• Energy Research
• 2021-2025close
• 13. Climate action close
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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.

Based on the observation monthly climatic data collected from 2766 weather observation stations on global during the period from 1981 to 2010, and the climatic scenarios data of SSP1_2.6、SSP1_4.5 and SSP1_8.5 scenarios released by CMIP6, the mean annual biotemperature, average total annual precipitation and potential evapotranspiration ratio on spatial resolution of 0.1º× 0.1º were respectively obtained by operating a high accuracy and speed method of surfacing modeling (HASM) (Yue, 2010, Yue et al., 2016) during all the four periods from 2020 to 2050 per decade. The method for surface modelling of land cover scenarios (SMLCS) has been developed to simulate the scenarios of land cover in Eurasia （Fan et al., 2019, 2020, 2021）. Finally, the scenario dataset of land cover under scenario SSP1_2.6、SSP1_4.5 and SSP1_8.5 were simulated by the SMLCS method from 2020 to 2050. 采用1981-2010年全球2766个气象观测站的观测月气候数据，以及CMIP6发布的SSP1_2.6、SSP1_4.5和SSP1_8.5情景的气候情景数据。通过运行高精度面建模方法（HASM）(Yue, 2010, Yue et al., 2016)，分别获得2020-2050年间每10年的空间分辨率为0.1º×0.1º的平均生物温度数据、多年平均年降水和潜在蒸散比率数据。采用自主研发的土地覆被情景曲面建模（SMLCS）方法（Fan et al., 2019, 2020, 2021），实现了SSP1_2.6、SSP1_4.5和SSP1_8.5情景的2020-2050年间每10年的全球土地覆被变化情景模拟。

Spatio-temporal variations in extreme drought in China during 1961–2015 Spatio-temporal variations in extreme drought in China during 1961–2015

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.

Studies of historical climate and environment changes in the eastern monsoonal region of China have made great progress in recent years. However, progressively studies indicate that the processes of climate and environment changes during the last 2000 years differed greatly in different regions. This is especially the case among studies based only on single-site records, possibly because of different materials, proxy indicators, dating accuracy, etc. Therefore, it is necessary to conduct comprehensive and integrated analyses of regional climate and environment changes at larger spatial scales. Here, multiple climate proxy records selected from 16 sites in southeastern China (i.e., approximately east of 105° E and south of 30° N) were used to synthesize and reconstruct the temperature and precipitation changes over the past 2000 years, and the possible forcing mechanisms behind these changes were explored. The results indicate that the integrated temperature sequence in the study region is quite comparable to the reconstructions for the entirety of China, eastern China, and the Northern Hemisphere. Several typical characteristic climate periods on centennial timescales, such as the Dark Age Cold Period, the Medieval Warm Period, the Little Ice Age, and the modern warm period of the 20th century, were well revealed in the present reconstruction. The integrated precipitation sequence shows that the dry and wet phases in southeastern China have changed significantly during the past 2000 years. Specifically, precipitation was relatively higher during the Medieval Warm Period, but it was relatively lower during the Little Ice Age (i.e., less precipitation occurred in the former part of the Little Ice Age and more precipitation occurred during the latter part). In general, the synthesized temperature and precipitation changes in southeastern China had relatively diverse hydrothermal combinations during the last 2000 years. However, it is noteworthy that the integrated precipitation sequence in southeastern China is weakly comparable to the sequence in northern China, reflecting great regional differences in historical precipitation changes. Thus, the forcing mechanisms might differ greatly from south to north in the monsoonal region of eastern China. Furthermore, the results suggest that large-scale atmosphere–ocean interactions, volcanic activities, and changes in solar radiation could have had significant effects on the climate and environment changes in southeastern China during the last 2000 years.

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.

