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Cyanobacterial biomass is important for biofuel and biofertilizer, however, biomass production requires expensive chemical growth nutrients. To address this issue, we explored the useof inexpensive growth nutrient media from an integrated manure-seawater system for cyanobacterial biomass production. Salt-tolerant cyanobacterial strain HSaC and salt-sensitive cyanobacterial strain LC were tested to evaluate the potential of integrated manure-seawater media for sustainable cyanobacterial biomass production. As a prerequisite for seawater experiments, strain HSaC was grown at different NaCl concentrations (0 mM, 60 mM, 120 mM, 180 mM, 240 mM and 300 mM) to identify the optimum salt concentration. The highest biomass yield and photosynthetic pigment contents were obtained at 120 mM NaCl concentration. The highest exo-polysaccharide (EPS) content was obtained at 180 mM NaCl concentration. The treatments for the manure-seawater media were cow manure, pig manure, chicken manure and BG11, each with distilled water, diluted seawater and non-diluted seawater. The highest biomass and photosynthetic pigment yield for cyanobacterial strains LC and HSaC were obtained from 0.5 dS/m and 10 dS/m diluted seawater integrated with cow manure, respectively, but pig and chicken manure performed poorly. Overall, the biomass production and photosynthetic pigment results from cow manure-seawater were relatively better than those from the reference media (BG11). Based on the current findings, it is concluded that the growth nutrients from integrated cow manure-seawater can wholly substitute for the BG11 without affecting cyanobacterial growth, thereby reducing the usage of expensive chemical growth media. Thus,The results of study help to enhance the biomass production of both salt-sensitive and salt-tolerant cyanobacteria for sustainable biofuel and biofertilizer production. Cyanobacterial biomass is important for biofuel and biofertilizer, however, biomass production requires expensive chemical growth nutrients. To address this issue, we explored the useof inexpensive growth nutrient media from an integrated manure-seawater system for cyanobacterial biomass production. Salt-tolerant cyanobacterial strain HSaC and salt-sensitive cyanobacterial strain LC were tested to evaluate the potential of integrated manure-seawater media for sustainable cyanobacterial biomass production. As a prerequisite for seawater experiments, strain HSaC was grown at different NaCl concentrations (0 mM, 60 mM, 120 mM, 180 mM, 240 mM and 300 mM) to identify the optimum salt concentration. The highest biomass yield and photosynthetic pigment contents were obtained at 120 mM NaCl concentration. The highest exo-polysaccharide (EPS) content was obtained at 180 mM NaCl concentration. The treatments for the manure-seawater media were cow manure, pig manure, chicken manure and BG11, each with distilled water, diluted seawater and non-diluted seawater. The highest biomass and photosynthetic pigment yield for cyanobacterial strains LC and HSaC were obtained from 0.5 dS/m and 10 dS/m diluted seawater integrated with cow manure, respectively, but pig and chicken manure performed poorly. Overall, the biomass production and photosynthetic pigment results from cow manure-seawater were relatively better than those from the reference media (BG11). Based on the current findings, it is concluded that the growth nutrients from integrated cow manure-seawater can wholly substitute for the BG11 without affecting cyanobacterial growth, thereby reducing the usage of expensive chemical growth media. Thus,The results of study help to enhance the biomass production of both salt-sensitive and salt-tolerant cyanobacteria for sustainable biofuel and biofertilizer production.

Comparison of the water budget for the typical cropland and pear orchard ecosystems in the North China Plain Comparison of the water budget for the typical cropland and pear orchard ecosystems in the North China Plain

Direct charge radioisotope battery having the advantages of long service lifetime, simple structure, high open circuit voltage and easily miniaturized, is a promising source for the great power of Micro-Electro-Mechanical System. Although the beta sources are the main choice for direct charge nuclear battery in the present studies,but no systematic analysis and comparison on beta sources is presented. In this work, the properties of six beta sources (including 3H(Ti3H2), 14C, 35S, 45Ca, 63Ni and 147Pm) were studied by software simulation and theoretical calculation. This study includes the differences of energy conversion efficiency and the theoretical output power for direct charge nuclear battery. The calculated results showed that the energy conversion efficiency was positively correlated with the average energy of emitted radioactive particles, and the theoretical output power was negatively correlated with half-life of beta source. 147Pm was the preferred choice considering long life, the energy conversion efficiency and the theoretical output power. Direct charge radioisotope battery having the advantages of long service lifetime, simple structure, high open circuit voltage and easily miniaturized, is a promising source for the great power of Micro-Electro-Mechanical System. Although the beta sources are the main choice for direct charge nuclear battery in the present studies,but no systematic analysis and comparison on beta sources is presented. In this work, the properties of six beta sources (including 3H(Ti3H2), 14C, 35S, 45Ca, 63Ni and 147Pm) were studied by software simulation and theoretical calculation. This study includes the differences of energy conversion efficiency and the theoretical output power for direct charge nuclear battery. The calculated results showed that the energy conversion efficiency was positively correlated with the average energy of emitted radioactive particles, and the theoretical output power was negatively correlated with half-life of beta source. 147Pm was the preferred choice considering long life, the energy conversion efficiency and the theoretical output power.

