Compared to lake area and water level,lake storage capacity more intuitively reflects regional climate changes.In this study,we first derived lakebed elevation profiles for individual ICESat-2 tracks based on the unde...Compared to lake area and water level,lake storage capacity more intuitively reflects regional climate changes.In this study,we first derived lakebed elevation profiles for individual ICESat-2 tracks based on the underwater stratification of laser photons,then integrating all valid elevation tracks within the water body to interpolate the bathymetry.On this basis,we calculated the capacity and its time series directly,with the aid of lake boundaries and water levels obtained from optical imagery and CryoSat-2 data.Next,we also applied an empirical formula to estimate the water volume changes of Bangdag Co by combining the area and water levels from 2010 to 2023.Finally,we compared the results of Bangdag Co's water volume changes obtained from the two different methods and conducted a detailed analysis of their performance and regional applicability.The bathymetric map of Bangdag Co reveals a distinct spatial pattern,with the northeastern part significantly deeper(with a maximum depth of 35.27 m)and the southwestern part shallower.The average depth of the lake is 13.99 m.We further estimated that the lake storage capacity in November 2023 was 2.95 km^(3).Water volume changes estimated using the empirical formula were highly consistent with those derived from the lake storage capacity time series(from 2010 to 2023,the lake storage capacity increased by 1.04 km^(3)).Our comparison revealed that the empirical formula method reflects only changes in water volume.In contrast,while our method can accurately estimate lake storage capacity,it is constrained to shallow,clear,and elongated east-west lakes(e.g.,Ayakkum Lake).In summary,the ICESat-2 laser altimetry data,which do not rely on measured water depths,offer an essential complement to underwater topography detection and provide a novel perspective on lake volume estimation research.展开更多
Methane adsorption is a critical assessment of the gas storage capacity(GSC)of shales with geological conditions.Although the related research of marine shales has been well-illustrated,the methane adsorption of marin...Methane adsorption is a critical assessment of the gas storage capacity(GSC)of shales with geological conditions.Although the related research of marine shales has been well-illustrated,the methane adsorption of marine-continental transitional(MCT)shales is still ambiguous.In this study,a method of combining experimental data with analytical models was used to investigate the methane adsorption characteristics and GSC of MCT shales collected from the Qinshui Basin,China.The Ono-Kondo model was used to fit the adsorption data to obtain the adsorption parameters.Subsequently,the geological model of GSC based on pore evolution was constructed using a representative shale sample with a total organic carbon(TOC)content of 1.71%,and the effects of reservoir pressure coefficient and water saturation on GSC were explored.In experimental results,compared to the composition of the MCT shale,the pore structure dominates the methane adsorption,and meanwhile,the maturity mainly governs the pore structure.Besides,maturity in the middle-eastern region of the Qinshui Basin shows a strong positive correlation with burial depth.The two parameters,micropore pore volume and non-micropore surface area,induce a good fit for the adsorption capacity data of the shale.In simulation results,the depth,pressure coefficient,and water saturation of the shale all affect the GSC.It demonstrates a promising shale gas potential of the MCT shale in a deeper block,especially with low water saturation.Specifically,the economic feasibility of shale gas could be a major consideration for the shale with a depth of<800 m and/or water saturation>60%in the Yushe-Wuxiang area.This study provides a valuable reference for the reservoir evaluation and favorable block search of MCT shale gas.展开更多
Praseodymium （Pr） was impregnated to CeO2-ZrO2 solid solution by an impregnation method. The as-obtained Pr modi- fied CeO2-ZrO2 was impregnated with 1 wt.% Pd to prepare the catalysts. The structure and reducibilit...Praseodymium （Pr） was impregnated to CeO2-ZrO2 solid solution by an impregnation method. The as-obtained Pr modi- fied CeO2-ZrO2 was impregnated with 1 wt.% Pd to prepare the catalysts. The structure and reducibility of the fresh and hydrother- really aged catalysts were characterized by X-ray diffraction （XRD）, Raman, X-ray photoelectron spectroscopy （XPS）, CO chemi- sorption and H2 temperature-programmed reduction （H2-TPR）. The oxygen storage capacity （OSC） was evaluated with CO serving as probe gas. Effects of impregnated Pr on the structure and oxygen storage capacity of catalysts were investigated. The results showed that the aged Pr-impregnated samples had much higher OSC and better reducibility than the unmodified ones. The scheme of structural evolutions of the catalysts with and without Pr was also established. Partial of the impregnated Pr diffused into the bulk of CeO2-ZrO2 during ageing, which inhibited the sintering, and increased the amount of oxygen vacancies in CeO2-ZrO2 support. Furthermore, those impregnated Pr species which covered on the surface of the support obstructed the strong metal-support interaction between Pd and Ce so as to reduce the encapsulation of Pd as well as the back spill-over of the oxygen during the catalytic process.展开更多
The concept of the carbon cycle in the old goaf of a coal mine based on CO_(2)utilization and storage was put forward adhering to the principle of low-carbon development,utilization of space resources in old goafs,and...The concept of the carbon cycle in the old goaf of a coal mine based on CO_(2)utilization and storage was put forward adhering to the principle of low-carbon development,utilization of space resources in old goafs,and associated gas resources development.Firstly,the evolution characteristics of overburden fissures in the goaf of the case was studied using a two-dimensional physical similarity simulation test,the sealing performance of the caprocks after stabilization was analyzed,and the fissures were counted and classi-fied.Then,the process of gaseous CO_(2)injection in the connected fissure was simulated by Ansys Fluent software,and the migration law and distribution characteristics of CO_(2)under the condition of gaseous CO_(2)injection were analyzed.Finally,the estimation models of free CO_(2)storage capacity in the old goaf were constructed considering the proportion of connected fissure and the effectiveness of CO_(2)injection.The CO_(2)storage capacity in the old goaf of the case coal mine was estimated.The results showed that a caprock group of“hard-thickness low-permeability hard-thickness”was formed after the caprock-fissures system in the goaf of the case tended to be stable vertically.The connected fissure,occlude cracks,and micro-fractures in the goaf accounted for 85.5%,8.5%,and 6%of the total fissures,respectively.Gaseous CO_(2)first migrated to the bottom of the connected fissure after CO_(2)was injected into the goaf,then spread horizontally along the bottom of the connected fissure after reaching the bottom,and finally spread longitudinally after filling the bottom of the entire connected fissure.The theoretical and effective storage capacities of free CO_(2)at normal temperature and pressure in the old goaf of the case were 9757 and 7477 t,respectively.The effective storage capacity of free CO_(2)at normal temperature and pressure in the old goaf after all minefield mined was 193404 t.The research can provide some reference for the coal mining industry to help the goal of“carbon peaking and carbon neutrality”.展开更多
