℃around the building.
文摘With the increasing spotlight in electric vehicles,there is a growing demand for high-energy-density batteries to enhance driving range.Consequently,several studies have been conducted on high-energy-density LiNi_(x)Co_(y)Mn_(z)O_(2)cathodes.However,there is a limit to permanent performance deterioration because of side reactions caused by moisture in the atmosphere and continuous microcracks during cycling as the Ni content to express high energy increases and the content of Mn and Co that maintain structural and electrochemical stabilization decreases.The direct modification of the surface and bulk regions aims to enhance the capacity and long-term performance of high-Ni cathode materials.Therefore,an efficient modification requires a study based on a thorough understanding of the degradation mechanisms in the surface and bulk region.In this review,a comprehensive analysis of various modifications,including doping,coating,concentration gradient,and single crystals,is conducted to solve degradation issues along with an analysis of the overall degradation mechanism occurring in high-Ni cathode materials.It also summarizes recent research developments related to the following modifications,aims to provide notable points and directions for post-studies,and provides valuable references for the commercialization of stable high-energy-density cathode materials.
基金Financial support from the National Natural Science Foundation of China(22075016 and 22103057)Fundamental Research Funds for the Central Universities(FRF-TP-20-020A3 and QNXM20220060)+1 种基金Interdisciplinary Research Project for Young Teachers of USTB(FRF-IDRY-21-011)111 Project(B170003 and B12015)
文摘The development of high-energy and long-lifespan NASICON-type cathode materials for sodium-ion batteries has always been a research hotspot but a daunting challenge.Although Na_(4)MnCr(PO_(4))_(3)has emerged as one of the most promising high-energy-density cathode materials owing to its three-electron reactions,it still suffers from serious structural distortion upon repetitive charge/discharge processes caused by the Jahn-Teller active Mn^(3+).Herein,the selective substitution of Cr by Zr in Na_(4)MnCr(PO_(4))_(3)was explored to enhance the structural stability,due to the pinning effect of Zr ions and the≈2.9-electron reactions,as-prepared Na_(3.9)MnCr_(0.9)Zr_(0.1)(PO_(4))_(3)/C delivers a high capacity retention of 85.94%over 500 cycles at 5 C and an ultrahigh capacity of 156.4 mAh g^(-1)at 0.1 C,enabling the stable energy output as high as 555.2 Wh kg^(-1).Moreover,during the whole charge/discharge process,a small volume change of only 6.7%was verified by in situ X-ray diffraction,and the reversible reactions of Cr^(3+)/Cr^(4+),Mn^(3+)/Mn^(4+),and Mn^(2+)/Mn^(3+)redox couples were identified via ex situ X-ray photoelectron spectroscopy analyses.Galvanostatic intermittent titration technique tests and density functional theory calculations further demonstrated the fast reaction kinetics of the Na_(3.9)MnCr_(0.9)Zr_(0.1)(PO_(4))_(3)/C electrode.This work offers new opportunities for designing high-energy and high-stability NASICON cathodes by ion doping.
文摘Since the first laser was invented,the pursuit of high-energy lasers(HELs)has always been enthusiastic.The first revolution of HELs was pushed by the fusion of laser and aerospace in the 1960s,with the chemical rocket engines giving fresh impetus to the birth of gas flow and chemical lasers,which finally turned megawatt lasers from dream into reality.Nowadays,the development of HELs has entered the age of electricity as well as the rocket engines.The properties of current electric rocket engines are highly consistent with HELs’goals,including electrical driving,effective heat dissipation,little medium consumption and extremely light weight and size,which inspired a second fusion of laser and aerospace and motivated the exploration for potential HELs.As an exploratory attempt,a new configuration of diode pumped metastable rare gas laser was demonstrated,with the gain generator resembling an electric rocket-engine for improved power scaling ability.
基金supported by the National Natural Science Foundation of China(Nos.31471988 and 31200287)。
文摘The environmental characteristics of hypothermia and hypoxia exert great selective pressure on the energy metabolism of high-altitude animals,especially the ectotherms.Current research on energy-limited adaptation of high-altitude ectotherms has focused on energy expenditures.However,the mechanisms of increasing energy intake in high-altitude ectotherms have been studied rarely.In order to investigate the adaptation mechanism of the small intestine,the key part of energy acquisition for animals,to energy limitation at high altitude in ectotherms,the gut proteins of Phrynocephalus vlangalii from high-and low-altitude populations were compared using label free proteomics.GO enrichment and KEGG pathway analysis showed that proteins associated with energy intake,such as those involved in oxidation-reduction processes,glutathione metabolism,oxidoreductase activity,cofactor binding,catalytic activity and metabolic pathways,were significantly up-regulated in high-altitude populations;while proteins associated with energy expenditure,such as immune responses and processes,membrane attack complexes,natural killer pathway and other immune-related processes,were significantly down-regulated in expression.