Wind turbine roll decay curves Wind turbine roll decay curves

This data set is the experimental data set of maize agroecosystem adaptation to climate change from 2018 to 2021 in Gucheng Station. It mainly contains the interannual and annual variation data of growth period, biomass, leaf area index, photosynthetic physiology, spectral characteristics, soil moisture, grain filling rate and yield of the same variety of maize at different sowing dates. This dataset has great significance for the revision of agrometeorological business service index, the improvement and regional application of agrometeorological simulation model, and the development of agrometeorological applicable technology for the study of maize ecosystem adaptation to climate change. This data set is the experimental data set of maize agroecosystem adaptation to climate change from 2018 to 2021 in Gucheng Station. It mainly contains the interannual and annual variation data of growth period, biomass, leaf area index, photosynthetic physiology, spectral characteristics, soil moisture, grain filling rate and yield of the same variety of maize at different sowing dates. This dataset has great significance for the revision of agrometeorological business service index, the improvement and regional application of agrometeorological simulation model, and the development of agrometeorological applicable technology for the study of maize ecosystem adaptation to climate change.

With the objective of carbon neutrality, renewable energy resources gradually become the main power supply, whose variability poses great challenges to the operation and optimization of the system, especially to the power distribution network. In order to solve the problem of reactive power caused by high penetration of renewable energy sources, a centralized optimization model is proposed, which takes reactive power optimization and “generation-network-load-storage” multi-energy integration into account. The model aims at optimizing the operating cost and minimizing network losses and carbon emissions of the system. Reactive power compensation, regulation of energy storage, and energy conversion are considered to achieve safe and low-carbon economic dispatch of the power and gas systems. An improved second-order cone relaxation method is used for the convex relaxation of non-linear equality constraints concerned with the distribution network. The switching capacity produced by discrete reactive power compensators can be exactly linearized by the application of the big M approach. The simulation results demonstrate that the proposed method could effectively compensate the reactive power required by the grid-connection point of wind turbine, coordinate the energy interaction between the power and gas, thus improving the stability and elasticity of the distribution network after integration of large-scale renewable energy sources, which helps promote the consumption of renewable energy.

The icing of wind turbine blade will seriously affect the power output of wind turbine and endanger the safe operation of wind turbine. Computational fluid dynamics (CFD) is used to study the icing characteristics of typical wind wing. Firstly, the impact characteristics of water droplets on NACA0012 type turbine under different attack angle of 0°,4°,8°are calculated. The calculated results are in good agreement with the experimental results, which shows that the calculation method is correct, and, the ice coating on the blade surface of typical wind turbine with different wind speed and temperature was simulated, and the variation trend of water collection coefficient and ice thickness with temperature and velocity was obtained. The results show that: 1) with the increase of wind speed, the ice thickness of blade surface increases and the icing adhesion area increases; 2) with the decrease of temperature, the ice thickness of blade surface increases; and 3) the anti-ice effect of S801 airfoil is obviously greater than that of S802 airfoil. The research result helps logically select turbine under low temperature conditions, providing reference for lowering the blade icing hazard.

The resource utilization of solid waste is an important way to achieve energy saving and emission reduction. A lauric acid (LA)/raw fly ash (RFA)-diatomite(DT)/carbon nanotubes(CNT) composite form-stable phase change materials (FSPCM) for thermal energy storage were prepared via simple direct impregnation method, in which LA, RFA-DT binary matrix and CNT were employed as phase change materials(PCMs), the supporting material, and thermal conductive additive, respectively. The loading capacity, structure and thermal properties of FSCPCM were investigated through the diffusion-oozing testing, Fourier transform infrared spectrometer (FTIR), differential scanning calorimetry (DSC), thermo gravimetry analysis (TGA) and paperless recorder, respectively. The results show that the RFA-DT binary material can effectively prevent the leakage of LA. When the mass fraction of LA in composite is 28%, the FSPCM without leakage can be obtained. What’s more, the utilization rate of RFA reaches 55%. The FTIR demonstrates that FSPCM has good compatibility between its four components, LA, RFA-DT, and CNT. The melting onset temperature of FSPCM is 45.79 ℃ measured by DSC, and the corresponding latent heat of FSPCM is determined as 51.06 J/g. TGA analysis shows LA/RFA-DT has good thermal stability. The storage/release performance curve indicates that when mass fraction of CNT is added with 5%, the melting and solidification time of LA/RFA-DT/CNT are decreased by 60% and 62.5%, respectively, indicating that the heat transfer performance is remarkably improved.

The existing FFT-WT algorithm and FFT-BP algorithm have advantages only for the detection of certain specific harmonics in photovoltaic systems. In this paper, the FFT-WT algorithm is improved, and a DFFT-WT algorithm is proposed. The FFT-BP algorithm is improved and an improved FFT-BP model is proposed. On the basis of this, the two are combined, the threshold interval is introduced to limit the search scope of the neural network iteration, and a DFFT-WT-BP(Double FFT-WT-BP) detection algorithm is proposed. The simulation results show that the algorithm can detect complex harmonic signals composed of multiple harmonics in the actual photovoltaic network inversion system, and is more accurate and practical.

The paper analyzes the advantages and disadvantages of two different energy management strategies which are the management strategy based on the dynamic system running state and the management strategy based on the driving cycle. The paper focuses on the study of the strategy based on the driving cycle, and points out that though the operation process of the global optimization strategy based on the driving cycle takes long and large amount of calculation so that it can hardly be used in the real vehicle. The strategy can be taken as the reference for the ideal optimization control target. In order to achieve the real-time optimal control, there are mainly the method based on the driving cycle of recognition control strategy and the method based on model predictive control, etc. It makes the exploration to predict the real-time optimal control strategy based on the driving cycle become real, and the effects of the control results get close to the offline global optimization. The proposed strategy is a new research hotspot and research trend of energy management strategy.