Compensating for photovoltaic(PV)power forecast errors is an important function of energy storage systems.As PV power outputs have strong random fluctuations and uncertainty,it is difficult to satisfy the grid-connect...Compensating for photovoltaic(PV)power forecast errors is an important function of energy storage systems.As PV power outputs have strong random fluctuations and uncertainty,it is difficult to satisfy the grid-connection requirements using fixed energy storage capacity configuration methods.In this paper,a method of configuring energy storage capacity is proposed based on the uncertainty of PV power generation.A k-means clustering algorithm is used to classify weather types based on differences in solar irradiance.The power forecast errors in different weather types are analyzed,and an energy storage system is used to compensate for the errors.The kernel density estimation is used to fit the distributions of the daily maximum power and maximum capacity requirements of the energy storage system;the power and capacity of the energy storage unit are calculated at different confidence levels.The optimized energy storage configuration of a PV plant is presented according to the calculated degrees of power and capacity satisfaction.The proposed method was validated using actual operating data from a PV power station.The results indicated that the required energy storage can be significantly reduced while compensating for power forecast errors.展开更多
CZO （CeO2-ZrO2） and CZYO （CeO2-ZrO2-Y2O3） series of mixed oxides were prepared by coprecipitaion, and a part of these oxides were loaded with precious metals （PM）. XRD, BET, and oxygen storage capacity （OSC） i...CZO （CeO2-ZrO2） and CZYO （CeO2-ZrO2-Y2O3） series of mixed oxides were prepared by coprecipitaion, and a part of these oxides were loaded with precious metals （PM）. XRD, BET, and oxygen storage capacity （OSC） investigations were performed on samples aged at 750, 900, and 1050 ℃. It was observed that BET surface area and OSC showed a marked decrease in CeO2 aged at high temperature, and the erystallite size showed an obvious increase. The CZO samples consist of cubic- and tetragonal crvstal phases, and their crystallite size increase rapidly when aged at high temperature. The CZYO samples consist of single crystal phase when the content of Y exceeds 0.15 mol, and their erystallite size increases slowly during high-temperature aging. It is concluded that additive Y can stabilize the performance of CZYO oxides. In the aged CZO and CZYO mixed-oxide systems, addition of a small amount of precious metals （Pt, Pd, Rh） increased the rate of reduction and led to an obvious improvement in OSC. OSC of CZO and CZYO with precious metals are related to their composition and the type of precious metal.展开更多
The interfacial performance of implanted neural electrodes is crucial for stimulation safety and the recording quality of neuronal activity.This paper proposes a novel surface architecture and optimization strategy fo...The interfacial performance of implanted neural electrodes is crucial for stimulation safety and the recording quality of neuronal activity.This paper proposes a novel surface architecture and optimization strategy for the platinum–iridium(Pt–Ir)electrode to optimize electrochemical performance and wettability.A series of surface micro/nano structures were fabricated on Pt–Ir electrodes with different combinations of four adjustable laser-processing parameters.Subsequently,the electrodes were characterized by scanning electron microscopy,energy-dispersive X-ray spectroscopy,cyclic voltammetry,electrochemical impedance spectroscopy,and wetting behavior.The results show that electrode performance strongly depends on the surface morphology.Increasing scanning overlap along with moderate pulse energy and the right number of pulses leads to enriched surface micro/nano structures and improved electrode performance.It raises the maximum charge storage capacity to 128.2 mC/cm^(2) and the interface capacitance of electrodes to 3.0×10^(4)μF/cm^(2) for the geometric area,compared with 4.6 mC/cm^(2) and 443.1μF/cm2,respectively,for the smooth Pt–Ir electrode.The corresponding optimal results for the optically measured area are 111.8 mC/cm^(2) and 2.6×10^(4)μF/cm^(2),which indicate the contribution of fner structures to the ablation profle.The hierarchical structures formed by the femtosecond laser dramatically enhanced the wettability of the electrode interface,giving it superwicking properties.A wicking speed of approximately 80 mm/s was reached.Our optimization strategy,leading to superior performance of the superwicking Pt–Ir interface,is promising for use in new neural electrodes.展开更多
Binary Ce-Zr（CZ）,Pr-Zr（PZ） and ternary Ce-Zr-Pr（CZP） mixed oxides were prepared by an ammonia-aided co-precipitation method,and were aged in a steam/air flow at 1050 °C.X-ray diffraction（XRD）,Raman spectr...Binary Ce-Zr（CZ）,Pr-Zr（PZ） and ternary Ce-Zr-Pr（CZP） mixed oxides were prepared by an ammonia-aided co-precipitation method,and were aged in a steam/air flow at 1050 °C.X-ray diffraction（XRD）,Raman spectra,X-photon spectra（XPS） and CO temperature programmed reduction（TPR） were carried out to characterize the micro-structure and reducibility of catalysts.The oxygen storage capacity（OSC） was evaluated with CO serving as probe gas.The results showed that a pseudo cubic structure was formed for the Zr-rich ceria-zirconia mixed oxides with Pr doping.The insertion of Pr prevented the phase segregation of the mixed oxides during the hydrothermal ageing.The Pr doped samples showed better redox performances in comparison with CZ,and the sample doped with 5 wt.% Pr showed the most remarkably promoted dynamic oxygen storage capacity.This phenomenon was closely related to both the reducibility and oxygen mobility of the mixed oxides.The introduction of praseodymium into ceria-zirconia could accelerate the oxygen migration by increasing the amount of oxygen vacancies,although it was difficult for Pr3＋ ions themselves to participate in the oxygen exchange process.展开更多
Cerium and cerium-based oxides are found to be an important element in three-way catalytic converter(TWC).The effective utilization of TWC is found to be reduced due to thermal loading which results in structural defo...Cerium and cerium-based oxides are found to be an important element in three-way catalytic converter(TWC).The effective utilization of TWC is found to be reduced due to thermal loading which results in structural deformation of ceria,Doping Zr^(4+)into the rare earth element can increase the oxygen storage capacity and thermal stability.Hence,an attempt was made to study the oxygen storage capacity and thermal stability of ceria by doping Zr^(4+)and Nd^(3+).Cerium-based nanocrystallite in the composition of Ce_(0.6)Zr_(0.4-x)Nd_(1.3)xO_(2)(0≤x≤0.4)was prepared by sol-gel synthesize technique with citric acid as a gel-forming agent.X-ray diffraction(XRD)result shows that doping Nd^(3+)into ceria lattice forms homogenous solid solution of cubic fluorite structure up to 25%of substitute only.Doping higher amount of Nd^(3+)into ceria lattice leads to the formation of Nd_(2)O_(3).Raman spectrum study confirms that oxygen storage capacity band is present in Ce_(0.6)Zr_(0.4)O2 and Ce_(0.6)Zr_(0.3)Nd_(0.13)O_(2).The oxygen storage capacity was calculated through weight loss of the sample during the second heating cycle with cyclic heating from30 to 800℃in thermogravimetric analysis(TGA).The TGA study reveals that the oxygen storage capacity of Ce_(0.6)Zr_(0.4)O2 decreases after the substitution of Nd^(3+),which is due to the larger ionic radius of Nd^(3+)compared with that of Zr4+and CeO2.展开更多