As a basic properties of forest vegetation, forest succession law is the basis of understanding forest community, managing forest and utilizing forest rationally. Typical evergreen broad-leaved forest is a zonal vegetation in the subtropical area of east China. The existing vegetation is mostly in different secondary succession stages due to human and natural disturbance. Plant species composition is an important indicator of the long-term terrestrial ecosystem observation of National Ecosystem Research Network of China (CNERN). It affects the biogeochemical cycle, productivity, carbon sequestration, biodiversity and ecosystem services of forest ecosystems. According to CNERN monitoring standards, Zhejiang Tiantong Forest Ecosystem National Observation and Research Station finished three investigations at three succession plots and established a dataset on species composition during 2008 and 2017. The dataset included species name, abundance, mean diameter and biomass of woody plants in the plot. The species composition database provides critical data for in-depth studies of forest species diversity, structure and function under succession or environment change, and can support forest management and ecosystem service evaluation in this region. As a basic properties of forest vegetation, forest succession law is the basis of understanding forest community, managing forest and utilizing forest rationally. Typical evergreen broad-leaved forest is a zonal vegetation in the subtropical area of east China. The existing vegetation is mostly in different secondary succession stages due to human and natural disturbance. Plant species composition is an important indicator of the long-term terrestrial ecosystem observation of National Ecosystem Research Network of China (CNERN). It affects the biogeochemical cycle, productivity, carbon sequestration, biodiversity and ecosystem services of forest ecosystems. According to CNERN monitoring standards, Zhejiang Tiantong Forest Ecosystem National Observation and Research Station finished three investigations at three succession plots and established a dataset on species composition during 2008 and 2017. The dataset included species name, abundance, mean diameter and biomass of woody plants in the plot. The species composition database provides critical data for in-depth studies of forest species diversity, structure and function under succession or environment change, and can support forest management and ecosystem service evaluation in this region.

In order to improve the competitiveness of wind power in participating in the power market, promote low-carbon operation of the power system, and meet the new requirements for the completeness and flexibility of the production simulation model due to the uncertainty of wind power output,this paper analyzes the electricity cost composition from the perspective of low-carbon economy, and applies the stochastic programming theory to propose a short-term production simulation model of power system containing wind power. Considering the participation of the carbon trading market, this model aims to minimize the expected cost of electricity production in a short-term time scale, and coordinately optimize the day-ahead power output, real-time power regulation, power reserve capacity, wind curtailment, and load shedding. Taking the modified IEEE 39-bus system as an example, this paper quantitatively evaluates the impact of carbon trading mechanism, carbon trading price, and wind power installed capacity on electricity costs and their contributions to carbon emission reduction. The simulation results show that the proposed model can effectively analyze the short-term electricity cost, carbon emissions, and operational risks of the power system containing wind power under the carbon trading environment, thus has a promise application prospect.

A day-ahead optimal decision-making model is established for an integrated electricity-heat energy system to participate in both the electric energy market and the spinning reserve market, and the step-by-step carbon trading is introduced into the proposed model. The conditional value at risk method is used to manage the uncertainty risk of renewable energy and electrical load. With the objective to minimize the operation scheme cost and carbon emission cost, an operation plan is developed and the reserve resources are arranged for the integrated electricity-heat energy system. The results of a case study show that the proposed model improves the reliability, economy, and low-carbon level by taking the complementary advantages of the integrated energy system and reasonably arranging reserve resources to deal with the risks caused by uncertain factors.

Currently, the utilization efficiency of energy still remains at low level, although the depletion of fossil fuel is approaching. Therefore, while vigorously developing new energy, it is of great significance to develop new materials with "passive self-adjustment ability". Phase change humidity storage composite materials is a kind of composite material with phase change and temperature controlling property and humidity storage and humidity controlling property, which are very promising in the field of building wall material. In this paper, the action principle of phase change humidity storage composite materials, packaging technique of phase change material, classification and selection of humidity-controlling material were introduced briefly in the first section. And then the application of phase change humidity storage composite materials in building wall material were reviewed and analyzed in detail. In the third part, characteristics of double-shell phase change micro-nano capsules, polyfatty acid/SiO2 phase change and humidity storage composite materials and decanoic acid-palmitic acid @ Ce-La/TiO2 composites were pointed out. Main problems and research status of phase change humidity storage composite materials were pointed. Finally, it was pointed out the optimized durability of phase change humidity storage composite materials, developing multi-functional phase change humidity storage composite materials are the main development directions of phase change humidity storage composite materials.