Missing interpolation model for wind power data based on the improved CEEMDAN method and generative adversarial interpolation network

Randomness and fluctuations in wind power output may cause changes in important parameters(e.g.,grid frequency and voltage),which in turn affect the stable operation of a power system.However,owing to external factors(such as weather),there are often various anomalies in wind power data,such as missing numerical values and unreasonable data.This significantly affects the accuracy of wind power generation predictions and operational decisions.Therefore,developing and applying reliable wind power interpolation methods is important for promoting the sustainable development of the wind power industry.In this study,the causes of abnormal data in wind power generation were first analyzed from a practical perspective.Second,an improved complete ensemble empirical mode decomposition with adaptive noise(ICEEMDAN)method with a generative adversarial interpolation network(GAIN)network was proposed to preprocess wind power generation and interpolate missing wind power generation sub-components.Finally,a complete wind power generation time series was reconstructed.Compared to traditional methods,the proposed ICEEMDAN-GAIN combination interpolation model has a higher interpolation accuracy and can effectively reduce the error impact caused by wind power generation sequence fluctuations.

Experimental Study of Microalgae Cultivation under Selective Illumination by Ag/CoSO_(4)for Bioelectrode Materials Preparation

Microalgae biomass is an ideal precursor to prepare renewable carbon materials,which has broad application.The bioaccumulation efficiency(lipids,proteins,carbohydrates)and biomass productivity of microalgae are influenced by spectroscopy during the culture process.In this study,a bilayer plate-type photobioreactor was designed to cultivate Chlorella protothecoides with spectral selectivity by nanofluids.Compared to culture without spectral selectivity,the spectral selectivity of Ag/CoSO_(4)nanofluids increased microalgae biomass by 5.76%,and the spectral selectivity of CoSO_(4)solution increased by 17.14%.In addition,the spectral selectivity of Ag/CoSO_(4)nanofluids was more conducive to the accumulation of nutrients(29.46%lipids,50.66%proteins,and 17.86%carbohydrates)in microalgae.Further cultured chlorella was utilized to prepare bioelectrode materials,it was found that algal based biochar had a good pore structure(micro specific surface area:1627.5314 m^(2)/g,average pore size:0.21294 nm).As the current density was 1 A/g,the specific capacitance reached 230 F/g,appearing good electrochemical performance.

“三把力”助推航海人行稳致远

苍穹之下,蔚蓝之上,在一望无际的大海,船员们见证美丽的朝霞和暮色,也曾在电闪雷鸣的光芒和轰响中,尽全力让船舶行驶在正确的航向上,他们是一群最勇敢的人。为世界创造美好的人,也必将被人们所牢记。2018年12月3日,习近平总书记在巴拿马运河与中远海运“玫瑰轮”船长通话。

Study on Preparation of Nitrogen-Doped Hierarchically Porous and High-Performance Carbon Materials from Seaweed Biomass

Use Enteromorpha clathrate as a carbon and nitrogen precursor could obtain the N-doped porous carbon mate-rials by two-step pyrolysis.In this paper,the exogenous nitrogen(urea,melamine)and activating agents(KOH,ZnCl_(2))were employed for the production of higher-performance carbon materials from seaweed biomass.SEM,BET,FTIR,XRD,XPS,Raman and ultimate analyses were carried out to investigate the morpho-structural and elemental peculiarities of the carbonaceous materials.Moreover,cyclic voltammetry(CV),galvanostatic charge-discharge(GCD)and cyclic charge-discharge tests were carried out to examine the electrochemical properties of the samples.The results showed that electrochemical performance of the carbonaceous materials improved by adding the appropriate nitrogen sources.This improvement was observed under either condition,when the nitro-gen source and activating agent were melamine and ZnCl_(2) or urea and KOH,respectively.Specifically,under the condition with KOH as the activator,the nitrogen content of carbon material without exogenous nitrogen was initially 1.46%.After the addition of urea or melamine,the nitrogen content increased to 4.86%and 6.18%,respectively.Under the condition with ZnCl_(2) as the activator,and without exogenous nitrogen,the nitrogen con-tent of carbon materials was initially 3.75%.However,after adding urea or melamine,the nitrogen content increased to 12.11%and 14.76%,respectively.The carbonaceous materials(prepared from urea/KOH and mel-amine/ZnCl_(2))showed excellent gravimetric capacitances of 172 and 151.5 F/g at 1A/g.Moreover,at a current density of 5 A/g,their specific capacitance retention rate reached 78.3%and 82.6%respectively after 1000 cycles.