Oxygen storage and adsorptive properties of praseodymium oxides were investigated by pulse experiments and temperature - programmed desportion/reduction (TPD/TPR) experiments. Pr2O3 possesses the similar oxygen storag...Oxygen storage and adsorptive properties of praseodymium oxides were investigated by pulse experiments and temperature - programmed desportion/reduction (TPD/TPR) experiments. Pr2O3 possesses the similar oxygen storage properties to CeO2, and its dynamic oxygen storage capacity is 14.9 mumol.g(-1). The studies on TPD Of O-2, H2O and CO and TPR show that Pr2O3 provides more active surface oxygen species and at a lower temperature than CeO2. It is suggested that Pr2O3 can be a well candidate as an oxygen storage component in automobile three-way catalyst.展开更多
Dynamic oxygen storage and release capability （OSC） measurement apparatus was designed to evaluate the OSC performance of ceria-based oxygen storage material. The optimum measurement condition was at a frequency of ...Dynamic oxygen storage and release capability （OSC） measurement apparatus was designed to evaluate the OSC performance of ceria-based oxygen storage material. The optimum measurement condition was at a frequency of 0.1 Hz with the inlet gas-flow sequence CO （5S）→O2（5S）→CO→O2 and a flow rate of 300 ml·min^-1. Under this condition, similar regular square wave in the inlet and outlet of the reactor was obtained to guarantee the reliability of the dynamic OSC results. The dynamic OSC performance of the CeO2 and Ce0.67Zr0.33O2 mixed oxide prepared using the citric sol-gel method was studied at the optimum measurement condition with focus on both quantitative and qualitative analyses, The results reveal distinctly that Ce0.67Zr0.33O2 had better dynamic OSC performance because of its higher oxygen migration rate than CeO2. Under dynamic conditions, two CO2 production peaks occurred corresponding to the CO pulse and the O2 pulse, respectively, during the entire cycle. The intensity and ratio between the two CO2 productions were highly influenced by temperature and frequency indicating complex surface phenomena during the oxygen storage/release process, As a result, this set-up can be applied to the evaluation of ceria-based material on the OSC performance.展开更多
This paper introduces the method of designation of water storage capacity for each grid cell within a catchment, which considers topography, vegetation and soil synthetically. For the purpose of hydrological process s...This paper introduces the method of designation of water storage capacity for each grid cell within a catchment, which considers topography, vegetation and soil synthetically. For the purpose of hydrological process simulation in semi-arid regions, a spatially varying storage capacity （VSC） model was developed based on the spatial distribution of water storage capacity and the vertical hybrid runoff mechanism. To verify the applicability of the VSC model, both the VSC model and a hybrid runoff model were used to simulate daily runoff processes in the catchment upstream of the Dianzi hydrological station from 1973 to 1979. The results showed that the annual average Nash-Sutcliffe coefficient was 0.80 for the VSC model, and only 0.67 for the hybrid runoff model. The higher annual average Nash-Sutcliffe coefficient of the VSC model means that this hydrological model can better simulate daily runoff processes in semi-arid regions. Furthermore, as a distributed hydrological model, the VSC model can be applied in regional water resource management.展开更多
The regulation and storage capacity of Poyang Lake is infl uenced by the fl ow from the main stream of the Yangtze River and the fi ve rivers in the Poyang Lake basin.After the operation of the Three Gorges Dam(TGD),h...The regulation and storage capacity of Poyang Lake is infl uenced by the fl ow from the main stream of the Yangtze River and the fi ve rivers in the Poyang Lake basin.After the operation of the Three Gorges Dam(TGD),hydrological changes in the main stream of the Yangtze River impact water exchange between the Yangtze River and Poyang Lake.Based on the analysis of measured data and factors infl uencing outfl ow at Hukou station,a new empirical formula describing outfl ow at Hukou station and critical water level for lake storage capacity is established.The change in monthly storage capacity of Poyang Lake before and after the construction of the TGD is analyzed quantitatively.The results show that the fl ows from the main stream of the Yangtze River and the fi ve rivers in the Poyang Lake basin affect outfl ow and water storage capacity by changing the water level difference between Xingzi and Hukou stations and by changing the water level at Hukou station.But the Yangtze River and the fi ve rivers in the Poyang Lake basin differ in process and degree.If the water level at Hukou station remains consistent,when the fl ow from the fi ver rivers increases by 1,000 m3/s,the outfl ow at Hukou station increases by 304 m3/s.When the fl ow from the main stream of the Yangtze River increases by 1,000 m3/s,the outfl ow at Hukou station decreases by 724 m3/s.In addition,the operation of the TGD affects the water storage capacity of Poyang Lake.The water volume of Poyang Lake decreases by 49.4%in September,but increases by 47.7%in May.展开更多
This study focuses on urgent research on restoring and enhancing carbon storage capacity in the Beibu Gulf Urban Agglomer-ation of China,a key area in the‘Belt and Road’Initiative,which aligns with carbon peaking an...This study focuses on urgent research on restoring and enhancing carbon storage capacity in the Beibu Gulf Urban Agglomer-ation of China,a key area in the‘Belt and Road’Initiative,which aligns with carbon peaking and neutrality goals.This research ana-lyzes the spatial characteristics of carbon metabolism from 2000 to 2020 and uses models to identify stable carbon sink areas,positive carbon flow corridors,and carbon sequestration nodes.The goal is to construct a carbon metabolism spatial security pattern(CMSSP)and propose territorial ecological restoration strategies under different development demand scenarios.The results show the following:1)in 2020,the study area’s carbon sink decreased by 8.29×10^(4) t C/yr compared with that in 2010 and by 10.83×10^(4) t C/yr compared with that in 2000.High-carbon sinks were found mainly in mountainous areas,whereas low-carbon sinks are concentrated in urban con-struction land,rural residential areas,and land margins.2)From 2000 to 2020,the spatial security pattern of carbon metabolism tended to be‘high in the middle of the east and west and low in the gulf.’In 2000,2010,and 2020,16 stable carbon sinks were identified.The carbon energy flow density in Guangxi was greater than that in Guangdong and Hainan,with positive carbon flow corridors located primarily in Guangxi and Guangdong.The number of carbon sequestration nodes remained stable at approximately 15,mainly in Guangxi and Hainan.3)Scenario simulations revealed that under the Nature-based mild restoration scenario,the carbon sink rate will reach 611.85×10^(4) t C/yr by 2030 and increase to 612.45×10^(4) t C/yr by 2060,with stable carbon sinks increasing to 18.In the restora-tion scenario based on Anti-globalization,the carbon sink will decrease from 610.24×10^(4) t C/yr in 2030 to 605.19×10^(4) t C/yr in 2060,with the disappearance of some positive carbon flow corridors and stable carbon sinks.Under the Human-based sustainable restoration scenario,the carbon sink area will decrease from 607.00×10^(4) t C/yr in 2030 to 596.39×10^(4) t C/yr in 2060,with carbon sink areas frag-menting and positive carbon flow corridors becoming less dense.4)On the basis of the current and predicted CMSSPs,this study ex-plores spatial ecological restoration strategies for high-carbon storage areas in bay urban agglomerations at four levels:the land control region,urban agglomeration structure system,carbon sink structure and bay structure control region.展开更多