基金supported by the National Natural Science Foundation of China(Grant No.62001338)the Open Funds for Sanya Science and Education Park(Grant No.2021KF0018)the Fundamental Research Funds for the Central Universities(Grant No.WUT:2021IVB029)
文摘Herein,we report the design,fabrication,and performance of two wireless energy harvesting devices based on highly flexible graphene macroscopic films(FGMFs).We first demonstrate that benefiting from the high conductivity of up to 1×10^(6)S m^(-1)and good resistive stability of FGMFs even under extensive bending,the FGMFs-based rectifying circuit(GRC)exhibits good flexibility and RF-to-DC efficiency of 53%at 2.1 GHz.Moreover,we further expand the application of FGMFs to a flexible wideband monopole rectenna and a 2.45 GHz wearable rectenna for harvesting wireless energy.The wideband rectenna at various bending conditions produces a maximum conversion efficiency of 52%,46%,and 44%at the 5th Generation(5G)2.1 GHz,Industrial Long-Term Evolution(LTE)2.3 GHz,and Scientific Medical(ISM)2.45 GHz,respectively.A 2.45 GHz GRC is optimized and integrated with an AMC-backed wearable antenna.The proposed 2.45 GHz wearable rectenna shows a maximum conversion efficiency of 55.7%.All the results indicate that the highly flexible graphene-film-based rectennas have great potential as a wireless power supplier for smart Internet of Things(loT)applications.
基金the funding from Natural Science Foundation of China(No.52003163)Guangdong Basic and Applied Basic Research Foundation(No.2022A1515010670)+1 种基金Science and Technology Innovation Commission of Shenzhen(Nos.KQTD20170810105439418 and 20200812112006001)NTUT-SZU Joint Research Program(Nos.2022005 and 2022015)
文摘Developing a simple scalable method to fabricate electrodes with high capacity and wide voltage range is desired for the real use of electrochemical supercapacitors.Herein,we synthesized amorphous NiCo-LDH nanosheets vertically aligned on activated carbon cloth substrate,which was in situ transformed from Co-metal-organic framework materials nano-columns by a simple ion exchange process at room temperature.Due to the amorphous and vertically aligned ultrathin structure of NiCo-LDH,the NiCo-LDH/activated carbon cloth composites present high areal capacities of 3770 and 1480 mF cm^(-2)as cathode and anode at 2 mA cm^(-2),and 79.5%and 80%capacity have been preserved at 50 mA cm^(-2).In the meantime,they all showed excellent cycling performance with negligible change after>10000 cycles.By fabricating them into an asymmetric supercapacitor,the device achieves high energy densities(5.61 mWh cm^(-2)and 0.352 mW cm^(-3)).This work provides an innovative strategy for simplifying the design of supercapacitors as well as providing a new understanding of improving the rate capabilities/cycling stability of NiCo-LDH materials.
基金supported by the National Key R&D Program of China(Grant No.2022YFE03050001)the National Natural Science Foundation of China(Grant Nos.12175160 and 12305284).The authors thank Suzhou Maxwell Technologies Co.,Ltd.for partial hardware and particle financial support to carry out the research.
文摘We deposited indium-tin-oxide(ITO)films on silicon and quartz substrates by magnetron sputtering technology in pure argon.Using electrostatic quadrupole plasma diagnostic technology,we investigate the effects of discharge power and discharge pressure on the ion flux and energy distribution function of incidence on the substrate surface,with special attention to the production of high-energy negative oxygen ions,and elucidate the mechanism behind its production.At the same time,the structure and properties of ITO films are systematically characterized to understand the potential effects of high energy oxygen ions on the growth of ITO films.Combining with the kinetic property analysis of sputtering damage mechanism of transparent conductive oxide(TCO)thin films,this study provides valuable physical understanding of optimization of TCO thin film deposition process.
基金supported by the National Natural Science Foundation of China(Nos.52004015,51874014,and 52311530070)the fellowship of China National Postdoctoral Program for Innovative Talents(No.BX2021033)+1 种基金the fellowship of China Postdoctoral Science Foundation(Nos.2021M700389 and 2023T0025)the Fundamental Research Funds for the Central Universities of China(No.FRF-IDRY-20-003,Interdisciplinary Research Project for Young Teachers of USTB).
文摘This article reviews the current status on the dynamic behavior of highly stressed rocks under disturbances.Firstly,the experimental apparatus,methods,and theories related to the disturbance dynamics of deep,high-stress rock are reviewed,followed by the introduction of scholars’research on deep rock deformation and failure from an energy perspective.Subsequently,with a backdrop of highstress phenomena in deep hard rock,such as rock bursts and core disking,we delve into the current state of research on rock microstructure analysis and residual stresses from the perspective of studying the energy storage mechanisms in rocks.Thereafter,the current state of research on the mechanical response and the energy dissipation of highly stressed rock formations is briefly retrospected.Finally,the insufficient aspects in the current research on the disturbance and failure mechanisms in deep,highly stressed rock formations are summarized,and prospects for future research are provided.This work provides new avenues for the research on the mechanical response and damage-fracture mechanisms of rocks under high-stress conditions.