Effect of supports on the redox performance of pyrite cinder in chemical looping combustion

Chemical looping combustion(CLC)is a clean and efficient flame-free combustion technology,which combust the fuels by lattice oxygen from a solid oxygen carrier with inherent CO_(2)capture.The development of oxygen carriers with low cost and high redox performance is crucial to the whole efficiency of CLC process.As the solid by-product from the sulfuric acid production,pyrite cinder presented excellent redox performance as an oxygen carrier in CLC process.The main components in pyrite cinder are Fe_(2)O_(3),CaSO_(4),Al_(2)O_(3)and SiO_(2)in which Fe_(2)O_(3)is the active component to provide lattice oxygen.In order to systematic investigate the functions of supports(CaSO_4,Al_(2)O_(3)and SiO_(2))in pyrite cinder,three oxygen carriers(Fe_(2)O_(3)-CaSO_(4),Fe_(2)O_(3)-Al_(2)O_(3)and Fe_(2)O_(3)-SiO_(2))were prepared and evaluated in this study.The results showed that Fe_(2)O_(3)-CaSO_(4) displayed high redox activity and cycling stability in the multiple redox cycles.However,both Fe_(2)O_(3)-Al_(2)O_(3)and Fe_(2)O_(3)-SiO_(2)experienced serious deactivation during redox reactions.It indicated that the inert Fe-Si solid solution(Fe_(2)SiO_(4))was formed in the spent Fe_(2)O_(3)-SiO_(2)sample,which decreased the oxygen carrying capacity of this sample.The XPS results showed that the oxygen species on the surface of Fe_(2)O_(3)-CaSO_(4) could be fully recovered after the 20 redox cycles.It can be concluded that CaSO_(4) is the key to the high redox activity and cycling stability of pyrite cinder.

Nutrient enrichment driven by canopy rainfall redistribution:Mechanism,quantification,and pattern

Vegetation canopies intercept and redistribute rainfall into throughfall and stemflow,which transfer substantial amounts of elements into the soil,influencing soil microbial community,plant survival,and plant community succession.Despite advancements in ecohydrological research,the implication of nutrient enrichment resulting from this redistribution of rainfall by canopies remains largely unexplored.To address this gap,we conducted a systematic review of 1020 papers published between 2000 and 2022,gathering data on nutrient concentration and enrichment for critical ions(including K^(+),Na^(+),Ca^(2+),Mg^(2+),NH_(4)^(+),Cl^(-),NO_(3)^(-)and SO_(4)^(2-))from the Web of Science and Chinese Knowledge Infrastructure databases.We aimed to synthesize the mechanisms,quantify the enrichments,and identify global patterns of nutrient enrichment in stemflow and throughfall across climate zones,and vegetation types and ecosystems.The results of this study indicate that stemflow exhibits,on average,2.1times greater ion concentration(6.13 mg L^(-1))compared to throughfall.In particular,among the investigated ions,SO_(4)^(2-)(12.45and 6.32 mg L^(-1))for stemflow and throughfall,respectively,and Cl^(-)(9.21 and 4.81 mg L^(-1))exhibit the highest concentrations in both rainfall redistribution components,while K^(+)(13.7 and 5.8)and Mg^(2+)(5.6 and 2.8)have the highest enrichment factors.Across climate zones,throughfall and stemflow show the lowest ion concentrations but the highest enrichment factors in extremely humid regions.Along the temperature gradient,ion concentrations are the highest in cold climates with no clear patterns observed for enrichment factors with increasing temperature.In addition,shrubs,conifers,mixed forests,and artificial ecosystems demonstrate enrichment factors 1.1 to 3.0 times greater than those of trees,broad-leaved plants,pure forests,and natural ecosystems.These findings emphasize the need for increased attentions to artificial ecosystems,such as urban and agricultural ecosystems,which often received limited research focus,especially regarding shrubs and conifers exhibiting stronger nutrients enrichment capabilities.Future investigations should integrate soil moisture analysis to better understand the impact of rainfall redistribution on the nutrient enrichment processes,patterns,and nutrient balance in global terrestrial ecosystems.