This work investigated the effect of Na_(2)CO_(3)on the char structures of cellulose and lignin,respective-ly,and examined the electrochemi-cal performance of the char by act-ing as an active material for coin cells.T...This work investigated the effect of Na_(2)CO_(3)on the char structures of cellulose and lignin,respective-ly,and examined the electrochemi-cal performance of the char by act-ing as an active material for coin cells.The morphology of char can be significantly steered by the con-centration of Na_(2)CO_(3).Scanning electron microscopy analysis demonstrated that the intro-duction of Na_(2)CO_(3)into cellulose at an appropriate concentration led to the formation of tubular structure on its surface after pyrolysis,whereas the tubular structure was absent in the lignin char with the addition of Na_(2)CO_(3)at any concentrations.X-ray diffraction and Ra-man spectroscopy characterizations revealed that all the obtained chars from both cellulose and lignin,with or without Na_(2)CO_(3),were ascribed to non-crystalline graphite.Nevertheless,the crystal orientation of graphite from cellulose and lignin changed after the catalysis of Na_(2)CO_(3).Further electrochemical tests showed that cellulose char had a higher sodium stor-age capacity than that of lignin char.The excellent electrochemical performance of carbon materials derived from cellulose might hold a prospective application in the field of energy storage.展开更多
Surface hydrogen storage facilities are limited and costly,making subsurface hydrogen storage in geological formations a more viable alternative due to its substantial capacity,safety,and economic feasibility.This met...Surface hydrogen storage facilities are limited and costly,making subsurface hydrogen storage in geological formations a more viable alternative due to its substantial capacity,safety,and economic feasibility.This method is essential for large-scale hydrogen storage to support renewable energy integration,fuel cell technologies,and other applications aimed at mitigating global climate change.This review examines underground hydrogen storage(UHS)in geological formations,focusing on recent experiments,modeling and simulations,and field applications.Geological formations such as depleted oil reservoirs,salt caverns,and depleted natural gas reservoirs are identified as favorable candidates due to minimal interactions with hydrogen,leading to low hydrogen loss.Globally,80%of UHS projects utilize depleted natural gas and oil reservoirs,with over 50%focused on depleted natural gas and oil condensate reservoirs due to cost-effective existing infrastructure.Among storage options,salt caverns are the most advantageous,offering self-healing properties,low caprock permeability,large storage capacity,rapid injection and withdrawal rates,and low contamination risk.Additionally,hydrogen produced from coal is the cheapest option,costing 1.2e2 USD/kg,whereas hydrogen from renewable sources,such as water,is the most expensive at 3e13 USD/kg.Despite its higher cost,green hydrogen from water,characterized by low carbon emissions,requires further research to reduce production costs.This review highlights critical research gaps,challenges,and policy recommendations to advance UHS technologies,ensuring their role in combating climate change.展开更多
The effect of Co doping on ceria-zirconia mixed oxides was investigated for Co0.1Ce0.6Zr0.3Ox sample prepared by sol-gel method. The Pd-only three-way catalyst （TWC） was obtained by incipient wetness impregnation wi...The effect of Co doping on ceria-zirconia mixed oxides was investigated for Co0.1Ce0.6Zr0.3Ox sample prepared by sol-gel method. The Pd-only three-way catalyst （TWC） was obtained by incipient wetness impregnation with 0.5 wt.% Pd loading. The structural and oxygen handling properties were analyzed by X-ray diffraction （XRD）, H2-temperature programmed reduction （H2-TPR） and the dynamic oxygen storage capacity （DOSC）. The introduction of Co into ceria-zirconia lattice strongly modified the mobility of oxygen and enhanced the DOSC performance. Pd-only TWC based on the Co0.1Ce0.6Zr0.3Ox support exhibited superior activity for water-gas shift and steam reforming and ampli- fied amplitude of stoichiometric window.展开更多
Nanorod-like Ce0.7Zr0.3O2 solid solutions were synthesized by a sodium dodecyl sulfate-assisted precipitation method. The samples were characterized by means of scanning electron microscopy, transmission electron micr...Nanorod-like Ce0.7Zr0.3O2 solid solutions were synthesized by a sodium dodecyl sulfate-assisted precipitation method. The samples were characterized by means of scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and specific surface area measurement. Typical Ce0.7Zr0.3O2 nanorods were 40 nm in average diameter and 450 nm in length, with specific surface area and oxygen storage capacity of 194 m2/g and 374 μmol/g, respectively.展开更多
Carbon dioxide(CO_(2))capture,utilization,and storage(CCUS)is an important pathway for China to achieve its“2060 carbon neutrality”strategy.Geological sequestration of CO_(2)in deep coals is one of the methods of CC...Carbon dioxide(CO_(2))capture,utilization,and storage(CCUS)is an important pathway for China to achieve its“2060 carbon neutrality”strategy.Geological sequestration of CO_(2)in deep coals is one of the methods of CCUS.Here,the No.3 anthracite in the Qinshui Basin was studied using the superposition of each CO_(2)geological storage category to construct models for theoretical CO_(2)geological storage capacity(TCGSC)assessment,and CO_(2)adsorption capacity variation with depth.CO_(2)geological storage potential of No.3 anthracite coal was assessed by integrating the adsorption capacity with the static storage and dissolution capacities.The results show that(1)CO_(2)adsorption capacities of XJ and SH coals initially increased with depth,peaked at 47.7 cm3/g and 41.5 cm3/g around 1000 m,and later decreased with depth.(2)four assessment areas and their geological model parameters were established based on CO_(2)phase variation and spatial distribution of coal thickness,(3)the abundance of CO_(2)geological storage capacity(ACGSC),which averages 40 cm3/g,shows an analogous circularity-sharp distribution,with the high abundance area influenced by depth and coal rank,and(4)the TCGSC and the effective CO_(2)geological storage capacity(ECGSC)are 9.72 Gt and 6.54 Gt;the gas subcritical area accounted for 76.41%of the total TCGSC.Although adsorption-related storage capacity accounted for more than 90%of total TCGSC,its proportion,however,decreased with depth.Future CO_(2)-ECBM project should focus on highrank coals in gas subcritical and gas-like supercritical areas.Such research will provide significant reference for assessment of CO_(2)geological storage capacity in deep coals.展开更多
With the rise and world wide deployment of cloud utilities, the principle of the cloud download is proposed to provide high-quality file content distribution by using dedicated servers as cloud cache to guarantee the ...With the rise and world wide deployment of cloud utilities, the principle of the cloud download is proposed to provide high-quality file content distribution by using dedicated servers as cloud cache to guarantee the data availability and enhance the data transfer rate. As the system scales up to a large population, how to design appropriate storage capacity of cloud cache is a key challenge for cloud download. In this paper, primary elements impacting on storage capacity are explored through deliberating in large-scale commercial cloud download system, i.e. general user usage pattern and available period. And based on statistical analysis of real-world traces, we formulate storage capacity related to these two elements, which is the original contribution different from all previous works. This model gives guidance of potential system policy design. Finally, the effectivity of this model is demonstrated by simulation results compared with empirical data of practical system.展开更多