基金financially supported by the National Natural Science Foundation of China(No.51933007,No.52373047,No.52302106)the Sichuan Youth Science and Technology Innovation Research Team Project(No.2022JDTD0012)+2 种基金the Program for Featured Directions of Engineering Multidisciplines of Sichuan University(No.2020SCUNG203)the Natural Science Foundation of Sichuan Province(No.2023NSFSC0418)the Program for State Key Laboratory of Polymer Materials Engineering(No.sklpme2022-3-10)。
文摘The tireless pursuit of supercapacitors with high energy density entails the parallel advancement of wellsuited electrode materials and elaborately engineered architectures.Polypyrrole(PPy)emerges as an exceedingly conductive polymer and a prospective pseudocapacitive materials for supercapacitors,yet the inferior cyclic stability and unpredictable polymerization patterns severely impede its real-world applicability.Here,for the first time,an innovative seed-induced in-situ polymerization assisted 3D printing strategy is proposed to fabricate PPy-reduced graphene oxide/poly(vinylidene difluoride-cohexafluoropropylene)(PVDF-HFP)(PPy-rGO/PH)electrodes with controllable polymerization behavior and exceptional areal mass loading.The preferred active sites uniformly pre-planted on the 3D-printed graphene substrates serve as reliable seeds to induce efficient polypyrrole deposition,achieving an impressive mass loading of 185.6 mg cm^(-2)(particularly 79.2 mg cm^(-2)for polypyrrole)and a superior areal capacitance of 25.2 F cm^(-2)at 2 mA cm^(-2)for a 12-layer electrode.In agreement with theses appealing features,an unprecedented areal energy density of 1.47 mW h cm^(-2)for a symmetrical device is registered,a rarely achieved value for other PPy/rGO-based supercapacitors.This work highlights a promising route to preparing high energy density energy storage modules for real-world applications.
基金This work was supported by the National Natural Science Foundation of China(No.12005239).
文摘The high-energy photon source(HEPS)is the first fourth-generation synchrotron light source facility in China.The HEPS injector consists of a linear accelerator(Linac)and a full energy booster.The booster captures the electron beam from the Linac and increases its energy to the value required for the storage ring.The full-energy beam could be injected to the storage ring directly or after“high-energy accumulation.”On November 17,2023,the key booster parameters successfully reached their corresponding target values.These milestone results were achieved based on numerous contributions,including nearly a decade of physical design,years of equipment development and installation,and months of beam commissioning.As measured at the extraction energy of 6 GeV,the averaged beam current and emittance reached 8.57 mA with 5 bunches and 30.37 nm rad with a single-bunch charge of 5.58 nC,compared with the corresponding target values of 6.6 mA and 35 nm rad,respectively.This paper presents the physical design,equipment development,installation,and commissioning process of the HEPS booster.
基金supported by the National Natural Science Foundation of China (Grant No. 42061004)the Joint Special Project of Agricultural Basic Research of Yunnan Province (Grant No. 202101BD070001093)the Youth Special Project of Xingdian Talent Support Program of Yunnan Province
文摘Abrupt near-surface temperature changes in mountainous areas are a special component of the mountain climate system.Fast and accurate measurements of the locations,intensity,and width of the near-surface changes are necessary but highly difficult due to the complicated environmental conditions and instrumental issues.This paper develops a spatial pattern recognition method to measure the near-surface high temperature increase(NSHTI),one of the lesser-attended changes.First,raster window measurement was proposed to calculate the temperature lapse rate using MODIS land surface temperature and SRTM DEM data.It fully considers the terrain heights of two neighboring cells on opposite or adjacent slopes with a moving window of 3×3 cell size.Second,a threshold selection was performed to identify the NSHTI cells using a threshold of-0.65℃/100 m.Then,the NSHTI strips were parameterized through raster vectorization and spatial analysis.Taking Yunnan,a mountainous province in southwestern China,as the study area,the results indicate that the NSHTI cells concentrate in a strip-like pattern along the mountains and valleys,and the strips are almost parallel to the altitude contours with a slight northward uplift.Also,they are located mostly at a 3/5 height of high mountains or within 400 m from the valley floors,where the controlling topographic index is the altitude of the terrain trend surface but not the absolute elevation and the topographic uplift height and cutting depth.Additionally,the NSHTI intensity varies with the geographic locations and the proportions increase with an exponential trend,and the horizontal width has a mean of about 1000 m and a maximum of over 5000 m.The result demonstrates that the proposed method can effectively recognize NSHTI boundaries over mountains,providing support for the modeling of weather and climate systems and the development of mountain resources.