基金supported financially by the National Nature Science Foundation of China(No.41901129)the University Natural Sciences Research Project of Anhui Educational committee(2024AH050270)the support from the Joint China–Sweden Mobility Grant funded by NSFC and STINT(CH2019-8250)。
文摘Compared to lake area and water level,lake storage capacity more intuitively reflects regional climate changes.In this study,we first derived lakebed elevation profiles for individual ICESat-2 tracks based on the underwater stratification of laser photons,then integrating all valid elevation tracks within the water body to interpolate the bathymetry.On this basis,we calculated the capacity and its time series directly,with the aid of lake boundaries and water levels obtained from optical imagery and CryoSat-2 data.Next,we also applied an empirical formula to estimate the water volume changes of Bangdag Co by combining the area and water levels from 2010 to 2023.Finally,we compared the results of Bangdag Co's water volume changes obtained from the two different methods and conducted a detailed analysis of their performance and regional applicability.The bathymetric map of Bangdag Co reveals a distinct spatial pattern,with the northeastern part significantly deeper(with a maximum depth of 35.27 m)and the southwestern part shallower.The average depth of the lake is 13.99 m.We further estimated that the lake storage capacity in November 2023 was 2.95 km^(3).Water volume changes estimated using the empirical formula were highly consistent with those derived from the lake storage capacity time series(from 2010 to 2023,the lake storage capacity increased by 1.04 km^(3)).Our comparison revealed that the empirical formula method reflects only changes in water volume.In contrast,while our method can accurately estimate lake storage capacity,it is constrained to shallow,clear,and elongated east-west lakes(e.g.,Ayakkum Lake).In summary,the ICESat-2 laser altimetry data,which do not rely on measured water depths,offer an essential complement to underwater topography detection and provide a novel perspective on lake volume estimation research.
基金jointly supported by the Science and Technology Department of Shanxi Province,China (20201101003)the National Natural Science Foundation of China (U1810201)the China Scholarship Council (202206400012)。
文摘Methane adsorption is a critical assessment of the gas storage capacity(GSC)of shales with geological conditions.Although the related research of marine shales has been well-illustrated,the methane adsorption of marine-continental transitional(MCT)shales is still ambiguous.In this study,a method of combining experimental data with analytical models was used to investigate the methane adsorption characteristics and GSC of MCT shales collected from the Qinshui Basin,China.The Ono-Kondo model was used to fit the adsorption data to obtain the adsorption parameters.Subsequently,the geological model of GSC based on pore evolution was constructed using a representative shale sample with a total organic carbon(TOC)content of 1.71%,and the effects of reservoir pressure coefficient and water saturation on GSC were explored.In experimental results,compared to the composition of the MCT shale,the pore structure dominates the methane adsorption,and meanwhile,the maturity mainly governs the pore structure.Besides,maturity in the middle-eastern region of the Qinshui Basin shows a strong positive correlation with burial depth.The two parameters,micropore pore volume and non-micropore surface area,induce a good fit for the adsorption capacity data of the shale.In simulation results,the depth,pressure coefficient,and water saturation of the shale all affect the GSC.It demonstrates a promising shale gas potential of the MCT shale in a deeper block,especially with low water saturation.Specifically,the economic feasibility of shale gas could be a major consideration for the shale with a depth of<800 m and/or water saturation>60%in the Yushe-Wuxiang area.This study provides a valuable reference for the reservoir evaluation and favorable block search of MCT shale gas.
基金supported by National Natural Science Foundation of China(51202116)Ministry of Science and Technology,China(2010CB732304,2013AA065302)
文摘Praseodymium （Pr） was impregnated to CeO2-ZrO2 solid solution by an impregnation method. The as-obtained Pr modi- fied CeO2-ZrO2 was impregnated with 1 wt.% Pd to prepare the catalysts. The structure and reducibility of the fresh and hydrother- really aged catalysts were characterized by X-ray diffraction （XRD）, Raman, X-ray photoelectron spectroscopy （XPS）, CO chemi- sorption and H2 temperature-programmed reduction （H2-TPR）. The oxygen storage capacity （OSC） was evaluated with CO serving as probe gas. Effects of impregnated Pr on the structure and oxygen storage capacity of catalysts were investigated. The results showed that the aged Pr-impregnated samples had much higher OSC and better reducibility than the unmodified ones. The scheme of structural evolutions of the catalysts with and without Pr was also established. Partial of the impregnated Pr diffused into the bulk of CeO2-ZrO2 during ageing, which inhibited the sintering, and increased the amount of oxygen vacancies in CeO2-ZrO2 support. Furthermore, those impregnated Pr species which covered on the surface of the support obstructed the strong metal-support interaction between Pd and Ce so as to reduce the encapsulation of Pd as well as the back spill-over of the oxygen during the catalytic process.
基金the financial support from the National Natural Science Foundation of China(No.52074217)the Natural Science Basic Research Program of Shaanxi Province(No.2021JLM-26).
文摘The concept of the carbon cycle in the old goaf of a coal mine based on CO_(2)utilization and storage was put forward adhering to the principle of low-carbon development,utilization of space resources in old goafs,and associated gas resources development.Firstly,the evolution characteristics of overburden fissures in the goaf of the case was studied using a two-dimensional physical similarity simulation test,the sealing performance of the caprocks after stabilization was analyzed,and the fissures were counted and classi-fied.Then,the process of gaseous CO_(2)injection in the connected fissure was simulated by Ansys Fluent software,and the migration law and distribution characteristics of CO_(2)under the condition of gaseous CO_(2)injection were analyzed.Finally,the estimation models of free CO_(2)storage capacity in the old goaf were constructed considering the proportion of connected fissure and the effectiveness of CO_(2)injection.The CO_(2)storage capacity in the old goaf of the case coal mine was estimated.The results showed that a caprock group of“hard-thickness low-permeability hard-thickness”was formed after the caprock-fissures system in the goaf of the case tended to be stable vertically.The connected fissure,occlude cracks,and micro-fractures in the goaf accounted for 85.5%,8.5%,and 6%of the total fissures,respectively.Gaseous CO_(2)first migrated to the bottom of the connected fissure after CO_(2)was injected into the goaf,then spread horizontally along the bottom of the connected fissure after reaching the bottom,and finally spread longitudinally after filling the bottom of the entire connected fissure.The theoretical and effective storage capacities of free CO_(2)at normal temperature and pressure in the old goaf of the case were 9757 and 7477 t,respectively.The effective storage capacity of free CO_(2)at normal temperature and pressure in the old goaf after all minefield mined was 193404 t.The research can provide some reference for the coal mining industry to help the goal of“carbon peaking and carbon neutrality”.
基金supported by Nation Key R&D Program of China(2021YFE0102400).
文摘Compensating for photovoltaic(PV)power forecast errors is an important function of energy storage systems.As PV power outputs have strong random fluctuations and uncertainty,it is difficult to satisfy the grid-connection requirements using fixed energy storage capacity configuration methods.In this paper,a method of configuring energy storage capacity is proposed based on the uncertainty of PV power generation.A k-means clustering algorithm is used to classify weather types based on differences in solar irradiance.The power forecast errors in different weather types are analyzed,and an energy storage system is used to compensate for the errors.The kernel density estimation is used to fit the distributions of the daily maximum power and maximum capacity requirements of the energy storage system;the power and capacity of the energy storage unit are calculated at different confidence levels.The optimized energy storage configuration of a PV plant is presented according to the calculated degrees of power and capacity satisfaction.The proposed method was validated using actual operating data from a PV power station.The results indicated that the required energy storage can be significantly reduced while compensating for power forecast errors.
基金Projects supported by the National"973"Project (2004CB719503) "863"Project (2004AA649400) National Natural Science Foundation of China (50502023)
文摘CZO （CeO2-ZrO2） and CZYO （CeO2-ZrO2-Y2O3） series of mixed oxides were prepared by coprecipitaion, and a part of these oxides were loaded with precious metals （PM）. XRD, BET, and oxygen storage capacity （OSC） investigations were performed on samples aged at 750, 900, and 1050 ℃. It was observed that BET surface area and OSC showed a marked decrease in CeO2 aged at high temperature, and the erystallite size showed an obvious increase. The CZO samples consist of cubic- and tetragonal crvstal phases, and their crystallite size increase rapidly when aged at high temperature. The CZYO samples consist of single crystal phase when the content of Y exceeds 0.15 mol, and their erystallite size increases slowly during high-temperature aging. It is concluded that additive Y can stabilize the performance of CZYO oxides. In the aged CZO and CZYO mixed-oxide systems, addition of a small amount of precious metals （Pt, Pd, Rh） increased the rate of reduction and led to an obvious improvement in OSC. OSC of CZO and CZYO with precious metals are related to their composition and the type of precious metal.
基金the National Natural Science Foundation of China(Nos.51777115 and 81527901)the National Key Research and Development Program of China(Nos.2016YFC0105502 and 2016YFC0105900)Tsinghua University Intiative Scientifc Research Program and Major Achievements Transformation Project of Beijing’s College.
文摘The interfacial performance of implanted neural electrodes is crucial for stimulation safety and the recording quality of neuronal activity.This paper proposes a novel surface architecture and optimization strategy for the platinum–iridium(Pt–Ir)electrode to optimize electrochemical performance and wettability.A series of surface micro/nano structures were fabricated on Pt–Ir electrodes with different combinations of four adjustable laser-processing parameters.Subsequently,the electrodes were characterized by scanning electron microscopy,energy-dispersive X-ray spectroscopy,cyclic voltammetry,electrochemical impedance spectroscopy,and wetting behavior.The results show that electrode performance strongly depends on the surface morphology.Increasing scanning overlap along with moderate pulse energy and the right number of pulses leads to enriched surface micro/nano structures and improved electrode performance.It raises the maximum charge storage capacity to 128.2 mC/cm^(2) and the interface capacitance of electrodes to 3.0×10^(4)μF/cm^(2) for the geometric area,compared with 4.6 mC/cm^(2) and 443.1μF/cm2,respectively,for the smooth Pt–Ir electrode.The corresponding optimal results for the optically measured area are 111.8 mC/cm^(2) and 2.6×10^(4)μF/cm^(2),which indicate the contribution of fner structures to the ablation profle.The hierarchical structures formed by the femtosecond laser dramatically enhanced the wettability of the electrode interface,giving it superwicking properties.A wicking speed of approximately 80 mm/s was reached.Our optimization strategy,leading to superior performance of the superwicking Pt–Ir interface,is promising for use in new neural electrodes.
基金Project supported by the National Natural Science Foundation of China (50972069)the Ministry of Science and Technology, China (2009AA064803)the Chinese Ministry of Industry and Information Technology
文摘Binary Ce-Zr（CZ）,Pr-Zr（PZ） and ternary Ce-Zr-Pr（CZP） mixed oxides were prepared by an ammonia-aided co-precipitation method,and were aged in a steam/air flow at 1050 °C.X-ray diffraction（XRD）,Raman spectra,X-photon spectra（XPS） and CO temperature programmed reduction（TPR） were carried out to characterize the micro-structure and reducibility of catalysts.The oxygen storage capacity（OSC） was evaluated with CO serving as probe gas.The results showed that a pseudo cubic structure was formed for the Zr-rich ceria-zirconia mixed oxides with Pr doping.The insertion of Pr prevented the phase segregation of the mixed oxides during the hydrothermal ageing.The Pr doped samples showed better redox performances in comparison with CZ,and the sample doped with 5 wt.% Pr showed the most remarkably promoted dynamic oxygen storage capacity.This phenomenon was closely related to both the reducibility and oxygen mobility of the mixed oxides.The introduction of praseodymium into ceria-zirconia could accelerate the oxygen migration by increasing the amount of oxygen vacancies,although it was difficult for Pr3＋ ions themselves to participate in the oxygen exchange process.
文摘Cerium and cerium-based oxides are found to be an important element in three-way catalytic converter(TWC).The effective utilization of TWC is found to be reduced due to thermal loading which results in structural deformation of ceria,Doping Zr^(4+)into the rare earth element can increase the oxygen storage capacity and thermal stability.Hence,an attempt was made to study the oxygen storage capacity and thermal stability of ceria by doping Zr^(4+)and Nd^(3+).Cerium-based nanocrystallite in the composition of Ce_(0.6)Zr_(0.4-x)Nd_(1.3)xO_(2)(0≤x≤0.4)was prepared by sol-gel synthesize technique with citric acid as a gel-forming agent.X-ray diffraction(XRD)result shows that doping Nd^(3+)into ceria lattice forms homogenous solid solution of cubic fluorite structure up to 25%of substitute only.Doping higher amount of Nd^(3+)into ceria lattice leads to the formation of Nd_(2)O_(3).Raman spectrum study confirms that oxygen storage capacity band is present in Ce_(0.6)Zr_(0.4)O2 and Ce_(0.6)Zr_(0.3)Nd_(0.13)O_(2).The oxygen storage capacity was calculated through weight loss of the sample during the second heating cycle with cyclic heating from30 to 800℃in thermogravimetric analysis(TGA).The TGA study reveals that the oxygen storage capacity of Ce_(0.6)Zr_(0.4)O2 decreases after the substitution of Nd^(3+),which is due to the larger ionic radius of Nd^(3+)compared with that of Zr4+and CeO2.
文摘Oxygen storage and adsorptive properties of praseodymium oxides were investigated by pulse experiments and temperature - programmed desportion/reduction (TPD/TPR) experiments. Pr2O3 possesses the similar oxygen storage properties to CeO2, and its dynamic oxygen storage capacity is 14.9 mumol.g(-1). The studies on TPD Of O-2, H2O and CO and TPR show that Pr2O3 provides more active surface oxygen species and at a lower temperature than CeO2. It is suggested that Pr2O3 can be a well candidate as an oxygen storage component in automobile three-way catalyst.
基金Project supported by the National"973"Project (2004CB719503) and the Programfor New Century Excellent Talents in University
文摘Dynamic oxygen storage and release capability （OSC） measurement apparatus was designed to evaluate the OSC performance of ceria-based oxygen storage material. The optimum measurement condition was at a frequency of 0.1 Hz with the inlet gas-flow sequence CO （5S）→O2（5S）→CO→O2 and a flow rate of 300 ml·min^-1. Under this condition, similar regular square wave in the inlet and outlet of the reactor was obtained to guarantee the reliability of the dynamic OSC results. The dynamic OSC performance of the CeO2 and Ce0.67Zr0.33O2 mixed oxide prepared using the citric sol-gel method was studied at the optimum measurement condition with focus on both quantitative and qualitative analyses, The results reveal distinctly that Ce0.67Zr0.33O2 had better dynamic OSC performance because of its higher oxygen migration rate than CeO2. Under dynamic conditions, two CO2 production peaks occurred corresponding to the CO pulse and the O2 pulse, respectively, during the entire cycle. The intensity and ratio between the two CO2 productions were highly influenced by temperature and frequency indicating complex surface phenomena during the oxygen storage/release process, As a result, this set-up can be applied to the evaluation of ceria-based material on the OSC performance.
基金supported by the National Key Basic Research Program of China (Grant No. 2006CB400502)the Special Basic Research Fund for Methodology in Hydrology (Grant No. 2007FY140900)the 111 Project (Grant No. B08048)
文摘This paper introduces the method of designation of water storage capacity for each grid cell within a catchment, which considers topography, vegetation and soil synthetically. For the purpose of hydrological process simulation in semi-arid regions, a spatially varying storage capacity （VSC） model was developed based on the spatial distribution of water storage capacity and the vertical hybrid runoff mechanism. To verify the applicability of the VSC model, both the VSC model and a hybrid runoff model were used to simulate daily runoff processes in the catchment upstream of the Dianzi hydrological station from 1973 to 1979. The results showed that the annual average Nash-Sutcliffe coefficient was 0.80 for the VSC model, and only 0.67 for the hybrid runoff model. The higher annual average Nash-Sutcliffe coefficient of the VSC model means that this hydrological model can better simulate daily runoff processes in semi-arid regions. Furthermore, as a distributed hydrological model, the VSC model can be applied in regional water resource management.
基金National Key R&D Program of China(2018YFC0407201).
文摘The regulation and storage capacity of Poyang Lake is infl uenced by the fl ow from the main stream of the Yangtze River and the fi ve rivers in the Poyang Lake basin.After the operation of the Three Gorges Dam(TGD),hydrological changes in the main stream of the Yangtze River impact water exchange between the Yangtze River and Poyang Lake.Based on the analysis of measured data and factors infl uencing outfl ow at Hukou station,a new empirical formula describing outfl ow at Hukou station and critical water level for lake storage capacity is established.The change in monthly storage capacity of Poyang Lake before and after the construction of the TGD is analyzed quantitatively.The results show that the fl ows from the main stream of the Yangtze River and the fi ve rivers in the Poyang Lake basin affect outfl ow and water storage capacity by changing the water level difference between Xingzi and Hukou stations and by changing the water level at Hukou station.But the Yangtze River and the fi ve rivers in the Poyang Lake basin differ in process and degree.If the water level at Hukou station remains consistent,when the fl ow from the fi ver rivers increases by 1,000 m3/s,the outfl ow at Hukou station increases by 304 m3/s.When the fl ow from the main stream of the Yangtze River increases by 1,000 m3/s,the outfl ow at Hukou station decreases by 724 m3/s.In addition,the operation of the TGD affects the water storage capacity of Poyang Lake.The water volume of Poyang Lake decreases by 49.4%in September,but increases by 47.7%in May.
基金Under the auspices of the National Natural Science Foundation of China(No.52268008)。
文摘This study focuses on urgent research on restoring and enhancing carbon storage capacity in the Beibu Gulf Urban Agglomer-ation of China,a key area in the‘Belt and Road’Initiative,which aligns with carbon peaking and neutrality goals.This research ana-lyzes the spatial characteristics of carbon metabolism from 2000 to 2020 and uses models to identify stable carbon sink areas,positive carbon flow corridors,and carbon sequestration nodes.The goal is to construct a carbon metabolism spatial security pattern(CMSSP)and propose territorial ecological restoration strategies under different development demand scenarios.The results show the following:1)in 2020,the study area’s carbon sink decreased by 8.29×10^(4) t C/yr compared with that in 2010 and by 10.83×10^(4) t C/yr compared with that in 2000.High-carbon sinks were found mainly in mountainous areas,whereas low-carbon sinks are concentrated in urban con-struction land,rural residential areas,and land margins.2)From 2000 to 2020,the spatial security pattern of carbon metabolism tended to be‘high in the middle of the east and west and low in the gulf.’In 2000,2010,and 2020,16 stable carbon sinks were identified.The carbon energy flow density in Guangxi was greater than that in Guangdong and Hainan,with positive carbon flow corridors located primarily in Guangxi and Guangdong.The number of carbon sequestration nodes remained stable at approximately 15,mainly in Guangxi and Hainan.3)Scenario simulations revealed that under the Nature-based mild restoration scenario,the carbon sink rate will reach 611.85×10^(4) t C/yr by 2030 and increase to 612.45×10^(4) t C/yr by 2060,with stable carbon sinks increasing to 18.In the restora-tion scenario based on Anti-globalization,the carbon sink will decrease from 610.24×10^(4) t C/yr in 2030 to 605.19×10^(4) t C/yr in 2060,with the disappearance of some positive carbon flow corridors and stable carbon sinks.Under the Human-based sustainable restoration scenario,the carbon sink area will decrease from 607.00×10^(4) t C/yr in 2030 to 596.39×10^(4) t C/yr in 2060,with carbon sink areas frag-menting and positive carbon flow corridors becoming less dense.4)On the basis of the current and predicted CMSSPs,this study ex-plores spatial ecological restoration strategies for high-carbon storage areas in bay urban agglomerations at four levels:the land control region,urban agglomeration structure system,carbon sink structure and bay structure control region.
基金supported by Foundation Project of Jihua Laboratory(X200191TL200).
文摘This work investigated the effect of Na_(2)CO_(3)on the char structures of cellulose and lignin,respective-ly,and examined the electrochemi-cal performance of the char by act-ing as an active material for coin cells.The morphology of char can be significantly steered by the con-centration of Na_(2)CO_(3).Scanning electron microscopy analysis demonstrated that the intro-duction of Na_(2)CO_(3)into cellulose at an appropriate concentration led to the formation of tubular structure on its surface after pyrolysis,whereas the tubular structure was absent in the lignin char with the addition of Na_(2)CO_(3)at any concentrations.X-ray diffraction and Ra-man spectroscopy characterizations revealed that all the obtained chars from both cellulose and lignin,with or without Na_(2)CO_(3),were ascribed to non-crystalline graphite.Nevertheless,the crystal orientation of graphite from cellulose and lignin changed after the catalysis of Na_(2)CO_(3).Further electrochemical tests showed that cellulose char had a higher sodium stor-age capacity than that of lignin char.The excellent electrochemical performance of carbon materials derived from cellulose might hold a prospective application in the field of energy storage.
基金the Chinese Scholarship Council for their support(Grant No.2022GXZ005733).
文摘Surface hydrogen storage facilities are limited and costly,making subsurface hydrogen storage in geological formations a more viable alternative due to its substantial capacity,safety,and economic feasibility.This method is essential for large-scale hydrogen storage to support renewable energy integration,fuel cell technologies,and other applications aimed at mitigating global climate change.This review examines underground hydrogen storage(UHS)in geological formations,focusing on recent experiments,modeling and simulations,and field applications.Geological formations such as depleted oil reservoirs,salt caverns,and depleted natural gas reservoirs are identified as favorable candidates due to minimal interactions with hydrogen,leading to low hydrogen loss.Globally,80%of UHS projects utilize depleted natural gas and oil reservoirs,with over 50%focused on depleted natural gas and oil condensate reservoirs due to cost-effective existing infrastructure.Among storage options,salt caverns are the most advantageous,offering self-healing properties,low caprock permeability,large storage capacity,rapid injection and withdrawal rates,and low contamination risk.Additionally,hydrogen produced from coal is the cheapest option,costing 1.2e2 USD/kg,whereas hydrogen from renewable sources,such as water,is the most expensive at 3e13 USD/kg.Despite its higher cost,green hydrogen from water,characterized by low carbon emissions,requires further research to reduce production costs.This review highlights critical research gaps,challenges,and policy recommendations to advance UHS technologies,ensuring their role in combating climate change.
基金Project supported by National High-Tech Research and Development Program of China (2011AA03A405)the Key Program of Tianjin Natural Science Foundation (09JCZDJC26600)
文摘The effect of Co doping on ceria-zirconia mixed oxides was investigated for Co0.1Ce0.6Zr0.3Ox sample prepared by sol-gel method. The Pd-only three-way catalyst （TWC） was obtained by incipient wetness impregnation with 0.5 wt.% Pd loading. The structural and oxygen handling properties were analyzed by X-ray diffraction （XRD）, H2-temperature programmed reduction （H2-TPR） and the dynamic oxygen storage capacity （DOSC）. The introduction of Co into ceria-zirconia lattice strongly modified the mobility of oxygen and enhanced the DOSC performance. Pd-only TWC based on the Co0.1Ce0.6Zr0.3Ox support exhibited superior activity for water-gas shift and steam reforming and ampli- fied amplitude of stoichiometric window.
文摘Nanorod-like Ce0.7Zr0.3O2 solid solutions were synthesized by a sodium dodecyl sulfate-assisted precipitation method. The samples were characterized by means of scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and specific surface area measurement. Typical Ce0.7Zr0.3O2 nanorods were 40 nm in average diameter and 450 nm in length, with specific surface area and oxygen storage capacity of 194 m2/g and 374 μmol/g, respectively.
基金The authors would like to acknowledge the financial support provided by National Natural Science Foundation of China(Nos.42102207,42141012 and 41727801)Major Project supported by Jiangsu Key Laboratory of Coal-based Greenhouse Gas Control and Utilization,China University of Mining and Technology(2020ZDZZ01C)+1 种基金the Peng Cheng Shang Xue Education Fund of CUMT Education Development Foundation(PCSX202203)A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institution(PAPD).
文摘Carbon dioxide(CO_(2))capture,utilization,and storage(CCUS)is an important pathway for China to achieve its“2060 carbon neutrality”strategy.Geological sequestration of CO_(2)in deep coals is one of the methods of CCUS.Here,the No.3 anthracite in the Qinshui Basin was studied using the superposition of each CO_(2)geological storage category to construct models for theoretical CO_(2)geological storage capacity(TCGSC)assessment,and CO_(2)adsorption capacity variation with depth.CO_(2)geological storage potential of No.3 anthracite coal was assessed by integrating the adsorption capacity with the static storage and dissolution capacities.The results show that(1)CO_(2)adsorption capacities of XJ and SH coals initially increased with depth,peaked at 47.7 cm3/g and 41.5 cm3/g around 1000 m,and later decreased with depth.(2)four assessment areas and their geological model parameters were established based on CO_(2)phase variation and spatial distribution of coal thickness,(3)the abundance of CO_(2)geological storage capacity(ACGSC),which averages 40 cm3/g,shows an analogous circularity-sharp distribution,with the high abundance area influenced by depth and coal rank,and(4)the TCGSC and the effective CO_(2)geological storage capacity(ECGSC)are 9.72 Gt and 6.54 Gt;the gas subcritical area accounted for 76.41%of the total TCGSC.Although adsorption-related storage capacity accounted for more than 90%of total TCGSC,its proportion,however,decreased with depth.Future CO_(2)-ECBM project should focus on highrank coals in gas subcritical and gas-like supercritical areas.Such research will provide significant reference for assessment of CO_(2)geological storage capacity in deep coals.
基金supported by the Fundamental Research Funds in Beijing Jiaotong University(W11JB00630)
文摘With the rise and world wide deployment of cloud utilities, the principle of the cloud download is proposed to provide high-quality file content distribution by using dedicated servers as cloud cache to guarantee the data availability and enhance the data transfer rate. As the system scales up to a large population, how to design appropriate storage capacity of cloud cache is a key challenge for cloud download. In this paper, primary elements impacting on storage capacity are explored through deliberating in large-scale commercial cloud download system, i.e. general user usage pattern and available period. And based on statistical analysis of real-world traces, we formulate storage capacity related to these two elements, which is the original contribution different from all previous works. This model gives guidance of potential system policy design. Finally, the effectivity of this model is demonstrated by simulation results compared with empirical data of practical system.
